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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. Selective oxidations of organosulfur model compounds and coal for the removal of organic sulfur

    SciTech Connect

    Fauth, D.J.; Baltrus, J.P.; Nowak, M.A.; Olson, G.J.

    1991-01-01

    Investigations with organosulfur compounds have established that potassium monopersulfate (Oxone) in aqueous ethanol and sodium perborate in glacial acetic acid are highly selective oxidants for the oxidation of organic sum ides and aromatic sulfur heterocycles to their corresponding sulfoxides and sulfones. In a series of selective oxidations, dibenzothiophene in ethanol, fluorene in ethanol, and a 50:50 mol mixture of dibenzothiophene (DBT) and fluoresce in ethanol were reacted with aqueous Oxone under mild conditions. Capillary gas chromatographic analyses showed conversions of DBT to DBT-5,5-dioxide, while its carbon analog, fluorene was recovered quantitatively in every case. Furthermore, selective oxidations with Oxone of a triboelectrostatically cleaned Illinois {number sign}6 ultrafine coal (400 mesh {times} 0) and an Illinois {number sign}6 coal (IBC-101) (200 mesh {times} 0) depyritized via microorganisms were investigated. X-ray photoelectron spectroscopic (XPS) data indicated oxidation of a large fraction of the organic sulfur on the coal surface. Approximately 55--85% of the total S 2p area could be attributed to oxidized organic sulfur in the form of sulfones.

  7. Selective oxidation of low-concentration coal mine gas to methanol in oleum over PbSO4 catalyst

    NASA Astrophysics Data System (ADS)

    Xu, Feng; Li, Fan; Zhu, Li-Hua; Wu, Yang

    2017-06-01

    Selective oxidation of low-concentration coal mine gas to methanol was carried out over PbSO4 catalyst in a concentration of 20% oleum. The effects of reaction temperature, reaction pressure, reaction time and catalyst dosage on the conversion of methane in gas as well as the yield of methanol were studied. What is more, the reaction mechanism of selective oxidation of low-concentration coal mine gas was also investigated. The results showed that the optimal reaction conditions are determined under the reaction temperature of 180°, the reaction pressure of 5MPa, the reaction time of 3h, and the PbSO4 dosage of 300μmol for selective oxidation of low-concentration coal mine gas to methanol by PbSO4 catalyst in oleum. Under this technological condition, the conversion ratio of methane in gas is 8.56% while the methanol selectivity is 78.59%. Mechanism research showed that methane in gas is transformed into methyl bisulfate firstly. Besides, the methyl bisulfate is hydrolyzed into methanol. The selective oxidation of low-concentration coal mine gas is following the mechanism of electrophilic substitution.

  8. 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 ...

  9. 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.

  10. 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.

  11. Selective Catalytic Oxidation of Hydrogen Sulfide to Elemental Sulfur from Coal-Derived Fuel Gases

    SciTech Connect

    Gardner, Todd H.; Berry, David A.; Lyons, K. David; Beer, Stephen K.; Monahan, Michael J.

    2001-11-06

    The development of low cost, highly efficient, desulfurization technology with integrated sulfur recovery remains a principle barrier issue for Vision 21 integrated gasification combined cycle (IGCC) power generation plants. In this plan, the U. S. Department of Energy will construct ultra-clean, modular, co-production IGCC power plants each with chemical products tailored to meet the demands of specific regional markets. The catalysts employed in these co-production modules, for example water-gas-shift and Fischer-Tropsch catalysts, are readily poisoned by hydrogen sulfide (H{sub 2}S), a sulfur contaminant, present in the coal-derived fuel gases. To prevent poisoning of these catalysts, the removal of H{sub 2}S down to the parts-per-billion level is necessary. Historically, research into the purification of coal-derived fuel gases has focused on dry technologies that offer the prospect of higher combined cycle efficiencies as well as improved thermal integration with co-production modules. Primarily, these concepts rely on a highly selective process separation step to remove low concentrations of H{sub 2}S present in the fuel gases and produce a concentrated stream of sulfur bearing effluent. This effluent must then undergo further processing to be converted to its final form, usually elemental sulfur. Ultimately, desulfurization of coal-derived fuel gases may cost as much as 15% of the total fixed capital investment (Chen et al., 1992). It is, therefore, desirable to develop new technology that can accomplish H{sub 2}S separation and direct conversion to elemental sulfur more efficiently and with a lower initial fixed capital investment.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Recent increases in nitrogen oxide (NOx) emissions from coal-fired electric generating units equipped with selective catalytic reduction.

    PubMed

    McNevin, Thomas F

    2016-01-01

    The most effective control technology available for the reduction of oxides of nitrogen (NOx) from coal-fired boilers is selective catalytic reduction (SCR). Installation of SCR on coal-fired electric generating units (EGUs) has grown substantially since the onset of the U.S. Environmental Protection Agency's (EPA) first cap and trade program for oxides of nitrogen in 1999, the Ozone Transport Commission (OTC) NOx Budget Program. Installations have increased from 6 units present in 1998 in the states that encompass the current Cross-State Air Pollution Rule (CSAPR) ozone season program to 250 in 2014. In recent years, however, the degree of usage of installed SCR technology has been dropping significantly at individual plants. Average seasonal NOx emission rates increased substantially during the Clean Air Interstate Rule (CAIR) program. These increases coincided with a collapse in the cost of CAIR allowances, which declined to less than the cost of the reagent required to operate installed SCR equipment, and was accompanied by a 77% decline in delivered natural gas prices from their peak in June of 2008 to April 2012, which in turn coincided with a 390% increase in shale gas production between 2008 and 2012. These years also witnessed a decline in national electric generation which, after peaking in 2007, declined through 2013 at an annualized rate of -0.3%. Scaling back the use of installed SCR on coal-fired plants has resulted in the release of over 290,000 tons of avoidable NOx during the past five ozone seasons in the states that participated in the CAIR program. To function as designed, a cap and trade program must maintain allowance costs that function as a disincentive for the release of the air pollutants that the program seeks to control. If the principle incentive for reducing NOx emissions is the avoidance of allowance costs, emissions may be expected to increase if costs fall below a critical value, in the absence of additional state or federal

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. Selective Catalytic Oxidation of Hydrogen Sulfide to Elemental Sulfur in the Presence of Coal-Derived Fuel Gas

    SciTech Connect

    Stevens, R.W., Jr.; Gardner, T.H.; Shekhawat, Dushyant; Berry, D.A.; Freed, A.D.

    2005-09-01

    A rotatable central composite design approach was utilized to examine the activity and selectivity of an activated carbon-based catalyst during partial oxidation of H2S to elemental sulfur. Tests were conducted at 400 psig with a 4000 ppmv H2S inlet concentration in the presence of coal-derived fuel gas (i.e., CO, CO2, H2, and H2O). Temperature, space velocity, and O2:H2S ratio were chosen as process variables for the study to generate response surface maps of elemental sulfur yield and longevity. Temperature was varied from 150-300°C; gas hourly space velocity varied from 1000 -15000 h-1 (STP); O2:H2S varied from 0.5-2.0. Evolution of SO2 and/or COS during some of the tests indicated the presence of side reactions. The relationship between the process variables and catalyst performance as well as the results of catalyst characterization is discussed.

  2. 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.

  3. 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.

  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

    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.

  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. 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.

  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. 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.

  7. 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.

  8. 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.

  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. 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.

  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: 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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%.

  18. 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.

  19. 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.

  20. 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.

  1. Electricity from Coal Combustion: Improving the hydrophobicity of oxidized coals

    NASA Astrophysics Data System (ADS)

    Seehra, Mohindar; Singh, Vivek

    2011-03-01

    To reduce pollution and improve efficiency, undesirable mineral impurities in coals are usually removed in coal preparation plants prior to combustion first by crushing and grinding coals followed by gravity separation using surfactant aided water flotation. However certain coals in the US are not amendable to this process because of their poor flotation characteristics resulting in a major loss of an energy resource. This problem has been linked to surface oxidation of mined coals which make these coals hydrophilic. In this project, we are investigating the surface and water flotation properties of the eight Argonne Premium (AP) coals using x-ray diffraction, IR spectroscopy and zeta potential measurements. The role of the surface functional groups, (phenolic -OH and carboxylic -COOH), produced as a result of chemisorptions of O2 on coals in determining their flotation behavior is being explored. The isoelectric point (IEP) in zeta potential measurements of good vs. poor floaters is being examined in order to improved the hydrophobicity of poor floating coals (e.g. Illinois #6). Results from XRD and IR will be presented along with recent findings from zeta potential measurements, and use of additives to improve hydrophobicity. Supported by USDOE/CAST, Contract #DE-FC26-05NT42457.

  2. Study of mercury oxidation by a selective catalytic reduction catalyst in a pilot-scale slipstream reactor at a utility boiler burning bituminous coal

    SciTech Connect

    Yan Cao; Bobby Chen; Jiang Wu; Hong Cui; John Smith; Chi-Kuan Chen; Paul Chu; Wei-Ping Pan

    2007-01-15

    One of the cost-effective mercury control technologies in coal-fired power plants is the enhanced oxidation of elemental mercury in selective catalytic reduction (SCR) followed by the capture of the oxidized mercury in the wet scrubber. This paper is the first in a series of two in which the validation of the SCR slipstream test and Hg speciation variation in runs with or without SCR catalysts inside the SCR slipstream reactor under special gas additions (HCl, Cl{sub 2}, SO{sub 2}, and SO{sub 3}) are presented. Tests indicate that the use of a catalyst in a SCR slipstream reactor can achieve greater than 90% NO reduction efficiency with a NH{sub 3}/NO ratio of about 1. There is no evidence to show that the reactor material affects mercury speciation. Both SCR catalysts used in this study exhibited a catalytic effect on the elemental mercury oxidation but had no apparent adsorption effect. SCR catalyst 2 seemed more sensitive to the operational temperature. The spike gas tests indicated that HCl can promote Hg{sup 0} oxidation but not Cl{sub 2}. The effect of Cl{sub 2} on mercury oxidation may be inhibited by higher concentrations of SO{sub 2}, NO, or H{sub 2}O in real flue-gas atmospheres within the typical SCR temperature range (300-350{sup o}C). SO{sub 2} seemed to inhibit mercury oxidation; however, SO{sub 3} may have some effect on the promotion of mercury oxidation in runs with or without SCR catalysts. 25 refs., 9 figs., 2 tabs.

  3. MOLECULAR ACCESSIBILITY IN OXIDIZED AND DRIED COALS

    SciTech Connect

    Lowell D. Kispert

    1999-07-01

    Changes in physical and chemical structure of the micropore system in eight solvent swelled Argonne Premium Coal Sample (APCS) coals upon weathering were studied using the EPR spin probe method. Spin probes, which are allowed to diffuse into the coal structure during swelling, are trapped when the swelling solvent is removed. Excess spin probes are removed from the coal surface and larger pores so that only the presence of spin probes trapped in pores which closely approximate the size of the spin probe are detected. Detailed explanations and illustrations of the experimental procedure used are given. Careful examination of the weathering process on coal as a function of rank was accomplished using the EPR spin probe method. The retention of spin probes in eight APCS coals provided valuable insight into both the loss of water and the oxidation which occur during the weathering process. The results could be explained in terms of the autoxidation process observed in other polymeric systems. It was shown that initial oxidation of coal can result in increased cross-linking in the coal structure. As the oxidation process continued, both the covalent and hydrogen bonded character of the coal were significantly altered. The retention character of some coals during oxidation was shown to change by as much as three orders of magnitude. Experiments were performed to study the effects of short term oxidation and dehydration on coal structure by exposing the coal samples to argon or oxygen for time periods up to five minutes. The results indicate that the structure of coal is extremely sensitive to environmental changes and exhibits significant changes in as little as 30 seconds. Exposure of Illinois No.6 coal to argon or oxygen for 30 seconds caused a decrease in the retention of polar spin probes by as much as an order of magnitude. The studies presented here suggest that the structure of coal is dynamic in nature, and has an intimate relationship with the nature of its

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Electrokinetic study on the oil flotation of oxidized coal. [Separation from ash materials and pyrite

    SciTech Connect

    Wen, W.W.; Sun, S.C.

    1981-01-01

    The objective of this investigation was to study the electrokinetic behavior of oxidized coals and of hydrocarbon emulsion droplets of flotation reagents to indicate the feasibility of separating the oxidized coals from ash materials and pyrite by an oil flotation process. The effects of surfactants and hydrolyzed metal ions were also included. The electrokinetic behavior of the oxidized coals and the hydrocarbon emulsion droplets were studied by an electrophoresis technique. Generally the isoelectric point (IEP) of the coals decreased with increasing degree of oxidation. A model of selective flotation of oxidized coal is postulated on the basis of the electrokinetic results. This model simply states that in the presence of a suitable amount of collector and frother, the optimal selective flotation of oxidized coal will occur at the IEP of the oxidized coal. To achieve this condition at the coal surface, it is necessary to adsorb heavy metal hydroxide ions prior to flotation and to absorb hydrocarbon oil droplets containing positively charged organic functional groups during flotation. Oxidized coal becomes more hydrophobic at its IEP because most of its surface is relatively non-polarizable surfaces and remain in suspension even when they are at an IEP. 14 figures.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. 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...

  18. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Final report

    SciTech Connect

    Doyle, F.M.

    1996-01-26

    Coal oxidation has been studies extensively in previous work. However, there is still no general agreement concerning the mechanisms of oxidation. Moreover, the oxidation behavior of coal and mineral matter have generally been regarded as separate processed. There is appreciable evidence that organic and inorganic oxidation process are actually coupled, consequently the changes in their surface properties induced by oxidation are difficult to predict. This makes the effectively of coal cleaning processes highly sensitive to the extent of weathering and oxidation that the coal has experienced. The objective of this research was to investigate the oxidation behavior of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with these surface properties that would influence the behavior in physical cleaning processes.

  19. 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.

  20. Bacterial Oxidation of Pyritic Materials in Coal

    PubMed Central

    Silverman, Melvin P.; Rogoff, Martin H.; Wender, Irving

    1961-01-01

    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 CaCO3 from a calcite-containing sample. PMID:16349610

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. (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.

  12. 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)

  13. Oxidation and carbonisation of coals: a case study of coal fire affected coals from the Wuda coalfield, Inner Mongolia, China

    NASA Astrophysics Data System (ADS)

    Kus, Jolanta; Meyer, Uwe; Ma, Jianwei; Chen-Brauchler, Dai

    2010-05-01

    At the coalfield of Wuda (Inner Mongolia, PR China) extensive underground coal fires cause widespread thermal and oxidative effects in coal seams. Within phase B of the Coal Fire Research Project of the Sino-German Initiative, methods for innovative fire-extinguishing technologies were investigated in multifaceted research approaches. Extensive investigations of oxidative and thermally affected coal seams in coal fire zone 18 were conducted in 2008 prior to application of new fire-extinguishing methods. We present results from the outcrop of coal seam No. 4 in the fire zone 18. The coal of seam No. 4 is of Early Permian age and belongs stratigraphically to the Shanxi Formation. The unaffected coal displays a high volatile bituminous A rank with a background value of random vitrinite reflectance ranging from 0.90 to 0.96 % Rr. Coal channel samples were coallected at actively extracted coal faces along multiple profiles with surface temperatures ranging from about 50° to 600°C. Microscopic examinations revealed a variety of products of coal exposure to the fire. Within coal samples, a marked rise in vitrinite reflectance from background values to 5.55% Rr (6.00 % Rmax) is encountered. In addition, a number of coal samples showed suppressed vitrinite reflectances ranging between 0.82 to 0.88% Rr. Further, seemingly heat unaffected coal samples display intensive development of oxidations rims at coal grain edges and cracks as well as shrinkage cracks and formation of iron oxides/hydroxides. Instead, thermally affected coal samples with higher coalification grade are further characterised by development of macropores (devolatilisation pores) in vitrinitic streaks, transformation of liptinite to meta-liptinite and micrinite as well as by natural coke particles of mostly porous nature and fine to coarse grained anisotropic mosaic. Coal petrographic investigations confirmed a hypothesis that both, oxidations as well as low temperature carbonisation govern the thermal

  14. 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.

  15. 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.

  16. 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.

  17. 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)

  18. 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.

  19. 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.

  20. Investigation of H{sub 2}O and CO{sub 2} reforming and partial oxidation of methane: catalytic effects of coal char and coal ash

    SciTech Connect

    Hongcang Zhou; Yan Cao; Houyin Zhao; Hongying Liu; Wei-Ping Pan

    2008-07-15

    Methane reforming and partial oxidation was studied to evaluate the catalytic effects of coal chars and coal ashes on methane (CH{sub 4}) conversion, sum selectivity (the sum of H{sub 2} and CO), and ratio selectivity (the ratio of H{sub 2}/CO) in an atmospheric fluidized bed. The kinetics study presented the possibility of CH{sub 4} reforming and partial oxidation with a favorable H{sub 2}/CO ratio, greater than 5. The higher H{sub 2}/CO ratio in CH{sub 4} reforming and the partial-oxidation process can reduce the consumption of CH{sub 4} needed to adjust the H{sub 2}/CO ratio during combined coal gasification and methane reforming. Coal ashes failed to be good candidates of catalysts on CH{sub 4} reforming and partial oxidation because of their very low specific surface area available for catalytic reactions. However, coal chars presented very promising catalytic performance on CH{sub 4} reforming and partial oxidation because of their larger specific surface area. In this study, no other constituents in coal fly ash or special surface properties of coal chars were correlated with the enhanced methane-conversion efficiency. It seems that the specific surface area is only variable in controlling methane-conversion efficiency. 16 refs., 9 figs.

  1. 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

  2. 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

  3. 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.

  4. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, [June--August 1993

    SciTech Connect

    Doyle, F.M.

    1993-09-30

    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 term of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the twelfth quarter, wet and dry oxidation tests were done at room temperature on coal samples from the Pennsylvania State Coal Bank. Previous results had indicated that oxidation at high temperatures induced changes in surface properties through loss of volatiles. 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 floatability of as-received and oxidized coals. Surface area measurements were done on as-received coals.

  5. 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.

  6. Humic substance formation via the oxidative weathering of coal

    SciTech Connect

    Chang, S.; Berner, R.A.

    1998-10-01

    Oxidative weathering of sedimentary organic matter in the Earth`s surficial environment is one of the major processes in the geochemical carbon cycle on geological time scales. It has been assumed in most geochemical models that there is complete oxidation of sedimentary organic matter only to CO{sub 2}. However, studies have shown that humic substances can be produced via the oxidation of coal. The authors have determined the aqueous oxidation kinetics of pyrite-free bituminous coal at 24 and 50 C by using a dual-cell flow-through method. At 24 C, dissolved carbon is removed from the coal-water system mainly in the form of CO{sub 2} and is equivalent to 30--50% of the consumed oxygen. The remaining 50--70% of the consumed oxygen is retained on the coal surface in the form of insoluble organic oxidation products. Formation of greater proportions of dissolved organic oxidation products is expected under natural conditions where water-rock contact time is much longer than in the authors` experiments. FTIR analysis indicates marked increases in carbonyl groups for coal oxidized in oxygenated water at 50 C. Both dissolution of the solid oxidation products and the oxygen consumption rate should be accelerated by an increase in pH.

  7. 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.

  8. 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...

  9. 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...

  10. 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.

  11. Selective solvent absorption in coal conversion

    SciTech Connect

    Larsen, J.W.; Amui, J.

    1992-06-01

    The objectives of this research 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 stages of direct coal liquefaction. Scope of work study the conversion of Argonne Premium coals in tetralin and 2-t-butyltetralin and compare the following: conversion to soluble products and product composition. Hydrogen donated by both solvents will be measured by gas chromatography and the same technique will be used to establish the amount of dealkylation of 2-t-butyltetralin. Reactions will be performed at several different temperatures for varying amounts of time.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  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: 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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...

  6. 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...

  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. 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.

  9. Treatment and recovery of larger particles of fine oxidized coal

    SciTech Connect

    Finch, R.E.

    1980-09-16

    This invention relates to a method and treating agent for increasing the yield of larger particles of fine oxidized coal where the particle size is 28 X 100 mesh and preferably 28 X 70 mesh and where said coal particles are concentrated by froth flotation. The method consists of utilizing as a promoter an alkali metal or ammonium polyacrylate. A preferred promoter is about 0.05-1.5 lbs of sodium polyacrylate latex per ton of dry coal (0.017-0.5 lb of dry sodium polyacrylate per ton of dry coal), having an average molecular weight of about 100,000, to 1, 000,000 and more, with a preferred range of 1,000,000 or more. This preferred promoter or frothing aid for oxidized coal is a water-in-oil latex of sodium polyacrylate used with a water-inoil emulsifier and preferably used with an alcohol-type frother. The latex may be utilized neat and self inverts with the assistance of an oil-in-water surfactant and the water in the system upon application to form an oil-in-water emulsion, or it may be used as a two part system with an activator (Aqueous) to promote inversion. Additionally, the latex emulsion recovers larger particles in the size 100 mesh and greater and preferably in the range 28 X 70 mesh.

  10. 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.

  11. 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

  12. 8-isoprostane as Oxidative Stress Marker in Coal Mine Workers.

    PubMed

    Zimet, Zlatko; Bilban, Marjan; Marc Malovrh, Mateja; Korošec, Peter; Poljšak, Borut; Osredkar, Joško; Šilar, Mira

    2016-08-01

    This study was to investigate whether working in conditions of elevated concentrations of mine gases (CO2, CO, CH4, DMS) and dust may result in oxidative stress. Coal miners (n=94) from the Velenje Coal mine who were arranged into control group and three groups according to a number of consecutive working days. 8-isoprostane as a biological marker of oxidative stress was measured in exhaled breath condensate (EBC). Miners who worked for three consecutive days had higher 8-isoprostane values in EBC compared to the control group. Gas/dust concentrations and exposure time of a single/two day shift seem too low to trigger immediate oxidative stress. Copyright © 2016 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  13. 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.

  14. 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.

  15. [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.

  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. Processing of converter sludges on the basis of thermal-oxidative coking with coals

    NASA Astrophysics Data System (ADS)

    Kuznetsov, S. N.; Shkoller, M. B.; Protopopov, E. V.; Kazimirov, S. A.; Temlyantsev, M. V.

    2017-09-01

    The paper deals with the solution of an important problem related to the recycling of converter sludge. High moisture and fine fractional composition of waste causes the application of their deep dehydration and lumping. To reduce environmental emissions the non-thermal method of dehydration is considered – adsorption-contact drying. As a sorbent, the pyrolysis product of coals from the Kansko-Achinsky basin – brown coal semi-coke (BSC) obtained by the technology “Thermokoks”. Experimental data on the dehydration of high-moisture wastes with the help of BSC showed high efficiency of the selected material. The lumping of the dried converter dust was carried out by thermo-chemical coking with coals of grades GZh (gas fat coal) and Zh (fat coal). As a result, an iron-containing product was obtained – ferrocoke, which is characterized by almost complete reduction of iron oxides, as well as zinc transition into a vapor state, and is removed with gaseous process products. Based on the results of the experimental data a process basic diagram of the utilization of converter sludge to produce ferrocoke was, which can be effectively used in various metallurgical aggregates, for example, blast furnaces, converters and electric arc furnaces. In the basic technological scheme heat generated by ferrocoke cooling and the energy of the combustion products after the separation of zinc in the gas turbine plant will be used.

  20. 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.

  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. 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.

  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. 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.

  6. 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.

  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. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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)

  13. Coal resources of selected coal beds and zones in the Northern and Central Appalachian Basin

    USGS Publications Warehouse

    Ruppert, Leslie; Tewalt, Susan; Bragg, Linda

    2002-01-01

    The Appalachian Basin is one of the most important coal-producing regions in the world. Bituminous coal has been mined in the basin for the last three centuries, and the cumulative production is estimated at 34.5 billion short tons. Annual production in 1998 was about 452 million short tons; the basin's production is mostly in the northern (32 percent) and central (63 percent) coal regions. The coal is used primarily within the Eastern United States for electric power generation, but some of it is suitable for metallurgical uses. The U.S. Geological Survey (USGS) is completing a National Coal Resource Assessment of five coal-producing regions of the United States, including the Appalachian Basin. The USGS, in cooperation with the State geological surveys of Kentucky, Maryland, Ohio, Pennsylvania, Virginia, and West Virginia, has completed a digital coal resource assessment of five of the top-producing coal beds and coal zones in the northern and central Appalachian Basin coal regions -- the Pittsburgh coal bed, the Upper Freeport coal bed, the Fire Clay and Pond Creek coal zones, and the Pocahontas No. 3 coal bed. Of the 93 billion short tons of original coal in these units, about 66 billion short tons remain.

  14. 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.

  15. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Draft final report

    SciTech Connect

    1996-06-14

    The primary goal of this project was to demonstrate the use of Selective Catalytic Reduction (SCR) to reduce NO{sub x} emissions from pulverized-coal utility boilers using medium- to high-sulfur US coal. The prototype SCR facility, built in and around the ductwork of Plant Crist Unit 5, consisted of three large SCR reactor units (Reactors A, B, and C), each with a design capacity of 5,000 standard cubic feet per minute (scfm) of flue gas, and six smaller reactors (Reactors D through J), each with a design capacity of 400 scfm of flue gas. The three large reactors contained commercially available SCR catalysts as offered by SCR catalyst suppliers. These reactors were coupled with small-scale air preheaters to evaluate (1) the long-term effects of SCR reaction chemistry on air preheater deposit formation and (2) the impact of these deposits on the performance of air preheaters. The small reactors were used to test additional varieties of commercially available catalysts. The demonstration project was organized into three phases: (1) Permitting, Environmental Monitoring Plan (EMP) Preparation, and Preliminary Engineering; (2) Detail Design Engineering and Construction; and (3) Operation, Testing, Disposition, and Final Report Preparation. Section 2 discusses the planned and actual EMP monitoring for gaseous, aqueous, and solid streams over the course of the SCR demonstration project; Section 3 summarizes sampling and analytical methods and discusses exceptions from the methods specified in the EMP; Section 4 presents and discusses the gas stream monitoring results; Section 5 presents and discusses the aqueous stream monitoring results; Section 6 presents and discusses the solid stream monitoring results; Section 7 discusses EMP-related quality assurance/quality control activities performed during the demonstration project; Section 8 summarizes compliance monitoring reporting activities; and Section 9 presents conclusions based on the EMP monitoring results.

  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. 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.

  18. 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.

  19. 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.

  20. 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.

  1. An evaluation of micronized coal reburning for nitrogen oxide emissions reduction in pulverized coal-fired electric utility boilers

    NASA Astrophysics Data System (ADS)

    de Angelo, Joseph Gerard

    Recent increases in the prices of imported fuels and increases in the cost of natural gas have underscored the need to consider other sources of energy for electric production in the United States. Our most abundant fuel source is coal, however the use of coal brings with it a set of environmental problems. This dissertation presents an investigation into the use of micronized coal reburning. This technology may provide a cost-effective solution to the requirements to reduce NOx emissions from pulverized coal-fired electric generating stations. This research effort evaluated the use of micronized coal as a reburning fuel to lower nitrogen oxide emissions from coal-fired boilers. The research effort included: (1) an investigation of all available literature on the subject, (2) planning and supervision of a number of baseline and parametric tests on a full-scale coal fired utility boiler. The testing was carried out on the former NYSEG generating unit, Milliken 1. Milliken Unit 1 is a 150 MW coal-fired electric utility boiler located in Lansing, NY on the eastern shore of Cayuga Lake, (3) development of a model to predict NOx emissions from a coal-fired boiler, and (4) completion of a conceptual design for a micronized coal reburning system. The original plan of the research effort was to include a full-scale micronized coal reburn installation and subsequent modeling and testing. However, in 1998 the deregulation of the electric utility industry in New York caused the focus of the dissertation to be narrowed. The test site, Milliken Station was sold to another entity, and the installation of the micronized coal reburn system was cancelled. The following conclusions were drawn from the research: (1) Testing showed that nitrogen oxide production was significantly influenced by changes in controllable boiler operating parameters. (2) The predictive model for baseline nitrogen oxide production was fairly accurate in estimating NOx emissions. The model had an average

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. Preparation of oxygen-containing organic products from bed-oxidized brown coal by ozonation

    SciTech Connect

    Semenova, S.A.; Patrakov, Y.F.; Batina, M.V.

    2009-01-15

    The possibility of modifying the functional composition of humic acids by gas-phase ozonation of bed-oxidized brown coal was examined. About 90% of the organic matter of brown coal was converted to low-molecular weight soluble oxygen-containing products by stepwise liquid-phase ozonation (in chloroform and acetic acid).

  7. Imprinted magnetic graphene oxide for the mini-solid phase extraction of Eu (III) from coal mine area

    NASA Astrophysics Data System (ADS)

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

    2017-05-01

    The present work represents the preparation of imprinted magnetic reduced graphene oxide and applied it for the selective removal of Eu (III) from local coal mines area. A simple solid phase extraction method was used for this purpose. The material shows a very high adsorption as well as removal efficiency towards Eu (III), which suggest that the material have potential to be used in future for their real time applications in removal of Eu (III) from complex matrices.

  8. 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.

  9. 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…

  10. 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…

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. Comparison of nickel molybdenum hydrous metal oxides with commercial catalysts for HDS/HDN of coal liquids

    SciTech Connect

    Lott, S.E.; Gardner, T.J.; McLaughlin, L.I.; Oelfke, J.B.

    1994-06-01

    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 used to develop catalysts for hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of coal liquids. For HYD of pyrone, unsupported NiMoHTO catalysts performed better than commercial benchmark catalysts on either a catalyst weight or active metals basis. In a side-by-side comparison of supported NiMoHTO catalysts with commercial counterparts, the supported NiMoHTO catalysts outperformed the Shell 324 and Amocat 1C catalysts for HYD of pyrene. For HDS/HDN of coal liquids, the supported and bulk forms of the NiMoHTO catalysts equaled the performance of the commercial catalysts at 500, 1000, and 1500 psig while containing less active metals. Possible reasons for the high activity of the NiMoHTO catalysts are a high dispersion of the active MoS{sub 2} phase and a high acidity of the bulk NiMoHTO.

  17. 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.

  18. 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.

  19. Flotation of oxidized coal with a latex emulsion of sodium polyacrylate used as a promoter

    SciTech Connect

    Finch, R.E.

    1980-09-16

    A method and treating agent for increasing the yield of oxidized coal or coal from surface or strip mines where said coal particles are concentrated by froth flotation. The method consists of utilizing as a promoter or frothing aid about 05-1.5 lbs of sodium polyacrylate latex per ton of dry coal (0.017-0.5 lb of dry sodium polyacrylate per ton of dry coal), having an average molecular weight of about 100,000 to 1,000,000 and more, with a preferred range of 1,000,000 or more. The preferred promoter or frothing aid for oxidized coal is a water-in-oil latex of sodium polyacrylate and preferably used with an alcohol-type frother. The latex may be utilized neat and self inverts with the assistance of an oil-in-water surfactant hydrophilic (Or activator) and the water in the system upon application to form an oil-in-water emulsion, or it may be used as a two-part system with an activator (Aqueous) to promote inversion. The latex emulsion has demonstrated superiority as a flotation promoter for oxidized coal over the dry polymer and exhibits synergism over the dry polymer and over the components of the latex emulsion including a paraffin solvent, a hydrophobic emulsifier such as sorbitan monooleate, a solvent such as espersol 3-e (Charter; an aromatic blend) and stabilizers such as polyisobutylene and aluminum tristearate.

  20. 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.

  1. Fossil resin flotation from coal by selective coagulation and depression of coal

    SciTech Connect

    Miller, J.D.; Yi, Y.

    1990-02-27

    This patent describes a method for separating minute resin particles from a slurry mixture of minute resin particles and minute coal particles. It comprises: adjusting the pH of the slurry mixture of minute resin particles and minute coal particles to above about 12 and subjecting the pH adjusted slurry mixture of particles to froth flotation in the presence of a frothing agent, to produce a froth fraction enriched with respect to the minute resin particles.

  2. 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...

  3. 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.

  4. 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.

  5. 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. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. A selective nanosensing probe for nitric oxide

    NASA Astrophysics Data System (ADS)

    Gouma, P. I.; Kalyanasundaram, K.

    2008-12-01

    Measurement of NO gas in exhaled human breath may be used to monitor oxidative stress and pulmonary diseases. Until now, only bulk, expensive, chemiluminescence-based NO monitors have been available to medicine. A nanosensing probe based on WO3 selectively detecting minute nitric oxide gas concentrations in the presence of interfering volatile compounds is presented. This is possible due to the chemical affinity of rhenium trioxide based phases to oxidizing gases. The NO nanoprobe is expected to lead to portable and affordable, noninvasive, single breath sampling, NO diagnostics.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Predicting extents of mercury oxidation in coal-derived flue gases.

    PubMed

    Niksa, Stephen; Fujiwara, Naoki

    2005-07-01

    The proposed mercury (Hg) oxidation mechanism consists of a 168-step gas phase mechanism that accounts for interaction among all important flue gas species and a heterogeneous oxidation mechanism on unburned carbon (UBC) particles, similar to established chemistry for dioxin production under comparable conditions. The mechanism was incorporated into a gas cleaning system simulator to predict the proportions of elemental and oxidized Hg species in the flue gases, given relevant coal properties (C/H/O/N/S/Cl/Hg), flue gas composition (O2, H2O, HCl), emissions (NO(X), SO(X), CO), the recovery of fly ash, fly ash loss-on-ignition (LOI), and a thermal history. Predictions are validated without parameter adjustments against datasets from lab-scale and from pilot-scale coal furnaces at 1 and 29 MWt. Collectively, the evaluations cover 16 coals representing ranks from sub-bituminous through high-volatile bituminous, including cases with Cl2 and CaCl2 injection. The predictions are, therefore, validated over virtually the entire domain of Cl-species concentrations and UBC levels of commercial interest. Additional predictions identify the most important operating conditions in the furnace and gas cleaning system, including stoichiometric ratio, NO(X), LOI, and residence time, as well as the most important coal properties, including coal-Cl.

  20. 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.

  1. 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 ...

  2. 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 ...

  3. Protocols for the selective cleavage of carbon-sulfur bonds in coal

    SciTech Connect

    Bausch, M.

    1991-01-01

    Removal of the organic sulfur in coal constitutes one of the major challenges facing fossil fuel scientists today. A cost--effective of desulfurizing Illinois coal is non-existent at the present time. Research in our group aims to develop a simple protocol for sulfur removal by gaining understanding of how various additives can enhance the rates of C-S bond cleavage in Illinois coal and coal model compounds, relative to fragmentation of the coal macromolecule via C-C, C-O, and C-N bond cleavage. During this funding period, we plan to carry out examinations of: (a) the effects of various reaction conditions on radical-initiated and Lewis acid-catalyzed C-S bond cleavages; (b) the effects of caustic impregnation and subsequent alcoholic reflux on C-S bond cleavage strategies; (c) the reactions of coal model compounds with electron-deficient substrates; (d) examinations of photooxidative C-S bond cleavage reactions; (e) the effects of moderate (300--400{degrees}C) temperatures and pressures as well as ultrasonic radiation on (a) - (c). Also planned are differential scanning calorimetric (DSC) examinations of selected C-S bond cleavage protocols, including those on Illinois coals that possess varying amounts of organic and inorganic sulfur.

  4. 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.

  5. 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.

  6. 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...

  7. 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...

  8. 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

  9. 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.

  10. 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.

  11. Protocols for the selective cleavage of carbon-sulfur bonds in coal. Technical report, December 1, 1991--February 29, 1992

    SciTech Connect

    Bausch, M.

    1992-08-01

    Planned in this project ``Protocols for the Selective Cleavage of Carbon-Sulfur Bonds in Coal`` are reactions in which organic free radicals and/or organic anions are allowed to react with physically cleaned Illinois coal and sulfur-containing coal model compounds. This quarterly report contains the results of photooxidation of coal model compounds, namely, benzyl phenyl sulfide, phenylsulfide, dibenzothiophene, benzothiophene and thiophene, in the presence of 9,10-dicyanoanthracene or anthracene. Quantitative product analysis for the matrix of reactions whereby the coal model compounds are subjected to various solvents and temperature changes is presented in this quarterly report. Further quantitative analyses of the products are being undertaken.

  12. 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.

  13. Coal tar residues produce both DNA adducts and oxidative DNA damage in human mammary epithelial cells.

    PubMed

    Leadon, S A; Sumerel, J; Minton, T A; Tischler, A

    1995-12-01

    In the present study we compare the metabolic activation of coal tar, as measured by the production of both DNA adducts and oxidative DNA damage, with that of a single carcinogen that is a constituent of this complex mixture in human mammary epithelial cells (HMEC). We find that a significant level of DNA adducts, detected by 32P-postlabeling, are formed in HMEC following exposure to coal tar residues. This treatment also results in the generation of high levels of oxidative DNA damage, as measured by the production of one type of oxidative base modification, thymine glycols. The amounts of both DNA adducts and thymine varied considerably between the various coal tar residues and did not correlate with either the total amount of polycyclic aromatic hydrocarbons (PAH) or the amount of benzo[a]pyrene (B[a]P) present in the residue. Fractionating the residue from one of the sites by sequential extraction with organic solvents indicated that while the ability to produce both types of DNA damage was contained mostly in a hexane-soluble fraction, a benzene-soluble fraction produced high levels of reactive oxygens relative to the number of total DNA adducts. We find that the total amount of PAH or B[a]P present in the coal tars from the various sites was not a predictor of the level of total DNA damage formed.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Ecology of Iron-Oxidizing Bacteria in Pyritic Materials Associated with Coal

    PubMed Central

    Belly, R. T.; Brock, T. D.

    1974-01-01

    A technique was developed for measuring 14CO2 uptake by chemolithotrophic bacteria directly in pyritic materials associated with coal and coal refuse. There was good correlation between 14CO2 uptake, as determined by this technique, and the most probable number of iron-oxidizing bacteria. Maximal 14CO2 uptake occurred in coal refuse material 2 to 3 years old, and only slight incorporation was demonstrated in fresh material or material 40 years old. Samples taken from the surface of the coal refuse pile always demonstrated maximal 14CO2 uptake, and in most samples, only slight activity was demonstrated at depths below 8 to 10 cm. Optimal uptake of 14CO2 by natural samples occurred at 20 to 30 C and at a moisture content of between 23 and 35%. In addition to chemolithotrophic bacteria, heterotrophic fungi and yeasts were also routinely isolated in high numbers from acidic coal refuse. In contrast, acidophilic, heterotrophic bacteria were either absent or present in low numbers in such acidic samples. PMID:4811543

  20. 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.

  1. COAL CLEANING VIA LIQUID-FLUIDIZED CLASSIFICAITON (LFBC) WITH SELECTIVE SOLVENT SWELLING

    SciTech Connect

    J. M. Calo

    2000-12-01

    The concept of coal beneficiation due to particle segregation in water-fluidized beds, and its improvement via selective solvent-swelling of organic material-rich coal particles, was investigated in this study. Particle size distributions and their behavior were determined using image analysis techniques, and beneficiation effects were explored via measurements of the ash content of segregated particle samples collected from different height locations in a 5 cm diameter liquid-fluidized bed column (LFBC). Both acetone and phenol were found to be effective swelling agents for both Kentucky No.9 and Illinois No.6 coals, considerably increasing mean particle diameters, and shifting particle size distributions to larger sizes. Acetone was a somewhat more effective swelling solvent than phenol. The use of phenol was investigated, however, to demonstrate that low cost, waste solvents can be effective as well. For unswollen coal particles, the trend of increasing particle size from top to bottom in the LFBC was observed in all cases. Since the organic matter in the coal tends to concentrate in the smaller particles, the larger particles are typically denser. Consequently, the LFBC naturally tends to separate coal particles according to mineral matter content, both due to density and size. The data for small (40-100 {micro}m), solvent-swollen particles clearly showed improved beneficiation with respect to segregation in the water-fluidized bed than was achieved with the corresponding unswollen particles. This size range is quite similar to that used in pulverized coal combustion. The original process concept was amply demonstrated in this project. Additional work remains to be done, however, in order to develop this concept into a full-scale process.

  2. 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.

  3. 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.

  4. Cost comparison of selected US and Colombian coal mines - analyses of cost-structure differences between steam coal mines in US and Colombia

    SciTech Connect

    Not Available

    1986-01-01

    The report presents the results from a study comparing the mine-mouth costs among selected steam-coal mines in Colombia and the United States. The study was done in response to a Congressional request to identify the differences in production costs, and those factors, including mine health, safety, and environmental requirements, that account for the difference. Three sets of mines are compared to determine the basic cost differences in mining between the two coal countries.

  5. Submicrometer elemental carbon as a selective measure of diesel particulate matter in coal mines.

    PubMed

    Birch, M Eileen; Noll, James D

    2004-10-01

    A monitoring method for diesel particulate matter was published as Method 5040 by the National Institute for Occupational Safety and Health (NIOSH). Organic and elemental carbon are determined by the method, but elemental carbon (EC) is a better exposure measure. The US Mine Safety and Health Administration (MSHA) proposed use of NIOSH 5040 for compliance determinations in metal and nonmetal mines. MSHA also published a rulemaking for coal mines, but no exposure standard was provided. A standard based on particulate carbon is not considered practical because of coal dust interference. Interference may not be a problem if an appropriate size-selective sampler and EC exposure standard are employed. Submicrometer dust concentrations found in previous surveys of nondieselized, underground coal mines were relatively low. If a large fraction of the submicrometer dust is organic and mineral matter, submicrometer EC concentrations would be much lower than submicrometer mass concentrations. Laboratory and field results reported herein indicate the amount of EC contributed by submicrometer coal dust is minor. In a laboratory test, a submicrometer EC concentration of 31 microg m(-3) was found when sampling a respirable coal dust concentration over three times the US compliance limit (2 mg m(-3)). Laboratory results are consistent with surveys of nondieselized coal mines, where EC results ranged from below the method limit of detection to 18 microg m(-3) when size-selective samplers were used to collect dust fractions having particle diameters below 1.5 microm-submicrometer EC concentrations were approximate 7 microg m(-3). In dieselized mines, submicrometer EC concentrations are much higher.

  6. 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)

  7. 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.

  8. 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

  9. 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

  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. 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.

  12. Quartz in Coal Dust Deposited on Internal Surface of Respirable Size Selective Samplers

    PubMed Central

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

    2016-01-01

    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. PMID:25204985

  13. 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.

  14. 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.

  15. Emergence of oxyl radicals as selective oxidants.

    PubMed

    Ramasarma, T

    2012-10-01

    Hydroxyl radicals (HO*) are derived in Fenton reaction with ferrous salt and H2O2 in acid medium, and at neutral pH, metal-oxyl radicals (M-O*) predominate. Evidence is accumulating that M-O* radicals are also active in oxidation reactions, in addition to metal-oxo (M=O) now shown in many publications. Reactivity of these radicals gives selective oxidized products useful in cellular activities, in contrast to purported indiscriminate cell damage by hydroxyl radicals. Reactions with vanadium compounds, such as diperoxovanadate, peroxo-bridged mixed valency divanadate, vanadium-oxyl radical, tetravalent vanadyl and decavanadate illustrates selective gain in oxidative capacity of oxo- and oxyl- species. Occurrence of ESR signals typical of hydroxyl radicals is demonstrated in cell homogenates and tissue perfusates treated with spin trap agents. It is known for a long time lipid peroxides are formed in tissue microsomal systems exclusively in presence of salts of iron, among many metals tested. Oxygen and a reducing agent, ascorbate (non-enzymic) or NADPH (enzymic) are required to produce 'ferryl', the chelated Fe=O active form (possibly Fe-O* and Fe-O-O-Fe ?) for the crucial step of H-atom abstraction. Yet literature is replete with unsupported affirmations that hydroxyl radicals initiate lipid peroxidation, an unexplained fixation of mindset. The best-known *OH generator, a mixture of ferrous salt and H2O2, does not promote lipid peroxidation, nor do the many hydroxyl radical quenching agents stop it. The availability of oxo and oxyl-radical forms with transition metals, and also with non metals, P, S, N and V, calls for expansion of vision beyond superoxide and hydroxyl radicals and explore functions of multiple oxygen radicals for their biological relevance.

  16. Catalytic effect of metallic oxides on combustion behavior of high ash coal

    SciTech Connect

    X.G. Li; B.G. Ma; L. Xu; Z.T. Luo; K. Wang

    2007-09-15

    By means of thermogravimetric analysis, the catalytic effect of metallic oxides (CuO, Fe{sub 2}O{sub 3}, and ZnO) on the combustion behavior of high-ash coal was investigated under nonisothermal conditions. Experiments were conducted from ambient temperature to 1000{sup o}C at a heating rate of 20{sup o}C{center_dot}min{sup -1}. The ignition temperature, burnout performance, and exothermic behavior were used to evaluate the catalytic effect. Moreover, the kinetics parameters (activation energy and pre-exponential factor) were determined using the Coats-Redfern method. It is indicated that, compared with the combustion characteristics of high-ash coal, the ignition temperature of the samples with metallic oxides decreases by 8-50{sup o}C. Metallic oxides can speed up the combustion rate and burnout of the fixed carbon. The exothermic values of samples incorporating metallic oxides increase by 15-30%, which may be due to the catalytic effect of metallic oxides on fixed carbon combustion. The activation energies of the samples decrease, and there is a linear connection between the activation energies and pre-exponential factors (ln A = 0.2683 x E-12.807). 19 refs., 2 figs., 2 tabs.

  17. 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.

  18. 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

  19. Effects of coal syngas impurities on anodes of solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Cayan, Fatma Nihan; Zhi, Mingjia; Pakalapati, Suryanarayana Raju; Celik, Ismail; Wu, Nianqiang; Gemmen, Randall

    A literature review is conducted to summarize the studies on the identification of impurities in coal syngas and their effects on the performance of Ni-yttria stabilized zirconia (Ni-YSZ) anode of solid oxide fuel cells (SOFCs). Coal syngas typically contains major species, CO, H 2, CO 2, H 2O, CH 4, N 2, and H 2S as well as trace impurities. Thermodynamic equilibrium calculations have indicated that trace impurities species such as Be, Cr, K, Na, and V in the coal syngas form condensed phases under warm gas cleanup conditions and can be effectively removed by the cleanup processes. For meaningful data comparison, a practical parameter is formulated to quantify the level of degradation normalized with respect to the relevant experimental parameters. Experimental results show that the existence of Hg, Si, Zn and NH 3 in the coal syngas does not significantly affect the performance of the Ni-YSZ anode. The presence of Cd and Se in the syngas impacts the SOFC anode performance to some extent. Impurity species such as Cl, Sb, As, and P cause severe cell voltage degradation due to attack on the Ni-YSZ anode. Sb, As and P have the potential to react with Ni to form secondary phases in the Ni-YSZ anode, which deteriorate the catalytic activity of the anode.

  20. 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.

  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. 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.

  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. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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).

  17. 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.

  18. 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.

  19. 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. Copyright © 2007 Elsevier B.V. All rights reserved.

  20. 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.

  1. 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.

  2. 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.

  3. Evolution of dissolved organic matter during abiotic oxidation of coal tar--comparison with contaminated soils under natural attenuation.

    PubMed

    Hanser, Ogier; Biache, Coralie; Boulangé, Marine; Parant, Stéphane; Lorgeoux, Catherine; Billet, David; Michels, Raymond; Faure, Pierre

    2015-01-01

    In former coal transformation plants (coking and gas ones), the major organic contamination of soils is coal tar, mainly composed of polycyclic aromatic compounds (PACs). Air oxidation of a fresh coal tar was chosen to simulate the abiotic natural attenuation impact on PAC-contaminated soils. Water-leaching experiments were subsequently performed on fresh and oxidized coal tars to study the influence of oxidation on dissolved organic matter (DOM) quality and quantity. The characterization of the DOM was performed using a combination of molecular and spectroscopic techniques (high-performance liquid chromatography-size-exclusion chromatography (HPLC-SEC), 3D fluorescence, and gas chromatography coupled with mass spectrometry (GC-MS)) and compared with the DOM from contaminated soils sampled on the field exposed to natural attenuation for several decades. An increase in the oxygenated polycyclic aromatic compound concentrations was observed with abiotic oxidation both in the coal tar and the associated DOM. Polycyclic aromatic hydrocarbon concentrations in the leachates exceeded pure water solubility limits, suggesting that co-solvation with other soluble organic compounds occurred. Furthermore, emission excitation matrix analysis combined with synchronous fluorescence spectra interpretation and size-exclusion chromatography suggests that oxidation induced condensation reactions which were responsible for the formation of higher-molecular weight compounds and potentially mobilized by water. Thus, the current composition of the DOM in aged soils may at least partly result from (1) a depletion in lower-molecular weight compounds of the initial contamination stock and (2) an oxidative condensation leading to the formation of a higher-molecular weight fraction. Abiotic oxidation and water leaching may therefore be a significant combination contributing to the evolution of coal tar-contaminated soils under natural attenuation.

  4. Monolithic solid oxide fuel cell technology advancement for coal-based power generation

    SciTech Connect

    Not Available

    1992-04-14

    The program is conducted by a team consisting of AiResearch Los Angeles Division of Allied-Signal Aerospace Company 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.

  5. 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.

  6. Interaction of coal-derived synthesis gas impurities with solid oxide fuel cell metallic components

    SciTech Connect

    Marina, Olga A.; Pederson, Larry R.; Coyle, Christopher A.; Edwards, Danny J.; Chou, Y. S.; Cramer, Carolyn N.

    2010-05-28

    Chromium-containing iron-based alloys Crofer22 APU and SS 441 and nickel-based alloy Inconel600, all commonly used in a solid oxide fuel cell (SOFC) stack as interconnect materials, heat exchanger and gas feeding pipes, were exposed at 700-850oC to a synthetic coal gas containing ≤2 ppm phosphine, arsine, sulfur and antimony. Samples were characterized by SEM/EDS and XRD to monitor the secondary phase formation. Exposure of ferritic stainless steels to P led to the formation of surface Cr-Mn-P-O and Fe-P-O compounds and increased temperatures accelerated the rate of interactions. Fewer interactions were observed after exposures to As and Sb. No sulfur containing compounds were found. Nickel-based alloy exhibited much stronger interactions with As and P in comparison with ferritic steels and the arsenic interactions were particularly strong. The difference between the iron- and nickel-based alloys is explained by the different chemistry and morphology of the scales grown on the alloy surfaces in coal gas. While P and As interactions with the metallic parts in the SOFC are likely to mitigate the nickel/zirconia anode poisoning, the other degradation mechanisms should be taken into consideration to avoid potential stack failures. Manganese spinels were found to be effective as phosphorus getters and could be used in coal gas cleanup.

  7. 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

  8. 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)

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  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. 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.

  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. 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.

  1. 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.

  2. Subsurface oxidation of pyritic coal-cleaning wastes by chemoautotrophic bacteria. [51 references

    SciTech Connect

    Schubert, J.P.; Miller, R.M.

    1982-11-01

    The presence of the iron-oxidizing bacterium Thiobacillus ferrooxidans was investigated in groundwater and surface water at two coal refuse disposal sites in southwestern Illinois. Piezometers placed in the saturated bases of reclaimed and unreclaimed refuse piles showed high populations of the bacteria. The reclaimed pile had lower populations than did the unreclaimed coal refuse, suggesting that the reclamation effort may have caused a decline in subsurface Thiobacillus population levels. Acidic runoff water from the two piles also contained T. ferrooxidans but the levels encountered are not as high as those found in the saturated bases. Population levels of T. ferrooxidans were not high in till below the gob pile or in slurry material at the Staunton site. This may be attributed to the lower acidity and dissolved iron concentrations in groundwater at these locations, as well as to the lack of pyrite in the till and slurry material. Statistical analysis of T. ferrooxidans populations and six water quality variables for runoff and groundwater samples from the two sites showed that all seven variables were significantly intercorrelated. More samples and additional variables must be evaluated before cause/effect relationships can be determined. High populations of T. ferrooxidans were found in the saturated bases of the two refuse piles, despite low levels (< 0.5 mg/L) of dissolved oxygen. If these bacteria can catalyze pyrite oxidation under the conditions present, reduction of acid formation by refuse burial may not be successful.

  3. 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

  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. Boiler materials for ultra-supercritical coal power plants—Steamside oxidation

    NASA Astrophysics Data System (ADS)

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

    2006-06-01

    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.

  6. Microbial Oxidation of Ethane within Seep Sediment at Coal Oil Point, Santa Barbara, CA

    NASA Astrophysics Data System (ADS)

    Mendes, S. D.; Duncombe, R.; Scarlett, R. D.; Shaffer, J.; Lensch, S.; Valentine, D. L.

    2013-12-01

    The hydrocarbon seep field at Coal Oil Point (COP), off the coast of Santa Barbara, California, releases more than 10^10 g of thermogenic natural gas each year. Only a fraction of this methane, ethane, propane, and butane reaches the atmosphere, and is instead consumed by marine microbes in both the sediment and water column. Bacterial respiration of these gases has been observed in aerobic and anaerobic conditions, with the exception of ethane (aerobic only) (Kniemeyer et. al 2007). This work seeks to quantify the rate of ethane oxidation (both aerobic and anaerobic) in marine sediment. A series of experiments, to be conducted using COP seep sediment aboard the R/V Atlantis in October 2013, will test how varying oxygen conditions impact ethane oxidation rate. Oxidation rates will be quantified using sensitive 3H-ethane tracers. Preliminary data from Shane's Seep, located within the COP seep field, indicates that ethane oxidation is restricted to the top 6 cm of sediment. This suggests that oxygen is a limiting factor, but further work is needed to establish if ethane oxidation is restricted to exclusively aerobic environments.

  7. Methane and carbon dioxide emissions from selected U.S. coal production regions and coal-fired power plants

    NASA Astrophysics Data System (ADS)

    Peischl, J.; Ryerson, T. B.; Trainer, M.

    2016-12-01

    Coal and natural gas each fueled 33% of the total electric power generated in the United States in 2015. Combined-cycle natural-gas-fired power plants emit less than half of the carbon dioxide per unit power produced than do coal-fired power plants. However, methane emissions prior to combustion as fuel must also be accounted for in order to determine the total greenhouse gas footprint of a fuel type choice. While many studies over the past few years have focused on methane emissions associated with natural gas production and its use, relatively few studies have focused on methane emissions associated with coal production and its use in coal-fired power plants. We present airborne methane data from two studies to quantify emissions from coal production regions in Alabama and Wyoming. We additionally quantify carbon dioxide and methane emissions from several coal-fired power plants. Our top-down emission estimates are then compared to the EPA greenhouse gas inventory when possible.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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

  13. Protocols for the selective cleavage of carbon-sulfur bonds in coal. Quarterly report, September 1, 1991--November 30, 1991

    SciTech Connect

    Bausch, M.

    1991-12-31

    Removal of the organic sulfur in coal constitutes one of the major challenges facing fossil fuel scientists today. A cost--effective of desulfurizing Illinois coal is non-existent at the present time. Research in our group aims to develop a simple protocol for sulfur removal by gaining understanding of how various additives can enhance the rates of C-S bond cleavage in Illinois coal and coal model compounds, relative to fragmentation of the coal macromolecule via C-C, C-O, and C-N bond cleavage. During this funding period, we plan to carry out examinations of: (a) the effects of various reaction conditions on radical-initiated and Lewis acid-catalyzed C-S bond cleavages; (b) the effects of caustic impregnation and subsequent alcoholic reflux on C-S bond cleavage strategies; (c) the reactions of coal model compounds with electron-deficient substrates; (d) examinations of photooxidative C-S bond cleavage reactions; (e) the effects of moderate (300--400{degrees}C) temperatures and pressures as well as ultrasonic radiation on (a) - (c). Also planned are differential scanning calorimetric (DSC) examinations of selected C-S bond cleavage protocols, including those on Illinois coals that possess varying amounts of organic and inorganic sulfur.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Coal and tire burning mixtures containing ultrafine and nanoparticulate materials induce oxidative stress and inflammatory activation in macrophages.

    PubMed

    Gasparotto, Juciano; Somensi, Nauana; Caregnato, Fernanda F; Rabelo, Thallita K; DaBoit, Kátia; Oliveira, Marcos L S; Moreira, José C F; Gelain, Daniel P

    2013-10-01

    Ultra-fine and nano-particulate materials resulting from mixtures of coal and non-coal fuels combustion for power generation release to the air components with toxic potential. We evaluated toxicological and inflammatory effects at cellular level that could be induced by ultrafine/nanoparticles-containing ashes from burning mixtures of coal and tires from an American power plant. Coal fly ashes (CFA) samples from the combustion of high-S coal and tire-derived fuel, the latter about 2-3% of the total fuel feed, in a 100-MW cyclone utility boiler, were suspended in the cell culture medium of RAW 264.7 macrophages. Cell viability, assessed by MTT reduction, SRB incorporation and contrast-phase microscopy analysis demonstrated that CFA did not induce acute toxicity. However, CFA at 1mg/mL induced an increase of approximately 338% in intracellular TNF-α, while release of this proinflammatory cytokine was increased by 1.6-fold. The expression of the inflammatory mediator CD40 receptor was enhanced by 2-fold, the receptor for advanced glycation endproducts (RAGE) had a 5.7-fold increase and the stress response protein HSP70 was increased nearly 12-fold by CFA at 1mg/mL. Although CFA did not induce cell death, parameters of oxidative stress and reactive species production were found to be altered at several degrees, such as nitrite accumulation (22% increase), DCFH oxidation (3.5-fold increase), catalase (5-fold increase) and superoxide dismutase (35% inhibition) activities, lipoperoxidation (4.2 fold-increase) and sulfhydryl oxidation (40% decrease in free SH groups). The present results suggest that CFA containing ultra-fine and nano-particulate materials from coal and tire combustion may induce sub-chronic cell damage, as they alter inflammatory and oxidative stress parameters at the molecular and cellular levels, but do not induce acute cell death. © 2013.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Exposure assessment for nitrogen oxides and carbon monoxide in German hard coal mining.

    PubMed

    Dahmann, Dirk; Morfeld, Peter; Monz, Christian; Noll, Birgit; Gast, Frank

    2009-11-01

    The exposure situation of German hard coal miners with respect to the components nitrogen monoxide and nitrogen dioxide. Carbon monoxide was measured additionally and the results are displayed but not discussed in detail in this paper. The data were used to estimate personal long-term exposures in an inception cohort. For all three components, time weighted 8-h shift values were determined for typical groups of coalminers according to the European measurement standard. An expert panel from the coal mining company made an effort to estimate major potential changes in the exposure situation. The main sources of nitrogen oxides and carbon monoxide in hard coal mining were the diesel engines. Blasting fumes contributed only to a lesser degree and with different exposure characteristics, e.g. much reduced NO(2) levels compared to the mines' rear areas. As rough 8 h-shift averages describing the current exposure situation, we found 1.35 ppm NO and 0.21 ppm NO(2) for the diesel engine drivers. Blasting specialists were more difficult to evaluate but rough 8 h-shift averages of 0.84 ppm NO and 0.014 ppm NO(2) could be estimated from our measurement series. By applying these data and the estimates of experts about the retrospective exposure situation to a cohort of 1,369 coalminers, we derived mean (max) cumulative exposures in ppm x number of shifts of 1,748 (5,928) for NO and 19.6 (1,013) for NO(2) when summarizing over the follow-up period from 1974 until 1998. Especially for the diesel engine drivers, exposure can be regarded as rather high, in particular, when compared to recommended limits by SCOEL and MAK, though the exposures have been in line with the enforced German occupational exposure limits. Whether this exposure situation has caused adverse health effects will be investigated epidemiologically.

  5. 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

  6. 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

  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. Selenium Adsorption onto Iron Oxide Layers beneath Coal-Mine Overburden Spoil.

    PubMed

    Donovan, Joseph J; Ziemkiewicz, Paul F

    2013-09-01

    A field experimental study to determine the feasibility of sequestering dissolved selenium (Se) leached from coal-mine waste rock used an iron (Fe)-oxide amendment obtained from a mine-drainage treatment wetland. Thirty lysimeters (4.9 × 7.3 m), each containing 57.7 t (1.2-1.8 m thickness) of mine-run carbonaceous shale overburden, were installed at the Hobet mine in southeastern West Virginia. The fine-grained Fe-oxide was determined to be primarily metal oxides (91.5% ferric and 4.37% aluminous), with minor (<3%) SO and Ca, perhaps as gypsum. The mineralogy of the Fe was goethite, although residual ferrihydrite may have been present. Various thicknesses of this amendment (0.0064, 0.057, 0.229, and 0.457 m, plus a zero-amendment control) were used, ranging from 0 to 2.2% weight percent of the spoil. The control and each treatment were replicated six times to estimate uncertainty due to compositional and hydrological variation. Infiltration of rainfall created leachate that drained to individual batch-collection tanks that were sampled 46 times at approximately 2-wk intervals from 2010 to 2012. Basal Fe-oxide layers in the three highest amendment categories removed up to 76.1% selenium (in comparison to unamended piles) from leachate by adsorption. Only lysimeters with very thin Fe-oxide layers showed no significant reduction compared with unamended piles. Reproducibility of replicates was within acceptable limits for amended and unamended lysimeters. Results indicate that in situ amendment using Fe-oxide obtained from treatment of mine water can sequester Se by adsorption on surfaces of goethite and possibly also ferrihydrite. This process is demonstrated to substantially reduce dissolved Se in leachate and improve compliance with regulatory discharge limits. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  9. Recent advances in heterogeneous selective oxidation catalysis for sustainable chemistry.

    PubMed

    Guo, Zhen; Liu, Bin; Zhang, Qinghong; Deng, Weiping; Wang, Ye; Yang, Yanhui

    2014-05-21

    Oxidation catalysis not only plays a crucial role in the current chemical industry for the production of key intermediates such as alcohols, epoxides, aldehydes, ketones and organic acids, but also will contribute to the establishment of novel green and sustainable chemical processes. This review is devoted to dealing with selective oxidation reactions, which are important from the viewpoint of green and sustainable chemistry and still remain challenging. Actually, some well-known highly challenging chemical reactions involve selective oxidation reactions, such as the selective oxidation of methane by oxygen. On the other hand some important oxidation reactions, such as the aerobic oxidation of alcohols in the liquid phase and the preferential oxidation of carbon monoxide in hydrogen, have attracted much attention in recent years because of their high significance in green or energy chemistry. This article summarizes recent advances in the development of new catalytic materials or novel catalytic systems for these challenging oxidation reactions. A deep scientific understanding of the mechanisms, active species and active structures for these systems are also discussed. Furthermore, connections among these distinct catalytic oxidation systems are highlighted, to gain insight for the breakthrough in rational design of efficient catalytic systems for challenging oxidation reactions.

  10. 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 .

  11. 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.

  12. Coulomb explosion sputtering of selectively oxidized Si

    NASA Astrophysics Data System (ADS)

    Karmakar, P.; Bhattacharjee, S.; Naik, V.; Sinha, A. K.; Chakrabarti, A.

    2010-05-01

    We have studied the sputtering of a unique system comprising of coexisting silicon and silicon oxide surfaces due to the impact of multiply charged Arq + ions. Such surfaces are produced by oblique angle oxygen ion bombardment on Si(100), which results in one side oxidized ripple formation due to preferential oxygen implantation. It is observed by atomic force microscopy and conducting atomic force microscopy studies that the higher the potential energy of the Arq + ion, the higher the sputtering yield of the nonconducting (oxide) side of the ripple as compared to the semiconducting side while ensuring an identical irradiation and measurement condition. It also shows experimentally the potential of highly charged ions in the gentle cleaning or tailoring of nanostructures. The results are explained in terms of the Coulomb explosion model, where potential sputtering depends on the conductivity of the ion impact sites.

  13. 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...

  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. 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...

  16. 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...

  17. 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...

  18. 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.

  19. Method for determining coal carbon in the reclaimed minesoils contaminated with coal

    SciTech Connect

    Ussiri, D.A.N.; Lai, R.

    2008-01-15

    Minesoils developed on the reclaimed surface-mined sites for coal are contaminated with coal particles resulting from mining and reclamation activities. Therefore, the total organic carbon (TOC) pool in these sites is a mixture of coal and plant-derived recent soil organic carbon (SOC). Accurate estimates of SOC pools and C sequestration rates in the reclaimed minesoils (RMS) is limited by the lack of a standard and cost-effective method for determination of coal C concentrations in the RMS. The chemi-thermal method, based on the oxidative resistance of coal, was developed and validated with radiocarbon analysis using selected artificial soil-coal mixtures and minesoil samples. Radiocarbon analysis of RMS samples indicated that minesoils from the top 10-cm depth developing from topsoil applied during reclamation was coal C free. The contribution of coal C and the radiocarbon age of TOC increased with increasing soil depth. The coal C fraction accounted for 0 to 92% of TOC in the RMS samples. The coal C fraction was highly correlated with {delta}{sup 13}C (r{sup 2} = 0.84), suggesting that stable isotope composition could estimate the coal C concentration in RMS samples. Analysis of coal and artificial soil and coal mixtures indicated that chemi-thermal treatment was effective in removing recent SOC with minimum effect on coal. Analysis of RMS samples indicated that both radiocarbon activity and the chemi-thermal method were effective in estimating coal C concentration in RMS of southeast Ohio. The coal C concentrations for both methods were highly correlated (r{sup 2} = 0.95), suggesting that the chemi-thermal method was as effective as radiocarbon activity measurement in estimating coal C concentration in these soils.

  20. 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.

  1. 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.

  2. Surface properties of photo-oxidized bituminous coals. Technical progress report, April 1995--June 1995

    SciTech Connect

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

    1995-08-01

    During this report period, analysis of the vitrinite concentrate samples of the Lower Kittanning (PSOC-1562) and Illinois No. 6 (DECS-24) seams were completed. These results show that the concentrates are in excess of 97 vol. % vitrinite and that the sample remains in good shape for microflotation and GC/MS experiments. Two new coal samples, the hvAb Banner seam (DECS-29) and the mvb Splashdam seam (DECS-30) were collected in mid-June. Preliminary processing of the channel samples suggests that the Banner seam sample is severely weathered and may need to be replaced. Collection of a third sample, the hvBb Ohio No. 4a seam, was delayed until next quarter. Surface oxidation of a powdered vitrinite concentrate sample of the Pittsburgh seam (DECS-23) was completed during this quarter. The technique of photo-oxidizing vitrain samples using our optical microscope was laborious and time consuming. Even after the procedure was streamlined the procedure of irradiating 1.4 g of vitrinite required 29 days. A limited number of samples will be irradiated in this manner in order to maintain continuity between our fluorometric measurements and microflotation experiments, but other methods of surface oxidation will be explored. Presentations were made at the DOE Contractor`s Review and Peer Review meetings held in Nashville, TN on June 13-14, 1995.

  3. 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.

  4. 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.

  5. 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).

  6. 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

  7. The Nitric Acid Oxidation of Selected Alcohols and Ketones.

    ERIC Educational Resources Information Center

    Field, Kurt W.; And Others

    1985-01-01

    Shows that nitric acid can be used as a rapid, versatile, and economical oxidant for selected organic substances. The experiments (with background information, procedures, and results provided) require one three-hour laboratory period but could serve as open-ended projects since substrates not described could be oxidized. (JN)

  8. 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.

  9. 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.

  10. Indexes of hydrologic data from selected coal-mining areas in northwestern Colorado

    USGS Publications Warehouse

    Gaggiani, N.G.

    1989-01-01

    Currently (1988), data from hydrologic studies related to coal mining that have been done in northwestern Colorado since the early 1970 's are stored in the files of private companies and government offices and in various computer systems. To compile these data for additional research, a trip to each office would have to be made to determine the availability and acceptability of the data. The U.S. Geological Survey, in cooperation with the U.S. Bureau of Land Management and the Colorado Mined Land Reclamation Division, has created a database (COALDATA) that includes stream discharge, groundwater levels, and chemical analysis of water samples that were collected by private companies and government agencies other than the U.S. Geological Survey in and near selected coal mines in northwestern Colorado. Indexes in this report list 93 surface water sites and 95 groundwater sites where hydrologic data are available in the COALDATA data base. The indexes also list 62 surface water sites and 480 groundwater sites in the U.S. Geological Survey data base, which is separate from the COALDATA data base and contains only data collected by the U.S. Geological Survey. The combined output of the COALDATA data base and the U.S. Geological Survey data base provides surface water and groundwater data that include most of the study area. (USGS)

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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. Copyright © 2015. Published by Elsevier B.V.

  2. 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.

  3. Photoelectrochemical Catalysis toward Selective Anaerobic Oxidation of Alcohols.

    PubMed

    Zhang, Ruikang; Shao, Mingfei; Li, Zhenhua; Ning, Fanyu; Wei, Min; Evans, David G; Duan, Xue

    2017-06-16

    Selective oxidation of alcohols to aldehydes plays an important role in perfumery, pharmaceuticals, and agrochemicals industry. Different from traditional catalysis or photocatalytic process, here we report an effective photoelectrochemical (PEC) approach for selective anaerobic oxidation of alcohols accompanied with H2 production by means of solar energy. By using TiO2 nanowires modified with graphitic carbon layer as photoanode, benzyl alcohol (BA) has been oxidized to benzaldehyde with high efficiency and selectivity (>99 %) in aqueous media at room temperature, superior to individual electrocatalytic or photocatalytic processes. Moreover, this PEC synthesis method can be effectively extended to the oxidation of several other aryl alcohols to their corresponding aldehydes under mild conditions. The electron spin resonance (ESR) results indicate the formation of intermediate active oxygen (O2(.-) ) on the photoanode, which further reacts with alcohols to produce final aldehyde compounds. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. 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.

  5. 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.

  6. 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

  7. Method for selective catalytic reduction of nitrogen oxides

    DOEpatents

    Mowery-Evans, Deborah L [Broomfield, CO; Gardner, Timothy J [Albuquerque, NM; McLaughlin, Linda I [Albuquerque, NM

    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.

  8. 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.

  9. 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.

  10. 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.

  11. Effects of pretreatment of coal by CO{sub 2} on nitric oxide emission and unburned carbon in various combustion environments

    SciTech Connect

    Gathitu, B.B.; Chen, W.Y.

    2009-12-15

    Polar solvents are known to swell coal, break hydrogen bonds in the macromolecular structure, and enhance coal liquefaction efficiencies. The effects of the pretreatment of coal using supercritical CO{sub 2} on its physical structure and combustion properties have been studied at the bench-scale level. Emphasis has been placed on NO reburning, NO emissions during air-fired and oxy-fired combustion, and loss on ignition (LOI). Pretreatment was found to increase porosity and to significantly alter the fuel nitrogen reaction pathways. Consequently, NO reduction during reburning using bituminous coal increased, and NO emissions during oxidation of lignite decreased. These two benefits were achieved without negative impacts on LOI.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Separation of aromatic carboxylic acids using quaternary ammonium salts on reversed-phase HPLC. 2. Application for the analysis of Loy Yang coal oxidation products

    SciTech Connect

    Kawamura, K.; Okuwaki, A.; Verheyen, T.V.; Perry, G.J.

    2006-07-01

    In order to develop separation processes and analytical methods for aromatic carboxylic acids for the coal oxidation products, the separation behavior of aromatic carboxylic acids on a reversed-phase HPLC using eluent containing quaternary ammonium salt was optimized using the solvent gradient method. This method was applied for the analysis of Loy Yang coal oxidation products. It was confirmed that the analytical data using this method were consistent with those determined using gas chromatography.

  17. 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

  18. 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.

  19. 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.

  20. Protocols for the selective cleavage of carbon-sulfur bonds in coal. Technical report, March 1, 1992--May 30, 1992

    SciTech Connect

    Bausch, M.

    1992-10-01

    Chemical reactions that result in carbon-sulfur bond cleavage are an essential aspect of any protocol designed to remove organic sulfur from coal. Unfortunately, several classes of reactions that lead to carbon-sulfur bond cleavage are not well understood. Planned in ``Protocols for the Selective Cleavage of Carbon-Sulfur Bonds in Coal`` are reactions in which organic sulfur-containing coal model compounds are subjected to different conditions of temperature, solvent mixtures and radiation. Summarized in this quarterly report are results of our investigations of the following topics: (a) the reactions of coal model compounds, namely, benzyl phenyl sulfide (BPS), diphenyl sulfide (hereafter referred to as phenylsulfide, PS) and dibenzothiophene (DBT) with various reagents (Lewis acid catalysts, radical initiators, electron acceptors) using different solvents and temperature in an attempt to maximize the degree of carbon-sulfur (C-S) bond cleavage; and (b) the results of photooxidation of coal model compounds under controlled conditions. Quantitative product analyses are presented in this report.

  1. 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

  2. Thermodynamic simulation of transfer of lead, cadmium, and zinc to the gas phase during oxidative and reductive thermal treatment of coals from some coal deposits of the Russian federation

    SciTech Connect

    L.N. Lebedeva; L.A. Kost; E.G. Gorlov; E.V. Samuilov

    2007-02-15

    The results of thermodynamic study of the distribution of Pb, Cd, and Zn during the thermal processing of coals from the Kuznetsk and Moscow basins and the Berezovskoe coal deposit of the Kansk-Achinsk basin at different excess oxidant (air) factors and in an inert (argon) medium are presented. The equilibrium forms of compounds were revealed, and their concentrations in the gas and condensed phase were calculated. Trace elements get into the gas phase during the heat treatment of coals in both oxidizing and reducing media. Their most intense transfer to the gas phase takes place at a = 0.4. An increase in temperature enhances this process, and an increase in the ash content of coal decreased the extent of transfer. 9 refs., 10 tabs.

  3. 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%.

  4. Ti-STT: a new zeotype shape selective oxidation catalyst.

    PubMed

    Eilertsen, Einar André; Giordanino, Filippo; Lamberti, Carlo; Bordiga, Silvia; Damin, Alessandro; Bonino, Francesca; Olsbye, Unni; Lillerud, Karl Petter

    2011-11-21

    A new zeotype titanium silicate oxidation catalyst with the STT topology has been synthesized from direct synthesis. Ti-STT has a microporous structure with small pore openings, allowing shape selective oxidation catalysis. The isomorphous substitution of Si by Ti in the framework has been confirmed by Raman, FT-IR, UV-VIS and XANES spectroscopies. This journal is © The Royal Society of Chemistry 2011

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  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. 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.

  13. Selective placement of carbon nanotubes on metal-oxide surfaces.

    PubMed

    Hannon, J B; Afzali, A; Klinke, Ch; Avouris, Ph

    2005-09-13

    We describe a method to selectively position carbon nanotubes on Al2O3 and HfO2 surfaces. The method exploits the selective binding of alkylphosphonic acids to oxide surfaces with large isoelectric points (i.e. basic rather than acidic surfaces). We have patterned oxide surfaces with acids using both microcontact printing and conventional lithography. With proper choice of the functional end group (e.g., -CH3 or -NH2), nanotube adhesion to the surface can be either prevented or enhanced.

  14. 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

  15. 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.

  16. 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.

  17. Oxygen transport and pyrite oxidation in unsaturated coal-mine spoil

    USGS Publications Warehouse

    Guo, Weixing; Cravotta, Charles A.

    1996-01-01

    An understanding of the mechanisms of oxygen (02) transport in unsaturated mine spoil is necessary to design and implement effective measures to exclude 02 from pyritic materials and to control the formation of acidic mine drainage. Partial pressure of oxygen (Po2) in pore gas, chemistry of pore water, and temperature were measured at different depths in unsaturated spoil at two reclaimed surface coal mines in Pennsylvania. At mine 1, where spoil was loose, blocky sandstone, Po2 changed little with depth, decreasing from 21 volume percent (vol%) at the ground surface to a minimum of about 18 vol% at 10 m depth. At mine 2, where spoil was compacted, friable shale, Po2 decreased to less than 2 vol% at depth of about 10 m. Although pore-water chemistry and temperature data indicate that acid-forming reactions were active at both mines, the pore-gas data indicate that mechanisms for 0 2 transport were different at each mine. A numerical model was developed to simulate 02 transport and pyrite oxidation in unsaturated mine spoil. The results of the numerical simulations indicate that differences in 02 transport at the two mines can be explained by differences in the air permeability of spoil. Po2 changes little with depth if advective transport of 02 dominates as at mine 1, but decreases greatly with depth if diffusive transport of 02 dominates, as in mine 2. Model results also indicate that advective transport becomes significant if the air permeability of spoil is greater than 10-9 m2, which is expected for blocky sandstone spoil. In the advective-dominant system, thermally-induced convective air flow, as a consequence of the exothermic oxidation of pyrite, supplies the 02 to maintain high Po2 within the deep unsaturated zone.

  18. 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.

  19. 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.

  20. Erosion-corrosion of selected metals in coal washing plant environments

    SciTech Connect

    Hoey, G.R.; Bednar, J.S.

    1983-04-01

    The erosion-corrosion wear resistance of C1020 mild steel, C1062 carbon steel at 4 hardness values, Ni-hard cast iron, 4 stainless steels and titanium was assessed in coal-water slurries. Corrosion resistance was found to be more important than hardness for wear resistance of these metals in coal slurries. The best overall performance of the metals tested was obtained from oxidised Ti. Cathodic protection was effective in greatly reducing the wear rate of C1020 steel in coal slurries. De-aeration reduced wear rates of C1020, C1062, Ni-hard and 440C SS. Data are presented on the effect of velocity, particle size, coal concentration, and dissolved oxygen concentration on erosion-corrosion of these metals in coal slurries.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Single transverse mode selectively oxidized vertical cavity lasers

    SciTech Connect

    CHOQUETTE,KENT D.

    2000-04-18

    Vertical cavity surface emitting laser (VCSEL) sources have been adopted into Gigabit Ethernet applications in a remarkably short time period. VCSELs are particularly suitable for multimode optical fiber local area networks (LANs), due to their reduced threshold current, circular output beam, and inexpensive and high volume manufacture. Moreover, selectively oxidized VCSELs are nearly ideal LAN sources since the oxide aperture within the laser cavity produces strong electrical and optical confinement which enables high electrical to optical conversion efficiency and minimal modal discrimination allowing emission into multiple transverse optical modes. In addition to the large demand for multimode lasers, VCSELs which emit into a single optical mode are also increasingly sought for emerging applications, which include data communication with single mode optical fiber, bar code scanning, laser printing, optical read/write heads, and modulation spectroscopy. To achieve single mode selectively oxidized VCSELs is a challenging task, since the inherent index confinement within these high performance lasers is very large.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. Mean annual streamflow of selected drainage basins in the coal area of southeastern Montana

    USGS Publications Warehouse

    Ferreira, Rodger F.

    1981-01-01

    Streamflow characteristics of drainage basins within the Forst Union coal region of southeastern Montana were estimated to provide premining data for evaluating the future effects of mining on the environment. Estimated annual mean streamflow at 22 data-collection stations for water years 1975-77 ranged from 0 to 887 cubic feet per second. These estimates are based on miscellaneous-streamflow records at each station and continuous-streamflow records from other stations in the study area. Estimated mean annual streamflow for a 10-year period (water years 1968-77) ranged from 0 to 572 cubic feet per second. These long-term estimates were based on data from stations in the surrounding area having continuous-streamflow records. Estimates mean annual runoff in inches for selected drainage basins within the study area showed no discernible pattern. Many of the drainage basins had a mean annual runoff of less than 0.60 inch; the maximum observed mean annual runoff was 4.45 inches. (USGS)

  14. 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.

  15. Influence of high carbon monoxide concentration on the carbon dioxide gasification of a selected coal char

    NASA Astrophysics Data System (ADS)

    Tsai, Nancy Ko-Chieh

    2000-11-01

    This study focuses on the effect of high CO concentration on CO2 gasification rates of chars of Illinois #6 coal, a bituminous coal that is industrially important because of its relatively high reactivity and low pollutant emissions. A pressurized thermogravimetric analyzer (PTGA) is used to obtain char gasification mass loss and surface area measurements. The mass loss profiles of Illinois #6 chars were measured at temperatures of 1200 and 1273K and pressures of 1.4, 10, and 25 atm in CO2-CO and CO2-N2 mixtures. CO concentrations between 10%--90% at 1.4 atm and 10%--85% at 25 atm were used. The surface areas of the chars are determined from room-temperature (298K) CO2 adsorption on chars after successive stages of partial gasification. A variable partial pressure gas adsorption technique was developed to effectively utilize the PTGA for CO2 surface area measurements. Using experimental mass loss and surface area data combined with structural and kinetics modeling, an overall gasification curve description of kinetically-limited char-CO2 gasification reactivity is formulated for the life span of the char. The model consists of an intrinsic char reactivity expression with a conversion-dependent surface area modifier. First the surface area modifier is developed based on a random pore model and particle mode of burning relations. It is used with the unified gasification curve concept to interpret the isothermal gasification profiles and extrapolate the data to obtain the reactivity at the onset of char conversion. These isothermal initial char reactivities determined at selected gasification conditions are then used to calculate rate coefficients in the kinetics component of the model. The proposed reaction mechanism contains paths for both gas phase and adsorbed CO to interfere with the gasification of Illinois #6 chars by CO 2. The main effect of adsorbed CO in the range of experimental conditions used in this study is to occupy carbon sites that could otherwise be

  16. 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.

  17. 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.

  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. 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.

  20. 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.

  1. 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

  2. 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).

  3. Selective solvent absorption in coal conversion. Quarterly report, July 1, 1992--September 30, 1992

    SciTech Connect

    Larsen, J.W.; Amui, J.

    1992-12-31

    The objectives of this program include: Determine the importance of the presence of added hydrogen donor compounds within the coal in the first stage of direct liquefaction processes; and to determine the composition of the solvent absorbed by and present within the coal in the first stages of direct coal liquefaction. The scope includes the study of the conversion of Argonne Premium coals in tetralin and 2-t-butyltetralin and a comparison of the following: Conversion to soluble products and product composition. Hydrogen donated by both solvents will be measured by gas chromatography and the same technique will be used to establish the amount of dealkylation of 2-t-butyltetralin. Reactions will be performed at several different temperatures for varying amounts of time.

  4. Selective solvent absorption in coal conversion. Quarterly report, April 1, 1992--June 30, 1992

    SciTech Connect

    Larsen, J.W.; Amui, J.

    1992-06-01

    The objectives of this research 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 stages of direct coal liquefaction. Scope of work study the conversion of Argonne Premium coals in tetralin and 2-t-butyltetralin and compare the following: conversion to soluble products and product composition. Hydrogen donated by both solvents will be measured by gas chromatography and the same technique will be used to establish the amount of dealkylation of 2-t-butyltetralin. Reactions will be performed at several different temperatures for varying amounts of time.

  5. 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.

  6. 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.

  7. Development of a Solid Oxide Fuel Cell for the utilization of coal mine gas

    NASA Astrophysics Data System (ADS)

    Groß, B.; Blum, L.; de Haart, L. G. J.; Dengel, A.

    Apart from natural gas there is another important natural source of methane. The so-called coal mine gas is a by-product of the geochemical process of the carbonization of sediments from marsh woods of the Earth's Carboniferous Period. Methane evaporates from the coal and has to be removed out of the active mines where it represents one of the main safety risks. Methane also evaporates in abandoned coal mines. In the federal state Saarland in Germany exists above ground a more than 110 km pipeline for the drained coal mine gas from 12 different sources. The content of methane varies between 25 and 90%, the oxygen content (from air) is in the range up to 10%. This wide range or variation, respectively, of fuel and oxygen content, causes a lot of problems for the use in conventional engines. Therefore the company Evonik New Energies GmbH is interested in using SOFC with coal mine gas as efficient as possible to produce electric power. For that purpose at Forschungszentrum Jülich the available SOFC technology was adapted to the use with coal mine gas and a test facility was designed to operate an SOFC stack (approximately 2 kW electrical power output) together with a pre-reformer. This paper presents the results of the coal mine gas analysis and the effect on the pre-reformer and the fuel cell. The composition of the coal mine gas was determined by means of micro-gas chromatography. The results obtained from preliminary tests using synthetic and real coal mine gas on the pre-reformer and on the fuel cell are discussed.

  8. 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.

  9. 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.

  10. 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.

  11. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Interaction of coal-derived synthesis gas impurities with solid oxide fuel cell metallic components

    NASA Astrophysics Data System (ADS)

    Marina, Olga A.; Pederson, Larry R.; Coyle, Christopher A.; Edwards, Danny J.; Chou, Yeong-Shyung; Cramer, Carolyn N.

    Oxidation-resistant alloys find use as interconnect materials, heat exchangers, and gas supply tubing in solid oxide fuel cell (SOFC) systems, especially when operated at temperatures below ∼800 °C. If fueled with synthesis gas derived from coal or biomass, such metallic components could be exposed to impurities contained in those fuel sources. In this study, coupons of ferritic stainless steels Crofer 22 APU and SS 441, austenitic nickel-chromium superalloy Inconel 600, and an alumina-forming high nickel alloy alumel were exposed to synthesis gas containing ≤2 ppm phosphorus, arsenic and antimony, and reaction products were tested. Crofer 22 APU coupons coated with a (Mn,Co) 3O 4 protective layer were also evaluated. Phosphorus was found to be the most reactive. On Crofer 22 APU, the (Mn,Cr) 3O 4 passivation layer reacted to form an Mn-P-O product, predicted to be manganese phosphate from thermochemical calculations, and Cr 2O 3. On SS 441, reaction of phosphorus with (Mn,Cr) 3O 4 led to the formation of manganese phosphate as well as an Fe-P product, predicted from thermochemical calculations to be Fe 3P. Minimal interactions with antimony or arsenic in synthesis gas were limited to Fe-Sb and Fe-As solid solution formation. Though not intended for use on the anode side, a (Mn,Co) 3O 4 spinel coating on Crofer 22 APU reacted with phosphorus in synthesis gas to produce products consistent with Mn 3(PO 4) 2 and Co 2P. A thin Cr 2O 3 passivation layer on Inconel 600 did not prevent the formation of nickel phosphides and arsenides and of iron phosphides and arsenides, though no reaction with Cr 2O 3 was apparent. On alumel, an Al 2O 3 passivation layer rich in Ni did not prevent the formation of nickel phosphides, arsenides, and antimonides, though no reaction with Al 2O 3 occurred. This work shows that unprotected metallic components of an SOFC stack and system can provide a sink for P, As and Sb impurities that may be present in fuel gases, and thus complicate

  13. 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

  14. 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.

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

    DOEpatents

    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.

  16. 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.

  17. Selective anaerobic oxidation of methane enables direct synthesis of methanol.

    PubMed

    Sushkevich, Vitaly L; Palagin, Dennis; Ranocchiari, Marco; van Bokhoven, Jeroen A

    2017-05-05

    Direct functionalization of methane in natural gas remains a key challenge. We present a direct stepwise method for converting methane into methanol with high selectivity (~97%) over a copper-containing zeolite, based on partial oxidation with water. The activation in helium at 673 kelvin (K), followed by consecutive catalyst exposures to 7 bars of methane and then water at 473 K, consistently produced 0.204 mole of CH3OH per mole of copper in zeolite. Isotopic labeling confirmed water as the source of oxygen to regenerate the zeolite active centers and renders methanol desorption energetically favorable. On the basis of in situ x-ray absorption spectroscopy, infrared spectroscopy, and density functional theory calculations, we propose a mechanism involving methane oxidation at Cu(II) oxide active centers, followed by Cu(I) reoxidation by water with concurrent formation of hydrogen. Copyright © 2017, American Association for the Advancement of Science.

  18. 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 ...

  19. 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 ...

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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).

  7. 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.

  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. 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...

  10. 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...

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Highly-Efficient Buried-Oxide-Waveguide Laser by selective Oxidation

    SciTech Connect

    VAWTER,GREGORY A.; SPAHN,OLGA B.; ALLERMAN,ANDREW A.; GAO,YING

    2000-02-15

    An edge-emitting buried-oxide waveguide (BOW) laser structure employing lateral selective oxidation of AlGaAs layers above and below the active region for waveguiding and current confinement is presented. This laser configuration has the potential for very small lateral optical mode size and high current confinement and is well suited for integrated optics applications where threshold current and overall efficiency are paramount. Optimization of the waveguide design, oxide layer placement, and bi-parabolic grading of the heterointerfaces on both sides of the AlGaAs oxidation layers has yielded 95% external differential quantum efficiency and 40% wall-plug efficiency from a laser that is very simple to fabricate and does not require epitaxial regrowth of any kind.

  16. 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.

  17. Single transverse mode selectively oxidized vertical cavity lasers

    SciTech Connect

    CHOQUETTE,KENT D.; GEIB,KENT M.; BRIGGS,RONALD D.; ALLERMAN,ANDREW A.; HINDI,JANA JO

    2000-04-26

    Vertical cavity surface emitting lasers (VCSELs) which operate in multiple transverse optical modes have been rapidly adopted into present data communication applications which rely on multi-mode optical fiber. However, operation only in the fundamental mode is required for free space interconnects and numerous other emerging VCSEL applications. Two device design strategies for obtaining single mode lasing in VCSELs based on mode selective loss or mode selective gain are reviewed and compared. Mode discrimination is attained with the use of a thick tapered oxide aperture positioned at a longitudinal field null. Mode selective gain is achieved by defining a gain aperture within the VCSEL active region to preferentially support the fundamental mode. VCSELs which exhibit greater than 3 mW of single mode output power at 850 nm with mode suppression ratio greater than 30 dB are reported.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. A step forwards in ethanol selective photo-oxidation.

    PubMed

    Ciambelli, P; Sannino, D; Palma, V; Vaiano, V; Mazzei, R S

    2009-05-01

    This work focuses on the optimization of a photocatalyst formulation for the selective oxidation of ethanol to acetaldehyde. VO(x)/TiO(2) catalysts at different vanadium loading were studied in a gas-solid photocatalytic fluidized bed reactor at high illumination efficiency, in which the bed is constituted by photocatalyst diluted with alpha-Al(2)O(3) or silica gel. Photocatalytic tests showed the selective formation of acetaldehyde, with ethylene and carbon dioxide as by-products. Selectivity is influenced by the vanadium loading. For ethanol inlet concentration of 0.2 vol%, maximum conversion and acetaldehyde selectivity of 73% and 97%, respectively, were obtained at 100 degrees C on catalyst at nominal 5 wt% V(2)O(5) content (53% of surface monolayer) mixed with alpha-Al(2)O(3). Selective sites were related to surface polymeric vanadates possessing Ti-O-V and V-O-V functionalities while the photoactivity appeared correlated with the catalyst equivalent band gap energy. Increasing the ethanol inlet concentration to 1 vol% and diluting the catalyst with silica gel, total ethanol conversion with about 97% selectivity to acetaldehyde was achieved with a photoreactivity of 0.34 mol m(irradiated)(-3) s(-1). This is three times higher than reported for other photoreactors.

  4. 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.

  5. 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.

  6. 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.

  7. Duquesne Light Company`s modifications for nitric oxide RACT compliance on a 200 MW face fired pulverized coal unit

    SciTech Connect

    Breen, B.P.; Bionda, J.P.; Gabrielson, J.E.; Hallo, A.; Gretz, G.F.

    1996-12-31

    This paper discusses the results of a research test program conducted on Duquesne Light Company`s Elrama Unit 4. The program was designed to determine the viability of achieving compliance with the recently enacted PA DER Reasonably Available Control Technology (RACT) regulations. These regulations stipulate presumptive RACT requirements for wall fired boilers which include the installation and operation of low NO{sub x} burners with separated overfire air. Duquesne Light Company contracted Energy Systems Associates (ESA) to aide in the design and testing of a novel low NO{sub x} burner design and separated overfire air system. A three-dimensional computational furnace model was developed by ESA of the Elrama Unit 4 furnace, and a two-dimensional fluid dynamics model was developed of the coal burner. By modifying the coal burners, it has been possible to reduce the nitric oxide emissions by 30% on Unit 4, with minimal impact of the unburned carbon in the ash. The burner modifications create fuel rich streams which are surrounded by air rich zones in the primary flame region, thus staging combustion at the burner. Additional nitric oxide reductions are realized when the combustion is further staged by use of the separated overfire air system.

  8. 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...

  9. 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.)

  10. 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.)

  11. 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...

  12. 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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Selectively oxidized vertical-cavity laser performance and technology

    SciTech Connect

    Choquette, K.D.; Hou, H.Q.; Geib, K.M.; Hammons, B.E.

    1998-02-01

    The authors discuss revolutionary performance advances in selectively oxidized vertical-cavity surface emitting lasers (VCSELs), which have enabled low operating power laser diodes appropriate for aerospace applications. Incorporating buried oxide layers converted from AIGaAs layers within the laser cavity produces enhanced optical and electrical confinement enabling superior laser performance, such as high efficiency and modulation bandwidth. VCSELs also shown to be viable over varied environmental conditions such as ambient temperature and ionized radiation. The development of novel VCSEL technologies for advanced system applications is also described. Two dimensional individually addressable VCSEL arrays exhibit uniform threshold and operating characteristics. Bottom emitting 850 nm VCSEL arrays fabricated using wafer fusion are also reported.

  14. 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

  15. Silica-lanthanum oxide: pioneer composite of rare-Earth metal oxide in selective phosphopeptides enrichment.

    PubMed

    Jabeen, Fahmida; Hussain, Dilshad; Fatima, Batool; Musharraf, S Ghulam; Huck, Christian W; Bonn, Gűnther K; Najam-ul-Haq, Muhammad

    2012-12-04

    Relying on the successful journey of metal oxides in phosphoproteomics, lanthanum oxide is employed for the engineering of an affinity material for phosphopeptide enrichment. The lanthanum oxide is chemically modified on the surface of silica and characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The obtained silica-lanthanum oxide composite is applied for the selective enrichment of phosphopeptides from tryptic digest of standard protein (α-casein, β-casein, and commercially available casein mixtures from bovine milk). The enriched entities are analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The mass spectroscopy (MS) results show that the silica-lanthanum oxide composite exhibits enhanced capability for phosphopeptide enrichment with sensitivity assessed to be 50 fmol. Sequence coverage of casein is interpreted showing successful recovery. As a real sample, a protein digest of nonfat milk is applied. Also, the ability of lanthanum in different formats is checked in the selective phosphopeptides enrichment. The composite holds promising future in economic ground as it also possesses the regenerative ability for repetitive use.

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

    USGS Publications Warehouse

    Plantz, Gerald G.

    1983-01-01

    The Kolob-Alton-Kaiparowits coal-field area (pi. 1) includes about 4,500 square miles in parts of the Colorado River Basin and the Great Basin. The area varies in altitude from less than 4,000 to more than 10,000 feet, and is comprised chiefly of plateaus, benches, and terraces that are dissected by deep, narrow canyons. Principal streams draining the area are 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. They were collected 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. The results of that study are to be published in a separate report.Several earlier coal-related hydrologic studies have been made in the Alton and Kolob coal-fields area. Hydrologic data collected during those studies may be found in the following reports: Goode (1964, 1966), Sandberg (1979), and Cordova (1981). Data collected at the streamflow-gaging stations shown on plate 1 are published separately in annual reports of the U.S. Geological Survey. Information about the availability of these data is given in table 8.The writer extends thanks to Judy Steiger and Dave Darby (former employees of the U.S. Geological Survey) for their contribution to this report. Officials of the following companies and agencies also were helpful and cooperative in providing data: Utah Power & Light Co.; El Paso Natural Gas Co.; U.S. Bureau of Reclamation; and U.S. Bureau of Land Management.

  17. 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.

  18. 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.

  19. Selective sequential precipitation of dissolved metals in mine drainage from coal mine

    NASA Astrophysics Data System (ADS)

    Yim, Giljae; Bok, Songmin; Ji, Sangwoo; Oh, Chamteut; Cheong, Youngwook; Han, Youngsoo; Ahn, Joosung

    2017-04-01

    In abandoned mines in Korea, a large amount of mine drainage continues to flow out and spread pollution. In purification of the mine drainage a massive amount of sludge is generated as waste. Since this metal sludge contains high Fe, Al and Mn oxides, developing the treatment method to recover homogeneous individual metal with high purity may beneficial to recycle waste metals as useful resources and reduce the amount of sludge production. In this regard, we established a dissolved metals selective precipitation process to treat Waryong Industry's mine drainage. The process that selectively precipitates metals dissolved in mine drainage is a continuous Fe-buffer-Al process, and each process consists of the neutralization tank, the coagulation tank, and the settling tank. Based on this process, this study verified the operational applicability of the Fe and Al selective precipitation. Our previous study revealed that high-purity Fe and Al precipitates could be recovered at a flow rate of 1.5 ton/day, while the lower purity was achieved when the rate was increased to about 3 ton/day due to the difficulty in reagent dosage control. In the current study was conducted to increase the capacity of the system to recover Fe and Al as high-purity precipitates at a flow rate of 10 ton/day with the ensured continuous operations by introducing an automatic reagent injection system. The previous study had a difficulty in controlling the pH and operating system continuously due to the manually controlled reagent injection system. To upgrade this and ensure the optimal pH in a stable way, a continuous reagent injection system was installed. The result of operation of the 10 ton/day system confirmed that the scaled-up process could maintain the stable recovery rates and purities of precipitates on site.

  20. 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.

  1. 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

  2. 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.

  3. Novel microorganism for selective separation of coal from ash and pyrite. Third quarterly technical progress report, March 1, 1994--May 31, 1994

    SciTech Connect

    Misra, M.; Smith, R.W.; Raichur, A.M.

    1994-11-01

    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 surface 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 organism 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 of fine coal from ash and pyrite.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. Enzymatic coal desulfurization

    SciTech Connect

    Kern, E.E.; Menger, W.M.; Odelson, D.A.; Sinskey, A.S.; Wise, D.L.; Trantolo, D.J.

    1992-03-10

    This patent describes a method for reducing the total sulfur content of a fossil fuel containing organic sulfur. It comprises contacting the fossil fuel with a solution containing sulfatase to release organic sulfur as water-soluble free sulfate; recovering from the solution a fossil fuel having a reduced sulfur content. Wherein the fossil fuel is coal, petroleum, or a process-derived product thereof. It further comprises the step of: contacting the fossil fuel with an oxidizing agent. Wherein the sulfatase is selected from the group consisting of Aerobacter species sulfatase, limpet sulfatase, abalone entrail sulfatase, and Helix species sulfatase.

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Reduced Sulfur in Ashes and Slags from the Gasification of Coals: Availability for Chemical and Microbial Oxidation

    PubMed Central

    Strayer, Richard F.; Davis, Edward C.

    1983-01-01

    This study was initiated to determine if reduced sulfur contained in coal gasifier ash and slag was available for microbial and chemical oxidation because eventual large-quantity landfill disposal of these solid wastes is expected. Continuous application of distilled water to a column containing a high-sulfur-content (4% [wt/wt]) gasifier slag yielded leachates with high sulfate levels (1,300 mg of sulfate liter−1) and low pH values (4.2). At the end of the experiment, a three-tube most-probable-number analysis indicated that the waste contained 1.3 × 107 thiosulfate-oxidizing bacteria per g. Slag samples obtained aseptically from the column produced sulfate under both abiotic and biotic conditions when incubated in a mineral nutrient solution. Both microbial and chemical sulfate syntheses were greatly stimulated by the addition of thiosulfate to the slag-mineral nutrient solution. These results led to a test of microbial versus chemical sulfur oxidation in ashes and slags from five gasification processes. Sulfate production was measured in sterile (autoclaved) and nonsterile suspensions of the solid wastes in a mineral nutrient solution. These ashes and slags varied in sulfur content from 0.3 to 4.0% (wt/wt). Four of these wastes demonstrated both chemical (2.0 to 27 μg of sulfate g−1 day−1) and microbial (3.1 to 114 μg of sulfate g−1 day−1) sulfur oxidation. Obvious relationships between sulfur oxidation rate and either sulfur content or particle size distribution of the wastes were not immediately evident. We conclude that the sulfur contained in all but one waste is available for oxidation to sulfuric acid and that microorganisms play a partial role in this process. PMID:16346240

  1. 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

  2. Electrochemical, Structural and Surface Characterization of Nickel/Zirconia Solid Oxide Fuel Cell Anodes in Coal Gas Containing Antimony

    SciTech Connect

    Marina, Olga A.; Pederson, Larry R.; Coyle, Christopher A.; Thomsen, Edwin C.; Nachimuthu, Ponnusamy; Edwards, Danny J.

    2011-02-27

    The interaction of antimony with the nickel-zirconia solid oxide fuel cell (SOFC) anode has been investigated. Tests with both anode-supported and electrolyte-supported button cells were performed at 700 and 800oC in synthetic coal gas containing 10 ppb to 9 ppm antimony. Minor performance loss was observed immediately after Sb introduction to coal gas resulting in ca. 5 % power output drop. While no further degradation was observed during the following several hundred hours of testing, cells abruptly and irreversibly failed after 800-1500 hours depending on Sb concentration and test temperature. Antimony was found to interact strongly with nickel and result in extensive alteration phase formation, consistent with expectations based on thermodynamic properties. Nickel antimonide phases, NiSb and Ni5Sb2, were partially coalesced into large grains and eventually affected electronic percolation through the anode support. Initial degradation was attributed to diffusion of antimony to the active anode/electrolyte interface to form an adsorption layer.

  3. 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)

  4. Microbial Oxidation of Natural Gas in a Plume Emanating from the Coal Oil Point Seep Field

    NASA Astrophysics Data System (ADS)

    Mendes, S. D.; Valentine, D. L.; Perez, C.; Scarlett, R.

    2012-12-01

    The hydrocarbon seep field at Coal Oil Point, off the coast of Santa Barbara, California, releases > 1010 g of thermogenic natural gas each year. Gases emitted from Coal Oil Point include methane, ethane, propane, and butane, which are atmospheric pollutants and greenhouse gases. Even though the seeps are at water depths of only 5-80 m, much of the gas dissolves and contributes to a plume that is transported by ocean currents. While hydrocarbons can support bacterial respiration, resulting in the removal of hydrocarbon gas from the plume, the time-scale for the bacterial respiratory response is unconstrained. To track hydrocarbon respiration 3H-ethane, propane, and butane were synthesized using Grignard reagents and tritiated water with yields of >70% and applied as tracers to samples up- and down-current from the seeps at Coal Oil Point. Validation experiments conducted in September 2011 aboard the R/V Atlantis show that 3H-labeled tracers are an order of magnitude more sensitive than previous methods using stable carbon isotopes (Valentine et. al 2010), making this technique preferable in natural systems. Application of the tracers concurrent with plume tracking in July-August 2012 show ethane, propane, and butane consumption are readily inducible on a timescale of days.

  5. 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. 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.

  7. 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.

  8. Expected ozone benefits of reducing nitrogen oxide (NOx) emissions from coal-fired electricity generating units in the eastern United States.

    PubMed

    Vinciguerra, Timothy; Bull, Emily; Canty, Timothy; He, Hao; Zalewsky, Eric; Woodman, Michael; Aburn, George; Ehrman, Sheryl; Dickerson, Russell R

    2017-03-01

    On hot summer days in the eastern United States, electricity demand rises, mainly because of increased use of air conditioning. Power plants must provide this additional energy, emitting additional pollutants when meteorological conditions are primed for poor air quality. To evaluate the impact of summertime NOx emissions from coal-fired electricity generating units (EGUs) on surface ozone formation, we performed a series of sensitivity modeling forecast scenarios utilizing EPA 2018 version 6.0 emissions (2011 base year) and CMAQ v5.0.2. Coal-fired EGU NOx emissions were adjusted to match the lowest NOx rates observed during the ozone seasons (April 1-October 31) of 2005-2012 (Scenario A), where ozone decreased by 3-4 ppb in affected areas. When compared to the highest emissions rates during the same time period (Scenario B), ozone increased ∼4-7 ppb. NOx emission rates adjusted to match the observed rates from 2011 (Scenario C) increased ozone by ∼4-5 ppb. Finally in Scenario D, the impact of additional NOx reductions was determined by assuming installation of selective catalytic reduction (SCR) controls on all units lacking postcombustion controls; this decreased ozone by an additional 2-4 ppb relative to Scenario A. Following the announcement of a stricter 8-hour ozone standard, this analysis outlines a strategy that would help bring coastal areas in the mid-Atlantic region closer to attainment, and would also provide profound benefits for upwind states where most of the regional EGU NOx originates, even if additional capital investments are not made (Scenario A). With the 8-hr maximum ozone National Ambient Air Quality Standard (NAAQS) decreasing from 75 to 70 ppb, modeling results indicate that use of postcombustion controls on coal-fired power plants in 2018 could help keep regions in attainment. By operating already existing nitrogen oxide (NOx) removal devices to their full potential, ozone could be significantly curtailed, achieving ozone reductions by

  9. 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.

  10. 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

  11. 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.''

  12. 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

  13. Materials selection for oxide-based resistive random access memories

    NASA Astrophysics Data System (ADS)

    Guo, Yuzheng; Robertson, John

    2014-12-01

    The energies of atomic processes in resistive random access memories (RRAMs) are calculated for four typical oxides, HfO2, TiO2, Ta2O5, and Al2O3, 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 Ta2O5 RRAM is related to its more stable amorphous phase and the adaptive lattice rearrangements of its O vacancy.

  14. 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.

  15. Increased Oxidative Stress as a Selective Anticancer Therapy

    PubMed Central

    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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Novel microorganism for selective separation of coal from ash and pyrite. Second quarterly technical progress report, 1 December 1993--28 February 1994

    SciTech Connect

    Misra, M.; Smith, R.W.; Raichur, A.M.

    1994-05-01

    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, the hydrophobicity of different coal samples was studied both in the presence and absence of M. phlei cells. In the absence of M. Phlei, Illinois No. 6 and Pennsylvania No. 8 exhibited higher contact angles as compared to Kentucky No. 9 coal. All the coal samples exhibited a maximum in contact angle around pH 5--7, which roughly coincides with the iso-electric point (iep) of different coals studied in this investigation. In the presence of M. phlei, maximum contact angle shifted to lower pH range of 2--3 which coincides with the iep of the M. phlei. These measurements reinforce the notion that good flocculation of coal with M. phlei can be achieved around pH 2--3. The amount of soluble fraction released during rupturing of M. phlei cells was studied as a function of sonication time. The rupturing experiments showed that the whole cells (unruptured cells) contain nearly 40% by weight of soluble fractions. Also, during the reporting period, the fabrication of the counter-current flocculation device was completed.

  2. 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.

  3. 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.

  4. 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.

  5. Sulfate formation catalyzed by coal fly ash, mineral dust and iron(iii) oxide: variable influence of temperature and light.

    PubMed

    Gankanda, Aruni; Coddens, Ellen M; Zhang, Yaping; Cwiertny, David M; Grassian, Vicki H

    2016-12-08

    Recent atmospheric field and modeling studies have highlighted a lack of understanding of the processes responsible for high levels of sulfate aerosol in the atmosphere, ultimately arising from a dearth of experimental data on such processes. Here we investigated the effect of temperature and simulated solar radiation on the catalytic oxidation of S(iv) to S(vi) (i.e., sulfite to sulfate) in aqueous suspensions of several metal-containing, atmospherically relevant particles including coal fly ash (FA), Arizona test dust (ATD) and an iron oxide (γ-Fe2O3). The effect of temperature and light on S(iv) oxidation was found to be very different for these three samples. For example, in the presence of FA and γ-Fe2O3 the temporal evolution of dissolved Fe(ii) (formed via reductive particle dissolution) correlated with S(iv) oxidation. Accordingly, we propose that S(iv) oxidation in most of these systems initially occurs primarily at the particle surface (i.e., a heterogeneous reaction pathway), although a solution-phase (i.e., homogeneous) catalytic pathway also contributes over later timescales due to the formation and accumulation of dissolved Fe(iii) (generated via oxidation of dissolved Fe(ii) by O2). It is likely that the homogeneous reaction pathway is operative at initial times in the presence of γ-Fe2O3 at 25 °C. In contrast, S(iv) oxidation in the presence of ATD appears to proceed entirely via a heterogeneous reaction, which notably does not lead to any iron dissolution. In fact, the greater overall rate of S(iv) loss in the presence of ATD compared to FA and γ-Fe2O3 suggests that other factors, including greater adsorption of sulfite, transition metal ion (TMI) catalysis by other metal ions (e.g., Ti), or different species of iron in ATD, play a role. Overall these studies suggest that the rate, extent and products of atmospheric S(iv) oxidation can be highly variable and dependent upon the nature of aerosol sources and ambient conditions (e.g., temperature

  6. Rheological properties of water-coal slurries based on brown coal in the presence of sodium lignosulfonates and alkali

    SciTech Connect

    D.P. Savitskii; A.S. Makarov; V.A. Zavgorodnii

    2009-07-01

    The effect of the oxidized surface of brown coal on the structural and rheological properties of water-coal slurries was found. The kinetics of structure formation processes in water-coal slurries based on as-received and oxidized brown coal was studied. The effect of lignosulfonate and alkali additives on the samples of brown coal was considered.

  7. 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.

  8. Establishment and maintenance of a coal sample bank and data base. [Including sample preparation without oxidation

    SciTech Connect

    Davis, A.

    1990-01-19

    Retrieval of 5-lb splits of -1/4 inch coal from designated 30-gallon drums was completed. Preparation and analysis of these samples for the second yearly quality evaluation is in progress. After consultation with the DOE Project Manager, two replacement samples were collected. These are the first of the series which will be stored in foil laminate bags. Both of these samples were placed in 30 gallon steel drums lined with polyethylene bags at the mine site. They were equipped with lid gaskets made from Tygon tubing, and 1/4 in. metal tubing fittings to purge and pressurize the drum with argon.

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. Investigating the Integration of a Solid Oxide Fuel Cell and a Gas Turbine System with Coal Gasification Technologies

    DTIC Science & Technology

    2