National Library of Energy BETA

Sample records for methyl tertiary-butyl ether

  1. State Restrictions on Methyl Tertiary Butyl Ether (released in AEO2006)

    Reports and Publications (EIA)

    2006-01-01

    By the end of 2005, 25 states had barred, or passed laws banning, any more than trace levels of methyl tertiary butyl ether (MTBE) in their gasoline supplies, and legislation to ban MTBE was pending in 4 others. Some state laws address only MTBE; others also address ethers such as ethyl tertiary butyl ether (ETBE) and tertiary amyl methyl ether (TAME). Annual Energy Outlook 2006 assumes that all state MTBE bans prohibit the use of all ethers for gasoline blending.

  2. Enhanced diisobutene production in the presence of methyl tertiary butyl ether

    DOE Patents [OSTI]

    Smith, Jr., Lawrence A. (Bellaire, TX)

    1983-01-01

    In the liquid phase reaction of isobutene in the presence of resin cation exchange resins with itself in a C.sub.4 hydrocarbon stream to form dimers, the formation of higher polymers, oligomers, and co-dimer by-products is suppressed by the presence of 0.0001 to 1 mole per mole of isobutene of methyl tertiary butyl ether.

  3. Enhanced diisobutene production in the presence of methyl tertiary butyl ether

    DOE Patents [OSTI]

    Smith, L.A. Jr.

    1983-03-01

    In the liquid phase reaction of isobutene in the presence of resin cation exchange resins with itself in a C[sub 4] hydrocarbon stream to form dimers, the formation of higher polymers, oligomers, and co-dimer by-products is suppressed by the presence of 0.0001 to 1 mole per mole of isobutene of methyl tertiary butyl ether. 1 fig.

  4. TABLE33.CHP:Corel VENTURA

    Gasoline and Diesel Fuel Update (EIA)

    ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether (TAME), tertiary butyl alcohol (TBA), and other aliphatic alcohols and ethers intended for motor gasoline blending...

  5. TABLE34.CHP:Corel VENTURA

    Gasoline and Diesel Fuel Update (EIA)

    ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether (TAME), tertiary butyl alcohol (TBA), and other aliphatic alcohols and ethers intended for motor gasoline blending...

  6. Vapor pressures of methyl tert-butyl ether, ethyl tert-butyl ether, isopropyl tert-butyl ether, tert-amyl methyl ether, and tert-amyl ethyl ether

    SciTech Connect (OSTI)

    Kraehenbuehl, M.A.; Gmehling, J. . Technische Chemie)

    1994-10-01

    The vapor pressures of methyl tert-butyl ether, ethyl tert-butyl ether, isopropyl tert-butyl ether, tert-amyl methyl ether, and tert-amyl ethyl ether were measured by ebulliometry or the static method in the pressure ranges 14--102 and 3--835 kPa (methyl tert-butyl ether), respectively. The data were correlated using the Antoine and Wagner equations. The experimental data of methyl tert-butyl ether and ethyl tert-butyl ether were compared with data available in the literature.

  7. Supply Impacts of an MTBE Ban

    Reports and Publications (EIA)

    2002-01-01

    This paper analyzes the supply impacts of removing methyl tertiary butyl ether (MTBE) from gasoline.

  8. Cytotoxic and DNA-damaging effects of methyl tert-butyl ether and its metabolites on HL-60 cells in vitro

    SciTech Connect (OSTI)

    Tang, G.H.; Shen, Y.; Shen, H.M.

    1996-12-31

    Methyl tert-butyl ether (MTBE) is a widely used oxygenate in unleaded gasoline; however, few studies have been conducted on the toxicity of this compound. This study evaluates the cytotoxic and DNA-damaging effects of MTBE and its metabolites in a human haemopoietic cell line, HL-60. The metabolites of MTBE studied include tertiary butyl alcohol (TBA), {alpha}-hydroxyisobutyric acid (HIBA), and formaldehyde. Comet assay is used to assess DNA damage, and the cytotoxicity is investigated by lactate dehydrogenease (LDH) release. The results show no significant cytotoxic effects of MTBE, TBA, and HIBA over a concentration ranging from 1 to 30 mM. Formaldehyde, in contrast, causes a substantial LDH release at a concentration of 5 {mu}M. Hydrogen peroxide, a known oxidative agent, at concentrations ranging from 10 to 100 {mu}M, produces a significant dose-related increase in DNA damage, whereas a much higher concentration of MTBE (1 to 30 mM) is required to produce a similar observation. The genotoxic effects of TBA and HIBA appear to be identical to that of MTBE. Conversely, DNA damage is observed for formaldehyde at a relatively low concentration range (5 to 100 {mu}M). These findings suggest that MTBE and its metabolites, except formaldehyde, have relatively low cytotoxic and genotoxic effects. 16 refs., 4 figs.

  9. Tropospheric oxidation mechanism of dimethyl ether and methyl formate

    SciTech Connect (OSTI)

    Good, D.A.; Francisco, J.S.

    2000-02-17

    The oxidation mechanism of dimethyl ether is investigated using ab initio methods. The structure and energetics of reactants, products, and transition structures are determined for all pathways involved in the oxidation mechanism. The detailed pathways leading to the experimentally observed products of dimethyl ether oxidation are presented. The energetics of over 50 species and transition structures involved in the oxidation process are calculated with G2 and G2(MP2) energies. The principal pathway following the initial attack of dimethyl ether (CH{sub 3}OCH{sub 3}) by the OH radical is the formation of the methoxymethyl radical (CH{sub 2}OCH{sub 3}). Oxidation steps lead to the formation of methyl formate, which is consistent with the experimentally observed products. Oxidation pathways of methyl formate are also considered.

  10. MTBE Production Economics (Released in the STEO April 2001)

    Reports and Publications (EIA)

    2001-01-01

    The purpose of this analysis is to evaluate the causes of methyl tertiary butyl ether (MTBE) price increases in 2000.

  11. Methyl aryl ethers from coal liquids as gasoline extenders and octane improvers

    SciTech Connect (OSTI)

    Singerman, G.M.

    1980-11-01

    A mixture of methyl aryl ethers derived from the phenols present in direct liquefaction coal liquids shows considerable promise as a gasoline blending agent and octane improver. The mixture of methyl aryl ethers was blended at five volume percent with a commercial, unleaded gasoline. The properties and performance of the blend in a variety of laboratory and automotive tests is reported. The tests show that the mixture of methyl aryl ethers improves gasoline octane without degrading other gasoline properties.

  12. Impact of Renewable Fuels Standard/MTBE Provisions of S. 517 Requested by Sens. Daschle & Murkowski

    Reports and Publications (EIA)

    2002-01-01

    Additional analysis of the impact of the Renewable Fuels Standard (RFS) and methyl tertiary butyl ether (MTBE) ban provisions of S. 517.

  13. This Week In Petroleum Printer-Friendly Version

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    this transition from Methyl Tertiary Butyl Ether (MTBE) reformulated gasoline (RFG) to ethanol RFG, since ethanol is not blended into the gasoline mixture until just before the...

  14. untitled

    Gasoline and Diesel Fuel Update (EIA)

    of "other" hydrocarbons and oxygenates include hydrogen and oxygenates especially fuel ethanol and methyl tertiary butyl ether (MTBE). The adjustment is equal to the...

  15. Total Blender Net Input of Petroleum Products

    U.S. Energy Information Administration (EIA) Indexed Site

    Normal Butane Isobutane Other Liquids OxygenatesRenewables Oxygenates (excl. Fuel Ethanol) Methyl Tertiary Butyl Ether (MTBE) All Other Oxygenates Renewable Fuels (incl. Fuel Ethanol...

  16. Refinery Stocks of Crude Oil and Petroleum Products

    U.S. Energy Information Administration (EIA) Indexed Site

    Hydrocarbons Oxygenates (excl. Fuel Ethanol) Methyl Tertiary Butyl Ether (MTBE) All Other Oxygenates Renewable Fuels (incl. Fuel Ethanol) Fuel Ethanol Renewable Diesel Fuel Other ...

  17. Motor Gasoline Market Spring 2007 and Implications for Spring...

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    began to decline, and with the transition from methyl tertiary butyl ether (MTBE) to ethanol completed and the end of the summer driving season drawing near, gasoline prices...

  18. Methyl tert-butyl ether and ethyl tert-butyl ether: A comparison of properties, synthesis techniques, and operating conditions

    SciTech Connect (OSTI)

    Sneesby, M.G.; Tade, M.O.; Datta, R.

    1996-12-31

    MTBE is currently the most industrially significant oxygenate but some of the properties of ETBE and the EPA ethanol mandate suggest that ETBE could become a viable competitor. Similar synthesis techniques are used for both ethers but the phase behaviour of the ETBE system requires slightly different operating conditions and creates some alternatives for product recovery. The process control strategy for both systems must address some unusual challenges. 9 refs., 1 tab.

  19. Separation of Dimethyl Ether from Syn-Gas Components by Poly(dimethylsiloxane) and Poly(4-methyl-1-pentene) Membranes

    SciTech Connect (OSTI)

    Christopher J. Orme; Frederick F. Stewart

    2011-05-01

    Permeability and selectivity in gas transport through poly(4-methyl-1-pentene) (TPX) and poly(dimethylsiloxane) (PDMS) using variable temperature mixed gas experiments is reported. Selected gases include H2, CO, CH4, CO2, and dimethyl ether (DME). The DME data is the first to be reported through these membranes. In this paper, the chosen polymers reflect both rubbery and crystalline materials. Rubbery polymers tend to be weakly size sieving, which, in this work, has resulted in larger permeabilities, lower separation factors, and lower activation energies of permeation (Ep). Conversely, the crystalline TPX membranes showed much greater sensitivity to penetrant size; although the gas condensability also played a role in transport.

  20. Preparations for Meeting New York and Connecticut MTBE Bans

    Reports and Publications (EIA)

    2003-01-01

    In response to a Congressional request, the Energy Information Administration examined the progress being made to meet the bans on the use of methyl tertiary butyl ether (MTBE) being implemented in New York and Connecticut at the end of 2003.

  1. APPENDXD.CHP:Corel VENTURA

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    Report The Form EIA-819, "Monthly Oxygenate Report" provides production data for fuel ethanol and methyl tertiary butyl ether (MTBE). End-of-month stock data held at ethanol...

  2. Table Definitions, Sources, and Explanatory Notes

    Gasoline and Diesel Fuel Update (EIA)

    Ethanol Plant Production Definitions Key Terms Definition Barrel A unit of volume equal to 42 U.S. gallons. Fuel Ethanol An anhydrous alcohol (ethanol with less than 1% water) intended for gasoline blending as described in the Oxygenates definition. Oxygenates Substances which, when added to gasoline, increase the amount of oxygen in that gasoline blend. Ethanol, Methyl Tertiary Butyl Ether (MTBE), Ethyl Tertiary Butyl Ether (ETBE), and methanol are common oxygenates. Fuel Ethanol: Blends of up

  3. 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.

  4. Using physiologically based pharmacokinetic modeling to address nonlinear kinetics and changes in rodent physiology and metabolism due to aging and adaptation in deriving reference values for propylene glycol methyl ether and propylene glycol methyl ether acetate.

    SciTech Connect (OSTI)

    Kirman, C R.; Sweeney, Lisa M.; Corley, Rick A.; Gargas, M L.

    2005-04-01

    Reference values, including an oral reference dose (RfD) and an inhalation reference concentration (RfC), were derived for propylene glycol methyl ether (PGME), and an oral RfD was derived for its acetate (PGMEA). These values were based upon transient sedation observed in F344 rats and B6C3F1 mice during a two-year inhalation study. The dose-response relationship for sedation was characterized using internal dose measures as predicted by a physiologically based pharmacokinetic (PBPK) model for PGME and its acetate. PBPK modeling was used to account for changes in rodent physiology and metabolism due to aging and adaptation, based on data collected during weeks 1, 2, 26, 52, and 78 of a chronic inhalation study. The peak concentration of PGME in richly perfused tissues was selected as the most appropriate internal dose measure based upon a consideration of the mode of action for sedation and similarities in tissue partitioning between brain and other richly perfused tissues. Internal doses (peak tissue concentrations of PGME) were designated as either no-observed-adverse-effect levels (NOAELs) or lowest-observed-adverse-effect levels (LOAELs) based upon the presence or absence of sedation at each time-point, species, and sex in the two year study. Distributions of the NOAEL and LOAEL values expressed in terms of internal dose were characterized using an arithmetic mean and standard deviation, with the mean internal NOAEL serving as the basis for the reference values, which was then divided by appropriate uncertainty factors. Where data were permitting, chemical-specific adjustment factors were derived to replace default uncertainty factor values of ten. Nonlinear kinetics are were predicted by the model in all species at PGME concentrations exceeding 100 ppm, which complicates interspecies and low-dose extrapolations. To address this complication, reference values were derived using two approaches which differ with respect to the order in which these extrapolations

  5. Manipulation of the HIF–Vegf pathway rescues methyl tert-butyl ether (MTBE)-induced vascular lesions

    SciTech Connect (OSTI)

    Bonventre, Josephine A.; Kung, Tiffany S.; White, Lori A.; Cooper, Keith R.

    2013-12-15

    Methyl tert-butyl ether (MTBE) has been shown to be specifically anti-angiogenic in piscine and mammalian model systems at concentrations that appear non-toxic in other organ systems. The mechanism by which MTBE targets developing vascular structures is unknown. A global transcriptome analysis of zebrafish embryos developmentally exposed to 0.00625–5 mM MTBE suggested that hypoxia inducible factor (HIF)-regulated pathways were affected. HIF-driven angiogenesis via vascular endothelial growth factor (vegf) is essential to the developing vasculature of an embryo. Three rescue studies were designed to rescue MTBE-induced vascular lesions: pooled blood in the common cardinal vein (CCV), cranial hemorrhages (CH), and abnormal intersegmental vessels (ISV), and test the hypothesis that MTBE toxicity was HIF–Vegf dependent. First, zebrafish vegf-a over-expression via plasmid injection, resulted in significantly fewer CH and ISV lesions, 46 and 35% respectively, in embryos exposed to 10 mM MTBE. Then HIF degradation was inhibited in two ways. Chemical rescue by N-oxaloylglycine significantly reduced CCV and CH lesions by 30 and 32% in 10 mM exposed embryos, and ISV lesions were reduced 24% in 5 mM exposed zebrafish. Finally, a morpholino designed to knock-down ubiquitin associated von Hippel–Lindau protein, significantly reduced CCV lesions by 35% in 10 mM exposed embryos. In addition, expression of some angiogenesis related genes altered by MTBE exposure were rescued. These studies demonstrated that MTBE vascular toxicity is mediated by a down regulation of HIF–Vegf driven angiogenesis. The selective toxicity of MTBE toward developing vasculature makes it a potentially useful chemical in the designing of new drugs or in elucidating roles for specific angiogenic proteins in future studies of vascular development. - Highlights: • Global gene expression of MTBE exposed zebrafish suggested altered HIF1 signaling. • Over expression of zebrafish vegf-a rescues MTBE

  6. Process for producing high purity isoolefins and dimers thereof by dissociation of ethers

    DOE Patents [OSTI]

    Smith, L.A. Jr.; Jones, E.M. Jr.; Hearn, D.

    1984-05-08

    Alkyl tertiary butyl ether or alkyl tertiary amyl ether is dissociated by vapor phase contact with a cation acidic exchange resin at temperatures in the range of 150 to 250 F at LHSV of 0.1 to 20 to produce a stream consisting of unreacted ether, isobutene or isoamylene and an alcohol corresponding to the alkyl radical. After the alcohol is removed, the ether/isoolefin stream may be fractionated to obtain a high purity isoolefin (99+%) or the ether/isoolefin stream can be contacted in liquid phase with a cation acidic exchange resin to selectively dimerize the isoolefin in a highly exothermic reaction, followed by fractionation of the dimerization product to produce high purity diisoolefin (97+%). In the case where the alkyl is C[sub 3] to C[sub 6] and the corresponding alcohol is produced on dissociation of the ether, combined dissociation-distillation may be carried out such that isoolefin is the overhead product and alcohol the bottom. 2 figs.

  7. Process for producing high purity isoolefins and dimers thereof by dissociation of ethers

    DOE Patents [OSTI]

    Smith, Jr., Lawrence A.; Jones, Jr., Edward M.; Hearn, Dennis

    1984-01-01

    Alkyl tertiary butyl ether or alkyl tertiary amyl ether is dissociated by vapor phase contact with a cation acidic exchange resin at temperatures in the range of 150.degree. to 250.degree. F. at LHSV of 0.1 to 20 to produce a stream consisting of unreacted ether, isobutene or isoamylene and an alcohol corresponding to the alkyl radical. After the alcohol is removed, the ether/isoolefin stream may be fractionated to obtain a high purity isoolefin (99+%) or the ether/isoolefin stream can be contacted in liquid phase with a cation acidic exchange resin to selectively dimerize the isoolefin in a highly exothermic reaction, followed by fractionation of the dimerization product to produce high purity diisoolefin (97+%). In the case where the alkyl is C.sub.3 to C.sub.6 and the corresponding alcohol is produced on dissociation of the ether, combined dissociation-distillation may be carried out such that isoolefin is the overhead product and alcohol the bottom.

  8. FCC LPG olefinicity and branching enhanced by octane catalysts

    SciTech Connect (OSTI)

    Keyworth, D.A.; Reid, T.A.; Kreider, K.R.; Yatsu, C.A.

    1989-05-29

    Refiners are increasingly recognizing the downstream opportunities for fluid catalytic cracking LPG olefins for the production of methyl tertiary butyl ether (MTBE), ethyl tertiary butyl ether (ETBE, if the ethanol subsidy is extended to the production of ETBE), and as petrochemical feedstocks. Some of new gasoline FCC octane-enhancing catalysts can support those opportunities because their low non-framework alumina (low NFA) preserve both LPG olefinicity and promote branching of the LPG streams from the FCCU. The combined effect results in more isobutane for alkylate feed, more propylene in the propane/propylene stream, and more isobutene - which makes the addition of an MTBE unit very enticing.

  9. Thermodynamic properties and ideal-gas enthalpies of formation for butyl vinyl ether, 1,2-dimethoxyethane, methyl glycolate, bicyclo[2.2.1]hept-2-ene, 5-vinylbicyclo[2.2.1]hept-2-ene, trans-azobenzene, butyl acrylate, di-tert-butyl ether, and hexane-1,6-diol

    SciTech Connect (OSTI)

    Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.; Smith, N.K.

    1996-11-01

    Ideal-gas enthalpies of formation of butyl vinyl ether, 1,2-dimethoxyethane, methyl glycolate, bicyclo-[2.2.1]hept-2-ene, 5-vinylbicyclo[2.2.1]hept-2-ene, trans-azobenzene, butyl acrylate, di-tert-butyl ether, and hexane-1,6-diol are reported. Enthalpies of fusion were determined for bicyclo[2.2.1]hept-2-ene and trans-azobenzene. Two-phase (solid + vapor) or (liquid + vapor) heat capacities were determined from 300 K to the critical region or earlier decomposition temperature for each compound studied. Liquid-phase densities along the saturation line were measured for bicyclo[2.2.1]hept-2-ene. For butyl vinyl ether and 1,2-dimethoxyethane, critical temperatures and critical densities were determined from the dsc results and corresponding critical pressures derived from the fitting procedures. Fitting procedures were used to derive critical temperatures, critical pressures, and critical densities for bicyclo[2.2.1]hept-2-ene, 5-vinylbicyclo[2.2.1]hept-2-ene, trans-azobenzene, butyl acrylate, and di-tert-butyl ether. Group-additivity parameters or ring-correction terms useful in the application of the Benson group-contribution correlations were derived.

  10. Motor Gasoline Outlook and State MTBE Bans

    Reports and Publications (EIA)

    2003-01-01

    The U.S. is beginning the summer 2003 driving season with lower gasoline inventories and higher prices than last year. Recovery from this tight gasoline market could be made more difficult by impending state bans on the blending of methyl tertiary butyl ether (MTBE) into gasoline that are scheduled to begin later this year.

  11. Impact of Renewable Fuels Standard/MTBE Provisions of S. 1766

    Reports and Publications (EIA)

    2002-01-01

    This service report addresses the Renewable Fuels Standard (RFS)/methyl tertiary butyl ether (MTBE) provisions of S. 1766. The 'S. 1766' Case reflects provisions of S. 1766 including a renewable fuels standard (RFS) reaching five billion gallons by 2012, a complete phase-out of MTBE within four years, and the option for states to waive the oxygen requirement for reformulated gasoline (RFG).

  12. U.S. Oxygenate Production

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

    By: Product Area May-15 Jun-15 Jul-15 Aug-15 Sep-15 Oct-15 View History Fuel Ethanol 29,666 29,684 30,256 29,621 28,543 30,139 1981-2015 Methyl Tertiary Butyl Ether (MTBE) 1,634...

  13. Status and Impacts of State MTBE Bans

    Reports and Publications (EIA)

    2003-01-01

    This paper describes legislation passed in 16 states banning or restricting the use of methyl tertiary butyl ether (MTBE) in gasoline. Analysis of the status and impact of these state MTBE bans is provided concerning the supply and potential price changes of gasoline.

  14. Eliminating MTBE in Gasoline in 2006

    Reports and Publications (EIA)

    2006-01-01

    A review of the market implications resulting from the rapid change from methyl tertiary butyl ether (MTBE) to ethanol-blended reformulated gasoline (RFG) on the East Coast and in Texas. Strains in ethanol supply and distribution will increase the potential for price volatility in these regions this summer.

  15. Quercetin 3-O-methyl ether protects FL83B cells from copper induced oxidative stress through the PI3K/Akt and MAPK/Erk pathway

    SciTech Connect (OSTI)

    Tseng, Hsiao-Ling; Li, Chia-Jung; Huang, Lin-Huang; Chen, Chun-Yao; Tsai, Chun-Hao; Lin, Chun-Nan; Department of Biological Science and Technology, School of Medicine, China Medical University, Taichung, Taiwan ; Hsu, Hsue-Yin

    2012-10-01

    Quercetin is a bioflavonoid that exhibits several biological functions in vitro and in vivo. Quercetin 3-O-methyl ether (Q3) is a natural product reported to have pharmaceutical activities, including antioxidative and anticancer activities. However, little is known about the mechanism by which it protects cells from oxidative stress. This study was designed to investigate the mechanisms by which Q3 protects against Cu{sup 2+}-induced cytotoxicity. Exposure to Cu{sup 2+} resulted in the death of mouse liver FL83B cells, characterized by apparent apoptotic features, including DNA fragmentation and increased nuclear condensation. Q3 markedly suppressed Cu{sup 2+}-induced apoptosis and mitochondrial dysfunction, characterized by reduced mitochondrial membrane potential, caspase-3 activation, and PARP cleavage, in Cu{sup 2+}-exposed cells. The involvement of PI3K, Akt, Erk, FOXO3A, and Mn-superoxide dismutase (MnSOD) was shown to be critical to the survival of Q3-treated FL83B cells. The liver of both larval and adult zebrafish showed severe damage after exposure to Cu{sup 2+} at a concentration of 5 μM. Hepatic damage induced by Cu{sup 2+} was reduced by cotreatment with Q3. Survival of Cu{sup 2+}-exposed larval zebrafish was significantly increased by cotreatment with 15 μM Q3. Our results indicated that Cu{sup 2+}-induced apoptosis in FL83B cells occurred via the generation of ROS, upregulation and phosphorylation of Erk, overexpression of 14-3-3, inactivation of Akt, and the downregulation of FOXO3A and MnSOD. Hence, these results also demonstrated that Q3 plays a protective role against oxidative damage in zebrafish liver and remarked the potential of Q3 to be used as an antioxidant for hepatocytes. Highlights: ► Protective effects of Q3 on Cu{sup 2+}-induced oxidative stress in vitro and in vivo. ► Cu{sup 2+} induced apoptosis in FL83B cells via ROS and the activation of Erk. ► Q3 abolishes Cu{sup 2+}-induced apoptosis through the PI3K/Akt and MAPK

  16. Oxygenates du`jour...MTBE? Ethanol? ETBE?

    SciTech Connect (OSTI)

    Wolfe, R.

    1995-12-31

    There are many different liquids that contain oxygen which could be blended into gasoline. The ones that have been tried and make the most sense are in the alcohol (R-OH) and ether (R-O-R) chemical family. The alcohols considered are: methanol (MeOH), ethanol (EtOH), tertiary butyl alcohol (TBA). The ethers are: methyl tertiary butyl ether (MTBE), ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether (TAME), tertiary amyl ethyl ether (TAEE), di-isopropyl ether (DIPE). Of the eight oxygenates listed above, the author describes the five that are still waiting for widespread marketing acceptance (methanol, TBA, TAME, TAEE, and DIPE). He then discusses the two most widely used oxygenates in the US, MTBE and ethanol, along with the up-and-coming ethanol ether, ETBE. Selected physical properties for all of these oxygenates can be found in Table 2 at the end of this paper. A figure shows a simplified alcohol/ether production flow chart for the oxygenates listed above and how they are interrelated.

  17. {gamma}-aminobutyric acid{sub A} (GABA{sub A}) receptor regulates ERK1/2 phosphorylation in rat hippocampus in high doses of Methyl Tert-Butyl Ether (MTBE)-induced impairment of spatial memory

    SciTech Connect (OSTI)

    Zheng Gang; Zhang Wenbin; Zhang Yun; Chen Yaoming; Liu Mingchao; Yao Ting; Yang Yanxia; Zhao Fang; Li Jingxia; Huang Chuanshu; Luo Wenjing Chen Jingyuan

    2009-04-15

    Experimental and occupational exposure to Methyl Tert-Butyl Ether (MTBE) has been reported to induce neurotoxicological and neurobehavioral effects, such as headache, nausea, dizziness, and disorientation, etc. However, the molecular mechanisms involved in MTBE-induced neurotoxicity are still not well understood. In the present study, we investigated the effects of MTBE on spatial memory and the expression and function of GABA{sub A} receptor in the hippocampus. Our results demonstrated that intraventricular injection of MTBE impaired the performance of the rats in a Morris water maze task, and significantly increased the expression of GABA{sub A} receptor {alpha}1 subunit in the hippocampus. The phosphorylation of ERK1/2 decreased after the MTBE injection. Furthermore, the decreased ability of learning and the reduction of phosphorylated ERK1/2 level of the MTBE-treated rats was partly reversed by bicuculline injected 30 min before the training. These results suggested that MTBE exposure could result in impaired spatial memory. GABA{sub A} receptor may play an important role in the MTBE-induced impairment of learning and memory by regulating the phosphorylation of ERK in the hippocampus.

  18. THE SEARCH FOR A COMPLEX MOLECULE IN A SELECTED HOT CORE REGION: A RIGOROUS ATTEMPT TO CONFIRM TRANS-ETHYL METHYL ETHER TOWARD W51 e1/e2

    SciTech Connect (OSTI)

    Carroll, P. Brandon; McGuire, Brett A.; Blake, Geoffrey A.; Apponi, A. J.; Ziurys, L. M.; Remijan, Anthony

    2015-01-20

    An extensive search has been conducted to confirm transitions of trans-ethyl methyl ether (tEME, C{sub 2}H{sub 5}OCH{sub 3}), toward the high-mass star forming region W51 e1/e2 using the 12 m Telescope of the Arizona Radio Observatory at wavelengths from 2 mm and 3 mm. In short, we cannot confirm the detection of tEME toward W51 e1/e2 and our results call into question the initial identification of this species by Fuchs et al. Additionally, re-evaluation of the data from the original detection indicates that tEME is not present toward W51 e1/e2 in the abundance reported by Fuchs and colleagues. Typical peak-to-peak noise levels for the present observations of W51 e1/e2 were between 10 and 30 mK, yielding an upper limit of the tEME column density of ≤1.5 × 10{sup 15} cm{sup –2}. This would make tEME at least a factor of two times less abundant than dimethyl ether (CH{sub 3}OCH{sub 3}) toward W51 e1/e2. We also performed an extensive search for this species toward the high-mass star forming region Sgr B2(N-LMH) with the National Radio Astronomy Observatory 100 m Green Bank Telescope. No transitions of tEME were detected and we were able to set an upper limit to the tEME column density of ≤4 × 10{sup 14} cm{sup –2} toward this source. Thus, we are able to show that tEME is not a new molecular component of the interstellar medium and that an exacting assessment must be carried out when assigning transitions of new molecular species to astronomical spectra to support the identification of large organic interstellar molecules.

  19. Update of Summer Reformulated Gasoline Supply Assessment for New York and Connecticut

    Reports and Publications (EIA)

    2004-01-01

    In October 2003, the Energy Information Administration (EIA) published a review of the status of the methyl tertiary butyl ether (MTBE) ban transition in New York (NY) and Connecticut (CT) that noted significant uncertainties in gasoline supply for those states for the summer of 2004. To obtain updated information, EIA spoke to major suppliers to the two states over the past several months as the petroleum industry began the switch from winter- to summer-grade gasoline.

  20. Total Crude Oil and Petroleum Products Exports

    U.S. Energy Information Administration (EIA) Indexed Site

    Product: Total Crude Oil and Petroleum Products Crude Oil Natural Gas Plant Liquids and Liquefied Refinery Gases Pentanes Plus Liquefied Petroleum Gases Ethane/Ethylene Propane/Propylene Normal Butane/Butylene Isobutane/Isobutylene Other Liquids Hydrogen/Oxygenates/Renewables/Other Hydrocarbons Oxygenates (excl. Fuel Ethanol) Methyl Tertiary Butyl Ether (MTBE) Other Oxygenates Renewable Fuels (incl. Fuel Ethanol) Fuel Ethanol Biomass-Based Diesel Unfinished Oils Naphthas and Lighter Kerosene and

  1. Total Crude Oil and Petroleum Products Imports by Area of Entry

    U.S. Energy Information Administration (EIA) Indexed Site

    Product: Total Crude Oil and Petroleum Products Crude Oil Natural Gas Plant Liquids and Liquefied Refinery Gases Pentanes Plus Liquefied Petroleum Gases Ethane Ethylene Propane Propylene Normal Butane Butylene Isobutane Isobutylene Other Liquids Hydrogen/Oxygenates/Renewables/Other Hydrocarbons Oxygenates (excl. Fuel Ethanol) Methyl Tertiary Butyl Ether (MTBE) Other Oxygenates Renewable Fuels (incl. Fuel Ethanol) Fuel Ethanol Biomass-Based Diesel Fuel Other Renewable Diesel Fuel Other Renewable

  2. MTEM Map

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

    MTBE Production Economics Tancred C. M. Lidderdale Contents 1. Summary 2. MTBE Production Costs 3. Relationship between price of MTBE and Reformulated Gasoline 4. Influence of Natural Gas Prices on the Gasoline Market 5. Regression Results 6. Data Sources 7. End Notes 1. Summary Last year the price of MTBE (methyl tertiary butyl ether) increased dramatically on two occasions (Figure 1) (see Data Sources at end of article.): 1. Between April and June 2000, the price (U.S. Gulf Coast waterborne

  3. Refinery & Blenders Net Input of Crude Oil

    U.S. Energy Information Administration (EIA) Indexed Site

    Product: Total Crude Oil & Petroleum Products Crude Oil Natural Gas Plant Liquids and Liquefied Refinery Gases Pentanes Plus Liquefied Petroleum Gases Ethane Normal Butane Isobutane Other Liquids Hydrogen/Oxygenates/Renewables/Other Hydrocarbons Hydrogen Oxygenates (excl. Fuel Ethanol) Methyl Tertiary Butyl Ether (MTBE) All Other Oxygenates Renewable Fuels (incl. Fuel Ethanol) Fuel Ethanol Renewable Diesel Fuel Other Renewable Fuels Other Hydrocarbons Unfinished Oils (net) Unfinished Oils,

  4. MTBE Production Economics

    Gasoline and Diesel Fuel Update (EIA)

    MTBE Production Economics Tancred C. M. Lidderdale Contents 1. Summary 2. MTBE Production Costs 3. Relationship between price of MTBE and Reformulated Gasoline 4. Influence of Natural Gas Prices on the Gasoline Market 5. Regression Results 6. Data Sources 7. End Notes 1. Summary Last year the price of MTBE (methyl tertiary butyl ether) increased dramatically on two occasions (Figure 1) (see Data Sources at end of article.): 1. Between April and June 2000, the price (U.S. Gulf Coast waterborne

  5. MTBE, Oxygenates, and Motor Gasoline

    Gasoline and Diesel Fuel Update (EIA)

    MTBE, Oxygenates, and Motor Gasoline Contents * Introduction * Federal gasoline product quality regulations * What are oxygenates? * Who gets gasoline with oxygenates? * Which areas get MTBE? * How much has been invested in MTBE production capacity? * What does new Ethanol capacity cost? * What would an MTBE ban cost? * On-line information resources * Endnotes * Summary of revisions to this analysis Introduction The blending of methyl tertiary butyl ether (MTBE) into motor gasoline has increased

  6. 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),

  7. 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),

  8. 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

  9. 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),

  10. Crown ethers in graphene

    SciTech Connect (OSTI)

    Guo, Junjie; Lee, Jaekwang; Contescu, Cristian I; Gallego, Nidia C; Pantelides, Sokrates T.; Pennycook, Stephen J; Moyer, Bruce A; Chisholm, Matthew F

    2014-01-01

    Crown ethers, introduced by Pedersen1, are at their most basic level neutral rings constructed of oxygen atoms linked by two- or three-carbon chains. They have attracted special attention for their ability to selectively incorporate various atoms2 or molecules within the cavity formed by the ring3-6. This property has led to the use of crown ethers and their compounds in a wide range of chemical and biological applications7,8. However, crown ethers are typically highly flexible, frustrating efforts to rigidify them for many uses that demand higher binding affinity and selectivity9,10. In this Letter, we report atomic-resolution images of the same basic structures of the original crown ethers embedded in graphene. This arrangement constrains the crown ethers to be rigid and planar and thus uniquely suited for the many applications that crown ethers are known for. First-principles calculations show that the close similarity of the structures seen in graphene with those of crown ether molecules also extends to their selectivity towards specific metal cations depending on the ring size. Atoms (or molecules) incorporated within the crown ethers in graphene offer a simple environment that can be easily and systematically probed and modeled. Thus, we expect that this discovery will introduce a new wave of investigations and applications of chemically functionalized graphene.

  11. Alternative Fuels Data Center: Dimethyl Ether

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    Dimethyl Ether to someone by E-mail Share Alternative Fuels Data Center: Dimethyl Ether on Facebook Tweet about Alternative Fuels Data Center: Dimethyl Ether on Twitter Bookmark Alternative Fuels Data Center: Dimethyl Ether on Google Bookmark Alternative Fuels Data Center: Dimethyl Ether on Delicious Rank Alternative Fuels Data Center: Dimethyl Ether on Digg Find More places to share Alternative Fuels Data Center: Dimethyl Ether on AddThis.com... More in this section... Biobutanol Dimethyl Ether

  12. Thermodynamics of Hydrogen Production from Dimethyl Ether Steam Reforming and Hydrolysis

    SciTech Connect (OSTI)

    T.A. Semelsberger

    2004-10-01

    The thermodynamic analyses of producing a hydrogen-rich fuel-cell feed from the process of dimethyl ether (DME) steam reforming were investigated as a function of steam-to-carbon ratio (0-4), temperature (100 C-600 C), pressure (1-5 atm), and product species: acetylene, ethanol, methanol, ethylene, methyl-ethyl ether, formaldehyde, formic acid, acetone, n-propanol, ethane and isopropyl alcohol. Results of the thermodynamic processing of dimethyl ether with steam indicate the complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide for temperatures greater than 200 C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure (P = 1 atm). Increasing the operating pressure was observed to shift the equilibrium toward the reactants; increasing the pressure from 1 atm to 5 atm decreased the conversion of dimethyl ether from 99.5% to 76.2%. The order of thermodynamically stable products in decreasing mole fraction was methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol--formaldehyde, formic acid, and acetylene were not observed. The optimal processing conditions for dimethyl ether steam reforming occurred at a steam-to-carbon ratio of 1.5, a pressure of 1 atm, and a temperature of 200 C. Modeling the thermodynamics of dimethyl ether hydrolysis (with methanol as the only product considered), the equilibrium conversion of dimethyl ether is limited. The equilibrium conversion was observed to increase with temperature and steam-to-carbon ratio, resulting in a maximum dimethyl ether conversion of approximately 68% at a steam-to-carbon ratio of 4.5 and a processing temperature of 600 C. Thermodynamically, dimethyl ether processed with steam can produce hydrogen-rich fuel-cell feeds--with hydrogen concentrations exceeding 70%. This substantiates dimethyl ether as a viable source of hydrogen for PEM fuel cells.

  13. Propenyl ether monomers for photopolymerization

    DOE Patents [OSTI]

    Crivello, James V.

    1996-01-01

    Propenyl ether monomers of formula V A(OCH.dbd.CHCH.sub.3).sub.n wherein n is an integer from one to six and A is selected from cyclic ethers, polyether and alkanes are disclosed. The monomers are readily polymerized in the presence of cationic photoinitiators, when exposed to actinic radiation, to form poly(propenyl ethers) that are useful for coatings, sealants, varnishes and adhesives. Compositions for preparing polymeric coatings comprising the compounds of formula V together with particular cationic photoinitiators are also disclosed, as are processes for making the monomers from allyl halides and readily available alcohols. The process involves rearranging the resulting allyl ethers to propenyl ethers.

  14. Propenyl ether monomers for photopolymerization

    DOE Patents [OSTI]

    Crivello, J.V.

    1996-10-22

    Propenyl ether monomers of formula A(OCH{double_bond}CHCH{sub 3}){sub n} wherein n is an integer from one to six and A is selected from cyclic ethers, polyether and alkanes are disclosed. The monomers are readily polymerized in the presence of cationic photoinitiators, when exposed to actinic radiation, to form poly(propenyl ethers) that are useful for coatings, sealants, varnishes and adhesives. Compositions for preparing polymeric coatings comprising the compounds of the above formula together with particular cationic photoinitiators are also disclosed, as are processes for making the monomers from allyl halides and readily available alcohols. The process involves rearranging the resulting allyl ethers to propenyl ethers.

  15. Reaction Pathways and Energetics of Etheric C−O Bond Cleavage Catalyzed by Lanthanide Triflates

    SciTech Connect (OSTI)

    Assary, Rajeev S.; Atesin, Abdurrahman C.; Li, Zhi; Curtiss, Larry A.; Marks, Tobin J.

    2013-07-15

    Efficient and selective cleavage of etheric C−O bonds is crucial for converting biomass into platform chemicals and liquid transportation fuels. In this contribution, computational methods at the DFT B3LYP level of theory are employed to understand the efficacy of lanthanide triflate catalysts (Ln(OTf)3, Ln = La, Ce, Sm, Gd, Yb, and Lu) in cleaving etheric C−O bonds. In agreement with experiment, the calculations indicate that the reaction pathway for C−O cleavage occurs via a C−H → O−H proton transfer in concert with weakening of the C−O bond of the coordinated ether substrate to ultimately yield a coordinated alkenol. The activation energy for this process falls as the lanthanide ionic radius decreases, reflecting enhanced metal ion electrophilicity. Details of the reaction mechanism for Yb(OTf)3-catalyzed ring opening are explored in depth, and for 1-methyl-d3-butyl phenyl ether, the computed primary kinetic isotope effect of 2.4 is in excellent agreement with experiment (2.7), confirming that etheric ring-opening pathway involves proton transfer from the methyl group alpha to the etheric oxygen atom, which is activated by the electrophilic lanthanide ion. Calculations of the catalytic pathway using eight different ether substrates indicate that the more rapid cleavage of acyclic versus cyclic ethers is largely due to entropic effects, with the former C−O bond scission processes increasing the degrees of freedom/particles as the transition state is approached.

  16. Oxygenate Supply/Demand Balances in the Short-Term Integrated Forecasting Model (Released in the STEO March 1998)

    Reports and Publications (EIA)

    1998-01-01

    The blending of oxygenates, such as fuel ethanol and methyl tertiary butyl ether (MTBE), into motor gasoline has increased dramatically in the last few years because of the oxygenated and reformulated gasoline programs. Because of the significant role oxygenates now have in petroleum product markets, the Short-Term Integrated Forecasting System (STIFS) was revised to include supply and demand balances for fuel ethanol and MTBE. The STIFS model is used for producing forecasts in the Short-Term Energy Outlook. A review of the historical data sources and forecasting methodology for oxygenate production, imports, inventories, and demand is presented in this report.

  17. MTBE, Oxygenates, and Motor Gasoline (Released in the STEO October 1999)

    Reports and Publications (EIA)

    1999-01-01

    The blending of methyl tertiary butyl ether (MTBE) into motor gasoline has increased dramatically since it was first produced 20 years ago. MTBE usage grew in the early 1980's in response to octane demand resulting initially from the phaseout of lead from gasoline and later from rising demand for premium gasoline. The oxygenated gasoline program stimulated an increase in MTBE production between 1990 and 1994. MTBE demand increased from 83,000 in 1990 to 161,000 barrels per day in 1994. The reformulated gasoline (RFG) program provided a further boost to oxygenate blending. The MTBE contained in motor gasoline increased to 269,000 barrels per day by 1997.

  18. California's Move Toward E10 (released in AEO2009)

    Reports and Publications (EIA)

    2009-01-01

    In Annual Energy Outlook 2009, (AEO) E10a gasoline blend containing 10% ethanolis assumed to be the maximum ethanol blend allowed in California erformulated gasoline (RFG), as opposed to the 5.7% blend assumed in earlier AEOs. The 5.7% blend had reflected decisions made when California decided to phase out use of the additive methyl tertiary butyl ether in its RFG program in 2003, opting instead to use ethanol in the minimum amount that would meet the requirement for 2.0% oxygen content under the Clean Air Act provisions in effect at that time.

  19. Fuel Ethanol Oxygenate Production

    Gasoline and Diesel Fuel Update (EIA)

    Product: Fuel Ethanol Methyl Tertiary Butyl Ether Merchant Plants Captive Plants Period-Unit: Monthly-Thousand Barrels Monthly-Thousand Barrels per Day Annual-Thousand Barrels Annual-Thousand Barrels per Day Download Series History Download Series History Definitions, Sources & Notes Definitions, Sources & Notes Show Data By: Product Area Jan-16 Feb-16 Mar-16 Apr-16 May-16 Jun-16 View History U.S. 30,319 28,678 30,812 28,059 30,228 30,258 1981-2016 East Coast (PADD 1) 641 698 804 725 734

  20. CATALYSTS FOR HIGH CETANE ETHERS AS DIESEL FUELS

    SciTech Connect (OSTI)

    Kamil Klier; Richard G. Herman; James G.C. Shen; Qisheng Ma

    2000-08-31

    A novel 1,2-ethanediol, bis(hydrogen sulfate), disodium salt precursor-based solid acid catalyst with a zirconia substrate was synthesized and demonstrated to have significantly enhanced activity and high selectivity in producing methyl isobutyl ether (MIBE) or isobutene from methanol-isobutanol mixtures. The precursor salt was synthesized and provided by Dr. T. H. Kalantar of the M.E. Pruitt Research Center, Dow Chemical Co., Midland, MI 48674. Molecular modeling of the catalyst synthesis steps and of the alcohol coupling reaction is being carried out. A representation of the methyl transfer from the surface activated methanol molecule (left) to the activated oxygen of the isobutanol molecule (right) to form an ether linkage to yield MIBE is shown.

  1. Radiation chemistry of alternative fuel oxygenates -- Substituted ethers

    SciTech Connect (OSTI)

    Mezyk, S. P.; Cooper, W. J.; Bartels, D. M.; Tobien, T.; O'Shea, K. E.

    1999-11-15

    The electron beam process, an advanced oxidation and reduction technology, is based in the field of radiation chemistry. Fundamental to the development of treatment processes is an understanding of the underlying chemistry. The authors have previously evaluated the bimolecular rate constants for the reactions of methyl tert-butyl ether (MTBE) and with this study have extended their studies to include ethyl tert-butyl ether (ETBE), di-isopropyl ether (DIPE) and tert-amyl methyl ether (TAME) with the hydroxyl radical, hydrogen atom and solvated electron using pulse radiolysis. For all of the oxygenates the reaction with the hydroxyl radical appears to be of primary interest in the destruction of the compounds in water. The rates with the solvated electron are limiting values as the rates appear to be relatively low. The hydrogen atom rate constants are relatively low, coupled with the low yield in radiolysis, they concluded that these are of little significance in the destruction of the alternative fuel oxygenates (and MTBE).

  2. Development of specialty chemicals from dimethyl ether

    SciTech Connect (OSTI)

    Tartamella, T.L.; Lee, S.

    1996-12-31

    Dimethyl ether (DME) may be efficiently produced from coal-bases syngas in a high pressure, mechanically agitated slurry reactor. DME synthesis occurs in the liquid phase using a dual catalyst. By operating in a dual catalyst mode, DME may be converted from in-situ produced methanol resulting in higher methyl productivities and syngas conversions over methanol conversion alone. The feasibility of utilizing DME as a building block for more valuable specialty chemicals has been examined. A wide variety of petrochemicals may be produced from DME including light olefins, gasoline range hydrocarbons, oxygenates, and glycol precursors. These chemicals represent an important part of petroleum industries inventory of fine chemicals. Carbonylation, hydrocarbonylation, and oxidative dimerization are but a few of the reactions in which DME may undergo conversion. DME provides an additional route for the production of industrially important petrochemicals.

  3. Sulfonimide-containing poly(arylene ether)s and poly(arylene ether sulfone)s, methods for producing the same, and uses thereof

    DOE Patents [OSTI]

    Hofmann, Michael A.

    2006-11-14

    The present invention is directed to sulfonimide-containing polymers, specifically sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, and processes for making the sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, for use conductive membranes and fuel cells.

  4. Energy and crude oil input requirements for the production of reformulated gasolines

    SciTech Connect (OSTI)

    Singh, M.; McNutt, B.

    1993-10-01

    The energy and crude oil requirements for the production of reformulated gasoline (RFG) are estimated. The scope of the study includes both the energy and crude oil embodied in the final product and the process energy required to manufacture the RFG and its components. The effects on energy and crude oil use of employing various oxygenates to meet the minimum oxygen-content level required by the Clean Air Act Amendments are evaluated. The analysis shows that production of RFG requires more total energy, but uses less crude oil, than that of conventional gasoline. The energy and crude oil use requirements of the different RFGs vary considerably. For the same emissions performance level, RFG with ethanol requires substantially more total energy and crude oil than does RFG with methyl tertiary butyl ether (MTBE) or ethyl tertiary butyl ether. A specific proposal by the US Environmental Protection Agency, designed to allow the use of ethanol in RFG, would increase the total energy required to produce RFG by 2% and the total crude oil required by 2.0 to 2.5% over the corresponding values for the base RFG with MTBE.

  5. Catalytic distillation process

    DOE Patents [OSTI]

    Smith, Jr., Lawrence A. (Bellaire, TX)

    1982-01-01

    A method for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C.sub.4 feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

  6. Catalytic distillation process

    DOE Patents [OSTI]

    Smith, L.A. Jr.

    1982-06-22

    A method is described for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C[sub 4] feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

  7. Aza crown ether compounds as anion receptors

    DOE Patents [OSTI]

    Lee, H.S.; Yang, X.O.; McBreen, J.

    1998-08-04

    A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the new family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of LI{sup +} ion in alkali metal batteries. 3 figs.

  8. Aza crown ether compounds as anion receptors

    DOE Patents [OSTI]

    Lee, Hung Sui; Yang, Xiao-Oing; McBreen, James

    1998-08-04

    A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the new family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of LI.sup.+ ion in alkali metal batteries.

  9. A laser and molecular beam mass spectrometer study of low-pressure dimethyl ether flames

    SciTech Connect (OSTI)

    Andrew McIlroy; Toby D. Hain; Hope A. Michelsen; Terrill A. Cool

    2000-12-15

    The oxidation of dimethyl ether (DME) is studied in low-pressure flames using new molecular beam mass spectrometer and laser diagnostics. Two 30.0-Torr, premixed DME/oxygen/argon flames are investigated with stoichiometries of 0.98 and 1.20. The height above burner profiles of nine stable species and two radicals are measured. These results are compared to the detailed chemical reaction mechanism of Curran and coworkers. Generally good agreement is found between the model and data. The largest discrepancies are found for the methyl radical profiles where the model predicts qualitatively different trends in the methyl concentration with stoichiometry than observed in the experiment.

  10. Crown ethers in graphene (Journal Article) | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    Crown ethers in graphene Prev Next Title: Crown ethers in graphene Crown ethers, ... them for many uses that demand higher binding affinity and selectivity9,10. In this ...

  11. Alternative Fuels lDimethyl Ether Rheology and Materials Studies...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Fuels lDimethyl Ether Rheology and Materials Studies Alternative Fuels lDimethyl Ether Rheology and Materials Studies 2004 Diesel Engine Emissions Reduction (DEER) Conference ...

  12. Role of acid catalysis in dimethyl ether conversion processes

    SciTech Connect (OSTI)

    Tartamella, T.L.; Lee, S.

    1996-12-31

    Acidity plays an important role in the conversion of methanol and dimethyl ether (DME) to hydrocarbons and oxygenates. In the conversion to hydrocarbons over zeolite catalyst, Broensted acidity is the main contributor to the first hydrocarbon formed. Here, acidity is also an important factor in determining olefin, paraffin, and aromatic content in the final product distribution. Catalyst life has also been found to be related to acidity content in zeolites. DME conversion to oxygenates is especially dependent on high acidity catalysts. Superacids like BF{sub 3}, HF-BF{sub 3}, and CF{sub 3}COOH have been used in the past for conversion of DME in carbonylation reactions to form methyl acetate and acetic acid at high pressures. Recently, heteropoly acids and their corresponding metal substituted salts have been used to convert DME to industrially important petrochemicals resulting in shorter reaction times and without the use of harsh operating conditions.

  13. The efficient use of natural gas in transportation

    SciTech Connect (OSTI)

    Stodolsky, F.; Santini, D.J.

    1992-04-01

    Concerns over air quality and greenhouse gas emissions have prompted discussion as well as action on alternative fuels and energy efficiency. Natural gas and natural gas derived fuels and fuel additives are prime alternative fuel candidates for the transportation sector. In this study, we reexamine and add to past work on energy efficiency and greenhouse gas emissions of natural gas fuels for transportation (DeLuchi 1991, Santini et a. 1989, Ho and Renner 1990, Unnasch et al. 1989). We add to past work by looking at Methyl tertiary butyl ether (from natural gas and butane component of natural gas), alkylate (from natural gas butanes), and gasoline from natural gas. We also reexamine compressed natural gas, liquified natural gas, liquified petroleum gas, and methanol based on our analysis of vehicle efficiency potential. We compare the results against nonoxygenated gasoline.

  14. The efficient use of natural gas in transportation

    SciTech Connect (OSTI)

    Stodolsky, F.; Santini, D.J.

    1992-01-01

    Concerns over air quality and greenhouse gas emissions have prompted discussion as well as action on alternative fuels and energy efficiency. Natural gas and natural gas derived fuels and fuel additives are prime alternative fuel candidates for the transportation sector. In this study, we reexamine and add to past work on energy efficiency and greenhouse gas emissions of natural gas fuels for transportation (DeLuchi 1991, Santini et a. 1989, Ho and Renner 1990, Unnasch et al. 1989). We add to past work by looking at Methyl tertiary butyl ether (from natural gas and butane component of natural gas), alkylate (from natural gas butanes), and gasoline from natural gas. We also reexamine compressed natural gas, liquified natural gas, liquified petroleum gas, and methanol based on our analysis of vehicle efficiency potential. We compare the results against nonoxygenated gasoline.

  15. Crown ethers in graphene (Journal Article) | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    Crown ethers in graphene Prev Next Title: Crown ethers in graphene You are ... them for many uses that demand higher binding affinity and selectivity9,10. In this ...

  16. Crown ethers in graphene (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Crown ethers in graphene Citation Details In-Document Search Title: Crown ethers in ... them for many uses that demand higher binding affinity and selectivity9,10. In this ...

  17. Process for making propenyl ethers and photopolymerizable compositions containing them

    DOE Patents [OSTI]

    Crivello, James V.

    1996-01-01

    Propenyl ether monomers of formula V A(OCH.dbd.CHCH.sub.3).sub.n wherein n is an integer from one to six and A is selected from cyclic ethers, polyether and alkanes are disclosed. The monomers are readily polymerized in the presence of cationic photoinitiators, when exposed to actinic radiation, to form poly(propenyl ethers) that are useful for coatings, sealants, varnishes and adhesives. Compositions for preparing polymeric coatings comprising the compounds of formula V together with particular cationic photoinitiators are also disclosed, as are processes for making the monomers from allyl halides and readily available alcohols. The process involves rearranging the resulting allyl ethers to propenyl ethers.

  18. Process for making propenyl ethers and photopolymerizable compositions containing them

    DOE Patents [OSTI]

    Crivello, J.V.

    1996-01-23

    Propenyl ether monomers of formula A(OCH{double_bond}CHCH{sub 3}){sub n} (V) wherein n is an integer from one to six and A is selected from cyclic ethers, polyether, and alkanes are disclosed. The monomers are readily polymerized in the presence of cationic photoinitiators, when exposed to actinic radiation, to form poly(propenyl ethers) that are useful for coatings, sealants, varnishes and adhesives. Compositions for preparing polymeric coatings comprising the compounds of formula V together with particular cationic photoinitiators are also disclosed, as are processes for making the monomers from allyl halides and readily available alcohols. The process involves rearranging the resulting allyl ethers to propenyl ethers.

  19. Degradation of Imidazolium- and Quaternary Ammonium-Functionalized Poly(fluorenyl ether ketone sulfone) Anion Exchange Membranes

    SciTech Connect (OSTI)

    Chen, DY; Hickner, MA

    2012-11-01

    Imidazolium and quaternary ammonium-functionalized poly(fluorenyl ether ketone sulfone)s were synthesized successfully with the same degree of cationic functionalization and identical polymer backbones for a comparative study of anion exchange membranes (AEMs) for solid-state alkaline membrane fuel cells (AMFCs). Both anion exchange membranes were synthesized using a new methyl-containing monomer that avoided the use of toxic chloromethylation reagents. The polymer chemical structures were confirmed by H-1 NMR and FTIR. The derived AEMs were fully characterized by water uptake, anion conductivity, stability under aqueous basic conditions, and thermal stability. Interestingly, both the cationic groups and the polymer backbone were found to be degraded in 1 M NaOH solution at 60 degrees C over 48 h as measured by changes of ion exchange capacity and intrinsic viscosity. Imidazolium-functionalized poly(fluorenyl ether ketone sulfone)s had similar aqueous alkaline stability to quaternary ammonium-functionalized materials at 60 degrees C but much lower stability at 80 degrees C. This work demonstrates that quaternary ammonium and imidazolium cationic groups are not stable on poly(arylene ether sulfone) backbones under relatively mild conditions. Additionally, the poly(arylene ether sulfone) backbone, which is one of the most common polymers used in ion exchange membrane applications, is not stable in the types of molecular configurations analyzed.

  20. Alternative Fuels lDimethyl Ether Rheology and Materials Studies |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Alternative Fuels lDimethyl Ether Rheology and Materials Studies Alternative Fuels lDimethyl Ether Rheology and Materials Studies 2004 Diesel Engine Emissions Reduction (DEER) Conference Presentation: The Pennsylvania State University 2004_deer_perez.pdf (548.66 KB) More Documents & Publications Research on Fuels & Lubricants Development of a Dimethyl Ether (DME)-Fueled Shuttle Bus Ionic Liquids as Multifunctional Ashless Additives for Engine Lubrication

  1. Divinyl ether synthase gene and protein, and uses thereof

    SciTech Connect (OSTI)

    Howe, Gregg A.; Itoh, Aya

    2011-09-13

    The present invention relates to divinyl ether synthase genes, proteins, and methods of their use. The present invention encompasses both native and recombinant wild-type forms of the synthase, as well as mutants and variant forms, some of which possess altered characteristics relative to the wild-type synthase. The present invention also relates to methods of using divinyl ether synthase genes and proteins, including in their expression in transgenic organisms and in the production of divinyl ether fatty acids, and to methods of suing divinyl ether fatty acids, including in the protection of plants from pathogens.

  2. Divinyl ether synthase gene, and protein and uses thereof

    DOE Patents [OSTI]

    Howe, Gregg A.; Itoh, Aya

    2006-12-26

    The present invention relates to divinyl ether synthase genes, proteins, and methods of their use. The present invention encompasses both native and recombinant wild-type forms of the synthase, as well as mutants and variant forms, some of which possess altered characteristics relative to the wild-type synthase. The present invention also relates to methods of using divinyl ether synthase genes and proteins, including in their expression in transgenic organisms and in the production of divinyl ether fatty acids, and to methods of suing divinyl ether fatty acids, including in the protection of plants from pathogens.

  3. Arylations of coal model systems. [Benzyl phenyl ether and l-naphthylmethyl phenyl ether

    SciTech Connect (OSTI)

    Smith, B.F.; Venier, C.G.; Squires, T.G.

    1984-01-01

    Currently, coal is converted to clean liquids or low melting solids by processes which utilize high temperature, high pressure, or both. These processes occur by thermal bond cleavages and involve the intermediacy of free radicals. In a search for chemistry which could liquefy coal under milder conditions, the authors have focussed on thermally less demanding ionic reactions. Of the functional groups which commonly occur in coals, ethers are the easiest to cleave under acid conditions. Depending on the density of these linkages and their importance as crosslinks in the macromolecular structure of coals, solubilization might be greatly enhanced solely by cleaving and capping either bonds. Benzylic ethers are particularly reactive and have been implicated in the initiation of coal pyrolysis and hydropyrolysis. Arylation, the use of acids to cleave bonds in coals in the presence of aromatic rings to trap the consequent incipient carbonium ions, has a long history. This paper discusses the use of benzyl phenyl ether and l-naphthylmethyl phenyl ether and polymers related to them as models to develop and evaluate the chemistry involved in the arylations. 9 references, 1 figure, 4 tables.

  4. Development of a Dimethyl Ether (DME)-Fueled Shuttle Bus | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Development of a Dimethyl Ether (DME)-Fueled Shuttle Bus Chapter 7 - Advancing Systems and Technologies to Produce Cleaner Fuels Alternative Fuels lDimethyl Ether Rheology and ...

  5. Process for producing dimethyl ether from synthesis gas

    DOE Patents [OSTI]

    Pierantozzi, R.

    1985-06-04

    This invention pertains to a Fischer Tropsch process for converting synthesis gas to an oxygenated hydrocarbon with particular emphasis on dimethyl ether. Synthesis gas comprising carbon monoxide and hydrogen are converted to dimethyl ether by carrying out the reaction in the presence of an alkali metal-manganese-iron carbonyl cluster incorporated onto a zirconia-alumina support.

  6. Process for producing dimethyl ether form synthesis gas

    DOE Patents [OSTI]

    Pierantozzi, Ronald

    1985-01-01

    This invention pertains to a Fischer Tropsch process for converting synthesis gas to an oxygenated hydrocarbon with particular emphasis on dimethyl ether. Synthesis gas comprising carbon monoxide and hydrogen are converted to dimethyl ether by carrying out the reaction in the presence of an alkali metal-manganese-iron carbonyl cluster incorporated onto a zirconia-alumina support.

  7. Mixed ether electrolytes for secondary lithium batteries with improved low temperature performance

    SciTech Connect (OSTI)

    Abraham, K.M.; Pasquariello, D.M.; Martin, F.J.

    1986-04-01

    Tetrahydrofuran (THF): 2-methyl-tetrahydrofuran (2Me-THF)/LiAsF/sub 6/ mixed solutions, despite their lower conductivity, have allowed significantly better low temperature performance in Li/TiS/sub 2/ cells than have THF/LiAsF/sub 6/, /sup 13/C NMR data suggest that this may be related to the structurally disordered Li/sup +/-solvates that exist in the mixed ether solutions. High cycling efficiencies for the Li electrode in THF:2Me-THF/LiAsF/sub 6/ solutions have been achieved by the use of 2Me-F as an additive. A 5 Ah capacity Li/TiS/sub 2/ cell has been cycled more than 100 times at 100, depth-of-discharge, with the cell capacity remaining at over 3 Ah at the 100th cycle.

  8. Origin of mechanical modifications in poly (ether ether ketone)/carbon nanotube composite

    SciTech Connect (OSTI)

    Pavlenko, Ekaterina; Puech, Pascal; Bacsa, Wolfgang; Boyer, François; Olivier, Philippe; Sapelkin, Andrei; King, Stephen; Heenan, Richard; Pons, François; Gauthier, Bénédicte; Cadaux, Pierre-Henri

    2014-06-21

    Variations in the hardness of a poly (ether ether ketone) beam electrically modified with multi-walled carbon nanotubes (MWCNT, 0.5%-3%) are investigated. It is shown that both rupture and hardness variations correlate with the changes in carbon nanotube concentration when using micro indentation and extended Raman imaging. Statistical analysis of the relative spectral intensities in the Raman image is used to estimate local tube concentration and polymer crystallinity. We show that the histogram of the Raman D band across the image provides information about the amount of MWCNTs and the dispersion of MWCNTs in the composite. We speculate that we have observed a local modification of the ordering between pure and modified polymer. This is partially supported by small angle neutron scattering measurements, which indicate that the agglomeration state of the MWCNTs is the same at the concentrations studied.

  9. Determination of Methyl tert-Butyl Ether and tert-Butyl Alcohol...

    Office of Scientific and Technical Information (OSTI)

    ... Authors: Oh, Keun-Chan ; Stringfellow, William T. Publication Date: 2003-10-02 OSTI Identifier: 820662 Report Number(s): LBNL--53866 R&D Project: G41101; TRN: US200405%%70 DOE ...

  10. High pressure injection of dimethyl ether

    SciTech Connect (OSTI)

    Glensvig, M.; Sorenson, S.C.; Abata, D.

    1996-12-31

    Partially oxygenated hydrocarbons produced from natural gas have been shown to be viable alternate fuels for the diesel engine, showing favorable combustion characteristics similar to that of diesel fuel but without exhaust particulates and with significantly reduced NO{sub x} emissions and lower engine noise. Further, engine studies have demonstrated that such compounds, like dimethyl ether (DME), can be injected at much lower pressures than conventional diesel fuel with better overall performance. This experimental study compares the injection of DME to that of conventional diesel fuel. Both fuels were injected into a quiescent high pressure chamber containing Nitrogen at pressures up to 25 atmospheres at room temperature with a pintle nozzle and jerk pump. Comparisons were obtained with high speed photography using a Hycam camera. Results indicate that there are significant differences in spray geometry and penetration which are not predictable with analytical models currently used for diesel fuels.

  11. Coupling of alcohols to ethers: The dominance of the surface S{sub N}2 reaction pathway

    SciTech Connect (OSTI)

    Klier, K.; Feeley, O.C.; Johansson, M.; Herman, R.G.

    1996-12-31

    Coupling of alcohols to ethers, important high value oxygenates, proceeds on acid catalysts via general pathways that uniquely control product composition, oxygen retention, chirality inversion, and kinetics. The dominant pathway is the S{sub N}2 reaction with competition of the alcohols for the surface acid sites. This is exemplified by formation of methyl(ethyl) isobutylether (M(E)IBE) from methanol(ethanol)/isobutanol mixtures, retention of oxygen ({sup 18}O) of the heavier alcohol, and optimum rate as a function of concentration of either reactant alcohol. The S{sub N}2 pathway in the confinement of zeolite pores exhibits additional features of a near-100% selectivity to dimethylether (DME) in H-mordenite and a near-100% selectivity to chiral inversion in 2-pentanol/ethanol coupling to 2-ethoxypentane in HZSM-5. A minor reaction pathway entails olefin or carbenium intermediates, as exemplified by the formation of methyl tertiarybutyl ether (MTBE) from methanol/isobutanol mixtures with oxygen retention of the lighter alcohol. Calculations of transition state and molecular modeling of the oxonium-involving pathways dramatically demonstrate how the reaction path selects the products.

  12. Preparation and characterization of polymer blend based on sulfonated poly (ether ether ketone) and polyetherimide (SPEEK/PEI) as proton exchange membranes for fuel cells

    SciTech Connect (OSTI)

    Hashim, Nordiana; Ali, Ab Malik Marwan; Lepit, Ajis; Rasmidi, Rosfayanti; Subban, Ri Hanum Yahaya; Yahya, Muhd Zu Azhan

    2015-08-28

    Blends of sulfonated poly (ether ether ketone) (SPEEK) and polyetherimide (PEI) were prepared in five different weight ratios using N-methyl-2-pyrrolidone (NMP) as solvent by the solution cast technique. The degree of sulfonation (DS) of the sulfonated PEEK was determined from deuterated dimethyl sulfoxide (DMSO-d{sub 6}) solution of the purified polymer using {sup 1}H NMR method. The properties studied in the present investigation includes conductivity, water uptake, thermal stability and structure analysis of pure SPEEK as well as SPEEK-PEI polymer blend membranes. The experimental results show that the conductivity of the membranes increased with increase in temperature from 30 to 80°C, except for that of pure SPEEK membrane which increased with temperature from 30 to 60°C while its conductivity decreased with increasing temperature from 60 to 80°C. The conductivity of 70wt.%SPEEK-30wt.%PEI blend membrane at 80% relative humidity (RH) is found to be 1.361 × 10{sup −3} Scm{sup −1} at 30°C and 3.383 × 10{sup −3} Scm{sup −1} at 80°C respectively. It was also found that water uptake and thermal stability of the membranes slightly improved upon blending with PEI. Structure analysis was carried out using Fourier Transform Infrared (FTIR) spectroscopy which revealed considerable interactions between sulfonic acid group of SPEEK and imide groups of PEI. Modification of SPEEK by blending with PEI shows good potential for improving the electrical and physical properties of proton exchange membranes.

  13. Synergistic effect of mixing dimethyl ether with methane, ethane, propane, and ethylene fuels on polycyclic aromatic hydrocarbon and soot formation

    SciTech Connect (OSTI)

    Yoon, S.S.; Anh, D.H.; Chung, S.H.

    2008-08-15

    Characteristics of polycyclic aromatic hydrocarbon (PAH) and soot formation in counterflow diffusion flames of methane, ethane, propane, and ethylene fuels mixed with dimethyl ether (DME) have been investigated. Planar laser-induced incandescence and fluorescence techniques were employed to measure relative soot volume fractions and PAH concentrations, respectively. Results showed that even though DME is known to be a clean fuel in terms of soot formation, DME mixture with ethylene fuel increases PAH and soot formation significantly as compared to the pure ethylene case, while the mixture of DME with methane, ethane, and propane decreases PAH and soot formation. Numerical calculations adopting a detailed kinetics showed that DME can be decomposed to produce a relatively large number of methyl radicals in the low-temperature region where PAH forms and grows; thus the mixture of DME with ethylene increases CH{sub 3} radicals significantly in the PAH formation region. Considering that the increase in the concentration of O radicals is minimal in the PAH formation region with DME mixture, the enhancement of PAH and soot formation in the mixture flames of DME and ethylene can be explained based on the role of methyl radicals in PAH and soot formation. Methyl radicals can increase the concentration of propargyls, which could enhance incipient benzene ring formation through the propargyl recombination reaction and subsequent PAH growth. Thus, the result substantiates the importance of methyl radicals in PAH and soot formation, especially in the PAH formation region of diffusion flames. (author)

  14. Atmospheric and combustion chemistry of dimethyl ether

    SciTech Connect (OSTI)

    Nielsen, O.J.; Egsgaard, H.; Larsen, E.; Sehested, J.; Wallington, T.J.

    1997-12-31

    It has been demonstrated that dimethyl ether (DME) is an ideal diesel fuel alternative. DME, CH{sub 3}OCH{sub 3}, combines good fuel properties with low exhaust emissions and low combustion noise. Large scale production of this fuel can take place using a single step catalytic process converting CH{sub 4} to DME. The fate of DME in the atmosphere has previously been studied. The atmospheric degradation is initiated by the reaction with hydroxyl radicals, which is also a common feature of combustion processes. Spectrokinetic investigations and product analysis were used to demonstrate that the intermediate oxy radical, CH{sub 3}OCH{sub 2}O, exhibits a novel reaction pathway of hydrogen atom ejection. The application of tandem mass spectrometry to chemi-ions based on supersonic molecular beam sampling has recently been demonstrated. The highly reactive ionic intermediates are sampled directly from the flame and identified by collision activation mass spectrometry and ion-molecule reactions. The mass spectrum reflects the distribution of the intermediates in the flame. The atmospheric degradation of DME as well as the unique fuel properties of a oxygen containing compound will be discussed.

  15. Controlling DNA Methylation

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

    Controlling DNA Methylation Though life on earth is composed of a diverse range of organisms, some with many different types of tissues and cells, all these are encoded by a molecule we call DNA. The information required to build a protein is stored in DNA within the cells. Not all the message in the DNA is used in each cell and not all the message is used all the time. During cell differentiation, the cells become dedicated for their specific function which involves selectively activating some

  16. Mechanisms of Selective Cleavage of C-O Bonds in Di-aryl Ethers...

    Office of Scientific and Technical Information (OSTI)

    Selective Cleavage of C-O Bonds in Di-aryl Ethers in Aqueous Phase Citation Details In-Document Search Title: Mechanisms of Selective Cleavage of C-O Bonds in Di-aryl Ethers in ...

  17. Li-air batteries having ether-based electrolytes

    DOE Patents [OSTI]

    Amine, Khalil; Curtiss, Larry A; Lu, Jun; Lau, Kah Chun; Zhang, Zhengcheng; Sun, Yang-Kook

    2015-03-03

    A lithium-air battery includes a cathode including a porous active carbon material, a separator, an anode including lithium, and an electrolyte including a lithium salt and polyalkylene glycol ether, where the porous active carbon material is free of a metal-based catalyst.

  18. HIGH-RESOLUTION EXPANDED VERY LARGE ARRAY IMAGE OF DIMETHYL ETHER (CH{sub 3}){sub 2}O IN ORION-KL

    SciTech Connect (OSTI)

    Favre, C.; Wootten, H. A.; Remijan, A. J.; Brouillet, N.; Despois, D.; Baudry, A.; Wilson, T. L. E-mail: brouillet@obs.u-bordeaux1.fr E-mail: baudry@obs.u-bordeaux1.fr E-mail: aremijan@nrao.edu

    2011-09-20

    We report the first subarcsecond (0.''65 x 0.''51) image of the dimethyl ether molecule, (CH{sub 3}){sub 2}O, toward the Orion Kleinmann-Low nebula. The observations were carried at 43.4 GHz with the Expanded Very Large Array (EVLA). The distribution of the lower energy transition 6{sub 1,5}-6{sub 0,6}, EE (E {sub u} = 21 K) mapped in this study is in excellent agreement with the published dimethyl ether emission maps imaged with a lower resolution. The main emission peaks are observed toward the Compact Ridge and Hot Core southwest components, at the northern parts of the Compact Ridge and in an intermediate position between the Compact Ridge and the Hot Core. A notable result is that the distribution of dimethyl ether is very similar to that of another important larger O-bearing species, the methyl formate (HCOOCH{sub 3}), imaged at a lower resolution. Our study shows that higher spectral resolution (WIDAR correlator) and increased spectral coverage provided by the EVLA offer new possibilities for imaging complex molecular species. The sensitivity improvement and the other EVLA improvements make this instrument well suited for high sensitivity, high angular resolution, and molecular line imaging.

  19. Ether and ester derivatives of the perborate icosahedron

    DOE Patents [OSTI]

    Hawthorne, M. Frederick; Peymann, Toralf; Maderna, Andreas

    2003-12-16

    New boron icosahedral ethers and esters formed from Cs.sub.2 [closo-B.sub.12 (OH).sub.12 ],; Cs[closo-1-H-1-CB.sub.11 (OH).sub.11 ]; and closo-1,12-H.sub.2 -1,12-C.sub.2 B.sub.10 (OH).sub.10 are disclosed. Also set forth are their preparation by reacting the icosahedral boranes [closo-B.sub.12 H.sub.12 ].sup.2-, [closo-1-CB.sub.11 H.sub.12 ].sup.- and closo-1,12-(CH.sub.2 OH).sub.2 -1,12-C.sub.2 B.sub.10 H.sub.10 with an acid anhdride or acid chloride to form the ester or an alkylating agent to form the ether.

  20. 2' and 3' Carboranyl uridines and their diethyl ether adducts

    DOE Patents [OSTI]

    Soloway, Albert H.; Barth, Rolf F.; Anisuzzaman, Abul K.; Alam, Fazlul; Tjarks, Werner

    1992-01-01

    There is disclosed a process for preparing carboranyl uridine nucleoside compounds and their diethyl ether adducts, which exhibit a tenfold increase in boron content over prior art boron containing nucleoside compounds. Said carboranyl uridine nucleoside compounds exhibit enhanced lipophilicity and hydrophilic properties adequate to enable solvation in aqueous media for subsequent incorporation of said compounds in methods for boron neutron capture therapy in mammalian tumor cells.

  1. High octane ethers from synthesis gas-derived alcohol

    SciTech Connect (OSTI)

    Klier, K.; Herman, R.G.; Bastian, R.D.; DeTavernier, S. . Dept. of Chemistry Lehigh Univ., Bethlehem, PA . Zettlemoyer Center for Surface Studies)

    1991-01-01

    The objective of the proposed research is to synthesize high octane ethers directly from coal-derived synthesis gas via alcohol mixtures that are rich in methanol and isobutanol. The overall scheme involves gasification of coal, purification and shifting of the synthesis gas, higher alcohol synthesis, and direct synthesis of ethers. Commercial acid and superacid resin catalysts were obtained and tested under one set of conditions to compare the activities and selectivities for forming the unsymmetric methylisobutylether (MIBE) by coupling methanol with isobutanol. It was found that both Nafion-H microsaddles and Amberlyst-15 resins are active for this synthesis reaction. While and the Nafion-H catalyst does form the MIBE product fairly selectively under the reaction conditions utilized, the Amberlyst-15 catalyst formed dimethylether (DME) as the major product. In addition, significantly larger quantities of the C{sub 4} hydrocarbon products were observed over the Amberlyst-15 catalyst at 123{degree}C and 13.6 atm. It has been demonstrated that methyltertiarybutylether (MTBE) MIBE, DME and diisobutylether (DIBE) are separated and quantitatively determined by using the proper analytical conditions. In order to gain insight into the role of superacidity in promoting the selective coupling of the alcohols to form the unsymmetric ether, the strengths of the acid sites on the catalysts are being probed by thermometric titrations in non-aqueous solutions. 18 refs., 20 figs., 4 tabs.

  2. Experimental study of the oxidation of methyl oleate in a jet-stirred reactor

    SciTech Connect (OSTI)

    Bax, Sarah; Hakka, Mohammed Hichem; Glaude, Pierre-Alexandre; Herbinet, Olivier; Battin-Leclerc, Frederique

    2010-06-15

    The experimental study of the oxidation of a blend containing n-decane and a large unsaturated ester, methyl oleate, was performed in a jet-stirred reactor over a wide range of temperature covering both low and high temperature regions (550-1100 K), at a residence time of 1.5 s, at quasi atmospheric pressure with high dilution in helium (n-decane and methyl oleate inlet mole fractions of 1.48 x 10{sup -3} and 5.2 x 10{sup -4}) and under stoichiometric conditions. The formation of numerous reaction products was observed. At low and intermediate temperatures, the oxidation of the blend led to the formation of species containing oxygen atoms like cyclic ethers, aldehydes and ketones deriving from n-decane and methyl oleate. At higher temperature, these species were not formed anymore and the presence of unsaturated species was observed. Because of the presence of the double bond in the middle of the alkyl chain of methyl oleate, the formation of some specific products was observed. These species are dienes and esters with two double bonds produced from the decomposition paths of methyl oleate and some species obtained from the addition of H-atoms, OH and HO{sub 2} radicals to the double bond. Experimental results were compared with former results of the oxidation of a blend of n-decane and methyl palmitate performed under similar conditions. This comparison allowed highlighting the similarities and the differences in the reactivity and in the distribution of the reaction products for the oxidation of large saturated and unsaturated esters. (author)

  3. Heterogeneous catalytic process for alcohol fuels from syngas. Final technical report

    SciTech Connect (OSTI)

    Dombek, B.D.

    1996-03-01

    The primary objective of this project has been the pursuit of a catalyst system which would allow the selective production from syngas of methanol and isobutanol. It is desirable to develop a process in which the methanol to isobutanol weight ratio could be varied from 70/30 to 30/70. The 70/30 mixture could be used directly as a fuel additive, while, with the appropriate downstream processing, the 30/70 mixture could be utilized for methyl tertiary-butyl ether (MTBE) synthesis. The indirect manufacture of MTBE from a coal derived syngas to methanol and isobutanol process would appear to be a viable solution to MTBE feedstock limitations. To become economically attractive, a process fro producing oxygenates from coal-derived syngas must form these products with high selectivity and good rates, and must be capable of operating with a low-hydrogen-content syngas. This was to be accomplished through extensions of known catalyst systems and by the rational design of novel catalyst systems.

  4. Biodegradation of petroleum hydrocarbons in fractured, unsaturated dolomite at a field site

    SciTech Connect (OSTI)

    McLinn, E.L.; Rehm, B.W.

    1997-12-31

    Gasoline constituents were detected in unsaturated soil and rock during abandonment of a leaky underground storage tank (UST). The unsaturated sequence beneath the former UST consists of 90 feet of silty till, fractured dolomite, and friable sandstone. Pore gas probes were installed in each of the unsaturated units, both in the source area and in a background on-site location. Pore gas samples were collected to evaluate the nature, extent, and fate of residual hydrocarbons in the vadose zone. Pore gas from the till and dolomite in the source area was enriched in petroleum hydrocarbons and carbon dioxide, and was depleted in oxygen, relative to pore gas from the background area. During two years of ground water monitoring at the site, methyl tertiary butyl ether was periodically detected in the ground water beneath the source area as pulses of recharge passed through the unsaturated zone, but not other gasoline constituents were detected. Apparently, the most degradable fraction of the gasoline (aromatic hydrocarbons) is being attenuated in the vadose zone before the water table is reached.

  5. Computational and experimental study of the effects of adding dimethyl ether and ethanol to nonpremixed ethylene/air flames

    SciTech Connect (OSTI)

    Bennett, Beth Anne V.; McEnally, Charles S.; Pfefferle, Lisa D.; Smooke, Mitchell D.; Colket, Meredith B.

    2009-06-15

    Two sets of axisymmetric laminar coflow flames, each consisting of ethylene/air nonpremixed flames with various amounts (up to 10%) of either dimethyl ether (CH{sub 3}-O-CH{sub 3}) or ethanol (CH{sub 3}-CH{sub 2}-OH) added to the fuel stream, have been examined both computationally and experimentally. Computationally, the local rectangular refinement method, which incorporates Newton's method, is used to solve the fully coupled nonlinear conservation equations on solution-adaptive grids for each flame in two spatial dimensions. The numerical model includes C6 chemical kinetic mechanisms with up to 59 species, detailed transport, and an optically thin radiation submodel. Experimentally, thermocouples are used to measure gas temperatures, and mass spectrometry is used to determine concentrations of over 35 species along the flame centerline. Computational results are examined throughout each flame, and validation of the model occurs through comparison with centerline measurements. Very good agreement is observed for temperature, major species, and several minor species. As the level of additive is increased, temperatures, some major species (CO{sub 2}, C{sub 2}H{sub 2}), flame lengths, and residence times are essentially unchanged. However, peak centerline concentrations of benzene (C{sub 6}H{sub 6}) increase, and this increase is largest when dimethyl ether is the additive. Computational and experimental results support the hypothesis that the dominant pathway to C{sub 6}H{sub 6} formation begins with the oxygenates decomposing into methyl radical (CH{sub 3}), which combines with C2 species to form propargyl (C{sub 3}H{sub 3}), which reacts with itself to form C{sub 6}H{sub 6}. (author)

  6. On the radiation stability of crown ethers in ionic liquids.

    SciTech Connect (OSTI)

    Shkrob, I.; Marin, T.; Dietz, M.

    2011-04-14

    Crown ethers (CEs) are macrocyclic ionophores used for the separation of strontium-90 from acidic nuclear waste streams. Room temperature ionic liquids (ILs) are presently being considered as replacements for traditional molecular solvents employed in such separations. It is desirable that the extraction efficacy obtained with such solvents should not deteriorate in the strong radiation fields generated by decaying radionuclides. This deterioration will depend on the extent of radiation damage to both the IL solvent and the CE solute. While radiation damage to ILs has been extensively studied, the issue of the radiation stability of crown ethers, particularly in an IL matrix, has not been adequately addressed. With this in mind, we have employed electron paramagnetic resonance (EPR) spectroscopy to study the formation of CE-related radicals in the radiolysis of selected CEs in ILs incorporating aromatic (imidazolium and pyridinium) cations. The crown ethers have been found to yield primarily hydrogen loss radicals, H atoms, and the formyl radical. In the low-dose regime, the relative yield of these radicals increases linearly with the mole fraction of the solute, suggesting negligible transfer of the excitation energy from the solvent to the solute; that is, the solvent has a 'radioprotective' effect. The damage to the CE in the loading region of practical interest is relatively low. Under such conditions, the main chemical pathway leading to decreased extraction performance is protonation of the macrocycle. At high radiation doses, sufficient to increase the acidity of the IL solvent significantly, such proton complexes compete with the solvent cations as electron traps. In this regime, the CEs will rapidly degrade as the result of H abstraction from the CE ring by the released H atoms. Thus, the radiation dose to which a CE/IL system is exposed must be maintained at a level sufficiently low to avoid this regime.

  7. An aging study of wire chambers with dimethyl ether

    SciTech Connect (OSTI)

    Jibaly, M.; Chrusch, P. Jr.; Hilgenberg, G.; Majewski, S.; Wojcik, R.; Sauli, F.; Gaudaen, J.

    1989-02-01

    The authors report results on the aging of different types of resistive and non-resistive wires in wire chambers filled with dimethyl ether (DME) of varying degrees of purity. Among the Freon impurities detected in our DME batches, only Freon-11 was found to contribute to the aging process. Of the resistive wires, Nicotin and Stablohm produced fast aging, whereas stainless steel withstood extended irradiation in purified DME (up to 1 C/cm) without any apparent damage. Gold-plated tungsten and molybdenum wires produced results comparable to those of the stainless steel.

  8. Dimethyl ether production from methanol and/or syngas

    DOE Patents [OSTI]

    Dagle, Robert A; Wang, Yong; Baker, Eddie G; Hu, Jianli

    2015-02-17

    Disclosed are methods for producing dimethyl ether (DME) from methanol and for producing DME directly from syngas, such as syngas from biomass. Also disclosed are apparatus for DME production. The disclosed processes generally function at higher temperatures with lower contact times and at lower pressures than conventional processes so as to produce higher DME yields than do conventional processes. Certain embodiments of the processes are carried out in reactors providing greater surface to volume ratios than the presently used DME reactors. Certain embodiments of the processes are carried out in systems comprising multiple microchannel reactors.

  9. DIMETHYL ETHER (DME)-FUELED SHUTTLE BUS DEMONSTRATION PROJECT

    SciTech Connect (OSTI)

    Elana M. Chapman; Shirish Bhide; Andre L. Boehman; David Klinikowski

    2003-04-01

    The objectives of this research and demonstration program are to convert a campus shuttle bus to operation on dimethyl ether, a potential ultra-clean alternative diesel fuel. To accomplish this objective, this project includes laboratory evaluation of a fuel conversion strategy, as well as field demonstration of the DME-fueled shuttle bus. Since DME is a fuel with no lubricity (i.e., it does not possess the lubricating quality of diesel fuel), conventional fuel delivery and fuel injection systems are not compatible with dimethyl ether. Therefore, to operate a diesel engine on DME one must develop a fuel-tolerant injection system, or find a way to provide the necessary lubricity to the DME. In this project, they have chosen the latter strategy in order to achieve the objective with minimal need to modify the engine. The strategy is to blend DME with diesel fuel, to obtain the necessary lubricity to protect the fuel injection system and to achieve low emissions. Within the Combustion Laboratory of the Penn State Energy Institute, they have installed and equipped a Navistar V-8 direct-injection turbodiesel engine for measurement of gaseous and particulate emissions and examination of the impact of fuel composition on diesel combustion. They have also reconfigured a high-pressure viscometer for studies of the viscosity, bulk modulus (compressibility) and miscibility of blends of diesel fuel, dimethyl ether and lubricity additives. The results include baseline emissions, performance and combustion measurements on the Navistar engine for operation on a federal low sulfur diesel fuel (300 ppm S). Most recently, they have examined blends of an oxygenated fuel additive (a liquid fuel called CETANER{trademark}) produced by Air Products, for comparison with dimethyl ether blended at the same weight of oxygen addition, 2 wt.%. While they have not operated the engine on DME yet, they are now preparing to do so. A fuel system for delivery of DME/Diesel blends has been configured

  10. Structure and Reactivity of Alkyl Ethers Adsorbed on CeO2(111) Model Catalysts

    SciTech Connect (OSTI)

    F Calaza; T Chen; D Mullins; S Overbury

    2011-12-31

    The effect of surface hydroxyls on the adsorption of ether on ceria was explored. Adsorption of dimethyl ether (DME) and diethyl ether (DEE) on oxidized and reduced CeO{sub 2}(111) films was studied and compared with Ru(0001) using RAIRS and sXPS within a UHV environment. On Ru(0001) the ethers adsorb weakly with the molecular plane close to parallel to the surface plane. On the ceria films, the adsorption of the ethers was stronger than on the metal surface, presumably due to stronger interaction of the ether oxygen lone pair electrons with a cerium cation. This interaction causes the ethers to tilt away from the surface plane compared to the Ru(0001) surface. No pronounced differences were found between oxidized (CeO{sub 2}) and reduced (CeOx) films. The adsorption of the ethers was found to be perturbed by the presence of OH groups on hydroxylated CeOx. In the case of DEE, the geometry of adsorption resembles that found on Ru, and in the case of dimethyl ether DME is in between that one found on clean CeOx and the metal surface. Decomposition of the DEE was observed on the OH/CeOx surface following high DEE exposure at 300 K and higher temperatures. Ethoxides and acetates were identified as adsorbed species on the surface by means of RAIRS and ethoxides and formates by s-XPS. No decomposition of dimethyl ether was observed on the OH/CeOx at these higher temperatures, implying that the dissociation of the C-O bond from ethers requires the presence of {beta}-hydrogen.

  11. Structure and Reactivity of Alkyl Ethers Adsorbed on CeO(2)(111) Model Catalysts

    SciTech Connect (OSTI)

    Calaza, Florencia C; Chen, Tsung-Liang; Mullins, David R; Overbury, Steven {Steve} H

    2011-01-01

    The effect of surface hydroxyls on the adsorption of ether on ceria was explored. Adsorption of dimethyl ether (DME) and diethyl ether (DEE) on oxidized and reduced CeO{sub 2}(111) films was studied and compared with Ru(0001) using RAIRS and sXPS within a UHV environment. On Ru(0001) the ethers adsorb weakly with the molecular plane close to parallel to the surface plane. On the ceria films, the adsorption of the ethers was stronger than on the metal surface, presumably due to stronger interaction of the ether oxygen lone pair electrons with a cerium cation. This interaction causes the ethers to tilt away from the surface plane compared to the Ru(0001) surface. No pronounced differences were found between oxidized (CeO{sub 2}) and reduced (CeOx) films. The adsorption of the ethers was found to be perturbed by the presence of OH groups on hydroxylated CeOx. In the case of DEE, the geometry of adsorption resembles that found on Ru, and in the case of dimethyl ether DME is in between that one found on clean CeOx and the metal surface. Decomposition of the DEE was observed on the OH/CeOx surface following high DEE exposure at 300 K and higher temperatures. Ethoxides and acetates were identified as adsorbed species on the surface by means of RAIRS and ethoxides and formates by s-XPS. No decomposition of dimethyl ether was observed on the OH/CeOx at these higher temperatures, implying that the dissociation of the C-O bond from ethers requires the presence of {beta}-hydrogen.

  12. Dimethyl ether synthesis from syngas in slurry phase

    SciTech Connect (OSTI)

    Han, Y.Z.; Fujimoto, K.; Shikata, T.

    1997-12-31

    Dimethyl ether (DME) is one of the important chemicals derived from synthesis gas. It can be widely used in syngas conversion, production of olefins, or MTG gasoline. Recently, is has been noticed as a substitute of LPG used as home fuel. In the present study, dimethyl ether was effectively synthesized from CO rich syngas (H{sub 2}/CO=1/1) over hybrid catalyst containing a Cu-Zn-Al(O) based methanol synthesis catalyst and {gamma}-alumina in an agitated slurry reactor under relatively mild reaction conditions: temperature 230--300 C, pressure 2.0--5.0 MPa, contact time 2.0--10 gram-cat.-h/mol. The catalysts used as the methanol active components were commercially available Cu-Zn-Al(O) based catalysts, BASF S385 and ICI 51-2. Two kinds of {gamma}-alumina ALO4 (standard catalyst of the Catalysis Society of Japan) and N612N (NIKKI Co., Japan) were used as the methanol dehydration components. The slurry was prepared by mixing the fine powder (<100 mesh) of catalyst components with purified n-hexadecane. The catalysts were reduced by a mixing gas containing 20% syngas and 80% nitrogen with a three-hour programmed temperature raising from room temperature to the final temperature. All products were analyzed by gas chromatographs. Results are given and discussed.

  13. Rational Design of Cesium-Selective Ionophores and Chemosensors: Dihydrocalix[4]arene Crown-6 Ethers

    SciTech Connect (OSTI)

    Sachleben, Richard A.; Bryan, Jeffrey C.; Brown, Gilbert M.; Engle, Nancy L.; Haverlock, Tamara J.; Hay, Benjamin P.; Urvoas, Agathe; Moyer, Bruce A.

    2003-12-15

    Molecular mechanics calculations performed on calix[4]arene crown-6 ethers predict that the 1,3-dihydro derivatives will exhibit greater complementarity for potassium and cesium ions than the parent 1,3-dialkoxy calix crowns. The X-ray crystal structures of 1,3-alt bis-octyloxycalix[4]arene benzocrown-6 ether, dihydrocalix[4]arene benzocrown-6 ether, and the cesium nitrate complex of dihydrocalix[4]arene benzocrown-6 ether were determined. The cesium complex structure corresponds closely to the structure predicted by molecular mechanics. The dihydrocalix[4]arene crown-6 ethers exhibit enhanced cesium selectivity in the extraction of alkali metal salts and provide a platform for a highly sensitive and selective cesium chemosensor.

  14. Deetherification process

    DOE Patents [OSTI]

    Smith, Jr., Lawrence A.

    1985-01-01

    Ethers such as isobutyl tertiary butyl ether are dissociated into their component alcohols and isolefins by heat stabilized catalyst compositions prepared from nuclear sulfonic acid, for example, macroporous crosslinked polyvinyl aromatic compounds containing sulfonic acid groups are neutralized with a metal of Al, Fe, Zn, Cu, Ni, ions or mixtures and alkali, alkaline earth metals or ammonium ions by contacting the resin containing the sulfonic acid with aqueous solutions of the metals salts and alkali, alkaline earth metal or ammonium salts. The catalysts have at least 50% of the sulfonic acid groups neutralized with metal ions and the balance of the sulfonic acid groups neutralized with alkali, alkaline earth ions or ammonium ions.

  15. Deetherification process

    DOE Patents [OSTI]

    Smith, L.A. Jr.

    1985-11-05

    Ethers such as isobutyl tertiary butyl ether are dissociated into their component alcohols and isoolefins by heat stabilized catalyst compositions prepared from nuclear sulfonic acid, for example, macroporous crosslinked polyvinyl aromatic compounds containing sulfonic acid groups are neutralized with a metal of Al, Fe, Zn, Cu, Ni, ions or mixtures and alkali, alkaline earth metals or ammonium ions by contacting the resin containing the sulfonic acid with aqueous solutions of the metals salts and alkali, alkaline earth metal or ammonium salts. The catalysts have at least 50% of the sulfonic acid groups neutralized with metal ions and the balance of the sulfonic acid groups neutralized with alkali, alkaline earth ions or ammonium ions.

  16. Dimethyl ether fuel proposed as an alternative to LNG

    SciTech Connect (OSTI)

    Kikkawa, Yoshitsugi; Aoki, Ichizo

    1998-04-06

    To cope with the emerging energy demand in Asia, alternative fuels to LNG must be considered. Alternative measures, which convert the natural gas to liquid fuel, include the Fischer-Tropsch conversion, methanol synthesis, and dimethyl ether (DME) synthesis. Comparisons are evaluated based on both transportation cost and feed-gas cost. The analysis will show that DME, one alternative to LNG as transportation fuel, will be more economical for longer distances between the natural-gas source and the consumer. LNG requires a costly tanker and receiving terminal. The break-even distance will be around 5,000--7,000 km and vary depending on the transported volume. There will be risk, however, since there has never been a DME plant the size of an LNG-equivalent plant [6 million metric tons/year (mty)].

  17. DIMETHYL ETHER (DME)-FUELED SHUTTLE BUS DEMONSTRATION PROJECT

    SciTech Connect (OSTI)

    Elana M. Chapman; Shirish Bhide; Jennifer Stefanik; Andre L. Boehman; David Klinikowski

    2003-04-01

    The objectives of this research and demonstration program are to convert a campus shuttle bus to operation on dimethyl ether, a potential ultra-clean alternative diesel fuel. To accomplish this objective, this project includes laboratory evaluation of a fuel conversion strategy, as well as, field demonstration of the DME-fueled shuttle bus. Since DME is a fuel with no lubricity (i.e., it does not possess the lubricating quality of diesel fuel), conventional fuel delivery and fuel injection systems are not compatible with dimethyl ether. Therefore, to operate a diesel engine on DME one must develop a fuel-tolerant injection system, or find a way to provide the necessary lubricity to the DME. In this project, they have chosen the latter strategy in order to achieve the objective with minimal need to modify the engine. The strategy is to blend DME with diesel fuel, to obtain the necessary lubricity to protect the fuel injection system and to achieve low emissions. The laboratory studies have included work with a Navistar V-8 turbodiesel engine, demonstration of engine operation on DME-diesel blends and instrumentation for evaluating fuel properties. The field studies have involved performance, efficiency and emissions measurements with the Champion Motorcoach ''Defender'' shuttle bus which will be converted to DME-fueling. The results include baseline emissions, performance and combustion measurements on the Navistar engine for operation on a federal low sulfur diesel fuel (300 ppm S). Most recently, they have completed engine combustion studies on DME-diesel blends up to 30 wt% DME addition.

  18. Shape-selective catalysis in dimethyl ether conversion

    SciTech Connect (OSTI)

    Sardesai, A.; Lee, S.

    1999-07-01

    Coal-derived syngas can be effectively converted to dimethyl ether (DME) in a single-stage, liquid-phase process. This Liquid Phase Dimethyl Ether (LPDME) process utilizes a dual catalytic system, which comprises of a physical blend between the methanol synthesis and the methanol dehydration catalyst slurried in an inert mineral oil. Such produced DME has vast potential as a building block chemical in the petrochemical industry to produce value-added specialty chemicals. The current research efforts are made to exploit the utilization of shape-selective catalysis using zeolites to produce targeted petrochemicals, including lower olefinic hydrocarbons. The catalysts probed in this investigation include zeolites of different physical, morphological, and chemical configurations. The effect of acidity of ZSM-5 type zeolites as well as the effect of the different channel size and orientation of the zeolites on product selectivity and catalyst deactivation are examined. Results obtained from experimentation of this study show that ZSM-5 type zeolite with low acidity (high SiO{sub 2}/Al{sub 2}O{sub 3} ratio, in this case 150) exhibits the highest selectivity towards lower (C{sub 2}-C{sub 4}) olefins in general. Controlled selectivity toward targeted olefinic species can be accomplished via devising catalytic reaction systems in such a way that the structural property of the catalyst and reactive interaction between molecules in the pores are geared toward formation of targeted molecular species which also at the same time prevent the formation of less desirable products. The internal morphology of the catalyst also has a pronounced effect on the deactivation phenomenon, where it is observed that zeolites possessing high acidity and a unidimensional channel structure are prone towards catalyst deactivation by coking and pore blockage.

  19. Single-Step Syngas-to-Distillates (S2D) Synthesis via Methanol and Dimethyl Ether Intermediates: Final Report

    SciTech Connect (OSTI)

    Dagle, Robert A.; Lebarbier, Vanessa MC; Lizarazo Adarme, Jair A.; King, David L.; Zhu, Yunhua; Gray, Michel J.; Jones, Susanne B.; Biddy, Mary J.; Hallen, Richard T.; Wang, Yong; White, James F.; Holladay, Johnathan E.; Palo, Daniel R.

    2013-11-26

    The objective of the work was to enhance price-competitive, synthesis gas (syngas)-based production of transportation fuels that are directly compatible with the existing vehicle fleet (i.e., vehicles fueled by gasoline, diesel, jet fuel, etc.). To accomplish this, modifications to the traditional methanol-to-gasoline (MTG) process were investigated. In this study, we investigated direct conversion of syngas to distillates using methanol and dimethyl ether intermediates. For this application, a Pd/ZnO/Al2O3 (PdZnAl) catalyst previously developed for methanol steam reforming was evaluated. The PdZnAl catalyst was shown to be far superior to a conventional copper-based methanol catalyst when operated at relatively high temperatures (i.e., >300°C), which is necessary for MTG-type applications. Catalytic performance was evaluated through parametric studies. Process conditions such as temperature, pressure, gas-hour-space velocity, and syngas feed ratio (i.e., hydrogen:carbon monoxide) were investigated. PdZnAl catalyst formulation also was optimized to maximize conversion and selectivity to methanol and dimethyl ether while suppressing methane formation. Thus, a PdZn/Al2O3 catalyst optimized for methanol and dimethyl ether formation was developed through combined catalytic material and process parameter exploration. However, even after compositional optimization, a significant amount of undesirable carbon dioxide was produced (formed via the water-gas-shift reaction), and some degree of methane formation could not be completely avoided. Pd/ZnO/Al2O3 used in combination with ZSM-5 was investigated for direct syngas-to-distillates conversion. High conversion was achieved as thermodynamic constraints are alleviated when methanol and dimethyl are intermediates for hydrocarbon formation. When methanol and/or dimethyl ether are products formed separately, equilibrium restrictions occur. Thermodynamic relaxation also enables the use of lower operating pressures than what

  20. Heterogeneous catalyst for the production of acetic anhydride from methyl acetate

    DOE Patents [OSTI]

    Ramprasad, D.; Waller, F.J.

    1999-04-06

    This invention relates to a process for producing acetic anhydride by the reaction of methyl acetate, carbon monoxide, and hydrogen at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that contains an insoluble polymer having pendant quaternized phosphine groups, some of which phosphine groups are ionically bonded to anionic Group VIII metal complexes, the remainder of the phosphine groups being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for consecutive runs without loss in activity. Bifunctional catalysts for use in carbonylating dimethyl ether are also provided.

  1. Heterogeneous catalyst for the production of acetic anhydride from methyl acetate

    DOE Patents [OSTI]

    Ramprasad, Dorai; Waller, Francis Joseph

    1999-01-01

    This invention relates to a process for producing acetic anhydride by the reaction of methyl acetate, carbon monoxide, and hydrogen at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that contains an insoluble polymer having pendant quaternized phosphine groups, some of which phosphine groups are ionically bonded to anionic Group VIII metal complexes, the remainder of the phosphine groups being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for consecutive runs without loss in activity. Bifunctional catalysts for use in carbonylating dimethyl ether are also provided.

  2. Combustion characterization of methylal in reciprocating engines

    SciTech Connect (OSTI)

    Dodge, L.; Naegeli, D.

    1994-06-01

    Methylal, CH{sub 3}OCH{sub 2}OCH{sub 3}, also known as dimethoxy-methane, is unique among oxygenates in that it has a low autoignition temperature, no carbon-carbon bonds, and is soluble in middle distillate fuels. Because of these properties, methylal has been shown to be a favorable fuel additive for reducing smoke in diesel engines. Recent measurements of ignition delay times indicate that methylal has a cetane number in the range of 45-50, which is compatible with diesel fuels. Engine tests have shown that adding methylal to diesel fuel significantly reduces smoke emissions. Gaseous emissions and combustion efficiencies obtained with methylal/diesel fuel blends remain essentially the same as those measured using neat diesel fuel. Lubricity measurements of methylal/diesel fuel blends with a ball on cylinder lubrication evaluator (BOCLE) show that methylal improves the lubricity of diesel fuel. Even though additions of methylal lower the fuel viscosity, the results of the BOCLE tests indicate that the methylal/diesel fuel blends cause less pump wear than neat diesel fuel. The one drawback is that methylal has a low boiling point (42{degrees}C) and a relatively high vapor pressure. As a result, it lowers the flash point of diesel fuel and causes a potential fuel tank flammability hazard. One solution to this increased volatility is to make polyoxymethylenes with the general formula of CH{sub 3}O(CH{sub 2}O){sub x}CH{sub 3} where x > 2. The molecules are similar to methylal, but have higher molecular weights and thus higher viscosities and substantially lower vapor pressures. Therefore, their flash points will be compatible with regular diesel fuel. The polyoxymethylenes are expected to have combustion properties similar to methylal. It is theorized that by analogy with hydrocarbons, the ignition quality (i.e., cetane number) of the polyoxymethylenes will be better than that of methylal.

  3. Conversion of dimethyl ether--boron trifluoride complex to potassium fluoborate

    DOE Patents [OSTI]

    Eberle, A.R.

    1957-06-18

    A method of preparing KBF/sub 4/ from the dimethyl ether complex of BF/sub 3/ is given. This may be accomplished by introducing the dimethyl ether complex of BF/sub 3/ into an aqueous solution of KF and alcohol, expelling the ether liberated from the complex by heating or stirring and recovering the KBF/sub 4/ so formed. The KBF/sub 4/ is then filtered from the alcohol-water solution, which may be recycled, to reduce the loss of KBF/sub 4/ which is not recovered by filtration.

  4. CONVERSION OF DIMETHYL ETHER-BORON TRIFLUORIDE COMPLEX TO POTASSIUM FLUOBORATE

    DOE Patents [OSTI]

    Eberle, A.R.

    1957-06-18

    A method of preparing KBF/sub 4/ from the dimethyl ether complex of BF/sub 3/ is given. This may be accomplished by introducing the dimethyl ether complex of BF/sub 3/ into an aqueous solution of KF and alcohol, expelling the ether liberated from the complex by heating or stirring and recovering the KBF/sub 4/ so formed. The KBF/sub 4/ is then filtered from the alcohol-water solution, which may be recycled, to reduce the loss of KBF/sub 4/ which is not recovered by filtration.

  5. EXTRACTION OF TETRAVALENT PLUTONIUM VALUES WITH METHYL ETHYL KETONE, METHYL ISOBUTYL KETONE ACETOPHENONE OR MENTHONE

    DOE Patents [OSTI]

    Seaborg, G.T.

    1961-08-01

    A process is described for extracting tetravalent plutonium from an aqueous acid solution with methyl ethyl ketone, methyl isobutyl ketone, or acetophenone and with the extraction of either tetravalent or hexavalent plutonium into menthone. (AEC)

  6. Sorbents for High Temperature Removal of Arsenic from Coal-Derived Synthesis Gas

    SciTech Connect (OSTI)

    Alptekin, G.O.; Copeland, R.; Dubovik, M.; Gershanovich, Y.

    2002-09-20

    Gasification technologies convert coal and other heavy feedstocks into synthesis gas feed streams that can be used in the production of a wide variety of chemicals, ranging from hydrogen through methanol, ammonia, acetic anhydride, dimethyl ether (DME), methyl tertiary butyl ether (MTBE), high molecular weight liquid hydrocarbons and waxes. Syngas can also be burned directly as a fuel in advanced power cycles to generate electricity with very high efficiency. However, the coal-derived synthesis gas contains a myriad of trace contaminants that may poison the catalysts that are used in the downstream manufacturing processes and may also be regulated in power plant emissions. Particularly, the catalysts used in the conversion of synthesis gas to methanol and other liquid fuels (Fischer-Tropsch liquids) have been found to be very sensitive to the low levels of poisons, especially arsenic, that are present in the synthesis gas from coal. TDA Research, Inc. (TDA) is developing an expendable high capacity, low-cost chemical absorbent to remove arsenic from coal-derived syngas. Unlike most of the commercially available sorbents that physically adsorb arsenic, TDA's sorbent operates at elevated temperatures and removes the arsenic through chemical reaction. The arsenic content in the coal gas stream is reduced to ppb levels with the sorbent by capturing and stabilizing the arsenic gas (As4) and arsenic hydrides (referred to as arsine, AsH3) in the solid state. To demonstrate the concept of high temperature arsenic removal from coal-derived syngas, we carried out bench-scale experiments to test the absorption capacity of a variety of sorbent formulations under representative conditions. Using on-line analysis techniques, we monitored the pre- and post-breakthrough arsine concentrations over different sorbent samples. Some of these samples exhibited pre-breakthrough arsine absorption capacity over 40% wt. (capacity is defined as lb of arsenic absorbed/lb of sorbent), while

  7. Photochemical dimerization and functionalization of alkanes, ethers, primary alcohols and silanes

    DOE Patents [OSTI]

    Crabtree, Robert H. (Bethany, CT); Brown, Stephen H. (East Haven, CT)

    1988-01-01

    The space-time yield and/or the selectivity of the photochemical dimerization of alkanes, ethers, primary alcohols and tertiary silanes with Hg and U.V. light is enhanced by refluxing the substrate in the irradiated reaction zone at a temperature at which the dimer product condenses and remains condensed promptly upon its formation. Cross-dimerization of the alkanes, ethers and silanes with primary alcohols is disclosed, as is the functionalization to aldehydes of the alkanes with carbon monoxide.

  8. Metal ion complexation by ionizable crown ethers. Final report, January 1, 1988--June 30, 1994

    SciTech Connect (OSTI)

    Bartsch, R.A.

    1994-12-31

    During the report period a variety of new lipophilic ionizable crown ethers with pendent proton-ionizable groups has been synthesized. The ligands possess one or more ionizable group (carboxylic acid, phosphonic acid monoethyl ester, para-nitrophenol, phosphonic acid) attached to crown ether, monoazacrown ether or diazacrown ether frameworks. These novel chelating agents have either pendent or inward-facing proton-ionizable groups. Such lipophilic proton-ionizable crown ethers are designed for use in multiphase metal ion separations (solvent extraction, liquid membrane transport). In addition a series of proton-ionizable crown ethers without lipophilic groups was prepared to study how structural variations within the ligand influence metal ion complexation in homogeneous media as assessed by NMR spectroscopy or titration calorimetry. A third class of new metal ion-complexing agents is a series of lipophilic acyclic polyether dicarboxylic acids. Competitive solvent extractions of alkali metal and alkaline earth cations and of the mixed species have been conducted to reveal the influence of ring size, nature and attachment site of the lipophilic group, sidearm length, and proton-ionizable group identity and location upon the selectivity and efficiency of metal ion complexation. In addition to such studies of structural variation within the lipophilic proton-ionizable crown ether, the effect of changing the organic solvent and variation of the stripping conditions have been assessed. The influence of structural variations within lipophilic acyclic polyether dicarboxylic acids upon competitive solvent extraction of alkaline earth cations has been probed. Also a new chromogenic, di-ionizable crown ether with extremely high selectivity for Hg{sup 2+} has been discovered.

  9. Photochemical dimerization and functionalization of alkanes, ethers, primary alcohols and silanes

    DOE Patents [OSTI]

    Crabtree, R.H.; Brown, S.H.

    1988-02-16

    The space-time yield and/or the selectivity of the photochemical dimerization of alkanes, ethers, primary alcohols and tertiary silanes with Hg and U.V. light is enhanced by refluxing the substrate in the irradiated reaction zone at a temperature at which the dimer product condenses and remains condensed promptly upon its formation. Cross-dimerization of the alkanes, ethers and silanes with primary alcohols is disclosed, as is the functionalization to aldehydes of the alkanes with carbon monoxide.

  10. Wide range modeling study of dimethyl ether oxidation

    SciTech Connect (OSTI)

    Pitz, W.J.; Marinov, N.M.; Westbrook, C.K.; Dagaut, P.; Boettner, J-C; Cathonnet, M.

    1997-04-01

    A detailed chemical kinetic model has been used to study dimethyl ether (DME) oxidation over a wide range of conditions. Experimental results obtained in a jet-stirred reactor (JSR) at I and 10 atm, 0.2 < 0 < 2.5, and 800 < T < 1300 K were modeled, in addition to those generated in a shock tube at 13 and 40 bar, 0 = 1.0 and 650 :5 T :5 1300 K. The JSR results are particularly valuable as they include concentration profiles of reactants, intermediates and products pertinent to the oxidation of DME. These data test the Idnetic model severely, as it must be able to predict the correct distribution and concentrations of intermediate and final products formed in the oxidation process. Additionally, the shock tube results are very useful, as they were taken at low temperatures and at high pressures, and thus undergo negative temperature dependence (NTC) behavior. This behavior is characteristic of the oxidation of saturated hydrocarbon fuels, (e.g. the primary reference fuels, n-heptane and iso- octane) under similar conditions. The numerical model consists of 78 chemical species and 336 chemical reactions. The thermodynamic properties of unknown species pertaining to DME oxidation were calculated using THERM.

  11. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    SciTech Connect (OSTI)

    BEN W.-L. JANG; GERALD N. CHOI; JAMES J. SPIVEY; JOSPEH R. ZOELLER; RICHARD D. COLBERG

    1999-01-20

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter(Oct.-Dec./98), we have investigated the condensation between methyl propionate and formaldehyde (MP/HCHO=4.5/1) at various reaction temperatures(280-360EC) over 5%, 10%, and 20% Nb O /SiO catalysts. The conversion of HCHO increases with reaction 2 5 2 temperature and niobium loading. MMA+MAA selectivity goes through a maximum with the temperature over both 10% and 20% Nb O /SiO . The selectivities to MMA+MAA are 67.2%, 2 5 2 72.3%and 58.1% at 320EC over 5%, 10%, 20% Nb O /SiO , respectively. However, the 2 5 2 conversion of formaldehyde decreases rapidly with time on stream. The results suggest that silica supported niobium catalysts are active and selective for condensation of MP with HCHO, but deactivation needs to be minimized for the consideration of commercial application. We have preliminarily investigated the partial oxidation of dimethyl ether(DME) over 5% Nb O /SiO catalyst. Reactant gas mixture of 0.1% DME, 0.1% O and balance nitrogen is 2 5 2 2 studied with temperature ranging from 200°C to 500°C. The conversion of DME first increases with temperature reaching an maximum at 400°C then decreases. The selectivity to HCHO also increases with reaction temperature first. But the selectivity to HCHO decreases at temperature above 350

  12. DIMETHYL ETHER (DME)-FUELED SHUTTLE BUS DEMONSTRATION PROJECT

    SciTech Connect (OSTI)

    Elana M. Chapman; Shirish Bhide; Jennifer Stefanik; Howard Glunt; Andre L. Boehman; Allen Homan; David Klinikowski

    2003-04-01

    The objectives of this research and demonstration program are to convert a campus shuttle bus to operation on dimethyl ether, a potential ultra-clean alternative diesel fuel. To accomplish this objective, this project includes laboratory evaluation of a fuel conversion strategy, as well as, field demonstration of the DME-fueled shuttle bus. Since DME is a fuel with no lubricity (i.e., it does not possess the lubricating quality of diesel fuel), conventional fuel delivery and fuel injection systems are not compatible with dimethyl ether. Therefore, to operate a diesel engine on DME one must develop a fuel-tolerant injection system, or find a way to provide the necessary lubricity to the DME. In this project, they have chosen the latter strategy in order to achieve the objective with minimal need to modify the engine. Their strategy is to blend DME with diesel fuel, to obtain the necessary lubricity to protect the fuel injection system and to achieve low emissions. The bulk of the efforts over the past year were focused on the conversion of the campus shuttle bus. This process, started in August 2001, took until April 2002 to complete. The process culminated in an event to celebrate the launching of the shuttle bus on DME-diesel operation on April 19, 2002. The design of the system on the shuttle bus was patterned after the system developed in the engine laboratory, but also was subjected to a rigorous failure modes effects analysis (FMEA, referred to by Air Products as a ''HAZOP'' analysis) with help from Dr. James Hansel of Air Products. The result of this FMEA was the addition of layers of redundancy and over-pressure protection to the system on the shuttle bus. The system became operational in February 2002. Preliminary emissions tests and basic operation of the shuttle bus took place at the Pennsylvania Transportation Institute's test track facility near the University Park airport. After modification and optimization of the system on the bus, operation on the

  13. MOF-based catalysts for selective hydrogenolysis of carbon–oxygen ether bonds

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

    Stavila, Vitalie; Parthasarathi, Ramakrishnan; Davis, Ryan W.; El Gabaly, Farid; Sale, Kenneth L.; Simmons, Blake A.; Singh, Seema; Allendorf, Mark D.

    2015-11-23

    We demonstrate that metal–organic frameworks (MOFs) can catalyze hydrogenolysis of aryl ether bonds under mild conditions. Mg-IRMOF-74(I) and Mg-IRMOF-74(II) are stable under reducing conditions and can cleave phenyl ethers containing β-O-4, α-O-4, and 4-O-5 linkages to the corresponding hydrocarbons and phenols. Reaction occurs at 10 bar H2 and 120 °C without added base. DFT-optimized structures and charge transfer analysis suggest that the MOF orients the substrate near Mg2+ ions on the pore walls. Ti and Ni doping further increase conversions to as high as 82% with 96% selectivity for hydrogenolysis versus ring hydrogenation. Thus repeated cycling induces no loss ofmore » activity, making this a promising route for mild aryl-ether bond scission.« less

  14. MOF-based catalysts for selective hydrogenolysis of carbon–oxygen ether bonds

    SciTech Connect (OSTI)

    Stavila, Vitalie; Parthasarathi, Ramakrishnan; Davis, Ryan W.; El Gabaly, Farid; Sale, Kenneth L.; Simmons, Blake A.; Singh, Seema; Allendorf, Mark D.

    2015-11-23

    We demonstrate that metal–organic frameworks (MOFs) can catalyze hydrogenolysis of aryl ether bonds under mild conditions. Mg-IRMOF-74(I) and Mg-IRMOF-74(II) are stable under reducing conditions and can cleave phenyl ethers containing β-O-4, α-O-4, and 4-O-5 linkages to the corresponding hydrocarbons and phenols. Reaction occurs at 10 bar H2 and 120 °C without added base. DFT-optimized structures and charge transfer analysis suggest that the MOF orients the substrate near Mg2+ ions on the pore walls. Ti and Ni doping further increase conversions to as high as 82% with 96% selectivity for hydrogenolysis versus ring hydrogenation. Thus repeated cycling induces no loss of activity, making this a promising route for mild aryl-ether bond scission.

  15. DIMETHYL ETHER (DME)-FUELED SHUTTLE BUS DEMONSTRATION PROJECT

    SciTech Connect (OSTI)

    Elana M. Chapman; Shirish Bhide; Jennifer Stefanik; Howard Glunt; Andre L. Boehman; Allen Homan; David Klinikowski

    2003-04-01

    The objectives of this research and demonstration program are to convert a campus shuttle bus to operation on dimethyl ether, a potential ultra-clean alternative diesel fuel. To accomplish this objective, this project includes laboratory evaluation of a fuel conversion strategy, as well as, field demonstration of the DME-fueled shuttle bus. Since DME is a fuel with no lubricity (i.e., it does not possess the lubricating quality of diesel fuel), conventional fuel delivery and fuel injection systems are not compatible with dimethylether. Therefore, to operate a diesel engine on DME one must develop a fuel-tolerant injection system, or find a way to provide the necessary lubricity to the DME. In this project, they have chosen the latter strategy in order to achieve the objective with minimal need to modify the engine. The strategy is to blend DME with diesel fuel, to obtain the necessary lubricity to protect the fuel injection system and to achieve low emissions. The bulk of the efforts over the past year were focused on the conversion of the campus shuttle bus. This process, started in August 2001, took until April 2002 to complete. The process culminated in an event to celebrate the launching of the shuttle bus on DME-diesel operation on April 19, 2002. The design of the system on the shuttle bus was patterned after the system developed in the engine laboratory, but also was subjected to a rigorous failure modes effects analysis with help from Dr. James Hansel of Air Products. The result of this FMEA was the addition of layers of redundancy and over-pressure protection to the system on the shuttle bus. The system became operation in February 2002. Preliminary emissions tests and basic operation of the shuttle bus took place at the Pennsylvania Transportation institute's test track facility near the University Park airport. After modification and optimization of the system on the bus, operation on the campus shuttle route began in early June 2002. However, the work

  16. 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.

  17. Photochemical dimerization and functionalization of alkanes, ethers, primary and secondary alcohols, phosphine oxides and silanes

    DOE Patents [OSTI]

    Crabtree, R.H.; Brown, S.H.

    1989-10-17

    The space-time yield and/or the selectivity of the photochemical dimerization of alkanes, ethers, primary and secondary alcohols, phosphine oxides and primary, secondary and tertiary silanes with Hg and U.V. light is enhanced by refluxing the substrate in the irradiated reaction zone at a temperature at which the dimer product condenses and remains condensed promptly upon its formation. Cross-dimerization of the alkanes, ethers and silanes with primary alcohols is disclosed, as is the functionalization to aldehydes of the alkanes with carbon monoxide.

  18. Photochemical dimerization and functionalization of alkanes, ethers, primary and secondary alcohols, phosphine oxides and silanes

    DOE Patents [OSTI]

    Crabtree, Robert H. (Bethany, CT); Brown, Stephen H. (East Haven, CT)

    1989-01-01

    The space-time yield and/or the selectivity of the photochemical dimerization of alkanes, ethers, primary and secondary alcohols, phosphine oxides and primary, secondary and tertiary silanes with Hg and U.V. light is enhanced by refluxing the substrate in the irradiated reaction zone at a temperature at which the dimer product condenses and remains condensed promptly upon its formation. Cross-dimerization of the alkanes, ethers and silanes with primary alcohols is disclosed, as is the functionalization to aldehydes of the alkanes with carbon monoxide.

  19. Mechanisms of Selective Cleavage of C-O Bonds in Di-aryl Ethers in Aqueous Phase

    SciTech Connect (OSTI)

    He, Jiayue; Zhao, Chen; Mei, Donghai; Lercher, Johannes A.

    2014-01-02

    A novel route for cleaving the C-O aryl ether bonds of p-substituted H-, CH3-, and OH- diphenyl ethers has been explored over Ni/SiO2 catalysts at very mild conditions. The C-O bond of diphenyl ether is cleaved by parallel hydrogenolysis and hydrolysis (hydrogenolysis combined with HO* addition) on Ni. The rates as a function of H2 pressure from 0 to 10 MPa indicate that the rate-determining step is the C-O bond cleavage on Ni. H* atoms compete with the organic reactant for adsorption leading to a maximum in the rate with increasing H2 pressure. In contrast to diphenyl ether, hydrogenolysis is the exclusive route for cleaving an ether C-O bond of di-p-tolyl ether to form p-cresol and toluene. 4,4'-dihydroxydiphenyl ether undergoes sequential surface hydrogenolysis, first to phenol and HOC6H4O* (adsorbed), which is then cleaved to phenol (C6H5O* with added H*) and H2O (O* with two added H*) in a second step. Density function theory supports the operation of this pathway. Notably, addition of H* to HOC6H4O* is less favorable than a further hydrogenolytic C-O bond cleavage. The TOFs of three aryl ethers with Ni/SiO2 in water followed the order 4,4'-dihydroxydiphenyl ether (69 h-1) > diphenyl ether (26 h-1) > di-p-tolyl ether (1.3 h-1), in line with the increasing apparent activation energies, ranging from 93 kJ∙mol-1 (4,4'-dihydroxydiphenyl ether) < diphenyl ether (98 kJ∙mol-1) to di-p-tolyl ether (105 kJ∙mol-1). D.M. thanks the support from the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. Computing time was granted by the grand challenge of computational catalysis of the William R

  20. Methylal and Methylal-Diesel Blended Fuels from Use In Compression-Ignition Engines

    SciTech Connect (OSTI)

    Keith D. Vertin; James M. Ohi; David W. Naegeli; Kenneth H. Childress; Gary P. Hagen; Chris I. McCarthy; Adelbert S. Cheng; Robert W. Dibble

    1999-05-05

    Gas-to-liquids catalytic conversion technologies show promise for liberating stranded natural gas reserves and for achieving energy diversity worldwide. Some gas-to-liquids products are used as transportation fuels and as blendstocks for upgrading crude derived fuels. Methylal (CH{sub 3}-O-CH{sub 2}-O-CH{sub 3}) also known as dimethoxymethane or DMM, is a gas-to-liquid chemical that has been evaluated for use as a diesel fuel component. Methylal contains 42% oxygen by weight and is soluble in diesel fuel. The physical and chemical properties of neat methylal and for blends of methylal in conventional diesel fuel are presented. Methylal was found to be more volatile than diesel fuel, and special precautions for distribution and fuel tank storage are discussed. Steady state engine tests were also performed using an unmodified Cummins 85.9 turbocharged diesel engine to examine the effect of methylal blend concentration on performance and emissions. Substantial reductions of particulate matter emissions h ave been demonstrated 3r IO to 30% blends of methylal in diesel fuel. This research indicates that methylal may be an effective blendstock for diesel fuel provided design changes are made to vehicle fuel handling systems.

  1. Fuel cycle evaluations of biomass-ethanol and reformulated gasoline. Volume 1

    SciTech Connect (OSTI)

    Tyson, K.S.

    1993-11-01

    The US Department of Energy (DOE) is using the total fuel cycle analysis (TFCA) methodology to evaluate energy choices. The National Energy Strategy (NES) identifies TFCA as a tool to describe and quantify the environmental, social, and economic costs and benefits associated with energy alternatives. A TFCA should quantify inputs and outputs, their impacts on society, and the value of those impacts that occur from each activity involved in producing and using fuels, cradle-to-grave. New fuels and energy technologies can be consistently evaluated and compared using TFCA, providing a sound basis for ranking policy options that expand the fuel choices available to consumers. This study is limited to creating an inventory of inputs and outputs for three transportation fuels: (1) reformulated gasoline (RFG) that meets the standards of the Clean Air Act Amendments of 1990 (CAAA) using methyl tertiary butyl ether (MTBE); (2) gasohol (E10), a mixture of 10% ethanol made from municipal solid waste (MSW) and 90% gasoline; and (3) E95, a mixture of 5% gasoline and 95% ethanol made from energy crops such as grasses and trees. The ethanol referred to in this study is produced from lignocellulosic material-trees, grass, and organic wastes -- called biomass. The biomass is converted to ethanol using an experimental technology described in more detail later. Corn-ethanol is not discussed in this report. This study is limited to estimating an inventory of inputs and outputs for each fuel cycle, similar to a mass balance study, for several reasons: (1) to manage the size of the project; (2) to provide the data required for others to conduct site-specific impact analysis on a case-by-case basis; (3) to reduce data requirements associated with projecting future environmental baselines and other variables that require an internally consistent scenario.

  2. Ethanol Demand in United States Production of Oxygenate-limited Gasoline

    SciTech Connect (OSTI)

    Hadder, G.R.

    2000-08-16

    Ethanol competes with methyl tertiary butyl ether (MTBE) to satisfy oxygen, octane, and volume requirements of certain gasolines. However, MTBE has water quality problems that may create significant market opportunities for ethanol. Oak Ridge National Laboratory (ORNL) has used its Refinery Yield Model to estimate ethanol demand in gasolines with restricted use of MTBE. Reduction of the use of MTBE would increase the costs of gasoline production and possibly reduce the gasoline output of U.S. refineries. The potential gasoline supply problems of an MTBE ban could be mitigated by allowing a modest 3 vol percent MTBE in all gasoline. In the U.S. East and Gulf Coast gasoline producing regions, the 3 vol percent MTBE option results in costs that are 40 percent less than an MTBE ban. In the U.S. Midwest gasoline producing region, with already high use of ethanol, an MTBE ban has minimal effect on ethanol demand unless gasoline producers in other regions bid away the local supply of ethanol. The ethanol/MTBE issue gained momentum in March 2000 when the Clinton Administration announced that it would ask Congress to amend the Clean Air Act to provide the authority to significantly reduce or eliminate the use of MTBE; to ensure that air quality gains are not diminished as MTBE use is reduced; and to replace the existing oxygenate requirement in the Clean Air Act with a renewable fuel standard for all gasoline. Premises for the ORNL study are consistent with the Administration announcement, and the ethanol demand curve estimates of this study can be used to evaluate the impact of the Administration principles and related policy initiatives.

  3. 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.

  4. Task 4.9 -- Value-added products from syngas. Semi-annual report, July 1--December 31, 1996

    SciTech Connect (OSTI)

    Olson, E.S.; Sharma, R.K.

    1997-08-01

    The work on advanced fuel forms in 1996 focused on the synthesis of higher alcohols from mixtures of hydrogen and carbon dioxide (syngas) from coal gasification. Initial work in this project utilized a novel molybdenum sulfide catalyst previously shown to be active for hydrodesulfurization reactions of coal liquids. A pressurized fixed-bed flow-through reactor was constructed, and the MoS{sub 2} catalysts were tested with syngas under a variety of conditions. Unfortunately, the catalysts, even with higher molybdenum loading and addition of promoters, failed to give alcohol products. A batch reactor test of the catalyst was also conducted, but did not produce alcohol products. Group VIII metals have been used previously in catalysts for syngas reactions. Ruthenium and rhodium catalysts were prepared by impregnation of a hydrotalcite support. Tests with these catalysts in flow-through reactors also did not produce the desired alcohol products. The formation of higher alcohols from smaller ones, such as methanol and ethanol, could be commercially important if high selectivity could be achieved. The methanol and ethanol would be derived from syngas and fermentation, respectively. Based on previous work in other laboratories, it was hypothesized that the hydrotalcite-supported MoS{sub 2} or Ru or Rh catalysts could catalyze the formation of butyl alcohols. Although the desired 1-butanol was obtained in batch reactions with the promoted ruthenium catalyst, the reaction was not as selective as desired. Product suitable for a lower-vapor-pressure gasoline oxygenate additive was obtained, but it may not be economical to market such products in competition with methyl tertiary-butyl ether (MTBE). Flow-through catalytic bed reactions were not successful.

  5. Low temperature synthesis of methyl formate

    DOE Patents [OSTI]

    Mahajan, Devinder; Slegeir, William A.; Sapienza, Richard S.; O'Hare, Thomas E.

    1986-01-01

    A gas reaction process for the preferential production of methyl formate over the co-production of methanol wherein the reactant ratio of CO/H.sub.2 is upgraded and this reaction takes place at low temperatures of 50.degree.-150.degree. C. and moderate pressures of .gtoreq.100 psi.

  6. Modulation of histone methylation and MLH1 gene silencing by...

    Office of Scientific and Technical Information (OSTI)

    ... Subject: 60 APPLIED LIFE SCIENCES; ARGININE; CARCINOGENS; CHROMIUM; DNA DAMAGES; GENES; HUMAN POPULATIONS; LUNGS; LYSINE; METHYLATION; NEOPLASMS; OCCUPATIONAL EXPOSURE; PROMOTERS ...

  7. Synthesis of methyl methacrylate from coal-derived syngas: Quarterly report,, October 1-December 31, 1997

    SciTech Connect (OSTI)

    1998-09-01

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of three steps of synthesis of a propionate, its condensation with formaldehyde, and esterification of resulting methacrylic acid (MAA) with methanol to produce MMA. Over the last quarter, Eastman developed two new processes which have resulted in two new invention reports. One process deals with carbonylation of benzyl ether which represents a model for coal liquefaction and the second focuses on the acceleration of carbonylation rates for propionic acid synthesis, via use of polar aprotic solvents. These two inventions are major improvements in the novel Mo-catalyzed homogeneous process for propionic acid synthesis technology, developed by Eastman. Over the last quarter, RTI completed three reaction cycles and two regeneration cycles as a part of long-term reaction regeneration cycle study on a 10% Nb{sub 2}O{sub 5}/Si0{sub 2} catalyst, for vapor phase condensation reaction of formaldehyde with propionic acid.

  8. Process to convert biomass and refuse derived fuel to ethers and/or alcohols

    DOE Patents [OSTI]

    Diebold, James P.; Scahill, John W.; Chum, Helena L.; Evans, Robert J.; Rejai, Bahman; Bain, Richard L.; Overend, Ralph P.

    1996-01-01

    A process for conversion of a feedstock selected from the group consisting of biomass and refuse derived fuel (RDF) to provide reformulated gasoline components comprising a substantial amount of materials selected from the group consisting of ethers, alcohols, or mixtures thereof, comprising: drying said feedstock; subjecting said dried feedstock to fast pyrolysis using a vortex reactor or other means; catalytically cracking vapors resulting from said pyrolysis using a zeolite catalyst; condensing any aromatic byproduct fraction; catalytically alkylating any benzene present in said vapors after condensation; catalytically oligomerizing any remaining ethylene and propylene to higher olefins; isomerizing said olefins to reactive iso-olefins; and catalytically reacting said iso-olefins with an alcohol to form ethers or with water to form alcohols.

  9. Process to convert biomass and refuse derived fuel to ethers and/or alcohols

    DOE Patents [OSTI]

    Diebold, J.P.; Scahill, J.W.; Chum, H.L.; Evans, R.J.; Rejai, B.; Bain, R.L.; Overend, R.P.

    1996-04-02

    A process is described for conversion of a feedstock selected from the group consisting of biomass and refuse derived fuel (RDF) to provide reformulated gasoline components comprising a substantial amount of materials selected from the group consisting of ethers, alcohols, or mixtures thereof, comprising: drying said feedstock; subjecting said dried feedstock to fast pyrolysis using a vortex reactor or other means; catalytically cracking vapors resulting from said pyrolysis using a zeolite catalyst; condensing any aromatic byproduct fraction; catalytically alkylating any benzene present in said vapors after condensation; catalytically oligomerizing any remaining ethylene and propylene to higher olefins; isomerizing said olefins to reactive iso-olefins; and catalytically reacting said iso-olefins with an alcohol to form ethers or with water to form alcohols. 35 figs.

  10. The effect of catalyst ratio on catalytic performance in liquid phase dimethyl ether process

    SciTech Connect (OSTI)

    Guo Junwang; Niu Yuqin; Zhang Bijiang

    1997-12-31

    In the liquid phase dimethyl ether (LPDME) process, two functionally different catalysts are slurried together in an inert liquid medium. Syngas reacts on the surface of the methanol catalyst and methanol is dehydrated on the surface of the dehydration catalyst dispersed in the liquid. The process is adaptable to carbon monoxide-rich syngas derived from second generation coal gasifiers. The effect of catalyst ratio on catalytic performances of the dual catalyst was studied in liquid phase dimethyl ether synthesis from syngas at 280 C, 4.0 MPa. CO conversion, H{sub 2} conversion and DME productivity increased with an increase of catalyst ratio initially, reached their maximum at a catalyst ratio of 4.0--5.0, and then decreased. Methanol productivity and methanol equivalent productivity had a similar trend to that of DME productivity. DME selectivity and hydrocarbon selectivity increased with an increase in catalyst ratio whereas methanol selectivity decreased with catalyst ratio.

  11. Molecular modeling of the morphology and transport properties of two direct methanol fuel cell membranes: phenylated sulfonated poly(ether ether ketone ketone) versus Nafion

    SciTech Connect (OSTI)

    Devanathan, Ramaswami; Idupulapati, Nagesh B.; Dupuis, Michel

    2012-08-14

    We have used molecular dynamics simulations to examine membrane morphology and the transport of water, methanol and hydronium in phenylated sulfonated poly ether ether ketone ketone (Ph-SPEEKK) and Nafion membranes at 360 K for a range of hydration levels. At comparable hydration levels, the pore diameter is smaller, the sulfonate groups are more closely packed, the hydronium ions are more strongly bound to sulfonate groups, and the diffusion of water and hydronium is slower in Ph-SPEEKK relative to the corresponding properties in Nafion. The aromatic carbon backbone of Ph-SPEEKK is less hydrophobic than the fluorocarbon backbone of Nafion. Water network percolation occurs at a hydration level ({lambda}) of {approx}8 H{sub 2}O/SO{sub 3}{sup -}. At {lambda} = 20, water, methanol and hydronium diffusion coefficients were 1.4 x 10{sup -5}, 0.6 x 10{sup -5} and 0.2 x 10{sup -5} cm{sup 2}/s, respectively. The pore network in Ph-SPEEKK evolves dynamically and develops wide pores for {lambda} > 20, which leads to a jump in methanol crossover and ion transport. This study demonstrates the potential of aromatic membranes as low-cost challengers to Nafion for direct methanol fuel cell applications and the need to develop innovative strategies to combat methanol crossover at high hydration levels.

  12. 2[prime] and 3[prime] Carboranyl uridines and their diethyl ether adducts

    DOE Patents [OSTI]

    Soloway, A.H.; Barth, R.F.; Anisuzzaman, A.K.; Alam, F.; Tjarks, W.

    1992-12-15

    A process is described for preparing carboranyl uridine nucleoside compounds and their diethyl ether adducts, which exhibit a tenfold increase in boron content over prior art boron containing nucleoside compounds. The carboranyl uridine nucleoside compounds exhibit enhanced lipophilicity and hydrophilic properties adequate to enable solvation in aqueous media for subsequent incorporation of the compounds in methods for boron neutron capture therapy in mammalian tumor cells. No Drawings

  13. Barrierless proton transfer across weak CH⋯O hydrogen bonds in dimethyl ether dimer

    SciTech Connect (OSTI)

    Yoder, Bruce L. West, Adam H. C.; Signorell, Ruth; Bravaya, Ksenia B.; Bodi, Andras; Sztáray, Bálint

    2015-03-21

    We present a combined computational and threshold photoelectron photoion coincidence study of two isotopologues of dimethyl ether, (DME − h{sub 6}){sub n} and (DME − d{sub 6}){sub n}n = 1 and 2, in the 9–14 eV photon energy range. Multiple isomers of neutral dimethyl ether dimer were considered, all of which may be present, and exhibited varying C–H⋯O interactions. Results from electronic structure calculations predict that all of them undergo barrierless proton transfer upon photoionization to the ground electronic state of the cation. In fact, all neutral isomers were found to relax to the same radical cation structure. The lowest energy dissociative photoionization channel of the dimer leads to CH{sub 3}OHCH{sub 3}{sup +} by the loss of CH{sub 2}OCH{sub 3} with a 0 K appearance energy of 9.71 ± 0.03 eV and 9.73 ± 0.03 eV for (DME − h{sub 6}){sub 2} and deuterated (DME − d{sub 6}){sub 2}, respectively. The ground state threshold photoelectron spectrum band of the dimethyl ether dimer is broad and exhibits no vibrational structure. Dimerization results in a 350 meV decrease of the valence band appearance energy, a 140 meV decrease of the band maximum, thus an almost twofold increase in the ground state band width, compared with DME − d{sub 6} monomer.

  14. An Experimental and Kinetic Modeling Study of Methyl Decanoate Combustion

    SciTech Connect (OSTI)

    Sarathy, S M; Thomson, M J; Pitz, W J; Lu, T

    2010-02-19

    Biodiesel is typically a mixture of long chain fatty acid methyl esters for use in compression ignition engines. Improving biofuel engine performance requires understanding its fundamental combustion properties and the pathways of combustion. This research study presents new combustion data for methyl decanoate in an opposed-flow diffusion flame. An improved detailed chemical kinetic model for methyl decanoate combustion is developed, which serves as the basis for deriving a skeletal mechanism via the direct relation graph method. The novel skeletal mechanism consists of 648 species and 2998 reactions. This mechanism well predicts the methyl decanoate opposed-flow diffusion flame data. The results from the flame simulations indicate that methyl decanoate is consumed via abstraction of hydrogen atoms to produce fuel radicals, which lead to the production of alkenes. The ester moiety in methyl decanoate leads to the formation of low molecular weight oxygenated compounds such as carbon monoxide, formaldehyde, and ketene.

  15. Improvement of performance and emissions of a compression ignition methanol engine with dimethyl ether

    SciTech Connect (OSTI)

    Guo, J.; Chikahisa, Takemi; Murayama, Tadashi; Miyano, Masaharu

    1994-10-01

    Dimethyl ether (DME) has very good compression ignition characteristics and can be converted from methanol using a {gamma}-alumina catalyst. In this study a torch ignition chamber (TIC) head with TIC close to the center of the main combustion chamber was designed for the TIC method. The possibility of improvements in reducing the quantities of DME and emission were investigated by optimizing the TIC position, methanol injection timing, DME injection timing, and intake and exhaust throttling. It was found that the necessary amount of DME was greatly reduced when optimizing methanol and DME injection timings. 2 refs., 16 figs., 1 tab.

  16. Lithium Methyl Carbonate as a Reaction Product of Metallic Lithiumand...

    Office of Scientific and Technical Information (OSTI)

    Lithium methyl carbonate is only one of the components, the others being lithium oxalate and lithium methoxide. Authors: Zhuang, Guorong V. ; Yang, Hui ; Ross Jr., Philip N. ; Xu, ...

  17. Conversion of Levulinic Acid to Methyl Tetrahydrofuran - Energy...

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

    acid is a highly desirable renewable chemical platform, which, using this process, can be converted into Methyl Tetrahydrofuran (Me-THF) with reasonable yield. The...

  18. High octane ethers from synthesis gas-derived alcohols. Quarterly technical progress report, April--June 1993

    SciTech Connect (OSTI)

    Klier, K.; Herman, R.G.; Menszak, J.; Johansson, M.A.; Feeley, O.C.; Kim, D.

    1993-07-01

    The results shown in Figures 10 and 11 demonstrate that the formation of butenes was very sensitive to the alcohol partial pressure. A small elevation of the alcohol pressure suppressed the formation of butenes rather drastically at both 90 and 117{degree}C. The synthesis rates of DME, MIBE, and MTBE ethers were not significantly affected at 90{degree}C, although there was a trend to increase the space time yield of DME as the alcohol pressure was increased. At the reaction temperature of 117{degree}C, all of the ethers showed increasing productivities as the pressure of the reactants was increased (Figure 11). An isotope labelling experiment was carried out to provide mechanistic insight into the manner in which methanol and isobutanol react together to form DME, MIBE, and MTBE ethers and to determine if MTBE were derived from MIBE.

  19. Theoretical spectroscopic characterization at low temperatures of S-methyl thioformate and O-methyl thioformate

    SciTech Connect (OSTI)

    Senent, M. L.; Puzzarini, C.; Hochlaf, M.; Domínguez-Gómez, R.; Carvajal, M.

    2014-09-14

    Highly correlated ab initio methods are employed to determine spectroscopic properties at low temperatures of two S-analogs of methyl formate: S-methyl thioformate CH{sub 3}-S-CHO (MSCHO) and O-methyl thioformate CH{sub 3}-O-CHS (MOCHS). Both species are detectable and they are expected to play an important role in Astrochemistry. Molecular properties are compared with those of the O-analog, methyl formate. Both isomers present two conformers cis and trans. cis-CH{sub 3}-S-CHO represents the most stable structure lying 4372.2 cm{sup −1} below cis-CH{sub 3}-O-CHS. The energy difference between the cis and trans forms is drastically lower for MSCHO (1134 cm{sup −1}) than for MOCHS (1963.6 cm{sup −1}). Harmonic and anharmonic fundamentals and the corresponding intensities, as well as the rotational constants for the ground vibrational and first excited torsional states and the centrifugal distortions constants, are provided. Low torsional energy levels have been obtained by solving variationally a two dimensional Hamiltonian expressed in terms of the two torsional degrees of freedom. The corresponding 2D potential energy surfaces have been computed at the CCSD(T)/aug-cc-pVTZ level of theory. The methyl torsional barriers V{sub 3}(cis) are determined to be 139.7 cm{sup −1} (CH{sub 3}-S-CHO) and 670.4 cm{sup −1} (CH{sub 3}-O-CHS). The A/E splitting of ground torsional state has been estimated to be 0.438 cm{sup −1} for CH{sub 3}-S-CHO and negligible for CH{sub 3}-O-CHS.

  20. Commercial-scale demonstration of the Liquid Phase Methanol (LPMEOH{trademark}) Process. Peroxide formation of dimethyl ether in methanol mixtures

    SciTech Connect (OSTI)

    Waller, F.J.

    1997-11-01

    Organic peroxides could form when dimethyl ether in methanol is stored for three to six months at a time. The objective of this work was to determine the level of peroxide formation from dimethyl ether in reagent grade methanol and raw methanol at room temperature under 3 atmospheres (45 psig) of air. Raw methanol is methanol made from syngas by the LPMEOH Process without distillation. Aliphatic ethers tend to react slowly with oxygen from the air to form unstable peroxides. However, there are no reports on peroxide formation from dimethyl ether. After 172 days of testing, dimethyl ether in either reagent methanol or raw methanol at room temperature and under 60--70 psig pressure of air does not form detectable peroxides. Lack of detectable peroxides suggests that dimethyl ether or dimethyl ether and methanol may be stored at ambient conditions. Since the compositions of {approximately} 1.3 mol% or {approximately} 4.5 mol% dimethyl ether in methanol do not form peroxides, these compositions can be considered for diesel fuel or an atmospheric turbine fuel, respectively.

  1. Calixarene crown ether solvent composition and use thereof for extraction of cesium from alkaline waste solutions

    DOE Patents [OSTI]

    Moyer, Bruce A. (Oak Ridge, TN); Sachleben, Richard A. (Knoxville, TN); Bonnesen, Peter V. (Knoxville, TN); Presley, Derek J. (Ooltewah, TN)

    2001-01-01

    A solvent composition and corresponding method for extracting cesium (Cs) from aqueous neutral and alkaline solutions containing Cs and perhaps other competing metal ions is described. The method entails contacting an aqueous Cs-containing solution with a solvent consisting of a specific class of lipophilic calix[4]arene-crown ether extractants dissolved in a hydrocarbon-based diluent containing a specific class of alkyl-aromatic ether alcohols as modifiers. The cesium values are subsequently recovered from the extractant, and the solvent subsequently recycled, by contacting the Cs-containing organic solution with an aqueous stripping solution. This combined extraction and stripping method is especially useful as a process for removal of the radionuclide cesium-137 from highly alkaline waste solutions which are also very concentrated in sodium and potassium. No pre-treatment of the waste solution is necessary, and the cesium can be recovered using a safe and inexpensive stripping process using water, dilute (millimolar) acid solutions, or dilute (millimolar) salt solutions. An important application for this invention would be treatment of alkaline nuclear tank wastes. Alternatively, the invention could be applied to decontamination of acidic reprocessing wastes containing cesium-137.

  2. Catalyst activity maintenance study for the liquid phase dimethyl ether process

    SciTech Connect (OSTI)

    Peng, X.D.; Toseland, B.A.; Underwood, R.P.

    1995-12-31

    The co-production of dimethyl ether (DME) and methanol from syngas is a process of considerable commercial attractiveness. DME coproduction can double the productivity of a LPMEOH process when using coal-derived syngas. This in itself may offer chemical producers and power companies increased flexibility and more profitable operation. DME is also known as a clean burning liquid fuel; Amoco and Haldor-Topsoe have recently announced the use of DME as an alternative diesel fuel. Moreover, DME can be an interesting intermediate in the production of chemicals such as olefins and vinyl acetate. The current APCl liquid phase dimethyl ether (LPDME) process utilizes a physical mixture of a commercial methanol synthesis catalyst and a dehydration catalyst (e.g., {gamma}-alumina). While this arrangement provides a synergy that results in much higher syngas conversion per pass compared to the methanol-only process, the stability of the catalyst system suffers. The present project is aimed at reducing catalyst deactivation both by understanding the cause(s) of catalyst deactivation and by developing modified catalyst systems. This paper describes the current understanding of the deactivation mechanism.

  3. Assessing the toxic effects of ethylene glycol ethers using Quantitative Structure Toxicity Relationship models

    SciTech Connect (OSTI)

    Ruiz, Patricia; Mumtaz, Moiz; Gombar, Vijay

    2011-07-15

    Experimental determination of toxicity profiles consumes a great deal of time, money, and other resources. Consequently, businesses, societies, and regulators strive for reliable alternatives such as Quantitative Structure Toxicity Relationship (QSTR) models to fill gaps in toxicity profiles of compounds of concern to human health. The use of glycol ethers and their health effects have recently attracted the attention of international organizations such as the World Health Organization (WHO). The board members of Concise International Chemical Assessment Documents (CICAD) recently identified inadequate testing as well as gaps in toxicity profiles of ethylene glycol mono-n-alkyl ethers (EGEs). The CICAD board requested the ATSDR Computational Toxicology and Methods Development Laboratory to conduct QSTR assessments of certain specific toxicity endpoints for these chemicals. In order to evaluate the potential health effects of EGEs, CICAD proposed a critical QSTR analysis of the mutagenicity, carcinogenicity, and developmental effects of EGEs and other selected chemicals. We report here results of the application of QSTRs to assess rodent carcinogenicity, mutagenicity, and developmental toxicity of four EGEs: 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, and 2-butoxyethanol and their metabolites. Neither mutagenicity nor carcinogenicity is indicated for the parent compounds, but these compounds are predicted to be developmental toxicants. The predicted toxicity effects were subjected to reverse QSTR (rQSTR) analysis to identify structural attributes that may be the main drivers of the developmental toxicity potential of these compounds.

  4. dimethyl ether

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

    Predictive Simulation of Engines Transportation Energy Consortiums Engine Combustion ... Schematic representation of the experimental set-up. Shown in the figure is the jet-stirre...

  5. Production of methyl-vinyl ketone from levulinic acid

    DOE Patents [OSTI]

    Dumesic, James A.; West; Ryan M.

    2011-06-14

    A method for converting levulinic acid to methyl vinyl ketone is described. The method includes the steps of reacting an aqueous solution of levulinic acid, over an acid catalyst, at a temperature of from room temperature to about 1100 K. Methyl vinyl ketone is thereby formed.

  6. Host cells and methods for producing 3-methyl-2-buten-1-ol, 3-methyl-3-buten-1-ol, and 3-methyl-butan-1-ol

    DOE Patents [OSTI]

    Chou, Howard H.; Keasling, Jay D.

    2011-07-26

    The invention provides for a method for producing a 5-carbon alcohol in a genetically modified host cell. In one embodiment, the method comprises culturing a genetically modified host cell which expresses a first enzyme capable of catalyzing the dephosphorylation of an isopentenyl pyrophosphate (IPP) or dimethylallyl diphosphate (DMAPP), such as a Bacillus subtilis phosphatase (YhfR), under a suitable condition so that 5-carbon alcohol is 3-methyl-2-buten-1-ol and/or 3-methyl-3-buten-1-ol is produced. Optionally, the host cell may further comprise a second enzyme capable of reducing a 3-methyl-2-buten-1-ol to 3-methyl-butan-1-ol, such as a reductase.

  7. EPA`s proposed renewable oxygenate requirement (ROR): Pros and cons

    SciTech Connect (OSTI)

    Czeskleba, H.M.

    1995-12-31

    In December 1993, the US Environmental Protection Agency (EPA) released its final rule that sets for the details for requirements to sell reformulated gasoline (RFG) in certain ozone non-attainment areas. At the same time, EPA also issued a proposed rule to require that 30% of the oxygen required in RFG be based on a renewable oxygenate. Renewables include ethanol and its ether derivatives such as ethyl tertiary butyl ether (ETBE). The RFG rule is a final rule, while the Renewable Oxygenate Requirement (ROR) rule is a proposed rule yet to be finalized and subject to revision. Included in this paper are brief reviews of Ashland petroleum Company`s ethanol usage, oxygenated fuel and reformulated gasoline blending economics, and some comments on the EPA proposed renewable oxygenate requirement.

  8. Methanol with dimethyl ether ignition promotor as fuel for compression ignition engines

    SciTech Connect (OSTI)

    Brook, D.L.; Cipolat, D.; Rallis, C.J.

    1984-08-01

    Reduction of the world dependence upon crude oil necessitates the use of long term alternative fuels for internal combustion engines. Alcohols appear to offer a solution as in the short term they can be manufactured from natural gas and coal, while ultimately they may be produced from agricultural products. A fair measure of success has been achieved in using alcohols in spark ignition engines. However the more widely used compression ignition engines cannot utilize unmodified pure alcohols. The current techniques for using alcohol fuels in compression ignition engines all have a number of shortcomings. This paper describes a novel technique where an ignition promotor, dimethyl ether (DME), is used to increase the cetane rating of methanol. The systems particular advantage is that the DME can be catalyzed from the methanol base fuel, in situ. This fuel system matches the performance characteristics of diesel oil fuel.

  9. Process for the production of ethylidene diacetate from dimethyl ether using a heterogeneous catalyst

    DOE Patents [OSTI]

    Ramprasad, Dorai; Waller, Francis Joseph

    1998-01-01

    This invention relates to a process for producing ethylidene diacetate by the reaction of dimethyl ether, acetic acid, hydrogen and carbon monoxide at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that is stable to hydrogenation and comprises an insoluble polymer having pendant quaternized heteroatoms, some of which heteroatoms are ionically bonded to anionic Group VIII metal complexes, the remainder of the heteroatoms being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for 3 consecutive runs without loss in activity.

  10. Process for the production of ethylidene diacetate from dimethyl ether using a heterogeneous catalyst

    DOE Patents [OSTI]

    Ramprasad, D.; Waller, F.J.

    1998-04-28

    This invention relates to a process for producing ethylidene diacetate by the reaction of dimethyl ether, acetic acid, hydrogen and carbon monoxide at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that is stable to hydrogenation and comprises an insoluble polymer having pendant quaternized heteroatoms, some of which heteroatoms are ionically bonded to anionic Group VIII metal complexes, the remainder of the heteroatoms being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for 3 consecutive runs without loss in activity.

  11. Use of aluminum phosphate as the dehydration catalyst in single step dimethyl ether process

    DOE Patents [OSTI]

    Peng, Xiang-Dong; Parris, Gene E.; Toseland, Bernard A.; Battavio, Paula J.

    1998-01-01

    The present invention pertains to a process for the coproduction of methanol and dimethyl ether (DME) directly from a synthesis gas in a single step (hereafter, the "single step DME process"). In this process, the synthesis gas comprising hydrogen and carbon oxides is contacted with a dual catalyst system comprising a physical mixture of a methanol synthesis catalyst and a methanol dehydration catalyst. The present invention is an improvement to this process for providing an active and stable catalyst system. The improvement comprises the use of an aluminum phosphate based catalyst as the methanol dehydration catalyst. Due to its moderate acidity, such a catalyst avoids the coke formation and catalyst interaction problems associated with the conventional dual catalyst systems taught for the single step DME process.

  12. Using Heteropolyacids in the Anode Catalyst Layer of Dimethyl Ether PEM Fuel Cells

    SciTech Connect (OSTI)

    Ferrell III, J. R.; Turner, J. A.; Herring, A. M.

    2008-01-01

    In this study, polarization experiments were performed on a direct dimethyl ether fuel cell (DMEFC). The experimental setup allowed for independent control of water and DME flow rates. Thus the DME flow rate, backpressure, and water flow rate were optimized. Three heteropoly acids, phosphomolybdic acid (PMA), phosphotungstic acid (PTA), and silicotungstic acid (STA) were incorporated into the anode catalyst layer in combination with Pt/C. Both PTA-Pt and STA-Pt showed higher performance than the Pt control at 30 psig of backpressure. Anodic polarizations were also performed, and Tafel slopes were extracted from the data. The trends in the Tafel slope values are in agreement with the polarization data. The addition of phosphotungstic acid more than doubled the power density of the fuel cell, compared to the Pt control.

  13. Role of methyl groups in dynamics and evolution of biomolecules

    SciTech Connect (OSTI)

    Nickels, Jonathan D [ORNL; Curtis, J. E. [National Institute of Standards and Technology (NIST), Gaithersburg, MD; Oneill, Hugh [Oak Ridge National Laboratory (ORNL); Sokolov, Alexei P [ORNL

    2012-01-01

    Recent studies have discovered strong differences between the dynamics of nucleic acids (RNA and DNA) and proteins, especially at low hydration and low temperatures. This difference is caused primarily by dynamics of methyl groups that are abundant in proteins, but are absent or very rare in RNA and DNA. In this paper, we present a hypothesis regarding the role of methyl groups as intrinsic plasticizers in proteins and their evolutionary selection to facilitate protein dynamics and activity. We demonstrate the profound effect methyl groups have on protein dynamics relative to nucleic acid dynamics, and note the apparent correlation of methyl group content in protein classes and their need for molecular flexibility. Moreover, we note the fastest methyl groups of some enzymes appear around dynamical centers such as hinges or active sites. Methyl groups are also of tremendous importance from a ydrophobicity/folding/entropy perspective. These significant roles, however, complement our hypothesis rather than preclude the recognition of methyl groups in the dynamics and evolution of biomolecules.

  14. Dcm methylation is detrimental to plasmid transformation in Clostridium thermocellum

    SciTech Connect (OSTI)

    Guss, Adam M; Olson, Daniel G.; Caiazza, Nicky; Lynd, Lee R

    2012-01-01

    BACKGROUND: Industrial production of biofuels and other products by cellulolytic microorganisms is of interest but hindered by the nascent state of genetic tools. Although a genetic system for Clostridium thermocellum DSM1313 has recently been developed, available methods achieve relatively low efficiency and similar plasmids can transform C. thermocellum at dramatically different efficiencies. RESULTS: We report an increase in transformation efficiency of C. thermocellum for a variety of plasmids by using DNA that has been methylated by Escherichia coli Dam but not Dcm methylases. When isolated from a dam+ dcm+ E. coli strain, pAMG206 transforms C. thermocellum 100-fold better than the similar plasmid pAMG205, which contains an additional Dcm methylation site in the pyrF gene. Upon removal of Dcm methylation, transformation with pAMG206 showed a four- to seven-fold increase in efficiency; however, transformation efficiency of pAMG205 increased 500-fold. Removal of the Dcm methylation site from the pAM205 pyrF gene via silent mutation resulted in increased transformation efficiencies equivalent to that of pAMG206. Upon proper methylation, transformation efficiency of plasmids bearing the pMK3 and pB6A origins of replication increased ca. three orders of magnitude. CONCLUSION: E. coli Dcm methylation decreases transformation efficiency in C. thermocellum DSM1313. The use of properly methylated plasmid DNA should facilitate genetic manipulation of this industrially relevant bacterium.

  15. Hydrogen production from the steam reforming of Dinethyl Ether and Methanol

    SciTech Connect (OSTI)

    Semelsberger, T. A.; Borup, R. L.

    2004-01-01

    This study investigates dimethyl ether (DME) steam reforming for the generation of hydrogen rich fuel cell feeds for fuel cell applications. Methanol has long been considered as a fuel for the generation of hydrogen rich fuel cell feeds due to its high energy density, low reforming temperature, and zero impurity content. However, it has not been accepted as the fuel of choice due its current limited availability, toxicity and corrosiveness. While methanol steam reforming for the generation of hydrogen rich fuel cell feeds has been extensively studied, the steam reforming of DME, CH{sub 3}OCH{sub 3} + 3H{sub 2}O = 2CO{sub 2} + 6H{sub 2}, has had limited research effort. DME is the simplest ether (CH{sub 3}OCH{sub 3}) and is a gas at ambient conditions. DME has physical properties similar to those of LPG fuels (i.e. propane and butane), resulting in similar storage and handling considerations. DME is currently used as an aerosol propellant and has been considercd as a diesel substitute due to the reduced NOx, SOx and particulate emissions. DME is also being considered as a substitute for LPG fuels, which is used extensively in Asia as a fuel for heating and cooking, and naptha, which is used for power generation. The potential advantages of both methanol and DME include low reforming temperature, decreased fuel proccssor startup energy, environmentally benign, visible flame, high heating value, and ease of storage and transportation. In addition, DME has the added advantages of low toxicity and being non-corrosive. Consequently, DME may be an ideal candidate for the generation of hydrogen rich fuel cell feeds for both automotive and portable power applications. The steam reforming of DME has been demonstrated to occur through a pair of reactions in series, where the first reaction is DME hydration followed by MeOH steam reforming to produce a hydrogen rich stream.

  16. Phase 2 Methyl Iodide Deep-Bed Adsorption Tests

    SciTech Connect (OSTI)

    Soelberg, Nick; Watson, Tony

    2014-09-01

    Nuclear fission produces fission products (FPs) and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Research, demonstrations, and some reprocessing plant experience have indicated that diatomic iodine can be captured with efficiencies high enough to meet regulatory requirements. Research on the capture of organic iodides has also been performed, but to a lesser extent. Several questions remain open regarding the capture of iodine bound in organic compounds. Deep-bed methyl iodide adsorption testing has progressed according to a multi-laboratory methyl iodide adsorption test plan. This report summarizes the second phase of methyl iodide adsorption work performed according to this test plan using the deep-bed iodine adsorption test system at the Idaho National Laboratory (INL), performed during the second half of Fiscal Year (FY) 2014. Test results continue to show that methyl iodide adsorption using AgZ can achieve total iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) above 1,000, until breakthrough occurred. However, mass transfer zone depths are deeper for methyl iodide adsorption compared to diatomic iodine (I2) adsorption. Methyl iodide DFs for the Ag Aerogel test adsorption efficiencies were less than 1,000, and the methyl iodide mass transfer zone depth exceeded 8 inches. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption under various conditions specified in the methyl iodide test plan, and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

  17. Distributions of methyl group rotational barriers in polycrystalline organic solids

    SciTech Connect (OSTI)

    Beckmann, Peter A. E-mail: wangxianlong@uestc.edu.cn; Conn, Kathleen G.; Division of Education and Human Services, Neumann University, One Neumann Drive, Aston, Pennsylvania 19014-1298 ; Mallory, Clelia W.; Department of Chemistry, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 ; Mallory, Frank B.; Rheingold, Arnold L.; Rotkina, Lolita; Wang, Xianlong E-mail: wangxianlong@uestc.edu.cn

    2013-11-28

    We bring together solid state {sup 1}H spin-lattice relaxation rate measurements, scanning electron microscopy, single crystal X-ray diffraction, and electronic structure calculations for two methyl substituted organic compounds to investigate methyl group (CH{sub 3}) rotational dynamics in the solid state. Methyl group rotational barrier heights are computed using electronic structure calculations, both in isolated molecules and in molecular clusters mimicking a perfect single crystal environment. The calculations are performed on suitable clusters built from the X-ray diffraction studies. These calculations allow for an estimate of the intramolecular and the intermolecular contributions to the barrier heights. The {sup 1}H relaxation measurements, on the other hand, are performed with polycrystalline samples which have been investigated with scanning electron microscopy. The {sup 1}H relaxation measurements are best fitted with a distribution of activation energies for methyl group rotation and we propose, based on the scanning electron microscopy images, that this distribution arises from molecules near crystallite surfaces or near other crystal imperfections (vacancies, dislocations, etc.). An activation energy characterizing this distribution is compared with a barrier height determined from the electronic structure calculations and a consistent model for methyl group rotation is developed. The compounds are 1,6-dimethylphenanthrene and 1,8-dimethylphenanthrene and the methyl group barriers being discussed and compared are in the 212 kJ?mol{sup ?1} range.

  18. Rape oil methyl ester (RME) and used cooking oil methyl ester (UOME) as alternative fuels

    SciTech Connect (OSTI)

    Hohl, G.H.

    1995-12-31

    The author presents a review about the fleet tests carried out by the Austrian Armed Forces concerning the practical application of a vegetable oil, i.e Rape Oil Methyl Ester (RME) and Used Cooking Oil Methyl Ester (UOME) as alternative fuels for vehicles under military conditions, and reviews other research results carried out in Austria. As a result of over-production in Western European agriculture, the increase in crop yields has led to tremendous surpluses. Alternative agricultural products have been sought. One alternative can be seen in biological fuel production for tractors, whereby the farmer is able to produce his own fuel supply as was the case when he previously provided self-made feed for his horses. For the market introduction different activities were necessary. A considerable number of institutes and organizations including the Austrian Armed Forces have investigated, tested and developed these alternative fuels. The increasing disposal problems of used cooking oil have initiated considerations for its use. The recycling of this otherwise waste product, and its preparation for use as an alternative fuel to diesel oil, seems to be most promising.

  19. Phytoremediation of ionic and methyl mercury pollution

    SciTech Connect (OSTI)

    Meagher, R.B.

    1998-06-01

    'The long-term objective of the research is to manipulate single-gene traits into plants, enabling them to process heavy metals and remediate heavy-metal pollution by resistance, sequestration, removal, and management of these contaminants. The authors are focused on mercury pollution as a case study of this plant genetic engineering approach. The working hypothesis behind this proposal was that transgenic plants expressing both the bacterial organo mercury lyase (merB) and the mercuric ion reductase gene (merA) will: (A) remove the mercury from polluted sites and (B) prevent methyl mercury from entering the food chain. The results from the research are so positive that the technology will undoubtedly be applied in the very near future to cleaning large mercury contaminates sites. Many such sites were not remediable previously due to the excessive costs and the negative environmental impact of conventional mechanical-chemical technologies. At the time this grant was awarded 20 months ago, the authors had successfully engineered a small model plant, Arabidopsis thaliana, to use a highly modified bacterial mercuric ion reductase gene, merA9, to detoxify ionic mercury (Hg(II)), reducing it to much less toxic and volatile metallic Hg(0) (Rugh et al., 1996). Seeds from these plants germinate, grow, and set seed at normal growth rates on levels of Hg(II) that are lethal to normal plants. In assays on transgenic seedlings suspended in a solution of Hg(II), 10 ng of Hg(0) was evolved per min per mg wet weight of plant tissue. At that time, the authors had no information on expression of merA in any other plant species, nor had the authors tested merB in any plant. However, the results were so startlingly positive and well received that they clearly presaged a paradigm shift in the field of environmental remediation.'

  20. Properties of some ionic liquids based on1-methyl-3-octylimidazolium and 4-methyl-N-butylpyridinium cations.

    SciTech Connect (OSTI)

    Papaiconomou, Nicolas; Yakelis, Neal; Salminen, Justin; Bergman,Robert; Prausnitz, John M.

    2005-09-29

    Syntheses are reported for ionic liquids containing 1-methyl-3octylimidazolium and 4-methyl-N-butylpyridinium cations, and trifluoromethansulfonate, dicyanamide, bis(trifluoromethylsulfonyl)imide, and nonafluorobutanesulfonate anions. Densities, melting points and glass transition points, solubility in water as well as polarities have been measured. Ionic liquids based on pyridinium cations exhibit higher melting points, lower solubility in water, and higher polarity than those based on imidazolium cations.

  1. The use of dimethyl ether as a starting aid for methanol-fueled SI engines at low temperatures

    SciTech Connect (OSTI)

    Kozole, K.H.; Wallace, J.S

    1988-01-01

    Methanol-fueled SI engines have proven to be difficult to start at ambient temperatures below approximately 10/sup 0/C. The use of dimethyl ether (DME) is proposed to improve the cold starting performance of methanol-fueled SI engines. Tests to evaluate this idea were carried out with a modified single-cylinder CFR research engine having a compression ratio of 12:1. The engine was fueled with combinations of gaseous dimethyl ether and liquid methanol having DME mass fractions of 30%, 40%, 60% and 70%. For comparison, tests were also carried out with 100% methanol and with winter grade premium unleaded gasoline. Overall stoichiometric mixtures were used in all tests.

  2. Carbon-carbon bond cleavage of 1,2-hydroxy ethers b7 vanadium(V) dipicolinate complexes

    SciTech Connect (OSTI)

    Hanson, Susan K; Gordon, John C; Thorn, David L; Scott, Brian L; Baker, R Tom

    2009-01-01

    The development of alternatives to current petroleum-based fuels and chemicals is becoming increasingly important due to concerns over climate change, growing world energy demand, and energy security issues. Using non-food derived biomass to produce renewable feedstocks for chemicals and fuels is a particularly attractive possibility. However, the majority of biomass is in the form of lignocellulose, which is often not fully utilized due to difficulties associated with breaking down both lignin and cellulose. Recently, a number of methods have been reported to transform cellulose directly into more valuable materials such as glucose, sorbitol, 5-(chloromethyl)furfural, and ethylene glycol. Less progress has been made with selective transformations of lignin, which is typically treated in paper and forest industries by kraft pulping (sodium hydroxide/sodium sulfide) or incineration. Our group has begun investigating aerobic oxidative C-C bond cleavage catalyzed by dipicolinate vanadium complexes, with the idea that a selective C-C cleavage reaction of this type could be used to produce valuable chemicals or intermediates from cellulose or lignin. Lignin is a randomized polymer containing methoxylated phenoxy propanol units. A number of different linkages occur naturally; one of the most prevalent is the {beta}-O-4 linkage shown in Figure 1, containing a C-C bond with 1,2-hydroxy ether substituents. While the oxidative C-C bond cleavage of 1,2-diols has been reported for a number of metals, including vanadium, iron, manganese, ruthenium, and polyoxometalate complexes, C-C bond cleavage of 1,2-hydroxy ethers is much less common. We report herein vanadium-mediated cleavage of C-C bonds between alcohol and ether functionalities in several lignin model complexes. In order to explore the scope and potential of vanadium complexes to effect oxidative C-C bond cleavage in 1,2-hydroxy ethers, we examined the reactivity of the lignin model complexes pinacol monomethyl ether (A

  3. Structural basis of stereospecificity in the bacterial enzymatic cleavage of β-aryl ether bonds in lignin

    SciTech Connect (OSTI)

    Helmich, Kate E.; Pereira, Jose Henrique; Gall, Daniel L.; Heins, Richard A.; McAndrew, Ryan P.; Bingman, Craig; Deng, Kai; Holland, Keefe C.; Noguera, Daniel R.; Simmons, Blake A.; Sale, Kenneth L.; Ralph, John; Donohue, Timothy J.; Adams, Paul D.; Phillips, George N.

    2015-12-04

    Here, lignin is a combinatorial polymer comprising monoaromatic units that are linked via covalent bonds. Although lignin is a potential source of valuable aromatic chemicals, its recalcitrance to chemical or biological digestion presents major obstacles to both the production of second-generation biofuels and the generation of valuable coproducts from lignin's monoaromatic units. Degradation of lignin has been relatively well characterized in fungi, but it is less well understood in bacteria. A catabolic pathway for the enzymatic breakdown of aromatic oligomers linked via β-aryl ether bonds typically found in lignin has been reported in the bacterium Sphingobium sp. SYK-6. Here, we present x-ray crystal structures and biochemical characterization of the glutathione-dependent β-etherases, LigE and LigF, from this pathway. The crystal structures show that both enzymes belong to the canonical two-domain fold and glutathione binding site architecture of the glutathione S-transferase family. Mutagenesis of the conserved active site serine in both LigE and LigF shows that, whereas the enzymatic activity is reduced, this amino acid side chain is not absolutely essential for catalysis. The results include descriptions of cofactor binding sites, substrate binding sites, and catalytic mechanisms. Because β-aryl ether bonds account for 50–70% of all interunit linkages in lignin, understanding the mechanism of enzymatic β-aryl ether cleavage has significant potential for informing ongoing studies on the valorization of lignin.

  4. Synthesis of dimethyl ether and alternative fuels in the liquid phase from coal-derived synthesis gas. Final technical report

    SciTech Connect (OSTI)

    Not Available

    1993-02-01

    Through the mid-1980s, Air Products has brought the liquid phase approach to a number of other synthesis gas reactions where effective heat management is a key issue. In 1989, in response to DOE`s PRDA No. DE-RA22-88PC88805, Air Products proposed a research and development program entitled ``Synthesis of Dimethyl Ether and Alternative Fuels in the Liquid Phase from Coal Derived Syngas.`` The proposal aimed at extending the LPMEOH experience to convert coal-derived synthesis gas to other useful fuels and chemicals. The work proposed included development of a novel one-step synthesis of dimethyl ether (DME) from syngas, and exploration of other liquid phase synthesis of alternative fuel directly from syngas. The one-step DME process, conceived in 1986 at Air Products as a means of increasing syngas conversion to liquid products, envisioned the concept of converting product methanol in situ to DME in a single reactor. The slurry reactor based liquid phase technology is ideally suited for such an application, since the second reaction (methanol to DME) can be accomplished by adding a second catalyst with dehydration activity to the methanol producing reactor. An area of exploration for other alternative fuels directly from syngas was single-step slurry phase synthesis of hydrocarbons via methanol and DME as intermediates. Other possibilities included the direct synthesis of mixed alcohols and mixed ethers in a slurry reactor.

  5. Structural basis of stereospecificity in the bacterial enzymatic cleavage of β-aryl ether bonds in lignin

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

    Helmich, Kate E.; Pereira, Jose Henrique; Gall, Daniel L.; Heins, Richard A.; McAndrew, Ryan P.; Bingman, Craig; Deng, Kai; Holland, Keefe C.; Noguera, Daniel R.; Simmons, Blake A.; et al

    2015-12-04

    Here, lignin is a combinatorial polymer comprising monoaromatic units that are linked via covalent bonds. Although lignin is a potential source of valuable aromatic chemicals, its recalcitrance to chemical or biological digestion presents major obstacles to both the production of second-generation biofuels and the generation of valuable coproducts from lignin's monoaromatic units. Degradation of lignin has been relatively well characterized in fungi, but it is less well understood in bacteria. A catabolic pathway for the enzymatic breakdown of aromatic oligomers linked via β-aryl ether bonds typically found in lignin has been reported in the bacterium Sphingobium sp. SYK-6. Here, wemore » present x-ray crystal structures and biochemical characterization of the glutathione-dependent β-etherases, LigE and LigF, from this pathway. The crystal structures show that both enzymes belong to the canonical two-domain fold and glutathione binding site architecture of the glutathione S-transferase family. Mutagenesis of the conserved active site serine in both LigE and LigF shows that, whereas the enzymatic activity is reduced, this amino acid side chain is not absolutely essential for catalysis. The results include descriptions of cofactor binding sites, substrate binding sites, and catalytic mechanisms. Because β-aryl ether bonds account for 50–70% of all interunit linkages in lignin, understanding the mechanism of enzymatic β-aryl ether cleavage has significant potential for informing ongoing studies on the valorization of lignin.« less

  6. Direct Numerical Simulations of Autoignition in Stratified Dimethyl-ether (DME)/Air Turbulent Mixtures

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

    Bansal, Gaurav; Mascarenhas, Ajith; Chen, Jacqueline H.

    2014-10-01

    In our paper, two- and three-dimensional direct numerical simulations (DNS) of autoignition phenomena in stratified dimethyl-ether (DME)/air turbulent mixtures are performed. A reduced DME oxidation mechanism, which was obtained using rigorous mathematical reduction and stiffness removal procedure from a detailed DME mechanism with 55 species, is used in the present DNS. The reduced DME mechanism consists of 30 chemical species. This study investigates the fundamental aspects of turbulence-mixing-autoignition interaction occurring in homogeneous charge compression ignition (HCCI) engine environments. A homogeneous isotropic turbulence spectrum is used to initialize the velocity field in the domain. Moreover, the computational configuration corresponds to amore » constant volume combustion vessel with inert mass source terms added to the governing equations to mimic the pressure rise due to piston motion, as present in practical engines. DME autoignition is found to be a complex three-staged process; each stage corresponds to a distinct chemical kinetic pathway. The distinct role of turbulence and reaction in generating scalar gradients and hence promoting molecular transport processes are investigated. Then, by applying numerical diagnostic techniques, the different heat release modes present in the igniting mixture are identified. In particular, the contribution of homogeneous autoignition, spontaneous ignition front propagation, and premixed deflagration towards the total heat release are quantified.« less

  7. New clean fuel from coal -- Direct dimethyl ether synthesis from hydrogen and carbon monoxide

    SciTech Connect (OSTI)

    Ogawa, T.; Ono, M.; Mizuguchi, M.; Tomura, K.; Shikada, T.; Ohono, Y.; Fujimoto, K.

    1997-12-31

    Dimethyl ether (DME), which has similar physical properties to propane and is easily liquefied at low pressure, has a significant possibility as a clean and non-toxic fuel from coal or coal bed methane. Equilibrium calculation also shows a big advantage of high carbon monoxide conversion of DME synthesis compared to methanol synthesis. By using a 50 kg/day DME bench scale test plant, direct synthesis of DME from hydrogen and carbon monoxide has been studied with newly developed catalysts which are very fine particles. This test plant features a high pressure three-phase slurry reactor and low temperature DME separator. DME is synthesized at temperatures around 533--553 K and at pressures around 3--5 MPa. According to the reaction stoichiometry, the same amount of hydrogen and carbon monoxide react to DME and carbon dioxide. Carbon conversion to DME is one third and the rest of carbon is converted to carbon dioxide. As a result of the experiments, make-up CO conversion is 35--50% on an once-through basis, which is extremely high compared to that of methanol synthesis from hydrogen and carbon monoxide. DME selectivity is around 60 c-mol %. Most of the by-product is CO{sub 2} with a small amount of methanol and water. No heavy by-products have been recognized. Effluent from the reactor is finally cooled to 233--253 K in a DME separator and liquid DME is recovered as a product.

  8. Experimental and Computational Study of Nonpremixed Ignition of Dimethyl Ether in Counterflow

    SciTech Connect (OSTI)

    Zheng, X L; Lu, T F; Law, C K; Westbrook, C K

    2003-12-19

    The ignition temperature of nitrogen-diluted dimethyl ether (DME) by heated air in counterflow was experimentally determined for DME concentration from 5.9 to 30%, system pressure from 1.5 to 3.0 atmospheres, and pressure-weighted strain rate from 110 to 170/s. These experimental data were compared with two mechanisms that were respectively available in 1998 and 2003, with the latter being a substantially updated version of the former. The comparison showed that while the 1998-mechanism uniformly over-predicted the ignition temperature, the 2003-mechanism yielded surprisingly close agreement for all experimental data. Sensitivity analysis for the near-ignition state based on both mechanisms identified the deficiencies of the 1998-mechanism, particularly the specifics of the low-temperature cool flame chemistry in effecting ignition at higher temperatures, as the fuel stream is being progressively heated from its cold boundary to the high-temperature ignition region around the hot-stream boundary. The 2003-mechanism, consisting of 79 species and 398 elementary reactions, was then systematically simplified by using the directed relation graph method to a skeletal mechanism of 49 species and 251 elementary reactions, which in turn was further simplified by using computational singular perturbation method and quasi-steady-state species assumption to a reduced mechanism consisting of 33 species and 28 lumped reactions. It was demonstrated that both the skeletal and reduced mechanisms mimicked the performance of the detailed mechanism with high accuracy.

  9. Slurry phase synthesis of dimethyl ether from syngas -- A reactor model simulation

    SciTech Connect (OSTI)

    Mizuguchi, Masatsugu; Ogawa, Takashi; Ono, Masami,; Tomura, Keiji; Shikada, Tsutomu; Ohno, Yotaro; Fujimoto, Kaoru

    1998-12-31

    Dimethyl ether (DME) would be an attractive alternative fuel for diesel, domestic use, and power generation, if it is economically synthesized directly from syngas (derived from coal gasification or natural gas reforming). DME, which is a colorless gas with a boiling point of {minus}25 C, is chemically stable and easily liquefied under pressure. Since the properties of DME are similar to LPG, it can be handled and stored with the same manner as LPG. The authors have performed the slurry phase DME synthesis by using the 50 kg/day bench-scale unit. DME was synthesized at high yield from syngas (H{sub 2}+CO) with the newly developed catalyst system. To establish the scale-up methodology, the reactor simulation technique is essential. The authors developed a mathematical model of the slurry phase bubble column reactor for DME synthesis, which is based on their experimental results. The performance of a commercial-scale DME reactor was simulated by this model, and the results were discussed.

  10. Direct Numerical Simulations of Autoignition in Stratified Dimethyl-ether (DME)/Air Turbulent Mixtures

    SciTech Connect (OSTI)

    Bansal, Gaurav; Mascarenhas, Ajith; Chen, Jacqueline H.

    2014-10-01

    In our paper, two- and three-dimensional direct numerical simulations (DNS) of autoignition phenomena in stratified dimethyl-ether (DME)/air turbulent mixtures are performed. A reduced DME oxidation mechanism, which was obtained using rigorous mathematical reduction and stiffness removal procedure from a detailed DME mechanism with 55 species, is used in the present DNS. The reduced DME mechanism consists of 30 chemical species. This study investigates the fundamental aspects of turbulence-mixing-autoignition interaction occurring in homogeneous charge compression ignition (HCCI) engine environments. A homogeneous isotropic turbulence spectrum is used to initialize the velocity field in the domain. Moreover, the computational configuration corresponds to a constant volume combustion vessel with inert mass source terms added to the governing equations to mimic the pressure rise due to piston motion, as present in practical engines. DME autoignition is found to be a complex three-staged process; each stage corresponds to a distinct chemical kinetic pathway. The distinct role of turbulence and reaction in generating scalar gradients and hence promoting molecular transport processes are investigated. Then, by applying numerical diagnostic techniques, the different heat release modes present in the igniting mixture are identified. In particular, the contribution of homogeneous autoignition, spontaneous ignition front propagation, and premixed deflagration towards the total heat release are quantified.

  11. A fluorescence-based method for rapid and direct determination of polybrominated diphenyl ethers in water

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

    Shan, Huimei; Liu, Chongxuan; Wang, Zheming; Ma, Teng; Shang, Jianying; Pan, Duoqiang

    2015-01-01

    A new method was developed for rapid and direct measurement of polybrominated diphenyl ethers (PBDEs) in aqueous samples using fluorescence spectroscopy. The fluorescence spectra of tri- to deca-BDE (BDE 28, 47, 99, 153, 190, and 209) commonly found in environment were measured at variable emission and excitation wavelengths. The results revealed that the PBDEs have distinct fluorescence spectral profiles and peak positions that can be exploited to identify these species and determine their concentrations in aqueous solutions. The detection limits as determined in deionized water spiked with PBDEs are 1.71-5.82 ng/L for BDE 28, BDE 47, BDE 190, and BDEmore » 209 and 45.55–69.95 ng/L for BDE 99 and BDE 153. The effects of environmental variables including pH, humic substance, and groundwater chemical composition on PBDEs measurements were also investigated. These environmental variables affected fluorescence intensity, but their effect can be corrected through linear additivity and separation of spectral signal contribution. Compared with conventional GC-based analytical methods, the fluorescence spectroscopy method is more efficient as it only uses a small amount of samples (2-4 mL), avoids lengthy complicated concentration and extraction steps, and has a low detection limit of a few ng/L.« less

  12. A fluorescence-based method for rapid and direct determination of polybrominated diphenyl ethers in water

    SciTech Connect (OSTI)

    Shan, Huimei; Liu, Chongxuan; Wang, Zheming; Ma, Teng; Shang, Jianying; Pan, Duoqiang

    2015-01-01

    A new method was developed for rapid and direct measurement of polybrominated diphenyl ethers (PBDEs) in aqueous samples using fluorescence spectroscopy. The fluorescence spectra of tri- to deca-BDE (BDE 28, 47, 99, 153, 190, and 209) commonly found in environment were measured at variable emission and excitation wavelengths. The results revealed that the PBDEs have distinct fluorescence spectral profiles and peak positions that can be exploited to identify these species and determine their concentrations in aqueous solutions. The detection limits as determined in deionized water spiked with PBDEs are 1.71-5.82 ng/L for BDE 28, BDE 47, BDE 190, and BDE 209 and 45.5569.95 ng/L for BDE 99 and BDE 153. The effects of environmental variables including pH, humic substance, and groundwater chemical composition on PBDEs measurements were also investigated. These environmental variables affected fluorescence intensity, but their effect can be corrected through linear additivity and separation of spectral signal contribution. Compared with conventional GC-based analytical methods, the fluorescence spectroscopy method is more efficient as it only uses a small amount of samples (2-4 mL), avoids lengthy complicated concentration and extraction steps, and has a low detection limit of a few ng/L.

  13. Hydrogen-bonding interactions and protic equilibria in room-temperature ionic liquids containing crown ethers.

    SciTech Connect (OSTI)

    Marin, T.; Shkrob, I.; Dietz, M.

    2011-04-14

    Nuclear magnetic resonance (NMR) spectroscopy has been used to study hydrogen-bonding interactions between water, associated and dissociated acids (i.e., nitric and methanesulfonic acids), and the constituent ions of several water-immiscible room-temperature ionic liquids (ILs). In chloroform solutions also containing a crown ether (CE), water molecules strongly associate with the IL ions, and there is rapid proton exchange between these bound water molecules and hydronium associated with the CE. In neat ILs, the acids form clusters differing in their degree of association and ionization, and their interactions with the CEs are weak. The CE can either promote proton exchange between different clusters in IL solution when their association is weak or inhibit such exchange when the association is strong. Even strongly hydrophobic ILs are shown to readily extract nitric acid from aqueous solution, typically via the formation of a 1:1:1 {l_brace}H{sub 3}O{sup +} {center_dot} CE{r_brace}NO{sub 3}{sup -} complex. In contrast, the extraction of methanesulfonic acid is less extensive and proceeds mainly by IL cation-hydronium ion exchange. The relationship of these protic equilibria to the practical application of hydrophobic ILs (e.g., in spent nuclear fuel reprocessing) is discussed.

  14. Study on systems based on coal and natural gas for producing dimethyl ether

    SciTech Connect (OSTI)

    Zhou, L.; Hu, S.Y.; Chen, D.J.; Li, Y.R.; Zhu, B.; Jin, Y.

    2009-04-15

    China is a coal-dependent country and will remain so for a long time. Dimethyl ether (DME), a potential substitute for liquid fuel, is a kind of clean diesel motor fuel. The production of DME from coal is meaningful and is studied in this article. Considering the C/H ratios of coal and natural gas (NG), the cofeed (coal and NG) system (CFS), which does not contain the water gas shift process, is studied. It can reduce CO{sub 2} emission and increase the conversion rate of carbon, producing more DME. The CFS is simulated and compared with the coal-based and NG-based systems with different recycling ratios. The part of the exhaust gas that is not recycled is burned, producing electricity. On the basis of the simulation results, the thermal efficiency, economic index, and CO{sub 2} emission ratio are calculated separately. The CFS with a 100% recycling ratio has the best comprehensive evaluation index, while the energy, economy, and environment were considered at the same time.

  15. Electron momentum spectroscopy of dimethyl ether taking account of nuclear dynamics in the electronic ground state

    SciTech Connect (OSTI)

    Morini, Filippo; Deleuze, Michael Simon; Watanabe, Noboru; Kojima, Masataka; Takahashi, Masahiko

    2015-10-07

    The influence of nuclear dynamics in the electronic ground state on the (e,2e) momentum profiles of dimethyl ether has been analyzed using the harmonic analytical quantum mechanical and Born-Oppenheimer molecular dynamics approaches. In spite of fundamental methodological differences, results obtained with both approaches consistently demonstrate that molecular vibrations in the electronic ground state have a most appreciable influence on the momentum profiles associated to the 2b{sub 1}, 6a{sub 1}, 4b{sub 2}, and 1a{sub 2} orbitals. Taking this influence into account considerably improves the agreement between theoretical and newly obtained experimental momentum profiles, with improved statistical accuracy. Both approaches point out in particular the most appreciable role which is played by a few specific molecular vibrations of A{sub 1}, B{sub 1}, and B{sub 2} symmetries, which correspond to C–H stretching and H–C–H bending modes. In line with the Herzberg-Teller principle, the influence of these molecular vibrations on the computed momentum profiles can be unraveled from considerations on the symmetry characteristics of orbitals and their energy spacing.

  16. Equilibria and dissociation kinetics of lanthanide complexes of diaza crown ether carboxylic acids

    SciTech Connect (OSTI)

    Chang, C.A.; Chang, P.H.L.; Manchanda, V.K.; Kasprzyk, S.P.

    1988-10-19

    The equilibria and dissociation kinetics of lanthanide and several transition-metal and Pb(II) complexes of some diaza crown ether carboxylic acids are studied. The ligands are K22MA (1,10-diaza-4,7,13,16-tetraoxacyclooctadecane-N-acetic acid), K22DP (1,10-diaza-4,7,13,16-tetraoxacyclooctadecane-N,N'-di-..beta..-propionic acid), and K22MP (1,10-diaza-4,7,13,16-tetraoxacyclooctadecane-N-..beta..-propionic acid). The protonation constants of these ligands are similar to those of the structural analogues and are in the range log K/sub 1/ = 8.80-9.01 and log K/sub 2/ = 7.26-8.16. The stability constants are all lower than that of their structural analogue K22DA (1,10-diaza-4,7,13,16-tetraoxacyclooctadecane-N,N'-diacetic acid) due to the reduction of the chelate effect or an unfavorable steric effect or both. The kinetic dissociation rates are all faster as compared to those of K22DA complexes. Acid-dependent (k/sub H/) and acid-independent (k/sub d/) rate constants are obtained by the measurement of rates at various pH values, and they correlate inversely with the values of stability constants. 15 references, 1 figure, 4 tables.

  17. Nested methylation-specific polymerase chain reaction cancer detection method

    DOE Patents [OSTI]

    Belinsky, Steven A.; Palmisano, William A.

    2007-05-08

    A molecular marker-based method for monitoring and detecting cancer in humans. Aberrant methylation of gene promoters is a marker for cancer risk in humans. A two-stage, or "nested" polymerase chain reaction method is disclosed for detecting methylated DNA sequences at sufficiently high levels of sensitivity to permit cancer screening in biological fluid samples, such as sputum, obtained non-invasively. The method is for detecting the aberrant methylation of the p16 gene, O 6-methylguanine-DNA methyltransferase gene, Death-associated protein kinase gene, RAS-associated family 1 gene, or other gene promoters. The method offers a potentially powerful approach to population-based screening for the detection of lung and other cancers.

  18. Geometric and Electronic Structures of the Ni(I) and Methyl-Ni(III)

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

    Intermediates of Methyl-Coenzyme M Reductase 9 Geometric and Electronic Structures of the Ni(I) and Methyl-Ni(III) Intermediates of Methyl-Coenzyme M Reductase Methyl-coenzyme M reductase (MCR) from methanogenic archaea catalyzes the terminal step in biological methane synthesis. Using coenzyme B (CoBSH) as the two-electron donor, MCR reduces methyl-coenzyme M (methyl-SCoM) to form methane and the heterodisulfide product, CoBS-SCoM. MCR contains an essential redox active nickel tetrapyrrolic

  19. Methods for detection of methyl-CpG dinucleotides

    DOE Patents [OSTI]

    Dunn, John J

    2013-11-26

    The invention provides methods for enriching methyl-CpG sequences from a DNA sample. The method makes use of conversion of cytosine residues to uracil under conditions in which methyl-cytosine residues are preserved. Additional methods of the invention enable to preservation of the context of me-CpG dinucleotides. The invention also provides a recombinant, full length and substantially pure McrA protein (rMcrA) for binding and isolation of DNA fragments containing the sequence 5'-C.sup.MeCpGG-3'. Methods for making and using the rMcrA protein, and derivatives thereof are provided.

  20. Methods for detection of methyl-CpG dinucleotides

    DOE Patents [OSTI]

    Dunn, John J.

    2012-09-11

    The invention provides methods for enriching methyl-CpG sequences from a DNA sample. The method makes use of conversion of cytosine residues to uracil under conditions in which methyl-cytosine residues are preserved. Additional methods of the invention enable to preservation of the context of me-CpG dinucleotides. The invention also provides a recombinant, full length and substantially pure McrA protein (rMcrA) for binding and isolation of DNA fragments containing the sequence 5'-C.sup.MeCpGG-3'. Methods for making and using the rMcrA protein, and derivatives thereof are provided.

  1. Methods for detection of methyl-CpG dinucleotides

    DOE Patents [OSTI]

    Dunn, John J.

    2013-01-29

    The invention provides methods for enriching methyl-CpG sequences from a DNA sample. The method makes use of conversion of cytosine residues to uracil under conditions in which methyl-cytosine residues are preserved. Additional methods of the invention enable to preservation of the context of me-CpG dinucleotides. The invention also provides a recombinant, full length and substantially pure McrA protein (rMcrA) for binding and isolation of DNA fragments containing the sequence 5'-C.sup.MeCpGG-3'. Methods for making and using the rMcrA protein, and derivatives thereof are provided.

  2. ULEV potential of a DI/TCI diesel passenger car engine operated on dimethyl ether

    SciTech Connect (OSTI)

    Kapus, P.E.; Cartellieri, W.P.

    1995-12-31

    This paper describes a feasibility test program on a 2 liter, 4 cylinder DI/TCI passenger car engine operated on the new alternative fuel Dimethyl Ether (DME) with the aim of demonstrating its potential of meeting ULEV (ultra low emission vehicle) emissions (0.2 g/mi NOx in the FTP 75 test cycle) when installed in a full size passenger car. Special attention is drawn to the fuel injection equipment (FIE) as well as combustion system requirements towards the reduction of NOx and combustion noise while keeping energetic fuel consumption at the level of he baseline DI/TCI diesel engine. FIE and combustion system parameters were optimized on the steady state dynamometer by variation of a number of parameters, such as rate of injection, number of nozzle holes, compression ratio, piston bowl shape and exhaust gas recirculation. The paper presents engine test results achieved with DME under various operating conditions and compares these results to those achieved with the diesel version of the same engine.The FTP 75 cycle results were projected from steady state engine maps using a vehicle simulation program taking into account vehicle data and road resistance data of a given vehicle.The cycle results are also compared to actual chassis dynamometer results achieved with the diesel version of the same engine installed in the same vehicle.the passenger car DI/TCI engine adapted for and operated on DME shows very promising results with respect to meeting ULEV NOx emissions without any soot emissions and without the need for a DENOX catalyst. DME fuel consumption on energy basis can be kept very close to the DI diesel value. An oxidation catalyst will be necessary to meet the stringent CO and HC ULEV emission limits.

  3. Mechanistic Investigation of Acid-Catalyzed Cleavage of Aryl-Ether Linkages: Implications for Lignin Depolymerization

    SciTech Connect (OSTI)

    Sturgeon, M. R.; Kim, S.; Chmely, S. C.; Foust, T. D.; Beckham, G. T.

    2013-01-01

    Carbon-oxygen bonds are the primary inter-monomer linkages lignin polymers in plant cell walls, and as such, catalyst development to cleave these linkages is of paramount importance to deconstruct biomass to its constituent monomers for the production of renewable fuels and chemicals. For many decades, acid catalysis has been used to depolymerize lignin. Lignin is a primary component of plant cell walls, which is connected primarily by aryl-ether linkages, and the mechanism of its deconstruction by acid is not well understood, likely due to its heterogeneous and complex nature compared to cellulose. For effective biomass conversion strategies, utilization of lignin is of significant relevance and as such understanding the mechanisms of catalytic lignin deconstruction to constituent monomers and oligomers is of keen interest. Here, we present a comprehensive experimental and theoretical study of the acid catalysis of a range of dimeric species exhibiting the b-O-4 linkage, the most common inter-monomer linkage in lignin. We demonstrate that the presence of a phenolic species dramatically increases the rate of cleavage in acid at 150 degrees C. Quantum mechanical calculations on dimers with the para-hydroxyl group demonstrate that this acid-catalyzed pathway differs from the nonphenolic dimmers. Importantly, this result implies that depolymerization of native lignin in the plant cell wall will proceed via an unzipping mechanism wherein b-O-4 linkages will be cleaved from the ends of the branched, polymer chains inwards toward the center of the polymer. To test this hypothesis further, we synthesized a homopolymer of b-O-4 with a phenolic hydroxyl group, and demonstrate that it is cleaved in acid from the end containing the phenolic hydroxyl group. This result suggests that genetic modifications to lignin biosynthesis pathways in plants that will enable lower severity processes to fractionate lignin for upgrading and for easier access to the carbohydrate fraction of

  4. Task 4.9 -- Value-added products from syngas

    SciTech Connect (OSTI)

    Olson, E.S.; Sharma, R.K.

    1997-02-01

    oxygenate additive was obtained, but it may not be economical to market such products in competition with methyl tertiary-butyl-ether. Flow-through catalytic bed reactions were not successful.

  5. Low Temperature Autoignition of C8H16O2 Ethyl and Methyl Esters...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Temperature Autoignition of C8H16O2 Ethyl and Methyl Esters in a Motored Engine Low Temperature Autoignition of C8H16O2 Ethyl and Methyl Esters in a Motored Engine qThe alkyl chain ...

  6. Infant sex-specific placental cadmium and DNA methylation associations

    SciTech Connect (OSTI)

    Mohanty, April F.; Farin, Fred M.; Bammler, Theo K.; MacDonald, James W.; Afsharinejad, Zahra; Burbacher, Thomas M.; Siscovick, David S.; and others

    2015-04-15

    Background: Recent evidence suggests that maternal cadmium (Cd) burden and fetal growth associations may vary by fetal sex. However, mechanisms contributing to these differences are unknown. Objectives: Among 24 maternal-infant pairs, we investigated infant sex-specific associations between placental Cd and placental genome-wide DNA methylation. Methods: We used ANOVA models to examine sex-stratified associations of placental Cd (dichotomized into high/low Cd using sex-specific Cd median cutoffs) with DNA methylation at each cytosine-phosphate-guanine site or region. Statistical significance was defined using a false discovery rate cutoff (<0.10). Results: Medians of placental Cd among females and males were 5 and 2 ng/g, respectively. Among females, three sites (near ADP-ribosylation factor-like 9 (ARL9), siah E3 ubiquitin protein ligase family member 3 (SIAH3), and heparin sulfate (glucosamine) 3-O-sulfotransferase 4 (HS3ST4) and one region on chromosome 7 (including carnitine O-octanoyltransferase (CROT) and TP5S target 1 (TP53TG1)) were hypomethylated in high Cd placentas. Among males, high placental Cd was associated with methylation of three sites, two (hypomethylated) near MDS1 and EVI1 complex locus (MECOM) and one (hypermethylated) near spalt-like transcription factor 1 (SALL1), and two regions (both hypomethylated, one on chromosome 3 including MECOM and another on chromosome 8 including rho guanine nucleotide exchange factor (GEF) 10 (ARHGEF10). Differentially methylated sites were at or close to transcription start sites of genes involved in cell damage response (SIAH3, HS3ST4, TP53TG1) in females and cell differentiation, angiogenesis and organ development (MECOM, SALL1) in males. Conclusions: Our preliminary study supports infant sex-specific placental Cd-DNA methylation associations, possibly accounting for previously reported differences in Cd-fetal growth associations across fetal sex. Larger studies are needed to replicate and extend these

  7. Ligand-Thickness Effect Leads to Enhanced Preference for Large Anions in Alkali Metal Extraction by Crown Ethers

    SciTech Connect (OSTI)

    Haverlock, T.J.; Moyer, B.A.; Sachleben, R.A.

    1999-07-11

    Jean-Marie Lehn (Nobel laureate, 1987) suggested ligand thickness to be an important consideration in the design of host molecules for cation recognition. We have recently expanded the role of this simple ligand property by demonstrating a case in which ligand thickness contributes significantly to anion discrimination. It was found that in the extraction of sodium nitrate and perchlorate by a simple crown ether, bis(t-octylbenzo)-14-crown-4 (BOB 14C4), the normal preference for perchlorate is almost completely lost when the complex cation has the open-face sandwich vs. the sandwich structure.

  8. Phase 1 Methyl Iodide Deep-Bed Adsorption Tests

    SciTech Connect (OSTI)

    Nick Soelberg; Tony Watson

    2014-08-01

    Nuclear fission results in the production of fission products (FPs) and activation products including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Research, demonstrations, and some reprocessing plant experience have indicated that diatomic iodine can be captured with efficiencies high enough to meet regulatory requirements. Research on the capture of organic iodides has also been performed, but to a lesser extent [Jubin 2012b]. Several questions remain open regarding the capture of iodine bound in organic compounds. Deep-bed methyl iodide adsorption testing has progressed according to a multi-laboratory methyl iodide adsorption test plan. This report summarizes the first phase of methyl iodide adsorption work performed according to this test plan using the deep-bed iodine adsorption test system at the Idaho National Laboratory (INL), performed during Fiscal Year (FY) 2013 and early FY-2014. Testing has been performed to address questions posed in the test plan, and followed the testing outline in the test plan. Tests established detection limits, developed procedures for sample analysis with minimal analytical interferences, and confirmed earlier results that show that the methyl iodide reacts when in contact with the AgZ sorbent, and not significantly in the gas flow upstream of the sorbent. The reaction(s) enable separation of the iodine from the organic moiety, so that the iodine can chemisorb onto the sorbent. The organic moiety can form other compounds, some of which are organic compounds that are detected and can be tentatively identified using GC-FID and GCMS. Test results also show that other gas constituents (NOx and/or H2O) can affect the methyl iodide reactions. With NOx and H2O present in the gas stream, the majority of uncaptured iodine exiting iodine-laden sorbent beds is in the form of I2 or HI, species that

  9. SYNTHESIS OF NOVEL CROWN ETHERS BEARING THE exo-cis-2,3-NORBORNYL GROUP AS POTENTIAL Na+ AND K+ EXTRACTANTS

    SciTech Connect (OSTI)

    Robeson, R.M.; Bonnesen, P.

    2007-01-01

    The synthesis of a series of novel dinorbornyl-16-crown-5 and dinorbornyl-18-crown-6 ethers that incorporate the exo-cis-2,3-norbornyl moiety within the macrocycle framework is described. The key starting material for the crown ethers, exo-cis-2,3-norbornanediol, was successfully prepared on a large (>30g) scale in 88% yield from norbornylene by osmium tetroxide-catalyzed hydroxylation. The syn and anti isomers of the dinorbornyl-16-crown-5 ether family were prepared using diethylene glycol with ring closure achieved using a methallyl linkage. The isomers cis-syn-cis and cis-anti-cis di-norbornano-15-methyleno-16-crown-5 (6A and 6B) could be separated using column chromatography, and a single crystal of the syn isomer 6A suitable for X-ray crystal structure analysis was obtained, thereby confi rming the syn orientation. The syn and anti isomers of the dinorbornyl-18-crown-6 ether family were successfully prepared employing a different synthetic strategy, involving the potassium–templated cyclization of two bis-hydroxyethoxy-substituted exo-cis-2,3-norbornyl groups under high dilution conditions. Attempts to fully separate cis-syn-cis di-norbornano-18-crown-6 (10A) and cis-anti-cis di-norbornano-18-crown-6 (10B) from one another using column chromatography were unsuccessful. All intermediates and products were checked for purity using either thin layer chromatography or gas chromatography, and characterized by proton and carbon NMR. Crown ethers 6AB and 10AB are to our knowledge the fi rst crown ethers to incorporate the exo-cis-2,3-norbornyl moiety into the crown ring to be successfully synthesized and characterized.

  10. Chemically induced Parkinson's disease: intermediates in the oxidation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine to the 1-methyl-4-phenyl-pyridinium ion

    SciTech Connect (OSTI)

    Chacon, J.N.; Chedekel, M.R.; Land, E.J.; Truscott, T.G.

    1987-04-29

    Various unstable intermediate oxidation states have been postulated in the metabolic activation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine to the 1-methyl-4-phenyl pyridinium ion. We now report the first direct observation of these free radical intermediates by pulse radiolysis and flash photolysis. Studies are described of various reactions of such species, in particular with dopamine whose autoxidation to dopamine quinone is reported to be potentiated by 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine.

  11. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    SciTech Connect (OSTI)

    Makarand R. Gogate; James J. Spivey; Joseph R. Zoeller; Richard D. Colberg; Gerald N. Choi; Samuel S. Tam

    1999-04-21

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter (January-March/99), in-situ formaldehyde generation and condensation with methyl propionate were tested over various catalysts and reaction conditions. The patent application is in preparation and the results are retained for future reports.

  12. Synthesis of 6-Methyl-9-n-propyldibenzothiophene-4-ol

    SciTech Connect (OSTI)

    Not Available

    1991-10-28

    The material presented here has been described to some extent in Status Reports 12, 13, and 14 and covers the progress toward the synthesis of the modified target molecules 9-isopropyl-4-methoxy-6-methyldibenzothiophene (13) and 9-isopropyl-6-methyldibenzothiophene-4-ol (14). It is divided into three parts: (a) Dehydrogenation experiments On tetrahydrodibenzothiophene 12. (b) methoxyl methyl cleavage of 13 to 14 using boron tribromide. (c) isolation and purification of methoxydibenzothiophene 13.

  13. "Seeing" Mercury Methylation in Progress

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

    Mercury in the environment can easily reach toxic levels. In a process called methylation, Hg is transformed into a form that can be accumulated in the muscle and fatty tissue of fish. Accumulated levels of methylmercury become higher as the fish grow, and levels are magnified up the food web as larger fish eat smaller fish, a process called biomagnification. As a result, mercury concentrations in fish can be millions of times higher than in surrounding waters [1]. Fish advisories have been set

  14. FY-2015 Methyl Iodide Deep-Bed Adsorption Test Report

    SciTech Connect (OSTI)

    Soelberg, Nicholas Ray; Watson, Tony Leroy

    2015-09-30

    Nuclear fission produces fission and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Deep-bed methyl iodide adsorption testing has continued in Fiscal Year 2015 according to a multi-laboratory methyl iodide adsorption test plan. Updates to the deep-bed test system have also been performed to enable the inclusion of evaporated HNO3 and increased NO2 concentrations in future tests. This report summarizes the result of those activities. Test results showed that iodine adsorption from gaseous methyl iodide using reduced silver zeolite (AgZ) resulted in initial iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) under 1,000 for the conditions of the long-duration test performed this year (45 ppm CH3I, 1,000 ppm each NO and NO2, very low H2O levels [3 ppm] in balance air). The mass transfer zone depth exceeded the cumulative 5-inch depth of 4 bed segments, which is deeper than the 2-4 inch depth estimated for the mass transfer zone for adsorbing I2 using AgZ in prior deep-bed tests. The maximum iodine adsorption capacity for the AgZ under the conditions of this test was 6.2% (6.2 g adsorbed I per 100 g sorbent). The maximum Ag utilization was 51%. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

  15. Exploratory study of coal-conversion chemistry. Quarterly report, June 20, 1980-September 19, 1980. [Diphenylmethane, diphenyl ether

    SciTech Connect (OSTI)

    Not Available

    1981-03-04

    This report describes work accomplished under two task: Task A, Mechanism of Cleavage of Key Bond types Present in Coals, and Task B, Catalysis of Conversion in CO-H/sub 2/O Systems. Under Task A, we have made additional measurements of catalytic carbon-carbon and carbon-oxygen bond cleavage in coal-related diphenylmethane and diphenyl ether structures. The results provide further support for, but do not definitely confirm, the tentative conclusion that the highly effective iron oxide catalysts involves oxidation to radical cation species. The homogeneous scission of carbon-oxygen bonds in diphenyl ether structure has also been studied. In the Task B studies of CO-H/sub 2/O systems, we typically obtain 50% benzene-soluble product material from 20 min. reaction of beneficiated Illinois No. 6 coal. This conversion level is obtained with aqueous solutions either at a starting pH above 12.6 or in neutral solutions with water-soluble catalysts present. We have studied a number of catalysts, including the potassium or sodium salts of molybdate, chromate, manganate, and tungstate; all are effective in the 3000 to 6000 ppM range. A striking result is that sodium nitrate at 6000 ppM is as effective as the metal salts. We found that the nitrate was converted to ammonium ion; also, formate was detected in the product aqueous phase. Finally, we find that catalytic quantities of sodium formate in CO/H/sub 2/O at pH 7 are effective in the conversion. However, in a control run in N/sub 2//H/sub 2/O, with a quantity of sodium formate equivalent to twice the molar quantity of hydrogen transferred to the coal in a successful run, the coal was converted to a product totally insoluble in benzene and with a lower hydrogen content than the starting coal.

  16. Solvent Modification in Ion-Pair Extraction: Effect on Sodium Nitrate Transport in Nitrobenzene Using a Crown Ether

    SciTech Connect (OSTI)

    Levitskaia, Tatiana G.; Lumetta, Gregg J.

    2005-10-31

    A comparative quantitative analysis of the effect of solvent modifiers on an ion-pair extraction of an inorganic salt by a crown ether was conducted. Two classes of the solvent modifiers that possess electron-pair donor (EPD) or hydrogen-bond donor (HBD) groups were investigated. The equilibrium constants corresponding to the extraction of sodium nitrate into nitrobenzene (NB) employing model neutral host cis-syn-cis-dicyclohexano-18-crown-6 (1) with and without solvent modifier were determined using the SXLSQI computer model. For a series of EPD modifiers—including tri-n-butyl- and tri-phenylphosphate, tri-n-butyl- and tri-phenylphosphine oxide, N,N-di-n-butyl- and N,N-di-phenyl acetamide—the enhancement of the NaNO3 extraction by 1 was found to be dependent on the hydrogen-bond acceptance ability of the modifier quantified by the b solvatochromic parameter. Application of the solvent EPD modifier improved solvation of the sodium ion, lowering the large energy barrier of Na+ partitioning into the extraction phase. A HBD modifier 3,5-di-t-butylphenol 8 that forms strong hydrogen bonds with nitrate anion in NB, exhibited even greater enhancement of the NaNO3 extraction by 1. The determined extraction constants were correlated with the b or a solvatochromic parameters of the solvent modifiers and linear trends were observed. Hydrogen bond interaction between 3,5-di-t-butylphenol 8 and nitrate anion in the presence of the sodium-loaded crown ether in the extraction phases was studied by vibrational spectroscopy. Formation of the simple 1:1 adduct was demonstrated.

  17. Vacuum ultraviolet and infrared spectra of condensed methyl acetate on cold astrochemical dust analogs

    SciTech Connect (OSTI)

    Sivaraman, B.; Nair, B. G.; Mason, N. J.; Lo, J.-I.; Cheng, B.-M.; Kundu, S.; Davis, D.; Prabhudesai, V.; Krishnakumar, E.; Raja Sekhar, B. N.

    2013-12-01

    Following the recent report of the first identification of methyl acetate (CH{sub 3}COOCH{sub 3}) in the interstellar medium (ISM), we have carried out vacuum ultraviolet (VUV) and infrared (IR) spectroscopy studies on methyl acetate from 10 K until sublimation in an ultrahigh vacuum chamber simulating astrochemical conditions. We present the first VUV and IR spectra of methyl acetate relevant to ISM conditions. Spectral signatures clearly showed molecular reorientation to have started in the ice by annealing the amorphous ice formed at 10 K. An irreversible phase change from amorphous to crystalline methyl acetate ice was found to occur between 110 K and 120 K.

  18. Phase 1 Methyl Iodide Deep-Bed Adsorption Tests (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    Tests established detection limits, developed procedures for sample analysis with minimal analytical interferences, and confirmed earlier results that show that the methyl iodide ...

  19. Exploring the roles of DNA methylation in the metal-reducing bacterium Shewanella oneidensis MR-1

    SciTech Connect (OSTI)

    Bendall, Matthew L.; Luong, Khai; Wetmore, Kelly M.; Blow, Matthew; Korlach, Jonas; Deutschbauer, Adam; Malmstrom, Rex

    2013-08-30

    We performed whole genome analyses of DNA methylation in Shewanella 17 oneidensis MR-1 to examine its possible role in regulating gene expression and 18 other cellular processes. Single-Molecule Real Time (SMRT) sequencing 19 revealed extensive methylation of adenine (N6mA) throughout the 20 genome. These methylated bases were located in five sequence motifs, 21 including three novel targets for Type I restriction/modification enzymes. The 22 sequence motifs targeted by putative methyltranferases were determined via 23 SMRT sequencing of gene knockout mutants. In addition, we found S. 24 oneidensis MR-1 cultures grown under various culture conditions displayed 25 different DNA methylation patterns. However, the small number of differentially 26 methylated sites could not be directly linked to the much larger number of 27 differentially expressed genes in these conditions, suggesting DNA methylation is 28 not a major regulator of gene expression in S. oneidensis MR-1. The enrichment 29 of methylated GATC motifs in the origin of replication indicate DNA methylation 30 may regulate genome replication in a manner similar to that seen in Escherichia 31 coli. Furthermore, comparative analyses suggest that many 32 Gammaproteobacteria, including all members of the Shewanellaceae family, may 33 also utilize DNA methylation to regulate genome replication.

  20. Evaluation of alternate routes for the synthesis of methyl methacrylate

    SciTech Connect (OSTI)

    Spivey, J.J.; Gogate, M.R.; Zoeller, J.R.; Colberg, R.D.; Choi, G.N.

    1998-12-31

    The use of coal-derived syngas to produce high value chemicals is an important means of upgrading this resource. One example of a chemical that can be produced from coal-derived syngas is methyl methacrylate (MMA). Poly-methyl methacrylate is widely used in coatings and in various industrial molded products. The most widely practiced commercial technology for the synthesis of MMA is the acetone cyanohydrin (ACH) process. This process requires handling of large quantities of toxic hydrogen cyanide and generates one mole of ammonium bisulfate waste per mole of MMA. This bisulfate must either be regenerated or discarded, either of which substantially increases the cost. The ACH technology is thus environmentally and economically untenable for any new MMA plant expansions that would be needed to meet increasing demand. The RTI-Eastman-Bechtel research team is developing an alternative, environmentally benign route to MMA consisting of three steps; (step 1) synthesis of a propionate from ethylene, carbon monoxide, and steam, (step 2) condensation of this propionate with formaldehyde, and (step 3) esterification of resulting methacrylic acid with methanol to form MMA. This paper describes the preliminary economics of the overall process compared to other emerging processes, and focuses on step 2, including long term testing of catalysts for the condensation of propionic acid with formaldehyde to form MAA.

  1. Catalytic Consequences of Acid Strength in the Conversion of Methanol to Dimethyl Ether

    SciTech Connect (OSTI)

    Carr, Robert T.; Neurock, Matthew; Iglesia, Enrique

    2011-02-14

    The effects of acid identity on CH{sub 3}OH dehydration are examined here using density functional theory (DFT) estimates of acid strength (as deprotonation energies, DPE) and reaction energies, combined with rate data on Keggin polyoxometalate (POM) clusters and zeolite H-BEA. Measured first-order (k{sub mono}) and zero-order (k{sub dimer}) CH3OH dehydration rate constants depend exponentially on DPE for POM clusters; the value of k{sub mono} depends more strongly on DPE than k{sub dimer} does. The chemical significance of these rate parameters and the basis for their dependences on acid strength were established by using DFT to estimate the energies of intermediates and transition states involved in elementary steps that are consistent with measured rate equations. We conclude from this treatment that CH{sub 3}OH dehydration proceeds via direct reactions of co-adsorbed CH{sub 3}OH molecules for relevant solid acids and reaction conditions. Methyl cations formed at ion-pair transition states in these direct routes are solvated by H{sub 2}O and CH{sub 3}OH more effectively than those in alternate sequential routes involving methoxide formation and subsequent reaction with CH{sub 3}OH. The stability of ion-pairs, prevalent as intermediates and transition states on solid acids, depends sensitively on DPE because of concomitant correlations between the stability of the conjugate anionic cluster and DPE. The chemical interpretation of k{sub mono} and k{sub dimer} from mechanism-based rate equations, together with thermochemical cycles of their respective transition state formations, show that similar charge distributions in the intermediate and transition state involved in k{sub dimer} cause its weaker dependence on DPE. Values of k{sub mono} involve uncharged reactants and the same ion-pair transition state as k{sub dimer}; these species sense acid strength differently and cause the larger effects of DPE on k{sub mono}. Confinement effects in H-BEA affect the value of

  2. Involvement of reactive oxygen species in brominated diphenyl ether-47-induced inflammatory cytokine release from human extravillous trophoblasts in vitro

    SciTech Connect (OSTI)

    Park, Hae-Ryung Kamau, Patricia W.; Loch-Caruso, Rita

    2014-01-15

    Polybrominated diphenyl ethers (PBDEs) are widely used flame retardant compounds. Brominated diphenyl ether (BDE)-47 is one of the most prevalent PBDE congeners found in human breast milk, serum and placenta. Despite the presence of PBDEs in human placenta, effects of PBDEs on placental cell function are poorly understood. The present study investigated BDE-47-induced reactive oxygen species (ROS) formation and its role in BDE-47-stimulated proinflammatory cytokine release in a first trimester human extravillous trophoblast cell line, HTR-8/SVneo. Exposure of HTR-8/SVneo cells for 4 h to 20 ?M BDE-47 increased ROS generation 1.7 fold as measured by the dichlorofluorescein (DCF) assay. Likewise, superoxide anion production increased approximately 5 fold at 10 and 15 ?M and 9 fold at 20 ?M BDE-47 with a 1-h exposure, as measured by cytochrome c reduction. BDE-47 (10, 15 and 20 ?M) decreased the mitochondrial membrane potential by 4764.5% at 4, 8 and 24 h as assessed with the fluorescent probe Rh123. Treatment with 15 and 20 ?M BDE-47 stimulated cellular release and mRNA expression of IL-6 and IL-8 after 12 and 24-h exposures: the greatest increases were a 35-fold increased mRNA expression at 12 h and a 12-fold increased protein concentration at 24 h for IL-6. Antioxidant treatments (deferoxamine mesylate, ()?-tocopherol, or tempol) suppressed BDE-47-stimulated IL-6 release by 54.1%, 56.3% and 37.7%, respectively, implicating a role for ROS in the regulation of inflammatory pathways in HTR-8/SVneo cells. Solvent (DMSO) controls exhibited statistically significantly decreased responses compared with non-treated controls for IL-6 release and IL-8 mRNA expression, but these responses were not consistent across experiments and times. Nonetheless, it is possible that DMSO (used to dissolve BDE-47) may have attenuated the stimulatory actions of BDE-47 on cytokine responses. Because abnormal activation of proinflammatory responses can disrupt trophoblast functions

  3. Changes in mitogen-activated protein kinase in cerebellar granule neurons by polybrominated diphenyl ethers and polychlorinated biphenyls

    SciTech Connect (OSTI)

    Fan Chunyang; Besas, Jonathan

    2010-05-15

    Polybrominated diphenyl ethers (PBDEs) are used as additive flame retardants and have been detected in human blood, adipose tissue, and breast milk. Both in vitro and in vivo studies have shown that the effects of PBDEs are similar to the known human developmental neurotoxicants such as polychlorinated biphenyls (PCBs) on a molar basis. Previously, we reported that PBDE mixtures and congeners, perturbed calcium homeostasis which is critical for the development and function of the nervous system. In the present study, we tested whether environmentally relevant PBDE/PCB mixtures and congeners affected mitogen-activated protein kinase (MAPK) pathways, which are down-stream events of calcium signaling in cerebellar granule neuronal cultures. In this study, phosphorylated extracellular signal-regulated kinase (pERK)1/2, a widely studied MAPK cascade and known to be involved in learning and memory, levels were quantitated using western blot technique with phospho-specific antibodies. Glutamate (a positive control) increased pERK1/2 in a time- and concentration-dependent manner reaching maximum activation at 5-30 min of exposure and at doses >= 10 muM. Both Aroclor 1254 (a commercial penta PCB mixture) and DE-71 (a commercial penta PBDE mixture) elevated phospho-ERK1/2, producing maximum stimulation at 30 min and at concentrations >= 3 mug/ml; Aroclor 1254 was more efficacious than DE-71. DE-79 (an octabrominated diphenyl ether mixture) also elevated phospho-ERK1/2, but to a lesser extent than that of DE-71. PBDE congeners 47, 77, 99, and 153 also increased phospo-ERK1/2 in a concentration-dependent manner. The data indicated that PBDE congeners are more potent than the commercial mixtures. PCB 47 also increased phospho-ERK1/2 like its structural analog PBDE 47, but to a lesser extent, suggesting that these chemicals affect similar pathways. Cytotoxicity, measured as %LDH release, data showed that higher concentrations (> 30 muM) and longer exposures (> 30 min) are

  4. Unexpected methyl migrations of ethanol dimer under synchrotron VUV radiation

    SciTech Connect (OSTI)

    Xiao, Weizhan; Hu, Yongjun E-mail: lssheng@ustc.edu.cn; Li, Weixing; Guan, Jiwen; Liu, Fuyi; Shan, Xiaobin; Sheng, Liusi E-mail: lssheng@ustc.edu.cn

    2015-01-14

    While methyl transfer is well known to occur in the enzyme- and metal-catalyzed reactions, the methyl transfer in the metal-free organic molecules induced by the photon ionization has been less concerned. Herein, vacuum ultraviolet single photon ionization and dissociation of ethanol dimer are investigated with synchrotron radiation photoionization mass spectroscopy and theoretical methods. Besides the protonated clusters cation (C{sub 2}H{sub 5}OH) ⋅ H{sup +} (m/z = 47) and the β-carbon-carbon bond cleavage fragment CH{sub 2}O ⋅ (C{sub 2}H{sub 5}OH)H{sup +} (m/z = 77), the measured mass spectra revealed that a new fragment (C{sub 2}H{sub 5}OH) ⋅ (CH{sub 3}){sup +} (m/z = 61) appeared at the photon energy of 12.1 and 15.0 eV, where the neutral dimer could be vertically ionized to higher ionic state. Thereafter, the generated carbonium ions are followed by a Wagner-Meerwein rearrangement and then dissociate to produce this new fragment, which is considered to generate after surmounting a few barriers including intra- and inter-molecular methyl migrations by the aid of theoretical calculations. The appearance energy of this new fragment is measured as 11.55 ± 0.05 eV by scanning photoionization efficiency curve. While the signal intensity of fragment m/z = 61 starts to increase, the fragments m/z = 47 and 77 tend to slowly incline around 11.55 eV photon energy. This suggests that the additional fragment channels other than (C{sub 2}H{sub 5}OH) ⋅ H{sup +} and CH{sub 2}O ⋅ (C{sub 2}H{sub 5}OH)H{sup +} have also been opened, which consume some dimer cations. The present report provides a clear description of the photoionization and dissociation processes of the ethanol dimer in the range of the photon energy 12-15 eV.

  5. Methyl-CpG island-associated genome signature tags

    DOE Patents [OSTI]

    Dunn, John J

    2014-05-20

    Disclosed is a method for analyzing the organismic complexity of a sample through analysis of the nucleic acid in the sample. In the disclosed method, through a series of steps, including digestion with a type II restriction enzyme, ligation of capture adapters and linkers and digestion with a type IIS restriction enzyme, genome signature tags are produced. The sequences of a statistically significant number of the signature tags are determined and the sequences are used to identify and quantify the organisms in the sample. Various embodiments of the invention described herein include methods for using single point genome signature tags to analyze the related families present in a sample, methods for analyzing sequences associated with hyper- and hypo-methylated CpG islands, methods for visualizing organismic complexity change in a sampling location over time and methods for generating the genome signature tag profile of a sample of fragmented DNA.

  6. High Temperature Chemical Kinetic Combustion Modeling of Lightly Methylated Alkanes

    SciTech Connect (OSTI)

    Sarathy, S M; Westbrook, C K; Pitz, W J; Mehl, M

    2011-03-01

    Conventional petroleum jet and diesel fuels, as well as alternative Fischer-Tropsch (FT) fuels and hydrotreated renewable jet (HRJ) fuels, contain high molecular weight lightly branched alkanes (i.e., methylalkanes) and straight chain alkanes (n-alkanes). Improving the combustion of these fuels in practical applications requires a fundamental understanding of large hydrocarbon combustion chemistry. This research project presents a detailed high temperature chemical kinetic mechanism for n-octane and three lightly branched isomers octane (i.e., 2-methylheptane, 3-methylheptane, and 2,5-dimethylhexane). The model is validated against experimental data from a variety of fundamental combustion devices. This new model is used to show how the location and number of methyl branches affects fuel reactivity including laminar flame speed and species formation.

  7. On the competition between hydrogen abstraction versus C-O bond fission in initiating dimethyl ether combustion

    SciTech Connect (OSTI)

    Francisco, J.

    1999-07-01

    There has been a growing interest in the potential use of dimethyl ether (DME) as a diesel fuel in compression ignition engines. There are two initiation steps involved in the combustion of DME, one involving C-O bond fission and the other involving hydrogen abstraction by molecular oxygen. The kinetics and thermodynamics of C-O bond fission were explored computationally in a previous paper. The present paper addresses the competing process--hydrogen abstraction by molecular oxygen. Ab initio molecular orbital calculations are used to study the structures and energetics of the reactants, products, and the transition state for the CH{sub 3}OCH{sub 3} + O{sub 2} reaction. The calculations predict a barrier for hydrogen abstraction from CH{sub 3}OCH{sub 3} by O{sub 2} of 47.4 kcal/mol. This is lower than the barrier height for C-O bond fission previously calculated to be 81.1 kcal/mol. The results support values used in current models for the combustion of DME. Moreover, an examination of rates for C-O bond fission versus hydrogen abstraction by O{sub 2} suggests that the bimolecular process is the dominant pathway.

  8. Calcitriol inhibits Ether-a go-go potassium channel expression and cell proliferation in human breast cancer cells

    SciTech Connect (OSTI)

    Garcia-Becerra, Rocio; Diaz, Lorenza; Camacho, Javier; Barrera, David; Ordaz-Rosado, David; Morales, Angelica; Ortiz, Cindy Sharon; Avila, Euclides; Bargallo, Enrique; Arrecillas, Myrna; Halhali, Ali; Larrea, Fernando

    2010-02-01

    Antiproliferative actions of calcitriol have been shown to occur in many cell types; however, little is known regarding the molecular basis of this process in breast carcinoma. Ether-a-go-go (Eag1) potassium channels promote oncogenesis and are implicated in breast cancer cell proliferation. Since calcitriol displays antineoplastic effects while Eag1 promotes tumorigenesis, and both factors antagonically regulate cell cycle progression, we investigated a possible regulatory effect of calcitriol upon Eag1 as a mean to uncover new molecular events involved in the antiproliferative activity of this hormone in human breast tumor-derived cells. RT real-time PCR and immunocytochemistry showed that calcitriol suppressed Eag1 expression by a vitamin D receptor (VDR)-dependent mechanism. This effect was accompanied by inhibition of cell proliferation, which was potentiated by astemizole, a nonspecific Eag1 inhibitor. Immunohistochemistry and Western blot demonstrated that Eag1 and VDR abundance was higher in invasive-ductal carcinoma than in fibroadenoma, and immunoreactivity of both proteins was located in ductal epithelial cells. Our results provide evidence of a novel mechanism involved in the antiproliferative effects of calcitriol and highlight VDR as a cancer therapeutic target for breast cancer treatment and prevention.

  9. Toxicity of polychlorinated diphenyl ethers in hydra attenuata and in rat whole-embryo culture. Master's thesis

    SciTech Connect (OSTI)

    Becker, M.C.

    1991-05-01

    Polychlorinated diphenyl ethers (PCDEs) are a class of biaryl compounds that have little commercial application, but appear to be widespread in the environment. They have been found in wood preservative waste dumpsites and in fly ash from municipal waste incinerators. They have been detected in bird eggs and tissues, fish, and other edible marine organisms in the United States, Canada, and Europe. There are limited reports in the extant literature on the toxicity of PCDEs. This study was designed to evaluate the toxicity of selected PCDEs in cultures of Hydra attenuata and post-implantation rat whole embryos. The toxicity of several closely related polychlorinated biphenyls (PCBs) was evaluated in both cultures and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was evaluated in whole embryo culture. Embryonic growth and development parameters (yolk sac diameter, crown-rump length, somite count, and DNA and protein content) and gross morphology were determined. Findings indicated that these chemicals were neither embryotoxic nor teratogenic. Thus, the PCDEs, which elicit other diverse toxic and biochemical responses in rodents, are relatively inactive in these bioassays for developmental toxicity.

  10. Electrochemical Investigation of Li–Al Anodes in Oligo(ethylene glycol) Dimethyl Ether/LiPF6

    SciTech Connect (OSTI)

    Zhou, Y.N.; Yang, X.; Wang, X.J.; Lee, H.S.; Nam, K.W.; Haas, O.

    2010-11-01

    1 M LiPF{sub 6} dissolved in oligo(ethylene glycol) dimethyl ether with a molecular weight 500 g mol{sup -1} was investigated as a new electrolyte (OEGDME500, 1 M LiPF{sub 6}) for metal deposition and battery applications. At 25 C a conductivity of 0.48 x 10{sup -3} S cm{sup -1} was obtained and at 85 C, 3.78 x 10{sup -3} S cm{sup -1}. The apparent activation barrier for ionic transport was evaluated to be 30.7 kJ mol{sup -1}. OEGDME500, 1 M LiPF{sub 6} allows operating temperature above 100 C with very attractive conductivity. The electrolyte shows excellent performance at negative and positive potentials. With this investigation, we report experimental results obtained with aluminum electrodes using this electrolyte. At low current densities lithium ion reduction and re-oxidation can be achieved on aluminum electrodes at potentials about 280 mV more positive than on lithium electrodes. In situ X-ray diffraction measurements collected during electrochemical lithium deposition on aluminum electrodes show that the shift to positive potentials is due to the negative Gibbs free energy change of the Li-Al alloy formation reaction.

  11. Electrochemical Investigation of Li-Al Anodes in Oligo (ethylene glycol) Dimethyl ether/LiPF6

    SciTech Connect (OSTI)

    Y Zhou; X Wang; H Lee; K Nam; X Yang; O Haas

    2011-12-31

    LiPF{sub 6} dissolved in oligo(ethylene glycol) dimethyl ether with a molecular weight 5 g mol{sup -1} was investigated as a new electrolyte (OEGDME5, 1 M LiPF{sub 6}) for metal deposition and battery applications. At 25 C a conductivity of .48 x 1{sup -3} S cm{sup -1} was obtained and at 85 C, 3.78 x 1{sup -3} S cm{sup -1}. The apparent activation barrier for ionic transport was evaluated to be 3.7 kJ mol{sup -1}. OEGDME5, 1 M LiPF{sub 6} allows operating temperature above 1 C with very attractive conductivity. The electrolyte shows excellent performance at negative and positive potentials. With this investigation, we report experimental results obtained with aluminum electrodes using this electrolyte. At low current densities lithium ion reduction and re-oxidation can be achieved on aluminum electrodes at potentials about 28 mV more positive than on lithium electrodes. In situ X-ray diffraction measurements collected during electrochemical lithium deposition on aluminum electrodes show that the shift to positive potentials is due to the negative Gibbs free energy change of the Li-Al alloy formation reaction.

  12. Heat Capacity Uncertainty Calculation for the Eutectic Mixture of Biphenyl/Diphenyl Ether Used as Heat Transfer Fluid: Preprint

    SciTech Connect (OSTI)

    Gomez, J. C.; Glatzmaier, G. C.; Mehos, M.

    2012-09-01

    The main objective of this study was to calculate the uncertainty at 95% confidence for the experimental values of heat capacity of the eutectic mixture of biphenyl/diphenyl ether (Therminol VP-1) determined from 300 to 370 degrees C. Twenty-five samples were evaluated using differential scanning calorimetry (DSC) to obtain the sample heat flow as a function of temperature. The ASTM E-1269-05 standard was used to determine the heat capacity using DSC evaluations. High-pressure crucibles were employed to contain the sample in the liquid state without vaporizing. Sample handling has a significant impact on the random uncertainty. It was determined that the fluid is difficult to handle, and a high variability of the data was produced. The heat capacity of Therminol VP-1 between 300 and 370 degrees C was measured to be equal to 0.0025T+0.8672 with an uncertainty of +/- 0.074 J/g.K (3.09%) at 95% confidence with T (temperature) in Kelvin.

  13. Global prevalence and distribution of genes and microorganisms involved in mercury methylation

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

    Podar, Mircea; Gilmour, C. C.; Brandt, Craig C.; Soren, Allyson; Brown, Steven D.; Crable, Bryan R.; Palumbo, Anthony Vito; Somenahally, Anil C.; Elias, Dwayne A.

    2015-01-01

    Mercury methylation produces the neurotoxic, highly bioaccumulative methylmercury (MeHg). Recent identification of the methylation genes (hgcAB) provides the foundation for broadly evaluating microbial Hg-methylation potential in nature without making explicit rate measurements. We first queried hgcAB diversity and distribution in all available microbial metagenomes, encompassing most environments. The genes were found in nearly all anaerobic, but not in aerobic, environments including oxygenated layers of the open ocean. Critically, hgcAB was effectively absent in ~1500 human microbiomes, suggesting a low risk of endogenous MeHg production. New potential methylation habitats were identified, including invertebrate guts, thawing permafrost, coastal dead zones, soils, sediments,more » and extreme environments, suggesting multiple routes for MeHg entry into food webs. Several new taxonomic groups potentially capable of Hg-methylation emerged, including lineages having no cultured representatives. We then begin to address long-standing evolutionary questions about Hg-methylation and ancient carbon fixation mechanisms while generating a new global view of Hg-methylation potential.« less

  14. Global prevalence and distribution of genes and microorganisms involved in mercury methylation

    SciTech Connect (OSTI)

    Podar, Mircea; Gilmour, C C; Brandt, Craig C; Bullock, Allyson L; Brown, Steven D; Crable, Bryan R; Palumbo, Anthony Vito; Somenahally, Anil C; Elias, Dwayne A

    2015-01-01

    Mercury methylation produces the neurotoxic, highly bioaccumulative methylmercury (MeHg). Recent identification of the methylation genes (hgcAB) provides the foundation for broadly evaluating microbial Hg-methylation potential in nature without making explicit rate measurements. We queried hgcAB diversity and distribution in all available microbial metagenomes, encompassing most environments. The genes were found in nearly all anaerobic, but not in aerobic, environments including oxygenated layers of the open ocean. Critically, hgcAB was effectively absent in ~1500 human microbiomes, suggesting a low risk of endogenous MeHg production. New potential methylation habitats were identified, including invertebrate guts, thawing permafrost, coastal dead zones , soils, sediments, and extreme environments, suggesting multiple routes for MeHg entry into food webs. Several new taxonomic groups potentially capable of Hg-methylation emerged, including lineages having no cultured representatives. We begin to address long-standing evolutionary questions about Hg-methylation and ancient carbon fixation mechanisms while generating a new global view of Hg-methylation potential.

  15. Global prevalence and distribution of genes and microorganisms involved in mercury methylation

    SciTech Connect (OSTI)

    Podar, Mircea; Gilmour, C. C.; Brandt, Craig C.; Soren, Allyson; Brown, Steven D.; Crable, Bryan R.; Palumbo, Anthony Vito; Somenahally, Anil C.; Elias, Dwayne A.

    2015-01-01

    Mercury methylation produces the neurotoxic, highly bioaccumulative methylmercury (MeHg). Recent identification of the methylation genes (hgcAB) provides the foundation for broadly evaluating microbial Hg-methylation potential in nature without making explicit rate measurements. We first queried hgcAB diversity and distribution in all available microbial metagenomes, encompassing most environments. The genes were found in nearly all anaerobic, but not in aerobic, environments including oxygenated layers of the open ocean. Critically, hgcAB was effectively absent in ~1500 human microbiomes, suggesting a low risk of endogenous MeHg production. New potential methylation habitats were identified, including invertebrate guts, thawing permafrost, coastal dead zones, soils, sediments, and extreme environments, suggesting multiple routes for MeHg entry into food webs. Several new taxonomic groups potentially capable of Hg-methylation emerged, including lineages having no cultured representatives. We then begin to address long-standing evolutionary questions about Hg-methylation and ancient carbon fixation mechanisms while generating a new global view of Hg-methylation potential.

  16. 1

    Office of Environmental Management (EM)

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

  17. Factors affecting the retention of methyl iodide by iodide-impregnated carbon

    SciTech Connect (OSTI)

    Hyder, M.L.; Malstrom, R.A.

    1990-12-31

    Iodide-impregnated activated carbon that had been in use for up to 30 months was studied to characterize those factors that affect its interaction with and retention of methyl iodide. Humidity and competing organic sorbents were observed to decrease the residence time of the methyl iodide on the carbon bed. Additionally, changes in the effective surface area and the loss of iodide from the surface are both important in determining the effectiveness of the carbon for retaining radioactive iodine from methyl iodide. A simple model incorporating both factors gave a fairly good fit to the experimental data.

  18. Factors affecting the retention of methyl iodide by iodide-impregnated carbon

    SciTech Connect (OSTI)

    Hyder, M.L.; Malstrom, R.A.

    1990-01-01

    Iodide-impregnated activated carbon that had been in use for up to 30 months was studied to characterize those factors that affect its interaction with and retention of methyl iodide. Humidity and competing organic sorbents were observed to decrease the residence time of the methyl iodide on the carbon bed. Additionally, changes in the effective surface area and the loss of iodide from the surface are both important in determining the effectiveness of the carbon for retaining radioactive iodine from methyl iodide. A simple model incorporating both factors gave a fairly good fit to the experimental data.

  19. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    SciTech Connect (OSTI)

    Makarand R. Gogate; James J. Spivey; Joseph R. Zoeller; Richard D. Colberg; Gerald N. Choi

    1999-07-19

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. During the April-June quarter(04-06/99) the first in-situ formaldehyde generation from DME and condensation with methyl propionate is demonstrated and the results are summarized. The supported niobium catalyst shows better condensation activity, but supported tungsten catalyst has higher formaldehyde selectivity. The project team has also completed a 200-hour long term test of PA-HCHO condensation over 30% Nb{sub 2}O{sub 5}/SiO{sub 2}. Three activity cycles and two regeneration cycles were carried out. 30% Nb{sub 2}O{sub 5}/SiO{sub 2} showed similar MAA yields as 10% Nb{sub 2}O{sub 5}/SiO{sub 2} at 300 C. However, the deactivation appears to be slower with 30% Nb{sub 2}O{sub 5}/SiO{sub 2} than 10% Nb{sub 2}O{sub 5}/SiO{sub 2}. An detailed economic analysis of PA-HCHO condensation process for a 250 million lb/yr MMA plant is currently studied by Bechtel. Using the Amoco data-based azeotropic distillation model as the basis, an ASPEN flow sheet model was constructed to simulate the formaldehyde and propionic acid condensation processing section based on RTI's design data. The RTI MAA effluent azeotropic distillation column was found to be much more difficult to converge. The presence of non-condensible gases along with the byproduct DEK (both of which were not presented in

  20. Thermochemistry of C-O, (CO)-O, and (CO)-C bond breaking in fatty acid methyl esters

    SciTech Connect (OSTI)

    Osmont, Antoine; Yahyaoui, Mohammed; Catoire, Laurent; Goekalp, Iskender; Swihart, Mark T.

    2008-10-15

    Density functional theory quantum chemical calculations corrected with empirical atomic increments have been used to examine C-O, (CO)-O, and (CO)-C bond scission enthalpies in gas-phase fatty acid methyl esters (FAMEs) present in biodiesel derived from rapeseed oil methyl ester and soybean oil methyl ester. Mechanistic information, currently not available elsewhere for these large species, is obtained based on thermochemical considerations and compared to thermochemical considerations reported for methyl butanoate, a small methyl ester sometimes used as a model for FAMEs. These results are compared to previously reported C-C and C-H bond scissions in these FAMEs, derived using this same protocol. (author)

  1. Synthesis of dimethyl ether and alternative fuels in the liquid phase from coal-derived synthesis gas

    SciTech Connect (OSTI)

    Bhatt, B.L.

    1992-09-01

    As part of the DOE-sponsored contract for the Synthesis of Dimethyl Ether (DME) and Alternative Fuels in the Liquid Phase from Coal- Derived Syngas, the single-step, slurry phase DME synthesis process was developed. The development involved screening of catalyst systems, process variable studies, and catalyst life studies in two 300 ml stirred autoclaves. As a spin-off of the Liquid Phase Methanol (LPMEOH*) process, the new process significantly improves the syngas conversion efficiency of the LPMEOH process. This improvement can be achieved by replacing a portion of methanol catalyst with a dehydration catalyst in the reactor, resulting in the product methanol being converted to DME, thus avoiding the thermodynamic equilibrium constraint of the methanol reaction. Overall, this increases syngas conversion per-pass. The selectivity and productivity of DME and methanol are affected by the catalyst system employed as well as operating conditions. A preferred catalyst system, consisting of a physical mixture of a methanol catalyst and a gamma alumina, was identified. An improvement of about 50% in methanol equivalent productivity was achieved compared to the LPMEOH process. Results from the process variable study indicate that higher pressure and CO[sub 2] removal benefit the process significantly. Limited life studies performed on the preferred catalyst system suggest somewhat higher than expected deactivation rate for the methanol catalyst. Several DME/methanol mixtures were measured for their key properties as transportation fuels. With small amounts of DME added, significant improvements in both flash points and Reid Vapor Pressure (RVP) were observed over the corresponding values of methanol alone.

  2. Auto-ignition during instationary jet evolution of dimethyl ether (DME) in a high-pressure atmosphere

    SciTech Connect (OSTI)

    Fast, G.; Kuhn, D.; Class, A.G.; Maas, U.

    2009-01-15

    The auto-ignition process during transient injection of gaseous dimethyl ether (DME) in a constant high-pressure atmosphere is studied experimentally by laser-optical methods and compared with numerical calculations. With different non-intrusive measurement techniques jet properties and auto-ignition are investigated at high temporal and spatial resolution. The open jet penetrates a constant pressure oxidative atmosphere of up to 4 MPa. During the transient evolution, the fuel jet entrains air at up to 720 K. The subsequent auto-ignition of the ignitable part of the jet occurs simultaneously over a wide spatial extension. The ignition delay times are not affected by variation of the nozzle exit velocity. Thus, the low-temperature oxidation is slow compared with the shorter time scales of mixing, so that chemical kinetics is dominating the process. The typical two-stage ignition is resolved optically with high-speed shadowgraphy at a sampling rate of 10 kHz. The 2D fields of jet velocity and transient mixture fraction are measured phase-coupled with Particle Image Velocimetry (PIV) and Tracer Laser Induced Fluorescence (LIF) during the time-frame of ignition. The instationary Probability Density Functions (PDF) of mixture fraction are described very well by Beta functions within the complete area of the open jet. Additional 1D flamelet simulations of the auto-ignition process are computed with a detailed reaction mechanism for DME [S. Fischer, F. Dryer, H. Curran, Int. J. Chem. Kinet. 32 (12) (2000) 713-740; H. Curran, S. Fischer, F. Dryer, Int. J. Chem. Kinet. 32 (12) (2000) 741-759]. Calculated ignition delay times are in very good agreement with the measured mean ignition delay times of 3 ms. Supplemental flamelet simulations address the influence of DME and air temperature, pressure and strain. Underneath a critical strain rate the air temperature is identified to be the most sensitive factor on ignition delay time. (author)

  3. Synthesis of Methyl Methacrylate from Coal-Derived Syngas

    SciTech Connect (OSTI)

    Gerald N. Choi; James J. Spivey; Jospeh R. Zoeller; Makarand R. Gogate; Richard D. Colberg; Samuel S. Tam

    1998-04-17

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. RTI has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, RTI is currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last month, RTI has finalized the design of a fixed-bed microreactor system for DME partial oxidation reactions. RTI incorporated some design changes to the feed blending system, so as to be able to blend varying proportions of DME and oxygen. RTI has also examined the flammability limits of DME-air mixtures. Since the lower flammability limit of DME in air is 3.6 volume percent, RTI will use a nominal feed composition of 1.6 percent in air, which is less than half the lower explosion limit for DME-air mixtures. This nominal feed composition is thus considered operationally safe, for DME partial oxidation reactions. RTI is also currently developing an analytical system for DME partial oxidation reaction system.

  4. Novel syngas-based process for methyl methacrylate

    SciTech Connect (OSTI)

    Gogate, M.R.; Spivey, J.J.; Zoeller, J.R.; Choi, G.N.; Tam, S.S.; Tischer, R.E.; Srivastava, R.D.

    1996-12-31

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel are developing a novel process for synthesis of methyl methacrylate (MMA) from coal-derived syngas, under a contract from the U.S. Department of Energy, Pittsburgh Energy Technology Center. This three-step process consists of synthesis of a propionate, its condensation with formaldehyde, and esterification of resulting methacrylic acid (MAA) with methanol to produce MMA. Eastman has focused on the research on propionate synthesis step. The resultant Mo catalysts work efficiently at much less severe conditions (170{degrees}C and 30 atm) than the conventional Ni catalysts (270{degrees}C and 180 atm). Bechtel has performed an extensive cost analysis, which shows that Eastman`s propionate synthesis process is competitive with other technologies to produce the anhydride. In the second step, RTI and Eastman have developed active and stable V-SI-P and Ta metal oxide catalysts for condensation reactions of propionates with formaldehyde. RTI has demonstrated a novel correlation among the catalyst acid-base properties, condensation reaction yield, and long-term catalyst activity. Current research focuses on enhancing the condensation reaction yields, acid-base properties, in situ condensation in a high- temperature, high-pressure (HTHP) slurry reactor, and alternate formaldehyde feedstocks. Based on Eastman and RTI laboratory reactor operating data, a cost estimate is also being developed for the integrated process.

  5. Optimized End-Stacking Provides Specificity of N-Methyl Mesoporphyrin...

    Office of Scientific and Technical Information (OSTI)

    Optimized End-Stacking Provides Specificity of N-Methyl Mesoporphyrin IX for Human Telomeric G-Quadruplex DNA Citation Details In-Document Search Title: Optimized End-Stacking ...

  6. Radio-methyl vorozole and methods for making and using the same

    DOE Patents [OSTI]

    Kim, Sung Won; Biegon, Anat; Fowler, Joanna S.

    2014-08-12

    Radiotracer vorozole compounds for in vivo and in vitro assaying, studying and imaging cytochrome P450 aromatase enzymes in humans, animals, and tissues and methods for making and using the same are provided. [N-radio-methyl] vorozole substantially separated from an N-3 radio-methyl isomer of vorozole is provided. Separation is accomplished through use of chromatography resins providing multiple mechanisms of selectivity.

  7. Radio-methyl vorozole and methods for making and using the same

    DOE Patents [OSTI]

    Kim, Sung Won; Biegon, Anat; Fowler, Joanna S.

    2014-08-05

    Radiotracer vorozole compounds for in vivo and in vitro assaying, studying and imaging cytochrome P450 aromatase enzymes in humans, animals, and tissues and methods for making and using the same are provided. [N-radio-methyl] vorozole substantially separated from an N-3 radio-methyl isomer of vorozole is provided. Separation is accomplished through use of chromatography resins providing multiple mechanisms of selectivity.

  8. Determination of Total Lipids as Fatty Acid Methyl Esters (FAME) by in situ

    Office of Scientific and Technical Information (OSTI)

    Transesterification: Laboratory Analytical Procedure (LAP) (Technical Report) | SciTech Connect Determination of Total Lipids as Fatty Acid Methyl Esters (FAME) by in situ Transesterification: Laboratory Analytical Procedure (LAP) Citation Details In-Document Search Title: Determination of Total Lipids as Fatty Acid Methyl Esters (FAME) by in situ Transesterification: Laboratory Analytical Procedure (LAP) This procedure is based on a whole biomass transesterification of lipids to fatty acid

  9. Experimental and Kinetic Modeling Study of Extinction and Ignition of Methyl Decanoate in Laminar Nonpremixed Flows

    SciTech Connect (OSTI)

    Seshadri, K; Lu, T; Herbinet, O; Humer, S; Niemann, U; Pitz, W J; Law, C K

    2008-01-09

    Methyl decanoate is a large methyl ester that can be used as a surrogate for biodiesel. In this experimental and computational study, the combustion of methyl decanoate is investigated in nonpremixed, nonuniform flows. Experiments are performed employing the counterflow configuration with a fuel stream made up of vaporized methyl decanoate and nitrogen, and an oxidizer stream of air. The mass fraction of fuel in the fuel stream is measured as a function of the strain rate at extinction, and critical conditions of ignition are measured in terms of the temperature of the oxidizer stream as a function of the strain rate. It is not possible to use a fully detailed mechanism for methyl decanoate to simulate the counterflow flames because the number of species and reactions is too large to employ with current flame codes and computer resources. Therefore a skeletal mechanism was deduced from a detailed mechanism of 8555 elementary reactions and 3036 species using 'directed relation graph' method. This skeletal mechanism has only 713 elementary reactions and 125 species. Critical conditions of ignition were calculated using this skeletal mechanism and are found to agree well with experimental data. The predicted strain rate at extinction is found to be lower than the measurements. In general, the methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.

  10. Synthesis of Methyl Methacrylate From Coal-Derived Syngas

    SciTech Connect (OSTI)

    Ben W.-L. Jang; Gerald N. Choi; James J. Spivey; Jospeh R. Zoeller; Richard D. Colberg; Samuel S. Tam

    1998-07-27

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. RTI has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, RTI is currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter(April-June, 1998), RTI has modified the reactor system including a new preheater and new temperature settings for the preheater. Continuous condensation of formaldehyde with propionic acid were carried out over 10% Nb O /SiO at 300°C without 2 5 2 interruption. Five activity and four regeneration cycles have been completed without plugging or material balance problems. The results show that 10% Nb O /SiO deactivates slowly with time 2 5 2 but can be regenerated, at least four times, to 100% of its original activity with 2% O in nitrogen 2 at 400°C. The cycles continue with consistent 90-95% of carbon balance. The reaction is scheduled to complete with 6 activity cycles and 5 regenerations. Used catalysts will be analyzed with TGA and XPS to determine bulk and surface coke content and coke properties. RTI will start the investigation of effects of propionic acid/formaldehyde ratio on reaction activity and product selectivity over 20% Nb O /SiO catalysts.