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Sample records for selectively oxidized coals

  1. Mild pyrolysis of selectively oxidized coals

    SciTech Connect

    Hippo, E.J.

    1991-01-01

    The primary objective of this study is to investigate the removal organic sulfur from selectively oxidized Illinois coals using mild thermal/chemical processes. Work completed this quarter includes the investigation of the mild pyrolysis of unoxidized coals plus a selection of selectively oxidized coals. In addition the effect of particle size and extent of oxidation on pyrolysis was investigated. Some preliminary data concerning pyrolysis under vacuum and ambient pressure was also obtained. Work completed this quarter supports the following conclusions: (1) Desulfurization of unoxidized coals increases with increasing pyrolysis temperature and correlates with the loss of volatile matter. (2) Particle size did not influence the extent of desulfurization significantly. (3) Removing pyrite prior to pyrolysis helps to achieve a lower sulfur product beyond that expected from the removal of pyrite alone. (4) The extent of selective oxidation in teh pretreatment step did not effect the level of desulfurization obtained by pyrolysis alone. However this factor was important in the desulfurization obtained with supercritical methanol (SCM)/base. (5) Up to 84% of the sulfur has been removed from the IBC 101 coal by combining selective oxidation and SCM/base reactions. (6) Evidence for regressive reactions between volatilized sulfur compounds and partially desulfurized products was obtained by studying how changes in pyrolysis pressure effected the product sulfur content.

  2. Mild pyrolysis of selectively oxidized coals. Technical report, September 1, 1991--August 31, 1992

    SciTech Connect

    Hippo, E.J.; Palmer, S.R.

    1992-12-31

    The primary objective of this study was to evaluate selective oxidation as a pretreatment for the enhanced desulfurization of Illinois Basin coals using a variety of mild thermal/chemical processes. Both an Illinois No.6 and an Indiana No.5 coal were selectively oxidized with peroxyacetic acid in the pretreatment step. The products were then treated with many hydroxide and carbonate bases using either water, methanol or ethanol as the solvent system. Other reaction variables investigated include reaction temperature, reaction time, pyrolysis pressure, particle size of the coal and the level of oxidation in the pretreatment step. Throughout the study the selectively oxidized coals were compared to unoxidized control coals. Model compounds were also studied. The results of these studies overwhelmingly show that selective oxidation with peroxyacetic acid significantly enhances the level of desulfurization obtained with subsequent chemical/thermal treatments. Indeed, every process investigated, including simple pyrolysis experiments, showed sulfur removal in the pretreatment step and the subsequent step to be substantially additive. In addition, considerable enhancement in the reactivity of the sulfur in the coal was obtained by the selective oxidation pretreatment. Sulfur contents lower than 0.25% were obtained for selectively oxidized coals. This represents an overall sulfur reduction of around 95%. This is beyond the level required for compliance with Clean Air Act legislation. No unoxidized coal, regardless of the desulfurization treatment, approached this level of sulfur removal.

  3. Mild pyrolysis of selectively oxidized coals. [Quarterly] technical report, March 1, 1992--May 31, 1992

    SciTech Connect

    Hippo, E.J.; Palmer, S.R.

    1992-10-01

    The primary objective of this study is to investigate the removal organic sulfur from selectively oxidized Illinois coals using mild thermal/chemical processes. Work completed this quarter primarily concerned the investigation of the desulfurization of the selectively oxidized coals using aqueous or alcoholic base mixtures. Model compound studies were initiated. Results were: Levels of desulfurization obtained in this study are at, or very close to, the 90% removal levels required for these coals to be in compliance with the Clean Air Act legislation; Up to 89.4% of the sulfur in the IBC 101 coal and 88.9% of the sulfur in the IBC 106 coal has been removed by combining selective oxidation and alcoholic/base reactions; Overall, selective oxidation pretreatment always led to a lower sulfur product than the untreated sample; Substantial enhancement in the reactivity of the sulfur in the coal has been achieved by the selective oxidation pretreatment; The highest levels of desulfurization obtained so far all involve bases as additives; The water/Na{sub 2}CO{sub 3} combination, was superior than any of the aqueous hydroxide bases. Possible synergistic interactions between the alcohol and the base are suspected. Over 70% of the sulfur in the IBC 101 coal can be removed by performing vacuum pyrolysis on the selectively oxidized coal. Lower sulfur contents are obtained by lowing the pyrolysis pressure.

  4. Mild pyrolysis of selectively oxidized coals. Technical report, September 1--November 30, 1991

    SciTech Connect

    Hippo, E.J.

    1991-12-31

    The primary objective of this study is to investigate the removal organic sulfur from selectively oxidized Illinois coals using mild thermal/chemical processes. Work completed this quarter includes the investigation of the mild pyrolysis of unoxidized coals plus a selection of selectively oxidized coals. In addition the effect of particle size and extent of oxidation on pyrolysis was investigated. Some preliminary data concerning pyrolysis under vacuum and ambient pressure was also obtained. Work completed this quarter supports the following conclusions: (1) Desulfurization of unoxidized coals increases with increasing pyrolysis temperature and correlates with the loss of volatile matter. (2) Particle size did not influence the extent of desulfurization significantly. (3) Removing pyrite prior to pyrolysis helps to achieve a lower sulfur product beyond that expected from the removal of pyrite alone. (4) The extent of selective oxidation in teh pretreatment step did not effect the level of desulfurization obtained by pyrolysis alone. However this factor was important in the desulfurization obtained with supercritical methanol (SCM)/base. (5) Up to 84% of the sulfur has been removed from the IBC 101 coal by combining selective oxidation and SCM/base reactions. (6) Evidence for regressive reactions between volatilized sulfur compounds and partially desulfurized products was obtained by studying how changes in pyrolysis pressure effected the product sulfur content.

  5. Mild pyrolysis of selectively oxidized coals. [Quarterly] technical report, December 1, 1991--February 29, 1992

    SciTech Connect

    Hippo, E.J.; Palmer, S.R.

    1992-08-01

    The primary objective of this study is to investigate the removal organic sulfur from selectively oxidized Illinois coals using mild thermal/chemical processes. Work completed this quarter primarily concerned establishing the level of selective oxidation required for successful desulfurization in subsequent treatments. Many desulfurization reactions were performed on pretreated as well as unoxidized coal. The results obtained support the following new conclusions: (1) The extent of selective oxidation in the pretreatment step does not effect the level of desulfurization obtained by pyrolysis alone. However this factor was important in the desulfurization obtained with supercritical methanol (SCM)/base. (2) Up to 84% of the sulfur in the IBC 106 coal and 86% of the sulfur in the IBC 106 coal has been removed by combining selective oxidation and SCM/base reactions. (3) Most desulfurizations at 250{degree}C did not produce significant levels of desulfurization. However as the temperature was increased levels of desulfurization increased considerably. (4) Although aqueous base was successful in removing sulfur from both pretreated and untreated samples, the most pronounced desulfurizations were obtained for the untreated samples. This is explained primarily by the dissolution of pyrite in the untreated samples. (5) The best desulfurizations involved SCM and base. Possible synergistic interactions between the methanol and the base are suspected. (6) Overall, selective oxidation pretreatment always led to a lower sulfur product. The severity of desulfurization is reduced by selective oxidation pretreatment.

  6. MERCURY OXIDATION PROMOTED BY A SELECTIVE CATALYTIC REDUCTION CATALYST UNDER SIMULATED POWDER RIVER BASIN COAL COMBUSTION CONDITIONS

    EPA Science Inventory

    A bench-scale reactor consisting of a natural gas burner and an electrically heated reactor housing a selective catalytic reduction (SCR) catalyst was constructed for studying elemental mercury oxidation under SCR conditions. A low sulfur Power River Basin (PRB) coal combustion ...

  7. A predictive mechanism for mercury oxidation on selective catalytic reduction catalysts under coal-derived flue gas

    SciTech Connect

    Stephen Niksa; Naoki Fujiwara

    2005-12-15

    This paper introduces a predictive mechanism for elemental mercury (Hg{sup 0}) oxidation on selective catalytic reduction (SCR) catalysts in coal-fired utility gas cleaning systems, given the ammonia (NH{sub 3})/nitric oxide (NO) ratio and concentrations of Hg{sup 0} and HCl at the monolith inlet, the monolith pitch and channel shape, and the SCR temperature and space velocity. A simple premise connects the established mechanism for catalytic NO reduction to the Hg{sup 0} oxidation behavior on SCRs: that hydrochloric acid (HCl) competes for surface sites with NH{sub 3} and that Hg{sup 0} contacts these chlorinated sites either from the gas phase or as a weakly adsorbed species. This mechanism explicitly accounts for the inhibition of Hg{sup 0} oxidation by NH{sub 3}, so that the monolith sustains two chemically distinct regions. In the inlet region, strong NH{sub 3} adsorption minimizes the coverage of chlorinated surface sites, so NO reduction inhibits Hg{sup 0} oxidation. But once NH{sub 3} has been consumed, the Hg{sup 0} oxidation rate rapidly accelerates, even while the HCl concentration in the gas phase is uniform. Factors that shorten the length of the NO reduction region factors that enhance surface chlorination, promote Hg{sup 0} oxidation. This mechanism accurately interprets the reported tendencies for greater extents of Hg{sup 0} oxidation on honeycomb monoliths with smaller channel pitches and hotter temperatures and the tendency for lower extents of Hg{sup 0} oxidation for hotter temperatures on plate monoliths. The mechanism reproduces the reported extents of Hg{sup 0} oxidation on a single catalyst for four coals that generated HCl concentrations from 8 to 241 ppm, which covers the entire range encountered in the U.S. utility industry. Similar performance is also demonstrated for full-scale SCRs with diverse coal types and operating conditions. 28 refs., 5 figs., 3 tabs.

  8. Mercury oxidation promoted by a selective catalytic reduction catalyst under simulated Powder River Basin coal combustion conditions.

    PubMed

    Lee, Chun W; Serre, Shannon D; Zhao, Yongxin; Lee, Sung Jun; Hastings, Thomas W

    2008-04-01

    A bench-scale reactor consisting of a natural gas burner and an electrically heated reactor housing a selective catalytic reduction (SCR) catalyst was constructed for studying elemental mercury (Hg(o)) oxidation under SCR conditions. A low sulfur Powder River Basin (PRB) subbituminous coal combustion fly ash was injected into the entrained-flow reactor along with sulfur dioxide (SO2), nitrogen oxides (NOx), hydrogen chloride (HCl), and trace Hg(o). Concentrations of Hg(o) and total mercury (Hg) upstream and downstream of the SCR catalyst were measured using a Hg monitor. The effects of HCl concentration, SCR operating temperature, catalyst space velocity, and feed rate of PRB fly ash on Hg(o) oxidation were evaluated. It was observed that HCl provides the source of chlorine for Hg(o) oxidation under simulated PRB coal-fired SCR conditions. The decrease in Hg mass balance closure across the catalyst with decreasing HCl concentration suggests that transient Hg capture on the SCR catalyst occurred during the short test exposure periods and that the outlet speciation observed may not be representative of steady-state operation at longer exposure times. Increasing the space velocity and operating temperature of the SCR led to less Hg(o) oxidized. Introduction of PRB coal fly ash resulted in slightly decreased outlet oxidized mercury (Hg2+) as a percentage of total inlet Hg and correspondingly resulted in an incremental increase in Hg capture. The injection of ammonia (NH3) for NOx reduction by SCR was found to have a strong effect to decrease Hg oxidation. The observations suggest that Hg(o) oxidation may occur near the exit region of commercial SCR reactors. Passage of flue gas through SCR systems without NH3 injection, such as during the low-ozone season, may also impact Hg speciation and capture in the flue gas.

  9. Plasma gasification of coal in different oxidants

    SciTech Connect

    Matveev, I.B.; Messerle, V.E.; Ustimenko, A.B.

    2008-12-15

    Oxidant selection is the highest priority for advanced coal gasification-process development. This paper presents comparative analysis of the Powder River Basin bituminous-coal gasification processes for entrained-flow plasma gasifier. Several oxidants, which might be employed for perspective commercial applications, have been chosen, including air, steam/carbon-dioxide blend, carbon dioxide, steam, steam/air, steam/oxygen, and oxygen. Synthesis gas composition, carbon gasification degree, specific power consumptions, and power efficiency for these processes were determined. The influence of the selected oxidant composition on the gasification-process main characteristics have been investigated.

  10. Impacts of halogen additions on mercury oxidation, in a slipstream selective catalyst reduction (SCR), reactor when burning sub-bituminous coal.

    PubMed

    Cao, Yan; Gao, Zhengyang; Zhu, Jiashun; Wang, Quanhai; Huang, Yaji; Chiu, Chengchung; Parker, Bruce; Chu, Paul; Pant, Wei-Ping

    2008-01-01

    This paper presents a comparison of impacts of halogen species on the elemental mercury (Hg(0)) oxidation in a real coal-derived flue gas atmosphere. It is reported there is a higher percentage of Hg(0) in the flue gas when burning sub-bituminous coal (herein Powder River Basin (PRB) coal) and lignite, even with the use of selective catalytic reduction (SCR). The higher Hg(0)concentration in the flue gas makes it difficult to use the wet-FGD process for the mercury emission control in coal-fired utility boilers. Investigation of enhanced Hg(0) oxidation by addition of hydrogen halogens (HF, HCl, HBr, and HI) was conducted in a slipstream reactor with and without SCR catalysts when burning PRB coal. Two commercial SCR catalysts were evaluated. SCR catalyst no. 1 showed higher efficiencies of both NO reduction and Hg(0) oxidation than those of SCR catalyst no. 2. NH3 addition seemed to inhibit the Hg(0) oxidation, which indicated competitive processes between NH3 reduction and Hg(0) oxidation on the surface of SCR catalysts. The hydrogen halogens, in the order of impact on Hg(0) oxidation, were HBr, HI, and HCl or HF. Addition of HBr at approximately 3 ppm could achieve 80% Hg(0) oxidation. Addition of HI at approximately 5 ppm could achieve 40% Hg(0) oxidation. In comparison to the empty reactor, 40% Hg(0) oxidation could be achieved when HCl addition was up to 300 ppm. The enhanced Hg(0) oxidation by addition of HBr and HI seemed not to be correlated to the catalytic effects by both evaluated SCR catalysts. The effectiveness of conversion of hydrogen halogens to halogen molecules or interhalogens seemed to be attributed to their impacts on Hg(0) oxidation.

  11. Impacts of halogen additions on mercury oxidation, in a slipstream selective catalyst reduction (SCR), reactor when burning sub-bituminous coal

    SciTech Connect

    Yan Cao; Zhengyang Gao; Jiashun Zhu; Quanhai Wang; Yaji Huang; Chengchung Chiu; Bruce Parker; Paul Chu; Wei-ping Pan

    2008-01-01

    This paper presents a comparison of impacts of halogen species on the elemental mercury (Hg(0)) oxidation in a real coal-derived flue gas atmosphere. It is reported there is a higher percentage of Hg(0) in the flue gas when burning sub-bituminous coal (herein Powder River Basin (PRB) coal) and lignite, even with the use of selective catalytic reduction (SCR). The higher Hg(0) concentration in the flue gas makes it difficult to use the wet-FGD process for the mercury emission control in coal-fired utility boilers. Investigation of enhanced Hg(0) oxidation by addition of hydrogen halogens (HF, HCl, HBr, and HI) was conducted in a slipstream reactor with and without SCR catalysts when burning PRB coal. Two commercial SCR catalysts were evaluated. SCR catalyst no. 1 showed higher efficiencies of both NO reduction and Hg(0) oxidation than those of SCR catalyst no. 2. NH{sub 3} addition seemed to inhibit the Hg(0) oxidation, which indicated competitive processes between NH{sub 3} reduction and Hg(0) oxidation on the surface of SCR catalysts. The hydrogen halogens, in the order of impact on Hg(0) oxidation, were HBr, HI, and HCl or HF. Addition of HBr at approximately 3 ppm could achieve 80% Hg(0) oxidation. Addition of HI at approximately 5 ppm could achieve 40% Hg(0) oxidation. In comparison to the empty reactor, 40% Hg(0) oxidation could be achieved when HCl addition was up to 300 ppm. The enhanced Hg(0) oxidation by addition of HBr and HI seemed not to be correlated to the catalytic effects by both evaluated SCR catalysts. The effectiveness of conversion of hydrogen halogens to halogen molecules or interhalogens seemed to be attributed to their impacts on Hg(0) oxidation. 30 refs., 4 figs.

  12. The cyclic oxidation resistance at 1200 C of beta-NiAl, FeAl, and CoAl alloys with selected third element additions

    NASA Technical Reports Server (NTRS)

    Barrett, C. A.; Titran, R. H.

    1992-01-01

    The intermetallic compounds Beta-NiAl, FeAl, and CoAl were tested in cyclic oxidation with selected third element alloy additions. Tests in static air for 200 1-hr cycles at 1200 C indicated by specific weight change/time data and x-ray diffraction analysis that the 5 at percent alloy additions did not significantly improve the oxidation resistance over the alumina forming baseline alloys without the additions. Many of the alloy additions were actually deleterious. Ta and Nb were the only alloy additions that actually altered the nature of the oxide(s) formed and still maintained the oxidation resistance of the protective alumina scale.

  13. REFORMULATION OF COAL-DERIVED TRANSPORTATION FUELS: SELECTIVE OXIDATION OF CARBON MONOXIDE ON METAL FOAM CATALYSTS

    SciTech Connect

    Paul Chin; George W. Roberts; James J. Spivey

    2003-12-31

    Uses for structured catalytic supports, such as ceramic straight-channel monoliths and ceramic foams, have been established for a long time. One of the most prominent examples is the washcoated ceramic monolith as a three-way catalytic converter for gasoline-powered automobiles. A distinct alternative to the ceramic monolith is the metal foam, with potential use in fuel cell-powered automobiles. The metal foams are characterized by their pores per inch (ppi) and density ({rho}). In previous research, using 5 wt% platinum (Pt) and 0.5 wt% iron (Fe) catalysts, washcoated metal foams, 5.08 cm in length and 2.54 cm in diameter, of both varying and similar ppi and {rho} were tested for their activity (X{sub CO}) and selectivity (S{sub CO}) on a CO preferential oxidation (PROX) reaction in the presence of a H{sub 2}-rich gas stream. The variances in these metal foams' activity and selectivity were much larger than expected. Other structured supports with 5 wt% Pt, 0-1 wt% Fe weight loading were also examined. A theory for this phenomenon states that even though these structured supports have a similar nominal catalyst weight loading, only a certain percentage of the Pt/Fe catalyst is exposed on the surface as an active site for CO adsorption. We will use two techniques, pulse chemisorption and temperature programmed desorption (TPD), to characterize our structured supports. Active metal count, metal dispersion, and other calculations will help clarify the causes for the activity and selectivity variations between the supports. Results on ceramic monoliths show that a higher Fe loading yields a lower dispersion, potentially because of Fe inhibition of the Pt surface for CO adsorption. This theory is used to explain the reason for activity and selectivity differences for varying ppi and {rho} metal foams; less active and selective metal foams have a lower Fe loading, which justifies their higher metal dispersion. Data on the CO desorption temperature and average metal

  14. Quality of Selected Hungarian Coals

    USGS Publications Warehouse

    Landis, E.R.; Rohrbacher, T.J.; Gluskoter, H.J.; Fodor, B.; Gombar, G.

    2007-01-01

    As part of a program conducted jointly by the U.S. Geological Survey and the Hungarian Geological Survey under the auspices of the United States-Hungarian Science and Technology Fund, a total of 39 samples from five coal mines in Hungary were selected for analysis. The mine areas sampled represent most of the coal mined recently in Hungary. Almost all the coal is used to generate electricity. Coals from the five mines (four underground, one surface) reflect differences in age, depositional setting, organic and inorganic components of the original sediments, and deformational history. Classified according to the ranking system of the American Society for Testing and Materials, the coals range in rank from lignite B (Pliocene[?] coals) to high volatile A bituminous (Jurassic coals). With respect to grade classification, based on seam-weighted averages of moisture, ash, and sulfur contents: (1) all contain high moisture (more than 10 percent), (2) all except the Eocene coals are high (more than 15 percent) in ash yield, and (3) two (Jurassic and Eocene coals) are high in sulfur (more than 3 percent) and three (Cretaceous, Miocene, and Pliocene coals) have medium sulfur contents (1 to 3 percent). Average heat values range from 4,000 to 8,650 British thermal units per pound.

  15. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NOx) emissions from high-sulfur coal-fired boilers

    SciTech Connect

    Not Available

    1991-11-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor.

  16. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO sub x ) emissions from high-sulfur coal-fired boilers

    SciTech Connect

    Not Available

    1991-08-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NOx) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NOx to convert it to nitrogen and water vapor, Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuel performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal.

  17. Innovative clean coal technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO sub x ) emissions from high-sulfur coal-fired boilers

    SciTech Connect

    Not Available

    1991-07-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NOx) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NOx to convert it to nitrogen and water vapor.

  18. Innovative clean coal technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Quarterly report No. 3, January--March 1991

    SciTech Connect

    Not Available

    1991-07-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NOx) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NOx to convert it to nitrogen and water vapor.

  19. Innovative Clean Coal Technology (ICCT): Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO sub x ) emissions from high-sulfur coal-fired boilers

    SciTech Connect

    Not Available

    1992-02-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NOx) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NOx to convert it to nitrogen and water vapor.

  20. Innovative Clean Coal Technology (ICCT): Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Quarterly report No. 6, October--December, 1991

    SciTech Connect

    Not Available

    1992-02-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NOx) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NOx to convert it to nitrogen and water vapor.

  1. Innovative Clean Coal Technology (ICCT). Demonstration of Selective Catalytic Reduction (SCR) technology for the control of Nitrogen Oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, third and fourth quarters 1995

    SciTech Connect

    1996-05-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from U.S., Japanese, and European catalyst suppliers on a high-sulfur U.S. coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor.

  2. REFORMULATION OF COAL-DERIVED TRANSPORTATION FUELS: SELECTIVE OXIDATION OF CARBON MONOXIDE ON METAL FOAM CATALYSTS

    SciTech Connect

    Paul Chin; Xiaolei Sun; George W. Roberts; Amornmart Sirijarhuphan; Sourabh Pansare; James G. Goodwin Jr; Richard W. Rice; James J. Spivey

    2005-06-01

    Hydrocarbon fuels must be reformed in a series of steps to provide hydrogen for use in proton exchange membrane fuel cells (PEMFCs). Preferential oxidation (PROX) is one method to reduce the CO concentration to less than 10 ppm in the presence of {approx}40% H{sub 2}, CO{sub 2}, and steam. This will prevent CO poisoning of the PEMFC anode. Structured supports, such as ceramic monoliths, can be used for the PROX reaction. Alternatively, metal foams offer a number of advantages over the traditional ceramic monolith.

  3. Coal combustion by wet oxidation

    SciTech Connect

    Bettinger, J.A.; Lamparter, R.A.; McDowell, D.C.

    1980-11-15

    The combustion of coal by wet oxidation was studied by the Center for Waste Management Programs, of Michigan Technological University. In wet oxidation a combustible material, such as coal, is reacted with oxygen in the presence of liquid water. The reaction is typically carried out in the range of 204/sup 0/C (400/sup 0/F) to 353/sup 0/C (650/sup 0/F) with sufficient pressure to maintain the water present in the liquid state, and provide the partial pressure of oxygen in the gas phase necessary to carry out the reaction. Experimental studies to explore the key reaction parameters of temperature, time, oxidant, catalyst, coal type, and mesh size were conducted by running batch tests in a one-gallon stirred autoclave. The factors exhibiting the greatest effect on the extent of reaction were temperature and residence time. The effect of temperature was studied from 204/sup 0/C (400/sup 0/F) to 260/sup 0/C (500/sup 0/F) with a residence time from 600 to 3600 seconds. From this data, the reaction activation energy of 2.7 x 10/sup 4/ calories per mole was determined for a high-volatile-A-Bituminous type coal. The reaction rate constant may be determined at any temperature from the activation energy using the Arrhenius equation. Additional data were generated on the effect of mesh size and different coal types. A sample of peat was also tested. Two catalysts were evaluated, and their effects on reaction rate presented in the report. In addition to the high temperature combustion, low temperature desulfurization is discussed. Desulfurization can improve low grade coal to be used in conventional combustion methods. It was found that 90% of the sulfur can be removed from the coal by wet oxidation with the carbon untouched. Further desulfurization studies are indicated.

  4. Innovative clean coal technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Fourth quarterly progress report

    SciTech Connect

    1992-12-31

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal.

  5. Innovative Clean Coal Technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, third and fourth quarters 1994

    SciTech Connect

    1995-11-01

    The objective of this project is to demonstrate and evaluate commercially available selective catalytic reduction (SCR) catalysts from U.S., Japanese, and European catalyst suppliers on a high-sulfur U.S. Coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to form nitrogen and water vapor. Although SCR is widely practiced in Japan and European gas-, oil-, and low-sulfur coal-fired boilers, there are several technical uncertainties associated with applying SCR to U.S. coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in U.S. coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; performance of a wide variety of SCR catalyst compositions, geometries, and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties are being explored by operating a series of small- scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal. The demonstration is being performed at Gulf Power Company`s Plant Crist Unit No. 5 (75 MW capacity) near Pensacola, Florida. The project is funded by the U.S. Department of Energy (DOE), Southern Company Services, Inc. (SCS on behalf of the entire Southern electric system), the Electric Power Research Institute (EPRI), and Ontario Hydro. SCS is the participant responsible for managing al aspects of this project. 1 ref., 69 figs., 45 tabs.

  6. Innovative Clean Coal Technology (ICCT): Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO[sub x]) emissions from high-sulfur coal-fired boilers

    SciTech Connect

    Not Available

    1992-11-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO[sub x]) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO[sub x] to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur, coal-fired boilers, there are several technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO[sub 2] and SO[sub 3] and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small- scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high-sulfur US coal. The demonstration will be performed at Gulf Power Company's Plant Crist Unit No. 5 (75 MW capacity) near Pensacola, Florida.

  7. Innovative Clean Coal Technology (ICCT): Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Third quarterly technical progress report 1992

    SciTech Connect

    Not Available

    1992-11-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur, coal-fired boilers, there are several technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3} and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small- scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high-sulfur US coal. The demonstration will be performed at Gulf Power Company`s Plant Crist Unit No. 5 (75 MW capacity) near Pensacola, Florida.

  8. Innovative Clean Coal Technology (ICCT): Demonstration of selective catalytic reduction technology for the control of nitrogen oxide emissions from high-sulfur coal-fired boilers. First and second quarterly technical progress reports, [January--June 1995]. Final report

    SciTech Connect

    1995-12-31

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia (NH{sub 3}) into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor containing a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur coal-fired boilers, there are several technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}. (3) performance of a wide variety of SCR catalyst compositions, geometries, and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties are being explored by operating a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal. The demonstration is being performed at Gulf Power Company`s Plant Crist Unit No. 5 (75 MW nameplate capacity) near Pensacola, Florida. The project is funded by the US Department of Energy (DOE), Southern Company Services, Inc. (SCS on behalf of the entire Southern electric system), the Electric Power Research Institute (EPRI), and Ontario Hydro. SCS is the participant responsible for managing all aspects of this project.

  9. Innovative Clean Coal Technology (ICCT). Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers: Volume 1. Final report

    SciTech Connect

    1996-10-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from U.S., Japanese and European catalyst suppliers on a high-sulfur U.S. coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO.) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO. to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur coal- fired boilers, there are several technical uncertainties associated with applying SCR to U.S. coals. These uncertainties include: 1) potential catalyst deactivation due to poisoning by trace metal species present in U.S. coals that are not present in other fuels. 2) performance of the technology and effects on the balance-of- plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}. 3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacturer under typical high-sulfur coal-fired utility operating conditions. These uncertainties were explored by operating nine small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal. In addition, the test facility operating experience provided a basis for an economic study investigating the implementation of SCR technology.

  10. Innovative Clean Coal Technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, October 1993--December 1993

    SciTech Connect

    1995-06-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from U.S., Japanese and European catalyst suppliers on a high-sulfur U.S. coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur coal-fired boilers, there are several technical uncertainties associated with applying SCR to U.S. coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in U.S. coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties are being explored by operating a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal.

  11. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. [Quarterly] technical progress report, April--June 1993

    SciTech Connect

    Doyle, F.M.

    1993-06-30

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The results will provide fundamental insight into oxidation, in terms of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the eleventh quarter, dry thermal oxidation tests were done on coal samples from the Pennsylvania State Coal Bank. As-received and oxidized coal samples were studied by ion-exchange methods to determine the carboxylate and phenolic group concentrations. Film flotation tests were done to characterize the flotability of as-received and oxidized coals. In addition, electrokinetic tests were done on different coals, to obtain information pertinent to the selection of flotation reagents. DRIFT analysis was done to characterize the structure of coals.

  12. Demonstration of Selective Catalytic Reduction Technology to Control Nitrogen Oxide Emissions From High-Sulfur, Coal-Fired Boilers: A DOE Assessment

    SciTech Connect

    Federal Energy Technology Center

    1999-12-01

    The goal of the U.S. Department of Energy (DOE) Clean Coal Technology (CCT) program is to furnish the energy marketplace with a number of advanced, more efficient, and environmentally responsible coal utilization technologies through demonstration projects. These projects seek to establish the commercial feasibility of the most promising advanced coal technologies that have developed beyond the proof-of-concept stage. This document serves as a DOE post-project assessment of a project selected in CCT Round 2. The project is described in the report ''Demonstration of Selective Catalytic Reduction (SCR) Technology for the Control of Nitrogen Oxide (NO{sub x}) Emissions from High-Sulfur, Coal-Fired Boilers'' (Southern Company Services 1990). In June 1990, Southern Company Services (Southern) entered into a cooperative agreement to conduct the study. Southern was a cofunder and served as the host at Gulf Power Company's Plant Crist. Other participants and cofunders were EPRI (formerly the Electric Power Research Institute) and Ontario Hydro. DOE provided 40 percent of the total project cost of $23 million. The long-term operation phase of the demonstration was started in July 1993 and was completed in July 1995. This independent evaluation is based primarily on information from Southern's Final Report (Southern Company Services 1996). The SCR process consists of injecting ammonia (NH{sub 3}) into boiler flue gas and passing the 3 flue gas through a catalyst bed where the NO{sub x} and NH{sub 3} react to form nitrogen and water vapor. The objectives of the demonstration project were to investigate: Performance of a wide variety of SCR catalyst compositions, geometries, and manufacturing methods at typical U.S. high-sulfur coal-fired utility operating conditions; Catalyst resistance to poisoning by trace metal species present in U.S. coals but not present, or present at much lower concentrations, in fuels from other countries; and Effects on the balance-of-plant equipment

  13. Process for coal liquefaction employing selective coal feed

    DOEpatents

    Hoover, David S.; Givens, Edwin N.

    1983-01-01

    An improved coal liquefaction process is provided whereby coal conversion is improved and yields of pentane soluble liquefaction products are increased. In this process, selected feed coal is pulverized and slurried with a process derived solvent, passed through a preheater and one or more dissolvers in the presence of hydrogen-rich gases at elevated temperatures and pressures, following which solids, including mineral ash and unconverted coal macerals, are separated from the condensed reactor effluent. The selected feed coals comprise washed coals having a substantial amount of mineral matter, preferably from about 25-75%, by weight, based upon run-of-mine coal, removed with at least 1.0% by weight of pyritic sulfur remaining and exhibiting vitrinite reflectance of less than about 0.70%.

  14. Selective flotation of inorganic sulfides from coal

    DOEpatents

    Miller, K.J.; Wen, Wu-Wey

    1988-05-31

    Pyritic sulfur is removed from coal or other carbonaceous material through the use of humic acid as a coal flotation depressant. Following the removal of coarse pyrite, the carbonaceous material is blended with humic acid, a pyrite flotation collector and a frothing agent within a flotation cell to selectively float pyritic sulfur leaving clean coal as an underflow. 1 fig., 2 tabs.

  15. Selective flotation of inorganic sulfides from coal

    DOEpatents

    Miller, Kenneth J.; Wen, Wu-Wey

    1989-01-01

    Pyritic sulfur is removed from coal or other carbonaceous material through the use of humic acid as a coal flotation depressant. Following the removal of coarse pyrite, the carbonaceous material is blended with humic acid, a pyrite flotation collector and a frothing agent within a flotation cell to selectively float pyritic sulfur leaving clean coal as an underflow.

  16. Flotation and flocculation chemistry of coal and oxidized coals

    SciTech Connect

    Somasundaran, P.

    1990-01-01

    The objective of this research project is to understand the fundamentals involved in the flotation and flocculation of coal and oxidized coals and elucidate mechanisms by which surface interactions between coal and various reagents enhance coal beneficiation. An understanding of the nature of the heterogeneity of coal surfaces arising from the intrinsic distribution of chemical moieties is fundamental to the elucidation of mechanism of coal surface modification and its role in interfacial processes such as flotation, flocculation and agglomeration. A new approach for determining the distribution in surface properties of coal particles was developed in this study and various techniques capable of providing such information were identified. Distributions in surface energy, contact angle and wettability were obtained using novel techniques such as centrifugal immersion and film flotation. Changes in these distributions upon oxidation and surface modifications were monitored and discussed. An approach to the modelling of coal surface site distributions based on thermodynamic information obtained from gas adsorption and immersion calorimetry is proposed. Polyacrylamide and dodecane was used to alter the coal surface. Methanol adsorption was also studied. 62 figs.

  17. Biogenic Methane from Coal: The Oxidation Factor

    NASA Astrophysics Data System (ADS)

    Gallagher, L. K.; Glossner, A. W.; Landkamer, L.; Figueroa, L. A.; Mandernack, K. W.; Munakata Marr, J.

    2011-12-01

    Vast reserves of coal represent an untapped resource that can be used to produce methane gas, a cleaner energy alternative compared to standard fossil fuels. Microorganisms have demonstrated the ability to utilize coal as a carbon source, producing biogenic methane. With increasing demand for cleaner energy resources, understanding and enhancing biogenic methane production has become an area of active research. The conversion of coal to methane by microorganisms has been demonstrated experimentally by a number of research groups, but the state of the coal used as a substrate has not always been reported and may impact biogenic methane production. Microcosm experiments were designed in order to assess how the oxidation state of coal might influence methane production (e.g. as in a dewatered coal-bed natural gas system). Oxidized and un-oxidized coal samples from the Powder River Basin were incubated in microcosms inoculated with an enrichment culture that was derived from coal. Microcosms were characterized by headspace gas analysis, organic acid production, functional gene abundance (qPCR), and pyrosequencing of the 16S rRNA gene. Although the microbial consortium demonstrated the ability to utilize both oxidized and un-oxidized coal as a sole carbon source to generate methane, it was produced in higher quantities from the un-oxidized coal. This microbial community was dominated by Methanobacteriaceae (45%), epsilon-Proteobacteria (32%) and delta-Proteobacteria (13%). The results of this study provide a basis to develop strategies to enhance biogenic methane production from coal, as well as demonstrate the need for careful substrate preparation for inter-study comparisons.

  18. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NOx) emissions from high-sulfur coal-fired boilers. Quarterly report No. 5, July--September 1991

    SciTech Connect

    Not Available

    1991-11-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor.

  19. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. [Coal pyrite electrodes

    SciTech Connect

    Doyle, F.M.

    1992-01-01

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The results will provide fundamental insight into oxidation, in terms of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the eighth quarter, wet chemical and dry oxidation tests were done on Upper Freeport coal from the Troutville [number sign]2 Mine, Clearfield County, Pennsylvania. In addition electrochemical experiments were done on electrodes prepared from Upper Freeport coal pyrite and Pittsburgh coal pyrite samples provided by the US Bureau of Mines, Pittsburgh Research Center, Pennsylvania.

  20. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Quarterly report No. 4, April--June 1991

    SciTech Connect

    Not Available

    1991-08-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NOx) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NOx to convert it to nitrogen and water vapor, Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuel performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal.

  1. Fluidized bed selective pyrolysis of coal

    DOEpatents

    Shang, Jer Y.; Cha, Chang Y.; Merriam, Norman W.

    1992-01-01

    The present invention discloses a process for the pyrolysis of coal which comprises the effective utilization of two zonal inclined fluidized beds, where said zones can be selectively controlled as to temperature and heating rate. The first zonal inclined fluidized bed serves as a dryer for crushed coal and additionally is controlled to selectively pyrolyze said coal producing substantially carbon dioxide for recycle use. The second zonal inclined fluidized bed further pyrolyzes the coal to gaseous, liquid and char products under controlled temperature and heating rate zones designed to economically integrate the product mix. The gas and liquid products are recovered from the gaseous effluent stream while the char which remains can be further treated or utilized in a subsequent process step.

  2. Fluidized bed selective pyrolysis of coal

    DOEpatents

    Shang, J.Y.; Cha, C.Y.; Merriam, N.W.

    1992-12-15

    The present invention discloses a process for the pyrolysis of coal which comprises the effective utilization of two zonal inclined fluidized beds, where said zones can be selectively controlled as to temperature and heating rate. The first zonal inclined fluidized bed serves as a dryer for crushed coal and additionally is controlled to selectively pyrolyze said coal producing substantially carbon dioxide for recycle use. The second zonal inclined fluidized bed further pyrolyses the coal to gaseous, liquid and char products under controlled temperature and heating rate zones designed to economically integrate the product mix. The gas and liquid products are recovered from the gaseous effluent stream while the char which remains can be further treated or utilized in a subsequent process step. 9 figs.

  3. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics

    SciTech Connect

    Doyle, F.M.

    1992-06-30

    during the seventh quarter, electrokinetic, humic acid extraction and film flotation tests were done on oxidized samples of Upper Freeport coal from the Troutville {number sign} 2 Mine, Clearfield County, Pennsylvania. Scanning electron microscopy and energy dispersive X-ray analysis was done to characterize the morphology and composition of the surface of as-received coal, oxidized coal, oxidized coal after extraction of humic acids and humic acid extracted from oxidized coal. In addition, electrochemical studies were done on electrodes prepared from coal pyrite samples.

  4. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics

    SciTech Connect

    Doyle, F.M.

    1992-01-01

    During the ninth quarter, electrochemical experiments were done on electrodes prepared from Upper Freeport coal pyrite and Pittsburgh coal pyrite samples provided by the US Bureau of Mines, Pittsburgh Research Center, Pennsylvania. Scanning electron microscopy and energy dispersive X-ray analysis were done to characterize the morphology and composition of the surface of as-received coal, oxidized coal and coal pyrite. In addition, electrokinetic tests were done on Upper Freeport coal pyrite.

  5. Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, first and second quarters 1994

    SciTech Connect

    1995-11-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from U.S., Japanese and European catalyst suppliers on a high-sulfur U.S. coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involve injecting ammonia into the flue gas generated from coal combustion in a boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to form nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur coal-fired boilers, there are several technical uncertainties associated with applying SCR to U.S. coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in U.S. coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties are being explored by operating a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal. The project is being conducted in the following three phases: permitting, environmental monitoring plan and preliminary engineering; detailed design engineering and construction; and operation, testing, disposition and final report. The project was in the operation and testing phase during this reporting period. Accomplishments for this period are described.

  6. COST OF SELECTIVE CATALYTIC REDUCTION (SCR) APPLICATION FOR NOX CONTROL ON COAL-FIRED BOILERS

    EPA Science Inventory

    The report provides a methodology for estimating budgetary costs associated with retrofit applications of selective catalytic reduction (SCR) technology on coal-fired boilers. SCR is a postcombustion nitrogen oxides (NOx) control technology capable of providing NOx reductions >90...

  7. Mechanisms for selective agglomeration of coals

    SciTech Connect

    Wheelock, T.D.; Drzymala, J.; Allen, R.W.; Hu, Y.-C.; Tyson, D.; Xiaoping, Qiu; Lessa, A.

    1989-05-01

    Work continued on the basic mechanisms which underlie various processes for beneficiating aqueous suspensions of coal by selective agglomeration with oil. A new method was demonstrated for characterizing the agglomerability of coal suspensions. This method utilizes a photometric dispersion analyzer to monitor changes in the turbidity of a particle suspension as increasing amounts of oil are added to the suspension in a batch agglomeration test. Agglomeration of the particles leads to a marked decrease in the turbidity of the suspension. Another experimental technique was also demonstrated for characterizing oil agglomeration. This technique involves measuring the rate of growth of agglomerates in a continuous flow system operating under stead-state conditions. The data are analyzed by means of a population balance. The results of a preliminary set of experiments in which Indiana V seam coal was agglomerated with tetralin seemed to fit a particular growth model very well. Equipment was also constructed for studying the kinetics of agglomeration in a batch process. While earlier work showed that quebracho (a commercially available dispersant) is a strong agglomeration depressant for pyrite, recent experiments with mixtures of Upper Freeport coal and mineral pyrite showed that quebracho does not appear to be sufficiently selective. Further consideration was given to the separation of mixtures of coal and pyrite agglomeration with heptane. 2 refs., 17 figs., 1 tab.

  8. Detection and modeling of subsurface coal oxidation

    USGS Publications Warehouse

    Leonhart, Leo S.; Rasmussen, William O.; Barringer, Anthony R.

    1980-01-01

    The oxidation and sustained ignition of coal and coaly wastes within surface coal mine spoils in the southwestern U.S. have hampered the success of reclamation efforts at these locations. To assess better the magnitude, depth, geometry, and dynamics of the oxidation process thermal infrared remote sensing data have been used. Digital thermal imagery was found to be useful for this purpose and was integrated with finite different heat transfer models to yield predictions of several characteristics of the thermal source. In addition to thermal infrared imagery, aerial color and false color infrared imagery were found to provide useful information for the interpretation of oxidation phenomena by means of variations in surface vegetation, color of the surface material, subsidence, etc. The combined use of thermal infrared imagery and thermal modeling techniques are well suited for use in exploration and interpretation of other thermal targets.

  9. Bacterial Oxidation of Pyritic Materials in Coal.

    PubMed

    Silverman, M P; Rogoff, M H; Wender, I

    1961-11-01

    Applicability of the manometric method for studying the oxidation of pyritic material in the presence of bacteria has been demonstrated. Resting cells of Ferrobacillus ferrooxidans accelerated the oxidation of coal pyrites and coarsely crystalline marcasite, but were inactive on coarsely crystalline pyrite. Resting cells of Thiobacillus thiooxidans were inactive on all pyrites tested. Oxidation rates in the presence of Ferrobacillus were increased by reducing the particle size of pyritic samples, and, in one case, by removing the CaCO(3) from a calcite-containing sample.

  10. Further studies of the effects of oxidation on the surface properties of coal and coal pyrite

    SciTech Connect

    Herrera, Miguel Nicolas

    1994-01-01

    The objective of this research was to investigate the oxidation behavior of coal and coal pyrite and to correlate the changes in the surface properties induced by oxidation, along with the intrinsic physical and chemical properties of these organic and inorganic materials, with the behavior in physical coal cleaning processes. This provide more fundamental knowledge for understanding the way in which different factors interact in a medium as heterogeneous as coal. Fourteen coal samples of different ranks ranging from high to medium sulfur content were studied by dry oxidation tests at different temperatures and humidities, and by wet oxidation tests using different oxidizing agents. The concentration of surface oxygen functional groups was determined by ion-exchange methods. The changes in the coal composition with oxidation were analyzed by spectroscopic techniques. The wettability of as-received and oxidized coal and coal pyrite samples was assessed by film flotation tests. The electrokinetic behavior of different coals and coal pyrite samples was studied by electrokinetic tests using electrophoresis. Possible oxidation mechanisms have been proposed to explain the changes on the coal surface induced by different oxidation treatments.

  11. Oxidation of Mercury in Products of Coal Combustion

    SciTech Connect

    Peter Walsh; Giang Tong; Neeles Bhopatkar; Thomas Gale; George Blankenship; Conrad Ingram; Selasi Blavo Tesfamariam Mehreteab; Victor Banjoko; Yohannes Ghirmazion; Heng Ban; April Sibley

    2009-09-14

    Laboratory measurements of mercury oxidation during selective catalytic reduction (SCR) of nitric oxide, simulation of pilot-scale measurements of mercury oxidation and adsorption by unburned carbon and fly ash, and synthesis of new materials for simultaneous oxidation and adsorption of mercury, were performed in support of the development of technology for control of mercury emissions from coal-fired boilers and furnaces. Conversion of gas-phase mercury from the elemental state to water-soluble oxidized form (HgCl{sub 2}) enables removal of mercury during wet flue gas desulfurization. The increase in mercury oxidation in a monolithic V{sub 2}O{sub 5}-WO{sub 3}/TiO{sub 2} SCR catalyst with increasing HCl at low levels of HCl (< 10 ppmv) and decrease in mercury oxidation with increasing NH{sub 3}/NO ratio during SCR were consistent with results of previous work by others. The most significant finding of the present work was the inhibition of mercury oxidation in the presence of CO during SCR of NO at low levels of HCl. In the presence of 2 ppmv HCl, expected in combustion products from some Powder River Basin coals, an increase in CO from 0 to 50 ppmv reduced the extent of mercury oxidation from 24 {+-} 3 to 1 {+-} 4%. Further increase in CO to 100 ppmv completely suppressed mercury oxidation. In the presence of 11-12 ppmv HCl, increasing CO from 0 to {approx}120 ppmv reduced mercury oxidation from {approx}70% to 50%. Conversion of SO{sub 2} to sulfate also decreased with increasing NH{sub 3}/NO ratio, but the effects of HCl and CO in flue gas on SO{sub 2} oxidation were unclear. Oxidation and adsorption of mercury by unburned carbon and fly ash enables mercury removal in a particulate control device. A chemical kinetic mechanism consisting of nine homogeneous and heterogeneous reactions for mercury oxidation and removal was developed to interpret pilot-scale measurements of mercury oxidation and adsorption by unburned carbon and fly ash in experiments at pilot

  12. Enhanced coal hydrogasification via oxidative pretreatment

    SciTech Connect

    Miller, D.J.

    1992-04-16

    The gasification of coal char by hydrogen is much slower than in steam or carbon dioxide; moreover, hydrogasification rate in pure hydrogen decreases sharply with conversion for most carbons. To overcome this kinetic behavior, the oxidation of the char prior to and during hydrogasification has been investigated as a means of enhancing hydro gasification rate. Kinetic rate studies under well-characterized conditions have been complemented by careful surface analyses to characterize oxygen on the char surface prior to and during hydrogasification.

  13. Microbial oxidation of pyrrhotites in coal chars

    USGS Publications Warehouse

    Miller, K.W.; Risatti, J.B.

    1988-01-01

    The ability of Thiobacillus ferrooxidans to oxidize pyrrhotite minerals occurring in coal chars was investigated, to evaluate the feasibility of microbial char desulphurization. Bio-oxidation of pyrrhotites in chars produced by two different processes was demonstrated conclusively. Microbial removal of sulphur from a char and its parent coal proceeded at the rate of 3.5% and 12% day-1, respectively with a total of 48% and 81% removal after 27 days. The pH of shake flask cultures containing the coal dropped naturally to a final value of 2.2, while the pH of cultures containing the corresponding char rose and had to be lowered artificially with additional acid. Amending char cultures with elemental sulphur to increase acidity upon bio-oxidation and prevent precipitation of ferric iron was successful; however, the extent of pyrrhotite removal, as demonstated by X-ray diffraction analysis, was not improved. As yet, there is no explanation for the failure of microbial removal of pyrrhotitic sulphur to go to completion. ?? 1988.

  14. Catalytic performance and deactivation of precipitated iron catalyst for selective oxidation of hydrogen sulfide to elemental sulfur in the waste gas streams from coal gasification

    SciTech Connect

    Mashapa, T.N.; Rademan, J.D.; van Vuuren, M.J.J.

    2007-09-15

    The selective oxidation of hydrogen sulfide to elemental sulfur, using a commercial, precipitated silica promoted ferric oxide based catalyst, was investigated in laboratory and pilot-plant reactors. Low levels of hydrogen sulfide (1-3 vol%) can be readily removed, but a continuous slow decrease in catalyst activity was apparent. X-ray photoelectron spectroscopy showed that the loss of activity was due to the formation of ferrous sulfate, which is known to be less active than the ferric oxide. In addition, studies using a model feed showed that the propene and HCN impurities in the plant feed stocks also act as potent catalyst poisons.

  15. Development of hydrous titanium oxide catalysts for upgrading coal liquids

    SciTech Connect

    Lott, S.; Dosch, R.

    1993-07-01

    Improved efficiency in direct coal liquefaction processes can be obtained by developing catalysts with better activity, selectivity, and life. In previous exploratory research at Sandia National Laboratories, catalysts prepared via hydrous metal oxide (HMO) ion exchangers have been shown to have potential for application to a number of reactions associated with the conversion of coal to liquid fuels. In the present effort, one member of this class of catalysts, hydrous titanium oxide (HTO), has been developed for use in hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of coal liquids. The unsupported (or bulk) NiMo-HTO catalyst performed well for HDS/HDN of a coal derived liquid as compared to the benchmark Shell 324 catalyst. The CoMo-HTO, while performing better than the Shell 324 catalyst, did not perform quite as well as the NiMo-HTO. In a side-by-side comparison of supported NiMo-HTO catalysts with commercial counterparts, the supported NiMo-HTO catalysts outperformed the Shell 324 and Amocat 1C catalysts on a weight of Mo basis. On a catalyst weight basis, the NiMo-HTO coated catalyst on a Shell 324 blank under performed Shell 324, while the NiMo-HTO coated catalyst on an Amocat 1C support performed as well as the Amocat 1C catalyst.

  16. Fast and Selective Preconcentration of Europium from Wastewater and Coal Soil by Graphene Oxide/Silane@Fe3O4 Dendritic Nanostructure.

    PubMed

    Patra, Santanu; Roy, Ekta; Madhuri, Rashmi; Sharma, Prashant K

    2015-05-19

    In this study, nanocomposite of graphene oxide and silane modified magnetic nanoparticles (silane@Fe3O4) were synthesized in a form of dendritic structure. For this, silane@Fe3O4 nanoparticle gets sandwiched between two layers of graphene oxide by chemical synthesis route. The synthesized dendritic structure was used as a monomer for synthesis of europium ion imprinted polymer. The synthesis of imprinted polymer was contemplated onto the surface of the vinyl group modified silica fiber by activated generated free radical atom-transfer radical polymerization, that is, AGET-ATRP technique. The synthesized dendritic monomer was characterized by XRD, FT-IR, VSM, FE-SEM, and TEM analyses. The imprinted polymer modified silica fiber was first validated in the aqueous and blood samples for successful extraction and detection of europium ion with limit of detection = 0.050 pg mL(-1) (signal/noise = 3). The imprinted polymer modified silica fiber was also used for preconcentration and separation of europium metal ion from various soil samples of coal mine areas. However, the same silica fiber was also used for wastewater treatment and shows 100% performance for europium removal. The findings herein suggested that dendritic nanocomposite could be potentially used as a highly effective material for the enrichment and preconcentration of europium or other trivalent lanthanides/actinides in nuclear waste management.

  17. Treatment of aqueous streams containing strong oxidants using bituminous coal

    SciTech Connect

    Doyle, F.M.; Bodine, D.L.

    1995-12-31

    Certain oxidizing contaminants, notably Cr(VI) and Mn(VII), are attenuated by reduction and sorption on organic matter in soils. Coals have some chemical similarity with this organic matter, and might be used on an industrial scale to treat effluents. We have studied the ability of acidic KMnO{sub 4} to oxidize Upper Freeport, bituminous coal with concurrent sorption of the resulting Mn(IV) and Mn(II). The oxidizing ability of Cr(VI) was briefly investigated. The ability of the oxidized coal to sorb Cu{sup 2+} and Cd{sup 2+} was then studied, and compared with coal oxidized by hydrogen peroxide. The effect of oxidation treatment, metal ion concentration, and solution pH on metal uptake kinetics and coal loading was investigated. Potential applications for treating effluents containing oxidizing ions are discussed.

  18. Oxidative decomposition of formaldehyde catalyzed by a bituminous coal

    SciTech Connect

    Haim Cohen; Uri Green

    2009-05-15

    It has been observed that molecular hydrogen is formed during long-term storage of bituminous coals via oxidative decomposition of formaldehyde by coal surface peroxides. This study has investigated the effects of coal quantity, temperature, and water content on the molecular hydrogen formation with a typical American coal (Pittsburgh No. 6). The results indicate that the coal's surface serves as a catalyst in the formation processes of molecular hydrogen. Furthermore, the results also indicate that low temperature emission of molecular hydrogen may possibly be the cause of unexplained explosions in confined spaces containing bituminous coals, for example, underground mines or ship holds. 20 refs., 4 figs., 6 tabs.

  19. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Progress report

    SciTech Connect

    Doyle, F.M.

    1995-02-28

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. Work during the eighteenth quarter has focused on severe oxidation of coal by thermal and chemical treatment, and on investigating the partition of metal ions between such strongly oxidized coal samples and aqueous solutions. This partitioning behavior is being followed to obtain further information on the chemistry of the coal surfaces after different oxidation treatments, for example, whether partition occurs by an ion-exchange mechanism, or whether the surface is capable of changing the oxidation state of metallic species, with concurrent surface or bulk precipitation.

  20. (Enhanced coal hydrogasification via oxidative pretreatment)

    SciTech Connect

    Not Available

    1990-01-01

    Work continued on coal hydrogasification. To date, twenty-one gasification runs have been conducted. These runs have focused on (1) obtaining a representative set of partially converted samples with which to determine pore structure and surface area development, (2) determining suitable conditions for the kinetic studies and (3) illustrating rate enhancement following oxidation. Also, ultimate-proximate analyses of the three samples were conducted at a commercial analytical laboratory. The high oxygen content of demineralized char is as yet unexplained. 6 figs., 2 tabs.

  1. A new approach in ultrapurification of coal by selective flocculation

    SciTech Connect

    Moudgil, B.M.

    1992-04-01

    The specific objective of the present investigation is to develop a mathematical and computational model to elicit values of active sites ({phi}) and fractional surface coverage ({theta}) which would yield optimum separation of coal from coal pyrite and coal refuse. Attempts are to be made to select appropriate flocculants and experimental conditions to obtain {phi} and {theta} values as dictated by the theoretical model so as to achieve the desired separation in naturally occurring samples of fine coal. (VC)

  2. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report

    SciTech Connect

    Doyle, F.M.

    1995-05-31

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. Work during the nineteenth quarter has concluded studies of the surface functional groups produced on coal by severe thermal and chemical oxidation, and on investigating the partition of metal ions between such strongly oxidized coal samples and aqueous solutions. This partitioning behavior was being followed to obtain further information on the chemistry of the coal surfaces after different oxidation treatments. Adsorption isotherms for the uptake of Cd{sup 2+} on coal oxidized by different methods were obtained, and these and the Cu{sup 2+} adsorption isotherms reported in the last report have been scrutinized, and interpreted more exhaustively. The apparent discrepancies noted in the last report for the analysis of surface functional groups have been investigated further. The adsorption behavior has been related to the surface chemistry of Upper Freeport coal oxidized by different methods.

  3. Selective solvent absorption in coal conversion

    SciTech Connect

    Larsen, J.W.; Lapucha, A.; Lazarov, L.; Amui, J.

    1992-04-01

    The objectives of this project are: (1) to determine the importance of the presence of added hydrogen donor compounds within the coal in the first stage of direct liquefaction processes; and (2) to determine the composition of the solvent absorbed by and present within the coal in the first stage of direct coal liquefaction.

  4. Selective agglomeration of a Pittsburgh Seam coal with isooctane

    SciTech Connect

    Lai, R.; Killmeyer, R.; Utz, B.; Richardson, A.; Sinha, K.

    1992-01-01

    The Pittsburgh Energy Technology Center initiated a research program in 1989 to investigate the fundamentals of selective agglomeration as applied to the cleaning of coals. The results of the initial study with Bruceton mine, Pittsburgh seam coal, using isooctane as an agglomerant, have been published. Subsequent to the successful reduction of the ash content of Bruceton coal to less than 0.9% after two cleaning stages, the study was extended to compare a coal from the same seam, but from Ohio. In the previous parameter optimization tests with Bruceton coal, particle size and slurry pH were found to be important parameters governing coal cleanability. Other researchers have obtained similar conclusions of the effects of particle size and coal slurry pH on the cleanability of various coals. In this study, the effects of these parameters on the cleanability of Powhatan coal were examined. Particle size reduction kinetics was examined first. Effects of size reduction (degree of mineral matter liberation), oil (isooctane)-to-coal ratio, and slurry pH on mineral matter rejection and combustible recovery were also examined. A petrographic comparison was conducted on the Powhatan and Bruceton coals to examine the degree of pyrite liberation as a function of particle size to elucidate why one coal from the same seam can be cleaned significantly better than another. (VC)

  5. Process for selective grinding of coal

    DOEpatents

    Venkatachari, Mukund K.; Benz, August D.; Huettenhain, Horst

    1991-01-01

    A process for preparing coal for use as a fuel. Forming a coal-water slurry having solid coal particles with a particle size not exceeding about 80 microns, transferring the coal-water slurry to a solid bowl centrifuge, and operating same to classify the ground coal-water slurry to provide a centrate containing solid particles with a particle size distribution of from about 5 microns to about 20 microns and a centrifuge cake of solids having a particle size distribution of from about 10 microns to about 80 microns. The classifer cake is reground and mixed with fresh feed to the solid bowl centrifuge for additional classification.

  6. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, [March--May 1992

    SciTech Connect

    Doyle, F.M.

    1992-06-30

    during the seventh quarter, electrokinetic, humic acid extraction and film flotation tests were done on oxidized samples of Upper Freeport coal from the Troutville {number_sign} 2 Mine, Clearfield County, Pennsylvania. Scanning electron microscopy and energy dispersive X-ray analysis was done to characterize the morphology and composition of the surface of as-received coal, oxidized coal, oxidized coal after extraction of humic acids and humic acid extracted from oxidized coal. In addition, electrochemical studies were done on electrodes prepared from coal pyrite samples.

  7. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, December 31, 1992

    SciTech Connect

    Doyle, F.M.

    1992-12-31

    During the ninth quarter, electrochemical experiments were done on electrodes prepared from Upper Freeport coal pyrite and Pittsburgh coal pyrite samples provided by the US Bureau of Mines, Pittsburgh Research Center, Pennsylvania. Scanning electron microscopy and energy dispersive X-ray analysis were done to characterize the morphology and composition of the surface of as-received coal, oxidized coal and coal pyrite. In addition, electrokinetic tests were done on Upper Freeport coal pyrite.

  8. Coal conversion wastewater treatment by catalytic oxidation in supercritical water

    SciTech Connect

    Phillip E. Savage

    1999-10-20

    Wastewaters from coal-conversion processes contain phenolic compounds in appreciable concentrations. These compounds need to be removed so that the water can be discharged or re-used. Catalytic oxidation in supercritical water is one potential means of treating coal-conversion wastewaters, and this project examined the reactions of phenol over different heterogeneous oxidation catalysts in supercritical water. More specifically, the authors examined the oxidation of phenol over a commercial catalyst and over bulk MnO{sub 2}, bulk TiO{sub 2}, and CuO supported on Al{sub 2}O{sub 3}. They used phenol as the model pollutant because it is ubiquitous in coal-conversion wastewaters and there is a large database for non-catalytic supercritical water oxidation (SCWO) with which they can contrast results from catalytic SCWO. The overall objective of this research project is to obtain the reaction engineering information required to evaluate the utility of catalytic supercritical water oxidation for treating wastes arising from coal conversion processes. All four materials were active for catalytic supercritical water oxidation. Indeed, all four materials produced phenol conversions and CO{sub 2} yields in excess of those obtained from purely homogeneous, uncatalyzed oxidation reactions. The commercial catalyst was so active that the authors could not reliably measure reaction rates that were not limited by pore diffusion. Therefore, they performed experiments with bulk transition metal oxides. The bulk MnO{sub 2} and TiO{sub 2} catalysts enhance both the phenol disappearance and CO{sub 2} formation rates during SCWO. MnO{sub 2} does not affect the selectivity to CO{sub 2}, or to the phenol dimers at a given phenol conversion. However, the selectivities to CO{sub 2} are increased and the selectivities to phenol dimers are decreased in the presence of TiO{sub 2}, which are desirable trends for a catalytic SCWO process. The role of the catalyst appears to be accelerating the

  9. COAL CONVERSION WASTEWATER TREATMENT BY CATALYTIC OXIDATION IN SUPERCRITICAL WATER

    SciTech Connect

    Phillip E. Savage

    1999-10-18

    Wastewaters from coal-conversion processes contain phenolic compounds in appreciable concentrations. These compounds need to be removed so that the water can be discharged or re-used. Catalytic oxidation in supercritical water is one potential means of treating coal-conversion wastewaters, and this project examined the reactions of phenol over different heterogeneous oxidation catalysts in supercritical water. More specifically, we examined the oxidation of phenol over a commercial catalyst and over bulk MnO{sub 2}, bulk TiO{sub 2}, and CuO supported on Al{sub 2} O{sub 3}. We used phenol as the model pollutant because it is ubiquitous in coal-conversion wastewaters and there is a large database for non-catalytic supercritical water oxidation (SCWO) with which we can contrast results from catalytic SCWO. The overall objective of this research project is to obtain the reaction engineering information required to evaluate the utility of catalytic supercritical water oxidation for treating wastes arising from coal conversion processes. All four materials were active for catalytic supercritical water oxidation. Indeed, all four materials produced phenol conversions and CO{sub 2} yields in excess of those obtained from purely homogeneous, uncatalyzed oxidation reactions. The commercial catalyst was so active that we could not reliably measure reaction rates that were not limited by pore diffusion. Therefore, we performed experiments with bulk transition metal oxides. The bulk MnO{sub 2} and TiO{sub 2} catalysts enhance both the phenol disappearance and CO{sub 2} formation rates during SCWO. MnO{sub 2} does not affect the selectivity to CO{sub 2}, or to the phenol dimers at a given phenol conversion. However, the selectivities to CO{sub 2} are increased and the selectivities to phenol dimers are decreased in the presence of TiO{sub 2} , which are desirable trends for a catalytic SCWO process. The role of the catalyst appears to be accelerating the rate of formation of

  10. Oxidative derivatization and solubilization of coal. Final report. Period: October 1, 1986 - April 30, 1988

    SciTech Connect

    Schulz, J.G.; Porowski, E.N.; Straub, A.M.

    1988-05-01

    We investigated the solubilization of coal by oxidative means to produce motor fuels. Nitric acid was used in the first of two approaches taken to cleave aliphatic linkages in coal and reduce the size of its macrostructure. Mild conditions, with temperatures up to a maximum of 75 C, and nitric acid concentrations below 20% by weight, characterize this process. The solid product, obtained in high yields, is soluble in polar organic solvents. Lower alcohols, methanol in particular, are of interest as carrier solvents in diesel fuel applications. Coals investigated were New York State peat, Wyodak subbituminous coal, North Dakota lignite, and Illinois No. 6 bituminous coal. The lower tank coals were easily converted and appear well suited to the process, while the bituminous Illinois No. 6 and Pitt Seam coals were unreactive. We concentrated our efforts on Wyodak coal and North Dakota lignite. Reaction conditions with regards to temperature, acid concentration, and time were optimized to obtain high product selectivity at maximum conversion. A continuous process scheme was developed for single pass coal conversions of about 50% to methanol-soluble product.

  11. Nitric oxide emission from pulverized coal blend flames

    SciTech Connect

    Kopparthi, V.; Gollahalli, S.R.

    1995-09-01

    An experimental study of the nitric oxide emission from pulverized blended coal flames as a function of blending mass ratio is presented. Coals of three ranks (anthracite, bituminous, and lignite), and of the same rank (bituminous), but of different origin (Oklahoma and Wyoming mines), were used as fuels. Also, their blends (anthracite-bituminous, anthracite-lignite, lignite-bituminous, and Oklahoma-Wyoming coals) at mass ratios of 20:80, 40:60, 60:40, and 80:20 were studied. Correlations of nitric oxide emission index (mass/unit energy release) with blend mass ratio are presented.

  12. Demonstration of selective catalytic reduction technology for the control of nitrogen oxide emissions from high-sulfur, coal-fired boilers

    SciTech Connect

    Hinton, W.S.; Powell, C.A.; Maxwell, J.D.

    1993-11-01

    This paper describes the status of the Innovative Clean Coal Technology project to demonstrate SCR technology for reduction of NO{sub x} emissions from flue gas of utility boilers burning US high-sulfur coal. The funding participants are the US Department of Energy (DOE), Southern Company Services, Inc. (SCS), on behalf of the entire Southern Company, Electric Power Research Institute (EPRI), and Ontario Hydro. SCS is the participant responsible for managing all aspects of the project. The project is being conducted on Gulf Power Company`s Plant Crist Unit 5 (75-MW nominal capacity), located near Pensacola, Florida, on US coals that have a sulfur content near 3.0%. The SCR facility treats a 17,400 scfm slip-stream of flue gas and consists of three 2.5-MW (5000 scfm) and six 0.2-MW (400 scfm) SCR reactors. The reactors operate in parallel with commercially available SCR catalysts obtained from vendors throughout the world. The design engineering and construction have been completed, and the startup/shakedown was completed in June 1993. Long-term performance testing began in July 1993 and will be conducted for two years. Test facility description and test plans, as well as start-up issues and preliminary commissioning test results are reported in this paper.

  13. Shield support selection based on geometric characteristics of coal seam

    SciTech Connect

    K. Goshtasbi; K. Oraee; F. Khakpour-yeganeh

    2006-01-15

    The most initial investment in longwall face equipping is the cost of powered support. Selection of proper shields for powered supports is based on load, geometric characterization of coal seams and economical considerations.

  14. NITRIC OXIDE FORMATION DURING PULVERIZED COAL COMBUSTION

    EPA Science Inventory

    Data on the overall conversion of coal-nitrogen to NOx were obtained at 1250 K and 1750 K for a residence time of one second. The conversion of coal-nitrogen to NOx decreased monotonically with increasing fuel/oxygen equivalence ratio and decreased slightly with increasing temper...

  15. Importance of coal properties in selecting coals for blast furnace injection

    SciTech Connect

    Hutny, W.P.; Giroux, L.; Macphee, J.A.; Price, J.T.

    1996-12-31

    The CANMET Energy Technology Centre (CETC), in cooperation with the Department of Energy of the Province of Alberta and the Canadian Carbonization Research Association (CCRA), has completed a program on the evaluation of Canadian and foreign coals for blast furnace injection. The program consisted of two parts: (1) theoretical assessment of cooling and coke replacement characteristics of coals using CETC`s computer model and (2) experimental determination of the combustibility of coals of different ranks and particle size as well as the influence of oxygen enrichment on burnout. The experimental part was conducted in a pilot-scale injection unit designed and built at CANMET that simulates blast furnace blowpipe-tuyere conditions. This paper describes the facility and methodology of work. It also discusses results. The prime objectives of this study were to provide essential information on coal combustion in the blast furnace and establish proper criteria for evaluating and selecting coals for blast furnace injection.

  16. Desulphurization of coal via low temperature atmospheric alkaline oxidation.

    PubMed

    Liu, Kaicheng; Yang, Ji; Jia, Jinping; Wang, Yaling

    2008-03-01

    Different from other options which usually required strict conditions, a method combining atmospheric oxidization and chemical cleaning with alkali solutions was employed to desulphur coals at temperature around 90 degrees C. The data show that 66% organic sulphur, 44% sulphide sulphur, and 15% pyrite sulphur were lost when the coal was treated in 0.25M NaOH at 90 degrees C, while the solution being aerated at the flow rate of 0.136m3h(-1). The rate increased to 73% for organic sulphur, 83% for sulphide sulphur and 84% for pyrite sulphur when the previous coal was further treated in acidic solution containing HCl at pH 1 for another hour. The mechanism of desulphurization was explored using inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy and infrared. It was found out that the bond of -CS was broken by atmospheric oxygen in basic environment, leading to the lost of organic sulphur in coal. Scanning electron microscope data show that the physical structure of the coal was not adversely affected by the treatment and thermogravimetric analysis results prove that the pyrolysis behavior remained unchanged, indicating that the burning process of the coal would not be adversely affected. Unlike other oxidizing methods, this technique does not lower the heating value of the coal which was manifested by relevant data.

  17. Biodegradation of air-oxidized Illinois No. 6 coal

    SciTech Connect

    Linehan, J.C.; Fredrickson, J.K.; Wilson, B.W.; Bean, R.M.; Stewart, D.L.; Thomas, B.L.; Campbell, J.A.; Franz, J.A.

    1988-09-01

    We have found that Illinois No. 6 coal, after an air-oxidation pretreatment, can be substantially biodegraded by Penicillium sp. to a product largely soluble in dilute base. It is the purpose of this paper to describe the chemical nature of the biotreated Illinois No. 6 coal and to compare it with the corresponding material from leonardite biosolubilization. 12 refs., 7 figs., 3 tabs.

  18. Oxidation of pyrite in coal to magnetite

    USGS Publications Warehouse

    Thorpe, A.N.; Senftle, F.E.; Alexander, C.C.; Dulong, F.T.

    1984-01-01

    When bituminous coal is heated in an inert atmosphere (He) containing small amounts of oxygen at 393-455 ??C, pyrite (FeS2) in coal is partially converted to magnetite (Fe304). The maximum amount of Fe304 formed during the time of heating corresponds to 5-20% of the total pyrite present, depending on the coal sample. The magnetite forms as an outer crust on the pyrite grains. The fact that the magnetic properties of the pyrite grains are substantially increased by the magnetite crust suggests that pyrite can be separated from coal by use of a low magnetic field. In a laboratory test, 75% removal is obtained by means of a 500 Oe magnet on three samples, and 60% on a fourth sample. ?? 1984.

  19. Innovative Clean Coal Technology (ICCT). Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers: Volume 2, Appendices A--N. Final report

    SciTech Connect

    1996-10-01

    Volume 2 contains the following appendices: Appendix A, Example Material Safety Data Sheet; Appendix B, Initial Site Characterization Test Results; Appendix C, Testing Proposal, Southern Research Institute; Appendix D, Example Laboratory Catalyst Test Protocol; Appendix E, Detailed Coal Analysis Data; Appendix F, Standard Methods-QA/QC Document; Appendix G, Task No. 1 Commissioning Tests; Appendix H, Task No. 2 Commissioning Tests; Appendix I, First Parametric Sequence Spreadsheets; Appendix J, Second Parametric Sequence Spreadsheets; Appendix K, Third Parametric Sequence Spreadsheets; Appendix L, Fourth Parametric Sequence Spreadsheets; Appendix M, Fifth Parametric Sequence Spreadsheets; and Appendix N, First Series-Manual APH Tests.

  20. Comparison of coal reactivityduring conversion into different oxidizing medium

    NASA Astrophysics Data System (ADS)

    Korotkikh, A. G.; Slyusarskiy, K. V.; Larionov, K. B.; Osipov, V. I.

    2016-10-01

    Acoal conversion process of different coal samples into three different types of oxidizing medium (argon, air and steam) were studied by means of thermogravimetry. Two coal types with different metamorphism degree (lignite and bituminous coal) were used. The experimental procedure was carried out in non-isothermal conditions in temperature range from 373 K to 1273 K with 20 K/min heating rate. Purge gas consisted of argon and oxidizer with volumetric ratio 1:24 and had 250 ml/min flow rate.The ignition and burnout indexes were calculated to evaluate sample reactivity at different oxidizing mediums. The highest reactivity coefficient values in same atmosphere were obtained for lignite. It was caused by higher particle special surface area and volatile matter content.

  1. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, [September--December 1991

    SciTech Connect

    Doyle, F.M.

    1992-01-28

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical coal cleaning processes. The results will provide fundamental insight into oxidation, in terms of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the fifth quarter, wet chemical and dry oxidation tests were done on Upper Freeport coal from the Troutville {number_sign}2 Mine, Clearfield County, Pennsylvania.

  2. Colloidal stability of coal-simulated suspensions in selective agglomeration

    SciTech Connect

    Schurger, M.L.

    1989-01-01

    A coal suspension was simulated by using graphite to simulate the carbonaceous fraction and kaolinite clay to simulate the ash fraction. Separate studies on each material established their response to additions of oxidized pyrite (ferrous sulfate) and a humic acid simulate (salicylic acid) in terms of zeta potentials profiles with pH and Ionic strength. Concentrations of iron and salicylic acid evaluated were 4.5 {times} 10{sup {minus}3} M and 2.0 {times} 10{sup {minus}4} M, respectively. The zeta potentials profiles of graphite, clay and hexadecane were negative throughout the pH ranges studied. The addition of iron lowered the zeta potentials all of the suspensions under all pH and ionic strength conditions. Salicylic acid decreased the graphite and hexadecane zeta potentials but had no effect on the clay zeta potential profiles. Agglomeration of graphite with bridging liquid shows distinct time dependent rate mechanisms, a initial growth of graphite agglomerates followed by consolidation phase. Graphite agglomeration was rapid with the maximum amount of agglomerate volume growth occurring in under 2-4 minutes. Agglomeration in the first two minutes was characterized by a 1st order rate mechanism. The presence of either Iron and salicylic acid generally improved the first order rates. The addition of clay also improved the first order rates except in the presence of salicylic acid. Heteroagglomeration of graphite with clay was found by hydrodynamic arguments to be unfavored. A multicomponent population balance model which had been developed for evaluating collision efficiencies of coal, ash and pyrite selective agglomeration was evaluated to explain these results. The growth and consolidation characteristics of graphite agglomeration for the experimental conditions examined herein revealed the limitations of such as model for this application.

  3. The effect of coal bed dewatering and partial oxidation on biogenic methane potential

    USGS Publications Warehouse

    Jones, Elizabeth J.P.; Harris, Steve H.; Barnhart, Elliott P.; Orem, William H.; Clark, Arthur C.; Corum, Margo D.; Kirshtein, Julie D.; Varonka, Matthew S.; Voytek, Mary A.

    2013-01-01

    Coal formation dewatering at a site in the Powder River Basin was associated with enhanced potential for secondary biogenic methane determined by using a bioassay. We hypothesized that dewatering can stimulate microbial activity and increase the bioavailability of coal. We analyzed one dewatered and two water-saturated coals to examine possible ways in which dewatering influences coal bed natural gas biogenesis by looking at differences with respect to the native coal microbial community, coal-methane organic intermediates, and residual coal oxidation potential. Microbial biomass did not increase in response to dewatering. Small Subunit rRNA sequences retrieved from all coals sampled represented members from genera known to be aerobic, anaerobic and facultatively anaerobic. A Bray Curtis similarity analysis indicated that the microbial communities in water-saturated coals were more similar to each other than to the dewatered coal, suggesting an effect of dewatering. There was a higher incidence of long chain and volatile fatty acid intermediates in incubations of the dewatered coal compared to the water-saturated coals, and this could either be due to differences in microbial enzymatic activities or to chemical oxidation of the coal associated with O2 exposure. Dilute H2O2 treatment of two fractions of structural coal (kerogen and bitumen + kerogen) was used as a proxy for chemical oxidation by O2. The dewatered coal had a low residual oxidation potential compared to the water-saturated coals. Oxidation with 5% H2O2 did increase the bioavailability of structural coal, and the increase in residual oxidation potential in the water saturated coals was approximately equivalent to the higher methanogenic potential measured in the dewatered coal. Evidence from this study supports the idea that coal bed dewatering could stimulate biogenic methanogenesis through partial oxidation of the structural organics in coal once anaerobic conditions are restored.

  4. Integrating catalytic coal gasifiers with solid oxide fuel cells

    SciTech Connect

    Siefert, N.; Shamsi, A.; Shekhawat, D.; Berry, D.

    2010-01-01

    A review was conducted for coal gasification technologies that integrate with solid oxide fuel cells (SOFC) to achieve system efficiencies near 60% while capturing and sequestering >90% of the carbon dioxide [1-2]. The overall system efficiency can reach 60% when a) the coal gasifier produces a syngas with a methane composition of roughly 25% on a dry volume basis, b) the carbon dioxide is separated from the methane-rich synthesis gas, c) the methane-rich syngas is sent to a SOFC, and d) the off-gases from the SOFC are recycled back to coal gasifier. The thermodynamics of this process will be reviewed and compared to conventional processes in order to highlight where available work (i.e. exergy) is lost in entrained-flow, high-temperature gasification, and where exergy is lost in hydrogen oxidation within the SOFC. The main advantage of steam gasification of coal to methane and carbon dioxide is that the amount of exergy consumed in the gasifier is small compared to conventional, high temperature, oxygen-blown gasifiers. However, the goal of limiting the amount of exergy destruction in the gasifier has the effect of limiting the rates of chemical reactions. Thus, one of the main advantages of steam gasification leads to one of its main problems: slow reaction kinetics. While conventional entrained-flow, high-temperature gasifiers consume a sizable portion of the available work in the coal oxidation, the consumed exergy speeds up the rates of reactions. And while the rates of steam gasification reactions can be increased through the use of catalysts, only a few catalysts can meet cost requirements because there is often significant deactivation due to chemical reactions between the inorganic species in the coal and the catalyst. Previous research into increasing the kinetics of steam gasification will be reviewed. The goal of this paper is to highlight both the challenges and advantages of integrating catalytic coal gasifiers with SOFCs.

  5. Ultrasound assisted, thermally activated persulfate oxidation of coal tar DNAPLs.

    PubMed

    Peng, Libin; Wang, Li; Hu, Xingting; Wu, Peihui; Wang, Xueqing; Huang, Chumei; Wang, Xiangyang; Deng, Dayi

    2016-11-15

    The feasibility of ultrasound assisted, thermally activated persulfate for effective oxidation of twenty 2-6 ringed coal tar PAHs in a biphasic tar/water system and a triphasic tar/soil/water system were investigated and established. The results indicate that ultrasonic assistance, persulfate and elevated reaction temperature are all required to achieve effective oxidation of coal tar PAHs, while the heating needed can be provided by ultrasonic induced heating as well. Further kinetic analysis reveals that the oxidation of individual PAH in the biphasic tar/water system follows the first-order kinetics, and individual PAH oxidation rate is primary determined by the mass transfer coefficients, tar/water interfacial areas, the aqueous solubility of individual PAH and its concentration in coal tar. Based on the kinetic analysis and experimental results, the contributions of ultrasound, persulfate and elevated reaction temperature to PAHs oxidation were characterized, and the effects of ultrasonic intensity and oxidant dosage on PAHs oxidation efficiency were investigated. In addition, the results indicate that individual PAH degradability is closely related to its reactivity as well, and the high reactivity of 4-6 ringed PAHs substantially improves their degradability.

  6. KINETICS OF DIRECT OXIDATION OF H2S IN COAL GAS TO ELEMENTAL SULFUR

    SciTech Connect

    K.C. Kwon

    2002-02-01

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced Vision 21 plants that employ coal and natural gas and produce electric power and clean transportation fuels. These Vision 21 plants will require highly clean coal gas with H{sub 2}S below 1 ppm and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation Vision 21 plants. To this end, a novel process is now under development at Research Triangle Institute (RTI) in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The objective of this research is to support the near- and long-term DOE efforts to commercialize this direct oxidation technology. Specifically, we aim to: Measure the kinetics of direct oxidation of H{sub 2}S to elemental sulfur over selective catalysts in the presence of major

  7. Analysis of peroxytrifluoroacetic acid oxidation products from Victorian brown coal

    SciTech Connect

    Verheyen, T.V.; Johns, R.B.

    1983-08-01

    A method is described for the detailed quantitative structural identification of the components present in the oxidation product mixtures of a highly aliphatic brown coal. The results showed them to be predominantly long chain diols, hydroxy acids, dicarboxylic acids and short chain polycarboxylic acids.

  8. OXIDATION AND DEVOLATILIZATION OF NITROGEN IN COAL CHAR

    EPA Science Inventory

    The reactions of organically-bound nitrogen in coal char during combustion have been studied in a laboratory furnace using size-graded char particles prepared by the pyrolysis of a Montana lignite. The time-resolved variations of nitrogen-to-carbon ratio during char oxidation hav...

  9. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, June 1995--August 1995

    SciTech Connect

    Doyle, F.M.

    1996-03-01

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The action of coal and pyrite as reducing agents and as waste processing sorptive material for wastes outside the industry are also discussed.

  10. Application of a. Delta. P technique to monitor oxidation of Nigerian coals

    SciTech Connect

    Ogunsola, O.I.; Mikula, R.J. )

    1992-10-01

    In this paper, the results of a study on the effect of oxidation on the {Delta}P index and acidity of three Nigerian coals are reported. The coals are oxidized in air over a period of 35 days at both 100 and 50{degrees} C. The heating value, slurry pH (acidity), and the {Delta}P index of three Nigerian coal samples were monitored as a function of oxidation time. The results revealed a decrease in {Delta}P index and an increase in the acidity of all three coals with increase in oxidation time. The heating value of the coals was also reduced by the oxidation.

  11. Experimental Study of the Ignition of Single Drops of Coal Suspensions and Coal Particles in the Oxidizer Flow

    NASA Astrophysics Data System (ADS)

    Vershinina, K. Yu.; Glushkov, D. O.; Kuznetsov, G. V.; Strizhak, P. A.

    2017-01-01

    An experimental study has been made of the process of ignition of single drops of water-coal and organic water-coal suspensions and coal particles heated by the oxidizer flow. The low-temperature (400-600°C) regime of the initiation of combustion of commensurate (from 1 to 3 mm) drops of water-coal and organic water-coal suspensions and coal particles has been considered. With the use of a high-speed (up to 105 frames/s) video camera and Tema Automative software, the influence of the oxidizer temperature, the gas flow velocity, the size of suspension fuel drops, and the coal particle size on the conditions and integral characteristics of the induction period has been determined. The ignition delay times and the duration of the combustion process of the investigated fuel samples have been established. The features of the stages of stable low-temperature initiation of combustion have been determined.

  12. Innovative clean coal technology (ICCT): demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emission from high-sulfur, coal-fired boilers - economic evaluation of commercial-scale SCR applications for utility boilers

    SciTech Connect

    Healy, E.C.; Maxwell, J.D.; Hinton, W.S.

    1996-09-01

    This report presents the results of an economic evaluation produced as part of the Innovative Clean Coal Technology project, which demonstrated selective catalytic reduction (SCR) technology for reduction of NO{sub x} emissions from utility boilers burning U.S. high-sulfur coal. The document includes a commercial-scale capital and O&M cost evaluation of SCR technology applied to a new facility, coal-fired boiler utilizing high-sulfur U.S. coal. The base case presented herein determines the total capital requirement, fixed and variable operating costs, and levelized costs for a new 250-MW pulverized coal utility boiler operating with a 60-percent NO{sub x} removal. Sensitivity evaluations are included to demonstrate the variation in cost due to changes in process variables and assumptions. This report also presents the results of a study completed by SCS to determine the cost and technical feasibility of retrofitting SCR technology to selected coal-fired generating units within the Southern electric system.

  13. Surface Properties of Photo-Oxidized Bituminous Coals: Final report

    SciTech Connect

    1998-09-01

    Natural weathering has a detrimental effect on the hydrophobic nature of coal, which in turn can influence clean-coal recovery during flotation. Few techniques are available that can establish the quality of coal surfaces and that have a short analysis time to provide input for process control. Luminescence emissions which can be quantified with an optical microscope and photometer system, are measurably influenced by degree of weathering as well as by mild storage deterioration. In addition, it has been shown that when vitrinite is irradiated with a relatively high intensity flux of violet- or ultraviolet- light in the presence of air, photo-oxidation of the surface occurs. The combination of measuring the change in luminescence emission intensity with degree of surface oxidation provided the impetus for the current investigation. The principal aim of this research was to determine whether clear correlations could be established among surface oxygen functionality, hydrophobicity induced by photo-oxidation, and measurements of luminescence intensity and alteration. If successful, the project would result in quantitative luminescence techniques based on optical microscopy that would provide a measure of the changes in surface properties as a function of oxidation and relate them to coal cleanability. Two analytical techniques were designed to achieve these goals. Polished surfaces of vitrain bands or a narrow size fraction of powdered vitrain concentrates were photo-oxidized using violet or ultraviolet light fluxes and then changes in surface properties and chemistry were measured using a variety of near-surface analytical techniques. Results from this investigation demonstrate that quantitative luminescence intensity measurements can be performed on fracture surfaces of bituminous rank coals (vitrains) and that the data obtained do reveal significant variations depending upon the level of surface oxidation. Photo-oxidation induced by violet or ultraviolet light

  14. [Comprehensive fuzzy evaluation of nitrogen oxide control technologies for coal-fired power plants].

    PubMed

    Yu, Chao; Wang, Shu-xiao; Hao, Ji-ming

    2010-07-01

    A multi-level assessment index system was established to quantitatively and comprehensively evaluate the performance of typical nitrogen oxide control technologies for coal-fired power plants. Comprehensive fuzzy evaluation was conducted to assess six NO, control technologies, including low NO, burner (LNB), over the fire (OFA), flue gas reburning (Reburning), selective catalyst reduction (SCR), selective non-catalyst reduction (SNCR) and hybrid SCR/SNCR. Case studies indicated that combination of SCR and LNB are the optimal choice for wall-fired boilers combusting anthracite coal which requires NO, removal efficiency to be over 70%, however, for W-flame or tangential boilers combusting bituminous and sub-bituminous coal which requires 30% NO, removal, LNB and reburning are better choices. Therefore, we recommend that in the developed and ecological frangible regions, large units burning anthracite or meager coal should install LNB and SCR and other units should install LNB and SNCR. In the regions with environmental capacity, units burning anthracite or meager coal shall install LNB and SNCR, and other units shall apply LNB to reduce NO, emissions.

  15. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, September 30, 1992

    SciTech Connect

    Doyle, F.M.

    1992-12-31

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The results will provide fundamental insight into oxidation, in terms of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the eighth quarter, wet chemical and dry oxidation tests were done on Upper Freeport coal from the Troutville {number_sign}2 Mine, Clearfield County, Pennsylvania. In addition electrochemical experiments were done on electrodes prepared from Upper Freeport coal pyrite and Pittsburgh coal pyrite samples provided by the US Bureau of Mines, Pittsburgh Research Center, Pennsylvania.

  16. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, May 31, 1995

    SciTech Connect

    Doyle, F.M.

    1995-12-31

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. Work during the nineteenth quarter has concluded studies of the surface functional groups produced on coal by severe thermal and chemical oxidation, and on investigating the partition of metal ions between such strongly oxidized coal samples and aqueous solutions. This partitioning behavior was being followed to obtain further information on the chemistry of the coal surfaces after different oxidation treatments. Adsorption isotherms for the uptake of Cd{sup 2+} on coal oxidized by different methods were obtained, and these and the Cu{sup 2+} adsorption isotherms reported in the last report have been scrutinized, and interpreted more exhaustively. The apparent discrepancies noted in the last report for the analysis of surface functional groups have been investigated further. The adsorption behavior has been related to the surface chemistry of Upper Freeport coal oxidized by different methods.

  17. Enhanced coal hydrogasification via oxidative pretreatment. Final technical report

    SciTech Connect

    Miller, D.J.

    1992-04-16

    The gasification of coal char by hydrogen is much slower than in steam or carbon dioxide; moreover, hydrogasification rate in pure hydrogen decreases sharply with conversion for most carbons. To overcome this kinetic behavior, the oxidation of the char prior to and during hydrogasification has been investigated as a means of enhancing hydro gasification rate. Kinetic rate studies under well-characterized conditions have been complemented by careful surface analyses to characterize oxygen on the char surface prior to and during hydrogasification.

  18. Indonesian low rank coal oxidation: The effect of H2O2 concentration and oxidation temperature

    NASA Astrophysics Data System (ADS)

    Rahayu, S. S.; Findiati, F.; Aprilia, F.

    2016-11-01

    Extraction of Indonesian low rank coals by alkaline solution has been performed to isolate the humic substances. Pretreatments of the coals by oxidation using H2O2 prior to extraction are required to have higher yield of humic substances. In the previous research, only the extraction process was considered. Therefore, the effects of reaction temperature and residence time on coal oxidation and composition of extract residues are also investigated in this research. The oxidation temperatures studied were 40°C, 50°C, and 70°C and the H2O2 concentrations studied were 5%, 15%, 20 %, and 30 %. All the oxidation variables were studied for 90 minutes. The results show that the higher the concentration of H2O2 used, the less oxidized coal produced. The same trend was obtained by using higher oxidation temperature. The effect of H2O2 concentration, oxidation temperature and reaction time to the yield of humic substances extraction have positive trends.

  19. Recovery of iron oxide from coal fly ash

    DOEpatents

    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.

  20. Selection of feed coals for production of premium fuel using column flotation and selective agglomeration processes

    SciTech Connect

    Jha, M.C.; Smit, F.J.

    1995-10-01

    Column flotation and selective agglomeration are promising advanced physical cleaning processes that can be developed for preparing premium quality coal-water slurry fuel from coal fines. Such a fuel could either replace oil or natural gas in certain industrial and utility boilers or else could be burned in advanced combustors currently under development. These applications require coal cleaned to sulfur and ash contents below 258 g/GJ and 430--860 g/GJ (0.6 lb/million Btu and 1--2 lb/million Btu), respectively, to meet clean air emission requirements. A highly loaded slurry must be produced in order to avoid derating the boilers, and the total cost of the fuel must be below $2.37/GJ ($2.50/million Btu) in order to penetrate the market by the turn of the century. Achieving these technical and economic goals depend critically on the selection of suitable feed coals. This paper describes the identification and evaluation of 18 coals and final selection of six coals from different regions of the United States as potential feedstock for preparation of premium fuel. The work is being performed under a cost-shared DOE project.

  1. STUDY OF THE EFFECT OF CHLORINE ADDITION ON MERCURY OXIDATION BY SCR CATALYST UNDER SIMULATED SUBBITUMINOUS COAL FLUE GAS

    EPA Science Inventory

    An entrained flow reactor is used to study the effect of addition of chlorine-containing species on the oxidation of elemental mercury (Hgo)by a selective catalytic reduction (SCR) catalyst in simulated subbituminous coal combustion flue gas. The combustion flue gas was doped wit...

  2. Nitrogen oxides emission control options for coal-fired electric utility boilers.

    PubMed

    Srivastava, Ravi K; Hall, Robert E; Khan, Sikander; Culligan, Kevin; Lani, Bruce W

    2005-09-01

    Recent regulations have required reductions in emissions of nitrogen oxides (NOx) from electric utility boilers. To comply with these regulatory requirements, it is increasingly important to implement state-of-the-art NOx control technologies on coal-fired utility boilers. This paper reviews NOx control options for these boilers. It discusses the established commercial primary and secondary control technologies and examines what is being done to use them more effectively. Furthermore, the paper discusses recent developments in NOx controls. The popular primary control technologies in use in the United States are low-NOx burners and overfire air. Data reflect that average NOx reductions for specific primary controls have ranged from 35% to 63% from 1995 emissions levels. The secondary NOx control technologies applied on U.S. coal-fired utility boilers include reburning, selective noncatalytic reduction (SNCR), and selective catalytic reduction (SCR). Thirty-six U.S. coal-fired utility boilers have installed SNCR, and reported NOx reductions achieved at these applications ranged from 15% to 66%. Recently, SCR has been installed at >150 U.S. coal-fired utility boilers. Data on the performance of 20 SCR systems operating in the United States with low-NOx emissions reflect that in 2003, these units achieved NOx emission rates between 0.04 and 0.07 lb/10(6) Btu.

  3. Selective Adsorption and Selective Transport Diffusion of CO2-CH4 Binary Mixture in Coal Ultramicropores.

    PubMed

    Zhao, Yongliang; Feng, Yanhui; Zhang, Xinxin

    2016-09-06

    The adsorption and diffusion of the CO2-CH4 mixture in coal and the underlying mechanisms significantly affect the design and operation of any CO2-enhanced coal-bed methane recovery (CO2-ECBM) project. In this study, bituminous coal was fabricated based on the Wiser molecular model and its ultramicroporous parameters were evaluated; molecular simulations were established through Grand Canonical Monte Carlo (GCMC) and Molecular Dynamic (MD) methods to study the effects of temperature, pressure, and species bulk mole fraction on the adsorption isotherms, adsorption selectivity, three distinct diffusion coefficients, and diffusivity selectivity of the binary mixture in the coal ultramicropores. It turns out that the absolute adsorption amount of each species in the mixture decreases as temperature increases, but increases as its own bulk mole fraction increases. The self-, corrected, and transport diffusion coefficients of pure CO2 and pure CH4 all increase as temperature or/and their own bulk mole fractions increase. Compared to CH4, the adsorption and diffusion of CO2 are preferential in the coal ultramicropores. Adsorption selectivity and diffusivity selectivity were simultaneously employed to reveal that the optimal injection depth for CO2-ECBM is 800-1000 m at 308-323 K temperature and 8.0-10.0 MPa.

  4. Selective flotation of fossil resin from western coal

    SciTech Connect

    Jensen, G.F.; Miller, J.D.

    1992-03-20

    The test program has demonstrated that: (1) technically, the new flotation technologies discovered at the University of Utah and then improved upon by Advanced Processing Technologies, Inc. provide a highly efficient means to selectively recover fossil resin from coal. The proof-of-concept continuous flotation circuit resulted in fossil resin recovery with the same separation efficiency as was obtained from laboratory bench-scale testing (more than 80% recovery at about 80% concentrate grade); and (2) economically, the selective flotation process has been shown to be sufficiently profitable to justify the development of a fossil resin industry based on this new flotation process. The proof-of-concept testing has resulted in significant interest from several coal mining companies and has sparked the desire of local and state government to establish a fossil resin industry in the Wasatch Plateau coal field. In this view, the results from the current proof-of-concept testing program have been successful. This special report provides theoretical and analytical data on some surface chemistry work pertinent to fossil resin characterization, and other efforts carried out during the past months.

  5. Oxidation of coal-water slurry feed to hydrogasifier

    DOEpatents

    Lee, Bernard S.

    1976-01-01

    An aqueous coal slurry is preheated, subjected to partial oxidation and vaporization by injection of high pressure oxygen and is introduced into a top section of a hydrogasifier in direct contact with hot methane-containing effluent gases where vaporization of the slurry is completed. The resulting solids are reacted in the hydrogasifier and the combined gases and vapors are withdrawn and subjected to purification and methanation to provide pipeline gas. The amount of oxygen injected into the slurry is controlled to provide the proper thermal balance whereby all of the water in the slurry can be evaporated in contact with the hot effluent gases from the hydrogasifier.

  6. Decaking of coal or oil shale during pyrolysis in the presence of iron oxides

    DOEpatents

    Khan, M. Rashid

    1989-01-01

    A method for producing a fuel from the pyrolysis of coal or oil shale in the presence of iron oxide in an inert gas atmosphere. The method includes the steps of pulverizing feed coal or oil shale, pulverizing iron oxide, mixing the pulverized feed and iron oxide, and heating the mixture in a gas atmosphere which is substantially inert to the mixture so as to form a product fuel, which may be gaseous, liquid and/or solid. The method of the invention reduces the swelling of coals, such as bituminous coal and the like, which are otherwise known to swell during pyrolysis.

  7. Decaking of coal or oil shale during pyrolysis in the presence of iron oxides

    DOEpatents

    Rashid Khan, M.

    1988-05-05

    A method for producing a fuel from the pyrolysis of coal or oil shale in the presence of iron oxide in an inert gas atmosphere is described. The method includes the steps of pulverizing feed coal or oil shale, pulverizing iron oxide, mixing the pulverized feed and iron oxide, and heating the mixture in a gas atmosphere which is substantially inert to the mixture so as to form a product fuel, which may be gaseous, liquid and/or solid. The method of the invention reduces the swelling of coals, such as bituminous coal and the like, which are otherwise known to swell during pyrolysis. 4 figs., 8 tabs.

  8. Kinetics of Direct Oxidation of H2S in Coal Gas to Elemental Sulfur

    SciTech Connect

    K.C. Kwon

    2005-11-01

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced Vision 21 plants that produce electric power and clean transportation fuels with coal and natural gas. These Vision 21 plants will require highly clean coal gas with H{sub 2}S below 1 ppm and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation Vision 21 plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. The direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The objectives of this research are to measure kinetics of direct

  9. Selective flotation of fossil resins from Northeast China coal

    SciTech Connect

    Hua, X.; Bo, H.; Qing, X.; Lijian, L.; Rong-Zeng, Z.

    1999-07-01

    For a feed which came from Northeast China containing 11.4 per cent fossil resin, by conventional single stage flotation, the fossil resin concentrate gained had a low grade. Adjusting the pH of the feed slurry with HCl or CaO before flotation or treating the feed with H{sub 2}O{sub 2} solution before flotation did not improve the selectivity of flotation. In order to improve the selectivity of flotation for fossil resin, the authors treated the feed slurry of flotation with several surfactants. Although most of them did not work very well, one surfactant was able to increase the grade of concentrate to over 80% as the recovery rate was higher than 82%. The result of mechanism research into the performance of the best surfactant indicated that the selective adsorption of the hydrophobic side of the surfactant onto the surface of coal particle made it more hydrophilic, so that the difference between the hydrophobicity of the coal particle's surface and that of the fossil resin's surface was enlarged.

  10. Studies on the Low-Temp Oxidation of Coal Containing Organic Sulfur and the Corresponding Model Compounds.

    PubMed

    Zhang, Lanjun; Li, Zenghua; Li, Jinhu; Zhou, Yinbo; Yang, Yongliang; Tang, Yibo

    2015-12-11

    This paper selects two typical compounds containing organic sulfur as model compounds. Then, by analyzing the chromatograms of gaseous low-temp oxidation products and GC/MS of the extractable matter of the oxidation residue, we summarizing the mechanism of low-temp sulfur model compound oxidation. The results show that between 30°C to 80°C, the interaction between diphenyl sulfide and oxygen is mainly one of physical adsorption. After 80°C, chemical adsorption and chemical reactions begin. The main reaction mechanism in the low-temp oxidation of the model compound diphenyl sulfide is diphenyl sulfide generates diphenyl sulfoxide, and then this sulfoxide is further oxidized to diphenyl sulphone. A small amount of free radicals is generated in the process. The model compound cysteine behaves differently from diphenyl sulfide. The main reaction low-temp oxidation mechanism involves the thiol being oxidized into a disulphide and finally evolving to sulfonic acid, along with SO₂ being released at 130°C and also a small amount of free radicals. We also conducted an experiment on coal from Xingcheng using X-ray photoelectron spectroscopy (XPS). The results show that the major forms of organic sulfur in the original coal sample are thiophene and sulfone. Therefore, it can be inferred that there is none or little mercaptan and thiophenol in the original coal. After low-temp oxidation, the form of organic sulfur changes. The sulfide sulfur is oxidized to the sulfoxide, and then the sulfoxide is further oxidized to a sulfone, and these steps can be easily carried out under experimental conditions. What's more, the results illustrate that oxidation promotes sulfur element enrichment on the surface of coal.

  11. A new approach in ultrapurification of coal by selective flocculation. Final report

    SciTech Connect

    Moudgil, B.M.

    1992-04-01

    The specific objective of the present investigation is to develop a mathematical and computational model to elicit values of active sites ({phi}) and fractional surface coverage ({theta}) which would yield optimum separation of coal from coal pyrite and coal refuse. Attempts are to be made to select appropriate flocculants and experimental conditions to obtain {phi} and {theta} values as dictated by the theoretical model so as to achieve the desired separation in naturally occurring samples of fine coal. (VC)

  12. Coal extraction - environmental prediction

    SciTech Connect

    C. Blaine Cecil; Susan J. Tewalt

    2002-08-01

    To predict and help minimize the impact of coal extraction in the Appalachian region, the U.S. Geological Survey (USGS) is addressing selected mine-drainage issues through the following four interrelated studies: spatial variability of deleterious materials in coal and coal-bearing strata; kinetics of pyrite oxidation; improved spatial geologic models of the potential for drainage from abandoned coal mines; and methodologies for the remediation of waters discharged from coal mines. As these goals are achieved, the recovery of coal resources will be enhanced. 2 figs.

  13. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics

    SciTech Connect

    Doyle, F.M.

    1993-04-01

    During the tenth quarter, electrochemical experiments were done on electrodes prepared from Upper Freeport coal pyrite, and Pittsburgh coal pyrite samples provided by the US Bureau of Mines, Pittsburgh Research Center, Pennsylvania. Electrokinetic tests were done on Upper Freeport and Pittsburgh coal pyrite. In addition, surface area measurements were done on Upper Freeport and Upper Clarion coals.

  14. Distribution of trace elements in selected pulverized coals as a function of particle size and density

    USGS Publications Warehouse

    Senior, C.L.; Zeng, T.; Che, J.; Ames, M.R.; Sarofim, A.F.; Olmez, I.; Huggins, Frank E.; Shah, N.; Huffman, G.P.; Kolker, A.; Mroczkowski, S.; Palmer, C.; Finkelman, R.

    2000-01-01

    Trace elements in coal have diverse modes of occurrence that will greatly influence their behavior in many coal utilization processes. Mode of occurrence is important in determining the partitioning during coal cleaning by conventional processes, the susceptibility to oxidation upon exposure to air, as well as the changes in physical properties upon heating. In this study, three complementary methods were used to determine the concentrations and chemical states of trace elements in pulverized samples of four US coals: Pittsburgh, Illinois No. 6, Elkhorn and Hazard, and Wyodak coals. Neutron Activation Analysis (NAA) was used to measure the absolute concentration of elements in the parent coals and in the size- and density-fractionated samples. Chemical leaching and X-ray absorption fine structure (XAFS) spectroscopy were used to provide information on the form of occurrence of an element in the parent coals. The composition differences between size-segregated coal samples of different density mainly reflect the large density difference between minerals, especially pyrite, and the organic portion of the coal. The heavy density fractions are therefore enriched in pyrite and the elements associated with pyrite, as also shown by the leaching and XAFS methods. Nearly all the As is associated with pyrite in the three bituminous coals studied. The sub-bituminous coal has a very low content of pyrite and arsenic; in this coal arsenic appears to be primarily organically associated. Selenium is mainly associated with pyrite in the bituminous coal samples. In two bituminous coal samples, zinc is mostly in the form of ZnS or associated with pyrite, whereas it appears to be associated with other minerals in the other two coals. Zinc is also the only trace element studied that is significantly more concentrated in the smaller (45 to 63 ??m) coal particles.

  15. National coal resource assessment non-proprietary data: Location, stratigraphy, and coal quality for selected tertiary coal in the Northern Rocky Mountains and Great Plains region

    USGS Publications Warehouse

    Flores, Romeo M.; Ochs, A.M.; Stricker, G.D.; Ellis, M.S.; Roberts, S.B.; Keighin, C.W.; Murphy, E.C.; Cavaroc, V.V.; Johnson, R.C.; Wilde, E.M.

    1999-01-01

    One of the objectives of the National Coal Resource Assessment in the Northern Rocky Mountains and Great Plains region was to compile stratigraphic and coal quality-trace-element data on selected and potentially minable coal beds and zones of the Fort Union Formation (Paleocene) and equivalent formations. In order to implement this objective, drill-hole information was compiled from hard-copy and digital files of the: (1) U.S. Bureau of Land Management (BLM) offices in Casper, Rawlins, and Rock Springs, Wyoming, and in Billings, Montana, (2) State geological surveys of Montana, North Dakota, and Wyoming, (3) Wyoming Department of Environmental Quality in Cheyenne, (4) U.S. Office of Surface Mining in Denver, Colorado, (5) U.S. Geological Survey, National Coal Resource Data System (NCRDS) in Reston, Virginia, (6) U.S. Geological Survey coal publications, (7) university theses, and (8) mining companies.

  16. Determination of the limit of oxidation in zones of sub-outcropping Chipanga Coal Seam, Moatize Coal Basin, Mozambique

    NASA Astrophysics Data System (ADS)

    Vasconcelos, Lopo; Chafy, Algy; Xerinda, Leonardo

    2014-11-01

    Moatize Coal Basin (MCB) in Mozambique is a graben with sediments of Karoo age with thick coal seams that are under exploration and exploitation by the Vale Moçambique company. Presently, the exploitation is as an open-pit mine and in the future the works will extend to the area where formerly underground mines were under exploitation. It is well known throughout the World that Moatize basin is a World class deposit for coking and thermal coal and therefore Vale Moçambique is developing studies to rationalize the coal resources of the area. Due to its geological and tectonic story, the general structure of the sedimentary (and coal) layers shows wide open synclines and anticlines, and, as a consequence, in many areas coal seams approach the surface or even outcrop. Therefore, the sub-outcropping/outcropping zones of the seams are subjected directly to the weathering agents, subjecting the coal to oxidation phenomena, which are considered as a factor altering negatively the coking properties of coals. The objective is to study down to which depth the oxidation zone goes, i.e., to trace the Line of Oxidation, also known as LOX. The study deals with Chipanga seam, which is the thickest of all seams and the one with a more wide representation throughout the graben. This seam also sub-outcrops/outcrops in many places, and therefore it is essential to define the LOX. A drilling and coal sampling campaign was then developed along profiles defined according to the seam dip to determine the depth at which the LOX is located. Samples were subjected to washability tests, and the crucible swelling index (CSI) of the Float 1.35 was determined. The study shows a direct relationship between the depth of the Chipanga seam and its degree of oxidation, shown by the sudden decrease of the CSI when the coal seam approaches the surface. The sudden change of CSI generally occurs at a depth of ca. 10 m, with small variations around this value. Therefore it can be said that the depth of

  17. Tri-State Synfuels Project Commercial Scale Coal Test: Volume 1. Selection of camp 1 coal. [Proposed Henderson, Kentucky coal to gasoline plant; selection and testing of coal supplies

    SciTech Connect

    Not Available

    1982-06-01

    This report focuses on the rationale for selecting Camp 1 coal for a commercial scale gasification test conducted at the Sasol One Plant. The initial coal quality evaluation consisted primarily of The Pennsylvania State University coal data from Illinois Basin Counties. In November 1980, a preliminary collection of Illinois Basin coal quality data was developed to support the selection of coals for potential plant supply and full scale commercial testing. The total sample and coarse and fine fractions were analyzed. Lurgi and Sasol examined the list and gave their reasons for selection but they had not examined the samples in their laboratories. In December 1980, the list of potential source mines for the 22,000 short ton sample of raw coal for the test was narrowed to three. The mines were Camp 1, Ken and Providence. The reasons for this selection are given. The three candidate mines were again sampled and representative splits of the run-of-mine samples were flown to Lurgi and to Sasol for examination. The Lurgi laboratory report indicated that both Camp 1 and Ken mine samples would qualify as suitable gasifier feed coals. Sasol concluded from an examination of the November report data that Camp 1 and Ken mine samples would be preferable since the free swelling indices are not excessive. Paul Weir Company examined the data and recommended Camp 1 mine since it operates in the seams contiguous to other potential candidate reserve sites and has the ability to transport the mine sample by belt to a barge loading facility to limit production of fines. The final selection of the Camp 1 mine for the test shipment resulted from considerations given in the report.

  18. Engineering and economical aspects of selection of coal conveying system in Czech underground mines

    SciTech Connect

    Polak, J.; Drozdek, K.

    1995-12-31

    Coal, rock and material conveying and men-riding presently represent the critical activities of the mining process. Coal when cut out in the face is continually transported towards the expedition from a mine. The selection of coal conveying system from face to the skip complex or directly to the surface depends mainly on the quantity of coal conveyed, the hauling distance, the local and time concentration of production and the lifetime of a system. Possibilities of belt conveying and combined belt conveying and locomotive haulage, used in Czech coal mines, are analyzed from the point of view of technological advantages and disadvantages and compared according to the economic parameters.

  19. Graphene quantum dots, graphene oxide, carbon quantum dots and graphite nanocrystals in coals

    NASA Astrophysics Data System (ADS)

    Dong, Yongqiang; Lin, Jianpeng; Chen, Yingmei; Fu, Fengfu; Chi, Yuwu; Chen, Guonan

    2014-06-01

    Six coal samples of different ranks have been used to prepare single-layer graphene quantum dots (S-GQDs). After chemical oxidation and a series of centrifugation separation, every coal could be treated into two fractions, namely, CoalA and CoalB. According to the characterization results of TEM, AFM, XRD, Raman and FTIR, CoalA was revealed to be mainly composed of S-GQDs, which have an average height of about 0.5 nm and an average plane dimension of about 10 nm. The obtained S-GQDs showed excitation-dependent fluorescence and excellent electrochemiluminescence. CoalB was found to be some other carbon-based nanomaterials (CNMs), including agglomerated GQDs, graphene oxide, carbon quantum dots and agglomerated carbon nanocrystals. Generally, low-ranked coals might be more suitable for the preparation of S-GQDs. The production yield of S-GQDs from the six investigated coals decreased from 56.30% to 14.66% when the coal rank increased gradually. In contrast, high-ranked coals had high production yield of CoalB and might be more suitable for preparing other CNMs that were contained in CoalB, although those CNMs were difficult to separate from each other in our experiment.Six coal samples of different ranks have been used to prepare single-layer graphene quantum dots (S-GQDs). After chemical oxidation and a series of centrifugation separation, every coal could be treated into two fractions, namely, CoalA and CoalB. According to the characterization results of TEM, AFM, XRD, Raman and FTIR, CoalA was revealed to be mainly composed of S-GQDs, which have an average height of about 0.5 nm and an average plane dimension of about 10 nm. The obtained S-GQDs showed excitation-dependent fluorescence and excellent electrochemiluminescence. CoalB was found to be some other carbon-based nanomaterials (CNMs), including agglomerated GQDs, graphene oxide, carbon quantum dots and agglomerated carbon nanocrystals. Generally, low-ranked coals might be more suitable for the preparation of

  20. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, December 1, 1993--May 31, 1994

    SciTech Connect

    Doyle, F.M.

    1994-08-01

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The results will provide fundamental insight into oxidation, in term of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the fourteenth and fifteenth quarters, flotation tests were done on Upper Freeport coal from the Troutvill {number_sign}2 Mine, Clearfield County, Pennsylvania and on coal samples from the Pennsylvania State Coal Bank. The influence of electrode potential on the surface properties of coal pyrite was tested using contact angle measurements on polarized Pittsburgh coal pyrite electrode.

  1. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Quarterly technical progress report, December 1, 1993--May 31, 1994

    SciTech Connect

    Doyle, F.M.

    1996-01-01

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The results will provide fundamental insight into oxidation, in term of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the fourteenth and fifteenth quarters, flotation tests were done on Upper Freeport coal from the Troutville No. 2 Mine, Clearfield County, Pennsylvania and on coal samples from the Pennsylvania State Coal Bank. The influence of electrode potential on the surface properties of coal pyrite was tested using contact angle measurements on polarized Pittsburgh coal pyrite electrode.

  2. Free radical reaction characteristics of coal low-temperature oxidation and its inhibition method.

    PubMed

    Li, Zenghua; Kong, Biao; Wei, Aizhu; Yang, Yongliang; Zhou, Yinbo; Zhang, Lanzhun

    2016-12-01

    Study on the mechanism of coal spontaneous combustion is significant for controlling fire disasters due to coal spontaneous combustion. The free radical reactions can explain the chemical process of coal at low-temperature oxidation. Electron spin resonance (ESR) spectroscopy was used to measure the change rules of the different sorts and different granularity of coal directly; ESR spectroscopy chart of free radicals following the changes of temperatures was compared by the coal samples applying air and blowing nitrogen, original coal samples, dry coal samples, and demineralized coal samples. The fragmentation process was the key factor of producing and initiating free radical reactions. Oxygen, moisture, and mineral accelerated the free radical reactions. Combination of the free radical reaction mechanism, the mechanical fragmentation leaded to the elevated CO concentration, fracturing of coal pillar was more prone to spontaneous combustion, and spontaneous combustion in goaf accounted for a large proportion of the fire in the mine were explained. The method of added diphenylamine can inhibit the self-oxidation of coal effectively, the action mechanism of diphenylamine was analyzed by free radical chain reaction, and this research can offer new method for the development of new flame retardant.

  3. Patterning by area selective oxidation

    SciTech Connect

    Nam, Chang-Yong; Kamcev, Jovan; Black, Charles T.; Grubbs, Robert

    2015-12-29

    Technologies are described for methods for producing a pattern of a material on a substrate. The methods may comprise receiving a patterned block copolymer on a substrate. The patterned block copolymer may include a first polymer block domain and a second polymer block domain. The method may comprise exposing the patterned block copolymer to a light effective to oxidize the first polymer block domain in the patterned block copolymer. The method may comprise applying a precursor to the block copolymer. The precursor may infuse into the oxidized first polymer block domain and generate the material. The method may comprise applying a removal agent to the block copolymer. The removal agent may be effective to remove the first polymer block domain and the second polymer block domain from the substrate, and may not be effective to remove the material in the oxidized first polymer block domain.

  4. Quality of selected coal seams from Indiana: Implications for carbonization

    USGS Publications Warehouse

    Walker, R.; Mastalerz, Maria; Padgett, P.

    2001-01-01

    The chemical properties of two high-volatile bituminous coals, the Danville Coal Member of the Dugger Formation and the Lower Block Coal Member of the Brazil Formation from southern Indiana, were compared to understand the differences in their coking behavior. It was determined that of the two, the Lower Block has better characteristics for coking. Observed factors that contribute to the differences in the coking behavior of the coals include carbon content, organic sulfur content, and oxygen/carbon (O/C) ratios. The Lower Block coal has greater carbon content than the Danville coal, leading to a lower O/C ratio, which is more favorable for coking. Organic sulfur content is higher in the Lower Block coal, and a strong correlation was found between organic sulfur and plasticity. The majority of the data for both seams plot in the Type III zone on a van Krevelen diagram, and several samples from the Lower Block coal plot into the Type II zone, suggesting a perhydrous character for those samples. This divergence in properties between the Lower Block and Danville coals may account for the superior coking behavior of the Lower Block coal. ?? 2001 Elsevier Science B.V. All rights reserved.

  5. Process and analytical studies of enhanced low severity co-processing using selective coal pretreatment

    SciTech Connect

    Baldwin, R.M.; Miller, R.L.

    1991-12-01

    The findings in the first phase were as follows: 1. Both reductive (non-selective) alkylation and selective oxygen alkylation brought about an increase in liquefaction reactivity for both coals. 2. Selective oxygen alkylation is more effective in enhancing the reactivity of low rank coals. In the second phase of studies, the major findings were as follows: 1. Liquefaction reactivity increases with increasing level of alkylation for both hydroliquefaction and co-processing reaction conditions. 2. the increase in reactivity found for O-alkylated Wyodak subbituminous coal is caused by chemical changes at phenolic and carboxylic functional sites. 3. O-methylation of Wyodak subbituminous coal reduced the apparent activation energy for liquefaction of this coal.

  6. Removal of sulfur and chlorine from Illinois coals by wet-grinding and selective flocculation

    SciTech Connect

    Chou, C.L.

    1999-07-01

    A coal-cleaning method for removing sulfur and chlorine from Illinois Basin coals was developed. The method includes four steps: (1) crushing raw coal to {minus}10 mesh, (2) using a concentrating table to remove pyrite and other minerals, (3) wet-grinding coal to an ultrafine particle size to liberate coal from pyrite and other minerals, and (4) conducting selective flocculation to separate coal from mineral particles and chlorine-containing water. A sample of Illinois Basin coal IBC-106 (9.0% ash and 3.77% sulfur) was ground to {minus}10 mesh and separated into five fractions on a concentrating table. The pyritic sulfur content decreased from 1.85% in feed coal to 1.49%, 0.85%, and 0.82% in clean, fine, and overflow fractions, respectively. Wet-grinding and selective flocculation tests were conducted on another sample of Illinois Basin coal IBC-105 (18.6% ash and 4.55% sulfur). The coal was ground in a stirred ball mill to generate a coal slurry with a particle size distribution of 90% <19 micrometer. The slurry was dispersed to make a complete suspension. Sodium metaphosphate was added as a dispersant. Various polymeric flocculants were tested to determine the selective flocculation performance of each. The acidity of the slurry (pH) and the flocculant dosage are critical in selective flocculation tests. When flocculant Calgon WCL-762 was used, the ash content decreased from 18.6% to 8.1% (56% reduction) in a single-stage flocculation process, and to 5.7% (69% reduction) in a two-stage process. Chlorine removal from coal was investigated on a high-chlorine coal sample IBC-109 (8.2% ash, 1.13% sulfur, and 0.42% chlorine). Wet-grinding the coal to 90% <20 micrometer, and subsequently dewatering the slurry by selective flocculation reduced the chlorine content from 0.42% to between 0.11% and 0.15% (64% to 74% reduction). In addition, ash content was reduced from 8.2% to between 4.0% and 5.4% (34% to 51% reduction) and pyritic sulfur content from 0.50% to between 0

  7. Upgrading selected Czech coals for home and industrial heating

    SciTech Connect

    Musich, M.A.; Young, B.C.

    1995-12-31

    The Czech Republic has large coal reserves, particularly brown coal and lignite, and to a lesser extent, bituminous coal. Concurrent with the recent political changes, there has been a reassessment of the role of coal for electrical and heating energy in the future economy, owing to the large dependence on brown coal and lignite and the implementation of more stringent environmental regulations. These coals have a relatively high sulfur content, typically 1-3 wt%, and ash content, leading to significant SO{sub 2} and other gaseous and particulate emissions. Some of the bituminous coals also exhibit high ash content. Against this background, the Energy & Environmental Research Center, on behalf of the U.S. Agency for International Development and the U.S. Department of Energy Office of Fossil Energy, undertook a project on upgrading Czech coals to achieve desired fuel properties. The purpose of the project was to assist the city of Usti nad Labem in Northern Bohemia in developing cost-effective alternatives for reducing environmental emissions from district and home heating systems.

  8. Sequential solvent extraction for forms of antimony in five selected coals

    USGS Publications Warehouse

    Qi, C.; Liu, Gaisheng; Kong, Y.; Chou, C.-L.; Wang, R.

    2008-01-01

    Abundance of antimony in bulk samples has been determined in five selected coals, three coals from Huaibei Coalfield, Anhui, China, and two from the Illinois Basin in the United States. The Sb abundance in these samples is in the range of 0.11-0.43 ??g/g. The forms of Sb in coals were studied by sequential solvent extraction. The six forms of Sb are water soluble, ion changeable, organic matter bound, carbonate bound, silicate bound, and sulfide bound. Results of sequential extraction show that silicate-bound Sb is the most abundant form in these coals. Silicate- plus sulfide-bound Sb accounts for more than half of the total Sb in all coals. Bituminous coals are higher in organic matterbound Sb than anthracite and natural coke, indicating that the Sb in the organic matter may be incorporated into silicate and sulfide minerals during metamorphism. ?? 2008 by The University of Chicago. All rights reserved.

  9. Sequential solvent extraction for forms of antimony in five selected coals

    SciTech Connect

    Qi, C.C.; Liu, G.J.; Kang, Y.; Chou, C.L.; Wang, R.W.

    2008-03-15

    Abundance of antimony in bulk samples has been determined in five selected coals, three coals from Huaibei Coalfield, Anhui, China, and two from the Illinois Basin in the United States. The Sb abundance in these samples is in the range of 0.11-0.43 {mu} g/g. The forms of Sb in coals were studied by sequential solvent extraction. The six forms of Sb are water soluble, ion changeable, organic matter bound, carbonate bound, silicate bound, and sulfide bound. Results of sequential extraction show that silicate-bound Sb is the most abundant form in these coals. Silicate-plus sulfide-bound Sb accounts for more than half of the total Sb in all coals. Bituminous coals are higher in organic matter bound Sb than anthracite and natural coke, indicating that the Sb in the organic matter may be incorporated into silicate and sulfide minerals during metamorphism.

  10. Multi-Attribute Selection of Coal Center Location: A Case Study in Thailand

    NASA Astrophysics Data System (ADS)

    Kuakunrittiwong, T.; Ratanakuakangwan, S.

    2016-11-01

    Under Power Development Plan 2015, Thailand has to diversify its heavily gas-fired electricity generation. The main owner of electricity transmission grids is responsible to implement several coal-fired power plants with clean coal technology. To environmentally handle and economically transport unprecedented quantities of sub-bituminous and bituminous coal, a coal center is required. The location of such facility is an important strategic decision and a paramount to the success of the energy plan. As site selection involves many criteria, Fuzzy Analytical Hierarchy Process or Fuzzy-AHP is applied to select the most suitable location among three candidates. Having analyzed relevant criteria and the potential alternatives, the result reveals that engineering and socioeconomic are important criteria and Map Ta Phut is the most suitable site for the coal center.

  11. Coal.

    ERIC Educational Resources Information Center

    Brant, Russell A.; Glass, Gary B.

    1983-01-01

    Principle work of 23 state geological surveys is summarized. Work includes mapping/estimating coal resources, centralizing data in National Coal Resources Data System through cooperative programs, exploration drilling, and others. Comments on U.S. Geological Survey activities, coal-related conferences/meetings, and industry research activities are…

  12. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxides (NOx) emissions from high sulfur coal-fired utility boilers at Plant Crist SCR test facility

    SciTech Connect

    Hinton, W.S.; Maxwell, J.D.; Baldwin, A.L.

    1996-01-01

    This paper describes the status of the Innovative Clean Coal Technology project to demonstrate SCR technology for reduction of NOx emissions from flue gas of utility boilers burning U.S. high-sulfur coal. The project is sponsored by the U.S. Department of Energy, managed and co- funded by Southern Company Services, Inc. on behalf of the Southern Company, and also co-funded by the Electric Power Research Institute and Ontario Hydro; and is located at Gulf Power Company`s Plant Crist Unit 5 (75 MW tangentially-fired boiler burning U.S. coals that have a sulfur content near 3.0%), near Pensacola, Florida. The test program is being conducted for approximately two years to evaluate catalyst deactivation and other SCR operational effects. The SCR test facility has nine reactors: three 2.5 MW (5000 scfm), and six 0.2 MW(400 scfm). Eight reactors operate on high-dust flue gas, while the ninth reactor operates on low-dust flue gas using a slip stream at the exit of the host unit`s hot side precipitator. The reactors operate in parallel with commercially available SCR catalysts obtained from vendors throughout the world. Long-term performance testing began in July 1993. A general test facility description and the results from three parametric test sequences and long term test data through December 1994 are presented in this paper.

  13. Cooperative research program in coal liquefaction

    SciTech Connect

    Huffman, G.P.; Sendlein, L.V.A.

    1991-01-01

    This report is a coordinated effort of the Consortium for Fossil Fuel Liquefaction Science. The topics concerning coal liquefaction discussed are: sulfate promoted metal oxides as direct coal liquefaction catalysts; low temperature depolymerization and liquefaction of premium R.S. coal samples; construction of continuous flow-through gas reactor for liquefaction investigations; generic structural characterization and liquefaction research; macerals, model compounds and iron catalyst dispersion; coal structure/liquefaction yield correlation by means of advanced NMR techniques; GC/MS of model compound mixtures; catalytic cracking, hydrogenation and liquefaction of coals under milder conditions; ENDOR investigations of coal liquefaction under mild conditions; catalytic dehydrogenation of model compounds in relation to direct coal liquefaction; surface characterization of catalyst added coal samples; computational chemistry of model compounds and molecular fragments of relevance to coal liquefaction; chemical characterization and hydrogenation reactions of single coal particles; thermolytic cleavage of selected coal-related linkages at mild temperatures; solvent sorption and FTIR studies on the effect of catalytic depolymerization reactions in coal; bioprocessing of coal; chemical routes to breaking bonds; novel liquefaction concepts cyclic olefins: novel new donors for coal liquefaction; better hydrogen transfer in coal liquefaction; catalytic hydropyrolysis and energized extraction of coals; gallium catalyst in mild coal liquefaction; potential of temperature microscope in coal liquefaction; evaluation of nitride catalysts for hydrotreatment and coal liquefaction; coprocessing and coal liquefaction with novel catalysts.

  14. NOVEL MERCURY OXIDANT AND SORBENT FOR MERCURY EMISSIONS CONTROL FROM COAL-FIRED POWER PLANTS

    EPA Science Inventory

    The authors have successfully developed novel efficient and cost-effective sorbent and oxidant for removing mercury from power plant flue gases. These sorbent and oxidant offer great promise for controlling mercury emissions from coal-fired power plants burning a wide range of c...

  15. Gas cleaning and hydrogen sulfide removal for COREX coal gas by sorption enhanced catalytic oxidation over recyclable activated carbon desulfurizer.

    PubMed

    Sun, Tonghua; Shen, Yafei; Jia, Jinping

    2014-02-18

    This paper proposes a novel self-developed JTS-01 desulfurizer and JZC-80 alkaline adsorbent for H2S removal and gas cleaning of the COREX coal gas in small-scale and commercial desulfurizing devices. JTS-01 desulfurizer was loaded with metal oxide (i.e., ferric oxides) catalysts on the surface of activated carbons (AC), and the catalyst capacity was improved dramatically by means of ultrasonically assisted impregnation. Consequently, the sulfur saturation capacity and sulfur capacity breakthrough increased by 30.3% and 27.9%, respectively. The whole desulfurizing process combined selective adsorption with catalytic oxidation. Moreover, JZC-80 adsorbent can effectively remove impurities such as HCl, HF, HCN, and ash in the COREX coal gas, stabilizing the system pressure drop. The JTS-01 desulfurizer and JZC-80 adsorbent have been successfully applied for the COREX coal gas cleaning in the commercial plant at Baosteel, Shanghai. The sulfur capacity of JTS-01 desulfurizer can reach more than 50% in industrial applications. Compared with the conventional dry desulfurization process, the modified AC desulfurizers have more merit, especially in terms of the JTS-01 desulfurizer with higher sulfur capacity and low pressure drop. Thus, this sorption enhanced catalytic desulfurization has promising prospects for H2S removal and other gas cleaning.

  16. Palynology of selected coal beds in the proposed Pennsylvanian System stratotype in West Virginia

    USGS Publications Warehouse

    Kosanke, Robert M.

    1984-01-01

    ) Wilson and Venkatachala, Schopfites dimorphus Kosanke, and Thymospora thiessenii (Kosanke) Wilson and Venkatachala. Some of the range zones are relatively short and extremely useful for correlation studies. For example, in the Charleston Sandstone, T. pseudothiessenii (Kosanke) Wilson and Venkatachala is present in the Upper No.5 Block coal (upper bench) and the No.6 Block coal, whereas Schopfites dimorphus Kosanke is restricted to the No.6 Block coal. Thymospora thiessenii (Kosanke) Wilson and Venkatachala is not restricted to the Pittsburgh No.8 coal, but it is the only coal known in which this taxon is so dominant (more than 70 percent of the palynomorph assemblage). This preliminary report has provided a framework for the correlation of a selected number of coals occurring in Ohio and eastern Kentucky with those of the proposed Pennsylvanian System stratotype of West Virginia. In other studies, additional samples from the stratotype would be examined for ultimate correlation with rocks of Pennsylvania and in adjacent States and elsewhere.

  17. Economic analysis of selective catalytic reduction applied to coal-fired boilers for NO{sub x} reduction

    SciTech Connect

    Healy, E.C.; Maxwell, J.D.; Hinton, W.S.; Baldwin, A.L.

    1997-12-31

    Selective Catalytic Reduction (SCR) technology is one of many compliance options electric utilities have at their disposal when considering reduction of nitrogen oxide (NO{sub x}) emissions at coal-fired power plants. This paper describes the results of an economic analysis that was completed as part of an Innovative Clean Coal Technology project, which demonstrated SCR technology for reduction of NO{sub x} emission from utility boilers burning high-sulfur coal. The project, conducted at Gulf Power Company`s Plant Crist Unit 5, was sponsored by the US Department of Energy, managed and cofunded by Southern Company Services, Inc., on behalf of Southern Company, and also cofunded by The Electric Power Research Institute and Ontario Hydro. The test program was conducted for approximately 2 years to evaluate catalyst deactivation and to quantify operational impacts of SCR technology employed in a high-sulfur environment. Measured data and operational lessons learned at the test facility form the basis of the technical premises and economic analysis. Capital and O and M costs were prepared for commercial-scale new and retrofit applications of SCR technology. Additionally, the results of the economic analysis presented in this paper are enhanced by incorporating current market trends based on US coal-fired SCR installations.

  18. Experimental laboratory measurement of thermophysical properties of selected coal types

    NASA Technical Reports Server (NTRS)

    Lloyd, W. G.

    1979-01-01

    A number of bituminous coals of moderate to high plasticity were examined, along with portions of their extrudates from the JPL 1.5-inch 850 F screw extruder. Portions of the condensed pyrolysis liquids released during extrusion, and of the gaseous products formed during extrusion were also analyzed. In addition to the traditional determinations, the coals and extrudates were examined in terms of microstructure (especially extractable fractions), thermal analysis (especially that associated with the plastic state), and reactivity towards thermal and catalyzed hydroliquefaction. The process of extrusion increases the fixed carbon content of coals by about 5% and tends to increase the surface area. Coals contaning 25% or more DMF-extractable material show an increase in extractables as a result of extrusion; those initially containing less than 20% extractables show a decrease as a result of extrusion. Both the raw and extruded samples of Kentucky #9 coal are highly reactive towards hydroliquefaction, undergoing conversions of 75 to 80% in 15 min and 85-94% in 60 min in a stirred clave.

  19. Genetic and oxidative damage of peripheral blood lymphocytes in workers with occupational exposure to coal.

    PubMed

    Rohr, Paula; Kvitko, Kátia; da Silva, Fernanda R; Menezes, Ana Paula Simões; Porto, Carem; Sarmento, Merielen; Decker, Natália; Reyes, Juliana M; Allgayer, Mariangela da C; Furtado, Tatiane Chao; Salvador, Mirian; Branco, Catia; da Silva, Juliana

    2013-12-12

    Coal is an important fossil fuel used to generate energy. Coal dust is constituted primarily of hydrocarbons and metals. During coal extraction, large quantities of coal dust particles are emitted, contributing to environmental pollution. Coal miners are constantly exposed to coal dust and its derivatives. The goal of this study was to evaluate the potential genotoxic effects of coal and oxidative stress in individuals from Candiota who were exposed to coal as part of their occupation. The comet assay and micronucleus (MN) test were used to assess these effects. This study involved 128 male participants of whom 71 reported work that included exposure to coal (exposed group) and 57 reported working at different jobs (unexposed group). The exposed group had a significantly increased damage index and damage frequency, as assessed using the comet assay, and increased MN and nucleoplasmic bridge frequencies, as assessed using the MN assay, compared with unexposed individuals. Significant and positive correlations between MN frequencies in the lymphocytes and buccal cells of control and exposed individuals were observed. The exposed individuals presented lower average levels of thiobarbituric acid reactive substances (TBARS) and catalase activity (CAT), while the mean superoxide dismutase activity (SOD) levels were higher in this group. The exposed group also had higher hematocrit levels. No correlation between DNA damage and inorganic elements, as identified using PIXE, was found; however, there was a correlation between the damage index and zinc. The evidence that exposure to coal and its derivatives presents a genetic hazard demonstrates the need for protective measures and educational programs for coal miners.

  20. Oxidative Activity of Heated Coal Affected by Antypirogens

    NASA Astrophysics Data System (ADS)

    Torosyan, V. F.; Torosyan, E. S.; Borovikov, I. F.; Yakutova, V. A.

    2016-04-01

    The effect of antypirogens on chemical activity of heated coal is studied. It is proved that ammonium sulfate, calcium phosphate, calcium chloride, calcium nitrate and acid fluoride are the most effective antypirogens.

  1. Toxic Substances From Coal Combustion - Phase I Coal Selection and Chaacterization

    SciTech Connect

    A. Kolker; A. Sarofim; C.A. Palmer; C.L. Senior; F.E. Huggins; G.P. Huffman; I. Olmez; N. Shah; R. Finkelman; S. Crowley; T. Zeng

    1998-07-16

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. Over the past decade, a large database identifying the partitioning and emitted concentrations of several toxic metals on the list of HAPs has been developed. Laboratory data have also been generated to help define the general behavior of several elements in combustion systems. These data have been used to develop empirical and probabalistic models to predict emissions of trace metals from coal-fired power plants. While useful for providing average emissions of toxic species, these empirically based models fail when extrapolated beyond their supporting database. This represents a critical gap; over the coming decades, new fuels and combustion systems will play an increasing role in our nation's power generation system. For example, new fuels, such as coal blends or beneficiated fuels, new operating conditions, such as low-NO burners or staged combustion, or new power x systems, for example, those being developed under the DoE sponsored Combustion 2000 programs and integrated gasification combined cycle (IGCC) systems, are all expected to play a role in power generation in the next century. The need for new predictive tools is not limited to new combustion systems, however. Existing combustion systems may have to employ controls for HAPs, should regulations be imposed. Testing of new control methods, at pilot and full scale, is expensive. A sound under-standing of the chemical transformations of both organic and inorganic HAPs will promote the development of new control methods in a cost-effective manner. To ensure that coal-fired power generation proceeds in an environmentally benign fashion, methods for the prediction and

  2. Determination of selected elements in whole coal and in coal ash from the eight argonne premium coal samples by atomic absorption spectrometry, atomic emission spectrometry, and ion-selective electrode

    USGS Publications Warehouse

    Doughten, M.W.; Gillison, J.R.

    1990-01-01

    Methods for the determination of 24 elements in whole coal and coal ash by inductively coupled argon plasma-atomic emission spectrometry, flame, graphite furnace, and cold vapor atomic absorption spectrometry, and by ion-selective electrode are described. Coal ashes were analyzed in triplicate to determine the precision of the methods. Results of the analyses of NBS Standard Reference Materials 1633, 1633a, 1632a, and 1635 are reported. Accuracy of the methods is determined by comparison of the analysis of standard reference materials to their certified values as well as other values in the literature.

  3. Occurrence and activity of iron- and sulfur-oxidizing microorganisms in alkaline coal strip mine spoils.

    PubMed

    Olson, G J; McFeters, G A; Temple, K L

    1981-03-01

    Spoils samples collected from a coal strip mine in southeastern Montana were examined for populations and activities of iron- and sulfur-oxidizing bacteria. Spoils examined were of three types: (a) acidic pyrite-rich waste coal, (b) oxidation halo material, and (c) alkaline material, which was the most widespread type. Bacterial numbers, sulfur oxidation, and(14)CO2 uptake activity declined to low levels in the summer when spoils were dry. Even in wetter spring months pyritic spoils contained relatively low numbers of acidophilic iron- and sulfur-oxidizing bacteria, probably indicative of water stress since the same spoils incubated with excess water or dilute mineral salts showed considerably greater bacterial numbers and activity. Certain wells in coal and spoils aquifers contained substantial populations of iron-oxidizing acidophilic bacteria. However, these wells were always of alkaline or neutral pH, indicating that bacterial pyrite oxidation occurred where groundwaters contacted either replaced spoils or coal that contained pyrite or other metal sulfides. Bacterial activity may contribute to trace metal and sulfate leaching in the area.

  4. Removal of ash, sulfur, and trace elements of environmental concern from eight selected Illinois coals

    USGS Publications Warehouse

    Demir, I.

    1998-01-01

    Release analysis (RA) and float-sink (F-S) data were generated to assess the beneficiation potential of washed coals from selected Illinois coal preparation plants through the use of advanced physical cleaning at -60 mesh size. Generally, the F-S process removed greater amounts of ash, sulfur, and trace elements of environmental concern from the coals than the RA process, indicating that the cleanability of Illinois coals by advanced methods can be estimated best by F-S testing. At an 80%-combustibles recovery, the ash yield in the clean F-S products decreased by 47-75%, relative to the parent coals. Average decreases for the elements As(67%), Cd(78%), Hg(73%), Mn(71%), and P(66%) exceeded the average decrease for ash yield (55%). Average decreases for other elements were: Co(31%), Cr(27%), F(39%), Ni(25%), Pb(50%), S(28%), Sb(20%), Se(39), Th(32%), and U(8%). Only Be was enriched (up to 120%) in the clean products relative to the parent coals. These results suggested that the concentration of elements with relatively high atmospheric mobilities (As, Cd, F, Hg, Pb, and Se) during coal combustion can be reduced substantially in Illinois coals through the use of advanced physical cleaning. Advanced physical cleaning can be effective also for the removal of inorganic S. Environmental risks from the emission of other elements with enrichment or relatively low cleanabilities could be small because these elements generally have very low concentrations in Illinois coals or are largely retained in solid residues during coal combustion. ?? 1998 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint.

  5. A Combined Raman Spectroscopic and Thermogravimetric Analysis Study on Oxidation of Coal with Different Ranks

    PubMed Central

    Zhang, Weiqing; Jiang, Shuguang; Hardacre, Christopher; Goodrich, Peter; Wang, Kai; Shao, Hao; Wu, Zhengyan

    2015-01-01

    Raman spectroscopy and nonisothermal thermogravimetric analysis (TGA) measurements have been reported for different rank coals (lignite, bituminous coal, and anthracite) and the relationship between the measurements was examined. It was found that the Raman spectra parameters can be used to characterize structure changes in the different rank coals, such as the band area ratios based on the curve-fitted results. Higher ranked coal was found to have higher values of IGR/IAll and I(G + GR)/IAll but lower values of ID/I(G+GR), IDL/I(G+GR), I(S + SL)/I(G+GR), and I(GL+GL')/I(G+GR). The oxidation properties of the coal samples were characterized by the reactivity indexes Tig, T20%, and Tmax from TGA data which were found to correlate well with the band area ratios of IGR/IAll, I(G + GR)/IAll, and I(S + SL)/I(G+GR). Based on these correlations, the Raman band area ratios were found to correlate with the oxidation activity of coal providing additional structural information which can be used to understand the changes in the TGA measurements. PMID:26682084

  6. Experimental and modeling study of the effect of CH(4) and pulverized coal on selective non-catalytic reduction process.

    PubMed

    Zhang, Yanwen; Cai, Ningsheng; Yang, Jingbiao; Xu, Bo

    2008-10-01

    The reduction of nitric oxide using ammonia combined with methane and pulverized coal additives has been studied in a drop tube furnace reactor. Simulated flue gas with 1000 ppm NO(x) and 3.4% excess oxygen was generated by cylinder gas. Experiments were performed in the temperature range of 700-1200 degrees C to investigate the effects of additives on the DeNO(x) performance. Subsequently, a kinetic mechanism was modified and validated based on experimental results, and a computational kinetic modeling with CHEMKIN was conducted to analyze the secondary pollutants. For both methane and pulverized coal additives, the temperature window is shifted towards lower temperatures. The appropriate reaction temperature is shifted to about 900 and 800 degrees C, respectively with 1000 ppm methane and 0.051 g min(-1) pulverized lignite coal. The addition of methane and pulverized coal widens the temperature window towards lower temperature suggesting a low temperature application of the process. Furthermore, selective non-catalytic reduction (SNCR) reaction rate is accelerated evidently with additives and the residence time to complete the reaction is shortened distinctly. NO(x) reduction efficiency with 80% is achieved in about 0.3s without additive at 1000 degrees C. However, it is achieved in only about 0.2s with 100 ppm methane as additive, and only 0.07 and 0.05s are needed respectively for the cases of 500 and 1000 ppm methane. The modified kinetic modeling agrees well with the experimental results and reveals additional information about the process. Investigation on the byproducts where NO(2) and N(2)O were analyzed by modeling and the others were investigated by experimental means indicates that emissions would not increase with methane and pulverized coal additions in SNCR process and the efficacious temperature range of SNCR reaction is widened approximately with 100 degrees C.

  7. Chemicl-looping combustion of coal with metal oxide oxygen carriers

    SciTech Connect

    Siriwardane, R.; Tian, H.; Richards, G.; Simonyi, T.; Poston, J.

    2009-01-01

    The combustion and reoxidation properties of direct coal chemical-looping combustion (CLC) over CuO, Fe2O3, Co3O4, NiO, and Mn2O3 were investigated using thermogravimetric analysis (TGA) and bench-scale fixed-bed flow reactor studies. When coal is heated in either nitrogen or carbon dioxide (CO2), 50% of weight loss was observed because of partial pyrolysis, consistent with the proximate analysis. Among various metal oxides evaluated, CuO showed the best reaction properties: CuO can initiate the reduction reaction as low as 500 °C and complete the full combustion at 700 °C. In addition, the reduced copper can be fully reoxidized by air at 700 °C. The combustion products formed during the CLC reaction of the coal/metal oxide mixture are CO2 and water, while no carbon monoxide was observed. Multicycle TGA tests and bench-scale fixed-bed flow reactor tests strongly supported the feasibility of CLC of coal by using CuO as an oxygen carrier. Scanning electron microscopy (SEM) images of solid reaction products indicated some changes in the surface morphology of a CuO-coal sample after reduction/oxidation reactions at 800 °C. However, significant surface sintering was not observed. The interactions of fly ash with metal oxides were investigated by X-ray diffraction and thermodynamic analysis. Overall, the results indicated that it is feasible to develop CLC with coal by metal oxides as oxygen carriers.

  8. Chemical-looping combustion of coal with metal oxide oxygen carriers

    SciTech Connect

    Ranjani Siriwardane; Hanjing Tian; George Richards; Thomas Simonyi; James Poston

    2009-08-15

    The combustion and reoxidation properties of direct coal chemical-looping combustion (CLC) over CuO, Fe{sub 2}O{sub 3}, CO{sub 3}O{sub 4}, NiO, and Mn{sub 2}O{sub 3} were investigated using thermogravimetric analysis (TGA) and bench-scale fixed-bed flow reactor studies. When coal is heated in either nitrogen or carbon dioxide (CO{sub 2}), 50% of weight loss was observed because of partial pyrolysis, consistent with the proximate analysis. Among various metal oxides evaluated, CuO showed the best reaction properties: CuO can initiate the reduction reaction as low as 500{sup o}C and complete the full combustion at 700{sup o}C. In addition, the reduced copper can be fully reoxidized by air at 700{sup o}C. The combustion products formed during the CLC reaction of the coal/metal oxide mixture are CO{sub 2} and water, while no carbon monoxide was observed. Multicycle TGA tests and bench-scale fixed-bed flow reactor tests strongly supported the feasibility of CLC of coal by using CuO as an oxygen carrier. Scanning electron microscopy (SEM) images of solid reaction products indicated some changes in the surface morphology of a CuO-coal sample after reduction/oxidation reactions at 800 {sup o}C. However, significant surface sintering was not observed. The interactions of fly ash with metal oxides were investigated by X-ray diffraction and thermodynamic analysis. Overall, the results indicated that it is feasible to develop CLC with coal by metal oxides as oxygen carriers. 22 refs., 12 figs., 2 tabs.

  9. The use of coal in a solid phase reduction of iron oxide

    NASA Astrophysics Data System (ADS)

    Nokhrina, O. I.; Rozhihina, I. D.; Hodosov, I. E.

    2015-09-01

    The results of the research process of producing metalized products by solid-phase reduction of iron using solid carbonaceous reducing agents. Thermodynamic modeling was carried out on the model of the unit the Fe-C-O and system with iron ore and coal. As a result of modeling the thermodynamic boundary reducing, oxidizing, and transition areas and the value of the ratio of carbon and oxygen in the system. Simulation of real systems carried out with the gas phase obtained in the pyrolys of coal. The simulation results allow to determine the optimal cost of coal required for complete reduction of iron ore from a given composition. The kinetics of the processes of solid-phase reduction of iron using coal of various technological brands.

  10. Comparison of selected parameters of biomass and coal

    NASA Astrophysics Data System (ADS)

    Lalak, Justyna; Martyniak, Danuta; Kasprzycka, Agnieszka; Żurek, Grzegorz; Moroń, Wojciech; Chmielewska, Mariola; Wiącek, Dariusz; Tys, Jerzy

    2016-10-01

    As a fuel, biomass differs in its properties from fossil fuels and acquisition thereof for energy purposes is limited; hence, the ongoing search for new bioenergetically useful plants. The article presents the results of physical and chemical analyses of seven species of perennial grasses: tall wheatgrass, tall wheatgrass `Bamar', brome grass, tall fescue ecotype, reed canary grass, giant miscanthus, and sorghum. The research involved technical and elemental analysis as well as analysis of the ash composition performed in order to determine their potential use for combustion process. The measurement results were compared with those obtained for hard coal and agricultural biomass, which is widely used in the energy industry. The results suggest that perennial grasses can successfully be combusted with similar performance to coal if burned in appropriate combustion installations.

  11. MECHANISMS OF NITROUS OXIDE FORMATION IN COAL FLAMES

    EPA Science Inventory

    The paper gives results of a study, using both detailed kinetic modeling and plug-flow simulator experiments, to investigate an unknown mechanism by which N2O is formed in coal flames. This mechanism has considerable importance in determining the influence of common and advanced ...

  12. The effect of selective solvent absorption on coal conversion. Final technical report

    SciTech Connect

    Larsen, J.W.

    1993-11-01

    Using a pair of different recycle oils from Wilsonville and {sup 1}H NMR, {sup 13}C NMR, gel permeation (GPC) chromatography, high pressure liquid chromatography (HPLC), and elemental analysis, no significant differences were observed between the composition of the recycle oil and that portion of the oil not absorbed by the coal. For these complex mixtures, coals are not selective absorbants. Since most of the heteroatoms responsible for most of the specific interactions have been removed by hydrogenolyses, this is perhaps not surprising. To address the issue of the role of hydrogen bond donors in the reused as hydrogen donor coal, tetralin and 2-t-butyltetralin were used as hydrogen donor solvents. This work is reported in detail in Section 2. The basic idea is that the presence of the t-butyl group on the aromatic ring will hinder or block diffusion of the hydrogen donor into the coal resulting in lower conversions and less hydrogen transferred with 2-t-butyltetralin than with tetralin. Observed was identical amounts of hydrogen transfer and nearly identical conversions to pyridine solubles for both hydrogen donors. Diffusion of hydrogen donors into the coal does not seem to play a significant role in coal conversion. Finally, in Section 3 is discussed the unfavorable impact on conversion of the structural rearrangements which occur when Illinois No. 6 coal is swollen with a solvent. We believe this rearrangement results in a more strongly associated solid leading to the diminution of coal reactions. Hydrogen donor diffusion does not seem to be a major factor in coal conversion while the structural rearrangement does. Both areas warrant further exploration.

  13. Evaluation of BOC'S Lotox Process for the Oxidation of Elemental Mercury in Flue Gas from a Coal-Fired Boiler

    SciTech Connect

    Khalid Omar

    2008-04-30

    Linde's Low Temperature Oxidation (LoTOx{trademark}) process has been demonstrated successfully to remove more than 90% of the NOx emitted from coal-fired boilers. Preliminary findings have shown that the LoTOx{trademark} process can be as effective for mercury emissions control as well. In the LoTOx{trademark} system, ozone is injected into a reaction duct, where NO and NO{sub 2} in the flue gas are selectively oxidized at relatively low temperatures and converted to higher nitrogen oxides, which are highly water soluble. Elemental mercury in the flue gas also reacts with ozone to form oxidized mercury, which unlike elemental mercury is water-soluble. Nitrogen oxides and oxidized mercury in the reaction duct and residual ozone, if any, are effectively removed in a wet scrubber. Thus, LoTOx{trademark} appears to be a viable technology for multi-pollutant emission control. To prove the feasibility of mercury oxidation with ozone in support of marketing LoTOx{trademark} for multi-pollutant emission control, Linde has performed a series of bench-scale tests with simulated flue gas streams. However, in order to enable Linde to evaluate the performance of the process with a flue gas stream that is more representative of a coal-fired boiler; one of Linde's bench-scale LoTOx{trademark} units was installed at WRI's combustion test facility (CTF), where a slipstream of flue gas from the CTF was treated. The degree of mercury and NOx oxidation taking place in the LoTOx{trademark} unit was quantified as a function of ozone injection rates, reactor temperatures, residence time, and ranks of coals. The overall conclusions from these tests are: (1) over 80% reduction in elemental mercury and over 90% reduction of NOx can be achieved with an O{sub 3}/NO{sub X} molar ratio of less than two, (2) in most of the cases, a lower reactor temperature is preferred over a higher temperature due to ozone dissociation, however, the combination of both low residence time and high temperature

  14. NOVEL ECONOMICAL HG(0) OXIDATION REAGENT FOR MERCURY EMISSIONS CONTROL FROM COAL-FIRED BOILERS

    EPA Science Inventory

    The authors have developed a novel economical additive for elemental mercury (Hg0) removal from coal-fired boilers. The oxidation reagent was rigorously tested in a lab-scale fixed-bed column with the Norit America's FGD activated carbon (DOE's benchmark sorbent) in a typical PRB...

  15. Selective thermal oxidation of hydrocarbons in zeolites by oxygen

    DOEpatents

    Frei, Heinz; Blatter, Fritz; Sun, Hai

    2000-01-01

    A process for selective thermal oxidation of hydrocarbons adsorbed onto zeolite matrices. A highly selective thermal oxidation of unsubstituted or alkyl substituted alkanes, alkenes, aromatics and cycloalkyls is carried out in solvent free zeolites under dark thermal conditions. The process oxidizes hydrocarbons almost completely selectively without substantial production of byproducts.

  16. DISTRIBUTION OF TRACE ELEMENTS IN COAL MINERALS OF SELECTED EASTERN UNITED STATES COALS.

    USGS Publications Warehouse

    Palmer, C.A.; Wandless, M.-V.

    1985-01-01

    The association of 34 elements with minerals found in coal was determined by a combination of analytical techniques on size and density fractions of low-temperature ash (LTA). Instrumental neutron activation analysis was used to determine the concentrations of the elements, and X-ray diffraction analysis, scanning electron microscopy, and scanning transmission electron microscopy were used to identify the minerals present in the LTA. The distribution of elemental and mineral concentrations in different size fractions was also determined. Between 35 and 60 weight percent of the LTA was composed of particles smaller than 2 mu m.

  17. Formation and destruction of nitrogen oxides in coal combustion. [Reburning

    SciTech Connect

    Chen, W.Y.; Lester, T.W.; Babcock, L.

    1988-01-01

    The study of stoichiometric constraints under equilibrium conditions provides us with the following information related to reburning as a NO reduction technology: (1) The stoichiometry of air to fuel is the most important stoichiometry of air to fuel is the most important stoichiometric variable for reburning; (2) based on equivalent energy production, the comparative reduction efficiencies of the reburning fuels follow the trend: methane > ethane, ammonia > butane > aromatics, coal > CO; (3) the nitrogen in burning coals causes increases in equilibrium NO; (4) equilibrium TFN is not very sensitive in inlet NO concentration; (5) the heat carried by the flue gas in reburning could push the NO reduction toward equilibrium. If so, reburning has a strong correlation with air staging with air preheat. Further experimental verification is required.

  18. Occupational airborne contamination in south Brazil: 1. Oxidative stress detected in the blood of coal miners.

    PubMed

    Avila Júnior, S; Possamai, F P; Budni, P; Backes, P; Parisotto, E B; Rizelio, V M; Torres, M A; Colepicolo, P; Wilhelm Filho, D

    2009-11-01

    Reactive oxygen species and nitrogen species have been implicated in the pathogenesis of coal dust-induced toxicity. The present study investigated several oxidative stress biomarkers (Contents of lipoperoxidation = TBARS, reduced = GSH, oxidized = GSSG and total glutathione = TG, alpha-tocopherol, and the activities of glutathione S-transferase = GST, glutathione reductase = GR, glutathione peroxidase = GPx, catalase = CAT and superoxide dismutase = SOD), in the blood of three different groups (n = 20 each) exposed to airborne contamination associated with coal mining activities: underground workers directly exposed, surface workers indirectly exposed, residents indirectly exposed (subjects living near the mines), and controls (non-exposed subjects). Plasma TBARS were increased and whole blood TG and GSH levels were decreased in all groups compared to controls. Plasma alpha-tocopherol contents showed approximately half the values in underground workers compared to controls. GST activity was induced in workers and also in residents at the vicinity of the mining plant, whilst CAT activity was induced only in mine workers. SOD activity was decreased in all groups examined, while GPx activity showed decreased values only in underground miners, and GR did not show any differences among the groups. The results showed that subjects directly and indirectly exposed to coal dusts face an oxidative stress condition. They also indicate that people living in the vicinity of the mine plant are in health risk regarding coal mining-related diseases.

  19. Studies of the effect of selected nondonor solvents on coal liquefaction yields

    SciTech Connect

    Jolley, R. L.; Rodgers, B. R.; Benjamin, B. M.; Poutsma, M. L.; Douglas, E. C.; McWhirter, D. A.

    1983-09-01

    The objective of this research program was to evaluate the effectiveness of selected nondonor solvents (i.e., solvents that are not generally considered to have hydrogen available for hydrogenolysis reactions) for the solubilization of coals. Principal criteria for selection of candidate solvents were that the compound should be representative of a major chemical class, should be present in reasonable concentration in coal liquid products, and should have the potential to participate in hydrogen redistribution reactions. Naphthalene, phenanthrene, pyrene, carbazole, phenanthridine, quinoline, 1-naphthol, and diphenyl ether were evaluated to determine their effect on coal liquefaction yields and were compared with phenol and two high-quality process solvents, Wilsonville SRC-I recycle solvent and Lummus ITSL heavy oil solvent. The high conversion efficacy of 1-naphthol may be attributed to its condensation to binaphthol and the consequent availability of hydrogen. The effectiveness of both the nitrogen heterocycles and the polycyclic aromatic hydrocarbon (PAH) compounds may be due to their polycyclic aromatic nature (i.e., possible hydrogen shuttling or transfer agents) and their physical solvent properties. The relative effectiveness for coal conversion of the Lummus ITSL heavy oil solvent as compared with the Wilsonville SRC-I process solvent may be attributed to the much higher concentration of 3-, 4-, and 5-ring PAH and hydroaromatic constituents in Lummus solvent. The chemistry of coal liquefaction and the development of recycle, hydrogen donor, and nondonor solvents are reviewed. The experimental methodology for tubing-bomb tests is outlined, and experimental problem areas are discussed.

  20. Geochemistry of Selected Coal Samples from Sumatra, Kalimantan, Sulawesi, and Papua, Indonesia

    USGS Publications Warehouse

    Belkin, Harvey E.; Tewalt, Susan J.

    2007-01-01

    and ash (generally <1 and < 10 wt.%, respectively). Coal mining for both local use and for export has a very strong future in Indonesia although, at present, there are concerns about the strong need for a major revision in mining laws and foreign investment policies (Wahju, 2004; United States Embassy Jakarta, 2004). The World Coal Quality Inventory (WoCQI) program of the U.S. Geological Survey (Tewalt and others, 2005) is a cooperative project with about 50 countries (out of 70 coal-producing countries world-wide). The WoCQI initiative has collected and published extensive coal quality data from the world's largest coal producers and consumers. The important aspects of the WoCQI program are; (1) samples from active mines are collected, (2) the data have a high degree of internal consistency with a broad array of coal quality parameters, and (3) the data are linked to GIS and available through the world-wide-web. The coal quality parameters include proximate and ultimate analysis, sulfur forms, major-, minor-, and trace-element concentrations and various technological tests. This report contains geochemical data from a selected group of Indonesian coal samples from a range of coal types, localities, and ages collected for the WoCQI program.

  1. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, March 31, 1993

    SciTech Connect

    Doyle, F.M.

    1993-04-01

    During the tenth quarter, electrochemical experiments were done on electrodes prepared from Upper Freeport coal pyrite, and Pittsburgh coal pyrite samples provided by the US Bureau of Mines, Pittsburgh Research Center, Pennsylvania. Electrokinetic tests were done on Upper Freeport and Pittsburgh coal pyrite. In addition, surface area measurements were done on Upper Freeport and Upper Clarion coals.

  2. Selective batch crushing in the coal-preparation shop at OAO NTMK

    SciTech Connect

    N.A. Berkutov; Yu.V. Stepanov; P.V. Shtark; L.A. Makhortova; N.K. Popova; D.A. Koshkarov; N.V. Tsarev

    2007-05-15

    In September 2004, after reconstruction at OAO Nizhnetagil'skii Metallurgicheskii Kombinat (NTMK), blast furnace 6 went into operation for the production of vanadium from hot metal. At the startup of furnace 6, besides optimising its composition; it was decided to restore selective crushing of the coal batch using pneumatic and mechanical separation in the third unit of the coal preparation shop. Additional increase in the mechanical strength of coke by 1.5-2.0% was predicted with a 0.5-1.0% decrease in wear.

  3. Effect of Coal Contaminants on Solid Oxide Fuel System Performance and Service Life

    SciTech Connect

    Gopala Krishnan; P. Jayaweera; J. Bao; J. Perez; K. H. Lau; M. Hornbostel; A. Sanjurjo; J. R. Albritton; R. P. Gupta

    2008-09-30

    The U.S. Department of Energy's SECA program envisions the development of high-efficiency, low-emission, CO{sub 2} sequestration-ready, and fuel-flexible technology to produce electricity from fossil fuels. One such technology is the integrated gasification-solid oxide fuel cell (SOFC) that produces electricity from the gas stream of a coal gasifier. SOFCs have high fuel-to-electricity conversion efficiency, environmental compatibility (low NO{sub x} production), and modularity. Naturally occurring coal has many impurities and some of these impurities end in the fuel gas stream either as a vapor or in the form of fine particulate matter. Establishing the tolerance limits of SOFCs for contaminants in the coal-derived gas will allow proper design of the fuel feed system that will not catastrophically damage the SOFC or allow long-term cumulative degradation. The anodes of Ni-cermet-based SOFCs are vulnerable to degradation in the presence of contaminants that are expected to be present in a coal-derived fuel gas stream. Whereas the effects of some contaminants such as H{sub 2}S, NH{sub 3} and HCl have been studied, the effects of other contaminants such as As, P, and Hg have not been ascertained. The primary objective of this study was to determine the sensitivity of the performance of solid oxide fuel cells to trace level contaminants present in a coal-derived gas stream in the temperature range 700 to 900 C. The results were used to assess catastrophic damage risk and long-term cumulative effects of the trace contaminants on the lifetime expectancy of SOFC systems fed with coal-derived gas streams.

  4. Surface properties of photo-oxidized bituminous coals. Technical progress report, July--September 1995

    SciTech Connect

    Mitchell, G.; Polat, H.; Davis, A.; Chander, S.

    1995-11-01

    During this report period, a new whole-seam channel sample (Ohio {number_sign}4a) was collected and analyzed, together with the Upper Banner and Splash Dam samples obtained last quarter. These additions bring to seven the number of coals obtained for this project and that range in rank from hvCb to mvb. Polished blocks of each coal containing 3-4 mm wide vitrain bands were prepared for contact angle measurements of fresh and photo-oxidized surfaces. An advancing-drop technique was used to measure contact angle. In this test a droplet of distilled water is grown initially on fresh surfaces and then moved across those irradiated in blue-light for 1, 5, and 10 minutes. The sequence of growth was recorded on video tape, and the change in contact angle measured relative to position at the air/water/surface interface. Contact angles were measured on five of the coals collected for this study, namely the Illinois {number_sign}6, Ohio {number_sign}4a, Lower Kittanning (PSOC-1563), Pittsburgh and Splash Dam seams. Preliminary results show that both coal rank and irradiation time influence surface wettability as measured by contact angle. With one exception, contact angle values decreased and remained low when the droplet advanced into an irradiated area. In most cases, one minute of irradiation resulted in only a slight decrease in contact angle, whereas after 5 and 10 minutes a more significant decrease was observed. The magnitude of change in contact angle values with degree of photo-oxidation decreased as rank increased, such that lower rank bituminous coals show the greatest change and medium volatile coal the least.

  5. A Sensor System Based on Semi-Conductor Metal Oxide Technology for In Situ Detection of Coal Fired Combustion Gases

    SciTech Connect

    Brent Marquis

    2007-05-31

    Sensor Research and Development Corporation (SRD) proposed a two-phase program to develop a robust, autonomous prototype analyzer for in situ, real-time detection, identification, and measurement of coal-fired combustion gases and perform field-testing at an approved power generation facility. SRD developed and selected sensor materials showing selective responses to carbon monoxide, carbon dioxide, nitric oxide, nitrogen dioxide, ammonia, sulfur dioxide and hydrogen chloride. Sensor support electronics were also developed to enable prototype to function in elevated temperatures without any issues. Field-testing at DOE approved facility showed the ability of the prototype to detect and estimate the concentration of combustion by-products accurately with relatively low false-alarm rates at very fast sampling intervals.

  6. Selected coal-related ground-water data, Wasatch Plateau-Book Cliffs area, Utah

    USGS Publications Warehouse

    Sumsion, C.T.

    1979-01-01

    The Wasatch Plateau-Book Cliffs area in east-central Utah consists of about 8,000 square miles within the upper Colorado River drainage system. Coal production in the area is expected to increase from 8 million tons to as much as 30 million tons annually within the next 10 years. Most sources of water supply will be subjected to possible contamination and increased demands by coal-related municipal and industrial growth in the area. The report presents a compilation of coal-related ground-water data from many unpublished sources for the use of local and regional water planners and users. The report includes generalized stratigraphic sections and hydrologic characteristics of rocks in the Wasatch Plateau-Book Cliffs area , records of selected test holes and water wells, logs of selected test holes and water wells, water levels in selected wells, records of selected springs, records of ground-water discharge from selected mines, and chemical analyses of water from selected test holes, water wells, springs, and mines. (Kosco-USGS)

  7. Significance of RuO2 modified SCR catalyst for elemental mercury oxidation in coal-fired flue gas.

    PubMed

    Yan, Naiqiang; Chen, Wanmiao; Chen, Jie; Qu, Zan; Guo, Yongfu; Yang, Shijian; Jia, Jinping

    2011-07-01

    Catalytic conversion of elemental mercury (Hg(0)) to its oxidized form has been considered as an effective way to enhance mercury removal from coal-fired power plants. In order to make good use of the existing selective catalytic reduction of NO(x) (SCR) catalysts as a cobenefit of Hg(0) conversion at lower level HCl in flue gas, various catalysts supported on titanium dioxide (TiO(2)) and commercial SCR catalysts were investigated at various cases. Among the tested catalysts, ruthenium oxides (RuO(2)) not only showed rather high catalytic activity on Hg(0) oxidation by itself, but also appeared to be well cooperative with the commercial SCR catalyst for Hg(0) conversion. In addition, the modified SCR catalyst with RuO(2) displayed an excellent tolerance to SO(2) and ammonia without any distinct negative effects on NO(x) reduction and SO(2) conversion. The demanded HCl concentration for Hg(0) oxidation can be reduced dramatically, and Hg(0) oxidation efficiency over RuO(2) doped SCR catalyst was over 90% even at about 5 ppm HCl in the simulated gases. Ru modified SCR catalyst shows a promising prospect for the cobenefit of mercury emission control.

  8. Catalysts for the selective oxidation of hydrogen sulfide to sulfur

    DOEpatents

    Srinivas, Girish; Bai, Chuansheng

    2000-08-08

    This invention provides catalysts for the oxidation of hydrogen sulfide. In particular, the invention provides catalysts for the partial oxidation of hydrogen sulfide to elemental sulfur and water. The catalytically active component of the catalyst comprises a mixture of metal oxides containing titanium oxide and one or more metal oxides which can be selected from the group of metal oxides or mixtures of metal oxides of transition metals or lanthanide metals. Preferred metal oxides for combination with TiO.sub.2 in the catalysts of this invention include oxides of V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Tc, Ru, Rh, Hf, Ta, W, Au, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Catalysts which comprise a homogeneous mixture of titanium oxide and niobium (Nb) oxide are also provided. A preferred method for preparing the precursor homogenous mixture of metal hydroxides is by coprecipitation of titanium hydroxide with one or more other selected metal hydroxides. Catalysts of this invention have improved activity and/or selectivity for elemental sulfur production. Further improvements of activity and/or selectivity can be obtained by introducing relatively low amounts (up to about 5 mol %)of a promoter metal oxide (preferably of metals other than titanium and that of the selected second metal oxide) into the homogeneous metal/titanium oxide catalysts of this invention.

  9. Process for selected gas oxide removal by radiofrequency catalysts

    DOEpatents

    Cha, Chang Y.

    1993-01-01

    This process to remove gas oxides from flue gas utilizes adsorption on a char bed subsequently followed by radiofrequency catalysis enhancing such removal through selected reactions. Common gas oxides include SO.sub.2 and NO.sub.x.

  10. Process and analytical studies of enhanced low severity co-processing using selective coal pretreatment. Final technical report

    SciTech Connect

    Baldwin, R.M.; Miller, R.L.

    1991-12-01

    The findings in the first phase were as follows: 1. Both reductive (non-selective) alkylation and selective oxygen alkylation brought about an increase in liquefaction reactivity for both coals. 2. Selective oxygen alkylation is more effective in enhancing the reactivity of low rank coals. In the second phase of studies, the major findings were as follows: 1. Liquefaction reactivity increases with increasing level of alkylation for both hydroliquefaction and co-processing reaction conditions. 2. the increase in reactivity found for O-alkylated Wyodak subbituminous coal is caused by chemical changes at phenolic and carboxylic functional sites. 3. O-methylation of Wyodak subbituminous coal reduced the apparent activation energy for liquefaction of this coal.

  11. Quartz in coal dust deposited on internal surface of respirable size selective samplers.

    PubMed

    Soo, Jhy-Charm; Lee, Taekhee; Kashon, Michael; Kusti, Mohannad; Harper, Martin

    2014-01-01

    The objective of the present study is to quantify quartz mass in coal dust deposited on the internal cassette surface of respirable size-selective samplers. Coal dust was collected with four different respirable size-selective samplers (10 mm Dorr-Oliver nylon [Sensidyne, St. Petersburg, Fla.], SKC Aluminum [SKC Inc., Eighty Four, Pa.], BGI4L [BGI USA Inc., Waltham, Mass.], and GK2.69 cyclones [BGI USA Inc.]) with two different cassette types (polystyrene and static-dissipative polypropylene cassettes). The coal dust was aerosolized in a calm air chamber by using a fluidized bed aerosol generator without neutralization under the assumption that the procedure is similar to field sampling conditions. The mass of coal dust was measured gravimetrically and quartz mass was determined by Fourier transform infrared spectroscopy according to the National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods, Method 7603. The mass fractions of the total quartz sample on the internal cassette surface are significantly different between polystyrene and static-dissipative cassettes for all cyclones (p < 0.05). No consistent relationship between quartz mass on cassette internal surface and coal dust filter mass was observed. The BGI4L cyclone showed a higher (but not significantly) and the GK2.69 cyclone showed a significantly lower (p < 0.05) internal surface deposit quartz mass fraction for polystyrene cassettes compared to other cyclones. This study confirms previous observations that the interior surface deposits in polystyrene cassettes attached to cyclone pre-selectors can be a substantial part of the sample, and therefore need to be included in any analysis for accurate exposure assessment. On the other hand, the research presented here supports the position that the internal surface deposits in static-dissipative cassettes used with size-selective cyclones are negligible and that it is only necessary to analyze the filter catch.

  12. Durable zinc oxide-containing sorbents for coal gas desulfurization

    DOEpatents

    Siriwardane, Ranjani V.

    1996-01-01

    Durable zinc-oxide containing sorbent pellets for removing hydrogen sulfide from a gas stream at an elevated temperature are made up to contain titania as a diluent, high-surface-area silica gel, and a binder. These materials are mixed, moistened, and formed into pellets, which are then dried and calcined. The resulting pellets undergo repeated cycles of sulfidation and regeneration without loss of reactivity and without mechanical degradation. Regeneration of the pellets is carried out by contacting the bed with an oxidizing gas mixture.

  13. KINETICS OF DIRECT OXIDATION OF H2S IN COAL GAS TO ELEMENTAL SULFUR

    SciTech Connect

    K.C. Kwon

    2005-01-01

    The direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and the hot-gas desulfurization using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process. The objective of this research is to support the near- and long-term process development efforts to commercialize this direct oxidation technology. The objectives of this research are to measure kinetics of direct oxidation of H{sub 2}S to elemental sulfur in the presence of a simulated coal gas mixture containing SO{sub 2}, H{sub 2}, and moisture, using 160-{micro}m C-500-04 alumina catalyst particles and a micro bubble reactor, and to develop kinetic rate equations and model the direct oxidation process to assist in the design of large-scale plants. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. To achieve the above-mentioned objectives, experiments on conversion of hydrogen sulfide into liquid elemental sulfur were carried out for the space time range of 0.059-0.87 seconds at 125-155 C to evaluate effects of reaction temperature, H{sub 2}S concentration, reaction pressure, and catalyst loading on conversion of hydrogen sulfide into liquid elemental sulfur. Simulated coal gas mixtures consist of 62-78 v% hydrogen, 3,000-7,000-ppmv hydrogen sulfide, 1,500-3,500 ppmv sulfur dioxide, and 10 vol % moisture, and nitrogen as remainder. Volumetric feed rates of a simulated coal gas mixture to a micro bubble reactor are 50 cm{sup 3}/min at room temperature and atmospheric pressure. The temperature of the reactor is controlled in an

  14. KINETICS OF DIRECT OXIDATION OF H2S IN COAL GAS TO ELEMENTAL SULFUR

    SciTech Connect

    K.C. Kwon

    2004-01-01

    The direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and the hot-gas desulfurization using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process. The objective of this research is to support the near- and long-term process development efforts to commercialize this direct oxidation technology. The objectives of this research are to measure kinetics of direct oxidation of H{sub 2}S to elemental sulfur in the presence of a simulated coal gas mixture containing SO{sub 2}, H{sub 2}, and moisture, using 160-{micro}m C-500-04 alumina catalyst particles and a micro bubble reactor, and to develop kinetic rate equations and model the direct oxidation process to assist in the design of large-scale plants. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. To achieve the above-mentioned objectives, experiments on conversion of hydrogen sulfide into liquid elemental sulfur were carried out for the space time range of 1-6 milliseconds at 125-155 C to evaluate effects of reaction temperature, moisture concentration, reaction pressure on conversion of hydrogen sulfide into liquid elemental sulfur. Simulated coal gas mixtures consist of 70 v% hydrogen, 2,500-7,500-ppmv hydrogen sulfide, 1,250-3,750 ppmv sulfur dioxide, and 0-15 vol% moisture, and nitrogen as remainder. Volumetric feed rates of a simulated coal gas mixture to a micro bubble reactor are 100 cm{sup 3}/min at room temperature and atmospheric pressure. The temperature of the reactor is controlled in an oven at 125-155 C. The

  15. The mechanism of coal gas desulfurization by iron oxide sorbents.

    PubMed

    Lin, Yi-Hsing; Chen, Yen-Chiao; Chu, Hsin

    2015-02-01

    This study aims to understand the roles of hydrogen and carbon monoxide during the desulfurization process in a coal gasification system that H2S of the syngas was removed by Fe2O3/SiO2 sorbents. The Fe2O3/SiO2 sorbents were prepared by incipient wetness impregnation. Through the breakthrough experiments and Fourier transform infrared spectroscopy analyses, the overall desulfurization mechanism of the Fe2O3/SiO2 sorbents was proposed in this study. The results show that the major reaction route is that Fe2O3 reacts with H2S to form FeS, and the existence of CO and H2 in the simulated gas significantly affects equilibrium concentrations of H2S and COS. The formation of COS occurs when the feeding gas is blended with CO and H2S, or CO2 and H2S. The pathways in the formation of products from the desulfurization process by the reaction of Fe2O3 with H2S have been successfully established.

  16. Enhanced Oxidative Reactivity for Anthracite Coal via a Reactive Ball Milling Pretreatment Step

    SciTech Connect

    Angela D. Lueking; Apurba Sakti; Dania Alvarez-Fonseca; Nichole Wonderling

    2009-09-15

    Reactive ball milling in a cyclohexene solvent significantly increases the oxidative reactivity of an anthracite coal, due to the combined effects of particle size reduction, metal introduction, introduction of volatile matter, and changes in carbon structure. Metals introduced during milling can be easily removed via a subsequent demineralization process, and the increased reactivity is retained. Solvent addition alters the morphological changes that occur during pyrolysis and leads to a char with significantly increased reactivity. When the solvent is omitted, similar effects are seen for the milled product, but a significant fraction of the char is resistant to oxidation. 33 refs., 3 figs., 1 tab.

  17. Ethylene/propylene oxide block copolymer interfacial phenomena in relation to coal cleaning by advanced flotation methods

    SciTech Connect

    McCloy, J.L.; Chander, S.

    1995-12-01

    Surface tension of aqueous ethylene/propylene oxide (EO/PO) block copolymer reagents were measured to understand their role in advanced coal flotation. Coal flotation is one of the most promising methods for separating the combustible matter in coal from ash forming minerals. The use of EO/PO block copolymer reagents enhances the rejection of ash minerals during coal flotation procedures. Since the mechanism whereby this enhancement is achieved is not known very well, an investigation of the surface tension characteristics of EO/PO block copolymer reagents was performed at various concentrations. Data obtained were used to compute adsorption densities at the liquid/gas interface. The adsorption characteristics of nine different EO/PO block copolymers were determined to examine the effect of percent ethylene oxide and formula weight. These studies predict that flotation experiments are most efficient when surfactants with low ethylene oxide percentages are utilized.

  18. Enzymatic desulfurization of coal

    SciTech Connect

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V.

    1991-05-16

    The overall objective of this program was to investigate the feasibility of an enzymatic desulfurization process specifically intended for organic sulfur removal from coal. Toward that end, a series of specific objectives were defined: (1) establish the feasibility of (bio)oxidative pretreatment followed by biochemical sulfate cleavage for representative sulfur-containing model compounds and coals using commercially-available enzymes; (2) investigate the potential for the isolation and selective use of enzyme preparations from coal-utilizing microbial systems for desulfurization of sulfur-containing model compounds and coals; and (3) develop a conceptual design and economic analysis of a process for enzymatic removal of organic sulfur from coal. Within the scope of this program, it was proposed to carry out a portion of each of these efforts concurrently. (VC)

  19. Blood anti-oxidant parameters at different stages of pneumoconiosis in coal workers.

    PubMed

    Engelen, J J; Borm, P J; van Sprundel, M; Leenaerts, L

    1990-03-01

    The pneumoconioses are associated with chronic inflammatory processes during which increased amounts of reactive oxygen species are formed in the lower respiratory tract. To characterize the effect(s) of these processes on the defense system against free radicals, we studied 91 individuals with long-term occupational exposure to coal mine dust. Thirty-one subjects were classified with radiological evidence to be pneumoconiotics, while 58 control miners had no pulmonary disorders. We measured antioxidant parameters in red blood cells, considering the latter to reflect the oxidative stress in the lung. Glutathione levels were significantly decreased (p = 0.04) in red blood cells of miners with coal workers' pneumoconiosis with radiograph classification 0/1 to 2/1, while in miners with classification 3/2 to 3/3, the plasma iron concentrations were significantly decreased (p = 0.04). Moreover, some factors of the anti-oxidant system (superoxide dismutase, catalase, glutathione peroxidase) were correlated in the diseased but not in the control miners. Taken together, all data support the role of the erythrocyte as a circulating anti-oxidant carrier and also that changes in red blood cell anti-oxidant factors reflect the oxidative stress imposed by the pneumoconiotic (inflammatory) processes in the lung.

  20. Blood anti-oxidant parameters at different stages of pneumoconiosis in coal workers.

    PubMed Central

    Engelen, J J; Borm, P J; van Sprundel, M; Leenaerts, L

    1990-01-01

    The pneumoconioses are associated with chronic inflammatory processes during which increased amounts of reactive oxygen species are formed in the lower respiratory tract. To characterize the effect(s) of these processes on the defense system against free radicals, we studied 91 individuals with long-term occupational exposure to coal mine dust. Thirty-one subjects were classified with radiological evidence to be pneumoconiotics, while 58 control miners had no pulmonary disorders. We measured antioxidant parameters in red blood cells, considering the latter to reflect the oxidative stress in the lung. Glutathione levels were significantly decreased (p = 0.04) in red blood cells of miners with coal workers' pneumoconiosis with radiograph classification 0/1 to 2/1, while in miners with classification 3/2 to 3/3, the plasma iron concentrations were significantly decreased (p = 0.04). Moreover, some factors of the anti-oxidant system (superoxide dismutase, catalase, glutathione peroxidase) were correlated in the diseased but not in the control miners. Taken together, all data support the role of the erythrocyte as a circulating anti-oxidant carrier and also that changes in red blood cell anti-oxidant factors reflect the oxidative stress imposed by the pneumoconiotic (inflammatory) processes in the lung. PMID:2351120

  1. Performance of solid oxide fuel cells operaated with coal syngas provided directly from a gasification process

    SciTech Connect

    Hackett, G.; Gerdes, K.; Song, X.; Chen, Y.; Shutthanandan, V.; Englehard, M.; Zhu, Z.; Thevuthasan, S.; Gemmen, R.

    2012-01-01

    Solid oxide fuel cells (SOFCs) are being developed for integrated gasification power plants that generate electricity from coal at 50% efficiency. The interaction of trace metals in coal syngas with Ni-based SOFC anodes is being investigated through thermodynamic analyses and in laboratory experiments, but test data from direct coal syngas exposure are sparsely available. This effort evaluates the significance of performance losses associated with exposure to direct coal syngas. Specimen are operated in a unique mobile test skid that is deployed to the research gasifier at NCCC in Wilsonville, AL. The test skid interfaces with a gasifier slipstream to deliver hot syngas to a parallel array of twelve SOFCs. During the 500 h test period, all twelve cells are monitored for performance at four current densities. Degradation is attributed to syngas exposure and trace material attack on the anode structure that is accelerated at increasing current densities. Cells that are operated at 0 and 125 mA cm{sup 2} degrade at 9.1 and 10.7% per 1000 h, respectively, while cells operated at 250 and 375 mA cm{sup 2} degrade at 18.9 and 16.2% per 1000 h, respectively. Spectroscopic analysis of the anodes showed carbon, sulfur, and phosphorus deposits; no secondary Ni-metal phases were found.

  2. Performance of solid oxide fuel cells operated with coal syngas provided directly from a gasification process

    NASA Astrophysics Data System (ADS)

    Hackett, Gregory A.; Gerdes, Kirk; Song, Xueyan; Chen, Yun; Shutthanandan, Vaithiyalingam; Engelhard, Mark; Zhu, Zihua; Thevuthasan, Suntharampillai; Gemmen, Randall

    2012-09-01

    Solid oxide fuel cells (SOFCs) are being developed for integrated gasification power plants that generate electricity from coal at 50+% efficiency. The interaction of trace metals in coal syngas with Ni-based SOFC anodes is being investigated through thermodynamic analyses and in laboratory experiments, but test data from direct coal syngas exposure are sparsely available. This effort evaluates the significance of performance losses associated with exposure to direct coal syngas. Specimen are operated in a unique mobile test skid that is deployed to the research gasifier at NCCC in Wilsonville, AL. The test skid interfaces with a gasifier slipstream to deliver hot syngas to a parallel array of twelve SOFCs. During the 500 h test period, all twelve cells are monitored for performance at four current densities. Degradation is attributed to syngas exposure and trace material attack on the anode structure that is accelerated at increasing current densities. Cells that are operated at 0 and 125 mA cm-2 degrade at 9.1 and 10.7% per 1000 h, respectively, while cells operated at 250 and 375 mA cm-2 degrade at 18.9 and 16.2% per 1000 h, respectively. Spectroscopic analysis of the anodes showed carbon, sulfur, and phosphorus deposits; no secondary Ni-metal phases were found.

  3. Fuel nitrogen conversion and release of nitrogen oxides during coal gangue calcination.

    PubMed

    Zhang, Yingyi; Ge, Xinlei; Liu, Lili; Wang, Xidong; Zhang, Zuotai

    2015-05-01

    The pollution emission during the widespread utilization of coal gangue in construction industry has long been neglected. In present study, the NO x release behaviors in a simulation experiment of coal gangue calcination in construction industry were systematically investigated. The corresponding evolution of nitrogen functionalities in coal gangue was also discussed. Results showed that pyrrolic (N-5) and pyridine N-oxide (N-6-O) forms nitrogen were relatively abundant in the raw gangue. During calcination, the N-5 and N-6-O form nitrogen greatly decreased and converted to quaternary nitrogen (N-Q). It was found that NO2 was formed under slowly heating-up condition and at 600 °C under isothermal condition, while only NO was detected with further increase of temperature. From 600 to 1000 °C, the conversion ratio of fuel nitrogen to NO x increased from 8 to 12 %. The char nitrogen was found greatly contribute to NO formation, which may bring difficulty to the abatement of NO x emission during coal gangue calcination.

  4. Effect of coal ash on growth and metal uptake by some selected ectomycorrhizal fungi in vitro

    SciTech Connect

    Ray, P.; Reddy, U.G.; Lapeyrie, F.; Adholeya, A.

    2005-07-01

    Six isolates of ectomycorrhizal fungi namely, Laccaria fraterna (EM-1083), Pisolithus tinctorius (EM-1081), Pisolithus tinctorius (EM-1290), Pisolithus tinctorius (EM-1293), Scleroderma verucosurn (EM-1283), and Scleroderma cepa (EM-1233), were grown on three variants of coal ash, namely electrostatically precipitated (ESP) ash, pond ash, and bottom ash moistened with Modified Melin-Norkans (MMN) medium in vitro. The colony diameter reflected the growth of the isolates on the coal ash. Metal accumulation in the mycelia was assayed by atomic absorption spectrophotometry. Six metals, namely aluminum, cadmium, chromium, iron, lead, and nickel were selected on the basis of their abundance in coal ash and toxicity potential for the present work. Growth of vegetative mycelium on fly ash variants and metal accumulation data indicated that Pisolithus tinctorius (EM-1290) was the most tolerant among the isolates tested for most of the metals. Since this isolate is known to be mycorrhizal with Eucalyptus, it could be used for the reclamation of coal ash over burdened sites.

  5. Enrichment and characteristics of mixed methane-oxidizing bacteria from a Chinese coal mine.

    PubMed

    Jiang, Hao; Duan, Changhong; Luo, Mingfang; Xing, Xin-Hui

    2016-12-01

    In methane-rich environments, methane-oxidizing bacteria usually occur predominantly among consortia including other types of microorganisms. In this study, artificial coal bed gas and methane gas were used to enrich mixed methanotrophic cultures from the soil of a coal mine in China, respectively. The changes in microbial community structure and function during the enrichment were examined. The microbial diversity was reduced as the enrichment proceeded, while the capacity for methane oxidation was significantly enhanced by the increased abundance of methanotrophs. The proportion of type II methanotrophs increased greatly from 7.84 % in the sampled soil to about 50 % in the enrichment cultures, due to the increase of methane concentration. After the microbial community of the cultures got stable, Methylomonas and Methylocystis became the dominant type I and type II methanotrophs, while Methylophilus was the prevailing methylotroph. The sequences affiliated with pigment-producing strains, Methylomonas rubra, Hydrogenophaga sp. AH-24, and Flavobacterium cucumis, could explain the orange appearance of the cultures. Comparing the two cultures, the multi-carbon sources in the artificial coal bed gas caused more variety of non-methanotrophic bacteria, but did not help to maintain the diversity or to increase the quantity and activity of methanotrophs. The results could help to understand the succession and interaction of microbial community in a methane-driven ecosystem.

  6. Selective Oxidation of Benzene to Phenol. Final Report

    SciTech Connect

    Sherif, F.; Kung, H.; Marshall, C.

    2000-09-30

    Direct catalytic oxidation of commodity aromatics to phenolic compounds was studied by a team from Akzo Nobel Chemicals, Argonne National Lab., and Northwestern University. Results did not exceed previously published performance. The object of the project was to selectively oxidize benzene to phenol using a conventional oxidant.

  7. OXIDATION OF MERCURY ACROSS SCR CATALYSTS IN COAL-FIRED POWER PLANTS BURNING LOW RANK FUELS

    SciTech Connect

    Constance Senior

    2004-12-31

    The objectives of this program were to measure the oxidation of mercury in flue gas across SCR catalyst in a coal-fired power plant burning low rank fuels using a slipstream reactor containing multiple commercial catalysts in parallel and to develop a greater understanding of mercury oxidation across SCR catalysts in the form of a simple model. The Electric Power Research Institute (EPRI) and Argillon GmbH provided co-funding for this program. REI used a multicatalyst slipstream reactor to determine oxidation of mercury across five commercial SCR catalysts at a power plant that burned a blend of 87% subbituminous coal and 13% bituminous coal. The chlorine content of the blend was 100 to 240 {micro}g/g on a dry basis. Mercury measurements were carried out when the catalysts were relatively new, corresponding to about 300 hours of operation and again after 2,200 hours of operation. NO{sub x}, O{sub 2} and gaseous mercury speciation at the inlet and at the outlet of each catalyst chamber were measured. In general, the catalysts all appeared capable of achieving about 90% NO{sub x} reduction at a space velocity of 3,000 hr{sup -1} when new, which is typical of full-scale installations; after 2,200 hours exposure to flue gas, some of the catalysts appeared to lose NO{sub x} activity. For the fresh commercial catalysts, oxidation of mercury was in the range of 25% to 65% at typical full-scale space velocities. A blank monolith showed no oxidation of mercury under any conditions. All catalysts showed higher mercury oxidation without ammonia, consistent with full-scale measurements. After exposure to flue gas for 2,200 hours, some of the catalysts showed reduced levels of mercury oxidation relative to the initial levels of oxidation. A model of Hg oxidation across SCRs was formulated based on full-scale data. The model took into account the effects of temperature, space velocity, catalyst type and HCl concentration in the flue gas.

  8. Co-Al mixed metal oxides/carbon nanotubes nanocomposite prepared via a precursor route and enhanced catalytic property

    SciTech Connect

    Fan Guoli; Wang Hui; Xiang Xu; Li Feng

    2013-01-15

    The present work reported the synthesis of Co-Al mixed metal oxides/carbon nanotubes (CoAl-MMO/CNT) nanocomposite from Co-Al layered double hydroxide/CNTs composite precursor (CoAl-LDH/CNT). The materials were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), low temperature nitrogen adsorption-desorption experiments, thermogravimetric and differential thermal analyses (TG-DTA), Raman spectra and X-ray photoelectron spectroscopy (XPS). The results revealed that in CoAl-MMO/CNT nanocomposite, the nanoparticles of cobalt oxide (CoO) and Co-containing spinel-type complex metal oxides could be well-dispersed on the surface of CNTs, thus forming the heterostructure of CoAl-MMO and CNTs. Furthermore, as-synthesized CoAl-MMO/CNT nanocomposite was utilized as additives for catalytic thermal decomposition of ammonium perchlorate (AP). Compared to those for pure AP and CoAl-MMO, the peak temperature of AP decomposition for CoAl-MMO/CNT was significantly decreased, which is attributed to the novel heterostructure and synergistic effect of multi-component metal oxides of nanocomposite. - Graphical abstract: Hybrid Co-Al mixed metal oxides/carbon nanotubes nanocomposite showed the enhanced catalytic activity in the thermal decomposition of ammonium perchlorate, as compared to carbon nanotubes and pure Co-Al mixed metal oxides. Highlights: Black-Right-Pointing-Pointer Co-Al mixed metal oxides/carbon nanotubes nanocomposite was synthesized. Black-Right-Pointing-Pointer Co-Al mixed metal oxides consisted of cobalt oxide and Co-containing spinels. Black-Right-Pointing-Pointer Nanocomposite exhibited excellent catalytic activity for the decomposition of AP. Black-Right-Pointing-Pointer The superior catalytic property is related to novel heterostructure and composition.

  9. The oxidative potential of PM10 from coal, briquettes and wood charcoal burnt in an experimental domestic stove

    NASA Astrophysics Data System (ADS)

    Shao, Longyi; Hou, Cong; Geng, Chunmei; Liu, Junxia; Hu, Ying; Wang, Jing; Jones, Tim; Zhao, Chengmei; BéruBé, Kelly

    2016-02-01

    Coal contains many potentially harmful trace elements. Coal combustion in unvented stoves, which is common in most parts of rural China, can release harmful emissions into the air that when inhaled cause health issues. However, few studies have dealt specifically with the toxicological mechanisms of the particulate matter (PM) released by coal and other solid fuel combustion. In this paper, PM10 particles that were generated during laboratory stove combustion of raw powdered coal, clay-mixed honeycomb briquettes, and wood charcoal were analysed for morphology, trace element compositions, and toxicity as represented by oxidative DNA damage. The analyses included Field Emission Scanning Electron Microscopy (FESEM), Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Plasmid Scission Assay (PSA). Gravimetric analysis indicated that the equivalent mass concentration of PM10 emitted by burning raw powdered coal was higher than that derived by burning honeycomb briquette. FESEM observation revealed that the coal burning-derived PM10 particles were mainly soot aggregates. The PSA results showed that the PM10 emitted by burning honeycomb briquettes had a higher oxidative capacity than that from burning raw powdered coal and wood charcoal. It is also demonstrated that the oxidative capacity of the whole particle suspensions were similar to those of the water soluble fractions; indicating that the DNA damage induced by coal burning-derived PM10 were mainly a result of the water-soluble fraction. An ICP-MS analysis revealed that the amount of total analysed water-soluble elements in the PM10 emitted by burning honeycomb briquettes was higher than that in PM produced by burning raw powdered coal, and both were higher than PM from burning wood charcoal. The total analysed water-soluble elements in these coal burning-derived PM10 samples had a significantly positive correlation with the level of DNA damage; indicating that the oxidative capacity of the coal burning

  10. OXIDATION OF MERCURY ACROSS SCR CATALYSTS IN COAL-FIRED POWER PLANTS BURNING LOW RANK FUELS

    SciTech Connect

    Constance Senior; Temi Linjewile

    2003-07-25

    This is the first Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-03NT41728. The objective of this program is to measure the oxidation of mercury in flue gas across SCR catalyst in a coal-fired power plant burning low rank fuels using a slipstream reactor containing multiple commercial catalysts in parallel. The Electric Power Research Institute (EPRI) and Ceramics GmbH are providing co-funding for this program. This program contains multiple tasks and good progress is being made on all fronts. During this quarter, analysis of the coal, ash and mercury speciation data from the first test series was completed. Good agreement was shown between different methods of measuring mercury in the flue gas: Ontario Hydro, semi-continuous emission monitor (SCEM) and coal composition. There was a loss of total mercury across the commercial catalysts, but not across the blank monolith. The blank monolith showed no oxidation. The data from the first test series show the same trend in mercury oxidation as a function of space velocity that has been seen elsewhere. At space velocities in the range of 6,000-7,000 hr{sup -1} the blank monolith did not show any mercury oxidation, with or without ammonia present. Two of the commercial catalysts clearly showed an effect of ammonia. Two other commercial catalysts showed an effect of ammonia, although the error bars for the no-ammonia case are large. A test plan was written for the second test series and is being reviewed.

  11. Surface properties of photo-oxidized bituminous coals. Technical progress report, January--March 1996

    SciTech Connect

    Mitchell, G.; Davis, A.; Chander, S.

    1996-12-31

    During this report period, a vitrinite concentrate from the mvb Splash Dam seam (DECS-30) was prepared and analyzed. Results show that the concentrate was 91 vol % vitrinite and that the sample has been adequately protected from oxidation under refrigerated storage in argon. The 9% level of contamination within the vitrinite resulted from the extreme friability of the coal and to the dispersion of fine grains of semifusinite and micrinite. Polished blocks containing vitrain bands that were prepared, irradiated in blue-light and employed in contact angle measurements were evaluated using specular reflectance-mode FT-IR for changes in functional group chemistry. Infrared spectra from unexposed areas of vitrinite and those irradiated for 1, 5 and 10 min for six coals ranging in rank from hvCb to mvb were obtained using a FTS 175 spectrometer with a Bio-Rad UMA 500 microscope accessory. Preliminary results demonstrate that photo-oxidation occurred during irradiation, becoming progressively more intense with increasing irradiation time; however, the magnitude of this change diminished with increasing rank. A relatively steady increase in the carbonyl region (1,800--1,650 cm{sup {minus}1}) and a decrease in the aliphatic region (2,950--2,850 cm{sup {minus}1}) of the spectra supports this observation and is similar to observations made in the past for natural weathering and laboratory oxidation of coals. A series of tests was initiated to photo-oxidize powdered vitrains using the BLAK-RAY ultraviolet lamp evaluated last quarter. Samples of four vitrinite concentrates were exposed to UV light for 10 mins per side. These and the corresponding whole-seam channel samples and raw vitrinite concentrates were submitted for initial microflotation tests which have not been completed at this time.

  12. Molybdenum-based additives to mixed-metal oxides for use in hot gas cleanup sorbents for the catalytic decomposition of ammonia in coal gases

    DOEpatents

    Ayala, Raul E.

    1993-01-01

    This invention relates to additives to mixed-metal oxides that act simultaneously as sorbents and catalysts in cleanup systems for hot coal gases. Such additives of this type, generally, act as a sorbent to remove sulfur from the coal gases while substantially simultaneously, catalytically decomposing appreciable amounts of ammonia from the coal gases.

  13. Selective enrichment of phenols from coal liquefaction oil by solid phase extraction method

    SciTech Connect

    Tian, M.; Feng, J.

    2009-07-01

    This study focuses on the solid phase extraction method for the enrichment and separation of phenol from coal liquefaction oil. The phenols' separation efficiency was compared on different solid phase extraction (SPE) cartridges, and the effect of solvents with different polarity and solubility parameter on amino-bonded silica was compared for selection of optimal elution solution. The result showed that amino-bonded silica has the highest selectivity and best extraction capability due to two factors, weak anion exchange adsorption and polar attraction adsorption.

  14. Demonstration Of Selective Catalytic Reduction For The Control Of NOx Emissions From High-Sulfur Coal-Fired Boilers, Project Performance Summary. Clean Coal Demonstration Program

    SciTech Connect

    None, None

    2002-11-30

    This project is part of the U.S. Department of Energy's (DOE) Clean Coal Technology Demonstration Program (CCTDP) established to address energy and environmental concerns related to coal use. DOE sought cost-shared partnerships with industry through five nationally competed solicitations to accelerate commercialization of the most promising advanced coal-based power generation and pollution control technologies. The CCTDP, valued at over five billion dollars, has significantly leveraged federal funding by forging effective partnerships founded on sound principles. For every federal dollar invested, CCTDP participants have invested two dollars. These participants include utilities, technology developers, state governments, and research organizations. This project is one of 16 selected from 55 proposals submitted in response to the CCTDP's second solicitation. Southern Company Services, Inc. (Southern), a subsidiary of Southern Company, conducted the Demonstration of Selective Catalytic Reduction for the Control of NOx Emissions from High-Sulfur, Coal-Fired Boilers project. Gulf Power Company's Plant Crist provided the host site and the Electric Power Research Institute (EPRI) and Ontario Hydro co-funded the project and provided technical input. The project began in June 1990 and operational testing occurred between July 1993 and July 1995. In simplistic terms, the selective catalytic reduction (SCR) process consists of injecting ammonia (NH3) into boiler flue gas and passing the flue gas through a catalyst bed where the oxides of nitrogen (NOx) and NH3 react to form water vapor and nitrogen (an element that comprises 78 percent of air).

  15. Geochemical study of products associated with spontaneous oxidation of coal in the Cerro Pelado Formation, Venezuela

    NASA Astrophysics Data System (ADS)

    Martínez, M.; Márquez, G.; Alejandre, F. J.; Del Río, J. J.; Hurtado, A.

    2009-02-01

    The aim of this research work is a geochemical, mineralogical, and textural characterization of spontaneously smouldered coal-derived products in northwestern Venezuela (Cerro Pelado Formation, some 10 km from Pedregal city). Several solid samples were collected from this formation, six of unweathering coal, an other six of resulting unmelted rocks forming on a surface coal bed, and the last four of mineralizations found accumulating around gas vents. The fresh coal and the unmelted material were analysed by scanning electron microscopy, X-ray diffraction, and proximate techniques. Products such as magnetite and chabazite-K were identified in the alteration rocks. Likewise, both materials were also studied in order to determine the mobilization of 17 elements into the environment; such elements were analysed through inductively coupled plasma atomic emission spectroscopy on extracts obtained by a sequential extraction method: each sample was firstly extracted with MilliQ water and then the resultant residue was washed. This and the subsequently resulting residues are extracted according to the mentioned procedure by using, respectively, ammonium acetate, chlorhydric acid, peroxide and chlorhydric acid, nitric acid and fluorhydric acid, and nitric acid. The studied elements are classified as highly mobile (Na, Ni, ...), nearly immobile (Ti, P) and partially mobile (Mg, Fe, K, ...). In regards to mineralizations around fumaroles associated with smoldering coal seams, Fourier-transform infrared spectroscopy and X-ray diffraction analyses have revealed the presence of salammoniac, mascagnite and other solid combustion compounds formed by reaction of gas emitted from coal oxidation, in addition to previously non-reported sulfur-rich by-products associated with gas fissures, particularly ammonium thiosulfate, a phase first obtained only synthetically in the laboratory. Another objective of the research was to collect and analyse gases escaping from surficial vents

  16. Selective placement of overburden in surface coal mining - problems and mining planning

    SciTech Connect

    Chang, J.L.; Kelley, J.H.

    1982-12-01

    Selective placement of overburden is one of the measures that can mitigate surface coal mining's impact on environment which is mandatory by the Public Law PL 95-87 of 1977. When the operation of selective placement of overburden is integrated into the mining cycle, its effectiveness is largely dependent on mining planning, pit design, and equipment scheduling and matching. This study is intended to provide a baseline information for the decision making of mining planning with respect to this particular operation. A review of OSM Permanent Regulatory Program as related to the requirement of selective placement of overburden around surface coal mine is presented. Parameters that might influence the mining planning of selective overburden handling are classified. Following the evaluation of the requirement on regulation and equipment feasibility of current operation, proposed mining schemes for both steep slope and area mining are presented. A case simulation and comparison of overburden handling cost of alternative tandem equipment combinations of a typical dragline operation revealed the competitive position of the scraper-loader-trucks and cross-pit conveyor subsystems in this particular mining layout. Finally, an index of selective overburden handling operation is provided which categorized independent and controlling factors of the mining sites and shows the relationship of mining planning considerations in this particular practices.

  17. Selection and adaptation of microalgae to growth in 100% unfiltered coal-fired flue gas.

    PubMed

    Aslam, Ambreen; Thomas-Hall, Skye R; Mughal, Tahira Aziz; Schenk, Peer M

    2017-06-01

    Microalgae have been considered for biological carbon capture and sequestration to offset carbon emissions from fossil fuel combustion. This study shows that mixed biodiverse microalgal communities can be selected for and adapted to tolerate growth in 100% flue gas from an unfiltered coal-fired power plant that contained 11% CO2. The high SOx and NOx emissions required slow adaptation of microalgae over many months, with step-wise increases from 10% to 100% flue gas supplementation and phosphate buffering at higher concentrations. After a rapid decline in biodiversity over the first few months, community profiling revealed Desmodesmus spp. as the dominant microalgae. To the authors' knowledge this work is the first to demonstrate that up 100% unfiltered flue gas from coal-fired power generation can be used for algae cultivation. Implementation of serial passages over a range of photobioreactors may contribute towards the development of microalgal-mediated carbon capture and sequestration processes.

  18. The use of starch to enhance sulfur and ash removal from coal by selective oil agglomeration

    SciTech Connect

    Good, R.J.; Badgujar, M.N.

    1990-01-01

    We have found that the use of starch or gelatin, as an additive in the Otisca T-Process of selective oil agglomeration of coal, leads to a considerable improvement in the reduction of pyritic sulfur and of ash-forming minerals. A patent application has been filed; (Good Badgugar). Improvement in rejection of pyritic sulfur by up to 55% has been found, and improvement in ash rejection by up to 28%. Carbon recovery of 97.5 to 99.1% was obtained when the starch concentration was in the range, 30 to 200 ppM in the water. Three different bituminous coals were used: Upper Freeport, Kentucky No. 9, and Illinois No. 6.

  19. Catalytic coal liquefaction process

    DOEpatents

    Garg, D.; Sunder, S.

    1986-12-02

    An improved process for catalytic solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a solvent comprises using as catalyst a mixture of a 1,2- or 1,4-quinone and an alkaline compound, selected from ammonium, alkali metal, and alkaline earth metal oxides, hydroxides or salts of weak acids. 1 fig.

  20. Catalytic coal liquefaction process

    DOEpatents

    Garg, Diwakar; Sunder, Swaminathan

    1986-01-01

    An improved process for catalytic solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a solvent comprises using as catalyst a mixture of a 1,2- or 1,4-quinone and an alkaline compound, selected from ammonium, alkali metal, and alkaline earth metal oxides, hydroxides or salts of weak acids.

  1. Selected elements in major minerals from bituminous coal as determined by INAA: Implications for removing environmentally sensitive elements from coal

    USGS Publications Warehouse

    Palmer, C.A.; Lyons, P.C.

    1996-01-01

    The four most abundant minerals generally found in Euramerican bituminous coals are quartz, kaolinite, illite and pyrite. These four minerals were isolated by density separation and handpicking from bituminous coal samples collected in the Ruhr Basin, Germany and the Appalachian basin, U.S.A. Trace-element concentrations of relatively pure (??? 99+%) separates of major minerals from these coals were determined directly by using instrumental neutron activation analysis (INAA). As expected, quartz contributes little to the trace-element mass balance. Illite generally has higher trace-element concentrations than kaolinite, but, for the concentrates analyzed in this study, Hf, Ta, W, Th and U are in lower concentrations in illite than in kaolinite. Pyrite has higher concentrations of chalcophile elements (e.g., As and Se) and is considerably lower in lithophile elements as compared to kaolinite and illite. Our study provides a direct and sensitive method of determining trace-element relationships with minerals in coal. Mass-balance calculations suggest that the trace-element content of coal can be explained mainly by three major minerals: pyrite, kaolinite and illite. This conclusion indicates that the size and textural relationships of these major coal minerals may be a more important consideration as to whether coal cleaning can effectively remove the most environmentally sensitive trace elements in coal than what trace minerals are present.

  2. Examination of lung toxicity, oxidant/antioxidant status and effect of erdosteine in rats kept in coal mine ambience.

    PubMed

    Armutcu, Ferah; Gun, Banu Dogan; Altin, Remzi; Gurel, Ahmet

    2007-09-01

    Occupational exposure to coal dust causes pneumoconiosis and other diseases. Reactive oxygen species (ROS) have been implicated in the pathogenesis of coal dust-induced lung toxicity. In this experimental study, we investigated the oxidant/antioxidant status, nitric oxide (NO) and hydroxyproline (HP) levels in lungs and blood of rats exposed to coal dust in mine ambience. In addition, we also investigated the attenuating effects of erdosteine. At the end of the experiment processes, tissue levels of HP, malondialdehyde (MDA) and NO, as well as the activities of superoxide dismutase, glutathione peroxidase, catalase, xanthine oxidase (XO), myeloperoxidase (MPO) and proinflammatory cytokines (IL-6 and TNF-α) were evaluated in the lung tissues, plasma samples or erythrocytes of rats. Exposure to coal dust resulted in a significant increase in the oxidant parameters (MDA, NO levels, and XO activity) and HP levels, as compared to the controls. A decrease in activities of antioxidant enzymes, and an increase in MPO activity were found in the study group, compared to the controls. Increased NO levels of lung were found in the study groups, that were significantly reduced by erdosteine. Our studies provide evidence that supports the hypothesis for ROS mediated coal workers' pneumoconiosis. Erdosteine may be beneficial in the coal dust-induced lung toxicity via antioxidant and free radical scavenger properties.

  3. Coal Ash Resources Research Consortium. Annual report and selected publications, 1 July 1992--30 June 1993

    SciTech Connect

    Pflughoeft-Hassett, D.F.; Dockter, B.A.; Eylands, K.E.; Hassett, D.J.; O`Leary, E.M.

    1994-04-01

    The Coal Ash Resources Research Consortium (CARRC, pronounced cars), formerly the Western Fly Ash Research, Development, and Data Center (WFARDDC), has continued fundamental and applied scientific and engineering research focused on promoting environmentally safe, economical use of coal combustion fly ash. The research tasks selected for the year included: (1) Coal Ash Properties Database Maintenance and Expansion, (2) Investigation of the High-Volume Use of Fly Ash for Flowable Backfill Applications, (3) Investigation of Hydrated Mineralogical Phases in Coal Combustion By-Products, (4) Comparison of Department of Transportation Specifications for Coal Ash Utilization, (5) Comparative Leaching Study of Coal Combustion By-Products and Competing Construction Materials, (6) Application of CCSEM for Coal Ash Characterization, (7) Determination of Types and Causes of Efflorescence in Regional Concrete Products, and (8) Sulfate Resistance of Fly Ash Concrete: A Literature Review and Evaluation of Research Priorities. The assembly of a database of information on coal fly ash has been a focus area for CARRC since its beginning in 1985. This year, CARRC members received an updated run time version of the Coal Ash Properties Database (CAPD) on computer disk for their use. The new, user-friendly database management format was developed over the year to facilitate the use of CAPD by members as well as CARRC researchers. It is anticipated that this direct access to CAPD by members as well as CARRC researchers. It is anticipated that this direct access to CAPD by members will be beneficial to each company`s utilization efforts, to CARRC, and to the coal ash industry in general. Many additions and improvements were made to CAPD during the year, and a three-year plan for computer database and modeling related to coal ash utilization was developed to guide both the database effort and the research effort.

  4. Modeling Selective Intergranular Oxidation of Binary Alloys

    SciTech Connect

    Xu, Zhijie; Li, Dongsheng; Schreiber, Daniel K.; Rosso, Kevin M.; Bruemmer, Stephen M.

    2015-01-07

    Intergranular attack of alloys under hydrothermal conditions is a complex problem that depends on metal and oxygen transport kinetics via solid-state and channel-like pathways to an advancing oxidation front. Experiments reveal very different rates of intergranular attack and minor element depletion distances ahead of the oxidation front for nickel-based binary alloys depending on the minor element. For example, a significant Cr depletion up to 9 µm ahead of grain boundary crack tips were documented for Ni-5Cr binary alloy, in contrast to relatively moderate Al depletion for Ni-5Al (~100s of nm). We present a mathematical kinetics model that adapts Wagner’s model for thick film growth to intergranular attack of binary alloys. The transport coefficients of elements O, Ni, Cr, and Al in bulk alloys and along grain boundaries were estimated from the literature. For planar surface oxidation, a critical concentration of the minor element can be determined from the model where the oxide of minor element becomes dominant over the major element. This generic model for simple grain boundary oxidation can predict oxidation penetration velocities and minor element depletion distances ahead of the advancing front that are comparable to experimental data. The significant distance of depletion of Cr in Ni-5Cr in contrast to the localized Al depletion in Ni-5Al can be explained by the model due to the combination of the relatively faster diffusion of Cr along the grain boundary and slower diffusion in bulk grains, relative to Al.

  5. Evaluation of reaction mechanism of coal-metal oxide interactions in chemical-looping combustion

    SciTech Connect

    Siriwardane, Ranjani; Richards, George; Poston, James; Tian, Hanjing; Miller, Duane; Simonyi, Thomas

    2010-11-15

    The knowledge of reaction mechanism is very important in designing reactors for chemical-looping combustion (CLC) of coal. Recent CLC studies have considered the more technically difficult problem of reactions between abundant solid fuels (i.e. coal and waste streams) and solid metal oxides. A definitive reaction mechanism has not been reported for CLC reaction of solid fuels. It has often been assumed that the solid/solid reaction is slow and therefore requires that reactions be conducted at temperatures high enough to gasify the solid fuel, or decompose the metal oxide. In contrast, data presented in this paper demonstrates that solid/solid reactions can be completed at much lower temperatures, with rates that are technically useful as long as adequate fuel/metal oxide contact is achieved. Density functional theory (DFT) simulations as well as experimental techniques such as thermo-gravimetric analysis (TGA), flow reactor studies, in situ X-ray photo electron spectroscopy (XPS), in situ X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used to evaluate how the proximal interaction between solid phases proceeds. The data indicate that carbon induces the Cu-O bond breaking process to initiate the combustion of carbon at temperatures significantly lower than the spontaneous decomposition temperature of CuO, and the type of reducing medium in the vicinity of the metal oxide influences the temperature at which the oxygen release from the metal oxide takes place. Surface melting of Cu and wetting of carbon may contribute to the solid-solid contacts necessary for the reaction. (author)

  6. Exhaled nitric oxide levels and lung function changes of underground coal miners in Newcastle, Australia.

    PubMed

    Liu, Xiaohui; Salter, Amy; Thomas, Paul; Leigh, James; Wang, He

    2010-01-01

    The possibility of exhaled nitric oxide (eNO) in combination with lung function as a marker of airway inflammation produced by coal mining exposure was determined presuming that workers exposed to airborne hazards would possess different concentrations of eNO and decreased lung function indices, relative to control subjects recruited from the same area. The effect of smoking was also considered. A study (exposed) group comprising 186 male subjects (aged 19-58 yr) was recruited from Newcastle coal mining companies with 86 male subjects (aged 20-64 yr) from the same area, but working outside of the coal mining location, serving as controls. The parameters examined were eNO, lung function, and variables derived from an interview-administered questionnaire survey. After adjustment for age, body weight, and smoking status, no significant differences between exposed coal mining workers and controls were found for various lung function parameters. However, the exposed group was shown to have significantly lower concentrations of eNO. In the exposed group, forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), and FEV(1) (%) predicted were found to be significantly different between nonsmokers and smokers. The concentrations of eNO were not significantly different between smoking and nonsmokers within the exposed group. The consideration of nonsmokers alone showed that eNO was significantly lower in the exposed group compared to the control group. The consideration of smokers alone found that eNO was significantly lower in exposed subjects. In the exposed group, no significant association was detected between eNO levels and underground work duration but a significant negative association was shown between eNO and age. Data suggest that exposure to airborne hazards in coal mining is not significantly associated with lung function changes but is correlated with decreased eNO concentrations in exposed workers. While underground work duration was not found to

  7. Structural features of a bituminous coal and their changes during low-temperature oxidation and loss of volatiles investigated by advanced solid-state NMR spectroscopy

    USGS Publications Warehouse

    Mao, J.-D.; Schimmelmann, A.; Mastalerz, Maria; Hatcher, P.G.; Li, Y.

    2010-01-01

    Quantitative and advanced 13C solid-state NMR techniques were employed to investigate (i) the chemical structure of a high volatile bituminous coal, as well as (ii) chemical structural changes of this coal after evacuation of adsorbed gases, (iii) during oxidative air exposure at room temperature, and (iv) after oxidative heating in air at 75 ??C. The solid-state NMR techniques employed in this study included quantitative direct polarization/magic angle spinning (DP/MAS) at a high spinning speed of 14 kHz, cross polarization/total sideband suppression (CP/TOSS), dipolar dephasing, CH, CH2, and CHn selection, 13C chemical shift anisotropy (CSA) filtering, two-dimensional (2D) 1H-13C heteronuclear correlation NMR (HETCOR), and 2D HETCOR with 1H spin diffusion. With spectral editing techniques, we identified methyl CCH 3, rigid and mobile methylene CCH2C, methine CCH, quaternary Cq, aromatic CH, aromatic carbons bonded to alkyls, small-sized condensed aromatic moieties, and aromatic C-O groups. With direct polarization combined with spectral-editing techniques, we quantified 11 different types of functional groups. 1H-13C 2D HETCOR NMR experiments indicated spatial proximity of aromatic and alkyl moieties in cross-linked structures. The proton spin diffusion experiments indicated that the magnetization was not equilibrated at a 1H spin diffusion time of 5 ms. Therefore, the heterogeneity in spatial distribution of different functional groups should be above 2 nm. Recoupled C-H long-range dipolar dephasing showed that the fraction of large charcoal-like clusters of polycondensed aromatic rings was relatively small. The exposure of this coal to atmospheric oxygen at room temperature for 6 months did not result in obvious chemical structural changes of the coal, whereas heating at 75 ??C in air for 10 days led to oxidation of coal and generated some COO groups. Evacuation removed most volatiles and caused a significant reduction in aliphatic signals in its DP

  8. Regional Emissions Data Base and Evaluation System (REDES): Volume 3, Environmental profiles of selected clean coal technologies

    SciTech Connect

    Poch, L.A.; Gillette, J.L.; Boyd, G.A.

    1988-06-01

    The clean coal technologies described in this report make use of advanced combustors, alternative fuels, coal preparation processes, fluidized-bed combustors, flue-gas cleanup technologies, coal liquefaction processes, and surface gasification. Each profile begins with a brief description of the technology, followed by an assessment of its applicability to the utility or industrial sector in terms of fuel sulfur content, boiler size, and boiler market (new, repower, and/or retrofit). The sulfur content of the coal is described as being low, medium, or high. Low-sulfur coal contains less than 1.5% sulfur, medium-sulfur coal has 1.5--3% sulfur, and high-sulfur coal contains greater than 3% sulfur. Boiler size (or unit output of electricity) is discussed in terms of being small, medium, or large. A small boiler has less than 100 MW output, a medium boiler has 100--400 MW output, and a large boiler has greater than 400 MW output. Removal efficiencies or emission levels for sulfur dioxide (SO/sub 2/), oxides of nitrogen (NO/sub x/), and particulates are described, as are the anticipated changes in heat rate that would result from the use of each technology. The wastes generated by each technology are also discussed. Following each technology's profile is a bibliography that lists the sources used to compile the values for the various parameters. 49 refs.

  9. Selected hydrologic data, Kolob-Alton-Kaiparowits coal-fields area, south-central Utah

    USGS Publications Warehouse

    Plantz, G.G.

    1983-01-01

    The Kolob-Alton-Kaiparowits coal field area includes about 4,500 sq mi in parts of the Colorado River Basin and the Great Basin. The area varies in altitude from < 4,000 to > 10,000 ft, and is comprised chiefly of plateaus, benches, and terraces that are dissected by deep, narrow canyons. Water quality was studied in principal streams draining the area, the Virgin, Sevier, Escalante, and Paria Rivers; and Coal, Kanab, and Wahweap Creeks. Most of the data included in this report were collected by the U.S. Geological Survey from October 1980 to September 1982, as part of a hydrologic study in cooperation with the U.S. Bureau of Land Management to evaluate potential impacts of coal mining on the area 's water resources. Data include: discharge, water temperature, specific conductance, and pH. Data collected from selected wells and springs include: specific conductance, pH, hardness, and dissolved quantities of calcium, magnesium, potassium, sodium, sulfates, chlorides, fluorides, silica, nitrogen, boron, iron, and manganese. (Lantz-PTT)

  10. Heavy-metal content and oxidative damage in Hypsiboas faber: the impact of coal-mining pollutants on amphibians.

    PubMed

    Zocche, Jairo José; da Silva, Luciano Acordi; Damiani, Adriani Paganini; Mendonça, Rodrigo Ávila; Peres, Poliana Bernardo; dos Santos, Carla Eliete Iochims; Debastiani, Rafaela; Dias, Johnny Ferraz; de Andrade, Vanessa Moraes; Pinho, Ricardo Aurino

    2014-01-01

    It has been identified worldwide that amphibians are experiencing massive population declines. This decrease could be further enhanced by the exposure of amphibians to pollutants, which would enhance reactive oxygen species production and cause subsequent alterations in oxidant defense levels. The present study was aimed at understanding the impact of mineral coal on amphibians. For this purpose, chemical elemental contents and oxidative stress indexes in Hypsiboas faber from coal-mining areas and in an unpolluted area in the Catarinense Coal Basin, Brazil, were assessed. The highest contents of sulfur, chlorine, iron, zinc, and bromine were registered in specimens from the coal-mining area, whereas the highest contents of potassium calcium, and silicon were registered in specimens from the control area. It was found that there was a significant increase (p < 0.05) in the activity of super oxide dismutase (SOD) and glutathione peroxidase (GPx) in the animals from the coal-mining area, whereas the level of catalase showed no differences between the animal groups. The levels of TBARS showed no differences between the tested groups. However, carbonylation decreased significantly (p < 0.05) in animals from the coal-mining area, and there was a significant increase (p < 0.05) in the formation of total thiols in animals from the coal-mining area. In conclusion, the antioxidant system of H. faber is sensitive to pollutants present in coal-mining wastes, and its SOD and GPx activity may be a potential biomarker for monitoring the level of contaminants in the environment.

  11. Pathways for conversion of char nitrogen to nitric oxide at pulverized coal combustion conditions.

    SciTech Connect

    Molina, Alejandro; Shaddix, Christopher R.; Blevins, Linda Gail; Murphy, Jeffrey J.

    2004-03-01

    The conversion of nitrogen in char (char-N) to NO was studied both experimentally and computationally. In the experiments, pulverized coal char was produced from a U.S. high-volatile bituminous coal and burned in a dilute suspension at 1170 K, 1370 K and 1570 K, at an excess oxygen concentration of 8% (dry), with different levels of background NO. In some experiments, hydrogen bromide (HBr) was added to the vitiated air as a tool to alter the concentration of gas-phase radicals. During char combustion, low NO concentration and high temperature promoted the conversion of char-N to NO. HBr addition altered NO production in a way that depended on temperature. At 1170 K the presence of HBr increased NO production by 80%, whereas the addition of HBr decreased NO production at higher temperatures by 20%. To explain these results, three mechanistic descriptions of char-N evolution during combustion were evaluated with computational models that simulated (a) homogeneous chemistry in a plug-flow reactor with entrained particle combustion, and (b) homogeneous chemistry in the boundary layer surrounding a reacting particle. The observed effect of HBr on NO production could only be captured by a chemical mechanism that considered significant release of HCN from the char particle. Release of HCN also explained changes in NO production with temperature and NO concentration. Thus, the combination of experiments and simulations suggests that HCN evolution from the char during pulverized coal combustion plays an essential role in net NO production. Keywords: Coal; Char; Nitric oxide; Halogen.

  12. Performance of solid oxide fuel cells operated with coal syngas provided directly from a gasification process

    SciTech Connect

    Hackett, Gregory A.; Gerdes, Kirk R.; Song, Xueyan; Chen, Yun; Shutthanandan, V.; Engelhard, Mark H.; Zhu, Zihua; Thevuthasan, Suntharampillai; Gemmen, Randall

    2012-09-15

    Solid oxide fuel cells (SOFCs) are presently being developed for gasification integrated power plants that generate electricity from coal at 50+% efficiency. The interaction of trace metals in coal syngas with the Ni-based SOFC anodes is being investigated through thermodynamic analyses and in laboratory experiments, but direct test data from coal syngas exposure are sparsely available. This research effort evaluates the significance of SOFC performance losses associated with exposure of a SOFC anode to direct coal syngas. SOFC specimen of industrially relevant composition are operated in a unique mobile test skid that was deployed to the research gasifier at the National Carbon Capture Center (NCCC) in Wilsonville, AL. The mobile test skid interfaces with a gasifier slipstream to deliver hot syngas (up to 300°C) directly to a parallel array of 12 button cell specimen, each of which possesses an active area of approximately 2 cm2. During the 500 hour test period, all twelve cells were monitored for performance at four discrete operating current densities, and all cells maintained contact with a data acquisition system. Of these twelve, nine demonstrated good performance throughout the test, while three of the cells were partially compromised. Degradation associated with the properly functioning cells was attributed to syngas exposure and trace material attack on the anode structure that was accelerated at increasing current densities. Cells that were operated at 0 and 125 mA/cm² degraded at 9.1 and 10.7% per 1000 hours, respectively, while cells operated at 250 and 375 mA/cm² degraded at 18.9 and 16.2% per 1000 hours, respectively. Post-trial spectroscopic analysis of the anodes showed carbon, sulfur, and phosphorus deposits; no secondary Ni-metal phases were found.

  13. Effect of selective catalytic reduction (SCR) on fine particle emission from two coal-fired power plants in China

    NASA Astrophysics Data System (ADS)

    Li, Zhen; Jiang, Jingkun; Ma, Zizhen; Wang, Shuxiao; Duan, Lei

    2015-11-01

    Nitrogen oxides (NOx) emission abatement of coal-fired power plants (CFPPs) requires large-scaled installation of selective catalytic reduction (SCR), which would reduce secondary fine particulate matter (PM2.5) (by reducing nitrate aerosol) in the atmosphere. However, our field measurement of two CFPPs equipped with SCR indicates a significant increase of SO42- and NH4+ emission in primary PM2.5, due to catalytic enhancement of SO2 oxidation to SO3 and introducing of NH3 as reducing agent. The subsequent formation of (NH4)2SO4 or NH4HSO4 aerosol is commonly concentrated in sub-micrometer particulate matter (PM1) with a bimodal pattern. The measurement at the inlet of stack also showed doubled primary PM2.5 emission by SCR operation. This effect should therefore be considered when updating emission inventory of CFPPs. By rough estimation, the enhanced primary PM2.5 emission from CFPPs by SCR operation would offset 12% of the ambient PM2.5 concentration reduction in cities as the benefit of national NOx emission abatement, which should draw attention of policy-makers for air pollution control.

  14. SELECTIVE OXIDATION IN SUPERCRITICAL CARBON DIOXIDE USING CLEAN OXIDANTS

    EPA Science Inventory

    We have systematically investigated heterogeneous catalytic oxidation of different substrates in supercritical carbon dioxide (SC-CO2). Three types of catagysts: a metal complex, 0.5% platinum g-alumina and 0.5% palladium g-alumina were used at a pressure of 200 bar, temperatures...

  15. Mathematical optimization techniques for managing selective catalytic reduction for a fleet of coal-fired power plants

    NASA Astrophysics Data System (ADS)

    Alanis Pena, Antonio Alejandro

    Major commercial electricity generation is done by burning fossil fuels out of which coal-fired power plants produce a substantial quantity of electricity worldwide. The United States has large reserves of coal, and it is cheaply available, making it a good choice for the generation of electricity on a large scale. However, one major problem associated with using coal for combustion is that it produces a group of pollutants known as nitrogen oxides (NO x). NOx are strong oxidizers and contribute to ozone formation and respiratory illness. The Environmental Protection Agency (EPA) regulates the quantity of NOx emitted to the atmosphere in the United States. One technique coal-fired power plants use to reduce NOx emissions is Selective Catalytic Reduction (SCR). SCR uses layers of catalyst that need to be added or changed to maintain the required performance. Power plants do add or change catalyst layers during temporary shutdowns, but it is expensive. However, many companies do not have only one power plant, but instead they can have a fleet of coal-fired power plants. A fleet of power plants can use EPA cap and trade programs to have an outlet NOx emission below the allowances for the fleet. For that reason, the main aim of this research is to develop an SCR management mathematical optimization methods that, with a given set of scheduled outages for a fleet of power plants, minimizes the total cost of the entire fleet of power plants and also maintain outlet NO x below the desired target for the entire fleet. We use a multi commodity network flow problem (MCFP) that creates edges that represent all the SCR catalyst layers for each plant. This MCFP is relaxed because it does not consider average daily NOx constraint, and it is solved by a binary integer program. After that, we add the average daily NOx constraint to the model with a schedule elimination constraint (MCFPwSEC). The MCFPwSEC eliminates, one by one, the solutions that do not satisfy the average daily

  16. Near-neutral oxidation of pyrite in coal slurry solids. [Quarterly] technical report, September 1--November 30, 1994

    SciTech Connect

    Frost, J.K.; Dreher, G.B.

    1994-12-31

    In this research project we plan to determine the rate of oxidation of pyrite associated with coaly particles (coal slurry solid) when the pH of the surrounding environment is held at approximately 7.8. Coaly particles that contain pyrite are generated during the preparation of Illinois Basin coal for market. These particles are discharged to an impoundment, which eventually must be reclaimed. The purpose for reclamation is either to prevent the generation of acidic solution as the pyrite in the coal slurry solid reacts with air, or to prevent the migration of the acidic solution to a groundwater aquifer. The reclamation is usually accomplished by covering the impoundment with a four-foot-thick layer of topsoil. One possible alternative method for reclamation of a coal slurry impoundment is to mix in alkaline residue from the fluidized-bed combustion of coal. This codisposal would slow the production of acid and would also neutralize any acid produced. If the codisposal method is found to be environmentally acceptable, it will save the coal mining companies part of their cost of reclamation, and also provide a safe and useful disposal outlet for a portion of the residue that is generated by the fluidized-bed combustion of coal. During this quarter we purchased and set up two automatic titrators, which will be used in determining the rate of pyrite oxidation at nearly neutral pH. The titrators will provide a means for maintaining the pH at the desired level. The rate at which sulfate ion is produced as a result of pyrite oxidation will be used to measure the amount of pyrite oxidized over time.

  17. OXIDATION OF MERCURY ACROSS SCR CATALYSTS IN COAL-FIRED POWER PLANTS BURNING LOW RANK FUELS

    SciTech Connect

    Constance Senior

    2004-10-29

    This is the seventh Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-03NT41728. The objective of this program is to measure the oxidation of mercury in flue gas across SCR catalyst in a coal-fired power plant burning low rank fuels using a slipstream reactor containing multiple commercial catalysts in parallel. The Electric Power Research Institute (EPRI) and Argillon GmbH are providing co-funding for this program. This program contains multiple tasks and good progress is being made on all fronts. During this quarter, a model of Hg oxidation across SCRs was formulated based on full-scale data. The model took into account the effects of temperature, space velocity, catalyst type and HCl concentration in the flue gas.

  18. MINIMIZING NET CO2 EMISSIONS BY OXIDATIVE CO-PYROLYSIS OF COAL / BIOMASS BLENDS

    SciTech Connect

    Todd Lang; Robert Hurt

    2001-12-23

    This study presents a set of thermodynamic calculations on the optimal mode of solid fuel utilization considering a wide range of fuel types and processing technologies. The technologies include stand-alone combustion, biomass/coal cofiring, oxidative pyrolysis, and straight carbonization with no energy recovery but with elemental carbon storage. The results show that the thermodynamically optimal way to process solid fuels depends strongly on the specific fuels and technologies available, the local demand for heat or for electricity, and the local baseline energy-production method. Burning renewable fuels reduces anthropogenic CO{sub 2} emissions as widely recognized. In certain cases, however, other processing methods are equally or more effective, including the simple carbonization or oxidative pyrolysis of biomass fuels.

  19. Removal of oxides of nitrogen from gases in multi-stage coal combustion

    DOEpatents

    Mollot, Darren J.; Bonk, Donald L.; Dowdy, Thomas E.

    1998-01-01

    Polluting NO.sub.x gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO.sub.x gases are removed is directed to introducing NO.sub.x -free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor.

  20. Removal of oxides of nitrogen from gases in multi-stage coal combustion

    DOEpatents

    Mollot, D.J.; Bonk, D.L.; Dowdy, T.E.

    1998-01-13

    Polluting NO{sub x} gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO{sub x} gases are removed is directed to introducing NO{sub x}-free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor. 2 figs.

  1. Semiconducting Metal Oxide Based Sensors for Selective Gas Pollutant Detection

    PubMed Central

    Kanan, Sofian M.; El-Kadri, Oussama M.; Abu-Yousef, Imad A.; Kanan, Marsha C.

    2009-01-01

    A review of some papers published in the last fifty years that focus on the semiconducting metal oxide (SMO) based sensors for the selective and sensitive detection of various environmental pollutants is presented. PMID:22408500

  2. Unprecedented Selective Oxidation of Styrene Derivatives using a Supported Iron Oxide Nanocatalyst in Aqueous Medium

    EPA Science Inventory

    Iron oxide nanoparticles supported on mesoporous silica-type materials have been successfully utilized in the aqueous selective oxidation of alkenes under mild conditions using hydrogen peroxide as a green oxidant. Catalysts could be easily recovered after completion of the reac...

  3. SELECTIVE OXIDATION OF ALCOHOLS OVER VANADIUM PHOSPHORUS OXIDE CATALYST USING HYDROGEN PEROXIDE

    EPA Science Inventory

    Oxidation of various alcohols is studied in liquid phase under nitrogen atmosphere over vanadium phosphorus oxide catalyst in an environmentally friendly protocol using hydrogen peroxide. The catalyst and the method are found to be suitable for the selective oxidation of a variet...

  4. Boiler materials for ultra-supercritical coal power plants - steamside oxidation

    SciTech Connect

    Viswanathan, R.; Sarver, J.; Tanzosh, J.M.

    2006-06-15

    The corrosion behavior of tubing materials carrying steam at high temperature is of great concern to fossil power plant operators. This is due to the fact that the oxide films formed on the steam side can lead to major failures and consequently to reduced plant availability. The wall loss of the pressure boundary caused by oxidation can increase the hoop stresses and cause premature creep failures; second, the increased insulation of the tubes due to the low thermal conductivity of the oxide film can lead to increased metal temperature, thereby exacerbating the fireside corrosion as well as creep problems. The third concern is that thicker oxides may spall more easily when the plant is cooled down. On restart, the spalled material may lodge somewhere in the system with the potential for causing tube blockages, or it may be swept out with the working fluid and enter the steam turbine causing erosion damage to the turbine nozzles and blades. Failures of tubing and turbine components by these mechanisms have been widely reported in the United States. In view of the importance of the steamside oxidation, a major study of the phenomenon is being carried out as part of a major national program sponsored by the U.S. Department of Energy and the Ohio Coal Development Office. As a prelude to the experimental work, a literature survey was performed to document the state of the art. Results of the review are reported here.

  5. Thermal oxidation purification of gaseous emissions to remove tar vapor and coal dust

    SciTech Connect

    Zhilina, N.B.; Andreikov, E.I.

    1983-01-01

    In the production of molded coke one source of emissions of toxic substances is the excess heat carrier gas (640 m/sup 3/ per ton of charge). In addition to the gaseous components, it contains, g/m/sup 3/: water 360, tar vapor 3-5, coal dust 2-6. The goal of the present article was to evaluate the possibility of purifying this gas by thermal oxidation. The investigations were conducted on a laboratory apparatus with a quartz reactor (length 200 mm, diameter 14 mm), heated by a tube furnace. The tar is injected by a plunger metering pump into a gas mixture, where it is evaporated at 150/sup 0/C in a current of gas; then the tar vapors enter the reactor. The tar for oxidation was obtained in the low-temperature (600/sup 0/C) semicoking of coal; in the experiments a fraction (70 wt.% tar) with a boiling point up to 360/sup 0/C was used. The fraction contained 8% bases, 35% phenols, and 57% neutral part, consisting of paraffins, naphthenes, alkyl-substituted aromatic hydrocarbons and neutral oxygen-containing compounds.

  6. Effect of the water-vapor content on the oxidative desulfurization of sulfur-rich coal

    SciTech Connect

    S. Pysh'yev; K. Shevchuk; L. Chmielarz; P. Kutrowski; A. Pattek-Janczyk

    2007-01-15

    Ukrainian sulfur-rich coal containing about 3.6 mass % of sulfur was studied. The desulfurization process was performed in the fluidized-bed reactor in dry (4 vol % of H{sub 2}O vapor) and wet (30-70 vol % of H{sub 2}O vapor) atmospheres in the temperature range of 350-450{sup o}C. A significant influence of the water-vapor content in the reaction mixture on the sulfur removal during the oxidative desulfurization of the coal was observed especially at low temperatures. The extent of FeS{sub 2} oxidation, the main sulfur-containing compound, was studied by Moessbauer spectroscopy. The Moessbauer data revealed different iron-containing products (FeSO{sub 4}nH{sub 2}O, Fe{sub 2}O{sub 3}, Fe{sub 3}O{sub 4}, and Fe{sub 1-x}S) formed in the course of the process carried out in dry and wet atmospheres. The promoting effect of water vapor on the pyrite transformation was observed especially at low temperatures. The mechanism of this promotion on the molecular scale was proposed. 19 refs., 6 figs., 4 tabs.

  7. Process for selected gas oxide removal by radiofrequency catalysts

    DOEpatents

    Cha, C.Y.

    1993-09-21

    This process to remove gas oxides from flue gas utilizes adsorption on a char bed subsequently followed by radiofrequency catalysis enhancing such removal through selected reactions. Common gas oxides include SO[sub 2] and NO[sub x]. 1 figure.

  8. KINETICS OF DIRECT OXIDATION OF H2S IN COAL GAS TO ELEMENTAL SULFUR

    SciTech Connect

    K.C. Kwon

    2003-01-01

    The direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The objective of this research is to support the near- and long-term DOE efforts to commercialize this direct oxidation technology. The objectives of this research are to measure kinetics of direct oxidation of H{sub 2}S to elemental sulfur in the presence of a simulated coal gas mixture containing SO{sub 2}, H{sub 2}, and moisture, using 60-{micro}m C-500-04 alumina catalyst particles and a PFA differential fixed-bed micro reactor, and to develop kinetic rate equations and model the direct oxidation process to assist in the design of large-scale plants. To achieve the above-mentioned objectives, experiments on conversion of hydrogen sulfide into elemental sulfur were carried out for the space time range of 0.01-0.047 seconds at 125-155 C to evaluate effects of reaction temperatures, moisture concentrations, reaction pressures on conversion of hydrogen sulfide into elemental sulfur. Simulated coal gas mixtures consist of 61-89 v% hydrogen, 2,300-9,200-ppmv hydrogen sulfide, 1,600-4,900 ppmv sulfur dioxide, and 2.6-13.7 vol % moisture, and nitrogen as remainder. Volumetric feed rates of a simulated coal gas mixture to the reactor are 100-110 cm{sup 3}/min at room temperature and atmospheric pressure (SCCM). The temperature of the reactor is controlled in an oven at 125-155 C. The pressure of the reactor is maintained at 28-127 psia. The following results were obtained based on experimental data generated from the differential reactor system, and their interpretations, (1) Concentration of moisture and concentrations of both H{sub 2}S and SO{sub 2} appear to affect slightly reaction

  9. Full scale calcium bromide injection with subsequent mercury oxidation and removal within wet flue gas desulphurization system: Experience at a 700 MW coal-fired power facility

    NASA Astrophysics Data System (ADS)

    Berry, Mark Simpson

    The Environmental Protection Agency promulgated the Mercury and Air Toxics Standards rule, which requires that existing power plants reduce mercury emissions to meet an emission rate of 1.2 lb/TBtu on a 30-day rolling average and that new plants meet a 0.0002 lb/GWHr emission rate. This translates to mercury removals greater than 90% for existing units and greater than 99% for new units. Current state-of-the-art technology for the control of mercury emissions uses activated carbon injected upstream of a fabric filter, a costly proposition. For example, a fabric filter, if not already available, would require a 200M capital investment for a 700 MW size unit. A lower-cost option involves the injection of activated carbon into an existing cold-side electrostatic precipitator. Both options would incur the cost of activated carbon, upwards of 3M per year. The combination of selective catalytic reduction (SCR) reactors and wet flue gas desulphurization (wet FGD) systems have demonstrated the ability to substantially reduce mercury emissions, especially at units that burn coals containing sufficient halogens. Halogens are necessary for transforming elemental mercury to oxidized mercury, which is water-soluble. Plants burning halogen-deficient coals such as Power River Basin (PRB) coals currently have no alternative but to install activated carbon-based approaches to control mercury emissions. This research consisted of investigating calcium bromide addition onto PRB coal as a method of increasing flue gas halogen concentration. The treated coal was combusted in a 700 MW boiler and the subsequent treated flue gas was introduced into a wet FGD. Short-term parametric and an 83-day longer-term tests were completed to determine the ability of calcium bromine to oxidize mercury and to study the removal of the mercury in a wet FGD. The research goal was to show that calcium bromine addition to PRB coal was a viable approach for meeting the Mercury and Air Toxics Standards rule

  10. The effect of emission from coal combustion in nonindustrial sources on deposition of sulfur and oxidized nitrogen in Poland.

    PubMed

    Kryza, Maciej; Werner, Małgorzata; Błaś, Marek; Dore, Anthony J; Sobik, Mieczysław

    2010-07-01

    Poland has one of the largest sulfur and nitrogen emissions in Europe. This is mainly because coal is a main fuel in industrial and nonindustrial combustion. The aim of this paper is to assess the amount of sulfur and nitrogen deposited from SNAP sector 02 (nonindustrial sources) coal combustion. To assess this issue, the Fine Resolution Atmospheric Multipollutant Exchange (FRAME) model was used. The results suggest that industrial combustion has the largest impact on deposition of oxidized sulfur, whereas the oxidized nitrogen national deposition budget is dominated by transboundary transport. The total mass of pollutants deposited in Poland, originating from nonindustrial coal combustion, is 45 Gg of sulfur and 2.5 Gg of nitrogen, which is over 18% of oxidized sulfur and nearly 2% of oxidized nitrogen deposited. SNAP 02 is responsible for up to 80% of dry-deposited sulfur and 11% of nitrogen. The contribution to wet deposition is largest in central Poland in the case of sulfur and in some areas can exceed 11%. For oxidized nitrogen, nonindustrial emissions contribute less than 1% over the whole area of Poland. The switch from coal to gas fuel in this sector will result in benefits in sulfur and nitrogen deposition reduction.

  11. Selective Electrocatalytic Activity of Ligand Stabilized Copper Oxide Nanoparticles

    SciTech Connect

    Kauffman, Douglas R; Ohodnicki, Paul R; Kail, Brian W; Matranga, Christopher

    2011-01-01

    Ligand stabilization can influence the surface chemistry of Cu oxide nanoparticles (NPs) and provide unique product distributions for electrocatalytic methanol (MeOH) oxidation and CO{sub 2} reduction reactions. Oleic acid (OA) stabilized Cu{sub 2}O and CuO NPs promote the MeOH oxidation reaction with 88% and 99.97% selective HCOH formation, respectively. Alternatively, CO{sub 2} is the only reaction product detected for bulk Cu oxides and Cu oxide NPs with no ligands or weakly interacting ligands. We also demonstrate that OA stabilized Cu oxide NPs can reduce CO{sub 2} into CO with a {approx}1.7-fold increase in CO/H{sub 2} production ratios compared to bulk Cu oxides. The OA stabilized Cu oxide NPs also show 7.6 and 9.1-fold increases in CO/H{sub 2} production ratios compared to weakly stabilized and non-stabilized Cu oxide NPs, respectively. Our data illustrates that the presence and type of surface ligand can substantially influence the catalytic product selectivity of Cu oxide NPs.

  12. Comparative analyses for selected clean coal technologies in the international marketplace

    SciTech Connect

    Szpunar, C.B.; Gillette, J.L.

    1990-07-01

    Clean coal technologies (CCTs) are being demonstrated in research and development programs under public and private sponsorship. Many of these technologies could be marketed internationally. To explore the scope of these international opportunities and to match particular technologies with markets appearing to have high potential, a study was undertaken that focused on seven representative countries: Italy, Japan, Morocco, Turkey, Pakistan, the Peoples' Republic of China, and Poland. The results suggest that there are international markets for CCTs and that these technologies can be cost competitive with more conventional alternatives. The identified markets include construction of new plants and refurbishment of existing ones, especially when decision makers want to decrease dependence on imported oil. This report describes potential international market niches for U.S. CCTs and discusses the status and implications of ongoing CCT demonstration activities. Twelve technologies were selected as representative of technologies under development for use in new or refurbished industrial or electric utility applications. Included are the following: Two generic precombustion technologies: two-stage froth-flotation coal beneficiation and coal-water mixtures (CWMs); Four combustion technologies: slagging combustors, integrated-gasification combined-cycle (IGCC) systems, atmospheric fluidized-bed combustors (AFBCs), and pressurized fluidized-bed combustors (PFBCs); and Six postcombustion technologies: limestone-injection multistage burner (LIMB) systems, gas-reburning sorbent-injection (GRSI) systems, dual-alkali flue-gas desulfurization (FGD), spray-dryer FGD, the NOXSO process, and selective catalytic reduction (SCR) systems. Major chapters of this report have been processed separately for inclusion on the data base.

  13. A hydrophobic ammonia-oxidizing archaeon of the Nitrosocosmicus clade isolated from coal tar-contaminated sediment.

    PubMed

    Jung, Man-Young; Kim, Jong-Geol; Sinninghe Damsté, Jaap S; Rijpstra, W Irene C; Madsen, Eugene L; Kim, So-Jeong; Hong, Heeji; Si, Ok-Ja; Kerou, Melina; Schleper, Christa; Rhee, Sung-Keun

    2016-12-01

    A wide diversity of ammonia-oxidizing archaea (AOA) within the phylum Thaumarchaeota exists and plays a key role in the N cycle in a variety of habitats. In this study, we isolated and characterized an ammonia-oxidizing archaeon, strain MY3, from a coal tar-contaminated sediment. Phylogenetically, strain MY3 falls in clade 'Nitrosocosmicus' of the thaumarchaeotal group I.1b. The cells of strain MY3 are large 'walnut-like' cocci, divide by binary fission along a central cingulum, and form aggregates. Strain MY3 is mesophilic and neutrophilic. An assay of (13) C-bicarbonate incorporation into archaeal membrane lipids indicated that strain MY3 is capable of autotrophy. In contrast to some other AOA, TCA cycle intermediates, i.e. pruvate, oxaloacetate and α-ketoglutarate, did not affect the growth rates and yields of strain MY3. The attachment of cells of strain MY3 to XAD-7 hydrophobic beads and to the adsorbent vermiculite demonstrated the potential of strain MY3 to form biofilms. The cell surface was confirmed to be hydrophobic by the extraction of strain MY3 from an aqueous medium with p-xylene. Our finding of a strong potential for surface attachment by strain MY3 may reflect an adaptation to the selective pressures in hydrophobic terrestrial environments.

  14. Selective flotation of fossil resin from Western coal. Final report, July 1, 1990--May 25, 1992

    SciTech Connect

    Jensen, G.F.; Miller, J.D.

    1992-05-25

    The proof-of-concept test program was designed to clarify a number of concerns that have been raised by coal companies who own the valuable resin resource. First, from laboratory bench-scale flotation experiments, a froth product from cleaner flotation containing more than 80% hexane-extractable resin at higher than 80% recovery can be produced. Pilot-plant testing was initiated to demonstrate the selective flotation of fossil resin and to establish a better confidence level in the new technology. Second, pilot-plant testing was designed to evaluate the effect and impact of random variation in slurry solids concentration and feed grade on this new selective fossil resin flotation technology. The flotation performance obtained under these industrial conditions is more realistic for process evaluation. Third, more accurate operating cost data was to be obtained for economic analysis. Fourth, sufficient quantities of the fossil resin concentrate were to be produced from the test program for evaluation by potential industrial users. Fifth, and finally, optimum levels for the operating variables were to be established. Such information was required for eventual scale-up and design of a fossil resin flotation plant. The pilot-plant proof-of-concept testing of selective resinate flotation has demonstrated that: (1) technically, the new flotation technologies discovered at the University of Utah and then improved upon by Advanced Processing Technologies, Inc. provide a highly efficient means to selectively recover fossil resin from coal. The proof-of-concept continuous flotation circuit (about 0.1 tph) resulted in fossil resin recovery with the same separation efficiency as was obtained from laboratory bench-scale testing (more than 80% recovery at about 80% concentrate grade); and (2) economically, the selective flotation process has been shown to be sufficiently profitable to justify the development of a fossil resin industry based on this new flotation process.

  15. Method and apparatus for the selective separation of gaseous coal gasification products by pressure swing adsorption

    DOEpatents

    Ghate, M.R.; Yang, R.T.

    1985-10-03

    Bulk separation of the gaseous components of multi-component gases provided by the gasification of coal including hydrogen, carbon monoxide, methane, and acid gases (carbon dioxide plus hydrogen sulfide) are selectively adsorbed by a pressure swing adsorption technique using activated carbon zeolite or a combination thereof as the adsorbent. By charging a column containing the adsorbent with a gas mixture and pressurizing the column to a pressure sufficient to cause the adsorption of the gases and then reducing the partial pressure of the contents of the column, the gases are selectively and sequentially desorbed. Hydrogen, the least absorbable gas of the gaseous mixture, is the first gas to be desorbed and is removed from the column in a co-current direction followed by the carbon monoxide, hydrogen and methane. With the pressure in the column reduced to about atmospheric pressure the column is evacuated in a countercurrent direction to remove the acid gases from the column. The present invention is particularly advantageous as a producer of high purity hydrogen from gaseous products of coal gasification and as an acid gas scrubber. 2 figs., 2 tabs.

  16. Method and apparatus for the selective separation of gaseous coal gasification products by pressure swing adsorption

    DOEpatents

    Ghate, Madhav R.; Yang, Ralph T.

    1987-01-01

    Bulk separation of the gaseous components of multi-component gases provided by the gasification of coal including hydrogen, carbon monoxide, methane, and acid gases (carbon dioxide plus hydrogen sulfide) are selectively adsorbed by a pressure swing adsorption technique using activated carbon, zeolite or a combination thereof as the adsorbent. By charging a column containing the adsorbent with a gas mixture and pressurizing the column to a pressure sufficient to cause the adsorption of the gases and then reducing the partial pressure of the contents of the column, the gases are selectively and sequentially desorbed. Hydrogen, the least absorbable gas of the gaseous mixture, is the first gas to be desorbed and is removed from the column in a co-current direction followed by the carbon monoxide, hydrogen and methane. With the pressure in the column reduced to about atmospheric pressure the column is evacuated in a countercurrent direction to remove the acid gases from the column. The present invention is particularly advantageous as a producer of high parity hydrogen from gaseous products of coal gasification and as an acid gas scrubber.

  17. Oxidation resistance of selected mechanical carbons at 650 deg C in dry flowing air

    NASA Technical Reports Server (NTRS)

    Allen, G. P.; Wisander, D. W.

    1973-01-01

    Oxidation experiments were conducted with several experimental mechanical carbons at 650 C in air flowing at 28 cu cm/sec (STP). Experiments indicate that boron carbide addition and zinc phosphate treatment definitely improved oxidation resistance. Impregnation with coal tar pitch before final graphitization had some beneficial effect on oxidation resistance and it markedly improved flexure strength and hardness. Graphitization temperature alone did not affect oxidation resistance, but with enough added boron carbide the oxidation resistance was increased although the hardness greatly decreased.

  18. Technical, Energetics, and Economic Comparison of NRL Oxidative Coal Liquefaction Process with some Developed Coal Liquefaction Processes.

    DTIC Science & Technology

    1980-03-05

    the synthesis step becomes two processes. synthesis CO + H2 catalyst ) methanol conversion methanol catalyst > gasoline + water Wiser states that...structure illustrates the main types of linkage between ring clusters and also some of the heteroatom forms that are found in coal. 20 APPENDIX II...used more widely as petroleum and natural gas resources are depleted and hydrogen for coal liquefaction processes will be produced predominantly from

  19. Charge transport-driven selective oxidation of graphene.

    PubMed

    Lee, Young Keun; Choi, Hongkyw; Lee, Changhwan; Lee, Hyunsoo; Goddeti, Kalyan C; Moon, Song Yi; Doh, Won Hui; Baik, Jaeyoon; Kim, Jin-Soo; Choi, Jin Sik; Choi, Choon-Gi; Park, Jeong Young

    2016-06-02

    Due to the tunability of the physical, electrical, and optical characteristics of graphene, precisely controlling graphene oxidation is of great importance for potential applications of graphene-based electronics. Here, we demonstrate a facile and precise way for graphene oxidation controlled by photoexcited charge transfer depending on the substrate and bias voltage. It is observed that graphene on TiO2 is easily oxidized under UV-ozone treatment, while graphene on SiO2 remains unchanged. The mechanism for the selective oxidation of graphene on TiO2 is associated with charge transfer from the TiO2 to the graphene. Raman spectra were used to investigate the graphene following applied bias voltages on the graphene/TiO2 diode under UV-ozone exposure. We found that under a reverse bias of 0.6 V on the graphene/TiO2 diode, graphene oxidation was accelerated under UV-ozone exposure, thus confirming the role of charge transfer between the graphene and the TiO2 that results in the selective oxidation of the graphene. The selective oxidation of graphene can be utilized for the precise, nanoscale patterning of the graphene oxide and locally patterned chemical doping, finally leading to the feasibility and expansion of a variety of graphene-based applications.

  20. 1999 resource assessment of selected Tertiary coal beds and zones in the Northern Rocky Mountains and Great Plains region

    USGS Publications Warehouse

    ,

    1999-01-01

    The USGS has assessed resources of selected coal of the Fort Union Formation and equivalent units in the Northern Rocky Mountains and Great Plains region. The assessment focused on coal in the Powder River, Williston, Hanna-Carbon, and Greater Green River basins most likely to be utilized in the next few decades. In other basins in the region Tertiary coal resources are summarized but not assessed. Disc 1, in PDF files, includes results of the assessment and chapters on coal geology, quantity and quality, and land use and ownership. Disc 2 provides GIS files for land use and ownership maps and geologic maps, and basic GIS data for the assessed basins. ArcView shapefiles, PDF files for cross sections and TIFF files are included along with ArcView Datapublisher software for Windows-based computer systems.

  1. Studies of incipient oxidation of coal-pyrite for improved pyrite rejection

    SciTech Connect

    Yoon, R.H.; Richardson, P.E.

    1992-01-01

    In order to foster the development of advanced coal cleaning technologies fundamental studies.of the initial stages of pyrite oxidation have been.initiated. This work is being done on pyrite surfaces that are freshly fractured in an electrolyte solution. This procedure produces surfaces that are initially unoxidized, allowing the subsequent oxidation processes to be studied in detail. It is shown that freshly fractured pyrite electrodes instantaneously (at fracture) assume a rest potential several hundred millivolts more negative than the usual open-circuit potential. A finite, anodic photocurrent, is also observed on the fractured electrodes. Following cleavage, the rest potential increases, indicating an oxidation reaction occurring on the electrodes. The photocurrent is relatively insensitive to this oxidation process, and to moderate anodic and cathodic polarization. However, strong cathodic polarization to about -0.76 V (SHE) at pH 9.2 causes the photocurrent to decrease to zero. No reversal in the sign of the photocurrent is observed and it is believed that the flat band potential occurs near -0.76 V, i.e., where the photocurrent goes to zero. Voltammetry indicates that pyrite also undergoes cathodic decomposition at -0.76 V. This establishes that pyrite must be cathodically decomposed to reach the flat band potential.

  2. Low temperature catalytic oxidation of hydrogen sulfide and methanethiol using wood and coal fly ash.

    PubMed

    Kastner, James R; Das, K C; Buquoi, Quentin; Melear, Nathan D

    2003-06-01

    The feasibility of reusing waste material as an inexpensive catalyst to remove sulfur compounds from gaseous waste streams has been demonstrated. Wood and coal fly ash were demonstrated to catalytically oxidize H2S and methanethiol (CH3SH) at low temperatures (23-25 degrees C). Wood ash had a significantly higher surface area compared to coal ash (44.9 vs 7.7 m2/g), resulting in a higher initial H2S removal rate (0.16 vs 0.018 mg/g/min) under similar conditions. Elemental sulfur was determined to be the end product of H2S oxidation, since X-ray diffraction analysis indicated the presence of crystalline sulfur. Catalytic decay occurred apparently due to surface deposition of sulfur and a subsequent decline in surface area (44.9-1.4 m2/g) during the reaction of H2S with the ash. Methanethiol was stoichiometrically converted to dimethyl disulfide ((CH3)2S2) without significant catalytic decay. Catalytic decay was reduced and H2S conversion increased (10% at 1.8 days vs 94% at 4.2 days) when H2S loading was decreased to levels typical of many environmental applications (500 ppmv inlet and 1.43 mg/min vs 60 ppmv, 0.09 mg/ min). Catalyst regeneration using hot water (85 degrees C) washing was possible, but only increased fractional conversion from 0.2 to 0.6 and the initial reaction rate to 50% of the original H2S oxidation activity.

  3. Two Catalysts for Selective Oxidation of Contaminant Gases

    NASA Technical Reports Server (NTRS)

    Wright, John D.

    2011-01-01

    Two catalysts for the selective oxidation of trace amounts of contaminant gases in air have been developed for use aboard the International Space Station. These catalysts might also be useful for reducing concentrations of fumes in terrestrial industrial facilities especially facilities that use halocarbons as solvents, refrigerant liquids, and foaming agents, as well as facilities that generate or utilize ammonia. The first catalyst is of the supported-precious-metal type. This catalyst is highly active for the oxidation of halocarbons, hydrocarbons, and oxygenates at low concentrations in air. This catalyst is more active for the oxidation of hydrocarbons and halocarbons than are competing catalysts developed in recent years. This catalyst completely converts these airborne contaminant gases to carbon dioxide, water, and mineral acids that can be easily removed from the air, and does not make any chlorine gas in the process. The catalyst is thermally stable and is not poisoned by chlorine or fluorine atoms produced on its surface during the destruction of a halocarbon. In addition, the catalyst can selectively oxidize ammonia to nitrogen at a temperature between 200 and 260 C, without making nitrogen oxides, which are toxic. The temperature of 260 C is higher than the operational temperature of any other precious-metal catalyst that can selectively oxidize ammonia. The purpose of the platinum in this catalyst is to oxidize hydrocarbons and to ensure that the oxidation of halocarbons goes to completion. However, the platinum exhibits little or no activity for initiating the destruction of halocarbons. Instead, the attack on the halocarbons is initiated by the support. The support also provides a high surface area for exposure of the platinum. Moreover, the support resists deactivation or destruction by halogens released during the destruction of halocarbons. The second catalyst is of the supported- metal-oxide type. This catalyst can selectively oxidize ammonia to

  4. Method For Selective Catalytic Reduction Of Nitrogen Oxides

    DOEpatents

    Mowery-Evans, Deborah L.; Gardner, Timothy J.; McLaughlin, Linda I.

    2005-02-15

    A method for catalytically reducing nitrogen oxide compounds (NO.sub.x, defined as nitric oxide, NO, +nitrogen dioxide, NO.sub.2) in a gas by a material comprising a base metal consisting essentially of CuO and Mn, and oxides of Mn, on an activated metal hydrous metal oxide support, such as HMO:Si. A promoter, such as tungsten oxide or molybdenum oxide, can be added and has been shown to increase conversion efficiency. This method provides good conversion of NO.sub.x to N.sub.2, good selectivity, good durability, resistance to SO.sub.2 aging and low toxicity compared with methods utilizing vanadia-based catalysts.

  5. Method for selective catalytic reduction of nitrogen oxides

    DOEpatents

    Mowery-Evans, Deborah L.; Gardner, Timothy J.; McLaughlin, Linda I.

    2005-02-15

    A method for catalytically reducing nitrogen oxide compounds (NO.sub.x, defined as nitric oxide, NO, +nitrogen dioxide, NO.sub.2) in a gas by a material comprising a base metal consisting essentially of CuO and Mn, and oxides of Mn, on an activated metal hydrous metal oxide support, such as HMO:Si. A promoter, such as tungsten oxide or molybdenum oxide, can be added and has been shown to increase conversion efficiency. This method provides good conversion of NO.sub.x to N.sub.2, good selectivity, good durability, resistance to SO.sub.2 aging and low toxicity compared with methods utilizing vanadia-based catalysts.

  6. Greenhouse gas emissions from Australian open-cut coal mines: contribution from spontaneous combustion and low-temperature oxidation.

    PubMed

    Day, Stuart J; Carras, John N; Fry, Robyn; Williams, David J

    2010-07-01

    Spontaneous combustion and low-temperature oxidation of waste coal and other carbonaceous material at open-cut coal mines are potentially significant sources of greenhouse gas emissions. However, the magnitude of these emissions is largely unknown. In this study, emissions from spontaneous combustion and low-temperature oxidation were estimated for six Australian open-cut coal mines with annual coal production ranging from 1.7 to more than 16 Mt. Greenhouse emissions from all other sources at these mines were also estimated and compared to those from spontaneous combustion and low-temperature oxidation. In all cases, fugitive emission of methane was the largest source of greenhouse gas; however, in some mines, spontaneous combustion accounted for almost a third of all emissions. For one mine, it was estimated that emissions from spontaneous combustion were around 250,000 t CO(2)-e per annum. The contribution from low-temperature oxidation was generally less than about 1% of the total for all six mines. Estimating areas of spoil affected by spontaneous combustion by ground-based surveys was prone to under-report the area. Airborne infrared imaging appears to be a more reliable method.

  7. Characterization of Manganese Oxide Precipitates from Appalachian Coal Mine Mine Drainage Treatment Systems

    SciTech Connect

    Tan, H.; Zhang, G; Heaney, P; Webb, S; Burgos, W

    2010-01-01

    The removal of Mn(II) from coal mine drainage (CMD) by chemical addition/active treatment can significantly increase treatment costs. Passive treatment for Mn removal involves promotion of biological oxidative precipitation of manganese oxides (MnO{sub x}). Manganese(II) removal was studied in three passive treatment systems in western Pennsylvania that differed based on their influent Mn(II) concentrations (20-150 mg/L), system construction ({+-}inoculation with patented Mn(II)-oxidizing bacteria), and bed materials (limestone vs. sandstone). Manganese(II) removal occurred at pH values as low as 5.0 and temperatures as low as 2 C, but was enhanced at circumneutral pH and warmer temperatures. Trace metals such as Zn, Ni and Co were removed effectively, in most cases preferentially, into the MnO{sub x} precipitates. Based on synchrotron radiation X-ray diffraction and Mn K-edge extended X-ray absorption fine structure spectroscopy, the predominant Mn oxides at all sites were poorly crystalline hexagonal birnessite, triclinic birnessite and todorokite. The surface morphology of the MnOx precipitates from all sites was coarse and 'sponge-like' composed of nm-sized lathes and thin sheets. Based on scanning electron microscopy (SEM), MnO{sub x} precipitates were found in close proximity to both prokaryotic and eukaryotic organisms. The greatest removal efficiency of Mn(II) occurred at the one site with a higher pH in the bed and a higher influent total organic C (TOC) concentration (provided by an upstream wetland). Biological oxidation of Mn(II) driven by heterotrophic activity was most likely the predominant Mn removal mechanism in these systems. Influent water chemistry and Mn(II) oxidation kinetics affected the relative distribution of MnOx mineral assemblages in CMD treatment systems.

  8. Progressive Oxidation of Pyrite in Five Bituminous Coal Samples: An As XANES and 57Fe Mossbauer Spectroscopic Study

    SciTech Connect

    Kolker,A.; Huggins, F.

    2007-01-01

    Naturally occurring pyrite commonly contains minor substituted metals and metalloids (As, Se, Hg, Cu, Ni, etc.) that can be released to the environment as a result of its weathering. Arsenic, often the most abundant minor constituent in pyrite, is a sensitive monitor of progressive pyrite oxidation in coal. To test the effect of pyrite composition and environmental parameters on the rate and extent of pyrite oxidation in coal, splits of five bituminous coal samples having differing amounts of pyrite and extents of As substitution in the pyrite, were exposed to a range of simulated weathering conditions over a period of 17 months. Samples investigated include a Springfield coal from Indiana (whole coal pyritic S = 2.13 wt.%; As in pyrite = detection limit (d.l.) to 0.06 wt.%), two Pittsburgh coal samples from West Virginia (pyritic S = 1.32-1.58 wt.%; As in pyrite = d.l. to 0.34 wt.%), and two samples from the Warrior Basin, Alabama (pyritic S = 0.26-0.27 wt.%; As in pyrite = d.l. to 2.72 wt.%). Samples were collected from active mine faces, and expected differences in the concentration of As in pyrite were confirmed by electron microprobe analysis. Experimental weathering conditions in test chambers were maintained as follows: (1) dry Ar atmosphere; (2) dry O{sub 2} atmosphere; (3) room atmosphere (relative humidity {approx}20-60%); and (4) room atmosphere with samples wetted periodically with double-distilled water. Sample splits were removed after one month, nine months, and 17 months to monitor the extent of As and Fe oxidation using As X-ray absorption near-edge structure (XANES) spectroscopy and {sup 57}Fe Mossbauer spectroscopy, respectively. Arsenic XANES spectroscopy shows progressive oxidation of pyritic As to arsenate, with wetted samples showing the most rapid oxidation. {sup 57}Fe Mossbauer spectroscopy also shows a much greater proportion of Fe{sup 3+} forms (jarosite, Fe{sup 3+} sulfate, FeOOH) for samples stored under wet conditions, but much less

  9. Progressive oxidation of pyrite in five bituminous coal samples: An As XANES and 57Fe Mössbauer spectroscopic study

    USGS Publications Warehouse

    Kolker, Allan; Huggins, Frank E.

    2007-01-01

    Naturally occurring pyrite commonly contains minor substituted metals and metalloids (As, Se, Hg, Cu, Ni, etc.) that can be released to the environment as a result of its weathering. Arsenic, often the most abundant minor constituent in pyrite, is a sensitive monitor of progressive pyrite oxidation in coal. To test the effect of pyrite composition and environmental parameters on the rate and extent of pyrite oxidation in coal, splits of five bituminous coal samples having differing amounts of pyrite and extents of As substitution in the pyrite, were exposed to a range of simulated weathering conditions over a period of 17 months. Samples investigated include a Springfield coal from Indiana (whole coal pyritic S = 2.13 wt.%; As in pyrite = detection limit (d.l.) to 0.06 wt.%), two Pittsburgh coal samples from West Virginia (pyritic S = 1.32–1.58 wt.%; As in pyrite = d.l. to 0.34 wt.%), and two samples from the Warrior Basin, Alabama (pyritic S = 0.26–0.27 wt.%; As in pyrite = d.l. to 2.72 wt.%). Samples were collected from active mine faces, and expected differences in the concentration of As in pyrite were confirmed by electron microprobe analysis. Experimental weathering conditions in test chambers were maintained as follows: (1) dry Ar atmosphere; (2) dry O2 atmosphere; (3) room atmosphere (relative humidity ∼20–60%); and (4) room atmosphere with samples wetted periodically with double-distilled water. Sample splits were removed after one month, nine months, and 17 months to monitor the extent of As and Fe oxidation using As X-ray absorption near-edge structure (XANES) spectroscopy and 57Fe Mössbauer spectroscopy, respectively. Arsenic XANES spectroscopy shows progressive oxidation of pyritic As to arsenate, with wetted samples showing the most rapid oxidation. 57Fe Mössbauer spectroscopy also shows a much greater proportion of Fe3+ forms (jarosite, Fe3+ sulfate, FeOOH) for samples stored under wet conditions, but much less

  10. Method and reaction pathway for selectively oxidizing organic compounds

    DOEpatents

    Camaioni, Donald M.; Lilga, Michael A.

    1998-01-01

    A method of selectively oxidizing an organic compound in a single vessel comprises: a) combining an organic compound, an acid solution in which the organic compound is soluble, a compound containing two oxygen atoms bonded to one another, and a metal ion reducing agent capable of reducing one of such oxygen atoms, and thereby forming a mixture; b) reducing the compound containing the two oxygen atoms by reducing one of such oxygen atoms with the metal ion reducing agent to, 1) oxidize the metal ion reducing agent to a higher valence state, and 2) produce an oxygen containing intermediate capable of oxidizing the organic compound; c) reacting the oxygen containing intermediate with the organic compound to oxidize the organic compound into an oxidized organic intermediate, the oxidized organic intermediate having an oxidized carbon atom; d) reacting the oxidized organic intermediate with the acid counter ion and higher valence state metal ion to bond the acid counter ion to the oxidized carbon atom and thereby produce a quantity of an ester incorporating the organic intermediate and acid counter ion; and e) reacting the oxidized organic intermediate with the higher valence state metal ion and water to produce a quantity of alcohol which is less than the quantity of ester, the acid counter ion incorporated in the ester rendering the carbon atom bonded to the counter ion less reactive with the oxygen containing intermediate in the mixture than is the alcohol with the oxygen containing intermediate.

  11. Heat removal from high temperature tubular solid oxide fuel cells utilizing product gas from coal gasifiers.

    SciTech Connect

    Parkinson, W. J. ,

    2003-01-01

    In this work we describe the results of a computer study used to investigate the practicality of several heat exchanger configurations that could be used to extract heat from tubular solid oxide fuel cells (SOFCs) . Two SOFC feed gas compositions were used in this study. They represent product gases from two different coal gasifier designs from the Zero Emission Coal study at Los Alamos National Laboratory . Both plant designs rely on the efficient use of the heat produced by the SOFCs . Both feed streams are relatively rich in hydrogen with a very small hydrocarbon content . One feed stream has a significant carbon monoxide content with a bit less hydrogen . Since neither stream has a significant hydrocarbon content, the common use of the endothermic reforming reaction to reduce the process heat is not possible for these feed streams . The process, the method, the computer code, and the results are presented as well as a discussion of the pros and cons of each configuration for each process .

  12. Characterization and evaluation of washability of Alaskan coals: Fifty selected seams from various coal fields: Final technical report, September 30, 1976-February 28, 1986. [50 coal seams

    SciTech Connect

    Rao, P.D.

    1986-09-01

    This final report is the result of a study initiated in 1976 to obtain washability data for Alaskan coals, to supplement the efforts of the US Department of Energy in their ongoing studies on washability of US coals. Washability characteristics were determined for fifty coal samples from the Northern Alaska, Chicago Creek, Unalakleet, Nenana, Matanuska, Beluga, Yentna and Herendeen Bay coal fields. The raw coal was crushed to 1-1/2 inches, 3/8 inch, 14 mesh and 65 mesh top sizes, and float-sink separations were made at 1.30, 1.40 and 1.60 specific gravities. A limited number of samples were also crushed to 200 and 325 mesh sizes prior to float-sink testing. Samples crushed to 65 mesh top size were also separated at 1.60 specific gravity and the float and sink products were characterized for proximate and ultimate analyses, ash composition and ash fusibility. 72 refs., 79 figs., 57 tabs.

  13. Small-Scale Coal-Biomass to Liquids Production Using Highly Selective Fischer-Tropsch Synthesis

    SciTech Connect

    Gangwal, Santosh K.; McCabe, Kevin

    2015-04-30

    The research project advanced coal-to-liquids (CTL) and coal-biomass to liquids (CBTL) processes by testing and validating Chevron’s highly selective and active cobalt-zeolite hybrid Fischer-Tropsch (FT) catalyst to convert gasifier syngas predominantly to gasoline, jet fuel and diesel range hydrocarbon liquids, thereby eliminating expensive wax upgrading operations The National Carbon Capture Center (NCCC) operated by Southern Company (SC) at Wilsonville, Alabama served as the host site for the gasifier slip-stream testing/demonstration. Southern Research designed, installed and commissioned a bench scale skid mounted FT reactor system (SR-CBTL test rig) that was fully integrated with a slip stream from SC/NCCC’s transport integrated gasifier (TRIGTM). The test-rig was designed to receive up to 5 lb/h raw syngas augmented with bottled syngas to adjust the H2/CO molar ratio to 2, clean it to cobalt FT catalyst specifications, and produce liquid FT products at the design capacity of 2 to 4 L/day. It employed a 2-inch diameter boiling water jacketed fixed-bed heat-exchange FT reactor incorporating Chevron’s catalyst in Intramicron’s high thermal conductivity micro-fibrous entrapped catalyst (MFEC) packing to efficiently remove heat produced by the highly exothermic FT reaction.

  14. Selective aerobic oxidation mediated by TiO(2) photocatalysis.

    PubMed

    Lang, Xianjun; Ma, Wanhong; Chen, Chuncheng; Ji, Hongwei; Zhao, Jincai

    2014-02-18

    TiO2 is one of the most studied metal oxide photocatalysts and has unparal-leled efficiency and stability. This cheap, abundant, and non-toxic material has the potential to address future environmental and energy concerns. Understanding about the photoinduced interfacial redox events on TiO2 could have profound effect on the degradation of organic pollutants, splitting of H2O into H2 and O2, and selective redox organic transformations. Scientists traditionally accept that for a semiconductor photocatalyst such as TiO2 under the illumination of light with energy larger than its band gap, two photocarriers will be created to carry out their independent reduction and oxidation processes. However, our recent discoveries indicate that it is the concerted rather than independent effect of both photocarriers of valence band hole (hvb(+)) and conduction band electron (ecb(-)) that dictate the product formation during interfacial oxidation event mediated by TiO2 photocatalysis. In this Account, we describe our recent findings on the selective oxidation of organic substrates with O2 mediated by TiO2 photocatalysis. The transfer of O-atoms from O2 to the corresponding products dominates the selective oxidation of alcohols, amines, and alkanes mediated by TiO2 photocatalysis. We ascribe this to the concerted effect of both hvb(+) and ecb(-) of TiO2 in contribution to the oxidation products. These findings imply that O2 plays a unique role in its transfer into the products rather than independent role of ecb(-) scavenger. More importantly, ecb(-) plays a crucial role to ensure the high selectivity for the oxygenation of organic substrates. We can also use the half reactions such as those of the conduction band electron of TiO2 for efficient oxidation reactions with O2. To this end, efficient selective oxidation of organic substrates such as alcohols, amines, and aromatic alkanes with O2 mediated by TiO2 photocatalysis under visible light irradiation has been achieved. In

  15. Partitioning of selected trace elements in coal combustion products from two coal-burning power plants in the United States

    USGS Publications Warehouse

    Swanson, Sharon M.; Engle, Mark A.; Ruppert, Leslie F.; Affolter, Ronald H.; Jones, Kevin B.

    2013-01-01

    Samples of feed coal (FC), bottom ash (BA), economizer fly ash (EFA), and fly ash (FA) were collected from power plants in the Central Appalachian basin and Colorado Plateau to determine the partitioning of As, Cr, Hg, Pb, and Se in coal combustion products (CCPs). The Appalachian plant burns a high-sulfur (about 3.9 wt.%) bituminous coal from the Upper Pennsylvanian Pittsburgh coal bed and operates with electrostatic precipitators (ESPs), with flue gas temperatures of about 163 °C in the ESPs. At this plant, As, Pb, Hg, and Se have the greatest median concentrations in FA samples, compared to BA and EFA. A mass balance (not including the FGD process) suggests that the following percentages of trace elements are captured in FA: As (48%), Cr (58%), Pb (54%), Se (20%), and Hg (2%). The relatively high temperatures of the flue gas in the ESPs and low amounts of unburned C in FA (0.5% loss-on-ignition for FA) may have led to the low amount of Hg captured in FA. The Colorado Plateau plant burns a blend of three low-S (about 0.74 wt.%) bituminous coals from the Upper Cretaceous Fruitland Formation and operates with fabric filters (FFs). Flue gas temperatures in the baghouses are about 104 °C. The elements As, Cr, Pb, Hg, and Se have the greatest median concentrations in the fine-grained fly ash product (FAP) produced by cyclone separators, compared to the other CCPs at this plant. The median concentration of Hg in FA (0.0983 ppm) at the Colorado Plateau plant is significantly higher than that for the Appalachian plant (0.0315 ppm); this higher concentration is related to the efficiency of FFs in Hg capture, the relatively low temperatures of flue gas in the baghouses (particularly in downstream compartments), and the amount of unburned C in FA (0.29% loss-on-ignition for FA).

  16. Combustion process and nitrogen oxides emission of Shenmu coal added with sodium acetate

    SciTech Connect

    Yang Weijuan; Zhou Junhu; Liu Maosheng; Zhou Zhijun; Liu Jianzhong; Cen Kefa

    2007-09-15

    Shenmu bituminous coal with 4% sodium acetate added was used to investigate the characteristics of combustion and nitrogen oxide (NOx) release in a fixed bed reactor heated by a tube furnace. The composition of the flue gas was analyzed to investigate the effects of sodium acetate on the combustion process and NOx emission. The experiments were carried out in a partial reductive atmosphere and a strong oxidative atmosphere. The O{sub 2} valley value in the partial reductive atmosphere was reduced by the added sodium acetate. Sodium acetate accelerated the combustion and shortened the combustion process. The experimental results showed that the emissions of NO, NO{sub 2}, and N{sub 2}O were affected by the reacting atmosphere and the combustion temperature. In the strong oxidative atmosphere, sodium acetate resulted in a slight NOx reduction. In the partial reductive atmosphere, sodium acetate reduced both the peak value of NO concentration and the total NO emission significantly. An over 30% NOx reduction efficiency was achieved at 900{sup o}C in the partial reductive atmosphere, which decreased with the increase in temperature. Sodium acetate was decomposed into hydrocarbon radicals and sodium hydroxide, which can both reduce NOx emissions due to their special reactions with the nitrogen component. 17 refs., 11 figs., 2 tabs.

  17. Reduction of Nitrogen Oxides Emissions from a Coal-Fired Boiler Unit

    NASA Astrophysics Data System (ADS)

    Zhuikov, Andrey V.; Feoktistov, Dmitry V.; Koshurnikova, Natalya N.; Zlenko, Lyudmila V.

    2016-02-01

    During combustion of fossil fuels a large amount of harmful substances are discharged into the atmospheres of cities by industrial heating boiler houses. The most harmful substances among them are nitrogen oxides. The paper presents one of the most effective technological solutions for suppressing nitrogen oxides; it is arrangement of circulation process with additional mounting of the nozzle directed into the bottom of the ash hopper. When brown high-moisture coals are burnt in the medium power boilers, generally fuel nitrogen oxides are produced. It is possible to reduce their production by two ways: lowering the temperature in the core of the torch or decreasing the excess-air factor in the boiler furnace. Proposed solution includes the arrangement of burning process with additional nozzle installed in the lower part of the ash hopper. Air supply from these nozzles creates vortex involving large unburned fuel particles in multiple circulations. Thereby time of their staying in the combustion zone is prolonging. The findings describe the results of the proposed solution; and recommendations for the use of this technological method are given for other boilers.

  18. Multiple sample characterization of coals and other substances by controlled-atmosphere programmed temperature oxidation

    DOEpatents

    LaCount, Robert B.

    1993-01-01

    A furnace with two hot zones holds multiple analysis tubes. Each tube has a separable sample-packing section positioned in the first hot zone and a catalyst-packing section positioned in the second hot zone. A mass flow controller is connected to an inlet of each sample tube, and gas is supplied to the mass flow controller. Oxygen is supplied through a mass flow controller to each tube to either or both of an inlet of the first tube and an intermediate portion between the tube sections to intermingle with and oxidize the entrained gases evolved from the sample. Oxidation of those gases is completed in the catalyst in each second tube section. A thermocouple within a sample reduces furnace temperature when an exothermic condition is sensed within the sample. Oxidized gases flow from outlets of the tubes to individual gas cells. The cells are sequentially aligned with an infrared detector, which senses the composition and quantities of the gas components. Each elongated cell is tapered inward toward the center from cell windows at the ends. Volume is reduced from a conventional cell, while permitting maximum interaction of gas with the light beam. Reduced volume and angulation of the cell inlets provide rapid purgings of the cell, providing shorter cycles between detections. For coal and other high molecular weight samples, from 50% to 100% oxygen is introduced to the tubes.

  19. Theoretically predicted rate constants for mercury oxidation by hydrogen chloride in coal combustion flue gases.

    PubMed

    Wilcox, Jennifer; Robles, Joe; Marsden, David C J; Blowers, Paul

    2003-09-15

    In this work, theoretical rate constants are estimated for mercury oxidation reactions by hydrogen chloride that may occur in the flue gases of coal combustion. Rate constants are calculated using transition state theory at the quadratic configuration interaction (QCI) level of theory with single and double excitations, and are compared to results obtained from density functional theory, both including high level pseudopotentials for mercury. Thermodynamic and kinetic data from the literature are used to assess the accuracy of the theoretical calculations when possible. Validation of the chosen methods and basis sets is based upon previous and current research on mercury reactions involving chlorine. The present research shows that the QCISD method with the 1992 Stevens et al. basis set leads to the most accurate kinetic and thermodynamic results for the oxidation of mercury via chlorine containing molecules. Also, a comparison of the heats of reaction data for a series of mercury oxidation reactions reveals that the density functional method, B3LYP, with the 1997 Stuttgart basis set provides reasonably accurate results for these large systems.

  20. Near-neutral oxidation of pyrite in coal slurry solids. Technical report, March 1--May 31, 1995

    SciTech Connect

    Frost, J.K.

    1995-12-31

    In this research project are determining the rate of oxidation of pyrite associated with coaly particles (coal slurry solid) when the pH of the surrounding environment is held at approximately 7.8. Coaly particles that contain pyrite are generated during the preparation of Illinois Basin coal for market. These particles are discharged to an impoundment, which eventually must be reclaimed. The purpose for reclamation is either to prevent the generation of acidic solution as the pyrite in the coal slurry solid reacts with air, or to prevent the migration of the acidic solution to a groundwater aquifer. The reclamation is usually accomplished by covering the impoundment with a four-foot-thick layer of topsoil. One possible alternative method for reclamation of a coal slurry impoundment is to mix in alkaline residue from the fluidized-bed combustion of coal. This codisposal would slow the production of acid and would also neutralize any acid produced. If the codisposal method is found to be environmentally acceptable, it will save the coal mining companies part of their cost of reclamation, and also provide a safe and useful disposal outlet for a portion of the residue that is generated by the fluidized-bed combustion of coal. Pyrite oxidation experiments were conducted during the quarter in the following manner. Air, free of carbon dioxide, is bubbled through water in a covered beaker. The pH is adjusted to 7.8 and the solution is circulated by a peristaltic pump through the coal slurry sample contained in a cellulose thimble in a Soxhlet tube mounted above the beaker. The pH of the solution is continuously statted to 7.8 by addition of NaOH solution. Samples are pipetted from the reaction solution for sulfate determination. The rate of oxidation of pyrite in coal slurry solids sample CSS-2a was calculated from the rate of production of sulfate ion to be 1.71 {times} 10{sup {minus}6} {micro}mole pyrite per minute per {micro}mole of pyrite present.

  1. Chemistry and origin of minor and trace elements in selected vitrinite concentrates from bituminous and anthracitic coals

    USGS Publications Warehouse

    Palmer, C.A.; Lyons, P.C.

    1990-01-01

    Twelve hand-picked vitrinite concentrates and companion whole-coal samples were analyzed for trace and minor elements by instrumental neutron activation analysis (INAA) and direct-current-arc spectrographic techniques (DCAS). The vitrinite concentrates contained 94 to nearly 100 vol.% vitrinite compared to 71-95 vol.% in the companion whole coals. The ash contents of the vitrinite concentrates were 2 to more than 190 times less than the ash contents of the companion whole coals. Organic and inorganic affinities were determined by comparing the elemental concentrations in the vitrinite concentrates to the concentrations in the companion whole coals. The ratios of these concentrations for 33 selected elements are shown in Figure 1. Ratios greater than 1 indicate organic affinity, and ratios less than 1 indicate inorganic affinity. Br and W generally showed organic affinity in all samples in this study. In the nine samples from the eastern United States (Fig. 1A-C) less than one-fourth of the trace elements show organic affinity compared to nearly one-half for the three English and Australian samples (Fig. 1D). The elements that generally show organic affinity in the non-U.S.A. samples studied include As, Cs, Hf, and Ni, which have generally inorganic affinities in the U.S.A. samples, and Cr, Sb, Se, and U, which have mixed (both organic and inorganic) affinities, in the U.S.A. coals studied, has an inorganic affinity in the English coals studied. B shows organic affinity in the samples from the Illinois basin (Fig. 1C). For the samples studied, Ba shows organic affinity in the Appalachian basin bituminous coals (Fig. 1B), inorganic affinity in the Illinois basin coals, and overall mixed affinities. In all the samples studied, Cu, Mn, Na, Sr, Ta, V, and Zn show mixed affinities, and A1, Co, Eu, Fe, Ga, K, La, Mg, Sc, Si, Th, Ti, and Ub have generally inorganic affinity. ?? 1990.

  2. The effect of selective absorption on coal conversion, October--December 1991

    SciTech Connect

    Larsen, J.W.; Lazarov, L.; Amui, J.

    1992-05-01

    The objectives of this report are to (1) determine the importance of the presence of added hydrogen donor compounds within the coal in the first stage of direct liquefaction processes; (2) determine the composition of the solvent absorbed by and present within the coal in the first stage of direct coal liquefaction.

  3. Selective solvent absorption in coal conversion. Quarterly report, July 1, 1991--September 30, 1991

    SciTech Connect

    Larsen, J.W.; Lapucha, A.; Lazarov, L.; Amui, J.

    1992-04-01

    The objectives of this project are: (1) to determine the importance of the presence of added hydrogen donor compounds within the coal in the first stage of direct liquefaction processes; and (2) to determine the composition of the solvent absorbed by and present within the coal in the first stage of direct coal liquefaction.

  4. THEORETICAL TECHNIQUE FOR DETERMINING THE CUMULATIVE IMPACT OF IRON AND MANGANESE OXIDATION IN STREAMS RECEIVING COAL-MINE DISCHARGE.

    USGS Publications Warehouse

    Bobay, Keith E.; Banaszak, Konrad J.; ,

    1985-01-01

    Two U. S. Geological Survey computer programs are modified and linked to predict the cumulative impact of iron and manganese oxidation in coal-mine discharge on the dissolved-chemical quality of a receiving stream. The coupled programs calculate the changes in dissolved-iron, dissolved-manganese, and dissolved-oxygen concentrations, and the pH of surface water downstream from the discharge. The cumulative impact of representative discharges from several coal mines on stream quality in a small watershed in southwestern Indiana was simulated to determine the effectiveness and sensitivity of the coupled programs.

  5. Porcelain enamelled absorbers, coated by spectral selective tin oxide

    SciTech Connect

    Simonis, F.; Faber, A.J.; Hoogendoorn, C.J.

    1987-02-01

    The use of porcelain enamelled absorbers in flat plate collectors features longevity thanks to the durability and thermal stability of the enamel finish. The porcelain enamel can be made spectral selective by coating with doped tin oxide or indium oxide. The application procedure involves an enamelling step followed by a pyrosol process with tin or indium compounds. The optical properties of tin oxide coated enamel yield values of 0.90-0.92 absorptance and 0.13-0.18 hemispherical emittance. The temperature dependence of the emittance is very small. The thermal stability has been proved up to 400/sup 0/C in air.

  6. Selection of fluxing agent for coal ash and investigation of fusion mechanism: a first-principles study

    SciTech Connect

    Jie Li; Mei-Fang Du; Zhong-Xiao Zhang; Rong-Qing Guan; Yu-Shuang Chen; Ting-Yu Liu

    2009-01-15

    An approach based on the ab initio quantum chemical modeling (CASTEP, generalized gradient approximation (GGA), and density functional theory (DFT)) was first employed to guide the selection of the appropriate fluxing agent to reduce the coal ash melting temperature. Two kinds of typical Chinese coal ash A and B with a high-melting temperature were chosen as the investigated subjects. Result of the calculation shows that mullite mineral, which is the main component of coal ash, is easier to combine with an electron acceptor than with an electron donor. Because the cations of borax (Na{sub 2}B{sub 4}O{sub 7}10H{sub 2}O) and limestone can act as electron acceptors, borax and limestone were selected as the fluxing agents in our experiment. Results of the experiment show that the melting temperatures of coal ash A and B are both decreased by borax and limestone, respectively. Moreover, borax has a better fluxing effect than limestone under the same conditions. The further numerical study on the coal ash fusing mechanism indicates that the Na{sup +} and Ca{sup 2+} cations, as acceptors, can enter into the crystal lattice of mullite mainly through O(7) and O(8) and then cause the Al(6)-O(8) and Al(5)-O(7) bonds to rupture in the (AlO{sub 6})-octahedron. From this, mullite is forced to transform to feldspar and corundum minerals that have a low binding energy. Because of the phase change of minerals in the coal ash, the coal ash melting temperature is decreased by adding borax and limestone. 27 refs., 8 figs., 3 tabs.

  7. Selective insertion of sulfur dioxide reduction intermediates on graphene oxide.

    PubMed

    Humeres, Eduardo; Debacher, Nito A; Smaniotto, Alessandra; de Castro, Karen M; Benetoli, Luís O B; de Souza, Eduardo P; Moreira, Regina de F P M; Lopes, Cristiane N; Schreiner, Wido H; Canle, Moisés; Santaballa, J Arturo

    2014-04-22

    Graphite microparticles (d50 6.20 μm) were oxidized by strong acids, and the resultant graphite oxide was thermally exfoliated to graphene oxide sheets (MPGO, C/O 1.53). Graphene oxide was treated with nonthermal plasma under a SO2 atmosphere at room temperature. The XPS spectrum showed that SO2 was inserted only as the oxidized intermediate at 168.7 eV in the S 2p region. Short thermal shocks at 600 and 400 °C, under an Ar atmosphere, produced reduced sulfur and carbon dioxide as shown by the XPS spectrum and TGA analysis coupled to FTIR. MPGO was also submitted to thermal reaction with SO2 at 630 °C, and the XPS spectrum in the S 2p region at 164.0 eV showed that this time only the nonoxidized episulfide intermediate was inserted. Plasma and thermal treatment produced a partial reduction of MPGO. The sequence of thermal reaction followed by plasma treatment inserted both sulfur intermediates. Because oxidized and nonoxidized intermediates have different reactivities, this selective insertion would allow the addition of selective types of organic fragments to the surface of graphene oxide.

  8. Selective cytotoxicity effect of cerium oxide nanoparticles under UV irradiation.

    PubMed

    Zhang, Li; Jiang, Hui; Selke, Matthias; Wang, Xuemei

    2014-02-01

    During photodynamic therapy (PDT) of cancers, there are numerous side effects, accompanied by damage to normal cells/tissues caused by the abnormal elevation of reactive oxygen species (ROS). In this paper, we aim to provide an effective method to reduce the relevant side effects of PDT by using cerium oxide nanoparticles. The well-dispersed poly(vinyl pyrrolidone) stabilized cerium oxide nanoparticles were successfully synthesized by using a one-pot method at 60 degrees C in slightly alkaline environment. The morphological and structural characterizations clearly illustrate the excellent lattice structures of cerium oxide, nanoparticles. The MTT assay indicates that these cerium oxide nanoparticles show no intrinsic cytotoxicity even at a concentration up to 300 micro g/mL. More importantly, the results demonstrate that these nanoparticles can selectively protect human normal cells but not the cancer cells from ROS damage after exposure to UV-radiation, suggesting their potential applications for PDT treatment. The rationale behind the selective protection effect can be attributed to the hindrance of the Ce (III)/Ce (IV) redox reaction cycle on the surface of cerium oxide nanoparticles due to the abnormal intracellular pH in cancer cells. Furthermore, these cerium oxide nanoparticles can be used as effective drug carriers for enhancing drug delivery efficiency to target cancer cells like hepatoma HepG2 cells. This raises the possibility of applying cerium oxide nanoparticles for multifunctional therapeutic applications, i.e., combination of efficient PDT and chemotherapy.

  9. Influence of composition of reaction mixture on selectivity in oxidation of aromatic compounds on oxide catalysts

    SciTech Connect

    Belokopytov, Yu.V.; Pyatnitskii, Yu.I.; Tatarinova, T.A.; Strashnenko, A.V.

    1985-07-01

    A general outline is given of a kinetic model of oxidation of a hydrocarbon under the conditions of coexistence on the catalyst surface of sections of different oxidation levels. An analytical dependence has been obtained of the selectivity of the process and conversion on the composition of the reaction mixture. A qualitative agreement has been established between the theoretical and experimental dependences of selectivity and conversion on the ratio of the benzene and oxygen concentrations in the reaction mixture.

  10. Effect of Coal Contaminants on Solid Oxide Fuel System Performance and Service Life

    SciTech Connect

    Krishnan, Gopala N.; Jayaweera, Palitha; Perez, Jordi; Hornbostel, M.; Albritton, John R.; Gupta, Raghubir P.

    2007-10-31

    The U.S. Department of Energy’s SECA program envisions the development of high-efficiency, low-emission, CO2 sequestration-ready, and fuel-flexible technology to produce electricity from fossil fuels. One such technology is the integrated gasification-solid oxide fuel cell (SOFC) that produces electricity from the gas stream of a coal gasifier. SOFCs have high fuel-to-electricity conversion efficiency, environmental compatibility (low NOx production), and modularity. The primary objective of the Phase I study was to determine the sensitivity of the performance of solid oxide fuel cells to trace level contaminants present in a coal-derived gas stream in the temperature range 700° to 900°C. Laboratory-scale tests were performed with 1-inch diameter solid oxide fuel cells procured from InDec B.V., Netherlands. These cells produce 0.15, 0.27, and 0.35 W/cm2 at 700°, 750°, and 800°C, respectively, in a H2 anode feed and are expected to be stable within 10% of the original performance over a period of 2000 h. A simulated coal-derived gas containing 30.0% CO, 30.6% H2 11.8% CO2, 27.6% H2O was used at a rate of ~100 standard cm3/min to determine the effect of contaminants on the electrical performance of the cells. Alumina or zirconia components were used for the gas manifold to prevent loss of contaminants by reaction with the surfaces of the gas manifold Short-term accelerated tests were conducted with several contaminants including As, P, CH3Cl, HCl, Hg, Sb, and Zn vapors. In these tests, AsH3, PH3, Cd vapor and CH3Cl identified as the potential contaminants that can affect the electrical performance of SOFCs. The effect of some of these contaminants varied with the operating temperature. Cell failure due to contact break inside the anode chamber occurred when the cell was exposed to 10 ppm arsenic vapor at 800°C. The electrical performance of SOFC

  11. Charge transport-driven selective oxidation of graphene

    NASA Astrophysics Data System (ADS)

    Lee, Young Keun; Choi, Hongkyw; Lee, Changhwan; Lee, Hyunsoo; Goddeti, Kalyan C.; Moon, Song Yi; Doh, Won Hui; Baik, Jaeyoon; Kim, Jin-Soo; Choi, Jin Sik; Choi, Choon-Gi; Park, Jeong Young

    2016-06-01

    Due to the tunability of the physical, electrical, and optical characteristics of graphene, precisely controlling graphene oxidation is of great importance for potential applications of graphene-based electronics. Here, we demonstrate a facile and precise way for graphene oxidation controlled by photoexcited charge transfer depending on the substrate and bias voltage. It is observed that graphene on TiO2 is easily oxidized under UV-ozone treatment, while graphene on SiO2 remains unchanged. The mechanism for the selective oxidation of graphene on TiO2 is associated with charge transfer from the TiO2 to the graphene. Raman spectra were used to investigate the graphene following applied bias voltages on the graphene/TiO2 diode under UV-ozone exposure. We found that under a reverse bias of 0.6 V on the graphene/TiO2 diode, graphene oxidation was accelerated under UV-ozone exposure, thus confirming the role of charge transfer between the graphene and the TiO2 that results in the selective oxidation of the graphene. The selective oxidation of graphene can be utilized for the precise, nanoscale patterning of the graphene oxide and locally patterned chemical doping, finally leading to the feasibility and expansion of a variety of graphene-based applications.Due to the tunability of the physical, electrical, and optical characteristics of graphene, precisely controlling graphene oxidation is of great importance for potential applications of graphene-based electronics. Here, we demonstrate a facile and precise way for graphene oxidation controlled by photoexcited charge transfer depending on the substrate and bias voltage. It is observed that graphene on TiO2 is easily oxidized under UV-ozone treatment, while graphene on SiO2 remains unchanged. The mechanism for the selective oxidation of graphene on TiO2 is associated with charge transfer from the TiO2 to the graphene. Raman spectra were used to investigate the graphene following applied bias voltages on the graphene/TiO2

  12. Testing of pyrite flotation techniques on selected Ohio coals: Final report

    SciTech Connect

    Arnold, B.J.; Torak, E.R.

    1989-05-01

    The project was conceived to demonstrate the combining of conventional physical coal cleaning with emerging advanced physical coal cleaning technologies in a cost-effective manner. The objectives of the program were to demonstrate that conventional coal cleaning followed by advanced coal cleaning of a crushed mid-gravity portion of the run-of-mine coal would produce a clean coal, suitable for use as a thermal coal, having a lower ash content and a lower sulfur dioxide emission potential than a coal cleaned only be current conventional cleaning technologies. As part of this program a number of advanced flotation techniques were tested to determine the feasibility of including them in the design of their Advanced Coal Preparation Facility. The program consisted of testing the Pittsburgh seam, the Middle Kittanning seam, and the Meigs Creek seam coals in the pilot flotation circuit at EPRI's Coal Quality Development Center (CQDC) in Homer City, Pennsylvania. This report contains all the data from OCDO's pilot flotation test program at the CQDC and the test data from the Middle Kittanning and Meigs Creek reverse flotation tests. 13 figs., 40 tabs.

  13. Kinetic parameters for the oxidation of pulverised coal as measured from drop tube tests

    SciTech Connect

    Ballester, J.; Jimenez, S.

    2005-08-01

    The methodology for measuring the oxidation parameters for pulverised coal combustion from drop-tube tests is reviewed, and some modifications to the traditional procedure (based on Arrhenius plots) are proposed. The work includes the experimental characterisation of an anthracite's combustion in a drop-tube furnace, which will be used as the reference data. One of the main points in the discussion is the consideration of a particle-size distribution instead of a single representative diameter. Since a true monosized sample cannot be obtained by sieving, the particles injected always display a size distribution and, therefore, the experimental results are the outcome of a range of oxidation rates. As a result, the assumption of a single particle size cannot explain some aspects of the experimental results (e.g., the 'curvature' of the burnoff curve) and may lead to significant deviations in the calculated parameters. On the other hand, an alternative method for deriving the parameters, based on calculating the particle's full combustion history, is proposed. The analysis presented here enables a more systematic and unambiguous approach for deriving the kinetic parameters for oxidation from experimental measurements. If the actual particle-size distribution is taken into account, the calculations are in good agreement with the experimental results and, in particular, reproduce the progressive decay in apparent oxidation rate while the fuel burns. Even though the deviations might still be reduced by using a more sophisticated model (e.g., accounting for heterogeneity in the particles' properties, or deactivation phenomena), the results obtained suggest that such corrections should be relatively small, the correct treatment of the size distribution of the particles being more important in this case.

  14. Advanced treatment of biologically pretreated coal gasification wastewater by a novel heterogeneous Fenton oxidation process.

    PubMed

    Zhuang, Haifeng; Han, Hongjun; Ma, Wencheng; Hou, Baolin; Jia, Shengyong; Zhao, Qian

    2015-07-01

    Sewage sludge from a biological wastewater treatment plant was converted into sewage sludge based activated carbon (SBAC) with ZnCl2 as activation agent, which was used as a support for ferric oxides to form a catalyst (FeOx/SBAC) by a simple impregnation method. The new material was then used to improve the performance of Fenton oxidation of real biologically pretreated coal gasification wastewater (CGW). The results indicated that the prepared FeOx/SBAC significantly enhanced the pollutant removal performance in the Fenton process, so that the treated wastewater was more biodegradable and less toxic. The best performance was obtained over a wide pH range from 2 to 7, temperature 30°C, 15 mg/L of H2O2 and 1g/L of catalyst, and the treated effluent concentrations of COD, total phenols, BOD5 and TOC all met the discharge limits in China. Meanwhile, on the basis of significant inhibition by a radical scavenger in the heterogeneous Fenton process as well as the evolution of FT-IR spectra of pollutant-saturated FeOx/BAC with and without H2O2, it was deduced that the catalytic activity was responsible for generating hydroxyl radicals, and a possible reaction pathway and interface mechanism were proposed. Moreover, FeOx/SBAC showed superior stability over five successive oxidation runs. Thus, heterogeneous Fenton oxidation of biologically pretreated CGW by FeOx/SBAC, with the advantages of being economical, efficient and sustainable, holds promise for engineering application.

  15. Brazilian coal mining residues and sulphide oxidation by Fenton's reaction: an accelerated weathering procedure to evaluate possible environmental impact.

    PubMed

    Silva, L F O; Querol, X; da Boit, K M; Fdez-Ortiz de Vallejuelo, S; Madariaga, J M

    2011-02-15

    Fenton's reaction is proposed as an accelerated weathering test for sulphides associated with Brazilian Coal Mining Residues (CMR), that are exposed to oxygen and water during the mining of coal. TEM and SEM/EDX were used to evaluate the nature, occurrence and distribution of minerals in remaining coals and other lithological units, before and after applying the test. Oxidation of CMRs was examined by analyzing soluble sulphur (sulphate) and dissolved metals by ICP-MS or ICP OES. As dissolved sulphate increases, dissolved Zn, Cd, Cu and Co concentrations increase, leading to undetectable amounts in the remaining solid phases; dissolved Ni and Mn also increase with the mobilized sulphur, but the remainder in the solids is the most important fraction; Fe and Pb are not mobilized due to precipitation as jarosite or hematite in the case of Fe or as sulphate in the case of Pb. Agreement between the observed results and the predictions by geochemical modelling is discussed.

  16. Selective oxidation of glycerol under acidic conditions using gold catalysts

    SciTech Connect

    Villa, Alberto; Veith, Gabriel M; Prati, Laura

    2010-01-01

    H-mordenite-supported PtAu nanoparticles are highly active and selective in the oxidation of glycerol under acidic conditions, which allows the direct preparation of free acids (see picture). The high selectivity for C{sub 3} compounds results from the negligible formation of H{sub 2}O{sub 2}, in contrast to PtAu nanoparticles supported on activated carbon.

  17. Selective electrochemical generation of hydrogen peroxide from water oxidation

    SciTech Connect

    Viswanathan, Venkatasubramanian; Hansen, Heine A.; Norskov, Jens K.

    2015-10-08

    Water is a life-giving source, fundamental to human existence, yet over a billion people lack access to clean drinking water. The present techniques for water treatment such as piped, treated water rely on time and resource intensive centralized solutions. In this work, we propose a decentralized device concept that can utilize sunlight to split water into hydrogen and hydrogen peroxide. The hydrogen peroxide can oxidize organics while the hydrogen bubbles out. In enabling this device, we require an electrocatalyst that can oxidize water while suppressing the thermodynamically favored oxygen evolution and form hydrogen peroxide. Using density functional theory calculations, we show that the free energy of adsorbed OH* can be used to determine selectivity trends between the 2e– water oxidation to H2O2 and the 4e– oxidation to O2. We show that materials which bind oxygen intermediates sufficiently weakly, such as SnO2, can activate hydrogen peroxide evolution. Furthermore, we present a rational design principle for the selectivity in electrochemical water oxidation and identify new material candidates that could perform H2O2 evolution selectively.

  18. Selective electrochemical generation of hydrogen peroxide from water oxidation

    DOE PAGES

    Viswanathan, Venkatasubramanian; Hansen, Heine A.; Norskov, Jens K.

    2015-10-08

    Water is a life-giving source, fundamental to human existence, yet over a billion people lack access to clean drinking water. The present techniques for water treatment such as piped, treated water rely on time and resource intensive centralized solutions. In this work, we propose a decentralized device concept that can utilize sunlight to split water into hydrogen and hydrogen peroxide. The hydrogen peroxide can oxidize organics while the hydrogen bubbles out. In enabling this device, we require an electrocatalyst that can oxidize water while suppressing the thermodynamically favored oxygen evolution and form hydrogen peroxide. Using density functional theory calculations, wemore » show that the free energy of adsorbed OH* can be used to determine selectivity trends between the 2e– water oxidation to H2O2 and the 4e– oxidation to O2. We show that materials which bind oxygen intermediates sufficiently weakly, such as SnO2, can activate hydrogen peroxide evolution. Furthermore, we present a rational design principle for the selectivity in electrochemical water oxidation and identify new material candidates that could perform H2O2 evolution selectively.« less

  19. Coal desulfurization in oxidative acid media using hydrogen peroxide and ozone: a kinetic and statistical approach

    SciTech Connect

    F.R. Carrillo-Pedroza; A. Davalos Sanchez; M. Soria-Aguilar; E.T. Pecina Trevino

    2009-07-15

    The removal of pyritic sulfur from a Mexican sub-bituminous coal in nitric, sulfuric, and hydrochloric acid solutions was investigated. The effect of the type and concentration of acid, in the presence of hydrogen peroxide and ozone as oxidants, in a temperature range of 20-60{sup o}C, was studied. The relevant factors in pyrite dissolution were determined by means of the statistical analysis of variance and optimized by the response surface method. Kinetic models were also evaluated, showing that the dissolution of pyritic sulfur follows the kinetic model of the shrinking core model, with diffusion through the solid product of the reaction as the controlling stage. The results of statistical analysis indicate that the use of ozone as an oxidant improves the pyrite dissolution because, at 0.25 M HNO{sub 3} or H{sub 2}SO{sub 4} at 20{sup o}C and 0.33 g/h O{sub 3}, the obtained dissolution is similar to that of 1 M H{sub 2}O{sub 2} and 1 M HNO{sub 3} or H{sub 2}SO{sub 4} at 40{sup o}C. 42 refs., 9 figs., 3 tabs.

  20. Selective electrocatalytic oxidation of sorbitol to fructose and sorbose.

    PubMed

    Kwon, Youngkook; de Jong, Ed; van der Waal, Jan Kees; Koper, Marc T M

    2015-03-01

    A new electrocatalytic method for the selective electrochemical oxidation of sorbitol to fructose and sorbose is demonstrated by using a platinum electrode promoted by p-block metal atoms. By the studying a range of C4, C5 and C6 polyols, it is found that the promoter interferes with the stereochemistry of the polyol and thereby modifies its reactivity.

  1. Shape-selective sieving layers on an oxide catalyst surface

    NASA Astrophysics Data System (ADS)

    Canlas, Christian P.; Lu, Junling; Ray, Natalie A.; Grosso-Giordano, Nicolas A.; Lee, Sungsik; Elam, Jeffrey W.; Winans, Randall E.; van Duyne, Richard P.; Stair, Peter C.; Notestein, Justin M.

    2012-12-01

    New porous materials such as zeolites, metal-organic frameworks and mesostructured oxides are of immense practical utility for gas storage, separations and heterogeneous catalysis. Their extended pore structures enable selective uptake of molecules or can modify the product selectivity (regioselectivity or enantioselectivity) of catalyst sites contained within. However, diffusion within pores can be problematic for biomass and fine chemicals, and not all catalyst classes can be readily synthesized with pores of the correct dimensions. Here, we present a novel approach that adds reactant selectivity to existing, non-porous oxide catalysts by first grafting the catalyst particles with single-molecule sacrificial templates, then partially overcoating the catalyst with a second oxide through atomic layer deposition. This technique is used to create sieving layers of Al2O3 (thickness, 0.4-0.7 nm) with ‘nanocavities’ (<2 nm in diameter) on a TiO2 photocatalyst. The additional layers result in selectivity (up to 9:1) towards less hindered reactants in otherwise unselective, competitive photocatalytic oxidations and transfer hydrogenations.

  2. Photocatalytic selective oxidation of hydrocarbons in the aqueous phase

    SciTech Connect

    Gonzalez, M.A.; Howell, S.G.; Sikdar, S.K.

    1999-04-01

    The sustainable transformation of an inert alkane into its corresponding oxygenates has been the subject of intense chemical research. These oxygenates typically produced from processes using stringent conditions and materials offer disadvantages that include decreased selectivities to the partial oxygenates and by-product formation. As environmental concerns and regulations become more rigorous, the need for alternative catalytic oxidation processes that use mild or ambient conditions is increased. In this Note, the authors have investigated the use of photocatalysis as a low-temperature and green alternative for the direct and selective oxidation of alkanes with molecular oxygen. Research has been directed toward the use of a heterogeneous liquid-phase reactor for the partial oxidation of cyclohexane, toluene, methylcyclohexane, ethylbenzene, and cumene to their corresponding oxygenates.

  3. Bioenergetic studies of coal sulfur oxidation by extremely thermophilic bacteria. Final report, September 15, 1992--August 31, 1997

    SciTech Connect

    Kelly, R.M.; Han, C.J.

    1997-12-31

    Thermoacidophilic microorganisms have been considered for inorganic sulfur removal from coal because of expected improvements in rates of both biotic and abiotic sulfur oxidation reactions with increasing temperature. In this study, the bioenergetic response of the extremely thermoacidophilic archaeon, Metallosphaera sedula, to environmental changes have been examined in relation to its capacity to catalyze pyrite oxidation in coal. Given an appropriate bioenergetic challenge, the metabolic response was to utilize additional amounts of energy sources (i.e., pyrite) to survive. Of particular interest were the consequences of exposing the organism to various forms of stress (chemical, nutritional, thermal, pH) in the presence of coal pyrite. Several approaches to take advantage of stress response to accelerate pyrite oxidation by this organism were examined, including attempts to promote acquired thermal tolerance to extend its functional range, exposure to chemical uncouplers and decouplers, and manipulation of heterotrophic and chemolithotrophic tendencies to optimize biomass concentration and biocatalytic activity. Promising strategies were investigated in a continuous culture system. This study identified environmental conditions that promote better coupling of biotic and abiotic oxidation reactions to improve biosulfurization rates of thermoacidophilic microorganisms.

  4. Geochemistry and petrology of selected coal samples from Sumatra, Kalimantan, Sulawesi, and Papua, Indonesia

    USGS Publications Warehouse

    Belkin, H.E.; Tewalt, S.J.; Hower, J.C.; Stucker, J.D.; O'Keefe, J. M. K.

    2009-01-01

    Indonesia has become the world's largest exporter of thermal coal and is a major supplier to the Asian coal market, particularly as the People's Republic of China is now (2007) and perhaps may remain a net importer of coal. Indonesia has had a long history of coal production, mainly in Sumatra and Kalimantan, but only in the last two decades have government and commercial forces resulted in a remarkable coal boom. A recent assessment of Indonesian coal-bed methane (CBM) potential has motivated active CBM exploration. Most of the coal is Paleogene and Neogene, low to moderate rank and has low ash yield and sulfur (generally < 10 and < 1??wt.%, respectively). Active tectonic and igneous activity has resulted in significant rank increase in some coal basins. Eight coal samples are described that represent the major export and/or resource potential of Sumatra, Kalimantan, Sulawesi, and Papua. Detailed geochemistry, including proximate and ultimate analysis, sulfur forms, and major, minor, and trace element determinations are presented. Organic petrology and vitrinite reflectance data reflect various precursor flora assemblages and rank variations, including sample composites from active igneous and tectonic areas. A comparison of Hazardous Air Pollutants (HAPs) elements abundance with world and US averages show that the Indonesian coals have low combustion pollution potential.

  5. Interaction of iron-copper mixed metal oxide oxygen carriers with simulated synthesis gas derived from steam gasification of coal

    SciTech Connect

    Siriwardane, Ranjani V.; Ksepko, Ewelina; Tian, Hanging

    2013-01-01

    The objective of this work was to prepare supported bimetallic Fe–Cu oxygen carriers and to evaluate their performance for the chemical-looping combustion (CLC) process with simulated synthesis gas derived from steam gasification of coal/air. Ten-cycle CLC tests were conducted with Fe–Cu oxygen carriers in an atmospheric thermogravimetric analyzer utilizing simulated synthesis gas derived from the steam gasification of Polish Janina coal and Illinois #6 coal as fuel. The effect of temperature on reaction rates, chemical stability, and oxygen transport capacity were determined. Fractional reduction, fractional oxidation, and global rates of reactions were calculated from the thermogravimetric analysis (TGA) data. The supports greatly affected reaction performance. Data showed that reaction rates and oxygen capacities were stable during the 10-cycle TGA tests for most Fe–Cu/support oxygen carriers. Bimetallic Fe–Cu/support oxygen carriers showed higher reduction rates than Fe-support oxygen carriers. The carriers containing higher Cu content showed better stabilities and better reduction rates. An increase in temperature from 800 °C to 900 °C did not have a significant effect on either the oxygen capacity or the reduction rates with synthesis gas derived from Janina coal. Oxidation reaction was significantly faster than reduction reaction for all supported Fe–Cu oxygen carriers. Carriers with higher Cu content had lower oxidation rates. Ten-cycle TGA data indicated that these oxygen carriers had stable performances at 800–900 °C and might be successfully used up to 900 °C for coal CLC reaction in the presence of steam.

  6. Sulfur and ash reduction potential and selected chemical and physical properties of United States coals. [Contains glossary

    SciTech Connect

    Cavallaro, J.A.; Deurbrouck, A.W.; Killmeyer, R.P.; Fuchs, W. . Coal Preparation Div.); Jacobsen, P.S. )

    1991-02-01

    This report presents the washability and comprehensive characterization results of 184 raw coal channel samples, including anthracite, bituminous and lignite coals, collected from the Central Region of the United States. This is the second of a three volume report on the coals of the United States. All the data are presented in six appendices. Statistical techniques and definitions are presented in Appendix A, and a glossary of terms is presented in Appendix B. The complete washability data and an in-depth characterization of each sample are presented alphabetically by state in Appendix C. In Appendix D, a statistical evaluation is given for the composited washability data, selected chemical and physical properties and washability data interpolated at various levels of Btu recovery. This presentation is shown by state, section, and region where four or more samples were collected. Appendix E presents coalbed codes and names for the Central Region coals. Graphical summations are presented by state, section and region showing the effects of crushing on impurity reductions, and the distribution of raw and clean coal samples meeting various levels of SO{sub 2} emissions. 35 figs., 5 tabs.

  7. Geochemical niches of iron-oxidizing acidophiles in acidic coal mine drainage.

    PubMed

    Jones, Daniel S; Kohl, Courtney; Grettenberger, Christen; Larson, Lance N; Burgos, William D; Macaladya, Jennifer L

    2015-02-01

    A legacy of coal mining in the Appalachians has provided a unique opportunity to study the ecological niches of iron-oxidizing microorganisms. Mine-impacted, anoxic groundwater with high dissolved-metal concentrations emerges at springs and seeps associated with iron oxide mounds and deposits. These deposits are colonized by iron-oxidizing microorganisms that in some cases efficiently remove most of the dissolved iron at low pH, making subsequent treatment of the polluted stream water less expensive. We used full-cycle rRNA methods to describe the composition of sediment communities at two geochemically similar acidic discharges, Upper and Lower Red Eyes in Somerset County, PA, USA. The dominant microorganisms at both discharges were acidophilic Gallionella-like organisms, “Ferrovum” spp., and Acidithiobacillus spp. Archaea and Leptospirillum spp. accounted for less than 2% of cells. The distribution of microorganisms at the two sites could be best explained by a combination of iron(II) concentration and pH. Populations of the Gallionella-like organisms were restricted to locations with pH>3 and iron(II) concentration of >4 mM, while Acidithiobacillus spp. were restricted to pH<3 and iron(II) concentration of <4 mM. Ferrovum spp. were present at low levels in most samples but dominated sediment communities at pH<3 and iron(II) concentration of >4 mM. Our findings offer a predictive framework that could prove useful for describing the distribution of microorganisms in acid mine drainage, based on readily accessible geochemical parameters.

  8. Geochemical Niches of Iron-Oxidizing Acidophiles in Acidic Coal Mine Drainage

    PubMed Central

    Kohl, Courtney; Grettenberger, Christen; Larson, Lance N.; Burgos, William D.

    2014-01-01

    A legacy of coal mining in the Appalachians has provided a unique opportunity to study the ecological niches of iron-oxidizing microorganisms. Mine-impacted, anoxic groundwater with high dissolved-metal concentrations emerges at springs and seeps associated with iron oxide mounds and deposits. These deposits are colonized by iron-oxidizing microorganisms that in some cases efficiently remove most of the dissolved iron at low pH, making subsequent treatment of the polluted stream water less expensive. We used full-cycle rRNA methods to describe the composition of sediment communities at two geochemically similar acidic discharges, Upper and Lower Red Eyes in Somerset County, PA, USA. The dominant microorganisms at both discharges were acidophilic Gallionella-like organisms, “Ferrovum” spp., and Acidithiobacillus spp. Archaea and Leptospirillum spp. accounted for less than 2% of cells. The distribution of microorganisms at the two sites could be best explained by a combination of iron(II) concentration and pH. Populations of the Gallionella-like organisms were restricted to locations with pH >3 and iron(II) concentration of >4 mM, while Acidithiobacillus spp. were restricted to pH <3 and iron(II) concentration of <4 mM. Ferrovum spp. were present at low levels in most samples but dominated sediment communities at pH <3 and iron(II) concentration of >4 mM. Our findings offer a predictive framework that could prove useful for describing the distribution of microorganisms in acid mine drainage, based on readily accessible geochemical parameters. PMID:25501473

  9. Biodesulfurization techniques: Application of selected microorganisms for organic sulfur removal from coals. Final report

    SciTech Connect

    Elmore, B.B.

    1993-08-01

    As an alternative to post-combustion desulfurization of coal and pre-combustion desulfurization using physicochemical techniques, the microbial desulfurization of coal may be accomplished through the use of microbial cultures that, in an application of various microbial species, may remove both the pyritic and organic fractions of sulfur found in coal. Organisms have been isolated that readily depyritize coal but often at prohibitively low rates of desulfurization. Microbes have also been isolated that may potentially remove the organic-sulfur fraction present in coal (showing promise when acting on organic sulfur model compounds such as dibenzothiophene). The isolation and study of microorganisms demonstrating a potential for removing organic sulfur from coal has been undertaken in this project. Additionally, the organisms and mechanisms by which coal is microbially depyritized has been investigated. Three cultures were isolated that grew on dibenzothiophene (DBT), a model organic-sulfur compound, as the sole sulfur source. These cultures (UMX3, UMX9, and IGTS8) also grew on coal samples as the sole sulfur source. Numerous techniques for pretreating and ``cotreating`` coal for depyritization were also evaluated for the ability to improve the rate or extent of microbial depyritization. These include prewashing the coal with various solvents and adding surfactants to the culture broth. Using a bituminous coal containing 0.61% (w/w) pyrite washed with organic solvents at low slurry concentrations (2% w/v), the extent of depyritization was increased approximately 25% in two weeks as compared to controls. At slurry concentrations of 20% w/v, a tetrachloroethylene treatment of the coal followed by depyritization with Thiobacillus ferrooxidans increased both the rate and extent of depyritization by approximately 10%.

  10. Desulfurization of coal by microbial column flotation.

    PubMed

    Ohmura, N; Saiki, H

    1994-06-05

    Twenty-three strains capable of oxidizing iron were isolated from coal and ore storage sites as well as coal and ore mines, volcanic areas, and hot spring. Four strains were found to have high iron-oxidizing activity. One strain (T-4) was selected for this experiment since the strain showed the fastest leaching rate of iron and sulfate from pyrite among the four strains. The T-4 strain was assigned for Thiobacillus ferrooxidans from its cultural and morphological characteristics.Bacterial treatment was applied to column flotation. An increase of cell density in the microbial column flotation resulted in the increase of pyrite removal from a coal-pyrite mixture (high sulfur imitated coal) with corresponding decrease of coal recovery. The addition of kerosene into the microbial column flotation increased the recovery of the imitated coal from 55% (without kerosene) to 81% (with 50 microL/L kerosene) with the reduction of pyrite sulfur content from 11% (feed coal) to 3.9% (product coal). The kerosene addition could reduce the pyritic sulfur content by collecting the coal in the recovery. However, the addition could not enhance separation of pyrite from the coal-pyrite mixture, since pyrite rejection was not affected by the increase of the kerosene addition. An excellent separation was obtained by the microbial flotation using a long column which had a length-diameter (L/D) ratio of 12.7. The long column flotation reduced the pyritic sulfur content from 11% (feed coal) to 1.8% (product coal) when 80% of the feed coal was recovered without the kerosene addition. The long column flotation not only attained an excellent separation but also reduced the amount of cells for desulfurization to as little as one-tenth of the reported amount.

  11. Hydrology of the Price River basin, Utah, with emphasis on selected coal-field areas

    USGS Publications Warehouse

    Waddell, Kidd M.; Dodge, J.E.; Darby, D.W.; Theobald, S.M.

    1986-01-01

    Data obtained during a hydrologic study of the Price River basin, Utah, are used to describe seasonal variations of flow of springs, relation between ground water and surface water, hydraulic properties of the ground-water reservoir, ground-water recharge and discharge, flood characteristics of streams, mineralogic composition and depositional rates of sediments, nutrient and inorganic loading in streams and Scofield Reservoir, and water budgets for selected basins. Additional study and monitoring are needed to detect possible hydrologic changes caused by coal mining. Much of the ground-water discharge from the Star Point Sandstone in the Mesaverde Group in the Wasatch Plateau occurs along faults. In the Book Cliffs, where faulting is less extensive, most of the ground-water discharge is from the Flagstaff Limestone. The Flagstaff Limestone is greatly diffusive, has a small storage coefficient, and contains water which is perched. Springs issuing from the Star Point Sandstone in the Mud Creek drainage (Wasatch Plateau) had recession indexes greater than 365 days per log cycle. Springs issuing at higher altitudes from the Colton Formation and the Flagstaff Limestone in the Soldier Creek area (Book Cliffs) have great seasonal variability, with recession indexes ranging from 24 to 115 days per log cycle. Estimated transmissivities in the Soldier Creek area ranged from 0.003 foot squared per day in the lower part of the Castlegate Sandstone to 0.07 foot squared per day in the Price River Formation. Seepage from the Star Point Sandstone is the major contributor to base flow of the stream in Eccles Canyon (Wasatch Plateau). Gains of as much as 230 gallons per minute occurred near a fault zone which crosses Eccles Canyon at the junction with South Fork Canyon. The potentiometric surface of water in the Blackhawk Formation in the Wasatch Plateau (Mud Creek drainage) and the Book Cliffs (Soldier Creek area) generally is above the coal zones, and dewatering will be necessary

  12. Selective enrichment and desalting of hydrophilic peptides using graphene oxide.

    PubMed

    Jiang, Miao; Qi, Linyu; Liu, Peiru; Wang, Zijun; Duan, Zhigui; Wang, Ying; Liu, Zhonghua; Chen, Ping

    2016-08-01

    The wide variety and low abundance of peptides in tissue brought great difficulties to the separation and identification of peptides, which is not in favor of the development of peptidomics. RP-HPLC, which could purify small molecules based on their hydrophobicity, has been widely used in the separation and enrichment of peptide due to its fast, good reproducibility and high resolution. However, RP-HPLC requires the instrument and expensive C18 column and its sample capacity is also limited. Recently, graphene oxide has been applied to the adsorption of amino acids. However, the enrichment efficiency and selectivity of graphene oxide for peptides remain unclear. In this study, the adsorption efficiency and selectivity of graphene oxide and RP-C18 matrix were compared on trypsinized α-actin and also on tissue extracts from pituitary gland and hippocampus. For α-actin, there exhibit similar elution peaks for total trypsinized products and those adsorpted by GO and C18 matrix. But peptides adsorbed by GO showed the higher hydrophilic peaks than which adsorbed by C18 matrix. The resulted RP-HPLC profile showed that most of peptides enriched by graphene oxide were eluted at low concentration of organic solvent, while peptides adsorbed by RP-C18 matrix were mostly eluted at relatively high concentration. Moreover, mass spectrometry analysis suggested that, in pituitary sample, there were 495 peptides enriched by graphene oxide, 447 peptides enriched by RP-C18 matrix while in hippocampus sample 333 and 243 peptides respectively. The GRAVY value analysis suggested that the graphene oxide has a stronger adsorption for highly hydrophilic peptides compared to the RP-C18 matrix. Furthermore, the combination of these two methods could notably increase the number of identification peptides but also the number of predicted protein precursors. Our study provided a new thought to the role of graphene oxide during the enrichment of peptides from tissue which should be useful for

  13. Exergy and Economic Analysis of Catalytic Coal Gasifiers Coupled With Solid Oxide Fuel Cells

    SciTech Connect

    Siefert, Nicholas; Litster, Shawn

    2011-01-01

    The National Energy Technology Laboratory (NETL) has undertaken a review of coal gasification technologies that integrate with solid oxide fuel cells (SOFC) to achieve system efficiencies near 60% while capturing and sequestering >90% of the carbon dioxide. One way to achieve an overall system efficiency of greater than 60% is in a power plant in which a catalytic coal gasifier produces a syngas with a methane composition of roughly 25% on a dry volume basis and this is sent to a SOFC, with CO{sub 2} capture occurring either before or after the SOFC. Integration of a catalytic gasifier with a SOFC, as opposed to a conventional entrained flow gasifier, is improved due to (a) decreased exergy destruction inside a catalytic, steam-coal gasifier producing a high-methane content syngas, and (b) decreased exergy destruction in the SOFC due to the ability to operate at lower air stoichiometric flow ratios. For example, thermal management of the SOFC is greatly improved due to the steam-methane reforming in the anode of the fuel cell. This paper has two main goals. First, we converted the levelized cost of electricity (LCOE) estimates of various research groups into an average internal rate of return on investment (IRR) in order to make comparisons between their results, and to underscore the increased rate of return on investment for advanced integrated gasification fuel cell systems with carbon capture & sequestration (IGFC-CCS) compared with conventional integrated gasification combined cycle (IGCC-CCS) systems and pulverized coal combustion (PCC-CCS) systems. Using capital, labor, and fuel costs from previous researchers and using an average price of baseload electricity generation of $61.50 / MW-hr, we calculated inflation-adjusted IRR values of up to 13%/yr for catalytic gasification with pressurized fuel cell and carbon dioxide capture and storage (CCS), whereas we calculate an IRR of ~4%/yr and ~2%/yr for new, conventional IGCC-CCS and PCC-CCS, respectively. If the

  14. Atmospheric oxidation of flue gases from coal-fired power plants—A comparison between conventional and scrubbed plumes

    NASA Astrophysics Data System (ADS)

    Meagher, J. F.; Stockburger, L.; Bonanno, R. J.; Bailey, E. M.; Luria, M.

    A series of plume samples was taken by instrumented aircraft to determine atmospheric oxidation rates of flue gases from coal-fired power plants. This study was carried out at two of TVA's large power plants: Colbert Steam Plant, located in Pride, Alabama, a conventional power plant that burns high (3.7%) sulfur coal; and Widows Creek Steam Plant, located at Stevenson, Alabama, which generates 29% of its electrical power from a boiler that burns high (3.9%) sulfur coal but that is equipped with a wet limestone SO 2 scrubber. The average atmospheric oxidation rates at both sites were almost identical, indicating that the atmospheric oxidation rate is not significantly affected by the presence of a scrubber. The average morning rates for SO 4= and NO 3- formation for both the scrubbed and unscrubbed plumes were found to be 0.012 and 0.029 h -1 respectively. Rates larger by a factor of two were found for the afternoon measurements. For both parts of this study, the average rate for NO conversion to NO 2 was found to be 0.51 h -1, and the rate for NO x removal was estimated to be 0.12 h -1. On one day during the second part of this study (August 23, 1978), net O 3 production in the plume was observed. Net production of O 3 was attributed to the mixing of the power plant plume with a polluted airmass transported from Chattanooga, Tennessee.

  15. Selective methane oxidation over promoted oxide catalysts. Quarterly report, September 1 - November 30, 1995

    SciTech Connect

    Klier, Kamil; Herman, R.G.; Wang, C.B.

    1995-12-31

    The objective of this research is the selective oxidation of methane to C{sub 2}H{sub 4} hydrocarbons and to oxygenates, in particular formaldehyde and methanol. Air, oxygen, or carbon dioxide rather than nitrous oxide, are utilized as the oxidizing gas at high gas hourly space velocity but mild reaction conditions (500-700{degrees}C, 1 atm total pressure). All the investigated processes are catalytic, aiming at minimizing gas phase reactions that are difficult to control. During this quarter, solid state {sup 51}V NMR and double catalyst bed experiments were conducted to demonstrate the unfavorable effect of the presence of bulk crystalline V{sub 2}O{sub 5} in V{sub 2}O{sub 5}-SiO{sub 2} xerogel catalysts on selective oxidation of methane to methanol and formaldehyde. Results are discussed.

  16. PILOT-SCALE STUDY OF THE EFFECT OF SELECTIVE CATALYTIC REDUCTION CATALYST ON MERCURY SPECIATION IN ILLINOIS AND POWDER RIVER BASIN COAL COMBUSTION FLUE GASES

    EPA Science Inventory

    A study was conducted to investigate the effect of selective catalytic reduction (SCR) catalyst on mercury (Hg) speciation in bituminous and subbituminous coal combustion flue gases. Three different Illinois Basin bituminous coals (from high to low sulfur and chlorine) and one Po...

  17. A summary of selected publications, project activities, and data sources related to hydrology in the Warrior and Plateau coal fields of Alabama

    USGS Publications Warehouse

    Kidd, Robert E.; Hill, Thomas J.

    1982-01-01

    The report is a reference source on hydrologic information related to coal-mining activities in the Warrior and Plateau coal fields of Alabama. It contains a bibliography of more than 200 references and selected annotations. Also included is information on maps, automated-data bases, water-monitoring programs, and data-source agencies and organizations.

  18. Selective etchant for oxide sacrificial material in semiconductor device fabrication

    SciTech Connect

    Clews, Peggy J.; Mani, Seethambal S.

    2005-05-17

    An etching composition and method is disclosed for removing an oxide sacrificial material during manufacture of semiconductor devices including micromechanical, microelectromechanical or microfluidic devices. The etching composition and method are based on the combination of hydrofluoric acid (HF) and sulfuric acid (H.sub.2 SO.sub.4). These acids can be used in the ratio of 1:3 to 3:1 HF:H.sub.2 SO.sub.4 to remove all or part of the oxide sacrificial material while providing a high etch selectivity for non-oxide materials including polysilicon, silicon nitride and metals comprising aluminum. Both the HF and H.sub.2 SO.sub.4 can be provided as "semiconductor grade" acids in concentrations of generally 40-50% by weight HF, and at least 90% by weight H.sub.2 SO.sub.4.

  19. Passivation oxide controlled selective carbon nanotube growth on metal substrates.

    PubMed

    Bult, J B; Sawyer, W G; Ajayan, P M; Schadler, L S

    2009-02-25

    Vertically aligned arrays of multi-wall carbon nanotubes (MWNT) are grown on Inconel 600, a nickel-based super-alloy. Using x-ray photoelectron spectroscopy (XPS) and chemical vapor deposition (CVD) growth of the MWNTs it is shown that a stable oxidation barrier is required for the stabilization of iron on the substrate and subsequent nanotube growth. This evidence for passivation oxide supported growth of MWNTs was then used to grow MWNTs on patterned oxidized substrates in a selective growth furnace. The unique advantage of this patterned growth on Inconel 600 is found to be the chromia passivation layer's electrical conductivity (measured value of 1.08 micro Omega m), creating the opportunity for low resistivity electrodes made from nanotubes. Inconel substrates with 100 microm long aligned MWNTs are demonstrated to exhibit an average resistance value of 2 Omega.

  20. SUBMICROSCOPIC ( less than 1 mu m) MINERAL CONTENTS OF VITRINITES IN SELECTED BITUMINOUS COAL BEDS.

    USGS Publications Warehouse

    Minkin, J.A.; Chao, E.C.T.; Thompson, C.L.; Wandless, M.-V.; Dulong, F.T.; Larson, R.R.; Neuzil, S.G.; ,

    1983-01-01

    An important aspect of the petrographic description of coal is the characterization of coal quality, including chemical attributes. For geologic investigations, data on the concentrations, distribution, and modes of occurrence of minor and trace elements provide a basis for reconstructing the probable geochemical environment of the swamp material that was converted into peat, and the geochemical conditions that prevailed during and subsequent to coalification. We have been using electron (EPMA) and proton (PIXE) microprobe analytical methods to obtain data on the chemical characteristics of specific coal constituents in their original associations within coal samples. The present study is aimed at evaluation of the nature of mineral occurrences and heterogeneous elemental concentrations within vitrinites. Vitrinites are usually the most abundant, and therefore most important, maceral group in bituminous coal. 8 refs.

  1. An assessment of the quality of selected EIA data series: Coal data, 1983--1988

    SciTech Connect

    Not Available

    1991-11-25

    The purpose of this report is to present information on the quality of some of the Energy Information Administration`s (EIA) coal data. This report contains discussions of data on production, direct labor hours, recoverable reserves, and prices from 1983 through 1988. Chapter 2 of this report presents a summary of the EIA coal data collection and identifies other sources providing similar data. Chapters 3 and 4 focus on data on coal production and direct labor hours, respectively. Detailed comparisons with data from the Mine Safety and Health Administration (MSHA) and State mining agencies are presented. Chapter 5 examines recoverable reserves. Included are internal comparisons as well as comparisons with other published reserve-related data, namely those of BXG, Inc. Chapter 6 describes how EIA obtains estimates of coal prices and discusses the variability in the prices caused by factors such as mine type, coal rank, and region. 5 figs., 5 tabs.

  2. Selective methane oxidation over promoted oxide catalysts. Topical report, September 8, 1992--September 7, 1996

    SciTech Connect

    Klier, K.; Herman, R.G.

    1996-12-31

    The objective of this research was to selectively oxidize methane to C{sub 2} hydrocarbons and to oxygenates, in particular formaldehyde and methanol, in high space time yields using air at the oxidant under milder reaction conditions that heretofore employed over industrially practical oxide catalysts. The research carried out under this US DOE-METC contract was divided into the following three tasks: Task 1, maximizing selective methane oxidation to C{sub 2}{sup +} products over promoted SrO/La{sub 2}O{sub 3} catalysts; Task 2, selective methane oxidation to oxygenates; and Task 3, catalyst characterization and optimization. Principal accomplishments include the following: the 1 wt% SO{sub 4}{sup 2{minus}}/SrO/La{sub 2}O{sub 3} promoted catalyst developed here produced over 2 kg of C{sub 2} hydrocarbons/kg catalyst/hr at 550 C; V{sub 2}O{sub 5}/SiO{sub 2} catalysts have been prepared that produce up to 1.5 kg formaldehyde/kg catalyst/hr at 630 C with low CO{sub 2} selectivities; and a novel dual bed catalyst system has been designed and utilized to produce over 100 g methanol/kg catalyst/hr at 600 C with the presence of steam in the reactant mixture.

  3. Microcharacterization of coal components for beneficiation

    SciTech Connect

    Straszheim, W.E.; Markuszewski, R.

    1989-02-01

    The capabilities of automated image analysis (AIA) have been improved, and the modified procedures have been applied to characterize the degree of association of mineral particles with the coal matrix for two coal samples subjected to cleaning by float-sink separation. Definitions of elemental intensity used to identify mineral particles during AIA have been expanded to include oxygen in the list of elements monitored. This new light-element analysis capability permits the identification of mineral phases such as iron oxides and iron carbonates which were previously indistinguishable. Definitions have been established for the identification of 20 phases present in coal and mineral matter based on the relative abundance of the elements present. These definitions have been tested using mineral standards and a sample of well-characterized Illinois No. 6 coal. The automated image analysis (AIA) techniques for measuring the degree of associated of mineral particles with coal have also expanded to measure the association for individual minerals with coal particles in order to predict and document selective removal in coal cleaning procedures. The AIA technique has been applied to {minus}200 mesh samples of feed, clean product, and refuse streams of two low-rank coals processed in-house by float-sink procedures at 1.6 specific gravity. Analyses of all three process streams permit a material balance in terms of coal mineral association. Results are reported for one of the coals from the Williams Fork Q bed. 3 refs., 7 figs., 5 tabs.

  4. Cuprous oxide nanoparticles selectively induce apoptosis of tumor cells

    PubMed Central

    Wang, Ye; Zi, Xiao-Yuan; Su, Juan; Zhang, Hong-Xia; Zhang, Xin-Rong; Zhu, Hai-Ying; Li, Jian-Xiu; Yin, Meng; Yang, Feng; Hu, Yi-Ping

    2012-01-01

    In the rapid development of nanoscience and nanotechnology, many researchers have discovered that metal oxide nanoparticles have very useful pharmacological effects. Cuprous oxide nanoparticles (CONPs) can selectively induce apoptosis and suppress the proliferation of tumor cells, showing great potential as a clinical cancer therapy. Treatment with CONPs caused a G1/G0 cell cycle arrest in tumor cells. Furthermore, CONPs enclosed in vesicles entered, or were taken up by mitochondria, which damaged their membranes, thereby inducing apoptosis. CONPs can also produce reactive oxygen species (ROS) and initiate lipid peroxidation of the liposomal membrane, thereby regulating many signaling pathways and influencing the vital movements of cells. Our results demonstrate that CONPs have selective cytotoxicity towards tumor cells, and indicate that CONPs might be a potential nanomedicine for cancer therapy. PMID:22679374

  5. Removal of Cu{sup 2+}, Cd{sup 2+} and Mn(VII) from dilute, aqueous solutions by oxidized bituminous coal

    SciTech Connect

    Bodine, D.L.; Doyle, F.M.

    1995-07-01

    The ability of oxidized Upper Freeport bituminous coal to adsorb Cu{sup 2+}, Cd{sup 2+} and MN(VII) from very dilute aqueous solutions has been studied. Low-rank coal is known to adsorb heavy metal ions from dilute, aqueous solutions, probably by ion exchange and/or chelation by acidic functional groups on the coal surface. However, it would be advantageous to use higher rank coals for water treatment. Coal samples were oxidized thermally or by 30% H{sub 2}O{sub 2} to increase the surface concentration of phenolic and carboxylic groups, then portions were shaken with Cu{sup 2+} and Cd{sup 2+} solutions. Acidic KMnO{sub 4} was also used to oxidize coal, with concurrent sorption of the resulting MN(IV) and Mn(II). The effect of oxidation treatment, metal ion concentration, and solution pH on metal uptake kinetics was investigated. Potential applications for treating effluents, especially those containing oxidizing ions, are discussed, along with possible flowsheet options.

  6. Advanced treatment of biologically pretreated coal gasification wastewater by a novel integration of catalytic ultrasound oxidation and membrane bioreactor.

    PubMed

    Jia, Shengyong; Han, Hongjun; Zhuang, Haifeng; Xu, Peng; Hou, Baolin

    2015-01-01

    Laboratorial scale experiments were conducted to investigate a novel system integrating catalytic ultrasound oxidation (CUO) with membrane bioreactor (CUO-MBR) on advanced treatment of biologically pretreated coal gasification wastewater. Results indicated that CUO with catalyst of FeOx/SBAC (sewage sludge based activated carbon (SBAC) which loaded Fe oxides) represented high efficiencies in eliminating TOC as well as improving the biodegradability. The integrated CUO-MBR system with low energy intensity and high frequency was more effective in eliminating COD, BOD5, TOC and reducing transmembrane pressure than either conventional MBR or ultrasound oxidation integrated MBR. The enhanced hydroxyl radical oxidation, facilitation of substrate diffusion and improvement of cell enzyme secretion were the mechanisms for CUO-MBR performance. Therefore, the integrated CUO-MBR was the promising technology for advanced treatment in engineering applications.

  7. Effects of calcium oxide on the surface properties of municipal wastewater sludge and its co-slurrying ability with coal.

    PubMed

    Wang, Ruikun; Liu, Jianzhong; Yu, Yujie; Zhou, Junhu; Cen, Kefa

    2013-07-01

    Urbanization has generated large volumes of municipal wastewater sludge (sludge for short) that threaten the environment and human health. As such, utilization of the sludge in a cost-effective manner is an important concern. The sludge, as a carbon-containing material, can be made into coal-sludge slurry (CSS) by mixing it with pulverized coal. However, the slurryability of the raw sludge is relatively poor due to the abundance of hydrophilic groups in the sludge and its loose floc structure. In this study, modification of the sludge with calcium oxide (CaO) showed positive effects on the sludge slurryability. The characteristic viscosity of the coal raw-sludge slurry (R-CSS) was 1635.3 mPa s. After modification of the sludge with 2 wt.% CaO for 24 h, the CSS viscosity decreased to 1184.4 mPa s. The hydrophobic group (CC and CH) content of the sludge increased from 61.5% to 74.9% as the CaO dosage increased from 0% to 4%, and the zeta potential increased from -55.1 eV to -36.2 eV. The optimum CaO dosage for improved slurryability was found to be 2 wt.%. Compared with R-CSS, the coal modified-sludge slurry (M-CSS) showed lower yield stress, weaker pseudoplastic and thixotropic behaviors, and poorer static stability.

  8. Hybridization of Zinc Oxide Tetrapods for Selective Gas Sensing Applications.

    PubMed

    Lupan, O; Postica, V; Gröttrup, J; Mishra, A K; de Leeuw, N H; Carreira, J F C; Rodrigues, J; Ben Sedrine, N; Correia, M R; Monteiro, T; Cretu, V; Tiginyanu, I; Smazna, D; Mishra, Y K; Adelung, R

    2017-02-01

    In this work, the exceptionally improved sensing capability of highly porous three-dimensional (3-D) hybrid ceramic networks toward reducing gases is demonstrated for the first time. The 3-D hybrid ceramic networks are based on doped metal oxides (MexOy and ZnxMe1-xOy, Me = Fe, Cu, Al) and alloyed zinc oxide tetrapods (ZnO-T) forming numerous junctions and heterojunctions. A change in morphology of the samples and formation of different complex microstructures is achieved by mixing the metallic (Fe, Cu, Al) microparticles with ZnO-T grown by the flame transport synthesis (FTS) in different weight ratios (ZnO-T:Me, e.g., 20:1) followed by subsequent thermal annealing in air. The gas sensing studies reveal the possibility to control and change/tune the selectivity of the materials, depending on the elemental content ratio and the type of added metal oxide in the 3-D ZnO-T hybrid networks. While pristine ZnO-T networks showed a good response to H2 gas, a change/tune in selectivity to ethanol vapor with a decrease in optimal operating temperature was observed in the networks hybridized with Fe-oxide and Cu-oxide. In the case of hybridization with ZnAl2O4, an improvement of H2 gas response (to ∼7.5) was reached at lower doping concentrations (20:1), whereas the increase in concentration of ZnAl2O4 (ZnO-T:Al, 10:1), the selectivity changes to methane CH4 gas (response is about 28). Selectivity tuning to different gases is attributed to the catalytic properties of the metal oxides after hybridization, while the gas sensitivity improvement is mainly associated with additional modulation of the electrical resistance by the built-in potential barriers between n-n and n-p heterojunctions, during adsorption and desorption of gaseous species. Density functional theory based calculations provided the mechanistic insights into the interactions between different hybrid networks and gas molecules to support the experimentally observed results. The studied networked materials and

  9. Arsenic remediation of drinking water using iron-oxide coated coal bottom ash

    SciTech Connect

    MATHIEU, JOHANNA L.; GADGIL, ASHOK J.; ADDY, SUSAN E.A.; KOWOLIK, KRISTIN

    2010-06-01

    We describe laboratory and field results of a novel arsenic removal adsorbent called 'Arsenic Removal Using Bottom Ash' (ARUBA). ARUBA is prepared by coating particles of coal bottom ash, a waste material from coal fired power plants, with iron (hydr)oxide. The coating process is simple and conducted at room temperature and atmospheric pressure. Material costs for ARUBA are estimated to be low (~;;$0.08 per kg) and arsenic remediation with ARUBA has the potential to be affordable to resource-constrained communities. ARUBA is used for removing arsenic via a dispersal-and-removal process, and we envision that ARUBA would be used in community-scale water treatment centers. We show that ARUBA is able to reduce arsenic concentrations in contaminated Bangladesh groundwater to below the Bangladesh standard of 50 ppb. Using the Langmuir isotherm (R2 = 0.77) ARUBA's adsorption capacity in treating real groundwater is 2.6x10-6 mol/g (0.20 mg/g). Time-to-90percent (defined as the time interval for ARUBA to remove 90percent of the total amount of arsenic that is removed at equilibrium) is less than one hour. Reaction rates (pseudo-second-order kinetic model, R2>_ 0.99) increase from 2.4x105 to 7.2x105 g mol-1 min-1 as the groundwater arsenic concentration decreases from 560 to 170 ppb. We show that ARUBA's arsenic adsorption density (AAD), defined as the milligrams of arsenic removed at equilibrium per gram of ARUBA added, is linearly dependent on the initial arsenic concentration of the groundwater sample, for initial arsenic concentrations of up to 1600 ppb and an ARUBA dose of 4.0 g/L. This makes it easy to determine the amount of ARUBA required to treat a groundwater source when its arsenic concentration is known and less than 1600 ppb. Storing contaminated groundwater for two to three days before treatment is seen to significantly increase ARUBA's AAD. ARUBA can be separated from treated water by coagulation and clarification, which is expected to be less expensive than

  10. Arsenic remediation of drinking water using iron-oxide coated coal bottom ash.

    PubMed

    Mathieu, Johanna L; Gadgil, Ashok J; Addy, Susan E A; Kowolik, Kristin

    2010-09-01

    We describe laboratory and field results of a novel arsenic removal adsorbent called 'Arsenic Removal Using Bottom Ash' (ARUBA). ARUBA is prepared by coating particles of coal bottom ash, a waste material from coal fired power plants, with iron (hydr)oxide. The coating process is simple and conducted at room temperature and atmospheric pressure. Material costs for ARUBA are estimated to be low (approximately $0.08 per kg) and arsenic remediation with ARUBA has the potential to be affordable to resource-constrained communities. ARUBA is used for removing arsenic via a dispersal-and-removal process, and we envision that ARUBA would be used in community-scale water treatment centers. We show that ARUBA is able to reduce arsenic concentrations in contaminated Bangladesh groundwater to below the Bangladesh standard of 50 ppb. Using the Langmuir isotherm (R(2) = 0.77) ARUBA's adsorption capacity in treating real groundwater is 2.6 x 10(- 6)mol/g (0.20 mg/g). Time-to-90% (defined as the time interval for ARUBA to remove 90% of the total amount of arsenic that is removed at equilibrium) is less than 1 hour. Reaction rates (pseudo-second-order kinetic model, R(2) > or = 0.99) increase from 2.4 x 10(5) to 7.2 x 10(5) g mol(- 1)min(- 1) as the groundwater arsenic concentration decreases from 560 to 170 ppb. We show that ARUBA's arsenic adsorption density (AAD), defined as the milligrams of arsenic removed at equilibrium per gram of ARUBA added, is linearly dependent on the initial arsenic concentration of the groundwater sample, for initial arsenic concentrations of up to 1600 ppb and an ARUBA dose of 4.0 g/L. This makes it easy to determine the amount of ARUBA required to treat a groundwater source when its arsenic concentration is known and less than 1600 ppb. Storing contaminated groundwater for two to three days before treatment is seen to significantly increase ARUBA's AAD. ARUBA can be separated from treated water by coagulation and clarification, which is expected to

  11. Sulfur and ash reduction potential and selected chemical and physical properties of United States coals. [Contains glossary

    SciTech Connect

    Cavallaro, J.A.; Deurbrouck, A.W.; Killmeyer, R.P.; Fuchs, W. ); Jacobsen, P.S. )

    1990-01-01

    This report presents the washability and comprehensive characterization results of 543 raw coal samples collected from the Eastern Region of the United States. This is the first volume of a three-volume report on the coals of the United States. All the data are presented in six appendices. Statistical techniques and definitions are presented in Appendix A, and a glossary of terms is presented in Appendix B. The complete washability data and an in- depth characterization of each sample are presented alphbetically by state in Appendix C. In Appendix D, a statistical evaluation is given for the composited washability data, selected chemical and physical properties, and washability data interpolated at various levels of Btu recovery. This presentation is shown by state, section, and region where four or more samples were collected. Appendix E presents coalbed codes and names for the Eastern Region coals. Graphical summations are presented by state, section, and region showing the effects of crushing on impurity reductions, and the distribution of raw and clean coal samples meeting various levels of SO{sub 2} emissions. 14 refs., 27 figs., 3 tabs.

  12. Evaluation of Suitability of Selected Set of Coal Plant Sites for Repowering with Small Modular Reactors

    SciTech Connect

    Belles, Randy; Copinger, Donald A; Mays, Gary T; Omitaomu, Olufemi A; Poore III, Willis P

    2013-03-01

    This report summarizes the approach that ORNL developed for screening a sample set of small coal stations for possible repowering with SMRs; the methodology employed, including spatial modeling; and initial results for these sample plants. The objective in conducting this type of siting evaluation is to demonstrate the capability to characterize specific sample coal plant sites to identify any particular issues associated with repowering existing coal stations with SMRs using OR-SAGE; it is not intended to be a definitive assessment per se as to the absolute suitability of any particular site.

  13. Selective methane oxidation over promoted oxide catalysts. Quarterly report, March--May 1995

    SciTech Connect

    Klier, K.; Herman, R.G.; Wang, Chaun-Bao; Shi, Chunlei; Sun, Qun

    1995-08-01

    The objective of this research is the selective oxidative coupling of methane to C{sub 2}H{sub 4} hydrocarbons and oxygenates, in particular formaldehyde and methanol. Air, oxygen or carbon dioxide, rather than nitrous oxide will be utilized as the oxidizing gas at high gas hourly space velocity, but mild reaction conditions (500-700 {degrees}C, 1 atm total pressure). All the investigated processes are catalytic, aiming at minimizing gas phase reactions that are difficult to control. The research is divided into the following three tasks: (1) maximizing selective methane oxidation to C{sub 2}H{sub 4} products over promoted Sr/La{sub 2}O{sub 3}; (2) selective methane oxidation to oxygenates; and (3) catalyst characterization and optimization. Task 1 dealt with the preparation, testing, and optimization of acidic promoted lanthana-based catalysts for the synthesis of C{sub 2}H{sub 4} hydrocarbons and is essentially completed. Task 2 aims at the formation and optimization of promoted catalysts for the synthesis of oxygenates, in particular formaldehyde and methanol. Task 3 involves characterization of the most promising catalysts so that optimization can be achieved under Task 2. Accomplishments for this period are presented.

  14. Chemicals from coal. Utilization of coal-derived phenolic compounds

    SciTech Connect

    Song, C.; Schobert, H.H.

    1999-07-01

    This article provides an overview for possible utilization of coal-derived phenolic compounds. Phenolic compounds are abundant in coal-derived liquids. Coal-derived phenolic compounds include phenol, cresol, catechol, methylcatechol, naphthol, and their derivatives. Liquids from coal liquefaction, pyrolysis, gasification, and carbonization are potential sources of phenolic chemicals, although certain processing and separation are needed. There are opportunities for coal-based phenolic chemicals, because there are existing industrial applications and potential new applications. Currently the petrochemical industry produces phenol in multi-step processes, and new research and development has resulted in a one-step process. Selective methylation of phenol can produce a precursor for aromatic engineering plastics. Catalytic oxidation of phenol has been commercialized recently for catechol production. There are potential new uses of phenol that could replace large-volume multi-step chemical processes that are based on benzene as the starting material. New chemical research on coal and coal-derived liquids can pave the way for their non-fuel uses for making chemicals and materials.

  15. Enzymatic desulfurization of coal

    SciTech Connect

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V. ); Marquis, J.K. . School of Medicine)

    1989-11-07

    Our experimental approach focuses on the use of enzymes which catalyze the addition of oxygen to organic compounds. In tailoring the application of these enzymes to coal processing, we are particularly interested in ensuring that oxidation occurs at sulfur and not at carbon-carbon bonds. Previous studies with DBT have shown that the reaction most frequently observed in microbial oxidative pathways is one in which DBT is oxidized at ring carbons. These reactions, as we have said, are accompanied by a considerable decrease in the energy content of the compound. In addition, microbial pathways have been identified in which the sulfur atom is sequentially oxidized to sulfoxide, to sulfone, to sulfonate, and finally to sulfuric acid. In this case, the fuel value of the desulfurized compounds is largely retained. We are evaluating the potential of commercially available enzymes to selectively catalyze oxidation at sulfur.

  16. Lipid oxidation volatiles absent in milk after selected ultrasound processing.

    PubMed

    Juliano, Pablo; Torkamani, Amir Ehsan; Leong, Thomas; Kolb, Veronika; Watkins, Peter; Ajlouni, Said; Singh, Tanoj Kumar

    2014-11-01

    Ultrasonic processing can suit a number of potential applications in the dairy industry. However, the impact of ultrasound treatment on milk stability during storage has not been fully explored under wider ranges of frequencies, specific energies and temperature applications. The effect of ultrasonication on lipid oxidation was investigated in various types of milk. Four batches of raw milk (up to 2L) were sonicated at various frequencies (20, 400, 1000, 1600 and 2000kHz), using different temperatures (4, 20, 45 and 63°C), sonication times and ultrasound energy inputs up to 409kJ/kg. Pasteurized skim milk was also sonicated at low and high frequency for comparison. In selected experiments, non-sonicated and sonicated samples were stored at 4°C and were drawn periodically up to 14days for SPME-GCMS analysis. The cavitational yield, characterized in all systems in water, was highest between 400kHz and 1000kHz. Volatile compounds from milk lipid oxidation were detected and exceeded their odor threshold values at 400kHz and 1000kHz at specific energies greater than 271kJ/kg in raw milk. However, no oxidative volatile compounds were detected below 230kJ/kg in batch systems at the tested frequencies under refrigerated conditions. Skim milk showed a lower energy threshold for oxidative volatile formation. The same oxidative volatiles were detected after various passes of milk through a 0.3L flow cell enclosing a 20kHz horn and operating above 90kJ/kg. This study showed that lipid oxidation in milk can be controlled by decreasing the sonication time and the temperature in the system depending on the fat content in the sample among other factors.

  17. Elucidating the mechanism of Cr(VI) formation upon the interaction with metal oxides during coal oxy-fuel combustion.

    PubMed

    Chen, Juan; Jiao, Facun; Zhang, Lian; Yao, Hong; Ninomiya, Yoshihiko

    2013-10-15

    The thermodynamics underpinning the interaction of Cr-bearing species with basic metal oxides, i.e. K2O, Fe2O3, MgO and CaO, during the air and oxy-fuel combustion of coal have been examined. The synchrotron-based X-ray adsorption near-edge spectroscopy (XANES) was used for Cr speciation. For the oxides tested, Cr(VI) formation is dominated by the reduction potential of the metals. The oxides of Ca(2+) with high reduction potential favored the oxidation of Cr(III), same for K(+). The other two basic metals, Fe2O3 and MgO with lower reduction potentials reacted with Cr(III) to form the corresponding chromites at the temperatures above 600°C. Coal combustion experiments in drop-tube furnace have confirmed the rapid capture of Cr vapors, either trivalent or hexavalent, by CaO into solid ash. The existence of HCl in flue gas favored the vaporization of Cr as CrO2Cl2, which was in turn captured by CaO into chromate. Both Fe2O3 and MgO exhibited less capability on scavenging the Cr(VI) vapor. Particularly, MgO alone exhibited a low capability for capturing the vaporized Cr(III) vapors. However, its co-existence with CaO in the furnace inhibited the Cr(VI) formation. This is beneficial for minimizing the toxicity of Cr in the coal combustion-derived fly ash.

  18. Magneto-transport properties of oriented Mn{sub 2}CoAl films sputtered on thermally oxidized Si substrates

    SciTech Connect

    Xu, G. Z.; Du, Y.; Zhang, X. M.; Liu, E. K.; Wang, W. H. Wu, G. H.; Zhang, H. G.

    2014-06-16

    Spin gapless semiconductors are interesting family of materials by embracing both magnetism and semiconducting due to their unique band structure. Its potential application in future spintronics requires realization in thin film form. In this Letter, we report fabrication and transport properties of spin gapless Mn{sub 2}CoAl films prepared on thermally oxidized Si substrates by magnetron sputtering deposition. The films deposited at 673 K are well oriented to (001) direction and display a uniform-crystalline surface. Magnetotransport measurements on the oriented films reveal a semiconducting-like resistivity, small anomalous Hall conductivity, and linear magnetoresistance representative of the transport signatures of spin gapless semiconductors. The magnetic properties of the films have also been investigated and compared to that of bulk Mn{sub 2}CoAl, showing small discrepancy induced by the composition deviation.

  19. Selective Catalytic Oxidation of Hydrogen Sulfide--IGCC Applications

    SciTech Connect

    Alvin, M.A.; Stevens, R.W.; Newby, R.A.; Keairns, D.L.

    2006-09-01

    Selective catalytic oxidation of hydrogen sulfide (SCOHS) to elemental sulfur using activated carbon and NETL-processed metal oxide catalyst systems has been investigated under bench-scale, simulated pressurized IGCC conditions for use in dry and humid gas cleaning process applications. For this technology to be successful, a 20% cost effective advantage and 1 percentage-point plant efficiency gain over current commercial technology, and <10-15 ppm total gas phase sulfur release into the effluent gas stream must be demonstrated. The results of our bench-scale catalyst/sorbent desulfurization and regeneration efforts for both bulk and polishing sulfur removal indicate that direct selective catalytic oxidation of H2S to elemental sulfur utilizing current activated carbon systems occurs only under conditions of low syngas temperature (<150°C), and in syngas effluent streams containing a low water and CO content. Thus the SCOHS desulfurization process is considered to be only potentially feasible for use in dry gas cleaning conditions for IGCC applications where syngas-CO is shifted to CO2, and regeneration of the catalyst occurs through heating in warm CO2, with simultaneous CO2 sequestration. SCOHS is not considered as a candidate desulfurization approach for use in humid IGCC gas cleaning applications.

  20. Fabrication of highly selective tungsten oxide ammonia sensors

    SciTech Connect

    Llobet, E.; Molas, G.; Molinas, P.; Calderer, J.; Vilanova, X.; Brezmes, J.; Sueiras, J.E.; Correig, X.

    2000-02-01

    Tungsten oxide is shown to be a very promising material for the fabrication of highly selective ammonia sensors. Films of WO{sub 3} were deposited onto a silicon substrate by means of the drop-coating method. Then, the films were annealed in dry air at two different temperatures (300 and 400 C). X-ray photoelectron spectroscopy was used to investigate the composition of the films. Tungsten appeared both in WO{sub 2} and WO{sub 3} oxidation states, but the second state was clearly dominant. Scanning electron microscopy results showed that the oxide was amorphous or nanocrystalline. The WO{sub 3}-based devices were sensitive to ammonia vapors when operated between 250 and 350 C. The optimal operating temperature for the highest sensitivity to ammonia was 300 C. Furthermore, when the devices were operated at 300 C, their sensitivity to other reducing species such as ethanol, methane, toluene, and water vapor was significantly lower, and this resulted in a high selectivity to ammonia. A model for the sensing mechanisms of the fabricated sensors is proposed.

  1. Changes in the chemical structure of low rank coal after low temperature oxidation or demineralisation by acid treatment: Analysis by FTIR and UV fluorescence

    SciTech Connect

    Kister, J.; Guiliano, M.; Mille, G.; Dou, H.

    1987-04-01

    The studies have been conducted on low rank coal: Flambant de Provence, France, PRV=0.44 FTIR and UV synchronous fluorescence spectroscopy are used to study structural changes in low rank coal after natural oxidation or acid (HCl/HF) demineralization. The observed variations deal mainly with a decrease in aliphatic structures and an increase in the oxygenated species. A quantitative oxidation study of the effect of temperature, time, mineral matter and oxygen concentrations has been conducted by FTIR. An attempt to describe the oxygenated species by FTIR and to compare their evolution has been conducted. Various oxidation mechanisms are proposed according to the results.

  2. Highly Selective H2 Separation Zeolite Membranes for Coal Gasification Membrane Reactor Applications

    SciTech Connect

    Mei Hong; Richard D. Noble; John L. Falconer

    2006-09-24

    Zeolite membranes are thermally, chemically, and mechanically stable. They also have tunable molecular sieving and catalytic ability. These unique properties make zeolite membrane an excellent candidate for use in catalytic membrane reactor applications related to coal conversion and gasification, which need high temperature and high pressure range separation in chemically challenging environment where existing technologies are inefficient or unable to operate. Small pore, good quality, and thin zeolite membranes are needed for highly selective H{sub 2} separation from other light gases (CO{sub 2}, CH{sub 4}, CO). However, zeolite membranes have not been successful for H{sub 2} separation from light gases because the zeolite pores are either too big or the membranes have a large number of defects. The objective of this study is to develop zeolite membranes that are more suitable for H{sub 2} separation. In an effort to tune the size of zeolite pores and/or to decrease the number of defects, medium-pore zeolite B-ZSM-5 (MFI) membranes were synthesized and silylated. Silylation on B-ZSM-5 crystals reduced MFI-zeolite pore volume, but had little effect on CO{sub 2} and CH{sub 4} adsorption. Silylation on B-ZSM-5 membranes increased H{sub 2} selectivity both in single component and in mixtures with CO{sub 2}CO{sub 2}, CH{sub 4}, or N2. Single gas and binary mixtures of H{sub 2}/CO{sub 2} and H{sub 2}/CH{sub 4} were separated through silylated B-ZSM-5 membranes at feed pressures up to 1.7 MPa and temperatures up to 773 K. For one BZSM-5 membrane after silylation, the H2/CO{sub 2} separation selectivity at 473 K increased from 1.4 to 37, whereas the H{sub 2}/CH{sub 4} separation selectivity increased from 1.6 to 33. Hydrogen permeance through a silylated B-ZSM-5 membrane was activated, but the CO{sub 2} and CH4 permeances decreased slightly with temperature in both single gas and in mixtures. Therefore, the H{sub 2} permeance and H{sub 2}/CO{sub 2} and H{sup 2} /CH{sub 4

  3. Process for removing sulfur from coal

    DOEpatents

    Aida, T.; Squires, T.G.; Venier, C.G.

    1983-08-11

    A process is disclosed for the removal of divalent organic and inorganic sulfur compounds from coal and other carbonaceous material. A slurry of pulverized carbonaceous material is contacted with an electrophilic oxidant which selectively oxidizes the divalent organic and inorganic compounds to trivalent and tetravalent compounds. The carbonaceous material is then contacted with a molten caustic which dissolves the oxidized sulfur compounds away from the hydrocarbon matrix.

  4. Process for removing sulfur from coal

    DOEpatents

    Aida, Tetsuo; Squires, Thomas G.; Venier, Clifford G.

    1985-02-05

    A process for the removal of divalent organic and inorganic sulfur compounds from coal and other carbonaceous material. A slurry of pulverized carbonaceous material is contacted with an electrophilic oxidant which selectively oxidizes the divalent organic and inorganic compounds to trivalent and tetravalent compounds. The carbonaceous material is then contacted with a molten caustic which dissolves the oxidized sulfur compounds away from the hydrocarbon matrix.

  5. Kinetic modeling of direct liquefaction of wyodak coal catalyzed by sulfated iron oxides

    SciTech Connect

    Prodhan, V.R.; Holder, G.D.; Wonder, I.; Tierney, J.W.

    1992-08-01

    This paper describes the kinetics of the direct liquefaction of Wyodak coal using tetralin and 1000 psig (cold) H[sub 2] were experimentally measured and mathematically modeled. Experiments were carried out in a 27-cm[sup 3] horizontally shaken autoclave microreactor at 648-698 K for reaction times of 5--120 min. Some experiments were carried out at lower temperatures to determine if the model would be accurate at such conditions. Three catalyst combinations were used, Mo/Fe[sub 2]O[sub 3]/SO[sub 4], Fe[sub 2]O[sub 3]/SO[sub 4], and Fe[sub 2]O[sub 3], each with elemental sulfur. Four reaction pathways were considered: coal to asphaltenes, coal to gas, coal to oils, and asphaltenes to oils. In each pathway (except for the conversion of coal to gas), parallel thermal and catalytic reactions were included. The conversion of coal to asphaltenes was found to be primarily thermal and conversion of asphaltenes to oils was primarily catalytic, while conversion of coal to oils had significant thermal and catalytic contributions. The frequency factor and activation energy of each significant rate constant were estimated by correlating data for all temperatures (16 parameters).

  6. Hierarchical zeolites and their catalytic performance in selective oxidative processes.

    PubMed

    Ojeda, Manuel; Grau-Atienza, Aida; Campos, Rafael; Romero, Antonio A; Serrano, Elena; Maria Marinas, Jose; García Martínez, Javier; Luque, Rafael

    2015-04-24

    Hierarchical ZSM-5 zeolites prepared using a simple alkali treatment and subsequent HCl washing are found to exhibit unprecedented catalytic activities in selective oxidation of benzyl alcohol under microwave irradiation. The metal-free zeolites promote the microwave-assisted oxidation of benzyl alcohol with hydrogen peroxide in yields ranging from 45-35 % after 5 min of reaction under mild reaction conditions as well as the epoxidation of cyclohexene to valuable products (40-60 % conversion). The hierarchically porous systems also exhibited an interesting catalytic activity in the dehydration of N,N-dimethylformamide (25-30 % conversion), representing the first example of transition-metal free catalysts in this reaction.

  7. Oxidative transformation of micropollutants during municipal wastewater treatment: comparison of kinetic aspects of selective (chlorine, chlorine dioxide, ferrate VI, and ozone) and non-selective oxidants (hydroxyl radical).

    PubMed

    Lee, Yunho; von Gunten, Urs

    2010-01-01

    Chemical oxidation processes have been widely applied to water treatment and may serve as a tool to minimize the release of micropollutants (e.g. pharmaceuticals and endocrine disruptors) from municipal wastewater effluents into the aquatic environment. The potential of several oxidants for the transformation of selected micropollutants such as atenolol, carbamazepine, 17 alpha-ethinylestradiol (EE2), ibuprofen, and sulfamethoxazole was assessed and compared. The oxidants include chlorine, chlorine dioxide, ferrate(VI), and ozone as selective oxidants versus hydroxyl radicals as non-selective oxidant. Second-order rate constants (k) for the reaction of each oxidant show that the selective oxidants react only with some electron-rich organic moieties (ERMs), such as phenols, anilines, olefins, and deprotonated-amines. In contrast, hydroxyl radicals show a nearly diffusion-controlled reactivity with almost all organic moieties (k>or=10(9)M(-1) s(-1)). Due to a competition for oxidants between a target micropollutant and wastewater matrix (i.e. effluent organic matter, EfOM), a higher reaction rate with a target micropollutant does not necessarily translate into more efficient transformation. For example, transformation efficiencies of EE2, a phenolic micropollutant, in a selected wastewater effluent at pH 8 varied only within a factor of 7 among the selective oxidants, even though the corresponding k for the reaction of each selective oxidant with EE2 varied over four orders of magnitude. In addition, for the selective oxidants, the competition disappears rapidly after the ERMs present in EfOM are consumed. In contrast, for hydroxyl radicals, the competition remains practically the same during the entire oxidation. Therefore, for a given oxidant dose, the selective oxidants were more efficient than hydroxyl radicals for transforming ERMs-containing micropollutants, while hydroxyl radicals are capable of transforming micropollutants even without ERMs. Besides Ef

  8. Dynamic simulation models for selective sulfur removal in coal gasification systems. Final report

    SciTech Connect

    Vysniauskas, T.; Sim, W.D.

    1985-07-01

    A study was conducted, under EPRI Agreement RP1038-6, to investigate the feasibility of using computer simulation models to predict the steady-state and transient behavior of selective acid gas treating units. One of the prime objectives was to determine whether these models could be used to simulate the acid gas absorption units in coal gasification-combined cycle (GCC) power plants. Two dynamic simulation models were investigated; one model was developed by S-Cubed (formerly Systems, Science and Software) and the other was an in-house program developed by Hyprotech Ltd. These models were tailored specifically for the Norton Co. SELEXOL process for this study and incorporated an empirically fitted property package to represent the solvent. Both models used the same property package and were tested against SELEXOL plant data provided from the Bi-Gas pilot plant in Homer City, Pennsylvania, the Texaco pilot plant in Montebello, California and the TVA pilot plant in Muscle Shoals, Alabama. The results of this study are presented in this report. Although there were inconsistencies in some of the plant data, the models appeared to compare favorably with the plant data. The S-Cubed and Hyprotech model yielded nearly identical results when tested against the Bi-Gas plant data. Overall, the Hyprotech model proved to be faster than the S-Cubed version by about an order of magnitude and therefore offered the more attractive option for general simulation applications. However, further work is still needed to improve the solvent property predictions in the model. 7 refs.

  9. Advanced treatment of biologically pretreated coal gasification wastewater by a novel integration of heterogeneous Fenton oxidation and biological process.

    PubMed

    Xu, Peng; Han, Hongjun; Zhuang, Haifeng; Hou, Baolin; Jia, Shengyong; Xu, Chunyan; Wang, Dexin

    2015-04-01

    Laboratorial scale experiments were conducted in order to investigate a novel system integrating heterogeneous Fenton oxidation (HFO) with anoxic moving bed biofilm reactor (ANMBBR) and biological aerated filter (BAF) process on advanced treatment of biologically pretreated coal gasification wastewater (CGW). The results indicated that HFO with the prepared catalyst (FeOx/SBAC, sewage sludge based activated carbon (SBAC) which loaded Fe oxides) played a key role in eliminating COD and COLOR as well as in improving the biodegradability of raw wastewater. The surface reaction and hydroxyl radicals (OH) oxidation were the mechanisms for FeOx/SBAC catalytic reaction. Compared with ANMBBR-BAF process, the integrated system was more effective in abating COD, BOD5, total phenols (TPs), total nitrogen (TN) and COLOR and could shorten the retention time. Therefore, the integrated system was a promising technology for engineering applications.

  10. Thermal Behavior Study of the MoVTeNb Oxide Catalyst for Selective Oxidation Process

    SciTech Connect

    Idris, R.; Hamid, S. B. Abd.

    2009-06-01

    Several parameters involved in preparing the multi metal oxide (MMO) catalysts (Mo{sub 1}V{sub 0.3}Te{sub 0.23}Nb{sub 0.12}O{sub x}) for selective oxidation of propane to acrylic acid (AA) were investigated. These included the proper pre-calcined and calcinations atmosphere effect on the performance of the catalysts. It was found that each metal element plays a critical role to the performance of an effective catalyst and also the calcinations under a non-flow inert atmosphere. The characterization results from XRD, SEM, TG and DSC show the important differences depending on the activation procedures of the MoVTeNb oxide catalyst. The XRD analysis is used to identify the phase inventory of the MoVTeNb oxide catalysts. The structure of orthorhombic M1, M2, TeMo{sub 5}O{sub 16}, V{sub 0.95}Mo{sub 0.97}O{sub 5} and Mo{sub 5}O{sub 14} phase was investigated. The orthorhombic M1 phase is the most active and selective phase and is responsible for the major of the efficiently of the best catalyst for selective oxidation process. TGA and DTG allow the identification of the number and types, of reactions involving evaporation of small molecules from removal of ligands and water to condensation or drying processes. From all these analyses it was proven that the activation procedures would affect the performance of the MoVTeNb oxide catalyst.

  11. Extraction, separation, and analysis of high sulfur coal

    SciTech Connect

    Olesik, S.V.; Pekay, L.A.; Larkins, W. Jr.

    1992-05-31

    The work described in this report studies the removal of sulfur by oxidative interaction of various cupric salts with coal and also considers the possibility of removing organic sulfur by the selective interaction of supercritical ethanol with the organic coal matrix. Either one of these methods could potentially be used to pretreat coals before burning. The primary purpose of these studies is to ascertain the nature of the chemical reactions occurring, the chemical composition of the resultant products, and information on possible reaction mechanisms. This information should allow prediction of reasonable reaction conditions for the removal of organosulfur compound from coal.

  12. Extraction, separation, and analysis of high sulfur coal. Final report

    SciTech Connect

    Olesik, S.V.; Pekay, L.A.; Larkins, W. Jr.

    1992-05-31

    The work described in this report studies the removal of sulfur by oxidative interaction of various cupric salts with coal and also considers the possibility of removing organic sulfur by the selective interaction of supercritical ethanol with the organic coal matrix. Either one of these methods could potentially be used to pretreat coals before burning. The primary purpose of these studies is to ascertain the nature of the chemical reactions occurring, the chemical composition of the resultant products, and information on possible reaction mechanisms. This information should allow prediction of reasonable reaction conditions for the removal of organosulfur compound from coal.

  13. Benefit-cost analysis of selected DOE/OHER investments in coal liquefaction.

    SciTech Connect

    Callaway, J.M.; Fillo, J.P.; Gray, R.H.; Felix, W.D.; Mahlum, D.D.

    1982-09-01

    Based in large part of the lack of specific information about the nature and magnitude of health impacts that could occur from commercialization of a coal liquefaction industry, DOE initiated a broad-based program to study the potential health and environmental fate and effects of process streams from several coal liquefaction process options. Responsibility for this research was assigned to OHER. Specific results of this research program that are important for the purpose of this analysis include findings that: the toxicity and teratogenic potential of coal liquids boiling below 450/sup 0/F is small; mutagenic and carcinogenic activity is typically expressed in coal liquids boiling above 750/sup 0/F; and mutagenic and carcinogenic activity increases markedly in coal liquids boiling above 800/sup 0/F. Based on the above findings, OHER funded research to evaluate the effect of various hydrotreatment levels on the biological activity of coal-derived liquids. Studies using the Ames assay or mammalian cell transformation assays indicated that hydrotreatment was effective in reducing biological activity of coal-derived liquids. Skin-painting studies demonstrated that carcinogenicity was also reduced by hydrotreatment. Studies in progress are evaluating the effects of hydrotreatment severity on biological activity. However, it appears reasonably clear that health risks can be reduced by hydrotreating only materials that boil above 750/sup 0/F. Materials boiling below 750/sup 0/ could be marketed directly without significant risk to individuals exposed to these products. The benefit-cost analysis presented is based on the premise that the cost differential between full and partial hydrotreatment provides the basis for approximating the potential benefits associated with the relevant OHER research investments.

  14. THz-Pulse-Induced Selective Catalytic CO Oxidation on Ru.

    PubMed

    LaRue, Jerry L; Katayama, Tetsuo; Lindenberg, Aaron; Fisher, Alan S; Öström, Henrik; Nilsson, Anders; Ogasawara, Hirohito

    2015-07-17

    We demonstrate the use of intense, quasi-half-cycle THz pulses, with an associated electric field component comparable to intramolecular electric fields, to direct the reaction coordinate of a chemical reaction by stimulating the nuclear motions of the reactants. Using a strong electric field from a THz pulse generated via coherent transition radiation from an ultrashort electron bunch, we present evidence that CO oxidation on Ru(0001) is selectively induced, while not promoting the thermally induced CO desorption process. The reaction is initiated by the motion of the O atoms on the surface driven by the electric field component of the THz pulse, rather than thermal heating of the surface.

  15. Selective oxidation of CO in hydrogen over gold supported on manganese oxides

    SciTech Connect

    Torres Sanchez, R.M.; Ueda, Atsushi; Tanaka, Koji

    1997-05-01

    To develop PEFCs for general use it is necessary to make catalysts that are able to operate at low temperature, that work in the presence of CO{sub 2} and H{sub 2}O, and which have the ability to selectively remove CO from reformed gas by oxidizing CO to CO{sub 2}, while at the same time being inactive for the oxidation of H{sub 2}. Through the screening of support materials which give the largest difference in catalytic activity between the oxidation of CO and H{sub 2}, we found Au/MnOx to be one of the best candidates for the removal of CO from hydrogen-rich fuel gases. Gold supported on manganese oxides has also been investigated by Hoflund and co-workers for CO oxidation reaction in an inert gas background and by Iwasawa and his co-workers for the preparation method by use of an organo gold complex in the liquid phase. Because supported gold catalysts prefer oxidizing pretreatments, our major concern has been whether Au/MnOx is stable in H{sub 2}. 13 refs., 3 figs.

  16. Studies of the fate of sulfur trioxide in coal-fired utility boilers based on modified selected condensation methods.

    PubMed

    Cao, Yan; Zhou, Hongcang; Jiang, Wu; Chen, Chien-Wei; Pan, Wei-Ping

    2010-05-01

    The formation of sulfur trioxide (SO(3)) in coal-fired utility boilers can have negative effects on boiler performance and operation, such as fouling and corrosion of equipment, efficiency loss in the air preheater (APH), increase in stack opacity, and the formation of PM(2.5). Sulfur trioxide can also compete with mercury when bonding with injected activated carbons. Tests in a lab-scale reactor confirmed there are major interferences between fly ash and SO(3) during SO(3) sampling. A modified SO(3) procedure to maximize the elimination of measurement biases, based on the inertial-filter-sampling and the selective-condensation-collecting of SO(3), was applied in SO(3) tests in three full-scale utility boilers. For the two units burning bituminous coal, SO(3) levels starting at 20 to 25 ppmv at the inlet to the selective catalytic reduction (SCR), increased slightly across the SCR, owing to catalytic conversion of SO(2) to SO(3,) and then declined in other air pollutant control device (APCD) modules downstream to approximately 5 ppmv and 15 ppmv at the two sites, respectively. In the unit burning sub-bituminous coal, the much lower initial concentration of SO(3) estimated to be approximately 1.5 ppmv at the inlet to the SCR was reduced to about 0.8 ppmv across the SCR and to about 0.3 ppmv at the exit of the wet flue gas desulfurization (WFGD). The SO(3) removal efficiency across the WFGD scrubbers at the three sites was generally 35% or less. Reductions in SO(3) across either the APH or the dry electrostatic precipitator (ESP) in units burning high-sulfur bituminous coal were attributed to operating temperatures being below the dew point of SO(3).

  17. A spectroscopic comparison of selected Chinese kaolinite, coal bearing kaolinite and halloysite--a mid-infrared and near-infrared study.

    PubMed

    Cheng, Hongfei; Yang, Jing; Liu, Qinfu; Zhang, Jinshan; Frost, Ray L

    2010-11-01

    Mid-infrared (MIR) and near-infrared (NIR) spectroscopy have been compared and evaluated for differentiating kaolinite, coal bearing kaolinite and halloysite. Kaolinite, coal bearing kaolinite and halloysite are the three relative abundant minerals of the kaolin group, especially in China. In the MIR spectra, the differences are shown in the 3000-3600 cm⁻¹ between kaolinite and halloysite. It cannot obviously differentiate the kaolinite and halloysite, leaving alone kaolinite and coal bearing kaolinite. However, NIR, together with MIR, gives us the sufficient evidence to differentiate the kaolinite and halloysite, especially kaolinite and coal bearing kaolinite. There are obvious differences between kaolinite and halloysite in all range of their spectra, and they also show some difference between kaolinite and coal bearing kaolinite. Therefore, the reproducibility of measurement, signal to noise ratio and richness of qualitative information should be simultaneously considered for proper selection of a spectroscopic method for mineral analysis.

  18. Colour and toxic characteristics of metakaolinite–hematite pigment for integrally coloured concrete, prepared from iron oxide recovered from a water treatment plant of an abandoned coal mine

    SciTech Connect

    Sadasivam, Sivachidambaram Thomas, Hywel Rhys

    2016-07-15

    A metakaolinite-hematite (KH) red pigment was prepared using an ocherous iron oxide sludge recovered from a water treatment plant of an abandoned coal mine. The KH pigment was prepared by heating the kaolinite and the iron oxide sludge at kaolinite's dehydroxylation temperature. Both the raw sludge and the KH specimen were characterised for their colour properties and toxic characteristics. The KH specimen could serve as a pigment for integrally coloured concrete and offers a potential use for the large volumes of the iron oxide sludge collected from mine water treatment plants. - Graphical abstract: A kaolinite based red pigment was prepared using an ocherous iron oxide sludge recovered from an abandoned coal mine water treatment plant. Display Omitted - Highlights: • A red pigment was prepared by heating a kaolinite and an iron oxide sludge. • The iron oxide and the pigment were characterised for their colour properties. • The red pigment can be a potential element for integrally coloured concrete.

  19. Selective Neuronal Vulnerability to Oxidative Stress in the Brain

    PubMed Central

    Wang, Xinkun; Michaelis, Elias K.

    2010-01-01

    Oxidative stress (OS), caused by the imbalance between the generation and detoxification of reactive oxygen and nitrogen species (ROS/RNS), plays an important role in brain aging, neurodegenerative diseases, and other related adverse conditions, such as ischemia. While ROS/RNS serve as signaling molecules at physiological levels, an excessive amount of these molecules leads to oxidative modification and, therefore, dysfunction of proteins, nucleic acids, and lipids. The response of neurons to this pervasive stress, however, is not uniform in the brain. While many brain neurons can cope with a rise in OS, there are select populations of neurons in the brain that are vulnerable. Because of their selective vulnerability, these neurons are usually the first to exhibit functional decline and cell death during normal aging, or in age-associated neurodegenerative diseases, such as Alzheimer's disease. Understanding the molecular and cellular mechanisms of selective neuronal vulnerability (SNV) to OS is important in the development of future intervention approaches to protect such vulnerable neurons from the stresses of the aging process and the pathological states that lead to neurodegeneration. In this review, the currently known molecular and cellular factors that contribute to SNV to OS are summarized. Included among the major underlying factors are high intrinsic OS, high demand for ROS/RNS-based signaling, low ATP production, mitochondrial dysfunction, and high inflammatory response in vulnerable neurons. The contribution to the selective vulnerability of neurons to OS by other intrinsic or extrinsic factors, such as deficient DNA damage repair, low calcium-buffering capacity, and glutamate excitotoxicity, are also discussed. PMID:20552050

  20. Evaluation of the Impact of Chlorine on Mercury Oxidation in a Pilot-Scale Coal Combustor--The Effect of Coal Blending

    EPA Science Inventory

    A study has been undertaken to investigate the effect of blending PRB coal with an Eastern bituminous coal on the speciation of Hg across an SCR catalyst. In this project, a pilot-scale (1.2 MWt) coal combustor equipped with an SCR reactor for NOx control was used for evaluating ...

  1. Monolithic solid oxide fuel cell technology advancement for coal-based power generation. Annual report, October 1991--September 1992

    SciTech Connect

    Not Available

    1993-05-01

    The program is being conducted by a team consisting of AlliedSignal Aerospace Systems & Equipment (ASE) (formerly AiResearch Los Angeles Division) and Argonne National Laboratory (ANL). The objective of the program is to advance materials and fabrication methodologies to develop a monolithic solid oxide fuel cell (MSOFC) system capable of meeting performance, life, and cost goals for coal-based power generation. The program focuses on materials research and development, fabrication process development, cell/stack performance testing and characterization, cost and system analysis, and quality development.

  2. Highly Selective H2 Separation Zeolite Membranes for Coal Gasification Membrane Reactor Applications

    SciTech Connect

    Mei Hong; Richard Noble; John Falconer

    2007-09-24

    Zeolite membranes are thermally, chemically, and mechanically stable. They also have tunable molecular sieving and catalytic ability. These unique properties make zeolite membrane an excellent candidate for use in catalytic membrane reactor applications related to coal conversion and gasification, which need high temperature and high pressure range separation in chemically challenging environment where existing technologies are inefficient or unable to operate. Small pore, good quality, and thin zeolite membranes are needed for highly selective H2 separation from other light gases (CO2, CH4, CO). However, current zeolite membranes have either too big zeolite pores or a large number of defects and have not been successful for H2 separation from light gases. The objective of this study is to develop zeolite membranes that are more suitable for H2 separation. In an effort to tune the size of zeolite pores and/or to decrease the number of defects, medium-pore zeolite B-ZSM-5 (MFI) membranes were synthesized and silylated. Silylation on B-ZSM-5 crystals reduced MFI-zeolite pore volume, but had little effect on CO2 and CH4 adsorption. Silylation on B-ZSM-5 membranes increased H2 selectivity both in single component and in mixtures with CO2, CH4, or N2. Single gas and binary mixtures of H2/CO2 and H2/CH4 were permeated through silylated B-ZSM-5 membranes at feed pressures up to 1.7 MPa and temperatures up to 773 K. For one B-ZSM-5 membrane after silylation, the H2/CO2 separation selectivity at 473 K increased from 1.4 to 37, whereas the H2/CH4 separation selectivity increased from 1.6 to 33. Hydrogen permeance through a silylated BZSM-5 membrane was activated with activation energy of {approx}10 kJ/mol, but the CO2 and CH4 permeances decreased slightly with temperature in both single gas and in mixtures. Therefore, the H2 permeance and H2/CO2 and H2/CH4 separation selectivities increased with temperature. At 673 K, the H2 permeance was 1.0x10-7 mol{center_dot}m-2{center

  3. Selective oxidation of bromide in wastewater brines from hydraulic fracturing.

    PubMed

    Sun, Mei; Lowry, Gregory V; Gregory, Kelvin B

    2013-07-01

    Brines generated from oil and natural gas production, including flowback water and produced water from hydraulic fracturing of shale gas, may contain elevated concentrations of bromide (~1 g/L). Bromide is a broad concern due to the potential for forming brominated disinfection byproducts (DBPs) during drinking water treatment. Conventional treatment processes for bromide removal is costly and not specific. Selective bromide removal is technically challenging due to the presence of other ions in the brine, especially chloride as high as 30-200 g/L. This study evaluates the ability of solid graphite electrodes to selectively oxidize bromide to bromine in flowback water and produced water from a shale gas operation in Southwestern PA. The bromine can then be outgassed from the solution and recovered, as a process well understood in the bromine industry. This study revealed that bromide may be selectively and rapidly removed from oil and gas brines (~10 h(-1) m(-2) for produced water and ~60 h(-1) m(-2) for flowback water). The electrolysis occurs with a current efficiency between 60 and 90%, and the estimated energy cost is ~6 kJ/g Br. These data are similar to those for the chlor-alkali process that is commonly used for chlorine gas and sodium hydroxide production. The results demonstrate that bromide may be selectively removed from oil and gas brines to create an opportunity for environmental protection and resource recovery.

  4. EVALUATION AND MITIGATION OF VISIBLE ACIDIC AEROSOL PLUMES FROM COAL FIRED POWER BOILERS

    EPA Science Inventory

    The formation of sulfur trioxide during the combustion of coal can increase significantly following the installation and operation of selective catalytic reduction systems for reduction of nitrogen oxides. This can in turn lead to adverse environmental impacts, including visible...

  5. Selective oxidation of cyclohexene through gold functionalized silica monolith microreactors

    NASA Astrophysics Data System (ADS)

    Alotaibi, Mohammed T.; Taylor, Martin J.; Liu, Dan; Beaumont, Simon K.; Kyriakou, Georgios

    2016-04-01

    Two simple, reproducible methods of preparing evenly distributed Au nanoparticle containing mesoporous silica monoliths are investigated. These Au nanoparticle containing monoliths are subsequently investigated as flow reactors for the selective oxidation of cyclohexene. In the first strategy, the silica monolith was directly impregnated with Au nanoparticles during the formation of the monolith. The second approach was to pre-functionalize the monolith with thiol groups tethered within the silica mesostructure. These can act as evenly distributed anchors for the Au nanoparticles to be incorporated by flowing a Au nanoparticle solution through the thiol functionalized monolith. Both methods led to successfully achieving even distribution of Au nanoparticles along the length of the monolith as demonstrated by ICP-OES. However, the impregnation method led to strong agglomeration of the Au nanoparticles during subsequent heating steps while the thiol anchoring procedure maintained the nanoparticles in the range of 6.8 ± 1.4 nm. Both Au nanoparticle containing monoliths as well as samples with no Au incorporated were tested for the selective oxidation of cyclohexene under constant flow at 30 °C. The Au free materials were found to be catalytically inactive with Au being the minimum necessary requirement for the reaction to proceed. The impregnated Au-containing monolith was found to be less active than the thiol functionalized Au-containing material, attributable to the low metal surface area of the Au nanoparticles. The reaction on the thiol functionalized Au-containing monolith was found to depend strongly on the type of oxidant used: tert-butyl hydroperoxide (TBHP) was more active than H2O2, likely due to the thiol induced hydrophobicity in the monolith.

  6. Variation of organic sulfur in macerals of selected Illinois Basin coals

    USGS Publications Warehouse

    Demir, I.; Harvey, R.D.

    1991-01-01

    An electron microbeam technique was used to determine the distribution of organic sulfur in the main macerals of five Illinois Basin coals. On average, sporinites are the highest, inertinites the lowest, and vitrinites intermediate in organic sulfur for each coal. The observed differences are likely due to varying affinities of the different pre-maceral materials for sulfur and/or local variation in the production of H2S primarily during the peat stage. Investigation of molecular structures of individual macerals in relation to the findings of this study may delineate the relative abundance of organic sulfur in various organic compounds and thus lead to the development of efficient desulfurization processes. ?? 1991.

  7. Novel microorganism for selective separation of coal from ash and pyrite; First quarterly technical progress report, September 1, 1993--November 30, 1993

    SciTech Connect

    Misra, M.; Smith, R.W.; Raichur, A.M.

    1993-12-31

    This report summarizes the progress made during the first quarter of the research project entitled ``A Novel Microorganism for Selective Separation of Coal from Ash and Pyrite,`` DOE Grant No. DE-FG22-93PC93215. The objective of this project is to study the effectiveness of a novel hydrophobic microorganism, Mycobacterium phlei (M. phlei), for the selective flocculation of coal from pyrite and ash-forming minerals. During the reporting period, three different coal samples: Illinois No. 6 coal, Kentucky No. 9 coal and Pittsburgh No. 8 coal, were collected to be used in the investigation. The microorganism, M. phlei, was obtained as freeze-dried cultures and the growth characteristics of the bacteria were studied. Scanning electron microphotographs revealed that M. phlei cells are coccal in shape and are approximately 1 {mu}m in diameter. Electrokinetic measurements showed that the Illinois No. 6 and Pittsburgh No. 8 coal samples had an isoelectric point (IEP) around pH 6 whereas M. phlei had an IEP around pH 1.5. Electrokinetic measurements of the ruptured microorganisms exhibited an increase in IEP. The increase in IEP of the ruputured cells was due to the release of fatty acids and polar groups from the cell membrane.

  8. Photolysis rates of selected polynuclear aromatic hydrocarbons in aqueous coal-oil systems. [Fluoranthene, benzo(a)anthracene

    SciTech Connect

    Picel, K.C.; Stamoudis, V.C.; Simmons, M.S.

    1983-01-01

    Four polynuclear aromatic hydrocarbons (PAH) from the neutral fraction of synfuels materials - fluoranthene (FLA), pyrene (PY), benzo(a)anthracene (BaA), and benzo(a)pyrene (BaP) - were selected as representative test compounds based on toxicity, abundance, and chemical characteristics. BaA and BaP are established carcinogens, and FLA is a suspected cocarcinogen. Pyrene, which is not thought to be carcinogenic, was included for comparison to FLA, which has the same molecular weight but different structural properties. The synthetic fuel material used in this study was CRM-1, a coal-oil comparative research material obtained from Oak Ridge National Laboratory. For PY, BaA, and BaP in aqueous systems, initial photolysis rates are six to nine times lower in coal-oil (CRM-1) saturated water than in pure water. However, the photolysis rate of FLA is not significantly different under the same conditions. It is possible that the photochemical mechanisms inhibited in the photoreactive PAH are not operational in FLA. Since the calculated light attenuation can account only partially for the observed reduction of the photolysis rates of PY, BaA, and BaP, it is likely that other factors - especially the presence of phenols - are affecting the photodegradation process of these PAH. Further studies are needed to investigate the individual effects on PAH photolysis rates of the various classes of compounds that make up the coal-oil matrix. 20 references, 2 figures, 4 tables.

  9. Engineering Development of Advanced Physical Fine Coal Cleaning for Premium Fuel Applications: Task 9 - Selective agglomeration Module Testing and Evaluation.

    SciTech Connect

    Moro, N.` Jha, M.C.

    1997-09-29

    The primary goal of this project was the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope included laboratory research and bench-scale testing of both processes on six coals to optimize the processes, followed by the design, construction, and operation of a 2 t/hr process development unit (PDU). The project began in October, 1992, and is scheduled for completion by September 1997. This report summarizes the findings of all the selective agglomeration (SA) test work performed with emphasis on the results of the PDU SA Module testing. Two light hydrocarbons, heptane and pentane, were tested as agglomerants in the laboratory research program which investigated two reactor design concepts: a conventional two-stage agglomeration circuit and a unitized reactor that combined the high- and low-shear operations in one vessel. The results were used to design and build a 25 lb/hr bench-scale unit with two-stage agglomeration. The unit also included a steam stripping and condensation circuit for recovery and recycle of heptane. It was tested on six coals to determine the optimum grind and other process conditions that resulted in the recovery of about 99% of the energy while producing low ash (1-2 lb/MBtu) products. The fineness of the grind was the most important variable with the D80 (80% passing size) varying in the 12 to 68 micron range. All the clean coals could be formulated into coal-water-slurry-fuels with acceptable properties. The bench-scale results were used for the conceptual and detailed design of the PDU SA Module which was integrated with the existing grinding and dewatering circuits. The PDU was operated for about 9 months. During the first three months, the shakedown testing was performed to fine tune the operation and control of various equipment. This was followed by parametric testing, optimization/confirmatory testing, and finally a

  10. Characterization of biodegraded coals

    SciTech Connect

    Bean, R.M.; Franz, J.A.; Campbell, J.A.; Linehan, J.C.; Stewart, D.L.; Thomas, B.L.

    1988-01-01

    Microbial degradation of coals to materials that are soluble in water has been a topic of intensive research for the last few years. The potential for economical recovery of low-grade coals, coupled with possibilities for further upgrading by microbial desulfurization or methanation has spurred intensive research at a number of laboratories. Until very recently, coal biodegradation has been accomplished using low-grade, naturally oxidized coals such as leonardiate, or coals subjected to pretreatment with oxidizing chemicals. The authors have been able to accomplish the biodegradation of bituminous Illinois 6 coal after a pretreatment consisting of air oxidation, using a culture of the fungus Penicillium sp. They report in this paper results of chemical and spectrometric analyses of the starting materials and products from Illinois 6 coal biodegradation, and compare the results with those previously reported from the biodegradation of leonardite.

  11. Selective oxidation of methanol and ethanol on supported ruthenium oxide clusters at low temperatures

    SciTech Connect

    Liu, Haichao; Iglesia, Enrique

    2004-03-04

    RuO2 domains supported on SnO2, ZrO2, TiO2, Al2O3, and SiO2 catalyze the oxidative conversion of methanol to formaldehyde, methylformate, and dimethoxymethane with unprecedented rates and high combined selectivity (>99 percent) and yield at low temperatures (300-400 K). Supports influence turnover rates and the ability of RuO2 domains to undergo redox cycles required for oxidation turnovers. Oxidative dehydrogenation turnover rates and rates of stoichiometric reduction of RuO2 in H2 increased in parallel when RuO2 domains were dispersed on more reducible supports. These support effects, the kinetic effects of CH3OH and O2 on reaction rates, and the observed kinetic isotope effects with CH3OD and CD3OD reactants are consistent with a sequence of elementary steps involving kinetically relevant H-abstraction from adsorbed methoxide species using lattice oxygen atoms and with methoxide formation in quasi-equilibrated CH3OH dissociation on nearly stoichiometric RuO2 surfaces. Anaerobic transient experiments confirmed that CH3OH oxidation to HCHO requires lattice oxygen atoms and that selectivities are not influenced by the presence of O2. Residence time effects on selectivity indicate that secondary HCHO-CH3OH acetalization reactions lead to hemiacetal or methoxymethanol intermediates that convert to dimethoxymethane in reactions with CH3OH on support acid sites or dehydrogenate to form methylformate on RuO2 and support redox sites. These conclusions are consistent with the tendency of Al2O3 and SiO2 supports to favor dimethoxymethane formation, while SnO2, ZrO2, and TiO2 preferentially form methylformate. These support effects on secondary reactions were confirmed by measured CH3OH oxidation rates and selectivities on physical mixtures of supported RuO2 catalysts and pure supports. Ethanol also reacts on supported RuO2 domains to form predominately acetaldehyde and diethoxyethane at 300-400 K. The bifunctional nature of these reaction pathways and the remarkable

  12. Carbon monoxide detection of chemisorbed oxygen in coal and other carbonaceous materials

    USGS Publications Warehouse

    Hinckley, C.C.; Wiltowski, T.; Wiltowska, T.; Ellison, D.W.; Shiley, R.H.; Wu, L.

    1990-01-01

    The oxidation of carbon monoxide by mildly oxidized and devolatilized coal samples was studied thermogravimetrically. The oxidation was attributed to oxygen chemisorbed on inorganic components of the coals. The reaction of CO with pyrite producing carbonyl sulphide, OCS, accompanied the oxidation. A mechanism for CO oxidation is proposed in which active oxygen chemisorbed on the inorganic components of the coal directly oxidized CO to CO2, and facilitates the chemisorption of CO on the coal as carbonate. A factor, ?? = ( 11 14) [1 - ( Wn Wc)], was derived where Wn is the sample weight loss not attributed to OCS formation, and Wc is the estimated weight of evolved CO2. This quantity is proportional to the fraction of CO2 produced by the direct oxidation of CO, and was used to compare the coal samples studied. Samples of an Illinois No. 5 coal yielded average ?? values of 0.7 and those of an Illinois No. 6 coal yielded values of 0.6, indicating that in these cases, the majority of CO2 produced came from the direct oxidation of CO. The results obtained for the coal samples are compared with a selection of carbonaceous samples for which the proposed mechanism does not apply. ?? 1990.

  13. Coal mine wastes. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-07-01

    The bibliography contains citations concerning coal mining wastes, refuse dumps, and spoil. The disposal, environmental impact, waste treatment, utilization, and pollution control of these wastes are discussed. The revegetation of mined lands using waste water sludge is also considered. (Contains a minimum of 243 citations and includes a subject term index and title list.)

  14. Coal mine wastes. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1994-05-01

    The bibliography contains citations concerning coal mining wastes, refuse dumps, and spoil. The disposal, environmental impact, waste treatment, utilization, and pollution control of these wastes are discussed. The revegetation of mined lands using waste water sludge is also considered. (Contains a minimum of 138 citations and includes a subject term index and title list.)

  15. XAFS SPECTROSCOPY ANALYSIS OF SELECTED HAP ELEMENTS IN FINE PM DERIVED FROM COAL COMBUSTION

    EPA Science Inventory

    X-ray absorption fine structure (XAFS) spectroscopy has been used to investigate the valence states and molecular structures of sulfur (S), chromium (Cr), arsenic (As), and zinc (Zn) in fine particulate matter (PM) separated from coal flyash produced in a realistic combustion sys...

  16. A risk-based decision support framework for selection of appropriate safety measure system for underground coal mines.

    PubMed

    Samantra, Chitrasen; Datta, Saurav; Mahapatra, Siba Sankar

    2017-03-01

    In the context of underground coal mining industry, the increased economic issues regarding implementation of additional safety measure systems, along with growing public awareness to ensure high level of workers safety, have put great pressure on the managers towards finding the best solution to ensure safe as well as economically viable alternative selection. Risk-based decision support system plays an important role in finding such solutions amongst candidate alternatives with respect to multiple decision criteria. Therefore, in this paper, a unified risk-based decision-making methodology has been proposed for selecting an appropriate safety measure system in relation to an underground coal mining industry with respect to multiple risk criteria such as financial risk, operating risk, and maintenance risk. The proposed methodology uses interval-valued fuzzy set theory for modelling vagueness and subjectivity in the estimates of fuzzy risk ratings for making appropriate decision. The methodology is based on the aggregative fuzzy risk analysis and multi-criteria decision making. The selection decisions are made within the context of understanding the total integrated risk that is likely to incur while adapting the particular safety system alternative. Effectiveness of the proposed methodology has been validated through a real-time case study. The result in the context of final priority ranking is seemed fairly consistent.

  17. Characterization of selected Ohio coals to predict their conversion behavior relative to 104 North American Coals. [Factors correlating with liquefaction behavior

    SciTech Connect

    Whitacre, T. P.; Hunt, T. J.; Kneller, W. A.

    1982-02-01

    Twenty-six coal samples from Ohio were collected as washed and seam samples, and lithobodies within the seams. Characterization of these samples included determination of % maceral, % anti R/sub max/, LTA, chlorine content and proximate/ultimate and qualitative mineral analyses. These data were compared to data from a similar project by Yarzab, R.F., et al., 1980 completed at Pennsylvania State University using tetralin as the hydrogen donor solvent. The characteristics of these coals were correlated with liquefaction conversion and other data accrued on 104 North American coals by statistical analyses. Utilizing percent carbon, sulfur, volatile matter, reflectance, vitrinite and total reactive macerals, Q-mode cluster analysis demonstrated that Ohio coals are more similar to the coals of the Interior province than to those of the Appalachian province. Linear multiple regression analysis for the 104 North American coals provided a prediction equation for conversion (R = .96). The predicted conversion values for the samples range from 58.8 to 79.6%, with the Lower Kittanning (No. 5) and the Middle Kittanning (No. 6) coal seams showing the highest predicted percent conversion (respectively, 73.4 and 72.2%). The moderately low FSI values for the No. 5 and No. 6 coals (respectively, 2.5 and 3) and their moderately high alkaline earth content (respectively, 0.69 and 0.74%) suggest that these coals possess the best overall properties for conversion. Stepwise regression has indicated that the most important coal characteristics affecting conversion are, in decreasing order of importance: % volatile matter, % vitrinite and % total sulfur. Conversion processes can be expected to produce higher yields with Ohio coals due to the presence of such mineral catalysts as pyrite and kaolinite. It is believed that the presence of these disposable catalysts increases the marketability of Ohio coals.

  18. Effects of Mikania glomerata Spreng. and Mikania laevigata Schultz Bip. ex Baker (Asteraceae) extracts on pulmonary inflammation and oxidative stress caused by acute coal dust exposure

    SciTech Connect

    Freitas, T.P.; Silveira, P.C.; Rocha, L.G.; Rezin, G.T.; Rocha, J.; Citadini-Zanette, V.; Romao, P.T.; Dal-Pizzol, F.; Pinho, R.A.; Andrade, V.M.; Streck, E.L.

    2008-12-15

    Several studies have reported biological effects of Mikania glomerata and Mikania laevigata, used in Brazilian folk medicine for respiratory diseases. Pneumoconiosis is characterized by pulmonary inflammation caused by coal dust exposure. In this work, we evaluated the effect of pretreatment with M. glomerata and M. laevigata extracts (MGE and MLE, respectively) (100 mg/kg, s.c.) on inflammatory and oxidative stress parameters in lung of rats subjected to a single coal dust intratracheal instillation. Rats were pretreated for 2 weeks with saline solution, MGE, or MLE. On day 15, the animals were anesthetized, and gross mineral coal dust or saline solutions were administered directly in the lung by intratracheal instillation. Fifteen days after coal dust instillation, the animals were killed. Bronchoalveolar lavage (BAL) was obtained; total cell count and lactate dehydrogenase (LDH) activity were determined. In the lung, myeloperoxidase activity, thiobarbituric acid-reactive substances (TBARS) level, and protein carbonyl and sulfhydryl contents were evaluated. In BAL of treated animals, we verified an increased total cell count and LDH activity. MGE and MLE prevented the increase in cell count, but only MLE prevented the increase in LDH. Myeloperoxidase and TBARS levels were not affected, protein carbonylation was increased, and the protein thiol levels were decreased by acute coal dust intratracheal administration. The findings also suggest that both extracts present an important protective effect on the oxidation of thiol groups. Moreover, pretreatment with MGE and MLE also diminished lung inflammatory infiltration induced by coal dust, as assessed by histopathologic analyses.

  19. Novel microorganism for selective separation of coal from ash and pyrite. Seventh quarterly technical progress report, April 1, 1995--June 30, 1995

    SciTech Connect

    Misra, M.; Smith, R.W.; Raichur, A.M.

    1996-12-31

    The selective separation of pyrite and ash-forming minerals from coal can be accomplished by flotation, agglomeration and selective flocculation. The methods currently used for selective flocculation of coals include addition of natural or synthetic polymeric flocculants along with precise pH control. In some cases, these flocculants are nonselective or work imperfectly. It is known that many highly charged planktonic algae and bacteria will adhere to certain solid surfaces if the charge or hydrophobic interaction between the organism and the solids are favorable for adhesion. The resultant microorganism-mineral entities, if formed, can flocculate and can be separated. In addition, many living organisms produce extracellular biopolymers that can also cause flocculation. The microorganism, M. phlei, has the properties of being both highly charged and highly hydrophobic. The aim of the present investigation is to study the effectiveness of M. phlei and biopolymers derived from the organism for selective flocculation and separation of fine coal from pyrite and ash.

  20. Mechanism of selective methanol oxidation over vanadium oxide-titanium oxide catalysts: a FT-IT and flow reactor study

    SciTech Connect

    Busca, G.; Elmi, A.S.; Forzatti, P.

    1987-09-24

    The mechanism of the selective oxidation of methanol on two V-Ti oxide catalyst samples, prepared by impregnation and coprecipitation techniques, respectively is investigated. The interaction of methanol and its oxidation products (i.e., formaldehyde, dimethoxymethane, formic acid, and methyl formate) is studied by FR-IR spectroscopy and compares with the results of flow reactor measurements performed at different temperatures, contact times, and methanol/oxygen molar feed ratios. The data are interpreted on the basis of a reaction mechanism which involved the following steps: (i) condensation of methanol with surface VOH groups; (ii) H abstraction from methoxy groups leading to coordinated formaldehyde; (iii) formation of dioxymethylene species by interaction of adsorbed formaldehyde with nucelophilic sites; (iv) reaction of dioxymethylene species with methanol to give dimethoxymethane; (v) successive oxidation of dioxymethylene groups to formate ions; (vi) reaction of these ions either with methanol to produce methyl formate or with water to give formic acid; (vii) decomposition of formate species to produce carbon monoxide; (viii) parallel oxidation of methanol to carbon dioxide. The behaviors of the surface species are compared with those monitored on other systems and the catalyst requirements for the title reaction are discussed.

  1. Selective methane oxidation over promoted oxide catalysts. Quarterly report, March 1 - May 31, 1996

    SciTech Connect

    Klier, K.; Herman, R.G.; Wang, C.-B.

    1996-12-31

    Series of catalysts consisting of MoO{sub 3}, V{sub 2}O{sub 5}, TiO{sub 2}, and SnO{sub 2} impregnated onto oxide supports consisting of SiO{sub 2} (Cab-O-Sil), TiO{sub 2} or SnO{sub 2} were previously prepared and tested for the selective oxidation of methane to oxygenates, and it was found that the V{sub 2}O{sub 5}/SiO{sub 2} catalyst was the most active and most selective toward the formation of formaldehyde. These catalysts have been characterized by laser Raman spectroscopy after dehydration and during the methane oxidation reaction with a CH{sub 4}/02 = 10/1 reaction mixture at 500{degrees}C in a continuous flow in situ reaction cell. With the V{sub 2}O{sub 5}/SiO{sub 2} catalyst (the most active catalyst among those studied), no significant structural changes were revealed by in situ Raman analyses, indicating that the fully oxidized surface sites were related to the high formaldehyde selectivivity. Over the V{sub 2}O{sub 5}/TiO{sub 2} and V{sub 2}O{sub 5}/SnO{sub 2} catalysts, CO and CO{sub 2} were the principal products produced by oxidation of methane. For the first time, in situ Raman analysis clearly showed that for these latter catalysts, the surface vanadium(V) oxide species were partially reduced under the steady-state reaction conditions. The performance of the V{sub 2}O{sub 5}/TiO{sub 2}/SiO{sub 2} catalyst was similar to that of the V{sub 2}O{sub 5}TiO{sub 2} catalyst, consistent with the earlier observation that vanadia was largely bound to the titania overlayer. It appears that formaldehyde selectivity decreased with increasing catalyst reducibility, but no direct correlation of catalyst activity with reductibility was observed.

  2. Materials selection for oxide-based resistive random access memories

    SciTech Connect

    Guo, Yuzheng; Robertson, John

    2014-12-01

    The energies of atomic processes in resistive random access memories (RRAMs) are calculated for four typical oxides, HfO{sub 2}, TiO{sub 2}, Ta{sub 2}O{sub 5}, and Al{sub 2}O{sub 3}, to define a materials selection process. O vacancies have the lowest defect formation energy in the O-poor limit and dominate the processes. A band diagram defines the operating Fermi energy and O chemical potential range. It is shown how the scavenger metal can be used to vary the O vacancy formation energy, via controlling the O chemical potential, and the mean Fermi energy. The high endurance of Ta{sub 2}O{sub 5} RRAM is related to its more stable amorphous phase and the adaptive lattice rearrangements of its O vacancy.

  3. Increased Oxidative Stress as a Selective Anticancer Therapy

    PubMed Central

    Liu, Jiahui; Wang, Zhichong

    2015-01-01

    Reactive oxygen species (ROS) are closely related to tumorgenesis. Under hypoxic environment, increased levels of ROS induce the expression of hypoxia inducible factors (HIFs) in cancer stem cells (CSCs), resulting in the promotion of the upregulation of CSC markers, and the reduction of intracellular ROS level, thus facilitating CSCs survival and proliferation. Although the ROS level is regulated by powerful antioxidant defense mechanisms in cancer cells, it is observed to remain higher than that in normal cells. Cancer cells may be more sensitive than normal cells to the accumulation of ROS; consequently, it is supposed that increased oxidative stress by exogenous ROS generation therapy has an effect on selectively killing cancer cells without affecting normal cells. This paper reviews the mechanisms of redox regulation in CSCs and the pivotal role of ROS in anticancer treatment. PMID:26273420

  4. Quinone-Catalyzed Selective Oxidation of Organic Molecules

    PubMed Central

    Wendlandt, Alison E.

    2016-01-01

    Lead In Quinones are common stoichiometric reagents in organic chemistry. High potential para-quinones, such as DDQ and chloranil, are widely used and typically promote hydride abstraction. In recent years, many catalytic applications of these methods have been achieved by using transition metals, electrochemistry or O2 to regenerate the oxidized quinone in situ. Complementary studies have led to the development of a different class of quinones that resemble the ortho-quinone cofactors in Copper Amine Oxidases and mediate efficient and selective aerobic and/or electrochemical dehydrogenation of amines. The latter reactions typically proceed via electrophilic transamination and/or addition-elimination reaction mechanisms, rather than hydride abstraction pathways. The collective observations show that the quinone structure has a significant influence on the reaction mechanism and have important implications for the development of new quinone reagents and quinone-catalyzed transformations. PMID:26530485

  5. A Highly Selective Vanadium Catalyst for Benzylic C–H Oxidation

    PubMed Central

    Xia, Ji-Bao; Cormier, Kevin W.; Chen, Chuo

    2012-01-01

    Vanadium complexes have been used extensively to catalyze olefin and alcohol oxidation. However, their application in C–H oxidation has not been well-studied. We report herein that commercially available Cp2VCl2 catalyzes benzylic C–H oxidation selectively and effectively, giving no aromatic oxidation products. PMID:22712051

  6. Desulfurization of coal by microbial column flotation

    SciTech Connect

    Ohmura, Naoya; Saiki, Hiroshi . Dept. of Biotechnology)

    1994-06-05

    Twenty-three strains capable of oxidizing iron were isolated from coal and ore storage sites as well as coal and ore mines, volcanic areas, and hot spring. Four strains were found to have high iron-oxidizing activity. One strain (T-4) was selected for this experiment since the strain showed the fastest leaching rate of iron and sulfate from pyrite among the four strains. The T-4 strain was assigned for Thiobacillus ferrooxidans from its cultural and morphological characteristics. Bacterial treatment was applied to column flotation. An increase of cell density in the microbial column flotation resulted in the increase of pyrite removal from a coal-pyrite mixture with corresponding decrease of coal recovery. The addition of kerosene into the microbial column flotation increased the recovery of the imitated coal from 55% (without kerosene) to 81% (with 50 [mu]L/L kerosene) with the reduction of pyrite sulfur content from11% (feed coal) to 3.9% (product coal). An excellent separation was obtained by the microbial flotation using a long column which had a length-diameter (L/D) ratio of 12.7.

  7. Selected attributes of polyphenols in targeting oxidative stress in cancer.

    PubMed

    Stepanic, Visnja; Gasparovic, Ana Cipak; Troselj, Koraljka Gall; Amic, Dragan; Zarkovic, Neven

    2015-01-01

    Various plant polyphenols have been recognized as redox active molecules. This review discusses some aspects of polyphenols' modes of redox action, corresponding structure-activity relationships and their potential to be applied as adjuvants to conventional cytostatic drugs. Polyphenols' antioxidative capacity has been discussed as the basis for targeting oxidative stress and, consequently, for their chemopreventive and anti-inflammatory activities, which may alleviate side-effects on normal cells arising from oxidative stress caused by cytostatics. Some polyphenols may scavenge various free radicals directly, and some of them are found to suppress free radical production through inhibiting NADPH oxidases and xanthine oxidase. Additionally, polyphenols may increase antioxidative defense in normal cells by increasing the activity of NRF2, transcription factor for many protective proteins. The activation of the NRF2-mediated signaling pathways in cancer cells results in chemoresistance. Luteolin, apigenin and chrysin reduce NRF2 expression and increase the chemosensitivity of cancer cells to cytostatic drugs. Their common 5,7-dihydroxy-4H-chromen-4-one moiety, may represent a starting pharmacophore model for designing novel, non-toxic compounds for overcoming chemoresistance. However, prooxidative activity of some polyphenols (quercetin, EGCG) may also provide a basis for their use as chemotherapeutic adjuvants since they may enhance cytotoxic effects of cytostatics selectively on cancer cells. However, considerable caution is needed in applying polyphenols to anticancer therapy, since their effects greatly depend on the applied dose, the cell type, exposure time and environmental conditions.

  8. Influence of Synbiotics on Selected Oxidative Stress Parameters

    PubMed Central

    2017-01-01

    The aim of the present study was to assess synbiotic (Lactobacillus casei + inulin) influence on oxidative stress parameters such as concentrations of malondialdehyde (MDA), hydrogen peroxide (H2O2), glutathione, and free sulfhydryl groups content. Experiments were carried out on healthy volunteers (n = 32). The subjects were divided into women group (n = 16) and men group (n = 16) and randomly assigned to synbiotic and control groups. Blood samples were collected before synbiotic supplementation and after 7 wks, at the end of the study. The administration of synbiotic resulted in a significant decrease in MDA (p < 0.01), H2O2 (p < 0.01), and GSSG concentrations (p < 0.05) as compared with the control groups and significant increase in the concentrations of GSHt (p < 0.001), GSH (p < 0.01), and -SH group content (p < 0.05) versus control. Synbiotics containing L. casei plus inulin may have positive influence on selected oxidative stress markers. PMID:28286605

  9. Aerobic sulfur-oxidizing bacteria: Environmental selection and diversification

    NASA Technical Reports Server (NTRS)

    Caldwell, D.

    1985-01-01

    Sulfur-oxidizing bacteria oxidize reduced inorganic compounds to sulfuric acid. Lithotrophic sulfur oxidizer use the energy obtained from oxidation for microbial growth. Heterotrophic sulfur oxidizers obtain energy from the oxidation of organic compounds. In sulfur-oxidizing mixotrophs energy are derived either from the oxidation of inorganic or organic compounds. Sulfur-oxidizing bacteria are usually located within the sulfide/oxygen interfaces of springs, sediments, soil microenvironments, and the hypolimnion. Colonization of the interface is necessary since sulfide auto-oxidizes and because both oxygen and sulfide are needed for growth. The environmental stresses associated with the colonization of these interfaces resulted in the evolution of morphologically diverse and unique aerobic sulfur oxidizers.

  10. Occurrence of microbial acetate-oxidation in ~2 km-deep coal-bearing sediments off the Shimokita Peninsula, Japan (IODP Expedition 337)

    NASA Astrophysics Data System (ADS)

    Ijiri, A.; Inagaki, F.

    2015-12-01

    During the Integrated Ocean Drilling Program (IODP) Expedition 337 in 2012, the riser-drilling vessel Chikyu extended the previous world depth record of scientific ocean drilling and made one of the deepest scientific borehole down to 2466 m below the seafloor (mbsf) at Site C0020 Hole A off the Shimokita Peninsula, Japan. The sedimentary sequence consists of 17 lignite layers below 1.5 km bellow the seafloor. Microbiological and geochemical data consistently showed evidence for the existence of microbial communities associated with lignite coal beds in the coal-bearing sediments (Inagaki and Hinrichs et al., Science, 2015). Since lignite coals produce substantial dissolved organic compounds during the burial alternation process, volatile fatty acids may play important roles for microbial life and its activity in the deep sedimentary environment. To address this hypothesis, we measured methanogenic and acetate-oxidation activities by radiotracer incubation experiments using 14C-labelled substrate ([2-14C]-acetate) immediately after core recovery. Activity of aceticlastic methanogenesis was observed in the sediment above the coal-baring layers (>1990 mbsf), ranging from 0.2 to 1.2 pmol cm-3 d-1. The highest activity was observed in a coal-bed horizon at 1990 mbsf. However, aceticlastic methanogenesis was below the detection limit in sediment samples below the 2 km-coal layers. Activity of acetate oxidation to CO2 was measured by 14CO2 production rate from [2-14C]-acetate. Interestingly, the acetate-oxidation activity was observed in sediments above the coal beds, which values were generally higher than those of methanogenesis with the maximum value of 33 pmol cm-3 d-1 at 1800 mbsf. The rates gradually decreased with increasing depth from 1800 mbsf and reached below the detection limit (i.e., 0.05 pmol cm-3 d-1) in 2 km-deep coal-bed samples. The occurrence of relatively high acetate oxidation at ~1800 mbsf above the coal formation suggests that microbes respire

  11. CeO2-TiO2 catalysts for catalytic oxidation of elemental mercury in low-rank coal combustion flue gas.

    PubMed

    Li, Hailong; Wu, Chang-Yu; Li, Ying; Zhang, Junying

    2011-09-01

    CeO(2)-TiO(2) (CeTi) catalysts synthesized by an ultrasound-assisted impregnation method were employed to oxidize elemental mercury (Hg(0)) in simulated low-rank (sub-bituminous and lignite) coal combustion flue gas. The CeTi catalysts with a CeO(2)/TiO(2) weight ratio of 1-2 exhibited high Hg(0) oxidation activity from 150 to 250 °C. The high concentrations of surface cerium and oxygen were responsible for their superior performance. Hg(0) oxidation over CeTi catalysts was proposed to follow the Langmuir-Hinshelwood mechanism whereby reactive species from adsorbed flue gas components react with adjacently adsorbed Hg(0). In the presence of O(2), a promotional effect of HCl, NO, and SO(2) on Hg(0) oxidation was observed. Without O(2), HCl and NO still promoted Hg(0) oxidation due to the surface oxygen, while SO(2) inhibited Hg(0) adsorption and subsequent oxidation. Water vapor also inhibited Hg(0) oxidation. HCl was the most effective flue gas component responsible for Hg(0) oxidation. However, the combination of SO(2) and NO without HCl also resulted in high Hg(0) oxidation efficiency. This superior oxidation capability is advantageous to Hg(0) oxidation in low-rank coal combustion flue gas with low HCl concentration.

  12. Effects of Ceric Oxide Coatings on Materials Performance of 430 Steel in Coal Synthetc Gas

    SciTech Connect

    Ziomek-Moroz, M. Jablonski, P

    2011-12-21

    The surfaces of low silicon and aluminum 430 stainless steel (UNS 43000) coupons with and without ceria (CeO2) surface treatment were investigated after exposure to simulated coal syngas based fuel at 800 C. The results indicate a different mechanism of carburization for the ceria treated steel than that for the untreated steel.

  13. The hydrothermal synthesis of tetragonal tungsten bronze-based catalysts for the selective oxidation of hydrocarbons.

    PubMed

    Botella, Pablo; Solsona, Benjamín; García-González, Ester; González-Calbet, José M; López Nieto, José M

    2007-12-21

    Mixed metal oxides with tetragonal tungsten bronze (TTB) structure, showing high activity and selectivity for the gas phase partial oxidation of olefins, have been prepared by hydrothermal synthesis from Keggin-type heteropolyacids.

  14. Prevention of formation of acid drainage from high-sulfur coal refuse by inhibition of iron- and sulfur-oxidizing microorganisms. I. Preliminary experiments in controlled shaken flasks.

    PubMed

    Dugan, P R

    1987-01-01

    Changes of pH and sulfate concentration in high-sulfur coal refuse slurries are used as measurements of microbial pyrite oxidation in the laboratory. Sodium lauryl sulfate (SLS), alkylbenzene sulfonate (ABS), benzoic acid (BZ) and combinations of SLS plus BZ and ABS plus BZ effectively inhibited formation of sulfate and acid when added in concentrations greater than 50 mg/L to inoculated 20 or 30% coal refuse slurries. Here 25 mg/L concentrations of SLS, ABS, and ABS + BZ stimulated acid production. Formic, hexanoic, oxalic, propionic, and pyruvic acids at 0.1% concentrations were also effective inhibitors. Four different lignin sulfonates were only slightly effective inhibitors at 0.1% concentrations. It was concluded that acid formation resulting from microbial oxidation in high-sulfur coal refuse can be inhibited.

  15. Engineering development of advanced physical fine coal cleaning for premium fuel applications. Task 6 -- Selective agglomeration laboratory research and engineering development for premium fuels

    SciTech Connect

    Moro, N.; Jha, M.C.

    1997-06-27

    The primary goal of this project is the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope included laboratory research and benchscale testing on six coals to optimize these processes, followed by the design, construction, and operation of a 2 t/hr process development unit (PDU). The project began in October, 1992, and is scheduled for completion by September 1997. This report represents the findings of Subtask 6.5 Selective Agglomeration Bench-Scale Testing and Process Scale-up. During this work, six project coals, namely Winifrede, Elkhorn No. 3, Sunnyside, Taggart, Indiana VII, and Hiawatha were processed in a 25 lb/hr continuous selective agglomeration bench-scale test unit.

  16. Effect of hydrogen sulfide on chemical looping combustion of coal-derived synthesis gas over bentonite-supported metal-oxide oxygen carriers

    SciTech Connect

    Tian, H.J.; Simonyi, T.; Poston, J.; Siriwardane, R.

    2009-09-15

    The effect of hydrogen sulfide (H{sub 2}S) on the chemical looping combustion of coal-derived synthesis gas with bentonite-supported metal oxides - such as iron oxide, nickel oxide, manganese oxide, and copper oxide - was investigated by thermogravimetric analysis, mass spectrometry, and X-ray photoelectron spectroscopy (XPS). During the reaction with synthesis gas containing H{sub 2}S, metal-oxide oxygen carriers were first reduced by carbon monoxide and hydrogen, and then interacted with H{sub 2}S to form metal sulfide, which resulted in a weight gain during the reduction/sulfidation step. The reduced/sulfurized compounds could be regenerated to form sulfur dioxide and oxides during the oxidation reaction with air. The reduction/oxidation capacities of iron oxide and nickel oxide were not affected by the presence of H{sub 2}S, but both manganese oxide and copper oxide showed decreased reduction/oxidation capacities. However, the rates of reduction and oxidation decreased in the presence of H{sub 2}S for all four metal oxides.

  17. Studies of incipient oxidation of coal-pyrite for improved pyrite rejection. Third quarterly technical progress report, April 1, 1993--June 30, 1993

    SciTech Connect

    Yoon, R.H.; Richardson, P.E.

    1993-11-01

    The initial stages of pyrite oxidation are being studied to develop methods to control pyrite surface chemistry and foster pyrite rejection in coal flotation circuits. A major objective of this work is to study incipient oxidation, which is accomplished by fracturing pyrite electrodes in an electrochemical cell. It has been shown that by holding the potential at various values during fracture and measuring the current passed at fracture, pyrite oxidation or reduction can be precisely controlled. The oxidation and reduction products on pyrite following fracture are being studied by a combination of voltammetry, photocurrent, and impedance spectroscopy techniques. During this report period, major effort was devoted to characterizing the surfaces by impedance spectroscopy.

  18. OXIDATIVE DAMAGE-RELATED GENES AKR1C3 AND OGG1 MODULATE RISKS FOR LUNG CANCER DUE TO EXPOSURE TO PAH-RICH COAL COMBUSTION EMISSIONS

    EPA Science Inventory

    We studied polymorphisms in genes that generate, prevent, or repair oxidative damage and lung cancer risk among 118 cases and 113 controls in Xuan Wei China, where extremely high lung cancer rates are caused by indoor exposure to smoky coal. SOD2-Vak16Ala and NQO1-Pro 187Ser were...

  19. Continuous coal processing method

    NASA Technical Reports Server (NTRS)

    Ryason, P. R. (Inventor)

    1980-01-01

    A coal pump is provided in which solid coal is heated in the barrel of an extruder under pressure to a temperature at which the coal assumes plastic properties. The coal is continuously extruded, without static zones, using, for example, screw extrusion preferably without venting through a reduced diameter die to form a dispersed spray. As a result, the dispersed coal may be continuously injected into vessels or combustors at any pressure up to the maximum pressure developed in the extrusion device. The coal may be premixed with other materials such as desulfurization aids or reducible metal ores so that reactions occur, during or after conversion to its plastic state. Alternatively, the coal may be processed and caused to react after extrusion, through the die, with, for example, liquid oxidizers, whereby a coal reactor is provided.

  20. Selective oxidation of buried AlGaAs for fabrication of vertical-cavity lasers

    SciTech Connect

    Choquette, K.D.; Geib, K.M.; Chui, H.C.; Hou, H.Q.; Hull, R.

    1996-06-01

    The authors discuss the selective conversion of buried layers of AlGaAs to a stable oxide and the implementation of this oxide into high performance vertical-cavity surface emitting lasers (VCSELs). The rate of lateral oxidation is shown to be linear with an Arrhenius temperature dependence. The measured activation energies vary with Al composition, providing a high degree of oxidation selectivity between AlGaAs alloys. Thus buried oxide layers can be selectively fabricated within the VCSEL through small compositional variations in the AlGaAs layers. The oxidation of AlGaAs alloys, as opposed to AlAs, is found to provide robust processing of reliable lasers. The insulating and low refractive index oxide provides enhanced electrical and optical confinement for ultralow threshold currents in oxide-apertured VCSELs.

  1. Selection and characterization of coal mine autochthonous rhizobia for the inoculation of herbaceous legumes.

    PubMed

    Hernández, Anabel González; de Moura, Ginaini Doin; Binati, Renato Leal; Nascimento, Francisco Xavier Inês; Londoño, Diana Morales; Mamede, Ana Carolina Peixoto; da Silva, Emanuela Pille; de Armas, Rafael Dutra; Giachini, Admir José; Rossi, Márcio José; Soares, Cláudio Roberto Fonsêca Sousa

    2017-04-05

    Coal open pit mining in the South of Santa Catarina state (Brazil) was inappropriately developed, affecting approximately 6.700 ha. Re-vegetation is an alternative for the recovery of these areas. Furthermore, the use of herbaceous legumes inoculated with nitrogen fixing bacteria is motivated due to the difficulty implementing a vegetation cover in these areas, mainly due to low nutrient availability. Therefore, the aim of this work was to evaluate, among 16 autochthonous rhizobia isolated from the coal mining areas, those with the greatest potential to increase growth of the herbaceous legumes Vicia sativa and Calopogonium mucunoides. Tests were conducted in greenhouse containing 17 inoculation treatments (16 autochthonous rhizobia + Brazilian recommended strain for each plant species), plus two treatments without inoculation (with and without mineral nitrogen). After 60 days, nodulation, growth, N uptake, and symbiotic efficiency were evaluated. Isolates characterization was assessed by the production of indole acetic acid, ACC deaminase, siderophores, and inorganic phosphate solubilization. The classification of the isolates was performed by 16 S rDNA gene sequencing. Only isolates UFSC-M4 and UFSC-M8 were able to nodulate C. mucunoides. Among rhizobia capable of nodulating V. sativa, only UFSC-M8 was considered efficient. It was found the presence of more than one growth-promoting attributes in the same organism, and isolate UFSC-M8 presented all of them. Isolates were classified as belonging to Rhizobium, Burkholderia and Curtobacterium. The results suggest the inoculation of Vicia sativa with strain UFSC-M8, classified as Rhizobium sp., as a promising alternative for the revegetation of coal mining degraded areas.

  2. Pathways for conversion of char nitrogen to nitric oxide during pulverized coal combustion

    SciTech Connect

    Molina, A.; Murphy, J.J.; Blevins, L.G.; Shaddix, C.R.; Winter, F.; Haynes, B.S.

    2009-03-15

    The conversion of nitrogen in char (char-N) to NO was studied both experimentally and computationally. In the experiments, pulverized coal char was produced from a U.S. high-volatile bituminous coal and burned in a dilute suspension at 1170 K, 1370 K and 1570 K, at an excess oxygen concentration of 8% (dry), with different levels of background NO. In some experiments, hydrogen bromide (HBr) was added to the vitiated air as a tool to alter the concentration of gas-phase radicals. During char combustion, low NO concentration and high temperature promoted the conversion of char-N to NO. HBr addition altered NO production in a way that depended on temperature. At 1170 K the presence of HBr increased NO production by 80%, whereas the addition of HBr decreased NO production at higher temperatures by 20%. To explain these results, three mechanistic descriptions of char-N evolution during combustion were evaluated with computational models that simulated (a) homogeneous chemistry in a plug-flow reactor with entrained particle combustion, and (b) homogeneous chemistry in the boundary layer surrounding a reacting particle. The observed effect of HBr on NO production could only be captured by a chemical mechanism that considered significant release of HCN from the char particle. Release of HCN also explained changes in NO production with temperature and NO concentration. Thus, the combination of experiments and simulations suggests that HCN evolution from the char during pulverized coal combustion plays an essential role in net NO production. (author)

  3. Coal Combustion Science

    SciTech Connect

    Hardesty, D.R.; Fletcher, T.H.; Hurt, R.H.; Baxter, L.L. )

    1991-08-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency Coal Combustion Science Project. Specific tasks for this activity include: (1) coal devolatilization - the objective of this risk is to characterize the physical and chemical processes that constitute the early devolatilization phase of coal combustion as a function of coal type, heating rate, particle size and temperature, and gas phase temperature and oxidizer concentration; (2) coal char combustion -the objective of this task is to characterize the physical and chemical processes involved during coal char combustion as a function of coal type, particle size and temperature, and gas phase temperature and oxygen concentration; (3) fate of mineral matter during coal combustion - the objective of this task is to establish a quantitative understanding of the mechanisms and rates of transformation, fragmentation, and deposition of mineral matter in coal combustion environments as a function of coal type, particle size and temperature, the initial forms and distribution of mineral species in the unreacted coal, and the local gas temperature and composition.

  4. Bioaugmentation of biological contact oxidation reactor (BCOR) with phenol-degrading bacteria for coal gasification wastewater (CGW) treatment.

    PubMed

    Fang, Fang; Han, Hongjun; Zhao, Qian; Xu, Chunyan; Zhang, Linghan

    2013-12-01

    This study was conducted to evaluate the performance of the biological contact oxidation reactor (BCOR) treating coal gasification wastewater (CGW) after augmented with phenol degrading bacteria (PDB). The PDB were isolated with phenol, 4-methyl phenol, 3,5-dimethyl phenol and resorcinol as carbon resources. Much of the refractory phenolic compounds were converted into easily-biodegradable compounds in spite of low TOC removal. The bioaugmentation with PDB significantly enhanced the removal of COD, total phenols (TP) and NH3-N, with efficiencies from 58% to 78%, 66% to 80%, and 5% to 25%, respectively. In addition, the augmented BCOR exhibited strong recovery capability in TP and COD removal while recovery of NH3-N removal needed longer time. Microbial community analysis revealed that the PDB presented as dominant populations in the bacteria consortia, which in turn determined the overall performance of the system.

  5. Selective laser sintering of MA956 oxide dispersion strengthened steel

    NASA Astrophysics Data System (ADS)

    Hunt, Ryan M.; Kramer, Kevin J.; El-Dasher, Bassem

    2015-09-01

    Oxide Dispersion Strengthened (ODS) steels' qualities of radiation damage resistance and high strength at high temperature make them promising nuclear structural materials. However, the dispersed yttria that gives ODS steel its beneficial qualities are generally compromised during joining processes, making fabrication difficult and expensive. The selective laser sintering process offers a potential path through this barrier by which net-shape parts can feasibly be built via additive manufacturing without fully melting the structure. Rastering a 400 W laser over a 110 μm MA956 ODS steel powder bed, we additively built parts with varying build conditions. Although density was achieved to within 97% of the wrought MA956, ultimate tensile strengths achieved only 65% of the wrought strength. Spectroscopy analysis points to the agglomeration of the yttria nano-particles as a possible explanation for the loss in strength. Further study might benefit from exploration of other parameters such as thinner powder build layers which would require less energy input to achieve sintering while minimizing time above the melting temperature.

  6. Desulfurization and de-ashing of a mixture of subbituminous coal and gangue minerals by selective oil agglomeration

    SciTech Connect

    Ayhan, F.D.

    2009-11-15

    The aim of this study was to investigate desulfurization and de-ashing of a mixture of subbituminous coal and gangue minerals by the agglomeration method. For this purpose, experimental studies were conducted on a mixture containing subbituminous coal, pyrite, quartz and calcite. The effects of some parameters that markedly influence the effectiveness of selective oil agglomeration, such as solid concentration, pH, bridging liquid type and concentration, and depressant type and amount, were investigated. Agglomeration results showed that the usage of various depressants (Na{sub 2}SiO{sub 3}, FeCl3, corn starch, wheat starch) in the agglomeration medium has a positive effect on the reduction of ash and total sulfur content of agglomerates. It was found that an agglomerate product containing 3.03% total sulfur and 25.01% ash with a total sulfur reduction of 56.71% was obtained from a feed that contained 7% total sulfur and 43.58% ash when FeCl{sub 3} was used in the agglomeration medium.

  7. Structure and thermoplasticity of coal

    SciTech Connect

    Komaki, I.; Itagaki, S.; Miura, T.

    2004-07-01

    Chapters cover: molecular structure and thermoplastic properties of coal; {sup 1}H-nmr study of relaxation mechanisms of coal aggregate; structural changes of coal macromolecules during softening; quantitative estimation of metaplsat in heat-treated coal by solvent extraction; effects of surface oxidation on thermoplastic properties of coal; analysis of dilatation and contraction of coal during carbonization; formation mechanisms of coke texture during resolidification; modified CPD model for coal devolatilization; mathematical modelling of coke mechanical structure; and simulating particulate dynamics in the carbonization process based on discrete element treatment.

  8. Effect of hydrogen sulfide on chemical looping of coal-derived synthesis gas over bentonite-supported metal---oxide oxygen carriers

    SciTech Connect

    Tian, H.; Simonyi, T.; Poston, J.; Siriwardane, R.

    2009-01-01

    The effect of hydrogen sulfide (H2S) on the chemical looping combustion of coal-derived synthesis gas with bentonite-supported metal oxidesssuch as iron oxide, nickel oxide, manganese oxide, and copper oxideswas investigated by thermogravimetric analysis, mass spectrometry, and X-ray photoelectron spectroscopy (XPS). During the reaction with synthesis gas containing H2S, metal-oxide oxygen carriers were first reduced by carbon monoxide and hydrogen, and then interacted with H2S to form metal sulfide, which resulted in a weight gain during the reduction/sulfidation step. The reduced/sulfurized compounds could be regenerated to form sulfur dioxide and oxides during the oxidation reaction with air. The reduction/oxidation capacities of iron oxide and nickel oxide were not affected by the presence of H2S, but both manganese oxide and copper oxide showed decreased reduction/oxidation capacities. However, the rates of reduction and oxidation decreased in the presence of H2S for all four metal oxides.

  9. Metallization of oxide-ore-containing wastes with the use of brown coal semicoke from Berezovsky deposit of the Kansk- Achinsk Basin

    NASA Astrophysics Data System (ADS)

    Anikin, A. E.; Galevsky, G. V.; Nozdrin, E. V.; Rudneva, V. V.; Galevsky, S. G.

    2016-09-01

    The research of the metallization process of the roll scale and sludge after gas treatment in the BOF production with the use of brown coal semicoke mined in Berezovsky field of the Kansk-Achinsk Basin was carried out. A flow diagram of “cold” briquetting using a water-soluble binder was offered. The reduction of iron from its oxide Fe2O3 with brown coal semicoke in the laboratory electric-tube furnace in the argon atmosphere was studied. The mathematical models of dependence of the metallization degree on variable factors were developed. The optimal values of technological factors and essential characteristics of the obtained metallized products were revealed.

  10. Geochemical characterisation of pyrite oxidation and environmental problems related to release and transport of metals from a coal washing low-grade waste dump, Shahrood, northeast Iran.

    PubMed

    Doulati Ardejani, Faramarz; Jodieri Shokri, Behshad; Moradzadeh, Ali; Shafaei, Seyed Ziadin; Kakaei, Reza

    2011-12-01

    Pyrite oxidation and release of the oxidation products from a low-grade coal waste dump to stream, groundwater and soil was investigated by geochemical and hydrogeochemical techniques at Alborz Sharghi coal washing plant, Shahrood, northeast Iran. Hydrogeochemical analysis of water samples indicates that the metal concentrations in the stream waters were low. Moreover, the pH of the water showed no considerable change. The analysis of the stream water samples shows that except the physical changes, pyrite oxidation process within the coal washing waste dump has not affected the quality of the stream water. Water type was determined to be calcium sulphate. The results of the analysis of groundwater samples indicate that the pH varies from 7.41 to 7.51. The concentrations of the toxic metals were low. The concentration of SO4 is slightly above than its standard concentration in potable water. It seems that the groundwater less affected by the coal washing operation in the study area. Geochemical analysis of the sediment samples shows that Fe concentration decreases gradually downstream the waste dump with pH rising. SO(4) decreases rapidly downstream direction. Copper, Zn and Co concentrations decrease with distance from the waste dump due to a dilution effect by the mixing of uncontaminated sediments. These elements, in particular, Zn are considerably elevated in sediment sample collected at the nearest distance to the waste dump. There is no doubt that such investigations can help to develop an appropriate water remediation plan.

  11. Selective Growth of Noble Gases at Metal/Oxide Interface.

    PubMed

    Takahashi, Keisuke; Oka, Hiroshi; Ohnuki, Somei

    2016-02-17

    The locations and roles of noble gases at an oxide/metal interface in oxide dispersed metal are theoretically and experimentally investigated. Oxide dispersed metal consisting of FCC Fe and Y2Hf2O7 (Y2Ti2O7) is synthesized by mechanical alloying under a saturated Ar gas environment. Transmission electron microscopy and density functional theory observes the strain field at the interface of FCC Fe {111} and Y2Hf2O7 {111} whose physical origin emerges from surface reconstruction due to charge transfer. Noble gases are experimentally observed at the oxide (Y2Ti2O7) site and calculations reveal that the noble gases segregate the interface and grow toward the oxide site. In general, the interface is defined as the trapping site for noble gases; however, transmission electron microscopy and density functional theory found evidence which shows that noble gases grow toward the oxide, contrary to the generally held idea that the interface is the final trapping site for noble gases. Furthermore, calculations show that the inclusion of He/Ar hardens the oxide, suggesting that material fractures could begin from the noble gas bubble within the oxides. Thus, experimental and theoretical results demonstrate that noble gases grow from the interface toward the oxide and that oxides behave as a trapping site for noble gases.

  12. A practical synthesis of betulonic acid using selective oxidation of betulin on aluminium solid support.

    PubMed

    Melnikova, Nina; Burlova, Irina; Kiseleva, Tatiana; Klabukova, Irina; Gulenova, Marina; Kislitsin, Capital A Cyrillicleksey; Vasin, Viktor; Tanaseichuk, Boris

    2012-10-09

    The room temperature oxidation of betulin by Cr(VI) compounds in aqueous acetone on solid supports such as alumina, zeolites and silica gel has been studied. The oxidation on alumina support leaded to a single product--betulonic acid--in quantitative yield. One hundred percent selective oxidation during 30 min of betulin up to betulonic aldehyde was determined when silica gel support was used. The oxidation of betulin using zeolites as a support gives a mixture of betulonic acid and aldehyde in a 2:1 ratio. It is proposed the selective oxidation up to betulonic acid is due to the influence of Al³⁺-ions.

  13. Reaction-driven surface restructuring and selectivity control in allylic alcohol catalytic aerobic oxidation over Pd.

    PubMed

    Lee, Adam F; Ellis, Christine V; Naughton, James N; Newton, Mark A; Parlett, Christopher M A; Wilson, Karen

    2011-04-20

    Synchronous, time-resolved DRIFTS/MS/XAS cycling studies of the vapor-phase selective aerobic oxidation of crotyl alcohol over nanoparticulate Pd have revealed surface oxide as the desired catalytically active phase, with dynamic, reaction-induced Pd redox processes controlling selective versus combustion pathways.

  14. Geologic setting and water quality of selected basins in the active coal-mining areas of Ohio, 1987-88

    USGS Publications Warehouse

    Sedam, A.C.

    1991-01-01

    This report presents hydrologic data from selected drainage basins in the active coal-mining areas of Ohio from July 1987 through October 1988. The study area is mostly within the unglaciated part of eastern Ohio along the western edge of the Appalachian Plateaus physiographic province. The 1987-88 work is the second phase of a 7-year study to assess baseline water quality in Ohio's coal region. The data collection network consisted of 41 long-term surface-water sites in 21 basins. The sites were measured and sampled twice yearly at low flow. In addition, six individual basins (three each year) selected for a more detailed representation of surface-water and ground-water quality. In 1987, the Sandy Creek, Middle Tuscarawas River and Sugar Creek, and Lower Tuscarawas River basins were chosen. In 1988, the Short and Wheeling Creeks, Upper Wills Creek, and Upper Raccoon Creek basins were chosen. Because of their proximity to the glaciated region and outwash drainage, the basins studied intensively in 1987 contain more shallow productive aquifers than do the basins studied in detail for 1988, in which shallow ground-water sources are very localized. Chemical analyses for 202 surface-water and 24 ground-water samples are presented. For field measurements made at surface-water sites, the specific conductance ranged from 295 to 3150 ? S/cm (microsiemens per centimeter at 25 degrees Celsius). For pH, the range was 2.8 to 8.6. Alkalinity ranged from 5 to 305 mg/L (milligrams per liter) as CaCO3.

  15. Water quality of selected streams in the coal area of southeastern Montana

    USGS Publications Warehouse

    Knapton, J.R.; McKinley, P.W.

    1977-01-01

    This report summarizes and evaluates water-quality data collected at 35 stream sites the the coal region of southeastern Montana. Sarpy Creek, Armells Creek, and Rosebud Creek sometimes have dissolved-solids concentrations that cause water to be marginal for agricultural purposes. At times of rainfall and snowmelt, the runoff water mixes with the base-flow component to improve the overall quality. Water in the Tongue River generally showed a downstream degradation in which some changes were related to lithology of the aquifers contributing water to streamflow. Water from Pumpkin Creek and Mizpah Creek is used mostly for cattle watering. To some extent water is used for irrigation although the salinity hazard was often high. The chemical quality of the Powder River changed little during flow downstream. High sediment loads of the river acted as transporting agents for many of the plant nutrients and trace-element constituents. (Woodard-USGS)

  16. Surface electrochemical control for fine coal and pyrite separation

    SciTech Connect

    Hu, Weibai; Huang, Qinping; Li, Jun; Zhu, Ximeng; Bodily, D.M.; Liang, Jun; Zhong, Tingke; Wadsworth, M.E.

    1991-01-01

    The ongoing work includes the characterization of coal pyrites, the floatability evaluation of three typical US coal samples, the flotation behavior of coal pyrites, the electrochemical measurement of the surface properties of coal pyrites, and the characterization of species produced at pyrite surfaces. This report contains three sections, Transpassive Oxidation of Pyrite,'' Flotation and Electrochemical Pretreatment,'' and Flotation Kinetics of Coal and Coal Pyrite.''

  17. Thiol adsorption on metal oxides: an approach for selective deposition on zinc oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Soares, Jason W.; Steeves, Diane M.; Singh, Jagdeep; Im, Jisun; Whitten, James E.

    2011-02-01

    We have previously discovered a novel, facile approach to encapsulate ZnO nanorods within thiol complexes. This approach results in a thiol uptake of 30-40% and a 400-500 nm thick thiol-Zn-thiol complex encapsulation layer surrounding ZnO nanorods. By controlling experimental parameters, it is possible to control the thiol deposition, enabling less uptake, which results in a surface monolayer instead of encapsulation. Through this approach, thiol modification of other metal oxide materials, namely TiO2, Al2O3, and MgO, has been attempted. FTIR analysis indicates that thiol adsorption occurs only on ZnO; chemisorption of thiols on other nanoparticles is not evident. Ultrahigh vacuum single crystal adsorption studies demonstrate that ZnO(0001) is also more susceptible to thiol monolayer formation, as evidenced by lack of methanethiol adsorption on TiO2(110) and MgO(0001). These results indicate that the facile thiol modification approach opens a new avenue for surface modification of multi-component metal oxide materials by enabling selective thiol modification of ZnO. This work has potential applicability for creating multiple ligand-functionalized materials, which could be useful for the design of novel multiplexing sensors and photovoltaics.

  18. Natural selection of PAH-degrading bacterial guilds at coal-tar disposal sites

    SciTech Connect

    Ghiorse, W.C.; Herrick, J.B.; Sandoli, R.L.; Madsen, E.L.

    1995-06-01

    Microbial activity patterns at buried coal-tar disposal sites have been under investigation for several years to determine the response of naturally occurring microflora to polycyclic aromatic hydrocarbons (PAHs) at the sites. At one site in upstate New York, data have shown enrichment of PAH-degrading bacteria in subsurface contaminated zones but not in uncontaminated zones. Similar work at a Midwestern site showed that the same trends existed in a heterogeneous disposal site except that a borehole outside the plume showed some PAH-mineralization activity. Polymerase chain reaction amplification of DNA extracted from sediment samples from the New York site indicated the presence of naphthalene metabolism genes nahAc and nahR, similar to those found on the NAH7 plasmid of Pseudomonas putida G7. Significant sequence polymorphism was observed in amplified nahAc products, indicating that divergent homologs of nahAc were present in the native community. Protozoan numbers were elevated in sediment samples displaying relatively high PAH-degrading activity, suggesting that a food chain was established based on PAH-degrading bacteria. Removal of the coal-tar source at the site occurred in 1991. In 1992, sampling of three key borehole stations revealed that mixing and backfilling operations had introduced soil microorganisms into the source area and introduced 14C-PAH-mineralization activity into the previously inactive pristine area. Thus removal of the source of the contaminants and restoration at the site have altered the microbial activity patterns outside the contaminant plume as well as in the source area. 15 refs., 3 figs.

  19. Selective reduction of nitric oxides with ammonia using a cellular block catalyst

    SciTech Connect

    M.V. D'yakov; A.I. Kozlov; E.S. Lukin

    2004-03-15

    An aluminum-vanadium cellular block catalyst for selective reduction of nitric oxides with ammonia has been developed. With an average degree of conversion of oxides over 90%, the efficiency of the proposed catalyst is significantly higher than that of industrial catalysts currently used. Such catalyst can be recommended for use in selective plants for purification of waste gases from nitric oxides, which makes it possible to significantly decrease the cost of making a catalyst block.

  20. Scientific basis for process and catalyst design in the selective oxidation of methane to formaldehyde.

    PubMed

    Arena, Francesco; Parmaliana, Adolfo

    2003-12-01

    The mechanism and kinetics of the gas-phase selective oxidation of methane to formaldehyde (MPO) are revised in the general context of catalytic oxidations. In agreement with ab initio calculations of the energy barrier for the activation of methane on transition metal oxide complexes, a formal Langmuir-Hinshelwood kinetic model is proposed which accounts for the "steady-state" conditions and activity-selectivity pattern of MPO catalysts, providing an original support to process design and catalyst development.

  1. Colour and toxic characteristics of metakaolinite-hematite pigment for integrally coloured concrete, prepared from iron oxide recovered from a water treatment plant of an abandoned coal mine

    NASA Astrophysics Data System (ADS)

    Sadasivam, Sivachidambaram; Thomas, Hywel Rhys

    2016-07-01

    A metakaolinite-hematite (KH) red pigment was prepared using an ocherous iron oxide sludge recovered from a water treatment plant of an abandoned coal mine. The KH pigment was prepared by heating the kaolinite and the iron oxide sludge at kaolinite's dehydroxylation temperature. Both the raw sludge and the KH specimen were characterised for their colour properties and toxic characteristics. The KH specimen could serve as a pigment for integrally coloured concrete and offers a potential use for the large volumes of the iron oxide sludge collected from mine water treatment plants.

  2. Selective Removal of Technetium from Water Using Graphene Oxide Membranes.

    PubMed

    Williams, Christopher D; Carbone, Paola

    2016-04-05

    The effective removal of radioactive technetium ((99)Tc) from contaminated water is of enormous importance from an environmental and public health perspective, yet many current methodologies are highly ineffective. In this work, however, we demonstrate that graphene oxide membranes may remove (99)Tc, present in the form of pertechnetate (TcO4(-)), from water with a high degree of selectivity, suggesting they provide a cost-effective and efficient means of achieving (99)Tc decontamination. The results were obtained by quantifying and comparing the free energy changes associated with the entry of the ions into the membrane capillaries (ΔFperm), using molecular dynamics simulations. Initially, three capillary widths were investigated (0.35, 0.68, and 1.02 nm). In each case, the entry of TcO4(-) from aqueous solution into the capillary is associated with a decrease in free energy, unlike the other anions (SO4(2-), I(-), and Cl(-)) investigated. For example, in the model with a capillary width of 0.68 nm, ΔFperm(TcO4(-)) = -6.3 kJ mol(-1), compared to ΔFperm(SO4(2-)) = +22.4 kJ mol(-1). We suggest an optimum capillary width (0.48 nm) and show that a capillary with this width results in a difference between ΔFperm(TcO4(-)) and ΔFperm(SO4(2-)) of 89 kJ mol(-1). The observed preference for TcO4(-) is due to its weakly hydrating nature, reflected in its low experimental hydration free energy.

  3. Catalytic Destruction of a Surrogate Organic Hazardous Air Pollutant as a Potential Co-benefit for Coal-fired Selective Catalyst Reduction Systems

    EPA Science Inventory

    Catalytic destruction of benzene (C6H6), a surrogate for organic hazardous air pollutants (HAPs) produced from coal combustion, was investigated using a commercial selective catalytic reduction (SCR) catalyst for evaluating the potential co-benefit of the SCR technology for reduc...

  4. Nitrous oxide emissions from a coal mine land reclaimed with stabilized manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mined land restoration using manure-based amendments may create soil conditions suitable for nitrous oxide production and emission. We measured nitrous oxide emissions from mine soil amended with composted poultry manure (Comp) or poultry manure mixed with paper mill sludge (Man+PMS) at C/N ratios o...

  5. Method for producing a dried coal fuel having a reduced tendency to spontaneously ignite from a low rank coal

    SciTech Connect

    Li, Y.H.; Bonnecaze, B.F.; Matthews, J.D.; Skinner, J.L.; Wunderlich, D.K.

    1983-08-02

    A method is disclosed for producing a dried coal fuel having a reduced tendency to spontaneously ignite from a low rank coal by drying the low rank coal and thereafter cooling the dried coal to a temperature below about 100/sup 0/F. Optionally the dried coal is partially oxidized prior to cooling and optionally the dried coal is mixed with a deactivating fluid.

  6. Dairy Biomass-Wyoming Coal Blends Fixed Gasification Using Air-Steam for Partial Oxidation

    DOE PAGES

    Gordillo, Gerardo; Annamalai, Kalyan

    2012-01-01

    Concenmore » trated animal feeding operations such as dairies produce a large amount of manure, termed as dairy biomass (DB), which could serve as renewable feedstock for thermal gasification. DB is a low-quality fuel compared to fossil fuels, and hence the product gases have lower heat content; however, the quality of gases can be improved by blending with coals. This paper deals with air-steam fixed-bed counterflow gasification of dairy biomass-Wyoming coal blend (DBWC). The effects of equivalence ratio ( 1.6 < Φ < 6.4 ) and steam-to-fuel ratio ( 0.4 < S : F < 0.8 ) on peak temperatures, gas composition, gross heating value of the products, and energy recovery are presented. According to experimental results, increasing Φ and ( S : F ) ratios decreases the peak temperature and increases the H 2 and CO 2 production, while CO production decreases. On the other hand, the concentrations of CH 4 and C 2 H 6 were lower compared to those of other gases and almost not affected by Φ.« less

  7. Bio-oxidation of thiocyanates typical of coal conversion effluents. Final report

    SciTech Connect

    Neufeld, R. D.; Mattson, L.; Lubon, P.

    1981-01-08

    Thiocyanates have been found in most coal conversion and coke plant effluents. The objectives of this study were to develop data for the biological degradation fate kinetics of thiocyanate removal, and to develop material balance information for the fate of sulfur and nitrogen resulting from such bio-decomposition of aqueous thiocyanates. A literature review of thiocyanate bio-degradation indicates that while much biochemistry information is available, little information in the biological processing arena is known. Based on both batch and continuous culture experiments utilizing an activated sludge type of system with strictly thiocyanate degradating organisms, the specific utilization rate for SCN degradation was found to follow a substrate inhibition biokinetic relationship as: d(SCN)/dt-X = 2.24/(1 + (5/SCN) + (SCN/1340)/sup 6/) where; d(SCN)/dt-X = lb SCN used/lb biomass-day, SCN = mg/L SCN in effluent. The observed biomass sludge production rate was quantified as a function of sludge age in the bio-reactor. The major metabolic by-products of SCN aerobic biodegradation are ammonia and sulfate, with such formation being stochiometric with SCN. High levels of SCN in coal conversion and Stretford system effluents may lead to biological nitrification process requirements to be added to the wastetreatment scheme for compliance with BAT effluent ammonia discharge restrictions.

  8. Investigating the Integration of a Solid Oxide Fuel Cell and a Gas Turbine System with Coal Gasification Technologies

    DTIC Science & Technology

    2001-09-01

    conceptually integrate the hybrid power system with existing and imminent coal gasification technologies. The gasification technologies include the Kellogg...Brown Root (KBR) Transport Reactor and entrained coal gasification . Parametric studies will be performed wherein pertinent fuel cell stack process...dependent variables of interest. Coal gasification data and a proven SOFC model will be used to test the theoretical integration. Feasibility and

  9. PH Dependent Interactions between Aqueous Iodide Ion and Selected Oxidizers.

    DTIC Science & Technology

    1985-12-06

    COSATI CODES I&. SUBJECT IERMS (Continue an evven d mocesaey and idoetfy by 510&k number) C’ ELD GROUP SUB-ROUP >Oxidize Iodometry Titration Oxidation... iodometry : hypochlorite interacts instantly with iodide ion. However, a kinetically rapid decon reaction may not be best for all possible situations. An

  10. Heavy metals in wild house mice from coal-mining areas of Colombia and expression of genes related to oxidative stress, DNA damage and exposure to metals.

    PubMed

    Guerrero-Castilla, Angélica; Olivero-Verbel, Jesús; Marrugo-Negrete, José

    2014-03-01

    Coal mining is a source of pollutants that impact on environmental and human health. This study examined the metal content and the transcriptional status of gene markers associated with oxidative stress, metal transport and DNA damage in livers of feral mice collected near coal-mining operations, in comparison with mice obtained from a reference site. Mus musculus specimens were caught from La Loma and La Jagua, two coal-mining sites in the north of Colombia, as well as from Valledupar (Cesar Department), a city located 100km north of the mines. Concentrations in liver tissue of Hg, Zn, Pb, Cd, Cu and As were determined by differential stripping voltammetry, and real-time PCR was used to measure gene expression. Compared with the reference group (Valledupar), hepatic concentrations of Cd, Cu and Zn were significantly higher in animals living near mining areas. In exposed animals, the mRNA expression of NQ01, MT1, SOD1, MT2, and DDIT3 was 4.2-, 7.3-, 2.5-, 4.6- and 3.4-fold greater in coal mining sites, respectively, than in animals from the reference site (p<0.05). These results suggest that activities related to coal mining may generate pollutants that could affect the biota, inducing the transcription of biochemical markers related to oxidative stress, metal exposure, and DNA damage. These changes may be in part linked to metal toxicity, and could have implications for the development of chronic disease. Therefore, it is essential to implement preventive measures to minimize the effects of coal mining on its nearby environment, in order to protect human health.

  11. Practical nitric oxide measurement employing a nitric oxide-selective electrode

    NASA Astrophysics Data System (ADS)

    Ichimori, K.; Ishida, H.; Fukahori, M.; Nakazawa, H.; Murakami, E.

    1994-08-01

    An NO-selective electrode was developed as an easily applicable tool for a real-time nitric oxide (NO) measurement. The working electrode (0.2 mm diam) was made from Pt/Ir alloy coated with a three-layered membrane. The counterelectrode was made from a carbon fiber. When a stable NO donor, S-nitroso-N-acetyl-dl-penicillamine, was applied, the electrode current increased in a dose-dependent fashion. The current and calculated NO concentration showed a linear relationship in the range from 0.2 nM (S/N=1) to 1 μM of NO. The response of the electrode was 1.14±0.09 s. The effects of temperature, pH, and chemicals other than NO on the electrode current were also evaluated. Electrodes which were placed in the luminal side of rat aortic rings exhibited 30 pA of current due to NO generation induced by the addition of 10-6 M of acetylcholine. The current was eliminated in the presence of 50 μM NG-monomethyl-L-arginine, an inhibitor of NO synthase. Thus, this NO-selective electrode is applicable to real-time NO assay in biological systems.

  12. Regenerable cobalt oxide loaded magnetosphere catalyst from fly ash for mercury removal in coal combustion flue gas.

    PubMed

    Yang, Jianping; Zhao, Yongchun; Zhang, Junying; Zheng, Chuguang

    2014-12-16

    To remove Hg(0) in coal combustion flue gas and eliminate secondary mercury pollution of the spent catalyst, a new regenerable magnetic catalyst based on cobalt oxide loaded magnetospheres from fly ash (Co-MF) was developed. The catalyst, with an optimal loading of 5.8% cobalt species, attained approximately 95% Hg(0) removal efficiency at 150 °C under simulated flue gas atmosphere. O2 could enhance the Hg(0) removal activity of magnetospheres catalyst via the Mars-Maessen mechanism. SO2 displayed an inhibitive effect on Hg(0) removal capacity. NO with lower concentration could promote the Hg(0) removal efficiency. However, when increasing the NO concentration to 300 ppm, a slightly inhibitive effect of NO was observed. In the presence of 10 ppm of HCl, greater than 95.5% Hg(0) removal efficiency was attained, which was attributed to the formation of active chlorine species on the surface. H2O presented a seriously inhibitive effect on Hg(0) removal efficiency. Repeated oxidation-regeneration cycles demonstrated that the spent Co-MF catalyst could be regenerated effectively via thermally treated at 400 °C for 2 h.

  13. Flocculation, hydrophobic agglomeration and filtration of ultrafine coal

    NASA Astrophysics Data System (ADS)

    Yu, Zhimin

    In coal preparation plant circuits, fine coal particles are aggregated either by oil agglomeration or by flocculation. In a new hydrophobic agglomeration process, recently developed hydrophobic latices are utilized. While the selectivity of such aggregation processes determines the beneficiation results, the degree of aggregation has a strong effect on fine coal filtration. The aim of this research was to study the fundamentals and analyze the common grounds for these processes, including the potential effect of the coal surface properties. The selective flocculation tests, in which three types of coal, which differed widely in surface wettability, and three additives (hydrophobic latices, a semi-hydrophobic flocculant and a typical hydrophilic polyelectrolyte) were utilized, showed that coal wettability plays a very important role in selective flocculation. The abstraction of a hydrophobic latex on coal and silica revealed that the latex had a much higher affinity towards hydrophobic coal than to hydrophilic mineral matter. As a result, the UBC-1 hydrophobic latex flocculated only hydrophobic coal particles while the polyelectrolyte (PAM) flocculated all the tested coal samples and minerals, showing no selectivity in the fine coal beneficiation. The oil agglomeration was tested using kerosene emulsified with various surfactants (e.g. cationic, anionic and non-ionic). Surfactants enhance not only oil emulsification, hence reducing oil consumption (down to 0.25--0.5%), but also entirely change the electrokinetic properties of the droplets and affect the interaction energy between oil droplets and coal particles. Consequently, the results found in the course of the experimental work strongly indicate that even oxidized coals can be agglomerated if cationic surfactants are used to emulsify the oil. Oil agglomeration of the Ford-4 ultrafine coal showed that even at extremely low oil consumption (0.25 to 0.5%), a clean coal product with an ash content around 5% at over

  14. Impact of blend ratio on the co-firing of a commercial torrefied biomass and coal via analysis of oxidation kinetics.

    PubMed

    Goldfarb, Jillian L; Liu, Chao

    2013-12-01

    Incorporation of torrefied biomass into coal-fired power plants could potentially lower the SOx and net CO2 emissions resulting from electricity generation. However, concerns over lower heating values and slightly higher ash content of torrefied biomass suggest that blending it with coal in industrial boilers may be preferable to complete fuel transition. By studying the oxidation kinetics of coal-torrefied biomass blends in a thermogravimetric analyzer at a heating rate of 100°C/min, we find an additive nature among the fuels for peak mass loss rates and enthalpies of combustion. The activation energy required to initiate decomposition decreases from 132.6 to 77.6 kJ/mol as the torrefied biomass increases from 0 to 100 wt%, with a sharp decrease between 0 and 40 wt%. Data suggest that incorporation of torrefied biomass into coal-fired boilers is dependent on the ability to sacrifice heating value for the lower emissions of SOx and net CO2 garnered using bio-coal.

  15. Microbial desulfurization of coal

    NASA Technical Reports Server (NTRS)

    Dastoor, M. N.; Kalvinskas, J. J.

    1978-01-01

    Experiments indicate that several sulfur-oxidizing bacteria strains have been very efficient in desulfurizing coal. Process occurs at room temperature and does not require large capital investments of high energy inputs. Process may expand use of abundant reserves of high-sulfur bituminous coal, which is currently restricted due to environmental pollution. On practical scale, process may be integrated with modern coal-slurry transportation lines.

  16. (Bioprocessing of lignite coals using reductive microorganisms)

    SciTech Connect

    Crawford, D.L.

    1990-01-01

    The objectives of this report are to: (1) characterize selected aerobic bacterial strains for their abilities to depolymerize lignite coal polymers, and isolate and identify the extracellular enzymes responsible for depolymerization of the coal; (2) characterize selected strictly anaerobic bacteria, that were previously shown to reductively transform coal substructure model compounds, for the ability to similarly transform polymeric coal; and (3) isolate more strains of anaerobic bacteria by enrichment using additional coal substructure model compounds and coal as substrates.

  17. The release of iron during coal combustion. Milestone report

    SciTech Connect

    Baxter, L.L.

    1995-06-01

    Iron plays an important role in the formation of both fly ash and deposits in many pulverized-coal-fired boilers. Several authors indicate that iron content is a significant indicator of the slagging propensity of a majority of US bituminous coals, in particular eastern bituminous coals. The pyritic iron content of these coals is shown to be a particularly relevant consideration. A series of investigations of iron release during combustion is reported for a suite of coals ranging in rank from lignite to low-volatile bituminous coal under combustion conditions ranging from oxidizing to inert. Experimental measurements are described in which, under selected conditions, major fractions of the iron in the coal are released within a 25 ms period immediately following coal devolatilization. Mechanistic interpretation of the data suggest that the iron is released as a consequence of oxygen attack on porous pyrrhotite particles. Experimental testing of the proposed mechanism reveals that the release is dependent on the presence of both pyrite in the raw coal and oxygen in the gas phase, that slow preoxidation (weathering) of the pyrite significantly inhibits the iron release, and that iron loss increases as oxygen penetration of the particle increases. Each observation is consistent with the postulated mechanism.

  18. Coal recovery process

    DOEpatents

    Good, Robert J.; Badgujar, Mohan

    1992-01-01

    A method for the beneficiation of coal by selective agglomeration and the beneficiated coal product thereof is disclosed wherein coal, comprising impurities, is comminuted to a particle size sufficient to allow impurities contained therein to disperse in water, an aqueous slurry is formed with the comminuted coal particles, treated with a compound, such as a polysaccharide and/or disaccharide, to increase the relative hydrophilicity of hydrophilic components, and thereafter the slurry is treated with sufficient liquid agglomerant to form a coagulum comprising reduced impurity coal.

  19. Mineral matter effects on char structural evolution and oxidation kinetics during coal char combustion

    SciTech Connect

    Lunden, M.; Yang, N.; Headley, T.; Shaddix, C.; Hardesty, D.

    1997-10-01

    The authors report on recent investigations of the evolution of char structure during carbon burnout and the role of mineral matter in determining this structure. Char samples collected in a carefully controlled laminar, flame-supported entrained flow reactor have been characterized using a number of microscopy tools. Observations of the inorganic structure of chars produced at a variety of combustion conditions are coupled with in-situ optical measurements of the char particle population with an eye towards identifying the mechanism of mineral interaction and its effects on carbon burnout kinetics during pulverized coal char combustion. Preliminary results show a surprising amount of inorganic mineral in solid solution with the carbonaceous matrix. This intimate mixing of organic and inorganic constituents may affect reactivity by both blocking oxygen access to active carbon sites and influencing the microscopic carbon structure that evolves during combustion.

  20. Amperometric nitric oxide sensors with enhanced selectivity over carbon monoxide via platinum oxide formation under alkaline conditions.

    PubMed

    Jensen, Gary C; Zheng, Zheng; Meyerhoff, Mark E

    2013-11-05

    An improved planar amperometric nitric oxide (NO) sensor with enhanced selectivity over carbon monoxide (CO), which represents a volatile interfering species for NO sensors that has been largely overlooked until recently, is described. Formation of an oxide film on the inner platinum working electrode via anodic polarization using an inner alkaline electrolyte solution provides the basis for improved selectivity. Cyclic voltammetry reveals that formation of an oxidized Pt film inhibits adsorption of CO to the electrode surface, which is a necessary initial step in the electrocatalytic oxidation of CO on Pt. Previous NO gas sensors that employ internal electrolyte solutions have been assembled using acidic internal solutions that inhibit the formation of a dense platinum oxide film on the working electrode surface. It is demonstrated herein that increasing the internal electrolyte pH promotes oxidized platinum film formation, resulting in improved selectivity over CO. Selectivity coefficients (log KNO,j) for sensors assembled with internal solutions at various pH values range from -0.08 at pH 2.0 to -2.06 at pH 11.7, with average NO sensitivities of 1.24 nA/μM and a limit of detection (LOD) of <1 nM.

  1. The influence of selected parameters on the efficiency and economic charactersistics of the oxy-type coal unit with a membrane-cryogenic oxygen separator

    NASA Astrophysics Data System (ADS)

    Kotowicz, Janusz; Berdowska, Sylwia

    2016-03-01

    In this paper a 600 MW oxy-type coal unit with a pulverized bed boiler and a membrane-cryogenic oxygen separator and carbon capture installation was analyzed. A membrane-cryogenic oxygen separation installation consists of a membrane module and two cryogenic distillation columns. In this system oxygen is produced with the purity equal to 95%. Installation of carbon capture was based on the physical separation method and allows to reduce the CO2 emission by 90%. In this work the influence of the main parameter of the membrane process - the selectivity coefficient, on the efficiency of the coal unit was presented. The economic analysis with the use of the break-even point method was carried out. The economic calculations were realized in view of the break-even price of electricity depending on a coal unit availability.

  2. Water quality of selected streams in the coal area of east-central Montana

    USGS Publications Warehouse

    McKinley, P.W.

    1979-01-01

    In October 1975 the U.S. Geological Survey established a network of nine data-collection stations on eight streams in Montana to monitor water quality in potential coal-mining areas. The report summarizes and evaluates the water-quality data that have been collected during the first 2 years (3 years for 1 station) of network operation. Big Dry Creek, Little Dry Creek, Timber Creek , and Nelson Creek are the principal streams forming the Big Dry Creek basin, which is tributary to the Missouri River. These streams all contain water of the sodium sulfate type. Concentrations were high for dissolved solids (433-4,570 mg/L) and generally low for nutrients and trace elements. Prairie Elk Creek, Sand Creek, and the Redwater River flow directly into the Missouri River. Prairie Elk and Sand Creeks have mainly sodium bicarbonate water, whereas the Redwater River is predominately sodium sulfate water. All three streams contained water of high dissolved-solids concentration (160-3,370 mg/L) and generally low nutrient and trace-element concentrations. Burns Creek is tributary to the Yellowstone River. The water type is generally sodium sulfate during the spring and summer and sodium bicarbonate during the fall and winter. Water from Burns Creek ranged from 382 to 1,420 mg/L dissolved solids. (Woodard-USGS)

  3. Hydrology of Selected Basins in the Warrior Coal Field, Alabama - A Progress Report

    USGS Publications Warehouse

    Puente, Celso; Newton, John G.; Hill, Thomas J.

    1980-01-01

    Hydrologic data are being collected in four basins in the Warrior coal field in Alabama to provide baseline information to aid in determining the effect mining will have on water resources. Basins monitored are in two different geologic and hydrologic environments. Two basins are underlain predominantly by relatively impermeable indurated rocks in the Pottsville Formation of Pennsylvanian age. The two remaining basins are underlain predominantly by unconsolidated permeable rocks in the Coker Formation of Late Cretaceous age. Well yields from the Pottsville Formation generally range from 0 to 0.3 liter per second, whereas well yields from the Coker Formation generally range form 0.3 to 6.4 liters per second. Streamflow distribution reflects seasonal precipitation. Storm runoff is characterized by sharply concentrated flows of short duration that rapidly recede to low-flow conditions. Streams draining basins underlain chiefly by the Pottsville Formation frequently go dry, whereas those draining basins underlain chiefly by the Coker Formation have well sustained low flows. Water in the Pottsville Formation is slightly acidic and moderately hard to very hard. Dissolved solids concentrations ranged from 176 to 268 milligrams per liter. Water in the Coker Formation is soft, far less mineralized, and more acidic than water in the Pottsville. Surface water is generally soft, acidic and low in dissolved solids concentrations. Water in streams draining basins underlain chiefly by the Pottsville Formation was slightly more mineralized and less acidic than water in streams draining the Coker Formation. (USGS)

  4. Counteraction of poly(4-vinylpyridine-n-oxide) on the depression of viral interferon induction by coal dust.

    PubMed Central

    Hahon, N

    1976-01-01

    The depressive activity of coal dust on interferon induction by influenza was markedly subverted when either coal dust or LLC-MK2 cell monolayers were pretreated with poly (4-vinylpyridine-N-oside). The polymer alone neither induced interferon synthesis, inhibited viral induction of interferon, influenced viral multiplication, nor affected cellular-induced resistance by interferon. Absorption of the polymer to coal dust not only occurred at a more rapid rate than to cell monolayers, but also less polymer was required to pretreat coal dust than cell monolayers to achieve comparable amelioration of interferon production. The polymer effectively negated the adverse activity of coal dust particles, irrespective of the latter's size (is less than 2.0 to 74.0 mum). Virus multiplication in the presence of coal dust=treated cell monolayers attained a level that was twofol higher than that noted with either polymer-pretreated coal dust or polymer-pretreated cell monolayers. Interferon production was almost completely inhibited in the presence of coal dust; pretreating coal dust or cells with the polymer abrogated this inhibitory activity of coal dust. It is tentatively suggested that coal dust particles per se directly interact with cell membranes to subvert interferon induction and that the formation of an absorbed polymerlayer on these complexes prevents their interaction. PMID:178603

  5. Counteraction of poly(4-vinylpyridine-n-oxide) on the depression of viral interferon induction by coal dust.

    PubMed

    Hahon, N

    1976-05-01

    The depressive activity of coal dust on interferon induction by influenza was markedly subverted when either coal dust or LLC-MK2 cell monolayers were pretreated with poly (4-vinylpyridine-N-oside). The polymer alone neither induced interferon synthesis, inhibited viral induction of interferon, influenced viral multiplication, nor affected cellular-induced resistance by interferon. Absorption of the polymer to coal dust not only occurred at a more rapid rate than to cell monolayers, but also less polymer was required to pretreat coal dust than cell monolayers to achieve comparable amelioration of interferon production. The polymer effectively negated the adverse activity of coal dust particles, irrespective of the latter's size (is less than 2.0 to 74.0 mum). Virus multiplication in the presence of coal dust=treated cell monolayers attained a level that was twofol higher than that noted with either polymer-pretreated coal dust or polymer-pretreated cell monolayers. Interferon production was almost completely inhibited in the presence of coal dust; pretreating coal dust or cells with the polymer abrogated this inhibitory activity of coal dust. It is tentatively suggested that coal dust particles per se directly interact with cell membranes to subvert interferon induction and that the formation of an absorbed polymerlayer on these complexes prevents their interaction.

  6. Evaluating the combustion reactivity of drop tube furnace and thermogravimetric analysis coal chars with a selection of metal additives

    SciTech Connect

    Katherine Le Manquais; Colin E. Snape; Ian McRobbie; Jim Barker

    2011-03-17

    Opportunities exist for effective coal combustion additives that can reduce the carbon content of pulverized fuel ash (PFA) to below 6%, thereby making it saleable for filler/building material applications without the need for postcombustion treatment. However, with only limited combustion data currently available for the multitude of potential additives, catalytic performance under pulverized fuel (PF) boiler conditions has received relatively little attention. This paper therefore compares the reactivity of catalyzed bituminous coal chars from thermogravimetric analysis (TGA) with those generated by devolatilization in a drop tube furnace (DTF). The principal aim was to explore the fundamental chemistry behind the chosen additives' relative reactivities. Accordingly, all eight of the investigated additives increased the TGA burnout rate of the TGA and DTF chars, with most of the catalysts demonstrating consistent reactivity levels across chars from both devolatilization methods. Copper(I) chloride, silver chloride, and copper nitrate were thus identified as the most successful additives tested, but it proved difficult to establish a definitive reactivity ranking. This was largely due to the use of physical mixtures for catalyst dispersion, the relatively narrow selection of additives examined, and the inherent variability of the DTF chars. Nevertheless, one crucial exception to normal additive behavior was discovered, with copper(I) chloride perceptibly deactivating during devolatilization in the DTF, even though it remained the most effective catalyst tested. As a prolonged burnout at over 1000{sup o}C was required to replicate this deactivation effect on the TGA, the phenomenon could not be detected by typical testing procedures. Subsequently, a comprehensive TGA study showed no obvious relationship between the catalyst-induced reductions in the reaction's apparent activation energy and the samples recorded burnout rates.

  7. SELECTIVE OXIDATION OF ALCOHOLS - COMPARING DIFFERENT CATALYTIC PROCESSES

    EPA Science Inventory

    Oxidation of alcohols to aldehydes, ketones or carboxylic acids is one of the most desirable chemical transformations in organic synthesis as these products are important precursors and intermediates for many drugs, vitamins and fragrances. Numerous methods are available for alc...

  8. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Phase 2, Overfire air tests

    SciTech Connect

    Smith, L.L.; Hooper, M.P.

    1992-07-13

    This Phase 2 Test Report summarizes the testing activities and results for the second testing phase of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The second phase demonstrates the Advanced Overfire Air (AOFA) retrofit with existing Foster Wheeler (FWEC) burners. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data supported by short-term characterization data. Ultimately a fifty percent NO{sub x} reduction target using combinations of combustion modifications has been established for this project.

  9. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO[sub x]) emissions from coal-fired boilers

    SciTech Connect

    Smith, L.L.; Hooper, M.P. )

    1992-07-13

    This Phase 2 Test Report summarizes the testing activities and results for the second testing phase of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO[sub x]) emissions from coal-fired boilers. The second phase demonstrates the Advanced Overfire Air (AOFA) retrofit with existing Foster Wheeler (FWEC) burners. The project is being conducted at Georgia Power Company's Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO[sub x] combustion equipment through the collection and analysis of long-term emissions data supported by short-term characterization data. Ultimately a fifty percent NO[sub x] reduction target using combinations of combustion modifications has been established for this project.

  10. Innovative Clean Coal Technology (ICCT): 180 MW demonstration of advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Topical report, LNCFS Levels 1 and 3 test results

    SciTech Connect

    Not Available

    1993-08-17

    This report presents results from the third phase of an Innovative Clean Coal Technology (ICC-1) project demonstrating advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from a coal-fired boiler. The purpose of this project was to study the NO{sub x} emissions characteristics of ABB Combustion Engineering`s (ABB CE) Low NO{sub x} Concentric Firing System (LNCFS) Levels I, II, and III. These technologies were installed and tested in a stepwise fashion at Gulf Power Company`s Plant Lansing Smith Unit 2. The objective of this report is to provide the results from Phase III. During that phase, Levels I and III of the ABB C-E Services Low NO{sub x} Concentric Firing System were tested. The LNCFS Level III technology includes separated overfire air, close coupled overfire air, clustered coal nozzles, flame attachment coal nozzle tips, and concentric firing. The LNCFS Level I was simulated by closing the separated overfire air nozzles of the LNCFS Level III system. Based upon long-term data, LNCFS Level HI reduced NO{sub x} emissions by 45 percent at full load. LOI levels with LNCFS Level III increased slightly, however, tests showed that LOI levels with LNCFS Level III were highly dependent upon coal fineness. After correcting for leakage air through the separated overfire air system, the simulated LNCFS Level I reduced NO{sub x} emissions by 37 percent. There was no increase in LOI with LNCFS Level I.

  11. State coal profiles, January 1994

    SciTech Connect

    Not Available

    1994-02-02

    The purpose of State Coal Profiles is to provide basic information about the deposits, production, and use of coal in each of the 27 States with coal production in 1992. Although considerable information on coal has been published on a national level, there is a lack of a uniform overview for the individual States. This report is intended to help fill that gap and also to serve as a framework for more detailed studies. While focusing on coal output, State Coal Profiles shows that the coal-producing States are major users of coal, together accounting for about three-fourths of total US coal consumption in 1992. Each coal-producing State is profiled with a description of its coal deposits and a discussion of the development of its coal industry. Estimates of coal reserves in 1992 are categorized by mining method and sulfur content. Trends, patterns, and other information concerning production, number of mines, miners, productivity, mine price of coal, disposition, and consumption of coal are detailed in statistical tables for selected years from 1980 through 1992. In addition, coal`s contribution to the State`s estimated total energy consumption is given for 1991, the latest year for which data are available. A US summary of all data is provided for comparing individual States with the Nation as a whole. Sources of information are given at the end of the tables.

  12. Studies of incipient oxidation of coal-pyrite for improved pyrite rejection. Technical Progress report, January 1, 1993--March 31, 1993

    SciTech Connect

    Yoon, R.H.; Richardson, P.E.

    1993-06-01

    To foster the development of advanced coal cleaning technologies, the initial stages of pyrite oxidation are being studied. The voltammetry behavior of polished pyrite at moderate overpotentials is known to be dominated by iron oxides and hydroxides that are generated during the polishing process. The present work is being done on pyrite surfaces that are freshly fractured in an electrolyte solution. The creation of fresh surfaces by in situ fracture allows studies of the initial oxidation of pyrite itself, without complications from overlayers of iron oxides and hydroxides produced by polishing. Chronoamperometry immediately after fracture and subsequent cyclic voltammetry is being used to elucidate the initial oxidation reaction that produces hydrophobic sulfur species on pyrite.

  13. Stable lead isotope compositions in selected coals from around the world and implications for present day aerosol source tracing

    SciTech Connect

    M. Diaz-Somoano; M.E. Kylander; M.A. Lopez-Anton; I. Suarez-Ruiz; M.R. Martinez-Tarazona; M. Ferrat; B. Kober; D.J. Weiss

    2009-02-15

    The phasing out of leaded gasoline in many countries around the world at the end of the last millennium has resulted in a complex mixture of lead sources in the atmosphere. Recent studies suggest that coal combustion has become an important source of Pb in aerosols in urban and remote areas. Lead concentration and isotopic composition is reported for 59 coal samples representing major coal deposits worldwide in an attempt to characterize this potential source. The average concentration in these coals is 35 {mu}g Pb g{sup -1}, with the highest values in coals from Spain and Peru and the lowest in coals from Australia and North America. The {sup 206}Pb/{sup 207}Pb isotope ratios range between 1.15 and 1.24, with less radiogenic Pb in coals from Europe and Asia compared to South and North America. Comparing the Pb isotopic signatures of coals from this and previous studies with those published for Northern and Southern Hemisphere aerosols, we hypothesize that coal combustion might now be an important Pb source in China, the eastern U.S., and to some extent, in Europe but not as yet in other regions including South Africa, South America, and western U.S. This supports the notion that 'old Pb pollution' from leaded gasoline reemitted into the atmosphere or long-range transport (i.e., from China to the western U.S.) is important. Comparing the isotope ratios of the coals, the age of the deposits, and Pb isotope evolution models for the major geochemical reservoirs suggests that the lead isotope ratios (PbIC) in coals is strongly influenced by the depositional coal forming environment. 47 refs., 3 figs., 1 tab.

  14. Method of extracting coal from a coal refuse pile

    DOEpatents

    Yavorsky, Paul M.

    1991-01-01

    A method of extracting coal from a coal refuse pile comprises soaking the coal refuse pile with an aqueous alkali solution and distributing an oxygen-containing gas throughout the coal refuse pile for a time period sufficient to effect oxidation of coal contained in the coal refuse pile. The method further comprises leaching the coal refuse pile with an aqueous alkali solution to solubilize and extract the oxidized coal as alkali salts of humic acids and collecting the resulting solution containing the alkali salts of humic acids. Calcium hydroxide may be added to the solution of alkali salts of humic acid to form precipitated humates useable as a low-ash, low-sulfur solid fuel.

  15. Selective coal mine overburden treatment with topsoil and compost to optimise pasture or native vegetation establishment.

    PubMed

    Spargo, A; Doley, D

    2016-11-01

    Overburden at a coal mine in the Hunter Valley, New South Wales, was stored in a flat-topped artificial mound with 14-degree side slopes. Topsoil was scarce, dispersive and readily eroded. A split-plot factorial experiment applied an enhanced municipal solid waste compost at 0, 60 or 100 t ha(-1) to untreated overburden or to overburden covered with 0.1 m of topsoil. Two seeding treatments, of trees and shrubs or of pasture species, were applied to two 0.5-ha replicates of each surface treatment. Substrate physical and chemical properties and vegetation attributes were assessed 2.5 years later. Compost application to both topsoil and overburden significantly increased total N, P, Cu and Zn, soluble K, Ca and Mg, and significantly reduced soluble Na and pH. Mean tree density, size and total canopy cover were significantly greater with compost applied at 60 t ha(-1) to overburden than with all other treatments, especially those on topsoil where tree growth was inhibited by undesired species. Compost application to overburden and topsoil at 100 t ha(-1) significantly increased biomass of desired pasture species and significantly reduced undesired species cover compared with unamended topsoil and the extent of bare ground compared with unamended overburden. Successful development of woody species on overburden and pastures on both overburden and topsoil treated with compost provides opportunities for new combinations of landscape design, surface preparation and plant species introductions to increase the stability of final landforms, the effectiveness of resource use, and the delivery of commercial and biodiversity benefits from mine site rehabilitation.

  16. Theoretical technique for predicting the cumulative impact of iron and manganese oxidation in streams receiving discharge from coal mines

    USGS Publications Warehouse

    Bobay, Keith E.

    1986-01-01

    Two U.S. Geological Survey computer programs are modified and linked to predict the cumulative impact of iron and manganese oxidation in coal-mine discharge water on the dissolved chemical quality of a receiving stream. The coupled programs calculate the changes in dissolved iron, dissolved manganese, and dissolved oxygen concentrations; alkalinity; and, pH of surface water downstream from the point of discharge. First, the one-dimensional, stead-state stream, water quality program uses a dissolved oxygen model to calculate the changes in concentration of elements as a function of the chemical reaction rates and time-of-travel. Second, a program (PHREEQE) combining pH, reduction-oxidation potential, and equilibrium equations uses an aqueous-ion association model to determine the saturation indices and to calculate pH; it then mixes the discharge with a receiving stream. The kinetic processes of the first program dominate the system, whereas the equilibrium thermodynamics of the second define the limits of the reactions. A comprehensive test of the technique was not possible because a complete set of data was unavailable. However, the cumulative impact of representative discharges from several coal mines on stream quality in a small watershed in southwestern Indiana was simulated to illustrate the operation of the technique and to determine its sensitivity to changes in physical, chemical, and kinetic parameters. Mine discharges averaged 2 cu ft/sec, with a pH of 6.0, and concentrations of 7.0 mg/L dissolved iron, 4.0 mg/L dissolved manganese, and 8.08 mg/L dissolved oxygen. The receiving stream discharge was 2 cu ft/sec, with a pH of 7.0, and concentrations of 0.1 mg/L dissolved iron, 0.1 mg/L dissolved manganese, and 8.70 mg/L dissolved oxygen. Results of the simulations indicated the following cumulative impact on the receiving stream from five discharges as compared with the effect from one discharge: 0.30 unit decrease in pH, 1.82 mg/L increase in dissolved

  17. Chemical-looping combustion of coal-derived synthesis gas over copper oxide oxygen carriers

    SciTech Connect

    Tian, H.; Chaudhari, K.; Simonyi, T.; Poston, J.; Liu, T.; Sanders, T.; Veser, G.; Siriwardane, R.

    2008-01-01

    CuO/bentonite and CuO-BHA nanocomposites were studied as oxygen carriers in chemical-looping combustion (CLC) of simulated synthesis gas. Global reaction rates of reduction and oxidation, as the function of reaction conversion, were calculated from 10-cycle oxidation/reduction tests utilizing thermogravimetric analysis at atmospheric pressure between 700 and 900 °C. It was found that the reduction reactions are always faster than oxidation reactions; reaction temperature and particle size do not significantly affect the reaction performance of CuO/bentonite. Multicycle CLC tests conducted in a high-pressure flow reactor showed stable reactivity for production of CO2 from fuel gas at 800 and 900 °C and full consumption of hydrogen during the reaction. Results of the tapered element oscillating microbalance showed a negative effect of pressure on the global rates of reduction-oxidation reactions at higher fractional conversions. X-ray diffraction patterns confirmed the presence of CuO in the bulk phase of the oxidized sample. Electron microanalysis showed significant morphology changes of reacted CuO/bentonite samples after the 10 oxidation-reduction cycles above 700 °C in an atmospheric thermogravimetric analyzer. The nanostructured CuO-BHA carrier also showed excellent stability and, in comparison to the CuO/bentonite system, slightly accelerated redox kinetics albeit at the expense of significantly increased complexity of manufacturing. Overall, both types of CuO carriers exhibited excellent reaction performance and thermal stability for the CLC process at 700-900 °C.

  18. Chemical-looping combustion of coal-derived synthesis gas over copper oxide oxygen carriers

    SciTech Connect

    Hanjing Tian; Karuna Chaudhari; Thomas Simonyi; James Poston; Tengfei Liu; Tom Sanders; Goetz Veser; Ranjani Siriwardane

    2008-11-15

    CuO/bentonite and CuO-BHA nanocomposites were studied as oxygen carriers in chemical-looping combustion (CLC) of simulated synthesis gas. Global reaction rates of reduction and oxidation, as the function of reaction conversion, were calculated from 10-cycle oxidation/reduction tests utilizing thermogravimetric analysis at atmospheric pressure between 700 and 900{degree}C. It was found that the reduction reactions are always faster than oxidation reactions; reaction temperature and particle size do not significantly affect the reaction performance of CuO/bentonite. Multicycle CLC tests conducted in a high-pressure flow reactor showed stable reactivity for production of CO{sub 2} from fuel gas at 800 and 900{degree}C and full consumption of hydrogen during the reaction. Results of the tapered element oscillating microbalance showed a negative effect of pressure on the global rates of reduction-oxidation reactions at higher fractional conversions. X-ray diffraction patterns confirmed the presence of CuO in the bulk phase of the oxidized sample. Electron microanalysis showed significant morphology changes of reacted CuO/bentonite samples after the 10 oxidation-reduction cycles above 700{degree}C in an atmospheric thermogravimetric analyzer. The nanostructured CuO-BHA carrier also showed excellent stability and, in comparison to the CuO/bentonite system, slightly accelerated redox kinetics albeit at the expense of significantly increased complexity of manufacturing. Overall, both types of CuO carriers exhibited excellent reaction performance and thermal stability for the CLC process at 700-900{degree}C. 48 refs., 12 figs., 8 tabs.

  19. Chemical-looping Combustion of Coal-derived Synthesis Gas Over Copper Oxide Oxygen Carriers

    SciTech Connect

    Tian, Hanjing; Chaudhari, K P; Simonyi, Thomas; Poston, J A; Liu, Tengfei; Sanders, Tom; Veser, Goetz; Siriwardane, R V

    2008-11-01

    CuO/bentonite and CuO-BHA nanocomposites were studied as oxygen carriers in chemical-looping combustion (CLC) of simulated synthesis gas. Global reaction rates of reduction and oxidation, as the function of reaction conversion, were calculated from 10-cycle oxidation/reduction tests utilizing thermogravimetric analysis at atmospheric pressure between 700 and 900 °C. It was found that the reduction reactions are always faster than oxidation reactions; reaction temperature and particle size do not significantly affect the reaction performance of CuO/bentonite. Multicycle CLC tests conducted in a high-pressure flow reactor showed stable reactivity for production of CO2 from fuel gas at 800 and 900 °C and full consumption of hydrogen during the reaction. Results of the tapered element oscillating microbalance showed a negative effect of pressure on the global rates of reduction-oxidation reactions at higher fractional conversions. X-ray diffraction patterns confirmed the presence of CuO in the bulk phase of the oxidized sample. Electron microanalysis showed significant morphology changes of reacted CuO/bentonite samples after the 10 oxidation-reduction cycles above 700 °C in an atmospheric thermogravimetric analyzer. The nanostructured CuO-BHA carrier also showed excellent stability and, in comparison to the CuO/bentonite system, slightly accelerated redox kinetics albeit at the expense of significantly increased complexity of manufacturing. Overall, both types of CuO carriers exhibited excellent reaction performance and thermal stability for the CLC process at 700-900 °C.

  20. Supported, Alkali-Promoted Cobalt Oxide Catalysts for NOx Removal from Coal Combustion Flue Gases

    SciTech Connect

    Morris D. Argyle

    2005-12-31

    A series of cobalt oxide catalysts supported on alumina ({gamma}-Al{sub 2}O{sub 3}) were synthesized with varying contents of cobalt and of added alkali metals, including lithium, sodium, potassium, rubidium, and cesium. Unsupported cobalt oxide catalysts and several cobalt oxide catalysts supported ceria (CeO{sub 2}) with varying contents of cobalt with added potassium were also prepared. The catalysts were characterized with UV-visible spectroscopy and were examined for NO{sub x} decomposition activity. The CoO{sub x}/Al{sub 2}O{sub 3} catalysts and particularly the CoO{sub x}/CeO{sub 2} catalysts show N{sub 2}O decomposition activity, but none of the catalysts (unsupported Co{sub 3}O{sub 4} or those supported on ceria or alumina) displayed significant, sustained NO decomposition activity. For the Al{sub 2}O{sub 3}-supported catalysts, N{sub 2}O decomposition activity was observed over a range of reaction temperatures beginning about 723 K, but significant (>50%) conversions of N{sub 2}O were observed only for reaction temperatures >900 K, which are too high for practical commercial use. However, the CeO{sub 2}-supported catalysts display N{sub 2}O decomposition rates similar to the Al{sub 2}O{sub 3}-supported catalysts at much lower reaction temperatures, with activity beginning at {approx}573 K. Conversions of >90% were achieved at 773 K for the best catalysts. Catalytic rates per cobalt atom increased with decreasing cobalt content, which corresponds to increasing edge energies obtained from the UV-visible spectra. The decrease in edge energies suggests that the size and dimensionality of the cobalt oxide surface domains increase with increasing cobalt oxide content. The rate data normalized per mass of catalyst that shows the activity of the CeO{sub 2}-supported catalysts increases with increasing cobalt oxide content. The combination of these data suggest that supported cobalt oxide species similar to bulk Co{sub 3}O{sub 4} are inherently more active than

  1. Facile preparation of highly-dispersed cobalt-silicon mixed oxide nanosphere and its catalytic application in cyclohexane selective oxidation

    PubMed Central

    2011-01-01

    Highly dispersed cobalt-silicon mixed oxide [Co-SiO2] nanosphere was successfully prepared with a modified reverse-phase microemulsion method. This material was characterized in detail by X-ray diffraction, transmission electron microscopy, Fourier transform infrared, ultraviolet-visible diffuse reflectance spectra, X-ray absorption spectroscopy near-edge structure, and N2 adsorption-desorption measurements. High valence state cobalt could be easily obtained without calcination, which is fascinating for the catalytic application for its strong oxidation ability. In the selective oxidation of cyclohexane, Co-SiO2 acted as an efficient catalyst, and good activity could be obtained under mild conditions. PMID:22067075

  2. Linking organic carbon, water content and nitrous oxide emission in a reclaimed coal mine soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Manure-based organic amendments can restore soil quality and allow for intensive sustained biomass production on degraded lands. However the large quantities of nitrogen and organic carbon added with such amendments could create soil conditions favorable for nitrous oxide production and emissions. T...

  3. Fabrication of Fe-Al nanoparticles by selective oxidation of Fe-Al thin films

    NASA Astrophysics Data System (ADS)

    Jang, Pyungwoo; Shin, Seungchan; Jung, Chip-Sup; Kim, Kwang-Ho; Seomoon, Kyu

    2013-04-01

    The possibility of a new technique for fabricating nanoparticles from thin films using selective oxidation in an atmosphere mixture of water vapor and hydrogen was investigated. Fe-5wt.%Al films were RF-sputtered and annealed in the atmosphere mixture at 900°C for up to 200 min, in order to oxidize aluminum selectively. Thermodynamics simulation showed that temperatures exceeding 800°C are necessary to prevent iron from being oxidized, as confirmed by the depth profile of XPS. As the annealing time increased, the morphology of the 200-nm Fe-Al films changed from the continuous to the discontinuous type; thus, particulate Fe-Al films formed after 100 min. The particulate 10- to 100-nm Fe-Al films showed super-paramagnetic behavior after the oxidation. Thus, a new technique for fabricating nanoparticles was successfully introduced using selective oxidation.

  4. Stresses in Selectively Oxidized GaAs/(AlGa){sub x}O{sub y} Structures

    SciTech Connect

    Blokhin, S.A.; Smirnov, A.N.; Sakharov, A.V.; Gladyshev, A.G.; Kryzhanovskaya, N.V.; Maleev, N.A.; Zhukov, A.E.; Semenova, E.S.; Bedarev, D.A.; Nikitina, E.V.; Kulagina, M.M.; Maksimov, M.V.; Ledentsov, N.N.; Ustinov, V.M.

    2005-07-15

    Raman scattering spectroscopy is used to study the process of selective oxidation of Al{sub 0.97}Ga{sub 0.03}As layers. Stresses arising in GaAs/(AlGa){sub x}O{sub y} layers as a result of selective oxidation under different conditions are determined. The effects of local heating of the samples with laser radiation during measurements of the Raman signals, photoresist hardening resulting from the oxidation, and overoxidation are analyzed. The instrumentation and method of selective oxidation are optimized; as a result, arrays of vertical-cavity surface-emitting lasers are fabricated. The active region of these lasers is based on two InGaAs quantum wells with top oxidized and bottom semiconductor distributed Bragg reflectors.

  5. Monolithic solid oxide fuel cell technology advancement for coal-based power generation

    NASA Astrophysics Data System (ADS)

    1994-05-01

    This project has successfully advanced the technology for MSOFC's for coal-based power generation. Major advances include: tape-calendering processing technology, leading to 3X improved performance at 1000 C; stack materials formulations and designs with sufficiently close thermal expansion match for no stack damage after repeated thermal cycling in air; electrically conducting bonding with excellent structural robustness; and sealants that form good mechanical seals for forming manifold structures. A stack testing facility was built for high-spower MSOFC stacks. Comprehensive models were developed for fuel cell performance and for analyzing structural stresses in multicell stacks and electrical resistance of various stack configurations. Mechanical and chemical compatibility properties of fuel cell components were measured; they show that the baseline Ca-, Co-doped interconnect expands and weakens in hydrogen fuel. This and the failure to develop adequate sealants were the reason for performance shortfalls in large stacks. Small (1-in. footprint) two-cell stacks were fabricated which achieved good performance (average area-specific-resistance 1.0 ohm-sq cm per cell); however, larger stacks had stress-induced structural defects causing poor performance.

  6. EVALUATION OF THE IMPACT OF CHLORINE ON MERCURY OXIDATION IN A PILOT-SCALE COAL COMBUSTION--THE EFFECT OF COAL BLENDING

    EPA Science Inventory

    Coal-fired power plants are a major source of mercury (Hg) released into the environment and the utility industry is currently investigating options to reduce Hg emissions. The EPA Clean Air Mercury Rule (CAMR) depends heavily on the co-benefit of mercury removal by existing and ...

  7. Sustainable development with clean coal

    SciTech Connect

    1997-08-01

    This paper discusses the opportunities available with clean coal technologies. Applications include new power plants, retrofitting and repowering of existing power plants, steelmaking, cement making, paper manufacturing, cogeneration facilities, and district heating plants. An appendix describes the clean coal technologies. These include coal preparation (physical cleaning, low-rank upgrading, bituminous coal preparation); combustion technologies (fluidized-bed combustion and NOx control); post-combustion cleaning (particulate control, sulfur dioxide control, nitrogen oxide control); and conversion with the integrated gasification combined cycle.

  8. Low temperature aqueous desulfurization of coal

    DOEpatents

    Slegeir, W.A.; Healy, F.E.; Sapienza, R.S.

    1985-04-18

    This invention describes a chemical process for desulfurizing coal, especially adaptable to the treatment of coal-water slurries, at temperatures as low as ambient, comprising treating the coal with aqueous titanous chloride whereby hydrogen sulfide is liberated and the desulfurized coal is separated with the conversion of titanous chloride to titanium oxides.

  9. Low temperature aqueous desulfurization of coal

    DOEpatents

    Slegeir, William A.; Healy, Francis E.; Sapienza, Richard S.

    1985-01-01

    This invention describes a chemical process for desulfurizing coal, especially adaptable to the treatment of coal-water slurries, at temperatures as low as ambient, comprising treating the coal with aqueous titanous chloride whereby hydrogen sulfide is liberated and the desulfurized coal is separated with the conversion of titanous chloride to titanium oxides.

  10. Selective Oxidation in the Presence of a Heterocycle.

    ERIC Educational Resources Information Center

    Bowles, K. Dean; And Others

    1986-01-01

    Background information and procedures are provided for an experiment (suitable for both advanced high school and undergraduate students) which: (1) illustrates the concept of a catalytic oxidation cycle; and (2) demonstrates the technique of using a gaseous reagent. Other uses of the experiment are noted. (JN)

  11. SUPERCRITICAL WATER OXIDATION MODEL DEVELOPMENT FOR SELECTED EPA PRIORITY POLLUTANTS

    EPA Science Inventory

    Supercritical Water Oxidation (SCWO) evaluated for five compounds: acetic acid, 2,4-dichlorophenol, pentachlorophenol, pyridine, 2,4-dichlorophenoxyacetic acid (methyl ester). inetic models were developed for acetic acid, 2,4-dichlorophenol, and pyridine. he test compounds were e...

  12. Selective oxidation of glycosyl sulfides to sulfoxides using magnesium monoperoxyphthalate and microwave irradiation.

    PubMed

    Chen, Ming-Yi; Patkar, Laxmikant Narhari; Lin, Chun-Cheng

    2004-04-16

    A protocol that uses moist magnesium monoperoxyphthalate (MMPP) as an oxidant under microwave irradiation rapidly yields a variety of glycosyl sulfoxides from corresponding sulfides in high yields with high selectivity.

  13. Superior catalysts for selective catalytic reduction of nitric oxide. Final technical report, October 1, 1993--September 30, 1995

    SciTech Connect

    Yang, R.T.; Li, W.B.; Chen, J.P.; Hausladen, M.C.; Cheng, L.S.; Kikkinides, E.S.

    1995-12-31

    The most advanced and proven technology for NO{sub x} control for stationary sources is Selective Catalytic Reduction (SCR). In SCR, NO{sub x} is reduced by NH{sub 3} to N{sub 2} and H{sub 2}O. The commercial catalysts are based on V{sub 2}O{sub 5}/TiO{sub 2}, and the vanadium-based catalysts are patented by the Japanese (Mitsubishi). However, there are three main advantages for the vanadium-based SCR catalyst: (a) a tendency to be poisoned in the flue gas; (b) oxidation of SO{sub 2} to SO{sub 3} by V{sub 2}O{sub 5}, this is a particularly severe problem due to the higher sulfur content of American coals compared with coals used in Japan (from Australia) and in Europe; (c) environmental problems involved in the disposal of the spent catalyst (due to the toxicity of vanadium). In order to overcome these problems, in addition to the undesirable dominance by the Japanese patent position, the authors have studied in this project a new type of catalyst for the SCR reaction; namely, pillared clays, which have adjustable, unique structures and acidity. Three types of catalysts were developed and tested for this reaction, i.e. Fe{sub 2}O{sub 3}-pillared clays, delaminated Fe{sub 2}O{sub 3}-pillared clays, and ion-exchanged pillared clays. The project was divided into sixteen tasks, and will be reported as such.

  14. Selective oxidation of cyclohexanol to cyclohexanone in the ionic liquid 1-octyl-3-methylimidazolium chloride.

    PubMed

    Chen, Long; Zhou, Teng; Chen, Lifang; Ye, Yinmei; Qi, Zhiwen; Freund, Hannsjörg; Sundmacher, Kai

    2011-09-07

    Ionic liquid (IL) 1-octyl-3-methylimidazolium chloride was found to effectively intensify cyclohexanol oxidation and resulted in 100% conversion of cyclohexanol with 100% selectivity to cyclohexanone using hydrogen peroxide as an oxidant and WO(3) as a catalyst. The effect of the IL as a solvent is discussed with the support of COSMO-RS theory.

  15. Activation of methane and ethane and their selective oxidation to the alcohols in protic media

    SciTech Connect

    Sen, A.; Benvenuto, M.A.; Lin, M.; Hutson, A.C.; Basickes, N. )

    1994-02-09

    The selective oxidation of methane and ethane to the alcohols in solvents ranging from strong acids to neutral aqueous medium has been studied. In 98% sulfuric acid, methane is oxidized to CH[sub 3]OSO[sub 3]H by a variety of 1e[sup [minus

  16. U.S. Geological Survey resource assessment of selected Tertiary coal zones in Wyoming, Montana and North Dakota

    USGS Publications Warehouse

    Nichols, D.J.; Ellis, M.S.

    2003-01-01

    In 1999, 1 Gt (1.1 billion st) of coal was produced in the United States. Of this total, 37% was produced in Wyoming, Montana and North Dakota. Coals of Tertiary age from these states typically have low ash contents. Most of these coals have sulfur contents that are in compliance with Clean Air Act standards and most have low concentrations of the trace elements that are of environmental concern. The U.S. Geological Survey (USGS) National Coal Resource Assessment for these states includes geologic, stratigraphic, palynologic and geochemical studies and resource calculations for major Tertiary coal zones in the Powder River, Williston, Greater Green River, Hanna and Carbon Basins. Calculated resources are 595 Gt (655 billion st). Results of the study are available in a USGS Professional Paper and a USGS Open-File Report, both in CD-ROM format.

  17. Near-infrared light controlled photocatalytic activity of carbon quantum dots for highly selective oxidation reaction

    NASA Astrophysics Data System (ADS)

    Li, Haitao; Liu, Ruihua; Lian, Suoyuan; Liu, Yang; Huang, Hui; Kang, Zhenhui

    2013-03-01

    Selective oxidation of alcohols is a fundamental and significant transformation for the large-scale production of fine chemicals, UV and visible light driven photocatalytic systems for alcohol oxidation have been developed, however, the long wavelength near infrared (NIR) and infrared (IR) light have not yet fully utilized by the present photocatalytic systems. Herein, we reported carbon quantum dots (CQDs) can function as an effective near infrared (NIR) light driven photocatalyst for the selective oxidation of benzyl alcohol to benzaldehyde. Based on the NIR light driven photo-induced electron transfer property and its photocatalytic activity for H2O2 decomposition, this metal-free catalyst could realize the transformation from benzyl alcohol to benzaldehyde with high selectivity (100%) and conversion (92%) under NIR light irradiation. HO&z.rad; is the main active oxygen specie in benzyl alcohol selective oxidative reaction confirmed by terephthalic acid photoluminescence probing assay (TA-PL), selecting toluene as the substrate. Such metal-free photocatalytic system also selectively converts other alcohol substrates to their corresponding aldehydes with high conversion, demonstrating a potential application of accessing traditional alcohol oxidation chemistry.Selective oxidation of alcohols is a fundamental and significant transformation for the large-scale production of fine chemicals, UV and visible light driven photocatalytic systems for alcohol oxidation have been developed, however, the long wavelength near infrared (NIR) and infrared (IR) light have not yet fully utilized by the present photocatalytic systems. Herein, we reported carbon quantum dots (CQDs) can function as an effective near infrared (NIR) light driven photocatalyst for the selective oxidation of benzyl alcohol to benzaldehyde. Based on the NIR light driven photo-induced electron transfer property and its photocatalytic activity for H2O2 decomposition, this metal-free catalyst could realize

  18. Enhanced Al and Zn removal from coal-mine drainage during rapid oxidation and precipitation of Fe oxides at near-neutral pH

    USGS Publications Warehouse

    Burrows, Jill E.; Cravotta, Charles A.; Peters, Stephen C.

    2017-01-01

    Net-alkaline, anoxic coal-mine drainage containing ∼20 mg/L FeII and ∼0.05 mg/L Al and Zn was subjected to parallel batch experiments: control, aeration (Aer 1 12.6 mL/s; Aer 2 16.8 mL/s; Aer 3 25.0 mL/s), and hydrogen peroxide (H2O2) to test the hypothesis that aeration increases pH, FeII oxidation, hydrous FeIII oxide (HFO) formation, and trace-metal removal through adsorption and coprecipitation with HFO. During 5.5-hr field experiments, pH increased from 6.4 to 6.7, 7.1, 7.6, and 8.1 for the control, Aer 1, Aer 2, and Aer 3, respectively, but decreased to 6.3 for the H2O2 treatment. Aeration accelerated removal of dissolved CO2, Fe, Al, and Zn. In Aer 3, dissolved Al was completely removed within 1 h, but increased to ∼20% of the initial concentration after 2.5 h when pH exceeded 7.5. H2O2 promoted rapid removal of all dissolved Fe and Al, and 13% of dissolved Zn.Kinetic modeling with PHREEQC simulated effects of aeration on pH, CO2, Fe, Zn, and Al. Aeration enhanced Zn adsorption by increasing pH and HFO formation while decreasing aqueous CO2 available to form ZnCO30 and Zn(CO3)22− at high pH. Al concentrations were inconsistent with solubility control by Al minerals or Al-containing HFO, but could be simulated by adsorption on HFO at pH < 7.5 and desorption at higher pH where Al(OH)4− was predominant. Thus, aeration or chemical oxidation with pH adjustment to ∼7.5 could be effective for treating high-Fe and moderate-Zn concentrations, whereas chemical oxidation without pH adjustment may be effective for treating high-Fe and moderate-Al concentrations.

  19. Oxidation of elemental mercury by modified spent TiO2-based SCR-DeNOx catalysts in simulated coal-fired flue gas.

    PubMed

    Zhao, Lingkui; Li, Caiting; Zhang, Xunan; Zeng, Guangming; Zhang, Jie; Xie, Yin'e

    2016-01-01

    In order to reduce the costs, the recycle of spent TiO2-based SCR-DeNOx catalysts were employed as a potential catalytic support material for elemental mercury (Hg(0)) oxidation in simulated coal-fired flue gas. The catalytic mechanism for simultaneous removal of Hg(0) and NO was also investigated. The catalysts were characterized by Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) method. Results indicated that spent TiO2-based SCR-DeNOx catalyst supported Ce-Mn mixed oxides catalyst (CeMn/SCR1) was highly active for Hg(0) oxidation at low temperatures. The Ce1.00Mn/SCR1 performed the best catalytic activities, and approximately 92.80% mercury oxidation efficiency was obtained at 150 °C. The inhibition effect of NH3 on Hg(0) oxidation was confirmed in that NH3 consumed the surface oxygen. Moreover, H2O inhibited Hg(0) oxidation while SO2 had a promotional effect with the aid of O2. The XPS results illustrated that the surface oxygen was responsible for Hg(0) oxidation and NO conversion. Besides, the Hg(0) oxidation and NO conversion were thought to be aided by synergistic effect between the manganese and cerium oxides.

  20. Oxidation of electrodeposited black chrome selective solar absorber films

    SciTech Connect

    Holloway, P.H.; Shanker, K.; Pettit, R.B.; Sowell, R.R.

    1980-01-01

    X-ray photoelectron and Auger electron spectroscopies have been used to study the composition and oxidation of electrodeposited black chrome films. The outer layer of the film is Cr/sub 2/O/sub 3/ with the inner layer being a continuously changing mixture of Cr + Cr/sub 2/O/sub 3/. Initially, approximately 40% by volume of the film is combined as Cr/sub 2/O/sub 3/, and the volume percentage of Cr/sub 2/O/sub 3/ increases to greater than 60% after only 136 hours at 250/sup 0/C. After approximately 3600 hours at 400/sup 0/C, the volume percentage of Cr/sub 2/O/sub 3/ increased to as high as 80%. The thermal emittance decreased approximately linearly with increasing oxide content, while the solar absorptance remained constant until the percentage of Cr/sub 2/O/sub 3/ exceeded approximately 70%. Oxidation was slower when the Cr/sup +3/ concentration in the plating bath was reduced from 16 g/l to 8 g/l, and when black chrome was deposited on stainless steel rather than sulfamate nickel.

  1. Microbial conversion of coal

    SciTech Connect

    Bean, R.M. )

    1989-10-01

    The objectives of this project were to describe in detail the degradation of coals by fungi and microbes, to expand the range of applicability of the process to include new microbes and other coal types, to identify the means by which biosolubilization of coal is accomplished, and to explore means to enhance the rates and extent of coal bioconversion. The project was initiated in a response to the discovery by Dr. Martin Cohen at the University of Hartford, of a fungal strain of Coriolus versicolor that would render a solid coal substance, leonardite, into a liquid product. The project has identified the principal agent of leonardite solubilization as a powerful metal chelator, most likely a fungal-produced siderophore. Another nonlaccase enzyme has also been identified as a unique biosolubilizing agent produced by C. versicolor. Assays were developed for the quantitative determination of biological coal conversion, and for the determination of potency of biosolubilizing agent. Screening studies uncovered several microbial organisms capable of coal biodegradation, and led to the discovery that prolonged heating in air at the moderate temperature of 150{degree}C allowed the biodegradation of Illinois {number sign}6 coal to material soluble in dilute base. Chemical studies showed that leonardite biosolubilization was accompanied by relatively small change in composition, while solubilization of Illinois {number sign}6 coal involves considerable oxidation of the coal. 24 refs., 32 figs., 27 tabs.

  2. Microbial solubilization of coals

    SciTech Connect

    Campbell, J.A.; Fredrickson, J.K.; Stewart, D.L.; Thomas, B.L.; McCulloch, M.; Wilson, B.W.; Bean, R.M.

    1988-11-01

    Microbial solubilization of coal may serve as a first step in a process to convert low-rank coals or coal-derived products to other fuels or products. For solubilization of coal to be an economically viable technology, a mechanistic understanding of the process is essential. Leonardite, a highly oxidized, low-rank coal, has been solubilized by the intact microorganism, cell-free filtrate, and cell-free enzyme of /ital Coriolus versicolor/. A spectrophotometric conversion assay was developed to quantify the amount of biosolubilized coal. In addition, a bituminous coal, Illinois No. 6, was solubilized by a species of /ital Penicillium/, but only after the coal had been preoxidized in air. Model compounds containing coal-related functionalities have been incubated with the leonardite-degrading fungus, its cell-free filtrate, and purified enzyme. The amount of degradation was determined by gas chromatography and the degradation products were identified by gas chromatography/mass spectrometry. We have also separated the cell-free filtrate of /ital C. versicolor/ into a <10,000 MW and >10,000 MW fraction by ultrafiltration techniques. Most of the coal biosolubilization activity is contained in the <10,000 MW fraction while the model compound degradation occurs in the >10,000 MW fraction. The >10,000 MW fraction appears to contain an enzyme with laccase-like activity. 10 refs., 8 figs., 5 tabs.

  3. Process for hydrogenating coal and coal solvents

    DOEpatents

    Tarrer, Arthur R.; Shridharani, Ketan G.

    1983-01-01

    A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260.degree. C. to 315.degree. C. in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275.degree. C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350.degree. C.

  4. Mechanism of the selective catalytic oxidation of slip ammonia over Ru-modified Ce-Zr complexes determined by in situ diffuse reflectance infrared Fourier transform spectroscopy.

    PubMed

    Chen, Wanmiao; Ma, Yongpeng; Qu, Zan; Liu, Qinghang; Huang, Wenjun; Hu, Xiaofang; Yan, Naiqiang

    2014-10-21

    The slip ammonia from selective catalytic reduction (SCR) of NOx in coal-fired flue gas can result in deterioration of the utilities or even the environmental issues. To achieve selective catalytic oxidation (SCO) of slip ammonia, Ru-modified Ce-Zr solid solution catalysts were prepared and evaluated under various conditions. It was found that the Ru/Ce(0.6)Zr(0.4)O2(polyvinylpyrrolidone (PVP)) catalyst displayed significant catalytic activity and the slip ammonia was almost completely removed with the coexistence of NOx and SO2. Interestingly, the effect of SO2 on NH3 oxidation was bifacial, and the N2 selectivity of the resulting products was as high as 100% in the presence of SO2 and NH3. The mechanism of the SCO of NH3 over Ru/Ce(0.6)Zr(0.4)O2(PVP) was studied using various techniques, and the results showed that NH3 oxidation follows an internal SCR (iSCR) mechanism. The adsorbed ammonia was first activated and reacted with lattice oxygen atoms to form an -HNO intermediate. Then, the -HNO mainly reacted with atomic oxygen from O2 to form NO. Meanwhile, the formed NO interacted with -NH2 to N2 with N2O as the byproduct, but the presence of SO2 can effectively inhibit the production of N2O.

  5. Kinetic features and industrial prospects of the selective oxidative cracking of light alkanes

    NASA Astrophysics Data System (ADS)

    Arutyunov, V. S.; Savchenko, V. I.; Sedov, I. V.; Nikitin, A. V.; Magomedov, R. N.; Proshina, A. Yu

    2017-01-01

    The results of kinetic investigations of selective oxidative cracking of light alkanes are analyzed and integrated. This process attracts researchers' attention owing to possible opportunities for designing new industrial processes based on light hydrocarbon feed. Particular attention is paid to ethane for which comprehensive and adequate models of oxidative conversion suitable for detailed analysis of the process kinetics have already been developed. The prospects for the practical application of methane homologues present in natural and associated gases in the selective oxidative cracking are discussed. The bibliography includes 85 references.

  6. Mode of occurrence of chromium in four US coals

    USGS Publications Warehouse

    Huggins, Frank E.; Shah, N.; Huffman, G.P.; Kolker, A.; Crowley, S.; Palmer, C.A.; Finkelman, R.B.

    2000-01-01

    The mode of occurrence of chromium in three US bituminous coals and one US subbituminous has been examined using both X-ray absorption fine structure (XAFS) spectroscopy and a selective leaching protocol supplemented by scanning electron microscopy (SEM) and electron microprobe measurements. A synthesis of results from both methods indicates that chromium occurs principally in two forms in the bituminous coals: the major occurrence of chromium is associated with the macerals and is not readily leached by any reagent, whereas a second, lesser occurrence, which is leachable in hydrofluoric acid (HF), is associated with the clay mineral, illite. The former occurrence is believed to be a small particle oxyhydroxide phase (CrO(OH)). One coal also contained a small fraction (<5%) of the chromium in the form of a chromian magnetite, and the leaching protocol indicated the possibility of a similar small fraction of chromium in sulfide form in all three coals. There was little agreement between the two techniques on the mode of occurrence of chromium in the subbituminous coal; however, only a limited number of subbituminous coals have been analyzed by either technique. The chromium in all four coals was trivalent as no evidence was found for the Cr6+ oxidation state in any coal.

  7. Highly dispersible edge-selectively oxidized graphene with improved electrical performance.

    PubMed

    Park, Jisoo; Kim, Yern Seung; Sung, Sae Jin; Kim, Taehoon; Park, Chong Rae

    2017-01-26

    We prepared liquid phase exfoliated edge-selectively oxidized graphene (LPEOG) with a high concentration in water (∼14.7 mg ml(-1)) and a high ratio of a single layer (70%). The edge of graphite was selectively oxidized by step II oxidation of the modified Hummers method, and we subsequently exfoliated the edge-selectively oxidized graphite (EOG) into LPEOG. The edge selective oxidation of the LPEOG was confirmed by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), zeta-potentiometry, Raman spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The highly concentrated LPEOG ink can be used in solution processing such as simple drawing or spin casting. Reduced LPEOG showed a higher conductivity (120 000 S m(-1)) than that of reduced graphene oxide (68 800 S m(-1)) despite the small lateral size. A transparent conducting film prepared from the LPEOG ink showed a lower surface resistance (∼2.97 kΩ sq(-1)) at a higher transmittance (>83.0 %T) compared to those of the graphene oxide based film. These results indicate that preservation of π-conjugation of the basal plane of graphene is critical for electrical performance of graphene. Our method facilitates solution processing of graphene for a wide range of applications.

  8. Comparative analysis of the influence of turbulence models on the description of the nitrogen oxides formation during the combustion of swirling pulverized coal flow

    NASA Astrophysics Data System (ADS)

    Kuznetsov, V.; Chernetskaya, N.; Chernetskiy, M.

    2016-10-01

    The paper presents the results of numerical research on the influence of the two- parametric k-ε, and k-ω SST turbulence models as well as Reynolds stress model (RSM) on the description of the nitrogen oxides formation during the combustion of pulverized coal in swirling flow. For the numerical simulation of turbulent flow of an incompressible liquid, we used the Reynolds equation taking into account the interfacial interactions. To solve the equation of thermal radiation transfer, the P1 approximation of spherical harmonics method was employed. The optical properties of gases were described based on the sum of gray gases model. To describe the motion of coal particles we used the method of Lagrange multipliers. Burning of coke residue was considered based on diffusion - kinetic approximation. Comparative analysis has shown that the choice of turbulence model has a significant impact on the root mean square (RMS) values of the velocity and temperature pulsation components. This leads to significant differences in the calculation of the nitrogen oxides formation process during the combustion of pulverized coal.

  9. An assessment of zinc oxide nanosheets as a selective adsorbent for cadmium

    PubMed Central

    2013-01-01

    Zinc oxide nanosheet is assessed as a selective adsorbent for the detection and adsorption of cadmium using simple eco-friendly extraction method. Pure zinc oxide nanosheet powders were characterized using field emission scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The zinc oxide nanosheets were applied to different metal ions, including Cd(II), Cu(II), Hg(II), La(III), Mn(II), Pb(II), Pd(II), and Y(III). Zinc oxide nanosheets were found to be selective for cadmium among these metal ions when determined by inductively coupled plasma-optical emission spectrometry. Moreover, adsorption isotherm data provided that the adsorption process was mainly monolayer on zinc oxide nanosheets. PMID:24011201

  10. Iron Complex Catalyzed Selective C-H Bond Oxidation with Broad Substrate Scope.

    PubMed

    Jana, Sandipan; Ghosh, Munmun; Ambule, Mayur; Sen Gupta, Sayam

    2017-02-17

    The use of a peroxidase-mimicking Fe complex has been reported on the basis of the biuret-modified TAML macrocyclic ligand framework (Fe-bTAML) as a catalyst to perform selective oxidation of unactivated 3° C-H bonds and activated 2° C-H bonds with low catalyst loading (1 mol %) and high product yield (excellent mass balance) under near-neutral conditions and broad substrate scope (18 substrates which includes arenes, heteroaromatics, and polar functional groups). Aliphatic C-H oxidation of 3° and 2° sites of complex substrates was achieved with predictable selectivity using steric, electronic, and stereoelectronic rules that govern site selectivity, which included oxidation of (+)-artemisinin to (+)-10β-hydroxyartemisinin. Mechanistic studies indicate Fe(V)(O) to be the active oxidant during these reactions.

  11. Selective air oxidation of cyclohexane in supercritical CO{sub 2}

    SciTech Connect

    Luan, Li; Buelow, S.J.; Tumas, W.

    1996-12-31

    We have explored the use of molecular oxygen as the oxidant for the selective oxidation of cyclohexane using cobalt catalysts in supercritical CO{sub 2}. We have chosen to use supercritial CO{sub 2} as a co-solvent for reasons: (1) oxygen, cyclohexane and acetic acid are miscible in supercritical CO{sub 2} and therefore oxidation can occur in a homogeneous phase; (2) C02 is inert for oxidation and can be easily separated from the reaction mixture; (3) CO{sub 2} is environmentally benign. Adipic acid was formed at 80 % selectivity with 5% conversion. Reaction rates and product selectivity will be reported as a function of temperature and pressure.

  12. Sulfur Tolerant Solid Oxide Fuel Cell for Coal Syngas Application: Experimental Study on Diverse Impurity Effects and Fundamental Modeling of Electrode Kinetics

    NASA Astrophysics Data System (ADS)

    Gong, Mingyang

    With demand over green energy economy, fuel cells have been developed as a promising energy conversion technology with higher efficiency and less emission. Solid oxide fuel cells (SOFC) can utilize various fuels in addition to hydrogen including coal derived sygas, and thus are favored for future power generation due to dependence on coal in electrical industry. However impurities such as sulfur and phosphorous present in coal syngas in parts per million (p.p.m.) levels can severely poison SOFC anode typically made of Ni/yttria-stabilized-zirconia (Ni-YSZ) and limit SOFC applicability in economically derivable fuels. The focus of the research is to develop strategy for application of high performance SOFC in coal syngas with tolerance against trace impurities such as H2S and PH3. To realize the research goal, the experimental study on sulfur tolerant anode materials and examination of various fuel impurity effects on SOFC anode are combined with electrochemical modeling of SOFC cathode kinetics in order to benefit design of direct-coal-syngas SOFC. Tolerant strategy for SOFC anode against sulfur is studied by using alternative materials which can both mitigate sulfur poisoning and function as active anode components. The Ni-YSZ anode was modified by incorporation of lanthanum doped ceria (LDC) nano-coatings via impregnation. Cell test in coal syngas containing 20 ppm H2S indicated the impregnated LDC coatings inhibited on-set of sulfur poisoning by over 10hrs. Cell analysis via X-ray photon spectroscopy (XPS), X-ray diffraction (XRD) and electrochemistry revealed LDC coatings reacted with H2S via chemisorptions, resulting in less sulfur blocking triple--phase-boundary and minimized performance loss. Meanwhile the effects of PH3 impurity on SOFC anode is examined by using Ni-YSZ anode supported SOFC. Degradation of cell is found to be irreversible due to adsorption of PH3 on TPB and further reaction with Ni to form secondary phases with low melting point. The

  13. Homogeneous and heterogeneous reactions of anthracene with selected atmospheric oxidants.

    PubMed

    Zhang, Yang; Shu, Jinian; Zhang, Yuanxun; Yang, Bo

    2013-09-01

    The reactions of gas-phase anthracene and suspended anthracene particles with O3 and O3-NO were conducted in a 200-L reaction chamber, respectively. The secondary organic aerosol (SOA) formations from gas-phase reactions of anthracene with O3 and O3-NO were observed. Meanwhile, the size distributions and mass concentrations of SOA were monitored with a scanning mobility particle sizer (SMPS) during the formation processes. The rapid exponential growths of SOA reveal that the atmospheric lifetimes of gas-phase anthracene towards O3 and O3-NO are less than 20.5 and 4.34 hr, respectively. The particulate oxidation products from homogeneous and heterogeneous reactions were analyzed with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUV-ATOFMS). Gas chromatograph/mass spectrometer (GC/MS) analyses of oxidation products of anthracene were carried out for assigning the time-of-flight (TOF) mass spectra of products from homogeneous and heterogeneous reactions. Anthrone, anthraquinone, 9,10-dihydroxyanthracene, and 1,9,10-trihydroxyanthracene were the ozonation products of anthracene, while anthrone, anthraquinone, 9-nitroanthracene, and 1,8-dihydroxyanthraquinone were the main products of anthracene with O3-NO.

  14. Endotoxin inactivation by selected drinking water treatment oxidants.

    PubMed

    Anderson, William B; Mayfield, Colin I; Dixon, D George; Huck, Peter M

    2003-11-01

    Exposure to endotoxins in treated drinking water can occur through ingestion, dermal abrasions, inhalation of water vapor, intravenous injection or during dialysis. While the risks associated with endotoxin ingestion and entry through dermal abrasions are not well quantified, adverse effects of intravenous injection and dialysis are well known and some studies indicate that inhalation of moisture-laden air may impact human health. This study quantifies the inactivation of endotoxin derived from Escherichia coli O55:B5 by three substances used either as disinfectants or oxidants in drinking water treatment: chlorine, monochloramine and potassium permanganate. Inactivation rates were found to be 1.4, 1.0 and 0.7 endotoxin units (EU)/mL h, for free chlorine, potassium permanganate and monochloramine, respectively. These rates are relatively slow given that contact times in drinking water distribution systems are typically less than 48 h. While small amounts of endotoxin may be removed by oxidation the observed removals are much less than those provided by physical removal processes. The significance of this finding is important for dialysis considerations but is as yet unclear with regard to inhalation, as the risk of inhaling sufficient quantities of endotoxin-containing aerosolized water droplets to adversely affect human health has not yet been adequately quantified.

  15. Development of Nanofiller-Modulated Polymeric Oxygen Enrichment Membranes for Reduction of Nitrogen Oxides in Coal Combustion

    SciTech Connect

    Jianzhong Lou; Shamsuddin Ilias

    2010-12-31

    North Carolina A&T State University in Greensboro, North Carolina, has undertaken this project to develop the knowledge and the material to improve the oxygen-enrichment polymer membrane, in order to provide high-grade oxygen-enriched streams for coal combustion and gasification applications. Both experimental and theoretical approaches were used in this project. The membranes evaluated thus far include single-walled carbon nano-tube, nano-fumed silica polydimethylsiloxane (PDMS), and zeolite-modulated polyimide membranes. To document the nanofiller-modulated polymer, molecular dynamics simulations have been conducted to calculate the theoretical oxygen molecular diffusion coefficient and nitrogen molecular coefficient inside single-walled carbon nano-tube PDMS membranes, in order to predict the effect of the nano-tubes on the gas-separation permeability. The team has performed permeation and diffusion experiments using polymers with nano-silica particles, nano-tubes, and zeolites as fillers; studied the influence of nano-fillers on the self diffusion, free volume, glass transition, oxygen diffusion and solubility, and perm-selectivity of oxygen in polymer membranes; developed molecular models of single-walled carbon nano-tube and nano-fumed silica PDMS membranes, and zeolites-modulated polyimide membranes. This project partially supported three graduate students (two finished degrees and one transferred to other institution). This project has resulted in two journal publications and additional publications will be prepared in the near future.

  16. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide emissions from coal-fired boilers

    SciTech Connect

    Sorge, J.N.; Larrimore, C.L.; Slatsky, M.D.; Menzies, W.R.; Smouse, S.M.; Stallings, J.W.

    1997-12-31

    This paper discusses the technical progress of a US Department of Energy Innovative Clean Coal Technology project demonstrating advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. The primary objectives of the demonstration is to determine the long-term NOx reduction performance of advanced overfire air (AOFA), low NOx burners (LNB), and advanced digital control optimization methodologies applied in a stepwise fashion to a 500 MW boiler. The focus of this paper is to report (1) on the installation of three on-line carbon-in-ash monitors and (2) the design and results to date from the advanced digital control/optimization phase of the project.

  17. The effect of coal syngas containing HCl on the performance of solid oxide fuel cells: Investigations into the effect of operational temperature and HCl concentration

    NASA Astrophysics Data System (ADS)

    Trembly, J. P.; Gemmen, R. S.; Bayless, D. J.

    The performance of solid oxide fuel cells (SOFCs) using simulated coal-derived syngas, with and without hydrogen chloride (HCl), was studied. Electrolyte-supported SOFCs were tested potentiostatically at 0.7 V at 800 and 900 °C with simulated coal syngas containing 0, 20, and 160 ppm HCl. The results from the tests without HCl show good performance with little degradation over 100 h of operation. Both 20 and 160 ppm HCl were shown to cause performance losses in the SOFCs after injection into the system. Although the tests presented in this paper show that HCl does cause degradation to SOFC performance, the cell performance was recoverable upon the removal of HCl from the fuel. Also recent results from anticipated Integrated Gasification Combined Cycle IGCC warm/hot-gas-cleanup technologies suggest that HCl will be removed to levels that will not cause any significant performance losses in SOFCs.

  18. Selective chemical modification of silicon nitride/silicon oxide nanostructures to develop label-free biosensors.

    PubMed

    Bañuls, María-José; González-Pedro, Victoria; Barrios, Carlos A; Puchades, Rosa; Maquieira, Angel

    2010-02-15

    The selective introduction of functional groups on the surface of silicon nitride/silicon oxide nanostructures was studied. Chemical strategies based on organosilane, Si-H and N-H reactivities were assayed. Among these strategies, the use of glutaraldehyde to selectively immobilize biomolecules only on the silicon nitride part of the chip surface was the most effective for the covalent attachment of proteins, maintaining also their bioavailability. The biomolecule surface coverage results up to 80% and the modification is selective versus silicon oxide; the biomolecule attaching only to silicon nitride and leaving the silicon oxide area of the device unmodified. The effectiveness of our novel selective surface modification procedure is also supported by comparing experimental and numerical calculations of the optical performance of a label-free optical ring resonator based on Si(3)N(4)/SiO(2) slot-waveguides.

  19. Understanding selected trace elements behavior in a coal-fired power plant in Malaysia for assessment of abatement technologies.

    PubMed

    Mokhtar, Mutahharah M; Taib, Rozainee M; Hassim, Mimi H

    2014-08-01

    The Proposed New Environmental Quality (Clean Air) Regulation 201X (Draft), which replaces the Malaysia Environmental Quality (Clean Air) 1978, specifies limits to additional pollutants from power generation using fossil fuel. The new pollutants include Hg, HCl, and HF with limits of 0.03, 100, and 15 mg/N-m3 at 6% O2, respectively. These pollutants are normally present in very small concentrations (known as trace elements [TEs]), and hence are often neglected in environmental air quality monitoring in Malaysia. Following the enactment of the new regulation, it is now imperative to understand the TEs behavior and to assess the capability of the existing abatement technologies to comply with the new emission limits. This paper presents the comparison of TEs behavior of the most volatile (Hg, Cl, F) and less volatile (As, Be, Cd, Cr, Ni, Se, Pb) elements in subbituminous and bituminous coal and coal combustion products (CCP) (i.e., fly ash and bottom ash) from separate firing of subbituminous and bituminous coal in a coal-fired power plant in Malaysia. The effect of air pollution control devices configuration in removal of TEs was also investigated to evaluate the effectiveness of abatement technologies used in the plant. This study showed that subbituminous and bituminous coals and their CCPs have different TEs behavior. It is speculated that ash content could be a factor for such diverse behavior In addition, the type of coal and the concentrations of TEs in feed coal were to some extent influenced by the emission of TEs in flue gas. The electrostatic precipitator (ESP) and seawater flue gas desulfurization (FGD) used in the studied coal-fired power plant were found effective in removing TEs in particulate and vapor form, respectively, as well as complying with the new specified emission limits. Implications: Coals used by power plants in Peninsular Malaysia come from the same supplier (Tenaga Nasional Berhad Fuel Services), which is a subsidiary of the Malaysia

  20. In situ vibrational spectroscopic investigation of C4 hydrocarbon selective oxidation over vanadium-phosphorus-oxide catalysts

    SciTech Connect

    Xue, Zhi -Yang

    1999-05-10

    n-Butane selective oxidation over the VPO catalyst to maleic anhydride is the first and only commercialized process of light alkane selective oxidation. The mechanism of this reaction is still not well known despite over twenty years of extensive studies, which can partially be attributed to the extreme difficulties to characterize catalytic reactions real-time under typical reaction conditions. In situ spectroscopic characterization techniques such as Infrared spectroscopy and laser Raman spectroscopy were used in the current mechanistic investigations of n-butane oxidation over VPO catalysts. To identify the reaction intermediates, oxidation of n-butane, 1,3-butadiene and related oxygenates on the VPO catalyst were monitored using FTIR spectroscopy under transient conditions. n-Butane was found to adsorb on the VPO catalyst to form olefinic species, which were further oxidized to unsaturated, noncyclic carbonyl species. The open chain dicarbonyl species then experienced cycloaddition to form maleic anhydride. VPO catalyst phase transformations were investigated using in situ laser Raman spectroscopy. This report contains Chapter 1: General introduction; Chapter 2: Literature review; and Chapter 5: Conclusion and recommendations.

  1. Partitioning of mercury, arsenic, selenium, boron, and chloride in a full-scale coal combustion process equipped with selective catalytic reduction, electrostatic precipitation, and flue gas desulfurization systems

    SciTech Connect

    Chin-Min Cheng; Pauline Hack; Paul Chu; Yung-Nan Chang; Ting-Yu Lin; Chih-Sheng Ko; Po-Han Chiang; Cheng-Chun He; Yuan-Min Lai; Wei-Ping Pan

    2009-09-15

    A full-scale field study was carried out at a 795 MWe coal-fired power plant equipped with selective catalytic reduction (SCR), an electrostatic precipitator (ESP), and wet flue gas desulfurization (FGD) systems to investigate the distribution of selected trace elements (i.e., mercury, arsenic, selenium, boron, and chloride) from coal, FGD reagent slurry, makeup water to flue gas, solid byproduct, and wastewater streams. Flue gases were collected from the SCR outlet, ESP inlet, FGD inlet, and stack. Concurrent with flue gas sampling, coal, bottom ash, economizer ash, and samples from the FGD process were also collected for elemental analysis. By combining plant operation parameters, the overall material balances of selected elements were established. The removal efficiencies of As, Se, Hg, and B by the ESP unit were 88, 56, 17, and 8%, respectively. Only about 2.5% of Cl was condensed and removed from flue gas by fly ash. The FGD process removed over 90% of Cl, 77% of B, 76% of Hg, 30% of Se, and 5% of As. About 90% and 99% of the FGD-removed Hg and Se were associated with gypsum. For B and Cl, over 99% were discharged from the coal combustion process with the wastewater. Mineral trona (trisodium hydrogendicarbonate dehydrate, Na{sub 3}H(CO{sub 3}){sub 2}.2H{sub 2}O) was injected before the ESP unit to control the emission of sulfur trioxide (SO{sub 3}). By comparing the trace elements compositions in the fly ash samples collected from the locations before and after the trona injection, the injection of trona did not show an observable effect on the partitioning behaviors of selenium and arsenic, but it significantly increased the adsorption of mercury onto fly ash. The stack emissions of mercury, boron, selenium, and chloride were for the most part in the gas phase. 47 refs., 3 figs., 11 tabs.

  2. Gasification of coal liquefaction residues

    SciTech Connect

    Lancet, M. S.

    1981-02-03

    A method is described for gasifying the bottoms fraction from a coal liquefaction process. The bottoms fraction are mixed with at least one finely-divided calcium compound selected from the group consisting of calcium oxide, calcium carbonate and calcium hydroxide with the calcium compound being of a size no larger than about -200 tyler mesh and present in an amount sufficient to produce agglomerate particles upon mixing with the bottoms fraction and thereafter the resulting agglomerate particles are gasified by reacting the agglomerate particles with steam in a fluidized bed.

  3. Selective oxidation of methanol to hydrogen over gold catalysts promoted by alkaline-earth-metal and lanthanum oxides.

    PubMed

    Hereijgers, Bart P C; Weckhuysen, Bert M

    2009-01-01

    A series of alumina-supported gold catalysts was investigated for the CO-free production of hydrogen by partial oxidation of methanol. The addition of alkaline-earth metal oxide promoters resulted in a significant improvement of the catalytic performance. The methanol conversion was ca. 85 % with all studied catalyst materials, however, the selectivity for hydrogen increased from 15 % to 51 % when going from the unpromoted to a BaO-promoted catalyst. The formation of the undesired byproducts CO, methane, and dimethyl ether was considerably reduced as well. The observed trend in catalyst performance follows the trend in increasing basicity of the studied promoter elements, indicating a chemical effect of the promoter material. Superior catalytic performance, in terms of H(2) and CO selectivity, was obtained with a Au/La(2)O(3) catalyst. At 300 degrees C the hydrogen selectivity reached 80 % with only 2 % CO formation, and the catalyst displayed a stable performance over at least 24 h on-stream. Furthermore, the formation of CO was found to be independent of the oxygen concentration in the feed. The commercial lanthanum oxide used in this study had a low specific surface area, which led to the formation of relative large gold particles. Therefore, the catalytic activity could be enhanced by decreasing the gold particle size through deposition on lanthanum oxide supported on high-surface-area alumina.

  4. CO2 hydrogenation over oxide-supported PtCo catalysts: The role of the oxide support in determining the product selectivity

    DOE PAGES

    Kattel, Shyam; Yu, Weiting; Yang, Xiaofang; ...

    2016-05-09

    By simply changing the oxide support, the selectivity of a metal–oxide catalysts can be tuned. For the CO2 hydrogenation over PtCo bimetallic catalysts supported on different reducible oxides (CeO2, ZrO2, and TiO2), replacing a TiO2 support by CeO2 or ZrO2 selectively strengthens the binding of C,O-bound and O-bound species at the PtCo–oxide interface, leading to a different product selectivity. Lastly, these results reveal mechanistic insights into how the catalytic performance of metal–oxide catalysts can be fine-tuned.

  5. CO2 Hydrogenation over Oxide-Supported PtCo Catalysts: The Role of the Oxide Support in Determining the Product Selectivity.

    PubMed

    Kattel, Shyam; Yu, Weiting; Yang, Xiaofang; Yan, Binhang; Huang, Yanqiang; Wan, Weiming; Liu, Ping; Chen, Jingguang G

    2016-07-04

    By simply changing the oxide support, the selectivity of a metal-oxide catalysts can be tuned. For the CO2 hydrogenation over PtCo bimetallic catalysts supported on different reducible oxides (CeO2 , ZrO2 , and TiO2 ), replacing a TiO2 support by CeO2 or ZrO2 selectively strengthens the binding of C,O-bound and O-bound species at the PtCo-oxide interface, leading to a different product selectivity. These results reveal mechanistic insights into how the catalytic performance of metal-oxide catalysts can be fine-tuned.

  6. Coal liquefaction process

    DOEpatents

    Carr, Norman L.; Moon, William G.; Prudich, Michael E.

    1983-01-01

    A C.sub.5 -900.degree. F. (C.sub.5 -482.degree. C.) liquid yield greater than 50 weight percent MAF feed coal is obtained in a coal liquefaction process wherein a selected combination of higher hydrogen partial pressure, longer slurry residence time and increased recycle ash content of the feed slurry are controlled within defined ranges.

  7. Evaluation of transition metal oxide as carrier-selective contacts for silicon heterojunction solar cells

    SciTech Connect

    Ding, L.; Boccard, Matthieu; Holman, Zachary; Bertoni, M.

    2015-04-06

    "Reducing light absorption in the non-active solar cell layers, while enabling the extraction of the photogenerated minority carriers at quasi-Fermi levels are two key factors to improve current generation and voltage, and therefore efficiency of silicon heterojunction solar devices. To address these two critical aspects, transition metal oxide materials have been proposed as alternative to the n- and p-type amorphous silicon used as electron and hole selective contacts, respectively. Indeed, transition metal oxides such as molybdenum oxide, titanium oxide, nickel oxide or tungsten oxide combine a wide band gap typically over 3 eV with a band structure and theoretical band alignment with silicon that results in high transparency to the solar spectrum and in selectivity for the transport of only one carrier type. Improving carrier extraction or injection using transition metal oxide has been a topic of investigation in the field of organic solar cells and organic LEDs; from these pioneering works a lot of knowledge has been gained on materials properties, ways to control these during synthesis and deposition, and their impact on device performance. Recently, the transfer of some of this knowledge to silicon solar cells and the successful application of some metal oxide to contact heterojunction devices have gained much attention. In this contribution, we investigate the suitability of various transition metal oxide films (molybdenum oxide, titanium oxide, and tungsten oxide) deposited either by thermal evaporation or sputtering as transparent hole or electron selective transport layer for silicon solar cells. In addition to systematically characterize their optical and structural properties, we use photoemission spectroscopy to relate compound stoichiometry to band structure and characterize band alignment to silicon. The direct silicon/metal oxide interface is further analyzed by quasi-steady state photoconductance decay method to assess the quality of surface

  8. Selective Inhibition of the Oxidation of Ferrous Iron or Sulfur in Thiobacillus ferrooxidans

    PubMed Central

    Harahuc, Lesia; Lizama, Hector M.; Suzuki, Isamu

    2000-01-01

    The oxidation of either ferrous iron or sulfur by Thiobacillus ferrooxidans was selectively inhibited or controlled by various anions, inhibitors, and osmotic pressure. Iron oxidation was more sensitive than sulfur oxidation to inhibition by chloride, phosphate, and nitrate at low concentrations (below 0.1 M) and also to inhibition by azide and cyanide. Sulfur oxidation was more sensitive than iron oxidation to the inhibitory effect of high osmotic pressure. These differences were evident not only between iron oxidation by iron-grown cells and sulfur oxidation by sulfur-grown cells but also between the iron and sulfur oxidation activities of the same iron-grown cells. Growth experiments with ferrous iron or sulfur as an oxidizable substrate confirmed the higher sensitivity of iron oxidation to inhibition by phosphate, chloride, azide, and cyanide. Sulfur oxidation was actually stimulated by 50 mM phosphate or chloride. Leaching of Fe and Zn from pyrite (FeS2) and sphalerite (ZnS) by T. ferrooxidans was differentially affected by phosphate and chloride, which inhibited the solubilization of Fe without significantly affecting the solubilization of Zn. PMID:10698768

  9. Assessment of coal-water slurry fuels for electric power generation in Southern Indiana: Part 1, Detailed resource characterization

    SciTech Connect

    Daniel, D.N.; Harvey, C.; Dazhen, T.

    1997-07-01

    Impounded coal fines, a by-product of wet coal preparation techniques, are a potential fuel resource for electric power generation due to their abundance and characteristics when burned as a coal-water slurry fuel (CWSF). Recent work by the Pennsylvania Electric Company and others has shown that co-firing CWSF composed of cleaned material from slurry impoundments can reduce emissions of nitrogen oxides by as much as twenty percent. The commercial reality of using impounded coal fines as a CWSF depends more on coal cost, processing requirements, and the value of emission reduction credits than on the quality or abundance of the material. Many Southern Indiana slurry impoundments, including those selected for characterization in this study, contain over one-million tons of fine coal. The older impoundments have a higher percentage of coarse coal. One impoundment filled prior to 1975 averages fifty percent coal particles greater than 30 mesh (600 {mu}). Improvements in preparation plant fine coal recovery circuits are reflected by an increasing percentage of less than 200 mesh (75 {mu}) coal in more recently filled impoundments. Another impoundment filled in 1995 averages forty-nine percent coal and mineral particles finer than 200 mesh. Bench scale sink/float testing showed that separating particles with a specific gravity greater than 1.7 produced a fine coal with ten percent ash and three percent sulfur. This is similar in quality, but finer in particle size, to the coal currently used in a typical coal fired power station burning typical Illinois Basin coals. Detailed characterization of two inactive impoundments highlighted the differences between coal fines in an older impoundment and one filled in the last ten years.

  10. DEVELOPMENT OF IMPROVED CATALYSTS FOR THE SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDES WITH HYDROCARBONS

    SciTech Connect

    Dr. Ates Akyurlu; Dr. Jale F. Akyurtlu

    2003-01-28

    Significant work has been done by the investigators on the cerium oxide-copper oxide based sorbent/catalysts for the combined removal of sulfur and nitrogen oxides from the flue gases of stationary sources. A relatively wide temperature window was established for the use of alumina-supported cerium oxide-copper oxide mixtures as regenerable sorbents for SO{sub 2} removal. Evaluation of these sorbents as catalysts for the selective reduction of NO{sub x} gave promising results with methane. Since the replacement of ammonia by methane is commercially very attractive, in this project, it was planned to investigate the effect of promoters on the activity and selectivity of copper oxide/cerium oxide-based catalysts and to obtain data on the reaction mechanism for the SCR with methane. The investigation of the reaction mechanism will help in the selection of promoters to improve the catalytic activity and selectivity of the sorbents in the SCR with methane. This will result in new catalyst formulations. The last component of the project involves our industrial partner TDA Research, and the objective is to evaluate long- term stability and durability of the prepared sorbent/catalysts. In the second year of the project, the catalysts were investigated for their SCR activity with methane in a microreactor setup and also, by the temperature-programmed desorption (TPD) technique. The results from the SCR experiments indicated that manganese is a more effective promoter than rhodium on the supported copper oxide-ceria catalysts under study; the effectiveness of the promoter increases with the increase in Ce/Cu ratio. The TPD profiles of the unpromoted catalyst (Cu/Ce=3) is different than those promoted with 0.1% rhodium. In the current reporting period, the screening of the promoted catalysts were completed, sufficient amount of the selected catalysts were prepared and delivered to TDA for long term deactivation testing.

  11. Selective Autooxidation of Ethanol over Titania-Supported Molybdenum Oxide Catalysts: Structure and Reactivity

    PubMed Central

    Caro, Carlos; Thirunavukkarasu, K; Anilkumar, M; Shiju, N R; Rothenberg, Gadi

    2012-01-01

    We study the selective catalytic oxidation of ethanol with air as a sustainable alternative route to acetaldehyde. The reaction is catalysed by molybdenum oxide supported on titania, in a flow reactor under ambient pressure. High selectivity to acetaldehyde (70%–89%, depending on the Mo loading) is obtained at 150 °C. Subsequently, we investigate the structure/performance relationship for various molybdenum oxide species using a combination of techniques including diffuse reflectance UV-visible, infrared, X-ray photoelectron spectroscopies, X-ray diffraction and temperature programmed reduction. As their surface density increases, the monomeric molybdenum oxide species undergo two-dimensional and three-dimensional oligomerisation. This results in polymolybdates and molybdenum oxide crystallites. Importantly, the ethanol oxidation rate depends not only on the overall molybdenum loading and dispersion, but also on the type of molybdenum oxide species prevalent at each surface density and on the domain size. As the molybdenum oxide oligomerisation increases, electron delocalisation becomes easier. This lowers the absorption edge energy and increases the reaction rate. PMID:23396482

  12. Clean coal

    SciTech Connect

    Liang-Shih Fan; Fanxing Li

    2006-07-15

    The article describes the physics-based techniques that are helping in clean coal conversion processes. The major challenge is to find a cost- effective way to remove carbon dioxide from the flue gas of power plants. One industrially proven method is to dissolve CO{sub 2} in the solvent monoethanolamine (MEA) at a temperature of 38{sup o}C and then release it from the solvent in another unit when heated to 150{sup o}C. This produces CO{sub 2} ready for sequestration. Research is in progress with alternative solvents that require less energy. Another technique is to use enriched oxygen in place of air in the combustion process which produces CO{sub 2} ready for sequestration. A process that is more attractive from an energy management viewpoint is to gasify coal so that it is partially oxidized, producing a fuel while consuming significantly less oxygen. Several IGCC schemes are in operation which produce syngas for use as a feedstock, in addition to electricity and hydrogen. These schemes are costly as they require an air separation unit. Novel approaches to coal gasification based on 'membrane separation' or chemical looping could reduce the costs significantly while effectively capturing carbon dioxide. 1 ref., 2 figs., 1 photo.

  13. Effect of oxidation on the removal CU{sup 2+}, Cd{sup 2+} and Mn (VII) from dilute aqueous solutions by Upper Freeport bituminous coal. Quarterly report, June--August 1995

    SciTech Connect

    Bodine, D.L.

    1995-12-31

    Upper Freeport bituminous coal was able to remove Mn (VII) from dilute aqueous solution by concurrent adsorption and reduction of the manganese to lower valence, less toxic states. This type of reaction indicated the potential of using coal to remove oxidizing contaminants from effluents. Since oxidizing anions can degrade ion exchange resins and membranes, coal may be a viable alternative for detoxification. On analysis of the kinetics of copper and cadmium uptake from dilute aqueous solution, adsorption equilibria and functional groups analyses, it was apparent that the different oxidative pre-treatments affected both the surfaces and pore structure of Upper Freeport coal. The large amount of carboxyl and phenolic functional groups remaining after contact with copper and cadmium solutions, as determined by functional groups analyses, indicated the low affinity of the surface acid groups for these cations. Furthermore, there was almost no metal ion removal at low solution pH`s, which precludes the use of Upper Freeport for treating acidic wastes and effluents such as acid mine drainage. The coal surface functional groups are indeed able to exchange with cations, since the amount of these groups are measured by ion exchange with Na{sup +} and Ba{sup 2+}, however, it may be more difficult to displace the waters of hydration around Cu{sup 2+} and Cd{sup 2+}, to allow their uptake on the coal surface functional groups. Improved metal ion removal might be obtained using a lower rank coal, such as a subbituminous coal, which would be more susceptible to oxidation.

  14. Metal/oxide interfacial effects on the selective oxidation of primary alcohols

    NASA Astrophysics Data System (ADS)

    Zhao, Guofeng; Yang, Fan; Chen, Zongjia; Liu, Qingfei; Ji, Yongjun; Zhang, Yi; Niu, Zhiqiang; Mao, Junjie; Bao, Xinhe; Hu, Peijun; Li, Yadong

    2017-01-01

    A main obstacle in the rational development of heterogeneous catalysts is the difficulty in identifying active sites. Here we show metal/oxide interfacial sites are highly active for the oxidation of benzyl alcohol and other industrially important primary alcohols on a range of metals and oxides combinations. Scanning tunnelling microscopy together with density functional theory calculations on FeO/Pt(111) reveals that benzyl alcohol enriches preferentially at the oxygen-terminated FeO/Pt(111) interface and undergoes readily O-H and C-H dissociations with the aid of interfacial oxygen, which is also validated in the model study of Cu2O/Ag(111). We demonstrate that the interfacial effects are independent of metal or oxide sizes and the way by which the interfaces were constructed. It inspires us to inversely support nano-oxides on micro-metals to make the structure more stable against sintering while the number of active sites is not sacrificed. The catalyst lifetime, by taking the inverse design, is thereby significantly prolonged.

  15. Metal/oxide interfacial effects on the selective oxidation of primary alcohols

    PubMed Central

    Zhao, Guofeng; Yang, Fan; Chen, Zongjia; Liu, Qingfei; Ji, Yongjun; Zhang, Yi; Niu, Zhiqiang; Mao, Junjie; Bao, Xinhe; Hu, Peijun; Li, Yadong

    2017-01-01

    A main obstacle in the rational development of heterogeneous catalysts is the difficulty in identifying active sites. Here we show metal/oxide interfacial sites are highly active for the oxidation of benzyl alcohol and other industrially important primary alcohols on a range of metals and oxides combinations. Scanning tunnelling microscopy together with density functional theory calculations on FeO/Pt(111) reveals that benzyl alcohol enriches preferentially at the oxygen-terminated FeO/Pt(111) interface and undergoes readily O–H and C–H dissociations with the aid of interfacial oxygen, which is also validated in the model study of Cu2O/Ag(111). We demonstrate that the interfacial effects are independent of metal or oxide sizes and the way by which the interfaces were constructed. It inspires us to inversely support nano-oxides on micro-metals to make the structure more stable against sintering while the number of active sites is not sacrificed. The catalyst lifetime, by taking the inverse design, is thereby significantly prolonged. PMID:28098146

  16. The use of starch to enhance sulfur and ash removal from coal by selective oil agglomeration. Quarterly technical progress report No. 12, July 1--September 30, 1990

    SciTech Connect

    Good, R.J.; Badgujar, M.N.

    1990-12-31

    We have found that the use of starch or gelatin, as an additive in the Otisca T-Process of selective oil agglomeration of coal, leads to a considerable improvement in the reduction of pyritic sulfur and of ash-forming minerals. A patent application has been filed; (Good & Badgugar). Improvement in rejection of pyritic sulfur by up to 55% has been found, and improvement in ash rejection by up to 28%. Carbon recovery of 97.5 to 99.1% was obtained when the starch concentration was in the range, 30 to 200 ppM in the water. Three different bituminous coals were used: Upper Freeport, Kentucky No. 9, and