National Library of Energy BETA

Sample records for ash impurities consisting

  1. Self-pumping impurity control

    DOE Patents [OSTI]

    Brooks, J.N.; Mattas, R.F.

    1983-12-21

    It is an object of the present invention to provide an apparatus for removing impurities from the plasma in a fusion reactor without an external vacuum pumping system. It is also an object of the present invention to provide an apparatus for removing the helium ash from a fusion reactor. It is another object of the present invention to provide an apparatus which removes helium ash and minimizes tritium recycling and inventory.

  2. Fluidized bed gasification ash reduction and removal process

    DOE Patents [OSTI]

    Schenone, Carl E.; Rosinski, Joseph

    1984-12-04

    In a fluidized bed gasification system an ash removal system to reduce the particulate ash to a maximum size or smaller, allow the ash to cool to a temperature lower than the gasifier and remove the ash from the gasifier system. The system consists of a crusher, a container containing level probes and a means for controlling the rotational speed of the crusher based on the level of ash within the container.

  3. Fluidized bed gasification ash reduction and removal system

    DOE Patents [OSTI]

    Schenone, Carl E.; Rosinski, Joseph

    1984-02-28

    In a fluidized bed gasification system an ash removal system to reduce the particulate ash to a maximum size or smaller, allow the ash to cool to a temperature lower than the gasifier and remove the ash from the gasifier system. The system consists of a crusher, a container containing level probes and a means for controlling the rotational speed of the crusher based on the level of ash within the container.

  4. ITER helium ash accumulation

    SciTech Connect (OSTI)

    Hogan, J.T.; Hillis, D.L.; Galambos, J.; Uckan, N.A. ); Dippel, K.H.; Finken, K.H. . Inst. fuer Plasmaphysik); Hulse, R.A.; Budny, R.V. . Plasma Physics Lab.)

    1990-01-01

    Many studies have shown the importance of the ratio {upsilon}{sub He}/{upsilon}{sub E} in determining the level of He ash accumulation in future reactor systems. Results of the first tokamak He removal experiments have been analysed, and a first estimate of the ratio {upsilon}{sub He}/{upsilon}{sub E} to be expected for future reactor systems has been made. The experiments were carried out for neutral beam heated plasmas in the TEXTOR tokamak, at KFA/Julich. Helium was injected both as a short puff and continuously, and subsequently extracted with the Advanced Limiter Test-II pump limiter. The rate at which the He density decays has been determined with absolutely calibrated charge exchange spectroscopy, and compared with theoretical models, using the Multiple Impurity Species Transport (MIST) code. An analysis of energy confinement has been made with PPPL TRANSP code, to distinguish beam from thermal confinement, especially for low density cases. The ALT-II pump limiter system is found to exhaust the He with maximum exhaust efficiency (8 pumps) of {approximately}8%. We find 1<{upsilon}{sub He}/{upsilon}{sub E}<3.3 for the database of cases analysed to date. Analysis with the ITER TETRA systems code shows that these values would be adequate to achieve the required He concentration with the present ITER divertor He extraction system.

  5. Impurity gettering in semiconductors

    DOE Patents [OSTI]

    Sopori, Bhushan L.

    1995-01-01

    A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500.degree. C. to about 700.degree. C. for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal.

  6. Impurity gettering in semiconductors

    DOE Patents [OSTI]

    Sopori, B.L.

    1995-06-20

    A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device is disclosed. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500 C to about 700 C for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal. 1 fig.

  7. Dynamical impurity problems

    SciTech Connect (OSTI)

    Emery, V.J.; Kivelson, S.A.

    1993-12-31

    In the past few years there has been a resurgence of interest in dynamical impurity problems, as a result of developments in the theory of correlated electron systems. The general dynamical impurity problem is a set of conduction electrons interacting with an impurity which has internal degrees of freedom. The simplest and earliest example, the Kondo problem, has attracted interest since the mid-sixties not only because of its physical importance but also as an example of a model displaying logarithmic divergences order by order in perturbation theory. It provided one of the earliest applications of the renormalization group method, which is designed to deal with just such a situation. As we shall see, the antiferromagnetic Kondo model is controlled by a strong-coupling fixed point, and the essence of the renormalization group solution is to carry out the global renormalization numerically starting from the original (weak-coupling) Hamiltonian. In these lectures, we shall describe an alternative route in which we identify an exactly solvable model which renormalizes to the same fixed point as the original dynamical impurity problem. This approach is akin to determining the critical behavior at a second order phase transition point by solving any model in a given universality class.

  8. Activation of fly ash

    DOE Patents [OSTI]

    Corbin, David R.; Velenyi, Louis J.; Pepera, Marc A.; Dolhyj, Serge R.

    1986-01-01

    Fly ash is activated by heating a screened magnetic fraction of the ash in a steam atmosphere and then reducing, oxidizing and again reducing the hydrothermally treated fraction. The activated fly ash can be used as a carbon monoxide disproportionating catalyst useful in the production of hydrogen and methane.

  9. Activation of fly ash

    DOE Patents [OSTI]

    Corbin, D.R.; Velenyi, L.J.; Pepera, M.A.; Dolhyj, S.R.

    1986-08-19

    Fly ash is activated by heating a screened magnetic fraction of the ash in a steam atmosphere and then reducing, oxidizing and again reducing the hydrothermally treated fraction. The activated fly ash can be used as a carbon monoxide disproportionating catalyst useful in the production of hydrogen and methane.

  10. Fly ash carbon passivation

    DOE Patents [OSTI]

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  11. Effect of fuel properties on the bottom ash generation rate by a laboratory fluidized bed combustor

    SciTech Connect (OSTI)

    Rozelle, P.L.; Pisupati, S.V.; Scaroni, A.W.

    2007-06-15

    The range of fuels that can be accommodated by an FBC boiler system is affected by the ability of the fuel, sorbent, and ash-handling equipment to move the required solids through the boiler. Of specific interest is the bottom ash handling equipment, which must have sufficient capacity to remove ash from the system in order to maintain a constant bed inventory level, and must have sufficient capability to cool the ash well below the bed temperature. Quantification of a fuel's bottom ash removal requirements can be useful for plant design. The effect of fuel properties on the rate of bottom ash production in a laboratory FBC test system was examined. The work used coal products ranging in ash content from 20 to 40+ wt. %. The system's classification of solids by particle size into flyash and bottom ash was characterized using a partition curve. Fuel fractions in the size range characteristic of bottom ash were further analyzed for distributions of ash content with respect to specific gravity, using float sink tests. The fuel fractions were then ashed in a fixed bed. In each case, the highest ash content fraction produced ash with the coarsest size consist (characteristic of bottom ash). The lower ash content fractions were found to produce ash in the size range characteristic of flyash, suggesting that the high ash content fractions were largely responsible for the production of bottom ash. The contributions of the specific gravity fractions to the composite ash in the fuels were quantified. The fuels were fired in the laboratory test system. Fuels with higher amounts of high specific gravity particles, in the size ranges characteristic of bottom ash, were found to produce more bottom ash, indicating the potential utility of float sink methods in the prediction of bottom ash removal requirements.

  12. Fundamental Study of Low NOx Combustion Fly Ash Utilization

    SciTech Connect (OSTI)

    E. M. Suubert; I. Kuloats; K. Smith; N. Sabanegh; R.H. Hurt; W. D. Lilly; Y. M. Gao

    1997-05-01

    This study is principally concerned with characterizing the organic part of coal combustion fly ashes. High carbon fly ashes are becoming more common as by-products of low-NOx combustion technology, and there is need to learn more about this fraction of the fly ash. The project team consists of two universities, Brown and Princeton, and an electrical utility, New England Power. A sample suite of over forty fly ashes has been gathered from utilities across the United States, and includes ashes from a coals ranging in rank from bituminous to lignite. The characterizations of these ashes include standard tests (LOI, Foam Index), as well as more detailed characterizations of their surface areas, porosity, extractability and adsorption behavior. The ultimate goal is, by better characterizing the material, to enable broadening the range of applications for coal fly ash re-use beyond the current main market as a pozzolanic agent for concretes. The potential for high carbon-content fly ashes to substitute for activated carbons is receiving particular attention. The work performed to date has already revealed how very different the surfaces of different ashes produced by the same utility can be, with respect to polarity of the residual carbon. This can help explain the large variations in acceptability of these ashes as concrete additives.

  13. Fundamental Study of Low-Nox Combustion Fly Ash Utilization

    SciTech Connect (OSTI)

    E. M. Suuberg; I. Kuloats; K. Smith; N. Sabanegh; R. H. Hurt; W. D. Lilly; Y. M. Gao

    1997-11-01

    This study is principally concerned with characterizing the organic part of coal combustion fly ashes. High carbon fly ashes are becoming more common as by-products of low-NOx combustion technology, and there is need to learn more about this fraction of the fly ash. The project team consists of two universities, Brown and Princeton, and an electrical utility, New England Power. A sample suite of over forty fly ashes has been gathered from utilities across the United States, and includes ashes from a coals ranging in rank from bituminous to lignite. The characterizations of these ashes include standard tests (LOI, Foam Index), as well as more detailed characterizations of their surface areas, porosity, extractability and adsorption behavior. The ultimate goal is, by better characterizing the material, to enable broadening the range of applications for coal fly ash re-use beyond the current main market as a pozzolanic agent for concretes. The potential for high carbon-content fly ashes to substitute for activated carbons is receiving particular attention. The work performed to date has already revealed how very different the surfaces of different ashes produced by the same utility can be, with respect to polarity of the residual carbon. This can help explain the large variations in acceptability of these ashes as concrete additives.

  14. Quantitative ion-exchange separation of plutonium from impurities

    SciTech Connect (OSTI)

    Pietri, C.E.; Freeman, B.P.; Weiss, J.R.

    1981-09-01

    The methods used at the New Brunswick Laboratory for the quantitative ion exchange separation of plutonium from impurities prior to plutonium assay are described. Other ion exchange separation procedures for impurity determination and for isotopic abundance measurements are given. The primary technique used consists of sorption of plutonium(IV) in 8N HNO/sub 3/ on Dowex-1 anion exchange resin and elution of the purified plutonium with 0.3N HCl-0.01N HF. Other methods consist of the anion exchange separation of plutonium(IV) in 12N HCl and the cation exchange separation of plutonium(III) in 0.2 N HNO/sub 3/. The application of these procedures to the subsequent assay of plutonium, isotopic analysis, and impurity determination is described.

  15. Steady-state tokamak reactor with non-divertor impurity control: STARFIRE

    SciTech Connect (OSTI)

    Baker, C.C.

    1980-01-01

    STARFIRE is a conceptual design study of a commercial tokamak fusion electric power plant. Particular emphasis has been placed on simplifying the reactor concept by developing design concepts to produce a steady-state tokamak with non-divertor impurity control and helium ash removal. The concepts of plasma current drive using lower hybrid rf waves and a limiter/vacuum system for reactor applications are described.

  16. Engineering Model for Ash Formation

    Energy Science and Technology Software Center (OSTI)

    1994-12-02

    Ash deposition is controlled by the impaction and sticking of individual ash particles to heat transfer surfaces. Prediction of deposition therefore requires that the important factors in this process be predictable from coal and operational parameters. Coal combustion, boiler heat transfer, ash formation, ash particle aerodynamic, and ash particle sticking models are all essential steps in this process. The model described herein addresses the prediction of ash particle size and composition distributions based upon combustionmore » conditions and coal parameters. Key features of the model include a mineral redistribution routine to invert CCSEM mineralogical data, and a mineral interaction routine that simulates the conversion of mineral matter into ash during coal burning and yields ash particle size and composition distributions.« less

  17. Impurity gettering in silicon using cavities formed by helium implantation and annealing

    DOE Patents [OSTI]

    Myers, S.M. Jr.; Bishop, D.M.; Follstaedt, D.M.

    1998-11-24

    Impurity gettering in silicon wafers is achieved by a new process consisting of helium ion implantation followed by annealing. This treatment creates cavities whose internal surfaces are highly chemically reactive due to the presence of numerous silicon dangling bonds. For two representative transition-metal impurities, copper and nickel, the binding energies at cavities were demonstrated to be larger than the binding energies in precipitates of metal silicide, which constitutes the basis of most current impurity gettering. As a result the residual concentration of such impurities after cavity gettering is smaller by several orders of magnitude than after precipitation gettering. Additionally, cavity gettering is effective regardless of the starting impurity concentration in the wafer, whereas precipitation gettering ceases when the impurity concentration reaches a characteristic solubility determined by the equilibrium phase diagram of the silicon-metal system. The strong cavity gettering was shown to induce dissolution of metal-silicide particles from the opposite side of a wafer. 4 figs.

  18. Impurity gettering in silicon using cavities formed by helium implantation and annealing

    DOE Patents [OSTI]

    Myers, Jr., Samuel M.; Bishop, Dawn M.; Follstaedt, David M.

    1998-01-01

    Impurity gettering in silicon wafers is achieved by a new process consisting of helium ion implantation followed by annealing. This treatment creates cavities whose internal surfaces are highly chemically reactive due to the presence of numerous silicon dangling bonds. For two representative transition-metal impurities, copper and nickel, the binding energies at cavities were demonstrated to be larger than the binding energies in precipitates of metal silicide, which constitutes the basis of most current impurity gettering. As a result the residual concentration of such impurities after cavity gettering is smaller by several orders of magnitude than after precipitation gettering. Additionally, cavity gettering is effective regardless of the starting impurity concentration in the wafer, whereas precipitation gettering ceases when the impurity concentration reaches a characteristic solubility determined by the equilibrium phase diagram of the silicon-metal system. The strong cavity gettering was shown to induce dissolution of metal-silicide particles from the opposite side of a wafer.

  19. Control of impurities in toroidal plasma devices

    DOE Patents [OSTI]

    Ohkawa, Tihiro (La Jolla, CA)

    1980-01-01

    A method and apparatus for plasma impurity control in closed flux plasma systems such as Tokamak reactors is disclosed. Local axisymmetrical injection of hydrogen gas is employed to reverse the normally inward flow of impurities into the plasma.

  20. Screening technology reduces ash in spiral circuits

    SciTech Connect (OSTI)

    Brodzik, P.

    2007-05-15

    In 2006, the James River Coal Co. selected the Stack Sizer to remove the minus 100 mesh high ash clay fraction from the clean coal spiral product circuits at the McCoy-Elkhorn Bevins Branch prep plant and at the Blue Diamond Leatherwood prep plant in Kentucky. The Stack Sizer is a multi-deck, high-frequency vibrating screen capable of separations as fine as 75 microns when fitted with Derrick Corp.'s patented high open area urethane screen panels. Full-scale lab tests and more than 10 months of continuous production have confirmed that the Stack Sizer fitted with Derrick 100 micron urethane screen panels consistently produces a clean coal fraction that ranges from 8 to 10% ash. Currently, each five-deck Stack Sizer operating at the Bevins Branch and Leatherwood prep plants is producing approximately 33 tons per hour of clean coal containing about 9% ash. This represents a clean coal yield of about 75% and an ash reduction of about 11% from the feed slurry. 3 figs. 2 tabs.

  1. Modeling volcanic ash dispersal

    ScienceCinema (OSTI)

    None

    2011-10-06

    Explosive volcanic eruptions inject into the atmosphere large amounts of volcanic material (ash, blocks and lapilli). Blocks and larger lapilli follow ballistic and non-ballistic trajectories and fall rapidly close to the volcano. In contrast, very fine ashes can remain entrapped in the atmosphere for months to years, and may affect the global climate in the case of large eruptions. Particles having sizes between these two end-members remain airborne from hours to days and can cover wide areas downwind. Such volcanic fallout entails a serious threat to aircraft safety and can create many undesirable effects to the communities located around the volcano. The assessment of volcanic fallout hazard is an important scientific, economic, and political issue, especially in densely populated areas. From a scientific point of view, considerable progress has been made during the last two decades through the use of increasingly powerful computational models and capabilities. Nowadays, models are used to quantify hazard scenarios and/or to give short-term forecasts during emergency situations. This talk will be focused on the main aspects related to modeling volcanic ash dispersal and fallout with application to the well known problem created by the Eyjafjöll volcano in Iceland. Moreover, a short description of the main volcanic monitoring techniques is presented.

  2. Self-pumping impurity control

    DOE Patents [OSTI]

    Brooks, Jeffrey N.; Mattas, Richard F.

    1991-01-01

    Apparatus for removing the helium ash from a fusion reactor having a D-T plasma comprises a helium trapping site within the reactor plasma confinement device, said trapping site being formed of a trapping material having negligible helium solubility and relatively high hydrogen solubility; and means for depositing said trapping material on said site at a rate sufficient to prevent saturation of helium trapping.

  3. Gaseous trace impurity analyzer and method

    DOE Patents [OSTI]

    Edwards, Jr., David (Bellport, NY); Schneider, William (Setauket, NY)

    1980-01-01

    Simple apparatus for analyzing trace impurities in a gas, such as helium or hydrogen, comprises means for drawing a measured volume of the gas as sample into a heated zone. A segregable portion of the zone is then chilled to condense trace impurities in the gas in the chilled portion. The gas sample is evacuated from the heated zone including the chilled portion. Finally, the chilled portion is warmed to vaporize the condensed impurities in the order of their boiling points. As the temperature of the chilled portion rises, pressure will develop in the evacuated, heated zone by the vaporization of an impurity. The temperature at which the pressure increase occurs identifies that impurity and the pressure increase attained until the vaporization of the next impurity causes a further pressure increase is a measure of the quantity of the preceding impurity.

  4. Distribution of arsenic and mercury in lime spray dryer ash

    SciTech Connect (OSTI)

    Panuwat Taerakul; Ping Sun; Danold W. Golightly; Harold W. Walker; Linda K. Weavers

    2006-08-15

    The partitioning of As and Hg in various components of lime spray dryer (LSD) ash samples from a coal-fired boiler was characterized to better understand the form and fate of these elements in flue gas desulfurization byproducts. LSD ash samples, collected from the McCracken Power Plant on the Ohio State University campus, were separated by a 140-mesh (106 {mu}m) sieve into two fractions: a fly-ash-/unburned-carbon-enriched fraction (> 106 {mu}m) and a calcium-enriched fraction (< 106 {mu}m). Unburned carbon and fly ash in the material > 106 {mu}m were subsequently separated by density using a lithium heteropolytungstate solution. The concentrations of As and Hg were significant in all fractions. The level of As was consistently greater in the calcium-enriched fraction, while Hg was evenly distributed in all components of LSD ash. Specific surface area was an important factor controlling the distribution of Hg in the different components of LSD ash, but not for As. Comparing the LSD ash data to samples collected from the economizer suggests that As was effectively captured by fly ash at 600{sup o}C, while Hg was not. Leaching tests demonstrated that As and Hg were more stable in the calcium-enriched fraction than in the fly-ash- or carbon-enriched fractions, potentially because of the greater pH of the leachate and subsequently greater stability of small amounts of calcium solids containing trace elements in these fractions. 37 refs., 8 figs., 2 tabs.

  5. Impurity-induced divertor plasma oscillations

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

    Smirnov, R. D.; Kukushkin, A. S.; Krasheninnikov, S. I.; Pigarov, A. Yu.; Rognlien, T. D.

    2016-01-07

    Two different oscillatory plasma regimes induced by seeding the plasma with high- and low-Z impurities are found for ITER-like divertor plasmas, using computer modeling with the DUSTT/UEDGE and SOLPS4.3 plasma-impurity transport codes. The oscillations are characterized by significant variations of the impurity-radiated power and of the peak heat load on the divertor targets. Qualitative analysis of the divertor plasma oscillations reveals different mechanisms driving the oscillations in the cases of high- and low-Z impurity seeding. The oscillations caused by the high-Z impurities are excited near the X-point by an impurity-related instability of the radiation-condensation type, accompanied by parallel impurity ionmore » transport affected by the thermal and plasma friction forces. The driving mechanism of the oscillations induced by the low-Z impurities is related to the cross-field transport of the impurity atoms, causing alteration between the high and low plasma temperature regimes in the plasma recycling region near the divertor targets. As a result, the implications of the impurity-induced plasma oscillations for divertor operation in the next generation tokamaks are also discussed.« less

  6. Optical properties of fly ash. Volume 2, Final report

    SciTech Connect (OSTI)

    Self, S.A.

    1994-12-01

    Research performed under this contract was divided into four tasks under the following headings: Task 1, Characterization of fly ash; Task 2, Measurements of the optical constants of slags; Task 3, Calculations of the radiant properties of fly ash dispersions; and Task 4, Measurements of the radiant properties of fly ash dispersions. Tasks 1 and 4 constituted the Ph.D. research topic of Sarbajit Ghosal, while Tasks 2 and 3 constituted the Ph.D. research topic of Jon Ebert. Together their doctoral dissertations give a complete account of the work performed. This final report, issued in two volumes consists of an executive summary of the whole program followed by the dissertation of Ghosal and Ebert. Volume 2 contains the dissertation of Ebert which covers the measurements of the optical constants of slags, and calculations of the radiant properties of fly ash dispersions. A list of publications and conference presentations resulting from the work is also included.

  7. Fly ash quality and utilization

    SciTech Connect (OSTI)

    Barta, L.E.; Lachner, L.; Wenzel, G.B.; Beer, M.J.

    1995-12-01

    The quality of fly ash is of considerable importance to fly ash utilizers. The fly ash puzzolanic activity is one of the most important properties that determines the role of fly ash as a binding agent in the cementing process. The puzzolanic activity, however is a function of fly ash particle size and chemical composition. These parameters are closely related to the process of fly ash formation in pulverized coal fired furnaces. In turn, it is essential to understand the transformation of mineral matter during coal combustion. Due to the particle-to-particle variation of coal properties and the random coalescence of mineral particles, the properties of fly ash particles e.g. size, SiO{sub 2} content, viscosity can change considerably from particle to particle. These variations can be described by the use of the probability theory. Since the mean values of these randomly changing parameters are not sufficient to describe the behavior of individual fly ash particles during the formation of concrete, therefore it is necessary to investigate the distribution of these variables. Examples of these variations were examined by the Computer Controlled Scanning Electron Microscopy (CCSEM) for particle size and chemical composition for Texas lignite and Eagel Butte mineral matter and fly ash. The effect of combustion on the variations of these properties for both the fly ash and mineral matter were studied by using a laminar flow reactor. It is shown in our paper, that there are significant variations (about 40-50% around the mean values) of the above-listed properties for both coal samples. By comparing the particle size and chemical composition distributions of the mineral matter and fly ash, it was possible to conclude that for the Texas lignite mineral matter, the combustion did not effect significantly the distribution of these properties, however, for the Eagel Butte coal the combustion had a major impact on these mineral matter parameters.

  8. Impact of Biodiesel Impurities on the Performance and Durability of DOC, DPF and SCR Technologies: Preprint

    SciTech Connect (OSTI)

    Williams, A.; McCormick, R.; Luecke, J.; Brezny, R.; Geisselmann, A.; Voss, K.; Hallstrom, K.; Leustek, M.; Parsons, J.; Abi-Akar, H.

    2011-04-01

    An accelerated durability test method determined the potential impact of biodiesel ash impurities, including engine testing with multiple diesel particulate filter substrate types, as well as diesel oxidation catalyst and selective catalyst reduction catalysts. The results showed no significant degradation in the thermo-mechanical properties of a DPF after exposure to 150,000-mile equivalent biodiesel ash and thermal aging. However, exposure to 435,000-mile equivalent aging resulted in a 69% decrease in thermal shock resistance. A decrease in DOC activity was seen after exposure to 150,000-mile equivalent aging, resulting in higher hydrocarbon slip and a reduction in NO2 formation. The SCR catalyst experienced a slight loss in activity after exposure to 435,000-mile equivalent aging. The SCR catalyst, placed downstream of the DPF and exposed to B20 exhaust suffered a 5% reduction in overall NOx conversion activity over the HDDT test cycle. It is estimated that the additional ash from 150,000 miles of biodiesel use would also result in a moderate increases in exhaust backpressure for a DPF. The results of this study suggest that long-term operation with B20 at the current specification limits for alkali and alkaline earth metal impurities will adversely impact the performance of DOC, DPF and SCR systems.

  9. Impurity-induced moments in underdoped cuprates

    SciTech Connect (OSTI)

    Khaliullin, G.; Kilian, R.; Krivenko, S.; Fulde, P.

    1997-11-01

    We examine the effect of a nonmagnetic impurity in a two-dimensional spin liquid in the spin-gap phase, employing a drone-fermion representation of spin-1/2 operators. The properties of the local moment induced in the vicinity of the impurity are investigated and an expression for the nuclear-magnetic-resonance Knight shift is derived, which we compare with experimental results. Introducing a second impurity into the spin liquid an antiferromagnetic interaction between the moments is found when the two impurities are located on different sublattices. The presence of many impurities leads to a screening of this interaction as is shown by means of a coherent-potential approximation. Further, the Kondo screening of an impurity-induced local spin by charge carriers is discussed. {copyright} {ital 1997} {ital The American Physical Society}

  10. Incineration and incinerator ash processing

    SciTech Connect (OSTI)

    Blum, T.W.

    1991-01-01

    Parallel small-scale studies on the dissolution and anion exchange recovery of plutonium from Rocky Flats Plant incinerator ash were conducted at the Los Alamos National Laboratory and at the Rocky Flats Plant. Results from these two studies are discussed in context with incinerator design considerations that might help to mitigate ash processing related problems. 11 refs., 1 fig., 1 tab.

  11. Method for detecting trace impurities in gases

    DOE Patents [OSTI]

    Freund, Samuel M.; Maier, II, William B.; Holland, Redus F.; Beattie, Willard H.

    1981-01-01

    A technique for considerably improving the sensitivity and specificity of infrared spectrometry as applied to quantitative determination of trace impurities in various carrier or solvent gases is presented. A gas to be examined for impurities is liquefied and infrared absorption spectra of the liquid are obtained. Spectral simplification and number densities of impurities in the optical path are substantially higher than are obtainable in similar gas-phase analyses. Carbon dioxide impurity (.about.2 ppm) present in commercial Xe and ppm levels of Freon 12 and vinyl chloride added to liquefied air are used to illustrate the method.

  12. Method for detecting trace impurities in gases

    DOE Patents [OSTI]

    Freund, S.M.; Maier, W.B. II; Holland, R.F.; Beattie, W.H.

    A technique for considerably improving the sensitivity and specificity of infrared spectrometry as applied to quantitative determination of trace impurities in various carrier or solvent gases is presented. A gas to be examined for impurities is liquefied and infrared absorption spectra of the liquid are obtained. Spectral simplification and number densities of impurities in the optical path are substantially higher than are obtainable in similar gas-phase analyses. Carbon dioxide impurity (approx. 2 ppM) present in commercial Xe and ppM levels of Freon 12 and vinyl chloride added to liquefied air are used to illustrate the method.

  13. Landfilling ash/sludge mixtures

    SciTech Connect (OSTI)

    Benoit, J.; Eighmy, T.T.; Crannell, B.S.

    1999-10-01

    The geotechnical properties of a mixture of municipal solid waste incinerator bottom ash and municipal wastewater treatment plant sludge was investigated for a proposed ash/sludge secure landfill. The components as well as mixtures ranging from 10:1 to 5:1 (ash:sludge, by volume) were evaluated, where appropriate, for a number of geotechnical index and mechanical properties including particle size, water content, specific gravity, density-moisture relationships, shear strength, and compressibility. The results from a compactibility study and stability analysis of the proposed landfill were used to help approve a landfill codisposal concept; a full-scale facility was constructed and is currently operating successfully.

  14. Impact of Biodiesel Impurities on the Performance and Durability of DOC, DPF and SCR Technologies

    SciTech Connect (OSTI)

    Williams, A.; McCormick, R.; Luecke, J.; Brezny, R.; Geisselmann, A.; Voss, K.; Hallstrom, K.; Leustek, M.; Parsons, J.; Abi-Akar, H.

    2011-06-01

    It is estimated that operating continuously on a B20 fuel containing the current allowable ASTM specification limits for metal impurities in biodiesel could result in a doubling of ash exposure relative to lube-oil derived ash. The purpose of this study was to determine if a fuel containing metals at the ASTM limits could cause adverse impacts on the performance and durability of diesel emission control systems. An accelerated durability test method was developed to determine the potential impact of these biodiesel impurities. The test program included engine testing with multiple DPF substrate types as well as DOC and SCR catalysts. The results showed no significant degradation in the thermo-mechanical properties of cordierite, aluminum titanate, or silicon carbide DPFs after exposure to 150,000 mile equivalent biodiesel ash and thermal aging. However, exposure of a cordierite DPF to 435,000 mile equivalent aging resulted in a 69% decrease in the thermal shock resistance parameter. It is estimated that the additional ash from 150,000 miles of biodiesel use would also result in a moderate increases in exhaust backpressure for a DPF. A decrease in DOC activity was seen after exposure to 150,000 mile equivalent aging, resulting in higher HC slip and a reduction in NO{sub 2} formation. The metal-zeolite SCR catalyst experienced a slight loss in activity after exposure to 435,000 mile equivalent aging. This catalyst, placed downstream of the DPF, showed a 5% reduction in overall NOx conversion activity over the HDDT test cycle.

  15. Effects of Impurities on Fuel Cell Performance and Durability...

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

    clemson.pdf More Documents & Publications Effects of Impurities on Fuel Cell Performance and Durability Effects of Impurities on Fuel Cell Performance and Durability Effects of ...

  16. Effects of Impurities on Fuel Cell Performance and Durability...

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

    More Documents & Publications Effects of Impurities on Fuel Cell Performance and Durability Effects of Impurities on Fuel Cell Performance and Durability Highly Dispersed Alloy ...

  17. Effects of Impurities on Fuel Cell Performance and Durability...

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

    lanl.pdf More Documents & Publications Effects of Impurities on Fuel Cell Performance and Durability Effects of Impurities on Fuel Cell Performance and Durability Advanced Cathode ...

  18. Accurate Detection of Impurities in Hydrogen Fuel at Lower Cost...

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

    Accurate Detection of Impurities in Hydrogen Fuel at Lower Cost Technology available for licensing: Two alternative strategies for detecting impurities in the hydrogen used in fuel...

  19. Multichannel Kondo Impurity Dynamics in a Majorana Device (Journal...

    Office of Scientific and Technical Information (OSTI)

    Multichannel Kondo Impurity Dynamics in a Majorana Device Title: Multichannel Kondo Impurity Dynamics in a Majorana Device Authors: Altland, A. ; Bri, B. ; Egger, R. ; Tsvelik, ...

  20. Impurity states in multiband s -wave superconductors: Analysis...

    Office of Scientific and Technical Information (OSTI)

    Impurity states in multiband s -wave superconductors: Analysis of iron pnictides Citation Details In-Document Search Title: Impurity states in multiband s -wave superconductors:...

  1. Long duration ash probe

    DOE Patents [OSTI]

    Hurley, J.P.; McCollor, D.P.; Selle, S.J.

    1994-07-26

    A long duration ash probe includes a pressure shell connected to a port in a combustor with a sample coupon mounted on a retractable carriage so as to retract the sample coupon within the pressure shell during soot blowing operation of the combustor. A valve mounted at the forward end of the pressure shell is selectively closeable to seal the sample coupon within the shell, and a heating element in the shell is operable to maintain the desired temperature of the sample coupon while retracted within the shell. The carriage is operably mounted on a pair of rails within the shell for longitudinal movement within the shell. A hollow carrier tube connects the hollow cylindrical sample coupon to the carriage, and extends through the carriage and out the rearward end thereof. Air lines are connected to the rearward end of the carrier tube and are operable to permit coolant to pass through the air lines and thence through the carrier tube to the sample coupon so as to cool the sample coupon. 8 figs.

  2. Long duration ash probe

    DOE Patents [OSTI]

    Hurley, John P.; McCollor, Don P.; Selle, Stanley J.

    1994-01-01

    A long duration ash probe includes a pressure shell connected to a port in a combustor with a sample coupon mounted on a retractable carriage so as to retract the sample coupon within the pressure shell during sootblowing operation of the combustor. A valve mounted at the forward end of the pressure shell is selectively closeable to seal the sample coupon within the shell, and a heating element in the shell is operable to maintain the desired temperature of the sample coupon while retracted within the shell. The carriage is operably mounted on a pair of rails within the shell for longitudinal movement within the shell. A hollow carrier tube connects the hollow cylindrical sample coupon to the carriage, and extends through the carriage and out the rearward end thereof. Air lines are connected to the rearward end of the carrier tube and are operable to permit coolant to pass through the air lines and thence through the carrier tube to the sample coupon so as to cool the sample coupon.

  3. Leaching of Mixtures of Biochar and Fly Ash

    SciTech Connect (OSTI)

    Palumbo, Anthony Vito; Porat, Iris; Phillips, Jana Randolph; Amonette, J. E.; Drake, Meghan M; Brown, Steven D; Schadt, Christopher Warren

    2009-01-01

    Increasing atmospheric levels of greenhouse gases, especially CO2, and their effects on global temperature have led to interest in the possibility of carbon storage in terrestrial environments.2, 5, 6 Both the residual char from biomass pyrolysis7-9, 12 (biochar) and fly ash from coal combustion1, 13, 14 have the potential to significantly expand terrestrial sequestration options. Both biochar and fly ash also have potentially beneficial effects on soil properties. Fly ash has been shown to increase porosity, water-holding capacity, pH, conductivity, and dissolved SO42-, CO32-, Cl- and basic cations.10, 11, 16 Adding biochar to soil generally raises pH, increases total nitrogen and total phosphorous, encourages greater root development, improves cation exchange capacity and reduces available aluminum.3, 17 Combinations of these benefits likely lead to the observed increased yields for crops including corn and sugarcane.17 with biochar addition to soil. In addition, it has been found that soils with added biochar emit lower amounts of other greenhouse gases (methane and nitrous oxide) 8, 17 than do unammended soils. Biochar and fly ash amendments may be useful in promoting terrestrial carbon sequestration on currently underutilized and degraded lands. For example, about 1% of the US surface lands consist of previously mined lands or highway rights-of-way.18 Poorly managed lands could count for another 15% of US area. Biochar and fly ash amendments could increase productivity of these lands and increase carbon storage in the soil Previous results showed minimal leaching of organic carbon and metals from a variety of fly ashes.15 Here, we are examining the properties of mixtures of biochar, fly ash, and soil and evaluating leaching of organic carbon and metals from the mixtures.

  4. Numerical Studies of Impurities in Fusion Plasmas

    DOE R&D Accomplishments [OSTI]

    Hulse, R. A.

    1982-09-01

    The coupled partial differential equations used to describe the behavior of impurity ions in magnetically confined controlled fusion plasmas require numerical solution for cases of practical interest. Computer codes developed for impurity modeling at the Princeton Plasma Physics Laboratory are used as examples of the types of codes employed for this purpose. These codes solve for the impurity ionization state densities and associated radiation rates using atomic physics appropriate for these low-density, high-temperature plasmas. The simpler codes solve local equations in zero spatial dimensions while more complex cases require codes which explicitly include transport of the impurity ions simultaneously with the atomic processes of ionization and recombination. Typical applications are discussed and computational results are presented for selected cases of interest.

  5. Fly ash chemical classification based on lime

    SciTech Connect (OSTI)

    Fox, J.

    2007-07-01

    Typically, total lime content (CaO) of fly ash is shown in fly ash reports, but its significance is not addressed in US specifications. For certain applications a low lime ash is preferred. When a class C fly ash must be cementitious, lime content above 20% is required. A ternary S-A-C phase diagram pilot is given showing the location of fly ash compositions by coal rank and source in North America. Fly ashes from subbituminous coal from the Powder River Basin usually contain sufficient lime to be cementitious but blending with other coals may result in calcium being present in phases other than tricalcium aluminate. 9 refs., 1 fig.

  6. Lazy arc consistency

    SciTech Connect (OSTI)

    Schiex, T.; Gaspin, C.; Regin, J.C.; Verfaillie, G.

    1996-12-31

    Arc consistency filtering is widely used in the framework of binary constraint satisfaction problems: with a low complexity, inconsistency may be detected and domains are filtered. In this paper, we show that when detecting inconsistency is the objective, a systematic domain filtering is useless and a lazy approach is more adequate. Whereas usual arc consistency algorithms produce the maximum arc consistent sub-domain, when it exists, we propose a method, called LAC{tau}, which only looks for any arc consistent sub-domain. The algorithm is then extended to provide the additional service of locating one variable with a minimum domain cardinality in the maximum arc consistent sub-domain, without necessarily computing all domain sizes. Finally, we compare traditional AC enforcing and lazy AC enforcing using several benchmark problems, both randomly generated CSP and real life problems.

  7. Overview of SOFC Anode Interactions with Coal Gas Impurities

    SciTech Connect (OSTI)

    Marina, Olga A.; Pederson, Larry R.; Gemmen, Randall; Gerdes, Kirk; Finklea, Harry; Celik, Ismail B.

    2009-08-11

    Efficiencies greater than 50 percent (higher heating value) have been projected for solid oxide fuel cell (SOFC) systems fueled with gasified coal, even with carbon sequestration. Multiple minor and trace components are present in coal that could affect fuel cell performance, however, which vary widely depending on coal origin and type. Minor and trace components have been classified into three groups: elements with low volatility that are likely to remain in the ash, elements that will partition between solid and gas phases, and highly volatile elements that are unlikely to condense. Those in the second group are of most concern. In the following, an overview of the results of SOFC anode interactions with phosphorus, arsenic, selenium, sulfur, antimony, and hydrogen chloride as single contaminants or in combinations is discussed. Tests were performed using both anode- and electrolyte-supported cells in synthetic coal gas. The ultimate purpose of this work is to establish maximum permissible concentrations for impurities in coal gas, to aid in the selection of appropriate coal gas clean-up technologies.

  8. Speciation of Selenium, Arsenic, and Zinc in Class C Fly Ash

    SciTech Connect (OSTI)

    Luo, Yun; Giammar, Daniel E.; Huhmann, Brittany L.; Catalano, Jeffrey G.

    2011-11-17

    A major environmental concern associated with coal fly ash is the mobilization of trace elements that may contaminate water. To better evaluate proper use of fly ash, determine appropriate disposal methods, and monitor postdisposal conditions, it is important to understand the speciation of trace elements in fly ash and their possible environmental impact. The speciation of selenium, arsenic, and zinc was determined in five representative Class C fly ash samples from combustion of sub-bituminous Powder River Basin coal using synchrotron-based X-ray absorption spectroscopy to provide an improved understanding of the mechanisms of trace element association with the fly ash. Selenium in all fly ash samples occurs predominantly as Se(IV), with the exception of one sample, in which there was a minor amount of Se(0). Se(0) is likely associated with the high content of unburned coal in the sample. Arsenic exists in the fly ash as a single phase most consistent with calcium pyroarsenate. In contrast, zinc occurs as two distinct species in the silicate glass matrix of the fly ash. This work demonstrates that residual carbon in fly ash may reduce potential Se mobility in the environment by retaining it as less soluble elemental Se instead of Se(IV). Further, this work suggests that As and Zn in Class C fly ash will display substantially different release and mobilization behaviors in aquatic environments. While As release will primarily depend upon the dissolution and hydrolysis of calcium pyroarsenate, Zn release will be controlled by the dissolution of alkaline aluminosilicate glass in the ash.

  9. Gasification of high ash, high ash fusion temperature bituminous coals

    DOE Patents [OSTI]

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

    This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

  10. Rising from the ashes: Coal ash in recycling and construction

    SciTech Connect (OSTI)

    Naquin, D.

    1998-02-01

    Beneficial Ash Management (BAM, Clearfield, Pa.) has won an environmental award for its use of ash and other waste to fight acid mine drainage. The company`s workers take various waste materials, mainly fly ash from coal-burning plants, to make a cement-like material or grouting, says Ernest Roselli, BAM president. The grouting covers the soil, which helps prevent water from contacting materials. This, in turn, helps control chemical reactions, reducing or eliminating formation of acid mine drainage. The company is restoring the 1,400-acre Bark Camp coal mine site near Penfield in Clearfield County, Pa. Under a no-cost contract with the state of Pennsylvania, BAM is using boiler slag, causticizing byproducts (lime) and nonreclaimable clarifier sludge from International Paper Co. (Erie, Pa.). The mine reclamation techniques developed and monitored at the site include using man-made wetlands to treat acid mine drainage and testing anhydrous ammonia as a similar treatment agent. BAM researches and tests fly ash mixed with lime-based activators as fill material for land reclamation, and develops and uses artificial soil material from paper mill and tannery biosolids.

  11. Coupling of ion temperature gradient and trapped electron modes in the presence of impurities in tokamak plasmas

    SciTech Connect (OSTI)

    Du, Huarong; Wang, Zheng-Xiong, E-mail: zxwang@dlut.edu.cn [MOE Key Laboratory of Materials Modification by Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [MOE Key Laboratory of Materials Modification by Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Dong, J. Q. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China) [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Southwestern Institute of Physics, Chengdu 610041 (China); Liu, S. F. [School of Physics, Nankai University, Tianjin 300071 (China)] [School of Physics, Nankai University, Tianjin 300071 (China)

    2014-05-15

    The coupling of ion temperature gradient (ITG or ?{sub i}) mode and trapped electron mode (TEM) in the presence of impurity ions is numerically investigated in toroidal collisionless plasmas, using the gyrokinetic integral eigenmode equation. A framework for excitations of the ITG modes and TEMs with respect to their driving sources is formulated first, and then the roles of impurity ions played in are analyzed comprehensively. In particular, the characteristics of the ITG and TEM instabilities in the presence of impurity ions are emphasized for both strong and weak coupling (hybrid and coexistent) cases. It is found that the impurity ions with inwardly (outwardly) peaked density profiles have stabilizing (destabilizing) effects on the hybrid (namely the TE-ITG) modes in consistence with previous works. A new finding of this work is that the impurity ions have stabilizing effects on TEMs in small ?{sub i} (?{sub i}?1) regime regardless of peaking directions of their density profiles whereas the impurity ions with density gradient L{sub ez}=L{sub ne}/L{sub nz}>1 (L{sub ez}<1) destabilize (stabilize) the TEMs in large ?{sub i} (?{sub i}?1) regime. In addition, the dependences of the growth rate, real frequency, eigenmode structure, and wave spectrum on charge concentration, charge number, and mass of impurity ions are analyzed in detail. The necessity for taking impurity ion effects on the features of turbulence into account in future transport experimental data analyses is also discussed.

  12. Publication sites productive uses of combustion ash

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

    Publication Sites Productive Uses of Combustion Ash For more information contact: e:mail: Public Affairs Golden, Colo., Jan. 23, 1997 -- A new technology brief published by the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) describes how ash use can reduce the cost of waste management and not harm the environment. Communities in the United States typically dump municipal solid waste combustion ash in landfills. The new technology brief describes recent studies where ash

  13. Coal Ash Corrosion Resistant Materials Testing

    SciTech Connect (OSTI)

    D. K. McDonald; P. L. Daniel; D. J. DeVault

    2003-08-31

    . The body of this report compares these for all of the samples in the test section. The 'Coal Ash Corrosion Resistant Materials Testing Program' is being conducted by The Babcock & Wilcox Company (B&W), the U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) at Reliant Energy's Niles plant in Niles, Ohio to provide full-scale, in-situ testing of recently developed boiler superheater materials. Fireside corrosion is a key issue for improving efficiency of new coal fired power plants and improving service life in existing plants. In November 1998, B&W began development of a system to permit testing of advanced tube materials at metal temperatures typical of advanced supercritical steam temperatures (1100 F and higher) in a boiler exhibiting coal ash corrosive conditions. Several materials producers including Oak Ridge National Laboratory (ORNL) contributed advanced materials to the project. In the spring of 1999 a system consisting of three identical sections, each containing multiple segments of twelve different materials, was installed. The sections are cooled by reheat steam, and are located just above the furnace entrance in Niles Unit No.1, a 110 MWe unit firing high sulfur Ohio coal. In November 2001 the first section was removed for thorough metallurgical evaluation after 29 months of operation. The second section was removed in August of 2003. Its evaluation has been completed and is the subject of this report. The final section remains in service and is expected to be removed in the spring of 2005. This paper describes the program; its importance, the design, fabrication, installation and operation of the test system, materials utilized, and experience to date. This report briefly reviews the results of the evaluation of the first section and then presents the results of the evaluation of the second section.

  14. A comparison between sludge ash and fly ash on the improvement in soft soil

    SciTech Connect (OSTI)

    Deng-Fong Lin; Kae-Long Lin; Huan-Lin Luo

    2007-01-15

    In this study, the strength of soft cohesive subgrade soil was improved by applying sewage sludge ash as a soil stabilizer. Test results obtained were compared with earlier tests conducted on soil samples treated with fly ash. Five different proportions of sludge ash and fly ash were mixed with soft cohesive soil, and tests such as pH value, compaction, California bearing ratio, unconfined compressive strength (UCS), and triaxial compression were performed to understand soil strength improvement because of the addition of both ashes. Results indicate that pH values increase with extending curing age for soil with sludge ash added. The UCS of sludge ash/soil were 1.4 2 times better than untreated soil. However, compressive strength of sludge ash/soil was 20 30 kPa less than fly ash/soil. The bearing capacities for both fly ash/soil and sludge ash/soil were five to six times and four times, respectively, higher than the original capacity. Moreover, the cohesive parameter of shear strength rose with increased amounts of either ash added. Friction angle, however, decreased with increased amounts of either ash. Consequently, results show that sewage sludge ash can potentially replace fly ash in the improvement of the soft cohesive soil. 9 refs., 5 figs., 2 tabs.

  15. Petrographic characterization of economizer fly ash

    SciTech Connect (OSTI)

    Valentim, B.; Hower, J.C.; Soares, S.; Guedes, A.; Garcia, C.; Flores, D.; Oliveira, A.

    2009-11-15

    Policies for reducing NOx emissions have led power plants to restrict O{sub 2}, resulting in high-carbon fly ash production. Therefore, some potentially useful fly ash, such as the economizer fly ash, is discarded without a thorough knowledge of its composition. In order to characterize this type of fly ash, samples were collected from the economizer Portuguese power plant burning two low-sulfur bituminous coals. Characterization was also performed on economizer fly ash subsamples after wet sieving, density and magnetic separation. Analysis included atomic absorption spectroscopy, loss-on-ignition, scanning electron microscopy/energy-dispersive X-ray spectroscopy, optical microscopy, and micro-Raman spectroscopy.

  16. Photosynthetic pigment concentrations, gas exchange and vegetative growth for selected monocots and dicots treated with two contrasting coal fly ashes

    SciTech Connect (OSTI)

    Yunusa, I.A.M.; Burchett, M.D.; Manoharan, V.; DeSilva, D.L.; Eamus, D.; Skilbeck, C.G.

    2009-07-15

    There is uncertainty as to the rates of coal fly ash needed for optimum physiological processes and growth. In the current study we tested the hyothesis that photosynthetic pigments concentrations and CO{sub 2} assimilation (A) are more sensitive than dry weights in plants grown on media amended with coal fly ash. We applied the Terrestrial Plant Growth Test (Guideline 208) protocols of the Organization for Economic Cooperation and Development (OECD) to monocots (barley (Hordeum vulgare) and ryegrass (Secale cereale)) and dicots (canola (Brasica napus), radish (Raphanus sativus), field peas (Pisum sativum), and lucerne (Medicago sativa)) on media amended with fly ashes derived from semi-bituminous (gray ash) or lignite (red ash) coals at rates of 0, 2.5, 5.0, 10, or 20 Mg ha(-1). The red ash had higher elemental concentrations and salinity than the gray ash. Fly ash addition had no significant effect on germination by any of the six species. At moderate rates ({<=}10 Mg ha{sup -1}) both ashes increased (P < 0.05) growth rates and concentrations of chlorophylls a and b, but reduced carotenoid concentrations. Addition of either ash increased A in radish and transpiration in barley. Growth rates and final dry weights were reduced for all of the six test species when addition rates exceeded 10 Mg ha{sup -1} for gray ash and 5 Mg ha{sup -1} for red ash. We concluded that plant dry weights, rather than pigment concentrations and/or instantaneous rates of photosynthesis, are more consistent for assessing subsequent growth in plants supplied with fly ash.

  17. Undercompensated Kondo Impurity with Quantum Critical Point

    SciTech Connect (OSTI)

    Schlottmann, P.

    2000-02-14

    The low-temperature properties of a magnetic impurity of spin S interacting with an electron gas via anisotropic spin exchange are studied via Bethe's ansatz. For S>1/2 the impurity is only partially compensated at T=0 , leaving an effective spin that is neither integer nor half integer. The entropy has an essential singularity at H=T=0 , and the susceptibility and the specific heat follow power laws of H and T with nonuniversal exponents, which are the consequence of a quantum critical point. The results for the generalization to an arbitrary number of channels are also reported. (c) 2000 The American Physical Society.

  18. ACAA fly ash basics: quick reference card

    SciTech Connect (OSTI)

    2006-07-01

    Fly ash is a fine powdery material created when coal is burned to generate electricity. Before escaping into the environment via the utility stacks, the ash is collected and may be stored for beneficial uses or disposed of, if necessary. The use of fly ash provides environmental benefits, such as the conservation of natural resources, the reduction of greenhouse gas emissions and eliminating the needed for ash disposal in landfills. It is also a valuable mineral resource that is used in construction and manufacturing. Fly ash is used in the production of Portland cement, concrete, mortars and stuccos, manufactured aggregates along with various agricultural applications. As mineral filler, fly ash can be used for paints, shingles, carpet backing, plastics, metal castings and other purposes. This quick reference card is intended to provide the reader basic source, identification and composition, information specifically related to fly ash.

  19. Evaluation of Impurity Extremes in a Plutonium-loaded Borosilicate Glass

    SciTech Connect (OSTI)

    Fox, K.M.; Crawford, C.L.; Marra, J.C.; Bibler, N.E.; Hoffman, E.N.; Edwards, T.B. [Savannah River National Laboratory, Aiken, SC (United States)

    2008-07-01

    A vitrification technology utilizing a lanthanide borosilicate (LaBS) glass appears to be a viable option for the disposition of excess weapons-usable plutonium that is not suitable for processing into mixed oxide (MOX) fuel. A significant effort to develop a glass formulation and vitrification process to immobilize plutonium was completed in the mid-1990's. The LaBS glass formulation was found to be capable of immobilizing in excess of 10 wt % Pu and to be tolerant of a range of impurities. To confirm the results of previous testing with surrogate Pu feeds containing impurities, four glass compositions were selected for fabrication with actual plutonium oxide and impurities. The four compositions represented extremes in impurity type and concentration. The homogeneity and durability of these four compositions were measured. The homogeneity of the glasses was evaluated using x-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS). The XRD results indicated that the glasses were amorphous with no evidence of crystalline species in the glass. The SEM/EDS analyses did show the presence of some undissolved PuO{sub 2} material. The EDS spectra indicated that some of the PuO{sub 2} crystals also contained hafnium oxide. The SEM/EDS analyses showed that there were no heterogeneities in the glass due to the feed impurities. The durability of the glasses was measured using the Product Consistency Test (PCT). The PCT results indicated that the durability of Pu impurity glasses was comparable with Pu glasses without impurities and significantly more durable than the Environmental Assessment (EA) glass used as the benchmark for repository disposition of high-level waste (HLW) glasses. (authors)

  20. Effects of Point Defects and Impurities on Kinetics in NaAlH4 | Department

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

    of Energy Point Defects and Impurities on Kinetics in NaAlH4 Effects of Point Defects and Impurities on Kinetics in NaAlH4 A presentation showing that point defects play an important role in the kinetics of NaAlH4 including vacancies and interstitials consistent with observed effects of Ti. effects_of_point_defects.pdf (503.7 KB) More Documents & Publications Catalytic Effect of Ti for Hydrogen Cycling in NaAlH4 FTA - SunLine Transit Agency - Final Report Proceedings of the 1998 U.S. DOE

  1. Process and system for removing impurities from a gas

    DOE Patents [OSTI]

    Henningsen, Gunnar; Knowlton, Teddy Merrill; Findlay, John George; Schlather, Jerry Neal; Turk, Brian S

    2014-04-15

    A fluidized reactor system for removing impurities from a gas and an associated process are provided. The system includes a fluidized absorber for contacting a feed gas with a sorbent stream to reduce the impurity content of the feed gas; a fluidized solids regenerator for contacting an impurity loaded sorbent stream with a regeneration gas to reduce the impurity content of the sorbent stream; a first non-mechanical gas seal forming solids transfer device adapted to receive an impurity loaded sorbent stream from the absorber and transport the impurity loaded sorbent stream to the regenerator at a controllable flow rate in response to an aeration gas; and a second non-mechanical gas seal forming solids transfer device adapted to receive a sorbent stream of reduced impurity content from the regenerator and transfer the sorbent stream of reduced impurity content to the absorber without changing the flow rate of the sorbent stream.

  2. Effect of Various Impurities on the Hydrogen Absorption on SAES...

    Office of Environmental Management (EM)

    Effect of Various Impurities on the Hydrogen Absorption on SAES ST198 Effect of Various Impurities on the Hydrogen Absorption on SAES ST198 Presentation from the 36th Tritium Focus ...

  3. The Potts model on a Bethe lattice with nonmagnetic impurities

    SciTech Connect (OSTI)

    Semkin, S. V. Smagin, V. P.

    2015-10-15

    We have obtained a solution for the Potts model on a Bethe lattice with mobile nonmagnetic impurities. A method is proposed for constructing a “pseudochaotic” impurity distribution by a vanishing correlation in the arrangement of impurity atoms for the nearest sites. For a pseudochaotic impurity distribution, we obtained the phase-transition temperature, magnetization, and spontaneous magnetization jumps at the phase-transition temperature.

  4. Fused salt processing of impure plutonium dioxide to high-purity plutonium metal

    SciTech Connect (OSTI)

    Mullins, L.J.; Christensen, D.C.; Babcock, B.R.

    1982-01-01

    A process for converting impure plutonium dioxide (approx. 96% pure) to high-purity plutonium metal (>99.9%) was developed. The process consists of reducing the oxide to an impure plutonium metal intermediate with calcium metal in molten calcium chloride. The impure intermediate metal is cast into an anode and electrorefined to produce high-purity plutonium metal. The oxide reduction step is being done now on a 0.6-kg scale with the resulting yield being >99.5%. The electrorefining is being done on a 4.0-kg scale with the resulting yield being 80 to 85%. The purity of the product, which averages 99.98%, is essentially insensitive to the purity of the feed metal. The yield, however, is directly dependent on the chemical composition of the feed. To date, approximately 250 kg of impure oxide has been converted to pure metal by this processing sequence. The availability of impure plutonium dioxide, together with the need for pure plutonium metal, makes this sequence a valuable plutonium processing tool.

  5. Characterization and validation of an in silico toxicology model to predict the mutagenic potential of drug impurities*

    SciTech Connect (OSTI)

    Valerio, Luis G.; Cross, Kevin P.

    2012-05-01

    Control and minimization of human exposure to potential genotoxic impurities found in drug substances and products is an important part of preclinical safety assessments of new drug products. The FDA's 2008 draft guidance on genotoxic and carcinogenic impurities in drug substances and products allows use of computational quantitative structureactivity relationships (QSAR) to identify structural alerts for known and expected impurities present at levels below qualified thresholds. This study provides the information necessary to establish the practical use of a new in silico toxicology model for predicting Salmonella t. mutagenicity (Ames assay outcome) of drug impurities and other chemicals. We describe the model's chemical content and toxicity fingerprint in terms of compound space, molecular and structural toxicophores, and have rigorously tested its predictive power using both cross-validation and external validation experiments, as well as case studies. Consistent with desired regulatory use, the model performs with high sensitivity (81%) and high negative predictivity (81%) based on external validation with 2368 compounds foreign to the model and having known mutagenicity. A database of drug impurities was created from proprietary FDA submissions and the public literature which found significant overlap between the structural features of drug impurities and training set chemicals in the QSAR model. Overall, the model's predictive performance was found to be acceptable for screening drug impurities for Salmonella mutagenicity. -- Highlights: ? We characterize a new in silico model to predict mutagenicity of drug impurities. ? The model predicts Salmonella mutagenicity and will be useful for safety assessment. ? We examine toxicity fingerprints and toxicophores of this Ames assay model. ? We compare these attributes to those found in drug impurities known to FDA/CDER. ? We validate the model and find it has a desired predictive performance.

  6. Coal Ash Corrosion Resistant Materials Testing Program

    SciTech Connect (OSTI)

    McDonald, D K

    2003-04-22

    The "Coal Ash Corrosion Resistant Materials Testing Program" is being conducted by The Babcock & Wilcox Company (B&W), the U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) at Reliant Energy's Niles plant in Niles, Ohio to provide full-scale, in-situ testing of recently developed boiler superheater materials. Fireside corrosion is a key issue for improving efficiency of new coal fired power plants and improving service life in existing plants. In November 1998, B&W began development of a system to permit testing of advanced tube materials at metal temperatures typical of advanced supercritical steam temperatures (1100°F and higher) in a boiler exhibiting coal ash corrosive conditions. Several materials producers including Oak Ridge National Laboratory (ORNL) contributed advanced materials to the project. In the spring of 1999 a system consisting of three identical sections, each containing multiple segments of twelve different materials, was installed. The sections are cooled by reheat steam, and are located just above the furnace entrance in Niles' Unit #1, a 110 MWe unit firing high sulfur Ohio coal. In November 2001 the first section was removed for thorough metallurgical evaluation after 33 months of operation. The second and third sections remain in service and the second is expected to be removed in the fall of 2003; the last is tentatively planned for the fall of 2004. This paper describes the program; its importance; the design, fabrication, installation and operation of the test system; materials utilized; experience to date; and results of the evaluation of the first section.

  7. Combustion with reduced carbon in the ash

    DOE Patents [OSTI]

    Kobayashi, Hisashi; Bool, III, Lawrence E.

    2005-12-27

    Combustion of coal in which oxygen is injected into the coal as it emerges from burner produces ash having reduced amounts of carbon.

  8. Power Radiated from ITER and CIT by Impurities

    DOE R&D Accomplishments [OSTI]

    Cummings, J.; Cohen, S. A.; Hulse, R.; Post, D. E.; Redi, M. H.; Perkins, J.

    1990-07-01

    The MIST code has been used to model impurity radiation from the edge and core plasmas in ITER and CIT. A broad range of parameters have been varied, including Z{sub eff}, impurity species, impurity transport coefficients, and plasma temperature and density profiles, especially at the edge. For a set of these parameters representative of the baseline ITER ignition scenario, it is seen that impurity radiation, which is produced in roughly equal amounts by the edge and core regions, can make a major improvement in divertor operation without compromising core energy confinement. Scalings of impurity radiation with atomic number and machine size are also discussed.

  9. Characterization of ash cenospheres in fly ash from Australian power stations

    SciTech Connect (OSTI)

    Ling-ngee Ngu; Hongwei Wu; Dong-ke Zhang

    2007-12-15

    Ash cenospheres in fly ashes from five Australian power stations have been characterized. The experimental data show that ash cenosphere yield varies across the power stations. Ash partitioning occurred in the process of ash cenosphere formation during combustion. Contradictory to conclusions from the literature, iron does not seem to be essential to ash cenosphere formation in the cases examined in the present work. Further investigation was also undertaken on a series of size-fractioned ash cenosphere samples from Tarong power station. It is found that about 70 wt% of ash cenospheres in the bulk sample have sizes between 45 and 150 {mu}m. There are two different ash cenosphere structures, that is, single-ring structure and network structure. The percentage of ash cenospheres of a network structure increases with increasing ash cenosphere size. Small ash cenospheres (in the size fractions {lt}150 {mu}m) have a high SiO{sub 2}/Al{sub 2}O{sub 3} ratio, and the majority of the ash cenospheres are spherical and of a single-ring structure. Large ash cenosphere particles (in the size fractions of 150-250 {mu}m and {gt}250 {mu}m) have a low SiO{sub 2}/Al{sub 2}O{sub 3} ratio, and a high proportion of the ash cenospheres are nonspherical and of a network structure. A novel quantitative technique has been developed to measure the diameter and wall thickness of ash cenospheres on a particle-to-particle basis. A monolayer of size-fractioned ash cenospheres was dispersed on a pellet, which was then polished carefully before being examined using a scanning electron microscope and image analysis. The ash cenosphere wall thickness broadly increases with increasing ash cenosphere size. The ratios between wall thickness and diameter of ash cenospheres are limited between an upper bound of about 10.5% and a lower bound of about 2.5%, irrespective of the ash cenosphere size. 52 refs., 9 figs., 4 tabs.

  10. Treatment of fly ash for use in concrete

    DOE Patents [OSTI]

    Boxley, Chett

    2012-05-15

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with a quantity of spray dryer ash (SDA) and water to initiate a geopolymerization reaction and form a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 40%, and in some cases less than 20%, of the foam index of the untreated fly ash. An optional alkaline activator may be mixed with the fly ash and SDA to facilitate the geopolymerization reaction. The alkaline activator may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  11. Motion of a distinguishable Impurity in the Bose gas: Arrested expansion without a lattice and impurity snaking

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

    Neil J. Robinson; Caux, Jean -Sebastien; Konik, Robert M.

    2016-04-07

    We consider the real-time dynamics of an initially localized distinguishable impurity injected into the ground state of the Lieb-Liniger model. Focusing on the case where integrability is preserved, we numerically compute the time evolution of the impurity density operator in regimes far from analytically tractable limits. We find that the injected impurity undergoes a stuttering motion as it moves and expands. For an initially stationary impurity, the interaction-driven formation of a quasibound state with a hole in the background gas leads to arrested expansion—a period of quasistationary behavior. In conclusion, when the impurity is injected with a finite center-of-mass momentum,more » the impurity moves through the background gas in a snaking manner, arising from a quantum Newton’s cradlelike scenario where momentum is exchanged back and forth between the impurity and the background gas.« less

  12. Hunt's Ash Springs Pool & Spa Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Hunt's Ash Springs Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Hunt's Ash Springs Pool & Spa Low Temperature Geothermal Facility Facility Hunt's...

  13. Impact of Biodiesel on Ash Emissions and Lubricant Properties...

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

    Biodiesel on Ash Emissions and Lubricant Properties Affecting Fuel Economy and Engine Wear Impact of Biodiesel on Ash Emissions and Lubricant Properties Affecting Fuel Economy and ...

  14. Entrained-flow dry-bottom gasification of high-ash coals in coal-water slurries

    SciTech Connect (OSTI)

    E.G. Gorlov; V.G. Andrienko; K.B. Nefedov; S.V. Lutsenko; B.K. Nefedov

    2009-04-15

    It was shown that the effective use of dry ash removal during entrained-flow gasification of coal-water slurries consists in simplification of the ash storage system and utilization of coal ash, a decrease in the coal demand, a reduction in the atmospheric emissions of noxious substances and particulate matter, and abandonment of the discharge of water used for ash slurry. According to the results of gasification of coal-water slurries (5-10 {mu}m) in a pilot oxygen-blow unit at a carbon conversion of >91%, synthesis gas containing 28.5% CO, 32.5% H{sub 2}, 8.2% CO{sub 2}, 1.5% CH{sub 4}, the rest being nitrogen, was obtained. The fly ash in its chemical composition, particle size, and density meets the requirements of the European standard EN 450 as a cement additive for concrete manufacture.

  15. Settlement of footing on compacted ash bed

    SciTech Connect (OSTI)

    Ramasamy, G.; Pusadkar, S.S.

    2007-11-15

    Compacted coal ash fills exhibit capillary stress due to contact moisture and preconsolidation stress due to the compaction process. As such, the conventional methods of estimating settlement of footing on cohesionless soils based on penetration tests become inapplicable in the case of footings on coal ash fills, although coal ash is also a cohesionless material. Therefore, a method of estimating load-settlement behavior of footings resting on coal ash fills accounting for the effect of capillary and preconsolidation stresses is presented here. The proposed method has been validated by conducting plate load tests on laboratory prepared compacted ash beds and comparing the observed and predicted load-settlement behavior. Overestimation of settlement greater than 100% occurs when capillary and preconsolidation stresses are not accounted for, as is the case in conventional methods.

  16. Geotechnical characterization of some Indian fly ashes

    SciTech Connect (OSTI)

    Das, S.K.; Yudhbir

    2005-10-01

    This paper reports the findings of experimental studies with regard to some common engineering properties (e.g., grain size, specific gravity, compaction characteristics, and unconfined compression strength) of both low and high calcium fly ashes, to evaluate their suitability as embankment materials and reclamation fills. In addition, morphology, chemistry, and mineralogy of fly ashes are studied using scanning electron microscope, electron dispersive x-ray analyzer, x-ray diffractometer, and infrared absorption spectroscopy. In high calcium fly ash, mineralogical and chemical differences are observed for particles, {gt}75 {mu} m and the particles of {lt} 45 {mu} m size. The mode and duration of curing significantly affect the strength and stress-strain behavior of fly ashes. The geotechnical properties of fly ash are governed by factors like lime content (CaO), iron content (Fe{sub 2}O{sub 3}) and loss on ignition. The distinct difference between self-hardening and pozzolanic reactivity has been emphasized.

  17. Silicon materials task of the low cost solar array project (Phase III). Effects of impurities and processing on silicon solar cells. Phase III summary and seventeenth quarterly report, Volume 2: analysis of impurity behavior

    SciTech Connect (OSTI)

    Hopkins, R.H.; Davis, J.R.; Rohatgi, A.; Campbell, R.B.; Blais, P.D.; Rai-Choudhury, P.; Stapleton, R.E.; Mollenkopf, H.C.; McCormick, J.R.

    1980-01-23

    The object of this phase of the program has been to investigate the effects of various processes, metal contaminants and contaminant-process interactions on the properties of silicon and on the performance of terrestrial silicon solar cells. The study encompassed topics including thermochemical (gettering) treatments, base doping concentration, base doping type (n vs. p), grain boundary-impurity interaction, non-uniformity of impurity distribution, long term effects of impurities, as well as synergic and complexing phenomena. The program approach consists in: (1) the growth of doubly and multiply-doped silicon single crystals containing a baseline boron or phosphorus dopant and specific impurities which produce deep levels in the forbidden band gap; (2) assessment of these crystals by chemical, microstructural, electrical and solar cell tests; (3) correlation of the impurity type and concentration with crystal quality and device performance; and (4) delineation of the role of impurities and processing on subsequent silicon solar cell performance. The overall results reported are based on the assessment of nearly 200 silicon ingots. (WHK)

  18. Treatment of fly ash for use in concrete

    DOE Patents [OSTI]

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2013-01-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  19. Treatment of fly ash for use in concrete

    DOE Patents [OSTI]

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2012-05-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  20. Assessment of Embrittlement of VHTR Structural Alloys in Impure Helium Environments

    SciTech Connect (OSTI)

    Crone, Wendy; Cao, Guoping; Sridhara, Kumar

    2013-05-31

    The helium coolant in high-temperature reactors inevitably contains low levels of impurities during steady-state operation, primarily consisting of small amounts of H{sub 2}, H{sub 2}O, CH{sub 4}, CO, CO{sub 2}, and N{sub 2} from a variety of sources in the reactor circuit. These impurities are problematic because they can cause significant long-term corrosion in the structural alloys used in the heat exchangers at elevated temperatures. Currently, the primary candidate materials for intermediate heat exchangers are Alloy 617, Haynes 230, Alloy 800H, and Hastelloy X. This project will evaluate the role of impurities in helium coolant on the stress-assisted grain boundary oxidation and creep crack growth in candidate alloys at elevated temperatures. The project team will: • Evaluate stress-assisted grain boundary oxidation and creep crack initiation and crack growth in the temperature range of 500-850°C in a prototypical helium environment. • Evaluate the effects of oxygen partial pressure on stress-assisted grain boundary oxidation and creep crack growth in impure helium at 500°C, 700°C, and 850°C respectively. • Characterize the microstructure of candidate alloys after long-term exposure to an impure helium environment in order to understand the correlation between stress-assisted grain boundary oxidation, creep crack growth, material composition, and impurities in the helium coolant. • Evaluate grain boundary engineering as a method to mitigate stress-assisted grain boundary oxidation and creep crack growth of candidate alloys in impure helium. The maximum primary helium coolant temperature in the high-temperature reactor is expected to be 850-1,000°C.Corrosion may involve oxidation, carburization, or decarburization mechanisms depending on the temperature, oxygen partial pressure, carbon activity, and alloy composition. These corrosion reactions can substantially affect long-term mechanical properties such as crack- growth rate and fracture

  1. Integrable Two-Impurity Kondo Model

    SciTech Connect (OSTI)

    Schlottmann, P.

    1998-06-01

    The exact solution by means of Bethe{close_quote}s {ital Ansatz} of a variant of the two-impurity Kondo problem is presented. The occupation of the singlet and triplet states, the expectation value {l_angle}{rvec S}{sub 1}{center_dot} {cflx S}{sub 2}{r_angle} , the homogeneous and staggered magnetic field susceptibilities, and the specific heat {gamma} coefficient are studied for the ground state as a function of the Ruderman-Kittel-Kasuya-Yosida{endash}coupling strength. {copyright} {ital 1998} {ital The American Physical Society}

  2. Leaching of mixtures of biochar and fly ash

    SciTech Connect (OSTI)

    Palumbo, Anthony V.; Porat, Iris; Phillips, Jana R.; Amonette, James E.; Drake, Meghan M.; Brown, Steven D.; Schadt, Christopher W.

    2009-06-22

    Increasing atmospheric levels of greenhouse gases, especially CO2, and their effects on global temperature have led to interest in the possibility of carbon storage in terrestrial environments. Both the residual char from biomass pyrolysis (biochar) and fly ash from coal combustion have the potential to significantly expand terrestrial sequestration options. Both biochar and fly ash also have potentially beneficial effects on soil properties. Fly ash has been shown to increase porosity, water-holding capacity, pH, conductivity, and dissolved SO42-, CO32-, Cl- and basic cations. Adding biochar to soil generally raises pH, increases total nitrogen and total phosphorous, encourages greater root development, improves cation exchange capacity and decreases available aluminum. A combination of these benefits likely is responsible for observed increases in yields for crops such as corn and sugarcane. In addition, it has been found that soils with added biochar emit lower amounts of other greenhouse gases (methane and nitrous oxide) than do unamended soils. Biochar and fly ash amendments may be useful in promoting terrestrial carbon sequestration on currently underutilized and degraded lands. For example, about 1% of the US surface lands consist of previously mined lands or highway rights-of-way. Poorly managed lands could count for another 15% of US area. Biochar and fly ash amendments could increase productivity of these lands and increase carbon storage in the soil. Previous results showed minimal leaching of organic carbon and metals from a variety of fly ashes. In the present study, we examined the properties of mixtures of biochar, fly ash, and soil and evaluated the leaching of organic carbon and metals from these mixtures. The carbon sorption experiments showed release of carbon from biochar, rather than sorption, except at the highest concentrations in the Biochar HW sample. Similar results were obtained by others for oxidative leaching of bituminous coal, in

  3. Statistical analysis of variations in impurity ion heating at...

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

    ... heating of majority ions has been studied; 16 and most recently, the charge and mass dependency of impurity ion heating has been investigated. 17 Despite many laboratory ...

  4. Measurement of plasma current dependent changes in impurity transport...

    Office of Scientific and Technical Information (OSTI)

    simultaneous agreement between experiment and simulation in both the impurity particle transport and ion heat transport channels is attainable within experimental more ...

  5. Direct Determination of the Chemical Bonding of Individual Impurities...

    Office of Scientific and Technical Information (OSTI)

    Publisher's Accepted Manuscript: Direct Determination of the Chemical Bonding of Individual Impurities in Graphene Prev Next Title: Direct Determination of the Chemical ...

  6. Rocky Flats ash test procedure (sludge stabilization)

    SciTech Connect (OSTI)

    Winstead, M.L.

    1995-09-14

    Rocky Flats Ash items have been identified as the next set of materials to be stabilized. This test is being run to determine charge sizes and soak times to completely stabilize the Rocky Flats Ash items. The information gathered will be used to generate the heating rampup cycle for stabilization. This test will also gain information on the effects of the glovebox atmosphere (moisture) on the stabilized material. This document provides instructions for testing Rocky Flats Ash in the HC-21C muffle furnace process.

  7. Potential products from North Dakota lignite fly ash. Final report

    SciTech Connect (OSTI)

    Anderson, G R

    1980-06-01

    Four major areas where fly ash can be used are explored. Concrete building blocks with fly ash replacing 50% of the portland cement have proven to be successful using current ASTM standards. Results in the ceramics area show that a ceramic-like product using fly ash and crushed glass with a small amount of clay as a green binder. Some preliminary results using sulfur ash in building materials are reported and with results of making wallboard from ash. (MHR)

  8. Ashe County- Wind Energy System Ordinance

    Broader source: Energy.gov [DOE]

    In 2007 Ashe County adopted a wind ordinance to regulate the use of wind-energy systems in unincorporated areas of the county and to describe the conditions by which a permit for installing such a...

  9. Fly ash system technology improves opacity

    SciTech Connect (OSTI)

    2007-06-15

    Unit 3 of the Dave Johnston Power Plant east of Glenrock, WY, USA had problems staying at or below the opacity limits set by the state. The unit makes use of a Lodge Cottrell precipitator. When the plant changed to burning Power River Basin coal, ash buildup became a significant issue as the fly ash control system was unable to properly evacuate hoppers on the unit. To overcome the problem, the PLC on the unit was replaced with a software optimization package called SmartAsh for the precipitator fly ash control system, at a cost of $500,000. After the upgrade, there have been no plugged hoppers and the opacity has been reduced from around 20% to 3-5%. 2 figs.

  10. Rocky Flats Ash test procedure (sludge stabilization)

    SciTech Connect (OSTI)

    Funston, G.A.

    1995-06-14

    Rocky Flats Ash items have been identified as the next set of materials to be stabilized. This test is being run to determine charge sizes and soak times to completely stabilize the Rocky Flats Ash items. The information gathered will be used to generate the heating rampup cycle for stabilization. The test will provide information to determine charge sizes, soak times and mesh screen sizes (if available at time of test) for stabilization of Rocky Flats Ash items to be processed in the HC-21C Muffle Furnace Process. Once the charge size and soak times have been established, a program for the temperature controller of the HC-21C Muffle Furnace process will be generated for processing Rocky Flats Ash.

  11. Flue gas desulfurization gypsum and fly ash

    SciTech Connect (OSTI)

    Not Available

    1992-05-01

    The Cumberland Fossil Plant (CUF) is located in Stewart County, Tennessee, and began commercial operation in 1972. This is the Tennessee Valley Authority`s newest fossil (coal-burning) steam electric generating plant. Under current operating conditions, the plant burns approximately seven million tons of coal annually. By-products from the combustion of coal are fly ash, approximately 428,000 tons annually, and bottom ash, approximately 115,000 tons annually. Based on historical load and projected ash production rates, a study was initially undertaken to identify feasible alternatives for marketing, utilization and disposal of ash by-products. The preferred alternative to ensure that facilities are planned for all by-products which will potentially be generated at CUF is to plan facilities to handle wet FGD gypsum and dry fly ash. A number of different sites were evaluated for their suitability for development as FGD gypsum and ash storage facilities. LAW Engineering was contracted to conduct onsite explorations of sites to develop information on the general mature of subsurface soil, rock and groundwater conditions in the site areas. Surveys were also conducted on each site to assess the presence of endangered and threatened species, wetlands and floodplains, archaeological and cultural resources, prime farmland and other site characteristics which must be considered from an environmental perspective.

  12. Impurity effects in superconducting UPt sub 3

    SciTech Connect (OSTI)

    Aronson, M.C. (The Harrison M. Randall Laboratory of Physics, The University of Michigan, Ann Arbor, Michigan 48109 (USA)); Vorenkamp, T.; Koziol, Z.; de Visser, A.; Bakker, K.; Franse, J.J.M. (Natuurkundig Laboratorium der Universiteit van Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam, The Netherlands (USA)); Smith, J.L. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (USA))

    1991-04-15

    Superconducting UPt{sub 3} is characterized by a novel and complex magnetic field-temperature phase diagram, with two superconducting transitions at {ital T}{sub {ital c}1} and {ital T}{sub {ital c}2} in zero field. We have studied the effects of Pd and Y impurities on the zero field superconducting properties of UPt{sub 3}. Resistance measurements show that both dopants increase the residual resistivity and decrease the spin fluctuation temperature in the normal state. {ital T}{sub {ital c}1} is depressed by both dopants, but more effectively by Pd. {vert bar}{ital T}{sub {ital c}1} {minus} {ital T}{sub {ital c}2}{vert bar} is essentially unaffected by Y doping, but increases dramatically with Pd doping.

  13. Impurity Transport Studies in the Wendelstein 7-AS Stellarator

    SciTech Connect (OSTI)

    Burhenn, Rainer; Baldzuhn, Juergen; Brakel, Rudolf

    2004-07-15

    The dependence of impurity transport on plasma parameters in the modular stellarator Wendelstein 7-AS was investigated by means of a laser blow-off technique. An increased impurity transport at higher heating power and lower magnetic field strength as well as no effect of the isotope composition on the impurity confinement was observed. The most critical scaling with respect to stationary operation at high density is the improved confinement of impurities at high densities, leading to a degradation of plasma energy by increasing radiation and to a loss of density control. This was attributed to a reduction of the impurity diffusion coefficient with density. After installation of island divertor modules, a transition from normal confinement into the high-density H-mode (HDH) at a certain power-dependent threshold density appeared. This transition is characterized by a strong reduction of the impurity confinement time and an increase in energy confinement time. In the HDH operational regime, access to even higher densities (4 x 10{sup 20} m{sup -3}) than achieved before became possible under stationary operation conditions. Impurity transport measurements and model predictions indicate that the reduction of the impurity confinement in HDH is caused by not only a reduction of the inward convection in the core plasma but also possibly by changes in the edge transport. Comparison of experimental data with an axisymmetric transport model should elucidate the role of stellarator-specific transport aspects.

  14. Quantum entanglement in the two-impurity Kondo model

    SciTech Connect (OSTI)

    Cho, Sam Young; McKenzie, Ross H.

    2006-01-15

    In order to quantify quantum entanglement in two-impurity Kondo systems, we calculate the concurrence, negativity, and von Neumann entropy. The entanglement of the two Kondo impurities is shown to be determined by two competing many-body effects, namely the Kondo effect and the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, I. Due to the spin-rotational invariance of the ground state, the concurrence and negativity are uniquely determined by the spin-spin correlation between the impurities. It is found that there exists a critical minimum value of the antiferromagnetic correlation between the impurity spins which is necessary for entanglement of the two impurity spins. The critical value is discussed in relation with the unstable fixed point in the two-impurity Kondo problem. Specifically, at the fixed point there is no entanglement between the impurity spins. Entanglement will only be created [and quantum information processing (QIP) will only be possible] if the RKKY interaction exchange energy, I, is at least several times larger than the Kondo temperature, T{sub K}. Quantitative criteria for QIP are given in terms of the impurity spin-spin correlation.

  15. Single atom impurity in a single molecular transistor

    SciTech Connect (OSTI)

    Ray, S. J.

    2014-10-21

    The influence of an impurity atom on the electrostatic behaviour of a Single Molecular Transistor was investigated through Ab-initio calculations in a double-gated geometry. The charge stability diagram carries unique signature of the position of the impurity atom in such devices which together with the charging energy of the molecule could be utilised as an electronic fingerprint for the detection of such impurity states in a nano-electronic device. The two gated geometry allows additional control over the electrostatics as can be seen from the total energy surfaces (for a specific charge state), which is sensitive to the positions of the impurity. These devices which are operational at room temperature can provide significant advantages over the conventional silicon based single dopant devices functional at low temperature. The present approach could be a very powerful tool for the detection and control of individual impurity atoms in a single molecular device and for applications in future molecular electronics.

  16. Effect of curing conditions on the geotechnical and geochemical properties of CFBC ashes

    SciTech Connect (OSTI)

    Bland, A.E.

    1999-07-01

    Western Research Institute, in cooperation with the US Department of Energy Federal Energy Technology Center, initiated a multi-year program to examine the relationship between CFBC ash chemistry and geotechnical properties as they relate to ash disposal and utilization. Four CFBC facilities supplied ash from their units for the study representing high-sulfur (4%) and medium-sulfur (1.8%) bituminous coal. Sub-bituminous coal (0.9% sulfur) and petroleum coke (5--6% sulfur) fired ashes were also included in the study. The ashes were composed principally of large quantities of anhydrite (CaSO{sub 4}) and lime (CaO) and minor amounts of calcite (CaCO{sub 3}). The ash curing study addressed the impact of curing conditions (sealed and saturated curing and 23 C and 5 C curing temperature) on the geochemical and geotechnical properties of the ash. The strength development and expansion varied with the type and characteristics of the ashes. The expansion appeared to be inversely related to strength development. As the strength decreased under saturated curing, the expansion increased significantly. The application of 5 C saturated curing resulted in further strength loss and increased expansion. The hydration reaction products appeared to be principally the hydration of lime (CaO) to portlandite (Ca[OH]{sub 2}), the hydration of anhydrite (CaSO{sub 4}) to gypsum (CaSO{sub 4} {center{underscore}dot} 2H{sub 2}O), and the precipitation of ettringite (Ca{sub 6}Al{sub 2}[SO{sub 4}]{sub 3}[OH]{sub 12} {center{underscore}dot} 26H{sub 2}O) from the soluble calcium, sulfates and alumina. No thaumasite was noted in the specimens. The ashes appeared to follow one of several hydration reaction trends: (1) ettringite-only development, (2) ettringite and/or gypsum early followed by later gypsum formation, or (3) gypsum-only formation. Testing confirmed that the hydration reaction chemistry was related to geotechnical properties of the ashes. Strength development and expansion appeared to

  17. Gel nanostructure in alkali-activated binders based on slag and fly ash, and effects of accelerated carbonation

    SciTech Connect (OSTI)

    Bernal, Susan A.; Provis, John L.; Walkley, Brant; San Nicolas, Rackel; Gehman, John D.; Brice, David G.; Kilcullen, Adam R.; Duxson, Peter; Deventer, Jannie S.J. van

    2013-11-15

    Binders formed through alkali-activation of slags and fly ashes, including ‘fly ash geopolymers’, provide appealing properties as binders for low-emissions concrete production. However, the changes in pH and pore solution chemistry induced during accelerated carbonation testing provide unrealistically low predictions of in-service carbonation resistance. The aluminosilicate gel remaining in an alkali-activated slag system after accelerated carbonation is highly polymerised, consistent with a decalcification mechanism, while fly ash-based binders mainly carbonate through precipitation of alkali salts (bicarbonates at elevated CO{sub 2} concentrations, or carbonates under natural exposure) from the pore solution, with little change in the binder gel identifiable by nuclear magnetic resonance spectroscopy. In activated fly ash/slag blends, two distinct gels (C–A–S–H and N–A–S–H) are formed; under accelerated carbonation, the N–A–S–H gel behaves comparably to fly ash-based systems, while the C–A–S–H gel is decalcified similarly to alkali-activated slag. This provides new scope for durability optimisation, and for developing appropriate testing methodologies. -- Highlights: •C-A-S-H gel in alkali-activated slag decalcifies during accelerated carbonation. •Alkali-activated fly ash gel changes much less under CO{sub 2} exposure. •Blended slag-fly ash binder contains two coexisting gel types. •These two gels respond differently to carbonation. •Understanding of carbonation mechanisms is essential in developing test methods.

  18. Apparatus for purifying arsine, phosphine, ammonia, and inert gases to remove Lewis acid and oxidant impurities therefrom

    DOE Patents [OSTI]

    Tom, Glenn M.; Brown, Duncan W.

    1991-01-08

    An apparatus for purifying a gaseous mixture comprising arsine, phosphine, ammonia, and/or inert gases, to remove Lewis acid and/or oxidant impurities therefrom, comprising a vessel containing a bed of a scavenger, the scavenger including a support having associated therewith an anion which is effective to remove such impurities, such anion being selected from one or more members of the group consisting of: (i) carbanions whose corresponding protonated compounds have a pK.sub.a value of from about 22 to about 36; and (ii) anions formed by reaction of such carbanions with the primary component of the mixture.

  19. Comparative study on the characteristics of fly ash and bottom ash geopolymers

    SciTech Connect (OSTI)

    Chindaprasirt, Prinya; Jaturapitakkul, Chai; Chalee, Wichian; Rattanasak, Ubolluk

    2009-02-15

    This research was conducted to compare geopolymers made from fly ash and ground bottom ash. Sodium hydroxide (NaOH) and sodium silicate (Na{sub 2}SiO{sub 3}) solutions were used as activators. A mass ratio of 1.5 Na{sub 2}SiO{sub 3}/NaOH and three concentrations of NaOH (5, 10, and 15 M) were used; the geopolymers were cured at 65 deg. C for 48 h. A Fourier transform infrared spectrometer (FT-IR), differential scanning calorimeter (DSC), and scanning electron microscope (SEM) were used on the geopolymer pastes. Geopolymer mortars were also prepared in order to investigate compressive strength. The results show that both fly ash and bottom ash can be utilized as source materials for the production of geopolymers. The properties of the geopolymers are dependent on source materials and the NaOH concentration. Fly ash is more reactive and produces a higher degree of geopolymerization in comparison with bottom ash. The moderate NaOH concentration of 10 M is found to be suitable and gives fly ash and bottom ash geopolymer mortars with compressive strengths of 35 and 18 MPa.

  20. Scale-Up and Demonstration of Fly Ash Ozonation Technology

    SciTech Connect (OSTI)

    Rui Afonso; R. Hurt; I. Kulaots

    2006-03-01

    The disposal of fly ash from the combustion of coal has become increasingly important. When the fly ash does not meet the required specification for the product or market intended, it is necessary to beneficiate it to achieve the desired quality. This project, conducted at PPL's Montour SES, is the first near full-scale ({approx}10 ton/day), demonstration of ash ozonation technology. Bituminous and sub bituminous ashes, including two ash samples that contained activated carbon, were treated during the project. Results from the tests were very promising. The ashes were successfully treated with ozone, yielding concrete-suitable ash quality. Preliminary process cost estimates indicate that capital and operating costs to treat unburned carbon are competitive with other commercial ash beneficiation technologies at a fraction of the cost of lost sales and/or ash disposal costs. This is the final technical report under DOE Cooperative Agreement No.: DE-FC26-03NT41730.

  1. Four-year prospective study of the respiratory effects of volcanic ash from Mt. St. Helens

    SciTech Connect (OSTI)

    Buist, A.S.; Vollmer, W.M.; Johnson, L.R.; Bernstein, R.S.; McCamant, L.E.

    1986-04-01

    This report describes the 4-yr follow-up of 712 loggers exposed over an extended period to varying levels of fresh volcanic ash from the 1980 eruptions of Mt. St. Helens. Concerns related to the irritant effect the ash might have on the airways and also to its fibrogenic potential if exposures were intense and continued over many years. Our subjects were divided into 3 groups: high, low, and no exposure. Baseline testing was begun in June 1980, 1 month after the major eruption, and follow-up testing continued on an annual basis through 1984; 88% of the loggers have been tested at least 3 times. Analysis of lung function data showed that a significant, exposure-related decline in FEV1 occurred during the first year after the eruption. The decline was short-lived, however, and by 1984 the differences between exposure groups were no longer significant. Self-reported symptoms of cough, phlegm, and wheeze showed a similar pattern. No ash-related changes were seen in chest roentgenograms taken in 1980 and in 1984. Our findings are consistent with the hypothesis that the inhaled ash caused mucus hypersecretion and/or airway inflammation that reversed when the exposure levels decreased. The ash levels to which the loggers were exposed were low compared with permissible occupational levels for nuisance dusts, but generally higher than the total suspended particulate levels permissible in ambient air.

  2. Tungsten impurity transport experiments in Alcator C-Mod to address...

    Office of Scientific and Technical Information (OSTI)

    Tungsten impurity transport experiments in Alcator C-Mod to address high priority research and development for ITER Citation Details In-Document Search Title: Tungsten impurity ...

  3. Hydrothermal reaction of fly ash. Final report

    SciTech Connect (OSTI)

    Brown, P.W.

    1994-12-31

    The reactions which occur when fly ash is treated under hydrothermal conditions were investigated. This was done for the following primary reasons. The first of these is to determine the nature of the phases that form to assess the stabilities of these phases in the ambient environment and, finally, to assess whether these phases are capable of sequestering hazardous species. The second reason for undertaking this study was whether, depending on the composition of the ash and the presence of selected additives, it would be possible under hydrothermal conditions to form compounds which have cementitious properties. Formation of four classes of compounds, which bracket likely fly ash compositional ranges, were selected for study. The classes are calcium silicate hydrates, calcium selenates, and calcium aluminosulfates, and silicate-based glasses. Specific compounds synthesized were determined and their stability regions assessed. As part of stability assessment, the extent to which selected hazardous species are sequestered was determined. Finally, the cementing properties of these compounds were established. The results obtained in this program have demonstrated that mild hydrothermal conditions can be employed to improve the reactivity of fly ash. Such improvements in reactivity can result in the formation of monolithic forms which may exhibit suitable mechanical properties for selected applications as building materials. If the ashes involved are considered hazardous, the mechanical properties exhibited indicated the forms could be handled in a manner which facilitates their disposal.

  4. Extraction process for removing metallic impurities from alkalide metals

    DOE Patents [OSTI]

    Royer, L.T.

    1987-03-20

    A development is described for removing metallic impurities from alkali metals by employing an extraction process wherein the metallic impurities are extracted from a molten alkali metal into molten lithium metal due to the immiscibility of the alkali metals in lithium and the miscibility of the metallic contaminants or impurities in the lithium. The purified alkali metal may be readily separated from the contaminant-containing lithium metal by simple decanting due to the differences in densities and melting temperatures of the alkali metals as compared to lithium.

  5. Alternating current response of carbon nanotubes with randomly distributed impurities

    SciTech Connect (OSTI)

    Hirai, Daisuke; Watanabe, Satoshi [Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Yamamoto, Takahiro [Department of Electrical Engineering and Department of Liberal Arts (Physics), Tokyo University of Science, 6-3-1 Niijuku, Katsushika, Tokyo 125-8585 (Japan)

    2014-10-27

    The increasing need for nanodevices has necessitated a better understanding of the electronic transport behavior of nanomaterials. We therefore theoretically examine the AC transport properties of metallic carbon nanotubes with randomly distributed impurities. We find that the long-range impurity scattering increases the emittance, but does not affect the DC conductance. The estimated dwell time of electrons increases with the potential amplitudes. That is, multiple scattering by the impurities increases the kinetic inductance in proportion to the dwell time, which eventually increases the emittance. We believe that our findings can contribute significantly to nanodevice development.

  6. Germanium blocked impurity band infrared detectors

    SciTech Connect (OSTI)

    Rossington, C.S.; Haller, E.E.

    1988-08-01

    Germanium blocked impurity band (BIB) photoconductors have been fabricated and characterized for responsivity, dark current, and noise equivalent power. BIB photoconductors theoretically provide an extension of the spectral response, a reduction in sensitivity to cosmic radiation and a reduction in noise characteristics compared with conventional photoconductors. Silicon BIB detectors have been successfully developed by researchers at Rockwell International, which do indeed meet their theoretical potential. In the proper configuration, these same Si BIB detectors are capable of continuous detection of individual photons in the wavelength range from 0.4 to 28 ..mu..m. Until the BIB concept was developed, detection of individual photons was only possible with photomultiplier tubes which detected visible light. Due to the successes of the Si BIB detectors, it seemed natural to extend this concept to Ge detectors, which would then allow an extension of the spectral response over conventional Ge detectors from /approximately/100 ..mu..m to /approximately/200 ..mu..m. 8 refs., 2 figs.

  7. Extraction of trace metals from fly ash

    DOE Patents [OSTI]

    Blander, Milton; Wai, Chien M.; Nagy, Zoltan

    1984-01-01

    A process for recovering silver, gallium and/or other trace metals from a fine grained industrial fly ash associated with a process for producing phosphorous, the fly ash having a silicate base and containing surface deposits of the trace metals as oxides, chlorides or the like, with the process being carried out by contacting the fly ash with AlCl.sub.3 in an alkali halide melt to react the trace metals with the AlCl.sub.3 to form compositions soluble in the melt and a residue containing the silicate and aluminum oxide or other aluminum precipitate, and separating the desired trace metal or metals from the melt by electrolysis or other separation techniques.

  8. Extraction of trace metals from fly ash

    DOE Patents [OSTI]

    Blander, M.; Wai, C.M.; Nagy, Z.

    1983-08-15

    A process is described for recovering silver, gallium and/or other trace metals from a fine grained industrial fly ash associated with a process for producing phosphorous. The fly ash has a silicate base and contains surface deposits of the trace metals as oxides, chlorides or the like. The process is carried out by contacting the fly ash with AlCl/sub 3/ in an alkali halide melt to react the trace metals with the AlCl/sub 3/ to form compositions soluble in the melt and a residue containing the silicate and aluminum oxide or other aluminum precipitate, and separating the desired trace metal or metals from the melt by electrolysis or other separation techniques.

  9. Correlation between the critical viscosity and ash fusion temperatures of coal gasifier ashes

    SciTech Connect (OSTI)

    Hsieh, Peter Y.; Kwong, Kyei-Sing; Bennett, James

    2015-09-27

    Coal gasification yields synthesis gas, an important intermediate in chemical manufacturing. It is also vital to the production of liquid fuels through the Fischer-Tropsch process and electricity in Integrated Gasification Combined Cycle power generation. Minerals naturally present in coal become molten in entrained-flow slagging gasifiers. Molten coal ash slag penetrates and dissolves refractory bricks, leading to costly plant shutdowns. The extent of coal ash slag penetration and refractory brick dissolution depends on the slag viscosity, the gasification temperature, and the composition of slag and bricks. Here, we measured the viscosity of several synthetic coal ash slags with a high-temperature rotary viscometer and their ash fusion temperatures through optical image analysis. We made all measurements in a carbon monoxide-carbon dioxide reducing atmosphere that approximates coal gasification conditions. Empirical correlation models based on ash fusion temperatures were used to calculate critical viscosity temperatures based on the coal ash compositions. These values were then compared with those obtained from thermodynamic phase-transition models. Finally, an understanding of slag viscosity as a function of ash composition is important to reducing refractory wear in slagging coal gasifiers, which would help to reduce the cost and environmental impact of coal for chemical and electricity production.

  10. Market assessment and technical feasibility study of PFBC ash use

    SciTech Connect (OSTI)

    Smith, V.E.; Bland, A.E.; Brown, T.H.; Georgiou, D.N.; Wheeldon, J.

    1994-10-01

    The overall objectives of this study are to determine the market potential and the technical feasibility of using PFBC ash in high volume ash use applications. The information will be of direct use to the utility industry in assessing the economics of PFBC power generation in light of ash disposal avoidance through ash marketing. In addition, the research is expected to result in the generation of generic data on the use of PFBC ash that could lead to novel processing options and procedures. The specific objectives of the proposed research and demonstration effort are: Define resent and future market potential of PFBC ash for a range of applications (Phase I); assess the technical feasibility of PFBC ash use in construction, civil engineering and agricultural applications (Phase II); and demonstrate the most promising of the market and ash use options in full-scale field demonstrations (Phase III).

  11. High carbon fly ash finds uses in highway construction

    SciTech Connect (OSTI)

    Wen, H.; Patton, R.

    2008-07-01

    The beneficial use of high carbon fly ash in a highway construction project is discussed. The fly ash also had a relatively high content of mercury and some other heavy metals. 1 fig., 4 photos.

  12. Eco-friendly fly ash utilization: potential for land application

    SciTech Connect (OSTI)

    Malik, A.; Thapliyal, A.

    2009-07-01

    The increase in demand for power in domestic, agricultural, and industrial sectors has increased the pressure on coal combustion and aggravated the problem of fly ash generation/disposal. Consequently the research targeting effective utilization of fly ash has also gained momentum. Fly ash has proved to be an economical substitute for expensive adsorbents as well as a suitable raw material for brick manufacturing, zeolite synthesis, etc. Fly ash is a reservoir of essential minerals but is deficient in nitrogen and phosphorus. By amending fly ash with soil and/or various organic materials (sewage sludge, bioprocess materials) as well as microbial inoculants like mycorrhizae, enhanced plant growth can be realized. Based on the sound results of large scale studies, fly ash utilization has grown into prominent discipline supported by various internationally renowned organizations. This paper reviews attempts directed toward various utilization of fly ash, with an emphasis on land application of organic/microbial inoculants amended fly ash.

  13. Uncovering Fundamental Ash-Formation Mechanisms and Potential...

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

    Results illustrate ash particle growth and formation pathways, and influence of lubricant chemistry and exhaust conditions on fundamental ash properties deer12kamp.pdf (9.21 MB) ...

  14. Recovery Act Workers Complete Environmental Cleanup of Coal Ash...

    Office of Environmental Management (EM)

    Site (SRS) recently cleaned up a 17- acre basin containing coal ash residues from Cold War ... Recovery Act Workers Complete Environmental Cleanup of Coal Ash Basin U.S. Depar tment of ...

  15. Utilization of blended fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash in geopolymer

    SciTech Connect (OSTI)

    Chindaprasirt, Prinya; Rattanasak, Ubolluk

    2010-04-15

    In this paper, synthesis of geopolymer from fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash was studied in order to effectively utilize both ashes. FBC-fly ash and bottom ash were inter-ground to three different finenesses. The ashes were mixed with as-received PCC-fly ash in various proportions and used as source material for synthesis of geopolymer. Sodium silicate (Na{sub 2}SiO{sub 3}) and 10 M sodium hydroxide (NaOH) solutions at mass ratio of Na{sub 2}SiO{sub 3}/NaOH of 1.5 and curing temperature of 65 deg. C for 48 h were used for making geopolymer. X-ray diffraction (XRD), scanning electron microscopy (SEM), degree of reaction, and thermal gravimetric analysis (TGA) were performed on the geopolymer pastes. Compressive strength was also tested on geopolymer mortars. The results show that high strength geopolymer mortars of 35.0-44.0 MPa can be produced using mixture of ground FBC ash and as-received PCC-fly ash. Fine FBC ash is more reactive and results in higher degree of reaction and higher strength geopolymer as compared to the use of coarser FBC ash. Grinding increases reactivity of ash by means of increasing surface area and the amount of reactive phase of the ash. In addition, the packing effect due to fine particles also contributed to increase in strength of geopolymers.

  16. Using fly ash to mitigate explosions

    SciTech Connect (OSTI)

    Taulbee, D.

    2008-07-01

    In 2005 the University of Kentucky's Center for Applied Energy Research was given funding to evaluate the use of coal combustion by-products (CCBs) to reduce the explosive potential of ammonium nitrate (AN) fertilizers. Fly ash C (FAC), fly ash F (FAF) and flue gas desulfurization by-product (FGD) were evaluated. It was found that applying a CCB coating to the AN particles at concentrations of 5 wt% or greater prevented the AN explosion from propagating. The article reports on results so far and outlines further work to be done. 6 figs.

  17. Fly Ash Characteristics and Carbon Sequestration Potential

    SciTech Connect (OSTI)

    Palumbo, Anthony V.; Amonette, James E.; Tarver, Jana R.; Fagan, Lisa A.; McNeilly, Meghan S.; Daniels, William L.

    2007-07-20

    Concerns for the effects of global warming have lead to an interest in the potential for inexpensive methods to sequester carbon dioxide (CO2). One of the proposed methods is the sequestration of carbon in soil though the growth of crops or forests.4,6 If there is an economic value placed on sequestration of carbon dioxide in soil there may be an an opportunity and funding to utilize fly ash in the reclamation of mine soils and other degraded lands. However, concerns associated with the use of fly ash must be addressed before this practice can be widely adopted. There is a vast extent of degraded lands across the world that has some degree of potential for use in carbon sequestration. Degraded lands comprise nearly 2 X 109 ha of land throughout the world.7 Although the potential is obviously smaller in the United States, there are still approximately 4 X 106 ha of degraded lands that previously resulted from mining operations14 and an additional 1.4 X 108 ha of poorly managed lands. Thus, according to Lal and others the potential is to sequester approximately 11 Pg of carbon over the next 50 years.1,10 The realization of this potential will likely be dependent on economic incentives and the use of soil amendments such as fly ash. There are many potential benefits documented for the use of fly ash as a soil amendment. For example, fly ash has been shown to increase porosity, water-holding capacity, pH, conductivity, and dissolved SO42-, CO32-, HCO3-, Cl- and basic cations, although some effects are notably decreased in high-clay soils.8,13,9 The potential is that these effects will promote increased growth of plants (either trees or grasses) and result in greater carbon accumulation in the soil than in untreated degraded soils. This paper addresses the potential for carbon sequestration in soils amended with fly ash and examines some of the issues that should be considered in planning this option. We describe retrospective studies of soil carbon accumulation on

  18. Utilization options for fly ash, bottom ash, and slag in Eastern Europe

    SciTech Connect (OSTI)

    Manz, O.E.

    1995-12-01

    Since 1967, at least six ash utilization symposiums have been held in the United States, with papers presented by several European authors on the utilization of coal by-products in Eastern Europe. There is currently over 80,000 megawatts of installed coal-fired capacity available in that region. Unfortunately, of the 117,778,000 tonnes of fly ash, bottom ash, and slag produced in Eastern Europe in 1989, only 13% was utilized. This paper outlines the research and levels and kinds of coal by-product utilization taking place in Eastern Europe since the late 1960s.

  19. Fast Diffusion of Native Defects and Impurities in Perovskite...

    Office of Scientific and Technical Information (OSTI)

    in Perovskite Solar Cell Material CH 3 NH 3 PbI 3 Citation Details In-Document Search Title: Fast Diffusion of Native Defects and Impurities in Perovskite Solar Cell Material CH ...

  20. Accurate Detection of Impurities in Hydrogen Fuel at Lower Cost...

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

    Hydrogen and Fuel Cell Hydrogen and Fuel Cell Find More Like This Return to Search Accurate Detection of Impurities in Hydrogen Fuel at Lower Cost Advancing the science of fuel ...

  1. Evolution of quasiparticle states with and without a Zn impurity...

    Office of Scientific and Technical Information (OSTI)

    Title: Evolution of quasiparticle states with and without a Zn impurity in doped 122 iron pnictides Authors: Pan, Lihua ; Li, Jian ; Tai, Yuan-Yen ; Graf, Matthias J. ; Zhu, ...

  2. Impact of Fission Products Impurity on the Plutonium Content...

    Office of Scientific and Technical Information (OSTI)

    Impact of Fission Products Impurity on the Plutonium Content of Metal- and Oxide- Fuels in Sodium Cooled Fast Reactors Citation Details In-Document Search Title: Impact of Fission ...

  3. Uncovering Fundamental Ash-Formation Mechanisms and Potential Means to

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

    Control the Impact on DPF Performance and Engine Efficiency | Department of Energy Uncovering Fundamental Ash-Formation Mechanisms and Potential Means to Control the Impact on DPF Performance and Engine Efficiency Uncovering Fundamental Ash-Formation Mechanisms and Potential Means to Control the Impact on DPF Performance and Engine Efficiency Results illustrate ash particle growth and formation pathways, and influence of lubricant chemistry and exhaust conditions on fundamental ash

  4. Literature review of metal corrosion sensitivity in high temperature, high impurity hot cell atmospheres

    SciTech Connect (OSTI)

    Eberle, C.S.

    1997-09-01

    The pyrochemical conditions of spent nuclear fuel for the purpose of final disposal is being demonstrated at Argonne National Laboratory (ANL). One aspect of this program is to develop a lithium preprocessing stage for the Fuel Conditioning Facility (FCF). One of the design considerations under investigation in this program is the system`s corrosion response in the presence of irradiated commercial fuel as well as atmospheric impurities. Static corrosion coupon tests have been completed which demonstrate the potential corrosivity of the salt matrix in a worse case environment as well as provide a boundary for allowable impurities in the system during operation. The literature concerning corrosion of either fused salts or molten metals consistently emphasizes three similar features which are common to both systems: (1) the overall corrosion rate is strongly dependent on temperature, impurity concentration and flow velocity; (2) many different mechanisms can be involved in a specific corrosion process; and (3) corrosion rates will significantly increase as all three of these independent variables are increased. The qualitative and quantitative understanding of these corrosion results is important for this spent fuel program since all of these variables will increase as the process scale increases. The purpose of this work was to determine if any data existed which could provide a quantitative expectation for corrosion rates of refractory metals in a lithium chloride salt bath.

  5. Effects of Impurities of Fuel Cell Performance and Durability | Department

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

    of Energy of Fuel Cell Performance and Durability Effects of Impurities of Fuel Cell Performance and Durability This presentation, which focuses on fuel cell performance and durability, was given by Trent Molter of the University of Connecticut at a February 2007 meeting on new fuel cell projects. new_fc_molter_uconn.pdf (680.96 KB) More Documents & Publications The Effect of Airborne Contaminants on Fuel Cell Performance & Durability Effects of Impurities on Fuel Cell Performance

  6. Effects of Impurities on Fuel Cell Performance and Durability | Department

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

    of Energy on Fuel Cell Performance and Durability Effects of Impurities on Fuel Cell Performance and Durability This presentation, which focuses on fuel cell performance and durability, was given by James Goodwin of Clemson Univeristy at a February 2007 meeting on new fuel cell projects. new_fc_goodwin_clemson.pdf (322.34 KB) More Documents & Publications Acid Doped Membranes for High Temperature PEMFC Biogas Impurities and Cleanup for Fuel Cells Integration of Non-Traditional Membranes

  7. Impurity control and corrosion resistance of magnesium-aluminum alloy

    SciTech Connect (OSTI)

    Liu, M. [GM China Lab] [GM China Lab; Song, GuangLing [ORNL] [ORNL

    2013-01-01

    The corrosion resistance of magnesium alloys is very sensitive to the contents of impurity elements such as iron. In this study, a series of diecast AXJ530 magnesium alloy samples were prepared with additions of Mn and Fe. Through a comprehensive phase diagram calculation and corrosion evaluation, the mechanisms for the tolerance limit of Fe in magnesium alloy are discussed. This adds a new dimension to control the alloying impurity in terms of alloying composition design and casting conditions.

  8. On the state of Mn impurity implanted in Si

    SciTech Connect (OSTI)

    Orlov, A. F.; Bublik, V. T.; Vdovin, V. I.; Agafonov, Yu. A.; Balagurov, L. A.; Zinenko, V. I.; Kulemanov, I. V.; Shcherbachev, K. D.

    2009-07-15

    The state of manganese impurity in implanted silicon at implantation doses of up to 5 x 10{sup 16} cm{sup -2} has been investigated by X-ray diffraction and transmission electron microscopy. It is established that, after short-term vacuum annealing at 850{sup o}C, most of the implanted manganese impurities are in microinclusions up to 20 nm in size formed by a tetragonal silicide phase of the Mn{sub 15}Si{sub 26} type.

  9. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Wednesday, 26 October 2005 00:00 Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a

  10. Utilization of CFB fly ash for construction applications

    SciTech Connect (OSTI)

    Conn, R.E.; Sellakumar, K.; Bland, A.E.

    1999-07-01

    Disposal in landfills has been the most common means of handling ash in circulating fluidized bed (CFB) boiler power plants. Recently, larger CFB boilers with generating capacities up to 300 MWe are currently being planned, resulting in increased volumes and disposal cost of ash by-product. Studies have shown that CFB ashes do not pose environmental concerns that should significantly limit their potential utilization. Many uses of CFB ash are being investigated by Foster Wheeler, which can provide more cost-effective ash management. Construction applications have been identified as one of the major uses for CFB ashes. Typically, CFB ash cannot be used as a cement replacement in concrete due to its unacceptably high sulfur content. However, CFB ashes can be used for other construction applications that require less stringent specifications including soil stabilization, road base, structural fill, and synthetic aggregate. In this study, potential construction applications were identified for fly ashes from several CFB boilers firing diverse fuels such as petroleum coke, refuse derived fuel (RDF) and coal. The compressive strength of hydrated fly ashes was measured in order to screen their potential for use in various construction applications. Based on the results of this work, the effects of both ash chemistry and carbon content on utilization potential were ascertained. Actual beneficial uses of ashes evaluated in this study are also discussed.

  11. Oil ash corrosion; A review of utility boiler experience

    SciTech Connect (OSTI)

    Paul, L.D. ); Seeley, R.R. )

    1991-02-01

    In this paper a review of experience with oil ash corrosion is presented along with current design practices used to avoid excessive tube wastage. Factors influencing oil ash corrosion include fuel chemistry, boiler operation, and boiler design. These factors are interdependent and determine the corrosion behavior in utility boilers. Oil ash corrosion occurs when vanadium-containing ash deposits on boiler tube surfaces become molten. These molten ash deposits dissolve protective oxides and scales causing accelerated tube wastage. Vanadium is the major fuel constituent responsible for oil ash corrosion. Vanadium reacts with sodium, sulfur, and chlorine during combustion to produce lower melting temperature ash compositions, which accelerate tube wastage. Limiting tube metal temperatures will prevent ash deposits from becoming molten, thereby avoiding the onset of oil ash corrosion. Tube metal temperatures are limited by the use of a parallel stream flow and by limiting steam outlet temperatures. Operating a boiler with low excess air has helped avoid oil ash corrosion by altering the corrosive combustion products. Air mixing and distribution are essential to the success of this palliative action. High chromium alloys and coatings form more stable protective scaled on tubing surfaces, which result in lower oil ash corrosion rates. However, there is not material totally resistant to oil ash corrosion.

  12. Local spectroscopy of a kondo impurity: Co on Au(111)

    SciTech Connect (OSTI)

    Madhavan, V.; Chen, W.; Jamneala, T.; Crommie, M.F.; Wingreen, N.S.

    2001-07-15

    We present a detailed study of the local electronic properties of the Kondo system formed from cobalt adatoms deposited onto Au(111) at a temperature of 6.6 K. Cryogenic scanning-tunneling spectroscopy was used to observe impurity-induced resonances at the Fermi energy and at the Au(111) surface-state band edge. The line shape of the Fermi-energy resonance, identified as a Kondo resonance, is observed to vary with lateral position from the impurity center and with impurity binding position on the reconstructed Au(111) surface. Little vertical dependence is seen in the resonance line shape for positions above the center of the impurity. Interaction effects between Kondo impurities are observed to remain small as cobalt coverage is increased up to 1 ML on the gold surface. The Kondo resonance is shown theoretically to be a member of a general class of Fano resonances arising from the interaction of a discrete impurity state with a conduction-electron continuum. The asymmetric line shape of the resonance thus reflects quantum interference between the d orbital and continuum conduction electron channels, as well as their coupling to the STM tip.

  13. Shallow-deep transitions of impurities in semiconductor nanostructures

    SciTech Connect (OSTI)

    Ranjan, V.; Singh, Vijay A.

    2001-06-01

    We study the hydrogenic impurity in a quantum dot (QD). We employ the effective mass theory with realistic barrier and variable effective mass. The model is simple, but it predicts features not previously observed. We observe that the shallow hydrogenic impurity becomes deeper as the dot size (R) is reduced and with further reduction of the dot size it becomes shallow and at times resonant with the conduction band. Such a shallow-deep (SHADE) transition is investigated and a critical size in terms of the impurity Bohr radius (a{sub I}{sup *}) is identified. A relevant aspect of a QD is reduction in the dielectric constant, {epsilon}, as its size decreases. Employing a size dependent {epsilon}(R), we demonstrate that the impurity level gets exceptionally deep in systems for which a{sub I}{sup *} is small. Thus, carrier {open_quotes}freeze out{close_quotes} is a distinct possibility in a wide class of materials such as ZnS, CdS, etc. The behavior of the impurity level with dot size is understood on the basis of simple scaling arguments. Calculations are presented for III{endash}V (AlGaAs) and II{endash}VI (ZnS, CdS) QDs. We speculate that the deepening of the impurity level is related to the high luminescence efficiency of QDs. It is suggested that quantum dots offer an opportunity for defect engineering. {copyright} 2001 American Institute of Physics.

  14. Quantification of the degree of reaction of fly ash

    SciTech Connect (OSTI)

    Ben Haha, M.; De Weerdt, K.; Lothenbach, B.

    2010-11-15

    The quantification of the fly ash (FA) in FA blended cements is an important parameter to understand the effect of the fly ash on the hydration of OPC and on the microstructural development. The FA reaction in two different blended OPC-FA systems was studied using a selective dissolution technique based on EDTA/NaOH, diluted NaOH solution, the portlandite content and by backscattered electron image analysis. The amount of FA determined by selective dissolution using EDTA/NaOH is found to be associated with a significant possible error as different assumptions lead to large differences in the estimate of FA reacted. In addition, at longer hydration times, the reaction of the FA is underestimated by this method due to the presence of non-dissolved hydrates and MgO rich particles. The dissolution of FA in diluted NaOH solution agreed during the first days well with the dissolution as observed by image analysis. At 28 days and longer, the formation of hydrates in the diluted solutions leads to an underestimation. Image analysis appears to give consistent results and to be most reliable technique studied.

  15. 488-D Ash Basin Vegetative Cover Treatibility Study

    SciTech Connect (OSTI)

    Barton, Christopher; Marx, Don; Blake, John; Adriano, Domy; Koo, Bon-Jun; Czapka, Stephen

    2003-01-01

    The 488-D Ash Basin is an unlined containment basin that received ash and coal reject material from the operation of a powerhouse at the USDOE's Savannah River Site, SC. They pyretic nature of the coal rejects has resulted in the formation of acidic drainage (AD), which has contributed to groundwater deterioration and threatens biota in down gradient wetlands. Establishment of a vegetative cover was examined as a remedial alternative for reducing AD generation within this system by enhanced utilization of rainwater and subsequent non-point source water pollution control. The low nutrient content, high acidity, and high salinity of the basin material, however, was deleterious to plant survivability. As such, studies to identify suitable plant species and potential adaptations, and pretreatment techniques in the form of amendments, tilling, and/or chemical stabilization were needed. A randomized block design consisting of three subsurface treatments (blocks) and five duplicated surface amendments (treatments) was developed. One hundred inoculated pine trees were planted on each plot. Herbaceous species were also planted on half of the plots in duplicated 1-m2 beds. After two growing seasons, deep ripping, subsurface amendments and surface covers were shown to be essential for the successful establishment of vegetation on the basin. This is the final report of the study.

  16. Phase relationship in coal ash corrosion products

    SciTech Connect (OSTI)

    Kalmanovitch, D.

    1996-12-31

    The corrosion of heat transfer surfaces in coal-fired utility boilers is a major concern to the efficient operation of these units. Despite the importance of the corrosion there has been limited research on the relationship between the ash components on the tube surface and the interactions and reactions between the various components and the steel surface. Mechanisms such as molten phase corrosion, sulfidation, and high temperature oxidation have been identified as leading to extensive wastage oftube metal. However, while the corrosion process can be identified using techniques such as metallography and x-ray diffraction there is limited insight into the role ofthe coal mineralogy and ash deposits on the surface in the corrosion process. This paper describes research into the formation of molten or sernimolten phases within ash deposits which are associated with corrosion of superheater and reheater fireside surfaces. For example, the phases potassium pyrosulfate (K{sub 2}S{sub 2}O{sub 7}) and potassium aluminum sulfate (K{sub 2}Al{sub 2}SO{sub 7}) have been determined by x-ray diffraction to be present in deposits where fireside corrosion has occurred. However, both these phases are not directly derived from coal minerals or the common matrix observed in ash deposits. The examination of the reactions and interactions within deposits which result in the formation of these and other phases associated with corrosion will be discussed in the paper.

  17. Assessing ecological risks to the fish community from residual coal fly ash in Watts Bar Reservoir, Tennessee

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

    Rigg, David K.; Wacksman, Mitch N.; Iannuzzi, Jacqueline; Baker, Tyler F.; Adams, Marshall; Greeley, Jr., Mark Stephen

    2014-12-18

    For this research, extensive site-specific biological and environmental data were collected to support an evaluation of risks to the fish community in Watts Bar Reservoir from residual ash from the December 2008 Tennessee Valley Authority (TVA) Kingston ash release. This paper describes the approach used and results of the risk assessment for the fish community, which consists of multiple measurement endpoints (measures of exposure and effects) for fish. The lines of evidence included 1) comparing postspill annual fish community assessments with nearby prespill data and data from other TVA reservoirs, 2) evaluating possible effects of exposures of fish eggs andmore » larval fish to ash in controlled laboratory toxicity tests, 3) evaluating reproductive competence of field-exposed fish, 4) assessing individual fish health through physical examination, histopathology, and blood chemistry, 5) comparing fish tissue concentrations with literature-based critical body residues, and 6) comparing concentrations of ash-related contaminants in surface waters with US Environmental Protection Agency's (USEPA) Ambient Water Quality Standards for Fish and Aquatic Life. These measurement endpoints were treated as independent lines of evidence that were integrated into an overall weight-of-evidence estimate of risk to the fish community. Collectively, the data and analysis presented here indicate that ash and ash-related constituents pose negligible risks to the fish communities in Watts Bar Reservoir. This conclusion contradicts the predictions by some researchers immediately following the ash release of devastating effects on the aquatic ecology of Watts Bar Reservoir. The information presented in this article reaffirms the wisdom of carefully evaluating the evidence before predicting probable ecological effects of a major event such as the TVA Kingston ash release. Lastly, this study demonstrates that a thorough and detailed investigation using multiple measurement endpoints

  18. Assessing ecological risks to the fish community from residual coal fly ash in Watts Bar Reservoir, Tennessee

    SciTech Connect (OSTI)

    Rigg, David K.; Wacksman, Mitch N.; Iannuzzi, Jacqueline; Baker, Tyler F.; Adams, Marshall; Greeley, Jr., Mark Stephen

    2014-12-18

    For this research, extensive site-specific biological and environmental data were collected to support an evaluation of risks to the fish community in Watts Bar Reservoir from residual ash from the December 2008 Tennessee Valley Authority (TVA) Kingston ash release. This paper describes the approach used and results of the risk assessment for the fish community, which consists of multiple measurement endpoints (measures of exposure and effects) for fish. The lines of evidence included 1) comparing postspill annual fish community assessments with nearby prespill data and data from other TVA reservoirs, 2) evaluating possible effects of exposures of fish eggs and larval fish to ash in controlled laboratory toxicity tests, 3) evaluating reproductive competence of field-exposed fish, 4) assessing individual fish health through physical examination, histopathology, and blood chemistry, 5) comparing fish tissue concentrations with literature-based critical body residues, and 6) comparing concentrations of ash-related contaminants in surface waters with US Environmental Protection Agency's (USEPA) Ambient Water Quality Standards for Fish and Aquatic Life. These measurement endpoints were treated as independent lines of evidence that were integrated into an overall weight-of-evidence estimate of risk to the fish community. Collectively, the data and analysis presented here indicate that ash and ash-related constituents pose negligible risks to the fish communities in Watts Bar Reservoir. This conclusion contradicts the predictions by some researchers immediately following the ash release of devastating effects on the aquatic ecology of Watts Bar Reservoir. The information presented in this article reaffirms the wisdom of carefully evaluating the evidence before predicting probable ecological effects of a major event such as the TVA Kingston ash release. Lastly, this study demonstrates that a thorough and detailed investigation using multiple measurement endpoints is needed

  19. Non-equilibrium STLS approach to transport properties of single impurity Anderson model

    SciTech Connect (OSTI)

    Rezai, Raheleh Ebrahimi, Farshad

    2014-04-15

    In this work, using the non-equilibrium Keldysh formalism, we study the effects of the electronelectron interaction and the electron-spin correlation on the non-equilibrium Kondo effect and the transport properties of the symmetric single impurity Anderson model (SIAM) at zero temperature by generalizing the self-consistent method of Singwi, Tosi, Land, and Sjolander (STLS) for a single-band tight-binding model with Hubbard type interaction to out of equilibrium steady-states. We at first determine in a self-consistent manner the non-equilibrium spin correlation function, the effective Hubbard interaction, and the double-occupancy at the impurity site. Then, using the non-equilibrium STLS spin polarization function in the non-equilibrium formalism of the iterative perturbation theory (IPT) of Yosida and Yamada, and Horvatic and Zlatic, we compute the spectral density, the currentvoltage characteristics and the differential conductance as functions of the applied bias and the strength of on-site Hubbard interaction. We compare our spectral densities at zero bias with the results of numerical renormalization group (NRG) and depict the effects of the electronelectron interaction and electron-spin correlation at the impurity site on the aforementioned properties by comparing our numerical result with the order U{sup 2} IPT. Finally, we show that the obtained numerical results on the differential conductance have a quadratic universal scaling behavior and the resulting Kondo temperature shows an exponential behavior. -- Highlights: We introduce for the first time the non-equilibrium method of STLS for Hubbard type models. We determine the transport properties of SIAM using the non-equilibrium STLS method. We compare our results with order-U2 IPT and NRG. We show that non-equilibrium STLS, contrary to the GW and self-consistent RPA, produces the two Hubbard peaks in DOS. We show that the method keeps the universal scaling behavior and correct exponential behavior

  20. Stabilizing soft fine-grained soils with fly ash

    SciTech Connect (OSTI)

    Edil, T.B.; Acosta, H.A.; Benson, C.H.

    2006-03-15

    The objective of this study was to evaluate the effectiveness of self-cementing fly ashes derived from combustion of subbituminous coal at electric power plants for stabilization of soft fine-grained soils. California bearing ratio (CBR) and resilient modulus (M{sub r}) tests were conducted on mixtures prepared with seven soft fine-grained soils (six inorganic soils and one organic soil) and four fly ashes. The soils were selected to represent a relatively broad range of plasticity, with plasticity indices ranging between 15 and 38. Two of the fly ashes are high quality Class C ashes (per ASTM C 618) that are normally used in Portland cement concrete. The other ashes are off-specification ashes, meaning they do not meet the Class C or Class F criteria in ASTM C 618. Tests were conducted on soils and soil-fly ash mixtures prepared at optimum water content (a standardized condition), 7% wet of optimum water content (representative of the typical in situ condition in Wisconsin), and 9-18% wet of optimum water content (representative of a very wet in situ condition). Addition of fly ash resulted in appreciable increases in the CBR and M{sub r} of the inorganic soils. For water contents 7% wet of optimum, CBRs of the soils alone ranged between 1 and 5. Addition of 10% fly ash resulted in CBRs ranging between 8 and 17, and 18% fly ash resulted in CBRs between 15 and 31. Similarly, M{sub r} of the soil alone ranged between 3 and 15 MPa at 7% wet of optimum, whereas addition of 10% fly ash resulted in M{sub r} between 12 and 60 MPa and 18% fly ash resulted in M{sub r} between 51 and 106 MPa. In contrast, except for one fly ash, addition of fly ash generally had little effect on CBR or M{sub r} of the organic soil.

  1. Research in Hydrogen Passivation of Defects and Impurities in Silicon: Final Report, 2 May 2000-2 July 2003

    SciTech Connect (OSTI)

    Ashok, S.

    2004-12-01

    This subcontract report describes hydrogenating Si samples by different methods such as low-energy implantation, electron cyclotron resonance (ECR) plasma, and thermal diffusion. The samples were provided through NREL. The experimental work, carried out at Penn State, involved the study of hydrogen interaction with defects, trapping, migration, and formation of complexes. The principal vehicle for the latter study was ion implantation, and the intent to understand mechanisms of defect passivation and activation by hydrogen. NREL implemented a study of hydrogen passivation of impurities and defects in silicon solar cells. The work included theoretical and experimental components performed at different universities. The theoretical studies consisted of the calculation of the structure and parameters related to hydrogen diffusion and interactions of hydrogen with transition-metal impurities in silicon. Experimental studies involved measurements of hydrogen and hydrogen-impurity complexes, and diffusion properties of various species of hydrogen in Si. The experimental work at Penn State included introduction of hydrogen in a variety of PV Si by ECR plasma, low-energy ion implantation, and thermal diffusion. The specific tasks were the evaluation of hydrogen interaction with defects engineered by ion implantation; defect passivation, activation, and migration in hydrogenated Si under thermal anneal; and electrical activity of hydrogen-impurity complexes. Electrical characterization entailed I-V and C-V measurements, spreading resistance, and deep-level transient spectroscopy (DLTS).

  2. Fly ash and concrete: a study determines whether biomass, or coal co-firing fly ash, can be used in concrete

    SciTech Connect (OSTI)

    Wang, Shuangzhen; Baxter, Larry

    2006-08-01

    Current US national standards for using fly ash in concrete (ASTM C618) state that fly ash must come from coal combustion, thus precluding biomass-coal co-firing fly ash. The co-fired ash comes from a large and increasing fraction of US power plants due to rapid increases in co-firing opportunity fuels with coal. The fly ashes include coal fly ash, wood fly ash from pure wood combustion, biomass and coal co-fired fly ash SW1 and SW2. Also wood fly ash is blended with Class C or Class F to produce Wood C and Wood E. Concrete samples were prepared with fly ash replacing cement by 25%. All fly ash mixes except wood have a lower water demand than the pure cement mix. Fly ashes, either from coal or non coal combustion, increase the required air entraining agent (AEA) to meet the design specification of the mixes. If AEA is added arbitrarily without considering the amount or existence of fly ash results could lead to air content in concrete that is either too low or too high. Biomass fly ash does not impact concrete setting behaviour disproportionately. Switch grass-coal co-fired fly ash and blended wood fly ash generally lie within the range of pure coal fly ash strength. The 56 day flexure strength of all the fly ash mixes is comparable to that of the pure cement mix. The flexure strength from the coal-biomass co-fired fly ash does not differ much from pure coal fly ash. All fly ash concrete mixes exhibit lower chloride permeability than the pure cement mixes. In conclusion biomass coal co-fired fly ash perform similarly to coal fly ash in fresh and hardened concrete. As a result, there is no reason to exclude biomass-coal co-fired fly ash in concrete.

  3. Removal of fluoride impurities from UF.sub.6 gas

    DOE Patents [OSTI]

    Beitz, James V.

    1985-01-01

    A method of purifying a UF.sub.6 gas stream containing one or more metal fluoride impurities composed of a transuranic metal, transition metal or mixtures thereof, is carried out by contacting the gas stream with a bed of UF.sub.5 in a reaction vessel under conditions where at least one impurity reacts with the UF.sub.5 to form a nongaseous product and a treated gas stream, and removing the treated gas stream from contact with the bed. The nongaseous products are subsequently removed in a reaction with an active fluorine affording agent to form a gaseous impurity which is removed from the reaction vessel. The bed of UF.sub.5 is formed by the reduction of UF.sub.6 in the presence of UV light. One embodiment of the reaction vessel includes a plurality of UV light sources as tubes on which UF.sub.5 is formed.

  4. Removal of fluoride impurities from UF/sub 6/ gas

    DOE Patents [OSTI]

    Beitz, J.V.

    1984-01-06

    A method of purifying a UF/sub 6/ gas stream containing one or more metal fluoride impurities composed of a transuranic metal, transition metal or mixtures thereof, is carried out by contacting the gas stream with a bed of UF/sub 5/ in a reaction vessel under conditions where at least one impurity reacts with the UF/sub 5/ to form a nongaseous product and a treated gas stream, and removing the treated gas stream from contact with the bed. The nongaseous products are subsequently removed in a reaction with an active fluorine affording agent to form a gaseous impurity which is removed from the reaction vessel. The bed of UF/sub 5/ is formed by the reduction of UF/sub 6/ in the presence of uv light. One embodiment of the reaction vessel includes a plurality of uv light sources as tubes on which UF/sub 5/ is formed. 2 figures.

  5. Blocked impurity band hybrid infrared focal plane arrays for astronomy

    SciTech Connect (OSTI)

    Reynolds, D.B.; Seib, D.H.; Stetson, S.B.; Herter, T.; Rowlands, N.; Schoenwald, J.

    1989-02-01

    High-performance infrared hybrid focal plane arrays using 10 x 50 element Si:As Blocked-Impurity-Band (BIB) detectors (cut-off wavelength = 28 ..mu..m) and matching switched MOSFET multiplexers have been developed and characterized for space astronomy. Use of impurity band conduction technology provides detectors which are nuclear radiation hard and free of the many anomalies associated with conventional silicon photoconductive detectors. Emphasis in this paper is on recent advances in detector material quality which have led to significantly improved detector and hybrid characteristics. Results demonstrating increase quantum efficiency (particular at short wavelength infrared), obtained by varying the Blocked-Impurity-Band detector properties (infrared active layer thickness and arsenic doping profile), are summarized. Read noise and dark current for different temperatures have been measured and are also described. The hybrid array performance achieved clearly demonstrates that BIB detectors are well suited for use in astronomical instrumentation.

  6. Application of solid ash based catalysts in heterogeneous catalysis

    SciTech Connect (OSTI)

    Shaobin Wang

    2008-10-01

    Solid wastes, fly ash, and bottom ash are generated from coal and biomass combustion. Fly ash is mainly composed of various metal oxides and possesses higher thermal stability. Utilization of fly ash for other industrial applications provides a cost-effective and environmentally friendly way of recycling this solid waste, significantly reducing its environmental effects. On the one hand, due to the higher stability of its major component, aluminosilicates, fly ash could be employed as catalyst support by impregnation of other active components for various reactions. On the other hand, other chemical compounds in fly ash such as Fe{sub 2}O{sub 3} could also provide an active component making fly ash a catalyst for some reactions. In this paper, physicochemical properties of fly ash and its applications for heterogeneous catalysis as a catalyst support or catalyst in a variety of catalytic reactions were reviewed. Fly-ash-supported catalysts have shown good catalytic activities for H{sub 2} production, deSOx, deNOx, hydrocarbon oxidation, and hydrocracking, which are comparable to commercially used catalysts. As a catalyst itself, fly ash can also be effective for gas-phase oxidation of volatile organic compounds, aqueous-phase oxidation of organics, solid plastic pyrolysis, and solvent-free organic synthesis. 107 refs., 4 figs., 2 tabs.

  7. The leaching characteristics of selenium from coal fly ashes

    SciTech Connect (OSTI)

    Wang, T.; Wang, J.; Burken, J.G.; Ban, H.; Ladwig, K.

    2007-11-15

    The leaching characteristics of selenium from several bituminous and subbituminous coal fly ashes under different pH conditions were investigated using batch methods. Results indicated that pH had a significant effect on selenium leaching from bituminous coal ash. The minimum selenium leaching occurred in the pH range between 3 and 4, while the maximum selenium leaching occurred at pH 12. The release of selenium from subbituminous coal ashes was very low for the entire experimental pH range, possibly due to the high content of calcium which can form hydration or precipitation products as a sink for selenium. The adsorption results for different selenium species indicated that Se(VI) was hardly adsorbable on either bituminous coal ashes or subbitumminous coal ashes at any pH. However, Se(I) was highly adsorbed by bituminous coal ashes under acidic pH conditions and was mostly removed by subbitumminous coal ashes across the entire pH range. This result suggests that the majority of selenium released from the tested fly ashes was Se(IV). A speciation-based model was developed to simulate the adsorption of Se(IV) on bituminous coal fly ash, and the pH-independent adsorption constants of HSeO{sup 3-} and SeO{sub 3}{sup 2-} were determined. The modeling approach is useful for understanding and predicting the release process of selenium from fly ash.

  8. Water quality investigation of Kingston Fossil Plant dry ash stacking

    SciTech Connect (OSTI)

    Bohac, C.E.

    1990-04-01

    Changing to a dry ash disposal systems at Kingston Fossil Plant (KFP) raises several water quality issues. The first is that removing the fly ash from the ash pond could alter the characteristics of the ash pond discharge to the river. The second concerns proper disposal of the runoff and possibly leachate from the dry ash stack. The third is that dry ash stacking might change the potential for groundwater contamination at the KFP. This report addresses each of these issues. The effects on the ash pond and its discharge are described first. The report is intended to provide reference material to TVA staff in preparation of environmental review documents for new ash disposal areas at Kingston. Although the investigation was directed toward analysis of dry stacking, considerations for other disposal options are also discussed. This report was reviewed in draft form under the title Assessment of Kingston Fossil Plant Dry Ash Stacking on the Ash Pond and Groundwater Quality.'' 11 refs., 3 figs., 18 tabs.

  9. Helium transport and ash control studies

    SciTech Connect (OSTI)

    Miley, G.H.

    1992-01-01

    The Primary goal of this research is to develop a helium (ash) transport scaling law based on experimental data from devices such as TFTR and JET. To illustrate the importance of this, we have studied ash accumulation effects on ignition requirements using a O-D transport model. Ash accumulation is characterized in the model by the ratio of the helium particle confinement time to the energy confinement time t{sub {alpha}}/t{sub E}. Results show that the ignition window'' shrinks rapidly as t{sub {alpha}}/t{sub E} increases, closing for high t{sub {alpha}}/t{sub E} increases, closing for high t{sub {alpha}}/t{sub E}. A best'' value for t{sub {alpha}}/t{sub E} will ultimately be determined from our scaling law studies. A helium transport scaling law is being sought that expresses the transport coefficients (D{sub {alpha}}, V{sub {alpha}}) as a function of the local plasma parameters. This is necessary for use in transport code calculations, e.g. for BALDUR. Based on experimental data from L-mode plasma operation in TFTR, a scaling law to a power law expression has been obtained using a least-square fit method. It is found that the transport coefficients are strongly affected by the local magnetic field and safety factor q. A preliminary conclusion from this work is that active control of ash buildup must be developed. To study control, we have developed a O-D plasma model which employs a simple pole-placement control model. Some preliminary calculations with this model are presented.

  10. Eirich technology for the preparation of ashes

    SciTech Connect (OSTI)

    Eirich, G.

    1994-12-31

    The paper describes a mixer manufactured by Maschinenfabrik Gustav Eirich that can be used in the agglomeration of power plant ashes and residues. No matter whether the power plant burns coal, fuel oil, wood, peat, or garbage or whether the power plant plans to dispose or utilize the residue, most flowsheets will contain an agglomeration step. The paper describes some of the uses to which this mixer can be put.

  11. Manufacture of ceramic tiles from fly ash

    DOE Patents [OSTI]

    Hnat, James G.; Mathur, Akshay; Simpson, James C.

    1999-01-01

    The present invention relates to a process for forming glass-ceramic tiles. Fly ash containing organic material, metal contaminants, and glass forming materials is oxidized under conditions effective to combust the organic material and partially oxidize the metallic contaminants and the glass forming materials. The oxidized glass forming materials are vitrified to form a glass melt. This glass melt is then formed into tiles containing metallic contaminants.

  12. Manufacture of ceramic tiles from fly ash

    DOE Patents [OSTI]

    Hnat, J.G.; Mathur, A.; Simpson, J.C.

    1999-08-10

    The present invention relates to a process for forming glass-ceramic tiles. Fly ash containing organic material, metal contaminants, and glass forming materials is oxidized under conditions effective to combust the organic material and partially oxidize the metallic contaminants and the glass forming materials. The oxidized glass forming materials are vitrified to form a glass melt. This glass melt is then formed into tiles containing metallic contaminants. 6 figs.

  13. Self-consistent klystron simulations

    SciTech Connect (OSTI)

    Carlsten, B.E.; Tallerico, P.J.

    1985-01-01

    A numerical analysis of large-signal klystron behavior based on general wave-particle interaction theory is presented. The computer code presented is tailored for the minimum amount of complexity needed in klystron simulation. The code includes self-consistent electron motion, space-charge fields, and intermediate and output fields. It also includes use of time periodicity to simplify the problem, accurate representation of the space-charge fields, accurate representation of the cavity standing-wave fields, and a sophisticated particle-pushing routine. In the paper, examples are given that show the effects of cavity detunings, of varying the magnetic field profile, of electron beam asymmetries from the gun, and of variations in external load impedance. 4 refs., 7 figs.

  14. Market assessment of PFBC ash use

    SciTech Connect (OSTI)

    Bland, A. E.; Brown, T. H., Western Research Institute

    1998-01-01

    Pressurized fluidized bed combustion (PFBC) of coal is undergoing demonstration in the United States, as well as throughout the world. American Electric Power`s (AEP`s) bubbling PFBC 70 MWe Tidd demonstration program in Ohio and pilot-scale development at Foster Wheeler Energia Oy 10 MWth circulating PFBC at Karhula, Finland, have demonstrated the advantages of PFBC technology. Further technology development in the US is planned with the deployment of the technology at the MacIntosh Clean Coal project in Lakeland, Florida. Development of uses for solid wastes from PFBC coal-fired power systems is being actively pursued as part of the demonstration of PFBC technologies. Ashes collected from Foster Wheeler Energia Oy pilot circulating PFBC tests in Karhula, Finland, operating on (1) low sulfur subbituminous and (2) high sulfur bituminous coal; and ash from the AEP`s high-sulfur bituminous coal-fired bubbling PFBC in Brilliant, Ohio, were evaluated in laboratory and pilot-scale ash use testing at Western Research Institute (WRI).

  15. Phase relationships in coal ash corrosion products

    SciTech Connect (OSTI)

    Kalmanovitch, D.

    1996-10-01

    The corrosion of heat transfer surfaces in coal-fired utility boilers is a major concern to the efficient operation of these units. Despite the importance of the corrosion there has been limited research on the relationship between the ash components on the tube surface and the interactions and reactions between the various components and the steel surface. Mechanisms such as molten phase corrosion, sulfidation, and high temperature oxidation have been identified as leading to extensive wastage of tube metal. This paper describes research into the formation of molten or semimolten phases within ash deposits which are associated with corrosion of superheater and reheater fireside surfaces. For example, the phases potassium pyrosulfate (K{sub 2}S{sub 2}O{sub 7}) and potassium aluminum sulfate (K{sub 2}Al{sub 2}SO{sub 7}) have been determined by x-ray diffraction to be present in deposits where fireside corrosion has occurred. However, both these phases are not directly derived from coal minerals or the common matrix observed in ash deposits. The examination of the reactions and interactions within deposits which result a the formation of these and other phases associated with corrosion will be discussed in the paper.

  16. JV Task 120 - Coal Ash Resources Research Consortium Research

    SciTech Connect (OSTI)

    Debra Pflughoeft-Hassett; Loreal Heebink; David Hassett; Bruce Dockter; Kurt Eylands; Tera Buckley; Erick Zacher

    2009-03-28

    projects provide an opportunity for non-CARRC members to sponsor specific research or technology transfer consistent with CARRC goals. This report covers CARRC activities from January 2007 through March 2009. These activities have been reported in CARRC Annual Reports and in member meetings over the past 2 years. CARRC continues to work with industry and various government agencies with its research, development, demonstration, and promotional activities nearing completion at the time of submission of this report. CARRC expects to continue its service to the coal ash industry in 2009 and beyond to work toward the common goal of advancing coal ash utilization by solving CCP-related technical issues and promoting the environmentally safe, technically sound, and economically viable management of these complex and changing materials.

  17. Vitrification of simulated radioactive Rocky Flats plutonium containing ash residue with a Stir Melter System

    SciTech Connect (OSTI)

    Marra, J.C.; Kormanyos, K.R.; Overcamp, T.J.

    1996-10-01

    A demonstration trial has been completed in which a simulated Rocky Flats ash consisting of an industrial fly-ash material doped with cerium oxide was vitrified in an alloy tank Stir-Melter{trademark} System. The cerium oxide served as a substitute for plutonium oxide present in the actual Rocky Flats residue stream. The glass developed falls within the SiO{sub 2} + Al{sub 2}O{sub 3}/{Sigma}Alkali/B{sub 2}O{sub 3} system. The glass batch contained approximately 40 wt% of ash, the ash was modified to contain {approximately} 5 wt% CeO{sub 2} to simulate plutonium chemistry in the glass. The ash simulant was mixed with water and fed to the Stir-Melter as a slurry with a 60 wt% water to 40 wt% solids ratio. Glass melting temperature was maintained at approximately 1,050 C during the melting trials. Melting rates as functions of impeller speed and slurry feed rate were determined. An optimal melting rate was established through a series of evolutionary variations of the control variables` settings. The optimal melting rate condition was used for a continuous six hour steady state run of the vitrification system. Glass mass flow rates of the melter were measured and correlated with the slurry feed mass flow. Melter off-gas was sampled for particulate and volatile species over a period of four hours during the steady state run. Glass composition and durability studies were run on samples collected during the steady state run.

  18. Utilization of ash from municipal solid waste combustion

    SciTech Connect (OSTI)

    Jones, C.; Hahn, J.; Magee, B.; Yuen, N.; Sandefur, K.; Tom, J.; Yap, C.

    1999-09-01

    This ash study investigated the beneficial use of municipal waste combustion combined ash from the H-POWER facility in Oahu. These uses were grouped into intermediate cover for final closure of the Waipahu landfill, daily cover at the Waimanalo Gulch Landfill, and partial replacement for aggregate in asphalt for road paving. All proposed uses examine combined fly and bottom ash from a modern waste-to-energy facility that meets requirements of the Clean Air Act Amendments for Maximum Achievable Control Technology.

  19. Development of Artificial Ash Accelerated Accumulation Test | Department of

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

    Energy Artificial Ash Accelerated Accumulation Test Development of Artificial Ash Accelerated Accumulation Test Poster presented at the 16th Directions in Engine-Efficiency and Emissions Research (DEER) Conference in Detroit, MI, September 27-30, 2010. p-04_fujii.pdf (138.91 KB) More Documents & Publications Impact of Honeycomb Ceramics Geometrical Cell Design on Urea SCR System Controlled Experiments on the Effects of Lubricant/Additive (Low-Ash, Ashless) Characteristics on DPF

  20. Lubricant Formulation and Consumption Effects on Diesel Exhaust Ash

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

    Emissions: | Department of Energy Lubricant Formulation and Consumption Effects on Diesel Exhaust Ash Emissions: Lubricant Formulation and Consumption Effects on Diesel Exhaust Ash Emissions: 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005_deer_plumley.pdf (398.5 KB) More Documents & Publications Detailed Characterization of Lubricant-Derived Ash-Related Species in Diesel Exhaust and Aftertreatment Systems Unraveling DPF Degradation using Chemical

  1. Recovery of aluminum and other metal values from fly ash

    DOE Patents [OSTI]

    McDowell, William J.; Seeley, Forest G.

    1981-01-01

    The invention described herein relates to a method for improving the acid leachability of aluminum and other metal values found in fly ash which comprises sintering the fly ash, prior to acid leaching, with a calcium sulfate-containing composition at a temperature at which the calcium sulfate is retained in said composition during sintering and for a time sufficient to quantitatively convert the aluminum in said fly ash into an acid-leachable form.

  2. Recovery of aluminum and other metal values from fly ash

    DOE Patents [OSTI]

    McDowell, W.J.; Seeley, F.G.

    1979-11-01

    The invention relates to a method for improving the acid leachability of aluminum and other metal values found in fly ash which comprises sintering the fly ash, prior to acid leaching, with a calcium sulfate-containing composition at a temperature at which the calcium sulfate is retained in said composition during sintering and for a time sufficient to quantitatively convert the aluminum in said fly ash into an acid-leachable form.

  3. High Carbon Fly Ash Treatment | netl.doe.gov

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

    High Carbon Fly Ash Treatment NETL Collaborators Invent Method for Treating High Carbon Fly Ash The U.S. Patent and Trademark Office has assigned Patent No. 8,440,015 to researchers from Waynesburg University and the National Energy Technology Laboratory (NETL) for a thermal method that retains yet passivates carbon and/or other components in fly ash. John Baltrus, a research chemist at NETL, along with Professor Robert LaCount and Douglas Kern of Waynesburg University cooperated on the

  4. Reducing Lubricant Ash Impact on Exhaust Aftertreatment with...

    Office of Environmental Management (EM)

    Reducing Lubricant Ash Impact on Exhaust Aftertreatment with a Oil Conditioning Filter Under the test conditions used in this study, the strong base filter had a significant and ...

  5. Retention of elemental mercury in fly ashes in different atmospheres

    SciTech Connect (OSTI)

    M.A. Lopez-Anton; M. Diaz-Somoano; M.R. Martinez-Tarazona

    2007-01-15

    Mercury is an extremely volatile element, which is emitted from coal combustion to the environment mostly in the vapor phase. To avoid the environmental problems that the toxic species of this element may cause, control technologies for the removal of mercury are necessary. Recent research has shown that certain fly ash materials have an affinity for mercury. Moreover, it has been observed that fly ashes may catalyze the oxidation of elemental mercury and facilitate its capture. However, the exact nature of Hg-fly ash interactions is still unknown, and mercury oxidation through fly ash needs to be investigated more thoroughly. In this work, the influence of a gas atmosphere on the retention of elemental mercury on fly ashes of different characteristics was evaluated. The retention capacity was estimated comparatively in inert and two gas atmospheres containing species present in coal gasification and coal combustion. Fly ashes produced in two pulverized coal combustion (PCC) plants, produced from coals of different rank (CTA and CTSR), and a fly ash (CTP) produced in a fluidized bed combustion (FBC) plant were used as raw materials. The mercury retention capacity of these fly ashes was compared to the retention obtained in different activated carbons. Although the capture of mercury is very similar in the gasification atmosphere and N{sub 2}, it is much more efficient in a coal combustion retention, being greater in fly ashes from PCC than those from FBC plants. 22 refs., 6 figs., 3 tabs.

  6. Data Summary Report for Hanford Site Coal Ash Characterization

    SciTech Connect (OSTI)

    Sulloway, H. M.

    2012-03-06

    The purpose of this report is to present data and findings from sampling and analysis of five distinct areas of coal ash within the Hanford Site River Corridor

  7. Development of an Accelerated Ash-Loading Protocol for Diesel...

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

    Development of an Accelerated Ash-Loading Protocol for Diesel Particulate Filters Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER ...

  8. Ashe County, North Carolina: Energy Resources | Open Energy Informatio...

    Open Energy Info (EERE)

    Ashe County, North Carolina: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 36.4339674, -81.4718387 Show Map Loading map......

  9. Ash Fork, Arizona: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Ash Fork, Arizona: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 35.2250114, -112.4840675 Show Map Loading map... "minzoom":false,"mappingser...

  10. Using fly ash and natural pozzolans in long life structures

    SciTech Connect (OSTI)

    Ramme, B.; Jacobsmeyer, J.

    2008-07-01

    The use of fly ash and natural pozzolans in various structures (roads, temples, bridges, buildings etc.) in the USA and Canada is discussed. 22 refs., 4 photos.

  11. Minimizing Lubricant-Ash Requirement and Impact on Emission Aftertreat...

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

    Reducing Lubricant Ash Impact on Exhaust Aftertreatment with a Oil Conditioning Filter Effects of Fuel Dilution with Biodiesel on Lubricant Acidity, Oxidation and Corrosion ...

  12. Use of co-combustion bottom ash to design an acoustic absorbing material for highway noise barriers

    SciTech Connect (OSTI)

    Arenas, Celia; Leiva, Carlos; Vilches, Luis F.

    2013-11-15

    Highlights: • The particle size of bottom ash influenced the acoustic behavior of the barrier. • The best sound absorption coefficients were measured for larger particle sizes. • The maximum noise absorption is displaced to lower frequencies for higher thickness. • A noise barrier was designed with better properties than commercial products. • Recycling products from bottom ash no present leaching and radioactivity problems. - Abstract: The present study aims to determine and evaluate the applicability of a new product consisting of coal bottom ash mixed with Portland cement in the application of highway noise barriers. In order to effectively recycle the bottom ash, the influence of the grain particle size of bottom ash, the thickness of the panel and the combination of different layers with various particle sizes have been studied, as well as some environmental properties including leachability (EN-12457-4, NEN-7345) and radioactivity tests. Based on the obtained results, the acoustic properties of the final composite material were similar or even better than those found in porous concrete used for the same application. According to this study, the material produced presented no environmental risk.

  13. Effect of inactive impurities on the burning of ICF targets

    SciTech Connect (OSTI)

    Gus'kov, S. Yu.; Il'in, D. V.; Sherman, V. E.

    2011-12-15

    The efficiency of thermonuclear burning of the spherical deuterium-tritium (DT) plasma of inertial confinement fusion (ICF) targets in the presence of low-Z impurities (such as lithium, carbon, or beryllium) with arbitrary concentrations is investigated. The effect of impurities produced due to the mixing of the thermonuclear fuel with the material of the structural elements of the target during its compression on the process of target burning is studied, and the possibility of using solid noncryogenic thermonuclear fuels in ICF targets is analyzed. Analytical dependences of the ignition energy and target thermonuclear gain on the impurity concentration are obtained. The models are constructed for homogeneous and inhomogeneous plasmas for the case in which the burning is initiated in the central heated region of the target and then propagates into the surrounding relatively cold fuel. Two possible configurations of an inhomogeneous plasma, namely, an isobaric configuration formed in the case of spark ignition of the target and an isochoric configuration formed in the case of fast ignition, are considered. The results of numerical simulations of the burning of the DT plasma of ICF targets in a wide range of impurity concentrations are presented. The simulations were performed using the TEPA one-dimensional code, in which the thermonuclear burning kinetics is calculated by the Monte Carlo method. It is shown that the strongest negative effect related to the presence of impurities is an increase in the energy of target ignition. It is substantiated that the most promising solid noncryogenic fuel is DT hydride of beryllium (BeDT). The requirements to the plasma parameters at which BeDT can be used as a fuel in noncryogenic ICF targets are determined. Variants of using noncryogenic targets with a solid thermonuclear fuel are proposed.

  14. Comment on "Kinetic theory for a mobile impurity in a degenerate...

    Office of Scientific and Technical Information (OSTI)

    Comment on "Kinetic theory for a mobile impurity in a degenerate Tonks-Girardeau gas" Citation Details In-Document Search Title: Comment on "Kinetic theory for a mobile impurity in ...

  15. Comment on "Kinetic theory for a mobile impurity in a degenerate...

    Office of Scientific and Technical Information (OSTI)

    Comment on "Kinetic theory for a mobile impurity in a degenerate Tonks-Girardeau gas" Title: Comment on "Kinetic theory for a mobile impurity in a degenerate Tonks-Girardeau gas" ...

  16. Effect of nonmagnetic impurities on the residual electron-spin-resonance linewidth of Er:Ag dilute alloys

    SciTech Connect (OSTI)

    Dahlberg, E.D.; Souletie, J.; Dodds, S.A.; Chock, E.P.; Orbach, R.L. )

    1990-06-01

    We have undertaken a systematic investigation of the effect of nonmagnetic impurities on the residual ({ital T}{r arrow}0 K) electron-spin-resonance linewidth of erbium in dilute (200 parts per million atomic (ppm)) Er:Ag alloys. The nonmagnetic impurities used were In, Sn, Sb, Y, and Lu in the concentration range of 500--4600 ppm. The linewidth broadening caused by these impurities was found to be 0.2{plus minus}0.11, 0.49{plus minus}0.1, 0.51{plus minus}0.11, 1.4{plus minus}0.18, and 1.37{plus minus}0.32 G/1000 ppm atomic frequency (GHz) for In, Sn, Sb, Y, and Lu, respectively. The most reasonable source of the Er line broadening is the mixing of the crystal-field levels of the Er by the Kohn-Vosko oscillations in the charge density. The broadening of the Er resonance line due to In, Sn, and Sb doping is consistent with the expected form of the oscillations. Also, Y and Lu are equivalent in the broadening of the Er line, as expected. However, the scaling of the Y and Lu broadening compared to that due to the In, Sn, and Sb is not consistent. The reasons for this are not understood.

  17. Research in Hydrogen Passivation of Defects and Impurities in Silicon: Final Subcontract Report, 2 May 2000--2 July 2003

    SciTech Connect (OSTI)

    Ashok, S.

    2004-05-01

    Our work consists of hydrogenating silicon (Si) samples by different methods such as low-energy implantation, electron cyclotron resonance (ECR) plasma, and thermal diffusion. The samples will be provided through NREL. The experimental work carried out at Penn State involves the study of hydrogen interaction with defects, trapping, migration, and formation of complexes. The principal vehicle for the latter study will be ion implantation, and the intent is to understand mechanisms of defect passivation and activation by hydrogen. The theoretical studies will consist of the calculation of the structure and parameters related to hydrogen diffusion and interactions of hydrogen with transition metal impurities in silicon. Experimental studies will involve measurements of hydrogen and hydrogen-impurity complexes, and diffusion properties of various species of hydrogen in Si. The experimental work at Penn State includes introduction of hydrogen in a variety of photovoltaic Si by ECR plasma, low-energy ion implantation, and thermal diffusion. The specific tasks will be the evaluation of hydrogen interaction with defects engineered by ion implantation; defect passivation, activation, and migration in hydrogenated Si under thermal anneal; and electrical activity of hydrogen-impurity complexes. Electrical characterization will entail I-V and C-V measurements, spreading resistance, and deep-level transient spectroscopy.

  18. Predicting and validating the tracking of a Volcanic Ash Cloud during the 2006 Eruption of Mt. Augustine Volcano

    SciTech Connect (OSTI)

    Webley, Peter W.; Atkinson, D.; Collins, Richard L.; Dean, K.; Fochesatto, J.; Sassen, Kenneth; Cahill, Catherine F.; Prata, A.; Flynn, Connor J.; Mizutani, K.

    2008-11-01

    On 11 January 2006, Mount Augustine volcano in southern Alaska began erupting after 20-year repose. The Anchorage Forecast Office of the National Weather Service (NWS) issued an advisory on 28 January for Kodiak City. On 31 January, Alaska Airlines cancelled all flights to and from Anchorage after multiple advisories from the NWS for Anchorage and the surrounding region. The Alaska Volcano Observatory (AVO) had reported the onset of the continuous eruption. AVO monitors the approximately 100 active volcanoes in the Northern Pacific. Ash clouds from these volcanoes can cause serious damage to an aircraft and pose a serious threat to the local communities, and to transcontinental air traffic throughout the Arctic and sub-Arctic region. Within AVO, a dispersion model has been developed to track the dispersion of volcanic ash clouds. The model, Puff, was used operational by AVO during the Augustine eruptive period. Here, we examine the dispersion of a volcanic ash cloud from Mount Augustine across Alaska from 29 January through the 2 February 2006. We present the synoptic meteorology, the Puff predictions, and measurements from aerosol samplers, laser radar (or lidar) systems, and satellites. UAF aerosol samplers revealed the presence of volcanic aerosols at the surface at sites where Puff predicted the ash clouds movement. Remote sensing satellite data showed the development of the ash cloud in close proximity to the volcano and a sulfur-dioxide cloud further from the volcano consistent with the Puff predictions. Lidars showed the presence of volcanic aerosol with consistent characteristics aloft over Alaska and were capable of detecting the aerosol, even in the presence of scattered clouds and where the cloud is too thin/disperse to be detected by remote sensing satellite data. The lidar measurements revealed the different trajectories of ash consistent with the Puff predictions. Dispersion models provide a forecast of volcanic ash cloud movement that might be

  19. Chemical leaching of coal to remove ash, alkali and vanadium

    SciTech Connect (OSTI)

    Smit, F.J.; Huggins, D.K.; Berggren, M.; Anast, K.R.

    1986-04-15

    A process is described for upgrading powdered coal to improve the usefulness thereof as a fuel for internal combustion engines which consists of: (a) pressure-leaching powdered coal having a particle size ranging from about 28 mesh to about 200 mesh in an aqueous caustic solution at a temperature ranging from about 175/sup 0/C, to about 350/sup 0/C., the amount of caustic in the solution ranging from about 5% to about 30% by weight, the amount of coal being sufficient to form a slurry comprising about 10% to 30% by weight of solids, (b) hydrochloric acid leaching the caustic leached coal to dissolve acid-soluble constituents resulting from the caustic leach, (c) pressure leaching the acid-leached coal with a liquid from the group consisting of water and dilute aqueous ammonia to remove sodium and chlorine, and thereafter (d) filtering and washing the pressure leached coal, whereby the coal is characterized by up to about 0.85% by weight of ash, up to about 150 ppm of alkali metals and up to about 4 ppm vanadium.

  20. Ab initio study of semiconductor atoms impurities in zigzag edge (10,0) carbon nanotubes

    SciTech Connect (OSTI)

    Muttaqien, Fahdzi Suprijadi

    2015-04-16

    The substitutional impurities in zigzag edge (10,0) carbon nanotubes have been studied by using first principles calculations. Silicon (Si), gallium (Ga), and arsenic (As) atom have been chosen as semiconductor based-atom for replacing carbon atoms in CNTs surface. The silicon atom changes the energy gap of pristine zigzag (10,0) CNT, it is 0.19 eV more narrow than that of pristine CNT. Geometrically, the silicon atom creates sp{sup 3} bond with three adjacent carbon atoms, where the tetrahedral form of its sp{sup 3} bond is consisted of free unoccupied state. The silicon atom does not induce magnetism to zigzag CNT. Due to gallium (Ga) and arsenic (As) atom substitution, the zigzag CNT becomes metallic and has magnetic moment of 1?{sub B}. The valance and conduction band are crossed each other, then the energy gap is vanished. The electronic properties of GaAs-doped CNT are dominantly affected by gallium atom and its magnetic properties are dominantly affected by arsenic atom. These results prove that the CNT with desired properties can be obtained with substitutional impurities without any giving structural defect.

  1. Effects of chemical composition of fly ash on efficiency of metal separation in ash-melting of municipal solid waste

    SciTech Connect (OSTI)

    Okada, Takashi; Tomikawa, Hiroki

    2013-03-15

    Highlights: ► Separation of Pb and Zn from Fe and Cu in ash-melting of municipal solid waste. ► Molar ratio of Cl to Na and K in fly ash affected the metal-separation efficiency. ► The low molar ratio and a non-oxidative atmosphere were better for the separation. - Abstract: In the process of metal separation by ash-melting, Fe and Cu in the incineration residue remain in the melting furnace as molten metal, whereas Pb and Zn in the residue are volatilized. This study investigated the effects of the chemical composition of incineration fly ash on the metal-separation efficiency of the ash-melting process. Incineration fly ash with different chemical compositions was melted with bottom ash in a lab-scale reactor, and the efficiency with which Pb and Zn were volatilized preventing the volatilization of Fe and Cu was evaluated. In addition, the behavior of these metals was simulated by thermodynamic equilibrium calculations. Depending on the exhaust gas treatment system used in the incinerator, the relationships among Na, K, and Cl concentrations in the incineration fly ash differed, which affected the efficiency of the metal separation. The amounts of Fe and Cu volatilized decreased by the decrease in the molar ratio of Cl to Na and K in the ash, promoting metal separation. The thermodynamic simulation predicted that the chlorination volatilization of Fe and Cu was prevented by the decrease in the molar ratio, as mentioned before. By melting incineration fly ash with the low molar ratio in a non-oxidative atmosphere, most of the Pb and Zn in the ash were volatilized leaving behind Fe and Cu.

  2. Process for the recovery of alumina from fly ash

    DOE Patents [OSTI]

    Murtha, M.J.

    1983-08-09

    An improvement in the lime-sinter process for recovering alumina from pulverized coal fly ash is disclosed. The addition of from 2 to 10 weight percent carbon and sulfur to the fly ash-calcium carbonate mixture increase alumina recovery at lower sintering temperatures.

  3. The recycling of the coal fly ash in glass production

    SciTech Connect (OSTI)

    Erol, M.M.; Kucukbayrak, S.; Ersoy-Mericboyu, A.

    2006-09-15

    The recycling of fly ash obtained from the combustion of coal in thermal power plant has been studied. Coal fly ash was vitrified by melting at 1773 K for 5 hours without any additives. The properties of glasses produced from coal fly ash were investigated by means of Differential Thermal Analysis (DTA), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. DTA study indicated that there was only one endothermic peak at 1003 K corresponding to the glass transition temperature. XRD analysis showed the amorphous state of the glass sample produced from coal fly ash. SEM investigations revealed that the coal fly ash based glass sample had smooth surface. The mechanical, physical and chemical properties of the glass sample were also determined. Recycling of coal fly ash by using vitrification technique resulted to a glass material that had good mechanical, physical and chemical properties. Toxicity characteristic leaching procedure (TCLP) results showed that the heavy metals of Pb, Cr, Zn and Mn were successfully immobilized into the glass. It can be said that glass sample obtained by the recycling of coal fly ash can be taken as a non-hazardous material. Overall, results indicated that the vitrification technique is an effective way for the stabilization and recycling of coal fly ash.

  4. Optimizing the use of fly ash in concrete

    SciTech Connect (OSTI)

    Thomas, M.

    2007-07-01

    The optimum amount of fly ash varies not only with the application, but also with composition and proportions of all the materials in the concrete mixture (especially the fly ash), the conditions during placing (especially temperature), construction practices (for example, finishing and curing) and the exposure conditions. This document discusses issues related to using low to very high levels of fly ash in concrete and provides guidance for the use of fly ash without compromising the construction process or the quality of the finished product. The nature of fly ashes including their physical, mineralogical and chemical properties is covered in detail, as well as fly ash variability due to coal composition and plant operating conditions. A discussion on the effects of fly ash characteristics on fresh and hardened concrete properties includes; workability, bleeding, air entrainment, setting time, heat of hydration, compressive strength development, creep, drying shrinkage, abrasion resistance, permeability, resistance to chlorides, alkali-silica reaction (ASR), sulfate resistance, carbonation, and resistance to freezing and thawing and deicer salt scaling. Case studies were selected as examples of some of the more demanding applications of fly ash concrete for ASR mitigation, chloride resistance, and green building.

  5. Fly ash and coal mineral matter surface transformations during heating

    SciTech Connect (OSTI)

    Baer, D R; Smith, R D

    1982-05-01

    A study is reported of surface segregation phenomena for fly ash and aluminosilicates representative of coal mineral matter during heating. The materials studied included a 20-..mu..m average diameter fly ash powder, a glass prepared from the fly ash, and Ca- and K-rich aluminosilicate minerals. The samples were heated both in air and under vacuum for extended periods at temperatures up to 1100/sup 0/C. XPS, Auger and SIMS methods were used to obtain relative surface elemental concentrations for major and minor components and depth profiles for some of the samples. Major differences were noted between samples heated in air (oxidizing) and those heated in vacuum (reducing) environments. For the fly ash glass heated in air Fe, Ti and Mg become enriched on the surfaces while heating in vacuum leads to Si surface segregation. Different trends upon heating were also observed for the Ca- and K-rich aluminosilicates. The results indicate two levels of surface enrichment upon the fly ash glass; a thin (< 500 A) layer and a thicker (1- to 2-..mu..m) layer most evident for heating in air where an Fe-rich layer is formed. The present results indicate that the rates of surface segregation may not be sufficiently fast on the time scale of fly ash formation to result in equilibrium surface segregation. It is concluded that condensation processes during fly ash formation probably play a major role in the observed fly ash surface enrichments.

  6. Hot-Gas Filter Ash Characterization Project

    SciTech Connect (OSTI)

    Swanson, M.L.; Hurley, J.P.; Dockter, B.A.; O`Keefe, C.A.

    1997-07-01

    Large-scale hot-gas filter testing over the past 10 years has revealed numerous cases of cake buildup on filter elements that has been difficult, if not impossible, to remove. At times, the cake can blind or bridge between candle filters, leading to filter failure. Physical factors, including particle-size distribution, particle shape, the aerodynamics of deposition, and system temperature, contribute to the difficulty in removing the cake, but chemical factors such as surface composition and gas-solid reactions also play roles in helping to bond the ash to the filters or to itself. This project is designed to perform the research necessary to determine the fuel-, sorbent-, and operations-related conditions that lead to blinding or bridging of hot-gas particle filters. The objectives of the project are threefold: (1) Determine the mechanisms by which a difficult-to-clean ash is formed and how it bridges hot-gas filters (2) Develop a method to determine the rate of bridging based on analyses of the feed coal and sorbent, filter properties, and system operating conditions and (3) Suggest and test ways to prevent filter bridging.

  7. STRATEGIES AND TECHNOLOGY FOR MANAGING HIGH-CARBON ASH

    SciTech Connect (OSTI)

    Robert Hurt; Eric Suuberg; John Veranth; Xu Chen

    2002-09-10

    The overall objective of the present project is to identify and assess strategies and solutions for the management of industry problems related to carbon in ash. Specific research issues to be addressed include: (1) the effect of parent fuel selection on ash properties and adsorptivity, including a first ever examination of the air entrainment behavior of ashes from alternative (non-coal) fuels; (2) the effect of various low-NOx firing modes on ash properties and adsorptivity; and (3) the kinetics and mechanism of ash ozonation. This data will provide scientific and engineering support of the ongoing process development activities. During this fourth project period we completed the characterization of ozone-treated carbon surfaces and wrote a comprehensive report on the mechanism through which ozone suppresses the adsorption of concrete surfactants.

  8. COAL-FIRED UTILITY BOILERS: SOLVING ASH DEPOSITION PROBLEMS

    SciTech Connect (OSTI)

    Christopher J. Zygarlicke; Donald P. McCollor; Steven A. Benson; Jay R. Gunderson

    2001-04-01

    The accumulation of slagging and fouling ash deposits in utility boilers has been a source of aggravation for coal-fired boiler operators for over a century. Many new developments in analytical, modeling, and combustion testing methods in the past 20 years have made it possible to identify root causes of ash deposition. A concise and comprehensive guidelines document has been assembled for solving ash deposition as related to coal-fired utility boilers. While this report accurately captures the current state of knowledge in ash deposition, note that substantial research and development is under way to more completely understand and mitigate slagging and fouling. Thus, while comprehensive, this document carries the title ''interim,'' with the idea that future work will provide additional insight. Primary target audiences include utility operators and engineers who face plant inefficiencies and significant operational and maintenance costs that are associated with ash deposition problems. Pulverized and cyclone-fired coal boilers are addressed specifically, although many of the diagnostics and solutions apply to other boiler types. Logic diagrams, ash deposit types, and boiler symptoms of ash deposition are used to aid the user in identifying an ash deposition problem, diagnosing and verifying root causes, determining remedial measures to alleviate or eliminate the problem, and then monitoring the situation to verify that the problem has been solved. In addition to a step-by-step method for identifying and remediating ash deposition problems, this guideline document (Appendix A) provides descriptions of analytical techniques for diagnostic testing and gives extensive fundamental and practical literature references and addresses of organizations that can provide help in alleviating ash deposition problems.

  9. Assessment of the impact of radionuclides in coal ash

    SciTech Connect (OSTI)

    Styron, C.E.; Bishop, C.T.; Casella, V.R.; Jenkins, P.H.; Yanko, W.H.

    1981-01-01

    An assessment of the potential environmental and health impacts of radionuclides in the coal fuel cycle is being conducted at Mound. This paper describes our studies evaluating the potential for migration of radionuclides from ash disposal sites. Studies at a power plant burning western US coal dealt with an assessment of potential radiation doses from coal ash ponds and leachate discharges of radionuclides from the ponds. Emanation of radon-222 from the ash is relatively low. The emanation of radon-222 from the ash pond (radium-226 at 4.5 pCi/g) is predicted to be about six times less than from soil (radium-226 at 1 pCi/g). Ash with radium-226 at 25 pCi/g would approximate emanation of radon-222 from soil. At 1000 m from the center of the ash pond area, radon-222 from the ash pond is predicted to be 1000 to 6000 times less than background (0.1 to 0.5 pCi/liter). Pathways exist for transport of radionuclides leached from ash into the aquifer beneath the holding ponds, but concentrations of radionuclides in water leaving the pond are lower than concentrations in groundwater which is upgradient of the ponds. Leachability of the ash is quite low, on the order of 0.002% in one month, and flow of ash sluicing water (3% of the volume of the ponds each day) has actually diluted normal background concentrations of radionuclides in the aquifer between the ponds and the adjacent river.

  10. A REVIEW OF RECENT IMPURITY MEASUREMENTS OF LANL MATERIAL

    SciTech Connect (OSTI)

    Edwards, T.

    2012-07-12

    The Applied Computational Engineering and Statistics (ACES) group of the Savannah River National Laboratory (SRNL) was asked to review recent measurements performed by the Los Alamos National Laboratory (LANL) on material from that facility that is being considered for processing through the Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF) at the Savannah River Site (SRS). There are specification limits for impurities in the feed to the MOX facility: a maximum limit and an exceptional limit. The limits for an impurity apply to the population of concentration values for that impurity for a class of material that is to be processed through MOX. For the purposes of this report, these limits were defined as follows. The concentration of an elemental impurity, expressed as micrograms of the element per gram of plutonium ({micro}g/g Pu), is to be no more than the maximum limit for that element for 98% of the material coming through MOX; that is, 98% of the material processed at MOX is to have a concentration of the given element less than the maximum limit. In addition, the concentration for a given element is to be no more than the exceptional limit for that element for 99.9% of the material processed through MOX. The measurements evaluated as part of this study included LANL blend lots 1 through 29 and cover carbon (C), chlorine (Cl), fluorine (F), nitrogen (N), phosphorous (P), and sulfur (S). Note that all of the measurements for each impurity were below their respective maximum (and obviously, therefore, their exceptional) limits. Thus, there is no immediate concern regarding the LANL material being suitable for processing through MOX. Two approaches were used to investigate the quantiles of the impurity populations. The first approach used was a nonparametric approach. While the results from this approach did not indicate any problems for any of the impurities, there was too little data available to lead to confident statements about satisfying the maximum and

  11. Quantum critical points of an anisotropic multichannel Kondo impurity

    SciTech Connect (OSTI)

    Schlottmann, P.

    2001-06-01

    The low-temperature behavior of a magnetic impurity of spin S interacting with an electron gas via an anisotropic spin exchange is studied via Bethe{close_quote}s ansatz. The multichannel Kondo model with U(1) invariance is integrable as a function of two continuous (the exchange and the anisotropy) and two discrete parameters, namely the impurity spin S and the number of channels n. As a function of S and n we distinguish: (i) the compensated case with n=2S, (ii) the overcompensated case if n{gt}2S, and (iii) the undercompensated case (n{lt}2S). While in case (i) the ground state is a singlet, the cases (ii), and (iii) yield quantum critical points. The undercompensated one is of a new type with the critical exponents depending on the anisotropy. {copyright} 2001 American Institute of Physics.

  12. Anisotropic charged impurity-limited carrier mobility in monolayer phosphorene

    SciTech Connect (OSTI)

    Ong, Zhun-Yong; Zhang, Gang; Zhang, Yong Wei

    2014-12-07

    The room temperature carrier mobility in atomically thin 2D materials is usually far below the intrinsic limit imposed by phonon scattering as a result of scattering by remote charged impurities in its environment. We simulate the charged impurity-limited carrier mobility μ in bare and encapsulated monolayer phosphorene. We find a significant temperature dependence in the carrier mobilities (μ ∝ T{sup −γ}) that results from the temperature variability of the charge screening and varies with the crystal orientation. The anisotropy in the effective mass leads to an anisotropic carrier mobility, with the mobility in the armchair direction about one order of magnitude larger than in the zigzag direction. In particular, this mobility anisotropy is enhanced at low temperatures and high carrier densities. Under encapsulation with a high-κ overlayer, the mobility increases by up to an order of magnitude although its temperature dependence and its anisotropy are reduced.

  13. Toxicity mitigation and solidification of municipal solid waste incinerator fly ash using alkaline activated coal ash

    SciTech Connect (OSTI)

    Ivan Diaz-Loya, E.; Allouche, Erez N.; Eklund, Sven; Joshi, Anupam R.; Kupwade-Patil, Kunal

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Incinerator fly ash (IFA) is added to an alkali activated coal fly ash (CFA) matrix. Black-Right-Pointing-Pointer Means of stabilizing the incinerator ash for use in construction applications. Black-Right-Pointing-Pointer Concrete made from IFA, CFA and IFA-CFA mixes was chemically characterized. Black-Right-Pointing-Pointer Environmentally friendly solution to IFA disposal by reducing its toxicity levels. - Abstract: Municipal solid waste (MSW) incineration is a common and effective practice to reduce the volume of solid waste in urban areas. However, the byproduct of this process is a fly ash (IFA), which contains large quantities of toxic contaminants. The purpose of this research study was to analyze the chemical, physical and mechanical behaviors resulting from the gradual introduction of IFA to an alkaline activated coal fly ash (CFA) matrix, as a mean of stabilizing the incinerator ash for use in industrial construction applications, where human exposure potential is limited. IFA and CFA were analyzed via X-ray fluorescence (XRF), X-ray diffraction (XRD) and Inductive coupled plasma (ICP) to obtain a full chemical analysis of the samples, its crystallographic characteristics and a detailed count of the eight heavy metals contemplated in US Title 40 of the Code of Federal Regulations (40 CFR). The particle size distribution of IFA and CFA was also recorded. EPA's Toxicity Characteristic Leaching Procedure (TCLP) was followed to monitor the leachability of the contaminants before and after the activation. Also images obtained via Scanning Electron Microscopy (SEM), before and after the activation, are presented. Concrete made from IFA, CFA and IFA-CFA mixes was subjected to a full mechanical characterization; tests include compressive strength, flexural strength, elastic modulus, Poisson's ratio and setting time. The leachable heavy metal contents (except for Se) were below the maximum allowable limits and in many cases

  14. Fluidization characteristics of power-plant fly ashes and fly ash-charcoal mixtures. [MS Thesis; 40 references

    SciTech Connect (OSTI)

    Nguyen, C.T.

    1980-03-01

    As a part of the continuing research on aluminum recovery from fly ash by HiChlor process, a plexiglass fluidization column system was constructed for measurement of fluidization parameters for power-plant fly ashes and fly ash-charcoal mixtures. Several bituminous and subbituminous coal fly ashes were tested and large differences in fluidization characteristics were observed. Fly ashes which were mechanically collected fluidized uniformly at low gas flow rates. Most fly ashes which were electrostatically precipitated exhibited channeling tendency and did not fluidize uniformly. Fluidization characteristics of electrostatically collected ashes improve when the finely divided charcoal powder is added to the mixture. The fluidization of the mixture was aided initially by a mechanical stirrer. Once the fluidization had succeeded, the beds were ready to fluidize without the assistance of a mechanical action. Smooth fluidization and large bed expansion were usually observed. The effects of charcoal size and aspect ratio on fluidization characteristics of the mixtures were also investigated. Fluidization characteristics of a fly ash-coal mixture were tested. The mixture fluidized only after being oven-dried for a few days.

  15. Sulfur-impurity Induced Amorphization of Nickel | Argonne Leadership

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

    Computing Facility Sulfur-impurity Induced Amorphization of Nickel Authors: Yuan, Z., Chen, H.P, Wang, W., Nomura, K., Kalia, R.K., Nakano, A., Vashishta, P. Recent experimental and theoretical studies have shown an essential role of sulfur segregation-induced amorphization of crystalline nickel leading to its embrittlement at a critical sulfur concentration of ∼14%, but the atomistic mechanism of the amorphization remains unexplained. Here, molecular dynamics simulations reveal that the

  16. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  17. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  18. The Role of Impurities in the Complex Hydrides

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

    Impurities in the Complex Hydrides Eric H. Majzoub Center for Nanoscience Department of Physics University of Missouri - St. Louis Acknowledgements UMSL Xianfeng Liu, David Peaslee, Tim Mason, Dongxue Zhao, Gang Wang, Chris Carr, Waruni Jayawardana, Alyssa McFarlane, Henry Hamper, Hua Ning SNL Vitalie Stavila, Mark Allendorf, Lennie Klebanoff * Department of Energy EERE * Boeing * NASA Space grant Consortium 2 Objectives and Overview I. Fundamental Limitations - density of hydrogen and

  19. METHOD FOR REDUCING THE IMPURITY RESISTIVITY OF SODIUM

    DOE Patents [OSTI]

    Post, R.F.; Taylor, C.E.

    1963-08-13

    The inherent resistivity of sodium, at cryogenic temperatures, can be reduced by clustering the impurity atoms within the crystal latiice structure of the sodium, thereby reducing the effective electron collision cross section and thus reducing the number of collisions between the electrons and such lattice imperfections. The clustering is effected by heating the sodium to a temperature approaching its melting point, and maintaining the temperature for a period of time ranging generally from two to six days. (AEC)

  20. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  1. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  2. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  3. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  4. Scandium resonant impurity level in PbTe

    SciTech Connect (OSTI)

    Skipetrov, E. P. Skipetrova, L. A.; Knotko, A. V.; Slynko, E. I.; Slynko, V. E.

    2014-04-07

    We synthesize a scandium-doped PbTe single-crystal ingot and investigate the phase and the elemental composition as well as galvanomagnetic properties of Pb{sub 1-y}Sc{sub y}Te alloys in weak magnetic fields (4.2?K???T???300?K, B???0.07?T) upon varying the scandium content (y???0.02). We find that all investigated samples are single-phase and n-type. The distribution of scandium impurities along the axis of the ingot is estimated to be exponential. An increase of scandium impurity content leads to a monotonous growth of the free electron concentration by four orders of magnitude (approximately from 10{sup 16}?cm{sup ?3} to 10{sup 20}?cm{sup ?3}). In heavily doped alloys (y?>?0.01), the free electron concentration at the liquid-helium temperature tends to saturation, indicating the pinning of the Fermi energy by the scandium resonant impurity level located on the background of the conduction band. Using the two-band Kane and six-band Dimmock dispersion relations for IV-VI semiconductors, dependences of the Fermi energy measured from the bottom of the conduction band E{sub c} on the scandium impurity content are calculated and the energy of the resonant scandium level is estimated to be E{sub Sc}???E{sub c}?+?280?meV. Diagrams of electronic structure rearrangement of Pb{sub 1-y}Sc{sub y}Te alloys upon doping are proposed.

  5. Localized states of a semi-infinite zigzag graphene sheet with impurity lines

    SciTech Connect (OSTI)

    Cunha, A. M. C.; Ahmed, Maher Z.; Cottam, M. G.; Filho, R. N. Costa

    2014-07-07

    The localized states of a semi-infinite zigzag graphene sheet are studied using a tight-binding model that allows for the inclusion of either one or two lines of impurities. These impurity lines of atoms are placed in rows labeled as n (n=1, 2, 3, ), where n=1 is the free edge. The localized defect modes associated with these impurities are studied analytically and numerically within a tridiagonal matrix formalism. For one impurity line, the modes are analyzed according to the position of that line on the sheet, whereas the modes for two impurities are studied also according to their separation and their positions relative to the edge. When an impurity line is located at the edge (n=1), it is found that the edge states are modified. When the impurities are positioned away from an edge (n>1), additional localized modes are found to occur that may be relatively flat in their dispersion.

  6. Multi-fluid code simulations including anomalous non-diffusive transport of plasma and impurities in the tokamak SOL

    SciTech Connect (OSTI)

    Pigarov, A Y; West, W; Soukhanovskii, V; Rognlien, T; Maingi, R; Lipschultz, B; Krasheninnikov, S; LaBombard, B

    2003-11-25

    Fast intermittent transport has been observed in the scrape-off layer (SOL) of major tokamaks including Alcator C-Mod, DIII-D, and NSTX. This kind of transport is not diffusive but rather convective. It strongly increases plasma flux to the chamber walls and enhances the recycling of neutral particles in the main chamber. We discuss anomalous cross-field convection (ACFC) model for impurity and main plasma ions and its relation to intermittent transport events, i.e. plasma density blobs and holes in the SOL. Along with plasma diffusivity coefficients, our transport model introduces time-independent anomalous cross-field convective velocity. In the discharge modelling, diffusivity coefficients and ACFC velocity profiles are adjusted to match a set of representative experimental data. We use this model in the edge plasma physics code UEDGE to simulate the multi-fluid two-dimensional transport for these three tokamaks. We present simulation results suggesting the dominance of anomalous convection in the far SOL transport. These results are consistent with the hypothesis that the chamber wall is an important source of impurities and that different impurity charge states have different directions of anomalous convective velocity.

  7. Theory of the Anderson impurity model: The Schrieffer{endash}Wolff transformation reexamined

    SciTech Connect (OSTI)

    Kehrein, S.K.; Mielke, A.

    1996-11-01

    We test the method of infinitesimal unitary transformations recently introduced by Wegner on the Anderson single impurity model. It is demonstrated that infinitesimal unitary transformations in contrast to the Schrieffer{endash}Wolff transformation allow the construction of an effective Kondo Hamiltonian consistent with the established results in this well understood model. The main reason for this is the intrinsic energy scale separation of Wegner`s approach with respect to arbitrary energy differences coupled by matrix elements. This allows the construction of an effective Hamiltonian without facing a vanishing energy denominator problem. Similar energy denominator problems are troublesome in many models. Infinitesimal unitary transformations have the potential to provide a general framework for the systematic derivation of effective Hamiltonians without such problems. Copyright {copyright} 1996 Academic Press, Inc.

  8. Scattering in graphene associated with charged out-of-plane impurities

    SciTech Connect (OSTI)

    Liu, Yue Goswami, Aditi; Liu, Feilong; Smith, Darryl L.; Ruden, P. Paul

    2014-12-21

    A charged impurity outside the plane of a graphene layer contributes to scattering of electrons (and holes) in the graphene. The interaction occurs through two distinct mechanisms associated with the charge: (1) the (screened) Coulomb potential, and (2) the electric field perpendicular to the graphene plane that causes a spatially varying Rashba spin-orbit interaction. Both types of scattering are examined, with the screened potential self-consistently calculated in nonlinear Thomas-Fermi approximation. Different selection rules for the two mechanisms lead to qualitative differences in the differential scattering cross-sections. Using accepted parameters for the Rashba interaction, the latter is found to make only a very small contribution to the scattering associated with a remote charge.

  9. Mutagenicity and genotoxicity of coal fly ash water leachate

    SciTech Connect (OSTI)

    Chakraborty, R.; Mukherjee, A.

    2009-03-15

    Fly ash is a by-product of coal-fired electricity generation plants. The prevalent practice of disposal is as slurry of ash and water to storage or ash ponds located near power stations. This has lain to waste thousands of hectares of land all over the world. Since leaching is often the cause of off-site contamination and pathway of introduction into the human environment, a study on the genotoxic effects of fly ash leachate is essential. Leachate prepared from the fly ash sample was analyzed for metal content, and tested for mutagenicity and genotoxicity. Analyses of metals show predominance of the metals - sodium, silicon, potassium, calcium, magnesium, iron, manganese, zinc, and sulphate. The Ames Salmonella mutagenicity assay, a short-term bacterial reverse mutation assay, was conducted on two-tester strains of Salmonella typhimurium strains TA97a and TA102. For genotoxicity, the alkaline version of comet assay on fly ash leachate was carried in vitro on human blood cells and in vivo on Nicotiana plants. The leachate was directly mutagenic and induced significantconcentration-dependent increases in DNA damage in whole blood cells, lymphocytes, and in Nicotiana plants. The comet parameters show increases in tail DNA percentage (%), tail length (mu m), and olive tail moment (arbitrary units). Our results indicate that leachate from fly ash dumpsites has the genotoxic potential and may lead to adverse effects on vegetation and on the health of exposed human populations.

  10. Water holding capacities of fly ashes: Effect of size fractionation

    SciTech Connect (OSTI)

    Sarkar, A.; Rano, R.

    2007-07-01

    Water holding capacities of fly ashes from different thermal power plants in Eastern India have been compared. Moreover, the effect of size fractionation (sieving) on the water holding capacities has also been determined. The desorption rate of water held by the fly ash fractions at ambient temperature (25-30{sup o}C) has been investigated. The effect of mixing various size fractions of fly ash in increasing the water holding capacities of fly ash has been studied. It is observed that the fly ash obtained from a thermal power plant working on stoker-fired combustor has the highest water holding capacity, followed by the one that works on pulverized fuel combustor. Fly ash collected from super thermal power plant has the least water holding capacity (40.7%). The coarser size fractions of fly ashes in general have higher water holding capacities than the finer ones. An attempt has been made to correlate the results obtained, with the potential use in agriculture.

  11. Characterization and possible uses of ashes from wastewater treatment plants

    SciTech Connect (OSTI)

    Merino, Ignacio; Arevalo, Luis F. . E-mail: fromero@ehu.es

    2005-07-01

    This work, on the ashes from the wastewater treatment plant of Galindo (Vizcaya, Spain), has been outlined with the purpose of finding their physico-chemical properties and suggesting possible applications. Ashes contain important quantities of iron, calcium, silica, alumina and phosphates. X-Ray diffraction data make it possible to estimate the mineralogical compositions of the original ashes and also, after thermal treatment at 1200 and 1300 deg. C, the main reactions occurring in thermal treatment. Particle size analysis makes it possible to classify ashes as a very fine powdered material. The thermal treatment leads to a densification of the material and provokes losses of weight mainly due to the elimination of water, carbon dioxide and sulphur trioxide. Application tests show that ashes are not suitable for landfill and similar applications, because of their plastic properties. Testing for pozzolanic character, after the ashes had been heated at 1200 deg. C, did not lead to a strong material probably due to low contents in silica and alumina or to requiring a higher heating temperature. Thermal treatment leads to densification of the material with a considerable increase of compressive strength of the probes. The use of additives (clays and powdered glass) to improve ceramic properties of ashes will be the aim of a future work.

  12. Bioaccumulation Studies Associated with the Kingston Fly Ash Spill, Spring 2009 - Fall 2010

    SciTech Connect (OSTI)

    Adams, Marshall; Brandt, Craig C; Fortner, Allison M

    2012-05-01

    four seasonal collections: Spring 2009, Fall 2009, Spring 2010, and Fall 2010. Both the Spring and Fall studies have focused on 3-4 sentinel fish species that represent different feeding habits, behaviors, and home ranges. In addition to bioaccumulation studies, the Spring investigations also included evaluation of fish health and reproductive integrity on the same fish used for bioaccumulation. Two associated reports present the fish health (Adams et al 2012) and reproductive studies (Greeley et al 2012) conducted in 2009 and 2010. The fish health study conducted in conjunction with the bioaccumulation and reproductive study is critical for assessing and evaluating possible causal relationships between contaminant exposure (bioaccumulation) and the response of fish to exposure as reflected by the various measurements of fish health. This report emphasizes evaluation of arsenic and selenium bioaccumulation in fish and consists of four related studies (Sections 2-5) including, (1) bioaccumulation in liver and ovaries, (2) bioaccumulation in whole body gizzard shad (Dorosoma cepedianum), (3) bioaccumulation in muscle tissue or fillets, and (4) a reconstruction analysis which establishes the relationship between selenium in muscle tissue and that of the whole body of bluegill (Lepomis machrochirus). Metals other than arsenic and selenium are evaluated separately in Section 6. This report focuses on selenium and arsenic for the following reasons: (1) based on baseline studies conducted in early 2009 in the Emory and Clinch River, only two potentially fly-ash related metals, selenium and arsenic, appeared to be elevated above background or reference levels, (2) selenium and arsenic are two of the metals in coal ash that are known to bioaccumulate and cause toxicity in wildlife, and (3) based on bioaccumulation studies of bluegill and carp (Cyprinus carpio) in the Stilling Pond during Spring 2009, which would represent a worst case situation for metal bioaccumulation

  13. Ash formation, deposition, corrosion, and erosion in conventional boilers

    SciTech Connect (OSTI)

    Benson, S.A.; Jones, M.L.

    1995-12-01

    The inorganic components (ash-forming species) associated with coals significantly affect boiler design, efficiency of operation, and lifetimes of boiler parts. During combustion in conventional pulverized fuel boilers, the inorganic components are transformed into inorganic gases, liquids, and solids. This partitioning depends upon the association of the inorganic components in the coal and combustion conditions. The inorganic components are associated as mineral grains and as organically associated elements, and these associations of inorganic components in the fuel directly influence their fate upon combustion. Combustion conditions, such as temperature and atmosphere, influence the volatility and the interaction of inorganic components during combustion and gas cooling, which influences the state and size composition distribution of the particulate and condensed ash species. The intermediate species are transported with the bulk gas flow through the combustion systems, during which time the gases and entrained ash are cooled. Deposition, corrosion, and erosion occur when the ash intermediate species are transported to the heat-transfer surface, react with the surface, accumulate, sinter, and develop strength. Research over the past decade has significantly advanced understanding of ash formation, deposition, corrosion, and erosion mechanisms. Many of the advances in understanding and predicting ash-related issues can be attributed to advanced analytical methods to determine the inorganic composition of fuels and the resulting ash materials. These new analytical techniques have been the key to elucidation of the mechanisms of ash formation and deposition. This information has been used to develop algorithms and computer models to predict the effects of ash on combustion system performance.

  14. Increasing Class C fly ash reduces alkali silica reactivity

    SciTech Connect (OSTI)

    Hicks, J.K.

    2007-07-01

    Contrary to earlier studies, it has been found that incremental additions of Class C fly ash do reduce alkali silica reactivity (ASR), in highly reactive, high alkali concrete mixes. AST can be further reduced by substituting 5% metakaolin or silica fume for the aggregate in concrete mixes with high (more than 30%) Class C fly ash substitution. The paper reports results of studies using Class C fly ash from the Labadie Station plant in Missouri which typically has between 1.3 and 1.45% available alkalis by ASTM C311. 7 figs.

  15. Recovery of iron oxide from coal fly ash

    DOE Patents [OSTI]

    Dobbins, Michael S.; Murtha, Marlyn J.

    1983-05-31

    A high quality iron oxide concentrate, suitable as a feed for blast and electric reduction furnaces is recovered from pulverized coal fly ash. The magnetic portion of the fly ash is separated and treated with a hot strong alkali solution which dissolves most of the silica and alumina in the fly ash, leaving a solid residue and forming a precipitate which is an acid soluble salt of aluminosilicate hydrate. The residue and precipitate are then treated with a strong mineral acid to dissolve the precipitate leaving a solid residue containing at least 90 weight percent iron oxide.

  16. Novel microorganism for selective separation of coal from pyrite and ash. Final report

    SciTech Connect (OSTI)

    Misra, M.; Smith, R.W.

    1995-09-01

    The separation of fine coal from ash and pyrite was evaluated using a microorganism Mycobacterium phlei.

  17. Coal Ash Corrosion Resistant Materials Testing

    SciTech Connect (OSTI)

    D. K. McDonald; P. L. Daniel; D. J. DeVault

    2007-12-31

    In April 1999, three identical superheater test sections were installed into the Niles Unit No.1 for the purpose of testing and ranking the coal ash corrosion resistance of candidate superheater alloys. The Niles boiler burns high sulfur coal (3% to 3.5%) that has a moderate alkali content (0.2% sodium equivalents), thus the constituents necessary for coal ash corrosion are present in the ash. The test sections were controlled to operate with an average surface metal temperature from approximately 1060 F to 1210 F which was within the temperature range over which coal ash corrosion occurs. Thus, this combination of aggressive environment and high temperature was appropriate for testing the performance of candidate corrosion-resistant tube materials. Analyses of the deposit and scale confirmed that aggressive alkali sulfate constituents were present at the metal surface and active in tube metal wastage. The test sections were constructed so that the response of twelve different candidate tube and/or coating materials could be studied. The plan was to remove and evaluate one of the three test sections at time intervals of 1 year, 3 years, and 5 years. This would permit an assessment of performance of the candidate materials as a function of time. Test Section A was removed in November 2001 after about 24 months of service at the desired steam temperature set point, with about 15.5 months of exposure at full temperature. A progress report, issued in October 2002, was written to document the performance of the candidate alloys in that test section. The evaluation described the condition of each tube sample after exposure. It involved a determination of the rate of wall thickness loss for these samples. In cases where there was more than one sample of a candidate material in the test section, an assessment was made of the performance of the alloy as a function of temperature. Test Sections B and C were examined during the November 2001 outage, and it was decided that

  18. Blue Ash, Ohio: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Hide Map This article is a stub. You can help OpenEI by expanding it. Blue Ash is a city in Hamilton County, Ohio. It falls under Ohio's 2nd congressional...

  19. Recoverable immobilization of transuranic elements in sulfate ash

    DOE Patents [OSTI]

    Greenhalgh, Wilbur O.

    1985-01-01

    Disclosed is a method of reversibly immobilizing sulfate ash at least about 20% of which is sulfates of transuranic elements. The ash is mixed with a metal which can be aluminum, cerium, samarium, europium, or a mixture thereof, in amounts sufficient to form an alloy with the transuranic elements, plus an additional amount to reduce the transuranic element sulfates to elemental form. Also added to the ash is a fluxing agent in an amount sufficient to lower the percentage of the transuranic element sulfates to about 1% to about 10%. The mixture of the ash, metal, and fluxing agent is heated to a temperature sufficient to melt the fluxing agent and the metal. The mixture is then cooled and the alloy is separated from the remainder of the mixture.

  20. Transcending Portland Cement with 100 percent fly ash concrete

    SciTech Connect (OSTI)

    Cross, D.; Akin, M.; Stephens, J.; Cuelh, E.

    2009-07-01

    The use of concrete, made with 100% fly ash and no Portland cement, in buildings at the Transportation Institute in Bozeman, MT, USA, is described. 3 refs., 7 figs.

  1. Recovery Act Workers Complete Environmental Cleanup of Coal Ash Basin

    Broader source: Energy.gov [DOE]

    The Savannah River Site (SRS) recently cleaned up a 17-acre basin containing coal ash residues from Cold War operations. The American Recovery and Reinvestment Act project was safely completed at a...

  2. Compressive strength of concrete and mortar containing fly ash

    DOE Patents [OSTI]

    Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

    1998-12-29

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specification required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs. 33 figs.

  3. Compressive strength of concrete and mortar containing fly ash

    DOE Patents [OSTI]

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1997-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specifications required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs.

  4. Compressive strength of concrete and mortar containing fly ash

    DOE Patents [OSTI]

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1998-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specification required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs.

  5. Compressive strength of concrete and mortar containing fly ash

    DOE Patents [OSTI]

    Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

    1997-04-29

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specifications required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs. 33 figs.

  6. How toxic is coal ash? A laboratory toxicity case study

    SciTech Connect (OSTI)

    Sherrard, Rick M.; Carriker, Neil; Greeley, Jr., Mark Stephen

    2014-12-08

    Under a consent agreement among the Environmental Protection Agency (EPA) and proponents both for and against stricter regulation, EPA is to issue a new coal ash disposal rule by the end of 2014. Laboratory toxicity investigations often yield conservative estimates of toxicity because many standard test species are more sensitive than resident species, thus could provide information useful to the rule-making. However, few laboratory studies of coal ash toxicity are available; most studies reported in the literature are based solely on field investigations. In this paper, we describe a broad range of toxicity studies conducted for the Tennessee Valley Authority (TVA) Kingston ash spill, results of which help provide additional perspective on the toxicity of coal ash.

  7. How toxic is coal ash? A laboratory toxicity case study

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

    Sherrard, Rick M.; Carriker, Neil; Greeley, Jr., Mark Stephen

    2014-12-08

    Under a consent agreement among the Environmental Protection Agency (EPA) and proponents both for and against stricter regulation, EPA is to issue a new coal ash disposal rule by the end of 2014. Laboratory toxicity investigations often yield conservative estimates of toxicity because many standard test species are more sensitive than resident species, thus could provide information useful to the rule-making. However, few laboratory studies of coal ash toxicity are available; most studies reported in the literature are based solely on field investigations. In this paper, we describe a broad range of toxicity studies conducted for the Tennessee Valley Authoritymore » (TVA) Kingston ash spill, results of which help provide additional perspective on the toxicity of coal ash.« less

  8. Overview of SOFC Anode Interactions with Coal Gas Impurities

    SciTech Connect (OSTI)

    O. A. Marina; L. R. Pederson; R. Gemmen; K. Gerdes; H. Finklea; I. B. Celik

    2010-03-01

    An overview of the results of SOFC anode interactions with phosphorus, arsenic, selenium, sulfur, antimony, and hydrogen chloride as single contaminants or in combinations is discussed. Tests were performed using both anode- and electrolyte-supported cells in synthetic and actual coal gas for periods greater than 1000 hours. Post-test analyses were performed to identify reaction products formed and their distribution, and compared to phases expected from thermochemical modeling. The ultimate purpose of this work is to establish maximum permissible concentrations for impurities in coal gas, to aid in the selection of appropriate coal gas clean-up technologies.

  9. Overview of SOFC Anode Interactions with Coal Gas Impurities

    SciTech Connect (OSTI)

    Marina, Olga A.; Pederson, Larry R.; Gemmen, Randall; Gerdes, Kirk; Finklea, Harry; Celik, Ismail B.

    2010-05-01

    An overview of the results of SOFC anode interactions with phosphorus, arsenic, selenium, sulfur, antimony, and hydrogen chloride as single contaminants or in combinations is discussed. Tests were performed using both anode- and electrolyte-supported cells in synthetic and actual coal gas for periods greater than 1000 hours. Post-test analyses were performed to identify reaction products formed and their distribution, and compared to phases expected from thermochemical modeling. The ultimate purpose of this work is to establish maximum permissible concentrations for impurities in coal gas, to aid in the selection of appropriate coal gas clean-up technologies.

  10. Ni/YSZ Anode Interactions with Impurities in Coal Gas

    SciTech Connect (OSTI)

    Marina, Olga A.; Pederson, Larry R.; Coyle, Christopher A.; Thomsen, Edwin C.; Coffey, Greg W.

    2009-10-16

    Performance of solid oxide fuel cell (SOFC) with nickel/zirconia anodes on synthetic coal gas in the presence of low levels of phosphorus, arsenic, selenium, sulfur, hydrogen chloride, and antimony impurities were evaluated. The presence of phosphorus and arsenic led to the slow and irreversible SOFC degradation due to the formation of secondary phases with nickel, particularly close to the gas inlet. Phosphorus and antimony surface adsorption layers were identified as well. Hydrogen chloride and sulfur interactions with the nickel were limited to the surface adsorption only, whereas selenium exposure also led to the formation of nickel selenide for highly polarized cells.

  11. Surface Plasma Source Electrode Activation by Surface Impurities

    SciTech Connect (OSTI)

    Dudnikov, Vadim; Han, Baoxi; Johnson, Rolland P.; Murray Jr, S N; Pennisi, Terry R; Santana, Manuel; Stockli, Martin P; Welton, Robert F

    2011-01-01

    In experiments with RF saddle antenna surface plasma sources (SPS), the efficiency of H- ion generation was increased by up to a factor of 5 by long time plasma electrode activation, without adding Cs from Cs supply, by heating the collar to high temperature using hot air flow and plasma discharge. Without cracking or heating the cesium ampoule, but likely with Cs recovery from impurities, the achieved energy efficiency was comparable to that of conventionally cesiated SNS RF sources with an external or internal Cs supply. In the experiments, perfect cesiation was produced (without additional Cs supply) by the collection and trapping of traces of remnant cesium compounds from SPS surfaces.

  12. Some transport properties of the two-channel Kondo impurity

    SciTech Connect (OSTI)

    Schlottmann, P.; Zvyagin, A.A.

    1997-04-01

    We consider conduction electrons moving along a ring in two different orbital channels interacting with a spin-1/2 impurity via isotropic spin exchange. The exchange is the same for both channels, but a crystalline field breaks the orbital symmetry. The tower structure of the finite size corrections to the ground state energy is derived from the Bethe ansatz equations and used to discuss the Aharonov{endash}Bohm{endash}Casher interference pattern in the persistent current and the magnetoresistivity. {copyright} {ital 1997 American Institute of Physics.}

  13. Minimizing Lubricant-Ash Requirement and Impact on Emission Aftertreatment

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

    Systems via an Oil Conditioning Filter | Department of Energy Minimizing Lubricant-Ash Requirement and Impact on Emission Aftertreatment Systems via an Oil Conditioning Filter Minimizing Lubricant-Ash Requirement and Impact on Emission Aftertreatment Systems via an Oil Conditioning Filter Presentation given at the 2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER 2007). 13-16 August, 2007, Detroit, Michigan. Sponsored by the U.S. Department of Energy's (DOE) Office of

  14. Ash Reduction of Corn Stover by Mild Hydrothermal Preprocessing

    SciTech Connect (OSTI)

    M. Toufiq Reza; Rachel Emerson; M. Helal Uddin; Garold Gresham; Charles J. Coronella

    2014-04-22

    Lignocellulosic biomass such as corn stover can contain high ash content, which may act as an inhibitor in downstream conversion processes. Most of the structural ash in biomass is located in the cross-linked structure of lignin, which is mildly reactive in basic solutions. Four organic acids (formic, oxalic, tartaric, and citric) were evaluated for effectiveness in ash reduction, with limited success. Because of sodium citrates chelating and basic characteristics, it is effective in ash removal. More than 75 % of structural and 85 % of whole ash was removed from the biomass by treatment with 0.1 g of sodium citrate per gram of biomass at 130 C and 2.7 bar. FTIR, fiber analysis, and chemical analyses show that cellulose and hemicellulose were unaffected by the treatment. ICPAES showed that all inorganics measured were reduced within the biomass feedstock, except sodium due to the addition of Na through the treatment. Sodium citrate addition to the preconversion process of corn stover is an effective way to reduced physiological ash content of the feedstock without negatively impacting carbohydrate and lignin content.

  15. Ash level meter for a fixed-bed coal gasifier

    DOE Patents [OSTI]

    Fasching, George E.

    1984-01-01

    An ash level meter for a fixed-bed coal gasifier is provided which utilizes the known ash level temperature profile to monitor the ash bed level. A bed stirrer which travels up and down through the extent of the bed ash level is modified by installing thermocouples to measure the bed temperature as the stirrer travels through the stirring cycle. The temperature measurement signals are transmitted to an electronic signal process system by an FM/FM telemetry system. The processing system uses the temperature signals together with an analog stirrer position signal, taken from a position transducer disposed to measure the stirrer position to compute the vertical location of the ash zone upper boundary. The circuit determines the fraction of each total stirrer cycle time the stirrer-derived bed temperature is below a selected set point, multiplies this fraction by the average stirrer signal level, multiplies this result by an appropriate constant and adds another constant such that a 1 to 5 volt signal from the processor corresponds to a 0 to 30 inch span of the ash upper boundary level. Three individual counters in the processor store clock counts that are representative of: (1) the time the stirrer temperature is below the set point (500.degree. F.), (2) the time duration of the corresponding stirrer travel cycle, and (3) the corresponding average stirrer vertical position. The inputs to all three counters are disconnected during any period that the stirrer is stopped, eliminating corruption of the measurement by stirrer stoppage.

  16. Batch methods for enriching trace impurities in hydrogen gas for their further analysis

    DOE Patents [OSTI]

    Ahmed, Shabbir; Lee, Sheldon H.D.; Kumar, Romesh; Papdias, Dionissios D.

    2014-07-15

    Provided herein are batch methods and devices for enriching trace quantities of impurities in gaseous mixtures, such as hydrogen fuel. The methods and devices rely on concentrating impurities using hydrogen transport membranes wherein the time period for concentrating the sample is calculated on the basis of optimized membrane characteristics, comprising its thickness and permeance, with optimization of temperature, and wherein the enrichment of trace impurities is proportional to the pressure ratio P.sub.hi/P.sub.lo and the volume ratio V.sub.1/V.sub.2, with following detection of the impurities using commonly-available detection methods.

  17. Detection of surface impurity phases in high T.sub.C superconductors using thermally stimulated luminescence

    DOE Patents [OSTI]

    Cooke, D. Wayne; Jahan, Muhammad S.

    1989-01-01

    Detection of surface impurity phases in high-temperature superconducting materials. Thermally stimulated luminescence has been found to occur in insulating impurity phases which commonly exist in high-temperature superconducting materials. The present invention is sensitive to impurity phases occurring at a level of less than 1% with a probe depth of about 1 .mu.m which is the region of interest for many superconductivity applications. Spectroscopic and spatial resolution of the emitted light from a sample permits identification and location of the impurity species. Absence of luminescence, and thus of insulating phases, can be correlated with low values of rf surface resistance.

  18. Effects of Fuel and Air Impurities on PEM Fuel Cell Performance

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

    Hydrogen,Fuel Cells and Infrastructure Technologies 2007 Kickoff Meeting Effects of Fuel and Air Impurities on PEM Fuel Cell Performance Rod Borup Eric Brosha Fernando Garzon (PI) ...

  19. Process for the removal of impurities from combustion fullerenes

    DOE Patents [OSTI]

    Alford, J. Michael; Bolskar, Robert

    2005-08-02

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

  20. When small is big: the role of impurities in electrocatalysis.

    SciTech Connect (OSTI)

    Strmcnik, Dusan; Li, Dongguo; Lopes, Pietro P.; Tripkovic, Dusan; Kodama, Kensaku; Stamenkovic, Vojislav R.; Markovic, Nenad M.

    2015-11-01

    Improvements in the fundamental understanding of electrocatalysis have started to revolutionize the development of electrochemical interfaces for the efficient conversion of chemical energy into electricity, as well as for the utilization of electrons to produce new chemicals that then can be re-used in energy conversion systems. Here, some facets of the role of trace level of impurities (from 10-7 to 10-6 M) in electrocatalysis of the oxygen reduction reaction, hydrogen oxidation and evolution reactions, and CO oxidation reactions are explored on well-characterized platinum single crystal surfaces and high surface area materials in alkaline and acidic environments. Of particular interest is the effect of anions (e.g., Cl-, NO3-) and cations (i.e., Cu2+) present in the supporting electrolytes as well as surface defects (i.e., ad-islands) that are present on metal surfaces. The examples presented are chosen to demonstrate that a small level of impurities may play a crucial role in governing the reactivity of electrochemical interfaces.

  1. Influence of impurity gases and operating conditions on PAFC performance

    SciTech Connect (OSTI)

    Hirai, K.; Iwasa, N.; Suzuki, M.; Okada, O.

    1996-12-31

    On-site Phosphoric Acid Fuel Cell (PAFC) Cogeneration system is installed at various test sites, such as at underground parking lot, within chemical plant premises and near urban streets. Since in the current PAFC system, cathode air is supplied to the cell with no particular pretreatment, impurity gases in the air might influence on cell performance. We have investigated the influence of various impurity gases in the cathode gas, on sub-scale single cells, and have found that NO{sub 2}, SO{sub 2} and toluene affect negatively on cell performance. The results of these experiments and the conceivable mechanism of these effects on cell degradation are reported. We have also investigated the influence of other operating parameters, such as temperature, current density, fuel utilization on cell performance. From these experiments, we have found that operating temperature is a significant factor, which mainly determines cell voltage decline rate. The results of sub-scale single cell tests and a short-stack verification test are also reported.

  2. Concordant plutonium-241-americium-241 dating of environmental samples: results from forest fire ash

    SciTech Connect (OSTI)

    Goldstein, Steven J; Oldham, Warren J; Murrell, Michael T; Katzman, Danny

    2010-12-07

    We have measured the Pu, {sup 237}Np, {sup 241}Am, and {sup 151}Sm isotopic systematics for a set of forest fire ash samples from various locations in the western U.S. including Montana, Wyoming, Idaho, and New Mexico. The goal of this study is to develop a concordant {sup 241}Pu (t{sub 1/2} = 14.4 y)-{sup 241}Am dating method for environmental collections. Environmental samples often contain mixtures of components including global fallout. There are a number of approaches for subtracting the global fallout component for such samples. One approach is to use {sup 242}/{sup 239}Pu as a normalizing isotope ratio in a three-isotope plot, where this ratio for the nonglobal fallout component can be estimated or assumed to be small. This study investigates a new, complementary method of normalization using the long-lived fission product, {sup 151}Sm (t{sub 1/2} = 90 y). We find that forest fire ash concentrates actinides and fission products with {approx}1E10 atoms {sup 239}Pu/g and {approx}1E8 atoms {sup 151}Sm/g, allowing us to measure these nuclides by mass spectrometric (MIC-TIMS) and radiometric (liquid scintillation counting) methods. The forest fire ash samples are characterized by a western U.S. regional isotopic signature representing varying mixtures of global fallout with a local component from atmospheric testing of nuclear weapons at the Nevada Test Site (NTS). Our results also show that {sup 151}Sm is well correlated with the Pu nuclides in the forest fire ash, suggesting that these nuclides have similar geochemical behavior in the environment. Results of this correlation indicate that the {sup 151}Sm/{sup 239}Pu atom ratio for global fallout is {approx}0.164, in agreement with an independent estimate of 0.165 based on {sup 137}Cs fission yields for atmospheric weapons tests at the NTS. {sup 241}Pu-{sup 241}Am dating of the non-global fallout component in the forest fire ash samples yield ages in the late 1950's-early 1960's, consistent with a peak in NTS

  3. Divertor impurity injection using high voltage arcs for impurity transport studies on the Mega Amp Spherical Tokamak

    SciTech Connect (OSTI)

    Leggate, H. J. Turner, M. M.; Lisgo, S. W.; Harrison, J. R.; Elmore, S.; Allan, S. Y.; Gaffka, R. C.; Stephen, R. C.

    2014-12-15

    The operation of next-generation fusion reactors will be significantly affected by impurity transport in the scrape-off layer (SOL). Current modelling efforts are restricted by a lack of detailed data on impurity transport in the SOL. In order to address this, a carbon injector has been designed and installed on the Mega Amp Spherical Tokamak (MAST). The injector creates short lived carbon plumes originating at the MAST divertor lasting less than 50 μs. High voltage capacitor banks are used to create a discharge across concentric carbon electrodes located in a probe mounted on the Divertor Science Facility in the MAST lower divertor. This results in a very short plume duration allowing observation of the evolution of the plume and precise localisation of the plume relative to the X-point on MAST. The emission from the carbon plume was imaged using fast visible cameras filtered in order to isolate the carbon II and carbon III emission lines centered around 514 nm and 465 nm.

  4. Impurity effects on short wavelength ion temperature gradient mode in elongated tokamak plasmas

    SciTech Connect (OSTI)

    Du, Huarong; Wang, Zheng-Xiong; Dong, J. Q.

    2015-02-15

    The effects of impurity ions on the short wavelength ion temperature gradient (SWITG) driven instability in elongated tokamak plasmas are numerically investigated with the gyrokinetic integral eigenmode equation. It is found that for a moderate electron density gradient, the SWITG mode is first destabilized and then stabilized with increasing elongation ?, which is different from the conventional long wavelength ITG mode. For a large electron density gradient, the elongation can effectively stabilize the SWITG mode. Moreover, the low Z impurity ions with inwardly (outwardly) peaked density profiles have stabilizing (destabilizing) effects on the SWITG modes in elongated plasmas. Interestingly, the high Z tungsten impurity ions with inwardly peaked density profiles play a stronger stabilizing role in the SWITG modes than the low Z impurity ions (such as carbon and oxygen) do. In particular, the high Z tungsten impurity ions with a weakly outwardly peaked density profile still have a stabilizing effect. Finally, the critical threshold of impurity density gradient scale length for exciting impurity mode is also numerically obtained, indicating that the impurity mode is harder to be excited in elongated plasmas than in circular ones.

  5. ADVANCED POWER SYSTEMS ASH BEHAVIOR IN POWER SYSTEMS

    SciTech Connect (OSTI)

    CHRISTOPHER J. ZYGARLICKE; DONALD P. MCCOLLOR; JOHN P. KAY; MICHAEL L. SWANSON

    1998-09-01

    The overall goal of this initiative is to develop fundamental knowledge of ash behavior in power systems for the purpose of increasing power production efficiency, reducing operation and maintenance costs, and reducing greenhouse gas emissions into the atmosphere. The specific objectives of this initiative focus primarily on ash behavior related to advanced power systems and include the following: ? Determine the current status of the fundamental ash interactions and deposition formation mechanisms as already reported through previous or ongoing projects at the EERC or in the literature. ? Determine sintering mechanisms for temperatures and particle compositions that are less well known and remain for the most part undetermined. ? Identify the relationship between the temperature of critical viscosity (Tcv ) as measured in a viscometer and the crystallization occurring in the melt. ? Perform a literature search on the use of heated-stage microscopy (HSM) for examining in situ ash-sintering phenomena and then validate the use of HSM in the determination of viscosity in spherical ash particles. ? Ascertain the formation and stability of specific mineral or amorphous phases in deposits typical of advanced power systems. ? Evaluate corrosion for alloys being used in supercritical combustion systems.

  6. Chloride chemical form in various types of fly ash

    SciTech Connect (OSTI)

    Fenfen Zhu; Masaki Takaoka; Kenji Shiota; Kazuyuki Oshita; Yoshinori Kitajima

    2008-06-01

    Chloride content is a critical problem for the reuse of fly ash as a raw material in cement, and the method used by recyclers to reduce the fly ash chloride content depends on the chemical form of the chlorides. However, limited information is available on the quantitative distribution of chlorides and the identity of some chlorides such as Friedel's salt. We examined chloride forms and percentages using X-ray absorption near edge structure and X-ray diffraction analyses, as well as corresponding washing experiments. Approximately 15% of the chlorine in raw fly ash was estimated to be in the form of NaCl, 10% in KCl, 50% in CaCl{sub 2}, and the remainder in the form of Friedel's salt. Fly ash collected in a bag filter with the injection of calcium hydroxide for acid gas removal (CaFA) contained 35% chlorine as NaCl, 11% as KCl, 37% as CaCl{sub 2}, 13% as Friedel's salt, and the remaining 4% as CaClOH. In fly ash collected in a bag filter with the injection of sodium bicarbonate for acid gas removal (NaFA), approximately 79% of chlorine was in NaCl, 12% was in KCl, and 9% was in Friedel's salt. 25 refs., 4 figs., 4 tabs.

  7. Release of Ammonium and Mercury from NOx Controlled Fly Ash

    SciTech Connect (OSTI)

    Schroeder, K.T.; Cardone, C.R.; Kim, A.G

    2007-07-01

    One of the goals of the Department of Energy is to increase the reuse of coal utilization byproducts (CUB) to 50% by 2010. This will require both developing new markets and maintaining traditional ones such as the use of fly ash in concrete. However, the addition of pollution control devices can introduce side-effects that affect the marketability of the CUB. Such can be the case when NOx control is achieved using selective catalytic or non-catalytic reduction (SCR or SNCR). Depending on site-specific details, the ammonia slip can cause elevated levels of NH3 in the fly ash. Disposal of ammoniated fly ash can present environmental concerns related to the amount of ammonia that might be released, the amount of water that might become contaminated, and the extent to which metals might be mobilized by the presence of the ammonia. Ammonia retained in fly ash appears to be present as either an ammonium salt or as a chemisorbed species. Mercury in the leachates correlated to neither the amount of leachable ammonium nor to the total amount of Hg in the ash. The strongest correlation was between the decreases in the amount of Hg leached with increased LOI.

  8. Impurity mixing and radiation asymmetry in massive gas injection simulations of DIII-D

    SciTech Connect (OSTI)

    Izzo, V. A.

    2013-05-15

    Simulations of neon massive gas injection into DIII-D are performed with the 3D MHD code NIMROD. The poloidal and toroidal distribution of the impurity source is varied. This report will focus on the effects of the source variation on impurity mixing and radiated power asymmetry. Even toroidally symmetric impurity injection is found to produce asymmetric radiated power due to asymmetric convective heat flux produced by the 1/1 mode. When the gas source is toroidally localized, the phase relationship between the mode and the source location is important, affecting both radiation peaking and impurity mixing. Under certain circumstances, a single, localized gas jet could produce better radiation symmetry during the disruption thermal quench than evenly distributed impurities.

  9. Ash bed level control system for a fixed-bed coal gasifier

    DOE Patents [OSTI]

    Fasching, George E.; Rotunda, John R.

    1984-01-01

    An ash level control system is provided which incorporates an ash level meter to automatically control the ash bed level of a coal gasifier at a selected level. The ash level signal from the ash level meter is updated during each cycle that a bed stirrer travels up and down through the extent of the ash bed level. The ash level signal is derived from temperature measurements made by thermocouples carried by the stirrer as it passes through the ash bed and into the fire zone immediately above the ash bed. The level signal is compared with selected threshold level signal to determine if the ash level is above or below the selected level once each stirrer cycle. A first counter is either incremented or decremented accordingly. The registered count of the first counter is preset in a down counter once each cycle and the preset count is counted down at a selected clock rate. A grate drive is activated to rotate a grate assembly supporting the ash bed for a period equal to the count down period to maintain the selected ash bed level. In order to avoid grate binding, the controller provides a short base operating duration time each stirrer cycle. If the ash bed level drops below a selected low level or exceeds a selected high level, means are provided to notify the operator.

  10. Cementation and solidification of Rocky Flats Plant incinerator ash

    SciTech Connect (OSTI)

    Phillips, J.A.; Semones, G.B.

    1994-04-01

    Cementation studies on various aqueous waste streams at Rocky Flats have shown this technology to be effective for immobilizing the RCRA constituents in the waste. Cementation is also being evaluated for encapsulation of incinerator ash. Experiments will initially evaluate a surrogate ash waste using a Taguchi experimental design to optimize the cement formulation and waste loading levels for this application. Variables of waste loading, fly ash additions, water/cement ratio, and cement type will be tested at three levels each during the course of this work. Tests will finally be conducted on actual waste using the optimized cement formulation developed from this testing. This progression of tests will evaluate the effectiveness of cement encapsulation for this waste stream without generating any additional wastes.