National Library of Energy BETA

Sample records for benzene toluene xylene

  1. Genotoxicity and apoptosis in Drosophila melanogaster exposed to benzene, toluene and xylene: Attenuation by quercetin and curcumin

    SciTech Connect (OSTI)

    Singh, Mahendra P.; Mishra, M.; Sharma, A.; Shukla, A.K.; Mudiam, M.K.R.; Patel, D.K.; Ram, K. Ravi; Chowdhuri, D. Kar

    2011-05-15

    Monocyclic aromatic hydrocarbons (MAHs) such as benzene, toluene and xylene are being extensively used for various industrial and household purposes. Exposure to these hydrocarbons, occupationally or non-occupationally, is harmful to organisms including human. Several studies tested for toxicity of benzene, toluene and xylene, and interestingly, only a few studies looked into the attenuation. We used Drosophila model to test the genotoxic and apoptotic potential of these compounds and subsequently evaluated the efficiency of two phytochemicals, namely, quercetin and curcumin in attenuating test chemical induced toxicity. We exposed third instar larvae of wild type Drosophila melanogaster (Oregon R{sup +}) to 1.0-100.0 mM benzene, toluene or xylene, individually, for 12, 24 and 48 h and examined their apoptotic and genotoxic potential. We observed significantly (P < 0.001) increased apoptotic markers and genotoxicity in a concentration- and time-dependent manner in organisms exposed to benzene, toluene or xylene. We also observed significantly (P < 0.001) increased cytochrome P450 activity in larvae exposed to test chemicals and this was significantly reduced in the presence of 3',4'-dimethoxyflavone, a known Aryl hydrocarbon receptor (AhR) blocker. Interestingly, we observed a significant reduction in cytochrome P450 activity, GST levels, oxidative stress parameters, genotoxic and apoptotic endpoints when organisms were exposed simultaneously to test chemical along with quercetin or curcumin. The study further suggests the suitability of D. melanogaster as an alternate animal model for toxicological studies involving benzene, toluene and xylene and its potential in studying the protective role(s) of phytochemicals.

  2. Headspace solid-phase microextraction (HS-SPME) for the determination of benzene, toluene, ethylbenzene, and xylenes (BTEX) in foundry molding sand

    SciTech Connect (OSTI)

    Dungan, R.S. [USDA ARS, Beltsville, MD (United States). Environmental Management & Byproducts Utilization Laboratory

    2005-07-01

    The use of headspace solid-phase microextraction (HS-SPME) to determine benzene, toluene, ethylbenzene, and xylenes (BTEX) in foundry molding sand, specifically a 'green sand' (clay-bonded sand) was investigated. The BTEX extraction was conducted using a 75 {mu} M carboxen-polydimethylsiloxane (CAR-PDMS) fiber, which was suspended above 10 g of sample. The SPME fiber was desorbed in a gas chromatograph injector port (280{sup o}C for 1 min) and the analytes were characterized by mass spectrometry. The effects of extraction time and temperature, water content, and clay and bituminous coal percentage on HS-SPME of BTEX were investigated. Because green sands contain bentonite clay and carbonaceous material such as crushed bituminous coal, a matrix effect was observed. The detection limits for BTEX were determined to be {lt}= 0.18 ng g{sup -1} of green sand.

  3. Mobility of Supercooled liquid Toluene, Ethylbenzene, and Benzene...

    Office of Scientific and Technical Information (OSTI)

    and Benzene near their Glass Transition Temperatures Investigated using Inert Gas Permeation Citation Details In-Document Search Title: Mobility of Supercooled liquid...

  4. Solubilities of Toluene, Benzene and TCE in High-Biomass Systems

    SciTech Connect (OSTI)

    Barton, John W.; Vodraska, Christopher D; Flanary, Sandie A.; Davison, Brian H

    2008-01-01

    We report measurements of solubility limits for benzene, toluene, and TCE in systems that contain varying levels of biomass up to 0.13 g/mL. The solubility limit increased from 20 to 48 mM when biomass (in the form of yeast) was added to aqueous batch systems containing benzene. The toluene solubility limit increased from 4.9 to greater than 20 mM. For TCE, the solubility increased from 8 mM to more than 1000 mM. Solubility for TCE was most heavily impacted by biomass levels, changing by two orders of magnitude.

  5. Reactions of the CN Radical with Benzene and Toluene: Product Detection and Low-Temperature Kinetics

    SciTech Connect (OSTI)

    Trevitt, Adam J.; Goulay, Fabien; Taatjes, Craig A.; Osborn, David L.; Leone, Stephen R.

    2009-12-23

    Low temperature rate coefficients are measured for the CN + benzene and CN + toluene reactions using the pulsed Laval nozzle expansion technique coupled with laser-induced fluorescence detection. The CN + benzene reaction rate coefficient at 105, 165 and 295 K is found to be relatively constant over this temperature range, 3.9 - 4.9 x 10-10 cm3 molecule-1 s-1. These rapid kinetics, along with the observed negligible temperature dependence, are consistent with a barrierless reaction entrance channel and reaction efficiencies approaching unity. The CN + toluene reaction is measured to have a slower rate coefficient of 1.3 x 10-10 cm3 molecule-1 s-1 at 105 K. At room temperature, non-exponential decay profiles are observed for this reaction that may suggest significant back-dissociation of intermediate complexes. In separate experiments, the products of these reactions are probed at room temperature using synchrotron VUV photoionization mass spectrometry. For CN + benzene, cyanobenzene (C6H5CN) is the only product recorded with no detectable evidence for a C6H5 + HCN product channel. In the case of CN + toluene, cyanotoluene (NCC6H4CH3) constitutes the only detected product. It is not possible to differentiate among the ortho, meta and para isomers of cyanotoluene because of their similar ionization energies and the ~;; 40 meV photon energy resolution of the experiment. There is no significant detection of benzyl radicals (C6H5CH2) that would suggest a H-abstraction or a HCN elimination channel is prominent at these conditions. As both reactions are measured to be rapid at 105 K, appearing to have barrierless entrance channels, it follows that they will proceed efficiently at the temperatures of Saturn?s moon Titan (~;;100 K) and are also likely to proceed at the temperature of interstellar clouds (10-20 K).

  6. Mobility of Supercooled liquid Toluene, Ethylbenzene, and Benzene near their Glass Transition Temperatures Investigated using Inert Gas Permeation

    SciTech Connect (OSTI)

    May, Robert A.; Smith, R. Scott; Kay, Bruce D.

    2013-11-21

    We investigate the mobility of supercooled liquid toluene, ethylbenzene, and benzene near their respective glass transition temperatures (Tg). The permeation rate of Ar, Kr, and Xe through the supercooled liquid created when initially amorphous overlayers heated above their glass transition temperature is used to determine the diffusivity. Amorphous benzene crystallizes at temperatures well below its Tg and as a result the inert gas underlayer remains trapped until the onset of benzene desorption. In contrast, for toluene and ethylbenzene the onset of inert gas permeation is observed at temperatues near Tg. The inert gas desorption peak temperature as a function of the heating rate and overlayer thickness is used to quantify the diffusivity of supercooled liquid toluene and ethylbenzene from 115 K to 135 K. In this temperature range, diffusivities are found to vary across five orders of magnitude (~10-14 to 10-9 cm2/s). These data are compared to viscosity measurements and used to determine the low temperature fractional Stokes-Einstein exponent. Efforts to determine the diffusivity of a mixture of benzene and ethylbenzene are detailed, and the effect of mixing these materials on benzene crystallization is explored using infrared spectroscopy.

  7. Degradative capacities and bioaugmentation potential of an anaerobic benzene-degrading bacterium strain DN11

    SciTech Connect (OSTI)

    Yuki Kasai; Yumiko Kodama; Yoh Takahata; Toshihiro Hoaki; Kazuya Watanabe

    2007-09-15

    Azoarcus sp. strain DN11 is a denitrifying bacterium capable of benzene degradation under anaerobic conditions. The present study evaluated strain DN11 for its application to bioaugmentation of benzene-contaminated underground aquifers. Strain DN11 could grow on benzene, toluene, m-xylene, and benzoate as the sole carbon and energy sources under nitrate-reducing conditions, although o- and p-xylenes were transformed in the presence of toluene. Phenol was not utilized under anaerobic conditions. Kinetic analysis of anaerobic benzene degradation estimated its apparent affinity and inhibition constants to be 0.82 and 11 {mu}M, respectively. Benzene-contaminated groundwater taken from a former coal-distillation plant site in Aichi, Japan was anaerobically incubated in laboratory bottles and supplemented with either inorganic nutrients (nitrogen, phosphorus, and nitrate) alone, or the nutrients plus strain DN11, showing that benzene was significantly degraded only when DN11 was introduced. Denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments, and quantitative PCR revealed that DN11 decreased after benzene was degraded. Following the decrease in DN11 16S rRNA gene fragments corresponding to bacteria related to Owenweeksia hongkongensis and Pelotomaculum isophthalicum, appeared as strong bands, suggesting possible metabolic interactions in anaerobic benzene degradation. Results suggest that DN11 is potentially useful for degrading benzene that contaminates underground aquifers at relatively low concentrations. 50 refs., 6 figs., 1 tab.

  8. Exposure Evaluation for Benzene, Lead and Noise in Vehicle and Equipment Repair Shops

    SciTech Connect (OSTI)

    Sweeney, Lynn C.

    2013-04-01

    An exposure assessment was performed at the equipment and vehicle maintenance repair shops operating at the U. S. Department of Energy Hanford site, in Richland, Washington. The maintenance shops repair and maintain vehicles and equipment used in support of the Hanford cleanup mission. There are three general mechanic shops and one auto body repair shop. The mechanics work on heavy equipment used in construction, cranes, commercial motor vehicles, passenger-type vehicles in addition to air compressors, generators, and farm equipment. Services include part fabrication, installation of equipment, repair and maintenance work in the engine compartment, and tire and brake services. Work performed at the auto body shop includes painting and surface preparation which involves applying body filler and sanding. 8-hour time-weighted-average samples were collected for benzene and noise exposure and task-based samples were collected for lead dust work activities involving painted metal surfaces. Benzene samples were obtained using 3M™ 3520 sampling badges and were analyzed for additional volatile organic compounds. These compounds were selected based on material safety data sheet information for the aerosol products used by the mechanics for each day of sampling. The compounds included acetone, ethyl ether, toluene, xylene, VM&P naphtha, methyl ethyl ketone, and trichloroethylene. Laboratory data for benzene, VM&P naphtha, methyl ethyl ketone and trichloroethylene were all below the reporting detection limit. Airborne concentrations for acetone, ethyl ether, toluene and xylene were all less than 10% of their occupational exposure limit. The task-based samples obtained for lead dusts were submitted for a metal scan analysis to identify other metals that might be present. Laboratory results for lead dusts were all below the reporting detection limit and airborne concentration for the other metals observed in the samples were less than 10% of the occupational exposure limit

  9. Biocatalytic conversion of ethylene to ethylene oxide using an engineered toluene monooxygenase

    SciTech Connect (OSTI)

    Carlin, DA; Bertolani, SJ; Siegel, JB

    2015-01-01

    Mutants of toluene o-xylene monooxygenase are demonstrated to oxidize ethylene to ethylene oxide in vivo at yields of >99%. The best mutant increases ethylene oxidation activity by >5500-fold relative to the native enzyme. This is the first report of a recombinant enzyme capable of carrying out this industrially significant chemical conversion.

  10. Polyfunctional catalyst for processiing benzene fractions

    SciTech Connect (OSTI)

    G. Byakov; B.D. Zubitskii; B.G. Tryasunov; I.Ya. Petrov

    2009-05-15

    A by-product of the coke industry is a raw benzene fraction benzene- 1 which may serve as for catalytic processes. The paper reports a study on the influence of the composition and temperatures on the activity and selectivity of NiO-V{sub 2}O{sub 6}-MoO{sub 3}/{gamma}-Al{sub 2}O{sub 3} catalysts and the corresponding binary and tertiary subsystems are studied by a pulse method in model reactions; the hydrodealkylating of toluene and the hydrodesulfurizing of thioprhene. The optimal catalyst composition is established. The new catalyst is compared with industrial catalysts.

  11. Modeling theta-theta Interactions with the Effective Fragment Potential Method: The Benzene Dimer and Substituents

    SciTech Connect (OSTI)

    Toni Smithl; Lyudmila V. Slipchenko; Mark S. Gordon

    2008-02-27

    This study compares the results of the general effective fragment potential (EFP2) method to the results of a previous combined coupled cluster with single, double, and perturbative triple excitations [CCSD(T)] and symmetry-adapted perturbation theory (SAPT) study [Sinnokrot and Sherrill, J. Am. Chem. Soc., 2004, 126, 7690] on substituent effects in {pi}-{pi} interactions. EFP2 is found to accurately model the binding energies of the benzene-benzene, benzene-phenol, benzene-toluene, benzene-fluorobenzene, and benzene-benzonitrile dimers, as compared with high-level methods [Sinnokrot and Sherrill, J. Am. Chem. Soc., 2004, 126, 7690], but at a fraction of the computational cost of CCSD(T). In addition, an EFP-based Monte Carlo/simulated annealing study was undertaken to examine the potential energy surface of the substituted dimers.

  12. A detailed kinetic modeling study of toluene oxidation in a premixed laminar flame

    SciTech Connect (OSTI)

    Tian, Z; Pitz, W J; Fournet, R; Glaude, P; Battin-Leclerc, F

    2009-12-18

    An improved chemical kinetic model for the toluene oxidation based on experimental data obtained in a premixed laminar low-pressure flame with vacuum ultraviolet (VUV) photoionization and molecular beam mass spectrometry (MBMS) techniques has been proposed. The present mechanism consists of 273 species up to chrysene and 1740 reactions. The rate constants of reactions of toluene, decomposition, reaction with oxygen, ipso-additions and metatheses with abstraction of phenylic H-atom are updated; new pathways of C{sub 4} + C{sub 2} species giving benzene and fulvene are added. Based on the experimental observations, combustion intermediates such as fulvenallene, naphtol, methylnaphthalene, acenaphthylene, 2-ethynylnaphthalene, phenanthrene, anthracene, 1-methylphenanthrene, pyrene and chrysene are involved in the present mechanism. The final toluene model leads to an overall satisfactory agreement between the experimentally observed and predicted mole fraction profiles for the major products and most combustion intermediates. The toluene depletion is governed by metathese giving benzyl radicals, ipso-addition forming benzene and metatheses leading to C{sub 6}H{sub 4}CH{sub 3} radicals. A sensitivity analysis indicates that the unimolecular decomposition via the cleavage of a C-H bond has a strong inhibiting effect, while decomposition via C-C bond breaking, ipso-addition of H-atom to toluene, decomposition of benzyl radicals and reactions related to C{sub 6}H{sub 4}CH{sub 3} radicals have promoting effect for the consumption of toluene. Moreover, flow rate analysis is performed to illustrate the formation pathways of mono- and polycyclic aromatics.

  13. Soot precursor measurements in benzene and hexane diffusion flames

    SciTech Connect (OSTI)

    Kobayashi, Y.; Furuhata, T.; Amagai, K.; Arai, M.

    2008-08-15

    To clarify the mechanism of soot formation in diffusion flames of liquid fuels, measurements of soot and its precursors were carried out. Sooting diffusion flames formed by a small pool combustion equipment system were used for this purpose. Benzene and hexane were used as typical aromatic and paraffin fuels. A laser-induced fluorescence (LIF) method was used to obtain spatial distributions of polycyclic aromatic hydrocarbons (PAHs), which are considered as soot particles. Spatial distributions of soot in test flames were measured by a laser-induced incandescence (LII) method. Soot diameter was estimated from the temporal change of LII intensity. A region of transition from PAHs to soot was defined from the results of LIF and LII. Flame temperatures, PAH species, and soot diameters in this transition region were investigated for both benzene and hexane flames. The results show that though the flame structures of benzene and hexane were different, the temperature in the PAHs-soot transition region of the benzene flame was similar to that of the hexane flame. Furthermore, the relationship between the PAH concentrations measured by gas chromatography in both flames and the PAH distributions obtained from LIF are discussed. It was found that PAHs with smaller molecular mass, such as benzene and toluene, remained in both the PAHs-soot transition and sooting regions, and it is thought that molecules heavier than pyrene are the leading candidates for soot precursor formation. (author)

  14. Toluene pyrolysis studies and high temperature reactions of propargyl chloride

    SciTech Connect (OSTI)

    Kern, R.D.; Chen, H.; Qin, Z.

    1993-12-01

    The main focus of this program is to investigate the thermal decompositions of fuels that play an important role in the pre-particle soot formation process. It has been demonstrated that the condition of maximum soot yield is established when the reaction conditions of temperature and pressure are sufficient to establish a radical pool to support the production of polyaromatic hydrocarbon species and the subsequent formation of soot particles. However, elevated temperatures result in lower soot yields which are attributed to thermolyses of aromatic ring structures and result in the bell-shaped dependence of soot yield on temperature. The authors have selected several acyclic hydrocarbons to evaluate the chemical thermodynamic and kinetic effects attendant to benzene formation. To assess the thermal stability of the aromatic ring, the authors have studied the pyrolyses of benzene, toluene, ethylbenzene, chlorobenzene and pyridine. Time-of-flight mass spectrometry (TOF) is employed to analyze the reaction zone behind reflected shock waves. Reaction time histories of the reactants, products, and intermediates are constructed and mechanisms are formulated to model the experimental data. The TOF work is often performed with use of laser schlieren densitometry (LS) to measure density gradients resulting from the heats of various reactions involved in a particular pyrolytic system. The two techniques, TOF and LS, provide independent and complementary information about ring formation and ring rupture reactions.

  15. Fuel Dependence of Benzene Pathways

    SciTech Connect (OSTI)

    Zhang, H; Eddings, E; Sarofim, A; Westbrook, C

    2008-07-14

    The relative importance of formation pathways for benzene, an important precursor to soot formation, was determined from the simulation of 22 premixed flames for a wide range of equivalence ratios (1.0 to 3.06), fuels (C{sub 1}-C{sub 12}), and pressures (20 to 760 torr). The maximum benzene concentrations in 15 out of these flames were well reproduced within 30% of the experimental data. Fuel structural properties were found to be critical for benzene production. Cyclohexanes and C{sub 3} and C{sub 4} fuels were found to be among the most productive in benzene formation; and long-chain normal paraffins produce the least amount of benzene. Other properties, such as equivalence ratio and combustion temperatures, were also found to be important in determining the amount of benzene produced in flames. Reaction pathways for benzene formation were examined critically in four premixed flames of structurally different fuels of acetylene, n-decane, butadiene, and cyclohexane. Reactions involving precursors, such as C{sub 3} and C{sub 4} species, were examined. Combination reactions of C{sub 3} species were identified to be the major benzene formation routes with the exception of the cyclohexane flame, in which benzene is formed exclusively from cascading fuel dehydrogenation via cyclohexene and cyclohexadiene intermediates. Acetylene addition makes a minor contribution to benzene formation, except in the butadiene flame where C{sub 4}H{sub 5} radicals are produced directly from the fuel, and in the n-decane flame where C{sub 4}H{sub 5} radicals are produced from large alkyl radical decomposition and H atom abstraction from the resulting large olefins.

  16. Collision lifetimes of polyatomic molecules at low temperatures: Benzenebenzene vs benzenerare gas atom collisions

    SciTech Connect (OSTI)

    Cui, Jie; Krems, Roman V.; Li, Zhiying

    2014-10-28

    We use classical trajectory calculations to study the effects of the interaction strength and the geometry of rigid polyatomic molecules on the formation of long-lived collision complexes at low collision energies. We first compare the results of the calculations for collisions of benzene molecules with rare gas atoms He, Ne, Ar, Kr, and Xe. The comparison illustrates that the mean lifetimes of the collision complexes increase monotonically with the strength of the atommolecule interaction. We then compare the results of the atombenzene calculations with those for benzenebenzene collisions. The comparison illustrates that the mean lifetimes of the benzenebenzene collision complexes are significantly reduced due to non-ergodic effects prohibiting the molecules from sampling the entire configuration space. We find that the thermally averaged lifetimes of the benzenebenzene collisions are much shorter than those for Xe with benzene and similar to those for Ne with benzene.

  17. Process for the preparation of ethyl benzene

    DOE Patents [OSTI]

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1995-01-01

    Ethyl benzene is produced in a catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 50.degree. C. to 300.degree. C., using as the catalyst a mole sieve characterized as acidic by feeding ethylene to the catalyst bed while benzene is conveniently added through the reflux to result in a molar excess present in the reactor to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene and diethyl benzene in the bottoms. The bottoms are fractionated, the ethyl benzene recovered and the bottoms are contacted with benzene in the liquid phase in a fixed bed straight pass reactor under conditions to transalkylate the benzene thereby converting most of the diethyl benzene to ethyl benzene which is again separated and recovered.

  18. Process for the preparation of ethyl benzene

    DOE Patents [OSTI]

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1995-12-19

    Ethyl benzene is produced in a catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 50 C to 300 C, using as the catalyst a mole sieve characterized as acidic by feeding ethylene to the catalyst bed while benzene is conveniently added through the reflux to result in a molar excess present in the reactor to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene and diethyl benzene in the bottoms. The bottoms are fractionated, the ethyl benzene recovered and the bottoms are contacted with benzene in the liquid phase in a fixed bed straight pass reactor under conditions to transalkylate the benzene thereby converting most of the diethyl benzene to ethyl benzene which is again separated and recovered. 2 figs.

  19. Evaluation of a Polyvinyl Toluene Neutron Counter Array (Conference...

    Office of Scientific and Technical Information (OSTI)

    Utilizing a compact array of borated Polyvinyl Toluene light pipes and Photomultiplier Tubes, pulse shape analysis, standard spectral histogramming, and multiplicity counting can ...

  20. Methods for the synthesis and polymerization of .alpha.,.alpha.'-dihalo-p-xylenes

    DOE Patents [OSTI]

    Ferraris, John P.; Neef, Charles J.

    2002-07-30

    The present invention describes an improved method for the polymerization of .alpha.,.alpha.-dihalo-p-xylene's such as the .alpha.,.alpha.'-dihalo-2-methoxy-5-(2-ethylhexyloxy)-xylene's. The procedure for synthesis is based on the specific order of addition of reagents and the use of an anionic initiator that allows control of the molecular weight of the polymer. The molecular weight control allows processability of the polymer which is important for its utility in applications including in light-emitting-diodes, field effect transistors and photovoltaic devices.

  1. In situ BTEX biotransformation under enhanced nitrate- and sulfate-reducing conditions

    SciTech Connect (OSTI)

    Reinhard, M.; Shang, S.; Kitanidis, P.K.; Orwin, E.; Hopkins, G.D.; LeBron, C.A.

    1997-01-01

    In situ anaerobic biotransformation of BTEX (benzene, toluene, ethylbenzene, o-xylene, and m-xylene) was investigated under enhanced nitrate- and sulfate-reducing conditions. Controlled amounts of BTEX compounds added to slugs of treated groundwater were released into a gasoline-contaminated aquifer at Seal Beach, CA. In a series of studies, the slugs, 470-1700 L in volume, were released into the aquifer through a multi-port injection/extraction well and were subsequently withdrawn over a 2-3 month period. To evaluate unamended in situ conditions, the injectate was treated with granular activated carbon (GAC) and augmented with bromide as a tracer. To evaluate nitrate- and sulfate-reducing conditions, the injectate was also deionized and augmented with 200-300 {mu}g/L BTEX, nitrate or sulfate, and background electrolytes. Under unamended conditions, transformation appeared to be limited to the slow removal of toluene and m,p-xylene (i.e. sum of m+p-xylene). Under nitrate-reducing conditions, toluene, ethylbenzene, and m-xylene were transformed without a lag phase in less than 10 days, and o-xylene was transformed in 72 days. Under sulfate-reducing conditions, toluene, m-xylene and o-xylene were completely transformed in less then 50 days, and ethylbenzene was removed in 60 days. Benzene appeared to be removed under sulfate-reducing conditions, but the trend was pronounced only at some levels. 47 refs., 11 figs., 2 tabs.

  2. Indirect validation of benzene exposure assessment by association with benzene poisoning

    SciTech Connect (OSTI)

    Dosemeci, M.; Linet, M.; Wacholder, S.

    1996-12-01

    We present a validation study of a quantitative retrospective exposure assessment method used in a follow-up study of workers exposed to benzene. Assessment of exposure to benzene was carried out in 672 factories in 12 cities in China. Historical exposure data were collected for 3179 unique job titles. The basic unit for exposure assessment was a factory/work unit/job title combination over seven periods between 1949 and 1987. A total of 18,435 exposure estimates was developed, using all available historical information, including 8477 monitoring data. Overall, 38% of the estimates were based on benzene monitoring data. The highest time-weighted average exposures were observed for the rubber industry (30.7 ppm) and for rubber glue applicators (52.6 ppm). Because of its recognized link with benzene exposure, the association between a clinical diagnosis of benzene poisoning and benzene exposure was evaluated to validate the assessment method that we used in the cohort study. Our confidence in the assessment method is supported by the observation of a strong positive trend between benzene poisoning and various measures, especially recent intensity of exposure to benzene. 23 refs., 6 figs., 2 tabs.

  3. Low level benzene exposure in Sweden: effect on blood elements and body burden of benzene

    SciTech Connect (OSTI)

    Berlin, M.

    1985-01-01

    Measurements for benzene exposure were performed for different work places. In addition, breath benzene concentrations were measured in different occupations in order to establish toxico-kinetics of benzene in man; chromosomal aberrations in lymphocytes of exposed workers were also examined. Smoking appears to result in a large increase in benzene concentration in exhaled breath. The smoke from one cigarette contains 60-80 micrograms of benzene. It was found that exposure levels of 10 ppm are rather uncommon among workers handling gasoline or gasoline equipment. It was concluded that the gasoline load of road tankers cannot be responsible for chromosome changes of the driver, as milk truck drivers showed the same changes. These results did not prove that benzene was the cause of the observed changes. Smoking is the confounding factor, with a potency of at least the same order of magnitude as benzene. In addition, our present knowledge about mechanisms of benzene is not sufficiently developed to permit quantitative conclusions as to the human health risks.

  4. Variations in the structure of aromatic solvents under the influence of microadditives of the C{sub 60} fullerene

    SciTech Connect (OSTI)

    Ginzburg, B. M. Tuichiev, Sh.

    2007-02-15

    The structural ordering of aromatic solvents is investigated using wide-angle X-ray diffraction. It is shown that the degree of structural ordering of aromatic solvents at room temperature decreases in the following sequence: benzene, toluene, and n-xylene. The introduction of the C{sub 60} fullerene ({approx}0.001%) into these solvents leads to an increase in the degree of their ordering. Upon introduction of the fullerene, the degree of structural ordering increases significantly in n-xylene and only slightly in toluene and remains virtually unchanged in benzene. An analysis of the small-angle X-ray diffraction patterns of C{sub 60} fullerene solutions in benzene likewise demonstrates that the introduction of the fullerene into benzene leads to an insignificant change in the degree of structural ordering of this solvent. The specific features of the structure and behavior of benzene upon interaction with C{sub 60} fullerene additives are discussed.

  5. Pilot-Scale Benzene Retention and Release Demonstration

    SciTech Connect (OSTI)

    Marek, J.C.

    2003-11-10

    During the initial months of In-Tank Precipitation radioactive operation in 1995 the process experienced high rates of tetraphenylborate decomposition with assumed corresponding high rates of benzene generation. In March 1996 after a two month quiescent period, a water addition to Tank 48H resulted in an unexpected benzene release to the tank vapor phase. This was the first time a low energy input resulted in a significant release rate. This led to questions about how benzene, generated in-situ by TPB decomposition, was retained in the surrounding potassium tetraphenylborate slurry. It was postulated the retention mechanism may have changed during the quiescent period prior to March so the benzene present became readily releasable to the vapor phase with low energy input to the slurry or that enough benzene accumulated that some of it was in a different, more releasable form. Readily releasable is a qualitative term defined as a rapid release of benzene at a rate approaching evaporation of a free benzene layer. It is intended to distinguish between benzene in a form with high liquid phase resistance to mass transfer diffusion controlled from benzene in a form with minimal liquid phase resistance to mass transfer free benzene layer evaporation. If a readily releasable form of benzene was present, the vapor space profile during release tests was anticipated to have an initial benzene vapor space concentration peak followed by a lower vapor concentration, longer duration release.

  6. Benzene reduction in RFG, a new low cost route

    SciTech Connect (OSTI)

    Gildert, R.; Gildert, G.

    1994-12-31

    Benzene has been targeted for reduction in reformulated gasoline because it is the largest single contributor to the toxic emissions group. This presentation describes processes of benzene removal for the petroleum refiner. By making maximum use of existing equipment, the refiner can minimize the changes necessary to produce reformulated gasoline with a reduction in benzene levels.

  7. Density and viscosity for mixtures of propanoic acid with aromatic hydrocarbons at 298.15 K

    SciTech Connect (OSTI)

    Singh, M.; Gupta, P.C.; Kesharwani, R.N.

    1995-03-01

    The density and viscosity of binary mixtures of propanic acid + benzene, + toluene, and + o-, + m-, and + p-xylenes have been measured at 298.15 K. Excess volumes have been calculated. The interactions existing between the components have been discussed. The results are used to theoretically justify the validity of the viscosity models.

  8. Toluene nitration in irradiated nitric acid and nitrite solution

    SciTech Connect (OSTI)

    Gracy Elias; Bruce J. Mincher; Stephen P. Mezyk; Jim Muller; Leigh R. Martin

    2011-04-01

    The kinetics, mechanisms, and stable products produced for the aryl alkyl mild ortho-para director - toluene, in irradiated nitric acid and neutral nitrite solutions were investigated using ?, and pulse radiolysis. Electron pulse radiolysis was used to determine the bimolecular rate constants for the reaction of toluene with different transient species produced by irradiation. HPLC with UV detection was primarily used to assess the stable reaction products. GC-MS and LC-MS were used to confirm the results from HPLC. Free-radical nitration reaction products were found in irradiated acidic and neutral media. In acidic medium, the ring substitution and side chain substitution and oxidation produced different nitro products. In ring substitution, nitrogen oxide radicals were added mainly to hydroxyl radical-produced cyclohexadienyl radical, and in side chain substitution they were added to the carbon-centered benzyl radical produced by H-atom abstraction. In neutral nitrite toluene solution, radiolytic ring nitration products approached a statistically random distribution, suggesting a free-radical reaction involving addition of the NO2 radical.

  9. Biofiltration control of VOC emissions: Butane and benzene

    SciTech Connect (OSTI)

    Allen, E.R.

    1995-12-31

    Laboratory studies were conducted on the biological elimination of n-butane and benzene from air streams using activated sludge-treated compost biofilters. Four types of experimental biofilter systems were developed: a bench scale packed tower system used primarily for kinetic studies; a small scale column system used to study the effects of different filter media on n-butane removal; a three stage system used to study benzene elimination; and a static batch biofilter system used to study the effects of temperature, compost water content, compost pH, and initial benzene concentrations on benzene elimination. Removal efficiencies greater than 90% were obtained for n-butane. Removal followed first order kinetics at inlet concentrations less than 25 ppM n-butane and zero order kinetics above 100 ppM n-butane. Removal of benzene followed fractional order kinetics for inlet concentrations from 15 to 200 ppM benzene. Thus, the removal of benzene is both mass transfer and bioreaction limited for the concentration range studied. The removal efficiency of benzene was found to be highly dependent on compost water content, compost pH, and temperature. Compost showed a low capacity for benzene removal, which suggested that degradation of these hydrocarbons required different species of microorganisms.

  10. Catalytic conversion of alcohols to hydrocarbons with low benzene content

    DOE Patents [OSTI]

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2016-03-08

    A method for converting an alcohol to a hydrocarbon fraction having a lowered benzene content, the method comprising: converting said alcohol to a hydrocarbon fraction by contacting said alcohol, under conditions suitable for converting said alcohol to said hydrocarbon fraction, with a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon fraction, and contacting said hydrocarbon fraction with a benzene alkylation catalyst, under conditions suitable for alkylating benzene, to form alkylated benzene product in said hydrocarbon fraction. Also described is a catalyst composition useful in the method, comprising a mixture of (i) a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon, and (ii) a benzene alkylation catalyst, in which (i) and (ii) may be in a mixed or separated state. A reactor for housing the catalyst and conducting the reaction is also described.

  11. Method of removing benzene from petroleum desalter brine

    SciTech Connect (OSTI)

    Hart, P.R.

    1993-08-17

    A method is described for removing benzene from petroleum refinery desalter effluent brine containing dispersed oil, solids, oily solids and benzene comprising contacting the brine with a sufficient amount for the purpose of flocculating oily solids of a combination of a aluminum chlorohydrate and a water soluble cationic polymer selected from the group consisting of polyamines and dialkyldiallylammonium polymers, in a ratio of from 1:10 to 100:1 at a temperature of about 250 F, separating the resulting floc from the brine; and thereafter contacting the brine with a sufficient amount for the purpose of reducing benzene levels in the brine of an oil solvent in combination with a demulsifier.

  12. Site-specific variability in BTEX biodegradation under denitrifying conditions

    SciTech Connect (OSTI)

    Kao, C.M.; Borden, R.C.

    1997-03-01

    Laboratory microcosm experiments were conducted to evaluate the feasibility of benzene, toluene, ethylbenzene, m-xylene, and o-xylene (BTEX) biodegradation under denitrifying conditions. Nine different sources of inocula, including contaminated and uncontaminated soil cores from four different sites and activated sludge, were used to establish microcosms. BTEX was not degraded under denitrifying conditions in microcosms inoculated with aquifer material from Rocky Point and Traverse City. However, rapid depletion of glucose under denitrifying conditions was observed in microcosms containing Rocky Point aquifer material. TEX degradation was observed in microcosms containing Rocky Point aquifer material. TEX degradation was observed in microcosms containing aquifer material from Fort Bragg and Sleeping Bear Dunes and sewage sludge. Benzene was recalcitrant in all microcosms tested. The degradation of o-xylene ceased after toluene, ethylbenzene, and m-xylene were depleted in the Fort Bragg and sludge microcosms, but o-xylene continued to degrade in microcosms with contaminated Sleeping Bear Dunes soil. The most probable number (MPN) of denitrifiers in these nine different inocula were measured using a microtiter technique. There was no correlation between the MPN of denitrifiers and the TEX degradation rate under denitrifying conditions. Experimental results indicate that the degradation sequence and TEX degradation rate under denitrifying conditions may differ among sites. Results also indicate that denitrification alone may not be a suitable bioremediation technology for gasoline-contaminated aquifers because of the inability of denitrifiers to degrade benzene.

  13. Control of benzene waste NESHAP emissions from a petroleum refinery

    SciTech Connect (OSTI)

    Truelove, R.D. )

    1992-02-01

    This paper discusses the control of benzene emissions from a petroleum refinery as regulated by the National Emission Standards for Hazardous Air Pollutants (NESHAO) Subpart FF - National Standard for Benzene Waste Operations. This regulation is complex and confusing, but it provides flexibility to achieve compliance through various strategies to control benzene emissions. The first step to achieve compliance with the benzene waste NESHAP is understanding the regulation itself. Therefore, this paper summarizes the regulation to provide the reader with sufficient background to understand why specific controls are required for specific processes. The flexibility provided by the regulation to achieve compliance is not always readily apparent. This paper summarizes some of these subtleties. The author's involvement with an industry trade association in meetings with the Environmental Protection Agency during the development of the regulation allows some of EPA's expressions of their intent and internal interpretation to also be contained in the summary. The second step to achieve compliance with the benzene waste NESHAP is to actually design and operate a cost effective solution for a specific set of existing conditions within a refinery. This paper provides a case study of the equipment necessary to achieve compliance with the substantive requirements of the regulation at a large, integrated refinery. The retrofit requirements are very specific to the circumstances of this facility. Therefore, they will not be a universal, cost effective means of compliance for other refineries.

  14. Products of the Benzene + O(3P) Reaction

    SciTech Connect (OSTI)

    Taatjes, Craig A.; Osborn, David L.; Selby, Talitha M.; Meloni, Giovanni; Trevitt, Adam J.; Epifanovsky, Evgeny; Krylov, Anna I.; Sirjean, Baptiste; Dames, Enoch; Wang, Hai

    2009-12-21

    The gas-phase reaction of benzene with O(3P) is of considerable interest for modeling of aromatic oxidation, and also because there exist fundamental questions concerning the prominence of intersystem crossing in the reaction. While its overall rate constant has been studied extensively, there are still significant uncertainties in the product distribution. The reaction proceeds mainly through the addition of the O atom to benzene, forming an initial triplet diradical adduct, which can either dissociate to form the phenoxy radical and H atom, or undergo intersystem crossing onto a singlet surface, followed by a multiplicity of internal isomerizations, leading to several possible reaction products. In this work, we examined the product branching ratios of the reaction between benzene and O(3P) over the temperature range of 300 to 1000 K and pressure range of 1 to 10 Torr. The reactions were initiated by pulsed-laser photolysis of NO2 in the presence of benzene and helium buffer in a slow-flow reactor, and reaction products were identified by using the multiplexed chemical kinetics photoionization mass spectrometer operating at the Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory. Phenol and phenoxy radical were detected and quantified. Cyclopentadiene and cyclopentadienyl radical were directly identified for the first time. Finally, ab initio calculations and master equation/RRKM modeling were used to reproduce the experimental branching ratios, yielding pressure-dependent rate expressions for the reaction channels, including phenoxy + H, phenol, cyclopentadiene + CO, which are proposed for kinetic modeling of benzene oxidation.

  15. Effect of ozonation on the composition of crude coal-tar benzene

    SciTech Connect (OSTI)

    Semenova, S.A.; Patrakov, Y.F.

    2007-05-15

    The effect of ozonation on the composition of crude benzene produced by the coal-tar chemical industry was studied.

  16. New packing in absorption systems for trapping benzene from coke-oven gas

    SciTech Connect (OSTI)

    V.V. Grabko; V.M. Li; T.A. Shevchenko; M.A. Solov'ev

    2009-07-15

    The efficiency of benzene removal from coke-oven gas in absorption units OAO Alchevskkoks with new packing is assessed.

  17. Table Definitions, Sources, and Explanatory Notes

    Gasoline and Diesel Fuel Update (EIA)

    Processing Area Definitions Key Terms Definition Aviation Gasoline Blending Components Naphthas which will be used for blending or compounding into finished aviation gasoline (e.g., straight-run gasoline, alkylate, reformate, benzene, toluene, and xylene). Excludes oxygenates (alcohols, ethers), butane, and pentanes plus. Oxygenates are reported as other hydrocarbons, hydrogen, and oxygenates. Barrel A unit of volume equal to 42 U.S. gallons. Conventional Blendstock for Oxygenate Blending (CBOB)

  18. Table Definitions, Sources, and Explanatory Notes

    Gasoline and Diesel Fuel Update (EIA)

    Imports & Exports Definitions Key Terms Definition All Other Motor Gasoline Blending Components Naphthas (e.g. straight-run gasoline, alkylate, reformate, benzene, toluene, xylene) used for blending or compounding into finished motor gasoline. Includes receipts and inputs of Gasoline Treated as Blendstock (GTAB). Excludes conventional blendstock for oxygenate blending (CBOB), reformulated blendstock for oxygenate blending, oxygenates (e.g. fuel ethanol and methyl tertiary butyl ether),

  19. Table Definitions, Sources, and Explanatory Notes

    Gasoline and Diesel Fuel Update (EIA)

    Production Capacity of Operable Petroleum Refineries Definitions Key Terms Definition Alkylate The product of an alkylation reaction. It usually refers to the high octane product from alkylation units. This alkylate is used in blending high octane gasoline. Aromatics Hydrocarbons characterized by unsaturated ring structures of carbon atoms. Commercial petroleum aromatics are benzene, toluene, and xylene (BTX). Asphalt A dark-brown-to-black cement-like material containing bitumens as the

  20. Table Definitions, Sources, and Explanatory Notes

    Gasoline and Diesel Fuel Update (EIA)

    Input Definitions Key Terms Definition Aviation Gasoline Blending Components Naphthas which will be used for blending or compounding into finished aviation gasoline (e.g., straight-run gasoline, alkylate, reformate, benzene, toluene, and xylene). Excludes oxygenates (alcohols, ethers), butane, and pentanes plus. Oxygenates are reported as other hydrocarbons, hydrogen, and oxygenates. Barrel A unit of volume equal to 42 U.S. gallons. Conventional Blendstock for Oxygenate Blending (CBOB) Motor

  1. Table Definitions, Sources, and Explanatory Notes

    Gasoline and Diesel Fuel Update (EIA)

    and Blender Net Inputs Definitions Key Terms Definition Aviation Gasoline Blending Components Naphthas which will be used for blending or compounding into finished aviation gasoline (e.g., straight-run gasoline, alkylate, reformate, benzene, toluene, and xylene). Excludes oxygenates (alcohols, ethers), butane, and pentanes plus. Oxygenates are reported as other hydrocarbons, hydrogen, and oxygenates. Barrel A unit of volume equal to 42 U.S. gallons. Blending Plant A facility which has no

  2. Table Definitions, Sources, and Explanatory Notes

    Gasoline and Diesel Fuel Update (EIA)

    Inputs & Utilization Definitions Key Terms Definition All Other Motor Gasoline Blending Components Naphthas (e.g. straight-run gasoline, alkylate, reformate, benzene, toluene, xylene) used for blending or compounding into finished motor gasoline. Includes receipts and inputs of Gasoline Treated as Blendstock (GTAB). Excludes conventional blendstock for oxygenate blending (CBOB), reformulated blendstock for oxygenate blending, oxygenates (e.g. fuel ethanol and methyl tertiary butyl ether),

  3. Table Definitions, Sources, and Explanatory Notes

    Gasoline and Diesel Fuel Update (EIA)

    Total Stocks Definitions Key Terms Definition All Other Motor Gasoline Blending Components Naphthas (e.g. straight-run gasoline, alkylate, reformate, benzene, toluene, xylene) used for blending or compounding into finished motor gasoline. Includes receipts and inputs of Gasoline Treated as Blendstock (GTAB). Excludes conventional blendstock for oxygenate blending (CBOB), reformulated blendstock for oxygenate blending, oxygenates (e.g. fuel ethanol and methyl tertiary butyl ether), butane, and

  4. Table Definitions, Sources, and Explanatory Notes

    Gasoline and Diesel Fuel Update (EIA)

    Weekly Supply Estimates Definitions Key Terms Definition All Other Motor Gasoline Blending Components Naphthas (e.g. straight-run gasoline, alkylate, reformate, benzene, toluene, xylene) used for blending or compounding into finished motor gasoline. Includes receipts and inputs of Gasoline Treated as Blendstock (GTAB). Excludes conventional blendstock for oxygenate blending (CBOB), reformulated blendstock for oxygenate blending, oxygenates (e.g. fuel ethanol and methyl tertiary butyl ether),

  5. Molecular dynamics simulations of the effects of salts on the aggregation properties of benzene in water.

    SciTech Connect (OSTI)

    Smith, P. E.

    2003-07-16

    The specific aims of the project were: to provide an atomic level description of the interactions between benzene, water and ions in solutions. To determine the degree of association between two benzene molecules in aqueous and salt solutions. To investigate the structure and dynamics of the interface between benzene and water or salt solution.

  6. Process for hydrocracking carbonaceous material to provide fuels or chemical feed stock

    DOE Patents [OSTI]

    Duncan, Dennis A.

    1980-01-01

    A process is disclosed for hydrocracking coal or other carbonaceous material to produce various aromatic hydrocarbons including benzene, toluene, xylene, ethylbenzene, phenol and cresols in variable relative concentrations while maintaining a near constant maximum temperature. Variations in relative aromatic concentrations are achieved by changing the kinetic severity of the hydrocracking reaction by altering the temperature profile up to and quenching from the final hydrocracking temperature. The relative concentration of benzene to the alkyl and hydroxyl aromatics is increased by imposing increased kinetic severity above that corresponding to constant heating rate followed by immediate quenching at about the same rate to below the temperature at which dehydroxylation and dealkylation reactions appreciably occur. Similarly phenols, cresols and xylenes are produced in enhanced concentrations by adjusting the temperature profile to provide a reduced kinetic severity relative to that employed when high benzene concentrations are desired. These variations in concentrations can be used to produce desired materials for chemical feed stocks or for fuels.

  7. Analysis of low molecular weight hydrocarbons including 1,3-butadiene in engine exhaust gases using an aluminum oxide porous-layer open-tubular fused-silica column

    SciTech Connect (OSTI)

    Pelz, N.; Dempster, N.M.; Shore, P.R. )

    1990-05-01

    A method for the quantitative analysis of individual hydrocarbons in the C1-C8 range emitted in engine exhaust gases is described. The procedure provides base-line or near base-line resolution of C4 components including 1,3-butadiene. With a run time of less than 50 min, the light aromatics (benzene, toluene, ethyl benzene, p- and m-xylene, and o-xylene) are resolved during the same analysis as aliphatic hydrocarbons in the C1-C8 range. It is shown that typical 1,3-butadiene levels in engine exhaust are about 5 ppm at each of two engine conditions. Aromatic hydrocarbon levels show a dependence on engine operating conditions, benzene being about 20 ppm at high speed and about 40 ppm at idle.

  8. Benzene distribution in product streams from in-tank processing

    SciTech Connect (OSTI)

    Walker, D.D.

    1987-01-15

    Benzene is the major product of radiolytic decomposition of tetraphenylborate salts during in-tank salt decontamination. Its production rate has been measured at the Savannah River Laboratory (SR) and at the University of Florida under various conditions of importance to the in-tank process. Recent work has been concerned with the extent of decomposition for long storage periods, and the composition of the product streams from the process. The major results from this work are: the stored potassium tetraphenylborate precipitate will decompose at a rate of 7.3 {plus minus} 1.1% per year; the major products of the decomposition are benzene, phenol, biphenyl, and phenylboric acid; decomposition is directly proportional to the total dose and is unaffected by dose rate; the decomposition produces acidic compounds which will cause a decrease in the pH of the storage tank. 13 refs., 6 figs., 6 tabs.

  9. Tip-contact related low-bias negative differential resistance and rectifying effects in benzeneporphyrinbenzene molecular junctions

    SciTech Connect (OSTI)

    Cheng, Jue-Fei; Zhou, Liping E-mail: leigao@suda.edu.cn; Liu, Man; Yan, Qiang; Han, Qin; Gao, Lei E-mail: leigao@suda.edu.cn

    2014-11-07

    The electronic transport properties of benzeneporphyrinbenzene (BPB) molecules coupled to gold (Au) electrodes were investigated. By successively removing the front-end Au atoms, several BPB junctions with different molecule-electrode contact symmetries were constructed. The calculated currentvoltage (IV) curves depended strongly on the contact configurations between the BPB molecules and the Au electrodes. In particular, a significant low-voltage negative differential resistance effect appeared at ?0.3 V in the junctions with pyramidal electrodes on both sides. Along with the breaking of this tip-contact symmetry, the low-bias negative differential resistance effect gradually disappeared. This tip-contact may be ideal for use in the design of future molecular devices because of its similarity with experimental processes.

  10. A novel plug-flow digester for biogasification of conventional and hazardous organics

    SciTech Connect (OSTI)

    Ghosh, S.; Kato, Y.; Liu, T.; Fukushi, K.

    1996-12-31

    A novel plug-flow digestion system of simple construction was designed, fabricated and operated for several years with a synthetic mixture of solid and liquid wastes simulating conditions south of the US-Mexican border and other developing countries. Benzene, toluene, and o-xylene (BTX) were mixed with the synthetic feed in several phases of this research to simulate field conditions where these solvents are discharged to public sewers and mixed with non-hazardous pollutants. The mesophilic plug-flow digester exhibited a high gas yield of 0.46 SCM /kg VS added, a methane content of 77 mol%, and a VS reduction of 75% at an HRT of 13 days with a 96% biodegradation of the feed toluene. At a feed concentration of 50 mg/l, toluene did not inhibit anaerobic fermentation. Gas and methane yields, and VS and COD conversion efficiencies were about the same with or without toluene present in the feed. At a reduced HRT of 8 days, a high feed COD concentration of 50,000 mg/l, and a loading rate of 0.48 kg VS/m{sup 3}-day, the digester afforded a gas yield of 3.1 SCM /kg VS added, and a methane content of 67 mol%. Benzene, toluene, and o-xylene were biodegraded at efficiencies of 94%, 90%, and 88%, respectively. The degradation kinetics of the xenobiotic compound could be described by a model based on cometabolic degradation of these secondary substrates.

  11. Occupational Exposure to Benzene from Painting with Epoxy and Other High Performance Coatings

    SciTech Connect (OSTI)

    JAHN, STEVEN

    2005-04-20

    Following the discovery of trace benzene in paint products, an assessment was needed to determine potential for benzene exposures to exceed the established ACGIH Threshold Limit Value (TLV) during painting operations. Sample data was collected by area industrial hygienists for benzene during routine maintenance and construction activities at Savannah River Site. A set of available data from the IH database, Sentry, was analyzed to provide guidance to the industrial hygiene staff and draw conclusions on the exposure potential during typical painting operations.

  12. Decomposition of toluene in a steady-state atmospheric-pressure glow discharge

    SciTech Connect (OSTI)

    Trushkin, A. N.; Grushin, M. E.; Kochetov, I. V.; Trushkin, N. I.; Akishev, Yu. S.

    2013-02-15

    Results are presented from experimental studies of decomposition of toluene (C{sub 6}H{sub 5}CH{sub 3}) in a polluted air flow by means of a steady-state atmospheric pressure glow discharge at different water vapor contents in the working gas. The experimental results on the degree of C{sub 6}H{sub 5}CH{sub 3} removal are compared with the results of computer simulations conducted in the framework of the developed kinetic model of plasma chemical decomposition of toluene in the N{sub 2}: O{sub 2}: H{sub 2}O gas mixture. A substantial influence of the gas flow humidity on toluene decomposition in the atmospheric pressure glow discharge is demonstrated. The main mechanisms of the influence of humidity on C{sub 6}H{sub 5}CH{sub 3} decomposition are determined. The existence of two stages in the process of toluene removal, which differ in their duration and the intensity of plasma chemical decomposition of C{sub 6}H{sub 5}CH{sub 3} is established. Based on the results of computer simulations, the composition of the products of plasma chemical reactions at the output of the reactor is analyzed as a function of the specific energy deposition and gas flow humidity. The existence of a catalytic cycle in which hydroxyl radical OH acts a catalyst and which substantially accelerates the recombination of oxygen atoms and suppression of ozone generation when the plasma-forming gas contains water vapor is established.

  13. First Principals and Classical Molecular Dynamics Simulations of Solvated Benzene

    SciTech Connect (OSTI)

    Allesch, M; Lightstone, F; Schwegler, E; Galli, G

    2007-09-11

    We have performed extensive ab initio and classical MD simulations of benzene in water in order to examine the unique solvation structures that are formed. Qualitative differences between classical and ab initio MD simulations are found and the importance of various technical simulation parameters is examined. Our comparison indicates that non-polarizable classical models are not capable of describing the solute-water interface correctly if local interactions become energetically comparable to water hydrogen bonds. In addition, a comparison is made between a rigid water model and fully flexible water within ab initio MD simulations which shows that both models agree qualitatively for this challenging system.

  14. Location of MTBE and toluene in the channel system of the zeolite mordenite: Adsorption and host-guest interactions

    SciTech Connect (OSTI)

    Arletti, Rossella; Martucci, Annalisa; Alberti, Alberto; Pasti, Luisa; Nassi, Marianna; Bagatin, Roberto

    2012-10-15

    This paper reports a study of the location of Methyl Tertiary Butyl Ether (MTBE) and toluene molecules adsorbed in the pores of the organophylic zeolite mordenite from an aqueous solution. The presence of these organic molecules in the zeolite channels was revealed by structure refinement performed by the Rietveld method. About 3 molecules of MTBE and 3.6 molecules of toluene per unit cell were incorporated into the cavities of mordenite, representing 75% and 80% of the total absorption capacity of this zeolite. In both cases a water molecule was localized inside the side pocket of mordenite. The saturation capacity determined by the adsorption isotherms, obtained by batch experiments, and the weight loss given by thermogravimetric (TG) analyses were in very good agreement with these values. The interatomic distances obtained after the structural refinements suggest MTBE could be connected to the framework through a water molecule, while toluene could be bonded to framework oxygen atoms. The rapid and high adsorption of these hydrocarbons into the organophylic mordenite zeolite makes this cheap and environmental friendly material a suitable candidate for the removal of these pollutants from water. - graphical abstract: Location of MTBE (a) and toluene (b) in mordenite channels (projection along the [001] direction). Highlights: Black-Right-Pointing-Pointer We investigated the MTBE and toluene adsorption process into an organophilic zeolite mordenite. Black-Right-Pointing-Pointer The presence of MTBE and toluene in mordenite was determined by X-ray diffraction studies. Black-Right-Pointing-Pointer About 3 molecules of MTBE and 3.6 molecules of toluene per unit cell were incorporated into the zeolite cavities. Black-Right-Pointing-Pointer MTBE is connected to the framework through a water molecule. Black-Right-Pointing-Pointer Toluene is directly bonded to framework oxygen atoms.

  15. Simulation of toluene decomposition in a pulse-periodic discharge operating in a mixture of molecular nitrogen and oxygen

    SciTech Connect (OSTI)

    Trushkin, A. N.; Kochetov, I. V.

    2012-05-15

    The kinetic model of toluene decomposition in nonequilibrium low-temperature plasma generated by a pulse-periodic discharge operating in a mixture of nitrogen and oxygen is developed. The results of numerical simulation of plasma-chemical conversion of toluene are presented; the main processes responsible for C{sub 6}H{sub 5}CH{sub 3} decomposition are identified; the contribution of each process to total removal of toluene is determined; and the intermediate and final products of C{sub 6}H{sub 5}CH{sub 3} decomposition are identified. It was shown that toluene in pure nitrogen is mostly decomposed in its reactions with metastable N{sub 2}(A{sub 3}{Sigma}{sub u}{sup +}) and N{sub 2}(a Prime {sup 1}{Sigma}{sub u}{sup -}) molecules. In the presence of oxygen, in the N{sub 2} : O{sub 2} gas mixture, the largest contribution to C{sub 6}H{sub 5}CH{sub 3} removal is made by the hydroxyl radical OH which is generated in this mixture exclusively due to plasma-chemical reactions between toluene and oxygen decomposition products. Numerical simulation showed the existence of an optimum oxygen concentration in the mixture, at which toluene removal is maximum at a fixed energy deposition.

  16. Intermolecular C?H bond activation of benzene and pyridines by a vanadium(III) alkylidene including a stepwise conversion of benzene to a vanadium-benzyne complex

    SciTech Connect (OSTI)

    Andino, Jos G.; Kilgore, Uriah J.; Pink, Maren; Ozarowski, Andrew; Krzystek, J.; Telser, Joshua; Baik, Mu-Hyun; Mindiola, Daniel J.

    2012-01-20

    Breaking of the carbon-hydrogen bond of benzene and pyridine is observed with (PNP)V(CH{sub 2}tBu){sub 2} (1), and in the case of benzene, the formation of an intermediate benzyne complex (C) is proposed, and indirect proof of its intermediacy is provided by identification of (PNP)VO({eta}{sup 2}-C{sub 6}H{sub 4}) in combination with DFT calculations.

  17. The relationship between low-level benzene exposure and leukemia in Canadian petroleum distribution workers

    SciTech Connect (OSTI)

    Schnatter, A.R.; Armstrong, T.W.; Nicolich, M.J.

    1996-12-01

    This study was conducted to evaluate the relationship between leukemia occurrence and long-term, low-level benzene exposures in petroleum distribution workers. Fourteen cases were identified among a previously studied cohort. Four controls per case were selected from the same cohort, controlling for birth year and time at risk. Industrial hygienists estimated workplace exposures for benzene, without knowledge of case-control status. Average benzene concentrations ranged from 0.01 to 6.2 ppm. Company medical records were used to abstract information on other potential confounders such as cigarette smoking. Odds ratios were calculated for several exposure metrics. Conditional logistic regression modeling was used to control for potential confounders. The risk of leukemia was not associated with increasing cumulative exposure to benzene for these exposure levels. Duration of benzene exposure was more closely associated with leukemia risk than other exposure metrics, although results were not statistically significant. A family history of cancer and cigarette smoking were the two strongest risk factors for leukemia, with cumulative benzene exposure showing no additional risk when considered in the same models. This study is consistent with other data in that it was unable to demonstrate a relationship between leukemia and long-term, low-level benzene exposures. The power of the study was limited. Thus, further study on benzene exposures in this concentration range are warranted. 20 refs., 1 fig., 6 tabs.

  18. Geographical distribution of benzene in air in northwestern Italy and personal exposure

    SciTech Connect (OSTI)

    Gilli, G.; Scursatone, E.; Bono, R.

    1996-12-01

    Benzene is a solvent strictly related to some industrial activities and to automotive emissions. After the reduction in lead content of fuel gasoline, and the consequent decrease in octane number, an increase in benzene and other aromatic hydrocarbons in gasoline occurred. Therefore, an increase in the concentration of these chemicals in the air as primary pollutants and as precursors of photochemical smog could occur in the future. The objectives of this study were to describe the benzene air pollution at three sites in northwestern Italy throughout 1991 and 1994; to examine the relationship between benzene air pollution in indoor, outdoor, and personal air as measured by a group of nonsmoking university students; and to determine the influence of environmental tobacco smoke on the level of benzene exposure in indoor air environments. The results indicate a direct relationship between population density and levels of contamination; an indoor/outdoor ratio of benzene air pollution higher than 1 during day and night; a similar level of personal and indoor air contamination; and a direct relationship between levels of personal exposure to benzene and intensity of exposure to tobacco smoke. Human exposure to airborne benzene has been found to depend principally on indoor air contamination not only in the home but also in many other confined environments. 29 refs., 2 figs., 6 tabs.

  19. Solubilities and other physical parameters of aromatic hydrocarbons in water and aqueous sodium chloride solutions as determined by headspace analysis

    SciTech Connect (OSTI)

    Lowry, M.A.H.

    1991-12-31

    The solubility, Henry`s law constant, aqueous-vapor partition coefficients, and oil-aqueous distribution coefficients of benzene, toluene, ethylbenzene, o-xylene,m-xylene and p-xylene were determined in water and aqueous sodium chloride solutions at 25C. Values are in agreement with using gas chromatography of headspace literature. The salting-out effect of sodium chloride on the solute properties measured was illustrated using the empirical relationship deduced by Setschenow (1889). The empirical relationship predicts that the logarithm of solubility will be a function of ionic strength. The solubility data obtained in this work obeys this relationship. It was also found that the logarithm of the Henry`s law constant, partition coefficient, and distribution coefficient are linear functions of ionic strength. 10 tabs, 6 figs.

  20. Solubilities of toluene and n-octane in aqueous protosurfactant and surfactant solutions

    SciTech Connect (OSTI)

    Ho, P.C.

    1985-01-01

    The solubilities of toluene and n-octane in aqueous protosurfactant and surfactant solutins were determined at 25/sup 0/C. The protosurfactants studied are sodium salts of cyclohexanecarboxylic acid, 2,5-diisopropylbenzenesulfonic acid, and 3,5-diisopropyisalicylic acid. Each of them has six alkyl carbons (S /SUB AC/ =6) and does not form micelles in water. The two micelle-forming surfactants used are sodium n-hexanoate with six alkyl carbons (S /SUB AC/ =6) and sodium n-octanoate with eight alkyl carbons (S /SUB AC/ =8). In three-component systems of toluene or n-octane with water and organic salt (either protosurfactant or surfactant), the solubility of the hydrocarbon in the aqueous phase increases as the number of alkyl carbons of the organic salt and as the aqueous concentration of the organic salt increases. However, in this study we found that sodium 3,5-diisopropyisalicylate causes much more pronounced increases in hydrocarbon solubility than these two surfactants. Sodium 2,5-diisopropylbenzenesulfonate, although not as effective in solubilization as the salicylate, has much stronger hydrotropic properties for hydrocarbons than either of these two surfactants. Sodium cyclohexanoate, with a compact arrangement of the six alkyl carbons, shows a higher hydrotropic effect than sodium n-hexanoate.

  1. Interaction of toluene with two-color asymmetric laser fields: Controlling the directional emission of molecular hydrogen fragments

    SciTech Connect (OSTI)

    Kaziannis, S.; Kotsina, N.; Kosmidis, C.

    2014-09-14

    The interaction of toluene with strong asymmetric two-color laser irradiation of 40 fs duration is studied by means of Time of flight mass spectrometry. Highly energetic H{sub 2}{sup +} and H{sub 3}{sup +} fragment ions are produced through an isomerization process taking place within transient multiply charged parent ions. Comparative study of deuterium labeled toluene isotopes enables the discrimination between molecular hydrogen fragments formed exclusively within the CH{sub 3}- part from those that require hydrogen atom exchange between the former and the phenyl moiety. It is demonstrated that by manipulating the relative phase of the ω/2ω field components the selective ionization of oriented toluene molecules can be used as a tool to control the directional emission of the H{sub 2}{sup +}, H{sub 3}{sup +} species.

  2. Numerical analysis of the effect of acetylene and benzene addition to low-pressure benzene-rich flat flames on polycyclic aromatic hydrocarbon formation

    SciTech Connect (OSTI)

    Kunioshi, Nilson; Komori, Seisaku; Fukutani, Seishiro

    2006-10-15

    A modification of the CHEMKIN II package has been proposed for modeling addition of an arbitrary species at an arbitrary temperature to an arbitrary distance from the burner along a flat flame. The modified program was applied to the problem of addition of acetylene or benzene to different positions of a 40-Torr, {phi}=2.4 benzene/O{sub 2}/40%-N{sub 2} premixed flame to reach final equivalence ratios of {phi}=2.5 and 2.681. The results obtained showed that acetylene addition to early positions of the flame led to significant increase in pyrene production rates, but pyrene concentrations were lower in the flames with acetylene addition in both the {phi}=2.5 and 2.681 cases. Addition of benzene to the flame did not alter pyrene production rates in either the {phi}=2.5 or 2.681 cases; however, for {phi}=2.5, pyrene concentrations increased with benzene addition, while for {phi}=2.681, pyrene contents decreased in comparison to the correspondent flames with no addition. Acetylene addition led to a significant increase in pyrene production rates, but the pyrene levels dropped due to increase in the flow velocity. Pyrene production rates were not sensitive to benzene addition, but pyrene contents increased with benzene addition when the flow velocity decreased. These results show that PAH concentration changes accompanying species addition to flames should be interpreted carefully, because an increase or decrease in the content of a PAH species does not necessarily reflect an effect on its formation rate or mechanism. (author)

  3. COSMIC-RAY-MEDIATED FORMATION OF BENZENE ON THE SURFACE OF SATURN'S MOON TITAN

    SciTech Connect (OSTI)

    Zhou Li; Zheng Weijun; Kaiser, Ralf I.; Landera, Alexander; Mebel, Alexander M.; Liang, Mao-Chang; Yung, Yuk L.

    2010-08-01

    The aromatic benzene molecule (C{sub 6}H{sub 6})-a central building block of polycyclic aromatic hydrocarbon molecules-is of crucial importance for the understanding of the organic chemistry of Saturn's largest moon, Titan. Here, we show via laboratory experiments and electronic structure calculations that the benzene molecule can be formed on Titan's surface in situ via non-equilibrium chemistry by cosmic-ray processing of low-temperature acetylene (C{sub 2}H{sub 2}) ices. The actual yield of benzene depends strongly on the surface coverage. We suggest that the cosmic-ray-mediated chemistry on Titan's surface could be the dominant source of benzene, i.e., a factor of at least two orders of magnitude higher compared to previously modeled precipitation rates, in those regions of the surface which have a high surface coverage of acetylene.

  4. Electron localization in a mixed-valence diniobium benzene complex

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gianetti, Thomas L.; Nocton, Grégory; Minasian, Stefan G.; Kaltsoyannis, Nikolas; Kilcoyne, A. L. David; Kozimor, Stosh A.; Shuh, David K.; Tyliszczak, Tolek; Bergman, Robert G.; Arnold, John

    2014-11-11

    Reaction of the neutral diniobium benzene complex {[Nb(BDI)NtBu]2(μ-C6H6)} (BDI = N,N'-diisopropylbenzene-β-diketiminate) with Ag[B(C6F5)4] results in a single electron oxidation to produce a cationic diniobium arene complex, {[Nb(BDI)NtBu]2(μ-C6H6)}{B(C6F5)4}. Investigation of the solid state and solution phase structure using single-crystal X-ray diffraction, cyclic voltammetry, magnetic susceptibility, and multinuclear NMR spectroscopy indicates that the oxidation results in an asymmetric molecule with two chemically inequivalent Nb atoms. Further characterization using density functional theory (DFT) calculations, UV-visible, Nb L3,2-edge X-ray absorption near-edge structure (XANES), and EPR spectroscopies supports assignment of a diniobium complex, in which one Nb atom carries a single unpaired electron that ismore » not largely delocalized on the second Nb atom. During the oxidative transformation, one electron is removed from the δ-bonding HOMO, which causes a destabilization of the molecule and formation of an asymmetric product. Subsequent reactivity studies indicate that the oxidized product allows access to metal-based chemistry with substrates that did not exhibit reactivity with the starting neutral complex.« less

  5. Electron localization in a mixed-valence diniobium benzene complex

    SciTech Connect (OSTI)

    Gianetti, Thomas L.; Nocton, Grgory; Minasian, Stefan G.; Kaltsoyannis, Nikolas; Kilcoyne, A. L. David; Kozimor, Stosh A.; Shuh, David K.; Tyliszczak, Tolek; Bergman, Robert G.; Arnold, John

    2014-11-11

    Reaction of the neutral diniobium benzene complex {[Nb(BDI)NtBu]2(?-C6H6)} (BDI = N,N'-diisopropylbenzene-?-diketiminate) with Ag[B(C6F5)4] results in a single electron oxidation to produce a cationic diniobium arene complex, {[Nb(BDI)NtBu]2(?-C6H6)}{B(C6F5)4}. Investigation of the solid state and solution phase structure using single-crystal X-ray diffraction, cyclic voltammetry, magnetic susceptibility, and multinuclear NMR spectroscopy indicates that the oxidation results in an asymmetric molecule with two chemically inequivalent Nb atoms. Further characterization using density functional theory (DFT) calculations, UV-visible, Nb L3,2-edge X-ray absorption near-edge structure (XANES), and EPR spectroscopies supports assignment of a diniobium complex, in which one Nb atom carries a single unpaired electron that is not largely delocalized on the second Nb atom. During the oxidative transformation, one electron is removed from the ?-bonding HOMO, which causes a destabilization of the molecule and formation of an asymmetric product. Subsequent reactivity studies indicate that the oxidized product allows access to metal-based chemistry with substrates that did not exhibit reactivity with the starting neutral complex.

  6. Diffusion of benzene confined in the oriented nanochannels of chrysotile asbestos fibers

    SciTech Connect (OSTI)

    Mamontov, E.; Kumzerov, Yu.A.; Vakhrushev, S.B.

    2005-11-01

    We used quasielastic neutron scattering to study the dynamics of benzene that completely fills the nanochannels of chrysotile asbestos fibers with a characteristic diameter of about 5 nm. The macroscopical alignment of the nanochannels in fibers provided an interesting opportunity to study anisotropy of the dynamics of confined benzene by means of collecting the data with the scattering vector either parallel or perpendicular to the fibers axes. The translational diffusive motion of benzene molecules was found to be isotropic. While bulk benzene freezes at 278.5 K, we observed the translational dynamics of the supercooled confined benzene on the time scale of hundreds of picoseconds even below 200 K, until at about 160 K its dynamics becomes too slow for the {mu}eV resolution of the neutron backscattering spectrometer. The residence time between jumps for the benzene molecules measured in the temperature range of 260 K to 320 K demonstrated low activation energy of 2.8 kJ/mol.

  7. Test of electron beam technology on Savannah River Laboratory low-activity aqueous waste for destruction of benzene, benzene derivatives, and bacteria

    SciTech Connect (OSTI)

    Dougal, R.A.

    1993-08-01

    High energy radiation was studied as a means for destroying hazardous organic chemical wastes. Tests were conducted at bench scale with a {sup 60}Co source, and at full scale (387 l/min) with a 1.5 MV electron beam source. Bench scale tests for both benzene and phenol included 32 permutations of water quality factors. For some water qualities, as much as 99.99% of benzene or 90% of phenol were removed by 775 krads of {sup 60}Co irradiation. Full scale testing for destruction of benzene in a simulated waste-water mix showed loss of 97% of benzene following an 800 krad dose and 88% following a 500 krad dose. At these loss rates, approximately 5 Mrad of electron beam irradiation is required to reduce concentrations from 100 g/l to drinking water quality (5 {mu}g/l). Since many waste streams are also inhabited by bacterial populations which may affect filtering operations, the effect of irradiation on those populations was also studied. {sup 60}Co and electron beam irradiation were both lethal to the bacteria studied at irradiation levels far lower than were necessary to remove organic contaminants.

  8. In utero exposure to benzene increases embryonic c-Myb and Pim-1 protein levels in CD-1 mice

    SciTech Connect (OSTI)

    Wan, Joanne; Winn, Louise M.

    2008-05-01

    Benzene is a known human leukemogen, but its role as an in utero leukemogen remains controversial. Epidemiological studies have correlated parental exposure to benzene with an increased incidence of childhood leukemias. We hypothesize that in utero exposure to benzene may cause leukemogenesis by affecting the embryonic c-Myb/Pim-1 signaling pathway and that this is mediated by oxidative stress. To investigate this hypothesis, pregnant CD-1 mice were treated with either 800 mg/kg of benzene or corn oil (i.p.) on days 10 and 11 of gestation and in some cases pretreated with 25 kU/kg of PEG-catalase. Phosphorylated and total embryonic c-Myb and Pim-1 protein levels were assessed using Western blotting and maternal and embryonic oxidative stress were assessed by measuring reduced to oxidized glutathione ratios. Our results show increased oxidative stress at 4 and 24 h after exposure, increased phosphorylated Pim-1 protein levels 4 h after benzene exposure, and increased Pim-1 levels at 24 and 48 h after benzene exposure. Embryonic c-Myb levels were elevated at 24 h after exposure. PEG-catalase pretreatment prevented benzene-mediated increases in embryonic c-Myb and Pim-1 protein levels, and benzene-induced oxidative stress. These results support a role for ROS in c-Myb and Pim-1 alterations after in utero benzene exposure.

  9. THE INFLUENCE OF BENZENE AS A TRACE REACTANT IN TITAN AEROSOL ANALOGS

    SciTech Connect (OSTI)

    Trainer, Melissa G.; Sebree, Joshua A.; Heidi Yoon, Y.; Tolbert, Margaret A.

    2013-03-20

    Benzene has been detected in Titan's atmosphere by Cassini instruments, with concentrations ranging from sub-ppb in the stratosphere to ppm in the ionosphere. Sustained levels of benzene in the haze formation region could signify that it is an important reactant in the formation of Titan's organic aerosol. To date, there have not been laboratory investigations to assess the influence of benzene on aerosol properties. We report a laboratory study on the chemical composition of organic aerosol formed from C{sub 6}H{sub 6}/CH{sub 4}/N{sub 2} via far ultraviolet irradiation (120-200 nm). The compositional results are compared to those from aerosol generated by a more ''traditional Titan'' mixture of CH{sub 4}/N{sub 2}. Our results show that even a trace amount of C{sub 6}H{sub 6} (10 ppm) has significant impact on the chemical composition and production rates of organic aerosol. There are several pathways by which photolyzed benzene may react to form larger molecules, both with and without the presence of CH{sub 4}, but many of these reaction mechanisms are only beginning to be explored for the conditions at Titan. Continued work investigating the influence of benzene in aerosol growth will advance understanding of this previously unstudied reaction system.

  10. Hydrogen-terminated silicon nanowire photocatalysis: Benzene oxidation and methyl red decomposition

    SciTech Connect (OSTI)

    Lian, Suoyuan; School of Chemical Engineering and Materials, Dalian Polytechnic University, Dalian 116034 ; Tsang, Chi Him A.; Centre of Super Diamond and Advanced Films, City University of Hong Kong, Hong Kong ; Kang, Zhenhui; Liu, Yang; Wong, Ningbew; Lee, Shuit-Tong; Centre of Super Diamond and Advanced Films, City University of Hong Kong, Hong Kong

    2011-12-15

    Graphical abstract: H-SiNWs can catalyze hydroxylation of benzene and degradation of methyl red under visible light irradiation. Highlights: Black-Right-Pointing-Pointer Hydrogen-terminated silicon nanowires were active photocatalyst in the hydroxylation of benzene under light. Black-Right-Pointing-Pointer Hydrogen-terminated silicon nanowires were also effective in the decomposition of methyl red dye. Black-Right-Pointing-Pointer The Si/SiO{sub x} core-shell structure is the main reason of the obtained high selectivity during the hydroxylation. -- Abstract: Hydrogen-terminated silicon nanowires (H-SiNWs) were used as heterogeneous photocatalysts for the hydroxylation of benzene and for the decomposition of methyl red under visible light irradiation. The above reactions were monitored by GC-MS and UV-Vis spectrophotometry, respectively, which shows 100% selectivity for the transformation of benzene to phenol. A complete decomposition of a 2 Multiplication-Sign 10{sup -4} M methyl red solution was achieved within 30 min. The high selectivity for the hydroxylation of benzene and the photodecomposition demonstrate the catalytic activity of ultrafine H-SiNWs during nanocatalysis.

  11. Total cross sections for positron scattering from benzene, cyclohexane, and aniline

    SciTech Connect (OSTI)

    Zecca, Antonio; Moser, Norberto; Perazzolli, Chiara; Salemi, Alessandro; Brunger, Michael J.

    2007-08-15

    We use a linear transmission technique to measure total cross sections for positron scattering from benzene, cyclohexane, and aniline. In the case of cyclohexane, the energy range of the present study is 0.1-20 eV, while for benzene and aniline it is 0.2-20 eV. With respect to benzene and cyclohexane, comparison is made to the only other existing results we know of [Makochekanwa and co-workers, Phys. Rev. A 68, 032707 (2003); 72, 042705 (2005)]. Agreement with those data is only marginal, being particularly poor at the overlap lower energies. Unlike Kimura et al. [J. Phys. B 37, 1461 (2004)], we find the low-energy dependence of the positron-benzene total cross sections to be qualitatively similar to those found in the electron channel [Gulley et al., J. Phys. B 31, 2735 (1998)]. We believe that the present positron-aniline total cross sections represent the first time such data have been measured. These cross sections are almost identical to those we found for benzene, suggesting that substitution of hydrogen by the amine group on the aromatic ring is largely irrelevant to the scattering process in the energy regimes considered.

  12. Revisiting benzene cluster cations for the chemical ionization of dimethyl sulfide and select volatile organic compounds

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kim, Michelle J.; Zoerb, Matthew C.; Campbell, Nicole R.; Zimmermann, Kathryn J.; Blomquist, Byron W.; Huebert, Barry J.; Bertram, Timothy H.

    2016-04-05

    Here, benzene cluster cations were revisited as a sensitive and selective reagent ion for the chemical ionization of dimethyl sulfide (DMS) and a select group of volatile organic compounds (VOCs). Laboratory characterization was performed using both a new set of compounds (i.e., DMS, β-caryophyllene) as well as previously studied VOCs (i.e., isoprene, α-pinene). Using a field deployable chemical-ionization time-of-flight mass spectrometer (CI-ToFMS), benzene cluster cations demonstrated high sensitivity (> 1 ncps ppt−1) to DMS, isoprene, and α-pinene standards. Parallel measurements conducted using a chemical-ionization quadrupole mass spectrometer, with a much weaker electric field, demonstrated that ion–molecule reactions likely proceed through a combinationmore » of ligand-switching and direct charge transfer mechanisms. Laboratory tests suggest that benzene cluster cations may be suitable for the selective ionization of sesquiterpenes, where minimal fragmentation (< 25 %) was observed for the detection of β-caryophyllene, a bicyclic sesquiterpene. The in-field stability of benzene cluster cations using CI-ToFMS was examined in the marine boundary layer during the High Wind Gas Exchange Study (HiWinGS). The use of benzene cluster cation chemistry for the selective detection of DMS was validated against an atmospheric pressure ionization mass spectrometer, where measurements from the two instruments were highly correlated (R2 > 0.95, 10 s averages) over a wide range of sampling conditions.« less

  13. Toluene diisocyanate: Induction of the autotaxin-lysophosphatidic acid axis and its association with airways symptoms

    SciTech Connect (OSTI)

    Broström, Julia M.; Ye, Zhi-wei; Axmon, Anna; Littorin, Margareta; Tinnerberg, Håkan; Lindh, Christian H.; Zheng, Huiyuan; Ghalali, Aram; Stenius, Ulla; Jönsson, Bo A.G.; Högberg, Johan

    2015-09-15

    Diisocyanates are industrial chemicals which have a wide range of applications in developed and developing countries. They are notorious lung toxicants and respiratory sensitizers. However, the mechanisms behind their adverse effects are not adequately characterized. Autotaxin (ATX) is an enzyme producing lysophosphatidic acid (LPA), and the ATX-LPA axis has been implicated in lung related inflammatory conditions and diseases, including allergic asthma, but not to toxicity of environmental low-molecular-weight chemicals. We investigated effects of toluene diisocyanate (TDI) on ATX induction in human lung epithelial cell models, and we correlated LPA-levels in plasma to biomarkers of TDI exposure in urine collected from workers exposed to < 5 ppb (parts per billion). Information on workers' symptoms was collected through interviews. One nanomolar TDI robustly induced ATX release within 10 min in vitro. A P2X7- and P2X4-dependent microvesicle formation was implicated in a rapid ATX release and a subsequent protein synthesis. Co-localization between purinergic receptors and ATX was documented by immunofluorescence and confocal microscopy. The release was modulated by monocyte chemoattractant protein-1 (MCP-1) and by extracellular ATP. In workers, we found a dose–response relationship between TDI exposure biomarkers in urine and LPA levels in plasma. Among symptomatic workers reporting “sneezing”, the LPA levels were higher than among non-symptomatic workers. This is the first report indicating induction of the ATX-LPA axis by an environmental low-molecular-weight chemical, and our data suggest a role for the ATX-LPA axis in TDI toxicity. - Highlights: • Human epithelial cells release autotaxin in response to 1 nM toluene diisocyanate (TDI). • The release involves P2X4 and P2X7 receptors and is modulated by ATP and MCP-1. • Lysophosphatidic acid (LPA) was measured in workers exposed to < 5 ppb TDI. • LPA in plasma correlated to TDI exposure biomarkers in

  14. Theoretical study of reactions of HO{sub 2} in low-temperature oxidation of benzene

    SciTech Connect (OSTI)

    Altarawneh, Mohammednoor; Dlugogorski, Bogdan Z.; Kennedy, Eric M.; Mackie, John C.

    2010-07-15

    We have generated a set of thermodynamic and kinetic parameters for the reactions involving HO{sub 2} in the very early stages of benzene oxidation at low temperatures using density functional theory (DFT). In particular, we report the rate constants for the reactions of HO{sub 2} with benzene and phenyl. The calculated reaction rate constant for the abstraction of H-C{sub 6}H{sub 5} by HO{sub 2} is found to be in good agreement with the limited experimental values. HO{sub 2} addition to benzene is found to be more important than direct abstraction. We show that the reactions of HO{sub 2} with the phenyl radical generate the propagating radical OH in a highly exoergic reaction. The results presented herein should be useful in modeling the oxidation of aromatic compounds at low temperatures. (author)

  15. Revisiting benzene cluster cations for the chemical ionization of dimethyl sulfide and select volatile organic compounds

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kim, M. J.; Zoerb, M. C.; Campbell, N. R.; Zimmermann, K. J.; Blomquist, B. W.; Huebert, B. J.; Bertram, T. H.

    2015-10-01

    Benzene cluster cations were revisited as a sensitive and selective reagent ion for the chemical ionization of dimethyl sulfide (DMS) and a select group of volatile organic compounds (VOCs). Laboratory characterization was performed using both a new set of compounds (i.e. DMS, ?-caryophyllene) as well as previously studied VOCs (i.e., isoprene, ?-pinene). Using a field deployable chemical ionization time-of-flight mass spectrometer (CI-ToFMS), benzene cluster cations demonstrated high sensitivity (> 1 ncps ppt?1) to DMS, isoprene, and ?-pinene standards. Parallel measurements conducted using a chemical-ionization quadrupole mass spectrometer, with a weaker electric field, demonstrated that ion-molecule reactions likely proceed through amorecombination of ligand-switching and direct charge transfer mechanisms. Laboratory tests suggest that benzene cluster cations may be suitable for the selective ionization of sesquiterpenes, where minimal fragmentation (R2=0.80) over a wide range of sampling conditions.less

  16. Anaerobic biodegradation of BTEX in aquifer material. Environmental research brief

    SciTech Connect (OSTI)

    Borden, R.C.; Hunt, M.J.; Shafer, M.B.; Barlaz, M.A.

    1997-08-01

    Laboratory and field experiments were conducted in two petroleum-contaminated aquifers to examine the anaerobic biodegradation of benzene, toluene, ethylbenzene and xylene isomers (BTEX) under ambient conditions. Aquifer material was collected from locations at the source, mid-plume and end-plume at both sites, incubated under ambient conditions, and monitored for disappearance of the test compounds. In the mid-plume location at the second site, in-situ column experiments were also conducted for comparison with the laboratory microscosm and field-scale results. In the end-plume microcosms, biodegradation was variable with extensive biodegradation in some microcosms and little or no biodegradation in others.

  17. Make aromatics from LPG

    SciTech Connect (OSTI)

    Doolan, P.C. ); Pujado, P.R. )

    1989-09-01

    Liquefied petroleum gas (LPG) consists mainly of the propane and butane fraction recovered from gas fields, associated petroleum gas and refinery operations. Apart from its use in steam cracking and stream reforming, LPG has few petrochemical applications. The relative abundance of LPG and the strong demand for aromatics - benzene, toluene and xylenes (BTX) - make it economically attractive to produce aromatics via the aromatization of propane and butanes. This paper describes the Cyclar process, which is based on a catalyst formulation developed by BP and which uses UOP's CCR catalyst regeneration technology, converts propane, butanes or mixtures thereof to petrochemical-quality aromatics in a single step.

  18. Secondary battery containing zinc electrode with modified separator and method

    DOE Patents [OSTI]

    Poa, D.S.

    1984-02-16

    A battery containing a zinc electrode with a porous separator between the anode and cathode. The separator is a microporous substrate carrying therewith an organic solvent of benzene, toluene or xylene with a tertiary organic amine therein, wherein the tertiary amine has three carbon chains each containing from six to eight carbon atoms. The separator reduces the rate of zinc dentrite growth in the separator during battery operation prolonging battery life by preventing short circuits. A method of making the separator is also disclosed.

  19. Secondary battery containing zinc electrode with modified separator and method

    DOE Patents [OSTI]

    Poa, David S.; Yao, Neng-Ping

    1985-01-01

    A battery containing a zinc electrode with a porous separator between the anode and cathode. The separator is a microporous substrate carrying therewith an organic solvent of benzene, toluene or xylene with a tertiary organic amine therein, wherein the tertiary amine has three carbon chains each containing from six to eight carbon atoms. The separator reduces the rate of zinc dentrite growth in the separator during battery operation prolonging battery life by preventing short circuits. A method of making the separator is also disclosed.

  20. Formation and aging of secondary organic aerosol from toluene: changes in chemical composition, volatility, and hygroscopicity

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hildebrandt Ruiz, L.; Paciga, A. L.; Cerully, K. M.; Nenes, A.; Donahue, N. M.; Pandis, S. N.

    2015-07-24

    Secondary organic aerosol (SOA) is transformed after its initial formation, but this chemical aging of SOA is poorly understood. Experiments were conducted in the Carnegie Mellon environmental chamber to form secondary organic aerosol (SOA) from the photo-oxidation of toluene and other small aromatic volatile organic compounds (VOCs) in the presence of NOx under different oxidizing conditions. The effects of the oxidizing condition on organic aerosol (OA) composition, mass yield, volatility, and hygroscopicity were explored. Higher exposure to the hydroxyl radical resulted in different OA composition, average carbon oxidation state (OSc), and mass yield. The OA oxidation state generally increased duringmore » photo-oxidation, and the final OA OSc ranged from -0.29 to 0.16 in the performed experiments. The volatility of OA formed in these different experiments varied by as much as a factor of 30, demonstrating that the OA formed under different oxidizing conditions can have a significantly different saturation concentration. There was no clear correlation between hygroscopicity and oxidation state for this relatively hygroscopic SOA.« less

  1. Mechanism reduction for multicomponent surrogates: A case study using toluene reference fuels

    SciTech Connect (OSTI)

    Niemeyer, Kyle E.; Sung, Chih-Jen

    2014-11-01

    Strategies and recommendations for performing skeletal reductions of multicomponent surrogate fuels are presented, through the generation and validation of skeletal mechanisms for a three-component toluene reference fuel. Using the directed relation graph with error propagation and sensitivity analysis method followed by a further unimportant reaction elimination stage, skeletal mechanisms valid over comprehensive and high-temperature ranges of conditions were developed at varying levels of detail. These skeletal mechanisms were generated based on autoignition simulations, and validation using ignition delay predictions showed good agreement with the detailed mechanism in the target range of conditions. When validated using phenomena other than autoignition, such as perfectly stirred reactor and laminar flame propagation, tight error control or more restrictions on the reduction during the sensitivity analysis stage were needed to ensure good agreement. In addition, tight error limits were needed for close prediction of ignition delay when varying the mixture composition away from that used for the reduction. In homogeneous compression-ignition engine simulations, the skeletal mechanisms closely matched the point of ignition and accurately predicted species profiles for lean to stoichiometric conditions. Furthermore, the efficacy of generating a multicomponent skeletal mechanism was compared to combining skeletal mechanisms produced separately for neat fuel components; using the same error limits, the latter resulted in a larger skeletal mechanism size that also lacked important cross reactions between fuel components. Based on the present results, general guidelines for reducing detailed mechanisms for multicomponent fuels are discussed.

  2. Mechanism reduction for multicomponent surrogates: A case study using toluene reference fuels

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Niemeyer, Kyle E.; Sung, Chih-Jen

    2014-11-01

    Strategies and recommendations for performing skeletal reductions of multicomponent surrogate fuels are presented, through the generation and validation of skeletal mechanisms for a three-component toluene reference fuel. Using the directed relation graph with error propagation and sensitivity analysis method followed by a further unimportant reaction elimination stage, skeletal mechanisms valid over comprehensive and high-temperature ranges of conditions were developed at varying levels of detail. These skeletal mechanisms were generated based on autoignition simulations, and validation using ignition delay predictions showed good agreement with the detailed mechanism in the target range of conditions. When validated using phenomena other than autoignition, suchmore » as perfectly stirred reactor and laminar flame propagation, tight error control or more restrictions on the reduction during the sensitivity analysis stage were needed to ensure good agreement. In addition, tight error limits were needed for close prediction of ignition delay when varying the mixture composition away from that used for the reduction. In homogeneous compression-ignition engine simulations, the skeletal mechanisms closely matched the point of ignition and accurately predicted species profiles for lean to stoichiometric conditions. Furthermore, the efficacy of generating a multicomponent skeletal mechanism was compared to combining skeletal mechanisms produced separately for neat fuel components; using the same error limits, the latter resulted in a larger skeletal mechanism size that also lacked important cross reactions between fuel components. Based on the present results, general guidelines for reducing detailed mechanisms for multicomponent fuels are discussed.« less

  3. In utero and in vitro effects of benzene and its metabolites on erythroid differentiation and the role of reactive oxygen species

    SciTech Connect (OSTI)

    Badham, Helen J.; Winn, Louise M.

    2010-05-01

    Benzene is a ubiquitous occupational and environmental toxicant. Exposures to benzene both prenatally and during adulthood are associated with the development of disorders such as aplastic anemia and leukemia. Mechanisms of benzene toxicity are unknown; however, generation of reactive oxygen species (ROS) by benzene metabolites may play a role. Little is known regarding the effects of benzene metabolites on erythropoiesis. Therefore, to determine the effects of in utero exposure to benzene on the growth and differentiation of fetal erythroid progenitor cells (CFU-E), pregnant CD-1 mice were exposed to benzene and CFU-E numbers were assessed in fetal liver (hematopoietic) tissue. In addition, to determine the effect of benzene metabolite-induced ROS generation on erythropoiesis, HD3 chicken erythroblast cells were exposed to benzene, phenol, or hydroquinone followed by stimulation of erythrocyte differentiation. Our results show that in utero exposure to benzene caused significant alterations in female offspring CFU-E numbers. In addition, exposure to hydroquinone, but not benzene or phenol, significantly reduced the percentage of differentiated HD3 cells, which was associated with an increase in ROS. Pretreatment of HD3 cells with polyethylene glycol-conjugated superoxide dismutase (PEG-SOD) prevented hydroquinone-induced inhibition of erythropoiesis, supporting the hypothesis that ROS generation is involved in the development of benzene erythrotoxicity. In conclusion, this study provided evidence that ROS generated as a result of benzene metabolism may significantly alter erythroid differentiation, potentially leading to the development of Blood Disorders.

  4. Formation of the diphenyl molecule in the crossed beam reaction of phenyl radicals with benzene

    SciTech Connect (OSTI)

    Zhang Fangtong; Gu Xibin; Kaiser, Ralf I.

    2008-02-28

    The chemical dynamics to form the D5-diphenyl molecule, C{sub 6}H{sub 5}C{sub 6}D{sub 5}, via the neutral-neutral reaction of phenyl radicals (C{sub 6}H{sub 5}) with D6-benzene (C{sub 6}D{sub 6}), was investigated in a crossed molecular beams experiment at a collision energy of 185 kJ mol{sup -1}. The laboratory angular distribution and time-of-flight spectra of the C{sub 6}H{sub 5}C{sub 6}D{sub 5} product were recorded at mass to charge m/z of 159. Forward-convolution fitting of our data reveals that the reaction dynamics are governed by an initial addition of the phenyl radical to the {pi} electron density of the D6-benzene molecule yielding a short-lived C{sub 6}H{sub 5}C{sub 6}D{sub 6} collision complex. The latter undergoes atomic deuterium elimination via a tight exit transition state located about 30 kJ mol{sup -1} above the separated reactants; the overall reaction to form D5-diphenyl from phenyl and D6-benzene was found to be weakly exoergic. The explicit identification of the D5-biphenyl molecules suggests that in high temperature combustion flames, a diphenyl molecule can be formed via a single collision event between a phenyl radical and a benzene molecule.

  5. Biofiltration control of VOC and air toxic emissions: n-Butane and benzene

    SciTech Connect (OSTI)

    Allen, E.R.

    1996-12-31

    n-Butane and benzene vapors are routinely observed in urban atmospheres. Their presence in urban airsheds is of concern because of their ozone production potential as volatile organic compounds (VOCs) and/or potential toxicity. Also, these saturated hydrocarbons are representative of airborne aliphatic and aromatic compounds. Separate laboratory studies have been conducted on the biological elimination of n-butane (n-C{sub 4}H{sub 10}) and benzene (C{sub 6}H{sub 6}) from airstreams using treated compost biofilters. The removal efficiencies were found to exceed 90% for a conditioned biofilter medium and pollutant low concentrations (< 25 ppm) and zeroth order kinetics at higher concentrations (> 100 ppm), whereas benzene vapor elimination followed zeroth order kinetics at concentrations up to 200 ppm. The maximum n-butane and benzene elimination capacities observed for the compost biofilters and conditions employed were 25 and 70 g pollutant m{sup -3} h{sup -1}, respectively. 13 refs., 6 figs., 2 tabs.

  6. Comparative Investigation of Benzene Steam Reforming over Spinel Supported Rh and Ir Catalysts

    SciTech Connect (OSTI)

    Mei, Donghai; Lebarbier, Vanessa M.; Rousseau, Roger; Glezakou, Vassiliki-Alexandra; Albrecht, Karl O.; Kovarik, Libor; Flake, Matt; Dagle, Robert A.

    2013-06-07

    In a combined experimental and first-principles density functional theory (DFT) study, benzene steam reforming (BSR) over MgAl2O4 supported Rh and Ir catalysts was investigated. Experimentally, it has been found that both highly dispersed Rh and Ir clusters (1-2 nm) on the MgAl2O4 spinel support are stable during the BSR in the temperature range of 700-850°C. Compared to the Ir/MgAl2O4 catalyst, the Rh/MgAl2O4 catalyst is more active with higher benzene turnover frequency and conversion. At typical steam conditions with the steam-to-carbon ratio > 12, the benzene conversion is only a weak function of the H2O concentration in the feed. This suggests that the initial benzene decomposition step rather than the benzene adsorption is most likely the rate-determined step in BSR over supported Rh and Ir catalysts. In order to understand the differences between the two catalysts, we followed with a comparative DFT study of initial benzene decomposition pathways over two representative model systems for each supported metal (Rh and Ir) catalysts. A periodic terrace (111) surface and an amorphous 50-atom metal cluster with a diameter of 1.0 nm were used to represent the two supported model catalysts under low and high dispersion conditions. Our DFT results show that the decreasing catalyst particle size enhances the benzene decomposition on supported Rh catalysts by lowering both C-C and C-H bond scission. The activation barriers of the C-C and the C-H bond scission decrease from 1.60 and 1.61 eV on the Rh(111) surface to 1.34 and 1.26 eV on the Rh50 cluster. For supported Ir catalysts, the decreasing particle size only affects the C-C scission. The activation barrier of the C-C scission of benzene decreases from 1.60 eV on the Ir(111) surface to 1.35 eV on the Ir50 cluster while the barriers of the C-H scission are practically the same. The experimentally measured higher BSR

  7. Products of the Benzene + O(3P) Reaction

    SciTech Connect (OSTI)

    Taatjes, Craig A.; Osborn, David L.; Selby, Talitha M.; Meloni, Giovanni; Trevitt, Adam J.; Epifanovsky, Evgeny; Krylov, Anna I.; Sirjean, Baptiste; Dames, Enoch; Wang, Hai

    2010-03-11

    The gas-phase reaction of benzene with O(3P) is of considerable interest for modeling of aromatic oxidation, and also because there exist fundamental questions concerning the prominence of intersystem crossing in the reaction. While its overall rate constant has been studied extensively, there are still significant uncertainties in the product distribution. The reaction proceeds mainly through the addition of the O atom to benzene, forming an initial triplet diradical adduct, which can either dissociate to form the phenoxy radical and H atom or undergo intersystem crossing onto a singlet surface, followed by a multiplicity of internal isomerizations, leading to several possible reaction products. In this work, we examined the product branching ratios of the reaction between benzene and O(3P) over the temperature range 300-1000 K and pressure range 1-10 Torr. The reactions were initiated by pulsed-laser photolysis of NO2 in the presence of benzene and helium buffer in a slow-flow reactor, and reaction products were identified by using the multiplexed chemical kinetics photoionization mass spectrometer operating at the Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory. Phenol and phenoxy radical were detected and quantified. Cyclopentadiene and cyclopentadienyl radical were directly identified for the first time. Finally, ab initio calculations and master equation/RRKM modeling were used to reproduce the experimental branching ratios, yielding pressure-dependent rate expressions for the reaction channels, including phenoxy + H, phenol, cyclopentadiene + CO, which are proposed for kinetic modeling of benzene oxidation.

  8. Revisiting benzene cluster cations for the chemical ionization of dimethyl sulfide and select volatile organic compounds

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kim, Michelle J.; Zoerb, Matthew C.; Campbell, Nicole R.; Zimmermann, Kathryn J.; Blomquist, Byron W.; Huebert, Barry J.; Bertram, Timothy H.

    2016-01-01

    Benzene cluster cations were revisited as a sensitive and selective reagent ion for the chemical ionization of dimethyl sulfide (DMS) and a select group of volatile organic compounds (VOCs). Laboratory characterization was performed using both a new set of compounds (i.e., DMS, β-caryophyllene) as well as previously studied VOCs (i.e., isoprene, α-pinene). Using a field deployable chemical-ionization time-of-flight mass spectrometer (CI-ToFMS), benzene cluster cations demonstrated high sensitivity (> 1 ncps ppt−1) to DMS, isoprene, and α-pinene standards. Parallel measurements conducted using a chemical-ionization quadrupole mass spectrometer, with a much weaker electric field, demonstrated that ion–molecule reactions likely proceed through a combination of ligand-switching and directmore » charge transfer mechanisms. Laboratory tests suggest that benzene cluster cations may be suitable for the selective ionization of sesquiterpenes, where minimal fragmentation (< 25 %) was observed for the detection of β-caryophyllene, a bicyclic sesquiterpene. The in-field stability of benzene cluster cations using CI-ToFMS was examined in the marine boundary layer during the High Wind Gas Exchange Study (HiWinGS). The use of benzene cluster cation chemistry for the selective detection of DMS was validated against an atmospheric pressure ionization mass spectrometer, where measurements from the two instruments were highly correlated (R2 > 0.95, 10 s averages) over a wide range of sampling conditions.« less

  9. On the role of delocalization in benzene: Theoretical and experimental investigation of the effects of strained ring fusion

    SciTech Connect (OSTI)

    Faust, R.

    1993-04-01

    When an important compound`s discovery dates back as far as 1825, one would imagine that every facet of its chemical and physical properties has been illuminated in the meantime. Benzene, however, has not ceased to challenge the chemist`s notion of structure and bonding since its first isolation by Michael Faraday. This report is divided into the following six chapters: 1. Aromaticity -- Criteria, manifestations, structural limitations; 2. The role of delocalization in benzene; 3. The thermochemical properties of benzocyclobutadienologs; 4. Ab initio study of benzenes fused to four-membered rings; 5. Non-planar polycyclic aromatic hydrocarbons; and 6. Experimental details and input decks. 210 Refs.

  10. Crystallographic Analysis of Active Site Contributions to Regiospecificity in the Diiron Enzyme Toluene 4-Monooxygenase

    SciTech Connect (OSTI)

    Bailey, Lucas J.; Acheson, Justin F.; McCoy, Jason G.; Elsen, Nathaniel L.; Phillips, Jr., George N.; Fox, Brian G.

    2014-10-02

    Crystal structures of toluene 4-monooxygenase hydroxylase in complex with reaction products and effector protein reveal active site interactions leading to regiospecificity. Complexes with phenolic products yield an asymmetric {mu}-phenoxo-bridged diiron center and a shift of diiron ligand E231 into a hydrogen bonding position with conserved T201. In contrast, complexes with inhibitors p-NH{sub 2}-benzoate and p-Br-benzoate showed a {mu}-1,1 coordination of carboxylate oxygen between the iron atoms and only a partial shift in the position of E231. Among active site residues, F176 trapped the aromatic ring of products against a surface of the active site cavity formed by G103, E104 and A107, while F196 positioned the aromatic ring against this surface via a {pi}-stacking interaction. The proximity of G103 and F176 to the para substituent of the substrate aromatic ring and the structure of G103L T4moHD suggest how changes in regiospecificity arise from mutations at G103. Although effector protein binding produced significant shifts in the positions of residues along the outer portion of the active site (T201, N202, and Q228) and in some iron ligands (E231 and E197), surprisingly minor shifts (<1 {angstrom}) were produced in F176, F196, and other interior residues of the active site. Likewise, products bound to the diiron center in either the presence or absence of effector protein did not significantly shift the position of the interior residues, suggesting that positioning of the cognate substrates will not be strongly influenced by effector protein binding. Thus, changes in product distributions in the absence of the effector protein are proposed to arise from differences in rates of chemical steps of the reaction relative to motion of substrates within the active site channel of the uncomplexed, less efficient enzyme, while structural changes in diiron ligand geometry associated with cycling between diferrous and diferric states are discussed for their potential

  11. Molecular Characterization of Brown Carbon (BrC) Chromophores in Secondary Organic Aerosol Generated From Photo-Oxidation of Toluene

    SciTech Connect (OSTI)

    Lin, Peng; Liu, Jiumeng; Shilling, John E.; Kathmann, Shawn M.; Laskin, Julia; Laskin, Alexander

    2015-09-28

    Atmospheric Brown carbon (BrC) is a significant contributor to light absorption and climate forcing. However, little is known about a fundamental relationship between the chemical composition of BrC and its optical properties. In this work, light-absorbing secondary organic aerosol (SOA) was generated in the PNNL chamber from toluene photo-oxidation in the presence of NOx (Tol-SOA). Molecular structures of BrC components were examined using nanospray desorption electrospray ionization (nano-DESI) and liquid chromatography (LC) combined with UV/Vis spectroscopy and electrospray ionization (ESI) high-resolution mass spectrometry (HRMS). The chemical composition of BrC chromophores and the light absorption properties of toluene SOA (Tol-SOA) depend strongly on the initial NOx concentration. Specifically, Tol-SOA generated under high-NOx conditions (defined here as initial NOx/toluene of 5/1) appears yellow and mass absorption coefficient of the bulk sample (MACbulk@365nm = 0.78 m2 g-1) is nearly 80 fold higher than that measured for the Tol-SOA sample generated under low-NOx conditions (NOx/toluene < 1/300). Fifteen compounds, most of which are nitrophenols, are identified as major BrC chromophores responsible for the enhanced light absorption of Tol-SOA material produced in the presence of NOx. The integrated absorbance of these fifteen chromophores accounts for 40-60% of the total light absorbance by Tol-SOA at wavelengths between 300 nm and 500 nm. The combination of tandem LC-UV/Vis-ESI/HRMS measurements provides an analytical platform for predictive understanding of light absorption properties by BrC and their relationship to the structure of individual chromophores. General trends in the UV/vis absorption by plausible isomers of the BrC chromophores were evaluated using theoretical chemistry calculations. The molecular-level understanding of BrC chemistry is helpful for better understanding the evolution and behavior of light absorbing aerosols in the atmosphere.

  12. Modeling Studies on the Transport of Benzene and H2S in CO2-Water Systems

    SciTech Connect (OSTI)

    Zheng, L.; Spycher, N.; Xu, T.; Apps, J.; Kharaka, Y.; Birkholzer, J.T.

    2010-11-05

    In this study, reactive transport simulations were used to assess the mobilization and transport of organics with supercritical CO{sub 2} (SCC), and the co-injection and transport of H{sub 2}S with SCC. These processes were evaluated at conditions of typical storage reservoirs, and for cases of hypothetical leakage from a reservoir to an overlying shallower fresh water aquifer. Modeling capabilities were developed to allow the simulation of multiphase flow and transport of H{sub 2}O, CO{sub 2}, H{sub 2}S, as well as specific organic compounds (benzene), coupled with multicomponent geochemical reaction and transport. This included the development of a new simulator, TMVOC-REACT, starting from existing modules of the TOUGH2 family of codes. This work also included an extensive literature review, calculation, and testing of phase-partitioning properties for mixtures of the phases considered. The reactive transport simulations presented in this report are primarily intended to illustrate the capabilities of the new simulator. They are also intended to help evaluate and understand various processes at play, in a more qualitative than quantitative manner, and only for hypothetical scenarios. Therefore, model results are not intended as realistic assessments of groundwater quality changes for specific locations, and they certainly do not provide an exhaustive evaluation of all possible site conditions, especially given the large variability and uncertainty in hydrogeologic and geochemical parameter input into simulations. The first step in evaluating the potential mobilization and transport of organics was the identification of compounds likely to be present in deep storage formations, and likely to negatively impact freshwater aquifers if mobilized by SCC. On the basis of a literature review related to the occurrence of these organic compounds, their solubility in water and SCC, and their toxicity (as reflected by their maximum contaminant levels MCL), benzene was

  13. Leukemia mortality by cell type in petroleum workers with potential exposure to benzene

    SciTech Connect (OSTI)

    Raabe, G.K.; Wong, O.

    1996-12-01

    Workers in the petroleum industry are potentially exposed to a variety of petrochemicals, including benzene or benzene-containing liquids. Although a large number of studies of petroleum workers have been conducted to examine leukemia and other cancer risks, few existing studies have investigated cell-type-specific leukemias. One of the major reasons for the lack of cell-type-specific analysis was the small number of deaths by cell type in individual studies. In the present investigation, all cohort studies of petroleum workers in the United States and the United Kingdom were combined into a single database for cell-type-specific leukemia analysis. The majority of these workers were petroleum refinery employees, but production, pipeline, and distribution workers in the petroleum industry were also included. The combined cohort consisted of more than 208,000 petroleum workers, who contributed more than 4.6 million person-years of observation. Based on a meta-analysis of the combined data, cell-type-specific leukemia risks were expressed in terms of standardized mortality ratios (meta-SMRs). The meta-SMR for acute myeloid leukemia was 0.96. The lack of an increase of acute myeloid leukemia was attributed to the low levels of benzene exposure in the petroleum industry, particularly in comparison to benzene exposure levels in some previous studies of workers in other industries, who had been found to experience an increased risk of acute myeloid leukemia. Similarly, no increase in chronic myeloid, acute lymphocytic, or chronic lymphocytic leukemias was found in petroleum workers (meta-SMRs of 0.89, 1.16, and 0.84, respectively). Stratified meta-analyses restricted to refinery studies or to studies with at least 15 years of follow-up yielded similar results. The findings are consistent with those from several recent case-control studies of cell-type-specific leukemia. 95 refs., 4 figs., 10 tabs.

  14. Carbon Nanothreads from Compressed Benzene | U.S. DOE Office of Science

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (SC) Carbon Nanothreads from Compressed Benzene Basic Energy Sciences (BES) BES Home About Research Facilities Science Highlights Benefits of BES Funding Opportunities Basic Energy Sciences Advisory Committee (BESAC) Community Resources Contact Information Basic Energy Sciences U.S. Department of Energy SC-22/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3081 F: (301) 903-6594 E: Email Us More Information » 04.01.15 Carbon Nanothreads from Compressed

  15. Adsorption characteristics of benzene on biosolid adsorbent and commercial activated carbons

    SciTech Connect (OSTI)

    Hung-Lung Chiang; Kuo-Hsiung Lin; Chih-Yu Chen; Ching-Guan Choa; Ching-Shyung Hwu; Nina Lai

    2006-05-15

    This study selected biosolids from a petrochemical wastewater treatment plant as the raw material. The sludge was immersed in 0.5-5 M of zinc chloride (ZnCl{sub 2}) solutions and pyrolyzed at different temperatures and times. Results indicated that the 1-M ZnCl{sub 2}-immersed biosolids pyrolyzed at 500{sup o}C for 30 min could be reused and were optimal biosolid adsorbents for benzene adsorption. Pore volume distribution analysis indicated that the mesopore contributed more than the macropore and micropore in the biosolid adsorbent. The benzene adsorption capacity of the biosolid adsorbent was 65 and 55% of the G206 (granular-activated carbon) and BPL (coal-based activated carbon; Calgon, Carbon Corp.) activated carbons, respectively. Data from the adsorption and desorption cycles indicated that the benzene adsorption capacity of the biosolid adsorbent was insignificantly reduced compared with the first-run capacity of the adsorbent; therefore, the biosolid adsorbent could be reused as a commercial adsorbent, although its production cost is high. 18 refs., 9 figs., 3 tabs.

  16. Testing of stripping columns for the removal of benzene from aqueous radioactive salt solution

    SciTech Connect (OSTI)

    Georgeton, G.K.; Taylor, G.A.; Gaughan, T.P.

    1995-06-27

    Radioactive high level wastes (HLW) generated from production of special nuclear materials at the Savannah River Site (SRS) are held in interim storage in 51 underground, million gallon tanks. Radioactive cesium ({sup 137}Cs) is segregated by evaporation of aqueous waste solution for interim storage in a salt matrix comprised of Na and K salts or in concentrated salt solution. The saltcake will be dissolved and {sup 137}Cs will be separated from the nonradioactive salts in solution in the In-Tank Precipitation (ITP) Process. The cesium will be combined with other radioactive species and glass formers to be melted and poured into stainless steel canisters in the Defense Waste Processing Facility (DWPF). The salt solution remaining after decontamination in the ITP process will be incorporated into grout for disposal at the site`s Saltstone facility. In the ITP facility, sodium tetraphenylborate (STPB) will be added to precipitate the cesium. Potassium in the waste solution also reacts with STPB and precipitates. Due to radiolytic and chemical degradation of the tetraphenylborate (TPB) precipitate, benzene is generated. The benzene dissolves into the decontaminated salt solution (DSS) and into water (WW) used to {open_quotes}wash{close_quotes} the precipitate to lower the soluble salt content of the slurry. Safety and processing requirements for disposal of the DSS and for temporary storage of the WW dictate that the benzene concentration be reduced.

  17. Comparative pharmacokinetic study of the role of gender and developmental differences in occupational and environmental exposure to benzene. Master's thesis

    SciTech Connect (OSTI)

    Brown, E.A.

    1994-09-01

    The purpose of this study is two-fold. First, it shows that physiological differences between men and women result in gender-specific exposures with respect to benzene. Second, it assesses the potential for a lactating woman's occupational and personal benzene exposure to impact a nursing infant's exposure, highlighting the possibility of subjecting an infant to the effects of industrial chemicals via breast feeding. This study employs physiologically based pharmacokinetic (PBPK) modeling to investigate the influence of physiological parameters and to evaluate the ability of inhaled benzene to transfer from mother to infant through breastmilk. The models are run through scenarios that simulate occupational, smoking, and background exposures. The gender comparison is facilitated by a sensitivity analysis. The blood/air partition coefficient and maximum velocity of metabolism were found to substantially impact model output. These values were both higher in women and caused an increase in the percentage of benzene metabolized in all of the exposure scenarios. The study of lactating women and infants is essentially theoretical. There is evidence that over 65% of an infant's benzene exposure can be attributed to contaminated breastmilk. A large portion of the ingested exposure can be eliminated by adjusting the mother's working or nursing schedule. Benzene, Physiologically based pharmacokinetics, PBPK.

  18. An Order-of-Magnitude Estimation of Benzene Concentration in Saltstone Vault

    SciTech Connect (OSTI)

    CHOI, A

    2006-03-20

    The contents of Tank 48H that include the tetraphenylborate (TPB) precipitates of potassium and cesium will be grouted and stored in the Saltstone vault. The grouting process is exothermic, which should accelerate the rate of decomposition of TPB precipitates eventually to benzene. Because the vault is not currently outfitted with an active ventilation system, there is a concern that a mixture of flammable gases may form in the vapor space of each cell filled with the curing grout. The purpose of this study was to determine if passive breathing induced by the diurnal fluctuations of barometric pressure would provide any mitigating measure against potential flammability in the cell vapor space. In Revision 0 of this document, a set of algorithms were presented that would predict the equilibrium concentration of benzene in the cell vapor space as a function of benzene generation rate, fill height, and passive breathing rate. The algorithms were derived based on several simplifying assumptions so that order of magnitude estimates could be made quickly for scoping purposes. In particular, it was assumed that passive breathing would occur solely due to barometric pressure fluctuations that were sinusoidal; the resulting algorithm for estimating the rate of passive breathing into or out of each cell is given in Eq. (10). Since Revision 0 was issued, the validity of this critical assumption on the mode of passive breathing was checked against available passive ventilation data for the Hanford waste tanks. It was found that the passive breathing rates estimated from Eq. (10) were on average 50 to 90% lower than those measured for 5 out of 6 Hanford tanks considered in this study (see Table 1); for Tank U-106, the estimated passive breathing rates were on average 20% lower than the measured data. These results indicate that Eq. (10) would most likely under predict passive breathing rates of the Saltstone vault. At a given fill height and benzene generation rate, under

  19. Superfund Record of Decision (EPA Region 2): Sayreville Landfill site, Borough of Sayreville, Middlesex County, New Jersey (first remedial action), September 28, 1990

    SciTech Connect (OSTI)

    Not Available

    1990-09-28

    The 35-acre Sayreville Landfill site is an inactive municipal and industrial landfill in the Borough of Sayreville, Middlesex County, New Jersey. Beginning in 1971, the landfill was used to dispose of municipal and hazardous wastes, including an estimated 50 to 150 drums containing hazardous wastes. The drums were buried in a 20-acre area of the site. In 1977, landfill operations ceased, but subsequent unauthorized dumping of hazardous waste may have occurred. In 1980, a landfill closure plan was implemented by the borough, but was not properly completed. In 1981, the State excavated 30 drums containing benzene, pesticide-, and acid-contaminated liquids. The Record of Decision (ROD) addresses remediation of onsite drummed wastes. A subsequent ROD will address further source remediation (leachate) and remediation of ground and surface waters. The primary contaminants of concern affecting the soil and debris are VOCs including benzene, toluene, and xylenes; other organics including pesticides and phenols; acids; and metals including arsenic, chromium, and lead.

  20. Benzene under high pressure: A story of molecular crystals transforming to saturated networks, with a possible intermediate metallic phase

    SciTech Connect (OSTI)

    Wen, Xiao-Dong; Hoffmann, Roald; Ashcroft, N. W.

    2011-01-01

    In a theoretical study, benzene is compressed up to 300 GPa. The transformations found between molecular phases generally match the experimental findings in the moderate pressure regime (<20 GPa): phase I (Pbca) is found to be stable up to 4 GPa, while phase II (P43212) is preferred in a narrow pressure range of 47 GPa. Phase III (P21/c) is at lowest enthalpy at higher pressures. Above 50 GPa, phase V (P21 at 0 GPa; P21/c at high pressure) comes into play, slightly more stable than phase III in the range of 5080 GP, but unstable to rearrangement to a saturated, four-coordinate (at C), one-dimensional polymer. Actually, throughout the entire pressure range, crystals of graphane possess lower enthalpy than molecular benzene structures; a simple thermochemical argument is given for why this is so. In several of the benzene phases there nevertheless are substantial barriers to rearranging the molecules to a saturated polymer, especially at low temperatures. Even at room temperature these barriers should allow one to study the effect of pressure on the metastable molecular phases. Molecular phase III (P21/c) is one such; it remains metastable to higher pressures up to ~200 GPa, at which point it too rearranges spontaneously to a saturated, tetracoordinate CH polymer. At 300 K the isomerization transition occurs at a lower pressure. Nevertheless, there may be a narrow region of pressure, between P = 180 and 200 GPa, where one could find a metallic, molecular benzene state. We explore several lower dimensional models for such a metallic benzene. We also probe the possible first steps in a localized, nucleated benzene polymerization by studying the dimerization of benzene molecules. Several new (C6H6)2 dimers are predicted.

  1. The flash pyrolysis and methanolysis of biomass (wood) for production of ethylene, benzene and methanol

    SciTech Connect (OSTI)

    Steinberg, M.; Fallon, P.T.; Sundaram, M.S.

    1990-02-01

    The process chemistry of the flash pyrolysis of biomass (wood) with the reactive gases, H{sub 2} and CH{sub 4} and with the non-reactive gases He and N{sub 2} is being determined in a 1 in. downflow tubular reactor at pressures from 20 to 1000 psi and temperatures from 600 to 1000{degrees}C. With hydrogen, flash hydropyrolysis leads to high yields of methane and CO which can be used for SNG and methanol fuel production. With methane, flash methanolysis leads to high yields of ethylene, benzene and CO which can be used for the production of valuable chemical feedstocks and methanol transportation fuel. At reactor conditions of 50 psi and 1000{degrees}C and approximately 1 sec residence time, the yields based on pine wood carbon conversion are up to 25% for ethylene, 25% for benzene, and 45% for CO, indicating that over 90% of the carbon in pine is converted to valuable products. Pine wood produces higher yields of hydrocarbon products than Douglas fir wood; the yield of ethylene is 2.3 times higher with methane than with helium or nitrogen, and for pine, the ratio is 7.5 times higher. The mechanism appears to be a free radical reaction between CH{sub 4} and the pyrolyzed wood. There appears to be no net production or consumption of methane. A preliminary process design and analysis indicates a potentially economical competitive system for the production of ethylene, benzene and methanol based on the methanolysis of wood. 10 refs., 18 figs., 1 tab.

  2. The benzene metabolite trans,trans-muconaldehyde blocks gap junction intercellular communication by cross-linking connexin43

    SciTech Connect (OSTI)

    Rivedal, Edgar Leithe, Edward

    2008-11-01

    Benzene is used at large volumes in many different human activities. Hematotoxicity and cancer-causation as a result of benzene exposure was recognized many years ago, but the mechanisms involved remain unclear. Aberrant regulation of gap junction intercellular communication (GJIC) has been linked to both cancer induction and interference with normal hematopoietic development. We have previously suggested that inhibition of GJIC may play a role in benzene toxicity since benzene metabolites were found to block GJIC, the ring-opened trans,trans-muconaldehyde (MUC) being the most potent metabolite. In the present work we have studied the molecular mechanisms underlying the MUC-induced inhibition of gap junctional communication. We show that MUC induces cross-linking of the gap junction protein connexin43 and that this is likely to be responsible for the induced inhibition of GJIC, as well as the loss of connexin43 observed in Western blots. We also show that glutaraldehyde possesses similar effects as MUC, and we compare the effects to that of formaldehyde. The fact that glutaraldehyde and formaldehyde have been associated with induction of leukemia as well as disturbance of hematopoiesis, strengthens the possible link between the effect of MUC on gap junctions, and the toxic effects of benzene.

  3. 1

    Office of Environmental Management (EM)

    Xylene, Ethyl acetate, Ethyl benzene, Ethyl ether, n-Butyl alcohol, Cyclohexanone, Methanol, Cresols, Cresylic acid, Nitroobenzene, Carbon disulfide, Isobutanol, Pyridine, 2-...

  4. ITP Chemicals: Energy and Environmental Profile of the U.S. Chemical Industry, May 2000

    Office of Energy Efficiency and Renewable Energy (EERE)

    Profiles about the ethylene chain, propylene chain, benzene-toulene-xylene chain, agricultural chemicals chain, chlor-alkali industry, and supporting processes

  5. JV Task 86 - Identifying the Source of Benzene in Indoor Air Using Different Compound Classes from TO-15 Data

    SciTech Connect (OSTI)

    Steven B. Hawthorne

    2007-04-15

    Volatile organic compound (VOC) data that had already been collected using EPA method TO-15 at four different sites under regulatory scrutiny (a school, strip mall, apartment complex, and business/residential neighborhood) were evaluated to determine whether the source of indoor air benzene was outdoor air or vapor intrusion from contaminated soil. Both the use of tracer organics characteristic of different sources and principal component statistical analysis demonstrated that the source of indoor air at virtually all indoor sampling locations was a result of outdoor air, and not contaminated soil in and near the indoor air-sampling locations. These results show that proposed remediation activities to remove benzene-contaminated soil are highly unlikely to reduce indoor air benzene concentrations. A manuscript describing these results is presently being prepared for submission to a peer-reviewed journal.

  6. Evolution of soot size distribution in premixed ethylene/air and ethylene/benzene/air flames: Experimental and modeling study

    SciTech Connect (OSTI)

    Echavarria, Carlos A.; Sarofim, Adel F.; Lighty, JoAnn S.; D'Anna, Andrea

    2011-01-15

    The effect of benzene concentration in the initial fuel on the evolution of soot size distribution in ethylene/air and ethylene/benzene/air flat flames was characterized by experimental measurements and model predictions of size and number concentration within the flames. Experimentally, a scanning mobility particle sizer was used to allow spatially resolved and online measurements of particle concentration and sizes in the nanometer-size range. The model couples a detailed kinetic scheme with a discrete-sectional approach to follow the transition from gas-phase to nascent particles and their coagulation to larger soot particles. The evolution of soot size distribution (experimental and modeled) in pure ethylene and ethylene flames doped with benzene showed a typical nucleation-sized (since particles do not actually nucleate in the classical sense particle inception is often used in place of nucleation) mode close to the burner surface, and a bimodal behavior at greater height above burner (HAB). However, major features were distinguished between the data sets. The growth of nucleation and agglomeration-sized particles was faster for ethylene/benzene/air flames, evidenced by the earlier presence of bimodality in these flames. The most significant changes in size distribution were attributed to an increase in benzene concentration in the initial fuel. However, these changes were more evident for high temperature flames. In agreement with the experimental data, the model also predicted the decrease of nucleation-sized particles in the postflame region for ethylene flames doped with benzene. This behavior was associated with the decrease of soot precursors after the main oxidation zone of the flames. (author)

  7. Exposure to methyl tert-butyl ether, benzene, and total hydrocarbons at the Singapore-Malaysia causeway immigration checkpoint

    SciTech Connect (OSTI)

    Tan, C.; Ong, H.Y.; Kok, P.W.

    1996-12-31

    The primary aim of this study was to determine the extent and levels of exposure to volatile organic compounds (VOCs) from automobile emissions in a group of immigration officers at a busy cross-border checkpoint. A majority (80%) of the workers monitored were exposed to benzene at levels between 0.01 and 0.5 ppm, with only 1.2% exceeding the current Occupational Safety and Health Administration occupational exposure limit of 1 ppm. The geometric mean (GM) concentrations of 8-hr time-weighted average exposure were 0.03 ppm, 0.9 ppm, and 2.46 ppm for methyl-tert-butyl ether (MTBE), benzene, and total hydrocarbons (THC), respectively. The highest time-weighted average concentrations measured were 1.05 ppm for MTBE, 2.01 ppm for benzene, and 34 ppm for THC. It was found that motorbikes emitted a more significant amount of pollutants compared with motor cars. On average, officers at the motorcycle booths were exposed to four to five times higher levels of VOCs (GMs of 0.07 ppm, 0.23 ppm, and 4.7 ppm for MTBE, benzene, and THC) than their counterparts at the motor car booths (GMs of 0.01 ppm, 0.05 ppm, and 1.5 ppm). The airborne concentrations of all three pollutants correlated with the flow of vehicle traffic. Close correlations were also noted for the concentrations in ambient air for the three pollutants measured. Benzene and MTBE had a correlation coefficient of 0.97. The overall findings showed that the concentrations of various VOCs were closely related to the traffic density, suggesting that they were from a common source, such as exhaust emissions from the vehicles. The results also indicated that although benzene, MTBE, and THC are known to be volatile, a significant amount could still be detected in the ambient environment, thus contributing to our exposure to these compounds. 4 refs., 6 figs.

  8. Effect of Key Parameters on the Photocatalytic Oxidation of Toluene at Low Concentrations in Air under 254 + 185 nm UV Irradiation

    SciTech Connect (OSTI)

    Quici, Natalia; Vera, Maria L.; Choi, Hyeok; Puma, Gianluca Li; Dionysiou, Dionysios D.; Litter, Marta I.; Destaillats, Hugo

    2009-07-01

    The effect of key experimental parameters on the removal of toluene under 254 + 185 nm irradiation was investigated using a benchtop photocatalytic flow reactor. Toluenewas introduced at low concentrations between 10 and 500 ppbv, typical of indoorenvironments, and reacted on TiO2-coated Raschig rings. Two different TiO2-coated rings were prepared: in one case, by dip-coating using a P25 aqueous suspension and, on the other, using an organic/inorganic sol-gel method that produced thin films of mesoporous anatase. Flow rates in the photoreactor varied between 4 L min-1 and 125 mL min-1, leading to residence times in the range 100 ms< tau< 2 s. For these conditions, toluene removal efficiencies were between 30 and 90percent, indicating that the system did not achieve total conversion in any case. For each air flow rate, the conversion oftoluene was significantly higher when the reactor length was 10 cm, as compared with 5 cm; however, only marginal increases in conversions were achieved in the two reactor lengths at equal residence time and different concentration of toluene, suggesting that that the reactor is effectively behaving as an ideal reactor and that the reaction is first-order in the concentration of toluene. Experiments were carried out between 0 and 66percent relative humidity (RH), the fastest reaction rate being observed at moderately low humidity conditions (10percent RH), with respect to both dry air and higher humidity levels. Formaldehyde was formed as a partial oxidation byproduct at low and at high residence times (240 and 960 ms), although higher formaldehyde molar yields (up to 20percent) were observed at low tau (240 ms) and moderate humidity conditions (10 and 33percent), suggesting that both tau and RH can be optimized toreduce the formation of harmful intermediates. Toluene removal efficiency increased with the TiO2 thickness (i.e., mass) until a maximum value of 500 nm, beyond which the removal efficiency decreased. This should be

  9. Adsorption, Desorption, and Dissociation of Benzene on TiO2(110) and Pd/TiO2(110)

    SciTech Connect (OSTI)

    Zhou, Jing; Dag, Sefa; Senanayake, Sanjaya D; Hathorn, Bryan C; Kalinin, Sergei V; Meunier, Vincent; Mullins, David R; Overbury, Steven {Steve} H; Baddorf, Arthur P

    2006-01-01

    Adsorption and reaction of benzene molecules on clean TiO{sub 2}(110) and on TiO{sub 2}(110) with deposited Pd nanoparticles are investigated using a combination of scanning tunneling microscopy (STM), temperature-programmed desorption, and first-principles calculations. Above {approx}50 K, the one-dimensional motion of benzene between bridging oxygen rows is shown to be too fast for STM imaging. At 40 K benzene molecules form chains on top of titanium rows, with calculations indicating every other benzene is rotated 30{sup o}. Both experimental and theoretical studies find no dissociative reactivity of benzene on the clean TiO{sub 2}(110) surface, due to little hybridization between TiO{sub 2} and benzene electronic states. After deposition of Pd nanoparticles, molecular benzene is observed with STM both on the substrate and adjacent to metallic particles. Upon heating to 800 K, benzene fully breaks down into its atomic constituents in a multistep decomposition process.

  10. Spectroscopic study on deuterated benzenes. I. Microwave spectra and molecular structure in the ground state

    SciTech Connect (OSTI)

    Kunishige, Sachi; Katori, Toshiharu; Baba, Masaaki; Nakajima, Masakazu; Endo, Yasuki

    2015-12-28

    We observed microwave absorption spectra of some deuterated benzenes and accurately determined the rotational constants of all H/D isotopomers in the ground vibrational state. Using synthetic analysis assuming that all bond angles are 120°, the mean bond lengths were obtained to be r{sub 0}(C–C) = 1.3971 Å and r{sub 0}(C–H) = r{sub 0}(C–D) = 1.0805 Å. It has been concluded that the effect of deuterium substitution on the molecular structure is negligibly small and that the mean bond lengths of C–H and C–D are identical unlike small aliphatic hydrocarbons, in which r{sub 0}(C–D) is about 5 mÅ shorter than r{sub 0}(C–H). It is considered that anharmonicity is very small in the C–H stretching vibration of aromatic hydrocarbons.

  11. Photocatalytic degradation of gaseous toluene over TiO{sub 2}-SiO{sub 2} composite nanotubes synthesized by sol-gel with template technique

    SciTech Connect (OSTI)

    Zou, Xuejun [State Key Laboratory of Fine Chemical and Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian, 116024 (China)] [State Key Laboratory of Fine Chemical and Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian, 116024 (China); Li, Xinyong, E-mail: xyli@dlut.edu.cn [State Key Laboratory of Fine Chemical and Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian, 116024 (China) [State Key Laboratory of Fine Chemical and Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian, 116024 (China); Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia); Qu, Zhenping; Zhao, Qidong; Shi, Yong; Chen, Yongying [State Key Laboratory of Fine Chemical and Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian, 116024 (China)] [State Key Laboratory of Fine Chemical and Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian, 116024 (China); Tade, Moses [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia)] [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia); Liu, Shaomin, E-mail: shaomin.liu@curtin.edu.au [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia)] [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia)

    2012-02-15

    Graphical abstract: TiO{sub 2}-SiO{sub 2} nanotubes (b) were fabricated by sol-gel method using ZnO nanowires (a) as template. Highlights: Black-Right-Pointing-Pointer A simple method to prepare TiO{sub 2}-SiO{sub 2} nanotubes for photocatalytic toluene removal. Black-Right-Pointing-Pointer The TiO{sub 2}-SiO{sub 2} nanotubes have a small blue shift and higher absorption intensity. Black-Right-Pointing-Pointer The TiO{sub 2}-SiO{sub 2} nanotubes have an enhanced photoactivity in degrading gaseous toluene. -- Abstract: TiO{sub 2}-SiO{sub 2} composite nanotubes were successfully synthesized by a facile sol-gel technique utilizing ZnO nanowires as template. The nanotubes were well characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, N{sub 2} adsorption-desorption analysis and UV-vis diffuse reflectance spectroscopy. The nanotubular TiO{sub 2}-SiO{sub 2} composite photocatalysts showed diameter of 300-325 nm, fine mesoporous structure and high specific surface area. The results indicated that the degradation efficiency of gaseous toluene could get 65% after 4 h reaction using the TiO{sub 2}-SiO{sub 2} composite as the photocatalyst under UV light illumination, which was higher than that of P25.

  12. Thermodynamic Features of Benzene-1,2-Diphosphonic Acid Complexes with Several Metal Ions

    SciTech Connect (OSTI)

    Syouhei Nishihama; Ryan P. Witty; Leigh R Martin; Kenneth L. Nash

    2013-08-01

    Among his many contributions to the advancement of f-element chemistry and separation science, Professor Gregory R. Choppins research group completed numerous investigations featuring the application of distribution techniques to the determination of metal complexation equilibrium quotients. Most of these studies focused on the chemistry of lanthanide and actinide complexes. In keeping with that tradition, this report discusses the complex formation equilibrium constants for complexes of trivalent europium (Eu3+) with benzene-1,2-diphosphonic acid (H4BzDP) determined using solvent extraction distribution experiments in 0.2 M (Na,H)ClO4 media in the temperature range of 5 45 degrees C. Protonation constants for HnBzDP4-n and stoichiometry and stability of BzDP4- complexes with Zn2+, Ni2+, and Cu2+ have also been determined using potentiometric titration (at I = 0.1 M) and 31P NMR spectroscopy. Heats of protonation of HnBzDPn-4 species have been determined by titration calorimetry. From the temperature dependence of the complex Eu3+-HnBzDPn-4 equilibrium constant, a composite enthalpy (?H = -15.1 (+/-1.0) kJ mol-1) of complexation has been computed. Comparing these thermodynamic parameters with literature reports on other diphosphonic acids and structurally similar carboxylic acids indicates that exothermic heats of complexation are unique to the Eu-BzDP system. Comparisons with thermodynamic data from the literature indicate that the fixed geometry imposed by the benzene ring enhances complex stability.

  13. Changes in the peripheral blood transcriptome associated with occupational benzene exposure identified by cross-comparison on two microarray platforms

    SciTech Connect (OSTI)

    McHale, Cliona M.; Zhang, Luoping; Lan, Qing; Li, Guilan; Hubbard, Alan E.; Forrest, Matthew S.; Vermeulen, Roel; Chen, Jinsong; Shen, Min; Rappaport, Stephen M.; Yin, Songnian; Smith, Martyn T.; Rothman, Nathaniel

    2009-03-01

    Benzene is an established cause of leukemia and a possible cause of lymphoma in humans but the molecular pathways underlying this remain largely undetermined. This study sought to determine if the use of two different microarray platforms could identify robust global gene expression and pathway changes associated with occupational benzene exposure in the peripheral blood mononuclear cell (PBMC) gene expression of a population of shoe-factory workers with well-characterized occupational exposures to benzene. Microarray data was analyzed by a robust t-test using a Quantile Transformation (QT) approach. Differential expression of 2692 genes using the Affymetrix platform and 1828 genes using the Illumina platform was found. While the overall concordance in genes identified as significantly associated with benzene exposure between the two platforms was 26% (475 genes), the most significant genes identified by either array were more likely to be ranked as significant by the other platform (Illumina = 64%, Affymetrix = 58%). Expression ratios were similar among the concordant genes (mean difference in expression ratio = 0.04, standard deviation = 0.17). Four genes (CXCL16, ZNF331, JUN and PF4), which we previously identified by microarray and confirmed by real-time PCR, were identified by both platforms in the current study and were among the top 100 genes. Gene Ontology analysis showed over representation of genes involved in apoptosis among the concordant genes while Ingenuity{reg_sign} Pathway Analysis (IPA) identified pathways related to lipid metabolism. Using a two-platform approach allows for robust changes in the PBMC transcriptome of benzene-exposed individuals to be identified.

  14. Sodium dodecyl benzene sulfonate-assisted synthesis through a hydrothermal reaction

    SciTech Connect (OSTI)

    Sobhani, Azam; Salavati-Niasari, Masoud; Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P.O. Box 8731751167, Islamic Republic of Iran

    2012-08-15

    Graphical abstract: Reaction of a SeCl{sub 4} aqueous solution with a NiCl{sub 2}6H{sub 2}O aqueous solution in presence of sodium dodecyl benzene sulfonate (SDBS) as capping agent and hydrazine (N{sub 2}H{sub 4}H{sub 2}O) as reductant, produces nanosized nickel selenide through a hydrothermal method. The effect of temperature, reaction time and amounts of reductant on the morphology, particle sizes of NiSe nanostructures has been investigated. Highlights: ? NiSe nanostructures were synthesized by hydrothermal method. ? A novel Se source was used to synthesize NiSe. ? SDBS as capping agent plays a crucial role on the morphology of products. ? A mixture of Ni{sub 3}Se{sub 2} and NiSe was prepared in the presence of 2 ml hydrazine. ? A pure phase of NiSe was prepared in the presence of 4 or 6 ml hydrazine. -- Abstract: The effects of the anionic surfactant on the morphology, size and crystallization of NiSe precipitated from NiCl{sub 2}6H{sub 2}O and SeCl{sub 4} in presence of hydrazine (N{sub 2}H{sub 4}H{sub 2}O) as reductant were investigated. The products have been successfully synthesized in presence of sodium dodecyl benzene sulfonate (SDBS) as surfactant via an improved hydrothermal route. A variety of synthesis parameters, such as reaction time and temperature, capping agent and amount of reducing agent have a significant effect on the particle size, phase purity and morphology of the obtained products. The sample size became bigger with decreasing reaction temperature and increasing reaction time. In the presence of 2 ml hydrazine, the samples were found to be the mixture of Ni{sub 3}Se{sub 2} and NiSe. With increasing the reaction time and amount of hydrazine a pure phase of hexagonal NiSe was obtained. X-ray diffraction analysis (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) images indicate phase, particle size and morphology of the products. Chemical composition and purity of the products were characterized by X

  15. Benzene metabolite levels in blood and bone marrow of B6C3F{sub 1} mice after low-level exposure

    SciTech Connect (OSTI)

    Bechtold, W.E.; Strunk, M.R.; Thornton-Manning, J.R.

    1995-12-01

    Studies at the Inhalation Toxicology Research Institute (ITRI) have explored the species-specific uptake and metabolism of benzene. Results have shown that metabolism is dependent on both dose and route of administration. Of particular interest were shifts in the major metabolic pathways as a function of exposure concentration. In these studies, B6C3F{sub 1} mice were exposed to increasing levels of benzene by either gavage or inhalation. As benzene internal dose increased, the relative amounts of muconic acid and hydroquinone decreased. In contrast, the relative amount of catechol increased with increasing exposure. These results show that the relative levels of toxic metabolites are a function of exposure level. Based on these results and assuming a linear relationship between exposure concentration and levels of bone marrow metabolites, it would be difficult to detect an elevation of any phenolic metabolites above background after occupational exposures to the OSHA Permissible Exposure Limit of 1 ppm benzene.

  16. Photocatalytic degradation of gaseous toluene over hollow spindle-like ?-Fe{sub 2}O{sub 3} loaded with Ag

    SciTech Connect (OSTI)

    Li, Hong [State Key Laboratory of Fine Chemical, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China) [State Key Laboratory of Fine Chemical, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Department of Basic, Dalian Naval Academy, Dalian 116018 (China); Zhao, Qidong [State Key Laboratory of Fine Chemical, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China)] [State Key Laboratory of Fine Chemical, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Li, Xinyong, E-mail: xyli@dlut.edu.cn [State Key Laboratory of Fine Chemical, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China) [State Key Laboratory of Fine Chemical, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia); Shi, Yong [State Key Laboratory of Fine Chemical, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China)] [State Key Laboratory of Fine Chemical, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Zhu, Zhengru [Research Center of Hydrology and Engineering, Academy of City and Environment, Liaoning Normal University, Dalian 116029 (China)] [Research Center of Hydrology and Engineering, Academy of City and Environment, Liaoning Normal University, Dalian 116029 (China); Tade, Moses [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia)] [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia); Liu, Shaomin, E-mail: shaomin.liu@curtin.edu.au [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia)] [Department of Chemical Engineering, Curtin University, Perth, WA 6845 (Australia)

    2012-06-15

    Highlights: ? Hollow ?-Fe{sub 2}O{sub 3} spindle-shaped microparticles were prepared for Ag support. ? The hollow ?-Fe{sub 2}O{sub 3} and Ag/?-Fe{sub 2}O{sub 3} materials were used to degrade gaseous toluene. ? Complete degradation of toluene occurred on the Ag/?-Fe{sub 2}O{sub 3} surface. -- Abstract: In this work, hollow spindle-like ?-Fe{sub 2}O{sub 3} nanoparticles were synthesized by a hydrothermal route. The Ag/?-Fe{sub 2}O{sub 3} catalyst was prepared based on the spindle-shaped ?-Fe{sub 2}O{sub 3} with CTAB as the surfactant, which showed excellent photoelectric property and photocatalytic activity. The structural properties of these samples were systematically investigated by X-ray powder diffraction, scanning electronic microscopy, transmission electronic microscopy, energy-dispersive X-ray spectra, and UVVis diffuse reflectance spectroscopy techniques. The photo-induced charge separation in the samples was demonstrated by surface photovoltage measurement. The photocatalytic performances of the Ag/?-Fe{sub 2}O{sub 3} and ?-Fe{sub 2}O{sub 3} samples were comparatively studied in the degradation of toluene under xenon lamp irradiation by in situ FTIR spectroscopy. Benzaldehyde and benzoic acid species could be observed on the ?-Fe{sub 2}O{sub 3} surface rather than Ag/?-Fe{sub 2}O{sub 3} surface. The results indicate that the Ag/?-Fe{sub 2}O{sub 3} sample exhibited higher photocatalytic efficiency.

  17. A pilot-scale field study on the anaerobic biotreatment of soil impacted with highly chlorinated benzenes

    SciTech Connect (OSTI)

    Ramanand, K.; Foulke, B.; Delnicki, W.A.; Ying, A.C.; Baek, N.H.; Coats, M.L.; Duffy, J.J.

    1995-12-31

    An on-site pilot-scale demonstration of anaerobic biodegradation of highly chlorinated benzenes was successfully performed at a chemical manufacturing industrial facility in Niagara Falls, New York. The field investigation was conducted in 6-yd{sup 3} capacity soil boxes. Approximately 4 yd{sup 3} of soil impacted with chlorinated compounds was placed in each soil box. Chlorinated benzenes with 3 or more chlorines accounted for about 85% of the total chemistry in the soil. The soil box amended with water, nutrients, and acclimated soil microbial inoculum exhibited greater than 78% reduction in the levels of highly chlorinated compounds after one year of field study. The total concentrations of hexa-, penta-, tetra-, and trichlorobenzenes decreased from 920 mg/kg to less than 190 mg/kg, while the total concentrations of di-, and monochlorobenzene increased from 8 mg/kg to greater than 400 mg/kg during one year of field operation. The control soil that did not receive any external nutrient or microbial amendments maintained the same percentage of the highly chlorinated benzenes after one year and di-, and monochlorobenzene never exceeded more than 4 mg/kg at any given time period. The anaerobic activity was further confirmed by monitored parameters such as nutrient consumption (butyrate, nitrogen, organic matter), sulfate depletion, and methane production.

  18. Benchmark Theoretical Study of the π–π Binding Energy in the Benzene Dimer

    SciTech Connect (OSTI)

    Miliordos, Evangelos; Apra, Edoardo; Xantheas, Sotiris S.

    2014-09-04

    We establish a new estimate for the interaction energy between two benzene molecules in the parallel displaced (PD) conformation by systematically converging (i) the intra- and intermolecular geometry at the minimum geometry, (ii) the expansion of the orbital basis set and (iii) the level of electron correlation. The calculations were performed at the second order Møller - Plesset perturbation (MP2) and the Coupled Cluster including Singles, Doubles and a perturbative estimate of Triples replacements [CCSD(T)] levels of electronic structure theory. At both levels of theory, by including results corrected for Basis Set Superposition Error (BSSE), we have estimated the Complete Basis Set (CBS) limit by employing the family of Dunning’s correlation consistent polarized valence basis sets. The largest MP2 calculation was performed with the cc-pV6Z basis set (2,772 basis functions), whereas the largest CCSD(T) calculation with the cc-pV5Z basis set (1,752 basis functions). The cluster geometries were optimized with basis sets up to quadruple-ζ quality, observing that both its intra- and inter-molecular parts have practically converged with the triple-ζ quality sets. The use of converged geometries was found to play an important role for obtaining accurate estimates for the CBS limits. Our results demonstrate that the binding energies with the families of the plain (cc-pVnZ) and augmented (aug-cc-pVnZ) sets converge [to within < 0.01 kcal/mol for MP2 and < 0.15 kcal/mol for CCSD(T)] to the same CBS limit. In addition, the average of the uncorrected and BSSEcorrected binding energies was found to converge to the same CBS limit must faster than either of the two constituents (uncorrected or BSSE-corrected binding energies). Due to the fact that the family of augmented basis sets (especially for the larger sets) causes serious linear dependency problems, the plain basis sets (for which no linear dependencies were found) are deemed as a more efficient and

  19. Catalytic Fast Pyrolysis for the Production of the Hydrocarbon Biofuels

    SciTech Connect (OSTI)

    Nimlos, M. R.; Robichaud, D. J.; Mukaratate, C.; Donohoe, B. S.; Iisa, K.

    2013-01-01

    Catalytic fast pyrolysis is a promising technique for conversion of biomass into hydrocarbons for use as transportation fuels. For over 30 years this process has been studied and it has been demonstrated that oils can be produced with high concentrations of hydrocarbons and low levels of oxygen. However, the yields from this type of conversion are typically low and the catalysts, which are often zeolites, are quickly deactivated through coking. In addition, the hydrocarbons produced are primarily aromatic molecules (benzene, toluene, xylene) that not desirable for petroleum refineries and are not well suited for diesel or jet engines. The goals of our research are to develop new multifunction catalysts for the production of gasoline, diesel and jet fuel range molecules and to improve process conditions for higher yields and low coking rates. We are investigating filtration and the use of hydrogen donor molecules to improve catalyst performance.

  20. Natural bioreclamation of alkylbenzenes (BTEX) from a gasoline spill in methanogenic groundwater. Book chapter

    SciTech Connect (OSTI)

    Wilson, J.T.; Kampbell, D.H.; Armstrong, J.

    1994-01-01

    A spill of gasoline from underground storage tanks (USTS) at the Sleeping Bear Dunes National Lakeshore in Benzie County, Michigan, produced a plume of contamination that reached the banks of the Platte River. The plume was short (70 feet) and it had a short residence time (5 to 53 weeks). The plume was in transmissive glacial sands and gravels. The groundwater is cold (10 to 11 C), hard (alkalinity 200 to 350 milligrams/L), and well buffered (pH 6.1 to 7.6). Along the most contaminated flow path, methanogenesis, nitrate reduction, sulfate reduction, iron reduction, and oxygen respiration accepted enough electrons to destroy 30, 14, 4.2, 1.1, and 0.8 milligrams/L of benzene, toluene, ethylbenzene, and xylenes (BTEX compounds) respectively. The actual concentration of BTEX compounds consumed was 42 milligrams/L.

  1. Eielson Air Force Base Operable Unit 2 baseline risk assessment

    SciTech Connect (OSTI)

    Lewis, R.E.; Jarvis, T.T.; Jarvis, M.R.; Whelan, G.

    1994-10-01

    Operable Unit 2 at Eielson Air Force Base (AFB) near Fairbanks, is one of several operable units characterized by petroleum, oil, and lubricant contamination, and by the presence of organic products floating at the water table, as a result of Air Force operations since the 1940s. The base is approximately 19,270 acres in size, and comprises the areas for military operations and a residential neighborhood for military dependents. Within Operable Unit 2, there are seven source areas. These source areas were grouped together primarily because of the contaminants released and hence are not necessarily in geographical proximity. Source area ST10 includes a surface water body (Hardfill Lake) next to a fuel spill area. The primary constituents of concern for human health include benzene, toluene, ethylbenzene, and xylenes (BTEX). Monitored data showed these volatile constituents to be present in groundwater wells. The data also showed an elevated level of trace metals in groundwater.

  2. Surfactant-modified zeolites as permeable barriers to organic and inorganic groundwater contaminants

    SciTech Connect (OSTI)

    Bowman, R.S.; Sullivan, E.J.

    1995-10-01

    We have shown in laboratory experiments that natural zeolites treated with hexadecyltrimethylammonium (HDTMA) are effective sorbents for nonpolar organics, inorganic cations, and inorganic anions. Due to their low cost ({approximately}$0.75/kg) and granular nature, HDTMA-zeolites appear ideal candidates for reactive, permeable subsurface barriers. The HDTMA-zeolites are stable over a wide range of pH (3-13), ionic strength (1 M Cs{sup +} or Ca{sup 2+}), and in organic solvents. Surfactant-modified zeolites sorb nonpolar organics (benzene, toluene, xylene, chlorinated aliphatics) via a partitioning mechanism, inorganic cations (Pb{sup 2+}) via ion exchange and surface complexation, and inorganic anions (CrO{sub 4}{sup 2-}, SeO{sub 4}{sup 2-}, SO{sub 4}{sup 2-}) via surface precipitation.The goal of this work is to demonstrate the use of surfactant-modified zeolite as a permeable barrier to ground water contaminants.

  3. Health assessment for Vogel Paint and Wax, Maurice, Sioux County, Iowa, Region 7. CERCLIS No. IAD980630487. Final report

    SciTech Connect (OSTI)

    Not Available

    1989-04-29

    The Vogel Paint and Wax National Priority List site is situated in northwest Iowa in Sioux County. Contaminants found at the site consist of heavy metals (particularly cadmium, chromium, lead, and mercury) and volatile organic compounds (benzene, ethylbenzene, methyl ethyl ketone, toluene, and xylene). Two towns, Maurice and Struble, and the Southern Sioux County Rural Water System well field are located within three miles of the site, and two families live within 1600 feet of the waste-disposal site. Environmental pathways include contaminated soil and ground water, as well as potential surface water and air contamination. Although there does not appear to be any immediate public health threat, the site is of potential health concern because of the possibility for further off-site migration of contaminants into the ground water aquifer and for direct on-site contact.

  4. Permeable sorptive walls for treatment of hydrophobic organic contaminant plumes in groundwater

    SciTech Connect (OSTI)

    Grathwohl, P.; Peschik, G.

    1997-12-31

    Highly hydrophobic contaminants are easily adsorbed from aqueous solutions. Since for many of these compounds sorption increases with increasing organic carbon content natural materials such as bituminous shales and coals may be used in permeable sorptive walls. This, however, only applies if sorption is at equilibrium, which may not always be the case in groundwater treatment using a funnel-and-gate system. In contrast to the natural solids, granular activated carbons (GACs) have very high sorption capacities and reasonably fast sorption kinetics. The laboratory results show that application of GACs (e.g. F100) is economically feasible for in situ removal of polycyclic aromatic hydrocarbons (PAH) from groundwater at a former manufactured gas plant site (MGP). For less sorbing compounds (such as benzene, toluene, xylenes) a combination of adsorption and biodegradation is necessary (i.e. sorptive + reactive treatment).

  5. Selective aromatization of C[sub 3] and C[sub 4] paraffins over modified encilite catalysts. 1. Qualitative study

    SciTech Connect (OSTI)

    Jana, A.K.; Rao, M.S. . Department of Chemical Engineering)

    1993-06-01

    The catalytic activity of Zn-encilite in the aromatization of propane and n-butane has been studied by a comparative study of the yields of benzene, toluene, and xylenes (BTX) using propane and n-butane as feeds. The results showed that n-butane had better activity and selectivity to BTX than propane. The effects of reaction temperature, contact time, inlet concentration, poisoning with ammonia on H-encilite, and different degrees of ion exchange with Zn[sup 2+] ion were studied in detail in order to obtain information on the reaction mechanism. The results indicated that the activity and the selectivity were dictated by the acidity and Zn loading on the catalyst.

  6. In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

    DOE Patents [OSTI]

    Taylor, R.T.; Jackson, K.J.; Duba, A.G.; Chen, C.I.

    1998-05-19

    An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants are described. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating. 21 figs.

  7. In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

    DOE Patents [OSTI]

    Taylor, Robert T.; Jackson, Kenneth J.; Duba, Alfred G.; Chen, Ching-I

    1998-01-01

    An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating.

  8. Impact of the revised OSHA exposure standard on evaluation and control of benzene and other volatile organic chemicals in the liquid petroleum pipeline industry

    SciTech Connect (OSTI)

    Mercer, D.O.

    1989-01-01

    The primary purpose of this study was to determine the benzene exposure potential of workers in the liquid petroleum pipeline industry and to assess the impact of compliance with the revised standard on this industry. In addition, exposure to ethylene dibromide (EDB), and ethylene dichloride (EDC), which have toxicological profiles similar to that of benzene and are routinely found in this industry, were evaluated and appropriate control protocols were recommended. Exposure potential to benzene in excess of the 0.5 ppm (8-hour TWA) OSHA action level was shown to be limited to three free product handling operations, and that this increased exposure potential was dependent on the length of time necessary to perform the operations. The incidence and magnitude of benzene overexposure was not severe and control could be accomplished with engineering methods, along with work practice controls and personal protective equipment. Through application of a risk assessment model it was shown that 14 excess leukemia deaths per one thousand workers could be expected in the employee population that routinely performs those operation having maximum benzene exposure potential. This compares to less than on excess leukemia death per one thousand workers in the total work population. The evaluation of EDB and EDC indicated that exposure potential to EDB was of greatest concern. Even though exposure could be limited through application of standard industrial hygiene methods, any control protocol short of total elimination of EDB from the product stream may be not sufficient to reduce exposure to accepted levels.

  9. Raman Spectroscopy of the Reaction of Thin Films of Solid-State Benzene with Vapor-Deposited Ag, Mg, and Al

    SciTech Connect (OSTI)

    Schalnat, Matthew C.; Hawkridge, Adam M.; Pemberton, Jeanne E.

    2011-07-21

    Thin films of solid-state benzene at 30 K were reacted with small quantities of vapor-deposited Ag, Mg, and Al under ultrahigh vacuum, and products were monitored using surface Raman spectroscopy. Although Ag and Mg produce small amounts of metalbenzene adduct products, the resulting Raman spectra are dominated by surface enhancement of the normal benzene modes from metallic nanoparticles suggesting rapid Ag or Mg metallization of the film. In contrast, large quantities of Al adduct products are observed. Vibrational modes of the products in all three systems suggest adducts that are formed through a pathway initiated by an electron transfer reaction. The difference in reactivity between these metals is ascribed to differences in ionization potential of the metal atoms; ionization potential values for Ag and Mg are similar but larger than that for Al. These studies demonstrate the importance of atomic parameters, such as ionization potential, in solid-state metalorganic reaction chemistry.

  10. Facile preparation of sphere-like copper ferrite nanostructures and their enhanced visible-light-induced photocatalytic conversion of benzene

    SciTech Connect (OSTI)

    Shen, Yu; Wu, Yanbo; Xu, Hongfeng; Fu, Jie; Li, Xinyong; Zhao, Qidong; Hou, Yang

    2013-10-15

    Graphical abstract: - Highlights: Spinel CuFe{sub 2}O{sub 4} nanospheres were successfully synthesized via a facile method. CuFe{sub 2}O{sub 4} nanospheres showed high photocatalytic activity toward benzene. Ethyl acetate, carboxylic acid and aldehyde were the intermediate products. - Abstract: Spinel copper ferrite nanospheres with diameters of about 116 nm were synthesized in high yield via a facile solvothermal route. The prepared nanospheres had cubic spinel structure and exhibited good size uniformity and regularity. The band-gap energy of CuFe{sub 2}O{sub 4} nanospheres was calculated to be about 1.69 eV, indicating their potential visible-light-induced photocatalytic activity. The dramatically enhanced photocatalytic activity of the CuFe{sub 2}O{sub 4} nanospheres was evaluated via the photocatalytic conversion of benzene under Xe lamp irradiation. By using the in situ FTIR technique, ethyl acetate, carboxylic acid and aldehyde could be regarded as the intermediate products, and CO{sub 2} was produced as the final product during the reaction process. This study provided new insight into the design and preparation of functional nanomaterials with sphere structure in high yield, and the as-grown architectures demonstrated an excellent ability to remove organic pollutants in the atmosphere.

  11. Molecular catalytic coal liquid conversion. Quarterly status...

    Office of Scientific and Technical Information (OSTI)

    The relationship between the turnover number of the catalyst and the reaction time was obtained. Other aromatic compounds such as toluene, n-butylbenzene, tetralin, o-xylene all ...

  12. DISCLAIMER

    Office of Legacy Management (LM)

    ... VOC U.S. Atomic Energy Commission Austral Oil Company Benzene, toluene, ethylbenzene, and ... predecessor agency to the DOE) and Austral Oil Company (Austral). 1. I Site Location. ...

  13. Effect of hydrotropic salts on phase relationships involving hydrocarbons, water, and alcohols

    SciTech Connect (OSTI)

    Ho, P.C.; Kraus, K.A.

    1980-01-01

    Hydrotropic salts, which can increase the solubility of organic materials in aqueous solutions, are useful to tertiary oil recovery. We have examined effects on solubility of hydrocarbons in water (with and without alcohols) through addition of inorganic hydrotropic salts, such as perchlorates, thiocyanates, and iodides - high in the usual Hofmeister series - and of organic salts such as short chain alkyl benzene sulfonates and other salts based on substituted benzene derivatives. Although the inorganic salts are relatively ineffective in increasing solubility of hydrocarbons in water, many of the organic salts are excellent hydrotropic agents for hydrocarbons. We have examined the phase relationships for several series of aromatic salts such as sulfonates, carboxylates and hydroxycarboxylates, as a function of alkyl-carbon substitution in three-component (hydrocarbon, salt, water) and in four-component (hydrocarbon, salt, alcohol, water) systems. We have also examined miscibility relationships for a given hydrotropic salt as the chain length of alkanes and alkyl benzenes is systematically varied. While miscibilities decrease with increase in chain length of the hydrocarbon, the hydrotropic properties in these systems increase rapidly with the number of alkyl carbons on the benzene ring of the salts and they are relatively insensitive to the type of charged group (sulfonate vs carboxylate) attached to the benzene ring. However, there were significant increases in hydrotropy as one goes from equally substituted sulfonates or carboxylates to salicylates. A number of salts have been identified which have much greater hydrotropic properties for hydrocarbons than such well-known hydrotropic materials as toluene and xylene sulfonates.

  14. Density functional theory (DFT) and ab initio molecular orbital calculations have been employed to determine the structures and energies of the isomers of the OH-toluene adduct, the methyl hydroxycyclohexadienyl radical, and their corresponding transitio

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Technical Report Laboratory Investigation of Organic Aerosol Formation from Aromatic Hydrocarbons (DOE Award No. DE-FG02-02ER63098) Prepared by Luisa T. Molina, Renyi Zhang and Mario J. Molina Our work for this DOE funded project includes: (1) measurements of the kinetics and mechanism of the gas-phase oxidation reactions of the aromatic hydrocarbons initiated by OH; (2) measurements of aerosol formation from the aromatic hydrocarbons; and (3) theoretical studies to elucidate the OH-toluene

  15. Mobilization and Transport of Organic Compounds from Reservoir Rock and Caprock in Geological Carbon Sequestration Sites

    SciTech Connect (OSTI)

    Zhong, Lirong; Cantrell, Kirk J.; Mitroshkov, Alexandre V.; Shewell, Jesse L.

    2014-05-06

    Supercritical CO2 (scCO2) is an excellent solvent for organic compounds, including benzene, toluene, ethyl-benzene, and xylene (BTEX), phenols, and polycyclic aromatic hydrocarbons (PAHs). Monitoring results from geological carbon sequestration (GCS) field tests has shown that organic compounds are mobilized following CO2 injection. Such results have raised concerns regarding the potential for groundwater contamination by toxic organic compounds mobilized during GCS. Knowledge of the mobilization mechanism of organic compounds and their transport and fate in the subsurface is essential for assessing risks associated with GCS. Extraction tests using scCO2 and methylene chloride (CH2Cl2) were conducted to study the mobilization of volatile organic compounds (VOCs, including BTEX), the PAH naphthalene, and n-alkanes (n-C20 – n-C30) by scCO2 from representative reservoir rock and caprock obtained from depleted oil reservoirs and coal from an enhanced coal-bed methane recovery site. More VOCs and naphthalene were extractable by scCO2 compared to the CH2Cl2 extractions, while scCO2 extractable alkane concentrations were much lower than concentrations extractable by CH2Cl2. In addition, dry scCO2 was found to extract more VOCs than water saturated scCO2, but water saturated scCO2 mobilized more naphthalene than dry scCO2. In sand column experiments, moisture content was found to have an important influence on the transport of the organic compounds. In dry sand columns the majority of the compounds were retained in the column except benzene and toluene. In wet sand columns the mobility of the BTEX was much higher than that of naphthalene. Based upon results determined for the reservoir rock, caprock, and coal samples studied here, the risk to aquifers from contamination by organic compounds appears to be relatively low; however, further work is necessary to fully evaluate risks from depleted oil reservoirs.

  16. A density functional theory study of magneto-electric Jones birefringence of noble gases, furan homologues, and mono-substituted benzenes

    SciTech Connect (OSTI)

    Fahleson, Tobias; Norman, Patrick; Coriani, Sonia; Rizzo, Antonio; Rikken, Geert L. J. A.

    2013-11-21

    We report on the results of a systematic ab initio study of the Jones birefringence of noble gases, of furan homologues, and of monosubstituted benzenes, in the gas phase, with the aim of analyzing the behavior and the trends within a list of systems of varying size and complexity, and of identifying candidates for a combined experimental/theoretical study of the effect. We resort here to analytic linear and nonlinear response functions in the framework of time-dependent density functional theory. A correlation is made between the observable (the Jones constant) and the atomic radius for noble gases, or the permanent electric dipole and a structure/chemical reactivity descriptor as the para Hammett constant for substituted benzenes.

  17. Benzene exposure in the petroleum distribution industry associated with leukemia in the United Kingdom: Overview of the methodology of a case-control study

    SciTech Connect (OSTI)

    Rushton, L.

    1996-12-01

    This paper describes basic principles underlying the methodology for obtaining quantitative estimates of benzene exposure in the petroleum marketing and distribution industry. Work histories for 91 cases of leukemia and 364 matched controls (4 per case) identified for a cohort of oil distribution workers up to the end of 1992 were obtained, primarily from personnel records. Information on the distribution sites, more than 90% of which were closed at the time of data collection, was obtained from site visits and archive material. Industrial hygiene measurements measured under known conditions were assembled for different tasks. These were adjusted for conditions where measured data were not available using variables known to influence exposure, such as temperature, technology, percentage of benzene in fuel handled, products handled, number of loads, and job activity. A quantitative estimate of dermal contact and peak exposure was also made. 20 refs., 1 fig., 3 tabs.

  18. Spectroscopic study on deuterated benzenes. II. High-resolution laser spectroscopy and rotational structure in the S{sub 1} state

    SciTech Connect (OSTI)

    Kunishige, Sachi; Katori, Toshiharu; Baba, Masaaki; Hayashi, Masato; Hasegawa, Hirokazu; Ohshima, Yasuhiro

    2015-12-28

    High-resolution spectra of the S{sub 1}←S{sub 0} transition in jet-cooled deuterated benzenes were observed using pulse dye amplification of single-mode laser light and mass-selective resonance enhanced multiphoton ionization (REMPI) detection. The vibrational and rotational structures were accurately analyzed for the vibronic levels in the S{sub 1} state. The degenerate 6{sup 1} levels of C{sub 6}H{sub 6} or C{sub 6}D{sub 6} are split into 6a{sup 1} and 6b{sup 1} in many of deuterated benzenes. The rigid-rotor rotational constants were assessed and found to be slightly different between 6a and 6b because of different mean molecular structures. Their rotational levels are significantly shifted by Coriolis interactions. It was found that the Coriolis parameter proportionally changed with the number of substituted D atoms.

  19. Association of genetic polymorphisms in GADD45A, MDM2, and p14{sup ARF} with the risk of chronic benzene poisoning in a Chinese occupational population

    SciTech Connect (OSTI)

    Sun Pin; Zhang Zhongbin; Wan Junxiang; Zhao Naiqing; Jin Xipeng; Xia Zhaolin

    2009-10-01

    Benzene reactive metabolites can lead to DNA damage and trigger the p53-dependent defense responses to maintain genomic stability. We hypothesized that the p53-dependent genes may play a role in the development of chronic benzene poisoning (CBP). In a case-control study of 303 patients with benzene poisoning and 295 workers occupationally exposed to benzene in south China, we investigated associations between the risk of CBP and polymorphisms in three p53-dependent genes. Potential interactions of these polymorphisms with lifestyle factors were also explored. We found p14{sup ARF} rs3731245 polymorphism was associated with risk of CBP (P = 0.014). Compared with those carrying the GG genotype, individuals carrying p14{sup ARF} rs3731245 GA+AA genotypes had a reduced risk of CBP ([adjusted odds ratio (OR{sub adj}) = 0.57, 95%CI = 0.36-0.89]. Further analysis showed p14{sup ARF} TGA/TAG diplotype was associated with an increased risk of CBP (P = 0.0006), whereas p14{sup ARF} TGG/TAA diplotype was associated with a decreased risk of CBP (P = 0.0000001). In addition, we found individuals carrying both MDM2 Del1518 WW genotype and p14{sup ARF} rs3731245 GA+AA genotypes had a lower risk of CBP (OR{sub adj} = 0.25; 95%CI = 0.10-0.62; P = 0.003). Although these results require confirmation and extension, our findings suggest that genetic polymorphisms in p14{sup ARF} may have an impact on the risk of CBP in the study population.

  20. Introducing constricted variational density functional theory in its relaxed self-consistent formulation (RSCF-CV-DFT) as an alternative to adiabatic time dependent density functional theory for studies of charge transfer transitions

    SciTech Connect (OSTI)

    Krykunov, Mykhaylo; Seth, Mike; Ziegler, Tom

    2014-05-14

    We have applied the relaxed and self-consistent extension of constricted variational density functional theory (RSCF-CV-DFT) for the calculation of the lowest charge transfer transitions in the molecular complex X-TCNE between X = benzene and TCNE = tetracyanoethylene. Use was made of functionals with a fixed fraction (α) of Hartree-Fock exchange ranging from α = 0 to α = 0.5 as well as functionals with a long range correction (LC) that introduces Hartree-Fock exchange for longer inter-electronic distances. A detailed comparison and analysis is given for each functional between the performance of RSCF-CV-DFT and adiabatic time-dependent density functional theory (TDDFT) within the Tamm-Dancoff approximation. It is shown that in this particular case, all functionals afford the same reasonable agreement with experiment for RSCF-CV-DFT whereas only the LC-functionals afford a fair agreement with experiment using TDDFT. We have in addition calculated the CT transition energy for X-TCNE with X = toluene, o-xylene, and naphthalene employing the same functionals as for X = benzene. It is shown that the calculated charge transfer excitation energies are in as good agreement with experiment as those obtained from highly optimized LC-functionals using adiabatic TDDFT. We finally discuss the relation between the optimization of length separation parameters and orbital relaxation in the RSCF-CV-DFT scheme.

  1. Characterization Of The Hydrogenation Products Of Bix (phenylethynyl) Benzene (DEB) Getter Using Combined GC/FTIR/MS, FT-Raman, and ATR Spectroscopies (U)

    SciTech Connect (OSTI)

    Smyrl, N. R.; Powell, G. L.

    2011-06-09

    Organic hydrogen getters are utilized to minimize hydrogen accumulation in sealed systems where such build up could produce either a safety problem from pressure build up or corrosion problem due the hydriding of metals contained in the sealed vessel. DEB (1,4 bis (phenyl ethynyl) benzene) is a hydrogen getter that is based on the palladium catalyzed hydrogenation of triple bonds to single bonds in aromatic aryl compound. DEB is a getter mixed with 25% carbon and 1% Pd and pressed into pellets with some porosity. The reaction mechanisms are complex involving solid state reactions with a heterogeneous catalyst leading to the many intermediates.

  2. State-selective laser photoionization of neutral benzene molecules ejected from keV ion bombarded C{sub 6}H{sub 6}/Ag{l_brace}111{r_brace}

    SciTech Connect (OSTI)

    Meserole, C. A.; Vandeweert, E.; Chatterjee, R.; Chakraborty, B. R.; Garrison, B. J.; Winograd, N.; Postawa, Z.

    1998-12-16

    One-color two-photon ionization spectroscopy was used to probe state-selectively neutral benzene molecules desorbed from a benzene overlayer physisorbed on a Ag{l_brace}111{r_brace} surface upon 8 keV Ar{sup +} bombardment. Time distributions were measured for benzene molecules ejected in the zero level of the molecular ground state and in the first state of the {nu}{sub 6} ' vibration. These distributions are found to show a strong dependence both on the internal energy of the ejected molecules and the degree of coverage of the Ag surface. Up to monolayer coverages, benzene molecules are ejected by direct collisions with Ag particles sputtered from the underlying substrate. Molecules with higher internal energy leave the surface with a distribution shifted towards lower flight times. At multilayer coverages, a second, thermal-like ejection mechanism gains significance. It is suggested that only molecules excited near the benzene-vacuum interface, survive the ejection process without being deexcited.

  3. FTIR study of the photocatalytic degradation of gaseous benzene over UV-irradiated TiO{sub 2} nanoballs synthesized by hydrothermal treatment in alkaline solution

    SciTech Connect (OSTI)

    Zhu, Zhengru [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian 116024 (China)] [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian 116024 (China); Li, Xinyong, E-mail: xyli@dlut.edu.cn [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian 116024 (China)] [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian 116024 (China); Zhao, Qidong; Qu, Zhenping; Hou, Yang; Zhao, Ling [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian 116024 (China)] [Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Sciences and Technology, Dalian University of Technology, Dalian 116024 (China); Liu, Shaomin [Department of Chemical Engineering, Curtin University of Technology, Perth, WA 6845 (Australia)] [Department of Chemical Engineering, Curtin University of Technology, Perth, WA 6845 (Australia); Chen, Guohua [Department of Chemical and Biomolecular Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)] [Department of Chemical and Biomolecular Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

    2010-12-15

    In this study, photocatalysts of TiO{sub 2} nanoballs were obtained via a hydrothermal treating of commercial P25 in alkaline solution, and then characterized with SEM, XRD, BET and surface photovoltage spectroscopy techniques. The UV-assisted photodegradation of gaseous benzene over P25 and the prepared TiO{sub 2} nanoballs was monitored by an in situ infrared technique. The results demonstrated that the prepared TiO{sub 2} nanoballs in anatase form were more active than commercial P25 in photocatalytic oxidation of gaseous benzene. The promoted activity of the hydrothermal-treated TiO{sub 2} is attributed to the increasing specific surface area and larger band gap induced by the reduced crystallite size. The spectra of FTIR indicated that weakly adsorbed phenol was formed as the reaction progress. Hydroxyl groups on the surface of TiO{sub 2} nanoballs are able to react with photo-produced phenol, which is then retained on the catalyst surface leading to the progressive deactivation of the catalyst in the gas-solid system.

  4. Assessing electronic structure approaches for gas-ligand interactions in metal-organic frameworks: The CO{sub 2}-benzene complex

    SciTech Connect (OSTI)

    Witte, Jonathon; Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 ; Neaton, Jeffrey B.; Head-Gordon, Martin; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720

    2014-03-14

    Adsorption of gas molecules in metal-organic frameworks is governed by many factors, the most dominant of which are the interaction of the gas with open metal sites, and the interaction of the gas with the ligands. Herein, we examine the latter class of interaction in the context of CO{sub 2} binding to benzene. We begin by clarifying the geometry of the CO{sub 2}benzene complex. We then generate a benchmark binding curve using a coupled-cluster approach with single, double, and perturbative triple excitations [CCSD(T)] at the complete basis set (CBS) limit. Against this ?CCSD(T)/CBS standard, we evaluate a plethora of electronic structure approximations: Hartree-Fock, second-order Mller-Plesset perturbation theory (MP2) with the resolution-of-the-identity approximation, attenuated MP2, and a number of density functionals with and without different empirical and nonempirical van der Waals corrections. We find that finite-basis MP2 significantly overbinds the complex. On the other hand, even the simplest empirical correction to standard density functionals is sufficient to bring the binding energies to well within 1 kJ/mol of the benchmark, corresponding to an error of less than 10%; PBE-D in particular performs well. Methods that explicitly include nonlocal correlation kernels, such as VV10, vdW-DF2, and ?B97X-V, perform with similar accuracy for this system, as do ?B97X and M06-L.

  5. Correlating Extent of PtNi Bond Formation with Low-temperature Hydrogenation of Benzene and 1,3-butadiene over Supported Pt/Ni Bimetallic Catalysts

    SciTech Connect (OSTI)

    Lonergan, W.; Vlachos, D; Chen, J

    2010-01-01

    Low-temperature hydrogenation of benzene and 1,3-butadiene on supported Pt/Ni catalysts have been used as probe reactions to correlate hydrogenation activity with the extent of Pt-Ni bimetallic bond formation. Pt/Ni bimetallic and Pt and Ni monometallic catalysts were supported on {gamma}-Al{sub 2}O{sub 3} using incipient wetness impregnation. Two sets of bimetallic catalysts were synthesized: one set to study the effect of metal atomic ratio and the other to study the effect of impregnation sequence. Fourier transform infrared spectroscopy (FTIR) CO adsorption studies were performed to characterize the surface composition of the bimetallic nanoparticles, and transmission electron microscopy (TEM) was utilized to characterize the particle size distribution. Batch reactor studies with FTIR demonstrated that all bimetallic catalysts outperformed monometallic catalysts for both benzene and 1,3-butadiene hydrogenation. Within the two sets of bimetallic catalysts, it was found that catalysts with a smaller Pt:Ni ratio possessed higher hydrogenation activity and that catalysts synthesized using co-impregnation had greater activity than sequentially impregnated catalysts. Extended X-ray absorption fine structure (EXAFS) measurements were performed in order to verify the extent of Pt-Ni bimetallic bond formation, which was found to correlate with the hydrogenation activity.

  6. Water on BN doped benzene: A hard test for exchange-correlation functionals and the impact of exact exchange on weak binding

    SciTech Connect (OSTI)

    Al-Hamdani, Yasmine S.; Alf, Dario; von Lilienfeld, O. Anatole; Michaelides, Angelos

    2014-10-22

    Density functional theory (DFT) studies of weakly interacting complexes have recently focused on the importance of van der Waals dispersion forces, whereas the role of exchange has received far less attention. Here, by exploiting the subtle binding between water and a boron and nitrogen doped benzene derivative (1,2-azaborine) we show how exact exchange can alter the binding conformation within a complex. Benchmark values have been calculated for three orientations of the water monomer on 1,2-azaborine from explicitly correlated quantum chemical methods, and we have also used diffusion quantum Monte Carlo. For a host of popular DFT exchange-correlation functionals we show that the lack of exact exchange leads to the wrong lowest energy orientation of water on 1,2-azaborine. As such, we suggest that a high proportion of exact exchange and the associated improvement in the electronic structure could be needed for the accurate prediction of physisorption sites on doped surfaces and in complex organic molecules. Meanwhile to predict correct absolute interaction energies an accurate description of exchange needs to be augmented by dispersion inclusive functionals, and certain non-local van der Waals functionals (optB88- and optB86b-vdW) perform very well for absolute interaction energies. Through a comparison with water on benzene and borazine (B?N?H?) we show that these results could have implications for the interaction of water with doped graphene surfaces, and suggest a possible way of tuning the interaction energy.

  7. Synthesis and characterization of d{sup 10} metal complexes with mixed 1,3-di(1H-imidazol-4-yl)benzene and multicarboxylate ligands

    SciTech Connect (OSTI)

    Chen, Zhi-Hao; Zhao, Yue; Chen, Shui-Sheng; Wang, Peng; Sun, Wei-Yin

    2013-06-15

    Seven new coordination polymers [Zn(H{sub 2}L)(mbdc)] (1), [Zn(H{sub 3}L)(btc)] (2), [Zn(H{sub 2}L)(Hbtc)] (3), [Zn(H{sub 2}L)(Hbtc)]H{sub 2}O (4), [Zn{sub 2}(H{sub 2}L)(btc)(?{sub 2}-OH)] (5), [Cd(H{sub 2}L)(mbdc)] (6) and [Cd{sub 3}(H{sub 2}L){sub 2}(btc){sub 2}(H{sub 2}O)]5H{sub 2}O (7) were synthesized by reactions of the corresponding metal salt with rigid ligand 1,3-di(1H-imidazol-4-yl)benzene (H{sub 2}L) and different carboxylic acids of 1,3-benzenedicarboxylic acid (H{sub 2}mbdc) and benzene-1,3,5-tricarboxylic acid (H{sub 3}btc), respectively. The results of X-ray crystallographic analysis indicate that complex 1 is 1D chain while 2 is a (3,3)-connected 2D network with Point (Schlfli) symbol of (4,8{sup 2}). Complexes 3 and 6 are 2D networks, 4 is a 3-fold interpenetrating 3D framework with Point (Schlfli) symbol of (6{sup 5},8) and 5 is a (3,8)-connected 2D network with Point (Schlfli) symbol of (3,4{sup 2}){sub 2}(3{sup 4},4{sup 6},5{sup 6},6{sup 8},7{sup 3},8), while 7 is a (3,10)-connected 3D net with Schlfli symbol of (3,4,5){sub 2}(3{sup 4},4{sup 8},5{sup 18},6{sup 12},7{sup 2},8). The thermal stability and photoluminescence of the complexes were investigated. Furthermore, DFT calculations were performed for 24 to discuss the temperature controlled self-assembly of the complexes. - Graphical abstract: Seven new coordination polymers with multicarboxylate and rigid ditopic 4-imidazole containing ligands have been obtained and found to show different structures and topologies. - Highlights: Metal complexes with diverse structures of 1D chain, 2D network and 3D framework. Mixed ligands of 1,3-di(1H-imidazol-4-yl)benzene and multicarboxylate. Photoluminescence property.

  8. Path integral Monte Carlo simulations of H{sub 2} adsorbed to lithium-doped benzene: A model for hydrogen storage materials

    SciTech Connect (OSTI)

    Lindoy, Lachlan P.; Kolmann, Stephen J.; D’Arcy, Jordan H.; Jordan, Meredith J. T.; Crittenden, Deborah L.

    2015-11-21

    Finite temperature quantum and anharmonic effects are studied in H{sub 2}–Li{sup +}-benzene, a model hydrogen storage material, using path integral Monte Carlo (PIMC) simulations on an interpolated potential energy surface refined over the eight intermolecular degrees of freedom based upon M05-2X/6-311+G(2df,p) density functional theory calculations. Rigid-body PIMC simulations are performed at temperatures ranging from 77 K to 150 K, producing both quantum and classical probability density histograms describing the adsorbed H{sub 2}. Quantum effects broaden the histograms with respect to their classical analogues and increase the expectation values of the radial and angular polar coordinates describing the location of the center-of-mass of the H{sub 2} molecule. The rigid-body PIMC simulations also provide estimates of the change in internal energy, ΔU{sub ads}, and enthalpy, ΔH{sub ads}, for H{sub 2} adsorption onto Li{sup +}-benzene, as a function of temperature. These estimates indicate that quantum effects are important even at room temperature and classical results should be interpreted with caution. Our results also show that anharmonicity is more important in the calculation of U and H than coupling—coupling between the intermolecular degrees of freedom becomes less important as temperature increases whereas anharmonicity becomes more important. The most anharmonic motions in H{sub 2}–Li{sup +}-benzene are the “helicopter” and “ferris wheel” H{sub 2} rotations. Treating these motions as one-dimensional free and hindered rotors, respectively, provides simple corrections to standard harmonic oscillator, rigid rotor thermochemical expressions for internal energy and enthalpy that encapsulate the majority of the anharmonicity. At 150 K, our best rigid-body PIMC estimates for ΔU{sub ads} and ΔH{sub ads} are −13.3 ± 0.1 and −14.5 ± 0.1 kJ mol{sup −1}, respectively.

  9. Benzene analogues of (quasi-)planar M@B{sub n}H{sub n} compounds (M = V{sup ?}, Cr, Mn{sup +}): A theoretical investigation

    SciTech Connect (OSTI)

    Li, Lifen; Xu, Chang; Jin, Baokang; Cheng, Longjiu

    2013-11-07

    The stability of M@B{sub n}H{sub n} (M = V{sup ?}, Cr, Mn{sup +}; n = 58) is investigated by density functional theory. For n = 68, the isomers possess (quasi-)planar local minima showed by geometry optimization at TPSSh/6-311+G{sup **} level. All the optimized structures are thermodynamics stable according to the large HOMO-LUMO gap, binding energy, vertical ionization potential, and vertical electron affinity analysis. The peripheral and central atomic radius fit each other best at n = 7 confirmed by the variation of the binding energy values. The availability of d atom orbitals in M for participation in the ?-delocalized bonding with the peripheral ring leads to the aromaticity of the (quasi-)planar structures and makes them the benzene analogues. This work establishes firmly the metal-doped borane rings as a new type of aromatic molecule.

  10. Water on BN doped benzene: A hard test for exchange-correlation functionals and the impact of exact exchange on weak binding

    SciTech Connect (OSTI)

    Al-Hamdani, Yasmine S.; Michaelides, Angelos; Alf, Dario; Lilienfeld, O. Anatole von

    2014-11-14

    Density functional theory (DFT) studies of weakly interacting complexes have recently focused on the importance of van der Waals dispersion forces, whereas the role of exchange has received far less attention. Here, by exploiting the subtle binding between water and a boron and nitrogen doped benzene derivative (1,2-azaborine) we show how exact exchange can alter the binding conformation within a complex. Benchmark values have been calculated for three orientations of the water monomer on 1,2-azaborine from explicitly correlated quantum chemical methods, and we have also used diffusion quantum Monte Carlo. For a host of popular DFT exchange-correlation functionals we show that the lack of exact exchange leads to the wrong lowest energy orientation of water on 1,2-azaborine. As such, we suggest that a high proportion of exact exchange and the associated improvement in the electronic structure could be needed for the accurate prediction of physisorption sites on doped surfaces and in complex organic molecules. Meanwhile to predict correct absolute interaction energies an accurate description of exchange needs to be augmented by dispersion inclusive functionals, and certain non-local van der Waals functionals (optB88- and optB86b-vdW) perform very well for absolute interaction energies. Through a comparison with water on benzene and borazine (B{sub 3}N{sub 3}H{sub 6}) we show that these results could have implications for the interaction of water with doped graphene surfaces, and suggest a possible way of tuning the interaction energy.

  11. Quantum effects and anharmonicity in the H{sub 2}-Li{sup +}-benzene complex: A model for hydrogen storage materials

    SciTech Connect (OSTI)

    Kolmann, Stephen J.; D'Arcy, Jordan H.; Jordan, Meredith J. T.

    2013-12-21

    Quantum and anharmonic effects are investigated in H{sub 2}-Li{sup +}-benzene, a model for hydrogen adsorption in metal-organic frameworks and carbon-based materials. Three- and 8-dimensional quantum diffusion Monte Carlo (QDMC) and rigid-body diffusion Monte Carlo (RBDMC) simulations are performed on potential energy surfaces interpolated from electronic structure calculations at the M05-2X/6-31+G(d,p) and M05-2X/6-311+G(2df,p) levels of theory using a three-dimensional spline or a modified Shepard interpolation. These calculations investigate the intermolecular interactions in this system, with three- and 8-dimensional 0 K H{sub 2} binding enthalpy estimates, ?H{sub bind} (0 K), being 16.5 kJmol{sup ?1} and 12.4 kJmol{sup ?1}, respectively: 0.1 and 0.6 kJmol{sup ?1} higher than harmonic values. Zero-point energy effects are 35%of the value of ?H{sub bind} (0 K) at M05-2X/6-311+G(2df,p) and cannot be neglected; uncorrected electronic binding energies overestimate ?H{sub bind} (0 K) by at least 6 kJmol{sup ?1}. Harmonic intermolecular binding enthalpies can be corrected by treating the H{sub 2} helicopter and ferris wheel rotations as free and hindered rotations, respectively. These simple corrections yield results within 2% of the 8-dimensional anharmonic calculations. Nuclear ground state probability density histograms obtained from the QDMC and RBDMC simulations indicate the H{sub 2} molecule is delocalized above the Li{sup +}-benzene system at 0 K.

  12. Water on BN doped benzene: A hard test for exchange-correlation functionals and the impact of exact exchange on weak binding

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Al-Hamdani, Yasmine S.; Alfè, Dario; von Lilienfeld, O. Anatole; Michaelides, Angelos

    2014-10-22

    Density functional theory (DFT) studies of weakly interacting complexes have recently focused on the importance of van der Waals dispersion forces, whereas the role of exchange has received far less attention. Here, by exploiting the subtle binding between water and a boron and nitrogen doped benzene derivative (1,2-azaborine) we show how exact exchange can alter the binding conformation within a complex. Benchmark values have been calculated for three orientations of the water monomer on 1,2-azaborine from explicitly correlated quantum chemical methods, and we have also used diffusion quantum Monte Carlo. For a host of popular DFT exchange-correlation functionals we showmore » that the lack of exact exchange leads to the wrong lowest energy orientation of water on 1,2-azaborine. As such, we suggest that a high proportion of exact exchange and the associated improvement in the electronic structure could be needed for the accurate prediction of physisorption sites on doped surfaces and in complex organic molecules. Meanwhile to predict correct absolute interaction energies an accurate description of exchange needs to be augmented by dispersion inclusive functionals, and certain non-local van der Waals functionals (optB88- and optB86b-vdW) perform very well for absolute interaction energies. Through a comparison with water on benzene and borazine (B₃N₃H₆) we show that these results could have implications for the interaction of water with doped graphene surfaces, and suggest a possible way of tuning the interaction energy.« less

  13. A case report of motor neuron disease in a patient showing significant level of DDTs, HCHs and organophosphate metabolites in hair as well as levels of hexane and toluene in blood

    SciTech Connect (OSTI)

    Kanavouras, Konstantinos; Tzatzarakis, Manolis N.; Mastorodemos, Vasileios; Plaitakis, Andreas; Tsatsakis, Aristidis M.

    2011-11-15

    Motor neuron disease is a devastating neurodegenerative condition, with the majority of sporadic, non-familial cases being of unknown etiology. Several epidemiological studies have suggested that occupational exposure to chemicals may be associated with disease pathogenesis. We report the case of a patient developing progressive motor neuron disease, who was chronically exposed to pesticides and organic solvents. The patient presented with leg spasticity and developed gradually clinical signs suggestive of amyotrophic lateral sclerosis, which was supported by the neurophysiologic and radiological findings. Our report is an evidence based case of combined exposure to organochlorine (DDTs), organophosphate pesticides (OPs) and organic solvents as confirmed by laboratory analysis in samples of blood and hair confirming systematic exposure. The concentration of non-specific dialkylphosphates metabolites (DAPs) of OPs in hair (dimethyphopshate (DMP) 1289.4 pg/mg and diethylphosphate (DEP) 709.4 pg/mg) and of DDTs (opDDE 484.0 pg/mg, ppDDE 526.6 pg/mg, opDDD 448.4 pg/mg, ppDDD + opDDT 259.9 pg/mg and ppDDT 573.7 pg/mg) were considerably significant. Toluene and n-hexane were also detected in blood on admission at hospital and quantified (1.23 and 0.87 {mu}g/l, respectively), while 3 months after hospitalization blood testing was found negative for toluene and n-hexane and hair analysis was provided decrease levels of HCHs, DDTs and DAPs. -- Highlights: Black-Right-Pointing-Pointer Exposure to pesticides and organic solvents might be a risk factor for sporadic MND. Black-Right-Pointing-Pointer We report a patient who developed progressive upper and lower motor neuron disease. Black-Right-Pointing-Pointer The patient had a history of occupational exposure to pesticides and solvents. Black-Right-Pointing-Pointer High DDTs' levels and increased levels of DMP and DEP were measured in his hair. Black-Right-Pointing-Pointer The patients' exposure to chemicals might have played

  14. Absorption of ethanol, acetone, benzene and 1,2-dichloroethane through human skin in vitro: a test of diffusion model predictions

    SciTech Connect (OSTI)

    Gajjar, Rachna M.; Kasting, Gerald B.

    2014-11-15

    The overall goal of this research was to further develop and improve an existing skin diffusion model by experimentally confirming the predicted absorption rates of topically-applied volatile organic compounds (VOCs) based on their physicochemical properties, the skin surface temperature, and the wind velocity. In vitro human skin permeation of two hydrophilic solvents (acetone and ethanol) and two lipophilic solvents (benzene and 1,2-dichloroethane) was studied in Franz cells placed in a fume hood. Four doses of each {sup 14}C-radiolabed compound were tested — 5, 10, 20, and 40 μL cm{sup −2}, corresponding to specific doses ranging in mass from 5.0 to 63 mg cm{sup −2}. The maximum percentage of radiolabel absorbed into the receptor solutions for all test conditions was 0.3%. Although the absolute absorption of each solvent increased with dose, percentage absorption decreased. This decrease was consistent with the concept of a stratum corneum deposition region, which traps small amounts of solvent in the upper skin layers, decreasing the evaporation rate. The diffusion model satisfactorily described the cumulative absorption of ethanol; however, values for the other VOCs were underpredicted in a manner related to their ability to disrupt or solubilize skin lipids. In order to more closely describe the permeation data, significant increases in the stratum corneum/water partition coefficients, K{sub sc}, and modest changes to the diffusion coefficients, D{sub sc}, were required. The analysis provided strong evidence for both skin swelling and barrier disruption by VOCs, even by the minute amounts absorbed under these in vitro test conditions. - Highlights: • Human skin absorption of small doses of VOCs was measured in vitro in a fume hood. • The VOCs tested were ethanol, acetone, benzene and 1,2-dichloroethane. • Fraction of dose absorbed for all compounds at all doses tested was less than 0.3%. • The more aggressive VOCs absorbed at higher levels than

  15. Ultra-low-temperature reactions of C({sup 3}P{sub 0}) atoms with benzene molecules in helium droplets

    SciTech Connect (OSTI)

    Krasnokutski, Serge A. Huisken, Friedrich

    2014-12-07

    The reaction of carbon atoms with benzene has been investigated in liquid helium droplets at T = 0.37 K. We found an addition of the carbon atom to form an initial intermediate complex followed by a ring opening and the formation of a seven-membered ring. In contrast to a previous gas phase study, the reaction is frozen after these steps and the loss of hydrogen does not occur. A calorimetric technique was applied to monitor the energy balance of the reaction. It was found that more than 267 kJ mol{sup ?1} were released in this reaction. This estimation is in line with quantum chemical calculations of the formation energy of a seven-membered carbon ring. It is suggested that reactions of this kind could be responsible for the low abundance of small polycyclic aromatic hydrocarbon molecules in the interstellar medium. We also found the formation of weakly bonded water-carbon adducts, in which the carbon atom is linked to the oxygen atom of the water molecule with a binding energy of about 33.4 kJ mol{sup ?1}.

  16. Superfund record of decision (EPA Region 4): Whitehouse Waste Oil Pits Site, Duval County, Jacksonville, FL. (First remedial action), (Amendment), June 1992. Final report

    SciTech Connect (OSTI)

    Not Available

    1992-06-16

    The 7-acre Whitehouse Waste Oil Pits site was used by Allied Petroleum Products (Allied) to dispose of acidic waste oil sludges from its oil reclamation process in Whitehouse, Duval County, Florida. A cypress swamp system and residential area are immediately adjacent to the site. The acid sludge produced in the first step and clay used to decolorize the oil were dumped into the unlined pits at the site. A 1985 ROD addressed source control as a containment remedy consisting of a slurry wall construction, soil cap, and a ground water recovery and treatment system; however, EPA has re-evaluated the 1985 ROD selection and determined that the containment remedy failed to meet the requirements of SARA. As a result, the ROD Amendment focuses on an alternative for treating Whitehouse wastes by eliminating direct contact risk associated with pit soil/sludge wastes and preventing contaminated ground water in the surficial aquifer from migrating laterally. The primary contaminants of concern that affect the soil, sediment, surface water, and ground water are VOCs, including benzene, toluene, and xylenes; organics, including PCBs and phenols; and metals, including arsenic, chromium, and lead. The amended remedial action for the site are included.

  17. High-temperature reprocessing of petroleum oily sludges

    SciTech Connect (OSTI)

    Hahn, W.J. )

    1994-08-01

    Crude oil tank bottoms and other petroleum oily sludges and emulsions containing paraffins and volatile hydrocarbons can be economically reprocessed with heavy-oil dehydration facilities to recover residual hydrocarbons and to achieve volume reductions. The main factors affecting the use of this alternative are (1) the characteristics of the sludges requiring treatment, (2) the availability of waste heat or existing high temperature (> 350 F) dehydration facilities, (3) air emissions from the process, and (4) effluent criteria for treated residues. This paper discusses operational variables that affect high-temperature reprocessing (HTR) and illustrates an application of the process. The example pilot project evaluated the feasibility of high-temperature reprocessing for tank-bottom sludges and skim oils from Kern County, CA, light- (>30[degree] API) oil-producing leases. The process performance was quantified in terms of general operating parameters (flash point and paraffin, oil, water, and solids content); specific constituent analyses for benzene, toluene, ethylbenzene, and xylene (BTEX); and analyses for total petroleum hydrocarbons (TPH) content. Information on the percent removal of these parameters, characteristics of the treated residues, and the hydrocarbon recovery efficiency of the process are presented.

  18. Health-hazard evaluation report HETA 91-254-2186, Ropes and Gray Photocopy Center, Boston, Massachusetts

    SciTech Connect (OSTI)

    Cook, C.K.; Crandall, M.S.

    1992-03-01

    In response to a request from a group of employees at the Pitney Bowes Management Services, Ropes and Gray Photocopy Center (SIC-7334), Boston, Massachusetts, an evaluation was undertaken of worker exposures to photocopy emissions. The photocopy center has been in operation for 2 years. Six full time employees worked the day shift operating six photocopiers of various models. Approximately 1 million copies were generated monthly at the site. Qualitative and quantitative analyses of air samples taken for volatile organic carbons revealed trace amounts of 1,1,1-trichloroethane (71556), isooctane (540841), toluene (108883), xylene (1330207), and benzene (71432). Ozone (10028156) concentrations as high as 0.41 parts per million (ppm) were detected at approximately 3 feet from the exhaust of each photocopier. Carbon-dioxide (124389) concentrations ranged from 300 to 825ppm. Respirable dust concentrations ranged from less than 10 to 50 micrograms per cubic meter. Carbon-monoxide (630080) was not detected. The authors conclude that the evaluation did not reveal a hazard to explain the respiratory symptoms experienced by the workers. The finding that the ventilation system moved too small an amount of air in a measured period of time may account for the accumulation of airborne contaminants within the building. Recommendations were made to improve the ventilation.

  19. Pyrolysis of scrap tires: Can it be profitable?

    SciTech Connect (OSTI)

    Wojtowicz, M.A.; Serio, M.A.

    1996-10-01

    Pyrolysis--the thermal degradation in the absence of oxygen--is one way to reprocess scrap tires. The products are fuel gas, oils, and a solid residue (char), which contains appreciable quantities of mineral matter and low-grade carbon black. The three products have comparable yields by weight. The two most important factors affecting process economics are the tipping fees charged for tire disposal and the selling prices of the products. Selling prices of the products yield low returns because of the low market value of the fuels and the low quality of the recovered char or carbon black. Therefore, to obtain a positive cash flow, it would be desirable to develop a process based on the recovery of value-added products such as high-grade carbon black, activated carbon, or valuable chemicals (e.g., benzene, toluene, and xylene). The authors believe that significant improvement in the economics can be accomplished by upgrading the primary pyrolysis products to secondary products of higher value.

  20. Risk-based approach for bioremediation of fuel hydrocarbons at a major airport

    SciTech Connect (OSTI)

    Wiedemeier, T.H.; Guest, P.R.; Blicker, B.R.

    1994-12-31

    This paper describes a risk-based approach for bioremediation of fuel-hydrocarbon-contaminated soil and ground water at a major airport in Colorado. In situ bioremediation pilot testing, natural attenuation modeling, and full-scale remedial action planning and implementation for soil and ground water contamination has conducted at four airport fuel farms. The sources of fuel contamination were leaking underground storage tanks (USTs) or pipelines transporting Jet A fuel and aviation gasoline. Continuing sources of contamination were present in several small cells of free-phase product and in fuel residuals trapped within the capillary fringe at depths 15 to 20 feet below ground surface. Bioventing pilot tests were conducted to assess the feasibility of using this technology to remediate contaminated soils. The pilot tests included measurement of initial soil gas chemistry at the site, determination of subsurface permeability, and in situ respiration tests to determine fuel biodegradation rates. A product recovery test was also conducted. ES designed and installed four full-scale bioventing systems to remediate the long-term sources of continuing fuel contamination. Benzene, toluene, ethylbenzene, and xylenes (BTEX) and total petroleum hydrocarbons (TPH) were detected in ground water at concentrations slightly above regulatory guidelines.

  1. Trip Report-Produced-Water Field Testing

    SciTech Connect (OSTI)

    Sullivan, Enid J.

    2012-05-25

    Los Alamos National Laboratory (LANL) conducted field testing of a produced-water pretreatment apparatus with assistance from faculty at the Texas A&M University (TAMU) protein separation sciences laboratory located on the TAMU main campus. The following report details all of the logistics surrounding the testing. The purpose of the test was to use a new, commercially-available filter media housing containing modified zeolite (surfactant-modified zeolite or SMZ) porous medium for use in pretreatment of oil and gas produced water (PW) and frac-flowback waters. The SMZ was tested previously in October, 2010 in a lab-constructed configuration ('old multicolumn system'), and performed well for removal of benzene, toluene, ethylbenzene, and xylenes (BTEX) from PW. However, a less-expensive, modular configuration is needed for field use. A modular system will allow the field operator to add or subtract SMZ filters as needed to accommodate site specific conditions, and to swap out used filters easily in a multi-unit system. This test demonstrated the use of a commercial filter housing with a simple flow modification and packed with SMZ for removing BTEX from a PW source in College Station, Texas. The system will be tested in June 2012 at a field site in Pennsylvania for treating frac-flowback waters. The goals of this test are: (1) to determine sorption efficiency of BTEX in the new configuration; and (2) to observe the range of flow rates, backpressures, and total volume treated at a given flow rate.

  2. Furan production from glycoaldehyde over HZSM-5

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kim, Seonah; Evans, Tabitha J.; Mukarakate, Calvin; Bu, Lintao; Beckham, Gregg T.; Nimlos, Mark R.; Paton, Robert S.; Robichaud, David J.

    2016-04-03

    Catalytic fast pyrolysis of biomass over zeolite catalysts results primarily in aromatic (e.g. benzene, toluene, xylene) and olefin products. However, furans are a higher value intermediate for their ability to be readily transformed into gasoline, diesel, and chemicals. Here we investigate possible mechanisms for the coupling of glycoaldehyde, a common product of cellulose pyrolysis, over HZSM-5 for the formation of furans. Experimental measurements of neat glycoaldehyde over a fixed bed of HZSM-5 confirm furans (e.g. furanone) are products of this reaction at temperatures below 300 degrees C with several aldol condensation products as co-products (e.g. benzoquinone). However, under typical catalyticmore » fast pyrolysis conditions (>400 degrees C), further reactions occur that lead to the usual aromatic product slate. ONIOM calculations were utilized to identify the pathway for glycoaldehyde coupling toward furanone and hydroxyfuranone products with dehydration reactions serving as the rate determining steps with typical intrinsic reaction barriers of 40 kcal mol-1. The reaction mechanisms for glycoaldehyde will likely be similar to that of other small oxygenates such as acetaldehyde, lactaldehyde, and hydroxyacetone and this study provides a generalizable mechanism of oxygenate coupling and furan formation over zeolite catalysts.« less

  3. Field-usable portable analyzer for chlorinated organic compounds

    SciTech Connect (OSTI)

    Buttner, W.J.; Penrose, W.R.; Stetter, J.R.

    1995-10-01

    Transducer Research, Inc. (TRI) has been working with the DOE Morgantown Energy Technology Center to develop a new chemical monitor based on a unique sensor which responds selectively to vapors of chlorinated solvents. We are also developing field applications for the monitor in actual DOE cleanup operations. During the initial phase, prototype instruments were built and field tested. Because of the high degree of selectivity that is obtained, no response was observed with common hydrocarbon organic compounds such as BTX (benzene, toluene, xylene) or POLs (petroleum, oil, lubricants), and in fact, no non-halogen-containing chemical has been identified which induces a measurable response. By the end of the Phase I effort, a finished instrument system was developed and test marketed. This instrument, called the RCL MONITOR, was designed to analyze individual samples or monitor an area with automated repetitive analyses. Vapor levels between 0 and 500 ppm can be determined in 90 s with a lower detection limit of 0.2 ppm using the handportable instrument. In addition to the development of the RCL MONITOR, advanced sampler systems are being developed to: (1) extend the dynamic range of the instrument through autodilution of the vapor and (2) allow chemical analyses to be performed on aqueous samples. When interfaced to the samplers, the RCL MONITOR is capable of measuring chlorinated solvent contamination in the vapor phase up to 5000 ppm and in water and other condensed media from 10 to over 10,000 ppb(wt)--without hydrocarbon and other organic interferences.

  4. Superfund Record of Decision (EPA Region 7): Vogel Paint and Wax, Maurice, IA. (First remedial action), September 1989. Final report

    SciTech Connect (OSTI)

    Not Available

    1989-09-20

    The Vogel Paint and Wax (VPW) site is an approximately two-acre disposal area two miles southwest of the town of Maurice, in Sioux County, Iowa. Adjacent land uses are primarily agricultural; however, several private residences are within one-quarter mile of the site. A surficial sand and gravel aquifer underlies the site and supplies nearby private wells and the Southern Sioux County Rural Water System, located a mile and one half southeast of the site. Paint sludge, resins, solvents, and other paint-manufacturing wastes were disposed of at the site between 1971 and 1979. VPW records indicate that approximately 43,000 gallons of aliphatic and aromatic hydrocarbons and 6,000 pounds of metals waste were buried at the site. The primary contaminants of concern affecting the soil and ground water are VOCs including benzene, toluene, and xylenes; and metals including chromium and lead. The selected remedial action for this site includes excavation of contaminated soil and separation of solid and liquid wastes; onsite bioremediation of 3,000 cubic yards of the contaminated soil in a fully contained surface impoundment unit, or onsite thermal treatment if soil contains high metal content; and stabilization of treated soil, if necessary to prevent leaching of metals, followed by disposal in the excavated area.

  5. Surface acoustic wave sensors/gas chromatography; and Low quality natural gas sulfur removal and recovery CNG Claus sulfur recovery process

    SciTech Connect (OSTI)

    Klint, B.W.; Dale, P.R.; Stephenson, C.

    1997-12-01

    This topical report consists of the two titled projects. Surface Acoustic Wave/Gas Chromatography (SAW/GC) provides a cost-effective system for collecting real-time field screening data for characterization of vapor streams contaminated with volatile organic compounds (VOCs). The Model 4100 can be used in a field screening mode to produce chromatograms in 10 seconds. This capability will allow a project manager to make immediate decisions and to avoid the long delays and high costs associated with analysis by off-site analytical laboratories. The Model 4100 is currently under evaluation by the California Environmental Protection Agency Technology Certification Program. Initial certification focuses upon the following organics: cis-dichloroethylene, chloroform, carbon tetrachloride, trichlorethylene, tetrachloroethylene, tetrachloroethane, benzene, ethylbenzene, toluene, and o-xylene. In the second study the CNG Claus process is being evaluated for conversion and recovery of elemental sulfur from hydrogen sulfide, especially found in low quality natural gas. This report describes the design, construction and operation of a pilot scale plant built to demonstrate the technical feasibility of the integrated CNG Claus process.

  6. Initial site characterization, environmental assessment, and corrective actions for underground storage tank 2315-U, Pine Ridge East Repeater Station, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect (OSTI)

    Eaton, J.M.; Ingram, E.M. )

    1991-02-01

    This document presents the Initial Site Characterization Report and information to date regarding environmental assessment and corrective actions for Underground Storage Tank (UST) 2315-U at the Pine Ridge East Repeater Station, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. This document was prepared following guidance in US Environmental Protection Agency (EPA) regulations promulgated under 40 CFR 280. The Pine Ridge East Repeater Station is located on Pine Ridge, which borders the Y-12 Plant to the north. One 64-gallon, asphalt-coated steel tank was located adjacent to the Repeater Station. This tank was used to store gasoline for the station's emergency power generator. Tank 2315-U was exempted from regulation under 40 CFR 280 and Tennessee Department of Health and Environment (TDHE) Rules 1200-1-15.-01 through 1200-1-15-.07 due to size and emergency generator exemptions. Because of an identified release discovered during initial corrective actions, TDHE requirements in revised Rule 1200-1-15-.06, promulgated April 15, 1990, regarding release response and corrective actions, apply to the site (TDHE, 1990). This report documents all activities, including initial abatement, initial site characterization, environmental assessment sampling, and corrective actions conducted to comply with TDHE regulations. Initial site characterization sampling data revealed that benzene, toluene, and xylene (BTX) concentrations exceeded applicable regulatory guidelines and lead values were elevated above levels expected for clean soils. 17 refs., 10 figs., 8 tabs.

  7. Superfund Record of Decision (EPA Region 2): Chemsol, Inc. , Piscataway, Middlesex County, NJ. (First remedial action), September 1991

    SciTech Connect (OSTI)

    Not Available

    1991-09-20

    The 40-acre Chemsol site is a former solvent recovery and waste reprocessing facility in Piscataway Township, Middlesex County, New Jersey. Land use in the area is predominantly commercial and residential, with an onsite marshy area that may be considered a wetlands. The site overlies a bedrock aquifer that is used as a regional drinking water source. Between 1980 and 1990, sampling of residential wells indicated the presence of organic contaminants and PCBs. The Record of Decision (ROD) provides an interim remedy to restrict the offsite migration of highly contaminated ground water. The primary contaminants of concern affecting the ground water are VOCs including benzene, toluene, and xylenes; other organics including pesticides and phenols; and metals including arsenic, chromium, and lead. The selected remedial action for this interim remedy includes installing a ground water collection trench; installing three ground water extraction wells to a depth of 130 feet; constructing an onsite treatment plant and treating contaminated ground water using air stripping, biological filtration, and activated carbon adsorption.

  8. Superfund Record of Decision (EPA Region 8): Rocky Mountain Arsenal (Operable Unit 21), CO. (Ninth remedial action), June 1991

    SciTech Connect (OSTI)

    Not Available

    1991-06-06

    The Rocky Mountain Arsenal (RMA) (Operable Unit 21) site comprises part of the 17,000-acre RMA site, which is a former U.S. Army chemical warfare and incendiary munitions manufacturing and assembly plant in Adams County, Colorado. From the 1950s until late 1969, the U.S. Army used the RMA facility to produce the nerve agent GB (isopropylmethyl-phosphonofluoridate). In addition, between 1947 and 1982, private industries leased major portions of the plant's facilities to manufacture various insecticides and herbicides. Operable Unit 21 (OU21), the South Tank Farm Plume (STFP), is one of several areas being addressed as part of the Other Contaminated Sources IRA. From 1947 to 1978, STF tanks 464A, 464B, and others were used intermittently to store bicycloheptadiene (BCHPD) and dicyclopentadiene (DCPD) bottoms generated from pesticide manufacturing. A number of U.S. Army investigations have revealed ground water contamination originating from the areas of light nonaqueous phase liquid (LNAPL) located near tank 464A. Recent investigations have shown that the STFP does not pose significant risk to public health or the environment. The ROD addresses interim management of migration of the STFP and is consistent with the Final Response Action. The primary contaminants of concern affecting the ground water are VOCs including benzene, toluene, and xylenes. The selected interim remedial action for the site is included.

  9. Use of Ambersorb{reg_sign} carbonaceous adsorbent for removal of BTEX compounds from oil-field produced water

    SciTech Connect (OSTI)

    Gallup, D.L.; Isacoff, E.G.; Smith, D.N. III

    1996-12-31

    The removal of high concentrations of BTEX compounds (benzene, toluene, ethylbenzene and xylenes) from oil-field produced waters using a carbonaceous adsorbent was successfully demonstrated in the field. The carbonaceous adsorbent was much more effective in removing BTEX compounds from produced water than activated carbon or modified clays. The primary objectives of the field studies were to evaluate the efficiency of oil removal processes to protect the adsorbent from fouling, to determine the BTEX removal efficiency of a carbonaceous adsorbent at a high flow rate loading, and to demonstrate regeneration of the adsorbent. Adsorbent fouling with oil was mitigated by mechanical coalescing for heavier crude and emulsion-breaking for lighter crude. Adsorbent extenders and filters did not control fouling in the presence of exceedingly emulsified crude oil. Carbonaceous adsorbent reduced BTEX compounds levels from the 25-130 mg/l range to less than 1 mg/l treating approximately 500 bed volumes of produced water per cycle. Regeneration of the adsorbent using low pressure steam or solvents was successfully achieved with regeneration efficiencies exceeding 95 percent. 13 refs., 7 figs., 4 tabs.

  10. Operable Unit 1 remedial investigation report, Eielson Air Force Base, Alaska

    SciTech Connect (OSTI)

    Gilmore, T.J.; Fruland, R.M.; Liikala, T.L.

    1994-06-01

    This remedial investigation report for operable Unit 1 (OU-1) at Eielson Air Force Base presents data, calculations, and conclusions as to the nature and extent of surface and subsurface contamination at the eight source areas that make up OU-1. The information is based on the 1993 field investigation result and previous investigations. This report is the first in a set of three for OU-1. The other reports are the baseline risk assessment and feasibility study. The information in these reports will lead to a Record of Decision that will guide and conclude the environmental restoration effort for OU-1 at Eielson Air Force Base. The primary contaminants of concern include fuels and fuel-related contaminants (diesel; benzene, toluene, ethylbenzene, and xylene; total petroleum hydrocarbon; polycyclic aromatic hydrocarbons), maintenance-related solvents and cleaners (volatile chlorinated hydrocarbons such as trichloroothylene), polychlorinated biphenyls, and dichlorodiphenyltrichloroethane (DDT). The origins of contaminants of concern include leaks from storage tanks, drums and piping, and spills. Ongoing operations and past sitewide practices also contribute to contaminants of concern at OU-1 source areas. These include spraying mixed oil and solvent wastes on unpaved roads and aerial spraying of DDT.

  11. Application and results of whole-body autoradiography in distribution studies of organic solvents

    SciTech Connect (OSTI)

    Bergman, K.

    1983-01-01

    With the growing concern for the health hazards of occupational exposure to toxic substances attention has been focused on the organic solvents, which are associated with both deleterious nervous system effects and specific tissue injuries. Relatively little is known about the distribution of organic solvents and their metabolites in the living organism. Knowledge of the specific tissue localizations and retention of solvents and solvent metabolites is of great value in revealing and understanding the sites and mechanisms of organic solvent toxicity. Whole-body autoradiography has been modified and applied to distribution studies of benzene, toluene, m-xylene, styrene, methylene chloride, chloroform, carbon tetrachloride, trichloroethylene and carbon disulfide. The high volatility of these substances has led to the development of cryo-techniques. Whole-body autoradiographic techniques applicable to the study of volatile substances are reviewed. The localizations of nonvolatile solvent metabolites and firmly bound metabolites have also been examined. The obtained results are discussed in relation to toxic effects and evaluated by comparison with other techniques used in distribution studies of organic solvents and their metabolites.

  12. Environmental Groundwater Monitoring Report

    Office of Legacy Management (LM)

    ... O F U.S. Atomic Energy Commission Austral Oil Company Benzene, toluene, ethylbenzene, and ... agency to the DOE), and Austral Oil Company (Austral). 1 I Site Location The ...

  13. I I

    Office of Legacy Management (LM)

    ... VOC U.S. Atomic Energy Commission Austral Oil Company Benzene, toluene, ethylbenzene, and ... predecessor agency to the DOE, and Austral Oil Company (Austral). 1 7 Site Location The ...

  14. Tank Closure and Waste Management Environmental Impact Statement...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... as shown in Table 5-192; toluene (339); formaldehyde (80); and benzene (17) (SAIC 2011a). ... and 3, which are included, respectively, in Alternative Combinations 2 and 3 (SAIC 2011a). ...

  15. Modeling of 1,3-hexadiene, 2,4-hexadiene and 1,4-hexadiene-doped methane flames: Flame modeling, benzene and styrene formation

    SciTech Connect (OSTI)

    Sharma, Sandeep; Harper, Michael R.; Green, William H.

    2010-07-15

    In this work, we have developed a detailed chemical kinetic model and reacting flow simulation for the hexadiene-doped 2-d methane diffusion flames studied experimentally by McEnally and Pfefferle. The GRI-Mech 2.11 methane oxidation and Lawrence Livermore butane oxidation mechanisms were used as the base mechanism to which hexadiene chemistry generated by Reaction Mechanism Generator (RMG) was added. Some important chemically activated pathways leading to aromatic species formation, including the reactions on C{sub 5}H{sub 7}, C{sub 6}H{sub 10}, C{sub 6}H{sub 9}, C{sub 6}H{sub 7}, C{sub 8}H{sub 8} and C{sub 8}H{sub 9} potential energy surfaces, are examined in great detail using quantum chemistry (CBS-QB3) and master equation analysis as implemented in Variflex. An efficient program to solve the doped methane diffusion flame was developed. The solver uses the method of lines to solve the species mass balance equation arising in the diffusion flame. It assumes that the temperature and velocity profiles of the doped flame are the same as those of the undoped flame. The mole fractions of various species as predicted by our model are compared to the experimentally measured mole fractions. The agreement between theory and experiments is quite good for most molecules. The added hexadiene dopants to the flame decompose to produce significant amount of cyclopentadienyl radical, which combines with methyl radical to produce benzene. We also show that styrene is formed primarily by recombination of cyclopentadienyl and propargyl radicals, a pathway which to our knowledge, has not been included in prior flame simulations. (author)

  16. Flash methanolysis of wood for the production of fuels and chemicals

    SciTech Connect (OSTI)

    Steinberg, M.; Fallon, P.T.; Sundaram, M.S.

    1983-01-01

    Biomass in the form of less than 1000 micron oven dried fir wood particles was flash pyrolyzed in the presence of methane (methanolysis) in a downflow 1 in. I.D. tubular reactor at pressures of 20 to 200 psi and temperatures between 800/sup 0/ and 1050/sup 0/C. The major products were benzene, toluene and xylene (BTX), a heavy oily liquid (greater than or equal to C/sub 9/), ethylene and carbon monoxide. As much as 12% of the available carbon in the wood was converted to BTX, 21% to ethylene and 48% to carbon monoxide at 50 psi and 1000/sup 0/C. The maximum heavier oil yield of 11% was observed at 50 psi and 800/sup 0/C. Wood particle residence times for all experiments were calculated to be less than 1 second at 20 and 50 psi and up to 2.8 sec at 200 psi. The yelds were found to be greatly influenced by the methane to wood feed ratio. Experiments were conducted to insure the results to be that produced from the wood and methane and not a catalytic effect of the reactor wall of foreign matter. Material balance, including char analyses, indicate approximately 75 to 80% of the available carbon in the feed wood reacted. Methane balances were within the margin of error of the measuring equipment showing that there is no significant net production or consumption of methane. A preliminary economic evaluation of a 2000 ton/day wood processing plant producing ethylene, benzene and methanol showed a reasonably cmpetitive plant investment of $29,000/barrel fuel oil equivalent/day assuming 15% return on investment and present market values for the products.

  17. Process for the production of ethylene and other hydrocarbons from coal

    DOE Patents [OSTI]

    Steinberg, M.; Fallon, P.

    1984-02-15

    The subject invention comprises the steps of first reacting particulate coal with methane at a temperature in the approximate range of 500/sup 0/C to 1100/sup 0/C and at a partial pressure of methane of less than about 200 psig for a period of less than 10 seconds. More preferably, the method of the subject invention is carried out at a temperature of approximately 850/sup 0/C to 1000/sup 0/C and a pressure of 50 psig for a period of approximately 1.5 seconds. Surprisingly, it has been found that in the practice of the subject invention not only are commercially significant quantities of ethylene produced, namely yields in excess of 10% (percent carbon converted to product), along with economically significant quantities of-benzene and light oils, namely toluene and xylene, but also that there is little, if any, net consumption of methane in the reaction and possibly even a small net production. Since it is apparent that the carbonaceous solids or char remaining after the reaction is carried out may be burned to provide the necessary energy to carry out the process of the subject invention, it is apparent that the subject invention advantageously provides a method for the conversion of coal to economically significant quantities of ethylene, benzene and light oils while requiring only coal and, possibly, small amounts of make-up methane. Other objects and advantages of the subject invention will be apparent to those skilled in the art from a consideration of the attached drawings, the detailed description of the invention, and the experimental examples set forth below.

  18. Functionalization/passivation of porous graphitic carbon with di-tert-amylperoxide

    SciTech Connect (OSTI)

    Jensen, David S.; Gupta, Vipul; Olsen, Rebecca E.; Miller, Alex T.; Davis, Robert C.; Ess, Daniel; Zhu, Zihua; Vail, Michael A.; Dadson, Andrew; Linford, Matthew R.

    2011-11-18

    Porous graphitic carbon (PGC) particles were functionalized/passivated in situ in packed beds at elevated temperature with neat di-tert-amylperoxide (DTAP) in a column oven. The performance of these particles for high performance liquid chromatography (HPLC) was assayed before and after this chemistry with the following analytes: benzene, toluene, ethyl benzene, n-propyl benzene, n-butyl benzene, p-xylene, phenol, 4-methylphenol, phenetole, 3,5-xylenol, and anisole. After the first functionalization/passivation, the retention factors, k, of these compounds decreased by about 5% and the number of theoretical plates (N) increased by ca. 15%. These values of k then remained roughly constant after a second functionalization/ passivation but a further increase in N was noticed. In addition, after each of the reactions, the peak asymmetries decreased by ca. 15%, for a total of ca. 30%. The columns were then subjected twice to methanol at 100 C for 5 h at 1 mL/min. After these stability tests, the values of k remained roughly constant, the number of plates increased, which is favorable, and the asymmetries rose and then declined, where they remained below the initial values for the unfunctionalized columns. Functionalized and unfunctionalized particles were characterized by scanning electron microscopy and BET measurements, which showed no difference between the functionalized and unfunctionalized materials, and X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry (ToF-SIMS), where ToF-SIMS suggested some chemical differences between the functionalized and unfunctionalized materials. In particular ToF-SIMS suggested that the expected five-carbon fragments from DTAP exist at higher concentrations on DTAP-functionalized PGC. First principle calculations on model graphitic surfaces suggest that the first addition of a DTAP radical to the surface proceeds in an approximately isothermal or slightly favorable fashion, but that subsequent DTAP

  19. Treatment of Produced Water Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System

    SciTech Connect (OSTI)

    Lynn E. Katz; Kerry A. Kinney; Robert S. Bowman; Enid J. Sullivan; Soondong Kwon; Elaine B. Darby; Li-Jung Chen; Craig R. Altare

    2006-01-31

    Co-produced water from the oil and gas industry accounts for a significant waste stream in the United States. Produced waters typically contain a high total dissolved solids content, dissolved organic constituents such as benzene and toluene, an oil and grease component as well as chemicals added during the oil-production process. It has been estimated that a total of 14 billion barrels of produced water were generated in 2002 from onshore operations (Veil, 2004). Although much of this produced water is disposed via reinjection, environmental and cost considerations can make surface discharge of this water a more practical means of disposal. In addition, reinjection is not always a feasible option because of geographic, economic, or regulatory considerations. In these situations, it may be desirable, and often necessary from a regulatory viewpoint, to treat produced water before discharge. It may also be feasible to treat waters that slightly exceed regulatory limits for re-use in arid or drought-prone areas, rather than losing them to reinjection. A previous project conducted under DOE Contract DE-AC26-99BC15221 demonstrated that surfactant modified zeolite (SMZ) represents a potential treatment technology for produced water containing BTEX. Laboratory and field experiments suggest that: (1) sorption of benzene, toluene, ethylbenzene and xylenes (BTEX) to SMZ follows linear isotherms in which sorption increases with increasing solute hydrophobicity; (2) the presence of high salt concentrations substantially increases the capacity of the SMZ for BTEX; (3) competitive sorption among the BTEX compounds is negligible; and, (4) complete recovery of the SMZ sorption capacity for BTEX can be achieved by air sparging the SMZ. This report summarizes research for a follow on project to optimize the regeneration process for multiple sorption/regeneration cycles, and to develop and incorporate a vapor phase bioreactor (VPB) system for treatment of the off-gas generated during

  20. Is It Homogeneous or Heterogeneous Catalysis Derived from [RhCp*Cl2]2? In Operando-XAFS, Kinetic and Crucial Kinetic Poisoning Evidence for Subnanometer Rh4 Cluster-Based Benzene Hydrogenation Catalysis

    SciTech Connect (OSTI)

    Bayram, Ercan; Linehan, John C.; Fulton, John L.; Roberts, John A.; Szymczak, Nathaniel; Smurthwaite, Tricia D.; Ozkar, Saim; Balasubramanian, Mahalingam; Finke, Richard G.

    2011-11-23

    Determining the true, kinetically dominant catalytically active species, in the classic benzene hydrogenation system pioneered by Maitlis and co-workers 34 years ago starting with [RhCp*Cl2]2 (Cp* = [{eta}5-C5(CH3)5]), has proven to be one of the most challenging case studies in the quest to distinguish single-metal-based 'homogeneous' from polymetallic, 'heterogeneous' catalysis. The reason, this study will show, is the previous failure to use the proper combination of (i) operando spectroscopy to determine the dominant form(s) of the precatalyst's mass under catalysis (i.e., operating) conditions, plus then and crucially also (ii) the previous lack of the necessary kinetic studies, catalysis being a 'wholly kinetic phenomenon' as J. Halpern long ago noted. An important contribution from this study will be to reveal the power of quantitiative kinetic poisoning experiments for distinguishing single-metal, or in this case subnanometer Rh4 cluster-based catalysis from larger, polymetallic Rh(0)n nanoparticle catalysis, at least under favorable conditions. The combined operando-XAFS (X-ray absorption fine structure) spectroscopy and kinetic evidences provide a compelling case for Rh4-based, with average stoichiometry 'Rh4Cp*2.4Cl4Hc', benzene hydrogenation catalysis in 2-propanol with added Et3N and at 100 C and 50 atm initial H2 pressure. The results also reveal, however, that if even ca. 1.4% of the total soluble Rh(0)n had formed nanoparticles, then those Rh(0)n nanoparticles would have been able to account for all the observed benzene hydrogenation catalytic rate (using commercial, ca. 2 nm, polyethyleneglycol-dodecylether hydrosol stabilized Rh(0)n nanoparticles as a model system). The results 'especially the poisoning methodology developed and employed' are of significant, broader interest since determining the nature of the true catalyst continues to be a central, often vexing issue in any and all catalytic reactions. The results are also of fundamental

  1. Method of uranium reclamation from aqueous systems by reactive ion exchange. [US DOE patent application; anion exchange resin of copolymerized divinyl-benzene and styrene having quarternary ammonium groups and bicarbonate ligands

    DOE Patents [OSTI]

    Maya, L.

    1981-11-05

    A reactive ion exchange method for separation and recovery of values of uranium, neptunium, plutonium, or americium from substantially neutral aqueous systems of said metals comprises contacting said system with an effective amount of a basic anion exchange resin of copolymerized divinyl-benzene and styrene having quarternary ammonium groups and bicarbonate ligands to achieve nearly 100% sorption of said actinyl ion onto said resin and an aqueous system practically free of said actinyl ions. The method is operational over an extensive range of concentrations from about 10/sup -6/ M to 1.0 M actinyl ion and a pH range of about 4 to 7. The method has particulr application to treatment of waste streams from Purex-type nuclear fuel reprocessing facilities and hydrometallurgical processes involving U, Np, P, or Am.

  2. A lean methane premixed laminar flame doped with components of diesel fuel part III: Indane and comparison between n-butylbenzene, n-propylcyclohexane and indane

    SciTech Connect (OSTI)

    Pousse, E.; Tian, Z.Y.; Glaude, P.A.; Fournet, R.; Battin-Leclerc, F. [Laboratoire des Reactions et de Genie des Procedes, CNRS, Nancy Universite, 1 rue Grandville, BP 20451, 54001 NANCY Cedex (France)

    2010-07-15

    To better understand the chemistry of the combustion of components of diesel fuel, the structure of a laminar lean premixed methane flame doped with indane has been investigated. The inlet gases contained 7.1% (molar) of methane, 36.8% of oxygen and 0.9% of indane corresponding to an equivalence ratio of 0.67 and a ratio C{sub 10}H{sub 14}/CH{sub 4} of 12.8%. The flame has been stabilized on a burner at a pressure of 6.7 kPa (50 Torr) using argon as diluent, with a gas velocity at the burner of 49.1 cm s{sup -1} at 333 K. Quantified species included the usual methane C{sub 0}-C{sub 2} combustion products, but also 16 C{sub 3}-C{sub 5} non-aromatic hydrocarbons, 6 C{sub 1}-C{sub 3} non-aromatic oxygenated compounds, as well as 22 aromatic products, namely benzene, toluene, xylenes, phenylacetylene, ethylbenzene, styrene, propenylbenzene, allylbenzene, n-propylbenzene, methylstyrenes, ethyltoluenes, trimethylbenzenes, n-butylbenzene, dimethylethylbenzene, indene, methylindenes, methylindane, benzocyclobutene, naphthalene, phenol, benzaldehyde, and benzofuran. A new mechanism for the oxidation of indane was proposed whose predictions were in satisfactory agreement with measured species profiles in both flames and jet-stirred reactor experiments. The main reaction pathways of consumption of indane have been derived from flow rate analyses in the two types of reactors. A comparison of the effect of the addition of three components of diesel fuel, namely indane, n-butylbenzene and n-propylcyclohexane (parts I and II of this series of paper), on the structure of a laminar lean premixed methane flame is also presented. (author)

  3. Metagenomics, metatranscriptomics and single cell genomics reveal functional response of active Oceanospirillales to Gulf oil spill

    SciTech Connect (OSTI)

    Mason, Olivia U.; Hazen, Terry C.; Borglin, Sharon; Chain, Patrick S. G.; Dubinsky, Eric A.; Fortney, Julian L.; Han, James; Holman, Hoi-Ying N.; Hultman, Jenni; Lamendella, Regina; Mackelprang, Rachel; Malfatti, Stephanie; Tom, Lauren M.; Tringe, Susannah G.; Woyke, Tanja; Zhou, Jizhong; Rubin, Edward M.; Jansson, Janet K.

    2012-06-12

    The Deepwater Horizon oil spill in the Gulf of Mexico resulted in a deep-sea hydrocarbon plume that caused a shift in the indigenous microbial community composition with unknown ecological consequences. Early in the spill history, a bloom of uncultured, thus uncharacterized, members of the Oceanospirillales was previously detected, but their role in oil disposition was unknown. Here our aim was to determine the functional role of the Oceanospirillales and other active members of the indigenous microbial community using deep sequencing of community DNA and RNA, as well as single-cell genomics. Shotgun metagenomic and metatranscriptomic sequencing revealed that genes for motility, chemotaxis and aliphatic hydrocarbon degradation were significantly enriched and expressed in the hydrocarbon plume samples compared with uncontaminated seawater collected from plume depth. In contrast, although genes coding for degradation of more recalcitrant compounds, such as benzene, toluene, ethylbenzene, total xylenes and polycyclic aromatic hydrocarbons, were identified in the metagenomes, they were expressed at low levels, or not at all based on analysis of the metatranscriptomes. Isolation and sequencing of two Oceanospirillales single cells revealed that both cells possessed genes coding for n-alkane and cycloalkane degradation. Specifically, the near-complete pathway for cyclohexane oxidation in the Oceanospirillales single cells was elucidated and supported by both metagenome and metatranscriptome data. The draft genome also included genes for chemotaxis, motility and nutrient acquisition strategies that were also identified in the metagenomes and metatranscriptomes. These data point towards a rapid response of members of the Oceanospirillales to aliphatic hydrocarbons in the deep sea.

  4. Assessment and remediation at former manufactured gas plants

    SciTech Connect (OSTI)

    Mehan, D.G.

    1995-12-01

    Over 1,000 former Manufactured Gas Plants (MGP) have been identified in the United States. Gal Plants were used to produce gas for lighting and heating from coal and oil from the mid-1800s until the 1950s. Former MGP sites are typically impacted by a variety of compounds that do not collectively lend themselves to {open_quotes}standard{close_quotes} assessment and remedial solutions. These compounds include the volatile organic compounds (VOCs) benzene, toluene, ethylbenzene, and xylene, a variety of semi-volatile organic compound, and inorganic compounds (iron and cyanide). The assessment of former MGP sites is complicated because many former sites are now located in developed and industrialized areas. MGP wastes and by-products were typically disposed on-site. Many modern buildings are now located over former MGP sites. Standard assessment tools such as augering and drilling tend to encounter former structures, making their use difficult and ineffective. Assessment by excavation and geophysical methods allows the acquisition of only shallow data. The remediation of impacted soils and ground water at former MGP sites poses significant challenges due to the differing characteristics of the typical MGP compounds. For example, soil vapor extraction and ground water treatment may decrease VOC concentrations, yet be ineffective on the inorganic and PAH compounds. Because of the variety of typical MGP associated wastes, risk assessment is a vital tool in assessing and selecting the appropriate remedial strategies. Several states have aggressively adopted clean-up programs that rely on risk assessment to determine the appropriate remedial strategy at former MGP sites. At numerous sites, no further action is employed because of the VOCs have attenuated over time, the PAH and inorganic compounds are relatively immobile, ground water contamination plumes are limited, and risk assessment indicates acceptable risks.

  5. Infrared identification of the {sigma}-complex of Cl-C{sub 6}H{sub 6} in the reaction of chlorine atom and benzene in solid para-hydrogen

    SciTech Connect (OSTI)

    Bahou, Mohammed; Witek, Henryk; Lee, Yuan-Pern

    2013-02-21

    The reaction of a chlorine atom with benzene (C{sub 6}H{sub 6}) is important in organic chemistry, especially in site-selective chlorination reactions, but its product has been a subject of debate for five decades. Previous experimental and theoretical studies provide no concrete conclusion on whether the product is a {pi}- or {sigma}-form of the Cl-C{sub 6}H{sub 6} complex. We took advantage of the diminished cage effect of para-hydrogen (p-H{sub 2}) to produce Cl in situ to react with C{sub 6}H{sub 6} (or C{sub 6}D{sub 6}) upon photolysis of a Cl{sub 2}/C{sub 6}H{sub 6} (or C{sub 6}D{sub 6})/p-H{sub 2} matrix at 3.2 K. The infrared spectrum, showing intense lines at 1430.5, 833.6, 719.8, 617.0, and 577.4 cm{sup -1}, and several weaker ones for Cl-C{sub 6}H{sub 6}, and the deuterium shifts of observed new lines unambiguously indicate that the product is a 6-chlorocyclohexadienyl radical, i.e., the {sigma}-complex of Cl-C{sub 6}H{sub 6}. Observation of the {sigma}-complex rather than the {pi}-complex indicates that the {sigma}-complex is more stable in solid p-H{sub 2} at 3.2 K. The spectral information is crucial for further investigations of the Cl + C{sub 6}H{sub 6} reaction either in the gaseous or solution phase.

  6. Metabolic analysis of the soil microbe Dechloromonas aromatica str. RCB: indications of a surprisingly complex life-style and cryptic anaerobic pathways for aromatic degradation

    SciTech Connect (OSTI)

    Salinero, Kennan Kellaris; Keller, Keith; Feil, William S.; Feil, Helene; Trong, Stephan; Di Bartolo, Genevieve; Lapidus, Alla

    2008-11-17

    Initial interest in Dechloromonas aromatica strain RCB arose from its ability to anaerobically degrade benzene. It is also able to reduce perchlorate and oxidize chlorobenzoate, toluene, and xylene, creating interest in using this organism for bioremediation. Little physiological data has been published for this microbe. It is considered to be a free-living organism. The a priori prediction that the D. aromatica genome would contain previously characterized 'central' enzymes involved in anaerobic aromatic degradation proved to be false, suggesting the presence of novel anaerobic aromatic degradation pathways in this species. These missing pathways include the benzyl succinyl synthase (bssABC) genes (responsible for formate addition to toluene) and the central benzoylCoA pathway for monoaromatics. In depth analyses using existing TIGRfam, COG, and InterPro models, and the creation of de novo HMM models, indicate a highly complex lifestyle with a large number of environmental sensors and signaling pathways, including a relatively large number of GGDEF domain signal receptors and multiple quorum sensors. A number of proteins indicate interactions with an as yet unknown host, as indicated by the presence of predicted cell host remodeling enzymes, effector enzymes, hemolysin-like proteins, adhesins, NO reductase, and both type III and type VI secretory complexes. Evidence of biofilm formation including a proposed exopolysaccharide complex with the somewhat rare exosortase (epsH), is also present. Annotation described in this paper also reveals evidence for several metabolic pathways that have yet to be observed experimentally, including a sulphur oxidation (soxFCDYZAXB) gene cluster, Calvin cycle enzymes, and nitrogen fixation (including RubisCo, ribulose-phosphate 3-epimerase, and nif gene families, respectively). Analysis of the D. aromatica genome indicates there is much to be learned regarding the metabolic capabilities, and life-style, for this microbial species

  7. Effect of uncertain hydraulic conductivity on the fate and transport of BTEX compounds at a field site

    SciTech Connect (OSTI)

    Lu, Guoping; Zheng, Chunmiao; Wolfsberg, Andrew

    2002-01-05

    A Monte Carlo analysis was conducted to investigate the effect of uncertain hydraulic conductivity on the fate and transport of BTEX compounds (benzene, toluene, ethyl benzene, and xylene) at a field site on Hill Air Force Base, Utah. Microbially mediated BTEX degradation has occurred at the site through multiple terminal electron-accepting processes, including aerobic respiration, denitrification, Fe(III) reduction, sulfate reduction, and methanogenesis degradation. Multiple realizations of the hydraulic conductivity field were generated and substituted into a multispecies reactive transport model developed and calibrated for the Hill AFB site in a previous study. Simulation results show that the calculated total BTEX masses (released from a constant-concentration source) that remain in the aquifer at the end of the simulation period statistically follow a lognormal distribution. In the first analysis (base case), the calculated total BTEX mass varies from a minimum of 12% less and a maximum of 60% more than that of the previously calibrated model. This suggests that the uncertainty in hydraulic conductivity can lead to significant uncertainties in modeling the fate and transport of BTEX. Geometric analyses of calculated plume configurations show that a higher BTEX mass is associated with wider lateral spreading, while a lower mass is associated with longer longitudinal extension. More BTEX mass in the aquifer causes either a large depletion of dissolved oxygen (DO) and NO{sub 3}{sup -}, or a large depletion of DO and a large production of Fe{sup 2+}, with moderately depleted NO{sub 3}{sup -}. In an additional analysis, the effect of varying degrees of aquifer heterogeneity and associated uncertainty is examined by considering hydraulic conductivity with different variances and correlation lengths. An increase in variance leads to a higher average BTEX mass in the aquifer, while an increase in correlation length results in a lower average. This observation is

  8. Density functional theory study of the interaction of vinyl radical, ethyne, and ethene with benzene, aimed to define an affordable computational level to investigate stability trends in large van der Waals complexes

    SciTech Connect (OSTI)

    Maranzana, Andrea E-mail: anna.giordana@hotmail.com E-mail: mauro.causa@unina.it Giordana, Anna E-mail: anna.giordana@hotmail.com E-mail: mauro.causa@unina.it Indarto, Antonius Tonachini, Glauco; Barone, Vincenzo E-mail: anna.giordana@hotmail.com E-mail: mauro.causa@unina.it; Causà, Mauro E-mail: anna.giordana@hotmail.com E-mail: mauro.causa@unina.it; Pavone, Michele E-mail: anna.giordana@hotmail.com E-mail: mauro.causa@unina.it

    2013-12-28

    Our purpose is to identify a computational level sufficiently dependable and affordable to assess trends in the interaction of a variety of radical or closed shell unsaturated hydro-carbons A adsorbed on soot platelet models B. These systems, of environmental interest, would unavoidably have rather large sizes, thus prompting to explore in this paper the performances of relatively low-level computational methods and compare them with higher-level reference results. To this end, the interaction of three complexes between non-polar species, vinyl radical, ethyne, or ethene (A) with benzene (B) is studied, since these species, involved themselves in growth processes of polycyclic aromatic hydrocarbons (PAHs) and soot particles, are small enough to allow high-level reference calculations of the interaction energy ΔE{sub AB}. Counterpoise-corrected interaction energies ΔE{sub AB} are used at all stages. (1) Density Functional Theory (DFT) unconstrained optimizations of the A−B complexes are carried out, using the B3LYP-D, ωB97X-D, and M06-2X functionals, with six basis sets: 6-31G(d), 6-311 (2d,p), and 6-311++G(3df,3pd); aug-cc-pVDZ and aug-cc-pVTZ; N07T. (2) Then, unconstrained optimizations by Møller-Plesset second order Perturbation Theory (MP2), with each basis set, allow subsequent single point Coupled Cluster Singles Doubles and perturbative estimate of the Triples energy computations with the same basis sets [CCSD(T)//MP2]. (3) Based on an additivity assumption of (i) the estimated MP2 energy at the complete basis set limit [E{sub MP2/CBS}] and (ii) the higher-order correlation energy effects in passing from MP2 to CCSD(T) at the aug-cc-pVTZ basis set, ΔE{sub CC-MP}, a CCSD(T)/CBS estimate is obtained and taken as a computational energy reference. At DFT, variations in ΔE{sub AB} with basis set are not large for the title molecules, and the three functionals perform rather satisfactorily even with rather small basis sets [6-31G(d) and N07T], exhibiting

  9. Evaluation of a Polyvinyl Toluene Neutron Counter Array (Conference...

    Office of Scientific and Technical Information (OSTI)

    Results demonstrate that analysis with Monte Carlo N-Particle (MCNP) can be used to obtain a better understanding of field measurement results and aid in algorithm development for ...

  10. Slide 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    MOFs can tune the critical point of gases Scientific Achievement Molecular simulations and NMR relaxometry experiments demonstrate that pure benzene or xylene confined in isoreticular metal-organic frameworks (IRMOFs) exhibit vapor-liquid phase equilibria where the critical point may be reduced by tuning the structure of the MOF. Significance and Impact The potential for tuning the critical point of a pure fluid necessitates revisiting pure and multicomponent phase behavior in nanoporous

  11. Development of a Hydrogasification Process for Co-Production of Substitute Natural Gas (SNG) and Electric Power from Western Coals

    SciTech Connect (OSTI)

    Sun, Xiaolei; Rink, Nancy

    2011-04-30

    This report presents the results of the research and development conducted on an Advanced Hydrogasification Process (AHP) conceived and developed by Arizona Public Service Company (APS) under U.S. Department of Energy (DOE) contract: DE-FC26-06NT42759 for Substitute Natural Gas (SNG) production from western coal. A double-wall (i.e., a hydrogasification contained within a pressure shell) down-flow hydrogasification reactor was designed, engineered, constructed, commissioned and operated by APS, Phoenix, AZ. The reactor is ASME-certified under Section VIII with a rating of 1150 pounds per square inch gage (psig) maximum allowable working pressure at 1950 degrees Fahrenheit ({degrees}F). The reaction zone had a 1.75 inch inner diameter and 13 feet length. The initial testing of a sub-bituminous coal demonstrated ~ 50% carbon conversion and ~10% methane yield in the product gas under 1625{degrees}F, 1000 psig pressure, with a 11 seconds (s) residence time, and 0.4 hydrogen-to-coal mass ratio. Liquid by-products mainly contained Benzene, Toluene, Xylene (BTX) and tar. Char collected from the bottom of the reactor had 9000-British thermal units per pound (Btu/lb) heating value. A three-dimensional (3D) computational fluid dynamic model simulation of the hydrodynamics around the reactor head was utilized to design the nozzles for injecting the hydrogen into the gasifier to optimize gas-solid mixing to achieve improved carbon conversion. The report also presents the evaluation of using algae for carbon dioxide (CO{sub 2}) management and biofuel production. Nannochloropsis, Selenastrum and Scenedesmus were determined to be the best algae strains for the project purpose and were studied in an outdoor system which included a 6-meter (6M) radius cultivator with a total surface area of 113 square meters (m{sup 2}) and a total culture volume between 10,000 to 15,000 liters (L); a CO{sub 2} on-demand feeding system; an on-line data collection system for temperature, p

  12. Superfund Record of Decision (EPA Region 2): Love Canal (93rd Street School), Niagara County, City of Niagara Falls, NY. (Third remedial action), (amendment), May 1991. Final report

    SciTech Connect (OSTI)

    Not Available

    1991-05-15

    The Love Canal (93rd Street) site is an inactive hazardous waste site located in Niagara Falls, New York. The 19-acre 93rd Street School site, one of several operable units for the Love Canal Superfund site, is the focus of the Record of Decision (ROD). The fill material is reported to contain fly ash and BHC (a pesticide) waste. The ROD amends the 1988 ROD, and addresses final remediation of onsite contaminated soil through excavation and offsite disposal. The primary contaminants of concern affecting the soil are VOCs including toluene and xylenes; other organics including PAHs and pesticides; and metals including arsenic, chromium, and lead.

  13. Process to recycle shredder residue

    DOE Patents [OSTI]

    Jody, Bassam J.; Daniels, Edward J.; Bonsignore, Patrick V.

    2001-01-01

    A system and process for recycling shredder residue, in which separating any polyurethane foam materials are first separated. Then separate a fines fraction of less than about 1/4 inch leaving a plastics-rich fraction. Thereafter, the plastics rich fraction is sequentially contacted with a series of solvents beginning with one or more of hexane or an alcohol to remove automotive fluids; acetone to remove ABS; one or more of EDC, THF or a ketone having a boiling point of not greater than about 125.degree. C. to remove PVC; and one or more of xylene or toluene to remove polypropylene and polyethylene. The solvents are recovered and recycled.

  14. Hoe Creek groundwater restoration, 1989

    SciTech Connect (OSTI)

    Renk, R.R.; Crader, S.E.; Lindblom, S.R.; Covell, J.R.

    1990-01-01

    During the summer of 1989, approximately 6.5 million gallons of contaminated groundwater were pumped from 23 wells at the Hoe Creek underground coal gasification site, near Gillette, Wyoming. The organic contaminants were removed using activated carbon before the water was sprayed on 15.4 acres at the sites. Approximately 2647 g (5.8 lb) of phenols and 10,714 g (23.6 lb) of benzene were removed from the site aquifers. Phenols, benzene, toluene, ethylbenzene, and naphthalene concentrations were measured in 43 wells. Benzene is the only contaminant at the site exceeds the federal standard for drinking water (5 {mu}g/L). Benzene leaches into the groundwater and is slow to biologically degrade; therefore, the benzene concentration has remained high in the groundwater at the site. The pumping operation affected groundwater elevations across the entire 80-acre site. The water levels rebounded quickly when the pumping operation was stopped on October 1, 1989. Removing contaminated groundwater by pumping is not an effective way to clean up the site because the continuous release of benzene from coal tars is slow. Benzene will continue to leach of the tars for a long time unless its source is removed or the leaching rate retarded through mitigation techniques. The application of the treated groundwater to the surface stimulated plant growth. No adverse effects were noted or recorded from some 60 soil samples taken from twenty locations in the spray field area. 20 refs., 52 figs., 8 tabs.

  15. Chemistry of Furan Conversion into Aromatics and Olefins over HZSM-5: A Model Biomass Conversion Reaction

    SciTech Connect (OSTI)

    Cheng, Yu-Ting; Huber, George W.

    2011-06-03

    The conversion of furan (a model of cellulosic biomass) over HZSM-5 was investigated in a thermogravimetric analysismass spectrometry system, in situ Fourier transform infrared analysis, and in a continuous-flow fixed-bed reactor. Furan adsorbed as oligomers at room temperature with a 1.73 of adsorbed furan/Al ratio. These oligomers were polycyclic aromatic compounds that were converted to CO, CO?, aromatics, and olefins at temperatures from 400 to 600 C. Aromatics (e.g., benzene, toluene, and naphthalene), oligomer isomers (e.g., benzofuran, 2,2-methylenebisfuran, and benzodioxane), and heavy oxygenates (C??{sub +} oligomers) were identified as intermediates formed inside HZSM-5 at different reaction temperatures. During furan conversion, graphite-type coke formed on the catalyst surface, which caused the aromatics and olefins formation to deactivate within the first 30 min of time on-stream. We have measured the effects of space velocity and temperature for furan conversion to help us understand the chemistry of biomass conversion inside zeolite catalysts. The major products for furan conversion included CO, CO?, allene, C?C? olefins, benzene, toluene, styrene, benzofuran, indene, and naphthalene. The aromatics (benzene and toluene) and olefins (ethylene and propylene) selectivity decreased with increasing space velocity. Unsaturated hydrocarbons such as allene, cyclopentadiene, and aromatics selectivity increased with increasing space velocity. The product distribution was selective to olefins and CO at high temperatures (650 C) but was selective to aromatics (benzene and toluene) at intermediate temperatures (450600 C). At low temperatures (450 C), benzofuran and coke contributed 60% of the carbon selectivity. Several different reactions were occurring for furan conversion over zeolites. Some important reactions that we have identified in this study include DielsAlder condensation (e.g., two furans form benzofuran and water), decarbonylation (e

  16. A Multicomponent Blend as a Diesel Fuel Surrogate for Compression Ignition Engine Applications

    SciTech Connect (OSTI)

    Pei, Yuanjiang; Mehl, Marco; Liu, Wei; Lu, Tianfeng; Pitz, William J.; Som, Sibendu

    2015-05-12

    A mixture of n-dodecane and m-xylene is investigated as a diesel fuel surrogate for compression ignition engine applications. Compared to neat n-dodecane, this binary mixture is more representative of diesel fuel because it contains an alkyl-benzene which represents an important chemical class present in diesel fuels. A detailed multi-component mechanism for n-dodecane and m-xylene was developed by combining a previously developed n-dodecane mechanism with a recently developed mechanism for xylenes. The xylene mechanism is shown to reproduce experimental ignition data from a rapid compression machine and shock tube, speciation data from the jet stirred reactor and flame speed data. This combined mechanism was validated by comparing predictions from the model with experimental data for ignition in shock tubes and for reactivity in a flow reactor. The combined mechanism, consisting of 2885 species and 11754 reactions, was reduced to a skeletal mechanism consisting 163 species and 887 reactions for 3D diesel engine simulations. The mechanism reduction was performed using directed relation graph (DRG) with expert knowledge (DRG-X) and DRG-aided sensitivity analysis (DRGASA) at a fixed fuel composition of 77% of n-dodecane and 23% m-xylene by volume. The sample space for the reduction covered pressure of 1 – 80 bar, equivalence ratio of 0.5 – 2.0, and initial temperature of 700 – 1600 K for ignition. The skeletal mechanism was compared with the detailed mechanism for ignition and flow reactor predictions. Finally, the skeletal mechanism was validated against a spray flame dataset under diesel engine conditions documented on the Engine Combustion Network (ECN) website. These multi-dimensional simulations were performed using a Representative Interactive Flame (RIF) turbulent combustion model. Encouraging results were obtained compared to the experiments with regards to the predictions of ignition delay and lift-off length at different ambient temperatures.

  17. Electron localization in a mixed-valence diniobium benzene complex...

    Office of Scientific and Technical Information (OSTI)

    Subsequent reactivity studies indicate that the oxidized product allows access to metal-based chemistry with substrates that did not exhibit reactivity with the starting neutral ...

  18. Electron localization in a mixed-valence diniobium benzene complex

    Office of Scientific and Technical Information (OSTI)

    Subsequent reactivity studies indicate that the oxidized product allows access to metal-based chemistry with substrates that did not exhibit reactivity with the starting neutral ...

  19. PREPARATION OF HIGH PURITY UF$sub 4$

    DOE Patents [OSTI]

    Magner, J.E.; Long, R.S.; Ellis, D.A.; Grinstead, R.R.

    1962-04-17

    S>A process for preparing very highly pure uranous tetrafluoride from impure uranium laden solvent extraction strip solutions, ion exchange process and resin-inpulp process eluate solutions which are at least 8M in hydrochloric acid is described. The process first comprises treating any of the above-mentioned solutions with a reducing agent to reduce the uranium to the + 4 oxidation state, and then contacting the reduced solution with an extractant phase comprising about 10 to 70% of tri-butyl phosphate in an organic solvent-diluent selected from benzene, ethyl-benzene, chlorobenzene, xylene, kerosene, or the like. The uranium is extracted into the extractant phase and is subsequently precipitated by treating the extractant with an aqueous fluoride solution. The highly pure uranous tetrafluoride precipitate is separated from the phases and recovered for subsequent utilization. (AEC)

  20. Chemical structures of low-pressure premixed methylcyclohexane flames as benchmarks for the development of a predictive combustion chemistry model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Skeen, Scott A.; Yang, Bin; Jasper, Ahren W.; Pitz, William J.; Hansen, Nils

    2011-11-14

    The chemical compositions of three low-pressure premixed flames of methylcyclohexane (MCH) are investigated with the emphasis on the chemistry of MCH decomposition and the formation of aromatic species, including benzene and toluene. The flames are stabilized on a flat-flame (McKenna type) burner at equivalence ratios of φ = 1.0, 1.75, and 1.9 and at low pressures between 15 Torr (= 20 mbar) and 30 Torr (= 40 mbar). The complex chemistry of MCH consumption is illustrated in the experimental identification of several C7H12, C7H10, C6H12, and C6H10 isomers sampled from the flames as a function of distance from the burner.more » Three initiation steps for MCH consumption are discussed: ring-opening to heptenes and methyl-hexenes (isomerization), methyl radical loss yielding the cyclohexyl radical (dissociation), and H abstraction from MCH. Mole fraction profiles as a function of distance from the burner for the C7 species supplemented by theoretical calculations are presented, indicating that flame structures resulting in steeper temperature gradients and/or greater peak temperatures can lead to a relative increase in MCH consumption through the dissociation and isomerization channels. Trends observed among the stable C6 species as well as 1,3-pentadiene and isoprene also support this conclusion. Relatively large amounts of toluene and benzene are observed in the experiments, illustrating the importance of sequential H-abstraction steps from MCH to toluene and from cyclohexyl to benzene. Furthermore, modeled results using the detailed chemical model of Pitz et al. (Proc. Combust. Inst.2007, 31, 267–275) are also provided to illustrate the use of these data as a benchmark for the improvement or future development of a MCH mechanism.« less

  1. Aerosol characterization study using multi-spectrum remote sensing measurement techniques.

    SciTech Connect (OSTI)

    Glen, Crystal Chanea; Sanchez, Andres L.; Lucero, Gabriel Anthony; Schmitt, Randal L.; Johnson, Mark S.; Tezak, Matthew Stephen; Servantes, Brandon Lee

    2013-09-01

    A unique aerosol flow chamber coupled with a bistatic LIDAR system was implemented to measure the optical scattering cross sections and depolarization ratio of common atmospheric particulates. Each of seven particle types (ammonium sulfate, ammonium nitrate, sodium chloride, potassium chloride, black carbon and Arizona road dust) was aged by three anthropogenically relevant mechanisms: 1. Sulfuric acid deposition, 2. Toluene ozonolysis reactions, and 3. m-Xylene ozonolysis reactions. The results of pure particle scattering properties were compared with their aged equivalents. Results show that as most particles age under industrial plume conditions, their scattering cross sections are similar to pure black carbon, which has significant impacts to our understanding of aerosol impacts on climate. In addition, evidence emerges that suggest chloride-containing aerosols are chemically altered during the organic aging process. Here we present the direct measured scattering cross section and depolarization ratios for pure and aged atmospheric particulates.

  2. The use of white-rot fungi as active biofilters

    SciTech Connect (OSTI)

    Braun-Luellemann, A.; Johannes, C.; Majcherczyk, A.; Huettermann, A.

    1995-12-31

    White-rot fungi, growing on lignocellulosic substrates, have been successfully used as active organisms in biofilters. Filters using these fungi have a very high biological active surface area, allowing for high degrees of retention, a comparatively low pressure drop, and a high physical stability. The unspecific action of the extracellular enzymes of the white-rot fungi allows for the degradation of a wide variety of substances by the same organism. Degradation of several compounds in the gas phase by the white-rot fungi Trametes versicolor, Pleurotus ostreatus, Bjerkandera adusta, and Phanerochaete chrysosporium was tested. Among the aromatic solvents, styrene was the compound that was most readily degraded, followed by ethylbenzene, xylenes, and toluene. Tetrahydrofuran and dichloromethane were also degraded, whereas dioxane could not be attacked by fungi under the conditions used. Acrylonitrile and aniline were degraded very well, whereas pyridine was resistant to degradation. The process for removing styrene is now in the scaling-up stage.

  3. Comparison of advanced distillation control methods. Third annual report

    SciTech Connect (OSTI)

    Riggs, J.B.

    1997-07-01

    Detailed dynamic simulations of three industrial distillation columns (a propylene/propane splitter, a xylene/toluene column, and a depropanizer) have been used to study the issue of configuration selection for diagonal PI dual composition controls, feedforward from a feed composition analyzer, and decouplers. Auto Tune Variation (ATV) identification with on-line detuning for setpoint changes was used for tuning the diagonal proportional integral (PI) composition controls. In addition, robustness tests were conducted by inducting reboiler duty upsets. For single composition control, the (L, V) configuration was found to be best. For dual composition control, the optimum configuration changes from one column to another. Moreover, the use of analysis tools, such as RGA, appears to be of little value in identifying the optimum configuration for dual composition control. Using feedforward from a feed composition analyzer and using decouplers are shown to offer significant advantages for certain specific cases.

  4. Storm-water characterization and lagoon sediment analysis, Grand Forks Air Force Base, North Dakota. Final report

    SciTech Connect (OSTI)

    Garland, J.G.; Vaughn, R.W.; Scott, P.T.

    1990-08-01

    Sampling was conducted in the wastewater treatment lagoons and stormwater runoff at Grand Forks AFB. The base was concerned about whether the unlined lagoons were creating a potential groundwater contamination problem and whether their stormwater runoff met North Dakota state stream standards. Lagoon sediment did not contain Extraction Procedure hazardous chemicals. Stormwater runoff exceeded state standards for boron, phosphates, and phenols and contained trace levels of methylene chloride. Characterization of lagoon influent showed it to be generally representative of domestic sewage, but also contained trace levels of boron, phenols, toluene, cyanide, chloroform, methylene chloride and ethyl benzene.

  5. Health assessment for Chemsol Inc. , Piscataway, Middlesex County, New Jersey, Region 2. CERCLIS No. NJD980528889. Preliminary report

    SciTech Connect (OSTI)

    Not Available

    1989-04-10

    The Chemsol Inc. Site is on the National Priorities List. The inactive 12-acre site is located in Piscataway (Middlesex County), New Jersey. EPA suspects that 40 drums of chemical waste are buried on-site. Access to the site is restricted. Removal actions have not occurred. Preliminary on-site sampling results have identified various volatile organic compounds. They include chloroform, tetrachloroethylene, trichloroethylene, carbon tetrachloride, toluene, and benzene. Neither the sampling results nor the environmental media where the contaminants were found were reported. The site is considered to be of potential public health concern because of the risk to human health caused by the possibility of human exposure to hazardous substances.

  6. Superfund Record of Decision (EPA region 5): Seymour Recycling Corporation, Seymour, Indiana, September 1986. Final report

    SciTech Connect (OSTI)

    Not Available

    1986-09-30

    The Seymour Recycling Corporation (SRC) operated a processing center for waste chemicals. Toxic and hazardous wastes, including solvents, metal finishing wastes, and other materials, accumulated on the site in 55-gallon drums, bulk tanks, and other containers. Wastes leaked and spilled from the drums creating fire and odor problems. A Consent Decree resulted in the removal of the upper one foot of contaminated soil from about 75% of the site's surface. Contaminated soil remains, however, and extends throughout the shallow and deep aquifer. The primary contaminants of concern include: VOCs, organics, TCE, DCE, benzene, toluene, and heavy metals. Selected remedies have been proposed and are included.

  7. Tracking a defined route for O[subscript 2] migration in a dioxygen-activating diiron enzyme

    SciTech Connect (OSTI)

    Song, Woon Ju; Gucinski, Grant; Sazinsky, Matthew H.; Lippard, Stephen J. (MIT); (Pomona)

    2011-09-08

    For numerous enzymes reactive toward small gaseous compounds, growing evidence indicates that these substrates diffuse into active site pockets through defined pathways in the protein matrix. Toluene/o-xylene monooxygenase hydroxylase is a dioxygen-activating enzyme. Structural analysis suggests two possible pathways for dioxygen access through the {alpha}-subunit to the diiron center: a channel or a series of hydrophobic cavities. To distinguish which is utilized as the O{sub 2} migration pathway, the dimensions of the cavities and the channel were independently varied by site-directed mutagenesis and confirmed by X-ray crystallography. The rate constants for dioxygen access to the diiron center were derived from the formation rates of a peroxodiiron(III) intermediate, generated upon treatment of the diiron(II) enzyme with O2. This reaction depends on the concentration of dioxygen to the first order. Altering the dimensions of the cavities, but not the channel, changed the rate of dioxygen reactivity with the enzyme. These results strongly suggest that voids comprising the cavities in toluene/o-xylene monooxygenase hydroxylase are not artifacts of protein packing/folding, but rather programmed routes for dioxygen migration through the protein matrix. Because the cavities are not fully connected into the diiron active center in the enzyme resting state, conformational changes will be required to facilitate dioxygen access to the diiron center. We propose that such temporary opening and closing of the cavities may occur in all bacterial multicomponent monooxygenases to control O{sub 2} consumption for efficient catalysis. Our findings suggest that other gas-utilizing enzymes may employ similar structural features to effect substrate passage through a protein matrix.

  8. Asymmetric energy flow in liquid alkylbenzenes: A computational study

    SciTech Connect (OSTI)

    Leitner, David M.; Pandey, Hari Datt

    2015-10-14

    Ultrafast IR-Raman experiments on substituted benzenes [B. C. Pein et al., J. Phys. Chem. B 117, 10898–10904 (2013)] reveal that energy can flow more efficiently in one direction along a molecule than in others. We carry out a computational study of energy flow in the three alkyl benzenes, toluene, isopropylbenzene, and t-butylbenzene, studied in these experiments, and find an asymmetry in the flow of vibrational energy between the two chemical groups of the molecule due to quantum mechanical vibrational relaxation bottlenecks, which give rise to a preferred direction of energy flow. We compare energy flow computed for all modes of the three alkylbenzenes over the relaxation time into the liquid with energy flow through the subset of modes monitored in the time-resolved Raman experiments and find qualitatively similar results when using the subset compared to all the modes.

  9. Nanoporous Materials Can Tune the Critical Point of a Pure Substance

    SciTech Connect (OSTI)

    Braun, Efrem; Chen, Joseph J.; Schnell, Sondre K.; Lin, Li-Chiang; Reimer, Jeffrey A.; Smit, Berend

    2015-09-30

    Molecular simulations and NMR relaxometry experiments demonstrate that pure benzene or xylene confined in isoreticular metal–organic frameworks (IRMOFs) exhibit true vapor–liquid phase equilibria where the effective critical point may be reduced by tuning the structure of the MOF. Our results are consistent with vapor and liquid phases extending over many MOF unit cells. These results are counterintuitive since the MOF pore diameters are approximately the same length scale as the adsorbate molecules. Lastly, as applications of these materials in catalysis, separations, and gas storage rely on the ability to tune the properties of adsorbed molecules, we anticipate that the ability to systematically control the critical point, thereby preparing spatially inhomogeneous local adsorbate densities, could add a new design tool for MOF applications.

  10. Nanoporous Materials Can Tune the Critical Point of a Pure Substance

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Braun, Efrem; Chen, Joseph J.; Schnell, Sondre K.; Lin, Li-Chiang; Reimer, Jeffrey A.; Smit, Berend

    2015-09-30

    Molecular simulations and NMR relaxometry experiments demonstrate that pure benzene or xylene confined in isoreticular metal–organic frameworks (IRMOFs) exhibit true vapor–liquid phase equilibria where the effective critical point may be reduced by tuning the structure of the MOF. Our results are consistent with vapor and liquid phases extending over many MOF unit cells. These results are counterintuitive since the MOF pore diameters are approximately the same length scale as the adsorbate molecules. Lastly, as applications of these materials in catalysis, separations, and gas storage rely on the ability to tune the properties of adsorbed molecules, we anticipate that the abilitymore » to systematically control the critical point, thereby preparing spatially inhomogeneous local adsorbate densities, could add a new design tool for MOF applications.« less

  11. Superfund Record of Decision (EPA Region 6): Petro-Chemical (Turtle Bayou), Liberty County, TX. (Second remedial action), September 1991. Final report

    SciTech Connect (OSTI)

    Not Available

    1991-09-06

    The 500-acre Petro-Chemical (Turtle Bayou) site is in Liberty County, Texas. Current land use in the area is divided among cropland, pasture, range, forest, and small rural communities. Since 1971, numerous undocumented disposal activities occurred onsite involving primarily petrochemical wastes. The ROD for OU2 focuses on three areas of contamination at the site affecting soil and ground water contamination, known as the main waste area, the east disposal area, and the Bayou disposal area. The primary contaminants of concern affecting the soil and ground water are VOCs including benzene and xylenes; other organics including PAHs; and metals including lead. The selected remedial action for the site includes treating 302,800 cubic yards of contaminated soil onsite using in-situ vapor extraction to remove VOCs, controlling vertical air infiltration using an engineered soil and synthetic liner cap; consolidating lead-contaminated soil in the Main Waste Area, followed by capping.

  12. Public health assessment for Petro-Chemical, Inc. (Turtle Bayou) Liberty, Liberty County, Texas, Region 6. CERCLIS No. TXD980873350. Final report

    SciTech Connect (OSTI)

    Not Available

    1993-03-30

    The Petro-Chemical Systems, Inc. site, located near Liberty, Texas, is a site where unauthorized disposal of petroleum-based oils has taken place. Although there is evidence of past exposure to site contaminants, the best available evidence does not indicate that humans are currently being exposed to site contaminants at levels that could cause adverse health effects. Contaminated ground water, surface water, soils, and surface water sediments have been found on the site. Although sampling was done for 144 priority pollutants, the primary contaminants of concern are benzene, ethylbenzene, xylene, naphthalene, polycyclic aromatic hydrocarbons, and lead. Because the greatest threat to public health would be contamination of drinking water, the Agency for Toxic Substances and Disease Registry (ATSDR) has recommended that necessary actions are taken to insure that private wells do not become contaminated with site contaminants.

  13. Feedstock effects in coal flash pyrolysis

    SciTech Connect (OSTI)

    Tatterson, D.F.; Robinson, K.K.; Guercio, R.; Marker, T.L.

    1990-10-01

    In this paper the impact of lower rank coals on yields and product qualities is examined in a large- scale flash pyrolysis reactor capable of achieving heating rates of 10{sup 6}{degrees}C/s and reactor times of 10 ms. A Montana lignite and a Minnesota peat were pyrolyzed and the results compared to those for Illinois No. 6 bituminous coal. The peat was found to be more reactive than the Illinois No. 6 coal and the lignite less reactive. Relatively high liquid yields were also obtained from the peat. This result demonstrates that high oxygen content in a feedstock does not necessarily correlate with low production of liquids. At high reactor severity, the peat is an excellent source of aromatics (benzene, toulene, and xylenes) and medium Btu gas, which could be converted to other chemical feedstocks.

  14. Henry's law constants for paint solvents and their implications on volatile organic compound emissions from automotive painting

    SciTech Connect (OSTI)

    Kim, B.R.; Kalis, E.M.; DeWulf, T.; Andrews, K.M.

    2000-02-01

    This paper describes experimental results of equilibrium partitioning of several significant paint solvents and formaldehyde between air and water to quantify the potential for capturing and retaining the constituents in spraybooth scrubber water during automotive painting. The compounds studied are toluene, n-butanol, methyl ethyl ketone methyl propyl ketone, methyl isobutyl ketone, methyl amyl ketone, butyl cellosolve, butyl cellosolve acetate, butyl carbitol, and n-methyl-2-pyrrolidinone. A set of field data collected at a Ford Motor Company assembly plant was also analyzed to determine whether data were consistent with the equilibrium phenomenon. The primary findings include: (a) There were more than six orders of magnitude difference in the Henry's law constants among the solvents studied. A solvent with a smaller constant is less easily stripped from water. The Henry's law constants decrease in the following order: toluene and xylenes > methyl ethyl ketone > n-butanol > butyl cellosolve acetate > butyl cellosolve > formaldehyde > butyl carbitol > n-methyl-2-pyrrolidinone. (b) Field data showed accumulation of n-methyl-2-pyrrolidinone and stable concentrations of butyl carbitol, butyl cellosolve, and n-butanol in the paint-sludge pit water during a 2-month period. Stable concentrations indicate a continuous, balanced capture and stripping of the solvents. Data were consistent with measured Henry's law constants. (c) The low Henry's law constant for formaldehyde is the result of the fact that it is hydrated when dissolved in water.

  15. Investigation of optical limiting properties of Aluminium nanoparticles prepared by pulsed laser ablation in different carrier media

    SciTech Connect (OSTI)

    Kuladeep, Rajamudili; Jyothi, L.; Narayana Rao, D.; Prakash, P.; Mayank Shekhar, S.; Durga Prasad, M.

    2013-12-28

    In this communication, we carried out the systematic investigation of nonlinear absorption and scattering properties of Aluminium nanoparticles (Al NPs) in various polar and non-polar solvents. Al NPs were synthesized with pulsed Nd:YAG laser operated at 1064 nm by ablating Al target in polar and non-polar liquid environment like chloroform, chlorobenzene, toluene, benzene, and carbon tetrachloride. Synthesized Al NPs colloids of various solvents differ in appearance and UV-Vis extinction spectra exhibit absorption in the UV region. The characterization of Al NPs performed by Transmission electron microscopy (TEM) studies reveal that NPs are made up of a well crystallized Al inner part (bright zone) embedded with an amorphous metal Al shell (dark region). Growth, aggregation, and precipitation mechanisms which influence the optical properties and stability of NPs are found to be related to the dipole moment of the surrounding liquid environment. The nonlinear absorption and scattering studies are performed by open aperture Z-scan technique with 532 nm under nanosecond pulse excitation. The Z-scan measurements are fitted theoretically to estimate both two-photon absorption (TPA) and nonlinear scattering (NLS) coefficients. In polar solvents like chlorobenzene, chloroform synthesized Al NPs exhibited higher TPA, NLS coefficient values, and lower optical limiting threshold values in comparison with partially polar solvent like toluene and non-polar solvents like benzene and carbontetrachloride. These results indicate the potential use of Al NPs as a versatile optical limiting material.

  16. Carbon-Supported bimetallic Pd-Fe catalysts for vapor-phase hydrodeoxygenation of guaiacol

    SciTech Connect (OSTI)

    Sun, Junming; Karim, Ayman M.; Zhang, He; Kovarik, Libor; Li, Xiaohong S.; Hensley, Alyssa; McEwen, Jean-Sabin; Wang, Yong

    2013-10-01

    Abstract Carbon supported metal catalysts (Cu/C, Fe/C, Pd/C, Pt/C, PdFe/C and Ru/C) have been prepared, characterized and tested for vapor-phase hydrodeoxygenation (HDO) of guaiacol (GUA) at atmospheric pressure. Phenol was the major intermediate on all catalysts. Over the noble metal catalysts saturation of the aromatic ring was the major pathway observed at low temperature (250 C), forming predominantly cyclohexanone and cyclohexanol. Substantial ring opening reaction was observed on Pt/C and Ru/C at higher reaction temperatures (e.g., 350 C). Base metal catalysts, especially Fe/C, were found to exhibit high HDO activity without ring-saturation or ring-opening with the main products being benzene, phenol along with small amounts of cresol, toluene and trimethylbenzene (TMB). A substantial enhancement in HDO activity was observed on the PdFe/C catalysts. Compared with Fe/C, the yield to oxygen-free aromatic products (i.e., benzene/toluene/TMB) on PdFe/C increased by a factor of four at 350 C, and by approximately a factor of two (83.2% versus 43.3%) at 450 C. The enhanced activity of PdFe/C is attributed to the formation of PdFe alloy as evidenced by STEM, EDS and TPR.

  17. Benzene TCLP results from saltstone prepared with 2X ITP flowsheet concentrations of phenylborates

    SciTech Connect (OSTI)

    Poirier, M.R.

    2000-07-25

    The Savannah River Site (SRS) teamed with the Pacific Northwest National Laboratory (PNNL), Oak Ridge National Laboratory (ORNL), and ITT Flygt Corporation to conduct a test program evaluating shrouded axial propeller mixers (Flygt mixers) for heel removal in SRS Tank 19. SRS is identifying and investigating techniques to remove sludge heels from waste tanks such as Tank 19.

  18. Non-Incineration Treatment to Reduce Benzene and VOC Emissions from Green Sand Molding Systems

    SciTech Connect (OSTI)

    Fred S. Cannon; Robert C. Voigt

    2002-06-28

    Final report describing laboratory, pilot scale and production scale evaluation of advanced oxidation systems for emissions and cost reduction in metal casting green sand systems.

  19. Superfund Record of Decision (EPA Region 2): Hooker-102nd Street Landfill, Niagara Falls, NY. (First remedial action), September 1990. Final report

    SciTech Connect (OSTI)

    Not Available

    1990-09-26

    The 22-acre Hooker-102nd Street site is a former industrial landfill in the city of Niagara Falls, Niagara County, New York. The site is adjacent to, and partially within the Niagara River's 100-year floodplain. These studies and the Remedial Investigation (RI) initiated in 1984, identified contamination in ground water, onsite and offsite soil, rivershore sediment, and within a storm sewer. Additionally, the presence of a leachate plume of non-aqueous phase liquids (NAPLs) was discovered emanating from the landfill area. The Record of Decision (ROD) is the final remedy which addresses all of the contaminated media. The primary contaminants of concern affecting the soil, sediment, and ground water are VOCs including benzene, TCE, and toluene; other organics including PCBs and phenols; and metals including arsenic.

  20. Product analysis from direct liquefaction of several high-moisture biomass feedstocks

    SciTech Connect (OSTI)

    Elliott, D.C.; Sealock, L.J. Jr.; Butner, R.S.

    1987-04-01

    Product analysis in support of the process development research in biomass direct liquefaction began at rudimentary level of determining solvent-soluble portions of the product. Analysis was soon extended to elemental analyses and proximate analyses, such as ash and moisture. Later, spectrometric analyses were performed followed by detailed chemical analyses used in conjunction with chromatographic separation techniques. At all stages of development, the significant differences in composition between the products of flash pyrolysis and high-pressure processing have been evident. While polar solvents are most effective for both products, less polar solvents such as methylene chloride and even benzene and toluene have been used as extractants for high-pressure product oils.

  1. Methods for chemical recovery of non-carrier-added radioactive tin from irradiated intermetallic Ti-Sb targets

    DOE Patents [OSTI]

    Lapshina, Elena V.; Zhuikov, Boris L.; Srivastava, Suresh C.; Ermolaev, Stanislav V.; Togaeva, Natalia R.

    2012-01-17

    The invention provides a method of chemical recovery of no-carrier-added radioactive tin (NCA radiotin) from intermetallide TiSb irradiated with accelerated charged particles. An irradiated sample of TiSb can be dissolved in acidic solutions. Antimony can be removed from the solution by extraction with dibutyl ether. Titanium in the form of peroxide can be separated from tin using chromatography on strong anion-exchange resin. In another embodiment NCA radiotin can be separated from iodide solution containing titanium by extraction with benzene, toluene or chloroform. NCA radiotin can be finally purified from the remaining antimony and other impurities using chromatography on silica gel. NCA tin-117m can be obtained from this process. NCA tin-117m can be used for labeling organic compounds and biological objects to be applied in medicine for imaging and therapy of various diseases.

  2. Superfund record of decision (EPA Region 2): Evor Phillips Leasing Company, Old Bidge Township, Middlesex County, NJ. (First remedial action), September 1992

    SciTech Connect (OSTI)

    Not Available

    1992-09-30

    The 6.5-acre Evor Phillips Leasing Company site is a former disposal facility in Old Bridge Township, Middlesex County, New Jersey. Beginning in 1969, Evor Phillips used the site for hauling activities until leasing the property to North American Metal and Chemical Company (NAMCC) in 1971. Silver recovery operations were conducted at the site by NAMCC. Additionally, the Naval Ammunition Depot Earle sent 2,000 gallons of drummed spent potassium hydroxide to the NAMCC. The ROD addresses an interim remedy for contaminated ground water at the site and a final remedy for the drum disposal areas as OU1. The primary contaminants of concern affecting the debris, and ground water are VOCs, including benzene, TCE, PCE, and toluene; other organics; and inorganics.

  3. Devices and methods to detect and quantify trace gases

    DOE Patents [OSTI]

    Allendorf, Mark D.; Robinson, Alex

    2016-05-03

    Sensing devices based on a surface acoustic wave ("SAW") device coated with an absorbent crystalline or amorphous layer for detecting at least one chemical analyte in a gaseous carrier. Methods for detecting the presence of a chemical analyte in a gaseous carrier using such devices are also disclosed. The sensing devices and methods for their use may be configured for sensing chemical analytes selected from the group consisting of water vapor, carbon dioxide, methanol, ethanol, carbon monoxide, nitric oxide, nitrous oxide, organic amines, organic compounds containing NO.sub.2 groups, halogenated hydrocarbons, acetone, hexane, toluene, isopropanol, alcohols, alkanes, alkenes, benzene, functionalized aromatics, ammonia (NH.sub.3), phosgene (COCl.sub.2), sulfur mustard, nerve agents, sulfur dioxide, tetrahydrofuran (THF) and methyltertbutyl ether (MTBE) and combinations thereof.

  4. Testing decisions of the TSCA Interagency Testing Committee for chemicals on the Canadian Environmental Protection Act Domestic Substances List and Priority Substances List: Di-tert-butylphenol, ethyl benzene, brominated flame retardants, phthalate esters, chloroparaffins, chlorinated benzenes, and anilines

    SciTech Connect (OSTI)

    Walker, J.D.

    1996-12-31

    In 1976, under section 4(e) of the Toxic Substances Control Act (TSCA), the US Congress created the TSCA Interagency Testing Committee (ITC) to decide which chemicals should be recommended to the Administrator of the US Environmental Protection Agency for testing. In 1988, under the Canadian Environmental Protection Act (CEPA), the Government of Canada created the Domestic Substances List and Priority Substances List. This paper briefly describes the ITC, the different ITC testing decisions and a few of the ITC`s 11,150 testing decisions for the 21,413 chemicals on the CEPA Domestic Substances List and some of the 24 testing decisions for the 44 chemicals and chemical groups on the CEPA.

  5. The benzene⋯naphthalene complex: A more challenging system than the benzene dimer for newly developed computational methods

    SciTech Connect (OSTI)

    Wang, Weizhou E-mail: ybw@gzu.edu.cn; Zhang, Yu; Sun, Tao; Wang, Yi-Bo E-mail: ybw@gzu.edu.cn

    2015-09-21

    High-level coupled cluster singles, doubles, and perturbative triples [CCSD(T)] computations with up to the aug-cc-pVQZ basis set (1924 basis functions) and various extrapolations toward the complete basis set (CBS) limit are presented for the sandwich, T-shaped, and parallel-displaced benzene⋯naphthalene complex. Using the CCSD(T)/CBS interaction energies as a benchmark, the performance of some newly developed wave function and density functional theory methods has been evaluated. The best performing methods were found to be the dispersion-corrected PBE0 functional (PBE0-D3) and spin-component scaled zeroth-order symmetry-adapted perturbation theory (SCS-SAPT0). The success of SCS-SAPT0 is very encouraging because it provides one method for energy component analysis of π-stacked complexes with 200 atoms or more. Most newly developed methods do, however, overestimate the interaction energies. The results of energy component analysis show that interaction energies are overestimated mainly due to the overestimation of dispersion energy.

  6. Superfund Record of Decision (Region 2): Love Canal/93rd Street, New York (third remedial action), September 1988

    SciTech Connect (OSTI)

    Not Available

    1988-09-26

    The Love Canal/93rd Street School site consists of approximately 19 acres and includes a school and an adjacent vacant lot. The site is located in Niagara Falls, New York, less than one mile northwest of Love Canal and is within the Love Canal Emergency Declaration Area. Hooker Chemicals and Plastics Corporation disposed of over 21,000 tons of various chemicals at the Love Canal site from 1942 to 1953, when the site was deeded over to the City of Niagara Falls Board of Education. Sampling has revealed that approximately 6,000 cu yds of soil are contaminated. During the 1950s, home construction accelerated in the area. Specifically, in 1950, the 93rd Street School was built, and in 1954, the 99th Street School was built adjacent to the middle portion of the Canal. Prior to construction of the 93rd Street School, a drainage swale crossed the site. Between 1938 and 1951, the swale was partially filled with soil and rock debris, followed by sand and fly ash materials. In 1980, the 93rd Street School was closed due to public health concerns related to the potentially contaminated fill material. The primary contaminants of concern affecting soil are VOCs, including toluene and xylenes, other organics including dioxins, PAHs and pesticides, and metals including arsenic and lead.

  7. Comparison of two tunnel studies for non methane hydrocarbons in Mexico City

    SciTech Connect (OSTI)

    Mugica A, V.; Vega R, E.; Ruiz S, M.E.; Seila, R.

    1998-12-31

    Emissions from vehicles have long been considered a major source of pollutants involved in smog formation and ozone production. During the last few years, different control strategies have been taking place to reduce the high levels of ozone and some other atmospheric pollutants. Some of these strategies are: improvement of fuels, a program for compulsory vehicular emission test and the introduction of catalytic converters to be used in conjunction with unleaded gasoline since 1991. The comparison of the vehicular NMHC emission source profiles measured in a tunnel in Mexico City during March 1992 and May 1996 is presented. Samples were collected using stainless steel SUMMA{reg_sign} canisters and subsequent analyzed by gas chromatography with flame ionized detector. It was found that in general, the source profiles are similar, however, some differences were detected for some species. The sum of acetylene, ethylene and ethane contents, which are a typical combustion products, is lower for the 1996 source profile than for the 1992. In the same way, there is a small decrease of paraffin and olefin contents, except for hexane. Finally, significant differences were found for aromatic compounds, mainly toluene and xylenes which increased in 1996.

  8. Process for the removal of impurities from combustion fullerenes

    DOE Patents [OSTI]

    Alford, J. Michael; Bolskar, Robert

    2005-08-02

    The invention generally relates to purification of carbon nanomaterials, particularly fullerenes, by removal of PAHs and other hydrocarbon impurities. The inventive process involves extracting a sample containing carbon nanomaterials with a solvent in which the PAHs are substantially soluble but in which the carbon nanomaterials are not substantially soluble. The sample can be repeatedly or continuously extracted with one or more solvents to remove a greater amount of impurities. Preferred solvents include ethanol, diethyl ether, and acetone. The invention also provides a process for efficiently separating solvent extractable fullerenes from samples containing fullerenes and PAHs wherein the sample is extracted with a solvent in which both fullerenes and PAHs are substantially soluble and the sample extract then undergoes selective extraction to remove PAHs. Suitable solvents in which both fullerenes and PAHs are soluble include o-xylene, toluene, and o-dichlorobenzene. The purification process is capable of treating quantities of combustion soot in excess of one kilogram and can produce fullerenes or fullerenic soot of suitable purity for many applications.

  9. Superfund Record of Decision (EPA Region 5): Naval Industrial Reserve Ordnance Plant, Fridley, MN. (First remedial action), September 1990

    SciTech Connect (OSTI)

    Not Available

    1990-09-28

    The 82.6-acre Naval Industrial Reserve Ordnance Plant (NIROP) site is a weapons system manufacturing facility in Fridley, Minnesota, which began operations in 1940. The site is a government-owned, contractor-operated, plant located just north of the FMC Corp. During the 1970s, paint sludge and chlorinated solvents were disposed of onsite in pits and trenches. In 1981, State investigations identified TCE in onsite water supply wells drawing from the Prairie DuChien/Jordan aquifer, and the wells were shut down. In 1983, EPA found drummed waste in the trenches or pits at the northern portion of the site, and as a result, during 1983 and 1984, the Navy authorized an installation restoration program, during which approximately 1,200 cubic yards of contaminated soil and 42 drums were excavated and landfilled offsite. The Record of Decision (ROD) addresses the remediation of a shallow ground water operable unit. The primary contaminants of concern affecting the ground water are VOCs including PCE, TCE, toluene, and xylene.

  10. Comparison of advanced distillation control methods. Second annual report

    SciTech Connect (OSTI)

    1996-11-01

    Detailed dynamic simulations of three industrial distillation columns (a propylene/propane splitter, a xylene/toluene column, and a depropanizer) have been used to study the issue of configuration selection for diagonal PI dual composition controls. ATV identification with on-line detuning was used for tuning the diagonal PI composition controllers. Each configuration was evaluated with respect to steady-state RGA values, sensitivity to feed composition changes, and open loop dynamic performance. Each configuration was tuned using setpoint changes over a wider range of operation for robustness and tested for feed composition upsets. Overall, configuration selection was shown to have a dominant effect upon control performance. Configuration analysis tools (e.g., RGA, condition number, disturbance sensitivity), were found to reject configuration choices that are obviously poor choices, but were unable to critically differentiate between the remaining viable choices. Configuration selection guidelines are given although it is demonstrated that the most reliable configuration selection approach is based upon testing the viable configurations using dynamic column simulators.

  11. Comparison of advanced distillation control methods. Second annual report

    SciTech Connect (OSTI)

    Riggs, J.B.

    1996-11-01

    Detailed dynamic simulations of two industrial distillation columns (a propylene/propane splitter and a xylene/toluene column) have been used to study the issue of configuration selection for diagonal PI dual composition controls. Auto Tune Variation (ATV) identification with on-line detuning was used for tuning the diagonal proportional integral (PI) composition controls. Each configuration was evaluated with respect to steady-state relative gain array (RGA) values, sensitivity to feed composition changes, and open loop dynamic performance. Each configuration was tuned using setpoint changes over a wider range of operation for robustness and tested for feed composition upsets. Overall, configuration selection was shown to have a dominant effect upon control performance. Configuration analysis tools (e.g., RGA, condition number, disturbance sensitivity) were found to reject configuration choices that are obviously poor choices, but were unable to critically differentiate between the remaining viable choices. Configuration selection guidelines are given although it is demonstrated that the most reliable configuration selection approach is based upon testing the viable configurations using dynamic column simulators.

  12. Comparison of advanced distillation control methods. Fourth annual report

    SciTech Connect (OSTI)

    Riggs, J.B.

    1998-09-01

    Detailed dynamic simulations of three industrial columns (a propylene/propane splitter, a xylene/toluene column, and a depropanizer) have been used to evaluate configuration selection for single-ended and dual-composition control as well as compare conventional and advanced control approaches. For each case considered, the controllers were tuned by using setpoint changes and tested using feed composition upsets. Proportional Integral (PI) control performance was used to evaluate the configuration selection problem. For single ended control, the energy balance configuration was found to yield the best performance. For dual composition control, nine configurations were considered. It was determined that in order to identify the optimum configuration, detailed testing using dynamic simulation is required. The optimum configurations were used to evaluate the control performance of conventional PI controllers, DMC (Dynamic Matrix Control), PMBC (Process Model Based Control), and ANN (Artificial Neural Networks) control. It was determined that DMC works best when one product is much more important than the other while PI was superior when both products were equally important. PMBC and ANN were not found to offer significant advantages over PI and DMC.

  13. Thermal stability, acidity, catalytic properties, and deactivation behaviour of SAPO-5 catalysts: Effect of silicon content, acid treatment, and Na exchange

    SciTech Connect (OSTI)

    Akolekar, D.B.

    1994-09-01

    Crystalline microporous SAPO-5 molecular sieves with different silicon content, acid-treated SAPO-5 and Na-exchanged SAPO-5 were investigated for their thermal stability, and acidic and catalytic properties. SAPO-5 materials with increasing SI framework content exhibited lower thermal stability. The effects of the thermal treatment and Na exchange on the N{sub 2}-sorption capacity (at 78 K) of these materials were studied. In situ IR spectroscopic investigations of pyridine chemisorbed on the aluminophosphate catalysts revealed that the concentration of Broensted and Lewis acid sites are strongly affected by the Si content in the AlPO{sub 4} framework, acid treatment, and Na exchange. The results of temperature programmed desorption (TPD) and stepwise thermal desorption of pyridine suggest that there exists a broad site energy distribution over the aluminophosphate catalysts increases with the increasing Si content in the AlPO{sub 4} framework. The acid treatment and Na exchange showed a decrease in the number of strong acid sites on SAPO-5. The TPD of pyridine over SAPO-5, acid-treated SAPO-5, and Na-exchanged SAPO-5 indicated the presence of two types of acid sites. Correlation between the number of strong acid sites (measured in terms of the chemisorption of pyridine at 673 K) and framework charge on the aluminophosphate catalysts has also been obtained. The catalytic activities of SAPO-5 catalysts in the ethanol, n-hexane, isooctane, toluene, and o-xylene conversion reactions were studied. 22 refs., 11 figs., 5 tabs.

  14. Genome analysis and physiological comparison of Alicycliphilus denitrificans strains BC and K601T

    SciTech Connect (OSTI)

    Oosterkamp, Margreet J.; Veuskens, Teun; Saia, Flavia Talarico; Weelink, Sander A.B.; Goodwin, Lynne A.; Daligault, Hajnalka E.; Bruce, David; Detter, J. Chris; Tapia, Roxanne; Han, Cliff; Land, Miriam L; Hauser, Loren John; Langenhoff, A. M.; Gerritse, Jan; Van Berkel, Willem J. H.; Pieper, Dietmar; Junca, Howard; Smidt, Hauke; Schraa, Gosse; Davids, Mark; Schaap, Peter J; Plugge, Caroline M.; Stams, Alfons J. M.

    2013-01-01

    The genomes of the Betaproteobacteria Alicycliphilus denitrificans strains BC and K601T have been sequenced to get insight into the physiology of the two strains. Strain BC degrades benzene with chlorate as electron acceptor. The cyclohexanol-degrading denitrifying strain K601T is not able to use chlorate as electron acceptor, while strain BC cannot degrade cyclohexanol. The 16S rRNA sequences of strains BC and K601T are identical and the fatty acid methyl ester patterns of the strains are similar. Basic Local Alignment Search Tool (BLAST) analysis of predicted open reading frames of both strains showed most hits with Acidovorax sp. JS42, a bacterium that degrades nitro-aromatics. The genomes include strain-specific plasmids (pAlide201 in strain K601T and pAlide01 and pAlide02 in strain BC). Key genes of chlorate reduction in strain BC were located on a 120 kb megaplasmid (pAlide01), which was absent in strain K601T. Genes involved in cyclohexanol degradation were only found in strain K601T. Benzene and toluene are degraded via oxygenase-mediated pathways in both strains. Genes involved in the meta-cleavage pathway of catechol are present in the genomes of both strains. Strain BC also contains all genes of the ortho-cleavage pathway. The large number of mono- and dioxygenase genes in the genomes suggests that the two strains have a broader substrate range than known thus far.

  15. Fossil fuel and hydrocarbon conversion using hydrogen-rich plasmas. Topical report February 1994--February 1995

    SciTech Connect (OSTI)

    1995-02-01

    Experiments were made on use of H and CH plasmas for converting waste materials and heavy oils to H-rich transportation fuels. Batch and continuous experiments were conducted with an industrial microwave generator and a commercial microwave oven. A continuously circulating reactor was constructed for conducting experiments on flowing oils. Experiments on decomposition of scrap tires showed that microwave plasmas can be used to decompose scrap tires into potentially useful liquid products. In a batch experiment using a commercial microwave oven, about 20% of the tire was converted to liquid products in about 9 minutes. Methane was decomposed in a microwave plasma to yield a liquid products composed of various compound types; GC/MS analyses identified unsaturated compounds including benzene, toluene, ethyl benzene, methyl and ethyl naphthalene, small amounts of larger aromatic rings, and olefinic compounds. Experiments on a crude oil in a continuously flowing reactor showed that distillate materials are produced using H and CH plasmas. Also, the recycle oils had an overall carbon aromaticity lower than that of starting feed material, indicating that some hydrogenation and methanation had taken place in the recycle oils.

  16. The oxidation of a gasoline surrogate in the negative temperature coefficient region

    SciTech Connect (OSTI)

    Lenhert, David B.; Miller, David L.; Cernansky, Nicholas P.; Owens, Kevin G.

    2009-03-15

    This experimental study investigated the preignition reactivity behavior of a gasoline surrogate in a pressurized flow reactor over the low and intermediate temperature regime (600-800 K) at elevated pressure (8 atm). The surrogate mixture, a volumetric blend of 4.6% 1-pentene, 31.8% toluene, 14.0% n-heptane, and 49.6% 2,2,4-trimethyl-pentane (iso-octane), was shown to reproduce the low and intermediate temperature reactivity of full boiling range fuels in a previous study. Each of the surrogate components were examined individually to identify the major intermediate species in order to improve existing kinetic models, where appropriate, and to provide a basis for examining constituent interactions in the surrogate mixture. n-Heptane and 1-pentene started reacting at 630 K and 640 K, respectively, and both fuels exhibited a strong negative temperature coefficient (NTC) behavior starting at 700 and 710 K, respectively. Iso-octane showed a small level of reactivity at 630 K and a weak NTC behavior starting at 665 K. Neat toluene was unreactive at these temperatures. The surrogate started reacting at 630 K and exhibited a strong NTC behavior starting at 693 K. The extent of fuel consumption varied for each of the surrogate constituents and was related to their general autoignition behavior. Most of the intermediates identified during the surrogate oxidation were species observed during the oxidation of the neat constituents; however, the surrogate mixture did exhibit a significant increase in intermediates associated with iso-octane oxidation, but not from n-heptane. While neat toluene was unreactive at these temperatures, in the mixture it reacted with the radical pool generated by the other surrogate components, forming benzaldehyde, benzene, phenol, and ethyl-benzene. The observed n-heptane, iso-octane, and surrogate oxidation behavior was compared to predictions using existing kinetic models. The n-heptane model reasonably predicted the disappearance of the fuel

  17. 1

    Office of Environmental Management (EM)

    Tetrachloroethylene, Trichloroethylene, Trichloroflouromethane, Acetone, Ethyl ether, Methanol, Methyl isobutyl ketone, n-Butyl alcohol, Xylene, Cresols, Cresylic acid,...

  18. Studies of Immobilized Homogeneous Metal Catalysts on Silica Supports

    SciTech Connect (OSTI)

    Keith James Stanger

    2003-05-31

    The tethered, chiral, chelating diphosphine rhodium complex, which catalyzes the enantioselective hydrogenation of methyl-{alpha}-acetamidocinnamate (MAC), has the illustrated structure as established by {sup 31}P NMR and IR studies. Spectral and catalytic investigations also suggest that the mechanism of action of the tethered complex is the same as that of the untethered complex in solution. The rhodium complexes, [Rh(COD)H]{sub 4}, [Rh(COD){sub 2}]{sup +}BF{sub 4}{sup -}, [Rh(COD)Cl]{sub 2}, and RhCl{sub 3} {center_dot} 3H{sub 2}O, adsorbed on SiO{sub 2} are optimally activated for toluene hydrogenation by pretreatment with H{sub 2} at 200 C. The same complexes on Pd-SiO{sub 2} are equally active without pretreatments. The active species in all cases is rhodium metal. The catalysts were characterized by XPS, TEM, DRIFTS, and mercury poisoning experiments. Rhodium on silica catalyzes the hydrogenation of fluorobenzene to produce predominantly fluorocyclohexane in heptane and 1,2-dichloroethane solvents. In heptane/methanol and heptane/water solvents, hydrodefluorination to benzene and subsequent hydrogenation to cyclohexane occurs exclusively. Benzene inhibits the hydrodefluorination of fluorobenzene. In DCE or heptane solvents, fluorocyclohexane reacts with hydrogen fluoride to form cyclohexene. Reaction conditions can be chosen to selectively yield fluorocyclohexane, cyclohexene, benzene, or cyclohexane. The oxorhenium(V) dithiolate catalyst [-S(CH{sub 2}){sub 3}s-]Re(O)(Me)(PPh{sub 3}) was modified by linking it to a tether that could be attached to a silica support. Spectroscopic investigation and catalytic oxidation reactivity showed the heterogenized catalyst's structure and reactivity to be similar to its homogeneous analog. However, the immobilized catalyst offered additional advantages of recyclability, extended stability, and increased resistance to deactivation.

  19. Atmosphere contamination following repainting of a human hyperbaric chamber complex

    SciTech Connect (OSTI)

    Lillo, R.S.; Morris, J.W.; Caldwell, J.M.; Balk, D.M.; Flynn, E.T. )

    1990-09-01

    The Naval Medical Research Institute currently conducts hyperbaric research in a Man-Rated Chamber Complex (MRCC) originally installed in 1977. Significant engineering alterations to the MRCC and rusting of some of its interior sections necessitated repainting, which was completed in 1988. Great care was taken in selecting an appropriate paint (polyamide epoxy) and in ensuring correct application and curing procedures. Only very low levels of hydrocarbons were found in the MRCC atmosphere before initial pressurization after painting and curing. After pressurization, however, significant chemical contamination was found. The primary contaminants were aromatic hydrocarbons: xylenes (which were a major component of both the primer and topcoat paint) and ethyl benzene. The role that pressure played in stimulating off-gassing from the paint is not clear; the off-gassing rate was observed to be similar over a large range in chamber pressures from 1.6 to 31.0 atm abs. Scrubbing the chamber atmosphere with the chemical absorbent Purafil was effective in removing the contaminants. Contamination has been observed to slowly decline with chamber use and is expected to continue to improve with time. However, this contamination experience emphasizes the need for a high precision gas analysis program at any diving facility to ensure the safety of the breathing gas and chamber atmosphere.

  20. Superfund Record of Decision (EPA Region 2): Kin-Buc Landfill, Edison Township, Middlesex County, NJ. (Second remedial action), September 1992. Final report

    SciTech Connect (OSTI)

    Not Available

    1992-09-28

    The 200-acre Kin-Buc Landfill consists of several inactive disposal areas and is located in Edison Township, Middlesex County, New Jersey. Land use in the area is predominantly industrial and commercial, with some residences within 2 miles north of the site. No drinking water supply wells are located within a 2-mile radius of the site. As a result of an oil spill in 1976, EPA conducted an investigation of the property. In 1980, clean-up activities were initiated under the Clean Water Act and included removal, treatment, and disposal of leachate and drummed waste. The ROD addresses a final remedy for OU2 consisting of the sediment and groundwater in the Edmonds Creek wetlands area, Mill Brook/Martins Creek, Mound B, and the low-lying area. The primary contaminants of concern affecting the sediment and ground water are VOCs, including benzene and xylenes; other organics, including PAHs, PCBs, and pesticides; and metals, including arsenic and lead. The selected remedy for the site are included.

  1. QER- Comment of Jeff Cobb 2

    Broader source: Energy.gov [DOE]

    'm doing, right now, the most important thing I could possibly be doing.' If you join the fight against climate change, that's what you'll get to say. - Bill McKibben Louisiana Department of Wildlife & Fisheries Attn: Chris Davis Re: Louisiana Natural and Scenic Rivers System Permit Applications # 896 & 902 Dear Mr. Davis, I am writing to request a public hearing on the two permits shown above. Both of these are vital natural Louisiana scenic river resources. As such, both are enjoyed by many citizens in our extended community. The thought of allowing fresh water to be pulled out of these rivers in such large quantities to satisfy the needs of large corporate industrial projects that will pollute the water to such a degree that it can never be safely returned to the eco-system is abhorrent. According to Wilma Subra*, the early phases of production after fracking, the produced water flows to the surface mixed with flowback water. The produced water is disposed of in injection/disposal wells. The produced water contains toxic chemical contaminants: volatile organic compounds, such as benzene, ethyl benzene, toluene and xylene semi-volatile organic compound such as naphthalene, phenanthrene heavy metals such as arsenic, cadmium, chromium, lead sulfur containing compounds NORM Radioactive Radium 226, Radium 228 and Uranium 238 These are only the first permits of what will become literally, thousands, should you allow this activity. I ask you to mindfully consider the impact of thousands of hydrofracturing wells in our area, depleting water supplies at alarming rates. Thank you for your time and consideration in this matter. I look forward to hearing from you regarding public hearings on these permit requests. Additionally, I would like to request a full Environmental Impact Statement regarding the use of our scenic rivers for such activity. Sincerely, Jeff Cobb *Subra holds degrees in Microbiology/Chemistry from the University of Southwestern Louisiana, received the Mac

  2. Source Term Modeling for Evaluating the Potential Impacts to Groundwater of Fluids Escaping from a Depleted Oil Reservoir Used for Carbon Sequestration

    SciTech Connect (OSTI)

    Cantrell, Kirk J.; Brown, Christopher F.

    2014-06-13

    In recent years depleted oil reservoirs have received special interest as carbon storage reservoirs because of their potential to offset costs through collaboration with enhanced oil recovery projects. Modeling is currently being conducted to evaluate potential risks to groundwater associated with leakage of fluids from depleted oil reservoirs used for storage of CO2. Modeling results reported here focused on understanding how toxic organic compounds found in oil will distribute between the various phases within a storage reservoir after introduction of CO2, understanding the migration potential of these compounds, and assessing potential groundwater impacts should leakage occur. Two model scenarios were conducted to evaluate how organic components in oil will distribute among the phases of interest (oil, CO2, and brine). The first case consisted of 50 wt.% oil and 50 wt.% water; the second case was 90 wt.% CO2 and 10 wt.% oil. Several key organic compounds were selected for special attention in this study based upon their occurrence in oil at significant concentrations, relative toxicity, or because they can serve as surrogate compounds for other more highly toxic compounds for which required input data are not available. The organic contaminants of interest (COI) selected for this study were benzene, toluene, naphthalene, phenanthrene, and anthracene. Partitioning of organic compounds between crude oil and supercritical CO2 was modeled using the Peng-Robinson equation of state over temperature and pressure conditions that represent the entire subsurface system (from those relevant to deep geologic carbon storage environments to near surface conditions). Results indicate that for a typical set of oil reservoir conditions (75°C, and 21,520 kPa) negligible amounts of the COI dissolve into the aqueous phase. When CO2 is introduced into the reservoir such that the final composition of the reservoir is 90 wt.% CO2 and 10 wt.% oil, a significant fraction of the oil

  3. Treatability study for WAG 6 (SWSA 6) trench water

    SciTech Connect (OSTI)

    Taylor, P.A.

    1991-08-01

    The Environmental Restoration Program at Oak Ridge National Laboratory (ORNL) is examining methods for remediation and final closure of Waste Area Grouping 6 (WAG 6) under a Resource Conservation and Recovery Act (RCRA) closure plan. WAG 6 consists primarily of Solid Waste Storage Area 6 (SWSA 6), where solid low- level radioactive waste (and some hazardous waste) was buried from 1968 to 1985 in shallow trenches. To support the feasibility study that is being prepared for closure of WAG 6, lab-scale treatability tests were performed on the water from selected trenches in SWSA 6 to determine if the trench water could be treated at the existing wastewater treatment plants at ORNL. Water from 23 of the 500 trenches in SWSA 6 has been sampled and analyzed to date, and the 4 most highly contaminated trenches identified thus far supplied the water used in the treatability tests. The softening and ion-exchange processes used in the Process Wastewater Treatment Plant (PWTP) reduced the {sup 90}Sr concentration, which was the only radionuclide present in the trench water at above the discharge limits, from 260 to 0.2 Bq/L. The air stripping and activated carbon adsorption processes used in the Nonradiological Wastewater Treatment Plant (NRWTP) removed volatile and semivolatile organics (mostly toluene, xylene, and naphthalene), which were the main contaminants in the trench water, to below detection limits. The trench water treated in the lab-scale equipment easily met all discharge limits for the PWTP and the NRWTP. 6 refs., 2 figs., 9 tabs.

  4. Growth and properties of Lithium Salicylate single crystals

    SciTech Connect (OSTI)

    Zaitseva, N; Newby, J; Hull, G; Saw, C; Carman, L; Cherepy, N; Payne, S

    2009-02-13

    An attractive feature of {sup 6}Li containing fluorescence materials that determines their potential application in radiation detection is the capture reaction with slow ({approx}< 100 keV) neutrons: {sup 6}Li + n = {sup 4}He + {sup 3}H + 4.8MeV. The use of {sup 6}Li-salicylate (LiSal, LiC{sub 6}H{sub 5}O{sub 3}) for thermal neutron detection was previously studied in liquid and polycrystalline scintillators. The studies showed that both liquid and polycrystalline LiSal scintillators could be utilized in pulse shape discrimination (PSD) techniques that enable separation of neutrons from the background gamma radiation. However, it was found that the efficiency of neutron detection using LiSal in liquid solutions was severely limited by its low solubility in commonly used organic solvents like, for example, toluene or xylene. Better results were obtained with neutron detectors containing the compound in its crystalline form, such as pressed pellets, or microscopic-scale (7-14 micron) crystals dispersed in various media. The expectation drown from these studies was that further improvement of pulse height, PSD, and efficiency characteristics could be reached with larger and more transparent LiSal crystals, growth of which has not been reported so far. In this paper, we present the first results on growth and characterization of relatively large, a cm-scale size, single crystals of LiSal with good optical quality. The crystals were grown both from aqueous and anhydrous (methanol) media, mainly for neutron detection studies. However, the results on growth and structural characterization may be interesting for other fields where LiSal, together with other alkali metal salicylates, is used for biological, medical, and chemical (as catalyst) applications.

  5. Comparison of Advanced Distillation Control Methods, Final Technical Report

    SciTech Connect (OSTI)

    Dr. James B. Riggs

    2000-11-30

    Detailed dynamic simulations of three industrial distillation columns (a propylene/propane splitter, a xylene/toluene column, and a depropanizer) have been used to evaluate configuration selections for single-ended and dual-composition control, as well as to compare conventional and advanced control approaches. In addition, a simulator of a main fractionator was used to compare the control performance of conventional and advanced control. For each case considered, the controllers were tuned by using setpoint changes and tested using feed composition upsets. Proportional Integral (PI) control performance was used to evaluate the configuration selection problem. For single ended control, the energy balance configuration was found to yield the best performance. For dual composition control, nine configurations were considered. It was determined that the use of dynamic simulations is required in order to identify the optimum configuration from among the nine possible choices. The optimum configurations were used to evaluate the relative control performance of conventional PI controllers, MPC (Model Predictive Control), PMBC (Process Model-Based Control), and ANN (Artificial Neural Networks) control. It was determined that MPC works best when one product is much more important than the other, while PI was superior when both products were equally important. PMBC and ANN were not found to offer significant advantages over PI and MPC. MPC was found to outperform conventional PI control for the main fractionator. MPC was applied to three industrial columns: one at Phillips Petroleum and two at Union Carbide. In each case, MPC was found to significantly outperform PI controls. The major advantage of the MPC controller is its ability to effectively handle a complex set of constraints and control objectives.

  6. Synthesis of the Stereoisomeric Clusters 1,2-Os3(CO)10(trans-dpmn) and 1,2-Os3(CO)10(cis-dpmn) [where dpmn = 2,3-bis(diphenylphosphinomethyl)-5-norbornene]: DFT Evaluation of the Isomeric Clusters 1,2-Os3(CO)10(dpmn) and Isomer-Dependent Diphosphine Ligand Activation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yang, Li; Nesterov, Vladimir N.; Wang, Xiaoping; Richmond, Michael G.

    2014-07-23

    The bicyclic diphosphines trans- and cis-2,3-bis(diphenylphosphinomethyl)-5-norbornene (dpmn) react with 1,2-Os3(CO)10(MeCN)2 (1) to furnish the corresponding ligand-bridged clusters Os3(CO)10(trans-dpmn) (2) and Os3(CO)10(cis-dpmn) (3). Both new products have been isolated and the molecular structures established by X-ray diffraction analyses. The dihydroxyl-bridged cluster 1,2-Os3(CO)8(μ-OH)2(cis-dpmn) (4), which accompanied the formation of 3 in one reaction, has been isolated and characterized by mass spectrometry and X-ray crystallography. Whereas cluster 2 is stable in toluene at 373 K, 3 is thermally sensitive under identical conditions and undergoes loss of CO (2 equiv), coupled with the activation of three norbornene C-H bonds and one P-C(phenyl) bond, tomore » furnish the dihydride cluster H2Os3(CO)8[μ3-2-PhPC-3-endo-Ph2PCH2(C7H7)] (5). The solid-state structure of 5 confirms the multiple activation of the cis-dpmn ligand and accompanying formation of the face-capping 2-PhPC-3-endo-Ph2PCH2(C7H7) moiety in the product. DFT calculations on 2 and 3 indicate that the former cluster is the thermodynamically more stable isomer, and the conversion of 3→ 5 + 2CO + benzene is computed to be exergonic by 12.7 kcal/mol and is entropically favored due to the release of the CO and benzene by-products.« less

  7. SYNTHESIS OF THE FULLY PROTECTED PHOSPHORAMIDITE OF THE BENZENE-DNA ADDUCT, N2- (4-HYDROXYPHENYL)-2'-DEOXYGUANOSINE AND INCORPORATION OF THE LATER INTO DNA OLIGOMERS

    SciTech Connect (OSTI)

    Chenna, Ahmed; Gupta, Ramesh C.; Bonala, Radha R.; Johnson, Francis; Huang, Bo

    2008-06-09

    N2-(4-Hydroxyphenyl)-2'-deoxyguanosine-5'-O-DMT-3'-phosphoramidite has been synthesized and used to incorporate the N2-(4-hydroxyphenyl)-2'-dG (N2-4-HOPh-dG) into DNA, using solid-state synthesis technology. The key step to obtaining the xenonucleoside is a palladium (Xantphos-chelated) catalyzed N2-arylation (Buchwald-Hartwig reaction) of a fully protected 2'-deoxyguanosine derivative by 4-isobutyryloxybromobenzene. The reaction proceeded in good yield and the adduct was converted to the required 5'-O-DMT-3'-O-phosphoramidite by standard methods. The latter was used to synthesize oligodeoxynucleotides in which the N2-4-HOPh-dG adduct was incorporated site-specifically. The oligomers were purified by reverse-phase HPLC. Enzymatic hydrolysis and HPLC analysis confirmed the presence of this adduct in the oligomers.

  8. Slide 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    chemicals and transportation fuels from lignocellulosic biomass. DMF has a high octane number and is the precursor to green para-xylene. CTH enables selective...

  9. Slide 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Kinetic Regimes in the Production of Renewable p-Xylene Work was performed at the Universities of Minnesota, Massachusetts and Delaware by the group of Dauenhauer, Fan, Caratzoulas ...

  10. Source profiles for nonmethane organic compounds in the atmosphere of Cairo, Egypt.

    SciTech Connect (OSTI)

    Doskey, P. V.; Fukui, Y.; Sultan, M.; Maghraby, A. A.; Taher, A.; Environmental Research; Cairo Univ.

    1999-07-01

    Profiles of the sources of nonmethane organic compounds (NMOCs) were developed for emissions from vehicles, petroleum fuels (gasoline, liquefied petroleum gas (LPG), and natural gas), a petroleum refinery, a smelter, and a cast iron factory in Cairo, Egypt. More than 100 hydrocarbons and oxygenated hydrocarbons were tentatively identified and quantified. Gasoline-vapor and whole-gasoline profiles could be distinguished from the other profiles by high concentrations of the C{sub 5} and C{sub 6} saturated hydrocarbons. The vehicle emission profile was similar to the whole-gasoline profile, with the exception of the unsaturated and aromatic hydrocarbons, which were present at higher concentrations in the vehicle emission profile. High levels of the C{sub 2}-C{sub 4} saturated hydrocarbons, particularly n-butane, were characteristic features of the petroleum refinery emissions. The smelter and cast iron factory emissions were similar to the refinery emissions; however, the levels of benzene and toluene were greater in the former two sources. The LPG and natural gas emissions contained high concentrations of n-butane and ethane, respectively. The NMOC source profiles for Cairo were distinctly different from profiles for U.S. sources, indicating that NMOC source profiles are sensitive to the particular composition of petroleum fuels that are used in a location.

  11. Vapor Sensing Using Conjugated Molecule-Linked Au Nanoparticles in a Silica Matrix

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dirk, Shawn M.; Howell, Stephen W.; Price, B. Katherine; Fan, Hongyou; Washburn, Cody; Wheeler, David R.; Tour, James M.; Whiting, Joshua; Simonson, R. Joseph

    2009-01-01

    Cross-linkedmore » assemblies of nanoparticles are of great value as chemiresistor-type sensors. Herein, we report a simple method to fabricate a chemiresistor-type sensor that minimizes the swelling transduction mechanism while optimizing the change in dielectric response. Sensors prepared with this methodology showed enhanced chemoselectivity for phosphonates which are useful surrogates for chemical weapons. Chemoselective sensors were fabricated using an aqueous solution of gold nanoparticles that were then cross-linked in the presence of the silica precursor, tetraethyl orthosilicate with the α -, ω -dithiolate (which is derived from the in situ deprotection of 1,4-di(Phenylethynyl- 4 ′ , 4 ″ -diacetylthio)-benzene ( 1 ) with wet triethylamine). The cross-linked nanoparticles and silica matrix were drop coated onto interdigitated electrodes having 8  μ m spacing. Samples were exposed to a series of analytes including dimethyl methylphosphonate (DMMP), octane, and toluene. A limit of detection was obtained for each analyte. Sensors assembled in this fashion were more sensitive to dimethyl methylphosphonate than to octane by a factor of 1000.« less

  12. Superfund Record of Decision (EPA Region 3): Rhinehart Tire Fire Dump, Operable Unit 2, Winchester, VA. (Second remedial action), September 1992

    SciTech Connect (OSTI)

    Not Available

    1992-09-29

    The Rhinehart Tire Fire Dump site is located in a 22-acre drainage area of a sparsely populated rural area in western Frederick County, Virginia. Surface water runoff flows into a north-south tributary that discharges to Hogue Creek, which is 4,000 feet downstream. Bedrock is noted to be highly fractured, and the ground water flow in the overburden aquifer is toward Massey Run. From 1972 to 1983, the site owner conducted a tire disposal operation, which consisted of transporting discarded tires from various locations and storing them on a 5-acre wooded slope behind his home. An estimated 5 to 7 million tires that had been accumulated caught on fire in October 1983 and burned until July 1984. As a result of the fire, a free-flowing oily-tar, which contained anthracene, benzene, cadmium, chromium, ethylbenzene, napthalene, nickel, pyrene, toluene, and zinc, began to seep out of the tire pile into Massey Run and on to Hogue Creek.

  13. Semi volatile organic compounds in ambient PM2.5. Seasonal trends and daily resolved source contributions

    SciTech Connect (OSTI)

    Juergen Schnelle-Kreis; Martin Sklorz; Juergen Orasche; Matthias Stoelzel; Annette Peters; Ralf Zimmermann

    2007-06-01

    Concentrations of ambient semivolatile organic compounds (SVOC) in the PM2.5 fraction of Augsburg, Germany, have been monitored on a daily basis from January 2003 through December 2004. Samples were taken in a large garden in the city center. Quantitative analysis of n-alkanes, alkanones, alkanoic acid methylesters, long chain linear alkyl benzenes and toluenes, hopanes, polycyclic aromatic hydrocarbons (PAH) and oxidized PAH, and some abietan type diterpenes was done. All compounds showed distinct seasonal variations in concentration. Most compounds showed highest concentrations during the cold seasons, but some n-alkanones and 6,10,14-trimethylpentadecanone showed maximum concentration during summer. Changes in patterns between and within compound classes were obvious, e.g., the hopane pattern exhibited a strong seasonal variation. The main source related contributions to changes observed were discussed. Using positive matrix factorization (PMF) for the statistical investigation of the data set, five factors have been separated. These factors are dominated by the pattern of single sources or groups of similar sources: factor 1, lubricating oil; factor 2, emissions of unburned diesel and heating oil consumption; factor 3, wood combustion; factor 4, brown coal combustion; and factor 5, biogenic emissions and transport components. Like the SVOC, the factors showed strong seasonality with highest values in winter for factors 1-4 and in summer for factor 5. 56 refs., 3 figs., 1 tab.

  14. Superfund Record of Decision (EPA Region 7): John Deere DDubuque Works, Dubuque, Iowa (first remedial action), September 1988. Final report

    SciTech Connect (OSTI)

    Not Available

    1988-09-29

    The John Deere Dubuque Works site is located approximately 2.5 miles north of the City of Dubuque, Iowa. The site is owned by Deere and Company, which has operated a manufacturing plant at the site since 1946. The plant property includes an area of 1,447 acres located in the flood plain at the confluence of the Little Maquoketa River and the Mississippi River. The waste-management history of the plant is complex, but the primary area of concern is an unlined landfill originally placed in a natural depression caused by the Little Maquoketa River. Prior to 1968, wastes were placed in the low areas of the landfill and combustible materials were burned. Another area of concern at the facility is the site of a 1980, 200,000-gallon diesel fuel spill. Investigations conducted by John Deere indicated that human health hazards at the landfill could be considered minimal with the primary hazard being the possibility of dissolved organic chemicals impacting offsite domestic wells located east of the plant along the Mississippi River. The primary contaminants of concern affecting the ground water are volatile organic compounds including benzene, PCE, TCE, and toluene. The selected remedial action for the site is included.

  15. Fullerene (C60) films for solid lubrication

    SciTech Connect (OSTI)

    Bhushan, B.; Gupta, B.K.; Van Cleef, G.W.; Capp, C.E.; Coe, J.V. )

    1993-10-01

    The advent of techniques for producing gram quantities of a new form of stable, pure, solid carbon, designated as fullerene, opens a profusion of possibilities to be explored in many disciplines including tribology. Fullerenes take the form of hollow geodesic domes, which are formed from a network of pentagons and hexagons with covalently bonded carbon atoms. The C60 molecule has the highest possible symmetry (icosahedral) and assumes the shape of a soccer ball. At room temperature, fullerene molecules pack in an fcc lattice bonded with weak van der Waals attractions. Fullerenes can be dissolved in solvents such as toluene and benzene and are easily sublimed. The low surface energy, high chemical stability, spherical shape, weak intermolecular bonding, and high load bearing capacity of C60 molecules offer potential for various mechanical and tribological applications. This paper describes the crystal structure and properties of fullerenes and proposes a mechanism for self-lubricating action. Sublimed films of C60 have been produced and friction and wear performance of these films in various operating environments are the subject of this paper. The results of this study indicate that C60, owing to its unique crystal structure and bonding, may be a promising solid lubricant. 31 refs.

  16. PREPARATION OF ALKYL PYROPHOSPHATE EXTRACTANTS

    DOE Patents [OSTI]

    Levine, C.A.; Skiens, W.E.; Moore, G.R.

    1960-08-01

    A process for providing superior solvent extractants for metal recovery processes is given wherein the extractant comprises an alkyl pyrophosphoric acid ester dissolved in an organic solvent diluent. Finely divided solid P/sub 2/O/ sub 5/ is slurried in an organic solvent-diluent selected from organic solvents such as kerosene, benzene, chlorobenzene, toluene, etc. An alcohol selected from the higher alcohols having 4 to 17 carbon atoms. e.g.. hexanol-1. heptanol-3, octanol-1. 2.6-dimethyl-heptanol-4, and decanol-1, is rapidly added to the P/sub 2/O/sub 5/ slurry in the amount of about 2 moles of alcohol to 1 mole of P/sub 2/ O/sub 5/. The temperature is maintained below about 110 deg C during the course of the P/sub 2/O/sub 5/-alcohol reaction. An alkyl pyrophosphate extractant compound is formed as a consequence of the reaction process. The alkyl pyrophosphate solvent-diluent extractant phase is useful in solvent extraction metal recovery processes.

  17. Photophysics and Luminescence Spectroelectrochemistry of [Tc(dmpe)3]+/2+ (dmpe = 1,2-bis(dimethylphosphino)ethane)

    SciTech Connect (OSTI)

    Chatterjee, Sayandev; Del Negro, Andrew S.; Smith, Frances N.; Wang, Zheming; Hightower, Sean E.; Sullivan, Brian P.; Heineman, William R.; Seliskar, Carl J.; Bryan, Samuel A.

    2013-12-05

    The ligand-to-metal charge transfer (LMCT) excited state luminescence of [Tc(dmpe)3]2+ (dmpe is 1,2-bis-(dimethylphosphino)ethane) has been measured in solution at room temperature, and is compared to its Re analogue. Surprisingly, both [M(dmpe)3]2+* (M = Re, Tc) species have extremely large excited-state potentials (ESPs) as oxidants - the highest for any simple coordination complex of a transition metal. Furthermore, this potential is available using a photon of visible light (calculated for M = Re(Tc); E1/2* = +2.61(2.48) V versus SCE; ?max = 526(585) nm). Open shell TDDFT calculations support the assignment of the lowest energy transition in both the technetium and rhenium complexes to be a doublet-doublet process that involve predominantly LMCT (dmpe-to-metal) character and is in agreement with past assignments for the Re system. As expected for highly oxidizing excited state potentials, quenching is observed for the excited states by both the rhenium and technetium complexes. Stern-Volmer analysis resulted in quenching parameters for both the rhenium and technetium complexes under identical conditions, and are compared using Rehm-Weller analysis. Of particular interest is the fact that both benzene and toluene are oxidized by both the Re and Tc systems.

  18. A Feasibility Study for Recycling Used Automotive Oil Filters In A Blast Furnace

    SciTech Connect (OSTI)

    Ralph M. Smailer; Gregory L. Dressel; Jennifer Hsu Hill

    2002-01-21

    This feasibility study has indicated that of the approximately 120,000 tons of steel available to be recycled from used oil filters (UOF's), a maximum blast furnace charge of 2% of the burden may be anticipated for short term use of a few months. The oil contained in the most readily processed UOF's being properly hot drained and crushed is approximately 12% to 14% by weight. This oil will be pyrolized at a rate of 98% resulting in additional fuel gas of 68% and a condensable hydrocarbon fraction of 30%, with the remaining 2% resulting as carbon being added into the burden. Based upon the writer's collected information and assessment, there appears to be no operational problems relating to the recycling of UOF's to the blast furnace. One steel plant in the US has been routinely charging UOF's at about 100 tons to 200 tons per month for many years. Extensive analysis and calculations appear to indicate no toxic consideration as a result of the pyrolysis of the small contained oil ( in the 'prepared' UOFs) within the blast furnace. However, a hydrocarbon condensate in the ''gasoline'' fraction will condense in the blast furnace scrubber water and may require additional processing the water treatment system to remove benzene and toluene from the condensate. Used oil filters represent an additional source of high quality iron units that may be effectively added to the charge of a blast furnace for beneficial value to the operator and to the removal of this resource from landfills.

  19. Electrolytes for power sources

    DOE Patents [OSTI]

    Doddapaneni, Narayan; Ingersoll, David

    1995-01-01

    Electrolytes for power sources, particularly alkaline and acidic power sources, comprising benzene polysulfonic acids and benzene polyphosphonic acids or salts of such acids.

  20. Electrolytes for power sources

    DOE Patents [OSTI]

    Doddapaneni, N.; Ingersoll, D.

    1995-01-03

    Electrolytes are disclosed for power sources, particularly alkaline and acidic power sources, comprising benzene polysulfonic acids and benzene polyphosphonic acids or salts of such acids. 7 figures.

  1. Synthesis of the Stereoisomeric Clusters 1,2-Os3(CO)10(trans-dpmn) and 1,2-Os3(CO)10(cis-dpmn) [where dpmn = 2,3-bis(diphenylphosphinomethyl)-5-norbornene]: DFT Evaluation of the Isomeric Clusters 1,2-Os3(CO)10(dpmn) and Isomer-Dependent Diphosphine Ligand Activation

    SciTech Connect (OSTI)

    Yang, Li; Nesterov, Vladimir N.; Wang, Xiaoping; Richmond, Michael G.

    2014-07-23

    The bicyclic diphosphines trans- and cis-2,3-bis(diphenylphosphinomethyl)-5-norbornene (dpmn) react with 1,2-Os3(CO)10(MeCN)2 (1) to furnish the corresponding ligand-bridged clusters Os3(CO)10(trans-dpmn) (2) and Os3(CO)10(cis-dpmn) (3). Both new products have been isolated and the molecular structures established by X-ray diffraction analyses. The dihydroxyl-bridged cluster 1,2-Os3(CO)8(μ-OH)2(cis-dpmn) (4), which accompanied the formation of 3 in one reaction, has been isolated and characterized by mass spectrometry and X-ray crystallography. Whereas cluster 2 is stable in toluene at 373 K, 3 is thermally sensitive under identical conditions and undergoes loss of CO (2 equiv), coupled with the activation of three norbornene C-H bonds and one P-C(phenyl) bond, to furnish the dihydride cluster H2Os3(CO)83-2-PhPC-3-endo-Ph2PCH2(C7H7)] (5). The solid-state structure of 5 confirms the multiple activation of the cis-dpmn ligand and accompanying formation of the face-capping 2-PhPC-3-endo-Ph2PCH2(C7H7) moiety in the product. DFT calculations on 2 and 3 indicate that the former cluster is the thermodynamically more stable isomer, and the conversion of 3→ 5 + 2CO + benzene is computed to be exergonic by 12.7 kcal/mol and is entropically favored due to the release of the CO and benzene by-products.

  2. Rapid microwave hydrothermal synthesis of ZnGa{sub 2}O{sub 4} with high photocatalytic activity toward aromatic compounds in air and dyes in liquid water

    SciTech Connect (OSTI)

    Sun Meng; Li Danzhen; Zhang Wenjuan; Chen Zhixin; Huang Hanjie; Li Wenjuan; He Yunhui; Fu Xianzhi

    2012-06-15

    ZnGa{sub 2}O{sub 4} was synthesized from Ga(NO{sub 3}){sub 3} and ZnCl{sub 2} via a rapid and facile microwave-assisted hydrothermal method. The photocatalytic properties of the as-prepared ZnGa{sub 2}O{sub 4} were evaluated by the degradation of pollutants in air and aqueous solution under ultraviolet (UV) light illumination. The results demonstrated that ZnGa{sub 2}O{sub 4} had exhibited efficient photocatalytic activities higher than that of commercial P25 (Degussa Co.) in the degradation of benzene, toluene, and ethylbenzene, respectively. In the liquid phase degradation of dyes (methyl orange, Rhodamine B, and methylene blue), ZnGa{sub 2}O{sub 4} has also exhibited remarkable activities higher than that of P25. After 32 min of UV light irradiation, the decomposition ratio of methyl orange (10 ppm, 150 mL) over ZnGa{sub 2}O{sub 4} (0.06 g) was up to 99%. The TOC tests revealed that the mineralization ratio of MO (10 ppm, 150 mL) was 88.1% after 90 min of reaction. A possible mechanism of the photocatalysis over ZnGa{sub 2}O{sub 4} was also proposed. - Graphical abstract: In the degradation of RhB under UV light irradiation, ZnGa{sub 2}O{sub 4} had exhibited efficient photo-activity, and after only 24 min of irradiation the decomposition ratio was up to 99.8%. Highlights: Black-Right-Pointing-Pointer A rapid and facile M-H method to synthesize ZnGa{sub 2}O{sub 4} photocatalyst. Black-Right-Pointing-Pointer The photocatalyst exhibits high activity toward benzene and dyes. Black-Right-Pointing-Pointer The catalyst possesses more surface hydroxyl sites than TiO{sub 2} (P25). Black-Right-Pointing-Pointer Deep oxidation of different aromatic compounds and dyes over catalyst.

  3. SALTSTONE VAULT CLASSIFICATION SAMPLES MODULAR CAUSTIC SIDE SOLVENT EXTRACTION UNIT/ACTINIDE REMOVAL PROCESS WASTE STREAM APRIL 2011

    SciTech Connect (OSTI)

    Eibling, R.

    2011-09-28

    Savannah River National Laboratory (SRNL) was asked to prepare saltstone from samples of Tank 50H obtained by SRNL on April 5, 2011 (Tank 50H sampling occurred on April 4, 2011) during 2QCY11 to determine the non-hazardous nature of the grout and for additional vault classification analyses. The samples were cured and shipped to Babcock & Wilcox Technical Services Group-Radioisotope and Analytical Chemistry Laboratory (B&W TSG-RACL) to perform the Toxic Characteristic Leaching Procedure (TCLP) and subsequent extract analysis on saltstone samples for the analytes required for the quarterly analysis saltstone sample. In addition to the eight toxic metals - arsenic, barium, cadmium, chromium, mercury, lead, selenium and silver - analytes included the underlying hazardous constituents (UHC) antimony, beryllium, nickel, and thallium which could not be eliminated from analysis by process knowledge. Additional inorganic species determined by B&W TSG-RACL include aluminum, boron, chloride, cobalt, copper, fluoride, iron, lithium, manganese, molybdenum, nitrate/nitrite as Nitrogen, strontium, sulfate, uranium, and zinc and the following radionuclides: gross alpha, gross beta/gamma, 3H, 60Co, 90Sr, 99Tc, 106Ru, 106Rh, 125Sb, 137Cs, 137mBa, 154Eu, 238Pu, 239/240Pu, 241Pu, 241Am, 242Cm, and 243/244Cm. B&W TSG-RACL provided subsamples to GEL Laboratories, LLC for analysis for the VOCs benzene, toluene, and 1-butanol. GEL also determines phenol (total) and the following radionuclides: 147Pm, 226Ra and 228Ra. Preparation of the 2QCY11 saltstone samples for the quarterly analysis and for vault classification purposes and the subsequent TCLP analyses of these samples showed that: (1) The saltstone waste form disposed of in the Saltstone Disposal Facility in 2QCY11 was not characteristically hazardous for toxicity. (2) The concentrations of the eight RCRA metals and UHCs identified as possible in the saltstone waste form were present at levels below the UTS. (3) Most of the

  4. TREATMENT OF PRODUCED OIL AND GAS WATERS WITH SURFACTANT-MODIFIED ZEOLITE

    SciTech Connect (OSTI)

    Lynn E. Katz; R.S. Bowman; E.J. Sullivan

    2003-11-01

    Co-produced water from the oil and gas industry accounts for a significant waste stream in the United States. It is by some estimates the largest single waste stream in the country, aside from nonhazardous industrial wastes. Characteristics of produced water include high total dissolved solids content, dissolved organic constituents such as benzene and toluene, an oil and grease component, and chemicals added during the oil-production process. While most of the produced water is disposed via reinjection, some must be treated to remove organic constituents before the water is discharged. Current treatment options are successful in reducing the organic content; however, they cannot always meet the levels of current or proposed regulations for discharged water. Therefore, an efficient, cost-effective treatment technology is needed. Surfactant-modified zeolite (SMZ) has been used successfully to treat contaminated ground water for organic and inorganic constituents. In addition, the low cost of natural zeolites makes their use attractive in water-treatment applications. This report summarizes the work and results of this four-year project. We tested the effectiveness of surfactant-modified zeolite (SMZ) for removal of BTEX with batch and column experiments using waters with BTEX concentrations that are comparable to those of produced waters. The data from our experimental investigations showed that BTEX sorption to SMZ can be described by a linear isotherm model, and competitive effects between compounds were not significant. The SMZ can be readily regenerated using air stripping. We field-tested a prototype SMZ-based water treatment system at produced water treatment facilities and found that the SMZ successfully removes BTEX from produced waters as predicted by laboratory studies. When compared to other existing treatment technologies, the cost of the SMZ system is very competitive. Furthermore, the SMZ system is relatively compact, does not require the storage of

  5. Synthesis metal nanoparticle

    DOE Patents [OSTI]

    Bunge, Scott D.; Boyle, Timothy J.

    2005-08-16

    A method for providing an anhydrous route for the synthesis of amine capped coinage-metal (copper, silver, and gold) nanoparticles (NPs) using the coinage-metal mesityl (mesityl=C.sub.6 H.sub.2 (CH.sub.3).sub.3 -2,4,6) derivatives. In this method, a solution of (Cu(C.sub.6 H.sub.2 (CH.sub.3).sub.3).sub.5, (Ag(C.sub.6 H.sub.2 (CH.sub.3).sub.3).sub.4, or (Au(C.sub.6 H.sub.2 (CH.sub.3).sub.3).sub.5 is dissolved in a coordinating solvent, such as a primary, secondary, or tertiary amine; primary, secondary, or tertiary phosphine, or alkyl thiol, to produce a mesityl precursor solution. This solution is subsequently injected into an organic solvent that is heated to a temperature greater than approximately 100.degree. C. After washing with an organic solvent, such as an alcohol (including methanol, ethanol, propanol, and higher molecular-weight alcohols), oxide free coinage NP are prepared that could be extracted with a solvent, such as an aromatic solvent (including, for example, toluene, benzene, and pyridine) or an alkane (including, for example, pentane, hexane, and heptane). Characterization by UV-Vis spectroscopy and transmission electron microscopy showed that the NPs were approximately 9.2.+-.2.3 nm in size for Cu.degree., (no surface oxide present), approximately 8.5.+-.1.1 nm Ag.degree. spheres, and approximately 8-80 nm for Au.degree..

  6. Remediation of a Classified Waste Landfill at Sandia National Laboratories, NM

    SciTech Connect (OSTI)

    Ward, D.C.

    1998-10-20

    The Sandia National Laboratory es/New Mexico (SNLiNM) Environmental Restoration Project is currently excavating the Classified Waste Landfill in Technical Area II (TA-H), which consists of disposal pits and trenches with discrete disposal cells. TA-11 is a secure, controlled assess, research facility managed by SNIJNM for the US Department of Energy (DOE). The 45-acre facility was established in 1948 for the assembly and maintenance of nuclear weapons. The assembly of weapons was discontinued in 1954. Since that time, TA-11 has been used primarily for explosive research and testing. Beginning is 1984, the DOE Er,vironmental Restoration Program conducted several environmental investigations across TA-11 and SNMNM. These investigations identified sites requiring firther study and possible corrective action. The majority of these sites were grouped into operable units (OUS). The TA-11 OU included 13 sites, one of which is identified as the Classified Waste Landfill (CWLF). The CWLF covers about 2.5 acres and was operated from approximately 1947 through 1987. It was the site for disposal of classified weapon components, s ome of which are potentially explosive, hazardous, ardor radioactively contarninatod. Until about 1958, no records were maintained for material disposed of in the CWLF. Information on the CWLF has been assembled horn interview notes, delivery to reckmation records and other sources. Items disposed of included security containers, hoppers, skids, missiles, wooden boxes, deactivated heat sources, tntium boosters, scintillation cocktails, weapons cases, shells, lasers, radar equipment and accountable mata-ials. Potential contaminants include tritium, thorium, cesium-137, strontium-90, uraniun, plutonium, beryllium, cadmium, lithium, chloroform, toluene, benzene ad other solvents.

  7. Non-Aqueous Phase Liquid Calculator

    Energy Science and Technology Software Center (OSTI)

    2004-02-19

    Non-Aqueous Phase Liquid or "NPAL" is a term that most environmental professionals are familiar with because NAPL has been recognized in the literature as a significant source of groundwater contamination. There are two types of NAPL: DNAPL and LNAPL. DNAPL is a ‘dense’ non-aqueous phase liquid. In this context, dense means having a density greater than water (1.0 kg/L). Trichloroethylene (TCE) and tetrachioroethylene (PCE) are examples of DNAPL compounds. A compound that is heaver thanmore » water means this type of NAPL will sink in an aquifer. Conversely, LNAPL is a ‘light’ non-aqueous phase liquid with a density less than water, and will float on top of the aquifer. Examples of LNAPL’s are benzene and toluene. LNAPL or DNAPL often manifest as a complex, multi-component mixture of organic compounds that can occur in environmental media. Complex multi-component mixtures distributed in soil pore-air, pore-water, soil particles and in free phase complicate residual saturation of single and multi component NAPL compounds in soil samples. The model output also includes estimates of the NAPL mass and volume and other physical and chemical properties that may be useful for characterization, modeling, and remedial system design and operation. The discovery of NAPL in the aquifer usually leads to a focused characterization for possible sources of NAPL in the vadose zone using a variety of innovative technologies and characterization methods. Often, the analytical data will indicated the presence of NAPL, yet, the NAPL will go unrecognized. Failure to recognize the NAPL can be attributed to the complicated processes of inter-media transfer or a general lack of knowledge about the physical characteristics of complex organic mixtures in environmental samples.« less

  8. Compounds for neutron radiation detectors and systems thereof

    DOE Patents [OSTI]

    Payne, Stephen A; Stoeffl, Wolfgang; Zaitseva, Natalia P; Cherepy, Nerine J; Carman, M. Leslie

    2014-05-27

    A material according to one embodiment exhibits an optical response signature for neutrons that is different than an optical response signature for gamma rays, said material exhibiting performance comparable to or superior to stilbene in terms of distinguishing neutrons from gamma rays, wherein the material is not stilbene, the material comprising a molecule selected from a group consisting of: two or more benzene rings, one or more benzene rings with a carboxylic acid group, one or more benzene rings with at least one double bound adjacent to said benzene ring, and one or more benzene rings for which at least one atom in the benzene ring is not carbon.

  9. Understanding and predicting soot generation in turbulent non-premixed jet flames.

    SciTech Connect (OSTI)

    Wang, Hai; Kook, Sanghoon; Doom, Jeffrey; Oefelein, Joseph Charles; Zhang, Jiayao; Shaddix, Christopher R.; Schefer, Robert W.; Pickett, Lyle M.

    2010-10-01

    This report documents the results of a project funded by DoD's Strategic Environmental Research and Development Program (SERDP) on the science behind development of predictive models for soot emission from gas turbine engines. Measurements of soot formation were performed in laminar flat premixed flames and turbulent non-premixed jet flames at 1 atm pressure and in turbulent liquid spray flames under representative conditions for takeoff in a gas turbine engine. The laminar flames and open jet flames used both ethylene and a prevaporized JP-8 surrogate fuel composed of n-dodecane and m-xylene. The pressurized turbulent jet flame measurements used the JP-8 surrogate fuel and compared its combustion and sooting characteristics to a world-average JP-8 fuel sample. The pressurized jet flame measurements demonstrated that the surrogate was representative of JP-8, with a somewhat higher tendency to soot formation. The premixed flame measurements revealed that flame temperature has a strong impact on the rate of soot nucleation and particle coagulation, but little sensitivity in the overall trends was found with different fuels. An extensive array of non-intrusive optical and laser-based measurements was performed in turbulent non-premixed jet flames established on specially designed piloted burners. Soot concentration data was collected throughout the flames, together with instantaneous images showing the relationship between soot and the OH radical and soot and PAH. A detailed chemical kinetic mechanism for ethylene combustion, including fuel-rich chemistry and benzene formation steps, was compiled, validated, and reduced. The reduced ethylene mechanism was incorporated into a high-fidelity LES code, together with a moment-based soot model and models for thermal radiation, to evaluate the ability of the chemistry and soot models to predict soot formation in the jet diffusion flame. The LES results highlight the importance of including an optically-thick radiation model

  10. CX-009107: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Xylene Measurement for Saltstone Antifoams CX(s) Applied: B3.6 Date: 08/27/2012 Location(s): South Carolina Offices(s): Savannah River Operations Office

  11. Method for making thin polypropylene film

    DOE Patents [OSTI]

    Behymer, R.D.; Scholten, J.A.

    1985-11-21

    An economical method is provided for making uniform thickness polypropylene film as thin as 100 Angstroms. A solution of polypropylene dissolved in xylene is formed by mixing granular polypropylene and xylene together in a flask at an elevated temperature. A substrate, such as a glass plate or microscope slide is immersed in the solution. When the glass plate is withdrawn from the solution at a uniform rate, a thin polypropylene film forms on a flat surface area of the glass plate as the result of xylene evaporation. The actual thickness of the polypropylene film is functional of the polypropylene in xylene solution concentration, and the particular withdrawal rate of the glass plate from the solution. After formation, the thin polypropylene film is floated from the glass plate onto the surface of water, from which it is picked up with a wire hoop.

  12. University of Delaware | CCEI Patents

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Patents and Patent Applications Production of Para-xylene by Catalytically Reacting 2,5-Dimethylfuran and Ethylene in a Solvent Dauenhauer, P. J.; Williams, C. L.; Vlachos, D. G.; ...

  13. Slide 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lewis acid zeolites (Zr-, Sn- and Ti-BEA) were developed for tandem Diels-Alder cycloaddition and dehydration of 2,5-dimethylfuran (DMF) and ethylene to p-xylene achieving the highest selectivity of 80% at 99% conversion of DMF, with improved recalcitrance to deactivation. Lewis Acid Zeolites for Production of Biorenewable p-xylene Work performed in CCEI at the Universities of Massachusetts, Minnesota and Pennsylvania CATALYSIS CENTER FOR ENERGY INNOVATION - http://www.efrc.udel.edu/ Research

  14. "Title","Creator/Author","Publication Date","OSTI Identifier...

    Office of Scientific and Technical Information (OSTI)

    BENZENE; LEUKEMOGENESIS; GEOTHERMAL INDUSTRY; ENVIRONMENTAL IMPACTS; HEALTH HAZARDS; HYDROGEN SULFIDES; BIOLOGICAL EFFECTS; MERCURY; RADON; SULFATES; ACCIDENTS; AIR POLLUTION;...

  15. TITLE AUTHORS SUBJECT SUBJECT RELATED DESCRIPTION PUBLISHER AVAILABILI...

    Office of Scientific and Technical Information (OSTI)

    BENZENE LEUKEMOGENESIS GEOTHERMAL INDUSTRY ENVIRONMENTAL IMPACTS HEALTH HAZARDS HYDROGEN SULFIDES BIOLOGICAL EFFECTS MERCURY RADON SULFATES ACCIDENTS AIR POLLUTION...

  16. Layton, D.W.; Anspaugh, L.R.; O'Banion, K.D. 15 GEOTHERMAL ENERGY...

    Office of Scientific and Technical Information (OSTI)

    BENZENE; LEUKEMOGENESIS; GEOTHERMAL INDUSTRY; ENVIRONMENTAL IMPACTS; HEALTH HAZARDS; HYDROGEN SULFIDES; BIOLOGICAL EFFECTS; MERCURY; RADON; SULFATES; ACCIDENTS; AIR POLLUTION;...

  17. Poly(ethylene oxide) functionalization (Patent) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    The polymer is dissolved in warmed toluene, treated with an excess of organic base and ... This procedure enables functionalization of the polymer while not requiring laborious ...

  18. DE-FE0000833

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Toluene 56. Diesel Range Organic C10-C28 57. Ethane 58. Formaldehyde 59. Methane 60. Methanol 61. Alkalinity, Carbonate 62. Alkalinity, Hydroxide 63. Alkalinity, Phenolphthalein...

  19. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    States) Fernald Environmental Management Project, OH (United States) FluxNet General ... backbone was varied from 8 to 85. The global conformation of the polymers in toluene ...

  20. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... less Full Text Available April 2008 , Health Physics http:www.ncbi.nlm.nih.govpubmed18332729 Evaluation of a Polyvinyl Toluene Neutron Counter Array Robert Hayes The ...

  1. Preliminary Evaluation of a Portable Handheld Combined Gamma...

    Office of Scientific and Technical Information (OSTI)

    Experimental procedures: Monte Carlo N-Particle (MCNP) analysis on a compact array of borated polyvinyl toluene light pipes and photomultiplier tubes, standard spectral ...

  2. Direct Push Groundwater Circulation Wells for Remediation of BTEX and Volatile Organics

    SciTech Connect (OSTI)

    Borden, R. E.; Cherry, Robert Stephen

    2000-09-01

    Direct push groundwater circulation wells (DP-GCW) are a promising technology for remediation of groundwater contaminated with dissolved hydrocarbons and chlorinated solvents. In these wells, groundwater is withdrawn from the formation at the bottom of the well, aerated and vapor stripped and injected back into the formation at or above the water table. Previous field studies have shown that: (a) GCWs can circulate significant volumes of groundwater; and (b) GCWs can effectively remove volatile compounds and add oxygen. In this work, we describe the development and field-testing of a system of DP-GCWs for remediation of volatile organics such as benzene, toluene, ethylbenzene, and toluene (BTEX). The GCWs were constructed with No. 20 slotted well screen (2.4 cm ID) and natural sand pack extending from 1.5 to 8.2 m below grade. Air is introduced ~7.5 m below grade via 0.6 cm tubing. Approximately 15% of the vertical length of the air supply tubing is wrapped in tangled mesh polypropylene geonet drainage fabric to provide surface area for biological growth and precipitation of oxidized iron. These materials were selected to allow rapid installation of the GCWs using 3.8 cm direct push Geoprobe® rods, greatly reducing well installation costs. Laboratory testing of these sparged wells and computational fluid dynamics (CFD) modeling showed that these wells, although they used only about 1 L/min of air, could circulate about 1 L/min of water through the surrounding aquifer. This flow was sufficient to capture all of a flowing contaminant if the wells are sufficiently closely together, about 1 meter on center depending on the air flow rate supplied, in a line across the plume. The CFD work showed the details of this ability to capture, and also showed that unforeseen heterogeneities in the aquifer such as a gradient of permeability or a thin impermeable layer (such as a clay layer) did not prevent the system from working largely as intended. The system was tested in a

  3. Direct Push Groundwater Circulation Wells for Remediation of BTEX and Volatile Organics

    SciTech Connect (OSTI)

    Borden, R.C.; Cherry, R.S.

    2000-09-30

    Direct push groundwater circulation wells (DP-GCW) are a promising technology for remediation of groundwater contaminated with dissolved hydrocarbons and chlorinated solvents. In these wells, groundwater is withdrawn from the formation at the bottom of the well, aerated and vapor stripped and injected back into the formation at or above the water table. Previous field studies have shown that: (a) GCWs can circulate significant volumes of groundwater; and (b) GCWs can effectively remove volatile compounds and add oxygen. In this work, we describe the development and field-testing of a system of DP-GCWs for remediation of volatile organics such as benzene, toluene, ethylbenzene, and toluene (BTEX). The GCWs were constructed with No. 20 slotted well screen (2.4 cm ID) and natural sand pack extending from 1.5 to 8.2 m below grade. Air is introduced {approximately}7.5 m below grade via 0.6 cm tubing. Approximately 15% of the vertical length of the air supply tubing is wrapped in tangled mesh polypropylene geonet drainage fabric to provide surface area for biological growth and precipitation of oxidized iron. These materials were selected to allow rapid installation of the GCWs using 3.8 cm direct push Geoprobe{reg_sign} rods, greatly reducing well installation costs. Laboratory testing of these sparged wells and computational fluid dynamics (CFD) modeling showed that these wells, although they used only about 1 L/min of air, could circulate about 1 L/min of water through the surrounding aquifer. This flow was sufficient to capture all of a flowing contaminant if the wells are sufficiently closely together, about 1 meter on center depending on the air flow rate supplied, in a line across the plume. The CFD work showed the details of this ability to capture, and also showed that unforeseen heterogeneities in the aquifer such as a gradient of permeability or a thin impermeable layer (such as a clay layer) did not prevent the system from working largely as intended. The

  4. Control of Substrate Access to the Active Site and Catalytic Mechanism of

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Methane and Toluene Monooxygenases | Stanford Synchrotron Radiation Lightsource Control of Substrate Access to the Active Site and Catalytic Mechanism of Methane and Toluene Monooxygenases Friday, June 22, 2012 - 3:30pm SSRL Main Conference Room 137-322 Prof. Stephen J. Lippard (MIT):

  5. A novel technique for measurement of thermal rate constants and temperature dependences of dissociative recombination: CO{sub 2}{sup +}, CF{sub 3}{sup +}, N{sub 2}O{sup +}, C{sub 7}H{sub 8}{sup +}, C{sub 7}H{sub 7}{sup +}, C{sub 6}H{sub 6}{sup +}, C{sub 6}H{sub 5}{sup +}, C{sub 5}H{sub 6}{sup +}, C{sub 4}H{sub 4}{sup +}, and C{sub 3}H{sub 3}{sup +}

    SciTech Connect (OSTI)

    Fournier, Joseph A.; Shuman, Nicholas S.; Melko, Joshua J.; Ard, Shaun G.; Viggiano, Albert A.

    2013-04-21

    A novel technique using a flowing afterglow-Langmuir probe apparatus for measurement of temperature dependences of rate constants for dissociative recombination (DR) is presented. Low ({approx}10{sup 11} cm{sup -3}) concentrations of a neutral precursor are added to a noble gas/electron afterglow plasma thermalized at 300-500 K. Charge exchange yields one or many cation species, each of which may undergo DR. Relative ion concentrations are monitored at a fixed reaction time while the initial plasma density is varied between 10{sup 9} and 10{sup 10} cm{sup -3}. Modeling of the decrease in concentration of each cation relative to the non-recombining noble gas cation yields the rate constant for DR. The technique is applied to several species (O{sub 2}{sup +}, CO{sub 2}{sup +}, CF{sub 3}{sup +}, N{sub 2}O{sup +}) with previously determined 300 K values, showing excellent agreement. The measurements of those species are extended to 500 K, with good agreement to literature values where they exist. Measurements are also made for a range of C{sub n}H{sub m}{sup +} (C{sub 7}H{sub 7}{sup +}, C{sub 7}H{sub 8}{sup +}, C{sub 5}H{sub 6}{sup +}, C{sub 4}H{sub 4}{sup +}, C{sub 6}H{sub 5}{sup +}, C{sub 3}H{sub 3}{sup +}, and C{sub 6}H{sub 6}{sup +}) derived from benzene and toluene neutral precursors. C{sub n}H{sub m}{sup +} DR rate constants vary from 8-12 Multiplication-Sign 10{sup -7} cm{sup 3} s{sup -1} at 300 K with temperature dependences of approximately T{sup -0.7}. Where prior measurements exist these results are in agreement, with the exception of C{sub 3}H{sub 3}{sup +} where the present results disagree with a previously reported flat temperature dependence.

  6. Study of the VOC emissions from a municipal solid waste storage pilot-scale cell: Comparison with biogases from municipal waste landfill site

    SciTech Connect (OSTI)

    Chiriac, R.; De Araujos Morais, J.; Carre, J.; Bayard, R.; Chovelon, J.M.; Gourdon, R.

    2011-11-15

    Highlights: > Follow-up of the emission of VOCs in a municipal waste pilot-scale cell during the acidogenesis and acetogenesis phases. > Study from the very start of waste storage leading to a better understanding of the decomposition/degradation of waste. > Comparison of the results obtained on the pilot-scale cell with those from 3 biogases coming from the same landfill site. > A methodology of characterization for the progression of the stabilization/maturation of waste is finally proposed. - Abstract: The emission of volatile organic compounds (VOCs) from municipal solid waste stored in a pilot-scale cell containing 6.4 tonnes of waste (storage facility which is left open during the first period (40 days) and then closed with recirculation of leachates during a second period (100 days)) was followed by dynamic sampling on activated carbon and analysed by GC-MS after solvent extraction. This was done in order to know the VOC emissions before the installation of a methanogenesis process for the entire waste mass. The results, expressed in reference to toluene, were exploited during the whole study on all the analyzable VOCs: alcohols, ketones and esters, alkanes, benzenic and cyclic compounds, chlorinated compounds, terpene, and organic sulphides. The results of this study on the pilot-scale cell are then compared with those concerning three biogases from a municipal waste landfill: biogas (1) coming from waste cells being filled or recently closed, biogas (2) from all the waste storage cells on site, and biogas (3) which is a residual gas from old storage cells without aspiration of the gas. The analysis of the results obtained revealed: (i) a high emission of VOCs, principally alcohols, ketones and esters during the acidogenesis; (ii) a decrease in the alkane content and an increase in the terpene content were observed in the VOCs emitted during the production of methane; (iii) the production of heavier alkanes and an increase in the average number of carbon

  7. TREATMENT OF PRODUCED WATERS USING A SURFACTANT MODIFIED ZEOLITE/VAPOR PHASE BIOREATOR SYSTEM

    SciTech Connect (OSTI)

    LYNN E. KATZ; KERRY A. KINNEY; R.S. BOWMAN; E.J. SULLIVAN

    2003-10-01

    Co-produced water from the oil and gas industry is by some estimates the largest single waste stream in the country, aside from nonhazardous industrial wastes. Characteristics of produced water include high total dissolved solids content, dissolved organic constituents such as benzene and toluene, an oil and grease component, and chemicals added during the oil-production process. While most of the produced water is disposed via reinjection, some of them must be treated to remove organic constituents before the water is discharged. An efficient, cost-effective treatment technology is needed to remove these constituents. Surfactant-modified zeolite (SMZ) has been used successfully to treat contaminated ground water for organic and inorganic constituents. In addition, the low cost of natural zeolites makes their use attractive in water-treatment applications. Our previous DOE research work (DE-AC26-99BC15221) demonstrated that SMZ could successfully remove BTEX compounds from the produced water. In addition, SMZ could be regenerated through a simple air sparging process. The primary goal of this project is to develop a robust SMZ/VPB treatment system to efficiently remove the organic constituents from produced water in a cost-effective manner. This report summarizes work of this project from March 2003 through September 2003. We have continued our investigation of SMZ regeneration from our previous DOE project. Ten saturation/stripping cycles have been completed for SMZ columns saturated with BTEX compounds. The results suggest that BTEX sorption capacity is not lost after ten saturation/regeneration cycles. The composition of produced water from a site operated by Crystal Solutions Ltd. in Wyoming has been characterized and was used to identify key semi-volatile components. Isotherms with selected semi-volatile components have been initiated and preliminary results have been obtained. The experimental vapor phase bioreactors for this project have been designed and

  8. ENZYME ACTIVITY PROBE AND GEOCHEMICAL ASSESSMENT FOR POTENTIAL AEROBIC COMETABOLISM OF TRICHLOROETHENE IN GROUNDWATER OF THE NORTHWEST PLUME, PADUCAH GASEOUS DIFFUSION PLANT, KENTUCKY

    SciTech Connect (OSTI)

    Looney, B; M. Hope Lee, M; S. K. Hampson, S

    2008-06-27

    The overarching objective of the Paducah Gaseous Diffusion Plant (PGDP) enzyme activity probe (EAP) effort is to determine if aerobic cometabolism is contributing to the attenuation of trichloroethene (TCE) and other chlorinated solvents in the contaminated groundwater beneath PGDP. The site-specific objective for the EAP assessment is to identify if key metabolic pathways are present and expressed in the microbial community--namely the pathways that are responsible for degradation of methane and aromatic (e.g. toluene, benzene, phenol) substrates. The enzymes produced to degrade methane and aromatic compounds also break down TCE through a process known as cometabolism. EAPs directly measure if methane and/or aromatic enzyme production pathways are operating and, for the aromatic pathways, provide an estimate of the number of active organisms in the sampled groundwater. This study in the groundwater plumes at PGDP is a major part of a larger scientific effort being conducted by Interstate Technology and Regulatory Council (ITRC), U.S. Department of Energy (DOE) Office of Environmental Management (EM), Savannah River National Laboratory (SRNL), and North Wind Inc. in which EAPs are being applied to contaminated groundwater from diverse hydrogeologic and plume settings throughout the U.S. to help standardize their application as well as their interpretation. While EAP data provide key information to support the site specific objective for PGDP, several additional lines of evidence are being evaluated to increase confidence in the determination of the occurrence of biodegradation and the rate and sustainability of aerobic cometabolism. These complementary efforts include: (1) Examination of plume flowpaths and comparison of TCE behavior to 'conservative' tracers in the plume (e.g., {sup 99}Tc); (2) Evaluation of geochemical conditions throughout the plume; and (3) Evaluation of stable isotopes in the contaminants and their daughter products throughout the plume. If

  9. Ambient aromatic hydrocarbon measurements at Welgegund, South Africa

    SciTech Connect (OSTI)

    Jaars, K.; Beukes, J. P.; van Zyl, P. G.; Venter, A. D.; Josipovic, M.; Pienaar, J. J.; Vakkari, Ville; Aaltonen, H.; Laakso, H.; Kulmala, M.; Tiitta, P.; Guenther, Alex B.; Hellen, H.; Laakso, L.; Hakola, H.

    2014-07-11

    Aromatic hydrocarbons are associated with direct adverse human health effects and can have negative impacts on ecosystems due to their toxicity, as well as indirect negative effects through the formation of tropospheric ozone and secondary organic aerosol that affect human health, crop production and regional climate. Measurements were conducted at the Welgegund measurement station (South Africa) that is considered to be a regionally representative background site. However, the site is occasionally impacted by plumes from major anthropogenic source regions in the interior of South Africa, which include the western Bushveld Igneous Complex (e.g. platinum, base metal and ferrochrome smelters), the eastern Bushveld Igneous Complex (platinum and ferrochrome smelters), the Johannesburg-Pretoria metropolitan conurbation (>10 million people), the Vaal Triangle (e.g. petrochemical and industries), the Mpumalanga Highveld (e.g. coal-fired power plants and petrochemical industry) and also a region of anti-cyclonic recirculation of air mass over the interior of South Africa. The aromatic hydrocarbon measurements were conducted with an automated sampler on Tenax-TA and Carbopack-B adsorbent tubes with heated inlet for one year. Samples were collected twice a week for two hours during daytime and two hours 1 during night-time. A thermal desorption unit, connected to a gas chromatograph and a mass 2 selective detector was used for sample preparation and analysis. Results indicated that the 3 monthly median total aromatic hydrocarbon concentrations ranged between 0.01 to 3.1 ppb. 4 Benzene levels did not exceed local air quality standards. Toluene was the most abundant 5 species, with an annual median concentration of 0.63 ppb. No statistically significant 6 differences in the concentrations measured during daytime and night-time were found and no distinct seasonal patterns were observed. Air mass back trajectory analysis proved that the lack of seasonal cycles could be

  10. Process for the preparation of cumene

    DOE Patents [OSTI]

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1991-01-01

    Cumene is produced in a catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 50.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic by feeding propylene to the catalyst bed while benzene is conveniently added through the reflux to result in a molar excess present in the reactor to that required to react with propylene, thereby reacting substantially all of the propylene and recovering benzene as the principal overhead and cumene and diisopropyl benzene in the bottoms. The bottoms are fractionated, the cumene recovered and the bottoms are contacted with benzene in the liquid phase in a fixed bed straight pass reactor under conditions to transalkylate the benzene thereby converting most of the diisopropyl benzene to cumene which is again separated and recovered.

  11. Process for the preparation of cumene

    DOE Patents [OSTI]

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1991-10-08

    Cumene is produced in a catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 50 C to 500 C, using as the catalyst a molecular sieve characterized as acidic by feeding propylene to the catalyst bed while benzene is conveniently added through the reflux to result in a molar excess present in the reactor to that required to react with propylene, thereby reacting substantially all of the propylene and recovering benzene as the principal overhead and cumene and diisopropyl benzene in the bottoms. The bottoms are fractionated, the cumene recovered and the bottoms are contacted with benzene in the liquid phase in a fixed bed straight pass reactor under conditions to transalkylate the benzene thereby converting most of the diisopropyl benzene to cumene which is again separated and recovered. 2 figures.

  12. Assessment of Standard Force Field Models against High-Quality ab initio Potential Curves for Prototypes of pi-pi, CH/pi, and SH/pi Interactions

    SciTech Connect (OSTI)

    Sumpter, Bobby G; Sherrill, David; Sinnokrot, Mutasem O; Marshall, Michael S.; Hohenstein, Edward G.; Walker, Ross; Gould, Ian R

    2009-01-01

    Several popular force fields, namely, CHARMM, AMBER, OPLS-AA, and MM3, have been tested for their ability to reproduce highly accurate quantum mechani- cal potential energy curves for noncovalent interactions in the benzene dimer, the benzene-CH4 complex, and the benzene-H2S complex. All of the force fields are semi-quantitatively correct, but none of them is consistently reliable quantitatively. Re-optimization of Lennard-Jones parameters and symmetry-adapted perturbation theory analysis for the benzene dimer suggests that better agreement cannot be expected unless more flexible functional forms (particularly for the electrostatic contributions)are employed for the empirical force fields.

  13. December 4, 2013 | Center for Gas SeparationsRelevant to Clean...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Previous Next List Jon Witte (Dept. of Chemistry, UC Berkeley) The CO2-benzene Complex: a Case Study for Assessing the Performances of Electronic Structure Approximations for...

  14. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... USE YMP Yucca Mountain Site Characterization Office, Las Vegas, NV (United ... health effects (carbonyl, PAH, NPAH, benzene) as well as PM particle count and size distribution. ...

  15. PRODUCTION OF SLIP CAST CALCIA HOLLOWWARE

    DOE Patents [OSTI]

    Stoddard, S.D.; Nuckolls, D.E.; Cowan, R.E.

    1963-12-31

    A method for producing slip cast calcia hollow ware in which a dense calcia grain is suspended in isobutyl acetate or a mixture of tertiary amyl alcohol and o-xylene is presented. A minor amount of triethanolamine and oleic acid is added to the suspension vehicle as viscosity adjusting agents and the suspension is cast in a plaster mold, dried, and fired. (AEC)

  16. Composite Materials for Hazard Mitigation of Reactive Metal Hydrides.

    SciTech Connect (OSTI)

    Pratt, Joseph William; Cordaro, Joseph Gabriel; Sartor, George B.; Dedrick, Daniel E.; Reeder, Craig L.

    2012-02-01

    under simulated usage and accident conditions. Mitigating the hazards associated with reactive metal hydrides during an accident while finding a way to keep the original capability of the active material intact during normal use has been the focus of this work. These composites were made by polymerizing vinyl monomers using free-radical polymerization chemistry, in the presence of the metal hydride, in this case a prepared sodium alanate (chosen as a representative reactive metal hydride). It was found that the polymerization of styrene and divinyl benzene could be initiated using AIBN in toluene at 70 degC. The resulting composite materials can be either hard or brittle solids depending on the cross-linking density. Thermal decomposition of these styrene-based composite materials is lower than neat polystyrene indicating that the chemical nature of the polymer is affected by the formation of the composite. The char-forming nature of cross-linked polystyrene is low and therefore, not an ideal polymer for hazard mitigation. To obtain composite materials containing a polymer with higher char-forming potential, siloxane-based monomers were investigated. Four vinyl-containing siloxane oligomers were polymerized with and without added styrene and divinyl benzene. Like the styrene materials, these composite materials exhibited thermal decomposition behavior significantly different than the neat polymers. Specifically, the thermal decomposition temperature was shifted approximately 100 degC lower than the neat polymer signifying a major chemical change to the polymer network. Thermal analysis of the cycled samples was performed on the siloxane-based composite materials. It was found that after 30 cycles the siloxane-containing polymer composite material has similar TGA/DSC-MS traces as the virgin composite material indicating that the polymer is physically intact upon cycling. Hydrogen capacity measurements revealed that addition of the polymer to the metal hydride in the form

  17. Control of Substrate Access to the Active Site and Catalytic...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Control of Substrate Access to the Active Site and Catalytic Mechanism of Methane and Toluene Monooxygenases Friday, June 22, 2012 - 3:30pm SSRL Main Conference Room 137-322 Prof....

  18. Center for Nanophase Materials Sciences (CNMS) - CNMS User Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    polymers is in a partially collapsed state in D2O, whereas it expands in toluene and methanol. SANS data also suggest that the individual polymers assume the shape of a rigid...

  19. Method of making fine-grained triaminotrinitrobenzene

    DOE Patents [OSTI]

    Benziger, Theodore M.

    1984-01-01

    A method of forming a fine-grained species of the insensitive high explosive sym-triaminotrinitrobenzene (TATB) without grinding. In accordance with the method, 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB) is aminated by reaction with gaseous ammonia in an emulsion of toluene in water. The ratio of water to toluene in the emulsion is selected so that toluene is the dispersed phase in the emulsion. The size of the dispersed TCTNB-containing toluene droplets determines the particle size of the resulting TATB. The emulsion is preferably formed with an emulsifier such as ammonium oleate, which may be generated in situ from oleic acid, and stabilized with a protective colloid such as polyvinyl alcohol.

  20. Theoretical Study of the Mechanism Behind the para-Selective...

    Office of Scientific and Technical Information (OSTI)

    in Zeolite H-Beta Citation Details In-Document Search Title: Theoretical Study of the Mechanism Behind the para-Selective Nitration of Toluene in Zeolite H-Beta Periodic ...

  1. Method of making fine-grained triaminotrinitrobenzene

    DOE Patents [OSTI]

    Benziger, T.M.

    1983-07-26

    A method is given for forming a fine-grained species of the insensitive high explosive sym-triaminotrinitrobenzene (TATB) without grinding. In accordance with the method, 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB) is aminated by reaction with gaseous ammonia in an emulsion of toluene in water. The ratio of water to toluene in the emulsion is selected so that toluene is the dispersed phase in the emulsion. The size of the dispersed TCTNB-containing toluene droplets determines the particle size of the resulting TATB. The emulsion is preferably formed with an emulsifier such as ammonium oleate, which may be generated in situ from oleic acid, and stabilized with a protective colloid such as polyvinyl alcohol.

  2. Hydrocarbon Effect on a Fe-zeolite Urea-SCR Catalyst: An Experimental and Modeling Study

    SciTech Connect (OSTI)

    Devarakonda, Maruthi N.; Tonkyn, Russell G.; Herling, Darrell R.

    2010-04-14

    Synergies between various catalytic converters such as SCR and DPF are vital to the success of an integrated aftertreatment system for simultaneous NOx and particulate matter control in diesel engines. Several issues such as hydrocarbon poisoning, thermal aging and other coupled aftertreatment dynamics need to be addressed to develop an effective emission control system. This paper reports an experimental and modeling study to understand the effect of hydrocarbons on a Fe-zeolite urea-SCR bench reactor. Several bench-reactor tests to understand the inhibition of NOx oxidation, to characterize hydrocarbon storage and to investigate the impact of hydrocarbons on SCR reactions were conducted. Toluene was chosen as a representative hydrocarbon in diesel exhaust and various tests using toluene reveal its inhibition of NO oxidation at low temperatures and its oxidation to CO and CO2 at high temperatures. Surface isotherm tests were conducted to characterize the adsorption-desorption equilibrium of toluene through Langmuir isotherms. Using the rate parameters, a toluene storage model was developed and validated in simulation. With toluene in the stream, controlled SCR tests were run on the reactor and performance metrics such as NOx conversion and NH3 slip were compared to a set of previously run tests with no toluene in the stream. Tests indicate a significant effect of toluene on NOx and NH3 conversion efficiencies even at temperatures greater than 300oC. A kinetic model to address the toluene inhibition during NO oxidation reaction was developed and is reported in the paper. This work is significant especially in an integrated DPF-SCR aftertreatment scenario where the SCR catalyst on the filter substrate is exposed to un-burnt diesel hydrocarbons during active regeneration of the particulate filter.

  3. The use Na, Li, K cations for modification of ZSM-5 zewolite to control hydrocarbon cold-start emission

    SciTech Connect (OSTI)

    Golubeva V.; Rohatgi U.; Korableva, A.; Anischenko, O.; Kustov, L.; Nissenbaum, V; Viola, M.B.

    2012-08-29

    This paper addresses the problem of controlling hydrocarbon emissions from cold-start of engines by investigating the adsorbents which could adsorb the hydrocarbons at cold temperatures and hold them to 250-300 ?. The materials, that has been studied, are based on the modification of ZSM-5 (SiO{sub 2}/Al{sub 2}O{sub 3} = 35) zeolite with Li, K, Na cations. It has been shown that the introduction of Li, Na and K in an amount that is equivalent to the content of Al in zeolite results in occurrence of toluene temperature desorption peaks at high-temperatures. The toluene temperature desorption curves for 5%Li-ZSM-5 and 2.3%Na-ZSM-5 zeolites are identical and have peak toluene desorption rate between 200 to 400 ?. Upon analysis of toluene adsorption isotherms for 2.3%Na-ZSM-5 and 5%Li-ZSM-5, it was concluded that the toluene diffusion inside of the modified zeolites channels is extremely slow and the sorption capacity of 2.3%Na-ZSM-5 is higher than with 5%Li-ZSM-5. The 2.3%Na-ZSM-5 didn't change toluene temperature programmed desorption (TPD) rate of curve after the treatment in environment with 10% ?{sub 2}? at 750-800 ? for about 28 h. The 2.3%Na-ZSM-5 zeolite is very promising as adsorbent to control the cold-start hydrocarbon emissions.

  4. FY12 ARRA-NRAP Report – Studies to Support Risk Assessment of Geologic Carbon Sequestration

    SciTech Connect (OSTI)

    Cantrell, Kirk J.; Shao, Hongbo; Thompson, C. J.; Zhong, Lirong; Jung, Hun Bok; Um, Wooyong

    2011-09-27

    the scCO2 was released from the reactor, less than 60% of the injected lighter compounds (benzene, toluene) were transported through dry sand column by the CO2, while more than 90% of the heavier organics were trapped in the sand column. For wet sand columns, most (80% to 100%) of the organic compounds injected into the sand column passed through, except for naphthalene which was substantial removed from the CO2 within the column. A spectrophotometric method was developed to measure pH in brines in contact with scCO2. This method provides an alternative to fragile glass pH electrodes and thermodynamic modeling approaches for estimating pH. The method was tested in simulated reservoir fluids (CO2–NaCl–H2O) at different temperatures, pressures, and ionic strength, and the results were compared with other experimental studies and geochemical models. Measured pH values were generally in agreement with the models, but inconsistencies were present between some of the models.

  5. Use of Advanced Oxidation and Aerobic Degradation for Remediation of Various Hydrocarbon Contaminates

    SciTech Connect (OSTI)

    Paul Fallgren

    2009-03-06

    Western Research Institute in conjunction with Sierra West Consultants, Inc., Tetra Tech, Inc., and the U.S. Department of Energy conducted laboratory and field studies to test different approaches to enhance degradation of hydrocarbons and associated contaminants. WRI in conjunction with Sierra West Consultants, Inc., conducted a laboratory and field study for using ozone to treat a site contaminated with MTBE and other hydrocarbons. Results from this study demonstrate that a TOD test can be used to resolve the O{sub 3} dosage problem by establishing a site-specific benchmark dosage for field ozone applications. The follow-up testing of the laboratory samples provided indications that intrinsic biodegradation could be stimulated by adding oxygen. Laboratory studies also suggests that O3 dosage in the full-scale field implementation could be dialed lower than stoichiometrically designed to eliminate the formation of Cr(VI). WRI conducted a study involving a series of different ISCO oxidant applications to diesel-contaminated soil and determined the effects on enhancing biodegradation to degrade the residual hydrocarbons. Soils treated with permanganate followed by nutrients and with persulfate followed by nutrients resulted in the largest decrease in TPH. The possible intermediates and conditions formed from NOM and TPH oxidation by permanganate and activated persulfate favors microbial TPH degrading activity. A 'passive-oxidation' method using microbial fuel cell (MFC) technology was conducted by WRI in conjunction with Tetra Tech, Inc., to degrade MTBE in groundwater. These experiments have demonstrated that a working MFC (i.e., one generating power) could be established in the laboratory using contaminated site water or buffered media inoculated with site water and spiked with MTBE, benzene, or toluene. Electrochemical methods were studied by WRI with goal of utilizing low voltage and amperage electrical sources for 'geo-oxidation' of organic contaminants. The

  6. Numerical study of the effect of oxygenated blending compounds on soot formation in shock tubes

    SciTech Connect (OSTI)

    Boehm, H.; Braun-Unkhoff, M.

    2008-04-15

    This numerical study deals with the influence of blends on the amount of soot formed in shock tubes, which were simulated by assuming a homogeneous plug flow reactor model. For this purpose, first, the reaction model used here was validated against experimental results previously obtained in the literature. Then, the soot volume fractions of various mixtures of methyl tert-butyl ether (MTBE)-benzene, isobutene-benzene, methanol-benzene, and ethanol-benzene diluted in argon were simulated and compared to the results of benzene-argon pyrolysis at 1721 K and 5.4 MPa. For MTBE, isobutene, methanol, and ethanol, small amounts of additives to benzene-argon mixtures promoted soot formation, for the shock tube model assumed, while higher concentrations of these additives led to smaller soot volume fractions in comparison to pure benzene-argon pyrolysis. The most significant soot promotion effect was found for the additives MTBE and isobutene. The channel for MTBE decomposition producing isobutene and methanol is very effective at temperatures beyond 1200 K. Thus, both MTBE-benzene and isobutene-benzene mixtures diluted in argon showed rather similar behavior in regard to soot formation. Special emphasis was directed toward the causes for the concentration-dependent influence of the blends on the amount of soot formed. Aromatic hydrocarbons and acetylene were identified as key gas-phase species that determine the trends in the formation of soot of various mixtures. From reaction flux analysis for phenanthrene, it was deduced that the combinative routes including phenyl species play a major role in forming PAHs, especially at early reaction times. It is found that the additives play an important role in providing material to grow side chains, such as by reaction channels including phenylacetylene or benzyl, which are confirmed to form aromatic hydrocarbons and thus to influence the amount of soot formed, particularly when the concentrations of the blends are increased

  7. Mobile Source Air Toxics Rule (released in AEO2008)

    Reports and Publications (EIA)

    2008-01-01

    On February 9, 2007, the Environmental Protection Agency (EPA) released its MSAT2 rule, which will establish controls on gasoline, passenger vehicles, and portable fuel containers. The controls are designed to reduce emissions of benzene and other hazardous air pollutants. Benzene is a known carcinogen, and the EPA estimates that mobile sources produced more than 70% of all benzene emissions in 1999. Other mobile source air toxics, including 1,3-butadiene, formaldehyde, acetaldehyde, acrolein, and naphthalene, also are thought to increase cancer rates or contribute to other serious health problems.

  8. Ecological Interactions Between Metals and Microbes

    SciTech Connect (OSTI)

    Konopka, Allan E.

    2004-06-01

    Analyses of chromium resistant microbes. Culturable xylene-degrading and chromate-resistant microbes were obtained from chronically cocontaminated soil using a microcosm enrichment technique, and shown to correlate to dominant soil populations using culture independent techniques. The soil microbial community proved able to mount a respiratory response to addition of xylene in the presence of chromate. The majority of isolates belonged to the ubiquitous but poorly studied high %G+C Gram positive genus Arthrobacter, and exhibited considerable genotypic and phenotypic variability. Phenotypic assays uncovered a wide variation in the levels of chromate resistance, even between very closely related strains. Primers designed against conserved motifs in the known chrA chromate efflux gene failed to detect similar sequences among the chromate resistant Arthrobacter isolates obtained through enrichment.

  9. DOE - Office of Legacy Management -- Hooker Chemical Co - NY 05

    Office of Legacy Management (LM)

    Hooker Chemical Co - NY 05 FUSRAP Considered Sites Site: Hooker Chemical Co. (NY.05) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: Occidental Chemical Corporation Hooker Electrochemical Corporation NY.05-1 NY.05-2 Location: Niagara Falls , New York NY.05-3 Evaluation Year: 1985 NY.05-1 NY.05-2 Site Operations: Design, engineering, construction, equipping and operation of a plant for the manufacture of Product 45 (xylene hexachloride); MFL (Miller's

  10. Crosslinked Polybenzimidazole Membrane For Gas Separation

    DOE Patents [OSTI]

    Jorgensen, Betty S. (Jemez Springs, NM); Young, Jennifer S. (Los Alamos, NM); Espinoza, Brent F. (Los Alamos, NM)

    2005-09-20

    A cross-linked, supported polybenzimidazole membrane for gas separation is prepared by layering a solution of polybenzimidazole (PBI) and a,a'dibromo-p-xylene onto a porous support and evaporating solvent. A supported membrane of cross-linked poly-2,2'-(m-phenylene)-5,5'-bibenzimidazole unexpectedly exhibits an enhanced gas permeability compared to the non-cross linked analog at temperatures over 265 C.

  11. Crosslinked Polybenzimidazole Membrane For Gas Separation

    DOE Patents [OSTI]

    Jorgensen, Betty S.; Young, Jennifer S.; Espinoza, Brent F.

    2005-09-20

    A cross-linked, supported polybenzimidazole membrane for gas separation is prepared by layering a solution of polybenzimidazole (PBI) and a,a'dibromo-p-xylene onto a porous support and evaporating solvent. A supported membrane of cross-linked poly-2,2'-(m-phenylene)-5,5'-bibenzimidazole unexpectedly exhibits an enhanced gas permeability compared to the non-cross linked analog at temperatures over 265° C.

  12. DIRECT DISPOSAL OF A RADIOACTIVE ORGANIC WASTE IN A CEMENTITIOUS WASTE FORM

    SciTech Connect (OSTI)

    Zamecnik, J; Alex Cozzi, A; Russell Eibling, R; Jonathan Duffey, J; Kim Crapse, K

    2007-02-22

    The disposition of {sup 137}Cs-containing tetraphenylborate (TPB) waste at the Savannah River Site (SRS) by immobilization in the cementitious waste form, or grout called ''saltstone'' was proposed as a straightforward, cost-effective method for disposal. Tests were performed to determine benzene release due to TPB decomposition in saltstone at several initial TPB concentrations and temperatures. The benzene release rates for simulants and radioactive samples were generally comparable at the same conditions. Saltstone monoliths with only the top surface exposed to air at 25 and 55 C at any tetraphenylborate concentration or at any temperature with 30 mg/L TPB gave insignificant releases of benzene. At higher TPB concentrations and 75 and 95 C, the benzene release could result in exceeding the Lower Flammable Limit in the saltstone vaults.

  13. Catalytic reactive separation system for energy-efficient production of cumene

    DOE Patents [OSTI]

    Buelna, Genoveva; Nenoff, Tina M.

    2009-07-28

    The present invention relates to an atmospheric pressure, reactive separation column packed with a solid acid zeolite catalyst for producing cumene from the reaction of benzene with propylene. Use of this un-pressurized column, where simultaneous reaction and partial separation occur during cumene production, allow separation of un-reacted, excess benzene from other products as they form. This high-yielding, energy-efficient system allows for one-step processing of cumene, with reduced need for product purification. Reacting propylene and benzene in the presence of beta zeolite catalysts generated a selectivity greater than 85% for catalytic separation reactions at a reaction temperature of 115 degrees C and at ambient pressure. Simultaneously, up to 76% of un-reacted benzene was separated from the product; which could be recycled back to the reactor for re-use.

  14. Alkylation of organic aromatic compounds

    DOE Patents [OSTI]

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1994-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  15. Alkylation of organic aromatic compounds

    DOE Patents [OSTI]

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1993-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  16. Alkylation of organic aromatic compounds

    DOE Patents [OSTI]

    Smith, Jr., Lawrence A.

    1989-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  17. Alkylation of organic aromatic compounds

    DOE Patents [OSTI]

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1994-06-14

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  18. Assessment of heavy oil conversion

    SciTech Connect (OSTI)

    Gleim, W.T.K.

    1983-08-01

    Removal of benzene insoluble asphaltene components greatly facilitates and improves the subsequent upgrading of residual oils, the desulfurization in particular. For the upgrading of Venezualean oils, the Aurobon process is still the only feasible solution.

  19. Alkylation of organic aromatic compounds

    DOE Patents [OSTI]

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1993-09-07

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 figures.

  20. Alkylation of organic aromatic compounds

    DOE Patents [OSTI]

    Smith, L.A. Jr.

    1989-07-18

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  1. Studies of thin films and surfaces with optical harmonic generation and electron spectroscopy

    SciTech Connect (OSTI)

    Wilk, D.E.

    1996-01-01

    Optical second harmonic generation (SHG) and sum frequency generation (SFG) were used to study C{sup 60} thin solid films (low energy ED forbidden electronic excitations), and electron spectroscopy was used to study organic overlayers (xylenes) on Pt(111). Theory of SHG from a thin film is described in terms of surface and bulk contributions as well as local and nonlocal contributions to the optical nonlinearities. (1)In situ SHG data on C{sub 60} films during UHV film growth can be described in terms of only nonlocal contributions to both surface and bulk nonlinear susceptibilities. Microscopic origin of SHG response is discussed in terms of electric quadrupole and ED transitions of C{sub 60}. (2)Adsorption and thermal decomposition of ortho- and para-xylene on Pt(111) is studied using HREELS, LEED, AES, and thermal desorption spectroscopy. We have observed preferential decomposition of the methyl groups which leads to distinct decomposition pathways for ortho- and para-xylene on Pt(111).

  2. APPLICATIONS OF CFD METHOD TO GAS MIXING ANALYSIS IN A LARGE-SCALED TANK

    SciTech Connect (OSTI)

    Lee, S; Richard Dimenna, R

    2007-03-19

    The computational fluid dynamics (CFD) modeling technique was applied to the estimation of maximum benzene concentration for the vapor space inside a large-scaled and high-level radioactive waste tank at Savannah River site (SRS). The objective of the work was to perform the calculations for the benzene mixing behavior in the vapor space of Tank 48 and its impact on the local concentration of benzene. The calculations were used to evaluate the degree to which purge air mixes with benzene evolving from the liquid surface and its ability to prevent an unacceptable concentration of benzene from forming. The analysis was focused on changing the tank operating conditions to establish internal recirculation and changing the benzene evolution rate from the liquid surface. The model used a three-dimensional momentum coupled with multi-species transport. The calculations included potential operating conditions for air inlet and exhaust flows, recirculation flow rate, and benzene evolution rate with prototypic tank geometry. The flow conditions are assumed to be fully turbulent since Reynolds numbers for typical operating conditions are in the range of 20,000 to 70,000 based on the inlet conditions of the air purge system. A standard two-equation turbulence model was used. The modeling results for the typical gas mixing problems available in the literature were compared and verified through comparisons with the test results. The benchmarking results showed that the predictions are in good agreement with the analytical solutions and literature data. Additional sensitivity calculations included a reduced benzene evolution rate, reduced air inlet and exhaust flow, and forced internal recirculation. The modeling results showed that the vapor space was fairly well mixed and that benzene concentrations were relatively low when forced recirculation and 72 cfm ventilation air through the tank boundary were imposed. For the same 72 cfm air inlet flow but without forced recirculation

  3. Metal-doped organic gels and method thereof

    DOE Patents [OSTI]

    Satcher, Jr., Joe H.; Baumann, Theodore F.

    2007-10-23

    Disclosed herein is a sol-gel polymerization process for synthesizing metal-doped organic gels. The process polymerizes metal salts of hydroxylated benzenes or hydroxylated benzene derivatives with alkyl or aryl aldehydes to form metal-doped, wet, organic gels. The gels can then be dried by supercritical solvent extraction to form metal-doped aerogels or by evaporation to form metal-doped xerogels. The aerogels and xerogels can then be pyrolyzed.

  4. TOXICITY CHARACTERISTIC LEACHING PROCEDURE APPLIED TO RADIOACTIVE SALTSTONE CONTAINING TETRAPHENYLBORATE: DEVELOPMENT OF A MODIFIED ZERO-HEADSPACE EXTRACTOR

    SciTech Connect (OSTI)

    Crapse, K.; Cozzi, A.; Crawford, C.; Jurgensen, A.

    2006-09-30

    In order to assess the effect of extended curing times at elevated temperatures on saltstone containing Tank 48H waste, saltstone samples prepared as a part of a separate study were analyzed for benzene using a modification of the United States Environmental Protection Agency (USEPA) method 1311 Toxicity Characteristic Leaching Procedure (TCLP). To carry out TCLP for volatile organic analytes (VOA), such as benzene, in the Savannah River National Laboratory (SRNL) shielded cells (SC), a modified TCLP Zero-Headspace Extractor (ZHE) was developed. The modified method was demonstrated to be acceptable in a side by side comparison with an EPA recommended ZHE using nonradioactive saltstone containing tetraphenylborate (TPB). TCLP results for all saltstone samples tested containing TPB (both simulant and actual Tank 48H waste) were below the regulatory limit for benzene (0.5 mg/L). In general, higher curing temperatures corresponded to higher concentrations of benzene in TCLP extract. The TCLP performed on the simulant samples cured under the most extreme conditions (3000 mg/L TPB in salt and cured at 95 C for at least 144 days) resulted in benzene values that were greater than half the regulatory limit. Taking into account that benzene in TCLP extract was measured on the same order of magnitude as the regulatory limit, that these experimental conditions may not be representative of actual curing profiles found in the saltstone vault and that there is significant uncertainty associated with the precision of the method, it is recommended that to increase confidence in TCLP results for benzene, the maximum curing temperature of saltstone be less than 95 C. At this time, no further benzene TCLP testing is warranted. Additional verification would be recommended, however, should future processing strategies result in significant changes to salt waste composition in saltstone as factors beyond the scope of this limited study may influence the decomposition of TPB in saltstone.

  5. Metal-doped organic gels and method thereof

    DOE Patents [OSTI]

    Satcher, Jr., Joe H.; Baumann, Theodore F.

    2003-09-02

    Disclosed herein is a sol-gel polymerization process for synthesizing metal-doped organic gels. The process polymerizes metal salts of hydroxylated benzenes or hydroxylated benzene derivatives with alkyl or aryl aldehydes to form metal-doped, wet, organic gels. The gels can then be dried by supercritical solvent extraction to form metal-doped aerogels or by evaporation to form metal-doped xerogels. The aerogels and xerogels can then be pyrolyzed.

  6. Detection of volatile organic compounds using surface enhanced Raman scattering

    SciTech Connect (OSTI)

    Chang, A S; Maiti, A; Ileri, N; Bora, M; Larson, C C; Britten, J A; Bond, T C

    2012-03-22

    The authors present the detection of volatile organic compounds directly in their vapor phase by surface-enhanced Raman scattering (SERS) substrates based on lithographically-defined two-dimensional rectangular array of nanopillars. The type of nanopillars is known as the tapered pillars. For the tapered pillars, SERS enhancement arises from the nanofocusing effect due to the sharp tip on top. SERS experiments were carried out on these substrates using various concentrations of toluene vapor. The results show that SERS signal from a toluene vapor concentration of ppm level can be achieved, and the toluene vapor can be detected within minutes of exposing the SERS substrate to the vapor. A simple adsorption model is developed which gives results matching the experimental data. The results also show promising potential for the use of these substrates in environmental monitoring of gases and vapors.

  7. Combined Air Sparge and Bioremediation of an Underground Coal Gasification Site

    SciTech Connect (OSTI)

    Covell, J.R.; Thomas, M.H.

    1996-12-01

    EG&G Technical Services of West Virginia (TSWV) Inc. is successfully remediating a former underground coal gasification (UCG) test site in northeastern Wyoming. EG&G is demonstrating the effectiveness of combined air sparge and biostimulation technology. This project is being conducted for the U.S. Department of Energy (DOE ) - Morgantown Energy Technology Center (METC), the lease holder of the site. UCG testing from 1976 through 1979 contaminated three water-bearing units at the site with benzene. Previous pump and treat operations at the site showed the presence of a persistent non-dissolved benzene source material. The Felix I coal seam is the most contaminated unit at the site and was the target unit for the initial demonstration. Air sparging was selected to strip dissolved benzene, volatilize the non- dissolved benzene source material, and to provide oxygen for increasing aerobic bacteria populations. Indigenous bacteria populations were stimulated with ammonium phosphate addition. EG&G designed the remediation system to take advantage of the hydrogeologic environment to produce a cost-effective approach to the groundwater remediation. Groundwater pumping was used to manipulate subsurface air flow, nutrient transport, and biomass management. Demonstration operations began on September 29, 1995, and were suspended on April 30, 1996 to begin demonstration expansion. Initial results of the demonstration show substantial reduction in benzene concentrations across the demonstration area. Benzene concentration reductions greater than 80% were observed two months after demonstration operations were suspended.

  8. The Reaction of bis(1,2,4-tri-t-butylcyclopentadienyl)ceriumbenzyl...

    Office of Scientific and Technical Information (OSTI)

    The reaction is complicated by the equilibrium between the benzyl derivative and the metallacycle 1,2,4-(Me3C)3C5H2 (Me3C)2C5H2C(CH3)2CH2Ce, plus toluene since the ...

  9. Charge transfer fluorescence and 34 nm exciton diffusion length in polymers with electron acceptor end traps

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zaikowski, Lori; Mauro, Gina; Bird, Matthew; Karten, Brianne; Asaoka, Sadayuki; Wu, Qin; Cook, Andrew R.; Miller, John R.

    2014-12-22

    Photoexcitation of conjugated poly-2,7-(9,9-dihexylfluorene) polyfluorenes with naphthylimide (NI) and anthraquinone (AQ) electron-acceptor end traps produces excitons that form charge transfer states at the end traps. Intramolecular singlet exciton transport to end traps was examined by steady state fluorescence for polyfluorenes of 17 to 127 repeat units in chloroform, dimethylformamide (DMF), tetrahydrofuran (THF), and p-xylene. End traps capture excitons and form charge transfer (CT) states at all polymer lengths and in all solvents. The CT nature of the end-trapped states is confirmed by their fluorescence spectra, solvent and trap group dependence and DFT descriptions. Quantum yields of CT fluorescence are asmore » large as 46%. This strong CT emission is understood in terms of intensity borrowing. Energies of the CT states from onsets of the fluorescence spectra give the depths of the traps which vary with solvent polarity. For NI end traps the trap depths are 0.06 (p-xylene), 0.13 (THF) and 0.19 eV (CHCl3). For AQ, CT fluorescence could be observed only in p-xylene where the trap depth is 0.27 eV. Quantum yields, emission energies, charge transfer energies, solvent reorganization and vibrational energies were calculated. Fluorescence measurements on chains >100 repeat units indicate that end traps capture ~50% of the excitons, and that the exciton diffusion length LD =34 nm, which is much larger than diffusion lengths reported in polymer films or than previously known for diffusion along isolated chains. As a result, the efficiency of exciton capture depends on chain length, but not on trap depth, solvent polarity or which trap group is present.« less

  10. Charge Transfer Fluorescence and 34 nm Exciton Diffusion Length in Polymers with Electron Acceptor End Traps

    SciTech Connect (OSTI)

    Zaikowski, L.; Mauro, G.; Bird, M.; Karten, B.; Asaoka, S.; Wu, Q.; Cook, A. R.; Miller, J.

    2014-12-22

    Photoexcitation of conjugated poly-2,7-(9,9-dihexylfluorene) polyfluorenes with naphthylimide (NI) and anthraquinone (AQ) electron-acceptor end traps produces excitons that form charge transfer states at the end traps. Intramolecular singlet exciton transport to end traps was examined by steady state fluorescence for polyfluorenes of 17 to 127 repeat units in chloroform, dimethylformamide (DMF), tetrahydrofuran (THF), and p-xylene. End traps capture excitons and form charge transfer (CT) states at all polymer lengths and in all solvents. The CT nature of the end-trapped states is confirmed by their fluorescence spectra, solvent and trap group dependence and DFT descriptions. Quantum yields of CT fluorescence are as large as 46%. This strong CT emission is understood in terms of intensity borrowing. Energies of the CT states from onsets of the fluorescence spectra give the depths of the traps which vary with solvent polarity. For NI end traps the trap depths are 0.06 (p-xylene), 0.13 (THF) and 0.19 eV (CHCl3). For AQ, CT fluorescence could be observed only in p-xylene where the trap depth is 0.27 eV. Quantum yields, emission energies, charge transfer energies, solvent reorganization and vibrational energies were calculated. Fluorescence measurements on chains >100 repeat units indicate that end traps capture ~50% of the excitons, and that the exciton diffusion length LD =34 nm, which is much larger than diffusion lengths reported in polymer films or than previously known for diffusion along isolated chains. The efficiency of exciton capture depends on chain length, but not on trap depth, solvent polarity or which trap group is present.

  11. Alkylation of organic aromatic compounds

    DOE Patents [OSTI]

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1993-01-01

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70.degree. C. and 500.degree. C. and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  12. New metal-organic nanomaterials synthesized by laser irradiation of organic liquids

    SciTech Connect (OSTI)

    Kuzmin, Stanislav L.; Wesolowski, Michal J.; Duley, Walter W.

    2014-03-31

    A new type of metal-organic composition consisting of clusters of nanoparticles has been synthesised by laser irradiation of metallocene/benzene solutions. The metallocene molecules in this reaction become the source of the metal. Exposure to high-energy femtosecond laser pulses dehydrogenate benzene molecules and initiate the high-temperature high-pressure conditions that results in the synthesis of new materials. Irradiation experiments have been carried out on ferrocene/benzene and on other solutions. With ferrocene the synthesis of a new compound has been confirmed by X-ray powder diffraction as the peaks detected do not correspond to any known substance in the Crystallography Open Database. Theoretical simulation of the periodic structure of this new carbide predicts that it has hexagonal symmetry and a unit cell with a = 3.2A and c =2.8A. The exact structure is still uncertain but may be determined from scanning tunneling microscope (STM) studies.

  13. Chapter 8: Pyrolysis Mechanisms of Lignin Model Compounds Using a Heated Micro-Reactor

    SciTech Connect (OSTI)

    Robichaud, David J.; Nimlos, Mark R.; Ellison, G. Barney

    2015-10-03

    Lignin is an important component of biomass, and the decomposition of its thermal deconstruction products is important in pyrolysis and gasification. In this chapter, we investigate the unimolecular pyrolysis chemistry through the use of singly and doubly substituted benzene molecules that are model compounds representative of lignin and its primary pyrolysis products. These model compounds are decomposed in a heated micro-reactor, and the products, including radicals and unstable intermediates, are measured using photoionization mass spectrometry and matrix isolation infrared spectroscopy. We show that the unimolecular chemistry can yield insight into the initial decomposition of these species. At pyrolysis and gasification severities, singly substituted benzenes typically undergo bond scission and elimination reactions to form radicals. Some require radical-driven chain reactions. For doubly substituted benzenes, proximity effects of the substituents can change the reaction pathways.

  14. Alkylation of organic aromatic compounds

    DOE Patents [OSTI]

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1993-01-05

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70 C and 500 C and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  15. Zeolite catalysis: technology

    SciTech Connect (OSTI)

    Heinemann, H.

    1980-07-01

    Zeolites have been used as catalysts in industry since the early nineteen sixties. The great majority of commercial applications employ one of three zeolite types: zeolite Y; Mordenite; ZSM-5. By far the largest use of zeolites is in catalytic cracking, and to a lesser extent in hydrocracking. This paper reviews the rapid development of zeolite catalysis and its application in industries such as: the production of gasoline by catalytic cracking of petroleum; isomerization of C/sub 5/ and C/sub 6/ paraffin hydrocarbons; alkylation of aromatics with olefins; xylene isomerization; and conversion of methanol to gasoline.

  16. Characterizing a fast-response, low-afterglow liquid scintillator for neutron time-of-flight diagnostics in fast ignition experiments

    SciTech Connect (OSTI)

    Abe, Y. Hosoda, H.; Arikawa, Y.; Nagai, T.; Kojima, S.; Sakata, S.; Inoue, H.; Iwasa, Y.; Iwano, K.; Yamanoi, K.; Fujioka, S.; Nakai, M.; Sarukura, N.; Shiraga, H.; Norimatsu, T.; Azechi, H.

    2014-11-15

    The characteristics of oxygen-enriched liquid scintillators with very low afterglow are investigated and optimized for application to a single-hit neutron spectrometer for fast ignition experiments. It is found that 1,2,4-trimethylbenzene has better characteristics as a liquid scintillator solvent than the conventional solvent, p-xylene. In addition, a benzophenon-doped BBQ liquid scintillator is shown to demonstrate very rapid time response, and therefore has potential for further use in neutron diagnostics with fast time resolution.

  17. Long period grating refractive-index sensor: optimal design for single wavelength interrogation

    SciTech Connect (OSTI)

    Kapoor, Amita; Sharma, Enakshi K.

    2009-11-01

    We report the design criteria for the use of long period gratings (LPGs) as refractive-index sensors with output power at a single interrogating wavelength as the measurement parameter. The design gives maximum sensitivity in a given refractive-index range when the interrogating wavelength is fixed. Use of the design criteria is illustrated by the design of refractive-index sensors for specific application to refractive-index variation of a sugar solution with a concentration and detection of mole fraction of xylene in heptane (paraffin).

  18. Testing a new NIF neutron time-of-flight detector with a bibenzyl scintillator on OMEGA

    SciTech Connect (OSTI)

    Glebov, V. Yu.; Forrest, C.; Knauer, J. P.; Pruyne, A.; Romanofsky, M.; Sangster, T. C.; Shoup, M. J. III; Stoeckl, C.; Caggiano, J. A.; Carman, M. L.; Clancy, T. J.; Hatarik, R.; McNaney, J.; Zaitseva, N. P.

    2012-10-15

    A new neutron time-of-flight (nTOF) detector with a bibenzyl crystal as a scintillator has been designed and manufactured for the National Ignition Facility (NIF). This detector will replace a nTOF20-Spec detector with an oxygenated xylene scintillator currently operational on the NIF to improve the areal-density measurements. In addition to areal density, the bibenzyl detector will measure the D-D and D-T neutron yield and the ion temperature of indirect- and direct-drive-implosion experiments. The design of the bibenzyl detector and results of tests on the OMEGA Laser System are presented.

  19. CASTING SLIPS FOR FABRICATION OF REFRACTORY METAL WARE

    DOE Patents [OSTI]

    Stoddard, S.D.; Nuckolls, D.E.; Cowan, R.E.

    1962-09-01

    A composition is given for slip casting tungsten metal. The composition consists essentially of tungsten metal with an average particle size of 0.9 micron, an organic vehicle such as methyl chloroform, o-xylene, n-butyl acetate, isobutyl acetate, and 1, 1, 2, 2-tetrachlorethane, and a suspending agent such as ethyl cellulose, with the approximate ratio of said vehicle to the tungsten metal being 12 cc of a solution containing from 5 to about 20 grams of said ethyl cellulose in 400 cc of said organic vehicle per 100 grams of metal. (AEC)

  20. Molybdenum carbide nanoparticles as catalysts for oil sands upgrading: Dynamics and free-energy profiles

    SciTech Connect (OSTI)

    Liu, Xingchen; Salahub, Dennis R.

    2015-12-31

    There is no doubt that a huge gap exists in understanding heterogeneous catalysis between a cluster model of a few atoms and a bulk model of periodic slabs. Nanoparticles, which are crucial in heterogeneous catalysis in industry, lie in the middle of the gap. We present here our work on the computational modelling of molybdenum carbide nanoparticles (MCNPs) as the catalysts for the upgrading of oil sands in the in-situ environment, using benzene hydrogenation as a model reaction. With a cluster model, efforts were first made to understand the mechanism of the reaction with a density functional theory (DFT) study on the adsorption of benzene and its hydrogenation product – cyclohexane, as well as the cyclic hydrogenation reaction intermediates on the Mo{sub 2}C(0001) surface. From the thermodynamic data, along with literature information, it was found that the benzene hydrogenation reaction on molybdenum carbide happens most likely through a Langmuir-Hinshelwood mechanism with the gradual lifting up of the benzene molecule. The electron localization function (ELF) was then used to help understand the nature of the interactions between the MCNPs, identifying strong multi-center interactions between the adsorbates and the MCNPs. To enable the treatment of larger nanoparticles, a fast semi-empirical density functional tight-binding (DFTB) method was parameterized. With this method, the potential energy profiles of benzene hydrogenation reactions on different sizes of MCNPs are calculated. The study was then extended to consider a MCNP embedded in solvent (benzene), using a quantum mechanical (DFTB) / molecular mechanical approach. Calculations on the free energies profiles with the umbrella sampling method show that the entropy of the MCNPs and the solvent are essential in understanding the catalytic activity of the transition metal related nanoparticles for solid/liquid heterogeneous catalysis.

  1. An Innovative System for the Efficient and Effective Treatment of Non-Traditional Waters for Reuse in Thermoelectric Power Generation

    SciTech Connect (OSTI)

    John Rodgers; James Castle

    2008-08-31

    , chemical oxygen demand (COD), and zinc. Similar to FGD waters, produced waters contained contaminants of concern that are predominantly inorganic (arsenic, cadmium, chlorides, chromium, copper, lead, mercury, nickel, sulfide, zinc, total dissolved solids), but also contained some organics (benzene, PAHs, toluene, total organic carbon, total suspended solids, and oil and grease). Constituents of concern that may cause chemical scaling, biofouling and corrosion, such as pH, hardness and ionic strength, and nutrients (P, K, and N) may also be found in all four non-traditional waters. NPDES permits were obtained for these non-traditional waters and these permit limits are summarized in tabular format within this report. These limits were used to establish treatment goals for this research along with toxicity values for Ceriodaphnia dubia, water quality criteria established by the US EPA, irrigation standards established by the United States Department of Agriculture (USDA), and reuse standards focused on minimization of damage to the power plant by treated waters. Constructed wetland treatment systems were designed for each non-traditional water source based on published literature reviews regarding remediation of the constituents of concern, biogeochemistry of the specific contaminants, and previous research. During this study, 4 non-traditional waters, which included ash basin water, cooling water, FGD water and produced water (PW) were obtained or simulated to measure constructed wetland treatment system performance. Based on data collected from FGD experiments, pilot-scale constructed wetland treatment systems can decrease aqueous concentrations of elements of concern (As, B, Hg, N, and Se). Percent removal was specific for each element, including ranges of 40.1% to 77.7% for As, 77.6% to 97.8% for Hg, 43.9% to 88.8% for N, and no measureable removal to 84.6% for Se. Other constituents of interest in final outflow samples should have aqueous characteristics sufficient for

  2. STRUCTURE AND FUNCTION OF SUBSURFACE MICROBIAL COMMUNITIES AFFECTING RADIONUCLIDE TRANSPORT AND BIOIMMOBILIZATION

    SciTech Connect (OSTI)

    Joel E. Kostka; Lee Kerkhof; Kuk-Jeong Chin; Martin Keller; Joseph W. Stucki

    2011-06-15

    50% to 100% of rRNA detected). (2) We demonstrated for the first time that the function of microbial communities can be quantified in subsurface sediments using messenger RNA assays (molecular proxies) under in situ conditions. (3) Active Geobacteraceae were identified and phylogenetically characterized from the cDNA of messenger RNA extracted from ORFRC subsurface sediment cores. Multiple clone sequences were retrieved from G. uraniireducens, G. daltonii, and G. metallireducens. (4) Results show that Geobacter strain FRC-32 is capable of growth on benzoate, toluene and benzene as the electron donor, thereby providing evidence that this strain is physiologically distinct from other described members of the subsurface Geobacter clade. (5) Fe(III)-reducing bacteria transform structural Fe in clay minerals from their layer edges rather than from their basal surfaces.

  3. C{sub 6}H{sub 6}/Au(111): Interface dipoles, band alignment, charging energy, and van der Waals interaction

    SciTech Connect (OSTI)

    Abad, E.; Martinez, J. I.; Flores, F.; Ortega, J.; Dappe, Y. J.

    2011-01-28

    We analyze the benzene/Au(111) interface taking into account charging energy effects to properly describe the electronic structure of the interface and van der Waals interactions to obtain the adsorption energy and geometry. We also analyze the interface dipoles and discuss the barrier formation as a function of the metal work-function. We interpret our DFT calculations within the induced density of interface states (IDIS) model. Our results compare well with experimental and other theoretical results, showing that the dipole formation of these interfaces is due to the charge transfer between the metal and benzene, as described in the IDIS model.

  4. Electric response of a metal-molecule-metal junction to laser pulse by solving hierarchical equations of motion

    SciTech Connect (OSTI)

    Cao, Hui Zhang, Mingdao; Tao, Tao; Song, Mingxia; Zhang, Chaozhi

    2015-02-28

    We have combined the quantum dissipative theory and the time dependent density functional theory to perform the first principle calculation of laser induced quantum dynamical electron transport through a molecule weak bridged to two electrodes. The formalism of hierarchical equations of motion based on non-equilibrium Green’s function theory has been taken in this work. Numerical simulations of optical absorption spectra of benzene, laser induced transient current without and with bias, charge pumping effect, as well as the spectrum analysis from the current in Au-benzene-Au molecular junction are presented and discussed.

  5. Source Apportionment of Stack Emissions from Research and Development Facilities Using Positive Matrix Factorization

    SciTech Connect (OSTI)

    Ballinger, Marcel Y.; Larson, Timothy V.

    2014-08-19

    Emissions from research and development (R&D) facilities are difficult to characterize due to the wide variety of processes used, changing nature of research, and large number of chemicals. Positive matrix factorization (PMF) was applied to volatile organic compounds (VOCs) concentrations measured in the main exhaust stacks of four different R&D buildings to identify the number and composition of major contributing sources. PMF identified from 9-11 source-related factors contributing to the stack emissions depending on the building. The factors that were similar between buildings were major contributors to trichloroethylene (TCE), acetone, and ethanol emissions. Several other factors had similar profiles for two or more buildings but not for all four. One factor for each building was a combination of p/m-xylene, o-xylene and ethylbenzene. At least one factor for each building was identified that contained a broad mix of many species and constraints were used in PMF to modify the factors to resemble more closely the off-shift concentration profiles. PMF accepted the constraints with little decrease in model fit. Although the PMF model predicted the profiles of the off-shift samples, the percent of total emissions was under-predicted by the model versus the measured data.

  6. Hydroprocessing of desalted directly liquefied biomass

    SciTech Connect (OSTI)

    Gevert, B.; Andersson, P.; Jaeras, S.; Sandqvist, S.

    1988-01-01

    Desalted directly liquefied biomass from the PERC process was consecutively extracted with iso-octane and xylene. The hydroprocessing was made in a downflow reactor at a constant hydrogen flow and pressure of 85 normal 1/h and 10.0 MPa, respectively. The catalyst used as a sulfided cobalt + molybdenum catalyst on gamma alumina. At a liquid flow of 180 ml/h, an hourly liquid space velocity of 1.20 and a temperature of 350/degree/C, the oxygen content of the desalted oil was reduced from 15.3 to 2.3% by weight. The effective H/C molar ratio was increased from 1.05 in the starting material to 1.35 and the amount of heavy material with normal atmospheric boiling points above 540/degree/C was reduced from 45.3 to 15.1% by weight. Hydroprocessing at 420/degree/C reduced this heavy material further to 4.5% by weight. The deoxygenation was only to a small degree dependent on whether the feed oil was desalted or extracted with iso-octane or xylene.

  7. Filamentous carbon catalytic deposition of coal-tar pitch fraction on corundum

    SciTech Connect (OSTI)

    Martynkova, G.S.; Supova, M.

    2007-01-15

    Our work was focused on deposition of volatile hydrocarbons of carbonaceous precursor on corundum wafer, taking advantage of a metallic catalyst incorporated in precursor. Coal tar-pitch, namely a fraction soluble in toluene, served as precursor material for deposition of filamentous material. The toluene-soluble fraction of tar-pitch originally contained metallic particles of iron and nickel. During heat treatment up to 1000{sup o}C, metallic particles accompanied the volatile hydrocarbons conducive to forming a filamentous deposit. The deposit obtained demonstrates a semicrystalline material that has an irregular filamentous structure with an average filament diameter of 30 {mu}m. The presence of catalysts after the deposition process was proved in the deposit but catalysts were not found in the residuum.

  8. HEAVY METAL LOADED PLASTIC SCINTILLATING COMPOSITIONS

    DOE Patents [OSTI]

    Hyman, M. Jr.

    1962-06-26

    Thls lnventlon relates to a plastlc sclntlllatlon composltlon havlng lncorporated ln the base plastlc a lead compound. Thls compound forms a haze- free sclntillator. The lead compound has the general formula (R/sub 4/) x from the group consisting of hydrogen, alky, and phenyl, R4 ls selected from the group conslstlng of acrylyl and methacryiyl radlcals, and x ls a number from 0,5 to 1; however, when R/sub 1/, R/sub 2/, and R/sub 3/ are all hydrogen the x ls equal to 1. The phosphor ln the sclntlllatlng compositlon and the lead compound can be dlssolved ln a polymerlc resln selected from the group conslsting of polyvinyl toluene and copolymers of vlnyl toluene and cyclohexyl methacrylate. (AEC)

  9. Aromatic-Hydroxyl Interaction of a Lignin Model Compound on SBA-15, Present at Pyrolysis Temperatures

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kandziolka, III, Michael V.; Kidder, Michelle; Gill, Lance W.; Wu, Zili; Savara, Aditya Ashi

    2014-07-14

    An aromatic alpha-aryl ether compound (a benzyl phenyl ether analogue) was covalently grafted to mesoporous silica SBA-15, to create BPEa-SBA-15. The BPEa-SBA-15 was subjected to successive heating cycles up to 600 °C, with in situ monitoring by DRIFTS. It was found that the toluene moiety coordinates to SBA-15 surface silanol hydroxyl groups via an aromatic–hydroxyl interaction. This interaction is evidenced by a red-shift of the aromatic C–H stretches, as well as a red-shift and broadening of the surface hydroxyl O–H stretches, which are features characteristic of a hydrogen bond. These features remain present during heating until ~400 °C whereupon themore » ether linkage of BPEa-SBA-15 is cleaved, accompanied by loss of the toluene moiety.« less

  10. Protein-style dynamical transition in a non-biological polymer and a non-aqueous solvent

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mamontov, E.; Sharma, V. K.; Borreguero, J. M.; Tyagi, M.

    2016-03-15

    Using neutron scattering and molecular dynamics simulation, techniques most often associated with protein dynamical transition studies, we have investigated the microscopic dynamics of one of the most common polymers, polystyrene, which was exposed to toluene vapor, mimicking the process of protein hydration from water vapor. Polystyrene with adsorbed toluene is an example of a solvent-solute system, which, unlike biopolymers, is anhydrous and lacks hydrogen bonding. Nevertheless, it exhibits the essential traits of the dynamical transition in biomolecules, such as a specific dependence of the microscopic dynamics of both solvent and host on the temperature and the amount of solvent adsorbed.more » Ultimately, we conclude that the protein dynamical transition is a manifestation of a universal solvent-solute dynamical relationship, which is not specific to either biomolecules as solute, or aqueous media as solvent, or even a particular type of interactions between solvent and solute.« less

  11. Modified resins for solid-phase extraction

    DOE Patents [OSTI]

    Fritz, James S.; Sun, Jeffrey J.

    1991-12-10

    A process of treating aqueous solutions to remove organic solute contaminants by contacting an aqueous solution containing polar organic solute contaminants with a functionalized polystyrene-divinyl benzene adsorbent resin, with the functionalization of said resin being accomplished by organic hydrophilic groups such as hydroxymethyl, acetyl and cyanomethyl.

  12. REMOVAL OF CHLORIDE FROM AQUEOUS SOLUTIONS

    DOE Patents [OSTI]

    Schulz, W.W.

    1959-08-01

    The removal of chlorides from aqueons solutions is described. The process involves contacting the aqueous chloride containing solution with a benzene solution about 0.005 M in phenyl mercuric acetate whereby the chloride anions are taken up by the organic phase and separating the organic phase from the aqueous solutions.

  13. Modified resins for solid-phase extraction

    DOE Patents [OSTI]

    Fritz, James S.; Sun, Jeffrey J.

    1993-07-27

    A process of treating aqueous solutions to remove organic solute contaminants by contacting an aqueous solution containing polar organic solute contaminants with a functionalized polystyrene-divinyl benzene adsorbent resin, with the functionalization of said resin being accomplished by organic hydrophilic groups such as hydroxymethyl, acetyl and cyanomethyl.

  14. Process for reducing aromatic compounds in ethylenediamine with calcium

    DOE Patents [OSTI]

    Benkeser, Robert A.; Laugal, James A.; Rappa, Angela

    1985-01-01

    Olefins are produced by containing an organic compound having at least one benzene ring with ethylenediamine and calcium metal, the calcium metal being used in large excess or alternatively in conjunction with an inert abrasive particulate substance. Substantially all of the organic compounds are converted to corresponding cyclic olefins, largely mono-olefins.

  15. Vibrational Coupling

    SciTech Connect (OSTI)

    2011-01-01

    By homing in on the distribution patterns of electrons around an atom, a team of scientists team with Berkeley Lab's Molecular Foundry showed how certain vibrations from benzene thiol cause electrical charge to "slosh" onto a gold surface (left), while others do not (right). The vibrations that cause this "sloshing" behavior yield a stronger SERS signal.

  16. Oxidation of anthracene and benzo[a]pyrene by laccases from Trametes versicolor

    SciTech Connect (OSTI)

    Collins, P.J.; Dobson, A.D.W.; Kotterman, M.J.J.; Field, J.A.

    1996-12-01

    Polycyclic aromatic hydrocarbons, particularly benzene homologs, are highly toxic organic pollutants. One of the three major groups of extracellular oxidative enzymes involved in the white rot fungal lignin degradative process are laccases. This study presents evidence indicating that laccase has a role in PAH oxidation by white rot fungi. 36 refs., 5 figs., 1 tab.

  17. Process for reducing aromatic compounds in ethylenediamine with calcium

    DOE Patents [OSTI]

    Benkeser, R.A.; Laugal, J.A.; Rappa, A.

    1985-08-06

    Olefins are produced by containing an organic compound having at least one benzene ring with ethylenediamine and calcium metal, the calcium metal being used in large excess or alternatively in conjunction with an inert abrasive particulate substance. Substantially all of the organic compounds are converted to corresponding cyclic olefins, largely mono-olefins.

  18. Colloidal polyaniline

    DOE Patents [OSTI]

    Armes, Steven P.; Aldissi, Mahmoud

    1990-01-01

    Processable electrically conductive latex polymer compositions including colloidal particles of an oxidized, polymerized amino-substituted aromatic monomer, a stabilizing effective amount of a random copolymer containing amino-benzene type moieties as side chain constituents, and dopant anions, and a method of preparing such polymer compositions are provided.

  19. Production of chemical feedstock by the methanolysis of wood

    DOE Patents [OSTI]

    Steinberg, Meyer; Fallon, Peter

    1984-07-31

    A process for the production of ethylene, benzene and carbon monoxide from particulated biomass such as wood by reaction with methane at a temperature of from 700.degree. C. to 1200.degree. C., at a pressure of from 20 psi to 100 psi for a period of from 0.2 to 10 seconds.

  20. Production of chemical feedstock by the methanolysis of wood

    DOE Patents [OSTI]

    Steinberg, M.; Fallon, P.

    1983-06-01

    A process is discussed for the production of ethylene, benzene and carbon monoxide from particulated biomass such as wood by reaction with methane at a temperature of from 700/sup 0/C to 1200/sup 0/C, at a pressure of from 20 psi to 100 psi for a period of from 0.2 to 10 seconds.

  1. Stereolithography models. Final report

    SciTech Connect (OSTI)

    Smith, R.E.

    1995-03-01

    This report describes the first stereolithographic models made, which proved in a new release of ProEngineer software (Parametric Technologies, or PTC) and 3D Systems (Valencia, California) software for the SLA 250 machine. They are a model of benzene and the {alpha}-carbon backbone of the variable region of an antibody.

  2. Electric Field Assisted Assembly of Perpendicular Oriented NanorodSuperlattices

    SciTech Connect (OSTI)

    Ryan, Kevin M.; Mastroianni, Alex; Stancil, Kimani A.; Liu,Haitao; Alivisatos, Paul A.

    2006-04-10

    We observe the assembly of CdS nanorod superlattices by thecombination of a DC electric field and solvent evaporation. In eachelectric field (1 V/um) assisted assembly, CdS nanorods (5 x 30 nm)suspended initially in toluene were observed to align perpendicularly tothe substrate. Azimuthal alignment along the nanorod crystal faces andthe presence of stacking faults indicate that both 2D and 3D assemblieswere formed by a process of controlled super crystal growth.

  3. Hazardous materials: Microbiological decomposition. (Latest citations from the Biobusiness database). Published Search

    SciTech Connect (OSTI)

    Not Available

    1993-12-01

    The bibliography contains citations concerning the decomposition of toxic materials by biological means. Bacteria, enzymes, and bioluminescence are among the methods discussed. Bacteria and enzymes that digest toluene, polychlorinated biphenyls (PCBs), selenium wastes, oil shale waste, uranium, oil sludge, pesticides, rubber wastes, and pentachlorophenol are discussed. Flavobacterium and white rot fungus are among the biological agents highlighted. (Contains 250 citations and includes a subject term index and title list.)

  4. Hazardous materials: Microbiological decomposition. (Latest citations from the Biobusiness database). NewSearch

    SciTech Connect (OSTI)

    Not Available

    1994-10-01

    The bibliography contains citations concerning the decomposition of toxic materials by biological means. Bacteria, enzymes, and bioluminescence are among the methods discussed. Bacteria and enzymes that digest toluene, polychlorinated biphenyls (PCBs), selenium wastes, oil shale waste, uranium, oil sludge, pesticides, rubber wastes, and pentachlorophenol are discussed. Flavobacterium and white rot fungus are among the biological agents highlighted. (Contains 250 citations and includes a subject term index and title list.)

  5. Probing the size and environment induced phase transformation in CdSe quantum dots

    SciTech Connect (OSTI)

    Karakoti, Ajay S.; Sanghavi, Shail P.; Nachimuthu, Ponnusamy; Yang, Ping; Thevuthasan, Suntharampillai

    2011-11-17

    The structural and electronic properties of CdSe quantum dots in toluene and drop-casted on Si wafer were investigated by in-situ micro X-ray diffraction, X-ray photoelectron spectroscopy and UV-Vis absorption and emission spectroscopy. The in-situ micro diffraction data show that the CdSe quantum dots capped with TOPO or hexadecylamine (HDA) in toluene exhibit predominantly wurtzite crystal structure, which undergoes a phase transformation to zinc blende crystal structure following drop casting on Si and this phase transition increases with decreasing the size of the CdSe quantum dots. Decreasing the size of quantum dots also increases the Se vacancies that facilitate the phase transformation. The X-ray photoelectron spectra show a systematic increase in the core level binding energies of Cd 3d and Se 3d, the band gap and the Cd/Se ratio as the size of the quantum dots decreases from 6.6nm to 2.1nm. This is attributed to the quantum confinement of CdSe crystallites by the capping ligands in toluene which increases with decreasing the size of the quantum dots. However, drop-casting quantum dots on Si alter the density and arrangement of capping ligands and solvent molecules on the quantum dots which causes significant phase transformation.

  6. Spin-symmetry conversion in methyl rotors induced by tunnel resonance at low temperature

    SciTech Connect (OSTI)

    Zhang, B.; Sun, C.; Horsewill, A. J.; Alsanoosi, A. M.; Aibout, A.

    2014-02-28

    Field-cycling NMR in the solid state at low temperature (4.2 K) has been employed to measure the tunneling spectra of methyl (CH{sub 3}) rotors in phenylacetone and toluene. The phenomenon of tunnel resonance reveals anomalies in {sup 1}H magnetization from which the following tunnel frequencies have been determined: phenylacetone, ν{sub t} = 6.58 ± 0.08 MHz; toluene, ν{sub t(1)} = 6.45 ± 0.06 GHz and ν{sub t(2)} = 7.07 ± 0.06 GHz. The tunnel frequencies in the two samples differ by three orders of magnitude, meaning different experimental approaches are required. In phenylacetone the magnetization anomalies are observed when the tunnel frequency matches one or two times the {sup 1}H Larmor frequency. In toluene, doping with free radicals enables magnetization anomalies to be observed when the tunnel frequency is equal to the electron spin Larmor frequency. Cross-polarization processes between the tunneling and Zeeman systems are proposed and form the basis of a thermodynamic model to simulate the tunnel resonance spectra. These invoke space-spin interactions to drive the changes in nuclear spin-symmetry. The tunnel resonance lineshapes are explained, showing good quantitative agreement between experiment and simulations.

  7. Cis-Chlorobenzene dihydrodiol dehydrogenase (TcbB) from Pseudomonas sp. strain P51, expressed in Escherichia coli DH5{alpha}(pTCB149), catalyzes enantioselective dehydrogenase reactions

    SciTech Connect (OSTI)

    Raschke, H.; Fleischmann, T.; Meer, J.R. van der; Kohler, H.P.E.

    1999-12-01

    cis-Chlorobenzene dihydrodiol dehydrogenase (CDD) from Pseudomonas sp. strain P51, cloned into Escherichia coli DH5{alpha}(pTCB149) was able to oxidize cis-dihydrodihydroxy derivatives (cis-dihydrodiols) of dihydronaphthalene, indene, and four para-substituted toluenes to the corresponding catechols. During the incubation of a nonracemic mixture of cis-1,2-indandiol, only the (+)-cis-(1R,2S) enantiomer was oxidized; the (-)-cis-(S,2R) enantiomer remained unchanged, CDD oxidized both enantiomers of cis-1,2-dihydroxy-1,2,3,4-tetrahydronaphthalene, but oxidation of the (+)-cis-(1S,2R) enantiomer was delayed until the (-)-cis-(1R,2S) enantiomer was completely depleted. When incubated with nonracemic mixtures of para-substituted cis-toluene dihydrodiols, CDD always oxidized the major enantiomer at a higher rate than the minor enantiomer. When incubated with racemic 1-indanol, CDD enantioselectively transformed the (+)-(1S) enatiomer to 1-indanone. This stereoselective transformation shows that CDD also acted as an alcohol dehydrogenase. Additionally, CDD was able to oxidize (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene, (+)-cis-monochlorobiphenyl dihydrodiols, and (+)-cis-toluene dihydrodiol to the corresponding catechols.

  8. HEAVY OIL PROCESS MONITOR: AUTOMATED ON-COLUMN ASPHALTENE PRECIPITATION AND RE-DISSOLUTION

    SciTech Connect (OSTI)

    John F. Schabron; Joseph F. Rovani Jr; Mark Sanderson

    2006-06-01

    About 37-50% (w/w) of the heptane asphaltenes from unpyrolyzed residua dissolve in cyclohexane. As pyrolysis progresses, this number decrease to below 15% as coke and toluene insoluble pre-coke materials appear. This solubility measurement can be used after coke begins to form, unlike the flocculation titration, which cannot be applied to multi-phase systems. Currently, the procedure for the isolation of heptane asphaltenes and the determination of the amount of asphaltenes soluble in cyclohexane spans three days. A more rapid method to measure asphaltene solubility was explored using a novel on-column asphaltene precipitation and re-dissolution technique. This was automated using high performance liquid chromatography (HPLC) equipment with a step gradient sequence using the solvents: heptane, cyclohexane, toluene:methanol (98:2). Results for four series of original and pyrolyzed residua were compared with data from the gravimetric method. The measurement time was reduced from three days to forty minutes. The separation was expanded further with the use of four solvents: heptane, cyclohexane, toluene, and cyclohexanone or methylene chloride. This provides a fourth peak which represents the most polar components, in the oil.

  9. Phase behavior of nanoparticle/diblock copolymer in a selective solvent.

    SciTech Connect (OSTI)

    Lo, C.-T.; Lee, B.; Winans, R. E.; Thiyagarajan, P.

    2007-01-01

    Solvents used for controlling the self-assembly of polymer nanocomposites have a strong influence on the order-disorder and order-order transition temperatures. We have investigated the phase behavior of complexes composed of poly(styrene-b-2-vinylpyridine) (PS-PVP) and thiol-terminated PS stabilized Au nanoparticles in toluene-d (a good solvent for PS) by using small-angle neutron scattering. We observe that the morphologies of the neat and nanoparticle-containing polymer solutions strongly depend on the concentration of nanoparticles and temperature. Comparison of the phase diagrams of the neat and nanoparticle-containing polymer solutions as a function of temperature clearly shows dramatic shifts in the order-disorder and order-order transition temperatures. This dramatic effect can be understood by a model wherein the added nanoparticles that sequester in the preferred PS domains increase the interfacial curvature, leading to the observed changes in the nanostructure of the complex. Some effects are similar to those of the selective solvent such as toluene on the nanostructure of PS-PVP. Knowledge gained from these studies on the effects of nanoparticle concentration and temperature on the phase behavior of the polymer nanocomposites will be valuable for tailoring the physical properties of novel nanocomposites.

  10. Dynamics of polymer film formation during spin coating

    SciTech Connect (OSTI)

    Mouhamad, Y.; Clarke, N.; Jones, R. A. L.; Geoghegan, M.; Mokarian-Tabari, P.

    2014-09-28

    Standard models explaining the spin coating of polymer solutions generally fail to describe the early stages of film formation, when hydrodynamic forces control the solution behavior. Using in situ light scattering alongside theoretical and semi-empirical models, it is shown that inertial forces (which initially cause a vertical gradient in the radial solvent velocity within the film) play a significant role in the rate of thinning of the solution. The development of thickness as a function of time of a solute-free liquid (toluene) and a blend of polystyrene and poly(methyl methacrylate) cast from toluene were fitted to different models as a function of toluene partial pressure. In the case of the formation of the polymer blend film, a concentration-dependent (Huggins) viscosity formula was used to account for changes in viscosity during spin coating. A semi-empirical model is introduced, which permits calculation of the solvent evaporation rate and the temporal evolution of the solute volume fraction and solution viscosity.

  11. Investigation of Phase and Emulsion Behavior, Surfactant Retention and Condensate Recovery for Condensate/Water/Ethanol Mixtures

    SciTech Connect (OSTI)

    Ramanathan Sampath

    2004-09-30

    This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FG26-02NT15447 during the period April 01, 2004 to September 30, 2004 which covers the fourth six months of the project. Presently work is in progress to characterize phase and emulsion behavior for ethylbenzene/water/ethanol system. Ethylbenzene that has the equivalent carbon number is used as the model condensate. During this reporting period, work was under way and the electrical conductivity experimental system was set up at the Atlanta University Center. Following the set-up of the emulsion measurement system, the electronic instruments and data acquisition modules involved were tested for proper operation of the system. Then, the conductivity output was normalized with that obtained for 10mM NaCl water. Radial coreflooding experiments with ethanol injection prior to and after water injection were completed to assess the effectiveness of the surfactant flooding in the recovery of condensate by our industrial partner, Surtek, CO, in this reporting period. In Run 1, 10 mM NaCl without ethanol injection recovered 31.5% of the initial ethyl benzene saturation. Injection of ethanol following 10 mM NaCl produced a tertiary ethyl benzene bank with maximum ethyl benzene cuts of 32%. In Run 2, 50 vol% of pure (100%) ethanol was injected and flowed through the Berea sandstone after Ethyl Benzene Saturation. 69% of the initial ethyl benzene was recovered. Results of the radial corefloods are very encouraging. Emulsion conductivity measurements for conjugate pair phases are in progress at Morehouse.

  12. Mechanism of Efficient Anti-Markovnikov Olefin Hydroarylation Catalyzed by Homogeneous Ir(III) Complexes

    SciTech Connect (OSTI)

    Bhalla, Gaurav; Bischof, Steven M; Ganesh, Somesh K; Liu, Xiang Y; Jones, C J; Borzenko, Andrey; Tenn, William J; Ess, Daniel H; Hashiguchi, Brian G; Lokare, Kapil S; Leung, Chin Hin; Oxgaard, Jonas; Goddard, William A; Periana, Roy A

    2011-01-01

    The mechanism of the hydroarylation reaction between unactivated olefins (ethylene, propylene, and styrene) and benzene catalyzed by [(R)Ir(?-acac-O,O,C{sup 3})-(acac-O,O){sub 2}]{sub 2} and [R-Ir(acac-O,O){sub 2}(L)] (R = acetylacetonato, CH{sub 3}, CH{sub 2}CH{sub 3}, Ph, or CH{sub 2}CH{sub 2}Ph, and L = H{sub 2}O or pyridine) Ir(III) complexes was studied by experimental methods. The system is selective for generating the anti-Markovnikov product of linear alkylarenes (61:39 for benzene + propylene and 98:2 for benzene + styrene). The reaction mechanism was found to follow a rate law with first-order dependence on benzene and catalyst, but a non-linear dependence on olefin. {sup 13}C-labelling studies with CH{sub 3}{sup 13}CH{sub 2}-Ir-Py showed that reversible ?-hydride elimination is facile, but unproductive, giving exclusively saturated alkylarene products. The migration of the {sup 13}C-label from the ? to ?-positions was found to be slower than the CH activation of benzene (and thus formation of ethane and Ph-d{sub 5}-Ir-Py). Kinetic analysis under steady state conditions gave a ratio of the rate constants for CH activation and ?-hydride elimination (k{sub CH}: k{sub ?}) of ~0.5. The comparable magnitude of these rates suggests a common rate determining transition state/intermediate, which has been shown previously with B3LYP density functional theory (DFT) calculations. Overall, the mechanism of hydroarylation proceeds through a series of pre-equilibrium dissociative steps involving rupture of the dinuclear species or the loss of L from Ph-Ir-L to the solvento, 16-electron species, Ph-Ir(acac-O,O){sub 2}-Sol (where Sol refers to coordinated solvent). This species then undergoes trans to cisisomerization of the acetylacetonato ligand to yield the pseudo octahedral species cis-Ph-Ir-Sol, which is followed by olefin insertion (the regioselective and rate determining step), and then activation of the CH bond of an incoming benzene to generate the product and

  13. Final alternatives assessment: Other contamination sources: Interim response action, South Tank Farm Plume. Final report

    SciTech Connect (OSTI)

    Not Available

    1990-08-01

    The South Tank Farm Plume (STFP) is located in the southern half of sections 1 and 2. It is a composite plume of C6H6, MEC6H5, XYLEN, DCPD, and BCHPD which is migrating from the area of tank 464A. Recent investigations have shown that the STFP is being biodegraded naturally and will not migrate into either Lake Ladora or Lower Derby Lake prior to implementation of the final remedy. Monitoring with the specific objectives of (1) Verifying the rate of migration and (2) Locating the leading edge of the plume over the time frame of the IRA is proposed as the preferred alternative action. Sections of this assessment provide information on: (1) Site description-history, previous investigations, hydrogeology, LNAPL plume; (2) IRA objectives and evaluation; and (3) Work plan of the IRA-well network, sampling frequency. Appendices include comments and responses.

  14. Industrial hygiene survey report of worker exposures to organotins at Norfolk Naval Shipyard, Portsmouth, Virginia

    SciTech Connect (OSTI)

    Eissler, A.W.; Ferrel, T.W.; Bloom, T.F.; Fajen, J.M.

    1985-06-24

    Breathing-zone samples were analyzed for organotin compounds, copper, and xylene during spray application of organotin containing marine antifouling paint at Norfolk Naval Shipyard, Portsmouth, Virginia, March, 1984. The survey was part of a NIOSH study of occupational exposures to organotin compounds, conducted as a component of an assessment to determine the feasibility of conducting a study of reproductive effects. Company personnel records were reviewed. Work practices were observed. The authors conclude that a potential exists for exposures to organotins and copper. As all employees were wearing respiratory protective equipment, actual exposures may be less than that indicated by the analytical data. The facility could contribute 16 potentially exposed workers to the reproductive effects study.

  15. A new neutron time-of-flight detector for fuel-areal-density measurements on OMEGA

    SciTech Connect (OSTI)

    Glebov, V. Yu. Forrest, C. J.; Marshall, K. L.; Romanofsky, M.; Sangster, T. C.; Shoup, M. J.; Stoeckl, C.

    2014-11-15

    A new neutron time-of-flight (nTOF) detector for fuel-areal-density measurements in cryogenic DT implosions was installed on the OMEGA Laser System. The nTOF detector has a cylindrical thin-wall, stainless-steel, 8-in.-diam, 4-in.-thick cavity filled with an oxygenated liquid xylene scintillator. Four gated photomultiplier tubes (PMTs) with different gains are used to measure primary DT and D{sub 2} neutrons, down-scattered neutrons in nT and nD kinematic edge regions, and to study tertiary neutrons in the same detector. The nTOF detector is located 13.4 m from target chamber center in a well-collimated line of sight. The design details of the nTOF detector, PMT optimization, and test results on OMEGA will be presented.

  16. Chemical vapor deposition of fluorinated polymers

    SciTech Connect (OSTI)

    Moore, J.A.; Lang, C.I.; Lu, T.M.; You, L.

    1993-12-31

    An overview of the authors` work directed toward the deposition of fluorinated polymers by condensation of thermally or photochemically generated intermediates directly from the vapor state will be presented. Previously known materials such as Teflon AF{reg_sign} and Parylene AF{sub 4} have been successfully deposited and are being evaluated for microelectronic application as on-chip dielectrics. A novel, one-step route to Parylene AF{sub 4} will be described which obviates the necessity of multistep organic synthesis to prepare precursors. A new, partially fluorinated parylene obtained from tetrafluoro-p-xylene will be described. It has also been observed that ultraviolet irradiation of the vapor of dimethyl tetrafluorobenzocyclobutene causes the deposition of an insoluble film which contains fluorine.

  17. Pilot-Scale Silicone Process for Low-Cost Carbon Dioxide Capture

    SciTech Connect (OSTI)

    Farnum, Rachel; Perry, Robert; Wood, Benjamin

    2014-12-31

    GE Global Research is developing technology to remove carbon dioxide (CO 2) from the flue gas of coal-fired powerplants. A mixture of 3-aminopropyl end-capped polydimethylsiloxane (GAP-1m) and triethylene glycol (TEG) is the preferred CO2-capture solvent. GE Global Research was contracted by the Department of Energy to test a pilot-scale continuous CO2 absorption/desorption system using a GAP-1m/TEG mixture as the solvent. As part of that effort, an Environmental, Health, and Safety (EH&S) assessment for a CO2-capture system for a 550 MW coal-fired powerplant was conducted. Five components of the solvent, CAS#2469-55-8 (GAP-0), CAS#106214-84-0 (GAP-1-4), TEG, and methanol and xylene (minor contaminants from the aminosilicone) are included in this assessment. One by-product, GAP- 1m/SOX salt, and dodecylbenzenesulfonicacid (DDBSA) were also identified foranalysis. An EH&S assessment was also completed for the manufacturing process for the GAP-1m solvent. The chemicals associated with the manufacturing process include methanol, xylene, allyl chloride, potassium cyanate, sodium hydroxide (NaOH), tetramethyldisiloxane (TMDSO), tetramethyl ammonium hydroxide, Karstedt catalyst, octamethylcyclotetrasiloxane (D4), Aliquat 336, methyl carbamate, potassium chloride, trimethylamine, and (3-aminopropyl) dimethyl silanol. The toxicological effects of each component of both the CO2 capture system and the manufacturing process were defined, and control mechanisms necessary to comply with U.S. EH&S regulations are summarized. Engineering and control systems, including environmental abatement, are described for minimizing exposure and release of the chemical components. Proper handling and storage recommendations are made for each chemical to minimize risk to workers and the surrounding community.

  18. Automobile proximity and indoor residential concentrations of BTEX and MTBE

    SciTech Connect (OSTI)

    Corsi, Dr. Richard; Morandi, Dr. Maria; Siegel, Dr. Jeffrey; Hun, Diana E

    2011-01-01

    Attached garages have been identified as important sources of indoor residential air pollution. However, the literature lacks information on how the proximity of cars to the living area affects indoor concentrations of gasoline-related compounds, and the origin of these pollutants. We analyzed data from the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study and evaluated 114 residences with cars in an attached garage, detached garage or carport, or without cars. Results indicate that homes with cars in attached garages were affected the most. Concentrations in homes with cars in detached garages and residences without cars were similar. The contribution from gasoline-related sources to indoor benzene and MTBE concentrations appeared to be dominated by car exhaust, or a combination of tailpipe and gasoline vapor emissions. Residing in a home with an attached garage could lead to benzene exposures ten times higher than exposures from commuting in heavy traffic.

  19. Collision dynamics of polyatomic molecules containing carbon rings at low temperatures

    SciTech Connect (OSTI)

    Li, Zhiying; Heller, Eric J.; Krems, Roman V.

    2014-09-14

    We explore the collision dynamics of complex hydrocarbon molecules (benzene, coronene, adamantane, and anthracene) containing carbon rings in a cold buffer gas of {sup 3}He. For benzene, we present a comparative analysis of the fully classical and fully quantum calculations of elastic and inelastic scattering cross sections at collision energies between 1 and 10 cm{sup ?1}. The quantum calculations are performed using the time-independent coupled channel approach and the coupled-states approximation. We show that the coupled-states approximation is accurate at collision energies between 1 and 20 cm{sup ?1}. For the classical dynamics calculations, we develop an approach exploiting the rigidity of the carbon rings and including low-energy vibrational modes without holonomic constraints. Our results illustrate the effect of the molecular shape and the vibrational degrees of freedom on the formation of long-lived resonance states that lead to low-temperature clustering.

  20. Reconstruction of ionization probabilities from spatially averaged data in N dimensions

    SciTech Connect (OSTI)

    Strohaber, J.; Kolomenskii, A. A.; Schuessler, H. A.

    2010-07-15

    We present an analytical inversion technique, which can be used to recover ionization probabilities from spatially averaged data in an N-dimensional detection scheme. The solution is given as a power series in intensity. For this reason, we call this technique a multiphoton expansion (MPE). The MPE formalism was verified with an exactly solvable inversion problem in two dimensions, and probabilities in the postsaturation region, where the intensity-selective scanning approach breaks down, were recovered. In three dimensions, ionization probabilities of Xe were successfully recovered with MPE from simulated (using the Ammosov-Delone-Krainov tunneling theory) ion yields. Finally, we tested our approach with intensity-resolved benzene-ion yields, which show a resonant multiphoton ionization process. By applying MPE to this data (which were artificially averaged), the resonant structure was recovered, which suggests that the resonance in benzene may have been observed in spatially averaged data taken elsewhere.

  1. Flash pyrolysis and hydropyrolysis of biomass

    SciTech Connect (OSTI)

    Steinberg, M.; Fallon, P.

    1982-04-01

    Process chemistry data on the flash pyrolysis and hydropyrolysis of wood is being obtained in a 1'' downflow entrained tubular reactor. The data indicates that at residence times of <1 second, and 900 to 1000/sup 0/C and 500 psi pressure, the flash hydropyrolysis of wood yields mainly methane and water. As the residence time increases to >3 seconds, the products are methane and CO. Almost complete conversion of the carbon to methane and CO are obtained in these experiments. At lower temperatures, in the order of 800/sup 0/C, 500 psi and residence times <4 seconds, significant amounts of benzene and ethane are produced. The experimental process chemistry data have been used to design and evaluate two processes in a preliminary manner. One process converts wood to high BTU pipeline gas and the other to methanol and chemical feedstocks consisting of benzene and ethylene. Reasonable plant investments which compare favorably with coal conversion plant estimates are derived.

  2. Flash pyrolysis and hydropyrolysis of biomass

    SciTech Connect (OSTI)

    Not Available

    1982-08-01

    Process chemistry data on the flash pyrolysis and hydropyrolysis of wood is being obtained in a 1'' downflow entrained tubular reactor. The data indicates that at residence times of <1 second, and 900 to 1000/sup 0/C and 500 psi pressure, the flash hydropyrolysis of wood yields mainly methane and water. As the residence time increases to >3 seconds, the products are methane and CO. Almost complete conversion of the carbon to methane and CO are obtained in these experiments. At lower temperatures, in the order of 800/sup 0/C, 500 psi and residence times <4 seconds, significant amounts of benzene and ethane are produced. The experimental process chemistry data have been used to design and evaluate two processes in a preliminary manner. One process converts wood to high BTU pipeline gas and the other to methanol and chemical feedstocks consisting of benzene and ethylene. Reasonable plant investments which compare favorably with coal conversion plant estimates are derived.

  3. Soot formation in methane/air nonpremixed flames doped with small quantities of C3 hydrocarbons

    SciTech Connect (OSTI)

    McEnally, C.S.; Pfefferle, L.D.

    1998-03-01

    Gas temperature, C1 to C12 stable hydrocarbon concentrations, and soot volume fractions were measured in an axisymmetry methane/air coflowing nonpremixed flame whose fuel was doped with one mole per cent allene, propene, and propane. The additives did not significantly alter the temperature field, methane mole fractions, or chain-carrying radical concentrations. However, soot volume fractions were increased, in the order allene > propene > propane. The hydrocarbon species measurements indicated that soot formation increases because the additives undergo reaction sequences that raise the concentrations of the benzene and phenyl radical precursors C{sub 3}H{sub 3}, C{sub 4}H{sub 3}, and C{sub 4}H{sub 5}, and consequently enhance the benzene/phenyl formation rate. Therefore, creation of these precursors and of the first aromatic ring are crucial rate-limiting soot formation steps in methane flames.

  4. Catalytic hydroprocessing of chlorinated hydrocarbons

    SciTech Connect (OSTI)

    Allen, D.T.

    1996-12-31

    Catalytic hydroprocessing is a promising technology for the treatment or recycling of chlorinated organic waste streams. This paper will describe the hydroprocessing kinetics and reaction pathways of chlorinated aromatics and aliphatics. The compounds investigated include chlorinated benzenes, chlorinated phenols, chlorinated pyridinols, perchloroethylene, trichloroethyene, and dichloroethylenes. Experiments were performed over a NiMo/Al{sub 2}O{sub 3} catalyst in the temperature range of 175{degrees}C to 350{degrees}C. For the chlorinated benzenes, removal of chlorine proceeded at comparable rates for all species from hexachlorobenzene to chlorobenzene. For the chlorophenols and chloropyridinols, dechlorination proceeded at a much higher rate than deoxygenation. Rates of dechlorination of aliphatics were approximately an order of magnitude faster than the rates for aromatics. 10 refs., 4 figs., 1 tab.

  5. Process for reducing organic compounds with calcium, amine, and alcohol

    DOE Patents [OSTI]

    Benkeser, Robert A.; Laugal, James A.; Rappa, Angela

    1985-01-01

    Olefins are produced by contacting an organic compound having at least one benzene ring with calcium metal, ethylenediamine, a low molecular weight aliphatic alcohol, and optionally a low molecular weight aliphatic primary amine, and/or an inert, abrasive particulate substance. The reduction is conducted at temperatures ranging from about -10.degree. C. to about 30.degree. C. or somewhat higher. Substantially all of the organic compounds are converted to corresponding cyclic olefins, primarily diolefins.

  6. Features of the spectral dependences of transmittance of organic semiconductors based on tert-butyl substituted lutetium phthalocyanine molecules

    SciTech Connect (OSTI)

    Belogorokhov, I. A.; Tikhonov, E. V.; Dronov, M. A.; Belogorokhova, L. I.; Ryabchikov, Yu. V.; Tomilova, L. G.; Khokhlov, D. R.

    2011-11-15

    Vibronic properties of organic semiconductors based on tert-butyl substituted phthalocyanine lutetium diphthalocyanine molecules are studied by IR and Raman spectroscopy. It is shown that substitution of several carbon atoms in initial phthalocyanine (Pc) ligands with {sup 13}C isotope atoms causes a spectral shift in the main absorption lines attributed to benzene, isoindol, and peripheral C-H groups. A comparison of spectral characteristics showed that the shift can vary from 3 to 1 cm{sup -1}.

  7. Towards Using Molecular States as Qubits

    SciTech Connect (OSTI)

    Goswami, Debabrata; Goswami, Tapas; Kumar, S. K. Karthick; Das, Dipak K.

    2011-09-23

    Molecular systems are presented as possible qubit systems by exploring non-resonant molecular fragmentation of n-propyl benzene with femtosecond laser pulses as a model case. We show that such laser fragmentation process is dependent on the phase and polarization characteristics of the laser. The effect of the chirp and polarization of the femtosecond pulse when applied simultaneously is mutually independent of each other, which makes chirp and polarization as useful 'logic' implementing parameters for such molecular qubits.

  8. Neutron Cross-Section Measurements on Structural Materials at ORELA

    SciTech Connect (OSTI)

    Guber, Klaus H; Koehler, Paul; Wiarda, Dorothea; Harvey, John A

    2011-01-01

    Neutron capture experiments, using isotopically enriched and natural samples of chromium and titanium, were performed on flight paths 6 and 7 at the 40 m flight station of ORELA. The experimental data were acquired using a pair of deuterated benzene detectors employing the now well-established pulse-height-weighting technique. These data were complemented by new total cross-section measurements where no useful previous data were available.

  9. Research Highlights - Joint Center for Energy Storage Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Research Highlights August 25, 2016, Research Highlights The Lightest Organic Radical Cation for Charge Storage in Redox Flow Batteries By systematically shedding molecular fragments of 2,5-di-tert-butyl-1,4-bis(2-methoxyethoxy)benzene that are considered important for radical cation steric stabilization, we discovered a minimalistic structure that retains long-term stability in its oxidized form and exhibits the intrinsic capacity of 161 mAh/g. Read More August 20, 2016, Research Highlights

  10. Organic molecules colliding with and desorbing from solid surfaces

    SciTech Connect (OSTI)

    Garrison, B.J.; Sundararam, V.; Taylor, R.S.

    1996-12-31

    The reactions induced by both 500 eV Ar bombardment of organic overlayers on Pt(111) and 20-60 eV benzene and phenyl radical scattering from a H-terminated diamond surface have been modeled with molecular dynamics simulations. We have used many-body potential developed by Brenner that allows for reactions among the particles. Examples of reactions observed in the simulations will be discussed.

  11. The nature of core excited states in C{sub 60} as exhibited by the Auger line shape

    SciTech Connect (OSTI)

    Ramaker, D.E.; Turner, N.H.; Milliken, J.A.

    1992-09-17

    This paper compares the C{sub 60} C KVV Auger line shape and {pi} band covalency to those of graphite and benzene to determine the core excited electronic states. Shakeup satellites are used to determine delocalization times of these core excited states relative to the core hole lifetime. Based on these, C {sub 60} appears to have excitations that delocalize in times that are short relative to the core hole decay.

  12. Synthesis of N-formyl-3,4-di-t-butoxycarbonyloxy-6(trimethylstannyl)-L-phenylalanine ethyl ester and its regioselective radiofluorodestannylation to 6-[{sup 18}F]fluoro-1-dopa

    DOE Patents [OSTI]

    Satyamurthy, N.; Barrio, J.R.; Bishop, A.J.; Namavari, M.; Bida, G.T.

    1996-04-23

    A process is revealed for forming a 6-fluoro derivative of compounds in the L-Dopa family comprising the steps of protecting the groups attached to the benzene ring in the compound followed by serially reacting the protected compound with (a) iodine and silver trifluoroacetic acid; (b) Bb{sub 3}; (c) dit-butyldicarbonate; (d) hexamethyltin; (e) a fluoro compound; (f) hydrobromic acid; and (g) raising the pH to {<=}7. 1 fig.

  13. Synthesis of N-formyl-3,4-di-t-butoxycarbonyloxy-6-(trimethylstannyl)-L-phenylalanine ethyl ester and its regioselective radiofluorodestannylation to 6- .sup.18 F!fluoro-1-dopa

    DOE Patents [OSTI]

    Satyamurthy, Nagichettiar; Barrio, Jorge R.; Bishop, Allyson J.; Namavari, Mohammad; Bida, Gerald T.

    1996-01-01

    A process for forming a 6-fluoro derivative of compounds in the L-Dopa family comprising the steps of protecting the groups attached to the benzene ring in the compound followed by serially reacting the protected compound with (a) iodine and silver trifluoroacetic acid; (b) Bb.sub.3 ; (c) dit-butyldicarbonate; (d) hexamethyltin; (e) a fluoro compound; (f) hydrobromic acid; and (g) raising the pH to .ltoreq.7.

  14. Process for reducing organic compounds with calcium, amine, and alcohol

    DOE Patents [OSTI]

    Benkeser, R.A.; Laugal, J.A.; Rappa, A.

    1985-08-06

    Olefins are produced by contacting an organic compound having at least one benzene ring with calcium metal, ethylenediamine, a low molecular weight aliphatic alcohol, and optionally a low molecular weight aliphatic primary amine, and/or an inert, abrasive particulate substance. The reduction is conducted at temperatures ranging from about [minus]10 C to about 30 C or somewhat higher. Substantially all of the organic compounds are converted to corresponding cyclic olefins, primarily diolefins.

  15. Integrated experimental and theoretical study of the thermophysical properties of fluid mixtures. Annual report, September 1984-September 1985

    SciTech Connect (OSTI)

    Haynes, W.M.

    1985-01-01

    This report summarizes the work done in the twelve months from September 30, 1984. Results include: PVT data for methanol (to 300/sup 0/C) and benzene (to 450/sup 0/C); basic studies of a fluid in nonequilibrium; high temperature VLE data for CO/sub 2//butane; viscosity experimental data and predictive procedures on association for coal liquids, and results on the phenomenon of shear induced phase changes.

  16. Joint Center for Energy Storage Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    August 25, 2016, Research Highlights The Lightest Organic Radical Cation for Charge Storage in Redox Flow Batteries By systematically shedding molecular fragments of 2,5-di-tert-butyl-1,4-bis(2-methoxyethoxy)benzene that are considered important for radical cation steric stabilization, we discovered a minimalistic structure that retains long-term stability in its oxidized form and exhibits the intrinsic capacity of 161 mAh/g. Read More August 24, 2016, Videos Sparingly Solvating Electrolytes

  17. Novel cross-linked polystyrenes with large space network as tailor-made catalyst supports for sustainable media

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Marrocchi, Assunta; Adriaensens, Peter; Bartollini, Elena; Barkakaty, Balaka; Carleer, Robert; Chen, Jihua; Hensley, Dale K.; Petrucci, Chiara; Tassi, Marco; Vaccaro, Luigi

    2015-10-09

    For a novel class of polystyrene-based gel-type resins (SPACeR, SP), containing the large 1,4-bis (4-vinylphenoxy)benzene cross-linker, is introduced; SP-immobilized 1,5,7-triazabicyclo [4.4.0]dec-5-ene (TBD) and triethylamine (TEA) bases are synthesized and characterized in terms of their structural, thermal and morphological features, and their catalytic efficiency in a series of fundamental chemical transformations under solvent-free conditions is investigated.

  18. Molecular near-field antenna effect in resonance hyper-Raman scattering: Intermolecular vibronic intensity borrowing of solvent from solute through dipole-dipole and dipole-quadrupole interactions

    SciTech Connect (OSTI)

    Shimada, Rintaro; Hamaguchi, Hiro-o

    2014-05-28

    We quantitatively interpret the recently discovered intriguing phenomenon related to resonance Hyper-Raman (HR) scattering. In resonance HR spectra of all-trans-?-carotene (?-carotene) in solution, vibrations of proximate solvent molecules are observed concomitantly with the solute ?-carotene HR bands. It has been shown that these solvent bands are subject to marked intensity enhancements by more than 5 orders of magnitude under the presence of ?-carotene. We have called this phenomenon the molecular-near field effect. Resonance HR spectra of ?-carotene in benzene, deuterated benzene, cyclohexane, and deuterated cyclohexane have been measured precisely for a quantitative analysis of this effect. The assignments of the observed peaks are made by referring to the infrared, Raman, and HR spectra of neat solvents. It has been revealed that infrared active and some Raman active vibrations are active in the HR molecular near-field effect. The observed spectra in the form of difference spectra (between benzene/deuterated benzene and cyclohexane/deuterated cyclohexane) are quantitatively analyzed on the basis of the extended vibronic theory of resonance HR scattering. The theory incorporates the coupling of excited electronic states of ?-carotene with the vibrations of a proximate solvent molecule through solutesolvent dipoledipole and dipolequadrupole interactions. It is shown that the infrared active modes arise from the dipoledipole interaction, whereas Raman active modes from the dipolequadrupole interaction. It is also shown that vibrations that give strongly polarized Raman bands are weak in the HR molecular near-field effect. The observed solvent HR spectra are simulated with the help of quantum chemical calculations for various orientations and distances of a solvent molecule with respect to the solute. The observed spectra are best simulated with random orientations of the solvent molecule at an intermolecular distance of 10.

  19. Liquid electrode

    DOE Patents [OSTI]

    Ekechukwu, Amy A.

    1994-01-01

    A dropping electrolyte electrode for use in electrochemical analysis of non-polar sample solutions, such as benzene or cyclohexane. The liquid electrode, preferably an aqueous salt solution immiscible in the sample solution, is introduced into the solution in dropwise fashion from a capillary. The electrolyte is introduced at a known rate, thus, the droplets each have the same volume and surface area. The electrode is used in making standard electrochemical measurements in order to determine properties of non-polar sample solutions.

  20. (E)-4-[(4-nitrophenyl)diazenyl]phenyl anthracene-9-carboxylate.

    SciTech Connect (OSTI)

    Vance, Andrew L.; Zifer, Thomas; Nichol, Jessica L.; Rodriguez, Mark Andrew; Leonard, Francois Leonard; Wong, Bryan Matthew

    2008-10-01

    In the title compound, C{sub 27}H{sub 17}N{sub 3}O{sub 4}, the azo group displays a trans conformation and the dihedral angles between the central benzene ring and the pendant anthracene and nitrobenzene rings are 82.94 (7) and 7.30 (9){sup o}, respectively. In the crystal structure, weak C-H...O hydrogen bonds, likely associated with a dipole moment present on the molecule, help to consolidate the packing.

  1. Efficiency of clay-TiO2 nanocomposites on the photocatalytic eliminationof a model hydrophobic air pollutant

    SciTech Connect (OSTI)

    Kibanova, Daria; Cervini-Silva, Javiera; Destaillats, Hugo

    2009-01-01

    Clay-supported TiO2 photocatalysts can potentially improve the performance of air treatment technologies via enhanced adsorption and reactivity of target volatile organic compounds (VOCs). In this study, a bench-top photocatalytic flow reactor was used to evaluate the efficiency of hectorite-TiO2 and kaolinite-TiO2, two novel composite materials synthesized in our laboratory. Toluene, a model hydrophobic VOC and a common indoor air pollutant, was introduced in the air stream at realistic concentrations, and reacted under UVA (gamma max = 365 nm) or UVC (gamma max = 254 nm) irradiation. The UVC lamp generated secondary emission at 185 nm, leading to the formation of ozone and other short-lived reactive species. Performance of clay-TiO2 composites was compared with that of pure TiO2 (Degussa P25), and with UV irradiation in the absence of photocatalyst under identical conditions. Films of clay-TiO2 composites and of P25 were prepared by a dip-coating method on the surface of Raschig rings, which were placed inside the flow reactor. An upstream toluene concentration of ~;;170 ppbv was generated by diluting a constant flow of toluene vapor from a diffusion source with dry air, or with humid air at 10, 33 and 66percent relative humidity (RH). Toluene concentrations were determined by collecting Tenax-TA (R) sorbent tubes downstream of the reactor, with subsequent thermal desorption -- GC/MS analysis. The fraction of toluene removed, percentR, and the reaction rate, Tr, were calculated for each experimental condition from the concentration changes measured with and without UV irradiation. Use of UVC light (UV/TiO2/O3) led to overall higher reactivity, which can be partially attributed to the contribution of gas phase reactions by short-lived radical species. When the reaction rate was normalized to the light irradiance, Tr/I gamma, the UV/TiO2 reaction under UVA irradiation was more efficient for samples with a higher content of TiO2 (P25 and Hecto-TiO2), but not for Kao

  2. ELECTRON-DRIVEN REACTIONS IN PROTO-PLANETARY ATMOSPHERES: METASTABLE ANIONS OF GASEOUS o-BENZYNE

    SciTech Connect (OSTI)

    Carelli, F.; Sebastianelli, F.; Baccarelli, I.; Gianturco, F. A.

    2010-03-20

    In this paper, we present an investigation into low-energy electron scattering (E < 15 eV) processes from a specific benzene-like polyatomic target such as ortho-benzyne, o-C{sub 6}H{sub 4}({sup 1}SIGMA), in order to gain a better understanding of the effects that possible low-lying metastable electron-attachment states could have on its nuclear fragmentation dynamics. The current importance of the dynamical evolution of this molecule lies in the fact that o-C{sub 6}H{sub 4} is considered to be relevant for the circumstellar synthesis of large polycyclic aromatic hydrocarbons (PAHs), as a precursor for C{sub 6}H{sub 6} production via ion-based ring closure reaction from C{sub 2}H{sub 2}. Our parameter-free scattering calculations are performed within the molecular reference frame, where we obtain the metastable anionic states for the nuclear equilibrium configuration and further characterize the properties of such transient anions with respect to those found earlier for the benzene molecule. Our quantum studies indicate that o-C{sub 6}H{sub 4} is a more efficient producer of compact, fairly long-lived anionic intermediates than benzene itself; hence, this should more rapidly enter the chemical reaction cycles of PAHs formation, thereby disappearing from possible direct observation as a stable anion.

  3. An Assessment of Density Functional Methods for Potential Energy Curves of Nonbonded Interactions: The XYG3 and B97-D Approximations

    SciTech Connect (OSTI)

    Vazquez-Mayagoitia, Alvaro; Sherrill, David; Apra, Edoardo; Sumpter, Bobby G

    2010-01-01

    A recently proposed double-hybrid functional called XYG3 and a semilocal GGA functional (B97-D) with a semiempirical correction for van der Waals interactions have been applied to study the potential energy curves along the dissociation coordinates of weakly bound pairs of molecules governed by London dispersion and induced dipole forces. Molecules treated in this work were the parallel sandwich, T-shaped, and parallel-displaced benzene dimer, (C6H6)2; hydrogen sulfide and benzene, H2S C6H6; methane and benzene, CH4 C6H6; the methane dimer, (CH4)2; and the pyridine dimer, (C5H5N)2. We compared the potential energy curves of these functionals with previously published benchmarks at the coupled cluster singles, doubles, and perturbative triplets [CCSD(T)] complete-basis-set limit. Both functionals, XYG3 and B97-D, exhibited very good performance, reproducing accurate energies for equilibrium distances and a smooth behavior along the dissociation coordinate. Overall, we found an agreement within a few tenths of one kcal mol-1 with the CCSD(T) results across the potential energy curves.

  4. Health-hazard evaluation report No. HETA-88-377-2120, Armco Coke Oven, Ashland Kentucky

    SciTech Connect (OSTI)

    Kinnes, G.M.; Fleeger, A.K.; Baron, S.L.

    1991-06-01

    In response to a request from the Oil, Chemical and Atomic Workers International Union, a study was made of possible hazardous working conditions at ARMCO Coke Oven (SIC-3312), Ashland, Kentucky. The facility produces about 1,000,000 tons of coke annually. Of the approximately 400 total employees at the coke oven site, 55 work in the by products area. Air quality sampling results indicated overexposure to both benzene (71432) and coal tar pitch volatiles (CTPVs). Airborne levels of benzene ranged as high as 117 parts per million (ppm) with three of 17 samples being above the OSHA limit of 1ppm. Airborne concentrations of CTPVs ranged as high as 0.38mg/cu m with two of six readings being above OSHA limit of 0.2mg/cu m. Several polynuclear aromatic hydrocarbons were also detected. The authors conclude that by products area workers are potentially overexposed to carcinogens, including benzene, CTPVs, and polynuclear aromatic hydrocarbons. An epidemiologic study is considered unlikely to yield meaningful information at this time, due to the small number of workers and the short follow up period. The authors recommend specific measures for reducing potential employee exposures, including an environmental sampling program, a preventive maintenance program, improved housekeeping procedures, and reducing exposure in operators' booths.

  5. Flash pyrolysis of biomass with reactive and non-reactive gases

    SciTech Connect (OSTI)

    Steinberg, M.; Fallon, P.T.; Sundaram, M.S.

    1984-03-01

    The process chemistry of the flash pyrolysis of biomass (wood) with the reactive gases, H/sub 2/ and CH/sub 4/ and with the non-reactive gases He and N/sub 2/ is being determined in an 1'' downflow tubular reactor at pressures from 20 to 1000 psi and temperatures from 600 to 1000/sup 0/C. With hydrogen, flash hydropyrolysis leads to high yields of ethylene, benzene and CO which can be used for the production of valuable chemical feedstocks and methanol transportation fuel. At reactor conditions of 50 psi and 1000/sup 0/C and approximately 1 sec residence time, the ethylene yield based on pine wood carbon conversion is 27%, for benzene it is 25% and for CO the yield is 39%, indicating that over 90% of the carbon in pine is converted to valuable products. Pine wood produces higher yields of hydrocarbon products than Douglas fir wood. The yield of ethylene is 2.3 times higher with methane than with helium or nitrogen, thus indicating a free radical reaction between CH/sub 4/ and the pyrolyzed wood. There appears to be no net production or consumption of methane. A preliminary process design and analysis indicate an economically competitive system for the production of ethylene, benzene and methanol based on the methanolysis of wood. 7 references, 13 figures, 1 table.

  6. Flash pyrolysis of biomass with reactive and non-reactive gases. Summary report, March 1982-March 1983

    SciTech Connect (OSTI)

    Steinberg, M.; Fallon, P.T.; Sundaram, M.S.

    1983-03-01

    The process chemistry of the flash pyrolysis of biomass (wood) with the reactive gases, H/sub 2/ and CH/sub 4/ and with the non-reactive gas He is being determined in a 1'' downflow tubular reactor at pressures from 20 to 1000 psi and temperatures from 600 to 1000/sup 0/C. With hydrogen, flash hydropyrolysis leads to high yields of methane and CO which can be used for SNG and methanol production. With methane, flash methanolysis of wood, leads to high yields of ethylene, benzene and CO which can be used for the production of valuable feedstocks and methanol fuel. At reactor conditions of 50 psi and 1000/sup 0/C and approximately 1 sec residence time, the ethylene yield based on wood carbon converted is 22%, benzene 12% and the CO yield is 48%. The yield of ethylene is 2.2 times higher with methane than with helium, thus indicating a free radical rection between CH/sub 4/ and the pyrolyzed wood. A preliminary process analysis indicates an economically competitive process for the production of ethylene, benzene and methanol based on the methanolysis of wood. It is recommended to further develop the data base for the flash pyrolysis of wood and other biomass materials with methane as well as with other reactive gases (e.g. CO and CO/sub 2/) and determine the role of the hemi-cellulose and lignin in the formation of these valuable fuels and feedstocks.

  7. Hydrogen-Bond Networks: Strengths of Different Types of Hydrogen Bonds and An Alternative to the Low Barrier Hydrogen-Bond Proposal

    SciTech Connect (OSTI)

    Shokri, Alireza; Wang, Yanping; O'Doherty, George A.; Wang, Xue B.; Kass, Steven R.

    2013-11-27

    We report quantifying the strengths of different types of hydrogen bonds in hydrogen bond networks (HBNs) via measurement of the adiabatic electron detachment energy of the conjugate base of a small covalent polyol model compound (i.e., (HOCH2CH2CH(OH)CH2)2CHOH) in the gas phase and the pKa of the corresponding acid in DMSO. The latter result reveals that the hydrogen bonds to the charged center and those that are one solvation shell further away (i.e., primary and secondary) provide 5.3 and 2.5 pKa units of stabilization per hydrogen bond in DMSO. Computations indicate that these energies increase to 8.4 and 3.9 pKa units in benzene and that the total stabilizations are 16 (DMSO) and 25 (benzene) pKa units. Calculations on a larger linear heptaol (i.e., (HOCH2CH2CH(OH)CH2CH(OH)CH2)2CHOH) reveal that the terminal hydroxyl groups each contribute 0.6 pKa units of stabilization in DMSO and 1.1 pKa units in benzene. All of these results taken together indicate that the presence of a charged center can provide a powerful energetic driving force for enzyme catalysis and conformational changes such as in protein folding due to multiple hydrogen bonds in a HBN.

  8. Characterization of Cerro Negro crude. Part II. Chemical analysis. [Project sponsored by Bartlesville Energy Technology Center and Institute de Tecnologico del Venezolana Petroleo

    SciTech Connect (OSTI)

    Sturm, G.P. Jr.; Grindstaff, Q.G.; Hirsch, D.E.; Scheppele, S.E.; Hazos, M.

    1981-09-01

    The cooperative research program is explained in Part I. An evaluation is presented of the resolution attained in the separation of a 425 to 550/sup 0/C petroleum distillate fraction according to compound classes using 2 chromatographic methods. Samples were separated by high performance liquid chromatography using 2 columns in series containing 2,4-dinitroanalinopropyl silica and silica, respectively. Initial elution was attained using 1% methylene chloride in pentane followed by a linear gradient up to 30% methylene chloride. In the 2nd method, developed in the American Petroleum Institute's Research Project 60, fractions designated as saturates, monoaromatics, diaromatics, and polyaromatics were collected froma dual silica/alumina column using step gradient elution with pentane, 5% benzene in pentane, 15% benzene in pentane, and 20% ethyl ether, 20% benzene, 60% methanol, followed by pure methanol. The results wil be used to evaluate the quality of the separation in terms of the success in producing fractions containing similar compound classes. 1 figure, 4 tables.

  9. Health-hazard evaluation report HETA 84-033-1576, Airco Carbon, St. Marys, Pennsylvania

    SciTech Connect (OSTI)

    Hartle, R.W.; Morawetz, J.S.

    1985-09-01

    Environmental and breathing-zone samples were analyzed for polynuclear aromatic hydrocarbons (PAH), total particulates, and respirable free silica at the Airco Company (SIC-3624), Saint Marys, Pennsylvania in January, 1984. The evaluation was requested confidentially because of concern over exposures to soot, coal tar pitch volatiles, and sand in the car bottom and sagger bake operations. Forty-three employees were interviewed. Two of 19 total particulate samples exceeded the OSHA standard of 15 milligrams per cubic meter (mg/m3), 17.3 and 32.7 mg/m3. Benzene soluble fractions ranged from 0.5 to 5.0 mg/m3. The OSHA standard for benzene soluble fractions is 0.2 mg/m3. Two of seven samples of silica were above the limit of detection, 0.09 and 0.06 mg/m3. In bulk samples, the benzene soluble fractions ranged from 0.44 to 860 mg/gram and the PAH content from 0 to 26,124 micrograms per gram. Employees working in the bake areas reported a significant excess incidence of symptoms such as skin, nose and eye irritation, cough, sore or dry throat, chest tightness, and breathing difficulty. The authors conclude that a health hazard exists at the facility. Recommendations include enclosing vehicles used in moving electrodes, cleaning up spilled dust, and controlling fumes emitted from the sagger kilns.

  10. Design and evaluation of Cities Service/Rockwell hydrogasification commercial plant

    SciTech Connect (OSTI)

    Agrawal, P.D.; Butt, N.M.; Sarma, K.R.

    1980-08-01

    This report covers a preliminary conceptual design and economic evaluation of a commercial scale plant capable of converting high-sulfur bituminous caking coal to a high-Btu pipeline quality SNG. The plant, which has a rated capacity of 250 Billion Btu per day SNG, is based on Cities Service/Rockwell hydrogasification technology. Two cases of plant design were examined to produce cost estimates accurate to +-25% in 1979 dollars. The base case, designed for moderate production of liquids (5.8% conversion of carbon to liquid product), has a cost of SNG of $4.43/MMBtu using the utility financing method (UFM) and $6.42/MMBtu using the discounted cash flow method (DCFM) of financing. The alternate case, zero liquids production, has gas costs of $5.00 (UFM) and $6.96 (DCFM). Further tests by Rockwell have indicated that 11.4% carbon conversion to liquid products (99% benzene) is possible. If the plant is scaled up to produce the same amoung of SNG with this increased yield of liquid, and if the value of the benzene produced is estimated to be $0.90 per gallon, the costs of gas for this case are $4.38/MMBtu (UFM) and $6,48/MMBtu (DCFM). If the value of benzene is taken as $2.00 per gallon, these costs become $3.14/MMBtu (UFM) and $5.23/MMBtu (DCFM). The economic assumptions involved in these calculations are detailed.

  11. Feet on the potential energy surface, head in the pi clouds

    SciTech Connect (OSTI)

    Smith, Quentin

    2011-01-01

    This work presents explorations of the potential energy surface of clusters of atoms and of the interactions between molecules. First, structures of small aluminum clusters are examined and classified as ground states, transition states, or higher-order saddle points. Subsequently, the focus shifts to dispersion-dominated π-π interactions when the potential energy surfaces of benzene, substituted benzene, and pyridine dimers are explored. Because DNA nucleotide bases can be thought of as substituted heterocycles, a natural extension of the substituted benzene and pyridine investigations is to model paired nucleotide bases. Finally, the success of the dispersion studies inspires the development of an extension to the computational method used, which will enable the dispersion energy to be modeled – and the potential energy surface explored – in additional chemical systems. The effective fragment potential (EFP) method is described, as well as various quantum mechanical methods. An ab inito quantum mechanical study of 13-atom aluminum clusters is described. EFP studies of aromatic dimers are reported in which dispersion energy makes a significant contribution to the attraction between monomers. Theory and code development toward a means of computing dispersion energy in mixed ab inito-EFP systems are described.

  12. Octamethyl-octaundecylcyclo[8]pyrrole: A Promising Sulfate Anion Extractant

    SciTech Connect (OSTI)

    Eller, Leah R; Stepien, Marcin; Fowler, Christopher J; Lee, Jeong Tae; Sessler, Jonathan L.; Moyer, Bruce A

    2008-01-01

    The diprotonated form of an organic-solubilized cyclo[8]pyrrole derivative, bearing eight undecyl chains on the {beta}-pyrrolic positions, was found to extract sulfate anion effectively from neutral aqueous media into a toluene organic phase. The kinetics of sulfate anion exchange between the two phases were found to be exceedingly slow in the absence of the phase-transfer catalyst, Aliquat 336-nitrate (A336N), but appreciable in its presence. The bisnitrate anion bound form of this cyclo[8]pyrrole could be generated in situ by subjecting the toluene phase containing initially 0.5 mM of the sulfate anion bound form and 0.1 mM trioctylamine (TOA) to successive equilibrations with aqueous 0.1 M HNO{sub 3} until sulfate was no longer detected in the aqueous phase. This bisnitrate complex, when studied as a 0.5 mM solution in toluene in the presence of 0.1 mM (TOAH){sup +}(NO{sub 3}{sup -}), was also found to be an effective extractant for sulfate anion. D{sub SO4} values of 0.001 and 1000 were observed at 1 M NaNO{sub 3}(aq) and 0.3 mM NaNO{sub 3}(aq), respectively, and the logarithm of the conditional exchange constant, log(K{prime}{sub exch}), was calculated to be 4.9 {+-} 0.4. The present cyclo[8]pyrrole system is thus noteworthy as being the first synthetic receptor that displays a high selectivity for sulfate anion in the presence of excess nitrate under conditions of solvent extraction.

  13. Synthesis and characterization of a series of Group 4 phenoxy-thiol derivatives

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Boyle, Timothy J.; Neville, Michael L.; Parkes, Marie V.

    2016-02-11

    In this study, a series of Group 4 phenoxy-thiols were developed from the reaction products of a series of metal tert-butoxides ([M(OBut)4]) with four equivalents of 4-mercaptophenol (H-4MP). The products were found by single crystal X-ray diffraction to adopt the general structure [(HOBut)(4MP)3M(μ-4MP)]2 [where M = Ti (1), Zr (2), Hf (3)] from toluene and [(py)2M(4MP)] where M = Ti (4), Zr (5) and [(py)(4MP)3Hf(μ-4MP)]2 (6) from pyridine (py). Varying the [Ti(OR)4] precursors (OR = iso-propoxide (OPri) or neo-pentoxide (ONep)) in toluene led to [(HOR)(4MP)3Ti(μ-4MP)]2 (OR = OPri (7), ONep (8)), which were structurally similar to 1. Lower stoichiometric reactionsmore » in toluene led to partial substitution by the 4MP ligands yielding [H][Ti(μ-4MP)(4MP)(ONep)3]2 (9). Independent of the stoichiometry, all of the Ti derivatives were found to be red in color, whereas the heavier congeners were colorless. Attempts to understand this phenomenon led to investigation with a series of varied –SH substituted phenols. From the reaction of H-2MP and H-3MP (2-mercaptophenol and 3-mercaptophenol, respectively), the isolated products had identical arrangements: [(ONep)2(2MP)Ti(μ,η2-2MP)]2 (10) and [(HOR)(3MP)M(μ-3MP)]2 (M/OR = Ti/ONep (11); Zr/OBut (12)) with a similar red color. Based on the simulated and observed UV–Vis spectra, it was reasoned that the color was generated due to a ligand-to-metal charge transfer for Ti that was not available for the larger congeners.« less

  14. Coal conversion processes. Quarterly report, December 13, 1983-March 12, 1984

    SciTech Connect (OSTI)

    Cobb, J.T. Jr.; Biloen, P.; Holder, G.D.; Klinzing, G.E.; Tierney, J.W.

    1984-05-01

    Experimental work is continuing on four separate projects related to coal conversion processes. The direct digital control of exothermic multiphase reactions is being studied in an experimental adiabatic flow reactor. The existence of two stable steady states for the Fischer-Tropsch reaction network at the same temperature and feed condition has been verified and quantified. Various absorbents for SO/sub 2/ and NO/sub X/ are being studied. The absorption of NO/sub 2/ by methanol and N-cyclohexyl-2-pyrrolidone has been extensively examined. Preliminary data have been obtained with triethylene-tetraamine. Hindered amines will be studied next. Procedures for the preparation of liquid membranes have been tested and the incorporation of hindered amines in them will now be examined. Isotopic switching is being used to study the way in which promoters affect supported metal catalysts. With improved resolution from the mass spectrometer, early quantitative results give indications of three different surface species and of non-statistical ingrowth of /sup 13/C into the product molecules. A program for the study of the extraction of coal and oil shale using supercritical fluids is being carried out. The effect of the presence of piperidine on the amount of toluene solubles produced by supercritical extraction of coal with toluene/piperidine mixture has been determined. A new kinetic model for the extraction/liquefaction of coal by supercritical toluene and THF has been developed and proven satisfactory. Bruceton coal and Hi Na lignite have been extracted with supercritical water. 3 references, 7 figures, 6 tables.

  15. Electrically conductive doped block copolymer of polyacetylene and polyisoprene

    DOE Patents [OSTI]

    Aldissi, Mahmoud

    1985-01-01

    An electrically conductive block copolymer of polyisoprene and polyacetyl and a method of making the same are disclosed. The polymer is prepared by first polymerizing isoprene with n-butyllithium in a toluene solution to form an active isoprenyllithium polymer. The active polymer is reacted with an equimolar amount of titanium butoxide and subsequently exposed to gaseous acetylene. A block copolymer of polyisoprene and polyacetylene is formed. The copolymer is soluble in common solvents and may be doped with I.sub.2 to give it an electrical conductivity in the metallic regime.

  16. Electrically conductive doped block copolymer of polyacetylene and polyisoprene. [Soluble in organic solvents

    DOE Patents [OSTI]

    Aldissi, M.

    1984-06-27

    An electrically conductive block copolymer of polyisoprene and polyacetylene and a method of making the same are disclosed. The polymer is prepared by first polymerizing isoprene with n-butyllithium in a toluene solution to form an active isoprenyllithium polymer. The active polymer is reacted with an equimolar amount of titanium butoxide and subsequently exposed to gaseous acetylene. A block copolymer of polyisoprene and polyacetylene is formed. The copolymer is soluble in common solvents and may be doped with I/sub 2/ to give it an electrical conductivity in the metallic regime.

  17. Process for fullerene functionalization

    DOE Patents [OSTI]

    Cahill, P.A.; Henderson, C.C.

    1995-12-12

    Di-addended and tetra-addended Buckminster fullerenes are synthesized through the use of novel organoborane intermediates. The C{sub 60}, C{sub 70}, or higher fullerene is reacted with a borane such as BH{sub 3} in a solvent such as toluene to form an organoborane intermediate. Reaction of the organoborane such as hydrolysis with water or alcohol results in the product di-addended and tetra-addended fullerene in up to 30% yields. Dihydrofullerenes and tetrahydrofullerenes are produced by the process of the invention. 7 figs.

  18. Testing of a model to estimate vapor concentration of various organic chemicals. Master's thesis

    SciTech Connect (OSTI)

    Bakalyar, S.M.

    1990-01-01

    A model developed by Dr. Parker C. Reist to predict the build-up and decay rates of vapor concentrations following a chemical spill and clean-up was tested. The chemicals tested were: acetone, butyl acetate, ethyl acetate, hexane, methylene chloride, methyl ethyl ketone, and toluene. The evaporation rates of these chemicals were determined both by prediction, using a model developed by I. Kawamura and D. Mackay, and empirically and these rates were used in the Reist model. Chamber experiments were done to measure actual building-up and decay of vapor concentrations for simulated spills and simulated clean-up.

  19. Organic Rankine-Cycle Power Systems Working Fluids Study: Topical report No. 3, 2-methylpyridine/water

    SciTech Connect (OSTI)

    Cole, R.L.; Demirgian, J.C.; Allen, J.W.

    1987-09-01

    A mixture of 35 mole percent (mol %) 2-methylpyridine and 65 mol % water was tested at 575, 625, and 675/degree/F in a dynamic loop. Samples of the degraded fluid were chemically analyzed to determine the identities of major degradation products and the quantity of degradation. Computed degradation rates were found to be higher than those for Fluorinol 85 or toluene. For this reason (and other reasons, related to fluid handling), other fluids are recommended as the first choice for service in organic Rankine-cycle systems in preference to 2-methylpyridine/water. 7 refs., 39 figs., 39 tabs.

  20. Catalyst system and process for benzyl ether fragmentation and coal liquefaction

    DOE Patents [OSTI]

    Zoeller, Joseph Robert (Kingsport, TN)

    1998-04-28

    Dibenzyl ether can be readily cleaved to form primarily benzaldehyde and toluene as products, along with minor amounts of bibenzyl and benzyl benzoate, in the presence of a catalyst system comprising a Group 6 metal, preferably molybdenum, a salt, and an organic halide. Although useful synthetically for the cleavage of benzyl ethers, this cleavage also represents a key model reaction for the liquefaction of coal; thus this catalyst system and process should be useful in coal liquefaction with the advantage of operating at significantly lower temperatures and pressures.

  1. Variation of stability constants of thorium and uranium oxalate complexes with ionic strength

    SciTech Connect (OSTI)

    Erten, H.N; Mohammed, A.K.; Choppin, G.R.

    1993-12-31

    Extraction of Th(IV) and UO{sub 2}{sup 2+} by a solution of TTA and HDEHP, respectively, in toluene was used to obtain stability constants of their oxalate complexes in 1, 3, 5, 7 and 9 M ionic strength (NaClO{sub 2}) solutions. The complexes formed were the MOx, MHOx, MOx{sub 2} and M(HOx){sub 2} (M = Th, UO{sub 2}) species. The values were analyzed by the Specific Interaction Theory and agreed to I {le} 3 M but required an additional term for fitting at I > 3 M.

  2. Pervaporation separation of ethanol-water mixtures using polyethylenimine composite membranes

    DOE Patents [OSTI]

    Neidlinger, H.H.; Schissel, P.O.; Orth, R.A.

    1985-06-19

    Synthetic, organic, polymeric membranes were prepared from polyethylenimine for use with pervaporation apparatus in the separation of ethanol-water mixtures. The polymeric material was prepared in dilute aqueous solution and coated onto a polysulfone support film, from which excess polymeric material was subsequently removed. Cross-links were then generated by limited exposure to toluene-2,4-diisocyanate solution, after which the prepared membrane was heat-cured. The resulting membrane structures showed high selectivity in permeating ethanol or water over a wide range of feed concentrations. 2 tabs.

  3. Pervaporation separation of ethanol-water mixtures using polyethylenimine composite membranes

    DOE Patents [OSTI]

    Neidlinger, H.H.; Schissel, P.O.; Orth, R.A.

    1987-04-21

    Synthetic, organic, polymeric membranes were prepared from polyethylenimine for use with pervaporation apparatus in the separation of ethanol-water mixtures. The polymeric material was prepared in dilute aqueous solution and coated onto a polysulfone support film, from which excess polymeric material was subsequently removed. Cross-links were then generated by limited exposure to toluene-2,4-diisocyanate solution, after which the prepared membrane was heat-cured. The resulting membrane structures showed high selectivity in permeating ethanol or water over a wide range of feed concentrations.

  4. Pervaporation separation of ethanol-water mixtures using polyacrylic acid composite membranes

    DOE Patents [OSTI]

    Neidlinger, H.H.

    1985-05-07

    Synthetic, organic, polymeric membranes were prepared from polyacrylic acid salts for use with pervaporation apparatus in the separation of ehthanol-water mixtures. The polymeric material was prepared in dilute aqueous solution and coated onto a polysulfone support film, from which excess polymeric material was subsequently removed. Cross-links were then generated by limited exposure to toluene-2,4-diisocyanata solution, after which the prepared membrane was heat-cured. The resulting membrane structure showed selectivity in permeating water over a wide range of feed concentrations. 4 tabs.

  5. Pervaporation separation of ethanol-water mixtures using polyethylenimine composite membranes

    DOE Patents [OSTI]

    Neidlinger, Hermann H.; Schissel, Paul O.; Orth, Richard A.

    1987-01-01

    Synthetic, organic, polymeric membranes were prepared from polyethylenimine for use with pervaporation apparatus in the separation of ethanol-water mixtures. The polymeric material was prepared in dilute aqueous solution and coated onto a polysulfone support film, from which excess polymeric material was subsequently removed. Cross-links were then generated by limited exposure to toluene-2,4-diisocyanate solution, after which the prepared membrane was heat-cured. The resulting membrane structures showed high selectivity in permeating ethanol or water over a wide range of feed concentrations.

  6. Cascaded organic rankine cycles for waste heat utilization

    DOE Patents [OSTI]

    Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

    2011-05-17

    A pair of organic Rankine cycle systems (20, 25) are combined and their respective organic working fluids are chosen such that the organic working fluid of the first organic Rankine cycle is condensed at a condensation temperature that is well above the boiling point of the organic working fluid of the second organic Rankine style system, and a single common heat exchanger (23) is used for both the condenser of the first organic Rankine cycle system and the evaporator of the second organic Rankine cycle system. A preferred organic working fluid of the first system is toluene and that of the second organic working fluid is R245fa.

  7. Process for fullerene functionalization

    DOE Patents [OSTI]

    Cahill, Paul A.; Henderson, Craig C.

    1995-01-01

    Di-addended and tetra-addended Buckminster fullerenes are synthesized through the use of novel organoborane intermediates. The C.sub.60, C.sub.70, or higher fullerene is reacted with a borane such as BH.sub.3 in a solvent such as toluene to form an organoborane intermediate. Reaction of the organoborane such as hydrolysis with water or alcohol results in the product di-addended and tetra-addended fullerene in up to 30% yields. Dihydrofullerenes and tetrahydrofullerenes are produced by the process of the invention.

  8. Thermal conductivities of Wilsonville solvent and Wilsonville solvent/Illinois No. 6 coal slurry. [Wilsonville solvent

    SciTech Connect (OSTI)

    Wilson, J.H.; Mrochek, J.E.; Johnson, J.K.

    1984-01-01

    Thermal conductivities of a Wilsonville solvent and of a slurry prepared from this solvent and Illinois No. 6 coal have been measured at temperatures from 295 up to 500 K. With increasing temperature, the thermal conductivity varied from 1.23 to 1.02 mW cm/sup -1/ K/sup -1/ (296 to 438 K) and from 1.51 to 1.02 mW cm/sup -1/ K/sup -1/ (295 to 505 K) for the solvent and the slurry, respectively. At room temperature, measurements on toluene were accurate to within 3% of literature values. 18 references, 9 figures, 7 tables.

  9. Poly(ethylene oxide) functionalization

    DOE Patents [OSTI]

    Pratt, Russell Clayton

    2014-04-08

    A simple procedure is provided by which the hydroxyl termini of poly(ethylene oxide) can be appended with functional groups to a useful extent by reaction and precipitation. The polymer is dissolved in warmed toluene, treated with an excess of organic base and somewhat less of an excess of a reactive acylating reagent, reacted for several hours, then precipitated in isopropanol so that the product can be isolated as a solid, and salt byproducts are washed away. This procedure enables functionalization of the polymer while not requiring laborious purification steps such as solvent-solvent extraction or dialysis to remove undesirable side products.

  10. Vapochromic LED

    DOE Patents [OSTI]

    Kunugi, Yoshihito; Mann, Kent R.; Miller, Larry L.; Exstrom, Christopher L.

    2002-01-15

    A sandwich device was prepared by electrodeposition of an insoluble layer of oligomerized tris(4-(2-thienyl)phenyl)amine onto conducting indium-tin oxide coated glass, spin coating the stacked platinum compound, tetrakis(p-decylphenylisocyano)platinum tetranitroplatinate, from toluene onto the oligomer layer, and then coating the platinum complex with aluminum by vapor deposition. This device showed rectification of current and gave electroluminescence. The electroluminescence spectrum (.mu..sub.max =545 nm) corresponded to the photoluminescence spectrum of the platinum complex. Exposure of the device to acetone vapor caused the electroemission to shift to 575 nm. Exposure to toluene vapor caused a return to the original spectrum. These results demonstrate a new type of sensor that reports the arrival of organic vapors with an electroluminescent signal. The sensor comprises (a) a first electrode; (b) a hole transport layer formed on the first electrode; (c) a sensing/emitting layer formed on the hole transport layer, the sensing/emitting layer comprising a material that changes color upon exposure to the analyte vapors; (d) an electron conductor layer formed on the sensing layer; and (e) a second electrode formed on the electron conductor layer. The hole transport layer emits light at a shorter wavelength than the sensing/emitting layer and at least the first electrode comprises an optically transparent material.

  11. Vapochromic LED

    DOE Patents [OSTI]

    Kunugi, Yoshihito; Mann, Kent R.; Miller, Larry L.; Exstrom, Christopher L.

    2003-06-17

    A sandwich device was prepared by electrodeposition of an insoluble layer of oligomerized tris(4-(2-thienyl)phenyl)amine onto conducting indium-tin oxide coated glass, spin coating the stacked platinum compound, tetrakis(p-decylphenylisocyano)platinum tetranitroplatinate, from toluene onto the oligomer layer, and then coating the platinum complex with aluminum by vapor deposition. This device showed rectification of current and gave electroluminescence. The electroluminescence spectrum (.lambda..sub.max =545 nm) corresponded to the photoluminescence spectrum of the platinum complex. Exposure of the device to acetone vapor caused the electroemission to shift to 575 nm. Exposure to toluene vapor caused a return to the original spectrum. These results demonstrate a new type of sensor that reports the arrival of organic vapors with an electroluminescent signal. The sensor comprises (a) a first electrode; (b) a hole transport layer formed on the first electrode; (c) a sensing/emitting layer formed on the hole transport layer, the sensing/emitting layer comprising a material that changes color upon exposure to the analyte vapors; (d) an electron conductor layer formed on the sensing layer; and (e) a second electrode formed on the electron conductor layer. The hole transport layer emits light at a shorter wavelength than the sensing/emitting layer and at least the first electrode comprises an optically transparent material.

  12. Synthesis of flower-like Boehmite (AlOOH) via a simple solvothermal process without surfactant

    SciTech Connect (OSTI)

    Li, Guangci; Liu, Yunqi; Liu, Di; Liu, Lihua; Liu, Chenguang

    2010-10-15

    Boehmite (AlOOH) with hierarchical flower-like structures was synthesized by the solvothermal reaction of AlCl{sub 3}.6H{sub 2}O in the presence of ethanol and toluene at 200 {sup o}C for 24 h. The product was characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that boehmite with flower-like nanostructures, which aggregated together by the weak hydrogen bonds, was formed through dissolution-deposition process of boehmite microcrystals and the toluene has a great effect on the morphology of product in the reaction system. Meanwhile, the {gamma}-Al{sub 2}O{sub 3} was also obtained by calcination of above product at 500 {sup o}C for 2 h, and the flower-like morphology kept no change. The surface area of {gamma}-Al{sub 2}O{sub 3} powder was determined to be 166.8 m{sup 2}/g by N{sub 2} adsorption measurement. The possible formation mechanism of flower-like boehmite nanostructures was proposed and discussed.

  13. Molecular Characterization of Organosulfates in Organic Aerosols from Shanghai and Los Angeles Urban Areas by Nanospray-Desorption Electrospray Ionization High-Resolution Mass Spectrometry

    SciTech Connect (OSTI)

    Tao, Shikang; Lu, Xiaohui; Levac, Nicole A.; Bateman, Adam P.; Nguyen, Tran B.; Bones, David L.; Nizkorodov, Sergey; Laskin, Julia; Laskin, Alexander; Yang, Xin

    2014-08-21

    Aerosol samples collected in the urban areas of Shanghai and Los Angeles were analyzed by nanospray-desorption electrospray ionization mass spectrometry (nano-DESI MS) with high mass resolution (m/?m=100,000). Solvent mixtures of acetonitrile/water and acetonitrile/toluene were used to extract and ionize polar and non-polar compounds, respectively. A diverse mixture of oxygenated hydrocarbons, organosulfates, organonitrates, and organics with reduced nitrogen were detected in the Los Angeles sample. Majority of the organics in the Shanghai sample were detected as organosulfates. The dominant organosulfates in the two samples have distinctly different molecular characteristics. Specifically, organosulfates in the Los Angeles sample were dominated by isoprene- or monoterpene-derived products, while organosulfates of yet unknown origin in the Shanghai sample had distinctive characteristics of long aliphatic carbon chains and low degree of oxidation and unsaturation. The use of acetonitrile/toluene solvent facilitated identification of this type of organosulfates, suggesting they could be missed in previous studies relying on sample extraction using common polar solvents. The high molecular weight and low degree of unsaturation and oxidization of the organosulfates detected in the Shanghai sample suggest that they may act as surfactants, and plausibly affect the surface tension and hygroscopicity of the atmospheric particulate matter. We propose that direct esterification of carbonyl or hydroxyl compounds by sulfates or sulfuric acid in liquid phase could be the formation pathway of these special organosulfates. Long-chain alkanes from vehicle emissions might be their precursors.

  14. Complete recovery of actinides from UREX-like raffinates using a combination of hard and soft donor ligands. II. soft donor structure variation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zalupski, Peter R.; Klaehn, John R.; Peterman, Dean R.

    2015-07-30

    The feasibility of simultaneous separation of uranium, neptunium, plutonium, americium, and curium from a simulated dissolved used fuel simulant adjusted to 1.0 M nitric acid is investigated using a mixture of the soft donor bis(bis-3,5-trifluoromethyl)phenyl) dithiophosphinic acid (“0”) and the hard donor synergist trioctylphosphine oxide (TOPO) dissolved in toluene. The results reported in this work are compared to our recent demonstration of a complete actinide recovery from a simulated dissolved fuel solution using a synergistic combination of bis(o-trifluoromethylphenyl)dithiophosphinic acid (“1”) and TOPO dissolved in either toluene or trifluoromethylphenyl sulfone. While the extraction efficiency of americium was enhanced for the liquid-liquidmore » system containing “0”, enabling to accomplish a trivalent An/Ln separation at 1.0 M HNO3, the extraction of neptunium was drastically diminished, relative to “1”. The partitioning behavior of curium was also negatively impacted, introducing an effective opportunity for americium/curium separation. Radiometric and spectrophotometric studies demonstrate that the complete actinide recovery using the solvent based upon “0” and TOPO is not feasible. Additionally, the importance of radiolytic degradation processes is discussed through the comparisons of extraction properties of liquid-liquid systems based on both soft donor reagents.« less

  15. Anaerobic metabolism of nitroaromatic compounds by sulfate-reducing and methanogenic bacteria

    SciTech Connect (OSTI)

    Boopathy, R.; Kulpa, C.F.

    1994-06-01

    Ecological observations suggest that sulfate-reducing and methanogenic bacteria might metabolize nitroaromatic compounds under anaerobic conditions if appropriate electron donors and electron acceptors are present in the environment, but this ability had not been demonstrated until recently. Most studies on the microbial metabolism of nitroaromatic compounds used aerobic microorganisms. In most cases no mineralization of nitroaromatics occurs, and only superficial modifications of the structures are reported. However, under anaerobic sulfate-reducing conditions, the nitroaromatic compounds reportedly undergo a series of reductions with the formation of amino compounds. For example, trinitrotoluene under sulfate-reducing conditions is reduced to triaminotoluene by the enzyme nitrite reductase, which is commonly found in many Desulfovibrio spp. The removal of ammonia from triaminotoluene is achieved by reductive deamination catalyzed by the enzyme reductive deaminase, with the production of ammonia and toluene. Some sulfate reducers can metabolize toluene to CO{sub 2}. Similar metabolic processes could be applied to other nitroaromatic compounds like nitrobenzene, nitrobenzoic acids, nitrophenols, and aniline. Many methanogenic bacteria can reduce nitroaromatic compounds to amino compounds. In this paper we review the anaerobic metabolic processes of nitroaromatic compounds under sulfate-reducing And methanogenic conditions.

  16. Modeling of autoignition and NO sensitization for the oxidation of IC engine surrogate fuels

    SciTech Connect (OSTI)

    Anderlohr, J.M. |; Bounaceur, R.; Battin-Leclerc, F.; Pires Da Cruz, A.

    2009-02-15

    This paper presents an approach for modeling with one single kinetic mechanism the chemistry of the autoignition and combustion processes inside an internal combustion engine, as well as the chemical kinetics governing the postoxidation of unburned hydrocarbons in engine exhaust gases. Therefore a new kinetic model was developed, valid over a wide range of temperatures including the negative temperature coefficient regime. The model simulates the autoignition and the oxidation of engine surrogate fuels composed of n-heptane, iso-octane, and toluene, which are sensitized by the presence of nitric oxides. The new model was obtained from previously published mechanisms for the oxidation of alkanes and toluene where the coupling reactions describing interactions between hydrocarbons and NO{sub x} were added. The mechanism was validated against a wide range of experimental data obtained in jet-stirred reactors, rapid compression machines, shock tubes, and homogeneous charge compression ignition engines. Flow rate and sensitivity analysis were performed in order to explain the low temperature chemical kinetics, especially the impact of NO{sub x} on hydrocarbon oxidation. (author)

  17. Molecular accessibility in solvent swelled coals. Quarterly report, [April--June 1993

    SciTech Connect (OSTI)

    Kispert, L.D.

    1993-08-01

    The effect of weathering (oxidation and dehydration upon exposure to air) on the molecular accessibility of potential catalysts was studied by the EPR spin probe technique. Fresh samples of all 8 APCS coals were exposed to air for periods up to 36 days. Weathering produced significant effects on the retention of spin probes in most of the APCS coals under 91 % carbon (dmmf). It was determined that the lower ranked coal (Beulah Zap and Wyodak) under went a structural collapse which precluded retention of even spin probe VIII. However, medium ranked coals exhibited improved retention upon weathering when swelled in toluene. Swelling with pyridine opened up small pores for 81--86% carbon which is not observed for swelling with toluene. Changes in coal structure were successfully followed by the EPR spin probe method. A detailed analysis of the data collected from the swelling of coals oxidized in a moisture free environment was completed to differentiate between weathering and oxidation. Eight vacuum dried APCS coals were oxidized in an enclosed, pure oxygen, moisture free environment, and the effects of oxidation alone on coal structure were studied by the intercalation of EPR spin probes. The data shows a factor of 5 increase in spin probe retention for some coals oxidized in O{sub 2} versus air., suggesting a large increase in oxidized material. Particular care was taken during the swelling procedures to avoid exposure of the coal samples to air or moisture. EPR spectra were then obtained for these 300 samples.

  18. Comparison between continuous stirred tank reactor extractor and soxhlet extractor for extraction of El-Lajjun oil shale

    SciTech Connect (OSTI)

    Anabtawi, M.Z. [Univ. of Bahrain, Isa Town (Bahrain)

    1996-02-01

    Extraction on El-Lajjun oil shale in a continuous stirred tank reactor extractor (CSTRE) and a Soxhlet extractor was carried out using toluene and chloroform as solvents. Solvents were recovered using two distillation stages, a simple distillation followed by a fractional distillation. Gas chromotography was used to test for the existence of trapped solvent in the yield. It was found that extraction using a CSTRE gave a 12% increase in yield on average compared with the Soxhlet extractor, and an optimum shale size of 1.0mm offered a better yield and solvent recovery for both techniques. It was also found that an optimum ratio of solvent to oil shale of 2:1 gave the best oil yield. The Soxhlet extractor was found to offer an extraction rate of 1 hour to complete extraction compared with 4 hours in a CSTRE. The yield in a CSTRE was found to increase on increase of stirring. When extraction was carried out at the boiling point of the solvents in a CSTRE, the yield was found to increase by 30% on average compared to that of extraction when the solvent was at room temperature. When toluene was used for extraction, the average amount of bitumen extracted was 0.032 g/g of oil shale and 76.4% of the solvent recovered, compared with 0.037 g/g of oil shale and 84.1% of the solvent recovered using a Soxhlet extractor.

  19. Chemical Characterization of Crude Petroleum Using Nanospray Desorption Electrospray Ionization Coupled with High-Resolution Mass Spectrometry

    SciTech Connect (OSTI)

    Eckert, Peter A.; Roach, Patrick J.; Laskin, Alexander; Laskin, Julia

    2012-02-07

    Nanospray desorption electrospray ionization (nano-DESI) combined with high-resolution mass spectrometry was used for the first time for the analysis of liquid petroleum crude oil samples. The analysis was performed in both positive and negative ionization modes using three solvents one of which (acetonitrile/toluene mixture) is commonly used in petroleomics studies while two other polar solvents (acetonitrile/water and methanol/water mixtures) are generally not compatible with petroleum characterization using mass spectrometry. The results demonstrate that nano-DESI analysis efficiently ionizes petroleum constituents soluble in a particular solvent. When acetonitrile/toluene is used as a solvent, nano-DESI generates electrospray-like spectra. In contrast, strikingly different spectra were obtained using acetonitrile/water and methanol/water. Comparison with the literature data indicates that these solvents selectively extract water-soluble constituents of the crude oil. Water-soluble compounds are predominantly observed as sodium adducts in nano-DESI spectra indicating that addition of sodium to the solvent may be a viable approach for efficient ionization of water-soluble crude oil constituents. Nano-DESI enables rapid screening of different classes of compounds in crude oil samples using solvents that are rarely used for petroleum characterization.

  20. Fuel-Specific Effect of Exhaust Gas Residuals on HCCI Combustion: A Modeling Study

    SciTech Connect (OSTI)

    Szybist, James P

    2008-01-01

    A modeling study was performed to investigate fuel-specific effects of exhaust gas recirculation (EGR) components on homogeneous charge compression ignition (HCCI) combustion at conditions relevant to the negative valve overlap (NVO) strategy using CHEMKIN-PRO. Four single-component fuels with well-established kinetic models were chosen: n-heptane, iso-octane, ethanol, and toluene. These fuels were chosen because they span a wide range of fuel chemistries, and produce a wide compositions range of complete stoichiometric products (CSP). The simulated engine conditions combined a typical spark ignition engine compression ratio (11.34) and high intake charge temperatures (500-550 K) that are relevant to NVO HCCI. It was found that over the conditions investigated, all the fuels had overlapping start of combustion (SOC) phasing, despite the wide range in octane number (RON = 0 to 120). The effect of the EGR components CO2 and H2O was to suppress the compression temperature because of their higher heat capacities, which retarded SOC. For a concentration of O2 higher than the stoichiometric amount, or excess O2, there was an effect of advancing SOC for n-heptane, iso-octane, and toluene, but SOC for ethanol was not advanced. Low temperature heat release (LTHR) for n-heptane was also found to be highly dependent on excess O2, and mild endothermic reaction was observed for cases when excess O2 was not present.

  1. Flash hydropyrolysis and methanolysis of biomass with hydrogen and methane

    SciTech Connect (OSTI)

    Steinberg, M.

    1985-04-01

    The process chemistry of the flash pyrolysis of biomass (wood) with the reactive gases, H/sub 2/ and CH/sub 4/ and with the non-reactive gases He and N/sub 2/ is being determined in a 1 in. downflow tubular reactor at pressures from 20 to 1000 psi and temperatures from 600 to 1000/sup 0/C. With hydrogen, flash hydropyrolysis leads to high yields of methane and CO which can be used for SNG and methanol fuel production. With methane, flash methanolysis leads to high yields of ethylene, benzene and CO which can be used for the production of valuable chemical feedstocks and methanol transportation fuel. At reactor conditions of 50 psi and 1000/sup 0/C and approximately 1 sec residence time, the yields based on pine wood carbon conversion are up to 30% for ethylene, 25% for benzene, and 45% for CO, indicating that over 90% of the carbon in pine is converted to valuable products. Pine wood produces higher yields of hydrocarbon products than Douglas fir wood; the yield of ethylene is 2.3 times higher with methane than with helium or nitrogen, and for pine, the ratio is 7.5 times higher. The mechanism appears to be a free radical reaction between CH/sub 4/ and the pyrolyzed wood. There appears to be no net production or consumption of methane. A preliminary process design and analysis indicates an economically competitive system for the production of ethylene, benzene and methanol based on the methanolysis of wood. 8 refs., 18 figs., 1 tab.

  2. Flash pyrolysis of biomass with reactive and non-reactive gases

    SciTech Connect (OSTI)

    Steinberg, M.; Fallon, P.T.; Sundaram, M.S.

    1985-03-01

    The process chemistry of the flash pyrolysis of biomass (wood) with the reactive gases, H/sub 2/ and CH/sub 4/ and with the non-reactive gases He and N/sub 2/ is being determined in a 1'' downflow tubular reactor at pressures from 20 to 1000 psi and temperatures from 600 to 1000/sup 0/C. With hydrogen, flash hydropyrolysis leads to high yields of methane and CO which can be used for SNG and methanol fuel production. With methane, flash methanolysis leads to high yields of ethylene, benzene and CO which can be used for the production of valuable chemical feedstocks and methanol transportation fuel. At reactor conditions of 50 psi and 1000/sup 0/C and approximately 1 sec residence time, the yields based on pine wood carbon conversion are up to 30% for ethylene, 25% for benzene, and 45% for CO, indicating that over 90% of the carbon in pine is converted to valuable products. Pine wood produces higher yields of hydrocarbon products than Douglas fir wood; the yield of ethylene is 2.3 times higher with methane than with helium or nitrogen, and for pine, the ratio is 7.5 times higher. The mechanism appears to be a free radical reaction between CH/sub 4/ and the pyrolyzed wood. There appears to be no net production or consumption of methane. A preliminary process design and analysis indicates an economically competitive system for the production of ethylene, benzene and methanol based on the methanolysis of wood. 8 refs., 18 figs., 1 tab.

  3. Impact of California Phase 2 reformulated gasoline on atmospheric reactivity of exhaust and evaporative emissions

    SciTech Connect (OSTI)

    Kirchstetter, T.W.; Singer, B.C.; Harley, R.A.; Kendall, G.R.; Traverse, M.

    1997-12-31

    Phase 2 of California`s reformulated gasoline (RFG) program took effect statewide in the first half of 1996. Changes to gasoline composition required by Phase 2 specifications included: lower vapor pressure; lower olefin, aromatic, benzene, and sulfur content; lower T50 and T90; and a minimum oxygen content. In this paper, impacts of Phase 2 RFG on the atmospheric reactivity of motor vehicle exhaust and evaporative emissions are described. Volatile organic compounds in motor vehicle exhaust were measured at the Caldecott tunnel in summer 1995 and 1996. Aggregate emissions of greater than 8000 vehicles were measured each day. Regular and premium grade gasoline samples were collected from service stations in Berkeley concurrently with tunnel measurements both summers. Liquid gasoline samples and their headspace vapors were analyzed to determine detailed chemical composition. Normalized reactivity was calculated for exhaust and evaporative emissions by applying maximum incremental reactivity values to the detailed speciation profiles. Results indicate that the composition of gasoline in 1996 differed markedly from that of 1995. Changes in liquid gasoline composition led to corresponding changes in the speciation of vehicle exhaust and of gasoline headspace vapors. Benzene concentration in liquid gasoline decreased from 2.0 to 0.6 wt%, which contributed to a 70 and 37% reduction in benzene weight fraction in headspace vapors and vehicle exhaust, respectively. Addition of MTBE and reduction of olefins and aromatics in gasoline led to significant reductions in the atmospheric reactivity of unburned gasoline and gasoline headspace vapors. The normalized reactivity of liquid gasoline and headspace vapors decreased by 23 and 19%, respectively, between 1995 and 1996. The normalized reactivity of non-methane organic compounds in vehicle exhaust decreased by about 8%, but the uncertainty in this change was large.

  4. Use of 2,5-dimethyl-2,5-hexane diamine as a curing agent for epoxy resins

    DOE Patents [OSTI]

    Rinde, James A. [Livermore, CA; Newey, Herbert A. [Lafayette, CA

    1981-02-24

    Primary diamines of the formula ##STR1## wherein R is a straight chain saturated hydrocarbon of 2 to 4 carbons, a disubstituted benzene ring, or disubstituted dibenzo methane for use as a curing agent for epoxy resins. These curing agents can be used to form epoxy resin mixtures useful in filament winding and pre-impregnated fiber molding and in formulating film adhesives, powder coatings and molding powders. The epoxy mixtures form for such uses as room temperature non-reacting, intermediate stable state which has a latent cross-linking capability.

  5. Use of 2,5-dimethyl-2,5-hexane diamine as a curing agent for epoxy resins

    DOE Patents [OSTI]

    Rinde, J.A.; Newey, H.A.

    1981-02-24

    Primary diamines are disclosed of the formula shown in a diagram wherein R is a straight chain saturated hydrocarbon of 2 to 4 carbons, a disubstituted benzene ring, or disubstituted dibenzomethane for use as a curing agent for epoxy resins. These curing agents can be used to form epoxy resin mixtures useful in filament winding and pre-impregnated fiber molding and in formulating film adhesives, powder coatings and molding powders. The epoxy mixtures form for such uses as room temperature non-reacting, intermediate stable state which has a latent cross-linking capability.

  6. Complex absorbing potential based Lorentzian fitting scheme and time dependent quantum transport

    SciTech Connect (OSTI)

    Xie, Hang Kwok, Yanho; Chen, GuanHua; Jiang, Feng; Zheng, Xiao

    2014-10-28

    Based on the complex absorbing potential (CAP) method, a Lorentzian expansion scheme is developed to express the self-energy. The CAP-based Lorentzian expansion of self-energy is employed to solve efficiently the Liouville-von Neumann equation of one-electron density matrix. The resulting method is applicable for both tight-binding and first-principles models and is used to simulate the transient currents through graphene nanoribbons and a benzene molecule sandwiched between two carbon-atom chains.

  7. A low energy electron microscopy study of the initial growth, structure, and thermal stability of 4,4{sup '}-biphenyldicarboxylic acid domains on Cu(001)

    SciTech Connect (OSTI)

    Khokhar, Fawad S.; Gastel, Raoul van; Schwarz, Daniel; Zandvliet, Harold J. W.; Poelsema, Bene

    2011-09-28

    The growth of 4,4{sup '}-biphenyldicarboxylic acid (BDA) on Cu(001) has been studied using low energy electron microscopy and selective area low energy electron diffraction. The emergence of large islands and hydrogen bonding to perpendicularly oriented, adjacent molecules is confirmed. The two benzene rings of adsorbed BDA are twisted along the molecular axis. Unconventional growth of the domains, followed by a second nucleation stage, is observed at room temperature. This unanticipated feature is attributed to the accumulation of stress in the islands. Ostwald ripening in the films and the decay of BDA domains at 448 K exhibits features that are consistent with diffusion limited behavior.

  8. An x-ray setup to investigate the atomic order of confined liquids in slit geometry

    SciTech Connect (OSTI)

    Lippmann, M.; Ehnes, A.; Seeck, O. H.

    2014-01-15

    A setup has been designed to investigate thin films of confined liquids with the use of X-ray scattering methods. The confinement is realized between the flat culets of a pair of diamonds by positioning and orienting the lower diamond with nanometer and micro radian accuracy. We routinely achieve gaps between 5 and 50 nm at culet diameters of 200 ?m. With this setup and a micro focused X-ray beam we have investigated the in-plane and the out-off-plane atomic order of benzene with atomic resolution.

  9. Monolayer-induced band shifts at Si(100) and Si(111) surfaces

    SciTech Connect (OSTI)

    Mkinen, A. J. Kim, Chul-Soo; Kushto, G. P.

    2014-01-27

    We report our study of the interfacial electronic structure of Si(100) and Si(111) surfaces that have been chemically modified with various organic monolayers, including octadecene and two para-substituted benzene derivatives. X-ray photoelectron spectroscopy reveals an upward band shift, associated with the assembly of these organic monolayers on the Si substrates, that does not correlate with either the dipole moment or the electron withdrawing/donating character of the molecular moieties. This suggests that the nature and quality of the self-assembled monolayer and the intrinsic electronic structure of the semiconductor material define the interfacial electronic structure of the functionalized Si(100) and Si(111) surfaces.

  10. Recent progress in electron scattering from atoms and molecules

    SciTech Connect (OSTI)

    Brunger, M. J.; Buckman, S. J.; Sullivan, J. P.; Palihawadana, P.; Jones, D. B.; Chiari, L.; Pettifer, Z.; Silva, G. B. da; Lopes, M. C. A.; Duque, H. V.; Masin, Z.; Gorfinkiel, J. D.; Garcia, G.; Hoshino, M.; Tanaka, H.; Limo-Vieira, P.

    2014-03-05

    We present and discuss recent results, both experimental and theoretical (where possible), for electron impact excitation of the 3s[3/2 ]{sub 1} and 3s?[1/2 ]{sub 1} electronic states in neon, elastic electron scattering from the structurally similar molecules benzene, pyrazine, and 1,4-dioxane and excitation of the electronic states of the important bio-molecule analogue ?-tetrahydrofurfuryl alcohol. While comparison between theoretical and experimental results suggests that benchmarked cross sections for electron scattering from atoms is feasible in the near-term, significant further theoretical development for electron-molecule collisions, particularly in respect to discrete excitation processes, is still required.

  11. Phonon interference effects in molecular junctions

    SciTech Connect (OSTI)

    Markussen, Troels

    2013-12-28

    We study coherent phonon transport through organic, ?-conjugated molecules. Using first principles calculations and Green's function methods, we find that the phonon transmission function in cross-conjugated molecules, like meta-connected benzene, exhibits destructive quantum interference features very analogous to those observed theoretically and experimentally for electron transport in similar molecules. The destructive interference features observed in four different cross-conjugated molecules significantly reduce the thermal conductance with respect to linear conjugated analogues. Such control of the thermal conductance by chemical modifications could be important for thermoelectric applications of molecular junctions.

  12. Laboratory investigations of irradiated acetonitrile-containing ices on an interstellar dust analog

    SciTech Connect (OSTI)

    Abdulgalil, Ali G. M.; Marchione, Demian; Rosu-Finsen, Alexander; Collings, Mark P.; McCoustra, Martin R. S.

    2012-07-15

    Reflection-absorption infrared spectroscopy is used to study the impact of low-energy electron irradiation of acetonitrile-containing ices, under conditions close to those in the dense star-forming regions in the interstellar medium. Both the incident electron energy and the surface coverage were varied. The experiments reveal that solid acetonitrile is desorbed from its ultrathin solid films with a cross section of the order of 10{sup -17} cm{sup 2}. Evidence is presented for a significantly larger desorption cross section for acetonitrile molecules at the water-ice interface, similar to that previously observed for the benzene-water system.

  13. Photo-degradation of Lexan polycarbonate studied using positron lifetime spectroscopy

    SciTech Connect (OSTI)

    Hareesh, K.; Sanjeev, Ganesh; Pandey, A. K.; Meghala, D.; Ranganathaiah, C.

    2013-02-05

    The free volume properties of pristine and UV irradiated Lexan polycarbonate have been investigated using Positron Lifetime Spectroscopy (PLS). The decrease in o-Ps life time and free volume size of irradiated sample is attributed to free volume modification and formation of more stable free radicals. These free radicals are formed due to the breakage of C-O bonds in Lexan polycarbonate after irradiation. This is also supported by the decrease in the intensity of C-O bond after exposure to UV-radiation as studied from Fourier Transform Infrared (FTIR) spectroscopy and it also shows that benzene ring does not undergo any changes after irradiation.

  14. Formation of carbon deposits from coal in an arc plasma

    SciTech Connect (OSTI)

    Wang, B.; Tian, Y.; Zhang, Y.; Zhu, S.; Lu, Y.; Zhang, Y.; Xie, K.

    2007-07-01

    The issue of deposited carbon (DC) on a reactor wall during the production of acetylene by the coal/arc plasma process is a potential obstacle for the industrialization process. The formation mechanism of DC is very difficult to reveal because the high complexity of coal and the volatile matter. Combining with quenching technique, the methane, liquid petroleum gas and benzene were employed as the model materials to roughly act as the light gas, chain and aromatic subcomponents of volatile matter, and then the reasonable formation mechanism of DC was subtly speculated accordingly.

  15. Chemical, FT-IR, and EXAFS study of the interaction between HFe/sub 4/(CH)(CO)/sup 12/ and partially dehydroxylated alumina

    SciTech Connect (OSTI)

    Drezdzon, M.A.; Tessier-Youngs, C.; Woodcock, C.; Blonsky, P.M.; Leal, O.; Teo, B.K.; Burwell, R.L. Jr.; Shriver, D.F.

    1985-07-17

    The initial reaction of HFe/sub 4/(CH)(CO)/sub 12/ with partially dehydroxylated alumina produces (HFe/sub 4/(C)(CO)/sub 12/)/sup -/, which is bound to the surface. Evolution of CO occurs slowly by extensive loss of CO from a small number of cluster molecules. This process leads to the coexistence of intact (HFe/sub 4/(C)(CO)/sub 12/)/sup -/ plus an iron or iron carbide like species. In keeping with this interpretation, the supported material displays activities for the reduction of Co and the hydrogenation of benzene and product distributions that are typical of iron metal.

  16. Process for the production of ethylene and other hydrocarbons from coal

    DOE Patents [OSTI]

    Steinberg, Meyer; Fallon, Peter

    1986-01-01

    A process for the production of economically significant amounts of ethyl and other hydrocarbon compounds, such as benzene, from coal is disclosed wherein coal is reacted with methane at a temperature in the approximate range of 500.degree. C. to 1100.degree. C. at a partial pressure less than about 200 psig for a period of less than 10 seconds. Ethylene and other hydrocarbon compounds may be separated from the product stream so produced, and the methane recycled for further production of ethylene. In another embodiment, other compounds produced, such as by-product tars, may be burned to heat the recycled methane.

  17. Aromatics oxidation and soot formation in flames

    SciTech Connect (OSTI)

    Howard, J.B.; Pope, C.J.; Shandross, R.A.; Yadav, T.

    1993-12-01

    This project is concerned with the kinetics and mechanisms of aromatics oxidation and soot and fullerenes formation in flames. The scope includes detailed measurements of profiles of stable and radical species concentrations in low-pressure one-dimensional premixed flames. Intermediate species identifications and mole fractions, fluxes, and net reaction rates calculated from the measured profiles are used to test postulated reaction mechanisms. Particular objectives are to identify and to determine or confirm rate constants for the main benzene oxidation reactions in flames, and to characterize fullerenes and their formation mechanisms and kinetics.

  18. Measurement of the quantum efficiency of TMAE and TEA from threshold to 120 nm

    SciTech Connect (OSTI)

    Holroyd, R.A.; Preses, J.M.; Woody, C.L.; Johnson, R.A.

    1986-01-01

    Several existing and planned high energy physics experiments incorporate detectors which use either TMAE (tetrakis-dimethylaminoethylene) or TEA (triethylamine) as their photosensitive agent. Understanding the operation of these devices requires knowledge of the absolute photoionization quantum efficiencies and absorption lengths of TMAE and TEA. In an experiment performed at the National Synchrotron Light source at Brookhaven National Laboratory, we have measured these parameters from 120 nm to 280 nm. The quantum efficiencies were normalized to the known photoionization yields of benzene and cis-2-butene. The results of these measurements and details of the experiment are presented in this paper.

  19. Preconversion catalytic deoxygenation of phenolic functional groups. Quarterly technical progress report, January 1, 1992--March 31, 1992

    SciTech Connect (OSTI)

    Kubiak, C.P.

    1992-08-01

    The deoxygenation of phenols is a conceptually simple, but unusually difficult chemical transformation to achieve. The phenolic C-O bond energy of 103 kcal/mol is as strong as a benzene C-H bond and over a 10 kcal/mol stronger than the C-O bonds of methanol and ethanol. The consequence of this is that the hydrogenation/deoxygenation methods in current use require severe conditions and give low selectivities. The ongoing research described herein is based on the unprecedented, but thermodynamically promising, use of carbon monoxide as the oxygen atom acceptor for the catalytic deoxygenation of phenols.

  20. Chemical Kinetics of Combustion Processes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of Combustion Processes Hai Wang B. Yang, J. Camacho, S. Lieb, S. Memarzadeh, S.-K. Gao and S. Koumlis University of Southern California 2010 CEFRC Conference Benzene + O( 3 P) → Products * Overall rate coefficient extensively studied, but the products and branching ratios not well known. * Theoretical challenges in dealing with spin-state crossing. Figure 1. Branching ratios observed as a function of temperature at 4 Torr for (a) m/z=94/93 and m/z=66/65 by magnetic sector mass spectrometer

  1. Liquid electrode

    DOE Patents [OSTI]

    Ekechukwu, A.A.

    1994-07-05

    A dropping electrolyte electrode is described for use in electrochemical analysis of non-polar sample solutions, such as benzene or cyclohexane. The liquid electrode, preferably an aqueous salt solution immiscible in the sample solution, is introduced into the solution in dropwise fashion from a capillary. The electrolyte is introduced at a known rate, thus, the droplets each have the same volume and surface area. The electrode is used in making standard electrochemical measurements in order to determine properties of non-polar sample solutions. 2 figures.

  2. Coal liquefaction with preasphaltene recycle

    DOE Patents [OSTI]

    Weimer, Robert F.; Miller, Robert N.

    1986-01-01

    A coal liquefaction system is disclosed with a novel preasphaltene recycle from a supercritical extraction unit to the slurry mix tank wherein the recycle stream contains at least 90% preasphaltenes (benzene insoluble, pyridine soluble organics) with other residual materials such as unconverted coal and ash. This subject process results in the production of asphaltene materials which can be subjected to hydrotreating to acquire a substitute for No. 6 fuel oil. The preasphaltene-predominant recycle reduces the hydrogen consumption for a process where asphaltene material is being sought.

  3. Partially-Premixed Flames in Internal Combustion Engines

    SciTech Connect (OSTI)

    Robert W. Pitz; Michael C. Drake; Todd D. Fansler; Volker Sick

    2003-11-05

    This was a joint university-industry research program funded by the Partnerships for the Academic-Industrial Research Program (PAIR). The research examined partially premixed flames in laboratory and internal combustion engine environments at Vanderbilt University, University of Michigan, and General Motors Research and Development. At Vanderbilt University, stretched and curved ''tubular'' premixed flames were measured in a unique optically accessible burner with laser-induced spontaneous Raman scattering. Comparisons of optically measured temperature and species concentration profiles to detailed transport, complex chemistry simulations showed good correspondence at low-stretch conditions in the tubular flame. However, there were significant discrepancies at high-stretch conditions near flame extinction. The tubular flame predictions were found to be very sensitive to the specific hydrogen-air chemical kinetic mechanism and four different mechanisms were compared. In addition, the thermo-diffusive properties of the deficient reactant, H2, strongly affected the tubular flame structure. The poor prediction near extinction is most likely due to deficiencies in the chemical kinetic mechanisms near extinction. At the University of Michigan, an optical direct-injected engine was built up for laser-induced fluorescence imaging experiments on mixing and combustion under stratified charge combustion conditions with the assistance of General Motors. Laser attenuation effects were characterized both experimentally and numerically to improve laser imaging during the initial phase of the gasoline-air mixture development. Toluene was added to the isooctane fuel to image the fuel-air equivalence ratio in an optically accessible direct-injected gasoline engine. Temperature effects on the toluene imaging of fuel-air equivalence ratio were characterized. For the first time, oxygen imaging was accomplished in an internal combustion engine by combination of two fluorescence trackers

  4. On the formation and decomposition of C{sub 7}H{sub 8}.

    SciTech Connect (OSTI)

    Klippenstein, S. J.; Harding, L. B.; Georgievskii, Y.; Chemistry; SNL

    2007-01-01

    The kinetics of reactions on the C{sub 7}H{sub 8} surface were studied with state-of-the-art ab initio transition state theory (TST) and master equation methodologies. A priori predictions of the capture rate for C{sub 6}H{sub 5} + CH{sub 3} and for C{sub 7}H{sub 7} + H are obtained from direct variable reaction coordinate TST simulations. These simulations employ small basis set CASPT2 interaction energies coupled with one-dimensional reaction path corrections based on higher level simulations for related reactions. For the C{sub 7}H{sub 7} + H reaction, predictions are obtained for both the total rate and for the branching between toluene, o-isotoluene and p-isotoluene. A mapping of the low energy pathways for isomerization from these three C{sub 7}H{sub 8} isomers identifies a number of processes with barriers at or below the dissociation threshold. Nevertheless, at combustion temperatures the dissociation rates are predicted to exceed the isomerization rates, and it is reasonable to treat the kinetics of each isomer as a simple single well association/dissociation equilibrium. Master equation simulations yield predictions for the temperature and pressure dependence of each of the recombination and dissociation processes, as well as for the C{sub 7}H{sub 7} + H {yields} C{sub 6}H{sub 5} + CH{sub 3} bimolecular reaction. These simulations implement collisional energy transfer probabilities based on the work of Luther and co-workers. The theoretical predictions are found to be in satisfactory agreement with the available experimental data for the photodissociation of toluene, the temperature and pressure dependent dissociation of toluene, and the reaction of benzyl radical with H. For the C{sub 6}H{sub 5} + CH{sub 3} recombination, the theoretical predictions exceed the experimental measurements of Lin and coworkers by a factor of 2 or more for all temperatures.

  5. Illinois biomass resources: annual crops and residues; canning and food-processing wastes. Preliminary assessment

    SciTech Connect (OSTI)

    Antonopoulos, A A

    1980-06-01

    Illinois, a major agricultural and food-processing state, produces vast amounts of renewable plant material having potential for energy production. This biomass, in the form of annual crops, crop residues, and food-processing wastes, can be converted to alternative fuels (such as ethanol) and industrial chemicals (such as furfural, ethylene, and xylene). The present study provides a preliminary assessment of these Illinois biomass resources, including (a) an appraisal of the effects of their use on both agriculture and industry; (b) an analysis of biomass conversion systems; and (c) an environmental and economic evaluation of products that could be generated from biomass. It is estimated that, of the 39 x 10/sup 6/ tons of residues generated in 1978 in Illinois from seven main crops, about 85% was collectible. The thermal energy equivalent of this material is 658 x 10/sup 6/ Btu, or 0.66 quad. And by fermenting 10% of the corn grain grown in Illinois, some 323 million gallons of ethanol could have been produced in 1978. Another 3 million gallons of ethanol could have been produced in the same year from wastes generated by the state's food-processing establishments. Clearly, Illinois can strengthen its economy substantially by the development of industries that produce biomass-derived fuels and chemicals. In addition, a thorough evaluation should be made of the potential for using the state's less-exploitable land for the growing of additional biomass.

  6. A case study on the importance of quality assurance and personnel training in environmental assessment of naturally occurring radionuclides

    SciTech Connect (OSTI)

    Wood, R.P.; Ijaz, T.; Rutz, E.

    1995-12-31

    An independent review of the remedial investigation activities at a Superfund site was performed at the request of the site owners. The site in question was being labeled as containing radioactive contamination by the state environmental protection agency based on the results of the remedial investigation sampling program, which reported above background concentrations of potassium-40 at the site. This determination would have resulted in the entire site being considered as a mixed waste hazard, with extreme consequences for the cleanup actions. The independent review of the site sampling, measurement techniques, data analysis, and report preparation discovered problems with each of these activities. These problems included failing to perform subcontractor quality assurance oversight, as well as internal quality assurance failures related to verification of critical data. Additionally, the staff at both the state environmental protection agency and the remedial contractor were poorly trained in the field of radioactive assessments and statistical data analysis. These problems delayed the site remedial actions on the most important contaminants, including xylene, arsenic, and various metals. The cost of the site remedial investigation was significantly increased, as over $300,000 were spent just on assessing and litigating the potassium-40 health hazard issue. The independent review concluded that the problems were caused by inadequate quality assurance programs compounded by a lack of proper training of the personnel performing the work. Either a good quality assurance program at the remediation contractor or use of effectively trained personnel analyzing the data would likely have avoided the problems.

  7. Computational screening of large molecule adsorption by metal-organic frameworks.

    SciTech Connect (OSTI)

    Allendorf, Mark D.; Greathouse, Jeffery A.

    2010-04-01

    Grand canonical Monte Carlo simulations were performed to investigate trends in low-pressure adsorption of a broad range of organic molecules by a set of metal-organic frameworks (MOFs). The organic analytes considered here are relevant to applications in chemical detection: small aromatics (o-, m-, and p-xylene), polycyclic aromatic hydrocarbons (naphthalene, anthracene, phenanthrene), explosives (TNT and RDX), and chemical warfare agents (GA and VM). The framework materials included several Zn-MOFs (IRMOFs 1-3, 7, 8), a Cr-MOF (CrMIL-53lp), and a Cu-MOF (HKUST-1). Many of the larger organics were significantly adsorbed by the target MOFs at low pressure, which is consistent with the exceptionally high isosteric heats of adsorption (25 kcal/mol - 60 kcal/mol) for this range of analyte. At a higher loading pressure of 101 kPa, the Zn-MOFs show a much higher volumetric uptake than either CrMIL-53-lp or HKUST-1 for all types of analyte. Within the Zn-MOF series, analyte loading is proportional to free volume, and loading decreases with increasing analyte size due to molecular packing effects. CrMIL-53lp showed the highest adsorption energy for all analytes, suggesting that this material may be suitable for low-level detection of organics.

  8. Synthesis and catalytic activity of polysaccharide templated nanocrystalline sulfated zirconia

    SciTech Connect (OSTI)

    Sherly, K. B.; Rakesh, K.

    2014-01-28

    Nanoscaled materials are of great interest due to their unique enhanced optical, electrical and magnetic properties. Sulfate-promoted zirconia has been shown to exhibit super acidic behavior and high activity for acid catalyzed reactions. Nanocrystalline zirconia was prepared in the presence of polysaccharide template by interaction between ZrOCl{sub 2}⋅8H{sub 2}O and chitosan template. The interaction was carried out in aqueous phase, followed by the removal of templates by calcination at optimum temperature and sulfation. The structural and textural features were characterized by powder XRD, TG, SEM and TEM. XRD patterns showed the peaks of the diffractogram were in agreement with the theoretical data of zirconia with the catalytically active tetragonal phase and average crystalline size of the particles was found to be 9 nm, which was confirmed by TEM. TPD using ammonia as probe, FTIR and BET surface area analysis were used for analyzing surface features like acidity and porosity. The BET surface area analysis showed the sample had moderately high surface area. FTIR was used to find the type species attached to the surface of zirconia. UV-DRS found the band gap of the zirconia was found to be 2.8 eV. The benzylation of o-xylene was carried out batchwise in atmospheric pressure and 433K temperature using sulfated zirconia as catalyst.

  9. Modeling gated neutron images of THD capsules

    SciTech Connect (OSTI)

    Wilson, Douglas Carl; Grim, Gary P; Tregillis, Ian L; Wilke, Mark D; Morgan, George L; Loomis, Eric N; Wilde, Carl H; Oertel, John A; Fatherley, Valerie E; Clark, David D; Schmitt, Mark J; Merrill, Frank E; Wang, Tai - Sen F; Danly, Christopher R; Batha, Steven H; Patel, M; Sepke, S; Hatarik, R; Fittinghoff, D; Bower, D; Marinak, M; Munro, D; Moran, M; Hilko, R; Frank, M; Buckles, R

    2010-01-01

    Time gating a neutron detector 28m from a NIF implosion can produce images at different energies. The brighter image near 14 MeV reflects the size and symmetry of the capsule 'hot spot'. Scattered neutrons, {approx}9.5-13 MeV, reflect the size and symmetry of colder, denser fuel, but with only {approx}1-7% of the neutrons. The gated detector records both the scattered neutron image, and, to a good approximation, an attenuated copy of the primary image left by scintillator decay. By modeling the imaging system the energy band for the scattered neutron image (10-12 MeV) can be chosen, trading off the decayed primary image and the decrease of scattered image brightness with energy. Modeling light decay from EJ399, BC422, BCF99-55, Xylene, DPAC-30, and Liquid A leads to a preference from BCF99-55 for the first NIF detector, but DPAC 30 and Liquid A would be preferred if incorporated into a system. Measurement of the delayed light from the NIF scintillator using implosions at the Omega laser shows BCF99-55 to be a good choice for down-scattered imaging at 28m.

  10. Solvent-refined-coal (SRC) process. Determination of trace hydrocarbon, sulfur, and nitrogen compounds in SRC-II process development Unit P-99 gas streams. [Impure hydrogen in recycle gas and low pressure gas processing

    SciTech Connect (OSTI)

    Gray, J.A.; Galli, R.D.; McCracken, J.H.

    1982-02-01

    A knowledge of the identity and concentration of trace hydrocarbon, sulfur, and nitrogen compounds in the various gas streams of the SRC-II Coal Liquefaction Process is needed in order to design the recycle gas purification and low pressure gas processing systems in large-scale plants. This report discusses the results of an experimental study to identify and quantify trace compounds in the various high and low pressure gas streams of SRC-II Process Development Unit P-99. A capillary column trace hydrocarbon analysis has been developed which can quantify 41 hydrocarbons from methane to xylenes in SRC-II gas streams. With more work a number of other hydrocarbons could be quantified. A fixed gas analysis was also developed which can be integrated with the hydrocarbon analysis to yield a complete stream analysis. A gas chromatographic procedure using a flame photometric detector was developed for trace sulfur compounds, and six sulfur compounds were identified and quantified. A chemiluminescence method was developed for determination of NO and NO/sub 2/ down to 10 ppB in concentration. A gas chromatographic procedure using an electron capture detector was developed for HCN analysis down to 5 ppM. Drager tube analyses gave semiquantitative data on HCl and NH/sub 3/ content of the gas streams.

  11. Acid-sludge characterization and remediation improve well productivity and save costs in the Permian Basin

    SciTech Connect (OSTI)

    Wong, T.C.; Hwang, R.J.; Beaty, D.W.; Dolan, J.D.; McCarty, R.A.; Franzen, A.L.

    1997-02-01

    Many oil wells in the Permian Basin have reported sludging problems associated with acid stimulations. The acid sludge is similar among wells and was identified as a viscous emulsion stabilized by asphaltene-rich organic solids. The sludging tendency of the oil increased with the concentrations of asphaltenes and resins, base number of the oil, and ferric ion content in the acid. Only three out of nine commercial acid systems tested were effective in preventing acid-sludge formation; they all use the same novel iron control technology, i.e., catalytic reduction of ferric ions. Several commercial and generic solvent systems were effective in dissolving acid sludge, including mixtures of an aromatic solvent (e.g., xylene) with either isopropyl alcohol (2:1 volume ratio), or ethylene glycol-monobutylether (EGMBE) (2:1 to 3:1 volume ratios). Selection of acid formulations and solvent systems was based on cost effectiveness and operation safety. Field implementation proved successful. If the results of this study had been implemented earlier in the lives of some of the Permian Basin properties, the recovery of 574 BOPD of lost or deferred production from 99 wells could have been realized. This would have resulted in an estimated increased revenue of over US $3 million in 1 year.

  12. Application of emulsifiers in the manufacture of cast boosters and related products

    SciTech Connect (OSTI)

    Joginadham, C.; Shankar, P.S.; Gupta, A.N.

    1996-12-01

    Cast boosters made with pentaerythritol tetranitrate (PETN) and trinitro toluene (TNT) give high velocities of detonation and are sensitive to initiation even under high pressures. However, the manufacture of the same involves heating of TNT to its melting temperature and mixing of dry PETN in it. In the present work, wet PETN, TNT and water soluble nitrate salts were used for the manufacture of the boosters. The nitrate salt solution formed with the excess water available in wet PETN was emulsified with the aid of emulsifiers. The velocities of detonation of boosters with various percentages of water were determined. The data of explosive characters of these boosters were compared with normal pentolite cast boosters.

  13. Method to prepare Semtex

    SciTech Connect (OSTI)

    Alcaraz, A; Dougan, A

    2006-11-26

    This procedure requires the binder and uncoated RDX be prepared in separate steps, see Figure 1: (1) The binder and dye are mixed by agitation with a water-insoluble organic solvent (e.g., toluene), I; (2) The RDX/PETN is agitated thoroughly with water, II; (3) The binder solution I is added to the RDX/water mixture at II with thorough mixing to form a slurry III; (4) In the next step the solvent is distilled off at IV leaving resulting granules; (5) The next step is followed by filtration at V, which may be done by vacuum; (6) The composition is then dried at VI to a dough-like consistency.

  14. Engine Materials Compatibility with Alternate Fuels

    SciTech Connect (OSTI)

    Thomson, Jeffery K; Pawel, Steven J; Wilson, Dane F

    2013-05-01

    The compatibility of aluminum and aluminum alloys with synthetic fuel blends comprised of ethanol and reference fuel C (a 50/50 mix of toluene and iso-octane) was examined as a function of water content and temperature. Commercially pure wrought aluminum and several cast aluminum alloys were observed to be similarly susceptible to substantial corrosion in dry (< 50 ppm water) ethanol. Corrosion rates of all the aluminum materials examined were accelerated by increased temperature and ethanol content in the fuel mixture, but inhibited by increased water content. Pretreatments designed to stabilize passive films on aluminum increased the incubation time for onset of corrosion, suggesting film stability is a significant factor in the mechanism of corrosion.

  15. Surface-enhanced Raman scattering activity of niobium surface after irradiation with femtosecond laser pulses

    SciTech Connect (OSTI)

    Ivanov, Victor G.; Vlakhov, Emil S.; Stan, George E.; Socol, Marcela; Zamfirescu, Marian; Albu, Catalina; Mihailescu, Natalia; Negut, Irina; Luculescu, Catalin; Ristoscu, Carmen; Mihailescu, Ion N.

    2015-11-28

    The chemical modification of the niobium (Nb) surface after irradiation with femtosecond laser pulses was investigated by scanning electron microscopy coupled with energy dispersive spectroscopy, atomic force microscopy, grazing incidence X-ray diffraction, and micro-Raman spectroscopy. The physical-chemical analyses indicated that the laser treatment results in oxidation of the Nb surface, as well as in the formation of Nb hydrides. Remarkably, after the samples' washing in ethanol, a strong Surface-Enhanced Raman Scattering (SERS) signal originating from the toluene residual traces was evidenced. Further, it was observed that the laser irradiated Nb surface is able to provide a SERS enhancement of ∼1.3 × 10{sup 3} times for rhodamine 6G solutions. Thus, for the first time it was shown that Nb/Nb oxide surfaces could exhibit SERS functionality, and so one can expect applications in biological/biochemical screening or for sensing of dangerous environmental substances.

  16. Separation and concentration of lower alcohols from dilute aqueous solutions

    DOE Patents [OSTI]

    Moore, Raymond H.; Eakin, David E.; Baker, Eddie G.; Hallen, Richard T.

    1991-01-01

    A process for producing, from a dilute aqueous solution of a lower (C.sub.1 -C.sub.5) alcohol, a concentrated liquid solution of the alcohol in an aromatic organic solvent is disclosed. Most of the water is removed from the dilute aqueous solution of alcohol by chilling sufficiently to form ice crystals. Simultaneously, the remaining liquid is extracted at substantially the same low temperature with a liquid organic solvent that is substantially immiscible in aqueous liquids and has an affinity for the alcohol at that temperature, causing the alcohol to transfer to the organic phase. After separating the organic liquid from the ice crystals, the organic liquid can be distilled to enrich the concentration of alcohol therein. Ethanol so separated from water and concentrated in an organic solvent such as toluene is useful as an anti-knock additive for gasoline.

  17. Detailed Kinetic Modeling of Gasoline Surrogate Mixtures

    SciTech Connect (OSTI)

    Mehl, M; Curran, H J; Pitz, W J; Westbrook, C K

    2009-03-09

    Real fuels are complex mixtures of thousands of hydrocarbon compounds including linear and branched paraffins, naphthenes, olefins and aromatics. It is generally agreed that their behavior can be effectively reproduced by simpler fuel surrogates containing a limited number of components. In this work, a recently revised version of the kinetic model by the authors is used to analyze the combustion behavior of several components relevant to gasoline surrogate formulation. Particular attention is devoted to linear and branched saturated hydrocarbons (PRF mixtures), olefins (1-hexene) and aromatics (toluene). Model predictions for pure components, binary mixtures and multi-component gasoline surrogates are compared with recent experimental information collected in rapid compression machine, shock tube and jet stirred reactors covering a wide range of conditions pertinent to internal combustion engines. Simulation results are discussed focusing attention on the mixing effects of the fuel components.

  18. Kinetic Modeling of Gasoline Surrogate Components and Mixtures under Engine Conditions

    SciTech Connect (OSTI)

    Mehl, M; Pitz, W J; Westbrook, C K; Curran, H J

    2010-01-11

    Real fuels are complex mixtures of thousands of hydrocarbon compounds including linear and branched paraffins, naphthenes, olefins and aromatics. It is generally agreed that their behavior can be effectively reproduced by simpler fuel surrogates containing a limited number of components. In this work, an improved version of the kinetic model by the authors is used to analyze the combustion behavior of several components relevant to gasoline surrogate formulation. Particular attention is devoted to linear and branched saturated hydrocarbons (PRF mixtures), olefins (1-hexene) and aromatics (toluene). Model predictions for pure components, binary mixtures and multicomponent gasoline surrogates are compared with recent experimental information collected in rapid compression machine, shock tube and jet stirred reactors covering a wide range of conditions pertinent to internal combustion engines (3-50 atm, 650-1200K, stoichiometric fuel/air mixtures). Simulation results are discussed focusing attention on the mixing effects of the fuel components.

  19. Chemical kinetic modeling of component mixtures relevant to gasoline

    SciTech Connect (OSTI)

    Mehl, M; Curran, H J; Pitz, W J; Westbrook, C K

    2009-02-13

    Real fuels are complex mixtures of thousands of hydrocarbon compounds including linear and branched paraffins, naphthenes, olefins and aromatics. It is generally agreed that their behavior can be effectively reproduced by simpler fuel surrogates containing a limited number of components. In this work, a recently revised version of the kinetic model by the authors is used to analyze the combustion behavior of several components relevant to gasoline surrogate formulation. Particular attention is devoted to linear and branched saturated hydrocarbons (PRF mixtures), olefins (1-hexene) and aromatics (toluene). Model predictions for pure components, binary mixtures and multi-component gasoline surrogates are compared with recent experimental information collected in rapid compression machine, shock tube and jet stirred reactors covering a wide range of conditions pertinent to internal combustion engines. Simulation results are discussed focusing attention on the mixing effects of the fuel components.

  20. Engine Materials Compatability with Alternative Fuels

    SciTech Connect (OSTI)

    Pawel, Steve; Moore, D.

    2013-04-05

    The compatibility of aluminum and aluminum alloys with synthetic fuel blends comprised of ethanol and reference fuel C (a 50/50 mix of toluene and iso-octane) was examined as a function of water content and temperature. Commercially pure wrought aluminum and several cast aluminum alloys were observed to be similarly susceptible to substantial corrosion in dry (< 50 ppm water) ethanol. Corrosion rates of all the aluminum materials examined were accelerated by increased temperature and ethanol content in the fuel mixture, but inhibited by increased water content. Pretreatments designed to stabilize passive films on aluminum increased the incubation time for onset of corrosion, suggesting film stability is a significant factor in the mechanism of corrosion.

  1. Susceptibility of Aluminum Alloys to Corrosion in Simulated Fuel Blends Containing Ethanol

    SciTech Connect (OSTI)

    Thomson, Jeffery K; Pawel, Steven J; Wilson, Dane F

    2013-01-01

    The compatibility of aluminum and aluminum alloys with synthetic fuel blends comprised of ethanol and reference fuel C (a 50/50 mix of toluene and iso-octane) was examined as a function of water content and temperature. Commercially pure wrought aluminum and several cast aluminum alloys were observed to be similarly susceptible to substantial corrosion in dry (< 50 ppm water) ethanol. Corrosion rates of all the aluminum materials examined was accelerated by increased temperature and ethanol content in the fuel mixture, but inhibited by increased water content. Pretreatments designed to stabilize passive films on aluminum increased the incubation time for onset of corrosion, suggesting film stability is a significant factor in the mechanism of corrosion.

  2. Next generation extractants for separation of cesium from high-level waste

    SciTech Connect (OSTI)

    Bartsch, R.A.; Zhou, H.; Delmau, L.H.; Moyer, B.A.

    2008-07-01

    Using calix[4]arene as a scaffold, lipophilic, proton-ionizable ligands for cesium ion extraction have been synthesized. In the 1,3-alternate conformation, lipophilic octyl groups are attached to distal oxygens on one side of the calix[4]arene molecule, and an alkylated benzo-crown-6 unit is connected to distal oxygens on the other side. One phenyl octyl ether unit bears an acidic group in the para-position which orients it directly over the polyether ring. Solvent extractions of trace cesium ion from aqueous solutions into toluene have been performed. The efficiency of cesium ion extraction as a function of the aqueous phase pH and the identity of the acidic group have been assessed. Promising results are obtained for this new series of cesium ion extractants. (authors)

  3. Feasibility of actinide separation from UREX-like raffinates using a combination of sulfur- and oxygen-donor extractants

    SciTech Connect (OSTI)

    Zalupski, P.R.; Peterman, D.R.; Riddle, C.L.

    2013-07-01

    A synergistic combination of bis(o-trifluoromethylphenyl)dithios-phosphinic acid and trioctylphosphine oxide has been recently shown to selectively remove uranium, neptunium, plutonium and americium from aqueous environment containing up to 0.5 M nitric acid and 5.5 g/l fission products. Here the feasibility of performing this complete actinide recovery from aqueous mixtures is forecasted for a new organic formulation containing sulfur donor extractant of modified structure based on Am(III) and Eu(III) extraction data. A mixture of bis(bis-m,m-trifluoromethyl)phenyl)-dithios-phosphinic acid and TOPO in toluene enhances the extraction performance, accomplishing Am/Eu differentiation in aqueous mixtures up to 1 M nitric acid. The new organic recipe is also less susceptible to oxidative damage resulting from radiolysis. (authors)

  4. Feasibility of actinide separation from UREX-like raffinates using a combination of sulfur- and oxygen-donor extractants

    SciTech Connect (OSTI)

    Peter R. Zalupski; Dean R. Peterman; Catherine L. Riddle

    2013-09-01

    A synergistic combination of bis(o-trifluoromethylphenyl)dithiosphosphinic acid and trioctylphosphine oxide has been recently shown to selectively remove uranium, neptunium, plutonium and americium from aqueous environment containing up to 0.5 M nitric acid and 5.5 g/L fission products. Here the feasibility of performing this complete actinide recovery from aqueous mixtures is forecasted for a new organic formulation containing sulfur donor extractant of modified structure based on Am(III) and Eu(III) extraction data. A mixture of bis(bis-m,m-trifluoromethyl)phenyl)-dithiosphosphinic acid and TOPO in toluene enhances the extraction performance, accomplishing Am/Eu differentiation in aqueous mixtures up to 1 M nitric acid. The new organic recipe is also less susceptible to oxidative damage resulting from radiolysis.

  5. Non-covalent interactions of nitrous oxide with aromatic compounds: Spectroscopic and computational evidence for the formation of 1:1 complexes

    SciTech Connect (OSTI)

    Cao, Qian; School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275 ; Gor, Gennady Y.; Krogh-Jespersen, Karsten; Khriachtchev, Leonid

    2014-04-14

    We present the first study of intermolecular interactions between nitrous oxide (N{sub 2}O) and three representative aromatic compounds (ACs): phenol, cresol, and toluene. The infrared spectroscopic experiments were performed in a Ne matrix and were supported by high-level quantum chemical calculations. Comparisons of the calculated and experimental vibrational spectra provide direct identification and characterization of the 1:1 N{sub 2}O-AC complexes. Our results show that N{sub 2}O is capable of forming non-covalently bonded complexes with ACs. Complex formation is dominated by dispersion forces, and the interaction energies are relatively low (about ?3 kcal mol{sup ?1}); however, the complexes are clearly detected by frequency shifts of the characteristic bands. These results suggest that N{sub 2}O can be bound to the amino-acid residues tyrosine or phenylalanine in the form of ? complexes.

  6. Vapor pressure osmometry studies on buckminsterfullerene

    SciTech Connect (OSTI)

    Honeychuck, R.V.; Cruger, T.W.; Milliken, J.

    1993-12-31

    Vapor pressure osmometry has been employed in studies of solutions of buckminsterfullerene (C{sub 60}. Two aromatic solvents were selected in order to obtain solutions which would be as concentrated as possible. The number-average molecular weights M{sub n} of C{sub 60} determined by analysis of the data are 930 {+-} 5 g mol{sup {minus}1} in chlorobenzene and 700 {+-} 10 g mol{sup {minus}1} in toluene), so the M{sub n} obtained in chlorobenzene is unexpected. Both determinations were performed with the same batch of C{sub 60}, which was processed to yield material of very high purity. The amount of interstitial N{sub 2} was determined using an appropriate method. The role if interstitial molecules, solvents in the crystal lattice, solvent-fullerene complexes, C{sub 70}, and C{sub 60} dimers in these measurements will be discussed.

  7. ES&H development activities for the W89 warhead

    SciTech Connect (OSTI)

    Pretzel, C.W.

    1995-08-01

    Environmental, Safety and Health (ES&H) issues became an important design consideration during the development of the W89 warhead for the SRAM 11 (Short-Range Attack Missile) missile. An action plan was developed to handle these issues at all the production agencies and at both the system and the component level. The main thrust was in the area of solvent substitution, in particular for solder flux removal. The cleaner d-limonene followed by an isopropyl alcohol rinse was selected for applications were the traditional cleaners were 1,1,1 trichloroethane or trichloroethylene. Compatibility testing rather than efficacy testing dominated the development effort. In addition to other solvent substitution applications, organic materials that were free of toluene diisocynate (TDI), and methylene dianiline (MDA) were explored for use in the W89.

  8. Catalytic production of metal carbonyls from metal oxides

    DOE Patents [OSTI]

    Sapienza, Richard S.; Slegeir, William A.; Foran, Michael T.

    1984-01-01

    This invention relates to the formation of metal carbonyls from metal oxides and specially the formation of molybdenum carbonyl and iron carbonyl from their respective oxides. Copper is used here in admixed form or used in chemically combined form as copper molybdate. The copper/metal oxide combination or combined copper is utilized with a solvent, such as toluene and subjected to carbon monoxide pressure of 25 atmospheres or greater at about 150.degree.-260.degree. C. The reducing metal copper is employed in catalytic concentrations or combined concentrations as CuMoO.sub.4 and both hydrogen and water present serve as promoters. It has been found that the yields by this process have been salutary and that additionally the catalytic metal may be reused in the process to good effect.

  9. Catalytic production of metal carbonyls from metal oxides

    DOE Patents [OSTI]

    Sapienza, R.S.; Slegeir, W.A.; Foran, M.T.

    1984-01-06

    This invention relates to the formation of metal carbonyls from metal oxides and specially the formation of molybdenum carbonyl and iron carbonyl from their respective oxides. Copper is used here in admixed form or used in chemically combined form as copper molybdate. The copper/metal oxide combination or combined copper is utilized with a solvent, such as toluene and subjected to carbon monoxide pressure of 25 atmospheres or greater at about 150 to 260/sup 0/C. The reducing metal copper is employed in catalytic concentrations or combined concentrations as CuMoO/sub 4/ and both hydrogen and water present serve as promoters. It has been found that the yields by this process have been salutary and that additionally the catalytic metal may be reused in the process to good effect. 3 tables.

  10. Innovative technology for expedited site remediation of extensive surface and subsurface contamination

    SciTech Connect (OSTI)

    Audibert, J.M.E.; Lew, L.R.

    1994-12-31

    Large scale surface and subsurface contamination resulted from numerous releases of feed stock, process streams, waste streams, and final product at a major chemical plant. Soil and groundwater was contaminated by numerous compounds including lead, tetraethyl lead, ethylene dibromide, ethylene dichloride, and toluene. The state administrative order dictated that the site be investigated fully, that remedial alternative be evaluated, and that the site be remediated within a year period. Because of the acute toxicity and extreme volatility of tetraethyl lead and other organic compounds present at the site and the short time frame ordered by the regulators, innovative approaches were needed to carry out the remediation while protecting plant workers, remediation workers, and the public.

  11. Treatment of VOCs in high strength wastes using an anaerobic expanded-bed GAC reactor

    SciTech Connect (OSTI)

    Narayanian, B.; Suidan, M.T.; Gelderloos, A.B.; Brenner, R.C.

    1993-01-01

    The potential of the expanded-bed granular activated carbon (GAC) anaerobic reactor in treating a high strength waste containing RCRA volatile organic compounds (VOCs) was studied. A total of six VOCs, methylene chloride, chlorobenzene, carbon tetrachloride, chloroform, toluene and tetrachloroethylene, were fed to the reactor in a high strength matrix of background solvents. Performance was evaluated. The reactor was found to effect excellent removal of all VOCs (97%). Chloroform, while itself removed at levels in excess of 97%, was found to inhibit the degradation of acetate and acetone, two of the background solvents. Without any source of chloroform in the feed, excellent COD removals were obtained in addition to near-complete removal of all the VOCs.

  12. Health assessment for S-Area Landfill/Hooker, Niagara Falls, New York, Region 2. CERCLIS No. NYD000000001. Preliminary report

    SciTech Connect (OSTI)

    Not Available

    1989-06-01

    The S-Area Landfill is a National Priorities List site located in Niagara Falls, New York, that was operated from 1947 to 1975 by the Occidental Chemical Corporation (OCC). From 1947 to 1975, OCC is reported to have disposed of an estimated 19,000 tons of chlorobenzenes and approximately 17,000 tons of hexachlorocyclopentadiene. Other wastes disposed of at the site include organic phosphates, hexachlorobutadiene, trichlorophenols, and chlorinated toluenes. Environmental contamination from the S-Area exists on-site and off-site in soils and ground water. Further off-site contamination potentially exists in the Niagara River. The S-Area presents a potential public health threat to the consumers of the City of Niagara Falls drinking water and an incremental increase in contamination to fish in the Niagara River.

  13. Thermally activated delayed fluorescence from {sup 3}n?* to {sup 1}n?* up-conversion and its application to organic light-emitting diodes

    SciTech Connect (OSTI)

    Li, Jie; Zhang, Qisheng; Nomura, Hiroko [Department of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Miyazaki, Hiroshi [Department of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Functional Materials Laboratory, Nippon Steel and Sumikin Chemical Co., Ltd, 4680 Nakabaru, Sakinohama, Tobata, Kitakyushu, Fukuoka 8048503 (Japan); Adachi, Chihaya, E-mail: adachi@cstf.kyushu-u.ac.jp [Department of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan)

    2014-07-07

    Intense n?* fluorescence from a nitrogen-rich heterocyclic compound, 2,5,8-tris(4-fluoro-3-methylphenyl)-1,3,4,6,7,9,9b-heptaazaphenalene (HAP-3MF), is demonstrated. The overlap-forbidden nature of the n?* transition and the higher energy of the {sup 3}??* state than the {sup 3}n?* one lead to a small energy difference between the lowest singlet (S{sub 1}) and triplet (T{sub 1}) excited states of HAP-3MF. Green-emitting HAP-3MF has a moderate photoluminescence quantum yield of 0.26 in both toluene and doped film. However, an organic light-emitting diode containing HAP-3MF achieved a high external quantum efficiency of 6.0%, indicating that HAP-3MF harvests singlet excitons through a thermally activated T{sub 1} ? S{sub 1} pathway in the electroluminescent process.

  14. Plasma flame for mass purification of contaminated air with chemical and biological warfare agents

    SciTech Connect (OSTI)

    Uhm, Han S.; Shin, Dong H.; Hong, Yong C.

    2006-09-18

    An elimination of airborne simulated chemical and biological warfare agents was carried out by making use of a plasma flame made of atmospheric plasma and a fuel-burning flame, which can purify the interior air of a large volume in isolated spaces such as buildings, public transportation systems, and military vehicles. The plasma flame generator consists of a microwave plasma torch connected in series to a fuel injector and a reaction chamber. For example, a reaction chamber, with the dimensions of a 22 cm diameter and 30 cm length, purifies an airflow rate of 5000 lpm contaminated with toluene (the simulated chemical agent) and soot from a diesel engine (the simulated aerosol for biological agents). Large volumes of purification by the plasma flame will free mankind from the threat of airborne warfare agents. The plasma flame may also effectively purify air that is contaminated with volatile organic compounds, in addition to eliminating soot from diesel engines as an environmental application.

  15. Inertial fusion target fabrication using polystyrene mandrels

    SciTech Connect (OSTI)

    Kim, H.; Powers, T.F.; Mason, J.F.

    1984-04-01

    Large-aspect-ratio, plastic-coated, metal shells are useful targets for obtaining valuable information on thermal transport in laser implosion experiments. We have found that by using polystyrene as a leachable mandrel, it is possible to fabricate such complex, inertial-fusion targets. The present fabrication technique offers advantages over previous techniques, including the hemispherical-shell approach, the leachable-metal-mandrel approach, and the coating of a prefabricated metal shell. For fabrication of such diagnostic targets, comprised of a high-aspect-ratio, plastic-coated, metal shell, a polystyrene sphere is mounted on a stalk, then coated with metal and parylene layers. A hole of 5--10 ..mu..m is drilled with a laser pulse through the layers and the polystyrene is then leached out by immersing the system in toluene. The concept of the present technique presents a number of possibilities for the fabrication of complex targets not possible previously.

  16. Optical Properties of CdSe Nanoparticle Assemblies

    SciTech Connect (OSTI)

    Huser, T; Gerion, D; Zaitseva, N; Krol, D M; Leon, F R

    2003-11-24

    We report on three-dimensional fluorescence imaging of micron-size faceted crystals precipitated from solutions of CdSe nanocrystals. Such crystals have previously been suggested to be superlattices of CdSe quantum dots [1,2]. Possible applications for these materials include their use in optical and optoelectronic devices. The micron-size crystals were grown by slow evaporation from toluene solutions of CdSe nanocrystals in the range of 3-6 nm, produced by traditional wet-chemistry techniques. By using a confocal microscope with laser illumination, three-dimensional raster-scanning and synchronized hyper-spectral detection, we have generated spatial profiles of the fluorescence emission intensity and spectrum. The fluorescence data of the micro-crystals were compared with spectra of individual nanocrystals obtained from the same solution. The results do not support the assertion that these microcrystals consist of CdSe superlattices.

  17. METHOD FOR PRODUCING CEMENTED CARBIDE ARTICLES

    DOE Patents [OSTI]

    Onstott, E.I.; Cremer, G.D.

    1959-07-14

    A method is described for making molded materials of intricate shape where the materials consist of mixtures of one or more hard metal carbides or oxides and matrix metals or binder metals thereof. In one embodiment of the invention 90% of finely comminuted tungsten carbide powder together with finely comminuted cobalt bonding agent is incorporated at 60 deg C into a slurry with methyl alcohol containing 1.5% paraffin, 3% camphor, 3.5% naphthalene, and 1.8% toluene. The compact is formed by the steps of placing the slurry in a mold at least one surface of which is porous to the fluid organic system, compacting the slurry, removing a portion of the mold from contact with the formed object and heating the formed object to remove the remaining organic matter and to sinter the compact.

  18. Intensity-resolved ionization yields of aniline with femtosecond laser pulses

    SciTech Connect (OSTI)

    Strohaber, J.; Hart, N.; Zhu, F.; Nava, R.; Pham, F.; Kolomenskii, A. A.; Paulus, G. G.; Schuessler, H. A.; Mohamed, T.; Schroeder, H.

    2011-12-15

    We present experimental results for the ionization of aniline and benzene molecules subjected to intense ultrashort laser pulses. Measured parent molecular ions yields were obtained using a recently developed technique capable of three-dimensional imaging of ion distributions within the focus of a laser beam. By selecting ions originating from the central region of the focus, where the spatial intensity distribution is nearly uniform, volumetric-free intensity-dependent ionization yields were obtained. The measured data revealed a previously unseen resonance-enhanced multiphoton ionization (REMPI)-like process. Comparison of benzene, aniline, and Xe ion yields demonstrates that the observed intensity-dependent structures are not due to geometric artifacts in the focus. Finally for intensities greater than {approx}3x10{sup 13} W/cm{sup 2}, we attribute the ionization of aniline to a stepwise process going through the {pi}{sigma}{sup *} state which sits three photons above the ground state and two photons below the continuum.

  19. In situ Formation of Highly Conducting Covalent Au-C Contacts for Single-Molecule Junctions

    SciTech Connect (OSTI)

    Cheng, Z.L.; Hybertsen, M.; Skouta, R.; Vazquez, H.; Widawsky, J.R.; Schneebeli, S.; Chen, W.; Breslow, R.; Venkataraman, L.

    2011-06-01

    Charge transport across metal-molecule interfaces has an important role in organic electronics. Typically, chemical link groups such as thiols or amines are used to bind organic molecules to metal electrodes in single-molecule circuits, with these groups controlling both the physical structure and the electronic coupling at the interface. Direct metal-carbon coupling has been shown through C60, benzene and {pi}-stacked benzene but ideally the carbon backbone of the molecule should be covalently bonded to the electrode without intervening link groups. Here, we demonstrate a method to create junctions with such contacts. Trimethyl tin (SnMe{sub 3})-terminated polymethylene chains are used to form single-molecule junctions with a break-junction technique. Gold atoms at the electrode displace the SnMe{sub 3} linkers, leading to the formation of direct Au-C bonded single-molecule junctions with a conductance that is {approx}100 times larger than analogous alkanes with most other terminations. The conductance of these Au-C bonded alkanes decreases exponentially with molecular length, with a decay constant of 0.97 per methylene, consistent with a non-resonant transport mechanism. Control experiments and ab initio calculations show that high conductances are achieved because a covalent Au-C sigma ({sigma}) bond is formed. This offers a new method for making reproducible and highly conducting metal-organic contacts.

  20. Electronic states of thiophene/phenylene co-oligomers: Extreme-ultra violet excited photoelectron spectroscopy observations and density functional theory calculations

    SciTech Connect (OSTI)

    Kawaguchi, Yoshizo; Sasaki, Fumio; Mochizuki, Hiroyuki; Ishitsuka, Tomoaki; Tomie, Toshihisa; Ootsuka, Teruhisa; Watanabe, Shuji; Shimoi, Yukihiro; Yamao, Takeshi; Hotta, Shu

    2013-02-28

    We have investigated electronic states in the valence electron bands for the thin films of three thiophene/phenylene co-oligomer (TPCO) compounds, 2,5-bis(4-biphenylyl)thiophene (BP1T), 1,4-bis(5-phenylthiophen-2-yl)benzene (AC5), and 1,4-bis{l_brace}5-[4-(trifluoromethyl)phenyl]thiophen-2-yl{r_brace}benzene (AC5-CF{sub 3}), by using extreme-UV excited photoelectron spectroscopy (EUPS). By comparing both EUPS spectra and secondary electron spectra between AC5 and AC5-CF{sub 3}, we confirm that CF{sub 3} substitution to AC5 deepens valence states by 2 eV, and increases the ionization energy by 3 eV. From the cut-off positions of secondary electron spectra, the work functions of AC5, AC5-CF{sub 3}, and BP1T are evaluated to be 3.8 eV, 4.8 eV, and 4.0 eV, respectively. We calculate molecular orbital (MO) energy levels by the density functional theory and compare results of calculations with those of experiments. Densities of states obtained by broadening MO levels well explain the overall features of experimental EUPS spectra of three TPCOs.