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Sample records for partial oxidation coal

  1. Production of reduction gases: partial oxidation of hydrocarbons and coal

    Energy Technology Data Exchange (ETDEWEB)

    Tippmer, K

    1976-04-01

    After some general remarks on reduction gas and quality demands, the Texaco process of partial oxidation with scrubbing is dealt with. A comparison of current iron-sponge techniques shows that a heat demand below 3 M kcal/t Fe should be envisaged, which means that heavy fuel oil or coal should be used. The special features of oxygen generation, coal processing, demands made on fuel oil, gasoline, and natural gas, gas generation, soot recovery, hydrogen sulphide-carbon dioxide scrubbing, system Benfield HP process, recycle-carbon dioxide scrubbing, auxiliary steam system, gas preheating, recycle gas cooling and compression, process data and heat balances for natural gas (one-heat system) and heating fuel oil or naphtha (two-heat system) are given.

  2. Partial oxidation of methane to methanol over catalyst ZSM-5 from coal fly ash and rice husk ash

    Directory of Open Access Journals (Sweden)

    Mirda Yanti Fusia

    2017-01-01

    Full Text Available Methane is one of the greenhouse gases that can be converted into liquid fuels such as methanol to retain most of the energy of methane and produce a cleaner environment. The conversion of methane to methanol using ZMS-5 represents a breakthrough in the utilization of methane. However, material sources for zeolite synthesis as catalyst usually are pro-analysis grade materials, which are expensive. Therefore, in this research, coal fly ash and rice husk ash were used as raw materials for mesoporous ZSM-5 zeolite synthesis. First, coal fly ash and rice husk were subjected to pre-treatment to extract silicate (SiO44− and aluminate (AlO45− and impurities separation. The ZSM-5 zeolite was synthesized through hydrothermal treatment using two types of templates. After ZSM-5 was synthesized, it was modified with Cobalt through impregnation method. The catalytic activity of both ZSM-5 and Co/ZSM-5 zeolites as heterogeneous catalysts in partial oxidation of methane were preliminary tested and compared with that commercial one. The result showed that the zeolite catalyst ZSM-5 from fly ash coal and rice husk ash has the potential to be used as catalysts in the partial oxidation of methane to methanol.

  3. Coke from partially briquetted preheated coal mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Belitskii, A.N.; Sklyar, M.G.; Toryanik, Eh.I.; Bronshtein, A.P.

    1988-07-01

    Analyzes effects of partial coal charge briquetting on coking and on quality of coke for metallurgy. Effects of mixing hot coal briquets on temperature and moisture of coal were investigated on an experimental scale in a coking plant. Coal with a moisture content of 12% was used. Coking mixture consisted of 30% briquets and 70% crushed coal. Fifteen minutes after briquet mixing with coal, the mean coal charge temperature increased to 100-105 C and moisture content was lower than 2-5%. Results of laboratory investigations were verified by tests on a commercial scale. Experiments showed briquetting of weakly caking or non-caking coal charge components to be an efficient way of preventing coke quality decline. Adding 15-20% briquets consisting of weakly caking coal did not influence coke quality. Mixing hot coal briquets reduced moisture content in crushed coal, increased its temperature and reduced coking time.

  4. Partial Oxidation Gas Turbine for Power and Hydrogen Co-Production from Coal-Derived Fuel in Industrial Applications

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Rabovitser

    2009-06-30

    The report presents a feasibility study of a new type of gas turbine. A partial oxidation gas turbine (POGT) shows potential for really high efficiency power generation and ultra low emissions. There are two main features that distinguish a POGT from a conventional gas turbine. These are associated with the design arrangement and the thermodynamic processes used in operation. A primary design difference of the POGT is utilization of a non?catalytic partial oxidation reactor (POR) in place of a conventional combustor. Another important distinction is that a much smaller compressor is required, one that typically supplies less than half of the air flow required in a conventional gas turbine. From an operational and thermodynamic point of view a key distinguishing feature is that the working fluid, fuel gas provided by the OR, has a much higher specific heat than lean combustion products and more energy per unit mass of fluid can be extracted by the POGT expander than in the conventional systems. The POGT exhaust stream contains unreacted fuel that can be combusted in different bottoming ycle or used as syngas for hydrogen or other chemicals production. POGT studies include feasibility design for conversion a conventional turbine to POGT duty, and system analyses of POGT based units for production of power solely, and combined production of power and yngas/hydrogen for different applications. Retrofit design study was completed for three engines, SGT 800, SGT 400, and SGT 100, and includes: replacing the combustor with the POR, compressor downsizing for about 50% design flow rate, generator replacement with 60 90% ower output increase, and overall unit integration, and extensive testing. POGT performances for four turbines with power output up to 350 MW in POGT mode were calculated. With a POGT as the topping cycle for power generation systems, the power output from the POGT ould be increased up to 90% compared to conventional engine keeping hot section temperatures

  5. Synthesis of ZSM-5 zeolite from coal fly ash and rice husk: characterization and application for partial oxidation of methane to methanol

    Science.gov (United States)

    Krisnandi, Y. K.; Yanti, F. M.; Murti, S. D. S.

    2017-04-01

    Indonesian fly ash (SiO2/Al2O3 mole ratio = 3.59) was used together with rice husk (SiO2 92%) as raw material for mesoporous ZSM-5 zeolite synthesis. Prior being used, coal fly ash and rice husk were subjected to pre-treatment in order to extract silicate (SiO4 4-) and aluminate (AlO4 5-) and to remove the impurities. Then the ZSM-5 zeolite were synthesized through hydrothermal treatment using two types of templates (TPAOH and PDDA). The as-synthesized ZSM-5 was characterized using FTIR, XRD, SEM-EDX, and BET. The result of FTIR showed peaks at 1250-950 cm-1 (v asymetric T-O), 820-650 cm-1 (v symetric T-O), and at 650-500 cm-1 confirming the presence of the five number ring of the pentasil structure. The result of XRD showed the appearance of certain peaks in the position 2 theta between 7-9° and 22-25° indicative of ZSM-5 structure, but also showed the pattern of low intensity magnetite and hematite. The SEM image showed the rough surface of hexagonal crystals from ZSM-5 structure, indicative of mesoporosity in the structure. EDX result showed Si/Al ratio of 20, while surface area analysis gave SA of 43.16. The ZSM-5 zeolites then was modified with cobalt oxide through impregnation method. The catalytic activity as heterogeneous catalysts in partial oxidation of methane was tested. The result showed that hence the catalytic activity of ZSM-5 and Co/ZSM-5 from fly ash and rice husk were still inferior compared to the pro-analysis sourced-counterpart, they were potential to be used as catalyst in the partial oxidation of methane to methanol.

  6. Development of coal partial hydropyrolysis process

    Energy Technology Data Exchange (ETDEWEB)

    Hideaki Yabe; Takafumi Kawamura; Kohichiroh Gotoh; Akemitsu Akimoto [Nippon Steel Corporation, Chiba (Japan)

    2005-07-01

    Coal partial hydropyrolysis process aims at co-production of high yield of light oil such as BTX and naphthalene and synthesis gas from a low rank coal under a mild hydropyrolysis condition. The characteristic of this process is in the two-staged entrained hydropyrolysis reactor composed of the reformer and gasifier. This reactor arrangement gives us high heat efficiency of this process. So far, in order to evaluate the process concept a small-scale basic experiment and a 1t/day process development unit study were carried out. The experimental results showed that coal volatiles were partially hydrogenated to increase the light oil and hydrocarbon gases at the condition of partial hydropyrolysis such as pressure of 2-3MPa, temperature of 700-900{sup o}C and hydrogen concentration of 30-50%. This process has a possibility of producing efficiently and economically liquid and gas products as chemicals and fuel for power generation. As a further development in the period of 2003 to 2008, a 20t/day pilot plant study named ECOPRO (efficient co-production with coal flash hydropyrolysis technology) has been started to establish the process technologies for commercialization. 12 refs., 6 figs., 3 tabs.

  7. Partial oxidation process

    International Nuclear Information System (INIS)

    Najjar, M.S.

    1987-01-01

    A process is described for the production of gaseous mixtures comprising H/sub 2/+CO by the partial oxidation of a fuel feedstock comprising a heavy liquid hydrocarbonaceous fuel having a nickel, iron, and vanadium-containing ash or petroleum coke having a nickel, iron, and vanadium-containing ash, or mixtures thereof. The feedstock includes a minimum of 0.5 wt. % of sulfur and the ash includes a minimum of 5.0 wt. % vanadium, a minimum of 0.5 ppm nickel, and a minimum of 0.5 ppm iron. The process comprises: (1) mixing together a copper-containing additive with the fuel feedstock; wherein the weight ratio of copper-containing additive to ash in the fuel feedstock is in the range of about 1.0-10.0, and there is at least 10 parts by weight of copper for each part by weight of vanadium; (2) reacting the mixture from (1) at a temperature in the range of 2200 0 F to 2900 0 F and a pressure in the range of about 5 to 250 atmospheres in a free-flow refactory lined partial oxidation reaction zone with a free-oxygen containing gas in the presence of a temperature moderator and in a reducing atmosphere to produce a hot raw effluent gas stream comprising H/sub 2/+CO and entrained molten slag; and where in the reaction zone and the copper-containing additive combines with at least a portion of the nickel and iron constituents and sulfur found in the feedstock to produce a liquid phase washing agent that collects and transports at least a portion of the vanadium-containing oxide laths and spinels and other ash components and refractory out of the reaction zone; and (3) separating nongaseous materials from the hot raw effluent gas stream

  8. Electrochemical and partial oxidation of methane

    Science.gov (United States)

    Singh, Rahul

    2008-10-01

    negligible coke formation on the novel fabricated anode by electroless plating process. Hydrogen is an environmentally cleaner source of energy. The recent increase in the demand of hydrogen as fuel for all types of fuel cells and petroleum refining process has boosted the need of production of hydrogen. Methane, a major component of natural gas is the major feedstock for production of hydrogen. The route of partial oxidation of methane to produce syngas (CO + H2) offers significant advantages over commercialized steam reforming process for higher efficiency and lower energy requirements. Partial oxidation of methane was studied by pulsing O2 into a CH4 flow over Rh/Al2O3 in a sequence of in situ infrared (IR) cell and fixed bed reactor at 773 K. The results obtained from the sequence of an IR cell followed by a fixed bed reactor show that (i) adsorbed CO produced possesses a long residence time, indicating that adsorbed oxygen leading to the formation of CO is significantly different from those leading to CO2 and (ii) CO2 is not an intermediate species for the formation of CO. In situ IR of pulse reaction coupled with alternating reactor sequence is an effective approach to study the primary and secondary reactions as well as the nature of their adsorbed species. As reported earlier, hydrogen remains to be the most effective fuel for fuel cells, the production of high purity hydrogen from naturally available resources such as coal, petroleum, and natural gas requires a number of energy-intensive steps, making fuel cell processes for stationary electric power generation prohibitively uneconomic. Direct use of coal or coal gas as the feed is a promising approach for low cost electricity generation. Coal gas solid oxide fuel cell was studied by pyrolyzing Ohio #5 coal to coal gas and transporting to a Cu anode solid oxide fuel cell to generate power. The study of coal-gas solid oxide fuel cell is divided into two sections, i.e., (i) understanding the composition of coal gas by

  9. Thermodynamic analysis and conceptual design for partial coal gasification air preheating coal-fired combined cycle

    Science.gov (United States)

    Xu, Yue; Wu, Yining; Deng, Shimin; Wei, Shirang

    2004-02-01

    The partial coal gasification air pre-heating coal-fired combined cycle (PGACC) is a cleaning coal power system, which integrates the coal gasification technology, circulating fluidized bed technology, and combined cycle technology. It has high efficiency and simple construction, and is a new selection of the cleaning coal power systems. A thermodynamic analysis of the PGACC is carried out. The effects of coal gasifying rate, pre-heating air temperature, and coal gas temperature on the performances of the power system are studied. In order to repower the power plant rated 100 MW by using the PGACC, a conceptual design is suggested. The computational results show that the PGACC is feasible for modernizing the old steam power plants and building the new cleaning power plants.

  10. Direct Coal Oxidation in Modified Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Gil, Vanesa; Ippolito, Davide

    2015-01-01

    Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon-carbonate s......Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon......-carbonate slurry or anode layer. The nature of the coal affects both open circuit voltage and power output. Highest OCV and power densities were observed for bituminous coal and by adding manganese oxide or praseodymium-doped ceria to the carbon/carbonate mixture. Comparing the carbon black fueled performance...... bituminous coal (73 mW/cm2). © 2015 ECS - The Electrochemical Society...

  11. Direct Coal Oxidation in Modified Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Gil, Vanesa; Ippolito, Davide

    2017-01-01

    Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon-carbonate s......Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon......-carbonate slurry or anode layer. The nature of the coal affects both open circuit voltage and power output. Highest OCV and power densities were observed for bituminous coal and by adding manganese oxide or praseodymium-doped ceria to the carbon/carbonate mixture. Comparing the carbon black fueled performance...... bituminous coal (73 mW/cm2)....

  12. Oxidation of coals in the course of mechanical treatment

    Energy Technology Data Exchange (ETDEWEB)

    A.G. Proidakov; G.A. Kalabin [Irkutsk State University, Irkutsk (Russian Federation)

    2009-04-15

    The results of a study of coal oxidation under stationary conditions and during mechanical treatment are presented. A considerable increase in the reaction rate constants of coal oxidation during mechanical treatment because of oxidative mechanical degradation was found.

  13. Partial oxidation of 2-propanol on perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Sumathi, R.; Viswanathan, B.; Varadarajan, T.K. [Indian Inst. of Tech., Madras (India). Dept. of Chemistry

    1998-12-31

    Partial oxidation of 2-propanol was carried out on AB{sub 1-x}B`{sub x}O{sub 3} (A=Ba, B=Pb, Ce, Ti; B`=Bi, Sb and Cu) type perovskite oxides. Acetone was the major product observed on all the catalysts. All the catalysts underwent partial reduction during the reaction depending on the composition of the reactant, nature of the B site cation and the extent of substitution at B site. The catalytic activity has been correlated with the reducibility of the perovskite oxides determined from Temperature Programmed Reduction (TPR) studies. (orig.)

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

    Science.gov (United States)

    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

  15. Modelling of a reverse flow catalytic membrane reactor for the partial oxidation of methane

    NARCIS (Netherlands)

    Smit, J.; van Sint Annaland, M.; Kuipers, J.A.M.

    2003-01-01

    Gas-To-Liquid (GTL) processes have great potential as alternative to conventional oil and coal processing for the production of liquid fuels. In GTL-processes the partial oxidation of methane (POM) is combined with the Fischer-Tropsch reaction. An important part of the investment costs of a

  16. Magnetic properties of partially oxidized Fe films

    Science.gov (United States)

    Garcia, Miguel Angel; Lopez-Dominguez, Victor; Hernando, Antonio

    Hybrid magnetic nanostructures exhibit appealing properties due to interface and proximity effects. A simple and interesting system of hybrid magnetic nanomaterials are partially oxidized ferromagnetic films. We have fabricated Fe films by thermal evaporation and performed a partial oxidation to magnetite (Fe3O4) by annealing in air at different times and temperatures. The magnetic properties of the films evolve from those of pure metallic iron to pure magnetite, showing intermediate states where the proximity effects control the magnetic behavior. At some stages, the magnetization curves obtained by SQUID and MOKE magnetometry exhibit important differences due to the dissimilar contribution of both phases to the magneto-optical response of the system This work has been supported by the Ministerio Español de Economia y Competitividad (MINECO) MAT2013-48009-C4-1. V.L.D and M.A.G. acknowledges financial support from BBVA foundation.

  17. Bactericidal activity of partially oxidized nanodiamonds.

    Science.gov (United States)

    Wehling, Julia; Dringen, Ralf; Zare, Richard N; Maas, Michael; Rezwan, Kurosch

    2014-06-24

    Nanodiamonds are a class of carbon-based nanoparticles that are rapidly gaining attention, particularly for biomedical applications, i.e., as drug carriers, for bioimaging, or as implant coatings. Nanodiamonds have generally been considered biocompatible with a broad variety of eukaryotic cells. We show that, depending on their surface composition, nanodiamonds kill Gram-positive and -negative bacteria rapidly and efficiently. We investigated six different types of nanodiamonds exhibiting diverse oxygen-containing surface groups that were created using standard pretreatment methods for forming nanodiamond dispersions. Our experiments suggest that the antibacterial activity of nanodiamond is linked to the presence of partially oxidized and negatively charged surfaces, specifically those containing acid anhydride groups. Furthermore, proteins were found to control the bactericidal properties of nanodiamonds by covering these surface groups, which explains the previously reported biocompatibility of nanodiamonds. Our findings describe the discovery of an exciting property of partially oxidized nanodiamonds as a potent antibacterial agent.

  18. Detection of the incipient oxidation of coal by petrographic techniques

    CSIR Research Space (South Africa)

    Kruszewska, KJ

    1996-05-01

    Full Text Available Two petrographic methods, namely long-wave fluorescence intensity measurements and a vitrinite elasticity index were developed and used to detect incipient oxidation in coals subjected to simulated weathering conditions. The two methods are based...

  19. Study of coal oxidation by charged particle activation analysis

    International Nuclear Information System (INIS)

    Schlyer, D.J.; Wolf, A.P.

    1980-01-01

    It has been possible, using the technique of changed particle activation analysis, to follow the time course of the oxidation of coal exposed to air. The kinetics have been studied and seem to be consistent with a rapid initial uptake of oxygen containing molecules followed by slow diffusion into the surface of the coal particles. In this latter regard a study has been undertaken to study the depth profile of the oxygen into the coal particle surface. The depth of penetration of the activating particle is determined by the incident energy and therefore, by comparison to the appropriate standards, the depth profile may be determined either by varying the incident energy or by varying the particle size. Both approaches have been used and give consistent results. The depth to which a significant amount of oxygen penetrates varies from about 3 μm for very high rank coals to about 20 μm for low rank coals. This diffusion depth seems to be related to the porosity of the coals. A model for the low temperature air oxidation of coal has been developed to explain the results from the above mentioned experiments

  20. Comparison of coal reactivity during conversion into different oxidizing medium

    International Nuclear Information System (INIS)

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

    2016-01-01

    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. (paper)

  1. Rebound of a coal tar creosote plume following partial source zone treatment with permanganate.

    Science.gov (United States)

    Thomson, N R; Fraser, M J; Lamarche, C; Barker, J F; Forsey, S P

    2008-11-14

    The long-term management of dissolved plumes originating from a coal tar creosote source is a technical challenge. For some sites stabilization of the source may be the best practical solution to decrease the contaminant mass loading to the plume and associated off-site migration. At the bench-scale, the deposition of manganese oxides, a permanganate reaction byproduct, has been shown to cause pore plugging and the formation of a manganese oxide layer adjacent to the non-aqueous phase liquid creosote which reduces post-treatment mass transfer and hence mass loading from the source. The objective of this study was to investigate the potential of partial permanganate treatment to reduce the ability of a coal tar creosote source zone to generate a multi-component plume at the pilot-scale over both the short-term (weeks to months) and the long-term (years) at a site where there is >10 years of comprehensive synoptic plume baseline data available. A series of preliminary bench-scale experiments were conducted to support this pilot-scale investigation. The results from the bench-scale experiments indicated that if sufficient mass removal of the reactive compounds is achieved then the effective solubility, aqueous concentration and rate of mass removal of the more abundant non-reactive coal tar creosote compounds such as biphenyl and dibenzofuran can be increased. Manganese oxide formation and deposition caused an order-of-magnitude decrease in hydraulic conductivity. Approximately 125 kg of permanganate were delivered into the pilot-scale source zone over 35 days, and based on mass balance estimates 35% reduction for all monitored compounds except for biphenyl, dibenzofuran and fluoranthene 150 days after treatment, which is consistent with the bench-scale experimental results. Pre- and post-treatment soil core data indicated a highly variable and random spatial distribution of mass within the source zone and provided no insight into the mass removed of any of the

  2. Effect of catalysts on heterogeneous oxidation of coal

    Energy Technology Data Exchange (ETDEWEB)

    Glazkova, A P; Kazarova, Yu A; Suslov, A V

    1978-01-01

    Analyzes the effects of catalysts on the heterogeneous oxidation of coal in deflagration processes of stoichiometric mixtures. The following substances are studied as catalysts: alkali and alkaline-earth metals, and compounds of copper, lead, chromium, iron, and sulfur. In the first case the catalysts are used in the form of nitrates and the nitrate simultaneously plays the role of an oxidizer. In the second case the catalysts are added to stoichiometric mixtures of ammonium nitrate with carbon. It is shown that during carbon oxidation by nitrates the catalytic efficiency of the metals studied forms the following order: sodium > lead > potassium > barium > aluminium > calcium > magnesium > copper. The calculated and experimental parameters of combustion are given. The problem of dependence of combustion rate on combustion heat, the mechanism of the combustion reaction and the catalytic effects of the additives are discussed. Features of heterogeneous catalysis in the oxidation process of carbon by various oxidizers are analyzed. The investigations on the combustion process are important as the process takes place during explosion of coal dust in underground coal mines and during burning of coal in industrial furnaces. (34 refs.) (In Russian)

  3. Catalytic partial oxidation of pyrolysis oils

    Science.gov (United States)

    Rennard, David Carl

    2009-12-01

    This thesis explores the catalytic partial oxidation (CPO) of pyrolysis oils to syngas and chemicals. First, an exploration of model compounds and their chemistries under CPO conditions is considered. Then CPO experiments of raw pyrolysis oils are detailed. Finally, plans for future development in this field are discussed. In Chapter 2, organic acids such as propionic acid and lactic acid are oxidized to syngas over Pt catalysts. Equilibrium production of syngas can be achieved over Rh-Ce catalysts; alternatively mechanistic evidence is derived using Pt catalysts in a fuel rich mixture. These experiments show that organic acids, present in pyrolysis oils up to 25%, can undergo CPO to syngas or for the production of chemicals. As the fossil fuels industry also provides organic chemicals such as monomers for plastics, the possibility of deriving such species from pyrolysis oils allows for a greater application of the CPO of biomass. However, chemical production is highly dependent on the originating molecular species. As bio oil comprises up to 400 chemicals, it is essential to understand how difficult it would be to develop a pure product stream. Chapter 3 continues the experimentation from Chapter 2, exploring the CPO of another organic functionality: the ester group. These experiments demonstrate that equilibrium syngas production is possible for esters as well as acids in autothermal operation with contact times as low as tau = 10 ms over Rh-based catalysts. Conversion for these experiments and those with organic acids is >98%, demonstrating the high reactivity of oxygenated compounds on noble metal catalysts. Under CPO conditions, esters decompose in a predictable manner: over Pt and with high fuel to oxygen, non-equilibrium products show a similarity to those from related acids. A mechanism is proposed in which ethyl esters thermally decompose to ethylene and an acid, which decarbonylates homogeneously, driven by heat produced at the catalyst surface. Chapter 4

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Recovery of iron oxide from coal fly ash

    Science.gov (United States)

    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.

  6. Low temperature oxidation and spontaneous combustion characteristics of upgraded low rank coal

    Energy Technology Data Exchange (ETDEWEB)

    Choi, H.K.; Kim, S.D.; Yoo, J.H.; Chun, D.H.; Rhim, Y.J.; Lee, S.H. [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

    2013-07-01

    The low temperature oxidation and spontaneous combustion characteristics of dried coal produced from low rank coal using the upgraded brown coal (UBC) process were investigated. To this end, proximate properties, crossing-point temperature (CPT), and isothermal oxidation characteristics of the coal were analyzed. The isothermal oxidation characteristics were estimated by considering the formation rates of CO and CO{sub 2} at low temperatures. The upgraded low rank coal had higher heating values than the raw coal. It also had less susceptibility to low temperature oxidation and spontaneous combustion. This seemed to result from the coating of the asphalt on the surface of the coal, which suppressed the active functional groups from reacting with oxygen in the air. The increasing upgrading pressure negatively affected the low temperature oxidation and spontaneous combustion.

  7. Partial briquetting of coal charges as a means of utilizing lower-grade coal for coke making

    Energy Technology Data Exchange (ETDEWEB)

    Pieters, B.J. (Iscor Limited, Newcastle (South Africa))

    1991-08-01

    The paper describes the difficulties experienced with inferior coking coals as Iscor began using larger blast furnaces for the production of liquid iron. Research conducted at Iscor from 1977 to 1979 showed that benefits could be gained from the use of partially briquetted charges, and it was decided to install briquetting plants at the Vanderbijlpark and Newcastle Works. Details are given of the latter plant, which was supplied by a consortium consisting of Voest Alpine, Didier Engineering, and Sumitomo Metal Industries. Sumitomo also supplied information on the optimization of coke quality along the lines of their Sumicoal System. The results have been a marked improvement in coke quality, much better blast-furnace operation, and increased productivity. 11 figs., 3 tabs.

  8. Mechanism and Thermochemistry of Coal Char Oxidation and Desorption of Surface Oxides

    DEFF Research Database (Denmark)

    Levi, Gianluca; Causà, Mauro; Lacovig, Paolo

    2017-01-01

    The present study investigates the coal char combustion by a combination of thermochemical and X-ray photoemission spectroscopy (XPS) analyses. Thermoanalytical methods (differential thermogravimetry, differential scanning calorimetry, and temperature-programmed desorption) are used to identify...... the key reactive steps that occur upon oxidation and heating of coal char (chemisorption, structural rearrangement and switchover of surface oxides, and desorption) and their energetics. XPS is used to reveal the chemical nature of the surface oxides that populate the char surface and to monitor...... functionalities prevail. The rearrangement of epoxy during preoxidation goes together with activation of the more stable and less reactive carbon sites. Results are in good agreement with semi-lumped kinetic models of carbon oxidation, which include (1) formation of "metastable" surface oxides, (2) complex...

  9. Flash pyrolysis of coal-solvent slurry prepared from the oxidized coal and the coal dissolved in solvent; Ichibu yokaishita sanka kaishitsutan slurry no jinsoku netsubunkai

    Energy Technology Data Exchange (ETDEWEB)

    Maki, T.; Mae, K.; Okutsu, H.; Miura, K. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

    1996-10-28

    In order to develop a high-efficiency coal pyrolysis method, flash pyrolysis was experimented on slurry prepared by using liquid-phase oxidation reformed coal and a methanol-based solvent mixture. Australian Morwell coal was used for the experiment. The oxidized coal, into which carboxyl groups have been introduced, has the condensation structure relaxed largely, and becomes highly fluid slurry by means of the solvent. Char production can be suppressed by making the oxidation-pretreated coal into slurry, resulting in drastically improved pyrolytic conversion. The slurry was divided into dissolved solution, dried substance, extracted residue, and residual slurry, which were pyrolized independently. The dissolved solution showed very high conversion. Improvement in the conversion is contributed by separating the dissolved substances (coal macromolecules) at molecular levels, coagulating the molecules, suppressing cross-link formation, and reducing molecular weight of the dissolved substances. Oxidized coal can be dissolved to 80% or higher by using several kinds of mixed solvents. As a result of the dissolution, a possibility was suggested on pyrolysis which is easy in handling and high in conversion. 7 refs., 6 figs., 2 tabs.

  10. Pyrolysis of coal in the presence of nitric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Berkowitz, N; Dammeyer, W

    1956-01-01

    Examination of tars obtained by low-temperature carbonization of a subbituminous coal in the presence of NO suggests that NO will both retard thermal decomposition and inhibit secondary polymerization in the tar phase. But both reactions are subject to the condition that NO is present at the start of incipient pyrolysis (they do not occur if NO is admitted to the retorts at a point above the decomposition temperature of the coal), and their extent depends sharply upon the concentration of NO. At comparatively low partial pressure of NO, the dominant reaction is retardation of decomposition; significant modification of the tar, leading to a greater proportion of low-boiling material, is confined to high-partial pressure of NO. Conclusions, after analyzing tar yields and infrared spectra of tar fractions, are that the inhibition of secondary polymerization in the tar phase involves the transient attachment of NO to primary tar molecules, and that the inhibitory effect of NO is essentially temporary. Tars modified by NO do not appear to be more stable than normal tars in the presence of light, and their composition, as determined by infrared spectroscopy, is not perceptibly different.

  11. Relating coal oxidation and hydrophobicity: a petrographic approach

    CSIR Research Space (South Africa)

    Kruszewska, KJ

    1996-11-01

    Full Text Available techniques, namely long-wave fluorescence relative intensity (FRI) measurements 3 and a vitrinite elasticity index .(EI) based on Vickers microhardness impression types 3'4, to assess the degree of oxidation of a set of four..., IEA Coal Research, London, 1990, pp. 57-60 3 Kruszewska, K. J. and du Cann, V. M. Fuel 1996, 75, 769 4 Nandi, B. N., Ciavaglia, L. A. and Montgomery, D. S. J. Microsc. 1977, 109, 93 5 Stach, E. et al. (Eds...

  12. Assessment of nitrogen oxide emission for designing boilers fired with coal dust

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Gusev, L.N.; Babii, V.I.

    1983-09-01

    A method for forecasting emission of nitrogen oxides from steam boilers fired with coal is described. The method produces accurate results when nitrogen oxide emission from furnaces with straight-flow burners and turbulent-type burners fired with coal dusts is forecast. Oxides formed by decomposition of chemical compounds in coal (so-called 'fuel' nitrogen oxides) and nitrogen oxides formed by oxidation of molecular nitrogen by atomic oxygen (so-called 'thermal' nitrogen oxides) are evaluated. Zones in which the two types of nitrogen oxide are formed in flames are characterized. Factors which influence formation of nitrogen oxides in a furnace are evaluated: excess air, flue gas recirculation, design of a furnace and burners, movement of air and coal dust mixture in a furnace, temperature, methods for coal dust preparation, coal dust properties. Equations for forecasting emission of nitrogen oxides from furnaces are derived. Nomograms for easy calculation of emission are also given. Examples of using the method for forecasting emission of nitrogen oxides from furnaces fired with coal from the Kuzbass, the Donbass and Ehkibastuz are discussed. Comparisons of emission of nitrogen oxides calculated on the basis of the method and emission determined experimentally show that forecasting accuracy is high and errors do not exceed 10%. 5 references.

  13. Advances in the Partial Oxidation of Methane to Synthesis Gas

    Institute of Scientific and Technical Information of China (English)

    Quanli Zhu; Xutao Zhao; Youquan Deng

    2004-01-01

    The conversion and utilization of natural gas is of significant meaning to the national economy,even to the everyday life of people. However, it has not become a popular industrial process as expected due to the technical obstacles. In the past decades, much investigation into the conversion of methane,predominant component of natural gas, has been carried out. Among the possible routes of methane conversion, the partial oxidation of methane to synthesis gas is considered as an effective and economically feasible one. In this article, a brief review of recent studies on the mechanism of the partial oxidation of methane to synthesis gas together with catalyst development is wherein presented.

  14. Development of pressurized coal partial combustor; Kaatsu sekitan bubun nenshoro gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T [Center for Coal Utilization, Japan, Tokyo (Japan); Kawamura, K [Kawasaki Heavy Industries, Ltd., Kobe (Japan); Tanaka, T [Chubu Electric Power Co. Inc., Nagoya (Japan); Muramatsu, T [Electric Power Development Co. Ltd., Tokyo (Japan)

    1996-09-01

    The coal partial combustor (CPC) uses a combustion technology with which coal is burned at elevated temperatures and under revolution, the constituents are captured on the furnace wall and removed as molten slag from the furnace. This is a combustion technology to reduce load of ash on subsequent devices. To generate a molten condition, it is necessary to raise the combustion temperature as high as possible (to about 1600 degC in the furnace), but this is effective for a gas turbine composite power generation system. An efficiency of higher than 45% may be expected at the power transmission terminal. As an operation on subsidy from the Agency of Natural Resources and Energy, the normal-pressure CPC technology has already been established, and a research on pressurized CPC is being progressed since fiscal 1991. The research is in progress with a schedule that elemental tests for 7 tons per day production are conducted until fiscal 1995, a 25 tons per day pilot plant will be completed by November 1997, and verification tests for long-term continuous operation will be implemented until 1998. The 7 tons per day elemental tests have identified gasification performance and slag extraction performance using five types of coal having different properties. 7 refs., 10 figs., 4 tabs.

  15. Catalytic Partial Oxidation of Biomass/Oil Mixture

    Czech Academy of Sciences Publication Activity Database

    Veselý, Václav; Hanika, Jiří; Tukač, V.; Lederer, J.; Kovač, D.

    2013-01-01

    Roč. 7, č. 10 (2013), s. 1940-1945 ISSN 1934-8983 R&D Projects: GA TA ČR TE01020080; GA MPO 2A-2TP1/024 Institutional support: RVO:67985858 Keywords : hydrocarbon oil * biomass * catalytic partial oxidation Subject RIV: CI - Industrial Chemistry, Chemical Engineering http://www.davidpublishing.com/journals_info.asp?jId=1718#

  16. Oxidative stress and partial migration in brown trout (Salmo trutta)

    DEFF Research Database (Denmark)

    Birnie-Gauvin, Kim; Peiman, K. S.; Larsen, Martin Hage

    2017-01-01

    of oxidative status in migration biology, particularly in fish. Semi-anadromous brown trout (Salmo trutta, Linnaeus 1758) exhibit partial migration, where some individuals smoltify and migrate to sea, and others become stream residents, providing us with an excellent model to investigate the link between...... oxidative stress and migration. Using the brown trout, we obtained blood samples from juveniles from a coastal stream in Denmark in the fall prior to peak seaward migration which occurs in the spring, and assayed for antioxidant capacity (oxygen radical absorbance capacity) and oxidative stress levels...

  17. Electrochemistry of carbonaceous materials; 1. Oxidation of Sardinian coal by Fe(III) ions

    Energy Technology Data Exchange (ETDEWEB)

    Tomat, R.; Salmaso, R.; Zecchin, S. (CNR-Instituto di Polarografia ed Elettrochimica Preparativa, Padova (Italy))

    1992-04-01

    Oxidation of subbitiminous coal (Sulcis basin, Sardinia, Italy) by Fe(III) ions in aqueous H{sub 2}SO{sub 4} solution was investigated over a wide temperature range (20-80{degree}C). Experimental results are in accord with a reaction scheme involving a reversible complex between coal particles and Fe(III) ions as a first step in the oxidation process. At low coal concentration, the reaction rate follows first-order kinetics in both coal and ferric ions (overall second order), while at sufficiently high coal concentration, the reaction rate is consistent with first-order kinetics in Fe(III) concentration, appearing to be independent of coal concentration. The kinetic results obtained give preliminary information on the advantageous use of the Fe(III)/slurried coal reaction system to depolarize the anodic compartment of an electrolysis cell, for the production of H{sub 2}. 11 refs., 5 figs.

  18. Heterogeneous Partial (ammOxidation and Oxidative Dehydrogenation Catalysis on Mixed Metal Oxides

    Directory of Open Access Journals (Sweden)

    Jacques C. Védrine

    2016-01-01

    Full Text Available This paper presents an overview of heterogeneous partial (ammoxidation and oxidative dehydrogenation (ODH of hydrocarbons. The review has been voluntarily restricted to metal oxide-type catalysts, as the partial oxidation field is very broad and the number of catalysts is quite high. The main factors of solid catalysts for such reactions, designated by Grasselli as the “seven pillars”, and playing a determining role in catalytic properties, are considered to be, namely: isolation of active sites (known to be composed of ensembles of atoms, Me–O bond strength, crystalline structure, redox features, phase cooperation, multi-functionality and the nature of the surface oxygen species. Other important features and physical and chemical properties of solid catalysts, more or less related to the seven pillars, are also emphasized, including reaction sensitivity to metal oxide structure, epitaxial contact between an active phase and a second phase or its support, synergy effect between several phases, acid-base aspects, electron transfer ability, catalyst preparation and activation and reaction atmospheres, etc. Some examples are presented to illustrate the importance of these key factors. They include light alkanes (C1–C4 oxidation, ethane oxidation to ethylene and acetic acid on MoVTe(SbNb-O and Nb doped NiO, propene oxidation to acrolein on BiMoCoFe-O systems, propane (ammoxidation to (acrylonitrile acrylic acid on MoVTe(SbNb-O mixed oxides, butane oxidation to maleic anhydride on VPO: (VO2P2O7-based catalyst, and isobutyric acid ODH to methacrylic acid on Fe hydroxyl phosphates. It is shown that active sites are composed of ensembles of atoms whose size and chemical composition depend on the reactants to be transformed (their chemical and size features and the reaction mechanism, often of Mars and van Krevelen type. An important aspect is the fact that surface composition and surface crystalline structure vary with reaction on stream until

  19. Ore controlling oxidized zonation epigenetic uranium-coal deposits and regularities in lignite transformations

    International Nuclear Information System (INIS)

    Uspenskij, V.A.; Kulakova, Ya.M.

    1982-01-01

    Complex of analytical methods was used to study epigenetic transformations in uranium-coal ore manifestation. To clarify the principle scheme of oxidized zonation in coals the materials, related to three similar objects were used. When comparing obtained epigenetic column with columns of similar ore objects the principle scheme of oxidized epigenetic zonation for ancient infiltration uranium-coal deposits was specified; general regularities of eignite transformations and characteristics of profile distribution of uranium and accessory metal zonations were revealed. Infiltration processes, proceeded in coal measureses, formed the steady epigenetic oxidized zonation: O - zone of barren unoxidized coals, 1 - zone of ore-bearing unoxidized coals, 2 - zone of weakly ore-bearing oxidized coals, 3 - zone of oxidized terrigenous rocks with zonules of development of yellow and red iron hydroxides. Capacities of some zones and zonules reflect the intensity and duration of ore-forming processes. Distribution of U and accessory elements obeys completely epigenetic zonation. It is assumed, that ancient infiltration uranium-coal deposits formed due to weakly uranium-bearing oxygen-containing waters

  20. Thermodynamic analysis of a coal-based polygeneration system with partial gasification

    International Nuclear Information System (INIS)

    Li, Yuanyuan; Zhang, Guoqiang; Yang, Yongping; Zhai, Dailong; Zhang, Kai; Xu, Gang

    2014-01-01

    This study proposed a polygeneration system based on coal partial gasification, in which methanol and power were generated. This proposed system, comprising chemical and power islands, was designed and its characteristics are analyzed. The commercial software Aspen Plus was used to perform the system analysis. In the case study, the energy and exergy efficiency values of the proposed polygeneration system were 51.16% and 50.58%, which are 2.34% and 2.10%, respectively, higher than that of the reference system. Energy-Utilization Diagram analysis showed that removing composition adjustment and recycling 72.7% of the unreacted gas could reduce the exergy destruction during methanol synthesis by 46.85% and that the char utilized to preheat the compressed air could reduce the exergy destruction during combustion by 10.28%. Sensitivity analysis was also performed. At the same capacity ratio, the energy and exergy efficiency values of the proposed system were 1.30%–2.48% and 1.21%–2.30% higher than that of the reference system, respectively. The range of chemical-to-power capacity ratio in the proposed system was 0.41–1.40, which was narrower than that in the reference system. But the range of 1.04–1.4 was not recommended for the disappearance of energy saving potential in methanol synthesis. - Highlights: • A novel polygeneration system based on coal partial gasification is proposed. • The efficient conversion method for methanol and power is explored. • The exergy destruction in chemical energy conversion processes is decreased. • Thermodynamic performance and system characteristics are analyzed

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2016-12-01

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

  3. Experimental study of reduce of nitrogen oxides emission in the Environment at the Ekibastuz coal combustion

    International Nuclear Information System (INIS)

    Korabejnikova, V.K.

    2004-01-01

    For revealing conditions decrease in emissions of nitrogen oxide in an environment at three-stage burning of coal dust Ekibastuz coal with use two-line burners (on were the experimental research of test on fiery the stand as a result of which acknowledgement of theoretical results is received. (author)

  4. Coal

    International Nuclear Information System (INIS)

    Teissie, J.; Bourgogne, D. de; Bautin, F.

    2001-12-01

    Coal world production represents 3.5 billions of tons, plus 900 millions of tons of lignite. 50% of coal is used for power generation, 16% by steel making industry, 5% by cement plants, and 29% for space heating and by other industries like carbo-chemistry. Coal reserves are enormous, about 1000 billions of tons (i.e. 250 years of consumption with the present day rate) but their exploitation will be in competition with less costly and less polluting energy sources. This documents treats of all aspects of coal: origin, composition, calorific value, classification, resources, reserves, production, international trade, sectoral consumption, cost, retail price, safety aspects of coal mining, environmental impacts (solid and gaseous effluents), different technologies of coal-fired power plants and their relative efficiency, alternative solutions for the recovery of coal energy (fuel cells, liquefaction). (J.S.)

  5. Problem of formation of nitrogen oxides during coal combustion in power plant steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Kuvaev, Yu.V.

    1992-07-01

    Analyzes a study of physical and chemical processes of nitrogen oxide formation during coal combustion conducted at Stanford University (USA). Experimental installation, pulverized coal feeding as well as measuring techniques and equipment are described. Experiments were conducted with 55 micron particles of semibituminous coal. An equation for the percentage of coal carbon converted to gaseous products is given. Active formation of NO from nitrogen content in the fuel was observed when oxygen content was under 4%. Conversion of the fuel nitrogen to NO[sub x] in the 1,350-1,850 K temperature range did not depend on gas temperature but rather on oxygen content. 2 refs.

  6. Change of brown coal oxidation kinetic characteristics by promoting additives appending in the form of copper salts

    Science.gov (United States)

    Larionov, K. B.; Mishakov, I. V.; Gromov, A. A.; Zenkov, A. V.

    2017-11-01

    Process of brown coal oxidation with 5%wt content of copper-salt additives of various nature (Cu (NO3)2, CuSO4 and Cu(CH3COO)2) was studied. The experiment has been performed by thermogravimetric analysis at a heating rate of 2.5°C/min to a maximum temperature of 600°C in the air. Analytical evaluation of oxidation process kinetic characteristics has been conducted based on the results of TGA. It has been established that addition of initiating agents leads to significant reduction in the initial ignition temperature of coal (ΔTi = 15÷40°C), shortening of the sample warm-up time to the ignition point (Δte = 6÷12 min) and reduction of the sample burning time (Δtf = 40÷54 min). The following series of additives activity affecting ignition temperature of coals has been established: Cu(CH3COO)2 > Cu(NO3)2 > CuSO4. Additionally, the opposite can be said about the effect of additives on residence time of the sample in its combustion area (CuSO4 > Cu(NO3)2 > Cu(CH3COO)2). According to mass spectrometric analysis, presence of NOx, SO2, CO2 (intense peaks at 190÷290°C) was recorded in oxidation products of modified samples, which is explained by partial or complete decomposition of salts.

  7. Interaction of dimethylamine with clean and partially oxidized copper surfaces

    Science.gov (United States)

    Kelber, J. A.; Rogers, J. W.; Banse, B. A.; Koel, B. E.

    1990-05-01

    The interaction of dimethylamine (DMA) with partially oxidized polycrystalline copper [Cu(poly)] and clean and partially oxidized Cu(110) between 110 and 500 K has been examined using electron stimulated desorption (ESD), high resolution electron energy loss spectroscopy (HREELS) and temperature programmed desorption (TPD). ESD mass spectra of the DMA adsorbed on O/Cu(poly) between 112 and 230 K consistently display peaks at 44 amu [(CH 3) 2N] + and 46 amu [(CH 3) 2NH-H] +, but no significant parent peak at 45 amu [(CH 3) 2NH] +, even though this last feature is prominent in the gas-phase mass spectrum. OH - is not observed at temperatures below 184 K and the yield at higher temperatures is much less than that of O +. HREELS of DMA on clean and oxygen covered Cu(110) obtained at temperatures between 100 and 320 K show characteristic vibrational spectra for molecular DMA and no OH(a) vibrational modes. TPD results show that the desorption profiles of all the major peaks in the DMA mass spectrum follow that of the parent peak with no evidence for production of H 2O. The ESD, HREELS and TPD results all indicate that DMA is molecularly and reversibly adsorbed, with no significant formation of surface hydroxyl species. The results indicate that preferential adsorption of amines from amine/epoxy mixtures onto metal oxide surfaces could passivate the surface and prevent subsequent bonding to the epoxy resin.

  8. The chemical energy unit partial oxidation reactor operation simulation modeling

    Science.gov (United States)

    Mrakin, A. N.; Selivanov, A. A.; Batrakov, P. A.; Sotnikov, D. G.

    2018-01-01

    The chemical energy unit scheme for synthesis gas, electric and heat energy production which is possible to be used both for the chemical industry on-site facilities and under field conditions is represented in the paper. The partial oxidation reactor gasification process mathematical model is described and reaction products composition and temperature determining algorithm flow diagram is shown. The developed software product verification showed good convergence of the experimental values and calculations according to the other programmes: the temperature determining relative discrepancy amounted from 4 to 5 %, while the absolute composition discrepancy ranged from 1 to 3%. The synthesis gas composition was found out practically not to depend on the supplied into the partial oxidation reactor (POR) water vapour enthalpy and compressor air pressure increase ratio. Moreover, air consumption coefficient α increase from 0.7 to 0.9 was found out to decrease synthesis gas target components (carbon and hydrogen oxides) specific yield by nearly 2 times and synthesis gas target components required ratio was revealed to be seen in the water vapour specific consumption area (from 5 to 6 kg/kg of fuel).

  9. Reactor modeling and process analysis for partial oxidation of natural gas

    NARCIS (Netherlands)

    Albrecht, B.A.

    2004-01-01

    This thesis analyses a novel process of partial oxidation of natural gas and develops a numerical tool for the partial oxidation reactor modeling. The proposed process generates syngas in an integrated plant of a partial oxidation reactor, a syngas turbine and an air separation unit. This is called

  10. Chemical polishing of partially oxidized T-111 alloy

    International Nuclear Information System (INIS)

    Teaney, P.E.

    1974-01-01

    The specimens were pressure-mounted in Bakelite and ground through 600 grit on silicon carbide papers. The specimens were rough-polished on a vibratory polisher for 4 to 6 h, using a water slurry of one micron alumina on Texmet, followed by 0.3-μ alumina on Texmet overnight. Final polishing was accomplished by continuous swabbing with a chemical polish. A chemical polish consisting of ten parts lactic acid, four parts nitric acid, and four parts hydrofluoric acid worked well for the T-111 parent material specimens; however, in the partially oxidized specimens, considerable pitting and staining occurred in the oxygen-affected zone and in the transition zone between the oxygen-affected zone and the parent material. A chemical polish was developed for the partially oxidized specimens by adjusting the ratio of the acids to ten parts lactic acid, two parts nitric acid, and two parts hydrofluoric acid. This slowed the chemical attack on the oxygen-affected zone considerably and, with continuous swabbing, the pitting and stain could be avoided. The specimens were rinsed and checked occasionally on the metallograph to determine when the proper polish had been obtained. Some specimens required intermittent polishing times up to 1 / 2 hour. No relationship could be established between the oxygen content of the specimen and the time required for chemical polishing in the partially oxidized specimens. However, the microstructure of the transition zone was the most difficult to obtain, and specimens with uniform reaction zones across the width of the specimen polished quicker than those with the transition zone

  11. Heterogeneous reduction of nitric oxide on synthetic coal chars

    Energy Technology Data Exchange (ETDEWEB)

    C. Pevida; A. Arenillas; F. Rubiera; J.J. Pis [Instituto Nacional del Carbon (CSIC), Oviedo (Spain)

    2005-12-01

    Model compounds, with a controlled heteroatoms content and well-defined functionalities, were used to study the release of nitrogen compounds from char combustion. In the present work, the mechanisms involved in NO-char heterogeneous reduction were studied with a synthetic coal (SC) char as carbon source. Another synthetic char (SN) without any nitrogen in its composition was also employed in these studies. Temperature programmed reduction (TPR) tests with a gas mixture of 400 ppm NO in argon and with isotopically labelled nitric oxide, {sup 15}NO (500 ppm {sup 15}NO in argon), were carried out. The gases produced were quantitatively determined by means of MS and FTIR analysers. Under the conditions of this work the main products of the NO-C reaction were found to be N{sub 2} and CO{sub 2}. The main path of reaction involves the formation of surface nitrogen compounds that afterwards react with nitrogen from the reactive gas to form N{sub 2}. It was observed that fuel-N also participates in the overall heterogeneous reduction reaction, although to a lesser extent.

  12. Laser-induced partial oxidation of cyclohexane in liquid phase

    International Nuclear Information System (INIS)

    Oshima, Y.; Wu, X.W.; Koda, S.

    1995-01-01

    A laser-induced partial oxidation of cyclohexane was studied in the liquid phase. With KrF excimer laser (248 nm) irradiation to neat liquid cyclohexane in which O 2 was dissolved, cyclohexanol and cyclohexanone were obtained with very high selectivities, together with cyclohexane as a minor product. Radical recombination reactions to produce dicyclohexyl ether and bicyclohexyl also took place, while these products were not observed in the gas phase reaction. These experimental results were considered to be due not only to higher concentration of cyclohexane but to the cage effect in the liquid phase oxidation. To clarify the reaction progress including the photoabsorption process, the effects of laser intensity and O 2 pressure on product distribution were studied. (author)

  13. Efficient direct coal liquefaction of a premium brown coal catalyzed by cobalt-promoted fumed oxides

    Energy Technology Data Exchange (ETDEWEB)

    Trautmann, M.; Loewe, A.; Traa, Y. [Stuttgart Univ. (Germany). Inst. of Chemical Technology

    2013-11-01

    The search for alternatives in the fuel sector is an important technological challenge. An interim solution could be provided by direct coal liquefaction. Hydrogen economy and the lack of an efficient catalyst are the main obstacles for this process. We used a premium German brown coal with a high H/C molar ratio of 1.25 and nanostructured cobalt catalysts to improve the efficiency of direct coal liquefaction. We were able to recover and recycle the catalyst efficiently and reached good brown coal conversions and oil yields with single-stage coal liquefaction. The oil quality observed almost reached that of a conventional crude oil considering higher heating value (HHV), H/C molar ratio and aliphatic content. (orig.)

  14. Oxidative Stress in Patients with Drug Resistant Partial Complex Seizure

    Directory of Open Access Journals (Sweden)

    Lourdes Lorigados Pedre

    2018-06-01

    Full Text Available Oxidative stress (OS has been implicated as a pathophysiological mechanism of drug-resistant epilepsy, but little is known about the relationship between OS markers and clinical parameters, such as the number of drugs, age onset of seizure and frequency of seizures per month. The current study’s aim was to evaluate several oxidative stress markers and antioxidants in 18 drug-resistant partial complex seizure (DRPCS patients compared to a control group (age and sex matched, and the results were related to clinical variables. We examined malondialdehyde (MDA, advanced oxidation protein products (AOPP, advanced glycation end products (AGEs, nitric oxide (NO, uric acid, superoxide dismutase (SOD, glutathione, vitamin C, 4-hydroxy-2-nonenal (4-HNE and nitrotyrosine (3-NT. All markers except 4-HNE and 3-NT were studied by spectrophotometry. The expressions of 4-HNE and 3-NT were evaluated by Western blot analysis. MDA levels in patients were significantly increased (p ≤ 0.0001 while AOPP levels were similar to the control group. AGEs, NO and uric acid concentrations were significantly decreased (p ≤ 0.004, p ≤ 0.005, p ≤ 0.0001, respectively. Expressions of 3-NT and 4-HNE were increased (p ≤ 0.005 similarly to SOD activity (p = 0.0001, whereas vitamin C was considerably diminished (p = 0.0001. Glutathione levels were similar to the control group. There was a positive correlation between NO and MDA with the number of drugs. The expression of 3-NT was positively related with the frequency of seizures per month. There was a negative relationship between MDA and age at onset of seizures, as well as vitamin C with seizure frequency/month. We detected an imbalance in the redox state in patients with DRCPS, supporting oxidative stress as a relevant mechanism in this pathology. Thus, it is apparent that some oxidant and antioxidant parameters are closely linked with clinical variables.

  15. Hydrologic and water quality characteristics of a partially-flooded, abandoned underground coal mine

    International Nuclear Information System (INIS)

    Aljoe, W.W.

    1994-01-01

    The hydrologic and water quality characteristics of a partially flooded, abandoned underground coal mine near Latrobe, PA, were studied to support the development of techniques for in situ abatement of its acidic discharge. A quantitative understanding of the conditions affecting discharge flow was considered to be very important in this regard. Statistical analysis of hydrologic data collected at the site shows that the flow rate of the main discharge (a borehole that penetrates the mine workings just behind a set of portal seals) is a linear function of the height of the mine pool above the borehole outlet. Seepage through or around the portal seals is collected by a set of french drains whose discharge rate is largely independent of the mine pool elevation. This seepage was enhanced after a breakthrough that occurred during a period of unusually high pool levels. The mine pool recharge rate during winter is about 2.5 times greater than that of any other season; recharge rates during spring, summer, and fall are approximately equal. Mine pool and discharge water quality information, along with bromide tracer tests, suggest that the original main entries discharge primarily to the french drains, while the borehole carries the discharge from an unmonitored set of entries northwest of the mains. The water quality of the east french drain discharge may have been improved substantially after seepage through the alkaline materials used to construct the portal seals

  16. Fundamental studies on the reaction process of partial hydropyrolysis of coal

    Energy Technology Data Exchange (ETDEWEB)

    O. Yamada; H. Yasuda; M. Kaiho [National Institute of Advanced Industrial Science and Technology, Ibaraki (Japan). Energy Technology Research Institute

    2005-07-01

    In order to make up a simulator to support the development of coal partial hydropyrolysis process, material balance of the reaction was investigated precisely. Amount of H{sub 2} evolved by pyrolysis under inert gas atmosphere was found almost equal to that of (CO+2CO{sub 2}), therefore, most of H{sub 2} seemed to be generated through water gas reaction and shift reaction. CH{sub 4} seemed to be stable even at 1073K and 7.1MPa of H{sub 2}, its generation was simply accelerated in proportion to H{sub 2} pressure. Hydrocarbons, other than CH{sub 4}, were fundamentally unstable at 1073K and 0.93 -7.1MPa of H{sub 2}, however the rate of decomposition of them were so slow that amounts of them evolved were apparently proportion to reaction time and H{sub 2} pressure. BTX and naphthalene were increased apparently with H{sub 2} pressure when the reaction time was less than 5s. 4 refs., 20 figs.

  17. Compressive strength performance of OPS lightweight aggregate concrete containing coal bottom ash as partial fine aggregate replacement

    Science.gov (United States)

    Muthusamy, K.; Mohamad Hafizuddin, R.; Mat Yahaya, F.; Sulaiman, M. A.; Syed Mohsin, S. M.; Tukimat, N. N.; Omar, R.; Chin, S. C.

    2018-04-01

    Concerns regarding the negative impact towards environment due to the increasing use of natural sand in construction industry and dumping of industrial solid wastes namely coal bottom ash (CBA) and oil palm shell (OPS) has resulted in the development of environmental friendly lightweight concrete. The present study investigates the effect of coal bottom ash as partial fine aggregate replacement towards workability and compressive strength of oil palm shell lightweight aggregate concrete (OPS LWAC). The fresh and mechanical properties of this concrete containing various percentage of coal bottom ash as partial fine aggregate replacement were investigated. The result was compared to OPS LWAC with 100 % sand as a control specimen. The concrete workability investigated by conducting slump test. All specimens were cast in form of cubes and water cured until the testing age. The compressive strength test was carried out at 7 and 28 days. The finding shows that integration of coal bottom ash at suitable proportion enhances the strength of oil palm shell lightweight aggregate concrete.

  18. Modeling of termokinetic oscillations at partial oxidation of methane

    Science.gov (United States)

    Arutyunov, A. V.; Belyaev, A. A.; Inovenkov, I. N.; Nefedov, V. V.

    2017-12-01

    Partial oxidation of natural gas at moderate temperatures below 1500 K has significant interest for a number of industrial applications. But such processes can proceed at different unstable regimes including oscillating modes. Nonlinear phenomena at partial oxidation of methane were observed at different conditions. The investigation of the complex nonlinear system of equations that describes this process is a real method to insure its stability at industrial conditions and, at the same time, is an effective tool for its further enhancement. Numerical analysis of methane oxidation kinetics in the continuous stirred-tank reactor, with the use of detailed kinetic model has shown the possibility of the appearance of oscillating modes in the appropriate range of reaction parameters that characterize the composition, pressure, reagents flow, thermophysical features of the system, and geometry of the reactor. The appearance of oscillating modes is connected both with the reaction kinetics, heat release and sink and reagents introduction and removing. At that, oscillations appear only at a limited range of parameters, but can be accompanied by significant change in the yield of products. We have determined the range of initial temperature and pressure at which oscillations can be observed, if all other parameters remained fixed. The boundaries of existence of oscillations on the phase plane were calculated. It was shown that depending on the position inside the oscillation region the oscillations have different frequency and amplitude. It was reviled the role of heat exchange with the environment: at the absence of heat exchange the oscillating modes are impossible. In the vicinity of the boundary of phase range, where oscillations exist, significant change of concentration of some products were observed, for example, that of CO2, which in this case one of the principal products is. At that, insignificant increase in pressure not only change the character of CO2 behaving

  19. Spectroscopy study of electron spin resonance of coal oxidation of different rank

    International Nuclear Information System (INIS)

    Enciso Prieto, Hector Manuel

    1992-01-01

    The present work constitutes an initial step for the knowledge of the coal oxidation, with the purpose of preventing the adverse influences caused by this phenomenon in the physical-chemical characteristics and in the tendency to the spontaneous combustion. Since the knowledge the influence of the free radicals in this process, their relative concentration was measured by means of the use of the technique of resonance spin electron. This technique measures the absorption of electromagnetic radiation, generally in the microwaves region, for the materials that not have electrons matched up in a strong magnetic field. In the essays of oxidation three coal of different range and different characteristics of mass were used and it was studied the influence of the temperature, particle size and the range. The results showed that the coal of Guacheta (bituminous low in volatile) it presents bigger concentration of free radicals, after the reaction with the atmospheric oxygen, with regard to the coal of the Cerrejon (bituminous high in volatile B) and Amaga (bituminous high in volatile C). Although this doesn't indicate that the coal of Guacheta is that more easily is oxidized, but rather it possibly presents stabilization of radicals for resonance. It concluded that there are differences in the oxidation mechanism between coal of different rank and different agglomeration properties

  20. Layered assembly of graphene oxide and Co-Al layered double hydroxide nanosheets as electrode materials for supercapacitors.

    Science.gov (United States)

    Wang, Lei; Wang, Dong; Dong, Xin Yi; Zhang, Zhi Jun; Pei, Xian Feng; Chen, Xin Jiang; Chen, Biao; Jin, Jian

    2011-03-28

    An innovative strategy of fabricating electrode material by layered assembling two kinds of one-atom-thick sheets, carboxylated graphene oxide (GO) and Co-Al layered double hydroxide nanosheet (Co-Al LDH-NS) for the application as a pseudocapacitor is reported. The Co-Al LDH-NS/GO composite exhibits good energy storage properties.

  1. Study of film graphene/graphene oxide obtained by partial reduction chemical of oxide graphite

    International Nuclear Information System (INIS)

    Gascho, J.L.S.; Costa, S.F.; Hoepfner, J.C.; Pezzin, S.H.

    2014-01-01

    This study investigated the morphology of graphene/graphene oxide film obtained by partial chemical reduction of graphite oxide (OG) as well as its resistance to solvents. Films of graphene/graphene oxide are great candidates for replacement of indium oxide doped with tin (ITO) in photoelectric devices. The OG was obtained from natural graphite, by Hummer's method modified, and its reduction is made by using sodium borohydride. Infrared spectroscopy analysis of Fourier transform (FTIR), Xray diffraction (XRD) and scanning electron microscopy, high-resolution (SEM/FEG) for the characterization of graphene/graphene oxide film obtained were performed. This film proved to be resilient, not dispersing in any of the various tested solvents (such as ethanol, acetone and THF), even under tip sonication, this resistance being an important property for the applications. Furthermore, the film had a morphology similar to that obtained by other preparation methods.(author)

  2. Electric plants to gas, influence of both Mineral Matter and Air Oxidation in coal pyrolysis

    International Nuclear Information System (INIS)

    Mondragon, F.; Jaramillo, A.; Quintero, G.

    1995-01-01

    In this work some coal samples from different Colombia's deposits are analyzed. In first stage, material matter is removed from coal by acid treatment with HF/HCl, and aerial oxidation of coal is made with air in oven to 150 Centigrade degree temperature. In second stage, pyrolysis is carried out in two different techniques: 1. Thermogravimetric Analysis (TGA) and 2. Programmed Temperature Pyrolysis (PTP) in a pyrolyzer equipped with a quadrupole mass spectrometer. In both techniques, the coal samples are heated in different rates to 650 Centigrade degree. During PTP trials the evolution of CH4, H2S, hydrocarbons (m/z=42), CO2, benzene and toluene are monitored. Studied coal samples showed: 1). A gas conversion range between 48.8% to 21.8%; 2). A decrease in the gas conversion between 2% to 4%, when oxidation it is applied; 3). The temperature at the one which is presented the maximum evolution of CH4 is similar for all coal samples; 4). The maximum evolution of H2S depends on mineral matter composition, occurs between 480 to 550 Centigrade degrees and is presented due to pyrite decomposition. 5). The evolution of CO2 occurs between 100 to 650 Centigrade degree, its production is generated in different stage of the mentioned temperature range, and in some coal samples is presented due to inorganic origin

  3. Numerical investigation of influence thermal preparation coal on nitric oxides formation in combustion process

    Energy Technology Data Exchange (ETDEWEB)

    Chernetskaya, N. [Siberian Federal Univ., Krasnoyarsk (Russian Federation); Chernetsky, M.; Dekterev, A. [Siberian Federal Univ., Krasnoyarsk (Russian Federation); Kutateladze Institute of Thermophysics, Novosibirsk (Russian Federation)

    2013-07-01

    Emissions of nitrogen oxides from coal combustion are a major environmental problem because they have been shown to contribute to the formation of acid rain and photochemical smog. Coal thermalpreparation before furnace delivery is effective method to reduce NOx emissions, shown by experiments in small-scale facilities (Babiy VI, Alaverdov PI, Influence of thermal preparation pulverized coal on nitric oxides outlet for combustion different metamorphized coal. ATI, 1983). This paper presents the mathematical model of burning thermal preparation coal. Validation of the model was carried out on laboratory-scale plant of All-Russia thermal engineering institute. Modeling of low-emissive burner with preliminary heating coal dust is made for the purpose of search of burner optimal constructions which provides low concentration of nitric oxides in the boiler. For modeling are used in-house CFD code ''{sigma}Flow'' (Dekterev AA, Gavrilov AA, Harlamov EB, Litvintcev KY, J Comput Technol 8(Part 1):250-255, 2003).

  4. Gradual combustion - method for nitrogen oxide suppression during brown coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.P.; Verzakov, V.N.; Lobov, T.V.

    1990-10-01

    Discusses combustion of brown coal in BKZ-500-140-1 boilers and factors that influence emission of nitrogen oxides. Temperature distribution in the furnace was evaluated. Effects of burner position, burner number and burner type as well as air excess ratio on chemical reactions during brown coal combustion, formation of nitrogen oxides and their emission were comparatively evaluated. Analyses showed that by optimum arrangement of burners and selecting the optimum air excess ratio a part of nitrogen oxides formed during the initial phase of combustion was reduced to molecular nitrogen in the second phase. On the basis of evaluations the following recommendations for furnace design are made: use of straight-flow burners characterized by a reduced mixing ratio with secondary air, parallel arrangement of burners which guarantees mixing of the combustion products from the burners with stable and unstable combustion (products of incomplete coal combustion), reducing the air excess ratio to below 1.0. 5 refs.

  5. Physical and chemical characterization of 50 pulverized coal ashes with respect to partial cement replacement in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Van der Sloot, H A; Weijers, E G

    1986-04-01

    Physical and chemical characterization of 50 pulverized coal ashes from Dutch, Belgian and German installations has been carried out to identify the parameters that have to be kept under control, when pulverized coal ashes are to be used as partial cement replacement in concrete. For a good workability of fly ash/cement mortars the particle size and the carbon content are important. By performing a mortar flow test (Heagermann) upon delivery exterme ashes can be easily eliminated. The compressive strength is largely determined by the fineness of the ash (weight fraction below 20 micron). A direct effect of carbon content on strength development is not observed, but a reduction in mortar slow due to carbon leads to loss in strength, while the workability has to be adjusted. Size distribution measurement by optical methods is recommended as the relevant part of the ash size distribution cannot be properly assessed by sieve methods. The net contribution of fly ash to the compressive strength of a fly ash/cement (20/80) mortar exhibits a minimum at 14 days curing, which is common to all 50 ashes studied. Improvements in ash quality as obtained from pulverized-coal fired installations can be achieved by improvements in coal milling and optimizing ash collection. 6 figs., 4 tabs., 19 refs.

  6. Effect of oxidation on the chemical nature and distribution of low-temperature pyrolysis products from bituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; MacPhee, J.A.; Vancea, L.; Ciavaglia, L.A.; Nandi, B.N.

    1983-04-01

    Two bituminous coals, a high volatile Eastern Canadian and a medium volatile Western Canadian, were used to investigate the effect of oxidation on yields and chemical composition of gases, liquids and chars produced during coal pyrolysis. Pyrolysis experiments were performed at 500 C using the Fischer assay method. Mild oxidation of coals resulted in a decrease of liquid hydrocarbon yields. Further coal oxidation increased the proportion of aromatic carbon in liquid products as determined by N.M.R. and also increased the content of oxygen in liquid products. The content of oxygen in chars was markedly lower than in corresponding coals. An attempt is made to explain reactions occurring during oxidation and subsequent pyrolysis of coal on the basis of differences in chemical composition of gases, liquids and chars. (19 refs.)

  7. Effect of oxidation on the chemical nature and distribution of low-temperature pyrolysis products from bituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; Ciavaglia, L.A.; MacPhee, J.A.; Nandi, B.N.; Vancea, L.

    1983-04-01

    Two bituminous coals, a high volatile Eastern Canadian and a medium volatile Western Canadian, were used to investigate the effect of oxidation on yields and chemical composition of gases, liquids and chars produced during coal pyrolysis. Pyrolysis experiments were performed at 500/sup 0/C using the Fischer assay method. Mild oxidation of coals resulted in a decrease of liquid hydrocarbon yields. Further coal oxidation increased the proportion of aromatic carbon in liquid products as determined by n.m.r., and also increased the content of oxygen in liquid products. The content of oxygen in chars was markedly lower than in corresponding coals. An attempt is made to explain reactions occurring during oxidation and subsequent pyrolysis of coal on the basis of differences in chemical composition of gases, liquids and chars.

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

    Directory of Open Access Journals (Sweden)

    Weiqing Zhang

    2015-01-01

    Full Text Available 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 IG+GR/IAll but lower values of ID/I(G+GR, IDL/I(G+GR, IS+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, IG+GR/IAll, and IS+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.

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

    Science.gov (United States)

    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 I GR/I All and I (G + GR)/I All but lower values of I D/I (G+GR), I DL/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 T ig, T 20%, and T max from TGA data which were found to correlate well with the band area ratios of I GR/I All, I (G + GR)/I All, 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.

  10. MECHANISMS OF NITROUS OXIDE FORMATION IN COAL FLAMES

    Science.gov (United States)

    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 ...

  11. Nitric oxide reduction over a synthetic coal char

    Energy Technology Data Exchange (ETDEWEB)

    C. Pevida; A. Arenillas; F. Rubiera; J.J. Pis [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

    2003-07-01

    In the present work, the mechanisms involved in the NO heterogeneous reduction have been investigated. A synthetic coal char was used as the carbon source. This synthetic coal was made from a mixture of model compounds and provides well-known functionalities, including nitrogenated ones, similar to those found in a high volatile bituminous coal. The char was obtained by pyrolysis of the synthetic coal, up to 1123 K, under helium atmosphere in a fixed bed reactor. Char texture and structure were characterised by N{sub 2} and CO{sub 2} adsorption isotherms at 77 and 273 K, respectively, X-ray diffraction, immersion calorimetry in C{sub 6}H{sub 6} and scanning electron microscopy (SEM). Temperature programmed reactions (TPR) were carried out in a thermogravimetric analyser using 400 ppm NO diluted in Ar as the reactant gas. The char was heated at 15 K min{sup -1} from room temperature to 1273 K. Gaseous products were simultaneously analysed by mass spectrometry (MS) and Fourier transform infrared spectroscopy (FTIR). The influence of nitrogen in the solid phase on the reduction mechanism was evaluated by comparing the results for chars with and without nitrogen in their composition. The results of this preliminary study showed that the presence of nitrogen in the chars composition did not favour the heterogeneous NO reduction. In addition, low temperature NO chemisorption on the carbon surface creates complexes that take an active part in the subsequent reactions with NO. 5 refs., 4 figs., 3 tabs.

  12. KINETICS OF DIRECT OXIDATION OF H2S IN COAL GAS TO ELEMENTAL SULFUR; F

    International Nuclear Information System (INIS)

    K.C. Kwon

    2002-01-01

    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

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

    Science.gov (United States)

    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...

  14. Decrease in emissions of nitric oxides during burning of Kuznetsk hard coal

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Gedike, I.A.; Lobov, G.V.

    1983-01-01

    Results are presented of introducing and studying the plan for gradual combustion of Kuznetsk hard coals on a BKZ-210-140 F type boiler. Supply of 16-18% theoretically necessary air through the nozzle of the tertiary injection made it possible to reduce 1.5-fold the emissions of nitric oxides without reducing the economy of the furnace process.

  15. Generation of synthesis gas by partial oxidation of natural gas in a gas turbine

    NARCIS (Netherlands)

    Cornelissen, R.; Tober, E.; Kok, Jacobus B.W.; van der Meer, Theodorus H.

    2006-01-01

    The application of partial oxidation in a gas turbine (PO-GT) in the production of synthesis gas for methanol production is explored. In PO-GT, methane is compressed, preheated, partial oxidized and expanded. For the methanol synthesis a 12% gain in thermal efficiency has been calculated for the

  16. Mixed conducting materials for partial oxidation of hydrocarbons

    Directory of Open Access Journals (Sweden)

    Frade, J. R.

    2004-06-01

    Full Text Available Thermodynamic calculations with additional conditions for the conservation of carbon and hydrogen were used to predict the gas composition obtained by partial oxidation of methane as a function of oxygen partial pressure and temperature; this was used to assess the stability and oxygen permeability requirements of mixed conducting membrane materials proposed for this purpose. A re-examination of known mixed conductors shows that most materials with highest permeability still fail to fulfil the requirements of stability under reducing conditions. Other materials possess sufficient stability but their oxygen permeability is insufficient. Different approaches were thus used to attempt to overcome those limitations, including changes in composition in the A and B site positions of ABO3 perovskites, and tests of materials with different structure types. Promising results were obtained mainly for some materials with perovskite or related K2NiF4-type structures. Limited stability of the most promising materials shows that one should rely mainly on kinetic limitations in the permeate side to protect the mixed conductor from severe reducing conditions.

    Se han usado cálculos termodinámicos con condiciones adicionales para la conservación del carbono e hidrógeno para predecir la composición del gas obtenido mediante la oxidación parcial del metano en función de la presión parcial de oxígeno y de la temperatura; esto se ha usado para asegurar los requerimientos de estabilidad y permeabilidad al oxígeno de los materiales conductores mixtos empleados como membrana para este propósito. Un nuevo exámen de los conductores mixtos conocidos muestra que la mayoría de los materiales con la mayor permeabilidad todavía fallan en el cumplimiento de los requerimientos de estabilidad bajo condiciones reductoras. Otros materiales poseen suficiente estabilidad, pero su permeabilidad al oxígeno es insuficiente. Por ello se han empleado diferentes

  17. Application of infiltrated LSCM-GDC oxide anode in direct carbon/coal fuel cells.

    Science.gov (United States)

    Yue, Xiangling; Arenillas, Ana; Irvine, John T S

    2016-08-15

    Hybrid direct carbon/coal fuel cells (HDCFCs) utilise an anode based upon a molten carbonate salt with an oxide conducting solid electrolyte for direct carbon/coal conversion. They can be fuelled by a wide range of carbon sources, and offer higher potential chemical to electrical energy conversion efficiency and have the potential to decrease CO2 emissions compared to coal-fired power plants. In this study, the application of (La, Sr)(Cr, Mn)O3 (LSCM) and (Gd, Ce)O2 (GDC) oxide anodes was explored in a HDCFC system running with two different carbon fuels, an organic xerogel and a raw bituminous coal. The electrochemical performance of the HDCFC based on a 1-2 mm thick 8 mol% yttria stabilised zirconia (YSZ) electrolyte and the GDC-LSCM anode fabricated by wet impregnation procedures was characterized and discussed. The infiltrated oxide anode showed a significantly higher performance than the conventional Ni-YSZ anode, without suffering from impurity formation under HDCFC operation conditions. Total polarisation resistance (Rp) reached 0.8-0.9 Ω cm(2) from DCFC with an oxide anode on xerogel and bituminous coal at 750 °C, with open circuit voltage (OCV) values in the range 1.1-1.2 V on both carbon forms. These indicated the potential application of LSCM-GDC oxide anode in HDCFCs. The chemical compatibility of LSCM/GDC with carbon/carbonate investigation revealed the emergence of an A2BO4 type oxide in place of an ABO3 perovskite structure in the LSCM in a reducing environment, due to Li attack as a result of intimate contact between the LSCM and Li2CO3, with GDC being stable under identical conditions. Such reaction between LSCM and Li2CO3 was not observed on a LSCM-YSZ pellet treated with Li-K carbonate in 5% H2/Ar at 700 °C, nor on a GDC-LSCM anode after HDCFC operation. The HDCFC durability tests of GDC-LSCM oxide on a xerogel and on raw bituminous coal were performed under potentiostatic operation at 0.7 V at 750 °C. The degradation mechanisms were

  18. Hyperspectral analysis of soil organic matter in coal mining regions using wavelets, correlations, and partial least squares regression.

    Science.gov (United States)

    Lin, Lixin; Wang, Yunjia; Teng, Jiyao; Wang, Xuchen

    2016-02-01

    Hyperspectral estimation of soil organic matter (SOM) in coal mining regions is an important tool for enhancing fertilization in soil restoration programs. The correlation--partial least squares regression (PLSR) method effectively solves the information loss problem of correlation--multiple linear stepwise regression, but results of the correlation analysis must be optimized to improve precision. This study considers the relationship between spectral reflectance and SOM based on spectral reflectance curves of soil samples collected from coal mining regions. Based on the major absorption troughs in the 400-1006 nm spectral range, PLSR analysis was performed using 289 independent bands of the second derivative (SDR) with three levels and measured SOM values. A wavelet-correlation-PLSR (W-C-PLSR) model was then constructed. By amplifying useful information that was previously obscured by noise, the W-C-PLSR model was optimal for estimating SOM content, with smaller prediction errors in both calibration (R(2) = 0.970, root mean square error (RMSEC) = 3.10, and mean relative error (MREC) = 8.75) and validation (RMSEV = 5.85 and MREV = 14.32) analyses, as compared with other models. Results indicate that W-C-PLSR has great potential to estimate SOM in coal mining regions.

  19. SUPERCRITICAL WATER PARTIAL OXIDATION PHASE I - PILOT-SCALE TESTING / FEASIBILITY STUDIES FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    SPRITZER,M; HONG,G

    2005-01-01

    Under Cooperative Agreement No. DE-FC36-00GO10529 for the Department of Energy, General Atomics (GA) is developing Supercritical Water Partial Oxidation (SWPO) as a means of producing hydrogen from low-grade biomass and other waste feeds. The Phase I Pilot-scale Testing/Feasibility Studies have been successfully completed and the results of that effort are described in this report. The Key potential advantages of the SWPO process is the use of partial oxidation in-situ to rapidly heat the gasification medium, resulting in less char formation and improved hydrogen yield. Another major advantage is that the high-pressure, high-density aqueous environment is ideal for reaching and gasifying organics of all types. The high water content of the medium encourages formation of hydrogen and hydrogen-rich products and is especially compatible with high water content feeds such as biomass materials. The high water content of the medium is also effective for gasification of hydrogen-poor materials such as coal. A versatile pilot plant for exploring gasification in supercritical water has been established at GA's facilities in San Diego. The Phase I testing of the SWPO process with wood and ethanol mixtures demonstrated gasification efficiencies of about 90%, comparable to those found in prior laboratory-scale SCW gasification work carreid out at the University of Hawaii at Manoa (UHM) as well as other biomass gasification experience with conventional gasifiers. As in the prior work at UHM, a significant amount of the hydrogen found in the gas phase products is derived from the water/steam matrix. The studies at UHM utilized an indirectly heated gasifier with an acitvated carbon catalyst. In contrast, the GA studies utilized a directly heated gasifier without catalyst, plus a surrogate waste fuel. Attainment of comparable gasification efficiencies without catalysis is an important advancement for the GA process, and opens the way for efficient hydrogen production from low

  20. Enhanced performance of solid oxide electrolysis cells by integration with a partial oxidation reactor: Energy and exergy analyses

    International Nuclear Information System (INIS)

    Visitdumrongkul, Nuttawut; Tippawan, Phanicha; Authayanun, Suthida; Assabumrungrat, Suttichai; Arpornwichanop, Amornchai

    2016-01-01

    Highlights: • Process design of solid oxide electrolyzer integrated with a partial oxidation reactor is studied. • Effect of key operating parameters of partial oxidation reactor on the electrolyzer performance is presented. • Exergy analysis of the electrolyzer process is performed. • Partial oxidation reactor can enhance the solid oxide electrolyzer performance. • Partial oxidation reactor in the process is the highest exergy destruction unit. - Abstract: Hydrogen production without carbon dioxide emission has received a large amount of attention recently. A solid oxide electrolysis cell (SOEC) can produce pure hydrogen and oxygen via a steam electrolysis reaction that does not emit greenhouse gases. Due to the high operating temperature of SOEC, an external heat source is required for operation, which also helps to improve SOEC performance and reduce operating electricity. The non-catalytic partial oxidation reaction (POX), which is a highly exothermic reaction, can be used as an external heat source and can be integrated with SOEC. Therefore, the aim of this work is to study the effect of operating parameters of non-catalytic POX (i.e., the oxygen to carbon ratio, operating temperature and pressure) on SOEC performance, including exergy analysis of the process. The study indicates that non-catalytic partial oxidation can enhance the hydrogen production rate and efficiency of the system. In terms of exergy analysis, the non-catalytic partial oxidation reactor is demonstrated to be the highest exergy destruction unit due to irreversible chemical reactions taking place, whereas SOEC is a low exergy destruction unit. This result indicates that the partial oxidation reactor should be improved and optimally designed to obtain a high energy and exergy system efficiency.

  1. Partial gasification of coal in a fluidized bed reactor: Comparison of a laboratory and pilot scale reactors

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, R.; Shen, L.H.; Zhang, M.Y.; Jin, B.S.; Xiong, Y.Q.; Duan, Y.F.; Zhong, Z.P.; Zhou, H.C.; Chen, X.P.; Huang, Y.J. [Southeast University, Nanjing (China)

    2007-01-15

    A 0.1 MWth lab-scale and 2 MWth pilot-scale experimental rigs were constructed to demonstrate the technical feasibility of a new process. The aim of the lab-scale study is to optimize coal partial gasification reactions operating conditions, which were applied in the pilot-scale tests. A comparison between the laboratory and pilot scale experimental results is presented in this paper in order to provide valuable information for scaling-up of the PFB coal partial reactor to industrial applications. The results show that trends and phenomena obtained in the laboratory reactor are confirmed in a pilot plant operating at similar conditions. However, many differences are observed in the two reactors. The higher heat loss in the lab-scale reactor is responsible for higher equivalence ratio (ER) and lower gas heating value at the similar reactor temperature. With respect to the pilot-scale reactor, mass transfer limitation between bubbles and emulsion phase may become important. Hence, longer contact time is required to achieve the same conversions as in the lab-scale reactor. This difference is explained by a significant change of the hydrodynamic conditions due to the formation of larger bubbles.

  2. Effect of hydrothermal treatment of coal on the oxidation susceptibility and electrical resistivity of HTT coke

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, N.B.; Sarkar, P.; Choudhury, A. [Central Fuel Research Institute, P.O. FRI, Dhanbad-828108, Jharkhand (India)

    2005-02-25

    The influence of hydrothermal treatment of coal prior to carbonization, on the oxidation susceptibility of resultant coke/char, calcined at 1350, 1800 and 2200 {sup o}C has been investigated. The non-isothermal thermogravimetric analysis technique has been employed, and parameters such as onset, DTG peak temperatures, and cumulative oxidation loss (wt.%) at different temperatures have been utilized to compare proneness to oxidation with respective untreated samples apart from electrical resistivity. Data suggest that all the cokes/chars samples produced from hydrothermally treated coals are less reactive and more electrically conductive (less resistive) than their respective untreated counterparts. But the extent of improvement of oxidation resistance and electrical conductivity appears to be coal-specific. The kinetic parameters obtained by non-linear regression analysis on multi-curve reveal that the n{sup th} order reaction model (where 'n' was found to vary from 0.9 to 1.3) is the best-fitted model. The higher activation energy values observed for hydrothermally treated coke samples are in agreement with the observation of TG analysis data. Overall results indicate the importance of introducing a hydrothermal treatment step for the improvement of oxidation resistance as well as electrical conductivity of the coke samples.

  3. Experimental Investigation of Flow Resistance in a Coal Mine Ventilation Air Methane Preheated Catalytic Oxidation Reactor

    OpenAIRE

    Zheng, Bin; Liu, Yongqi; Liu, Ruixiang; Meng, Jian; Mao, Mingming

    2015-01-01

    This paper reports the results of experimental investigation of flow resistance in a coal mine ventilation air methane preheated catalytic oxidation reactor. The experimental system was installed at the Energy Research Institute of Shandong University of Technology. The system has been used to investigate the effects of flow rate (200 Nm3/h to 1000 Nm3/h) and catalytic oxidation bed average temperature (20°C to 560°C) within the preheated catalytic oxidation reactor. The pressure drop and res...

  4. Mineral distribution in two southwest colombian coals using cyclone separation and oxidation at low temperature

    International Nuclear Information System (INIS)

    Rojas Andres F; Barraza, Juan M; Rojas, Andres F.

    2010-01-01

    It was studied the mineral distribution of two Colombian coals using a cyclone separation and oxidation at low temperature, OLT. The cyclone separation was carried out at two densities (1.3 and 1.4), three particle size (1000+ 600?m, 600+ 425?m and 425+ 250?m) and two processing stages. To determine the mineral matter, feed and under flow fractions from hydrocyclone were concentrated in mineral matter by OLT in a fluidized bed (T<300 celsius degrade). 18 minerals were identified by X Ray Diffraction, XRD. XRD results showed 13 minerals from Golondrinas and 15 minerals from Guachinte coal. It was found that kaolinite and quartz were the most abundant minerals in coal fractions from Golondrinas and Guachinte. Furthermore, it was found that mainly minerals kaolinite, quartz, dolomite, jarosite, gypsum and pyrite, exhibited affinity towards mineral matter, while siderite and valerite showed affinity towards organic matter.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  7. Fuel processor integrated H{sub 2}S catalytic partial oxidation technology for sulfur removal in fuel cell power plants

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, T.H.; Berry, D.A.; Lyons, K.D.; Beer, S.K.; Freed, A.D. [U.S. Department of Energy, Morgantown, WV (USA). National Energy Technology Laboratory

    2002-12-01

    H{sub 2}S catalytic partial oxidation technology with an activated carbon catalyst was found to be a promising method for the removal of hydrogen sulfide from fuel cell hydrocarbon feedstocks. Three different fuel cell feedstocks were considered for analysis: sour natural gas, sour effluent from a liquid middle distillate fuel processor and a Texaco O{sub 2}-blown coal-derived synthesis gas. The H{sub 2}S catalytic partial oxidation reaction, its integratability into fuel cell power plants with different hydrocarbon feedstocks and its salient features are discussed. Experimental results indicate that H{sub 2}S concentration can be removed down to the part-per-million level in these plants. Additionally, a power law rate expression was developed and reaction kinetics compared to prior literature. The activation energy for this reaction was determined to be 34.4 kJ/g mol with the reaction being first order in H{sub 2}S and 0.3 order in O{sub 2}. 18 refs., 14 figs., 3 tabs.

  8. Experimental Investigation of Flow Resistance in a Coal Mine Ventilation Air Methane Preheated Catalytic Oxidation Reactor

    Directory of Open Access Journals (Sweden)

    Bin Zheng

    2015-01-01

    Full Text Available This paper reports the results of experimental investigation of flow resistance in a coal mine ventilation air methane preheated catalytic oxidation reactor. The experimental system was installed at the Energy Research Institute of Shandong University of Technology. The system has been used to investigate the effects of flow rate (200 Nm3/h to 1000 Nm3/h and catalytic oxidation bed average temperature (20°C to 560°C within the preheated catalytic oxidation reactor. The pressure drop and resistance proportion of catalytic oxidation bed, the heat exchanger preheating section, and the heat exchanger flue gas section were measured. In addition, based on a large number of experimental data, the empirical equations of flow resistance are obtained by the least square method. It can also be used in deriving much needed data for preheated catalytic oxidation designs when employed in industry.

  9. Oxidation of mercury across selective catalytic reduction catalysts in coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Constance L. Senior [Reaction Engineering International, Salt Lake City, UT (United States)

    2006-01-15

    A kinetic model for predicting the amount of mercury (Hg) oxidation across selective catalytic reduction (SCR) systems in coal-fired power plants was developed and tested. The model incorporated the effects of diffusion within the porous SCR catalyst and the competition between ammonia and Hg for active sites on the catalyst. Laboratory data on Hg oxidation in simulated flue gas and slipstream data on Hg oxidation in flue gas from power plants were modeled. The model provided good fits to the data for eight different catalysts, both plate and monolith, across a temperature range of 280-420{sup o}C, with space velocities varying from 1900 to 5000 hr{sup -1}. Space velocity, temperature, hydrochloric acid content of the flue gas, ratio of ammonia to nitric oxide, and catalyst design all affected Hg oxidation across the SCR catalyst. The model can be used to predict the impact of coal properties, catalyst design, and operating conditions on Hg oxidation across SCRs. 20 refs., 9 figs., 2 tabs.

  10. Partial oxidation of methane in a temperature-controlled dielectric barrier discharge reactor

    KAUST Repository

    Zhang, Xuming; Cha, Min

    2015-01-01

    We studied the relative importance of the reduced field intensity and the background reaction temperature in the partial oxidation of methane in a temperature-controlled dielectric barrier discharge reactor. We obtained important mechanistic insight

  11. Hydrogen or Soot?: Partial Oxidation of High-boiling Hydrocarbon Wastes

    Czech Academy of Sciences Publication Activity Database

    Lederer, J.; Hanika, Jiří; Nečesaný, F.; Poslední, W.; Tukač, V.; Veselý, Václav

    2015-01-01

    Roč. 29, č. 1 (2015), s. 5-11 ISSN 0352-9568 Institutional support: RVO:67985858 Keywords : partial oxidation * waste * hydrocarbon Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.675, year: 2015

  12. Nitrogen oxide suppression by using a new design of pulverized-coal burners

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Cameron, S.D.; Grekhov, L.L. [All-Russian Thermal Engineering Institute, Moscow (Russian Federation)

    1996-07-01

    The results of testing a low-NO{sub x} swirl burner are presented. This burner was developed by Babcock Energy Ltd., for reducing nitrogen oxide emissions when burning Ekibastuz and Kuznetsk low-caking coals in power boilers. The tests conducted at a large plant of the BEL Technological Center showed that the new burner reduces NO{sub x} emissions by approximately two times. 6 refs., 6 figs., 1 tab.

  13. The Technology of Nitrogen Oxide Emissions Reduction at Pulverized Coal Burning

    Directory of Open Access Journals (Sweden)

    Dunaevska, N.I.

    2016-11-01

    Full Text Available To assess the effectiveness of the influence of thermochemical preparation of anthracite on the formation of nitrogen oxides the three-dimensional numerical model of the TPP-210A boiler`s furnace for standard and modified burners was created. The calculation results are shown the decrease of NOx concentration across the height of the furnace and reduce of the unburnt coal for the modified burners in comparison with standard ones.

  14. Effect of primary air content on formation of nitrogen oxides during combustion of Ehkibastuz coal

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Imankulov, Eh.R.

    1986-01-01

    Investigations are discussed carried out in a pilot plant at the Kaz. Power Engineering Scientific Research Institute into the effect of the amount of primary air in coal-dust flame on the final concentration of nitrogen oxides in flue gases. The tests were carried out in a 7500 mm high, 1600 mm dia vertical cylindrical combustion chamber having type P-57 burner, and air dispersed fuel plus additional air supplies located at the top. Amounts of coal dust fed by a drum feeder along the air pipe varied from 100-600 kg/h. The required air was supplied by 5000 m/sup 3//h Type TK-700/5 blowers at 0.04 MPa. Ehkibastuz coal samples contained: 1.3% moisture; 48.1% ash; 38.02% carbon; 2.56% hydrogen; 0.73% sulfur; 0.60% nitrogen; heat of combustion was 14.3 MJ/kg. Results obtained indicate that variations in the amount of primary air in swirl flow burners affect formation of fuel nitrogen; there is an optimum volume at which minimum quantities of nitrogen oxides are formed. Either an increase or decrease in the primary air results in a rise in nitrogen oxide concentration. 3 references.

  15. Coal structure construction system with construction knowledge and partial energy evaluation; Kochiku chishiki to bubunteki energy hyoka ni yoru sekitan bunshi kozo kochiku system

    Energy Technology Data Exchange (ETDEWEB)

    Okawa, T.; Sasai, T.; Komoda, N. [Osaka University, Osaka (Japan). Faculty of Engineering

    1996-10-28

    The computer aided coal structure construction system is proposed, and a computational construction example is presented. The coal structure construction engine of this system fabricates molecular structure by connecting fragments sequentially inputted through a user interface. The best structure candidate is determined using construction knowledge and partial energy evaluation every addition of one fragment, and this process is subsequently repeated. The structure evaluation engine analyzes the 3-D conformation candidate by molecular dynamics, and evaluates the conformation by determining the energy value of an optimum structure. As an example, this system was applied to construction of coal molecular structure based on the actual data of partial structure composed of 26 structures from 2l kinds of aromatic cluster structures, 27 bonds from 2 kinds of bridged bonds, and 16 groups from 2 kinds of terminal substitutional groups. As a result, this system could construct a superior structure according to expert knowledge from the viewpoint of energy. 6 refs., 5 figs., 2 tabs.

  16. Characterization of a new Hencken burner with a transition from a reducing-to-oxidizing environment for fundamental coal studies

    Science.gov (United States)

    Adeosun, Adewale; Huang, Qian; Li, Tianxiang; Gopan, Akshay; Wang, Xuebin; Li, Shuiqing; Axelbaum, Richard L.

    2018-02-01

    In pulverized coal burners, coal particles usually transition from a locally reducing environment to an oxidizing environment. The locally reducing environment in the near-burner region is due to a dense region of coal particles undergoing devolatilization. Following this region, the particles move into an oxidizing environment. This "reducing-to-oxidizing" transition can influence combustion processes such as ignition, particulate formation, and char burnout. To understand these processes at a fundamental level, a system is required that mimics such a transition. Hence, we have developed and characterized a two-stage Hencken burner to evaluate the effect of the reducing-to-oxidizing transition and particle-to-particle interaction (which characterizes dense region of coal particles) on ignition and ultrafine aerosol formation. The two-stage Hencken burner allows coal particles to experience a reducing environment followed by a transition to an oxidizing environment. This work presents the results of the design and characterization of the new two-stage Hencken burner and its new coal feeder. In a unique approach to the operation of the flat-flame of the Hencken burner, the flame configurations are operated as either a normal flame or inverse flame. Gas temperatures and oxygen concentrations for the Hencken burner are measured in reducing-to-oxidizing and oxidizing environments. The results show that stable flames with well-controlled conditions, relatively uniform temperatures, and species concentrations can be achieved in both flame configurations. This new Hencken burner provides an effective system for evaluating the effect of the reducing-to-oxidizing transition and particle-to-particle interaction on early-stage processes of coal combustion such as ignition and ultrafine particle formation.

  17. Direct Partial Oxidation of Natural Gas to Liquid Chemicals

    DEFF Research Database (Denmark)

    Rasmussen, Christian Lund

    2007-01-01

    Direkte delvis oxidation af naturgas til flydende kemikalier er en attraktiv industriel proces, hvor naturgas omdannes til stoffer; primært methanol (CH3OH) som let kan transporteres over store afstande. Omdannelsen sker i en simpel et-trinsproces under højt tryk, lave forbrændingstemperaturer, s...

  18. Nitric oxide reduction in coal combustion: role of char surface complexes in heterogeneous reactions

    Energy Technology Data Exchange (ETDEWEB)

    Arenillas, A.; Rubiera, F.; Pis, J.J. [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

    2002-12-15

    Nitrogen oxides are one of the major environmental problems arising from fossil fuel combustion. Coal char is relatively rich in nitrogen, and so this is an important source of nitrogen oxides during coal combustion. However, due to its carbonaceous nature, char can also reduce NO through heterogeneous reduction. The objectives of this work were on one hand to compare NO emissions from coal combustion in two different types of equipment and on the other hand to study the influence of char surface chemistry on NO reduction. A series of combustion tests were carried out in two different scale devices: a thermogravimetric analyzer coupled to a mass spectrometer and an FTIR (TG-MS-FTIR) and a fluidized bed reactor with on-line battery of analyzers. According to the results obtained, it can be said that the TG-MS-FTIR system provides valuable information about NO heterogeneous reduction and it can give good trends of the behaviour in other combustion equipments, i.e. fluidized bed combustors. It has been also pointed out that NO-char interaction depends to a large extent on temperature. In the low-temperature range NO heterogeneous reduction seems to be controlled by the evolution of surface complexes. In the high-temperature range a different mechanism is involved in NO heterogeneous reduction, the nature of the carbon matrix being a key factor. 27 refs., 6 figs., 1 tab.

  19. Nitric oxide reduction in coal combustion: role of char surface complexes in heterogeneous reactions.

    Science.gov (United States)

    Arenillas, Ana; Rubiera, Fernando; Pis, José J

    2002-12-15

    Nitrogen oxides are one of the major environmental problems arising from fossil fuel combustion. Coal char is relatively rich in nitrogen, and so this is an important source of nitrogen oxides during coal combustion. However, due to its carbonaceous nature, char can also reduce NO through heterogeneous reduction. The objectives of this work were on one hand to compare NO emissions from coal combustion in two different types of equipment and on the other hand to study the influence of char surface chemistry on NO reduction. A series of combustion tests were carried out in two different scale devices: a thermogravimetric analyzer coupled to a mass spectrometer and an FTIR (TG-MS-FTIR) and a fluidized bed reactor with an on line battery of analyzers. The TG-MS-FTIR system was also used to perform a specific study on NO heterogeneous reduction reactions using chars with different surface chemistry. According to the results obtained, it can be said that the TG-MS-FTIR system provides valuable information about NO heterogeneous reduction and it can give good trends of the behavior in other combustion equipments (i.e., fluidized bed combustors). It has been also pointed out that NO-char interaction depends to a large extent on temperature. In the low-temperature range (800 degrees C), a different mechanism is involved in NO heterogeneous reduction, the nature of the carbon matrix being a key factor.

  20. Study of propane partial oxidation on vanadium-containing catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Komashko, G.A.; Khalamejda, S.V.; Zazhigalov, V.A. [AN Ukrainskoj SSR, Kiev (Ukraine). Inst. Fizicheskoj Khimii

    1998-12-31

    The present results indicate that maximum selectivity to acrylic acid can be reached over V-P-Zr-O catalysts. When the hydrocarbon concentration is 5.1 vol.% the selectivity is about 30% at quite high paraffin conversion. Conclusively, some explanations to the observed facts can be given. The V-P-O catalyst promotion with lanthanum by means of mechanochemical treatment is distinguished by the additive uniform spreading all over the matrix surface. Such twophase system is highly active in propane conversion (lanthanum oxide) and further oxidation of the desired products. The similar properties are attributed to V-P-Bi-La-O catalyst. Bismuth, tellurium and zirconium additives having clearly defined acidic properties provoke the surface acidity strengthening and make easier desorption of the acidic product (acrylic acid) from the surface lowering its further oxidation. Additionally, since bismuth and zirconium are able to form phosphates and, according to, to create space limitations for the paraffin molecule movement out of the active group boundaries, this can be one more support in favour of the selectivity increase. With this point of view very interesting results were obtained. It has been shown that the more limited the size of the vanadium unit, the higher the selectivity is. Monoclinic phase AV{sub 2}P{sub 2}O{sub 10} which consists in clusters of four vanadium atoms is sensibly more reactive than the orthorhombic phase consists in V{sub {infinity}} infinite chains. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. New Approach to Study the Ignition Processes of Organic Coal-Water Fuels in an Oxidizer Flow

    Directory of Open Access Journals (Sweden)

    Valiullin T.R.

    2016-01-01

    Full Text Available To converge the conditions of organic water-coal fuel composition combustion in the typical power equipment we developed a new approach and installed an experimental setup, eliminating the traditional fixing the fuel droplets on the thermocouples or rods. Specialized cone-shaped chamber was used to implement the process of lingering of organic water-coal fuel droplets. Necessary and sufficient conditions for the lingering of organic water-coal fuel droplets were established. We determined the parameters of the system (droplet size of 0.4-0.6 mm, temperatures 823-903 K and the velocity of the oxidizer flow 1.5-6 m/s at which the droplets were consistently ignited in the process of lingering. Minimum temperatures and ignition delay times of organic water-coal fuel droplets based on brown coal, used motor, turbine, transformer oils, kerosene, gasoline and water were defined.

  3. Oxidation of C/SiC Composites at Reduced Oxygen Partial Pressures

    Science.gov (United States)

    Opila, Elizabeth J.; Serra, Jessica

    2009-01-01

    Carbon-fiber reinforced SiC (C/SiC) composites are proposed for leading edge applications of hypersonic vehicles due to the superior strength of carbon fibers at high temperatures (greater than 1500 C). However, the vulnerability of the carbon fibers in C/SiC to oxidation over a wide range of temperatures remains a problem. Previous oxidation studies of C/SiC have mainly been conducted in air or oxygen, so that the oxidation behavior of C/SiC at reduced oxygen partial pressures of the hypersonic flight regime are less well understood. In this study, both carbon fibers and C/SiC composites were oxidized over a wide range of temperatures and oxygen partial pressures to facilitate the understanding and modeling of C/SiC oxidation kinetics for hypersonic flight conditions.

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

    Science.gov (United States)

    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.

  5. Design and implementation of a field pilot study on using coal fly ash to prevent oxidation of reactive mine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.L.; Shang, J.Q.; Xu, Y.Q.; Yanful, E.K. [Western Ontario Univ., London, ON (Canada). Dept. of Civil and Environmental Engineering; Hmidi, N. [Goldcorp Inc., Musselwhite Mine, Thunder Bay, ON (Canada)

    2009-07-01

    This paper reported on a pilot scale study that investigated the feasibility of using coal fly ash in mine tailings management and acid mine drainage (AMD) treatment at Goldcorp's Musselwhite Mine site in northern Ontario. The principles and key aspects of the fly ash application in mine tailings management were described. Fly ash from the Atikokan coal-fired power generating plant was added to the Musselwhite tailings as a mixture as well as intermediate and top layers. The physical, chemical and hydrogeological effects of the two approaches were monitored. The paper provided details of the design, implementation, monitoring, sampling and testing over 2 years. The objectives were to evaluate the optimum mass ratio of coal fly ash and mine tailings, effectiveness in reducing the infiltration of precipitation, and projected long-term durability and performance on tailings oxidation prevention. The pilot study was designed based on the principles of cementitious materials formation and secondary mineral formation by the reactions of coal fly ash and water/AMD. Calcium oxide, aluminum oxide, silicon oxide, and ferric oxide are major components of coal fly ash. The preliminary test results revealed that water did not accumulate and cracks did not form on top of 4 tanks. The settlements of the mixing approaches were lower than that of the stratified approach and the temperature distributions in the 4 tanks were comparable. 9 refs., 3 tabs., 11 figs.

  6. Design and implementation of a field pilot study on using coal fly ash to prevent oxidation of reactive mine tailings

    International Nuclear Information System (INIS)

    Wang, H.L.; Shang, J.Q.; Xu, Y.Q.; Yanful, E.K.

    2009-01-01

    This paper reported on a pilot scale study that investigated the feasibility of using coal fly ash in mine tailings management and acid mine drainage (AMD) treatment at Goldcorp's Musselwhite Mine site in northern Ontario. The principles and key aspects of the fly ash application in mine tailings management were described. Fly ash from the Atikokan coal-fired power generating plant was added to the Musselwhite tailings as a mixture as well as intermediate and top layers. The physical, chemical and hydrogeological effects of the two approaches were monitored. The paper provided details of the design, implementation, monitoring, sampling and testing over 2 years. The objectives were to evaluate the optimum mass ratio of coal fly ash and mine tailings, effectiveness in reducing the infiltration of precipitation, and projected long-term durability and performance on tailings oxidation prevention. The pilot study was designed based on the principles of cementitious materials formation and secondary mineral formation by the reactions of coal fly ash and water/AMD. Calcium oxide, aluminum oxide, silicon oxide, and ferric oxide are major components of coal fly ash. The preliminary test results revealed that water did not accumulate and cracks did not form on top of 4 tanks. The settlements of the mixing approaches were lower than that of the stratified approach and the temperature distributions in the 4 tanks were comparable. 9 refs., 3 tabs., 11 figs.

  7. Negative Effect of Calcination to Catalytic Performance of Coal Char-loaded TiO2 Catalyst in Styrene Oxidation with Hydrogen Peroxide as Oxidant

    Directory of Open Access Journals (Sweden)

    Mukhamad Nurhadi

    2018-01-01

    How to Cite: Nurhadi, M., Kusumawardani, R., Nur, H. (2018. Negative Effect of Calcination to Catalytic Performance of Coal Char-loaded TiO2 Catalyst in Styrene Oxidation with Hydrogen Peroxide as Oxidant. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1: 113-118 (doi:10.9767/bcrec.13.1.1171.113-118

  8. Experimental and simulation analysis of hydrogen production by partial oxidation of methanol

    Energy Technology Data Exchange (ETDEWEB)

    Sikander, U. [National Univ. of Science and Technology, Islamabad (Pakistan)

    2014-10-15

    Partial oxidation of methanol is the only self-sustaining process for onboard production of hydrogen. For this a fixed bed catalytic reactor is designed, based on heterogeneous catalytic reaction. To develop an optimized process, simulation is carried out using ASPEN HYSYS v 7.1. Reaction kinetics is developed on the basis of Langmuir Hinshel wood model. 45:55:5 of CuO: ZnO: Al/sub 2/O/sub 3/ is used as a catalyst. Simulation results are studied in detail to understand the phenomenon of partial oxidation of methanol inside the reactor. An experimental rig is developed for hydrogen production through partial oxidation of methanol. Results obtained from process simulation and experimental work; are compared with each other. (author)

  9. Partial oxidation of methane in a temperature-controlled dielectric barrier discharge reactor

    KAUST Repository

    Zhang, Xuming

    2015-01-01

    We studied the relative importance of the reduced field intensity and the background reaction temperature in the partial oxidation of methane in a temperature-controlled dielectric barrier discharge reactor. We obtained important mechanistic insight from studying high-temperature and low-pressure conditions with similar reduced field intensities. In the tested range of background temperatures (297 < T < 773 K), we found that the conversion of methane and oxygen depended on both the electron-induced chemistry and the thermo-chemistry, whereas the chemical pathways to the products were overall controlled by the thermo-chemistry at a given temperature. We also found that the thermo-chemistry enhanced the plasma-assisted partial oxidation process. Our findings expand our understanding of the plasma-assisted partial oxidation process and may be helpful in the design of cost-effective plasma reformers. © 2014 The Combustion Institute.

  10. SUPERCRITICAL WATER PARTIAL OXIDATION PHASE I - PILOT-SCALE TESTING/FEASIBILTY SUDIES FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    SPRITZER.M; HONG,G

    2005-01-01

    General Atomics (GA) is developing Supercritical Water Partial Oxidation (SWPO) as a means of producing hydrogen from low-grade biomass and other waste feeds. The Phase I Pilot-scale Testing/Feasibility Studies have been successfully completed and the results of that effort are described in this report. The key potential advantage of the SWPO process is the use of partial oxidation in-situ to rapidly heat the gasification medium, resulting in less char formation and improved hydrogen yield. Another major advantage is that the high-pressure, high-density aqueous environment is ideal for reacting and gasifying organics of all types. The high water content of the medium encourages formation of hydrogen and hydrogen-rich products and is especially compatible with high water content feeds such as biomass materials. The high water content of the medium is also effective for gasification of hydrogen-poor materials such as coal. A versatile pilot plant for exploring gasification in supercritical water has been established at GA's facilities in San Diego. The Phase I testing of the SWPO process with wood and ethanol mixtures demonstrated gasification efficiencies of about 90%, comparable to those found in prior laboratory-scale SCW gasification work carried out at the University of Hawaii at Manoa (UHM), as well as other biomass gasification experience with conventional gasifiers. As in the prior work at UHM, a significant amount of the hydrogen found in the gas phase products is derived from the water/steam matrix. The studies at UHM utilized an indirectly heated gasifier with an activated carbon catalyst. In contrast, the GA studies utilized a directly heated gasifier without catalyst, plus a surrogate waste fuel. Attainment of comparable gasification efficiencies without catalysis is an important advancement for the GA process, and opens the way for efficient hydrogen production from low-value, dirty feed materials. The Phase I results indicate that a practical

  11. Reducing emission of nitrogen oxides during combustion of black coal from the Kuzbass

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Lobov, G.V.; Gedike, I.A.

    1983-02-01

    Black coal from the Kuzbass used as fuel by the ZapSibTEhTs fossil-fuel power plant is rich in nitrogen: nitrogen content ranges from 2.8% to 3.5%. Under these conditions conventional methods of combustion cause air pollution exceeding permissible levels. A method for combustion of coal dust in stages has been successfully tested at the plant: some of the burners located in the top zone of the furnace (the BKZ-210-140F boiler) are used for air supply. From 16% to 18% of air supplied to the furnace is directed to the upper burners. Use of this system (called tertiary air supply as opposed to the secondary air system) reduced nitrogen oxide emission by 1.5 times (from 0.87 to 0.57 g/m/sup 3/). Position of nozzles used for tertiary air supply in relation to the burners used for supply of coal dust in the tangential shaped furnace is shown in a scheme. The optimum position of tertiary air supply system in relation to burners taking into account corrosion hazards as well as the hazards of reducing combustion efficiency is discussed. Recommendation on furnace design and burner position which prevent efficiency decrease and corrosion hazards are made.

  12. Effect of oxygen partial pressure on oxidation of Mo-metal

    Science.gov (United States)

    Sharma, Rabindar Kumar; Kumar, Prabhat; Singh, Megha; Gopal, Pawar; Reddy, G. B.

    2018-05-01

    This report explains the effect of oxygen partial pressure (PO2 ) on oxidation of Mo-metal in oxygen plasma. XRD results indulge that oxide layers formed on Mo-surfaces at different oxygen partial pressures have two different oxide phases (i.e. orthorhombic MoO3 and monoclinic Mo8O23). Intense XRD peaks at high pressure (i.e. 2.0×10-1 Torr) points out the formation of thick oxide layer on Mo-surface due to presence of large oxygen species in chamber and less oxide volatilization. Whereas, at low PO2 (6.5×10-2 and 7.5×10-2 Torr.) the reduced peak strength is owing to high oxide volatilization rate. SEM micrographs and thickness measurements also support XRD results and confirm that the optimum -2value of PO2 to deposited thicker and uniform oxide film on glass substrate is 7.5×10-2 Torr through plasma assistedoxidation process. Further to study the compositional properties, EDX of the sample M2 (the best sample) is carried out, which confirms that the stoichiometric ratio is less than 3 (i.e. 2.88). Less stoichiometric ratio again confirms the presence of sub oxides in oxide layers on Mo metal as evidenced by XRD results. All the observed results are well in consonance with each other.

  13. Ce-Fe-O mixed oxide as oxygen carrier for the direct partial oxidation of methane to syngas

    Institute of Scientific and Technical Information of China (English)

    魏永刚; 王华; 李孔斋

    2010-01-01

    The Ce-Fe-O mixed oxide with a ratio of Ce/Fe=7:3, which was prepared by coprecipitation method and employed as oxygen carrier, for direct partial oxidation of methane to syngas in the absence of gaseous oxygen was explored. The mixed oxide was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), and the catalytic performances were studied in a fixed-bed quartz reactor and a thermogravimetric reactor, respectively. Approximately 99.4% H2 se...

  14. Direct Partial Oxidations Using Molecular Oxygen - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, Richard [Univ. of New Mexico, Albuquerque, NM (United States)

    2017-11-01

    In 2006, Richard A. Kemp (University of New Mexico) and Karen I. Goldberg (University of Washington) formed a team and began to investigate new strategies to accomplish direct selective aerobic oxidations, with a particular emphasis on the epoxidation of propylene and higher olefins. This DOE-BES funded project was renewed twice and concluded after a no-cost extension earlier this year. Multiple novel strategies involving homogeneous catalyst systems were initiated and investigated during the award. Important fundamental understanding and insight concerning requirements for promotion of aerobic olefin epoxidation was generated. During the tenure of this project, new knowledge was generated concerning the synthesis, characterization and aerobic reactivity of metal hydrides and hydroxides. Key results describing synthetic strategies and optimization of the preparation of mononuclear late metal hydrides were published. The team reported the first example of O2 insertion into a Pd-H bond, a reaction which had been proposed in the literature but never previously observed. Our experimental investigation of the mechanism was later followed by computational work, and a description of what is now referred to as the Hydrogen Atom Abstraction (HAA) pathway for this reaction has been widely accepted in the community. After investigation of many other late metal hydrides, both experimentally and computationally, the team put together a chapter that included a description of key contributing factors that allow reaction by the HAA mechanism. A brief sampling of other classic papers from our project include hydrogenolysis reactions of late metal hydroxide and alkoxide complexes, the synthesis of nickel-hydrides, and the involvement of hemilabile ligands in promoting new reaction pathways.

  15. Study on the Low-Temperature Oxidation Law in the Co-Mining Face of Coal and Oil Shale in a Goaf—A Case Study in the Liangjia Coal Mine, China

    Directory of Open Access Journals (Sweden)

    Gang Wang

    2018-01-01

    Full Text Available The low-temperature oxidation law of coal and rock mass is the basis to study spontaneous combustion in goafs. In this paper, the low-temperature oxidation laws of coal, oil shale, and mixtures of coal and oil shale were studied by using laboratory programmed heating experiments combined with a field beam tube monitoring system. The results from the programmed heating experiments showed that the heat released from oil shale was less than that from coal. Coal had a lower carbon monoxide (CO-producing temperature than oil shale, and the mixture showed obvious inhibiting effects on CO production with an average CO concentration of about 38% of that for coal. Index gases were selected in different stages to determine the critical turning point temperature for each stage. The field beam tube monitoring system showed that the temperature field of the 1105 co-mining face of coal and oil shale in the goaf of the Liangjia Coal Mine presented a ladder-like distribution, and CO concentration was the highest for coal and lower for the mixture of coal and oil shale, indicating that the mixture of coal with oil shale had an inhibiting effect on CO production, consistent with the results from the programmed heating experiments.

  16. Numerical simulations for the coal/oxidant distribution effects between two-stages for multi opposite burners (MOB) gasifier

    International Nuclear Information System (INIS)

    Unar, Imran Nazir; Wang, Lijun; Pathan, Abdul Ghani; Mahar, Rasool Bux; Li, Rundong; Uqaili, M. Aslam

    2014-01-01

    Highlights: • We simulated a double stage 3D entrained flow coal gasifier with multi-opposite burners. • The various reaction mechanisms have evaluated with experimental results. • The effects of coal and oxygen distribution between two stages on the performance of gasifier have investigated. • The local coal to oxygen ratio is affecting the overall efficiency of gasifier. - Abstract: A 3D CFD model for two-stage entrained flow dry feed coal gasifier with multi opposite burners (MOB) has been developed in this paper. At each stage two opposite nozzles are impinging whereas the two other opposite nozzles are slightly tangential. Various numerical simulations were carried out in standard CFD software to investigate the impacts of coal and oxidant distributions between the two stages of the gasifier. Chemical process was described by Finite Rate/Eddy Dissipation model. Heterogeneous and homogeneous reactions were defined using the published kinetic data and realizable k–ε turbulent model was used to solve the turbulence equations. Gas–solid interaction was defined by Euler–Lagrangian frame work. Different reaction mechanism were investigated first for the validation of the model from published experimental results. Then further investigations were made through the validated model for important parameters like species concentrations in syngas, char conversion, maximum inside temperature and syngas exit temperature. The analysis of the results from various simulated cases shows that coal/oxidant distribution between the stages has great influence on the overall performance of gasifier. The maximum char conversion was found 99.79% with coal 60% and oxygen 50% of upper level of injection. The minimum char conversion was observed 95.45% at 30% coal with 40% oxygen at same level. In general with oxygen and coal above or equal to 50% of total at upper injection level has shown an optimized performance

  17. Modelling of the partial oxidation of {alpha}, {beta}-unsaturated aldehydes on Mo-V-oxides based catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Boehnke, H.; Petzoldt, J.C.; Stein, B.; Weimer, C.; Gaube, J.W. [Technische Univ. Darmstadt (Germany). Inst. fuer Chemische Technologie

    1998-12-31

    A kinetic model based on the Mars-van Krevelen mechanism that allows to describe the microkinetics of the heterogeneously catalysed partial oxidation of {alpha}, {beta}-unsaturated aldehydes is presented. This conversion is represented by a network, composed of the oxidation of the {alpha}, {beta}-unsaturated aldehyde towards the {alpha}, {beta}-unsaturated carboxylic acid and the consecutive oxidation of the acid as well as the parallel reaction of the aldehyde to products of deeper oxidation. The reaction steps of aldehyde respectively acid oxidation and catalyst reoxidation have been investigated separately in transient experiments. The combination of steady state and transient experiments has led to an improved understanding of the interaction of the catalyst with the aldehyde and the carboxylic acids as well as to a support of the kinetic model assumptions. (orig.)

  18. Air oxidation of aqueous sodium sulfide solutions with coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Mallik, D; Chaudhuri, S K [Southern Illinois University, Carbondale, IL (United States). Dept. of Mining Engineering

    1999-02-01

    The paper investigated the potential of coal fly ash as a catalyst in the air oxidation of aqueous sodium sulfide (Na{sub 2}S) solutions in the temperature range of 303-333 K. The rate of oxidation was found to be independent of the initial concentration of Na{sub 2}S in the range of 5.80 x 10{sup -2} - 28.45 x 10{sup -2} kmol/m{sup 3}. The effects of fly ash loading, source of fly ash, speed of agitation, air flow rate, fly ash particle size were also studied. Experimental results suggested a film-diffusion controlled reaction mechanism. The deactivation of the catalytic effect of fly ash was found to be less than 31% even after five repeated uses.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. COAL CONVERSION WASTEWATER TREATMENT BY CATALYTIC OXIDATION IN SUPERCRITICAL WATER; FINAL

    International Nuclear Information System (INIS)

    Phillip E. Savage

    1999-01-01

    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

  1. Investigation of partial oxidation of hydrogen sulfide for dry desulfurisation of fuel gases; Untersuchung der Partialoxidation von Schwefelwasserstoff zur Trockenentschwefelung von Brenngasen

    Energy Technology Data Exchange (ETDEWEB)

    Kliemczak, U.

    2002-07-01

    Three process variants for direct desulfurisation in the dry state of coal gasification gases by partial oxidation of H{sub 2}S were investigated in Prenflo conditions: 1. Heterogeneously catalyzed partial oxidation of H{sub 2}S on fly dust followed by sulfur deposition on the dust; 2. Non-catalyzed partial oxidation of H{sub 2}S in a homogeneous gaseous phase followed by sulfur deposition in a spray separator; 3. Heterogeneously catalyzed partial oxidation of H{sub 2}S in a fixed bed. The experiments were carried out in conditions similar to the crude gas conditions of slag bath gasification at SVZ Schwarze Pumpe. The fixed bed materials investigated were hearth furnace coke, Berl saddles, and an activated carbon developed specially for the investigations, Oxorbon CJ. The focus of the investigations was on the envisaged continuous operation of the process. [German] Im Rahmen der vorliegenden Arbeit wurde an einer zu diesem Zweck modifizierten Technikumsanlage die trockene Direktentschwefelung von Brenngasen aus der Kohlevergasung durch partielle Oxidation von H{sub 2}S untersucht. Im Vordergrund standen zwei Verfahrensvarianten, deren Eignung fuer die Bedingungen der Prenflo-Vergasung ueberprueft werden sollte: Variante 1: die heterogen katalysierte Partialoxidation von H{sub 2}S an Flugstaub mit anschliessender Schwefelabscheidung auf dem Staub und, Variante 2: die nichtkatalysierte Partialoxidation von H{sub 2}S in homogener Gasphase mit anschliessender Schwefelabscheidung in einem Spruehabscheider. Ausgehend von den Versuchsergebnissen der Verfahrensvarianten 1 und 2 wurde zusaetzlich als Verfahrensvariante 3 die heterogen katalysierte Partialoxidation von H{sub 2}S am Festbett untersucht. Diese Versuche orientierten sich an den Rohgasbedingungen der Schlackebadvergasung des SVZ Schwarze Pumpe. Als Festbettmaterialien kamen Herdofenkoks, Berlsaettel und eine, speziell fuer diese Verfahrensvariante entwickelte Aktivkohle Oxorbon CJ, zum Einsatz. Die Eignung des

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

    Science.gov (United States)

    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.

  3. A polygeneration from a dual-gas partial catalytic oxidation coupling with an oxygen-permeable membrane reactor

    International Nuclear Information System (INIS)

    Hao, Yanhong; Huang, Yi; Gong, Minhui; Li, Wenying; Feng, Jie; Yi, Qun

    2015-01-01

    Highlights: • A new polygeneration system (PL-PCO-OPMR) to DME/methanol/power is proposed. • Exergeo-economic analysis is adopted to disclose the performance of systems. • Key technological conditions and parameters for PL-PCO-OPMR are optimized. • PL-PCO-OPMR shows high energy efficiency and low CO_2 emission. • PL-PCO-OPMR is an attractive way for high efficient and clean use of COG and CGG. - Abstract: Polygeneration system, typically involving chemicals/fuels and electricity co-production, is a promising technology for the sustainable development of energy and environment. In this study, a new polygeneration system based on coal and coke oven gas (COG) inputs for co-production of dimethyl ether (DME)/methanol and electricity is proposed. In the new system, an appropriate syngas for the synthesis of DME is from coal gasified gas (CGG) reforming of COG coupled with an oxygen-permeable membrane reactor, in which both COG and CGG reforming process and fuel combustion process are incorporated, which reduces exergy destruction in the whole reforming process. In order to obtain the best performance of CO_2 reduction, energy saving and economic benefit, the key operation parameters of the proposed process are analyzed and optimized. The new system is compared with the process based on CH_4/CO_2 dry reforming, in terms of exergy efficiency, exergy cost and CO_2 emissions. Through the new system, the exergy efficiency can be increased by 7.8%, the exergy cost can be reduced by 0.88 USD/GJ and the CO_2 emission can be reduced by 0.023 kg/MJ. These results suggest that the polygeneration system from CGG and COG partial catalytic oxidation coupling with an oxygen-permeable membrane reactor (PL-PCO-OPMR) would be a more attractive way for highly efficient and clean use of CGG and COG.

  4. Coal-fuelled systems for peaking power with 100% CO2 capture through integration of solid oxide fuel cells with compressed air energy storage

    Science.gov (United States)

    Nease, Jake; Adams, Thomas A.

    2014-04-01

    In this study, a coal-fuelled integrated solid oxide fuel cell (SOFC) and compressed air energy storage (CAES) system in a load-following power production scenario is discussed. Sixteen SOFC-based plants with optional carbon capture and sequestration (CCS) and syngas shifting steps are simulated and compared to a state-of-the-art supercritical pulverised coal (SCPC) plant. Simulations are performed using a combination of MATLAB and Aspen Plus v7.3. It was found that adding CAES to a SOFC-based plant can provide load-following capabilities with relatively small effects on efficiencies (1-2% HHV depending on the system configuration) and levelized costs of electricity (∼0.35 ¢ kW-1 h-1). The load-following capabilities, as measured by least-squares metrics, show that this system may utilize coal and achieve excellent load-tracking that is not adversely affected by the inclusion of CCS. Adding CCS to the SOFC/CAES system reduces measurable direct CO2 emission to zero. A seasonal partial plant shutdown schedule is found to reduce fuel consumption by 9.5% while allowing for cleaning and maintenance windows for the SOFC stacks without significantly affecting the performance of the system (∼1% HHV reduction in efficiency). The SOFC-based systems with CCS are found to become economically attractive relative to SCPC above carbon taxes of 22 ton-1.

  5. Reaction scheme of partial oxidation of methane to synthesis gas over yttrium-stabilized zirconia

    NARCIS (Netherlands)

    Zhu, J.J.; van Ommen, J.G.; Lefferts, Leonardus

    2004-01-01

    The partial oxidation of methane to synthesis gas over yttrium-stabilized zirconia (YSZ) was studied with in situ FTIR and both steady-state and transient experiments. The four major products, CO, H2, CO2, and H2O, are primary products of CPOM over YSZ. Besides these major products and traces of

  6. The influence of partial oxidation mechanisms on tar destruction in TwoStage biomass gasification

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Egsgaard, Helge; Stelte, Wolfgang

    2013-01-01

    adsorption and determined by stable isotope dilution analysis. The results have shown that partial oxidation reduces and converts primary tars into low molecular weight, polycyclic aromatic hydrocarbons (PAHs), primarily naphthalene. At temperatures above 950°C practically all phenol is converted...

  7. Development of a novel reactor concept for the partial oxidation of methane to syngas

    NARCIS (Netherlands)

    Smit, J.; van Sint Annaland, M.; Kuipers, J.A.M.

    2004-01-01

    The gas-to-liquid process, consisting of the partial oxidation of methane (POM) followed by the Fischer-Tropsch reaction, is a promising alternative to conventional oil processing for the production of liquid fuels. The cost of a conventional POM process is mainly determined by cryogenic air

  8. Partial Oxidation of High-Boiling Hydrocarbon Mixtures in the Pilot Unit

    Czech Academy of Sciences Publication Activity Database

    Hanika, Jiří; Lederer, J.; Nečesaný, F.; Poslední, W.; Tukač, V.; Veselý, Václav

    2014-01-01

    Roč. 68, č. 12 (2014), s. 1701-1706 ISSN 0366-6352 Institutional support: RVO:67985858 Keywords : partial oxidation * high-boiling hydrocarbons * pilot plant Subject RIV: CI - Industrial Chemistry , Chemical Engineering Impact factor: 1.468, year: 2014

  9. Hydrogen generator, via catalytic partial oxidation of methane for fuel cells

    Science.gov (United States)

    Recupero, Vincenzo; Pino, Lidia; Di Leonardo, Raffaele; Lagana', Massimo; Maggio, Gaetano

    It is well known that the most acknowledged process for generation of hydrogen for fuel cells is based upon the steam reforming of methane or natural gas. A valid alternative could be a process based on partial oxidation of methane, since the process is mildly exothermic and therefore not energy intensive. Consequently, great interest is expected from conversion of methane into syngas, if an autothermal, low energy intensive, compact and reliable process could be developed. This paper covers the activities, performed by the CNR Institute of Transformation and Storage of Energy (CNR-TAE), on theoretical and experimental studies for a compact hydrogen generator, via catalytic selective partial oxidation of methane, integrated with second generation fuel cells (EC-JOU2 contract). In particular, the project focuses the attention on methane partial oxidation via heterogeneous selective catalysts, in order to: demonstrate the basic catalytic selective partial oxidation of methane (CSPOM) technology in a subscale prototype, equivalent to a nominal output of 5 kWe; develop the CSPOM technology for its application in electric energy production by means of fuel cells; assess, by a balance of plant analysis, and a techno-economic evaluation, the potential benefits of the CSPOM for different categories of fuel cells.

  10. Kinetics of the partial oxidation of methanol over a Fe-Mo catalyst

    NARCIS (Netherlands)

    Deshmukh, S.A.R.K.; Sint Annaland, van M.; Kuipers, J.A.M.

    2005-01-01

    The intrinsic steady-state kinetics of the partial oxidation of methanol to formaldehyde over a commercial Fe-Mo catalyst has been studied experimentally in a differentially operated reactor at temperatures of 230–260 °C, over a wide range of methanol and oxygen concentrations. The principal

  11. Kinetics of the partial oxidation of methanol over a Fe-Mo catalyst

    NARCIS (Netherlands)

    Deshmukh, S.A.R.K.; van Sint Annaland, M.; Kuipers, J.A.M.

    2005-01-01

    The intrinsic steady-state kinetics of the partial oxidation of methanol to formaldehyde over a commercial Fe-Mo catalyst has been studied experimentally in a differentially operated reactor at temperatures of 230¿260 °C, over a wide range of methanol and oxygen concentrations. The principal

  12. Oxygen partial pressure: a key to alloying and discovery in metal oxide--metal eutectic systems

    International Nuclear Information System (INIS)

    Holder, J.D.; Clark, G.W.; Oliver, B.F.

    1978-01-01

    Control of oxygen partial pressure is essential in the directional solidification of oxide--metal eutectic composites by techniques involving gas-solid and gas-liquid interactions. The existence of end components in the eutectic composite is Po 2 sensitive as are melt stoichiometry, solid phase compositions, and vapor losses due to oxidation-volatilization. Simple criteria are postulated which can aid the experimentalist in selecting the proper gas mixture for oxide--metal eutectic composite growth. The Cr 2 O 3 --Mo--Cr systems was used to verify certain aspects of the proposed criteria

  13. Development of a simultaneous partial nitrification and anaerobic ammonia oxidation process in a single reactor.

    Science.gov (United States)

    Cho, Sunja; Fujii, Naoki; Lee, Taeho; Okabe, Satoshi

    2011-01-01

    Up-flow oxygen-controlled biofilm reactors equipped with a non-woven fabric support were used as a single reactor system for autotrophic nitrogen removal based on a combined partial nitrification and anaerobic ammonium oxidation (anammox) reaction. The up-flow biofilm reactors were initiated as either a partial nitrifying reactor or an anammox reactor, respectively, and simultaneous partial nitrification and anammox was established by careful control of the aeration rate. The combined partial nitrification and anammox reaction was successfully developed in both biofilm reactors without additional biomass inoculation. The reactor initiated as the anammox reactor gave a slightly higher and more stable mean nitrogen removal rate of 0.35 (±0.19) kg-N m(-3) d(-1) than the reactor initiated as the partial nitrifying reactor (0.23 (±0.16) kg-N m(-3) d(-1)). FISH analysis revealed that the biofilm in the reactor started as the anammox reactor were composed of anammox bacteria located in inner anoxic layers that were surrounded by surface aerobic AOB layers, whereas AOB and anammox bacteria were mixed without a distinguishable niche in the biofilm in the reactor started as the partial nitrifying reactor. However, it was difficult to efficiently maintain the stable partial nitrification owing to inefficient aeration in the reactor, which is a key to development of the combined partial nitrification and anammox reaction in a single biofilm reactor. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Report on the achievements in the Sunshine Project in fiscal 1993 on development of a jet flow bed gasification electric power plant. Investigative research on a technology to treat coals used for coal gasification (investigation for coal type selection); 1993 nendo funryusho gas ka hatsuden plant kaihatsu seika hokokusho. Sekitan gas kayotan no shori gijutsu ni kansuru chosa kenkyu (tanshu sentei chosa)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1984-03-01

    This paper describes the achievements in the Sunshine Project in fiscal 1993 in the investigation for coal type selection. The investigation is purposed to elucidate the status of existence and resources of coals as the raw material for coal gasification and liquefaction, the coal quality features, and the gasification and liquefaction characteristics. The results will be used as the fundamental materials for technological development. Discussions will also be given on the coal applicability to the composite gasification power generation system in which liquefied residue generated in the process are mixed with the supplied coal. Coal quality analysis and a liquefaction test under the standard condition were completed on 389 test samples composed of 136 kinds of coals produced in Canada, Australia, the U.S.A., China and Indonesia. Coal types were enumerated according to the oil yield. A gasification test was performed on the specific gravity separated coals of Chinese coals to discuss the effect of change in the ash amount on the gasification characteristics. A partial coal combustion test revealed that fuel ratio, oxygen partial pressure, and oxygen molar fraction parameters affect the combustion characteristics. The micro-gravity field is effective in discussing the combustion characteristics of particulate groups of dust coal. A coal oxidizing test was performed, wherein oxidizing characteristics and spontaneous ignition performance were estimated successfully from temperature rise of heat stored in coal. The coal type matrix data were prepared. (NEDO)

  15. Biological degradation of partially oxidated constituents of stabilized sapropel; Biologischer Abbau teiloxidierter Inhaltsstoffe stabilisierter Faulschlaemme

    Energy Technology Data Exchange (ETDEWEB)

    Scheminski, A.; Krull, R.; Hempel, D.C. [Technische Univ. Braunschweig (Germany). Inst. fuer Bioverfahrenstechnik

    1999-07-01

    Partial oxidation of sapropel with ozone destroys the cell walls of microorganisms in sludge and releases the cell constituents. Substances that are not biologically degraded because of the size or structure of their molecules are transformed into smaller, water-soluble and biologically degradable fractions by the reaction with ozone. The experiments aim to render the partially oxidated sewage sludge constituents highly biologically degradable using a minimum of oxidation agents. For the experiments described, stabilized sapropels with low biological activity are used. Hence the ozone is mainly used for the partial oxidation of recalcitrant constituents. (orig.) [German] Durch partielle Oxidation von Faulschlaemmen mit Ozon werden die Zellwaende der Mikroorganismen im Schlamm zerstoert und die Zellinhaltsstoffe freigesetzt. Dabei werden Substanzen, die aufgrund ihrer Molekuelgroesse oder -struktur biologisch nicht abgebaut werden, durch die Reaktion mit Ozon in kleinere, wasserloesliche und biologisch abbaubare Bruchstuecke ueberfuehrt. Ziel der Versuche ist es, durch den Einsatz moeglichst geringer Mengen an Oxidationsmitteln eine hohe biologische Abbaubarkeit der teiloxidierten Klaerschlamminhaltsstoffe zu erreichen. Fuer die hier vorgestellten Experimente wurden stabilisierte Faulschlaemme mit geringer biologischer Aktivitaet eingesetzt. Dadurch wird das Ozon vorwiegend zur Teiloxidation recalcitranter Inhaltsstoffe genutzt. (orig.)

  16. One-Pot Synthesis of Cu(II Complex with Partially Oxidized TTF Moieties

    Directory of Open Access Journals (Sweden)

    Hiroki Oshio

    2012-07-01

    Full Text Available The one-pot synthesis of a Cu(II complex with partially oxidized tetrathiafulvalene (TTF moieties in its capping MT-Hsae-TTF ligands, [CuII(MT-sae-TTF2] [CuICl2] was realized by the simultaneous occurrence of Cu(II complexation and CuIICl2 mediated oxidation of TTF moieties. The crystal structure was composed of one-dimensional columns formed by partially oxidized TTF moieties and thus the cation radical salt showed relatively high electrical conductivity. Tight binding band structure calculations indicated the existence of a Peierls gap due to the tetramerization of the TTF moieties in the one-dimensional stacking column at room temperature, which is consistent with the semiconducting behavior of this salt.

  17. Preparation of fulvic acid and low-molecular organic acids by oxidation of weathered coal humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shinozuka, T.; Ito, A.; Sasaki, O.; Yazawa, Y.; Yamaguchi, T. [Chiba Institute of Technolgy, Chiba (Japan). Dept. of Industrial Chemistry

    2002-07-01

    Weathered coal contains much humic acid and a little fulvic acid. Therefore, the production of fulvic acid, the most valuable humic substance because of its water-solubility, was examined by ozone and hydrogen peroxide oxidation of humic acid extracted form Xinjiang (China) weathered coal. The resulting products of the oxidation were water soluble fulvic acid and organic acids, mainly formic acid and oxalic acid. The product yield of fulvic acid was 20 (C%) and that of organic acids were 39 (C%) for formic and acid 13 (C%) for oxalic acid. The formed fulvic acid showed a higher content of oxygen and carboxyl groups, than those of the extracted one from the original weathered coal.

  18. Characterization of manganese oxide precipitates from Appalachian coal mine drainage treatment systems

    International Nuclear Information System (INIS)

    Tan Hui; Zhang Gengxin; Heaney, Peter J.; Webb, Samuel M.; Burgos, William D.

    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 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 deg. 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 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 MnO x precipitates from all sites was coarse and 'sponge-like' composed of nm-sized lathes and thin sheets. Based on scanning electron microscopy (SEM), MnO 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 MnO x mineral assemblages in CMD treatment systems.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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...

  1. Oxidation of SiC/BN/SiC Composites in Reduced Oxygen Partial Pressures

    Science.gov (United States)

    Opila, Elizabeth J.; Boyd, Meredith

    2010-01-01

    SiC fiber-reinforced SiC composites with a BN interphase are proposed for use as leading edge structures of hypersonic vehicles. The durability of these materials under hypersonic flight conditions is therefore of interest. Thermogravimetric analysis was used to characterize the oxidation kinetics of both the constituent fibers and composite coupons at four temperatures: 816, 1149, 1343, and 1538 C (1500, 2100, 2450, and 2800 F) and in oxygen partial pressures between 5% and 0.1% (balance argon) at 1 atm total pressure. One edge of the coupons was ground off so the effects of oxygen ingress into the composite could be monitored by post-test SEM and EDS. Additional characterization of the oxidation products was conducted by XPS and TOF-SIMS. Under most conditions, the BN oxidized rapidly, leading to the formation of borosilicate glass. Rapid initial oxidation followed by volatilization of boria lead to protective oxide formation and further oxidation was slow. At 1538C in 5% oxygen, both the fibers and coupons exhibited borosilicate glass formation and bubbling. At 1538C in 0.1% oxygen, active oxidation of both the fibers and the composites was observed leading to rapid SiC degradation. BN oxidation at 1538C in 0.1% oxygen was not significant.

  2. Partial oxidation of n- and i-pentane over promoted vanadium-phosphorus oxide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Zazhigalov, V.A.; Mikhajluk, B.D.; Komashko, G.A. [AN Ukrainskoj SSR, Kiev (Ukraine). Inst. Fizicheskoj Khimii

    1998-12-31

    It is known, that the cost of raw materials for catalytic oxidation processes is about 60% of the product price. Cheap initial compounds to produce variety of products and to replace olefins and aromatic hydrocarbons are paraffins. That is why catalytic systems which could be possibly rather efficient in selective oxidation of paraffin hydrocarbons are under very close investigation now. One of such processes in n-pentane oxidation. The obtained results on n-pentane oxidation over VPO catalysts were quite encouraging in respect of possible reach high selectivity and yield of phthalic anhydride. However, in our work it was shown that the main product of n-pentane oxidation in the presence of VPO catalytic system as well as VPMeO was maleic anhydride. Some later our results were confirmed in, where to grow the selectivity towards phthalic anhydride the Co-additive was introduced. On the basis of the proposal made before on the mechanism of paraffins conversion over the vanadyl pyrophosphate surface with their activation at the first and fourth carbon atoms, we assumed possible methylmaleic (citraconic) anhydride forming at n- and i-pentane oxidation. This assumption has been recently supported by both our and other researchers` experimental results. In it was also hypothized possible mechanistic features for phthalic anhydride forming from n-pentane. The present work deals with the results of n- and i-pentane oxidation over VPO catalysts promoted with Bi, Cs, Te, Zr. (orig.)

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Zhuikov Andrey V.

    2016-01-01

    Full Text Available 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.

  5. Extractive de-sulfurization and de-ashing of high sulfur coals by oxidation with ionic liquids

    International Nuclear Information System (INIS)

    Saikia, Binoy K.; Khound, Kakoli; Baruah, Bimala P.

    2014-01-01

    Highlights: • Extractive de-sulfurization and de-ashing process for cleaning high sulfur coals. • The process removes inorganic as well as organic sulfur components from high sulfur coals. • The process has less risk to chemists and other surroundings. - Abstract: The environmental consequences of energy production from coals are well known, and are driving the development of desulfurization technologies. In this investigation, ionic liquids were examined for extractive desulfurization and de-ashing in industrially important high sulfur sub-bituminous Indian coals. The ionic liquids, namely, 1-n-butyl-3-methylimidazolium tetrafluoroborate (IL1) and 1-n-butyl 3-methylimidazolium chloride (IL2) were employed for desulfurization of a few Indian coal samples in presence of HCOOH/H 2 O 2 and V 2 O 5 . Results show the maximum removal of 50.20% of the total sulfur, 48.00% of the organic sulfur, and 70.37 wt% of the ash in this process. The ionic liquids were recovered and subsequently used for further desulfurization. FT-IR spectra reveal the transformation of organic sulfur functionalities into the sulfoxides (S=O) and sulfones (-SO 2 ) due to the oxidative reactions. The sulfate, pyrite and sulfides (aryls) signals in the near edge X-ray absorption fine structure (NEXAFS) of the oxidized coal samples showed sulfur transformation during the desulfurization process. The study demonstrates the removal of significant amount of inorganic as well as organic sulfur (aryls) components from the original high sulfur coal samples to make them cleaner

  6. Models for the Configuration and Integrity of Partially Oxidized Fuel Rod Cladding at High Temperatures

    International Nuclear Information System (INIS)

    Siefken, L.J.

    1999-01-01

    Models were designed to resolve deficiencies in the SCDAP/RELAP5/MOD3.2 calculations of the configuration and integrity of hot, partially oxidized cladding. These models are expected to improve the calculations of several important aspects of fuel rod behavior. First, an improved mapping was established from a compilation of PIE results from severe fuel damage tests of the configuration of melted metallic cladding that is retained by an oxide layer. The improved mapping accounts for the relocation of melted cladding in the circumferential direction. Then, rules based on PIE results were established for calculating the effect of cladding that has relocated from above on the oxidation and integrity of the lower intact cladding upon which it solidifies. Next, three different methods were identified for calculating the extent of dissolution of the oxidic part of the cladding due to its contact with the metallic part. The extent of dissolution effects the stress and thus the integrity of the oxidic part of the cladding. Then, an empirical equation was presented for calculating the stress in the oxidic part of the cladding and evaluating its integrity based on this calculated stress. This empirical equation replaces the current criterion for loss of integrity which is based on temperature and extent of oxidation. Finally, a new rule based on theoretical and experimental results was established for identifying the regions of a fuel rod with oxidation of both the inside and outside surfaces of the cladding. The implementation of these models is expected to eliminate the tendency of the SCDAP/RELAP5 code to overpredict the extent of oxidation of the upper part of fuel rods and to underpredict the extent of oxidation of the lower part of fuel rods and the part with a high concentration of relocated material. This report is a revision and reissue of the report entitled, Improvements in Modeling of Cladding Oxidation and Meltdown

  7. Partial oxidation of methane over Ni/Mg/Al/La mixed oxides prepared from layered double hydrotalcites

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jun [Low Carbon Energy Conversion Center, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201203 (China); State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Zhao, Ning; Wei, Wei [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi (China); Sun, Yuhan [Low Carbon Energy Conversion Center, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201203 (China); State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi (China)

    2010-11-15

    A series of Ni/Mg/Al/La mixed oxides prepared by thermal decomposition of layered double hydrotalcites (HT) were characterized by XRD, ICP, EXAFS, TGA, TPR-H{sub 2}, SEM, and N{sub 2} adsorption/desorption technique. The results revealed the formation of periclase-type catalysts with mesoporous structure, and the addition of La{sup 3+} lowered the phase crystallization with the formation of small oxide particles. Such catalysts had both high activities and stabilities toward partial oxidation of methane (POM). The catalyst containing 6.5 mol.% La{sup 3+} showed the highest performance at 1053 K with CH{sub 4} conversion of 99%, CO selectivity of 93% and H{sub 2} selectivity of 96%, which could be attributed to the presence of highly dispersed nickel and then the resistance to coke formation due to the promotion effect of lanthanum. (author)

  8. Hydrogen Production via Synthetic Gas by Biomass/Oil Partial Oxidation

    Czech Academy of Sciences Publication Activity Database

    Hanika, Jiří; Lederer, J.; Tukač, V.; Veselý, Václav; Kováč, D.

    176-177, - (2011), s. 286-290 ISSN 1385-8947. [International Conference on Chemical Reactors CHEMREACTOR-19 /19./. Vienna, 05.09.2010-09.09.2010] R&D Projects: GA MPO 2A-2TP1/024 Institutional research plan: CEZ:AV0Z40720504 Keywords : hydrogen * biomass * partial oxidation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.461, year: 2011

  9. Thermodynamic Study on the Catalytic Partial Oxidation of Methane to Syngas

    Institute of Scientific and Technical Information of China (English)

    XUJian; WEIWeisheng; 等

    2002-01-01

    The catalytic partial oxidation of methane to syngas (CO+H2) has been simulated thermodynamically with the advanced process simulator PRO/Ⅱ. The influences of temperature,pressure,CH4/O2 ratio and steam addition in feed gas on the conversion of CH4 selectively to syngas and heat duty required were investigated, and their effects on carbon formation were also discussed. The simulation results were in good agreement with the literature data taken from a spouted bed reactor.

  10. Visualizing a Catalyst at Work during the Ignition of the Catalytic Partial Oxidation of Methane

    DEFF Research Database (Denmark)

    Kimmerle, Bertram; Grunwaldt, Jan-Dierk; Baiker, Alfons

    2009-01-01

    We present a spatiotemporal operando X-ray absorption study of a highly dynamic process, the ignition of the noble metal catalyzed partial oxidation of methane. Evolvement and propagation of the platinum component's structural changes are investigated with a high-speed X-ray camera, which...... in combination with temperature profiling by IR-thermography and catalytic activity measurements by online mass spectrometry gives insight into the first stages of the ignition of the reaction toward hydrogen and carbon monoxide....

  11. Kinetic studies of isooctane partial oxidation over a nickel-based catalyst

    International Nuclear Information System (INIS)

    Ibrahim, Hussameldin; Idem, Raphael; Aboudheir, Ahmed

    2006-01-01

    The production of hydrogen (H 2 ) for fuel cell applications in mobile vehicles by reforming technologies such as partial oxidation of various fossil fuels has gained much attention recently. In this study, the production of H 2 by the catalytic partial oxidation of isooctane ((C 8 H 18 ) used here as a surrogate for gasoline) was investigated over alumina (AI 2 O 3 )supported nickel (Ni) catalyst. The work investigated the kinetics of the partial oxidation of isooctane over a stable Ni/□-AI 2 O 3 catalyst in the range of 863 to 913 K, at atmospheric pressure, W/F i c8 in the range of 1.97 to 8.58 g h mol - 1, and molar feed ratio in the range of 2.0 to 8.0 experiments to obtain kinetic data were performed in a 12.7 mm diameter Inconel micro-reactor housed in an electrically controlled furnace. The chemical reaction was then modeled using rate models developed from the Langmuir-Hinshelwood-hougen-Watson (LHHW) and Eley-Rideal (ER) formulations. The model parameters were estimated using an adaptive Gauss-Newton and Marquardi-Levenberg minimization algorithm. Rival models were screened for their thermodynamic consistency and physicochemical significance of estimated parameters. Langmuir-Hinshelwood-hougen-Watson mechanism requiring the dissociative adsorption of isooctane and oxygen on two different sites appeared to be the most likely pathway for the partial oxidation reaction of isooctane. Reaction order with respect to isooctane indicates the strong coverage of nickel by isooctane. The activation energy of 73±3.1 kJ mol - 1 estimated from the LHHW model is consistent with the trend observed with lower hydrocarbons.(Author)

  12. Adiabatic Gasification and Pyrolysis of Coffee Husk Using Air-Steam for Partial Oxidation

    OpenAIRE

    Catalina Rodriguez; Gerardo Gordillo

    2011-01-01

    Colombian coffee industry produces about 0.6 million tons of husk (CH) per year which could serve as feedstock for thermal gasification to produce gaseous and liquid fuels. The current paper deals with: (i) CH adiabatic gasification modeling using air-steam blends for partial oxidation and (ii) experimental thermogravimetric analysis to determine the CH activation energy (E). The Chemical Equilibrium with Applications Program (CEA), developed by NASA, was used to estimate the effect of equiva...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  14. Study for drifts of the oxidation in nitrous oxide of an activated coal

    International Nuclear Information System (INIS)

    Diaz Velasquez; Jose de Jesus; Carballo Suarez, Luis M; Freitas, Madalena; Farias, Joaquim Luis Faria; Figueiredo, Jose Luis

    2001-01-01

    In order to obtain materials with different surface properties, an activated carbon was modified by thermal treatment with 20% of nitrous oxide in nitrogen at 500 centigrade degrees, for different periods of time, and also with 5 % of oxygen in nitrogen at 425 centigrade degrees for 600 minutes and 100% of hydrogen at 950 centigrade degrees for 360 minutes. Drifts were used to characterize the surface chemistry of the material treated. The qualitative result s show that the treatments with N2O have larger effects on the intensity of the surface groups. These changes could be associated to the incorporation of nitrogen into the carbon matrix. In agreement with literature reports, it could be said that the gas phase oxidation of the activated carbon shows mainly superficial groups such as carboxylic anhydrides, phenols and carboxylates, lactones and quinones

  15. Complete and Partial Photo-oxidation of Dissolved Organic Matter Draining Permafrost Soils.

    Science.gov (United States)

    Ward, Collin P; Cory, Rose M

    2016-04-05

    Photochemical degradation of dissolved organic matter (DOM) to carbon dioxide (CO2) and partially oxidized compounds is an important component of the carbon cycle in the Arctic. Thawing permafrost soils will change the chemical composition of DOM exported to arctic surface waters, but the molecular controls on DOM photodegradation remain poorly understood, making it difficult to predict how inputs of thawing permafrost DOM may alter its photodegradation. To address this knowledge gap, we quantified the susceptibility of DOM draining the shallow organic mat and the deeper permafrost layer of arctic soils to complete and partial photo-oxidation and investigated changes in the chemical composition of each DOM source following sunlight exposure. Permafrost and organic mat DOM had similar lability to photomineralization despite substantial differences in initial chemical composition. Concurrent losses of carboxyl moieties and shifts in chemical composition during photodegradation indicated that photodecarboxylation could account for 40-90% of DOM photomineralized to CO2. Permafrost DOM had a higher susceptibility to partial photo-oxidation compared to organic mat DOM, potentially due to a lower abundance of phenolic moieties with antioxidant properties. These results suggest that photodegradation will likely continue to be an important control on DOM fate in arctic freshwaters as the climate warms and permafrost soils thaw.

  16. Partial oxidation of n-hexadecane through decomposition of hydrogen peroxide in supercritical water

    KAUST Repository

    Alshammari, Y.M.

    2015-01-01

    © 2014 The Institution of Chemical Engineers. This work reports the experimental analysis of partial oxidation of n-hexadecane under supercritical water conditions. A novel reactor flow system was developed which allows for total decomposition of hydrogen peroxide in a separate reactor followed partial oxidation of n-hexadecane in a gasification reactor instead of having both reactions in one reactor. The kinetics of hydrothermal decomposition of hydrogen peroxide was studied in order to confirm its full conversion into water and oxygen under the desired partial oxidation conditions, and the kinetic data were found in a good agreement with previously reported literature. The gas yield and gasification efficiency were investigated under different operating parameters. Furthermore, the profile of C-C/C=C ratio was studied which showed the favourable conditions for maximising yields of n-alkanes via hydrogenation of their corresponding 1-alkenes. Enhanced hydrogenation of 1-alkenes was observed at higher O/C ratios and higher residence times, shown by the increase in the C-C/C=C ratio to more than unity, while increasing the temperature has shown much less effect on the C-C/C=C ratio at the current experimental conditions. In addition, GC-MS analysis of liquid samples revealed the formation of heavy oxygenated compounds which may suggest a new addition reaction to account for their formation under the current experimental conditions. Results show new promising routes for hydrogen production with in situ hydrogenation of heavy hydrocarbons in a supercritical water reactor.

  17. major oxides and trace element distributions in coal and coaly shale ...

    African Journals Online (AJOL)

    Admin

    Coal is a complex organic rock comprised mainly of decayed plants conditioned by syngenetic, diagenetic, epigenetic and detrital inorganic elements. (Orem and Finkelman, 2003). Coal has been globally recognised as an important source of energy. Geological epoch favouring the formation of coal include.

  18. Partial oxidation of landfill leachate in supercritical water: Optimization by response surface methodology

    International Nuclear Information System (INIS)

    Gong, Yanmeng; Wang, Shuzhong; Xu, Haidong; Guo, Yang; Tang, Xingying

    2015-01-01

    Highlights: • Partial oxidation of landfill leachate in supercritical water was investigated. • The process was optimized by Box–Behnken design and response surface methodology. • GY H2 , TRE and CR could exhibit up to 14.32 mmol·gTOC −1 , 82.54% and 94.56%. • Small amounts of oxidant can decrease the generation of tar and char. - Abstract: To achieve the maximum H 2 yield (GY H2 ), TOC removal rate (TRE) and carbon recovery rate (CR), response surface methodology was applied to optimize the process parameters for supercritical water partial oxidation (SWPO) of landfill leachate in a batch reactor. Quadratic polynomial models for GY H2 , CR and TRE were established with Box–Behnken design. GY H2 , CR and TRE reached up to 14.32 mmol·gTOC −1 , 82.54% and 94.56% under optimum conditions, respectively. TRE was invariably above 91.87%. In contrast, TC removal rate (TR) only changed from 8.76% to 32.98%. Furthermore, carbonate and bicarbonate were the most abundant carbonaceous substances in product, whereas CO 2 and H 2 were the most abundant gaseous products. As a product of nitrogen-containing organics, NH 3 has an important effect on gas composition. The carbon balance cannot be reached duo to the formation of tar and char. CR increased with the increase of temperature and oxidation coefficient

  19. Oxidation of trichloroethylene, toluene, and ethanol vapors by a partially saturated permeable reactive barrier

    Science.gov (United States)

    Mahmoodlu, Mojtaba G.; Hassanizadeh, S. Majid; Hartog, Niels; Raoof, Amir

    2014-08-01

    The mitigation of volatile organic compound (VOC) vapors in the unsaturated zone largely relies on the active removal of vapor by ventilation. In this study we considered an alternative method involving the use of solid potassium permanganate to create a horizontal permeable reactive barrier for oxidizing VOC vapors. Column experiments were carried out to investigate the oxidation of trichloroethylene (TCE), toluene, and ethanol vapors using a partially saturated mixture of potassium permanganate and sand grains. Results showed a significant removal of VOC vapors due to the oxidation. We found that water saturation has a major effect on the removal capacity of the permeable reactive layer. We observed a high removal efficiency and reactivity of potassium permanganate for all target compounds at the highest water saturation (Sw = 0.6). A change in pH within the reactive layer reduced oxidation rate of VOCs. The use of carbonate minerals increased the reactivity of potassium permanganate during the oxidation of TCE vapor by buffering the pH. Reactive transport of VOC vapors diffusing through the permeable reactive layer was modeled, including the pH effect on the oxidation rates. The model accurately described the observed breakthrough curve of TCE and toluene vapors in the headspace of the column. However, miscibility of ethanol in water in combination with produced water during oxidation made the modeling results less accurate for ethanol. A linear relationship was found between total oxidized mass of VOC vapors per unit volume of permeable reactive layer and initial water saturation. This behavior indicates that pH changes control the overall reactivity and longevity of the permeable reactive layer during oxidation of VOCs. The results suggest that field application of a horizontal permeable reactive barrier can be a viable technology against upward migration of VOC vapors through the unsaturated zone.

  20. Staged combustion - main method for suppressing nitrogen oxides in pulverized-coal fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R. (Vsesoyuznyi Teplotekhnicheskii Institut (USSR))

    1989-08-01

    Describes principles behind staged combustion, which is based on organizing furnace operations so that only part of the air from the fuel is taken into the furnace. The remaining air, which is needed for combustion, is fed as a tertiary blast jet into the intermediate flame zone. Following inflammation and combustion of the volatile matter, the oxygen concentration in the flame drops sharply causing a retardation of the oxidation reactions forming NO and an intensification of the reactions causing the nitrogen-containing radicals NH{sub i} and CN to be converted into N{sub 2}. When the reducing agents CO, H{sub 2} and CH{sub 4} are present in certain flame zones, even the nitrogen oxide is reduced to N{sub 2}. The NO concentrations in the flame are reduced until the jet of tertiary air is introduced. Discusses with reference to practice in the USA and Western Europe how to achieve maximum effect of this method for different types of boiler and presents the results of observations of the introduction of staged combustion to the BKZ-210-140 boiler burning Kuznetsk gassy coal. 5 refs.

  1. Method for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

    Science.gov (United States)

    Grindley, Thomas

    1989-01-01

    A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600.degree. to 1800.degree. F. and are partially quenched with water to 1000.degree. to 1200.degree. F. before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime/limestone.

  2. Chemical structure changes in coals after low-temperature oxidation and demineralization by acid treatment as revealed by high resolution solid state 13C NMR

    International Nuclear Information System (INIS)

    Tekely, P.; Nicole, D.; Delpuech, J.-J.; Totino, E.; Muller, J.F.

    1987-01-01

    13 C CP/MAS NMR has been used for characterization of chemical structure changes in coals after low-temperature oxidation and prolonged demineralization by acid treatment. In both cases the changes take place mainly in the aliphatic part of coal molecules. 21 refs.; 3 figs.; 2 tabs

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  4. Technical surveys on MHD combustors. Surveys on incorporation of pressurized coal partial combustion furnaces; MHD combustor gijutsu chosa. Kaatsugata sekitan bubun nenshoro no donyu chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-03-01

    The pressurized coal partial combustion (PCPC) furnace is surveyed/studied for its incorporation in MHD generation. The technical development of the atmospheric CPC has been basically completed, and the concept is demonstrated using a test system of commercial size. Many techniques developed for the atmospheric CPC are applicable to the PCPC system. These include structures of the CPC furnace walls, and slag handling and simulation techniques. Combination of PFBC with PCPC or IGCC can bring about many merits, e.g., enhanced efficiency and abated NOx emissions for the combined cycle power generation. These topping cycles, therefore, should be developed in the early stage. MHD power generation is one of the concepts that can enhance efficiency. In particular, the techniques for closed cycle MHD generation have notably advanced recently. The PCPC techniques are useful for coal combustors for MHD generation. Full-scale development works for the direct coal combustion gas turbine systems have been just started for the IGCC systems of the next generation, and the PCPC-related techniques are expected to serve as the central techniques for these turbine systems. (NEDO)

  5. Partial Oxidation of n-Butane over a Sol-Gel Prepared Vanadium Phosphorous Oxide

    Directory of Open Access Journals (Sweden)

    Juan M. Salazar

    2013-01-01

    Full Text Available Vanadium phosphorous oxide (VPO is traditionally manufactured from solid vanadium oxides by synthesizing VOHPO4∙0.5H2O (the precursor followed by in situ activation to produce (VO2P2O7 (the active phase. This paper discusses an alternative synthesis method based on sol-gel techniques. Vanadium (V triisopropoxide oxide was reacted with ortho-phosphoric acid in an aprotic solvent. The products were dried at high pressure in an autoclave with a controlled excess of solvent. This procedure produced a gel of VOPO4 with interlayer entrapped molecules. The surface area of the obtained materials was between 50 and 120 m2/g. Alcohol produced by the alkoxide hydrolysis reduced the vanadium during the drying step, thus VOPO4 was converted to the precursor. This procedure yielded non-agglomerated platelets, which were dehydrated and evaluated in a butane-air mixture. Catalysts were significantly more selective than the traditionally prepared materials with similar intrinsic activity. It is suggested that the small crystallite size obtained increased their selectivity towards maleic anhydride.

  6. Modification of Coal Char-loaded TiO2 by Sulfonation and Alkylsilylation to Enhance Catalytic Activity in Styrene Oxidation with Hydrogen Peroxide as Oxidant

    Directory of Open Access Journals (Sweden)

    Mukhamad Nurhadi

    2017-04-01

    Full Text Available The modified coal char from low-rank coal by sulfonation, titanium impregnation and followed by alkyl silylation possesses high catalytic activity in styrene oxidation. The surface of coal char was undergone several steps as such: modification using concentrated sulfuric acid in the sulfonation process, impregnation of 500 mmol titanium(IV isopropoxide and followed by alkyl silylation of n-octadecyltriclorosilane (OTS. The catalysts were characterized by X-ray diffraction (XRD, IR spectroscopy, nitrogen adsorption, and hydrophobicity. The catalytic activity of the catalysts has been examined in the liquid phase styrene oxidation by using aqueous hydrogen peroxide as oxidant. The catalytic study showed the alkyl silylation could enhance the catalytic activity of Ti-SO3H/CC-600(2.0. High catalytic activity and reusability of the o-Ti-SO3H/CC-600(2.0 were related to the modification of local environment of titanium active sites and the enhancement the hydrophobicity of catalyst particle by alkyl silylation. Copyright © 2017 BCREC GROUP. All rights reserved Received: 24th May 2016; Revised: 11st October 2016; Accepted: 18th October 2016 How to Cite: Nurhadi, M. (2017. Modification of Coal Char-loaded TiO2 by Sulfonation and Alkylsilylation to Enhance Catalytic Activity in Styrene Oxidation with Hydrogen Peroxide as Oxidant. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (1: 55-61 (doi:10.9767/bcrec.12.1.501.55-61 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.1.501.55-61

  7. A novel technique for hydrogen production from hog-manure in supercritical partial oxidation (SCWPO)

    Energy Technology Data Exchange (ETDEWEB)

    Youssef, Emhemmed A.; Charpentier, Paul [Western Ontario Univ., London, ON (Canada). Dept. of Chemical and Biochemical Engineering; Nakhla, George [Western Ontario Univ., London, ON (Canada). Dept. of Chemical and Biochemical Engineering; Western Ontario Univ., London, ON (Canada). Dept. of Civil and Environmental Engineering; Elbeshbishy, Elsayed; Hafez, Hisham [Western Ontario Univ., London, ON (Canada). Dept. of Civil and Environmental Engineering

    2010-07-01

    In this study, the catalytic hydrogen production from hog manure using supercritical water partial oxidation was investigated in a batch reactor at a temperature of 500 C, and pressure of 28 MPa using several metallic catalysts. Hog manure was characterized by a total and soluble chemical oxygen demand (TCOD, SCOD) of 57000 and 28000 mg/L, total and volatile suspended solids (TSS, VSS) of 25000, 19000, and ammonia of 2400 mg/L, respectively. The order of H{sub 2} production was the following: Pd/AC > Ru/Al{sub 2}O{sub 3} > Ru/AC > AC > NaOH. The order of COD reduction efficiency was as follows: NaOH > Ru/AC > AC > Ru/Al{sub 2}O{sub 3} > Pd/AC. The behaviour of the volatile fatty acids (VFA's), ethanol, methanol, ammonia, H{sub 2}S, and Sulfate was investigated experimentally and discussed. A 35 % reduction in the H{sub 2} and CH{sub 4} yields was observed in the sequential gasification partial oxidation (oxidant at an 80 % of theoretical requirement) experiments compared to the gasification experiments (catalyst only). Moreover, this reduction in gas yields was coincided with a 45 % reduction in the liquid effluent chemical oxygen demand (COD), 60 % reduction of the ammonia concentration in the liquid effluent, and 20 % reduction in the H{sub 2}S concentration in the effluent gas. (orig.)

  8. Partially oxidized atomic cobalt layers for carbon dioxide electroreduction to liquid fuel

    Science.gov (United States)

    Gao, Shan; Lin, Yue; Jiao, Xingchen; Sun, Yongfu; Luo, Qiquan; Zhang, Wenhua; Li, Dianqi; Yang, Jinlong; Xie, Yi

    2016-01-01

    Electroreduction of CO2 into useful fuels, especially if driven by renewable energy, represents a potentially ‘clean’ strategy for replacing fossil feedstocks and dealing with increasing CO2 emissions and their adverse effects on climate. The critical bottleneck lies in activating CO2 into the CO2•- radical anion or other intermediates that can be converted further, as the activation usually requires impractically high overpotentials. Recently, electrocatalysts based on oxide-derived metal nanostructures have been shown to enable CO2 reduction at low overpotentials. However, it remains unclear how the electrocatalytic activity of these metals is influenced by their native oxides, mainly because microstructural features such as interfaces and defects influence CO2 reduction activity yet are difficult to control. To evaluate the role of the two different catalytic sites, here we fabricate two kinds of four-atom-thick layers: pure cobalt metal, and co-existing domains of cobalt metal and cobalt oxide. Cobalt mainly produces formate (HCOO-) during CO2 electroreduction; we find that surface cobalt atoms of the atomically thin layers have higher intrinsic activity and selectivity towards formate production, at lower overpotentials, than do surface cobalt atoms on bulk samples. Partial oxidation of the atomic layers further increases their intrinsic activity, allowing us to realize stable current densities of about 10 milliamperes per square centimetre over 40 hours, with approximately 90 per cent formate selectivity at an overpotential of only 0.24 volts, which outperforms previously reported metal or metal oxide electrodes evaluated under comparable conditions. The correct morphology and oxidation state can thus transform a material from one considered nearly non-catalytic for the CO2 electroreduction reaction into an active catalyst. These findings point to new opportunities for manipulating and improving the CO2 electroreduction properties of metal systems

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

    Science.gov (United States)

    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.

  10. Study of mobilization and speciation of trace elements in coal pyrolysis

    International Nuclear Information System (INIS)

    Ting, B.T.G.

    1979-01-01

    Various types of coal contain high levels of a number of trace elements. Little is known of the fates of these trace elements during the conversion of coal to liquid and gaseous products. Studies were undertaken of mobilization and speciation of trace elements in coal pyrolysis, one of the major coal conversion processes. The bituminous coal was pyrolyzed to produce liquid and gaseous products. The pyrolysis products were collected in traps in an inert gas stream. In addition mildly hydrogenated coal was prepared by mixing with tetralin, a hydrogen donor solvent, at boiling temperature. In order to characterize each element specifically during pyrolysis, base samples of coal and mildly hydrogenated coal (H-coal) were spiked with heavy metal sulfides, trace metals bound to partially oxidized coal (coal humates), and halide salts prior to carrying out pyrolysis. Eight elements were investigated in this research. They are As, Br, Cl, Co, Cr, Mn, Se, and V. Pre-spiked hydrogenated coal, i.e., pulverized coal spiked with halide salts and heavy metal sulfides then hydrogenated with tetralin, was prepared and studied for the fates of these elements during pyrolysis. Chlorinated and brominated coals were also prepared to compare the volatility differences between organically and inorganically bound halogens during the pyrolysis reaction. These products and the coal char residues were analyzed for the spiked elements mainly by neutron activation analysis for the spiked elements to determine their degree of volatility. Volatility and recovery (mass balance) will be discussed for those elements that appeared highly volatile during pyrolysis. In order to understand the halogenated compounds in the pyrolysis products, gas chromatograms were taken to the collected pyrolysis products of coal, hydrogenated coal, NaCl spiked coal, NaBr spiked coal, chlorinated coal, and brominated coal

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

    Science.gov (United States)

    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.

  12. Rational Design of Mixed-Metal Oxides for Chemical Looping Combustion of Coal via Coupled Computational-Experimental Studies

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Amit [North Carolina State Univ., Raleigh, NC (United States); Li, Fanxing [North Carolina State Univ., Raleigh, NC (United States); Santiso, Erik [North Carolina State Univ., Raleigh, NC (United States)

    2017-09-18

    Energy and global climate change are two grand challenges to the modern society. An urgent need exists for development of clean and efficient energy conversion processes. The chemical looping strategy, which utilizes regenerable oxygen carriers (OCs) to indirectly convert carbonaceous fuels via redox reactions, is considered to be one of the more promising approaches for CO2 capture by the U.S. Department of Energy (USDOE). To date, most long-term chemical looping operations were conducted using gaseous fuels, even though direct conversion of coal is more desirable from both economics and CO2 capture viewpoints. The main challenges for direct coal conversion reside in the stringent requirements on oxygen carrier performances. In addition, coal char and volatile compounds are more challenging to convert than gaseous fuels. A promising approach for direct conversion of coal is the so called chemical looping with oxygen uncoupling (CLOU) technique. In the CLOU process, a metal oxide that decomposes at the looping temperature, and releases oxygen to the gas phase is used as the OC. The overarching objective of this project was to discover the fundamental principles for rational design and optimization of oxygen carriers (OC) in coal chemical looping combustion (CLC) processes. It directly addresses Topic Area B of the funding opportunity announcement (FOA) in terms of “predictive description of the phase behavior and mechanical properties” of “mixed metal oxide” based OCs and rational development of new OC materials with superior functionality. This was achieved through studies exploring i) iron-containing mixed-oxide composites as oxygen carriers for CLOU, ii) Ca1-xAxMnO3-δ (A = Sr and Ba) as oxygen carriers for CLOU, iii) CaMn1-xBxO3-δ (B=Al, V, Fe, Co, and Ni) as oxygen carrier for CLOU and iv) vacancy creation energy in Mn-containing perovskites as an indicator chemical looping with oxygen uncoupling.

  13. Effects of Oxygen Partial Pressure on Oxidation Behavior of CMnSi TRIP Steel in an Oxidation-Reduction Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong-Hwan; Huh, Joo-Youl [Korea University, Seoul (Korea, Republic of); Kim, Myung-Soo; Kim, Jong-Sang [POSCO Technical Research Laboratories, Gwangyang (Korea, Republic of)

    2017-02-15

    An oxidation-reduction scheme is an alternative approach for improving the galvanizability of advanced high-strength steel in the continuous hot-dip galvanizing process. Here, we investigated the effect of oxygen partial pressure (Po{sub 2}) on the oxidation behavior of a transformation-induced plasticity steel containing 1.5 wt% Si and 1.6 wt% Mn during heating to and holding for 60 s at 700 ℃ under atmospheres with various Po{sub 2} values. Irrespective of Po{sub 2}, a thin amorphous Si-rich layer of Si-Mn-O was formed underneath the Fe oxide scale (a Fe{sub 2}O{sub 3}/Fe{sub 3}O{sub 4} bilayer) in the heating stage. In contrast to Si, Mn tended to segregate at the scale surface as (Fe,Mn){sub 2}O{sub 3}. The multilayered structure of (Fe,Mn){sub 2}O{sub 3}/Fe{sub 2}O{sub 3}/Fe{sub 3}O{sub 4}/amorphous Si-Mn-O remained even after extended oxidizing at 700 ℃ for 60 s. Fe{sub 2}O{sub 3} was the dominantly growing oxide phase in the scale. The enhanced growth rate of Fe{sub 2}O{sub 3} with increasing Po{sub 2} resulted in the formation of more Kirkendall voids in the amorphous Si-rich layer and a less Mn segregation at the scale surface. The mechanisms underlying the absence of FeO and the formation of Kirkendall voids are discussed.

  14. Influence of coal rank and pyrolysis/hydropyrolysis temperature on nitrogen oxide emission during coal char combustion

    Energy Technology Data Exchange (ETDEWEB)

    Stanczyk, K.; Miga, K. [Polish Academy of Sciences, Gliwice (Poland). Institute of Coal Chemistry

    1999-07-01

    The formation of NO during the combustion of chars was investigated. The formation of NO was correlated with carbon oxides emission. The way in which the reactivity of chars influences NO emission was investigated. 6 refs., 2 figs., 2 tabs.

  15. Partial oxidation of landfill leachate in supercritical water: Optimization by response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yanmeng; Wang, Shuzhong; Xu, Haidong; Guo, Yang; Tang, Xingying

    2015-09-15

    Highlights: • Partial oxidation of landfill leachate in supercritical water was investigated. • The process was optimized by Box–Behnken design and response surface methodology. • GY{sub H2}, TRE and CR could exhibit up to 14.32 mmol·gTOC{sup −1}, 82.54% and 94.56%. • Small amounts of oxidant can decrease the generation of tar and char. - Abstract: To achieve the maximum H{sub 2} yield (GY{sub H2}), TOC removal rate (TRE) and carbon recovery rate (CR), response surface methodology was applied to optimize the process parameters for supercritical water partial oxidation (SWPO) of landfill leachate in a batch reactor. Quadratic polynomial models for GY{sub H2}, CR and TRE were established with Box–Behnken design. GY{sub H2}, CR and TRE reached up to 14.32 mmol·gTOC{sup −1}, 82.54% and 94.56% under optimum conditions, respectively. TRE was invariably above 91.87%. In contrast, TC removal rate (TR) only changed from 8.76% to 32.98%. Furthermore, carbonate and bicarbonate were the most abundant carbonaceous substances in product, whereas CO{sub 2} and H{sub 2} were the most abundant gaseous products. As a product of nitrogen-containing organics, NH{sub 3} has an important effect on gas composition. The carbon balance cannot be reached duo to the formation of tar and char. CR increased with the increase of temperature and oxidation coefficient.

  16. New method of reducing emission of nitrogen oxides at coal-dust burning thermal power plants in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.

    1987-05-01

    New method of suppressing nitrogen oxide formation in the combustion process makes use of SGR- or PM-burners in the combustion chamber, augmented with auxiliary burners positioned higher in the chamber for secondary fuel with insufficient air and nozzles above the latter for tertiary air. A description of laboratory experiments on the reduction of nitrogen oxides using the above burner configuration as well as a description of the reaction process taking place during combustion are presented. Results of industrial testing of the three-stage combustion of high-nitrogen Australian black coal in a cylindrical combustion chamber developed by Hitachi-Zosen are presented.

  17. Nitrous Oxide Production in a Granule-based Partial Nitritation Reactor: A Model-based Evaluation.

    Science.gov (United States)

    Peng, Lai; Sun, Jing; Liu, Yiwen; Dai, Xiaohu; Ni, Bing-Jie

    2017-04-03

    Sustainable wastewater treatment has been attracting increasing attentions over the past decades. However, the production of nitrous oxide (N 2 O), a potent GHG, from the energy-efficient granule-based autotrophic nitrogen removal is largely unknown. This study applied a previously established N 2 O model, which incorporated two N 2 O production pathways by ammonia-oxidizing bacteria (AOB) (AOB denitrification and the hydroxylamine (NH 2 OH) oxidation). The two-pathway model was used to describe N 2 O production from a granule-based partial nitritation (PN) reactor and provide insights into the N 2 O distribution inside granules. The model was evaluated by comparing simulation results with N 2 O monitoring profiles as well as isotopic measurement data from the PN reactor. The model demonstrated its good predictive ability against N 2 O dynamics and provided useful information about the shift of N 2 O production pathways inside granules for the first time. The simulation results indicated that the increase of oxygen concentration and granule size would significantly enhance N 2 O production. The results further revealed a linear relationship between N 2 O production and ammonia oxidation rate (AOR) (R 2  = 0.99) under the conditions of varying oxygen levels and granule diameters, suggesting that bulk oxygen and granule size may exert an indirect effect on N 2 O production by causing a change in AOR.

  18. Partial oxidation of municipal sludge with activited carbon catalyst in supercritical water

    International Nuclear Information System (INIS)

    Guo Yang; Wang Shuzhong; Gong Yanmeng; Xu Donghai; Tang Xingying; Ma Honghe

    2010-01-01

    The partial oxidation (POX) characteristics of municipal sludge in supercritical water (SCW) were investigated by using batch reactor. Effects of reaction parameters such as oxidant equivalent ratio (OER), reaction time and temperature were investigated. Activated carbon (AC) could effectively improve the mole fraction of H 2 in gas product at low OER. However, high OER (greater than 0.3) not only led to the combustion reaction of CO and H 2 , but also caused corrosion of reactor inner wall. Hydrogenation and polymerization of the intermediate products are possible reasons for the relative low COD removal rate in our tests. Metal oxide leached from the reactor inner wall and the main components of the granular sludge were deposited in the AC catalyst. Reaction time had more significant effect on BET surface area of AC than OER had. Long reaction time led to the methanation reaction following hydrolysis and oxidation reaction of AC in SCW in the presence of oxygen. Correspondingly, the possible reaction mechanisms were proposed.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  20. Steam and partial oxidation reforming options for hydrogen production from fossil fuels for PEM fuel cells

    Directory of Open Access Journals (Sweden)

    Yousri M.A. Welaya

    2012-06-01

    Full Text Available Proton exchange membrane fuel cell (PEM generates electrical power from air and from hydrogen or hydrogen rich gas mixtures. Therefore, there is an increasing interest in converting current hydrocarbon based marine fuels such as natural gas, gasoline, and diesel into hydrogen rich gases acceptable to the PEM fuel cells on board ships. Using chemical flow sheeting software, the total system efficiency has been calculated. Natural gas appears to be the best fuel for hydrogen rich gas production due to its favorable composition of lower molecular weight compounds. This paper presents a study for a 250 kW net electrical power PEM fuel cell system utilizing a partial oxidation in one case study and steam reformers in the second. This study has shown that steam-reforming process is the most competitive fuel processing option in terms of fuel processing efficiency. Partial oxidation process has proved to posses the lowest fuel processing efficiency. Among the options studied, the highest fuel processing efficiency is achieved with natural gas steam reforming system.

  1. Hydrogen production by ethanol partial oxidation over nano-iron oxide catalysts produced by chemical vapour synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Wael Ahmed Abou Taleb Sayed

    2011-01-13

    This work presents the experimental results of the synthesis of unsupported and supported SiC iron oxide nanoparticles and their catalytic activity towards ethanol partial oxidation. For comparison, further unsupported iron oxide phases were investigated towards the ethanol partial oxidation. These {gamma}-Fe{sub 2}O{sub 3} and {alpha}/{gamma}-Fe{sub 2}O{sub 3} phase catalysts were prepared by the CVS method using Fe(CO){sub 5} as precursor, supplied by another author. The {alpha}-Fe{sub 2}O{sub 3} and SiC nanoparticles were prepared by the CVS method using a home made hot wall reactor technique at atmospheric pressure. Ferrocene and tetramethylsilane were used as precursor for the production process. Process parameters of precursor evaporation temperature, precursor concentration, gas mixture velocity and gas mixture dilution were investigated and optimised to produce particle sizes in a range of 10 nm. For Fe{sub 2}O{sub 3}/SiC catalyst series production, a new hot wall reactor setup was used. The particles were produced by simultaneous thermal decomposition of ferrocene and tetramethylsilane in one reactor from both sides. The production parameters of inlet tube distance inside the reactor, precursor evaporation temperature and carrier gas flow were investigated to produce a series of samples with different iron oxide content. The prepared catalysts composition, physical and chemical properties were characterized by XRD, EDX, SEM, BET surface area, FTIR, XPS and dynamic light scattering (DLS) techniques. The catalytic activity for the ethanol gas-phase oxidation was investigated in a temperature range from 260 C to 290 C. The product distributions obtained over all catalysts were analysed with mass spectrometry analysis tool. The activity of bulk Fe{sub 2}O{sub 3} and SiC nanoparticles was compared with prepared nano-iron oxide phase catalysts. The reaction parameters, such as reaction temperature and O{sub 2}/ethanol ratio were investigated. The catalysts

  2. Partial catalytic oxidation of CH{sub 4} to synthesis gas for power generation - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mantzaras, I.; Schneider, A.

    2006-03-15

    The partial oxidation of methane to synthesis gas over rhodium catalysts has been investigated experimentally and numerically in the pressure range of 4 to 10 bar. The methane/oxidizer feed has been diluted with large amounts of H{sub 2}O and CO{sub 2} (up to 70% vol.) in order to simulate new power generation cycles with large exhaust gas recycle. Experiments were carried out in an optically accessible channel-flow reactor that facilitated laser-based in situ measurements, and also in a subscale gas-turbine catalytic reactor. Full-elliptic steady and transient two-dimensional numerical codes were used, which included elementary hetero-/homogeneous chemical reaction schemes. The following are the key conclusions: a) Heterogeneous (catalytic) and homogeneous (gas-phase) schemes have been validated for the partial catalytic oxidation of methane with large exhaust gas recycle. b) The impact of added H{sub 2}O and CO{sub 2} has been elucidated. The added H{sub 2}O increased the methane conversion and hydrogen selectivity, while it decreased the CO selectivity. The chemical impact of CO{sub 2} (dry reforming) was minimal. c) The numerical model reproduced the measured catalytic ignition times. It was further shown that the chemical impact of H{sub 2}O and CO{sub 2} on the catalytic ignition delay times was minimal. d) The noble metal dispersion increased with different support materials, in the order Rh/{alpha}-Al{sub 2}O{sub 3}, Rh/ZrO{sub 2}, and Rh/Ce-ZrO{sub 2}. An evident relationship was established between the noble metal dispersion and the catalytic behavior. (authors)

  3. Partial oxidation process for producing a stream of hot purified gas

    Science.gov (United States)

    Leininger, T.F.; Robin, A.M.; Wolfenbarger, J.K.; Suggitt, R.M.

    1995-03-28

    A partial oxidation process is described for the production of a stream of hot clean gas substantially free from particulate matter, ammonia, alkali metal compounds, halides and sulfur-containing gas for use as synthesis gas, reducing gas, or fuel gas. A hydrocarbonaceous fuel comprising a solid carbonaceous fuel with or without liquid hydrocarbonaceous fuel or gaseous hydrocarbon fuel, wherein said hydrocarbonaceous fuel contains halides, alkali metal compounds, sulfur, nitrogen and inorganic ash containing components, is reacted in a gasifier by partial oxidation to produce a hot raw gas stream comprising H{sub 2}, CO, CO{sub 2}, H{sub 2}O, CH{sub 4}, NH{sub 3}, HCl, HF, H{sub 2}S, COS, N{sub 2}, Ar, particulate matter, vapor phase alkali metal compounds, and molten slag. The hot raw gas stream from the gasifier is split into two streams which are separately deslagged, cleaned and recombined. Ammonia in the gas mixture is catalytically disproportionated into N{sub 2} and H{sub 2}. The ammonia-free gas stream is then cooled and halides in the gas stream are reacted with a supplementary alkali metal compound to remove HCl and HF. Alkali metal halides, vaporized alkali metal compounds and residual fine particulate matter are removed from the gas stream by further cooling and filtering. The sulfur-containing gases in the process gas stream are then reacted at high temperature with a regenerable sulfur-reactive mixed metal oxide sulfur sorbent material to produce a sulfided sorbent material which is then separated from the hot clean purified gas stream having a temperature of at least 1000 F. 1 figure.

  4. The influence of the oxygen partial pressure on the quasi-ternary system Cr-Mn-Ti-oxide

    International Nuclear Information System (INIS)

    Garcia-Rosales, C.; Schulze, H.A.; Naoumidis, A.; Nickel, H.

    1991-05-01

    The passivation layers formed by the oxidizing corrosion of high temperature alloys consist primarily of oxides and mixed oxides of the elements chromium, manganese and titanium. For a reproducible formation and characterization of such oxide layers it is necessary to know the phase equilibria of these oxide systems at temperature and oxygen partial pressure conditions which will be relevant during their application. For the investigation of the quasi-ternary system Cr-Mn-Ti-oxide, oxide powders were prepared and annealed at 1000deg C under different oxygen partial pressures ranging from 0.21 bar to 10 -21 bar. Phase identification and determination of lattice parameter using X-ray diffraction analysis as well as the direct measurement of phase boundaries as a function of oxygen partial pressure using the emf-methode were carried out for these investigations. In the quasi-ternary system Cr-Mn-Ti-oxide the spinels play a decisive role in the oxigen partial pressure range examined. The spinel MnCr 2 O 4 may be regarded as the most significant compound. Part of the chronium can be replaced by trivalent manganese at high oxygen partial pressures and by trivalent titanium at low pressures, and the formation of a solid solution with the spinel Mn 2 TiO 4 is possible in all cases. In this way a coherent single-phase spinel region is observed which extends over the entire oxygen partial pressure range form 0.21 bar to 10 -21 bar examined at 1000deg C. (orig.) [de

  5. Microbial, algal, and fungal strategies for manganese oxidation at a Shade Township coal mine, Somerset County, Pennsylvania

    International Nuclear Information System (INIS)

    Robbins, E.I.; Brant, D.L.; Ziemkiewicz, P.F.

    1999-01-01

    Successful designs to eliminate Mn from mine discharge are necessary for both restoring abandoned mine lands and permitting the mining of high sulfur coal in the eastern United States. A passive in-line system that meets Mn discharge limits was built at the discharge from the former Shade Township coal mine in south central Pennsylvania. Qualitative research on monthly changes in the microbial and algal community that removes Mn is underway. Epilithic attachment of microorganisms was analyzed on artificial (glass microscope slides) and natural substrates (limestone thin sections) that were immersed in surface water for one month periods over 6 months. Organisms attached to both glass and limestone substrates. Limestone became coated with 34--86% more Mn that did glass surfaces. Light microscopy revealed 12 different strategies are being used by bacteria, cyan bacteria, diatoms, green algae, and fungi to oxidize Mn. the dominant method used by the epilithic community to oxidize Mn is coating of holdfasts by the iron bacterium, Liptothrix discophora, and the green alga, Ulothrix sp. Other methods for Mn removal by oxidation include coating of individual cells, filaments/sheaths/hyphae, extracellular polysaccharides, and biofilms. The unplanned community at the site is multifaceted and extremely efficient in its Mn removal ability. Community interactions or complexity may play roles in the stability of the ecosystem and the efficiency of its Mn oxidizing ability

  6. Microbial, algal, and fungal strategies for manganese oxidation at a Shade Township coal mine, Somerset County, Pennsylvania

    Energy Technology Data Exchange (ETDEWEB)

    Robbins, E.I.; Brant, D.L.; Ziemkiewicz, P.F.

    1999-07-01

    Successful designs to eliminate Mn from mine discharge are necessary for both restoring abandoned mine lands and permitting the mining of high sulfur coal in the eastern United States. A passive in-line system that meets Mn discharge limits was built at the discharge from the former Shade Township coal mine in south central Pennsylvania. Qualitative research on monthly changes in the microbial and algal community that removes Mn is underway. Epilithic attachment of microorganisms was analyzed on artificial (glass microscope slides) and natural substrates (limestone thin sections) that were immersed in surface water for one month periods over 6 months. Organisms attached to both glass and limestone substrates. Limestone became coated with 34--86% more Mn that did glass surfaces. Light microscopy revealed 12 different strategies are being used by bacteria, cyan bacteria, diatoms, green algae, and fungi to oxidize Mn. the dominant method used by the epilithic community to oxidize Mn is coating of holdfasts by the iron bacterium, Liptothrix discophora, and the green alga, Ulothrix sp. Other methods for Mn removal by oxidation include coating of individual cells, filaments/sheaths/hyphae, extracellular polysaccharides, and biofilms. The unplanned community at the site is multifaceted and extremely efficient in its Mn removal ability. Community interactions or complexity may play roles in the stability of the ecosystem and the efficiency of its Mn oxidizing ability.

  7. Identification of key nitrous oxide production pathways in aerobic partial nitrifying granules.

    Science.gov (United States)

    Ishii, Satoshi; Song, Yanjun; Rathnayake, Lashitha; Tumendelger, Azzaya; Satoh, Hisashi; Toyoda, Sakae; Yoshida, Naohiro; Okabe, Satoshi

    2014-10-01

    The identification of the key nitrous oxide (N2O) production pathways is important to establish a strategy to mitigate N2O emission. In this study, we combined real-time gas-monitoring analysis, (15)N stable isotope analysis, denitrification functional gene transcriptome analysis and microscale N2O concentration measurements to identify the main N2O producers in a partial nitrification (PN) aerobic granule reactor, which was fed with ammonium and acetate. Our results suggest that heterotrophic denitrification was the main contributor to N2O production in our PN aerobic granule reactor. The heterotrophic denitrifiers were probably related to Rhodocyclales bacteria, although different types of bacteria were active in the initial and latter stages of the PN reaction cycles, most likely in response to the presence of acetate. Hydroxylamine oxidation and nitrifier denitrification occurred, but their contribution to N2O emission was relatively small (20-30%) compared with heterotrophic denitrification. Our approach can be useful to quantitatively examine the relative contributions of the three pathways (hydroxylamine oxidation, nitrifier denitrification and heterotrophic denitrification) to N2O emission in mixed microbial populations. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  8. Catalytic partial oxidation of methane over porous silica supported VO{sub x} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Pirovano, C.; Schoenborn, E.; Kalevaru, V.N.; Wohlrab, S.; Luecke, B.; Martin, A. [University Rostock e.V., Rostock (Germany). Leibniz Inst. for Catalysis

    2011-07-01

    High surface area mesoporous siliceous MCM-41 and SBA-15 materials have been used as supports to disperse vanadium oxide species using wet impregnation and incipient wetness impregnation methods. These materials were used as catalysts for the partial oxidation of methane (POM) to formaldehyde. The physico-chemical properties of the solids were studied by means of BET, DR-UV/Vis spectroscopy, Py-FTIR and TEM. The influence of support and the preparation method on the dispersion of VOx is also investigated. The catalytic properties of the catalysts were examined in a fixed bed stainless steel reactor at 923 K. So far a maximum production of formaldehyde can be detected on SBA-15 supported VOx-catalysts prepared by incipient wetness impregnation. On this V/SBA-15 material a covalent attachment of catalytic active molecular vanadium species dominates, which in turn leads to a lower activation temperature and thereby reduced over-oxidation. From the best case, the space time yield of HCHO could be reached close to 775 g{sub HCHO} Kg{sub cat}{sup -1} h{sup -1}. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Xu, G. Z.; Du, Y.; Zhang, X. M.; Liu, E. K.; Wang, W. H., E-mail: wenhong.wang@iphy.ac.cn; Wu, G. H. [State Key Laboratory for Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zhang, H. G. [College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 (China)

    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.

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

    Science.gov (United States)

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

  11. Spectroscopy study of electron spin resonance of coal oxidation of different rank; Estudio por espectroscopia de resonancia espin electron de la oxidacion de carbones de diferente rango

    Energy Technology Data Exchange (ETDEWEB)

    Enciso Prieto, Hector Manuel

    1992-07-01

    The present work constitutes an initial step for the knowledge of the coal oxidation, with the purpose of preventing the adverse influences caused by this phenomenon in the physical-chemical characteristics and in the tendency to the spontaneous combustion. Since the knowledge the influence of the free radicals in this process, their relative concentration was measured by means of the use of the technique of resonance spin electron. This technique measures the absorption of electromagnetic radiation, generally in the microwaves region, for the materials that not have electrons matched up in a strong magnetic field. In the essays of oxidation three coal of different range and different characteristics of mass were used and it was studied the influence of the temperature, particle size and the range. The results showed that the coal of Guacheta (bituminous low in volatile) it presents bigger concentration of free radicals, after the reaction with the atmospheric oxygen, with regard to the coal of the Cerrejon (bituminous high in volatile B) and Amaga (bituminous high in volatile C). Although this doesn't indicate that the coal of Guacheta is that more easily is oxidized, but rather it possibly presents stabilization of radicals for resonance. It concluded that there are differences in the oxidation mechanism between coal of different rank and different agglomeration properties.

  12. Direct-on-Filter α-Quartz Estimation in Respirable Coal Mine Dust Using Transmission Fourier Transform Infrared Spectrometry and Partial Least Squares Regression.

    Science.gov (United States)

    Miller, Arthur L; Weakley, Andrew Todd; Griffiths, Peter R; Cauda, Emanuele G; Bayman, Sean

    2017-05-01

    In order to help reduce silicosis in miners, the National Institute for Occupational Health and Safety (NIOSH) is developing field-portable methods for measuring airborne respirable crystalline silica (RCS), specifically the polymorph α-quartz, in mine dusts. In this study we demonstrate the feasibility of end-of-shift measurement of α-quartz using a direct-on-filter (DoF) method to analyze coal mine dust samples deposited onto polyvinyl chloride filters. The DoF method is potentially amenable for on-site analyses, but deviates from the current regulatory determination of RCS for coal mines by eliminating two sample preparation steps: ashing the sampling filter and redepositing the ash prior to quantification by Fourier transform infrared (FT-IR) spectrometry. In this study, the FT-IR spectra of 66 coal dust samples from active mines were used, and the RCS was quantified by using: (1) an ordinary least squares (OLS) calibration approach that utilizes standard silica material as done in the Mine Safety and Health Administration's P7 method; and (2) a partial least squares (PLS) regression approach. Both were capable of accounting for kaolinite, which can confound the IR analysis of silica. The OLS method utilized analytical standards for silica calibration and kaolin correction, resulting in a good linear correlation with P7 results and minimal bias but with the accuracy limited by the presence of kaolinite. The PLS approach also produced predictions well-correlated to the P7 method, as well as better accuracy in RCS prediction, and no bias due to variable kaolinite mass. Besides decreased sensitivity to mineral or substrate confounders, PLS has the advantage that the analyst is not required to correct for the presence of kaolinite or background interferences related to the substrate, making the method potentially viable for automated RCS prediction in the field. This study demonstrated the efficacy of FT-IR transmission spectrometry for silica determination in

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

    Science.gov (United States)

    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. Temperature oscillations in methanol partial oxidation reactor for the production of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinsu; Byeon, Jeonguk; Seo, Il Gyu; Lee, Hyun Chan; Kim, Dong Hyun; Lee, Jietae [Kyungpook National University, Daegu (Korea, Republic of)

    2013-04-15

    Methanol partial oxidation (POX) is a well-known reforming reaction for the production of hydrogen from methanol. Since POX is relatively fast and highly exothermic, this reforming method will be efficient for the fast start-up and load-following operation. However, POX generates hot spots around catalyst and even oscillations in the reactor temperature. These should be relieved for longer operations of the reactor without catalyst degradations. For this, temperature oscillations in a POX reactor are investigated experimentally. Various patterns of temperature oscillations according to feed flow rates of reactants and reactor temperatures are obtained. The bifurcation phenomena from regular oscillations to chaotic oscillations are found as the methanol flow rate increases. These experimental results can be used for theoretical analyses of oscillations and for designing safe reforming reactors.

  15. Temperature oscillations in methanol partial oxidation reactor for the production of hydrogen

    International Nuclear Information System (INIS)

    Kim, Jinsu; Byeon, Jeonguk; Seo, Il Gyu; Lee, Hyun Chan; Kim, Dong Hyun; Lee, Jietae

    2013-01-01

    Methanol partial oxidation (POX) is a well-known reforming reaction for the production of hydrogen from methanol. Since POX is relatively fast and highly exothermic, this reforming method will be efficient for the fast start-up and load-following operation. However, POX generates hot spots around catalyst and even oscillations in the reactor temperature. These should be relieved for longer operations of the reactor without catalyst degradations. For this, temperature oscillations in a POX reactor are investigated experimentally. Various patterns of temperature oscillations according to feed flow rates of reactants and reactor temperatures are obtained. The bifurcation phenomena from regular oscillations to chaotic oscillations are found as the methanol flow rate increases. These experimental results can be used for theoretical analyses of oscillations and for designing safe reforming reactors

  16. Partial thermodynamic functions of hydrogen in complex hydrated vanadium(5) and tungsten(6) oxides

    International Nuclear Information System (INIS)

    Volkov, V.L.; Zakharova, G.S.

    2003-01-01

    The partial thermodynamic characteristics of hydrogen in the complex hydrated vanadium(5) and tungsten(6) oxides, obtained through the sol-gel method, of the general formula H 2 V 12-y W y O 31+δ ·nH 2 O (0 ≤ x ≤ 0.33) are determined through the emf method. The changes in these values (ΔG-bar(H 2 ), ΔH-bar(H 2 ) and ΔS-bar(H 2 )) in dependence on the compound composition are discussed. It is established that ΔG-bar(H 2 ) phases, amorphous to X-rays are determined by the ΔS-bar(H 2 ) value and crystalline ones by ΔH-bar(H 2 ). The scheme of the phase relationships of the H 2 O-H-WO 3 -V 2 O 5 system, whereto the given phases are related are presented [ru

  17. Microbial resource management for the mitigation of nitrous oxide emissions from the Partial Nitritation- Anammox process

    DEFF Research Database (Denmark)

    Blum, Jan-Michael

    Urban wastewater treatment plants are designed to remove pathogens and pollutants from wastewater in order to provide sanitation and to protect receiving water bodies from eutrophication. Reactive nitrogen, mainly in the form of ammonium, is one of the components in wastewater that is converted...... to dinitrogen gas during treatment. The Partial Nitritation-Anammox process (PNA) uses the capacity of autotrophic aerobic and anaerobic ammonia oxidizing bacteria (AOB and AnAOB) to perform this task. The process is mainly applied to treat ammonium-rich wastewater streams with low concentrations of organic...... with the specific ammonia removal rate, while during non-aerated phases net N2O production rates were positively correlated with the nitrite concentration (NO2-). Operation of PNA at reduced specific ammonia removal rates is, therefore, a feasible strategy to mitigate N2O emissions. However, when high ammonium...

  18. Adiabatic Gasification and Pyrolysis of Coffee Husk Using Air-Steam for Partial Oxidation

    Directory of Open Access Journals (Sweden)

    Catalina Rodriguez

    2011-01-01

    Full Text Available Colombian coffee industry produces about 0.6 million tons of husk (CH per year which could serve as feedstock for thermal gasification to produce gaseous and liquid fuels. The current paper deals with: (i CH adiabatic gasification modeling using air-steam blends for partial oxidation and (ii experimental thermogravimetric analysis to determine the CH activation energy (E. The Chemical Equilibrium with Applications Program (CEA, developed by NASA, was used to estimate the effect of equivalence ratio (ER and steam to fuel ratio (S : F on equilibrium temperature and gas composition of ~150 species. Also, an atom balance model was developed for comparison purposes. The results showed that increased ER and (S : F ratios produce mixtures that are rich in H2 and CO2 but poor in CO. The value for the activation energy was estimated to be 221 kJ/kmol.

  19. Simulation study of a PEM fuel cell system fed by hydrogen produced by partial oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Ozdogan, S [Marmara University, Faculty of Engineering, Istanbul (Turkey); Ersoz, A; Olgun, H [TUBITAK Marmara Research Center, Energy Systems and Environmental Research Institute, Kocaeli (Turkey)

    2003-09-01

    Within the frame of sustainable development, efficient and clean, if possible zero emission energy production technologies are of utmost importance in various sectors such as utilities, industry, households and transportation. Low-temperature fuel cell systems are suitable for powering transportation systems such as automobiles and trucks in an efficient and low-emitting manner. Proton exchange membrane (PEM) fuel cell systems constitute the most promising low temperature fuel cell option being developed globally. PEM fuel cells generate electric power from air and hydrogen or from a hydrogen rich gas via electrochemical reactions. Water and waste heat are the only by-products of PEM fuel cells. There is great interest in converting current hydrocarbon based common transportation fuels such as gasoline and diesel into hydrogen rich gases acceptable by PEM fuel cells. Hydrogen rich gases can be produced from conventional transportation fuels via various reforming technologies. Steam reforming, partial oxidation and auto-thermal reforming are the three major reforming technologies. In this paper, we discuss the results of a simulation study for a PEM fuel cell with partial oxidation. The Aspen HYSYS 3.1 code has been used for simulation purposes. Two liquid hydrocarbon fuels have been selected to investigate the effect of average molecular weights of hydrocarbons, on the fuel processing efficiency. The overall system efficiency depends on the fuel preparation and fuel cell efficiencies as well as on the heat integration within the system. It is desired to investigate the overall system efficiencies for net electrical power production at 100 kW considering bigger scale transport applications. Results indicate that fuel properties, fuel preparation system operating parameters and PEM fuel cell polarization curve characteristics all affect the overall system efficiency. (authors)

  20. Depolymerization of coal by oxidation and alkylation; Sanka bunkai to alkyl ka ni yoru sekitan kaijugo

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, H.; Isoda, T.; Kusakabe, K.; Morooka, S. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Hayashi, J. [Hokkaido University, Sapporo (Japan). Center for Advanced Research of Energy Technology

    1996-10-28

    Change in depolymerization degree and coal structure was studied for depolymerization treatment of coal in various alcohol containing aqueous hydrogen peroxide. In experiment, the mixture of Yallourn coal, alcohol and aqueous hydrogen peroxide was agitated in nitrogen atmosphere of normal pressure at 70{degree}C for 12 hours. As the experimental result, the methanol solubility of only 5% of raw coal increased up to 35.2% by hydrogen peroxide treatment, while the yield of insoluble matters also decreased from 94% to 62%. Most of the gas produced during treatment was composed of inorganic gases such as CO and CO2, and its carbon loss was extremely decreased by adding alcohol. From the analytical result of carbon loss in hydrogen peroxide treatment, it was clarified that alkylation advances with introduction of alkyl group derived from alcohol into coal by hydrogen peroxide treatment under a coexistence of alcohol, and depolymerization reaction of coal itself is thus promoted by alcohol. 4 refs., 7 figs., 1 tab.

  1. Characteristic of nitrous oxide production in partial denitrification process with high nitrite accumulation.

    Science.gov (United States)

    Du, Rui; Peng, Yongzhen; Cao, Shenbin; Wang, Shuying; Niu, Meng

    2016-03-01

    Nitrous oxide (N2O) production during the partial denitrification process with nitrate (NO3(-)-N) to nitrite (NO2(-)-N) transformation ratio of 80% was investigated in this study. Results showed that N2O was seldom observed before complete depletion of NO3(-)-N, but it was closely related to the reduction of NO2(-)-N rather than NO3(-)-N. High COD/NO3(-)-N was in favor of N2O production in partial denitrification with high NO2(-)-N accumulation. It was seriously enhanced at constant acidic pH due to the free nitrous acid (FNA) inhibition. However, the N2O production was much lower at initial pH of 5.5 and 6.5 due to the pH increase during denitrification process. Significantly, the pH turning point could be chosen as a controlled parameter to denote the end of NO3(-)-N reduction, which could not only achieve high NO2(-)-N accumulation but also decrease the N2O production significantly for practical application. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Method and apparatus for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

    Science.gov (United States)

    Grindley, T.

    1988-04-05

    A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier is described. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600 to 1800 F and are partially quenched with water to 1000 to 1200 F before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime /limestone. 1 fig.

  3. Catalyst development and systems analysis of methanol partial oxidation for the fuel processor - fuel cell integration

    Energy Technology Data Exchange (ETDEWEB)

    Newson, E; Mizsey, P; Hottinger, P; Truong, T B; Roth, F von; Schucan, Th H [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Methanol partial oxidation (pox) to produce hydrogen for mobile fuel cell applications has proved initially more successful than hydrocarbon pox. Recent results of catalyst screening and kinetic studies with methanol show that hydrogen production rates have reached 7000 litres/hour/(litre reactor volume) for the dry pox route and 12,000 litres/hour/(litre reactor volume) for wet pox. These rates are equivalent to 21 and 35 kW{sub th}/(litre reactor volume) respectively. The reaction engineering problems remain to be solved for dry pox due to the significant exotherm of the reaction (hot spots of 100-200{sup o}C), but wet pox is essentially isothermal in operation. Analyses of the integrated fuel processor - fuel cell systems show that two routes are available to satisfy the sensitivity of the fuel cell catalysts to carbon monoxide, i.e. a preferential oxidation reactor or a membrane separator. Targets for individual system components are evaluated for the base and best case systems for both routes to reach the combined 40% efficiency required for the integrated fuel processor - fuel cell system. (author) 2 figs., 1 tab., 3 refs.

  4. Proposition of primary methods for nitrogen oxides emissions reduction at coal-fired 200 MW power unit (Yugoslavia)

    International Nuclear Information System (INIS)

    Repic, B.; Mladenovic, R.; Crnomarkovic, N.

    1997-01-01

    The combustion of coal is followed by increased pollution of the environment with toxic products. Together with the generation of other pollutants, the emission of nitrogen oxides (NO x ) represents, due to its high toxicity, a great environmental risk. Appropriate measures must be taken for lowering NO x emission, both on new facilities and those already in operation. Basic technologies (primary reduction methods) of several generations, developed until now and used in practice, are presented in the paper. The technologies applicable on domestic facilities and adjusted to domestic coals have been given particular consideration. Proposition of primary methods for NO x emission reduction at coal-fired 200 MW power unit at TPS 'Nikola Tesla' is analyzed. The following methods have been considered in detail: flue gases recirculation, multi-stage combustion, low-NO x burners, additional over-fire air, multi-stage air intake into the furnace, staged fuel injection, grinding fineness increase, etc. Considerations were performed according to existing constructive characteristics of the furnace and the burners, and characteristics of used fuels, i. e. lignites from Kolubara pit. (Author)

  5. Hybrid Nitrous Oxide Production from a Partial Nitrifying Bioreactor: Hydroxylamine Interactions with Nitrite.

    Science.gov (United States)

    Terada, Akihiko; Sugawara, Sho; Hojo, Keisuke; Takeuchi, Yuki; Riya, Shohei; Harper, Willie F; Yamamoto, Tomoko; Kuroiwa, Megumi; Isobe, Kazuo; Katsuyama, Chie; Suwa, Yuichi; Koba, Keisuke; Hosomi, Masaaki

    2017-03-07

    The goal of this study was to elucidate the mechanisms of nitrous oxide (N 2 O) production from a bioreactor for partial nitrification (PN). Ammonia-oxidizing bacteria (AOB) enriched from a sequencing batch reactor (SBR) were subjected to N 2 O production pathway tests. The N 2 O pathway test was initiated by supplying an inorganic medium to ensure an initial NH 4 + -N concentration of 160 mg-N/L, followed by 15 NO 2 - (20 mg-N/L) and dual 15 NH 2 OH (each 17 mg-N/L) spikings to quantify isotopologs of gaseous N 2 O ( 44 N 2 O, 45 N 2 O, and 46 N 2 O). N 2 O production was boosted by 15 NH 2 OH spiking, causing exponential increases in mRNA transcription levels of AOB functional genes encoding hydroxylamine oxidoreductase (haoA), nitrite reductase (nirK), and nitric oxide reductase (norB) genes. Predominant production of 45 N 2 O among N 2 O isotopologs (46% of total produced N 2 O) indicated that coupling of 15 NH 2 OH with 14 NO 2 - produced N 2 O via N-nitrosation hybrid reaction as a predominant pathway. Abiotic hybrid N 2 O production was also observed in the absence of the AOB-enriched biomass, indicating multiple pathways for N 2 O production in a PN bioreactor. The additional N 2 O pathway test, where 15 NH 4 + was spiked into 400 mg-N/L of NO 2 - concentration, confirmed that the hybrid N 2 O production was a dominant pathway, accounting for approximately 51% of the total N 2 O production.

  6. Enzymatic Upgrading of Heavy Crudes via Partial Oxidation or Conversion of PAHs

    Energy Technology Data Exchange (ETDEWEB)

    Borole, A P; Davison, B H; Kuritz, T

    2002-07-01

    The objective of this program was to investigate new enzyme-based technologies for upgrading of heavy oils. Enzymes were selected for screening from those capable of conversion of polyaromatic hydrocarbons (PAHs) reported in the literature. Oxidative reactions of PAHs using hydrogen peroxide as an oxidant with conversion to partially oxidized products were used. The enzymes (lignin peroxidase, cytochrome c) were tested in various organic solvents and found to loose activity in pure organic solvents. A thermodynamic analysis revealed lack of effective interaction between the substrate and enzyme as the cause for low activity. The protein cytochrome c was modified to work in organic media by chemical hydrophobic group attachment. Two different modifications were made: attachment of polyethylene glycol (PEG) and alkyl groups. Alkyl groups, being small could be attached at interior locations within the core of the enzyme and possibly near the active site. Increase in the threshold solvent concentration where maximum enzyme activity occurred indicated potential of this strategy for effective enzyme-substrate interaction. Further improvements in enzyme activity called for other diverse methods due to the unavailability of sufficient chemical modification sites. Genetic techniques were therefore explored for further improvements. These experiments focused on cloning of a gene for the fungal enzyme lignin peroxidase (lip) into yeast Pichia pastoris, which would allow easy manipulation of the gene. However, differences in the fungal and yeast cellular machinery impeded significant expression of the fungal enzyme. Several strategies were explored to allow higher-level expression of the enzyme, which was required for enzyme improvement. The strategies used in this investigation are described in the report. Industrial in-kind support was available throughout the project period. review of the research results was carried out on a regular basis (bimonthly reports and annual

  7. Review biodepyritisation of coal

    Energy Technology Data Exchange (ETDEWEB)

    Acharya, C.; Sukla, L.B.; Misra, V.N. [Regional Research Lab., Orissa (India)

    2004-01-01

    This review provides a detailed summary of the recent and past research activities in the area of biodesulfurisation of coal. It provides information about microorganisms important for biodesulfurisation of coal, with the emphasis on Thiobacillus ferrooxidans. The review presents an insight into various methods of desulfurisation of coal combining physical and biological methods. Also, there are discussions on coal structure, distribution, mechanism and kinetics of pyrite oxidation and jarosite precipitation. Finally, areas requiring further research are identified.

  8. Oscillatory Behavior during the Catalytic Partial Oxidation of Methane: Following Dynamic Structural Changes of Palladium Using the QEXAFS Technique

    DEFF Research Database (Denmark)

    Stoetzel, Jan; Frahm, Ronald; Kimmerle, Bertram

    2012-01-01

    oxidation of methane, the catalyst reduced from the end to the beginning of the catalyst bed and oxidized again toward the end as soon as the entire catalyst bed was reduced. On an entirely oxidized catalyst bed, only total oxidation of methane was observed and consumed the oxygen until the conditions...... of the Pd particles at increasing age of the catalyst was observed, which leads to a lower oscillation frequency. Effects of particle size, oven temperature, and oxygen/methane ratio on the oscillation behavior were studied in detail. The deactivation period (reoxidation of Pd) was much less influenced...... by the oven temperature than the ignition behavior of the catalytic partial oxidation of methane. This indicates that deactivation is caused by an autoreduction of the palladium at the beginning of the catalyst bed due to the high temperature achieved by total oxidation of methane....

  9. The application of an isotopic ratio technique to a study of the atmospheric oxidation of sulfur dioxide in the plume from a coal fired power plant

    International Nuclear Information System (INIS)

    Newman, L.; Forrest, J.; Manowitz, B.

    1975-01-01

    The extent of oxidation of sulfur dioxide to sulfate in the plume of a coal fired plant has been studied by using sampling with a single engine aircraft. A technique employing isotopic ratio measurements was utilized in conjunction with simultaneous concentration measurements of sulfur dioxide and sulfate. The use of sulfur hexafluroide as a conservative tracer was explored. The heterogeneous mechanism postulated in an oil fired plume study appears to pertain to the coal fired plume. However, the extent of oxidation seldom exceeded 5% and is limited by the relatively low particulate content of the coal fired plume. Evidence is presented for the apparent dropping out of sulfate from the plume. Implications pertaining to the ambient oxidation of sulfur dioxide are presented. (author)

  10. Development of oxidation heat of the coal left in the mined-out area of a longwall face: Modelling using the fluent software

    Directory of Open Access Journals (Sweden)

    Taraba B.

    2008-01-01

    Full Text Available A commercial CFD software program, Fluent, was used to study oxidation processes in the longwall mined-out (gob area. A three-dimensional model of the gob area with an advancing coal face has been developed. For the model, typical oxidation behavior of a bituminous coal from the Ostrava-Karviná District was incorporated as resulted from laboratory investigations. The longwall gob area was designed on the basis of the actual longwall face district. Detailed measurements in the district then enabled re-verification of the model outputs with actual data in situ. The main attention was paid to modelling the effect of grain size of the coal left in the mined-out area on the oxidation heat and gases evolution. Numerical simulations confirmed the existence of an 'optimal' zone for intense development of the spontaneous heating process in the gob area.

  11. Plasma-assisted partial oxidation of methane at low temperatures: numerical analysis of gas-phase chemical mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Goujard, Valentin; Nozaki, Tomohiro; Yuzawa, Shuhei; Okazaki, Ken [Department of Mechanical and Control Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, 1528552, Tokyo (Japan); Agiral, Anil, E-mail: tnozaki@mech.titech.ac.jp [Mesoscale Chemical Systems, MESA Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, PO Box 217, 7500 AE, Enschede (Netherlands)

    2011-07-13

    Methane partial oxidation was investigated using a plasma microreactor. The experiments were performed at 5 and 300 deg. C. Microreactor configuration allows an efficient evacuation of the heat generated by methane partial oxidation and dielectric barrier discharges, allowing at the same time a better temperature control. At 5 deg. C, liquid condensation of low vapour pressure compounds, such as formaldehyde and methanol, occurs. {sup 1}H-NMR analysis allowed us to demonstrate significant CH{sub 3}OOH formation during plasma-assisted partial oxidation of methane. Conversion and product selectivity were discussed for both temperatures. In the second part of this work, a numerical simulation was performed and a gas-phase chemical mechanism was proposed and discussed. From the comparison between the experimental results and the simulation it was found that CH{sub 3}OO{center_dot} formation has a determinant role in oxygenated compound production, since its fast formation disfavoured radical recombination. At 5 deg. C the oxidation leads mainly towards oxygenated compound formation, and plasma dissociation was the major phenomenon responsible for CH{sub 4} conversion. At 300 deg. C, higher CH{sub 4} conversion resulted from oxidative reactions induced by {center_dot}OH radicals with a chemistry predominantly oxidative, producing CO, H{sub 2}, CO{sub 2} and H{sub 2}O.

  12. Reducing the emissions of nitrogen oxides when burning Kuznetsk bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.

    1983-02-01

    Bituminous coals from the Kuzbass have a high nitrogen content. As a result, emissions of NO/SUB/x from power stations burning these coals frequently exceed the existing Standard. In order to reduce NO/SUB/x emissions tests were carried out using stage-wise combustion, supplying to the burners only part of the air required for complete combustion. The remaining air is supplied via tertiary nozzles situated about 14 m above the burners. As a result of the tests, this method of combustion is recommended for low-sulphur Kuznetsk coals for all sub-critical boilers having dry-bottom furnaces. Extension to boilers with wet-bottom furnaces and to supercritical boilers requires further investigation.

  13. Partial oxidation of TiN coating by hydrothermal treatment and ozone treatment to improve its osteoconductivity

    International Nuclear Information System (INIS)

    Shi, Xingling; Xu, Lingli; Le, Thi Bang; Zhou, Guanghong; Zheng, Chuanbo; Tsuru, Kanji; Ishikawa, Kunio

    2016-01-01

    Dental implants made of pure titanium suffer from abrasion and scratch during routine oral hygiene procedures. This results in an irreversible surface damage, facilitates bacteria adhesion and increases risk of peri-implantitis. To overcome these problems, titanium nitride (TiN) coating was introduced to increase surface hardness of pure titanium. However, the osteoconductivity of TiN is considered to be similar or superior to that of titanium and its alloys and therefore surface modification is necessary. In this study, TiN coating prepared through gas nitriding was partially oxidized by hydrothermal (HT) treatment and ozone (O 3 ) treatment in pure water to improve its osteoconductivity. The effects of HT treatment and O 3 treatment on surface properties of TiN were investigated and the osteoconductivity after undergoing treatment was assessed in vitro using osteoblast evaluation. The results showed that the critical temperature for HT treatment was 100 °C since higher temperatures would impair the hardness of TiN coating. By contrast, O 3 treatment was more effective in oxidizing TiN surfaces, improving its wettability while preserving its morphology and hardness. Osteoblast attachment, proliferation, alkaline phosphatase (ALP) expression and mineralization were improved on oxidized specimens, especially on O 3 treated specimens, compared with untreated ones. These effects seemed to be consequences of partial oxidation, as well as improved hydrophilicity and surface decontamination. Finally, it was concluded that, partially oxidized TiN is a promising coating to be used for dental implant. - Highlights: • TiN coating surface was oxidized by hydrothermal or ozone treatment while preserving its hardness. • Improved wettability, decontamination and interstitial N promoted osteoblast responses. • Partial oxidation makes TiN a promising coating for dental implant with good osteoconductivity.

  14. Partial oxidation of TiN coating by hydrothermal treatment and ozone treatment to improve its osteoconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xingling [School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Department of Biomaterials, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582 (Japan); Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003 (China); Xu, Lingli, E-mail: linly311@163.com [School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Le, Thi Bang [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Zhou, Guanghong [Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003 (China); Zheng, Chuanbo, E-mail: zjust316@163.com [School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Tsuru, Kanji; Ishikawa, Kunio [Department of Biomaterials, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582 (Japan)

    2016-02-01

    Dental implants made of pure titanium suffer from abrasion and scratch during routine oral hygiene procedures. This results in an irreversible surface damage, facilitates bacteria adhesion and increases risk of peri-implantitis. To overcome these problems, titanium nitride (TiN) coating was introduced to increase surface hardness of pure titanium. However, the osteoconductivity of TiN is considered to be similar or superior to that of titanium and its alloys and therefore surface modification is necessary. In this study, TiN coating prepared through gas nitriding was partially oxidized by hydrothermal (HT) treatment and ozone (O{sub 3}) treatment in pure water to improve its osteoconductivity. The effects of HT treatment and O{sub 3} treatment on surface properties of TiN were investigated and the osteoconductivity after undergoing treatment was assessed in vitro using osteoblast evaluation. The results showed that the critical temperature for HT treatment was 100 °C since higher temperatures would impair the hardness of TiN coating. By contrast, O{sub 3} treatment was more effective in oxidizing TiN surfaces, improving its wettability while preserving its morphology and hardness. Osteoblast attachment, proliferation, alkaline phosphatase (ALP) expression and mineralization were improved on oxidized specimens, especially on O{sub 3} treated specimens, compared with untreated ones. These effects seemed to be consequences of partial oxidation, as well as improved hydrophilicity and surface decontamination. Finally, it was concluded that, partially oxidized TiN is a promising coating to be used for dental implant. - Highlights: • TiN coating surface was oxidized by hydrothermal or ozone treatment while preserving its hardness. • Improved wettability, decontamination and interstitial N promoted osteoblast responses. • Partial oxidation makes TiN a promising coating for dental implant with good osteoconductivity.

  15. Development of a membrane-assisted fluidized bed reactor - 2 - Experimental demonstration and modeling for the partial oxidation of methanol

    NARCIS (Netherlands)

    Deshmukh, S.A.R.K.; Laverman, J.A.; van Sint Annaland, M.; Kuipers, J.A.M.

    2005-01-01

    A small laboratory-scale membrane-assisted fluidized bed reactor (MAFBR) was constructed in order to experimentally demonstrate the reactor concept for the partial oxidation of methanol to formaldehyde. Methanol conversion and product selectivities were measured at various overall fluidization

  16. Palm H-FAME Production through Partially Hydrogenation using Nickel/Carbon Catalyst to Increase Oxidation Stability

    Directory of Open Access Journals (Sweden)

    Ramayeni Elsa

    2018-01-01

    Full Text Available One of the methods to improve the oxidation stability of palm biodiesel is through partially hydrogenation. The production using Nickel/Carbon catalyst to speed up the reaction rate. Product is called Palm H-FAME (Hydrogenated FAME. Partial hydrogenation breaks the unsaturated bond on FAME (Fatty Acid Methyl Ester, which is a key component of the determination of oxidative properties. Changes in FAME composition by partial hydrogenation are predicted to change the oxidation stability so it does not cause deposits that can damage the injection system of diesel engine, pump system, and storage tank. Partial hydrogenation is carried out under operating conditions of 120 °C and 6 bar with 100:1, 100:3, 100:5, 100:10 % wt catalyst in the stirred batch autoclave reactor. H-FAME synthesis with 100:5 % wt Ni/C catalyst can decrease the iodine number which is the empirical measure of the number of unsaturated bonds from 91.78 to 82.38 (g-I2/100 g with an increase of oxidation stability from 585 to 602 minutes.

  17. Effect of surface composition of yttrium-stabilized zirconia on partial oxidation of methane to synthesis gas.

    NARCIS (Netherlands)

    Zhu, J.J.; van Ommen, J.G.; Knoester, A.; Lefferts, Leonardus

    2005-01-01

    Catalytic partial oxidation of methane to synthesis gas (CPOM) over yttrium-stabilized zirconia (YSZ) was studied within a wide temperature window (500¿1100 °C). The catalysts were characterized by X-ray fluorescence (XRF) and low-energy ion scattering (LEIS). The influence of calcination

  18. Coal background paper. Coal demand

    International Nuclear Information System (INIS)

    1997-01-01

    Statistical data are presented on coal demands in IEA and OECD member countries and in other countries. Coal coaking and coaking coal consumption data are tabulated, and IEA secretariat's coal demand projections are summarized. Coal supply and production data by countries are given. Finally, coal trade data are presented, broken down for hard coal, steam coal, coking coal (imports and export). (R.P.)

  19. 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

    Energy Technology Data Exchange (ETDEWEB)

    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. [University Extremo Catarinense, Criciuma (Brazil)

    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.

  20. Depolymerization of coal by O2 oxidation followed by acid hydrolysis; Sanso sanka-kasui bunkai ni yoru sekitan no teionkai jugo

    Energy Technology Data Exchange (ETDEWEB)

    Aizawa, S.; Hayashi, J.; Kumagai, H.; Chiba, T. [Hokkaido University, Sapporo (Japan). Center for Advanced Research of Energy Technology; Morooka, S. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

    1996-10-28

    With an objective to elucidate characteristics of oxygen addition to coal, and characteristics of solvent extraction by means of depolymerization, experiments were performed on oxygen oxidation and acid hydrolysis of brown coals. Coals used for the experiments are Morwell (MW), Yallourn (YL) , South Banko (SB) and Wyoming (WY) coals. Test samples were suspended in weak alkaline aqueous solution, and then oxygen was blown into them with pressure kept at atmospheric pressure. After a lapse of a predetermined time, the samples were cooled, and made as acidic as pH 1.3 in hydrochloric acid, followed by acid hydrolysis. Oxygen consumption increased with the reaction time, and with the MW coal, one mol oxygen reacted to 11 mols of coal. Spectral analysis on the YL and WY coal experiments revealed that aliphatic carbon combined with aromatic carbon or ether group has turned to peroxide, whose C-C or C-O bond was broken down as a result of acid hydrolysis of the peroxide, producing oxygen containing compounds. As a result of the depolymerization, the rate of extraction by using DMF, DMSO and methanol/THF mixed solvent increased to 90% or higher. Proportion of bond and cutting-off affects largely collapse of the cross-link structure. The carbon conversion to volatiles was at most 4%. 1 ref., 10 figs.

  1. Exploring the chemical kinetics of partially oxidized intermediates by combining experiments, theory, and kinetic modeling.

    Science.gov (United States)

    Hoyermann, Karlheinz; Mauß, Fabian; Olzmann, Matthias; Welz, Oliver; Zeuch, Thomas

    2017-07-19

    Partially oxidized intermediates play a central role in combustion and atmospheric chemistry. In this perspective, we focus on the chemical kinetics of alkoxy radicals, peroxy radicals, and Criegee intermediates, which are key species in both combustion and atmospheric environments. These reactive intermediates feature a broad spectrum of chemical diversity. Their reactivity is central to our understanding of how volatile organic compounds are degraded in the atmosphere and converted into secondary organic aerosol. Moreover, they sensitively determine ignition timing in internal combustion engines. The intention of this perspective article is to provide the reader with information about the general mechanisms of reactions initiated by addition of atomic and molecular oxygen to alkyl radicals and ozone to alkenes. We will focus on critical branching points in the subsequent reaction mechanisms and discuss them from a consistent point of view. As a first example of our integrated approach, we will show how experiment, theory, and kinetic modeling have been successfully combined in the first infrared detection of Criegee intermediates during the gas phase ozonolysis. As a second example, we will examine the ignition timing of n-heptane/air mixtures at low and intermediate temperatures. Here, we present a reduced, fuel size independent kinetic model of the complex chemistry initiated by peroxy radicals that has been successfully applied to simulate standard n-heptane combustion experiments.

  2. The production of hydrogen through the uncatalyzed partial oxidation of methane in an internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Karim, Ghazi A.; Wierzba, I. [Department of Mechanical and Manufacturing Engineering, Schulich School of Engineering, University of Calgary, Calgary (Canada)

    2008-04-15

    The thermodynamic and kinetic limitations of the uncatalyzed partial oxidation of methane for the production of synthesis gas, which is made up of mostly hydrogen and carbon monoxide in a variety of proportions, are reviewed. It is suggested that such processes can be made to proceed successfully in a conventional internal combustion engine when operated on excessively rich mixtures of methane and oxygenated air. This is achieved while simultaneously producing power and regenerative exhaust gas heating. Experimental results are described that show a dual fuel engine of the compression ignition type with pilot liquid fuel injection can be operated on excessively rich mixtures of methane and air supplemented with oxygen gas to produce hydrogen rich gas with high methane conversion rates. Similarly, a spark ignition engine was reported to be equally capable of such production and performance. It is shown that there are viable prospects for the simultaneous production of synthesis gas in engines with efficient useful mechanical power and exhaust gas regenerative heating. (author)

  3. The syngas production by partial oxidation using a homogeneous charge compression ignition engine

    International Nuclear Information System (INIS)

    Yang, Yoon Cheol; Lim, Mun Sup; Chun, Young Nam

    2009-01-01

    It is essential to develop the environment-friendly alternative energies urgently considering the limited fossil fuel and the global warming caused by environmental destruction. In this research, the new technology was studied to produce syngas from methane or simulated biogas with a HCCI reforming engine. The purpose is to provide the basics for the research on biogas treatment mainly comprising of methane and carbon dioxide, the cause of global warming. This experiment was conducted on the changes in syngas concentration according to the variations of oxygen/methane ratio, total flow rate, intake heating temperature, CO 2 in mixture and oxygen enrichment with partial oxidation. Through the parametric screening studies, optimum conditions and their results in this study was taken as follows; The maximum content of syngas was; 27.4% at 0.3 of oxygen/methane ratio, 32.38% at 117.3 L/min of total flow rate, and 35.83% at 355 C of intake heating temperature. 41.06% of syngas was produced at 50.33% of oxygen enrichment ratio. (author)

  4. Partially reduced graphene oxide based FRET on fiber-optic interferometer for biochemical detection.

    Science.gov (United States)

    Yao, B C; Wu, Y; Yu, C B; He, J R; Rao, Y J; Gong, Y; Fu, F; Chen, Y F; Li, Y R

    2016-03-24

    Fluorescent resonance energy transfer (FRET) with naturally exceptional selectivity is a powerful technique and widely used in chemical and biomedical analysis. However, it is still challenging for conventional FRET to perform as a high sensitivity compact sensor. Here we propose a novel 'FRET on Fiber' concept, in which a partially reduced graphene oxide (prGO) film is deposited on a fiber-optic modal interferometer, acting as both the fluorescent quencher for the FRET and the sensitive cladding for optical phase measurement due to refractive index changes in biochemical detection. The target analytes induced fluorescence recovery with good selectivity and optical phase shift with high sensitivity are measured simultaneously. The functionalized prGO film coated on the fiber-optic interferometer shows high sensitivities for the detections of metal ion, dopamine and single-stranded DNA (ssDNA), with detection limits of 1.2 nM, 1.3 μM and 1 pM, respectively. Such a prGO based 'FRET on fiber' configuration, bridging the FRET and the fiber-optic sensing technology, may serve as a platform for the realization of series of integrated 'FRET on Fiber' sensors for on-line environmental, chemical, and biomedical detection, with excellent compactness, high sensitivity, good selectivity and fast response.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

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

  6. CO{sub 2} separation by calcium looping from full and partial fuel oxidation processes

    Energy Technology Data Exchange (ETDEWEB)

    Sivalingam, Senthoorselvan

    2013-06-05

    This thesis work deals with the research and development of calcium looping process for CO{sub 2} separation from full and partial fuel oxidation based power generation systems. CO{sub 2} is the main greenhouse gas and undoubtedly a major contributor to the global warming. It is estimated that more than one third of the total anthropogenic CO{sub 2} emissions come from fossil fuel based heat and power generation. Moreover, fossil fuels are unlikely to be phased out rapidly, since developing alternative energy sources not only take time but also require huge investments and infrastructure. An alternative way to reduce emissions in a medium term is to capture the CO{sub 2} from fossil fueled power plants and store it away from the atmosphere. This process system combining a bunch of technologies is called carbon capture and storage (CCS). CO{sub 2} capture is an important and costly part of CCS and an array of technologies is considered for this. Calcium looping (CaL) is one of such and seems to offer effective and efficient CO{sub 2} separation from fuel oxidation processes. CaL process involves separation of CO{sub 2} at high temperatures (600-700 C) by calcium sorbents (CaO). CO{sub 2} reacts with CaO in a carbonation process and produces CaCO{sub 3}. In a subsequent thermal regeneration (>850 C) called calcination, the CO{sub 2} is released from CaCO{sub 3}. By alternating carbonations and calcinations over multiple cycles, CO{sub 2} is separated from a gas stream. Moreover, the CaL is realised in industrial scale with dual fluidised bed reactors for CO{sub 2} capture (the carbonator) and sorbent regeneration (the calciner). As a process in the development, research is still required in many aspects from thermodynamic modeling to experimental studies. Research works have been carried out in process simulations, sorbent reactivity and optimisation studies in a controlled reactor environment and process parametric studies in a semi-pilot scale CaL test facility

  7. CO2 separation by calcium looping from full and partial fuel oxidation processes

    International Nuclear Information System (INIS)

    Sivalingam, Senthoorselvan

    2013-01-01

    This thesis work deals with the research and development of calcium looping process for CO 2 separation from full and partial fuel oxidation based power generation systems. CO 2 is the main greenhouse gas and undoubtedly a major contributor to the global warming. It is estimated that more than one third of the total anthropogenic CO 2 emissions come from fossil fuel based heat and power generation. Moreover, fossil fuels are unlikely to be phased out rapidly, since developing alternative energy sources not only take time but also require huge investments and infrastructure. An alternative way to reduce emissions in a medium term is to capture the CO 2 from fossil fueled power plants and store it away from the atmosphere. This process system combining a bunch of technologies is called carbon capture and storage (CCS). CO 2 capture is an important and costly part of CCS and an array of technologies is considered for this. Calcium looping (CaL) is one of such and seems to offer effective and efficient CO 2 separation from fuel oxidation processes. CaL process involves separation of CO 2 at high temperatures (600-700 C) by calcium sorbents (CaO). CO 2 reacts with CaO in a carbonation process and produces CaCO 3 . In a subsequent thermal regeneration (>850 C) called calcination, the CO 2 is released from CaCO 3 . By alternating carbonations and calcinations over multiple cycles, CO 2 is separated from a gas stream. Moreover, the CaL is realised in industrial scale with dual fluidised bed reactors for CO 2 capture (the carbonator) and sorbent regeneration (the calciner). As a process in the development, research is still required in many aspects from thermodynamic modeling to experimental studies. Research works have been carried out in process simulations, sorbent reactivity and optimisation studies in a controlled reactor environment and process parametric studies in a semi-pilot scale CaL test facility. ASPEN Plus power plant simulations integrating the CaL based CO 2

  8. Prevention of formation of acid drainage from high-sulfur coal refuse by inhibition of iron- and sulfur-oxidizing microorganisms. 1. Preliminary experiments in controlled shaken flasks

    Energy Technology Data Exchange (ETDEWEB)

    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 plus 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. 22 references.

  9. Reduction in soil loss from erosion-susceptible soils amended with humic substances from oxidized coal

    International Nuclear Information System (INIS)

    Piccolo, A.; Pietramellara, G.; Mbagwu, J.S.C.

    1997-01-01

    Soils that pose high risk of erosion require amendment with either natural or synthetic soil conditioners to reduce soil loss hazards. The objective of this study was to evaluate the potential of using coal-derived humic substances (as soil conditioners) to reduce runoff erosion on erosion-susceptible soils. Surface samples of severely degraded soils from Principina in Tuscany and Bovolone in Venice in Italy were used to assess the effects of five rates (0, 0.05, 0.01, 0.50 and 1.00 g/kg) of humic acids (HA) on soil loss and other hydrological parameters. The results showed that amending erosion-susceptible soils with low rates of coal-derived humic substances is a potentially effective soil management practice for reducing erosion rates

  10. Fuel saving, carbon dioxide emission avoidance, and syngas production by tri-reforming of flue gases from coal- and gas-fired power stations, and by the carbothermic reduction of iron oxide

    International Nuclear Information System (INIS)

    Halmann, M.; Steinfeld, A.

    2006-01-01

    Flue gases from coal, gas, or oil-fired power stations, as well as from several heavy industries, such as the production of iron, lime and cement, are major anthropogenic sources of global CO 2 emissions. The newly proposed process for syngas production based on the tri-reforming of such flue gases with natural gas could be an important route for CO 2 emission avoidance. In addition, by combining the carbothermic reduction of iron oxide with the partial oxidation of the carbon source, an overall thermoneutral process can be designed for the co-production of iron and syngas rich in CO. Water-gas shift (WGS) of CO to H 2 enables the production of useful syngas. The reaction process heat, or the conditions for thermoneutrality, are derived by thermochemical equilibrium calculations. The thermodynamic constraints are determined for the production of syngas suitable for methanol, hydrogen, or ammonia synthesis. The environmental and economic consequences are assessed for large-scale commercial production of these chemical commodities. Preliminary evaluations with natural gas, coke, or coal as carbon source indicate that such combined processes should be economically competitive, as well as promising significant fuel saving and CO 2 emission avoidance. The production of ammonia in the above processes seems particularly attractive, as it consumes the nitrogen in the flue gases

  11. On the formation of nitrogen oxides during the combustion of partially pre-vaporized droplets

    Energy Technology Data Exchange (ETDEWEB)

    Moesl, Klaus Georg

    2012-12-12

    This study contributes to the topic of nitrogen oxide (NO{sub x}) formation at the level of single droplet and droplet array combustion. The influence of the degree of droplet vaporization and the influence of ambient conditions on NO{sub x} emissions are studied in detail by experiments as well as by numerical simulations. Consequently, this study illustrates correlations and dependencies of the most relevant parameters with respect to the formation of NO{sub x}. It merges the fields of droplet pre-vaporization, ignition, combustion, and exhaust gas formation, including a sophisticated approach to NO{sub x} determination. Even though the study was conducted in order to help understand the fundamental process of burning idealized droplets, the processes in spray combustion have also been taken into consideration within its scope. The portability of results obtained from those idealized droplet burning regimes is evaluated for real applications. Thus, this study may also help to derive design recommendations for liquid-fueled combustion devices. While the experimental part focuses on droplet array combustion, the numerical part highlights spherically symmetric single droplet combustion. By performing experiments in a microgravity environment, quasi-spherical conditions were facilitated for droplet burning, and comparability was provided for the experimental and numerical results. A novelty of the numerical part is the investigation of mechanisms of NO{sub x} formation under technically relevant conditions. This includes partial pre-vaporization of the droplets as well as droplet combustion in a hot exhaust gas environment, such as an aero-engine. The results show that the trade-off between ambient temperature and available oxygen determines the NO{sub x} formation of droplets burning in hot exhaust gas. If the ambient temperature is high and there is still sufficient oxygen for full oxidation of the fuel provided by the droplet, the maximum of NOx formation is

  12. Isotopic evidence for nitrous oxide production pathways in a partial nitritation-anammox reactor.

    Science.gov (United States)

    Harris, Eliza; Joss, Adriano; Emmenegger, Lukas; Kipf, Marco; Wolf, Benjamin; Mohn, Joachim; Wunderlin, Pascal

    2015-10-15

    Nitrous oxide (N2O) production pathways in a single stage, continuously fed partial nitritation-anammox reactor were investigated using online isotopic analysis of offgas N2O with quantum cascade laser absorption spectroscopy (QCLAS). N2O emissions increased when reactor operating conditions were not optimal, for example, high dissolved oxygen concentration. SP measurements indicated that the increase in N2O was due to enhanced nitrifier denitrification, generally related to nitrite build-up in the reactor. The results of this study confirm that process control via online N2O monitoring is an ideal method to detect imbalances in reactor operation and regulate aeration, to ensure optimal reactor conditions and minimise N2O emissions. Under normal operating conditions, the N2O isotopic site preference (SP) was much higher than expected - up to 40‰ - which could not be explained within the current understanding of N2O production pathways. Various targeted experiments were conducted to investigate the characteristics of N2O formation in the reactor. The high SP measurements during both normal operating and experimental conditions could potentially be explained by a number of hypotheses: i) unexpectedly strong heterotrophic N2O reduction, ii) unknown inorganic or anammox-associated N2O production pathway, iii) previous underestimation of SP fractionation during N2O production from NH2OH, or strong variations in SP from this pathway depending on reactor conditions. The second hypothesis - an unknown or incompletely characterised production pathway - was most consistent with results, however the other possibilities cannot be discounted. Further experiments are needed to distinguish between these hypotheses and fully resolve N2O production pathways in PN-anammox systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Optimization geometries of a vortex gliding-arc reactor for partial oxidation of methane

    International Nuclear Information System (INIS)

    Guofeng, Xu; Xinwei, Ding

    2012-01-01

    The effects of the geometry of gliding-arc reactor – such as distance between the electrodes, outlet diameter, and inlet position – on the reactor characteristics (methane conversion, hydrogen yield, and energy efficiency) have not been fully investigated. In this paper, AC gliding-arc reactors including the vortex flow configuration are designed to produce hydrogen from the methane by partial oxidation. The influence of vortex flow configuration on the reactor characteristics is also studied by varying the inlet position. When the inlet of the gliding-arc reactor is positioned close to the outlet, reverse vortex flow reactor (RVFR), the maximum energy efficiency reaches 50% and the yields of hydrogen and carbon monoxide are 40% and 65%, respectively. As the distance between electrodes increases from 5 mm to 15 mm, both hydrogen yield and energy efficiency increase approximately 10% for the RVFR. The energy efficiency and hydrogen yield are highest when the ratio of the outlet diameter to the inner diameter is 0.5 for the RVFR. Experimental results indicate that the flow field in the plasma reactor has an important influence on the reactor performance. Furthermore, hydrogen production increases as the number of feed gas flows in contact with the plasma zone increases. -- Highlights: ► Gliding-arc reactors were designed to produce hydrogen for studying the characteristics of the vortex flow reactor. ► Hydrogen yield of reverse vortex flow reactor was 10% higher than that of forward vortex flow reactor. ► Maximum energy efficiency was 50% for reverse vortex flow reactor. ► If discharge power was supplied to the reactors, the reactor performance increased with increasing distance between electrodes. ► Optimum ratio of the outlet and inner diameter was 1/2.

  14. Coal preparation

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    The acid rain control legislation has prompted the Department of Energy (DOE) to seek new technology using the Clean Coal Technology program solicitation. The main goal of the program is to reduce SO 2 emissions below 9 Mt/a (10 million stpy) and NO x emission below 5.4 Mt/a (6 million stpy) by the year 2000. This would be accomplished by using precombustion, combustion, post combustion and conversion technology. Utilities are considering installing new scrubbers, switching fuel or possibly deep clean. However, the time required to implement the control technology is short. Due to the legislation, about 110 plants will have to adopt one of the approaches. This paper reports that in characterization of coal, Ames Laboratory used a scanning electron microscope- based, automated image analysis (SEM-AIA) technique to identify coal and mineral matter association. Various forms of organic sulfur were identified using peroxyacetic acid oxidation of coal. This was followed by subsequent microscopic, GC-MS, and HRMS analysis by Southern Illinois University. In ultrafine grinding of coal, it was reported by the Mining and Mineral Institute of Alabama that silica sand or flint shot used less energy compared to steel ball mills

  15. Effects of dissolved oxygen and pH on nitrous oxide production rates in autotrophic partial nitrification granules.

    Science.gov (United States)

    Rathnayake, Rathnayake M L D; Oshiki, Mamoru; Ishii, Satoshi; Segawa, Takahiro; Satoh, Hisashi; Okabe, Satoshi

    2015-12-01

    The effects of dissolved oxygen (DO) and pH on nitrous oxide (N2O) production rates and pathways in autotrophic partial nitrification (PN) granules were investigated at the granular level. N2O was primarily produced by betaproteobacterial ammonia-oxidizing bacteria, mainly Nitrosomonas europaea, in the oxic surface layer (production increased with increasing bulk DO concentration owing to activation of the ammonia (i.e., hydroxylamine) oxidation in this layer. The highest N2O emissions were observed at pH 7.5, although the ammonia oxidation rate was unchanged between pH 6.5 and 8.5. Overall, the results of this study suggest that in situ analyses of PN granules are essential to gaining insight into N2O emission mechanisms in a granule. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. The partial pressure of oxygen affects biomarkers of oxidative stress in cultured rainbow trout (Oncorhynchus mykiss) hepatocytes.

    Science.gov (United States)

    Finne, E F; Olsvik, P A; Berntssen, M H G; Hylland, K; Tollefsen, K E

    2008-09-01

    Oxidative stress, the imbalance between production of reactive oxygen species and the cellular detoxification of these reactive compounds, is believed to be involved in the pathology of various diseases. Several biomarkers for oxidative stress have been proposed to serve as tools in toxicological and ecotoxicological research. Not only may exposure to various pro-oxidants create conditions of cellular oxidative stress, but hyperoxic conditions may also increase the production of reactive oxygen species. The objective of the current study was to determine the extent to which differences in oxygen partial pressure would affect biomarkers of oxidative stress in a primary culture of hepatocytes from rainbow trout (Oncorhynchus mykiss). Membrane integrity, metabolic activity, levels of total and oxidized glutathione (tGSH/GSSG) was determined, as well as mRNA expression levels of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R), gamma-glutamyl-cystein synthetase (GCS) and thioredoxin (TRX). The results show that different biomarkers of oxidative stress are affected when the cell culture is exposed to atmospheric oxygen, and that changes such as increased GSSG content and induction of GSSG-R and GSH-Px can be reduced by culturing the cells under lower oxygen tension. Oxygen tension may thus influence results of in vitro based cell research and is particularly important when assessing parameters in the antioxidant defence system. Further research is needed to establish the magnitude of this effect in different cellular systems.

  17. Direct Synthesis of Methanol by Partial Oxidation of Methane with Oxygen over Cobalt Modified Mesoporous H-ZSM-5 Catalyst

    Directory of Open Access Journals (Sweden)

    Yuni Krisyuningsih Krisnandi

    2015-11-01

    Full Text Available Partial oxidation of methane over mesoporous catalyst cobalt modified H-ZSM-5 has been carried out. Mesoporous Na-ZSM-5 (Si/Al = 35.4 was successfully synthesized using double template method which has high surface area (450 m2/g and average pore diameter distribution of 1.9 nm. The as-synthesized Na-ZSM-5 was converted to H-ZSM-5 through multi-exchange treatment with ammonium ion solution, causing decreased crystallinity and surface area, but increased porous diameter, due to dealumination during treatment process. Moreover, H-ZSM-5 was loaded with cobalt (Co = 2.5% w by the incipient impregnation method and calcined at 550 °C. Partial oxidation of methane was performed in the batch reactor with 0.75 bar methane and 2 bar of nitrogen (with impurities of 0.5% oxygen as the input at various reaction time (30, 60 and 120 min. The reaction results show that cobalt species in catalyst has an important role, because H-ZSM-5 cannot produce methanol in partial oxidation of methane. The presence of molecular oxygen increased the percentage of methanol yield. The reaction is time-dependent with the highest methanol yield (79% was acquired using Co/H-ZSM-5 catalyst for 60 min.

  18. Nitrous oxide emissions from a coal mine land reclaimed with stabilized manure

    Science.gov (United States)

    Mined land restoration using manure-based amendments may create soil conditions suitable for nitrous oxide production and emission. We measured nitrous oxide emissions from mine soil amended with composted poultry manure (Comp) or poultry manure mixed with paper mill sludge (Man+PMS) at C/N ratios o...

  19. Coal comes clean

    International Nuclear Information System (INIS)

    Minchener, A.

    1991-01-01

    Coal's status as the dominant fuel for electricity generation is under threat because of concern over the environmental impacts of acid rain and the greenhouse effect. Sulphur dioxide and nitrogen oxides cause acid rain and carbon dioxide is the main greenhouse gas. All are produced when coal is burnt. Governments are therefore tightening the emission limits for fossil-fuel power plants. In the United Kingdom phased reductions of sulphur dioxide and nitrogen oxides emissions are planned. It will be the responsibility of the power generator to take the necessary steps to reduce the emissions. This will be done using a number of technologies which are explained and outlined briefly - flue gas desulfurization, separation of coal into high and low-sulphur coal, direct desulfurization of coal, circulating fluidised bed combustion, integrated-gasification combined cycle systems and topping cycles. All these technologies are aiming at cleaner, more efficient combustion of coal. (UK)

  20. Clean coal technologies

    International Nuclear Information System (INIS)

    Bourillon, C.

    1994-01-01

    In 1993 more than 3.4 billion tonnes of coal was produced, of which half was used to generate over 44 per cent of the world's electricity. The use of coal - and of other fossil fuels- presents several environmental problems such as emissions of sulphur dioxide (SO 2 ), nitrogen oxides (NO 2 ), and carbon dioxide (CO 2 ) into the atmosphere. This article reviews the measures now available to mitigate the environmental impacts of coal. (author)

  1. Colour and toxic characteristics of metakaolinite-hematite pigment for integrally coloured concrete, prepared from iron oxide recovered from a water treatment plant of an abandoned coal mine

    Science.gov (United States)

    Sadasivam, Sivachidambaram; Thomas, Hywel Rhys

    2016-07-01

    A metakaolinite-hematite (KH) red pigment was prepared using an ocherous iron oxide sludge recovered from a water treatment plant of an abandoned coal mine. The KH pigment was prepared by heating the kaolinite and the iron oxide sludge at kaolinite's dehydroxylation temperature. Both the raw sludge and the KH specimen were characterised for their colour properties and toxic characteristics. The KH specimen could serve as a pigment for integrally coloured concrete and offers a potential use for the large volumes of the iron oxide sludge collected from mine water treatment plants.

  2. A comparison of spontaneous combustion susceptibility of coal from ...

    African Journals Online (AJOL)

    Although the CPT of Onyeama coal and Owukpa coal is identical to each other as they are the sub-bituminous, Owukpa coal has a lower initial oxidation temperature (IOT) and maximum oxidation temperature (MOT) than those of Onyeama coal. This means that although each coal has the same rank and CPT, spontaneous ...

  3. Regenerable cobalt oxide loaded magnetosphere catalyst from fly ash for mercury removal in coal combustion flue gas.

    Science.gov (United States)

    Yang, Jianping; Zhao, Yongchun; Zhang, Junying; Zheng, Chuguang

    2014-12-16

    To remove Hg(0) in coal combustion flue gas and eliminate secondary mercury pollution of the spent catalyst, a new regenerable magnetic catalyst based on cobalt oxide loaded magnetospheres from fly ash (Co-MF) was developed. The catalyst, with an optimal loading of 5.8% cobalt species, attained approximately 95% Hg(0) removal efficiency at 150 °C under simulated flue gas atmosphere. O2 could enhance the Hg(0) removal activity of magnetospheres catalyst via the Mars-Maessen mechanism. SO2 displayed an inhibitive effect on Hg(0) removal capacity. NO with lower concentration could promote the Hg(0) removal efficiency. However, when increasing the NO concentration to 300 ppm, a slightly inhibitive effect of NO was observed. In the presence of 10 ppm of HCl, greater than 95.5% Hg(0) removal efficiency was attained, which was attributed to the formation of active chlorine species on the surface. H2O presented a seriously inhibitive effect on Hg(0) removal efficiency. Repeated oxidation-regeneration cycles demonstrated that the spent Co-MF catalyst could be regenerated effectively via thermally treated at 400 °C for 2 h.

  4. A novel partial SOI LDMOSFET with periodic buried oxide for breakdown voltage and self heating effect enhancement

    Science.gov (United States)

    Jamali Mahabadi, S. E.; Rajabi, Saba; Loiacono, Julian

    2015-09-01

    In this paper a partial silicon on insulator (PSOI) lateral double diffused metal oxide semiconductor field effect transistor (LDMOSFET) with periodic buried oxide layer (PBO) for enhancing breakdown voltage (BV) and self-heating effects (SHEs) is proposed for the first time. This new structure is called periodic buried oxide partial silicon on insulator (PBO-PSOI). In this structure, periodic small pieces of SiO2 were used as the buried oxide (BOX) layer in PSOI to modulate the electric field in the structure. It was demonstrated that the electric field is distributed more evenly by producing additional electric field peaks, which decrease the common peaks near the drain and gate junctions in the PBO-PSOI structure. Hence, the area underneath the electric field curve increases which leads to higher breakdown voltage. Also a p-type Si window was introduced in the source side to force the substrate to share the vertical voltage drop, leading to a higher vertical BV. Furthermore, the Si window under the source and those between periodic pieces of SiO2 create parallel conduction paths between the active layer and substrate thereby alleviating the SHEs. Simulations with the two dimensional ATLAS device simulator from the Silvaco suite of simulation tools show that the BV of PBO-PSOI is 100% higher than that of the conventional partial SOI (C-PSOI) structure. Furthermore the PBO-PSOI structure alleviates SHEs to a greater extent than its C-PSOI counterpart. The achieved drain current for the PBO-PSOI structure (100 μA), at drain-source voltage of VDS = 100 V and gate-source voltage of VGS = 25 V, is shown to be significantly larger than that in C-PSOI and fully depleted SOI (FD-SOI) structures (87 μA and 51 μA respectively). Drain current can be further improved at the expense of BV by increasing the doping of the drift region.

  5. Coal geopolitics

    International Nuclear Information System (INIS)

    Giraud, P.N.; Suissa, A.; Coiffard, J.; Cretin, D.

    1991-01-01

    This book divided into seven chapters, describes coal economic cycle. Chapter one: coals definition; the principle characteristics and properties (origin, calorific power, international classification...) Chapter two: the international coal cycle: coal mining, exploration, coal reserves estimation, coal handling coal industry and environmental impacts. Chapter three: the world coal reserves. Chapter four: the consumptions, productions and trade. Chapter five: the international coal market (exporting mining companies; importing companies; distributors and spot market operators) chapter six: the international coal trade chapter seven: the coal price formation. 234 refs.; 94 figs. and tabs [fr

  6. Integrated removal of NO and mercury from coal combustion flue gas using manganese oxides supported on TiO2.

    Science.gov (United States)

    Zhang, Shibo; Zhao, Yongchun; Wang, Zonghua; Zhang, Junying; Wang, Lulu; Zheng, Chuguang

    2017-03-01

    A catalyst composed of manganese oxides supported on titania (MnO x /TiO 2 ) synthesized by a sol-gel method was selected to remove nitric oxide and mercury jointly at a relatively low temperature in simulated flue gas from coal-fired power plants. The physico-chemical characteristics of catalysts were investigated by X-ray fluorescence (XRF), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses, etc. The effects of Mn loading, reaction temperature and individual flue gas components on denitration and Hg 0 removal were examined. The results indicated that the optimal Mn/Ti molar ratio was 0.8 and the best working temperature was 240°C for NO conversion. O 2 and a proper ratio of [NH 3 ]/[NO] are essential for the denitration reaction. Both NO conversion and Hg 0 removal efficiency could reach more than 80% when NO and Hg 0 were removed simultaneously using Mn0.8Ti at 240°C. Hg 0 removal efficiency slightly declined as the Mn content increased in the catalysts. The reaction temperature had no significant effect on Hg 0 removal efficiency. O 2 and HCl had a promotional effect on Hg 0 removal. SO 2 and NH 3 were observed to weaken Hg 0 removal because of competitive adsorption. NO first facilitated Hg 0 removal and then had an inhibiting effect as NO concentration increased without O 2 , and it exhibited weak inhibition of Hg 0 removal efficiency in the presence of O 2 . The oxidation of Hg 0 on MnO x /TiO 2 follows the Mars-Maessen and Langmuir-Hinshelwood mechanisms. Copyright © 2016. Published by Elsevier B.V.

  7. Innovative Clean Coal Technology (ICCT): 180 MW demonstration of advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Topical report, LNCFS Levels 1 and 3 test results

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-17

    This report presents results from the third phase of an Innovative Clean Coal Technology (ICC-1) project demonstrating advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from a coal-fired boiler. The purpose of this project was to study the NO{sub x} emissions characteristics of ABB Combustion Engineering`s (ABB CE) Low NO{sub x} Concentric Firing System (LNCFS) Levels I, II, and III. These technologies were installed and tested in a stepwise fashion at Gulf Power Company`s Plant Lansing Smith Unit 2. The objective of this report is to provide the results from Phase III. During that phase, Levels I and III of the ABB C-E Services Low NO{sub x} Concentric Firing System were tested. The LNCFS Level III technology includes separated overfire air, close coupled overfire air, clustered coal nozzles, flame attachment coal nozzle tips, and concentric firing. The LNCFS Level I was simulated by closing the separated overfire air nozzles of the LNCFS Level III system. Based upon long-term data, LNCFS Level HI reduced NO{sub x} emissions by 45 percent at full load. LOI levels with LNCFS Level III increased slightly, however, tests showed that LOI levels with LNCFS Level III were highly dependent upon coal fineness. After correcting for leakage air through the separated overfire air system, the simulated LNCFS Level I reduced NO{sub x} emissions by 37 percent. There was no increase in LOI with LNCFS Level I.

  8. Development of Nanofiller-Modulated Polymeric Oxygen Enrichment Membranes for Reduction of Nitrogen Oxides in Coal Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Jianzhong Lou; Shamsuddin Ilias

    2010-12-31

    North Carolina A&T State University in Greensboro, North Carolina, has undertaken this project to develop the knowledge and the material to improve the oxygen-enrichment polymer membrane, in order to provide high-grade oxygen-enriched streams for coal combustion and gasification applications. Both experimental and theoretical approaches were used in this project. The membranes evaluated thus far include single-walled carbon nano-tube, nano-fumed silica polydimethylsiloxane (PDMS), and zeolite-modulated polyimide membranes. To document the nanofiller-modulated polymer, molecular dynamics simulations have been conducted to calculate the theoretical oxygen molecular diffusion coefficient and nitrogen molecular coefficient inside single-walled carbon nano-tube PDMS membranes, in order to predict the effect of the nano-tubes on the gas-separation permeability. The team has performed permeation and diffusion experiments using polymers with nano-silica particles, nano-tubes, and zeolites as fillers; studied the influence of nano-fillers on the self diffusion, free volume, glass transition, oxygen diffusion and solubility, and perm-selectivity of oxygen in polymer membranes; developed molecular models of single-walled carbon nano-tube and nano-fumed silica PDMS membranes, and zeolites-modulated polyimide membranes. This project partially supported three graduate students (two finished degrees and one transferred to other institution). This project has resulted in two journal publications and additional publications will be prepared in the near future.

  9. Potential hydrogen and oxygen partial pressures in legacy plutonium oxide packages at Oak Ridge

    Energy Technology Data Exchange (ETDEWEB)

    Veirs, Douglas K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-07-07

    An approach to estimate the maximum hydrogen and oxygen partial pressures within sealed containers is described and applied to a set of packages containing high-purity plutonium dioxide. The approach uses experimentally determined maximum hydrogen and oxygen partial pressures and scales the experimentally determined pressures to the relevant packaged material properties. The important material properties are the specific wattage and specific surface area (SSA). Important results from the experimental determination of maximum partial pressures are (1) the ratio of hydrogen to oxygen is stoichiometric, and (2) the maximum pressures increase with increasing initial rates of production. The material properties that influence the rates are the material specific wattage and the SSA. The unusual properties of these materials, high specific wattage and high SSA, result in higher predicted maximum pressures than typical plutonium dioxide in storage. The pressures are well within the deflagration range for mixtures of hydrogen and oxygen.

  10. Linking organic carbon, water content and nitrous oxide emission in a reclaimed coal mine soil

    Science.gov (United States)

    Manure-based organic amendments can restore soil quality and allow for intensive sustained biomass production on degraded lands. However the large quantities of nitrogen and organic carbon added with such amendments could create soil conditions favorable for nitrous oxide production and emissions. T...

  11. Unburnt carbon from coal fly ashes as a precursor of activated carbon for nitric oxide removal.

    Science.gov (United States)

    Rubio, Begoña; Izquierdo, M Teresa; Mayoral, M Carmen; Bona, M Teresa; Andres, Jose M

    2007-05-08

    The aim of this work is to evaluate the characteristics of an activated carbon obtained from unburnt carbon in coal fly ashes to be used in the removal of NO. Carbon-rich fraction was obtained by mechanical sieving of fly ashes. The mineral matter was removed by conventional HCl and HF demineralization procedure. Activation was carried out with steam at 900 degrees C in order to develop porosity onto the sample. Characterization of samples was performed by several techniques with a main objective: to follow the mineral matter content, composition and distribution on the samples in order to better understand how to remove it from unburnt carbon in fly ashes. To study the use of this unburnt carbon as a precursor for the preparation of activated carbons for gas cleaning, the NO removal by ammonia using activated carbon as a catalyst at low temperature was performed. Results show a good performance of activated carbon in this reaction that is in relationship with BET surface area.

  12. 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

    International Nuclear Information System (INIS)

    Sadasivam, Sivachidambaram; Thomas, Hywel Rhys

    2016-01-01

    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. - 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.

  13. Oscillatory behaviour of catalytic properties, structure and temperature during the catalytic partial oxidation of methane on Pd/Al2O3

    DEFF Research Database (Denmark)

    Kimmerle, B.; Baiker, A.; Grunwaldt, Jan-Dierk

    2010-01-01

    Pd/Al2O3 catalysts showed an oscillatory behaviour during the catalytic partial oxidation (CPO) of methane, which was investigated simultaneously by IR-thermography, X-ray absorption spectroscopy, and online mass-spectrometry to correlate the temperature, state of the catalyst and catalytic...... to self-reduction leading to extinction of the process. The latter was the key driver for the oscillations and thus gave additional insight into the mechanism of partial methane oxidation....

  14. Carbon-coated magnetic palladium: applications in partial oxidation of alcohols and coupling reactions.

    Science.gov (United States)

    Magnetic carbon supported Pd catalyst has been synthesized via in situ generation of nanoferrites and incorporation of carbon from renewable cellulose via calcination; catalyst can be used for oxidation of alcohols, amination reaction and arylation of aryl halides (cross coupli...

  15. In situ photoemission spectroscopy using synchrotron radiation for O2 translational kinetic energy induced oxidation processes of partially-oxidized Si(001) surfaces

    International Nuclear Information System (INIS)

    Teraoka, Yuden; Yoshigoe, Akitaka

    2001-01-01

    The influence of translational kinetic energy of incident O 2 molecules for the passive oxidation process of partially-oxidized Si(001) surfaces has been studied by photoemission spectroscopy. The translational kinetic energy of O 2 molecules was controlled up to 3 eV by a supersonic seed beam technique using a high temperature nozzle. Two translational kinetic energy thresholds (1.0 eV and 2.6 eV) were found out in accordance with the first-principles calculation for the oxidation of clean surfaces. Si-2p photoemission spectra measured in representative translational kinetic energies revealed that the translational kinetic energy dependent oxidation of dimers and the second layer (subsurface) backbonds were caused by the direct dissociative chemisorption of O 2 molecules. Moreover, the difference in chemical bonds for oxygen atoms was found out to be as low and high binding energy components in O-1s photoemission spectra. Especially, the low binding energy component increased with increasing the translational kinetic energy that indicates the translational kinetic energy induced oxidation in backbonds. (author)

  16. Partial oxidation of dimethyl ether using the structured catalyst Rh/Al2O3/Al prepared through the anodic oxidation of aluminum.

    Science.gov (United States)

    Yu, B Y; Lee, K H; Kim, K; Byun, D J; Ha, H P; Byun, J Y

    2011-07-01

    The partial oxidation of dimethyl ether (DME) was investigated using the structured catalyst Rh/Al2O3/Al. The porous Al2O3 layer was synthesized on the aluminum plate through anodic oxidation in an oxalic-acid solution. It was observed that about 20 nm nanopores were well developed in the Al2O3 layer. The thickness of Al2O3 layer can be adjusted by controlling the anodizing time and current density. After pore-widening and hot-water treatment, the Al2O3/Al plate was calcined at 500 degrees C for 3 h. The obtained delta-Al2O3 had a specific surface area of 160 m2/g, making it fit to be used as a catalyst support. A microchannel reactor was designed and fabricated to evaluate the catalytic activity of Rh/Al2O3/Al in the partial oxidation of DME. The structured catalyst showed an 86% maximum hydrogen yield at 450 degrees C. On the other hand, the maximum syngas yield by a pack-bed-type catalyst could be attained by using a more than fivefold Rh amount compared to that used in the structured Rh/Al2O3/Al catalyst.

  17. Strategies for catalyst development: possibilities of the ``rational approach`` illustrated with partial oxidation reactions

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, W.; Schedel-Niedrig, T.; Schloegl, R. [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin (Germany). Abt. Oberflaechenphysik

    1998-12-31

    The paper discusses two petrochemical selective oxidation reactions namely the practised formation of styrene (STY) and the desired oxidative functionalisation of propane. The present knowledge about the mode of operation of oxide catalysts is critically considered. The dehydrogenation of ethylbenzene (EB) should be described by an oxidehydration with water acting as oxidant. The potential role of the coke formed during catalytic reaction as co-catalyst will be discussed. Selective oxidation is connected with the participation of lattice oxygen mechanism which transforms unselective gas phase oxygen into selective oxygen. The atomistic description of this process is still quite unclear as well as the electron structural properties of the activated oxygen atom. The Role of solid state acidity as compared to the role of lattice oxygen is much less well investigated modern multiphase-multielement oxide (MMO) catalysts. The rationale is that the significant efforts made to improve current MMO systems by chemical modifications can be very much more fruitful when in a first step the mode of action of a catalyst is clarified on the basis of suitable experiments. Such time-consuming experiments at the beginning of a campaign for catalyst improvement pay back their investment in later stages of the project when strategies of chemical development can be derived on grounds of understanding. (orig.)

  18. Sustainable development with clean coal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-08-01

    This paper discusses the opportunities available with clean coal technologies. Applications include new power plants, retrofitting and repowering of existing power plants, steelmaking, cement making, paper manufacturing, cogeneration facilities, and district heating plants. An appendix describes the clean coal technologies. These include coal preparation (physical cleaning, low-rank upgrading, bituminous coal preparation); combustion technologies (fluidized-bed combustion and NOx control); post-combustion cleaning (particulate control, sulfur dioxide control, nitrogen oxide control); and conversion with the integrated gasification combined cycle.

  19. Characteristic analysis of methane-gas generation by oxidizing heat of stored coal and hold ventilation control; Sekitan unpansen ni okeru sanka hatsunetsu ni yoru methane gas hassei to sonai kankyo seigyo ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Fukuchi, N; Nakashima, T [Kyushu Univ., Fukuoka (Japan); Kudo, S

    1999-12-31

    A demand of coal shows the tendency in the increase worldwide, with this, the marine transportation of the coal gradually increases, and the collier has also enlarged. The traffic pattern of coal is mainly the bulk transportation. In this transportation system, by the oxidation exothermic reaction of the coal, methane gas is produced, simultaneously the coal quality such as coking property or heat quantity is decreased and sometimes spontaneous ignition is caused. Therefore, it is necessary to equip with a ventilator to control the concentration of methane gas and to avoid the self heating of the coal. In this study, the quantity of methane-gas produced by heating coal using an electric furnace was measured and the experiment to investigate the temperature dependency of the methane-gas generated from the coal was conducted. By using the result of the measurement, the quantity of methane-gas produced from the coal stored in the hold of a coal cargo was estimated. And, the mathematical analyses on the changing degree depend on the times of a temperature in the hold under navigation, a concentration of oxygen and a concentration of methane-gas, were conducted. 11 refs., 19 figs., 2 tabs.

  20. Coal gasification and the power production market

    International Nuclear Information System (INIS)

    Howington, K.; Flandermeyer, G.

    1995-01-01

    The US electric power production market is experiencing significant changes sparking interest in the current and future alternatives for power production. Coal gasification technology is being marketed to satisfy the needs of the volatile power production industry. Coal gasification is a promising power production process in which solid coal is burned to produce a synthesis gas (syn gas). The syn gas may be used to fuel combustion integrated into a facility producing electric power. Advantages of this technology include efficient power production, low flue gas emissions, flexible fuel utilization, broad capability for facility integration, useful process byproducts, and decreased waste disposal. The primary disadvantages are relatively high capital costs and lack of proven long-term operating experience. Developers of coal gasification intend to improve on these disadvantages and lop a strong position in the power generation market. This paper is a marketing analysis of the partial oxidation coal gasification processes emerging in the US in response to the market factors of the power production industry. A brief history of these processes is presented, including the results of recent projects exploring the feasibility of integrated gasification combined cycle (IGCC) as a power production alternative. The current power generation market factors are discussed, and the status of current projects is presented including projected performance

  1. Process for hydrogenating coal and coal solvents

    Energy Technology Data Exchange (ETDEWEB)

    Shridharani, K.G.; Tarrer, A.R.

    1983-02-15

    A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260/sup 0/ C to 315/sup 0/ C in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275/sup 0/ C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350/sup 0/ C.

  2. Process for hydrogenating coal and coal solvents

    Science.gov (United States)

    Tarrer, Arthur R.; Shridharani, Ketan G.

    1983-01-01

    A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260.degree. C. to 315.degree. C. in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275.degree. C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350.degree. C.

  3. Heavy metals in wild house mice from coal-mining areas of Colombia and expression of genes related to oxidative stress, DNA damage and exposure to metals.

    Science.gov (United States)

    Guerrero-Castilla, Angélica; Olivero-Verbel, Jesús; Marrugo-Negrete, José

    2014-03-01

    Coal mining is a source of pollutants that impact on environmental and human health. This study examined the metal content and the transcriptional status of gene markers associated with oxidative stress, metal transport and DNA damage in livers of feral mice collected near coal-mining operations, in comparison with mice obtained from a reference site. Mus musculus specimens were caught from La Loma and La Jagua, two coal-mining sites in the north of Colombia, as well as from Valledupar (Cesar Department), a city located 100km north of the mines. Concentrations in liver tissue of Hg, Zn, Pb, Cd, Cu and As were determined by differential stripping voltammetry, and real-time PCR was used to measure gene expression. Compared with the reference group (Valledupar), hepatic concentrations of Cd, Cu and Zn were significantly higher in animals living near mining areas. In exposed animals, the mRNA expression of NQ01, MT1, SOD1, MT2, and DDIT3 was 4.2-, 7.3-, 2.5-, 4.6- and 3.4-fold greater in coal mining sites, respectively, than in animals from the reference site (pmining may generate pollutants that could affect the biota, inducing the transcription of biochemical markers related to oxidative stress, metal exposure, and DNA damage. These changes may be in part linked to metal toxicity, and could have implications for the development of chronic disease. Therefore, it is essential to implement preventive measures to minimize the effects of coal mining on its nearby environment, in order to protect human health. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Effect of various coal contaminants on the performance of solid oxide fuel cells: Part I. Accelerated testing

    Energy Technology Data Exchange (ETDEWEB)

    Bao, JianEr; Krishnan, Gopala N.; Jayaweera, Palitha; Perez-Mariano, Jordi; Sanjurjo, Angel [SRI International, 333 Ravenswood Ave, Menlo Park, CA 94025 (United States)

    2009-09-05

    The contaminants that are potentially present in the coal-derived gas stream and their thermochemical nature are discussed. Accelerated testing was carried out on Ni-YSZ/YSZ/LSM solid oxide fuel cells (YSZ: yttria stabilized zirconia and LSM: lanthanum strontium manganese oxide) for eight main kind of contaminants: CH{sub 3}Cl, HCl, As, P, Zn, Hg, Cd and Sb at the temperature range of 750-850 C. The As and P species, at 10 and 35 ppm, respectively, resulted in severe power density degradation at temperatures 800 C and below. SEM and EDX analysis indicated that As attacked the Ni region of the anode surface and the Ni current collector, caused the break of the current collector and the eventual cell failure at 800 C. The phosphorous containing species were found in the bulk of the anode, they were segregated and formed ''grain boundary'' like phases separating large Ni patches. These species are presumably nickel phosphide/phosphate and zirconia phosphate, which could break the Ni network for electron transport and inhibit the YSZ network for oxygen ion transport. The presence of 40 ppm CH{sub 3}Cl and 5 ppm Cd only affected the cell power density at above 800 C and Cd caused significant performance loss. Whereas the presence of 9 ppm Zn, 7 ppm Hg and 8 ppm Sb only degraded the cell power density by less than 1% during the 100 h test in the temperature range of 750-850 C. (author)

  5. Measurement and modeling of advanced coal conversion processes, Volume III

    Energy Technology Data Exchange (ETDEWEB)

    Ghani, M.U.; Hobbs, M.L.; Hamblen, D.G. [and others

    1993-08-01

    A generalized one-dimensional, heterogeneous, steady-state, fixed-bed model for coal gasification and combustion is presented. The model, FBED-1, is a design and analysis tool that can be used to simulate a variety of gasification, devolatilization, and combustion processes. The model considers separate gas and solid temperatures, axially variable solid and gas flow rates, variable bed void fraction, coal drying, devolatilization based on chemical functional group composition, depolymerization, vaporization and crosslinking, oxidation, and gasification of char, and partial equilibrium in the gas phase.

  6. Borax partially prevents neurologic disability and oxidative stress in experimental spinal cord ischemia/reperfusion injury.

    Science.gov (United States)

    Koc, Emine Rabia; Gökce, Emre Cemal; Sönmez, Mehmet Akif; Namuslu, Mehmet; Gökce, Aysun; Bodur, A Said

    2015-01-01

    The aim of this study is to investigate the potential effects of borax on ischemia/reperfusion injury of the rat spinal cord. Twenty-one Wistar albino rats were divided into 3 groups: sham (no ischemia/reperfusion), ischemia/reperfusion, and borax (ischemia/reperfusion + borax); each group was consist of 7 animals. Infrarenal aortic cross clamp was applied for 30 minutes to generate spinal cord ischemia. Animals were evaluated functionally with the Basso, Beattie, and Bresnahan scoring system and inclined-plane test. The spinal cord tissue samples were harvested to analyze tissue concentrations of nitric oxide, nitric oxide synthase activity, xanthine oxidase activity, total antioxidant capacity, and total oxidant status and to perform histopathological examination. At the 72nd hour after ischemia, the borax group had significantly higher Basso, Beattie, and Bresnahan and inclined-plane scores than those of ischemia/reperfusion group. Histopathological examination of spinal cord tissues in borax group showed that treatment with borax significantly reduced the degree of spinal cord edema, inflammation, and tissue injury disclosed by light microscopy. Xanthine oxidase activity and total oxidant status levels of the ischemia/reperfusion group were significantly higher than those of the sham and borax groups (P borax group were significantly higher than those of the ischemia/reperfusion group (P borax groups in terms of total antioxidant capacity levels (P > .05). The nitric oxide levels and nitric oxide synthase activity of all groups were similar (P > .05). Borax treatment seems to protect the spinal cord against injury in a rat ischemia/reperfusion model and improve neurological outcome. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  7. Nitrous oxide production in intermittently aerated Partial Nitritation-Anammox reactor: oxic N2O production dominates and relates with ammonia removal rate

    DEFF Research Database (Denmark)

    Blum, Jan-Michael; Jensen, Marlene Mark; Smets, Barth F.

    2018-01-01

    Emissions of the greenhouse gas nitrous oxide from the Partial Nitritation-Anammox process are of concern and can determine the carbon footprint of the process. In order to reduce nitrous oxide emissions intermittent aeration regimes have been shown to be a promising mode of operation, possibly due...

  8. Characteristics of hydrogen produced by partial oxidation and auto-thermal reforming in a small methanol reformer

    Science.gov (United States)

    Horng, Rong-Fang; Chou, Huann-Ming; Lee, Chiou-Hwang; Tsai, Hsien-Te

    This paper investigates experimentally, the transient characteristics of a small methanol reformer using partial oxidation (POX) and auto-thermal reforming (ATR) for fuel cell applications. The parameters varied were heating temperature, methanol supply rate, steady mode shifting temperature, O 2/C (O 2/CH 3OH) and S/C (H 2O/CH 3OH) molar ratios with the main aim of promoting a rapid response and a high flow rate of hydrogen. The experiments showed that a high steady mode shifting temperature resulted in a faster temperature rise at the catalyst outlet and vice versa and that a low steady mode shifting temperature resulted in a lower final hydrogen concentration. However, when the mode shifting temperature was too high, the hydrogen production response was not necessarily improved. It was subsequently shown that the optimum steady mode shifting temperature for this experimental set-up was approximately 75 °C. Further, the hydrogen concentration produced by the auto-thermal process was as high as 49.12% and the volume flow rate up to 23.0 L min -1 compared to 40.0% and 20.5 L min -1 produced by partial oxidation.

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

    Science.gov (United States)

    Berry, Mark Simpson

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

  10. Oxidation of X20 in Water Vapour: The Effect of Temperature and Oxygen Partial Pressure

    DEFF Research Database (Denmark)

    Hansson, Anette Nørgaard; Montgomery, Melanie; Somers, Marcel A. J.

    2009-01-01

    The oxidation behaviour of X20 in various mixtures of water, oxygen and hydrogen was investigated at temperatures between 500 C and 700 C (time: 336 h). The samples were characterised using reflected light microscopy and scanning electron microscopy equipped with energy dispersive spectroscopy...

  11. Catalytic ring-​opening copolymerization of limonene oxide and phthalic anhydride : toward partially renewable polyesters

    NARCIS (Netherlands)

    Hosseini Nejad, E.; Pionasari, A; Melis, van C.G.W.; Koning, C.E.; Duchateau, R.

    2013-01-01

    Catalytic ring-¿opening copolymn. of limonene oxide with phthalic anhydride was performed applying metal t-¿Bu-¿salophen complexes (t-¿Bu-¿salophen)¿MX; M = Cr, X = Cl (1)¿, M = Al, X = Cl (2)¿, M = Co, X = OAc (3)¿, M = Mn, X = Cl (4)¿, t-¿Bu-¿salophen =

  12. Catalysis by Atomic-Sized Centers: Methane Activation for Partial Oxidation and Combustion

    Science.gov (United States)

    2015-07-21

    example, H adsorbed alone on an oxide surface will bind to oxygen to form a hydroxide . However, if a Lewis base (e.g. any electron donor) is...that on a gold surface, which is not surprising considering the bonding character between the cluster and metal surfaces. The high mobility verifies

  13. Oxidation behavior of V-Cr-Ti alloys in low-partial-pressure oxygen environments

    International Nuclear Information System (INIS)

    Natesan, K.; Uz, M.

    1998-01-01

    A test program is in progress at Argonne National Laboratory to evaluate the effect of pO 2 in the exposure environment on oxygen uptake, scaling kinetics, and scale microstructure in V-Cr-Ti alloys. The data indicate that the oxidation process follows parabolic kinetics in all of the environments used in the present study. From the weight change data, parabolic rate constants were evaluated as a function of temperature and exposure environment. The temperature dependence of the parabolic rate constants was described by an Arrhenius relationship. Activation energy for the oxidation process was fairly constant in the oxygen pressure range of 1 x 10 -6 to 1 x 10 -1 torr for both the alloys. The activation energy for oxidation in air was significantly lower than in low-pO 2 environments, and for oxidation in pure O 2 at 760 torr was much lower than in low-pO 2 environments. X-ray diffraction analysis of the specimens showed that VO 2 was the dominant phase in low-pO 2 environments, while V 2 O 5 was dominant in air and in pure oxygen at 76f0 torr

  14. Enhanced Al and Zn removal from coal-mine drainage during rapid oxidation and precipitation of Fe oxides at near-neutral pH

    Science.gov (United States)

    Burrows, Jill E.; Cravotta, Charles A.; Peters, Stephen C.

    2017-01-01

    Net-alkaline, anoxic coal-mine drainage containing ∼20 mg/L FeII and ∼0.05 mg/L Al and Zn was subjected to parallel batch experiments: control, aeration (Aer 1 12.6 mL/s; Aer 2 16.8 mL/s; Aer 3 25.0 mL/s), and hydrogen peroxide (H2O2) to test the hypothesis that aeration increases pH, FeII oxidation, hydrous FeIII oxide (HFO) formation, and trace-metal removal through adsorption and coprecipitation with HFO. During 5.5-hr field experiments, pH increased from 6.4 to 6.7, 7.1, 7.6, and 8.1 for the control, Aer 1, Aer 2, and Aer 3, respectively, but decreased to 6.3 for the H2O2 treatment. Aeration accelerated removal of dissolved CO2, Fe, Al, and Zn. In Aer 3, dissolved Al was completely removed within 1 h, but increased to ∼20% of the initial concentration after 2.5 h when pH exceeded 7.5. H2O2 promoted rapid removal of all dissolved Fe and Al, and 13% of dissolved Zn.Kinetic modeling with PHREEQC simulated effects of aeration on pH, CO2, Fe, Zn, and Al. Aeration enhanced Zn adsorption by increasing pH and HFO formation while decreasing aqueous CO2 available to form ZnCO30 and Zn(CO3)22− at high pH. Al concentrations were inconsistent with solubility control by Al minerals or Al-containing HFO, but could be simulated by adsorption on HFO at pH oxidation with pH adjustment to ∼7.5 could be effective for treating high-Fe and moderate-Zn concentrations, whereas chemical oxidation without pH adjustment may be effective for treating high-Fe and moderate-Al concentrations.

  15. Nitrous oxide production pathways in a partial nitritation-anammox reactor: Isotopic evidence for nitrous oxide production associated anaerobic ammonium oxidation?

    Science.gov (United States)

    Wunderlin, P.; Harris, E. J.; Joss, A.; Emmenegger, L.; Kipf, M.; Mohn, J.; Siegrist, H.

    2014-12-01

    Nitrous oxide (N2O) is a strong greenhouse gas and a major sink for stratospheric ozone. In biological wastewater treatment N2O can be produced via several pathways. This study investigates the dynamics of N2O emissions from a nitritation-anammox reactor, and links its interpretation to the nitrogen and oxygen isotopic signature of the emitted N2O. A 400-litre single-stage nitritation-anammox reactor was operated and continuously fed with digester liquid. The isotopic composition of N2O emissions was monitored online with quantum cascade laser absorption spectroscopy (QCLAS; Aerodyne Research, Inc.; Waechter et al., 2008). Dissolved ammonium and nitrate were monitored online (ISEmax, Endress + Hauser), while nitrite was measured with test strips (Nitrite-test 0-24mgN/l, Merck). Table 1. Summary of experiments conducted to understand N2O emissions Experimental conditions O2[mgO2/L] NO2-[mgN/L] NH4+[mgN/L] N2O/NH4+[%] Normal operation production pathway, which is hypothesized to be mediated by anammox activity (Figure 1). A less likely explanation is that the SP of N2O was increased by partial N2O reduction by heterotrophic denitrification. Various experiments were conducted to further investigate N2O formation pathways in the reactor. Our data reveal that N2O emissions increased when reactor operation was not ideal, for example when dissolved oxygen was too high (Table 1). SP measurements confirmed that these N2O peaks were due to enhanced nitrifier denitrification, generally related to nitrite build-up in the reactor (Figure 1; Table 1). Overall, process control via online N2O monitoring was confirmed to be an ideal method to detect imbalances in reactor operation and regulate aeration, to ensure optimal reactor conditions and minimise N2O emissions. ReferencesWaechter H. et al. (2008) Optics Express, 16: 9239-9244. Wunderlin, P et al. (2013) Environmental Science & Technology 47: 1339-1348.

  16. Oxidation of elemental mercury by modified spent TiO2-based SCR-DeNOx catalysts in simulated coal-fired flue gas.

    Science.gov (United States)

    Zhao, Lingkui; Li, Caiting; Zhang, Xunan; Zeng, Guangming; Zhang, Jie; Xie, Yin'e

    2016-01-01

    In order to reduce the costs, the recycle of spent TiO2-based SCR-DeNOx catalysts were employed as a potential catalytic support material for elemental mercury (Hg(0)) oxidation in simulated coal-fired flue gas. The catalytic mechanism for simultaneous removal of Hg(0) and NO was also investigated. The catalysts were characterized by Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) method. Results indicated that spent TiO2-based SCR-DeNOx catalyst supported Ce-Mn mixed oxides catalyst (CeMn/SCR1) was highly active for Hg(0) oxidation at low temperatures. The Ce1.00Mn/SCR1 performed the best catalytic activities, and approximately 92.80% mercury oxidation efficiency was obtained at 150 °C. The inhibition effect of NH3 on Hg(0) oxidation was confirmed in that NH3 consumed the surface oxygen. Moreover, H2O inhibited Hg(0) oxidation while SO2 had a promotional effect with the aid of O2. The XPS results illustrated that the surface oxygen was responsible for Hg(0) oxidation and NO conversion. Besides, the Hg(0) oxidation and NO conversion were thought to be aided by synergistic effect between the manganese and cerium oxides.

  17. A new partial SOI-LDMOSFET with a modified buried oxide layer for improving self-heating and breakdown voltage

    International Nuclear Information System (INIS)

    Jamali Mahabadi, S E; Orouji, Ali A; Keshavarzi, P; Moghadam, Hamid Amini

    2011-01-01

    In this paper, for the first time, we propose a partial silicon-on-insulator (P-SOI) lateral double-diffused metal-oxide-semiconductor-field-effect-transistor (LDMOSFET) with a modified buried layer in order to improve breakdown voltage (BV) and self-heating effects (SHEs). The main idea of this work is to control the electric field by shaping the buried layer. With two steps introduced in the buried layer, the electric field distribution is modified. Also a P-type window introduced makes the substrate share the vertical voltage drop, leading to a high vertical BV. Moreover, four interface electric field peaks are introduced by the buried P-layer, the Si window and two steps, which modulate the electric field in the SOI layer and the substrate. Hence, a more uniform electric field is obtained; consequently, a high BV is achieved. Furthermore, the Si window creates a conduction path between the active layer and substrate and alleviates the SHE. Two-dimensional simulations show that the BV of double step partial silicon on insulator is nearly 69% higher and alleviates SHEs 17% in comparison with its single step partial SOI counterpart and nearly 265% higher and alleviate SHEs 18% in comparison with its conventional SOI counterpart

  18. Comparison of partial and full nitrification processes applied for treating high-strength nitrogen wastewaters: microbial ecology through nitrous oxide production.

    Science.gov (United States)

    Ahn, Joon Ho; Kwan, Tiffany; Chandran, Kartik

    2011-04-01

    The goal of this study was to compare the microbial ecology, gene expression, biokinetics, and N2O emissions from a lab-scale bioreactor operated sequentially in full-nitrification and partial-nitrification modes. Based on sequencing of 16S rRNA and ammonia monooxygenase subunit A (amoA) genes, ammonia oxidizing bacteria (AOB) populations during full- and partial-nitrification modes were distinct from one another. The concentrations of AOB (XAOB) and their respiration rates during full- and partial-nitrification modes were statistically similar, whereas the concentrations of nitrite oxidizing bacteria (XNOB) and their respiration rates declined significantly after the switch from full- to partial-nitrification. The transition from full-nitrification to partial nitrification resulted in a protracted transient spike of nitrous oxide (N2O) and nitric oxide (NO) emissions, which later stabilized. The trends in N2O and NO emissions correlated well with trends in the expression of nirK and norB genes that code for the production of these gases in AOB. Both the transient and stabilized N2O and NO emissions during partial nitrification were statistically higher than those during steady-state full-nitrification. Based on these results, partial nitrification strategies for biological nitrogen removal, although attractive for their reduced operating costs and energy demand, may need to be optimized against the higher carbon foot-print attributed to their N2O emissions.

  19. Desulfurization and oxidation behavior of ultra-fine CaO particles prepared from brown coal; Kattan wo mochiite choseishita CaO chobiryushi no datsuryu tokusei to sanka tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin, G.; Roman, M.; Yamazaki, Y.; Abe, H.; Harano, Y.; Takarada, Y. [Gunma University, Gunma (Japan). Faculty of Engineering

    1996-10-28

    The effect of reaction temperature and oxygen concentration on the desulfurization and oxidation behavior of ion-exchanged brown coal by Ca as new desulfurizing agent was studied. In experiment, Yallourn coal was used for ion- exchange, and limestone produced in Tochigi prefecture was also used for comparative study. Ca-exchanged brown coal was prepared by agitating coal in Ca(OH)2 slurry for 24 hours. The desulfurization behavior of a desulfurizing agent was obtained by measuring H2S and sulfur compounds in outlet gas of a reactor, and the oxidation behavior by measuring SO2 emission in outlet gas after oxidation reaction. As the experimental result, CaO produced from Ca-exchanged brown coal offered the extremely high activity to desulfurization reaction in a temperature range of 850-950{degree}C as compared with limestone. Although the oxidation behavior was dependent on oxidation temperature and oxygen concentration, CaS obtained from Ca-exchanged brown coal was more rapidly converted to CaSO4 than limestone. 3 refs., 8 figs., 2 tabs.

  20. Increased penile expression of transforming growth factor and elevated systemic oxidative stress in rabbits with chronic partial bladder outlet obstruction.

    Science.gov (United States)

    Lin, W-Y; Chang, P-J; Lin, Y-P; Wu, S-B; Chen, C-S; Levin, R M; Wei, Y-H

    2012-02-01

    There is a growing body of evidence to support the direct link between obstructive bladder dysfunction and erectile dysfunction (ED). However, there have been few pathophysiological studies to determine the relationship between lower urinary tract syndrome (LUTS) and ED. As the transforming growth factor-β1 (TGF-β1) that induces the synthesis of collagen in the penile tissues is critical for the development of ED, the first aim of this study was to investigate the expression of TGF-β1 in the penis from male rabbits with chronic partial bladder outlet obstruction (PBOO). Besides, it has been suggested that oxidative stress plays a significant role in the pathophysiological mechanism of ED. Thus, the second aim of this study was to further investigate whether the urinary or serum oxidative stress markers are involved in chronic PBOO-induced penile dysfunction. A total of 16 male New Zealand White rabbits were separated equally into four groups: a control group and PBOO groups obstructed for 2, 4 and 8 weeks respectively. Using the RT-PCR and Western blot analysis, a progressive increase of TGF-β1 in penis was found at 2, 4 and 8 weeks after obstruction. Moreover, the biomarkers for oxidative stress or oxidative damage were significantly detected in the penis of rabbits after PBOO, which include the enhancement of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in urine and plasma, plasma malondialdehyde (MDA) and total antioxidant capacity (TAC), as well as reduction of glutathione (GSH). On the basis of our results, the increase of TGF-β1 and elevated systemic oxidative stress may play key roles to contribute to penile dysfunction after chronic PBOO. © 2011 The Authors. International Journal of Andrology © 2011 European Academy of Andrology.

  1. Effects of Urtica dioica on oxidative stress, proliferation and apoptosis after partial hepatectomy in rats.

    Science.gov (United States)

    Oguz, Serhat; Kanter, Mehmet; Erboga, Mustafa; Toydemir, Toygar; Sayhan, Mustafa Burak; Onur, Hatice

    2015-05-01

    The present study was performed to investigate the effect of Urtica dioica (UD) on liver regeneration after partial hepatectomy (PH) in rats. A total of 24 male Sprague Dawley rats were divided into three groups: sham-operated, PH and PH + UD; each group contains eight animals. The rats in UD-treated groups were given UD oils (2 ml/kg/day) once a day orally for 7 days starting 3 days prior to hepatectomy operation. At day 7 after resection, liver samples were collected. The levels of malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) were estimated in liver homogenates. Moreover, histopathological examination, mitotic index (MI), proliferating cell nuclear antigen labeling, proliferation index (PI), transferase-mediated deoxyuridine triphosphate nick end-labeling assay, apoptotic index (AI) were evaluated at day 7 after hepatectomy. As a result, UD significantly increased MI and PI, significantly decreased AI and also attenuated hepatic vacuolar degeneration and sinusoidal congestion in PH rats. UD treatment significantly decreased the elevated tissue MDA level and increased the reduced SOD activity and GSH level in the tissues. These results suggest that UD pretreatment was beneficial for rat liver regeneration after partial hepatectomy. © The Author(s) 2013.

  2. Sulfur Tolerant Solid Oxide Fuel Cell for Coal Syngas Application: Experimental Study on Diverse Impurity Effects and Fundamental Modeling of Electrode Kinetics

    Science.gov (United States)

    Gong, Mingyang

    With demand over green energy economy, fuel cells have been developed as a promising energy conversion technology with higher efficiency and less emission. Solid oxide fuel cells (SOFC) can utilize various fuels in addition to hydrogen including coal derived sygas, and thus are favored for future power generation due to dependence on coal in electrical industry. However impurities such as sulfur and phosphorous present in coal syngas in parts per million (p.p.m.) levels can severely poison SOFC anode typically made of Ni/yttria-stabilized-zirconia (Ni-YSZ) and limit SOFC applicability in economically derivable fuels. The focus of the research is to develop strategy for application of high performance SOFC in coal syngas with tolerance against trace impurities such as H2S and PH3. To realize the research goal, the experimental study on sulfur tolerant anode materials and examination of various fuel impurity effects on SOFC anode are combined with electrochemical modeling of SOFC cathode kinetics in order to benefit design of direct-coal-syngas SOFC. Tolerant strategy for SOFC anode against sulfur is studied by using alternative materials which can both mitigate sulfur poisoning and function as active anode components. The Ni-YSZ anode was modified by incorporation of lanthanum doped ceria (LDC) nano-coatings via impregnation. Cell test in coal syngas containing 20 ppm H2S indicated the impregnated LDC coatings inhibited on-set of sulfur poisoning by over 10hrs. Cell analysis via X-ray photon spectroscopy (XPS), X-ray diffraction (XRD) and electrochemistry revealed LDC coatings reacted with H2S via chemisorptions, resulting in less sulfur blocking triple--phase-boundary and minimized performance loss. Meanwhile the effects of PH3 impurity on SOFC anode is examined by using Ni-YSZ anode supported SOFC. Degradation of cell is found to be irreversible due to adsorption of PH3 on TPB and further reaction with Ni to form secondary phases with low melting point. The

  3. Results of Study of Sulfur Oxide Reduction During Combustion of Coal-Water Slurry Fuel Through use of Sulfur Capturing Agents

    Directory of Open Access Journals (Sweden)

    Murko Vasiliy I.

    2016-01-01

    Full Text Available It is shown that an effective way of burning high sulfur coal is to burn coal-water slurry fuel (CWF prepared on its basis containing a sulfur capture agent (SCA entered in the slurry at the stage of preparation. The technique of thermodynamic analysis of chemical reactions during CWF burning has been developed including burning in the presence of SCA. Using the developed calculation program, the optimal temperature conditions have been determined as required for the effective reduction of sulfur oxides in flue gases when using different types of SCA. According to the results of calculating the composition of CWF combustion products when entering various substances in the burner space as SCA it has been determined that magnesite, calcite, and dolomite are the most effective natural minerals. The analysis of calculated and experimental data proves the efficiency of SCA addition as well as validity of the obtained results.

  4. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide emissions from coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Sorge, J.N.; Larrimore, C.L.; Slatsky, M.D.; Menzies, W.R.; Smouse, S.M.; Stallings, J.W.

    1997-12-31

    This paper discusses the technical progress of a US Department of Energy Innovative Clean Coal Technology project demonstrating advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. The primary objectives of the demonstration is to determine the long-term NOx reduction performance of advanced overfire air (AOFA), low NOx burners (LNB), and advanced digital control optimization methodologies applied in a stepwise fashion to a 500 MW boiler. The focus of this paper is to report (1) on the installation of three on-line carbon-in-ash monitors and (2) the design and results to date from the advanced digital control/optimization phase of the project.

  5. Obtainment of zirconium oxide and partially stabilized zirconium oxide with yttrium and rare earth oxides, from Brazilian zirconite, for ceramic aim

    International Nuclear Information System (INIS)

    Ribeiro, S.

    1991-05-01

    This work presents experimental results for processing of brazilian zirconite in order to obtain zirconium oxide with Yttrium and Rare Earth oxide by mutual coprecipitation for ceramics purposes. Due to analysis of experimental results was possible to obtain the optimum conditions for each one of technological route stage, such as: alkaline fusion; acid leaching; sulfactation and coprecipitation. (author)

  6. OXIDATIVE-REFORMING OF METHANE AND PARTIAL OXIDATION OF METHANE REACTIONS OVER NiO/PrO2/ZrO2 CATALYSTS: EFFECT OF NICKEL CONTENT

    Directory of Open Access Journals (Sweden)

    Y. J. O. Asencios

    Full Text Available Abstract In this work the behavior of NiO-PrO2-ZrO2 catalysts containing various nickel loadings was evaluated in the partial oxidation of methane and oxidative-reforming reactions of methane. The catalysts were characterized by X-Ray Diffraction Analysis (in situ-XRD, Temperature Programmed Reduction (H2-TPR, Scanning Electron Microscopy (SEM/EDX and Adsorption-Desorption of nitrogen (BET area. The reactions were carried out at 750 °C and 1 atm for 5 hours. The catalysts were studied with different nickel content: 0, 5, 10 and 15% (related to total weight of catalyst, wt%. In both reactions, the catalyst containing the mixture of the three oxides (NiO/PrO2/ZrO2 with 15% nickel (15NiPrZr catalyst showed the best activity for the conversion of the reactants into Syngas and showed high selectivity for H2 and CO. The results suggest that the promoter PrO2 and the Niº centers are in a good proportion in the catalyst with 15% Ni. Our results showed that low nickel concentrations in the catalyst led to high metallic dispersion; however, very low nickel concentrations did not favor the methane transformation into Syngas. The catalyst containing only NiO/ZrO2 in the mixture was not sufficient for the catalysis. The presence of the promoter PrO2 was very important for the catalysis of the POM.

  7. Partial IGF-1 deficiency induces brain oxidative damage and edema, which are ameliorated by replacement therapy.

    Science.gov (United States)

    Puche, Juan E; Muñoz, Úrsula; García-Magariño, Mariano; Sádaba, María C; Castilla-Cortázar, Inma

    2016-01-01

    Insulin-like growth factor 1 (IGF-1) induces multiple cytoprotective effects on every tissue, including the brain. Since the mechanisms by which IGF-1 produces neuroprotection are not fully understood, the aim of this work was to delve into the underlying mechanisms. IGF-1 deficient mice (Hz) were compared with wild type (WT) and Hz mice treated with low doses of IGF-1 (2 µg/100 g body weight/day) for 10 days (Hz + IGF). Gene expression, quantitative PCR, histology, and magnetic resonance imaging were performed in the three groups. IGF-1 deficiency induced increased oxidative damage determined by markers of lipid peroxidation and hypoxia, as well as gene expression of heat shock proteins, antioxidant enzymes, and molecules involved in inflammation, apoptosis, and mitochondrial protection. These changes correlated with edema and learning impairment in Hz mice. IGF-1 therapy improved all these alterations. In conclusion, IGF-1 deficiency is responsible for increased brain oxidative damage, edema, and impaired learning and memory capabilities which are rescued by IGF-1 replacement therapy. © 2016 International Union of Biochemistry and Molecular Biology.

  8. The uptake and excretion of partially oxidized sulfur expands the repertoire of energy resources metabolized by hydrothermal vent symbioses.

    Science.gov (United States)

    Beinart, R A; Gartman, A; Sanders, J G; Luther, G W; Girguis, P R

    2015-05-07

    Symbiotic associations between animals and chemoautotrophic bacteria crowd around hydrothermal vents. In these associations, symbiotic bacteria use chemical reductants from venting fluid for the energy to support autotrophy, providing primary nutrition for the host. At vents along the Eastern Lau Spreading Center, the partially oxidized sulfur compounds (POSCs) thiosulfate and polysulfide have been detected in and around animal communities but away from venting fluid. The use of POSCs for autotrophy, as an alternative to the chemical substrates in venting fluid, could mitigate competition in these communities. To determine whether ESLC symbioses could use thiosulfate to support carbon fixation or produce POSCs during sulfide oxidation, we used high-pressure, flow-through incubations to assess the productivity of three symbiotic mollusc genera-the snails Alviniconcha spp. and Ifremeria nautilei, and the mussel Bathymodiolus brevior-when oxidizing sulfide and thiosulfate. Via the incorporation of isotopically labelled inorganic carbon, we found that the symbionts of all three genera supported autotrophy while oxidizing both sulfide and thiosulfate, though at different rates. Additionally, by concurrently measuring their effect on sulfur compounds in the aquaria with voltammetric microelectrodes, we showed that these symbioses excreted POSCs under highly sulfidic conditions, illustrating that these symbioses could represent a source for POSCs in their habitat. Furthermore, we revealed spatial disparity in the rates of carbon fixation among the animals in our incubations, which might have implications for the variability of productivity in situ. Together, these results re-shape our thinking about sulfur cycling and productivity by vent symbioses, demonstrating that thiosulfate may be an ecologically important energy source for vent symbioses and that they also likely impact the local geochemical regime through the excretion of POSCs.

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

    International Nuclear Information System (INIS)

    Federal Energy Technology Center

    1999-01-01

    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

  10. Characterization of coal fly ash nanoparticles and induced oxidative DNA damage in human peripheral blood mononuclear cells

    International Nuclear Information System (INIS)

    Dwivedi, Sourabh; Saquib, Quaiser; Al-Khedhairy, Abdulaziz A.; Ali, Al-Yousef Sulaiman; Musarrat, Javed

    2012-01-01

    The nano-sized particles present in coal fly ash (CFA) were characterized through the X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM, SEM), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) analyses. The XRD data revealed the average crystallite size of the CFA nanoparticles (CFA-NPs) as 14 nm. TEM and SEM imaging demonstrated predominantly spherical and some polymorphic structures in the size range of 11 to 25 nm. The amount of heavy metal associated with CFA particles (μg/g) were determined as Fe (34160.0 ± 1.38), Ni (150.8 ± 0.78), Cu (99.3 ± 0.56) and Cr (64.0 ± 0.86). However, the bioavailability of heavy metals in terms of percent release was in the order as Cr > Ni > Cu > Fe in CFA-dimethyl sulfoxide (DMSO) extract. The comet and cytokinesis blocked micronucleus (CBMN) assays revealed substantial genomic DNA damage in peripheral blood mononuclear (PBMN) cells treated with CFA-NPs in Aq and DMSO extracts. About 1.8 and 3.6 strand breaks per unit of DNA were estimated through alkaline unwinding assay at 1:100 DNA nucleotide/CFA ppm ratios with the Aq and DMSO extracts, respectively. The DNA and mitochondrial damage was invariably greater with CFA-DMSO extract vis-à-vis -Aq extract. Generation of superoxide anions (O 2 • − ) and intracellular reactive oxygen species (ROS) through metal redox-cycling, alteration in mitochondrial potential and 8-oxodG production elucidated CFA-NPs induced oxidative stress as a plausible mechanism for CFA-induced genotoxicity. -- Highlights: ► CFA consists of spherical crystalline nanoparticles in size range of 11–25 nm. ► Alkaline unwinding assay revealed single-strandedness in CFA treated ctDNA. ► CFA nanoparticles exhibited the ability to induce ROS and oxidative DNA damage. ► Comet and CBMN assays revealed DNA and chromosomal breakage in PBMN cells. ► CFA-NPs resulted in mitochondrial membrane damage in PBMN cells.

  11. Characterization of coal fly ash nanoparticles and induced oxidative DNA damage in human peripheral blood mononuclear cells

    Energy Technology Data Exchange (ETDEWEB)

    Dwivedi, Sourabh; Saquib, Quaiser; Al-Khedhairy, Abdulaziz A. [Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Ali, Al-Yousef Sulaiman [Department of Medical Laboratory Sciences, College of Applied Medical Science, University of Dammam, P.O. Box 1683, Hafr Al Batin-31991 (Saudi Arabia); Musarrat, Javed, E-mail: musarratj1@yahoo.com [Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Department of Agricultural Microbiology, Faculty of Agricultural Sciences, AMU, Aligarh202002 (India)

    2012-10-15

    The nano-sized particles present in coal fly ash (CFA) were characterized through the X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM, SEM), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) analyses. The XRD data revealed the average crystallite size of the CFA nanoparticles (CFA-NPs) as 14 nm. TEM and SEM imaging demonstrated predominantly spherical and some polymorphic structures in the size range of 11 to 25 nm. The amount of heavy metal associated with CFA particles ({mu}g/g) were determined as Fe (34160.0 {+-} 1.38), Ni (150.8 {+-} 0.78), Cu (99.3 {+-} 0.56) and Cr (64.0 {+-} 0.86). However, the bioavailability of heavy metals in terms of percent release was in the order as Cr > Ni > Cu > Fe in CFA-dimethyl sulfoxide (DMSO) extract. The comet and cytokinesis blocked micronucleus (CBMN) assays revealed substantial genomic DNA damage in peripheral blood mononuclear (PBMN) cells treated with CFA-NPs in Aq and DMSO extracts. About 1.8 and 3.6 strand breaks per unit of DNA were estimated through alkaline unwinding assay at 1:100 DNA nucleotide/CFA ppm ratios with the Aq and DMSO extracts, respectively. The DNA and mitochondrial damage was invariably greater with CFA-DMSO extract vis-a-vis -Aq extract. Generation of superoxide anions (O{sub 2} Bullet {sup -}) and intracellular reactive oxygen species (ROS) through metal redox-cycling, alteration in mitochondrial potential and 8-oxodG production elucidated CFA-NPs induced oxidative stress as a plausible mechanism for CFA-induced genotoxicity. -- Highlights: Black-Right-Pointing-Pointer CFA consists of spherical crystalline nanoparticles in size range of 11-25 nm. Black-Right-Pointing-Pointer Alkaline unwinding assay revealed single-strandedness in CFA treated ctDNA. Black-Right-Pointing-Pointer CFA nanoparticles exhibited the ability to induce ROS and oxidative DNA damage. Black-Right-Pointing-Pointer Comet and CBMN assays revealed DNA and chromosomal

  12. Partially and fully de-alloyed glassy ribbons based on Au: Application in methanol electro-oxidation studies

    Energy Technology Data Exchange (ETDEWEB)

    Paschalidou, Eirini Maria, E-mail: epaschal@unito.it [Dipartimento di Chimica e Centro Interdipartimentale NIS (Nanostructured Surfaces and Interfaces), Università di Torino, Via Pietro Giuria 7, 10125, Torino (Italy); Scaglione, Federico [Dipartimento di Chimica e Centro Interdipartimentale NIS (Nanostructured Surfaces and Interfaces), Università di Torino, Via Pietro Giuria 7, 10125, Torino (Italy); Gebert, Annett; Oswald, Steffen [Leibniz Institut für Festkörper- und Werkstoffforschung IFW, Helmholtzstraße 20, 01069, Dresden (Germany); Rizzi, Paola; Battezzati, Livio [Dipartimento di Chimica e Centro Interdipartimentale NIS (Nanostructured Surfaces and Interfaces), Università di Torino, Via Pietro Giuria 7, 10125, Torino (Italy)

    2016-05-15

    In this work, electrochemical de-alloying of an amorphous alloy, Au{sub 40}Cu{sub 28}Ag{sub 7}Pd{sub 5}Si{sub 20}, cast in ribbon form by melt spinning, has been performed, obtaining self standing nanoporous materials suitable for use as electrodes for electrocatalytic applications. The de-alloying encompasses removal of less noble elements and the crystallization of Au, resulting in interconnected ligaments whose size and morphology are described as a function of time. Depending on de-alloying time, the crystals may contain residual amounts of Cu, Ag and Pd, as shown by Auger Electron Spectroscopy (AES), Energy Dispersive Spectroscopy (EDS) and Cyclic Voltammetry (CV) in a basic solution. Current density peaks in the 0.16–0.28 V range (vs Ag/AgCl) indicate that the porous ribbons are active for the electro-oxidation of methanol. The partially de-alloyed samples, which still partially contain the amorphous phase because of the shorter etching times, have finer ligaments and display peaks at lower potential. However, the current density decreases rapidly during repeated potential scans. This is attributed to the obstruction of Au sites, mainly by the Cu oxides formed during the scans. The fully de-alloyed ribbons display current peaks at about 0.20 V and remain active for hundreds of scans at more than 60% of the initial current density. They can be fully re-activated to achieve the same performance levels after a brief immersion in nitric acid. The good activity is due to trapped Ag and Pd atoms in combination with ligament morphology. - Graphical abstract: Fine ligaments and pores made by de-alloying a glassy ribbon of a Au-based alloy, homogeneously produced across the thickness (25 μm) for studying methanol's electro-oxidation behavior. - Highlights: • Size and composition of nanoporous layers tailored in de-alloying Au-based glassy ribbons. • From amorphous precursor fine crystals occur in ligaments with residual Pd and Ag. • Fully de

  13. Rare earth oxide-doped titania nanocomposites with enhanced photocatalytic activity towards the degradation of partially hydrolysis polyacrylamide

    International Nuclear Information System (INIS)

    Li Jinhuan; Yang Xia; Yu Xiaodan; Xu, Leilei; Kang Wanli; Yan Wenhua; Gao Hongfeng; Liu Zhonghe; Guo Yihang

    2009-01-01

    Rare-earth oxide-doped titania nanocomposites (RE 3+ /TiO 2 , where RE = Eu 3+ , Pr 3+ , Gd 3+ , Nd 3+ , and Y 3+ ) were prepared by a one-step sol-gel-solvothermal method. The products exhibited anatase phase structure, mesoporosity, and interesting surface compositions with three oxygen species and two titanium species. The products were used as the photocatalysts to degrade a partially hydrolysis polyacrylamide (HPAM) under UV-light irradiation, a very useful polymer in oil recovery. For comparison, Degussa P25 and as-prepared pure TiO 2 were also tested under the same conditions. The enhanced photocatalytic activity was obtained on as-prepared Eu 3+ (Gd 3+ , Pr 3+ )/TiO 2 composites, and the reasons were explained. Finally, the degradation pathway of HPAM over the RE 3+ /TiO 2 composite was put forward based on the intermediates produced during the photocatalysis procedure.

  14. The Indonesian coal industry

    International Nuclear Information System (INIS)

    Cook, A.; Daulay, B.

    2000-01-01

    In this comprehensive article the authors describe the origins and progress of the Indonesian coal industry and the role it plays, and will play, in the domestic energy scene and world coal trade. In the '80s, the Indonesian coal industry laid the basis for major expansion such that coal production rose from under a million tonnes in 1983 to 10.6 million tonnes in 1990, 50.9 million tonnes by 1996 and 61.2 million tonnes in 1992. At the same time, exports have increased from 0.4 million tonnes to 44.8 million tonnes. Current export levels are higher than originally expected, due in part to a slow down in the construction of electric power stations and a partial switch to natural gas. This has slowed the rate at which domestic coal demand has built up. The majority of coals currently exported are low rank steam coals, but some of the higher rank and very low ash coals are used for blast furnace injection, and a very small proportion may even be used within coking blends, even though they have poor coking properties. The Indonesian coal industry has developed very rapidly over the last six years to become a significant exporter, especially within the ASEAN context. The resources base appears to be large enough to support further increases in production above those already planned. It is probable that resources and reserves can be increased above the current levels. It is likely that some reserves of high value coals can be found, but it is also probable that the majority of additions to reserves will be lower in rank (and therefore quality) compared with the average of coals currently being mined. Reserves of qualities suitable for export will support that industry for a considerable period of time. However, in the longer term, the emphasis of production will increasingly swing to the domestic market

  15. Study of the dynamics of the MoO2-Mo2C system for catalytic partial oxidation reactions

    Science.gov (United States)

    Cuba Torres, Christian Martin

    On a global scale, the energy demand is largely supplied by the combustion of non-renewable fossil fuels. However, their rapid depletion coupled with environmental and sustainability concerns are the main drivers to seek for alternative energetic strategies. To this end, the sustainable generation of hydrogen from renewable resources such as biodiesel would represent an attractive alternative solution to fossil fuels. Furthermore, hydrogen's lower environmental impact and greater independence from foreign control make it a strong contender for solving this global problem. Among a wide variety of methods for hydrogen production, the catalytic partial oxidation offers numerous advantages for compact and mobile fuel processing systems. For this reaction, the present work explores the versatility of the Mo--O--C catalytic system under different synthesis methods and reforming conditions using methyl oleate as a surrogate biodiesel. MoO2 exhibits good catalytic activity and exhibits high coke-resistance even under reforming conditions where long-chain oxygenated compounds are prone to form coke. Moreover, the lattice oxygen present in MoO2 promotes the Mars-Van Krevelen mechanism. Also, it is introduced a novel beta-Mo2C synthesis by the in-situ formation method that does not utilize external H2 inputs. Herein, the MoO 2/Mo2C system maintains high catalytic activity for partial oxidation while the lattice oxygen serves as a carbon buffer for preventing coke formation. This unique feature allows for longer operation reforming times despite slightly lower catalytic activity compared to the catalysts prepared by the traditional temperature-programmed reaction method. Moreover, it is demonstrated by a pulse reaction technique that during the phase transformation of MoO2 to beta-Mo2C, the formation of Mo metal as an intermediate is not responsible for the sintering of the material wrongly assumed by the temperature-programmed method.

  16. Hydrogen or synthesis gas production via the partial oxidation of methane over supported nickel-cobalt catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Alaric C.W. [Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Institute of Chemical and Engineering Sciences, 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore); Chen, Luwei; Lin, Jianyi [Institute of Chemical and Engineering Sciences, 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore); Kee Leong, Weng [Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Johnson, Brian F.G.; Khimyak, Tetyana [University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge, UK CB2 1EW (United Kingdom)

    2007-05-15

    Activity, selectivity, and coking-resistance of a series of Ni{sub x}Co{sub y} (where x,y are the respective metal loadings of 0, 1, 2 or 3 wt.%; x+y=3) bimetallic catalysts supported on CaAl{sub 2}O{sub 4}/Al{sub 2}O{sub 3} have been studied for hydrogen/synthesis gas production via the catalytic partial oxidation (CPO) of methane. Catalysts were characterized by temperature programmed reduction (TPR), transmission electron microscopy (TEM) and X-ray fluorescence multi-element analysis (XRF). Their activity for the partial oxidation of methane to hydrogen and carbon monoxide (at 1 bar, gas hourly space velocity (GHSV) of 144,000cm{sup 3}g{sup -1}h{sup -1} and CH{sub 4}/O{sub 2} molar ratio of 2) was investigated, and coke deposited on the spent catalysts was studied by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and thermogravimetric analysis (TGA). The activity was found to decrease in the order of Ni{sub 2}Co>Ni{sub 3}>NiCo{sub 2}>>Co{sub 3}, while CO and H{sub 2} selectivities were found to be in the order ofNi{sub 2}Co>Ni{sub 3}{approx}NiCo{sub 2}>Co{sub 3}. Ni{sub 2}Co is also shown to be more resistant to coking as compared to Ni{sub 3}, which is a current catalyst of choice. Results show that not only does Ni{sub 2}Co have the highest activity and selectivity among all the catalysts tested, it is also relatively resistant to coking. This finding would be helpful for catalyst design to achieve high coking resistivity catalysts for hydrogen production from CPO of methane. (author)

  17. Adiabatic Fixed-Bed Gasification of Colombian Coffee Husk Using Air-Steam Blends for Partial Oxidation

    Directory of Open Access Journals (Sweden)

    Javier Bonilla

    2017-01-01

    Full Text Available The increasing energy consumption, mostly supplied by fossil fuels, has motivated the research and development of alternative fuel technologies to decrease the humanity’s dependence on fossil fuels, which leads to pollution of natural sources. Small-scale biomass gasification, using air-steam blends for partial oxidation, is a good alternative since biomass is a neutral carbon feedstock for sustainable energy generation. This research presents results obtained from an experimental study on coffee husk (CH gasification, using air-steam blends for partial oxidation in a 10 kW fixed-bed gasifier. Parametric studies on equivalence ratio (ER (1.53 < ER < 6.11 and steam-fuel (SF ratio (0.23 < SF < 0.89 were carried out. The results show that increasing both SF and ER results in a syngas rich in CH4 and H2 but poor in CO. Also, decreased SF and ER decrease the peak temperature (Tpeak at the gasifier combustion zone. The syngas high heating value (HHV ranged from 3112 kJ/SATPm3 to 5085 kJ/SATPm3 and its maximum value was obtained at SF = 0.87 and ER = 4.09. The dry basis molar concentrations of the species, produced under those operating conditions (1.53 < ER < 6.11 and 0.23 < SF < 0.89, were between 1.12 and 4.1% for CH4, between 7.77 and 13.49% for CO, and between 7.54 and 19.07% for H2. Other species were in trace amount.

  18. Reaction phenomena of catalytic partial oxidation of methane under the impact of carbon dioxide addition and heat recirculation

    International Nuclear Information System (INIS)

    Chen, Wei-Hsin; Lin, Shih-Cheng

    2015-01-01

    The reaction phenomena of CPOM (catalytic partial oxidation of methane) in a Swiss-roll reactor are studied numerically where a rhodium-based catalyst bed is embedded at the center of the reactor. CO 2 is added into the feed gas and excess enthalpy recovery is performed to evaluate their influences on CPOM performance. In the study, the mole ratio of O 2 to CH 4 (O 2 /CH 4 ratio) is fixed at 0.5 and the mole ratio of CO 2 to O 2 (CO 2 /O 2 ratio) is in the range of 0–2. The results reveal that CO 2 addition into the influent has a slight effect on methane combustion, but significantly enhances dry reforming and suppresses steam reforming. The reaction extents of steam reforming and dry reforming in CPOM without heat recovery and CO 2 addition are in a comparable state. Once CO 2 is added into the feed gas, the dry reforming is enhanced, thereby dominating CH 4 consumption. Compared to the reactor without excess enthalpy recovery, heat recirculation drastically increases the maximum reaction temperature and CH 4 conversion in the catalyst bed; it also intensifies the H 2 selectivity, H 2 yield, CO 2 conversion, and syngas production rate. The predictions indicate that the heat recirculation is able to improve the syngas formation up to 45%. - Highlights: • Catalytic partial oxidation of methane with CO 2 addition and heat recovery is studied. • CO 2 addition has a slight effect on methane combustion. • CO 2 addition significantly enhances dry reforming and suppresses steam reforming. • Dry reforming dominates CH 4 consumption when CO 2 addition is large. • Heat recirculation can improve the syngas formation up to 45%

  19. Enzymatic desulfurization of coal

    Energy Technology Data Exchange (ETDEWEB)

    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)

  20. Partial oxidation of D-xylose to maleic anhydride and acrylic acid over vanadyl pyrophosphate

    International Nuclear Information System (INIS)

    Ghaznavi, Touraj; Neagoe, Cristian; Patience, Gregory S.

    2014-01-01

    Xylose is the second most abundant sugar after glucose. Despite its tremendous potential to serve as a renewable feedstock, few commercial processes exploit this resource. Here, we report a new technology in which a two-fluid nozzle atomizes a xylose-water solution into a capillary fluidized bed operating above 300 °C. Xylose-water droplets form at the tip of the injector, vaporize then react with a heterogeneous mixed oxide catalyst. A syringe pump metered the solution to the reactor charged with 1 g of catalyst. Product yield over vanadyl pyrophosphate was higher compared to molybdenum trioxide-cobalt oxide and iron molybdate; it reached 25% for maleic anhydride, 17% for acrylic acid and 11% for acrolein. Gas residence time was 0.2 s. The catalyst was free of coke even after operating for 4 h – based on a thermogravimetric analysis of catalyst withdrawn from the reactor. Below 300 °C, powder agglomerated at the tip of the injector at 300 °C; it also agglomerated with a xylose mass fraction of 7% in water. - Highlights: • D-xylose reacts to form maleic anhydride and acrylic acid above 250 °C. • Vanadyl pyrophosphate is both active and selective for maleic and acrylic acid. • Acid and acrolein yield approaches 50% for a xylose mass fraction of 3% in water. • Catalyst agglomerates at low temperatures and high xylose aqueous mass fraction. • Atomization quality is a determining factor to minimize agglomeration

  1. Oxidative regeneration of Ni-Mo-gamma-Al/sub 2/O/sub 3/ catalysts used for hydrotreatment of coal-derived oil

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, Yuji; Furimsky, Edward; Sato, Toshio; Shimada, Hiromichi; Matsubayashi, Nobuyuki; Nishijima, Akio

    1986-10-23

    In order to easily find the oxidative reaction characteristics of carbonaceous materials and sulfur deposited on the catalysts used for hydrogenation, oxidative regeneration behavior as studied with a fixed bed reactor, and the surfaces of the spent catalysts were analyzed by XPS to find the changes in form of active metals and sulfur on the catalysts. Ni-Mo-gamma-Al/sub 2/O/sub 3/ catalysts were used for hydrotreatment of primary coal-derived oil from Morwell coal. The spent catalysts were extracted by THF, dried and crushed into 100-200 mesh powder. The relation between catalyst regeneration temperature and CO/sub 2/ or SO/sub 2/, the relation between generated gas compositions and temperature in regeneration, and the activation energy of carbon and sulfur in the catalysts for oxidative reaction were indicated with data. As a result, it was found that a part of the active metals turned to sulfates by hydrotreatment and the residual sulfur existed in form of sulfate. ( 6 figs, 2 tabs, 4 refs )

  2. Excellent performance of Pt-C/TiO2 for methanol oxidation: Contribution of mesopores and partially coated carbon

    Science.gov (United States)

    Wu, Xinbing; Zhuang, Wei; Lu, Linghong; Li, Licheng; Zhu, Jiahua; Mu, Liwen; Li, Wei; Zhu, Yudan; Lu, Xiaohua

    2017-12-01

    Partial deposition of carbon onto mesoporous TiO2 (C/TiO2) were prepared as supporting substrate for Pt catalyst development. Carbon deposition is achieved by in-situ carbonization of furfuryl alcohol. The hybrid catalysts were characterized by XRD, Raman, SEM and TEM and exhibited outstanding catalytic activity and stability in methanol oxidation reaction. The heterogeneous carbon coated on mesoporous TiO2 fibers provided excellent electrical conductivity and strong interfacial interaction between TiO2 support and Pt metal nanoparticles. Methanol oxidation reaction results showed that the activity of Pt-C/TiO2 is 3.0 and 1.5 times higher than that of Pt-TiO2 and Pt-C, respectively. In addition, the Pt-C/TiO2 exhibited a 6.7 times enhanced stability compared with Pt-C after 2000 cycles. The synergistic effect of C/TiO2 is responsible for the enhanced activity of Pt-C/TiO2, and its excellent durability could be ascribed to the strong interfacial interaction between Pt nanoparticles and C/TiO2 support.

  3. Effect of systemic nitric oxide synthase inhibition on optic disc oxygen partial pressure in normoxia and in hypercapnia.

    Science.gov (United States)

    Petropoulos, Ioannis K; Pournaras, Jean-Antoine C; Stangos, Alexandros N; Pournaras, Constantin J

    2009-01-01

    To investigate the effect of systemic nitric oxide synthase (NOS) inhibition on optic disc oxygen partial pressure (PO(2)) in normoxia and hypercapnia. Intervascular optic disc PO(2) was measured in 12 anesthetized minipigs by using oxygen-sensitive microelectrodes placed 0.1), despite a 21% increase of mean arterial pressure. Optic disc PO(2) increase under hypercapnia was blunted after L-NAME injection (DeltaPO(2) = 0.6 +/- 1.1 mm Hg; 3%; P > 0.1), and this effect was reversible by L-arginine. Moreover, L-NAME reduced the response to carbogen by 29% (DeltaPO(2) = 9.1 +/- 4.4 mm Hg; 49%; P = 0.01 versus before L-NAME). The response to hyperoxia was not affected. Whereas systemic NOS inhibition did not affect optic disc PO(2) in normoxia, a blunting effect was noted on the CO(2)-induced optic disc PO(2) increase. Nitric oxide appears to mediate the hypercapnic optic disc PO(2) increase.

  4. Catalytic Activity Studies of Vanadia/Silica–Titania Catalysts in SVOC Partial Oxidation to Formaldehyde: Focus on the Catalyst Composition

    Directory of Open Access Journals (Sweden)

    Niina Koivikko

    2018-02-01

    Full Text Available In this work, silica–titania supported catalysts were prepared by a sol–gel method with various compositions. Vanadia was impregnated on SiO2-TiO2 with different loadings, and materials were investigated in the partial oxidation of methanol and methyl mercaptan to formaldehyde. The materials were characterized by using N2 physisorption, X-ray diffraction (XRD, X-ray fluorescence spectroscopy (XRF, X-ray photoelectron spectroscopy (XPS, Scanning transmission electron microscope (STEM, NH3-TPD, and Raman techniques. The activity results show the high importance of an optimized SiO2-TiO2 ratio to reach a high reactant conversion and formaldehyde yield. The characteristics of mixed oxides ensure a better dispersion of the active phase on the support and in this way increase the activity of the catalysts. The addition of vanadium pentoxide on the support lowered the optimal temperature of the reaction significantly. Increasing the vanadia loading from 1.5% to 2.5% did not result in higher formaldehyde concentration. Over the 1.5%V2O5/SiO2 + 30%TiO2 catalyst, the optimal selectivity was reached at 415 °C when the maximum formaldehyde concentration was ~1000 ppm.

  5. Calculation of gas-flow in plasma reactor for carbon partial oxidation

    Science.gov (United States)

    Bespala, Evgeny; Myshkin, Vyacheslav; Novoselov, Ivan; Pavliuk, Alexander; Makarevich, Semen; Bespala, Yuliya

    2018-03-01

    The paper discusses isotopic effects at carbon oxidation in low temperature non-equilibrium plasma at constant magnetic field. There is described routine of experiment and defined optimal parameters ensuring maximum enrichment factor at given electrophysical, gas-dynamic, and thermodymanical parameters. It has been demonstrated that at high-frequency generator capacity of 4 kW, supply frequency of 27 MHz and field density of 44 mT the concentration of paramagnetic heavy nuclei 13C in gaseous phase increases up to 1.78 % compared to 1.11 % for natural concentration. Authors explain isotopic effect decrease during plasmachemical separation induced by mixing gas flows enriched in different isotopes at the lack of product quench. With the help of modeling the motion of gas flows inside the plasma-chemical reactor based on numerical calculation of Navier-Stokes equation authors determine zones of gas mixing and cooling speed. To increase isotopic effects and proportion of 13C in gaseous phase it has been proposed to use quench in the form of Laval nozzle of refractory steel. The article represents results on calculation of optimal Laval Nozzle parameters for plasma-chemical reactor of chosen geometry of. There are also given dependences of quench time of products on pressure at the diffuser output and on critical section diameter. Authors determine the location of quench inside the plasma-chemical reactor in the paper.

  6. Partial oxidation of methane to syngas on Rh/Al{sub 2}O{sub 3} and Rh/Ce-ZrO{sub 2} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Raquel L.; Bitencourt, Isabela G.; Passos, Fabio B., E-mail: fbpassos@vm.uff.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Quimica e Petroleo

    2013-01-15

    The partial oxidation of methane with {gamma}-Al{sub 2}O{sub 3}-, CeO{sub 2}-, ZrO{sub 2}- and Ce-ZrO{sub 2}-supported rhodium catalysts was investigated. DRIFTS (diffuse reflectance infrared spectroscopy) measurements of adsorbed CO showed the formation of different rhodium species on different supports, which influenced the dispersion of the metal. The effects of the metal dispersion, oxygen storage capacity on the activity of these catalysts for the partial oxidation of methane are discussed. (author)

  7. Lycium barbarum (wolfberry reduces secondary degeneration and oxidative stress, and inhibits JNK pathway in retina after partial optic nerve transection.

    Directory of Open Access Journals (Sweden)

    Hongying Li

    Full Text Available Our group has shown that the polysaccharides extracted from Lycium barbarum (LBP are neuroprotective for retinal ganglion cells (RGCs in different animal models. Protecting RGCs from secondary degeneration is a promising direction for therapy in glaucoma management. The complete optic nerve transection (CONT model can be used to study primary degeneration of RGCs, while the partial optic nerve transection (PONT model can be used to study secondary degeneration of RGCs because primary degeneration of RGCs and secondary degeneration can be separated in location in the same retina in this model; in other situations, these types of degeneration can be difficult to distinguish. In order to examine which kind of degeneration LBP could delay, both CONT and PONT models were used in this study. Rats were fed with LBP or vehicle daily from 7 days before surgery until sacrifice at different time-points and the surviving numbers of RGCs were evaluated. The expression of several proteins related to inflammation, oxidative stress, and the c-jun N-terminal kinase (JNK pathways were detected with Western-blot analysis. LBP did not delay primary degeneration of RGCs after either CONT or PONT, but it did delay secondary degeneration of RGCs after PONT. We found that LBP appeared to exert these protective effects by inhibiting oxidative stress and the JNK/c-jun pathway and by transiently increasing production of insulin-like growth factor-1 (IGF-1. This study suggests that LBP can delay secondary degeneration of RGCs and this effect may be linked to inhibition of oxidative stress and the JNK/c-jun pathway in the retina.

  8. Lycium Barbarum (Wolfberry) Reduces Secondary Degeneration and Oxidative Stress, and Inhibits JNK Pathway in Retina after Partial Optic Nerve Transection

    Science.gov (United States)

    Li, Hongying; Liang, Yuxiang; Chiu, Kin; Yuan, Qiuju; Lin, Bin; Chang, Raymond Chuen-Chung; So, Kwok-Fai

    2013-01-01

    Our group has shown that the polysaccharides extracted from Lycium barbarum (LBP) are neuroprotective for retinal ganglion cells (RGCs) in different animal models. Protecting RGCs from secondary degeneration is a promising direction for therapy in glaucoma management. The complete optic nerve transection (CONT) model can be used to study primary degeneration of RGCs, while the partial optic nerve transection (PONT) model can be used to study secondary degeneration of RGCs because primary degeneration of RGCs and secondary degeneration can be separated in location in the same retina in this model; in other situations, these types of degeneration can be difficult to distinguish. In order to examine which kind of degeneration LBP could delay, both CONT and PONT models were used in this study. Rats were fed with LBP or vehicle daily from 7 days before surgery until sacrifice at different time-points and the surviving numbers of RGCs were evaluated. The expression of several proteins related to inflammation, oxidative stress, and the c-jun N-terminal kinase (JNK) pathways were detected with Western-blot analysis. LBP did not delay primary degeneration of RGCs after either CONT or PONT, but it did delay secondary degeneration of RGCs after PONT. We found that LBP appeared to exert these protective effects by inhibiting oxidative stress and the JNK/c-jun pathway and by transiently increasing production of insulin-like growth factor-1 (IGF-1). This study suggests that LBP can delay secondary degeneration of RGCs and this effect may be linked to inhibition of oxidative stress and the JNK/c-jun pathway in the retina. PMID:23894366

  9. Comparison of Elemental Mercury Oxidation Across Vanadium and Cerium Based Catalysts in Coal Combustion Flue Gas: Catalytic Performances and Particulate Matter Effects.

    Science.gov (United States)

    Wan, Qi; Yao, Qiang; Duan, Lei; Li, Xinghua; Zhang, Lei; Hao, Jiming

    2018-03-06

    This paper discussed the field test results of mercury oxidation activities over vanadium and cerium based catalysts in both coal-fired circulating fluidized bed boiler (CFBB) and chain grate boiler (CGB) flue gases. The characterizations of the catalysts and effects of flue gas components, specifically the particulate matter (PM) species, were also discussed. The catalytic performance results indicated that both catalysts exhibited mercury oxidation preference in CGB flue gas rather than in CFBB flue gas. Flue gas component studies before and after dust removal equipment implied that the mercury oxidation was well related to PM, together with gaseous components such as NO, SO 2 , and NH 3 . Further investigations demonstrated a negative PM concentration-induced effect on the mercury oxidation activity in the flue gases before the dust removal, which was attributed to the surface coverage by the large amount of PM. In addition, the PM concentrations in the flue gases after the dust removal failed in determining the mercury oxidation efficiency, wherein the presence of different chemical species in PM, such as elemental carbon (EC), organic carbon (OC) and alkali (earth) metals (Na, Mg, K, and Ca) in the flue gases dominated the catalytic oxidation of mercury.

  10. Ozone decomposition kinetics on alumina: effects of ozone partial pressure, relative humidity and repeated oxidation cycles

    Directory of Open Access Journals (Sweden)

    R. C. Sullivan

    2004-01-01

    Full Text Available The room temperature kinetics of gas-phase ozone loss via heterogeneous interactions with thin alumina films has been studied in real-time using 254nm absorption spectroscopy to monitor ozone concentrations. The films were prepared from dispersions of fine alumina powder in methanol and their surface areas were determined by an in situ procedure using adsorption of krypton at 77K. The alumina was found to lose reactivity with increasing ozone exposure. However, some of the lost reactivity could be recovered over timescales of days in an environment free of water, ozone and carbon dioxide. From multiple exposures of ozone to the same film, it was found that the number of active sites is large, greater than 1.4x1014 active sites per cm2 of surface area or comparable to the total number of surface sites. The films maintain some reactivity at this point, which is consistent with there being some degree of active site regeneration during the experiment and with ozone loss being catalytic to some degree. The initial uptake coefficients on fresh films were found to be inversely dependent on the ozone concentration, varying from roughly 10-6 for ozone concentrations of 1014 molecules/cm3 to 10-5 at 1013 molecules/cm3. The initial uptake coefficients were not dependent on the relative humidity, up to 75%, within the precision of the experiment. The reaction mechanism is discussed, as well as the implications these results have for assessing the effect of mineral dust on atmospheric oxidant levels.

  11. A DRIFTS study of the partial oxidation of ethanol on Rh catalysts; Estudo da oxidacao parcial do etanol em catalisadores de Rh por DRIFTS

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Raquel Lima; Passos, Fabio Barboza, E-mail: fbpassos@vm.uff.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Departamento de Engenharia Quimica e de Petroleo

    2013-09-01

    The partial oxidation of ethanol on {gamma}-Al{sub 2}O{sub 3}, CeO{sub 2}, ZrO{sub 2} and Ce{sub x}Zr{sub 1-x}O{sub 2} supported rhodium catalysts was investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). The catalysts were characterized by temperature-programmed reduction (TPR) and cyclohexane dehydrogenation. DRIFTS studies on the partial oxidation of ethanol showed that ethanol is adsorbed dissociatively, through O-H bond breaking, with the formation of ethoxy species, followed by successive dehydrogenation to acetaldehyde and acetyl species. Further oxidation to acetate and carbonate species lead to the formation of CO, CH{sub 4} and H{sub 2} by decomposition. The presence of CeO{sub 2} in the catalysts favored the oxidation steps due to its oxygen storage capacity. (author)

  12. High temperature mechanisms and kinetics of SiC oxidation under low partial pressures of oxygen: application to the fuel cladding of gas fast reactors

    International Nuclear Information System (INIS)

    Hun, N.

    2011-01-01

    Gas Fast Reactor (GFR) is one of the different Generation IV concepts under investigation for energy production. SiC/SiC composites are candidates of primary interest for a GFR fuel cladding use, thanks to good corrosion resistance among other properties. The mechanisms and kinetics of SiC oxidation under operating conditions have to be identified and quantified as the corrosion can decrease the mechanical properties of the composite. An experimental device has been developed to study the oxidation of silicon carbide under high temperature and low oxygen partial pressure. The results pointed out that not only parabolic oxidation, but also interfacial reactions and volatilization occur under such conditions. After determining the kinetics of each mechanism, as functions of oxygen partial pressure and temperature, the data are used for the modeling of the composites oxidation. The model will be used to predict the lifetime of the composite in operating conditions. (author) [fr

  13. Investigation into the effects of trace coal syn gas species on the performance of solid oxide fuel cell anodes, PhD. thesis, Russ College of Engineering and Technology of Ohio University

    Energy Technology Data Exchange (ETDEWEB)

    Trembly, Jason P. [Ohio Univ., Athens, OH (United States). Russ College of Engineering and Technology

    2007-06-01

    Coal is the United States’ most widely used fossil fuel for the production of electric power. Coal’s availability and cost dictates that it will be used for many years to come in the United States for power production. As a result of the environmental impact of burning coal for power production more efficient and environmentally benign power production processes using coal are sought. Solid oxide fuel cells (SOFCs) combined with gasification technologies represent a potential methodology to produce electric power using coal in a much more efficient and cleaner manner. It has been shown in the past that trace species contained in coal, such as sulfur, severely degrade the performance of solid oxide fuel cells rendering them useless. Coal derived syngas cleanup technologies have been developed that efficiently remove sulfur to levels that do not cause any performance losses in solid oxide fuel cells. The ability of these systems to clean other trace species contained in syngas is not known nor is the effect of these trace species on the performance of solid oxide fuel cells. This works presents the thermodynamic and diffusion transport simulations that were combined with experimental testing to evaluate the effects of the trace species on the performance of solid oxide fuel cells. The results show that some trace species contained in coal will interact with the SOFC anode. In addition to the transport and thermodynamic simulations that were completed experimental tests were completed investigating the effect of HCl and AsH3 on the performance of SOFCs.

  14. Effects of coal storage in air on physical and chemical properties of coal and on gas adsorption

    Science.gov (United States)

    Mastalerz, Maria; Solano-Acosta, W.; Schimmelmann, A.; Drobniak, A.

    2009-01-01

    This paper investigates changes in the high-volatile bituminous Lower Block Coal Member from Indiana owing to moisture availability and oxidation in air at ambient pressure and temperature over storage time. Specifically, it investigates changes in chemistry, in surface area, and pore structure, as well as changes in methane and carbon dioxide adsorption capacities. Our results document that the methane adsorption capacity increased by 40%, whereas CO2 adsorption capacity increased by 18% during a 13-month time period. These changes in adsorption are accompanied by changes in chemistry and surface area of the coal. The observed changes in adsorption capacity indicate that special care must be taken when collecting samples and preserving coals until adsorption characteristics are measured in the laboratory. High-pressure isotherms from partially dried coal samples would likely cause overestimation of gas adsorption capacities, lead to a miscalculation of coal-bed methane prospects, and provide deceptively optimistic prognoses for recovery of coal-bed methane or capture of anthropogenic CO2. ?? 2009 Elsevier B.V. All rights reserved.

  15. New coal

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-01

    Specially dedicated to coal, this edition comprises a series of articles of general interest dealing with the position of the French coalmining industry (interview with M.P. Gardent), the coal market in France, the work of CERCHAR, etc. New techniques, in-situ gasification of deep coal, gasification of coal by nuclear methods, the conversion of coal into petrol, the Emile Huchet power plant of Houilleres du Bassin de Lorraine, etc., are dealt with.

  16. Coal upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, S. [IEA Clean Coal Centre, London (United Kingdom)

    2009-10-15

    This report examines current technologies and those likely to be used to produce cleaner coal and coal products, principally for use in power generation and metallurgical applications. Consideration is also given to coal production in the leading coal producing countries, both with developed and developing industries. A range of technologies are considered. These include the coal-based liquid fuel called coal water mixture (CWM) that may compete with diesel, the production of ultra-clean coal (UCC) and coal liquefaction which competes with oil and its products. Technologies for upgrading coal are considered, especially for low rank coals (LRC), since these have the potential to fill the gap generated by the increasing demand for coal that cannot be met by higher quality coals. Potential advantages and downsides of coal upgrading are outlined. Taking into account the environmental benefits of reduced pollution achieved through cleaner coal and reduced transport costs, as well as other positive aspects such as a predictable product leading to better boiler design, the advantages appear to be significant. The drying of low rank coals improves the energy productively released during combustion and may also be used as an adjunct or as part of other coal processing procedures. Coal washing technologies vary in different countries and the implications of this are outlined. Dry separation technologies, such as dry jigging and electrostatic separation, are also described. The demonstration of new technologies is key to their further development and demonstrations of various clean coal technologies are considered. A number of approaches to briquetting and pelletising are available and their use varies from country to country. Finally, developments in upgrading low rank coals are described in the leading coal producing countries. This is an area that is developing rapidly and in which there are significant corporate and state players. 81 refs., 32 figs., 3 tabs.

  17. Experimental research on influencing factors of wet removal of NO from coal-fired flue gas by UV/H2O2 advanced oxidation process

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Wet removal of NO from coal-fired flue gas by UV/H2O2 Advanced Oxidation Process (AOP) were investigated in a self-designed UV-bubble reactor. Several main influencing factors (UV intensity, H2O2 initial concentration, initial pH value, solution temperature, NO initial concentration, liquid-gas ratio and O2 percentage content) on the NO removal efficiency were studied. The results showed that UV intensity, H2O2 initial concentration, NO initial concentration and liquid-gas ratio are the main influencing factors. In the best conditions, the highest NO removal efficiency by UV/H2O2 advanced oxidation process could reach 82.9%. Based on the experimental study, the influencing mechanism of the relevant influencing factors were discussed in depth.

  18. Solubilization of low-rank coal by Trichoderma atroviride: Evidence for the involvement of hydrolytic and oxidative enzymes by using C-14-labelled lignite

    Energy Technology Data Exchange (ETDEWEB)

    Holker, U.; Schmiers, H.; Grosse, S.; Winkelhofer, M.; Polsakiewicz, M.; Ludwig, S.; Dohse, J.; Hofer, M. [University of Bonn, Bonn (Germany). Inst. of Botany

    2002-04-01

    The deuteromycete Trichoderma atroviride is able to solubilize lignite in dependence on a given carbon source for growth. When cultivated on media containing glutamate, this mold excreted a set of different enzymes with hydrolytic activity. Addition of lignite to the growth media induced the synthesis of extracellular lignite-specific esterase activity but no evidence has been provided for its direct involvement in the process of lignite solubilization. Hence, the basic capability of T. atroviride enzymes to degrade a variety of ester and ether bonds at the surface or within the bulky lignite structure was tested using coal following its direct labelling with C-14-alkyl iodide. The participation of hydrolytic and oxidative enzymes in lignite degradation was assessed by measuring the release of C-14 radioactivity from selectively alkylated carboxylic and phenolic OH groups. T. atroviride cleaved both carboxylic esters using esterases and the phenolic ether bonds by using oxidative enzymes, most likely laccases.

  19. Preparation and tumor cell model based biobehavioral evaluation of the nanocarrier system using partially reduced graphene oxide functionalized by surfactant

    Directory of Open Access Journals (Sweden)

    Wang Y

    2015-07-01

    Full Text Available Yimin Wang,1 Kunping Liu,1,2 Zewei Luo,1 Yixiang Duan1 1Research Center of Analytical Instrumentation, Key Laboratory of Bio-resource and Eco-environment, Ministry of Education, College of Life Science, Sichuan University, 2Faculty of Biotechnology Industry, Chengdu University, Chengdu, People’s Republic of China Background: Currently, surfactant-functionalized nanomaterials are tending toward development of novel tumor-targeted drug carriers to overcome multidrug resistance in cancer therapy. Now, investigating the biocompatibility and uptake mechanism of specific drug delivery systems is a growing trend, but usually a troublesome issue, in simple pharmaceutical research.Methods: We first reported the partially reduced graphene oxide modified with poly(sodium 4-styrenesulfonate (PSS as a nanocarrier system. Then, the nanocarrier was characterized by atomic force microscope, scanning electron microscope, high-resolution transmission electron microscope, ultraviolet–visible (UV-vis spectroscopy, Fourier transform infrared spectroscopy, X-Ray powder diffraction, and Raman spectroscopy. Epirubicin (EPI was attached to PSSG via π–π stacking, hydrogen bonding, and physical absorption to form conjugates of PSSG–EPI. The adsorption and desorption profiles, cytotoxicity coupled with drug accumulation, and uptake of PSSG and PSSG–EPI were evaluated. Finally, the subcellular behaviors, distribution, and biological fate of the drug delivery system were explored by confocal laser scanning microscope using direct fluorescence colocalization imaging and transmission electron microscopy.Results: The partially reduced graphene oxide sheets functionalized by surfactant exhibit good dispersibility. Moreover, due to much less carboxyl groups retained on the edge of PSSG sheets, the nanocarriers exhibit biocompatibility in vitro. The obtained PSSG shows a high drug-loading capacity of 2.22 mg/mg. The complexes of PSSG–EPI can be transferred to

  20. Initial oxidation processes of Si(001) surfaces by supersonic O2 molecular beams. Different oxidation mechanisms for clean and partially-oxidized surfaces

    International Nuclear Information System (INIS)

    Teraoka, Yuden; Yoshigoe, Akitaka

    2002-01-01

    Potential energy barriers for dissociative chemisorption of O 2 molecules on Si(001) clean surfaces were investigated using supersonic O 2 molecular beams and photoemission spectroscopy. Relative initial sticking probabilities of O 2 molecules and the saturated oxygen amount on the Si(001) surface were measured as a function of incident energy of O 2 molecules. Although the probability was independent on the incident energy in the region larger than 1 eV, the saturated oxygen amount was dependent on the incident energy without energy thresholds. An Si-2p photoemission spectrum of the Si(001) surface oxidized by thermal O 2 gas revealed the oxygen insertion into dimer backbond sites. These facts indicate that a reaction path of the oxygen insertion into dimer backbonds through bridge sites is open for the clean surface oxidation, and the direct chemisorption probability at the backbonds is negligibly small comparing with that at the bridge sites. (author)

  1. Vitamin E and Lycopene Reduce Coal Burning Fluorosis-induced Spermatogenic Cell Apoptosis via Oxidative Stress-mediated JNK and ERK Signaling Pathways.

    Science.gov (United States)

    Tian, Yuan; Xiao, Yuehai; Wang, Bolin; Sun, Chao; Tang, Kaifa; Sun, Fa

    2017-12-22

    Although fluoride has been widely used in toothpaste, mouthwash, and drinking water to prevent dental caries, the excessive intake of fluoride can cause fluorosis which is associated with dental, skeletal, and soft tissue fluorosis. Recent evidences have drawn the attention to its adverse effects on male reproductive system that include spermatogenesis defect, sperm count loss, and sperm maturation impairment. Fluoride induces oxidative stress through the activation of mitogen activated protein kinase (MAPK) cascade which can lead to cell apoptosis. Vitamin E (VE) and lycopene are two common anti-oxidants, being protective to reactive oxygen species (ROS)-induced toxic effects. However, whether and how these two anti-oxidants prevent fluoride-induced spermatogenic cell apoptosis are largely unknown. In the present study, a male rat model for coal burning fluorosis was established and the histological lesions and spermatogenic cell apoptosis in rat testes were observed. The decreased expression of clusterin, a heterodimeric glycoprotein reported to regulate spermatogenic cell apoptosis, is detected in fluoride-treated rat testes. Interestingly, the co-administration with VE or lycopene reduced fluorosis-mediated testicular toxicity and rescued clusterin expression. Further, fluoride caused the enhanced Jun N-terminal kinase (JNK) and extracellular signal-regulated protein kinase (ERK) phosphorylation, which was reduced by VE or lycopene. Thus, VE and lycopene prevent coal burning fluorosis-induced spermatogenic cell apoptosis through the suppression of oxidative stress-mediated JNK and ERK signaling pathway, which could be an alternative therapeutic strategy for the treatment of fluorosis. ©2017 The Author(s).

  2. Effect of Mass-Transport Limitations on the Performance of a Packed Bed Membrane Reactor for Partial Oxidations. Transport from the Membrane to the Packed Bed

    NARCIS (Netherlands)

    van Sint Annaland, M.; Kurten, U.; Kuipers, J.A.M.

    2007-01-01

    With a packed bed membrane reactor, the product yield can be significantly enhanced for partial oxidation systems, via distributive addition of oxygen to the reaction mixture along the axial coordinate of the reactor, provided that the reaction order in oxygen of the formation rate of the target

  3. Effect of mass-transport limitations on the performance of a packed bed membrane reactor for partial oxidations. Transport from the membrane to the packed bed

    NARCIS (Netherlands)

    Sint Annaland, van M.; Kurten, U.; Kuipers, J.A.M.

    2007-01-01

    With a packed bed membrane reactor, the product yield can be significantly enhanced for partial oxidation systems, via distributive addition of oxygen to the reaction mixture along the axial coordinate of the reactor, provided that the reaction order in oxygen of the formation rate of the target

  4. Effect of mass-transport limitations on the performance of a packed bed membrane reactor for partial oxidations. Intraparticle mass transport

    NARCIS (Netherlands)

    Sint Annaland, van M.; Kurten, U.; Kuipers, J.A.M.

    2007-01-01

    For partial oxidation systems, where the reaction order in oxygen of the formation rate of the target product is smaller than the reaction order in oxygen of the consecutive reaction rate toward the waste product, a packed bed membrane reactor can be applied to distributively dose oxygen along the

  5. Effect of Mass-Transport Limitations on the Performance of a Packed Bed Membrane Reactor for Partial Oxidations. Intraparticle Mass Transport

    NARCIS (Netherlands)

    van Sint Annaland, M.; Kurten, U.; Kuipers, J.A.M.

    2007-01-01

    For partial oxidation systems, where the reaction order in oxygen of the formation rate of the target product is smaller than the reaction order in oxygen of the consecutive reaction rate toward the waste product, a packed bed membrane reactor can be applied to distributively dose oxygen along the

  6. Methane partial oxidation over a LaCr0.85Ru0.15O3 catalyst : Characterization, activity tests and kinetic modeling

    NARCIS (Netherlands)

    Melchiori, T.; Di Felice, L.; Mota, N.; Navarro, R.M.; Fierro, J.L.G.; Sint Annaland, van M.; Gallucci, F.

    2014-01-01

    A new LaCr0.85Ru0.15O3 perovskite-type catalyst for CH4 partial oxidation with a high activity and selectivity for syngas with good thermal stability and resistance against coking has been developed. In this paper, the catalyst preparation method, catalyst characterization, results of catalytic

  7. The reaction mechanism of the partial oxidation of methane to synthesis gas: a transient kinetic study over rhodium and a comparison with platinum

    NARCIS (Netherlands)

    Mallens, E.P.J.; Hoebink, J.H.B.J.; Marin, G.B.M.M.

    1997-01-01

    The partial oxidation of methane to synthesis gas over rhodium sponge has been investigated by admitting pulses of pure methane and pure oxygen as well as mixtures of methane and oxygen to rhodium sponge at temperatures from 873 to 1023 K. Moreover, pulses of oxygen followed by methane and vice

  8. Coal-92

    International Nuclear Information System (INIS)

    Hillring, B.; Sparre, C.

    1992-11-01

    Swedish consumption of coal and coke during 1991 and trends in technology, environment and market aspects of coal use are reported. Steam coal use in the heating sector was unchanged from 1991, 1.2 Mtons. Reduced consumption in smaller district heating units (due to conversion to biofuels and gas) was compensated by increased use for power generation in cogeneration plants. Coal consumption in industry fell 0.10 Mton to 0.84 Mton due to lower production in one industry branch. Import of steam coal was 1.1 Mton (down 0.5 Mton from 1990) since new rules for strategic reserves allowed a reduction of stocks. During the last five years stocks have been reduced by 2 Mtons. Import of metallurgical coal was 1.6 Mton, unchanged from 1990. The report also gives statistics for the coal using plants in Sweden, on coal R and D, and on emission laws for coal firing. (9 tabs., 2 figs.)

  9. Utilisation of chemically treated coal

    Directory of Open Access Journals (Sweden)

    Bežovská Mária

    2002-03-01

    Full Text Available The numerous application of coal with high content of humic substances are known. They are used in many branches of industry. The complex study of the composition of coal from upper Nitra mines has directed research to its application in the field of ecology and agriculture. The effective sorption layers of this coal and their humic acids can to trap a broad spectrum of toxic harmful substances present in industrial wastes, particularly heavy metals. A major source of humic acids is coal - the most abundant and predominant product of plant residue coalification. All ranks of coal containt humic acids but lignite from Nováky deposit represents the most easily available and concentrated form of humic acids. Deep oxidation of coal by HNO3 oxidation - degradation has been performed to produce water-soluble-organic acids. The possibilities of utilisation of oxidised coal and humic acids to remove heavy metals from waste waters was studied. The residual concentrations of the investigated metals in the aqueous phase were determined by AAs. From the results follows that the samples of oxidised coal and theirs humic acids can be used for the heavy metal removal from metal solutions and the real acid mine water.Oxidised coal with a high content of humic acids and nitrogen is used in agriculture a fertilizer. Humic acids are active component in coal and help to utilize almost quantitatively nitrogen in soil. The humic substances block and stabiliz toxic metal residues already present in soil.

  10. Formation of polymerization compounds during thermal oxidation of cottonseed oil, partially hydrogenated cottonseed oil and their blends

    Directory of Open Access Journals (Sweden)

    Barrera-Arellano, D. Laboratório de Óleos e Gorduras, Departa

    2006-09-01

    Full Text Available Samples of cottonseed oil, partially hydrogenated cottonseed oil and their blends, with iodine values between 60 and 110, tocopherol-stripped or not by aluminium oxide treatment, were submitted to thermal oxidation, at 180 °C, for 10 hours. Samples were collected at 0, 2, 5, 8 and 10 hours, for the determination of dimers and polymers (degradation compounds and of tocopherols. The influence of the degree of hydrogenation on the formation of dimers and polymers and the role of originally present tocopherols in the protection of fats and oils against thermal degradation was verified. The degradation curves for tocopherols showed a fast destruction rate for the tocopherols present in cottonseed fats and oil (α and γ-tocopherols, with residual levels close to zero after 10 hours under thermal oxidation conditions. Nevertheless, samples with their natural tocopherols presented a slower rate of thermal degradation. The unsaturation degree was apparently more important in the protection against thermal degradation than the content of tocopherolsMuestras de aceite de algodón, aceite de algodón parcialmente hidrogenado y sus mezclas, con índices de yodo de 60 a 110, tratadas o no con óxido de aluminio, fueron sometidas a termoxidación, a 180 °C, durante 10 horas. Se retiraron muestras en los tiempos 0, 2, 5, 8 y 10 horas, para determinación de dímeros y polímeros (compuestos de degradación y de tocoferoles. Se verificó la influencia del grado de hidrogenación sobre la formación de dímeros y polímeros, y también el papel de los tocoferoles originalmente presentes en el aceite y en las grasas, en la protección contra la degradación térmica. Las curvas de degradación de los tocoferoles mostraron una destrucción bastante rápida de los tocoferoles presentes en el aceite y en las grasas de algodón (α y γ-tocoferoles, con niveles residuales próximos a cero después de 10 horas de termoxidación. Aún así, muestras con sus

  11. Bio-oil steam reforming, partial oxidation or oxidative steam reforming coupled with bio-oil dry reforming to eliminate CO{sub 2} emission

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xun [State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Lu, Gongxuan [State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2010-07-15

    Biomass is carbon-neutral and utilization of biomass as hydrogen resource shows no impact on atmospheric CO{sub 2} level. Nevertheless, a significant amount of CO{sub 2} is always produced in biomass gasification processes. If the CO{sub 2} produced can further react with biomass, then the biomass gasification coupled with CO{sub 2} reforming of biomass will result in a net decrease of CO{sub 2} level in atmosphere and produce the chemical raw material, syngas. To achieve this concept, a ''Y'' type reactor is developed and applied in bio-oil steam reforming, partial oxidation, or oxidative steam reforming coupled with CO{sub 2} reforming of bio-oil to eliminate the emission of CO{sub 2}. The experimental results show that the reaction systems can efficiently suppress the emission of CO{sub 2} from various reforming processes. The different coupled reaction systems generate the syngas with different molar ratio of CO/H{sub 2}. In addition, coke deposition is encountered in the different reforming processes. Both catalysts and experimental parameters significantly affect the coke deposition. Ni/La{sub 2}O{sub 3} catalyst shows much higher resistivity toward coke deposition than Ni/Al{sub 2}O{sub 3} catalyst, while employing high reaction temperature is vital for elimination of coke deposition. Although the different coupled reaction systems show different characteristic in terms of product distribution and coke deposition, which all can serve as methods for storage of the carbon from fossil fuels or air. (author)

  12. Coal 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    ACR's Coal 1992, the successor to the ACR Coal Marketing Manual, contains a comprehensive set of data on many aspects of the Australian coal industry for several years leading up to 1992. Tables and text give details of coal production and consumption in New South Wales, Queensland and other states. Statistics of the Australian export industry are complemented by those of South Africa, USA, New Zealand, Canada, Indonesia, China, Colombia, Poland and ex-USSR. Also listed are prices of Australian coking and non-coking coal, Australian coal stocks (and those of other major countries), loading port capacities, freight rates and coal quality requirements (analysis of coals by brand and supplier). A listing of Australian coal exporting companies is provided. A description of the spot Coal Screen Dealing System is given. World hard coal imports are listed by country and coal imports by major Asian countries tabulated. A forecast of demand by coal type and country up to the year 2000 is included.

  13. Proceedings of the international symposium on coal - science, technology, industry, business, environment

    Energy Technology Data Exchange (ETDEWEB)

    Narasimhan, K.S.; Sen, S. [eds.

    1996-12-31

    Papers were presented which covered the areas of coal science, advanced coal preparation, coal utilization, coal chemicals and the environment. These included carbon aromaticity, mineral studies, utilization of low rank coals, bioconversion of methane, swelling of coals, photocatalytic activity, flotation and effects of oxidation, microbial desulfurization, deashing, briquetting, commercial scale conversion of coal to fuels and chemicals, role of coal in iron and steel making, coal-water mixtures, dyes and chemical products, nitrogen oxides emissions and pollution control. 45 papers have been abstracted separately for the IEA Coal Research CD-ROM.

  14. Second annual clean coal technology conference: Proceedings

    International Nuclear Information System (INIS)

    1993-01-01

    This report contains paper on the following topics: coal combustion/coal processing; advanced electric power generation systems; combined nitrogen oxide/sulfur dioxide control technologies; and emerging clean coal issues and environmental concerns. These paper have been cataloged separately elsewhere

  15. Experimental and Numerical Investigation of Effect of Coal Rank on Burn-off Time in Pulverized Coal Combustion

    OpenAIRE

    Nozawa, Sohei; Wada, Nozomi; Matsushita, Yosuke; Yamamoto, Tsuyoshi; Omori, Motohira; Harada, Tatsuro

    2012-01-01

    Thermogravimetry (TG) for two different coal ranks, Loy Yang coal and Newlands coal, was carried out in an atmospheric air environment. Detailed parameters of the heterogeneous oxidation reaction for each coal rank were estimated by analyzing the TG results. Heat and mass transfer of a single pulverized coal particle that was heated at a constant temperature were numerically simulated. In this calculation, the decrease in the mass ratio caused by the oxidation reaction was considered. The num...

  16. Coal pump

    Science.gov (United States)

    Bonin, John H.; Meyer, John W.; Daniel, Jr., Arnold D.

    1983-01-01

    A device for pressurizing pulverized coal and circulating a carrier gas is disclosed. This device has utility in a coal gasification process and eliminates the need for a separate collection hopper and eliminates the separate compressor.

  17. Innovative clean coal technology: 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. Final report, Phases 1 - 3B

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This report presents the results of a U.S. Department of Energy (DOE) Innovative Clean Coal Technology (ICCT) project demonstrating advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. The project was conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The technologies demonstrated at this site include Foster Wheeler Energy Corporation`s advanced overfire air system and Controlled Flow/Split Flame low NOx burner. The primary objective of the demonstration at Hammond Unit 4 was to determine the long-term effects of commercially available wall-fired low NOx combustion technologies on NOx emissions and boiler performance. Short-term tests of each technology were also performed to provide engineering information about emissions and performance trends. A target of achieving fifty percent NOx reduction using combustion modifications was established for the project. Short-term and long-term baseline testing was conducted in an {open_quotes}as-found{close_quotes} condition from November 1989 through March 1990. Following retrofit of the AOFA system during a four-week outage in spring 1990, the AOFA configuration was tested from August 1990 through March 1991. The FWEC CF/SF low NOx burners were then installed during a seven-week outage starting on March 8, 1991 and continuing to May 5, 1991. Following optimization of the LNBs and ancillary combustion equipment by FWEC personnel, LNB testing commenced during July 1991 and continued until January 1992. Testing in the LNB+AOFA configuration was completed during August 1993. This report provides documentation on the design criteria used in the performance of this project as it pertains to the scope involved with the low NOx burners and advanced overfire systems.

  18. Gaseous emissions from coal stockpiles

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-01-15

    Stockpiled coal undergoes atmospheric oxidation and desorption processes during open air storage. These processes release gases to the environment which may effect health and safety by their toxicity and flammability. In extreme cases, this could lead to a fire. This report discusses gaseous emissions from coal stockpiles. It covers gas emission mechanisms, and gas sampling and testing methods, before examining in more detail the principal gases that have been emitted. It concludes that there is limited research in this area and more data are needed to evaluate the risks of gaseous emissions. Some methods used to prevent coal self-heating and spontaneous combustion can be applied to reduce emissions from coal stockpiles.

  19. Effect of PEEP and inhaled nitric oxide on pulmonary gas exchange during gaseous and partial liquid ventilation with small volumes of perfluorocarbon.

    Science.gov (United States)

    Max, M; Kuhlen, R; Falter, F; Reyle-Hahn, M; Dembinski, R; Rossaint, R

    2000-04-01

    Partial liquid ventilation, positive end-expiratory pressure (PEEP) and inhaled nitric oxide (NO) can improve ventilation/perfusion mismatch in acute lung injury (ALI). The aim of the present study was to compare gas exchange and hemodynamics in experimental ALI during gaseous and partial liquid ventilation at two different levels of PEEP, with and without the inhalation of nitric oxide. Seven pigs (24+/-2 kg BW) were surfactant-depleted by repeated lung lavage with saline. Gas exchange and hemodynamic parameters were assessed in all animals during gaseous and subsequent partial liquid ventilation at two levels of PEEP (5 and 15 cmH2O) and intermittent inhalation of 10 ppm NO. Arterial oxygenation increased significantly with a simultaneous decrease in cardiac output when PEEP 15 cmH2O was applied during gaseous and partial liquid ventilation. All other hemodynamic parameters revealed no relevant changes. Inhalation of NO and instillation of perfluorocarbon had no additive effects on pulmonary gas exchange when compared to PEEP 15 cmH2O alone. In experimental lung injury, improvements in gas exchange are most distinct during mechanical ventilation with PEEP 15 cmH2O without significantly impairing hemodynamics. Partial liquid ventilation and inhaled NO did not cause an additive increase of PaO2.

  20. Effect of the parameters of a straight-through pulverized coal spray on formation of nitrogen oxides

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.

    1987-04-01

    Experiments were conducted on varying the parameters affecting intensity of the mixing process at the starting point of a pulverized coal spray. Investigations were carried out using Donetsk black coal in a BKZ-210-140FZhSh steam generator equipped with a tangential combustion chamber. The plant featured liquid slag removal and direct blow-in as well as a medium-speed model VSM-140 mill. Four experiments were conducted in which gas samples were taken from the combustion chamber and analyzed for RO/sub 2/ and O/sub 2/ as well as CO and H/sub 2/. A relationship between reducing gases at the starting point of the torch and the initial air feed factor was demonstrated. Experiments were conducted to determine a relationship between NO/sub x/ concentrations in exhaust gases and the initial air feed factor. 5 refs.

  1. Formation and destruction mechanisms of nitrogen oxides during coal combustion in circulating fluidized beds; Mecanismes de formation et de destruction des oxydes d`azote lors de la combustion du charbon en lit fluidise circulant

    Energy Technology Data Exchange (ETDEWEB)

    Borrel, G.; Lecuyer, I. [Universite du Haut-Rhin, 68 - Mulhouse (France)

    1997-01-01

    Formation and reduction of nitrogen oxides (NO and N{sub 2}O) during coal combustion in a circulating fluidized bed (CFBC) are very complicated and yet badly known. The aim of the present study was to better characterize these phenomena on a small-sized experimental unit (reactor diameter: 5 cm), with the possibility to re-inject the solids in the bottom of the furnace, as in a real industrial unit. This should allow then to develop a numerical set of chemical reactions involving the nitrogen oxides. The experimental results showed that coal ash plays a great role in reducing nitrogen oxides, the determining parameter being the quantity of unburnt carbon remaining in the ash. The study then detailed the interaction between nitrogen oxides and de-volatilized (char) according to the temperature, NO{sub x} concentration and the mass of solid. In the absence of oxygen small quantities of char can very significantly reduce NO as well as N{sub 2}O. It was possible to establish destruction kinetics on these particles, and orders of reaction could be determined versus the NO{sub x} concentration and the char particle mass (heterogeneous phase chemical reactions). Then, the coal pyrolysis study enabled to identify the products released during coal devolatilization and thermogravimetric analyses displayed several successive weight losses due CO, CO{sub 2} and CH{sub 4} releases, during a linear temperature increase. Lastly coal combustion was studied in the small pilot with variable experimental conditions. Using the previous experimental was studied in the small pilot with variable experimental conditions. Using the previous experimental results, a model was developed to calculate NO{sub x} concentrations during the coal combustion and validated. The NO and N{sub 2}O contents calculated are thoroughly correlated with the experimental data whatever the injection carbon/oxygen ratio is. (author) 96 refs.

  2. Bias-induced migration of ionized donors in amorphous oxide semiconductor thin-film transistors with full bottom-gate and partial top-gate structures

    Directory of Open Access Journals (Sweden)

    Mallory Mativenga

    2012-09-01

    Full Text Available Bias-induced charge migration in amorphous oxide semiconductor thin-film transistors (TFTs confirmed by overshoots of mobility after bias stressing dual gated TFTs is presented. The overshoots in mobility are reversible and only occur in TFTs with a full bottom-gate (covers the whole channel and partial top-gate (covers only a portion of the channel, indicating a bias-induced uneven distribution of ionized donors: Ionized donors migrate towards the region of the channel that is located underneath the partial top-gate and the decrease in the density of ionized donors in the uncovered portion results in the reversible increase in mobility.

  3. Internal reforming characteristics of cermet supported solid oxide fuel cell using yttria stabilized zirconia fed with partially reformed methane

    Energy Technology Data Exchange (ETDEWEB)

    Momma, Akihiko; Takano, Kiyonami; Tanaka, Yohei; Negishi, Akira; Kato, Ken; Nozaki, Ken; Kato, Tohru [Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono Tsukuba Ibaraki, 305-8568 (Japan); Ichigi, Takenori; Matsuda, Kazuyuki; Ryu, Takashi [Application Development Project, Corporate R and D, NGK Insulators, Ltd., 2-56 Suda-cho Mizuho-ku Nagoya-shi Aichi, 467-8530 (Japan)

    2009-08-01

    In order to investigate the internal reforming characteristics in a cermet supported solid oxide fuel cell (SOFC) using YSZ as the electrolyte, the concentration profiles of the gaseous species along the gas flow direction in the anode were measured. Partially reformed methane using a pre-reformer kept at a constant temperature is supplied to the center of the cell which is operated with a seal-less structure at the gas outlet. The anode gas is sucked in via silica capillaries to the initially evacuated gas tanks. The process is simultaneously carried out using five sampling ports. The sampled gas is analyzed by a gas chromatograph. Most of the measurements are made at the cell temperature (T{sub cell}) of 750 C and at various temperatures of the pre-reformer (T{sub ref}) with various fuel utilizations (U{sub f}) of the cell. The composition of the fuel at the inlet of the anode was confirmed to be almost the same as that theoretically calculated assuming equilibrium at the temperature of the pre-reformer. The effect of internal reforming in the anode is clearly observed as a steady decrease in the methane concentration along the flow axis. The effect of the water-gas shift reaction is also observed as a decrease in the CO{sub 2} concentration and an increase of CO concentration around the gas inlet region, as the water-gas shift reaction inversely proceeds when T{sub cell} is higher than T{sub ref}. The diffusion of nitrogen from the seal-less outermost edge is observed, and the diffusion is confirmed to be more significant as U{sub f} decreases. The observations are compared with the results obtained by the SOFC supported by lanthanum gallate electrolyte. With respect to the internal reforming performance, the cell investigated here is found to be more effective when compared to the previously reported electrolyte supported cell. (author)

  4. Internal reforming characteristics of cermet supported solid oxide fuel cell using yttria stabilized zirconia fed with partially reformed methane

    Science.gov (United States)

    Momma, Akihiko; Takano, Kiyonami; Tanaka, Yohei; Negishi, Akira; Kato, Ken; Nozaki, Ken; Kato, Tohru; Ichigi, Takenori; Matsuda, Kazuyuki; Ryu, Takashi

    In order to investigate the internal reforming characteristics in a cermet supported solid oxide fuel cell (SOFC) using YSZ as the electrolyte, the concentration profiles of the gaseous species along the gas flow direction in the anode were measured. Partially reformed methane using a pre-reformer kept at a constant temperature is supplied to the center of the cell which is operated with a seal-less structure at the gas outlet. The anode gas is sucked in via silica capillaries to the initially evacuated gas tanks. The process is simultaneously carried out using five sampling ports. The sampled gas is analyzed by a gas chromatograph. Most of the measurements are made at the cell temperature (T cell) of 750 °C and at various temperatures of the pre-reformer (T ref) with various fuel utilizations (U f) of the cell. The composition of the fuel at the inlet of the anode was confirmed to be almost the same as that theoretically calculated assuming equilibrium at the temperature of the pre-reformer. The effect of internal reforming in the anode is clearly observed as a steady decrease in the methane concentration along the flow axis. The effect of the water-gas shift reaction is also observed as a decrease in the CO 2 concentration and an increase of CO concentration around the gas inlet region, as the water-gas shift reaction inversely proceeds when T cell is higher than T ref. The diffusion of nitrogen from the seal-less outermost edge is observed, and the diffusion is confirmed to be more significant as U f decreases. The observations are compared with the results obtained by the SOFC supported by lanthanum gallate electrolyte. With respect to the internal reforming performance, the cell investigated here is found to be more effective when compared to the previously reported electrolyte supported cell.

  5. Activated, coal-based carbon foam

    Science.gov (United States)

    Rogers, Darren Kenneth; Plucinski, Janusz Wladyslaw

    2004-12-21

    An ablation resistant, monolithic, activated, carbon foam produced by the activation of a coal-based carbon foam through the action of carbon dioxide, ozone or some similar oxidative agent that pits and/or partially oxidizes the carbon foam skeleton, thereby significantly increasing its overall surface area and concurrently increasing its filtering ability. Such activated carbon foams are suitable for application in virtually all areas where particulate or gel form activated carbon materials have been used. Such an activated carbon foam can be fabricated, i.e. sawed, machined and otherwise shaped to fit virtually any required filtering location by simple insertion and without the need for handling the "dirty" and friable particulate activated carbon foam materials of the prior art.

  6. Shell coal gasification process

    Energy Technology Data Exchange (ETDEWEB)

    Hennekes, B. [Shell Global Solutions (US) Inc. (United States). Technology Marketing

    2002-07-01

    The presentation, on which 17 slides/overheads are included in the papers, explained the principles of the Shell coal gasification process and the methods incorporated for control of sulfur dioxide, nitrogen oxides, particulates and mercury. The economics of the process were discussed. The differences between gasification and burning, and the differences between the Shell process and other processes were discussed.

  7. Coal slurries: An environmental bonus?

    International Nuclear Information System (INIS)

    Basta, N.; Moore, S.; Ondrey, G.

    1994-01-01

    Developers and promoters of coal-water slurries and similar CWF (coal-water fuel) technologies have had a hard time winning converts since they unveiled their first commercial processes in the 1970s. The economic appeal of such processes, marginal at best, varies with the price of oil. Nevertheless, the technology is percolating, as geopolitics and environmental pressures drive new processes. Such fuels are becoming increasingly important to coal-rich, oil-poor nations such as China, as they attempt to build an onshore fuel supply. Meanwhile, improvements are changing the way coal-fired processes are viewed. Where air pollution regulations once discouraged the use of coal fuels, new coal processes have been developed that cut nitrous oxides (NOx) emissions and provide a use for coal fines, previously viewed as waste. The latest developments in the field were all on display at the 19th International Technical Conference on Coal Utilization and Fuel Systems, held in Clearwater, Fla., on March 21--24. At this annual meeting, sponsored by the Coal and Slurry Technology Association, (Washington, D.C.) and the Pittsburgh Energy Technology Center of the US Dept. of Energy (PETC), some 200 visitors from around the work gathered to discuss the latest developments in coal slurry utilization--new and improved processes, and onstream plants. This paper presents highlights from the conference

  8. Heterogeneous catalytic ozonation of biologically pretreated Lurgi coal gasification wastewater using sewage sludge based activated carbon supported manganese and ferric oxides as catalysts.

    Science.gov (United States)

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

    2014-08-01

    Sewage sludge of biological wastewater treatment plant was converted into sewage sludge based activated carbon (SBAC) with ZnCl₂ as activation agent, which supported manganese and ferric oxides as catalysts (including SBAC) to improve the performance of ozonation of real biologically pretreated Lurgi coal gasification wastewater. The results indicated catalytic ozonation with the prepared catalysts significantly enhanced performance of pollutants removal and the treated wastewater was more biodegradable and less toxic than that in ozonation alone. On the basis of positive effect of higher pH and significant inhibition of radical scavengers in catalytic ozonation, it was deduced that the enhancement of catalytic activity was responsible for generating hydroxyl radicals and the possible reaction pathway was proposed. Moreover, the prepared catalysts showed superior stability and most of toxic and refractory compounds were eliminated at successive catalytic ozonation runs. Thus, the process with economical, efficient and sustainable advantages was beneficial to engineering application. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Creep life prediction of super heater coils used in coal based thermal power plants subjected to fly ash erosion and oxide scale formation

    Science.gov (United States)

    Srinivasan, P.; Kushwaha, Shashank

    2018-04-01

    Super heater coils of the coal based thermal power plants and subjected to severe operating conditions from both steam side and gas side. Formation of oxide scale due to prolonged service lead to temperature raise of the tube and erosion due to fly ash present in the combusted gases leads to tube thinning. Both these factors lead to creep rupture of the coils much before the designed service life. Failure of super heater coils during service of the boiler leads to power loss and huge monitory loss to the power plants. An attempt is made to model the creep damage caused to the super heater coils using heat transfer analysis tube thinning due to erosive wear of the tubes. Combined effects of these parameters are taken into consideration to predict the life of the super heater coils. This model may be used to estimate the life of the coils operating under the severe operating conditions to prevent the unexpected failure of the coils.

  10. Structural changes of noble metal catalysts during ignition and extinction of the partial oxidation of methane studied by advanced QEXAFS techniques

    DEFF Research Database (Denmark)

    Grunwaldt, Jan-Dierk; Beier, M.; Kimmerle, B.

    2009-01-01

    The dynamics of the ignition and extinction of the catalytic partial oxidation (CPO) of methane to hydrogen and carbon monoxide over Pt-Rh/Al2O3 and Pt/Al2O3 were studied in the subsecond timescale using quick-EXAFS with a novel cam-driven X-ray monochromator employing Si(111) and Si(311) crystals...... to discuss the potential and limitation of this technique in catalysis and related areas. With respect to the noble metal catalysed partial oxidation of methane, several interesting observations were made: structural changes during ignition were-independent of the chosen reaction conditions......-significantly faster than during the extinction of the reaction. The dynamic behavior of the catalysts was dependent on the flow conditions and the respective noble metal component(s). Higher reaction gas flow led to a faster ignition process. While the ignition over Pt-Rh/Al2O3 occurred at lower temperature than over...

  11. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUIDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    Energy Technology Data Exchange (ETDEWEB)

    Archie Robertson

    2003-10-29

    Foster Wheeler Power Group, Inc. is working under US Department of Energy contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% and produce near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines, or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The amount of syngas and char produced by the PGM can be tailored to fit the production objectives of the overall plant, i.e., power generation, clean liquid fuel production, chemicals production, etc. Hence, PGM is a robust building bock that offers all the advantages of coal gasification but in a more user-friendly form; it is also fuel flexible in that it can use alternative fuels such as biomass, sewerage sludge, etc. This report describes the work performed during the July 1--September 30, 2003 time period.

  12. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUIDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2003-01-30

    Foster Wheeler Power Group, Inc. is working under US Department of Energy contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% and produce near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines, or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The amount of syngas and char produced by the PGM can be tailored to fit the production objectives of the overall plant, i.e., power generation, clean liquid fuel production, chemicals production, etc. Hence, PGM is a robust building bock that offers all the advantages of coal gasification but in a more user-friendly form; it is also fuel flexible in that it can use alternative fuels such as biomass, sewerage sludge, etc. This report describes the work performed during the October 1--December 31, 2002 time period.

  13. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUIDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    Energy Technology Data Exchange (ETDEWEB)

    Archie Robertson

    2003-07-23

    Foster Wheeler Power Group, Inc. is working under US Department of Energy contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% and produce near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines, or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The amount of syngas and char produced by the PGM can be tailored to fit the production objectives of the overall plant, i.e., power generation, clean liquid fuel production, chemicals production, etc. Hence, PGM is a robust building bock that offers all the advantages of coal gasification but in a more user-friendly form; it is also fuel flexible in that it can use alternative fuels such as biomass, sewerage sludge, etc. This report describes the work performed during the April 1--June 30, 2003 time period.

  14. Development of Pressurized Circulating Fluidized Bed Partial Gasification Module (PGM)

    Energy Technology Data Exchange (ETDEWEB)

    A. Robertson

    2003-12-31

    Foster Wheeler Power Group, Inc. is working under US Department of Energy contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% and produce near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines, or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The amount of syngas and char produced by the PGM can be tailored to fit the production objectives of the overall plant, i.e., power generation, clean liquid fuel production, chemicals production, etc. Hence, PGM is a robust building bock that offers all the advantages of coal gasification but in a more user-friendly form; it is also fuel flexible in that it can use alternative fuels such as biomass, sewerage sludge, etc. This report describes the work performed during the October 1 - December 31, 2003 time period.

  15. Study of film graphene/graphene oxide obtained by partial reduction chemical of oxide graphite; Estudo de filme de grafeno/oxido de grafeno obtido por reducao quimica parcial do oxido de grafite

    Energy Technology Data Exchange (ETDEWEB)

    Gascho, J.L.S.; Costa, S.F.; Hoepfner, J.C.; Pezzin, S.H., E-mail: juliagascho@hotmail.com [Universidade do Estado de Santa Catarina (UDESC), Joinville, SC (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais

    2014-07-01

    This study investigated the morphology of graphene/graphene oxide film obtained by partial chemical reduction of graphite oxide (OG) as well as its resistance to solvents. Films of graphene/graphene oxide are great candidates for replacement of indium oxide doped with tin (ITO) in photoelectric devices. The OG was obtained from natural graphite, by Hummer's method modified, and its reduction is made by using sodium borohydride. Infrared spectroscopy analysis of Fourier transform (FTIR), Xray diffraction (XRD) and scanning electron microscopy, high-resolution (SEM/FEG) for the characterization of graphene/graphene oxide film obtained were performed. This film proved to be resilient, not dispersing in any of the various tested solvents (such as ethanol, acetone and THF), even under tip sonication, this resistance being an important property for the applications. Furthermore, the film had a morphology similar to that obtained by other preparation methods.(author)

  16. Axial Changes of Catalyst Structure and Temperature in a Fixed-Bed Microreactor During Noble Metal Catalysed Partial Oxidation of Methane

    DEFF Research Database (Denmark)

    Hannemann, S.; Grunwaldt, Jan-Dierk; Kimmerle, B.

    2009-01-01

    The catalytic partial oxidation of methane (CPO) over flame-made 2.5%Rh-2.5%Pt/Al2O3 and 2.5%Rh/Al2O3 in 6%CH4/3%O-2/He shows the potential of in situ studies using miniaturized fixed-bed reactors, the importance of spatially resolved studies and its combination with infrared thermography and on-...

  17. Coal gasification integration with solid oxide fuel cell and chemical looping combustion for high-efficiency power generation with inherent CO2 capture

    International Nuclear Information System (INIS)

    Chen, Shiyi; Lior, Noam; Xiang, Wenguo

    2015-01-01

    Highlights: • A novel power system integrating coal gasification with SOFC and chemical looping combustion. • The plant net power efficiency reaches 49.8% with complete CO 2 separation. • Energy and exergy analysis of the entire plant is conducted. • Sensitivity analysis shows a nearly constant power output when SOFC temperature and pressure vary. • NiO oxygen carrier shows higher plant efficiency than using Fe 2 O 3 and CuO. - Abstract: Since solid oxide fuel cells (SOFC) produce electricity with high energy conversion efficiency, and chemical looping combustion (CLC) is a process for fuel conversion with inherent CO 2 separation, a novel combined cycle integrating coal gasification, solid oxide fuel cell, and chemical looping combustion was configured and analyzed. A thermodynamic analysis based on energy and exergy was performed to investigate the performance of the integrated system and its sensitivity to major operating parameters. The major findings include that (1) the plant net power efficiency reaches 49.8% with ∼100% CO 2 capture for SOFC at 900 °C, 15 bar, fuel utilization factor = 0.85, fuel reactor temperature = 900 °C and air reactor temperature = 950 °C, using NiO as the oxygen carrier in the CLC unit. (2) In this parameter neighborhood the fuel utilization factor, the SOFC temperature and SOFC pressure have small effects on the plant net power efficiency because changes in pressure and temperature that increase the power generation by the SOFC tend to decrease the power generation by the gas turbine and steam cycle, and v.v.; an advantage of this system characteristic is that it maintains a nearly constant power output even when the temperature and pressure vary. (3) The largest exergy loss is in the gasification process, followed by those in the CO 2 compression and the SOFC. (4) Compared with the CLC Fe 2 O 3 and CuO oxygen carriers, NiO results in higher plant net power efficiency. To the authors’ knowledge, this is the first

  18. Prevention of spontaneous combustion in coal stockpiles : Experimental results in coal storage yard

    NARCIS (Netherlands)

    Fierro, V.; Miranda, J.L.; Romero, C.; Andrés, J.M.; Arriaga, A.; Schmal, D.; Visser, G.H.

    1999-01-01

    The spontaneous ignition of coal stockpiles is a serious economic and safety problem. This paper deals with oxidation and spontaneous combustion of coal piles laid in coal storage yard and the measures to avoid the heat losses produced. Investigations on self heating were carried out with five test

  19. Prevention of formation of acid drainage from high-sulfur coal refuse by inhibition of iron- and sulfur-oxidizing microorganisms. II. Inhibition in run of mine refuse under simulated field conditions

    Energy Technology Data Exchange (ETDEWEB)

    Dugan, P.R.

    1987-01-01

    The combination of sodium lauryl sulfate and benzoic acid effectively inhibits iron- and sulfur-oxidizing bacteria in coal refuse and prevents the conversion of iron pyrite to sulfate, ferric iron, and sulfuric acid, thereby significantly reducing the formation of acidic drainage from coal refuse. The inhibitors were effective in a concentration of 1.1. mg/kg refuse, and data indicate that the SLS was in excess of the concentration required. The treatment was compatible with the use of lime for neutralization of acid present prior to inhibition of its formation.

  20. A low-temperature partial-oxidation-methanol micro reformer with high fuel conversion rate and hydrogen production yield

    International Nuclear Information System (INIS)

    Wang, Hsueh-Sheng; Huang, Kuo-Yang; Huang, Yuh-Jeen; Su, Yu-Chuan; Tseng, Fan-Gang

    2015-01-01

    Highlights: • A low-operating temperature of the POM-mode micro methanol reformer is obtained. • The effect of channel design on the performance is studied. • The effect of solid content and binder’ ratio on the performance is studied. • The centrifugal process is benefit for the modification of performance. • 98% of methanol conversion rate of the micro reformer can be obtained at 180 °C. - Abstract: A partial oxidation methanol micro reformer (POM-μReformer) with finger-shaped channels for low operating temperature and high conversing efficiency is proposed in this study. The micro reformer employs POM reaction for low temperature operation (less than 200 °C), exothermic reaction, and quick start-up, as well as air feeding capability; and the finger type reaction chambers for increasing catalyst loading as well as reaction area for performance enhancement. In this study, centrifugal technique was introduced to assist on the catalyst loading with high amount and uniform distribution. The solid content (S), binder’s ratio (B), and channel design (the ratio between channel’s length and width, R) were investigated in detail to optimize the design parameters. Scanning electron microscopy (SEM), gas chromatography (GC), and inductively coupled plasma-mass spectrometer (ICP-MS) were employed to analyze the performance of the POM-μReformer. The result depicted that the catalyst content and reactive area could be much improved at the optimized condition, and the conversion rate and hydrogen selectivity approached 97.9% and 97.4%, respectively, at a very low operating temperature of 180 °C with scarce or no binder in catalyst. The POM-μReformer can supply hydrogen to fuel cells by generating 2.23 J/min for 80% H 2 utilization and 60% fuel cell efficiency at 2 ml/min of supplied reactant gas, including methanol, oxygen and argon at a mixing ratio of 12.2%, 6.1% and 81.7%, respectively

  1. Australian coal

    Energy Technology Data Exchange (ETDEWEB)

    1985-11-01

    Total export shipments of coal in Australia in the year ending June 30 1985 reached a record of 83.8 Mt. The export trade is expected to bring in an income of 4 billion Australian dollars in the current year making coal Australia's biggest revenue-earning export commodity. This article presents a brief overview of the Australian coal industry with production and export statistics and information on major open pit and underground mines.

  2. Coal - 96

    International Nuclear Information System (INIS)

    Sparre, C.

    1996-09-01

    The report deals mainly with coal consumption, but also gives some information about technology, environmental aspects and markets. Data have been collected by questionnaires or via telephone. The use of steam coal for heating was 0.8 Mtons (down 20% from 1994). Cogeneration plants were the main users. Taxes and environmental reasons cause a reduction of the coal use that will probably continue the next years. Use of steam coal in industry has been constant at a level of 0.7 Mtons. The import of metallurgical coal rests constant at a level of 1.6 Mtons. 1.2 Mtons of coke was produced, and 0.3 Mtons imported. The PFBC-plant at Vaertan, Stockholm used 0.13 Mtons of coal, while some coal fired power plants have been converted to peat and wood fuels. The average price of steam coal imported to Sweden in 1995 was 333 SEK/ton, 6% higher than in 1994. The contract prices for delivery 1996 are about the same as at the end of 1995. All cogeneration plants have some sort of SO 2 removal system, mostly wet-dry. The largest plant, at Vaesteraas, has recently invested in a SCR system for NO x removal. Most other plants are using low NO x burners or SNCR systems, based on ammonia or urea, which reduce the emissions 50 - 70%. Some statistic about the world coal market is also given in the report

  3. Venezuelan coal

    International Nuclear Information System (INIS)

    Vazquez, L.U.

    1991-01-01

    The existence of coal deposits in Venezuela has been known since the early nineteenth century, when the Naricual Mines were discovered in the State of Anzoategui Eastern Venezuela. Through the years the Venezuelan coal business had its ups and downs, but it was not until 1988 that we could properly say that our coal began to play a role in the international market. This paper reports that it is only now, in the nineties, that Venezuelan coal projects have come under a planning, promotional and developmental policy preparing the ground for the great projects Venezuela will have in the not-too-distant future

  4. Effect of partial oxygen pressure on physicochemical properties of Kh18N10T steel at isothermal oxidation

    International Nuclear Information System (INIS)

    Alekseev, V.N.; Oshe, E.K.; Fokin, M.N.; Bogdanova, S.V.; Loskutov, A.I.

    1990-01-01

    Auger-electron spectroscopy, photoelectric polarization, conductometry methods have been used to analyze chemical and defect composition of surface oxide layers, formed on stainless steel Kh18N10T in vacuum (10 -9 - 10 -2 torr) and at temperatures 593-673 K. The boundary conditions of manifestation of extermal behaviour of the dependence of the surface oxide growth rate at isothermal oxidation of this steel are determined. The relation between passivation properties of the surface oxide and the magnitude of the edge angle of the surface wetting with molten tin is revealed

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

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

  6. Coal summit II

    Energy Technology Data Exchange (ETDEWEB)

    1983-01-01

    Various papers were presented on world coal trade. Papers include: Poland as a producer and exporter of coal; the dynamics of world coal trade; Cerrejon coal production perspectives; present state of the Australian coal industry; present state of the EC coal market and future prospects; prospects of US coal exports to Europe; forecast of Italian coal supply and demand through 1990; statistics from coal transportation outlook; status of world coal ports.

  7. Thief carbon catalyst for oxidation of mercury in effluent stream

    Science.gov (United States)

    Granite, Evan J [Wexford, PA; Pennline, Henry W [Bethel Park, PA

    2011-12-06

    A catalyst for the oxidation of heavy metal contaminants, especially mercury (Hg), in an effluent stream is presented. The catalyst facilitates removal of mercury through the oxidation of elemental Hg into mercury (II) moieties. The active component of the catalyst is partially combusted coal, or "Thief" carbon, which can be pre-treated with a halogen. An untreated Thief carbon catalyst can be self-promoting in the presence of an effluent gas streams entrained with a halogen.

  8. Advanced STEM/EDX investigation on an oxide scale thermally grown on a high-chromium iron–nickel alloy under very low oxygen partial pressure

    International Nuclear Information System (INIS)

    Latu-Romain, L.; Madi, Y.; Mathieu, S.; Robaut, F.; Petit, J.-P.; Wouters, Y.

    2015-01-01

    Highlights: • A scale grown on a high-chromium iron–nickel alloy under low oxygen partial pressure was studied. • STEM-EDX maps at high resolution on a transversal thin lamella have been conducted. • The real complexity of the oxide layer has been highlighted. • These results explain the elevated number of semiconducting contributions. - Abstract: A thermal oxide scale has been grown on a high-chromium iron-nickel alloy under very low oxygen partial pressure (1050 °C, 10"−"1"0 Pa). In this paper, a special attention has been paid to morphological and chemical characterizations of the scale by scanning transmission electron microscopy and energy dispersive X-ray analysis at high resolution on a cross-section thin lamella beforehand prepared by using a combined focused ion beam/scanning electron microscope instrument. The complexity of the oxide layer is highlighted, and the correlation between the present results and the ones of a photoelectrochemical study is discussed.

  9. The chemical transformation of calcium in Shenhua coal during combustion in a muffle furnace

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Sida [North China Electric Power Univ., Beijing (China). School of Energy, Power and Mechanical Engineering; Ministry of Education, Beijing (China). Key Lab. of Condition Monitoring and Control for Power Plant Equipment; Zhuo, Yuqun; Chen, Changhe [Tsinghua Univ., Beijing (China). Dept. of Thermal Engineering; Ministry of Education, Beijing (China). Key Lab. for Thermal Science and Power Engineering; Shu, Xinqian [China Univ. of Mining and Technology, Beijing (China). School of Chemical and Environmental Engineering

    2013-07-01

    The chemical reaction characteristics of calcium in three samples of Shenhua coal, i.e. raw sample, hydrochloric acid washed sample and hydrochloric acid washed light fraction, during combustion in a muffle furnace have been investigated in this paper. Ca is bound by calcite and organic matter in Shenhua coal. X ray diffraction (XRD) phase analysis has been conducted to these samples' combustion products obtained by heating at different temperatures. It has been found that the organically-bound calcium could easily react with clays and transform into gehlenite and anorthite partially if combusted under 815 C, whilst the excluded minerals promoted the conversion of gehlenite to anorthite. Calcite in Shenhua coal decomposed into calcium oxide and partially transformed into calcium sulfate under 815 C, and formed gehlenite and anorthite under 1,050 C. Calcite and other HCl-dissolved minerals in Shenhua coal were responsible mainly for the characteristic that the clay minerals in Shenhua coal hardly became mullite during combustion.

  10. Hydroseeding on anthracite coal-mine spoils

    Science.gov (United States)

    Miroslaw M. Czapowskyj; Ross Writer

    1970-01-01

    A study was made of the performance of selected species of legumes, grasses, and trees hydroseeded on anthracite coal-mine spoils in a slurry of lime, fertilizer, and mulch. Hydroseeding failed on coal-breaker refuse, but was partially successful on strip-mine spoils.

  11. International Coal Report's coal year 1991

    Energy Technology Data Exchange (ETDEWEB)

    McCloskey, G [ed.

    1991-05-31

    Following introductory articles on factors affecting trade in coal and developments in the freight market, tables are given for coal exports and coal imports for major countries worldwide for 1989 and 1990. Figures are also included for coal consumption in Canada and the Eastern bloc,, power station consumption in Japan, coal supply and demand in the UK, electric utility coal consumption and stocks in the USA, coal production in Australia, Canada and USA by state, and world hard coal production. A final section gives electricity production and hard coal deliveries in the EEC, sales of imported and local coal and world production of pig iron and steel.

  12. Ways of intensifying the conventional chamber carbonization of hard coal

    Energy Technology Data Exchange (ETDEWEB)

    Pelagalli, M.

    1986-12-01

    The intensification measures are intended to reduce both the investment cost and the operating cost via an increased performance factor. Automation had good results both in coal blending and in process monitoring and control. Coal blending, compression, and partial briquetting extend the range of coking coals.

  13. Analyzing the dependence of oxygen incorporation current density on overpotential and oxygen partial pressure in mixed conducting oxide electrodes.

    Science.gov (United States)

    Guan, Zixuan; Chen, Di; Chueh, William C

    2017-08-30

    The oxygen incorporation reaction, which involves the transformation of an oxygen gas molecule to two lattice oxygen ions in a mixed ionic and electronic conducting solid, is a ubiquitous and fundamental reaction in solid-state electrochemistry. To understand the reaction pathway and to identify the rate-determining step, near-equilibrium measurements have been employed to quantify the exchange coefficients as a function of oxygen partial pressure and temperature. However, because the exchange coefficient contains contributions from both forward and reverse reaction rate constants and depends on both oxygen partial pressure and oxygen fugacity in the solid, unique and definitive mechanistic assessment has been challenging. In this work, we derive a current density equation as a function of both oxygen partial pressure and overpotential, and consider both near and far from equilibrium limits. Rather than considering specific reaction pathways, we generalize the multi-step oxygen incorporation reaction into the rate-determining step, preceding and following quasi-equilibrium steps, and consider the number of oxygen ions and electrons involved in each. By evaluating the dependence of current density on oxygen partial pressure and overpotential separately, one obtains the reaction orders for oxygen gas molecules and for solid-state species in the electrode. We simulated the oxygen incorporation current density-overpotential curves for praseodymium-doped ceria for various candidate rate-determining steps. This work highlights a promising method for studying the exchange kinetics far away from equilibrium.

  14. Converting coal

    Energy Technology Data Exchange (ETDEWEB)

    Avigliano, A. [Bedeschi (Italy)

    2006-10-15

    In September 2005, Bedeschi was commissioned to design and supply a coal unloading, conveying and storage facility for a new raw coal line system within Hatien II Cement Co. The new plant is composed of a grab unloader, a conveyor system, a storage shed with stacking and reclaiming facilities, a complete dedusting system and civil and steel structure engineering. The scope of supply includes a local fabrication portion; however, main components will be imported. The project will be completed in 21 months. The paper looks into the mechanics of loading and unloading coal. 4 figs., 4 photos.

  15. Innovative clean coal technology (ICCT): demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NOx) emission from high-sulfur, coal-fired boilers - economic evaluation of commercial-scale SCR applications for utility boilers

    International Nuclear Information System (INIS)

    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 x emissions from utility boilers burning U.S. high-sulfur coal. The document includes a commercial-scale capital and O ampersand 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 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

  16. Method to liquefy coal

    Energy Technology Data Exchange (ETDEWEB)

    Cronauer, D.C.; Kehl, W.L.

    1977-06-08

    In a method to liquify coal in the presence of hydrogen and hydrogen-transfer solvents, a hydrogenation catalyst is used in which an amorphous aluminium phosphate is taken as catalyst carrier. The particular advantage of aluminium phosphate catalyst carriers is their property of not loosing their mechanical strength even after manifold oxidizing regeneration (burning off the deposited carbon). The quantity of carbon deposited on the catalyst when using an aluminium phosphate carrier is considerably loss than with usual catalyst carriers.

  17. The marriage of gas turbines and coal

    International Nuclear Information System (INIS)

    Bajura, R.A.; Webb, H.A.

    1991-01-01

    This paper reports on developing gas turbine systems that can use coal or a coal-based fuel ensures that the United States will have cost-effective environmentally sound options for supplying future power generation needs. Power generation systems that marry coal or a coal-based fuel to a gas turbine? Some matchmakers would consider this an unlikely marriage. Historically, most gas turbines have been operated only on premium fuels, primarily natural gas or distillate oil. The perceived problems from using coal or coal-based fuels in turbines are: Erosion and deposition: Coal ash particles in the hot combustion gases passing through the expander turbine could erode or deposit on the turbine blades. Corrosion: Coal combustion will release alkali compounds form the coal ash. Alkali in the hot gases passing through the expander turbine can cause corrosion of high-temperature metallic surfaces. Emissions: coal contains higher levels of ash, fuel-bound sulfur and nitrogen compounds, and trace contaminants than premium fuels. Meeting stringent environmental regulations for particulates, sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), and trace contaminants will be difficult. Economics: Coal-based systems are expensive to build. The difference in price between coal and premium fuels must be large enough to justify the higher capital cost

  18. Power generation from lignite coal in Bulgaria - problems and solutions

    International Nuclear Information System (INIS)

    Batov, S.; Gadjanov, P.; Panchev, T.

    1997-01-01

    The bulk of lignite coal produced in Bulgaria is used as fuel for the thermal power plants (TPP) built in Maritsa East coal field. A small part of it goes to production of briquettes and to fuel the auxiliary power plants of industrial enterprises. The total installed capacity of the power plants in the region of Maritsa East is 2490 MW, and the electric power generated by them is about 30% of the total power generated in the country. It should be noted that these power plants were subjected to a number of rehabilitations aiming to improve their technical and economic parameters. Irrespective of that, however, solution has still to be sought to a number of problems related to utilisation of the low-grade lignite coal for power generation. On the whole, they can be divided in the following groups: Those related to lignite coal mining can be referred to the first group. Lignite coal is mined in comparatively complicated mining and geological conditions characterized mainly by earth creep and deformation. The second group of problems is related to coal quality control. It is a fact of major significance that the quality indices of coal keep changing all the time in uneven steps without any definite laws to govern it. That creates hard problems in the process of coal transportation, crushing and combustion. The next group of problems concerns operation and upgrading of the power generation equipment. That applies especially to the existing boilers which bum low-grade fuel in order to improve their operation in terms of higher thermal efficiency, controllability, reliability, improved environmental indices, etc. An increasingly high importance is attached to environmental impact problems incident to lignite coal utilisation. Abatement of sulphur oxide emissions and dust pollution is a problem solution of which cannot wait. The possibilities for partial solution of the environmental problems through increasing the thermal efficiency of facilities at the thermal Power

  19. Graphene-oxide-supported CuAl and CoAl layered double hydroxides as enhanced catalysts for carbon-carbon coupling via Ullmann reaction

    Science.gov (United States)

    Ahmed, Nesreen S.; Menzel, Robert; Wang, Yifan; Garcia-Gallastegui, Ainara; Bawaked, Salem M.; Obaid, Abdullah Y.; Basahel, Sulaiman N.; Mokhtar, Mohamed

    2017-02-01

    Two efficient catalyst based on CuAl and CoAl layered double hydroxides (LDHs) supported on graphene oxide (GO) for the carbon-carbon coupling (Classic Ullmann Homocoupling Reaction) are reported. The pure and hybrid materials were synthesised by direct precipitation of the LDH nanoparticles onto GO, followed by a chemical, structural and physical characterisation by electron microscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), surface area measurements and X-ray photoelectron spectroscopy (XPS). The GO-supported and unsupported CuAl-LDH and CoAl-LDH hybrids were tested over the Classic Ullman Homocoupling Reaction of iodobenzene. In the current study CuAl- and CoAl-LDHs have shown excellent yields (91% and 98%, respectively) at very short reaction times (25 min). GO provides a light-weight, charge complementary and two-dimensional material that interacts effectively with the 2D LDHs, in turn enhancing the stability of LDH. After 5 re-use cycles, the catalytic activity of the LDH/GO hybrid is up to 2 times higher than for the unsupported LDH.

  20. Biochemical Removal of HAP Precursors From Coal

    International Nuclear Information System (INIS)

    Olson, G.; Tucker, L.; Richards, J.

    1997-07-01

    This project addresses DOE's interest in advanced concepts for controlling emissions of air toxics from coal-fired utility boilers. We are determining the feasibility of developing a biochemical process for the precombustion removal of substantial percentages of 13 inorganic hazardous air pollutant (HAP) precursors from coal. These HAP precursors are Sb, As, Be, Cd, Cr, Cl, Co, F, Pb, Hg, Mn, Ni, and Se. Although rapid physical coal cleaning is done routinely in preparation plants, biochemical processes for removal of HAP precursors from coal potentially offer advantages of deeper cleaning, more specificity, and less coal loss. Compared to chemical processes for coal cleaning, biochemical processes potentially offer lower costs and milder process conditions. Pyrite oxidizing bacteria, most notably Thiobacillusferrooxidans, are being evaluated in this project for their ability to remove HAP precursors from U.S. coals

  1. Biochemical Removal of HAP Precursors From Coal

    Energy Technology Data Exchange (ETDEWEB)

    Olson, G.; Tucker, L.; Richards, J.

    1997-07-01

    This project addresses DOE`s interest in advanced concepts for controlling emissions of air toxics from coal-fired utility boilers. We are determining the feasibility of developing a biochemical process for the precombustion removal of substantial percentages of 13 inorganic hazardous air pollutant (HAP) precursors from coal. These HAP precursors are Sb, As, Be, Cd, Cr, Cl, Co, F, Pb, Hg, Mn, Ni, and Se. Although rapid physical coal cleaning is done routinely in preparation plants, biochemical processes for removal of HAP precursors from coal potentially offer advantages of deeper cleaning, more specificity, and less coal loss. Compared to chemical processes for coal cleaning, biochemical processes potentially offer lower costs and milder process conditions. Pyrite oxidizing bacteria, most notably Thiobacillusferrooxidans, are being evaluated in this project for their ability to remove HAP precursors from U.S. coals.

  2. A novel oxidative method for the absorption of Hg0 from flue gas of coal fired power plants using task specific ionic liquid scrubber

    International Nuclear Information System (INIS)

    Barnea, Zach; Sachs, Tatyana; Chidambaram, Mandan; Sasson, Yoel

    2013-01-01

    Highlights: ► Ionic liquid used as absorption media due to negligible vapor pressure. ► Formation of a stable complex between the oxidation agent and the absorption liquid prevents its sublimation. ► Remarkable concentration factor of six orders of magnitude of mercury/IL unlike active carbon injection that absorb ppb of Hg from flue. ► Reduced metallic mercury swiftly precipitated from the solution and could be quantitatively separated and collected. -- Abstract: A simple continuous process is described for the removal of mercury from gas streams (such as flue gas of a coal fired power stations) using imidazolium based Task Specific Ionic Liquids [TSILs] with the general structure ([RMIM][XI 2 − ]) where X = Cl, Br or I. The latter are formed by blending dialkylimidazolium halide salts with iodine. When applied in a gas/liquid scrubber, these salts were shown to absorb >99% of elemental mercury originally present in a gas stream in concentration of 75–400 ppb. The mercury abatement is attained by oxidating the mercury to HgI 2 which is bound as a stable IL complex ([RMIM + ][XHgI 2 − ]. The novel absorption system exhibits a remarkable mercury concentration factor of seven orders of magnitude. The final solution obtained contains up to 50% (w/w) mercury in the IL. Upon exposure to sodium formate, directly added to the saturated IL at 45 °C, reduced metallic mercury swiftly precipitated from the solution and could be quantitatively separated and collected. The free IL could be fully recycled

  3. Coal competitiveness?

    International Nuclear Information System (INIS)

    Rogeaux, B.

    2006-01-01

    Will coal electrical plants be more competitive in the coming years? Answering this one cannot be limited to merely comparing estimates based on reference electricity production costs. The competitiveness of coal will indeed depend on the final product marketed, as the MWhs are not equal: is the purpose to produce base, half-base MWh? Does the electrical equipment structure require flexible MWh (for instance in the event of significant intermittent renewable energy amounts), and therefore plants able to adjust their power rapidly? But the competitiveness of coal will also depend on many factors that will correct reference cost estimates: uncertainties, risks, externalities. These factors will need to be appreciated on a case by case basis. We introduce some of the reasoning used to better appreciate the future competitiveness of coal, and the main factors conditioning it in three contrasting regions of the world: Europe, USA, china. (author)

  4. Coal - 97

    International Nuclear Information System (INIS)

    Sparre, C.

    1997-01-01

    The report deals with the use of coal and coke during 1996. Some information about techniques, environmental questions and markets are also given. Data have been collected by questionnaires to major users and by telephone to minor users. Preliminary statistical data from SCB have also been used. The use of steam coal for heating purposes during 1996 was 1,2 mill tons and 50% higher than in 1995. The increase is probably temporary and due to high prices of electricity because of lack of water power. The co-generation plants were the main users of coal. The minor plants have increased their use of forest fuels. Probably the use of steam coal will go down in the immediate years both in the heat generating and the co-generation plants. During the top year 1987 coal was used in 18 hotwater plants and 11 co-generation plants. 1996 these figures are 3 and 12. Taxes and environmental reasons explain this trend. The use of steam coal in the industry has been constant at the level 700 000 tons. This level is supposed to be constant or to vary with business cycles. The import of metallurgical coal in 1996 was 1,6 mill tons like the year before. 1,2 mill tons coke were produced. The coke consumption in the industry was 1,5 mill tons. 0,3 mill tons of coke were imported. The average price of steam coal imported in Sweden in 1996 was 340 SEK/ton or 2% higher than in 1995. For the world, the average import price was 51,5 USD/ton, nearly the same as the year before. The contract prices for delivery during 1997 are about equal as the end of 1996. All Swedish plants meet their emission limits of dust, SO 2 and NO x given by county administrations or concession boards

  5. Mine Water Treatment in Hongai Coal Mines

    OpenAIRE

    Dang Phuong Thao; Dang Vu Chi

    2018-01-01

    Acid mine drainage (AMD) is recognized as one of the most serious environmental problem associated with mining industry. Acid water, also known as acid mine drainage forms when iron sulfide minerals found in the rock of coal seams are exposed to oxidizing conditions in coal mining. Until 2009, mine drainage in Hongai coal mines was not treated, leading to harmful effects on humans, animals and aquatic ecosystem. This report has examined acid mine drainage problem and techniques for acid mine ...

  6. MHD power station with coal gasification

    International Nuclear Information System (INIS)

    Brzozowski, W.S.; Dul, J.; Pudlik, W.

    1976-01-01

    A description is given of the proposed operating method of a MHD-power station including a complete coal gasification into lean gas with a simultaneous partial gas production for the use of outside consumers. A comparison with coal gasification methods actually being used and full capabilities of power stations heated with coal-derived gas shows distinct advantages resulting from applying the method of coal gasification with waste heat from MHD generators working within the boundaries of the thermal-electric power station. (author)

  7. The Relationship Between Structural and Catalytic Activity of α and γ-Bismuth-Molybdate Catalysts for Partial Oxidation of Propylene to Acrolein

    Science.gov (United States)

    Fansuri, H.; Pham, G. H.; Wibawanta, S.; Zhang, D. K.; French, David

    Bismuth-molybdate catalysts are known to be effective for catalytic partial oxidation of propylene to acrolein. Their properties and the kinetics and reaction mechanisms for acrolein production have been extensively studied, especially in their basic forms, such as α, β, and γ-bismuth-molybdate. Although the reaction mechanisms have been reported widely in the literature, a general agreement has not been reached, especially from a catalyst-structure point of view. The present contribution reports an effort to understand the structural changes of α and γ-bismuth-molybdate catalysts at varying temperatures as examined using high temperature XRD and to relate the catalyst performance (activity and selectivity) for propylene partial oxidation to acrolein. The XRD analysis was performed at temperature between 250 and 450°C in ambient atmosphere and the Rietveld refinement method was used to extract unit cell parameters. The results showed a distinct similarity between the shapes of the thermal expansion of the catalysts and their activity and selectivity curves, indicating a significant role that the catalyst interatomic structure plays in the overall reaction mechanism.

  8. Influence of oxygen partial pressure and salinity on the community composition of ammonia-oxidizing bacteria in the Schelde estuary

    NARCIS (Netherlands)

    Bollmann, A.; Laanbroek, H.J.

    2002-01-01

    The influence of environmental factors on the community structure of ammonia-oxidizing bacteria (AOB) was investigated in the Schelde estuary. Simultaneously with the increase of oxygen and salinity, a shift of the dominant AOB was observed. Molecular analysis based on 16S rRNA genes showed that the

  9. Monitoring, field experiments, and geochemical modeling of Fe(II) oxidation kinetics in a stream dominated by net-alkaline coal-mine drainage, Pennsylvania, USA

    Science.gov (United States)

    Cravotta,, Charles A.

    2015-01-01

    Watershed-scale monitoring, field aeration experiments, and geochemical equilibrium and kinetic modeling were conducted to evaluate interdependent changes in pH, dissolved CO2, O2, and Fe(II) concentrations that typically take place downstream of net-alkaline, circumneutral coal-mine drainage (CMD) outfalls and during aerobic treatment of such CMD. The kinetic modeling approach, using PHREEQC, accurately simulates observed variations in pH, Fe(II) oxidation, alkalinity consumption, and associated dissolved gas concentrations during transport downstream of the CMD outfalls (natural attenuation) and during 6-h batch aeration tests on the CMD using bubble diffusers (enhanced attenuation). The batch aeration experiments demonstrated that aeration promoted CO2 outgassing, thereby increasing pH and the rate of Fe(II) oxidation. The rate of Fe(II) oxidation was accurately estimated by the abiotic homogeneous oxidation rate law −d[Fe(II)]/dt = k1·[O2]·[H+]−2·[Fe(II)] that indicates an increase in pH by 1 unit at pH 5–8 and at constant dissolved O2 (DO) concentration results in a 100-fold increase in the rate of Fe(II) oxidation. Adjusting for sample temperature, a narrow range of values for the apparent homogeneous Fe(II) oxidation rate constant (k1′) of 0.5–1.7 times the reference value of k1 = 3 × 10−12 mol/L/min (for pH 5–8 and 20 °C), reported by Stumm and Morgan (1996), was indicated by the calibrated models for the 5-km stream reach below the CMD outfalls and the aerated CMD. The rates of CO2 outgassing and O2ingassing in the model were estimated with first-order asymptotic functions, whereby the driving force is the gradient of the dissolved gas concentration relative to equilibrium with the ambient atmosphere. Although the progressive increase in DO concentration to saturation could be accurately modeled as a kinetic function for the conditions evaluated, the simulation of DO as an instantaneous equilibrium process did not affect the

  10. Contribution to the combustion and emission of nitrogen oxides of Kosovo and Kolubara coals in fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Radovanovic, M.; Savic, R.

    1996-12-31

    In this paper, the results of combustion of different sizes of domestic lignites Kosovo and Kolubara are presented. Investigation has been carried on a laboratory experimental facility for combustion in fluidized bed, power 1 kW. Specified amount of fuel is put into fluidized bed and temperature and concentration of combustion products (O{sub 2}, CO{sub 2}, CO, NO, NO{sub s} and SO{sub 2}) are recorded and produced. The emission of nitrogen oxides is specially treated in this paper. Also, the ignition delay of volatile matter, combustion of volatiles and total time of combustion are found. 25 refs., 9 figs., 4 tabs.

  11. Inclined fluidized bed system for drying fine coal

    Science.gov (United States)

    Cha, Chang Y.; Merriam, Norman W.; Boysen, John E.

    1992-02-11

    Coal is processed in an inclined fluidized bed dryer operated in a plug-flow manner with zonal temperature and composition control, and an inert fluidizing gas, such as carbon dioxide or combustion gas. Recycled carbon dioxide, which is used for drying, pyrolysis, quenching, and cooling, is produced by partial decarboxylation of the coal. The coal is heated sufficiently to mobilize coal tar by further pyrolysis, which seals micropores upon quenching. Further cooling with carbon dioxide enhances stabilization.

  12. Coal -98

    International Nuclear Information System (INIS)

    Sparre, C.

    1998-01-01

    The following report deals with the use of coal and coke during 1997. Some information about technic, environmental questions and markets are also given. Data have been collected by questionnaires to major users and by telephone to minor users. Preliminary statistical data from SCB have also been used. The use of steam coal for heating purposes during 1997 was 730 000 tons and about 500 000 tons lower than in 1996. The extremely high figures of 1996 were due to twice the production of electricity because of lack of hydro power. The co-generation plants were the main users of coal. The minor plants have increased their use of forest fuels. Probably the use of steam coal will go down in the immediate years both in the heat generating and the co-generating plants. Some foreign analysts, however, estimate a doubled use of coal for energy use after 2020 because of the plans to phase out the nuclear power. During the top year 1987 coal was used in 18 hot water plants and 11 co-generation plants. 1997 these figures are 2 and 8. Taxes and environmental reasons explain this trend. The use of steam coal in the industry has been constant at the level 700 000 tons. This level is supposed to be constant or to vary with business cycles. The import of metallurgical coal in 1997 was 1.6 mill tons like the year before. 1.2 mill tons coke were produced. The coke consumption in the industry was 1.5 Mill tons. 0.3 mill tons of coke were imported. Several other plants have plans to replace the coal with forest fuels, waste fuels and NG. Even the biggest plant, Vaesteraas, has plans to build a block for bio fuels. Helsingborg has started to use wood pellets. The pellets replace most of the coal for the heat production in the co-generation plant. Norrkoeping Kraft AB has taken a fluid bed boiler for different fuels in operation, leading to more than half the coal consumption compared with previous years. They have also rebuilt one of their travelling grates for bio fuels. Stockholm

  13. Graphene-oxide-supported CuAl and CoAl layered double hydroxides as enhanced catalysts for carbon-carbon coupling via Ullmann reaction

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Nesreen S. [Department of Chemistry, Faculty of Science, King Abdulaziz University (Saudi Arabia); Surface Chemistry and Catalytic Studies Group, King Abdulaziz University (Saudi Arabia); Menzel, Robert [Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Bio Nano Consulting, The Gridiron Building, One Pancras Square, London N1C 4AG (United Kingdom); Wang, Yifan [Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Garcia-Gallastegui, Ainara [Bio Nano Consulting, The Gridiron Building, One Pancras Square, London N1C 4AG (United Kingdom); Bawaked, Salem M.; Obaid, Abdullah Y.; Basahel, Sulaiman N. [Department of Chemistry, Faculty of Science, King Abdulaziz University (Saudi Arabia); Surface Chemistry and Catalytic Studies Group, King Abdulaziz University (Saudi Arabia); Mokhtar, Mohamed, E-mail: mmokhtar2000@yahoo.com [Department of Chemistry, Faculty of Science, King Abdulaziz University (Saudi Arabia); Surface Chemistry and Catalytic Studies Group, King Abdulaziz University (Saudi Arabia)

    2017-02-15

    Two efficient catalyst based on CuAl and CoAl layered double hydroxides (LDHs) supported on graphene oxide (GO) for the carbon-carbon coupling (Classic Ullmann Homocoupling Reaction) are reported. The pure and hybrid materials were synthesised by direct precipitation of the LDH nanoparticles onto GO, followed by a chemical, structural and physical characterisation by electron microscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), surface area measurements and X-ray photoelectron spectroscopy (XPS). The GO-supported and unsupported CuAl-LDH and CoAl-LDH hybrids were tested over the Classic Ullman Homocoupling Reaction of iodobenzene. In the current study CuAl- and CoAl-LDHs have shown excellent yields (91% and 98%, respectively) at very short reaction times (25 min). GO provides a light-weight, charge complementary and two-dimensional material that interacts effectively with the 2D LDHs, in turn enhancing the stability of LDH. After 5 re-use cycles, the catalytic activity of the LDH/GO hybrid is up to 2 times higher than for the unsupported LDH. - Graphical abstract: CuAl- and CoAl-LDHs have shown excellent yields (91% and 98%, respectively) at very short reaction times (25 min). GO provides a light-weight, charge complementary, two-dimensional material that interacts effectively with the 2D LDHs, in turn enhancing the stability of LDH. - Highlights: • CuAl LDH/GO and CoAl LDH/GO hybrid materials with different LDH compositions were prepared. • Hybrids were fully characterised and their catalytic efficiency over the Classic Ullman Reaction was studied. • CuAl- and CoAl-LDHs have shown excellent yields (91% and 98%, respectively) in 25 min reaction times. • GO provides a light-weight, charge complementary, two-dimensional material that interacts effectively with the 2D LDHs. • After 5 re-use cycles, the catalytic activity of the LDH/GO hybrid is up to 2 times higher than for the unsupported LDH.

  14. Biochemical Removal of HAP Precursors from Coal

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Gregory J

    1997-05-12

    Column biooxidation tests with Kentucky coal confirmed results of earlier shake flask tests showing significant removal from the coal of arsenic, selenium, cobalt, manganese, nickel and cadmium. Rates of pyrite biooxidation in Kentucky coal were only slightly more than half the rates found previously for Indiana and Pittsburgh coals. Removal of pyrite from Pittsburgh coal by ferric ion oxidation slows markedly as ferrous ions accumulate in solution, requiring maintenance of high redox potentials in processes designed for removal of pyrite and hazardous air pollutant (HAP) precursors by circulation of ferric solutions through coal. The pyrite oxidation rates obtained in these tests were used by Unifield Engineering to support the conceptual designs for alternative pyrite and HAP precursor bioleaching processes for the phase 2 pilot plant. Thermophilic microorganisms were tested to determine if mercury could be mobilized from coal under elevated growth temperatures. There was no evidence for mercury removal from coal under these conditions. However, the activity of the organisms may have liberated mercury physically. It is also possible that the organisms dissolved mercury and it readsorbed to the clay preferentially. Both of these possibilities are undergoing further testing. The Idaho National Engineering and Environmental Laboratory's (INEEL) slurry column reactor was operated and several batches of feed coal, product coal, waste solids and leach solutions were submitted to LBL for HAP precursor analysis. Results to date indicate significant removal of mercury, arsenic and other HAP precursors in the combined physical-biological process.

  15. Simulation of coal low-temperature oxidation heating process in gob with “U+L” ventilation

    Directory of Open Access Journals (Sweden)

    Zhou Pei Ling

    2016-01-01

    Full Text Available In a gob with U + L ventilation, a tail roadway exists, which has important effects on the oxidation heating process and gas concentration in gob areas. Research on the heating process and gas concentration in the “U+L” ventilation can provide the basis for the prevention of spontaneous combustion, thus, the regularities of the oxidation heating process and gas concentration in gob areas were researched by simulation. Results showed that compared with U ventilation, U + L ventilation caused the high temperature zone and high temperature points in the gob areas to increase in depth and width and to be influenced by the distance between the crossheading of the tail roadway and workface. The heating rate of the high-temperature point in the gob with tail roadway was 1.5 times of that in gob without tail roadway, but was unaffected by the location of the tail roadway. Tail roadway had diversion effects on the airflow, especially near return side and the maximum reduction of gas concentration can be 0.36%.

  16. The desulfurization mechanism of iron-manganese compound oxide desulfurizer for removal of COS from coal gas

    Energy Technology Data Exchange (ETDEWEB)

    Wang Fang-fang; Zhao Hai; Zhang De-xiang; Gao Jin-sheng [East China University of Science and Technology. Shanghai (China). School of Resource and Environmental Engineering

    2008-02-15

    The sorbent, atmospheric and components of outlet gas were analyzed by mass spectra, XRD, SEM, EDS etc. Desulfurisation performance of sorbents is good at 240 - 400 {sup o}C, atmospheric pressure and space speed of 500 - 2,000 h {sup -1}. The possible mechanism of desulfurisation reactions was obtained by analyzing the reduction- adsorption-sulfidation process. Carbon oxysulfide (COS) was converted to H{sub 2}S by hydrogen in strongly reducing atmosphere firstly. Then H{sub 2}S was adsorbed on the surface of desulfurizers, reacted with active component and transformed metal sulfides and water. Efficiency of removal of carbonyl sulfur is better in an atmosphere without carbonaceous oxide than in one with it, under test conditions. The existence of carbonaceous oxide restrains hydrogenation and the hydrolytic process of COS, which leads to a higher concentration of COS in the outlet. It is shown that chemical conversion is the main pathway in the reaction system of COS. Hydrogenation is the main process in the removal of COS from syngas. COS is preferentially catalyzed with active components n desulfurization sorbents, and generates H{sub 2}S which is subsequently absorbed. 13 refs., 4 figs., 2 tabs.

  17. REGULATION OF COAL POLYMER DEGRADATION BY FUNGI

    Energy Technology Data Exchange (ETDEWEB)

    John A. Bumpus

    1998-11-30

    A variety of lignin degrading fungi mediate solubilization and subsequent biodegradation of coal macromolecules (a.k.a. coal polymer) from highly oxidized low rank coals such as leonardites. It appears that oxalate or possibly other metal chelators (i.e., certain Krebs Cycle intermediates) mediate solubilization of low rank coals while extracellular oxidases have a role in subsequent oxidation of solubilized coal macromolecule. These processes are under nutritional control. For example, in the case of P. chrysosporium, solubilization of leonardite occurred when the fungi were cultured on most but not all nutrient agars tested and subsequent biodegradation occurred only in nutrient nitrogen limited cultures. Lignin peroxidases mediate oxidation of coal macromolecule in a reaction that is dependent on the presence of veratryl alcohol and hydrogen peroxide. Kinetic evidence suggests that veratryl alcohol is oxidized to the veratryl alcohol cation radical which then mediates oxidation of the coal macromolecule. Results by others suggest that Mn peroxidases mediate formation of reactive Mn{sup 3+} complexes which also mediate oxidation of coal macromolecule. A biomimetic approach was used to study solubilization of a North Dakota leonardite. It was found that a concentration {approximately}75 mM sodium oxalate was optimal for solubilization of this low rank coal. This is important because this is well above the concentration of oxalate produced by fungi in liquid culture. Higher local concentrations probably occur in solid agar cultures and thus may account for the observation that greater solubilization occurs in agar media relative to liquid media. The characteristics of biomimetically solubilized leonardite were similar to those of biologically solubilized leonardite. Perhaps our most interesting observation was that in addition to oxalate, other common Lewis bases (phosphate/hydrogen phosphate/dihydrogen phosphate and bicarbonate/carbonate ions) are able to mediate

  18. Influence of Ti Content on the Partial Oxidation of TixFeCoNi Thin Films in Vacuum Annealing

    Directory of Open Access Journals (Sweden)

    Ya-Chu Yang

    2017-09-01

    Full Text Available This study investigated the effects of Ti content and vacuum annealing on the microstructure evolution of TixFeCoNi (x = 0, 0.5, and 1 thin films and the underlying mechanisms. The as-deposited thin film transformed from an FCC (face center cubic structure at x = 0 into an amorphous structure at x = 1, which can be explained by determining topological instability and a hard ball model. After annealing was performed at 1000 °C for 30 min, the films presented a layered structure comprising metal solid solutions and oxygen-deficient oxides, which can be major attributed to oxygen traces in the vacuum furnace. Different Ti contents provided various phase separation and layered structures. The underlying mechanism is mainly related to the competition among possible oxides in terms of free energy production at 1000 °C.

  19. Coal 95

    International Nuclear Information System (INIS)

    Sparre, C.

    1995-01-01

    The report deals with the use of coal and coke in Sweden during 1994. Some information about technology, environmental questions and markets are also given. Data have been collected by questionnaires to major users and by telephone to minor users. Preliminary statistical data from Statistics Sweden have also been used.The use of steam coal for heating purposes has been unchanged during 1994 at a level of 1 Mtons. The production in the cogeneration plants has been constant, but has increased for electricity production. The minor plants have increased their use of forest fuels. The use of steam coal will probably go down in the next years both for heat and cogeneration plants. During the top year 1987 coal was used in 18 hot water and 11 cogeneration plants. 1994 these figures are 3 and 12. Taxes and environmental reasons explain this trend. The use of steam coal in industry has been constant at the level 0.7 Mtons. The import of metallurgical coal in 1993 was 1.6 Mtons, like 1992. Import of 0.3 Mtons of coke gives the total consumption of coke in industry as 1.5 Mtons. the average price of steam coal imported to Sweden was 317 SEK/ton, 3% higher than 1993. All Swedish plants meet their emission limit of dust, SO 2 and NO x as given by county administrations or concession boards. The cogeneration plants all have some SO 2 removal system. The biggest cogeneration plant (Vaesteraas) has recently invested in a SCR NO x cleaning system. Most other plants use low NO x burners or SNR injection systems based on ammonia or urea. 2 figs, 13 tabs

  20. Geochemistry of Coal Ash in the Equatorial Wet Disposal System Environment

    OpenAIRE

    Kolay P. K.; Singh H.

    2013-01-01

    The coal utilization in thermal power plants in Malaysia has increased significantly which produces an enormous amount of coal combustion by-product (CCBP) or coal ash and poses severe disposal problem. As each coal ash is distinct, this study presents the geochemistry of the coal ash, in particular fly ash, produced from the combustion of local coal from Kuching Sarawak, Malaysia. The geochemical composition of the ash showed a high amount of silica, alumina, iron oxides and alkalies which w...

  1. Electrospun cerium-based TiO2 nanofibers for photocatalytic oxidation of elemental mercury in coal combustion flue gas.

    Science.gov (United States)

    Wang, Lulu; Zhao, Yongchun; Zhang, Junying

    2017-10-01

    Photocatalytic oxidation is an attractive method for Hg-rich flue gas treatment. In the present study, a novel cerium-based TiO 2 nanofibers was prepared and selected as the catalyst to remove mercury in flue gas. Accordingly, physical/chemical properties of those nanofibers were clarified. The effects of some important parameters, such as calcination temperature, cerium dopant content and different illumination conditions on the removal of Hg 0 using the photocatalysis process were investigated. In addition, the removal mechanism of Hg 0 over cerium-based TiO 2 nanofibers focused on UV irradiation was proposed. The results show that catalyst which was calcined at 400 °C exhibited better performance. The addition of 0.3 wt% Ce into TiO 2 led to the highest removal efficiency at 91% under UV irradiation. As-prepared samples showed promising stability for long-term use in the test. However, the photoluminescence intensity of nanofibers incorporating ceria was significantly lower than TiO 2 , which was attributed to better photoelectron-hole separation. Although UV and O 2 are essential factors, the enhancement of Hg 0 removal is more obviously related to the participation of catalyst. The coexistence of Ce 3+ and Ce 4+ , which leads to the efficient oxidation of Hg 0 , was detected on samples. Hg 2+ is the final product in the reaction of Hg 0 removal. As a consequence, the emissions of Hg 0 from flue gas can be significantly suppressed. These indicate that combining photocatalysis technology with cerium-based TiO 2 nanofibers is a promising strategy for reducing Hg 0 efficiently. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Microwave-Assisted Coprecipitation Synthesis of LaCoO3 Nanoparticles and Their Catalytic Activity for Syngas Production by Partial Oxidation of Methane

    Directory of Open Access Journals (Sweden)

    Consuelo Alvarez-Galvan

    2018-04-01

    Full Text Available LaCoO3 perovskite-type oxides were prepared by microwave-assisted coprecipitation route and investigated in the catalytic partial oxidation of methane (CPOM to syngas. This preparation method aims to achieve higher specific surface areas (ssa than soft-chemical methods commonly used in the preparation of engineered materials. In an attempt to accomplish the creation of mesostructured porous LaCoO3, an ionic template such as cetyl trimethyl ammonium bromide has been used as endotemplate in some samples. The influence of pH and the type of precipitating agent has been studied. The materials have been characterized at different levels: morphology has been studied by scanning electron microscopy, textural properties by nitrogen adsorption–desorption at −196°C, structural analysis by X-ray diffraction, surface composition by X-ray photoelectron spectroscopy, thermal stability by thermogravimetric analysis, and carbon formation in spent catalysts by Raman spectroscopy. Structure-activity correlations point out that the precipitating agent has a key role on the morphology and porosity of the resultant oxide, as well as on the average crystalline domain of lanthanum perovskite (catalyst precursor. Thus, the use of ammonium hydroxide as precipitant leads to materials with a higher surface area and a greater ssa of cobalt (per unit mass, improving their catalytic performance for the CPOM reaction. The best catalytic performance was found for the catalyst prepared using ammonium hydroxide as precipitant (pH 9 and without adding CTAB as endotemplate.

  3. Ni/SiO2 Catalyst Prepared with Nickel Nitrate Precursor for Combination of CO2 Reforming and Partial Oxidation of Methane: Characterization and Deactivation Mechanism Investigation

    Directory of Open Access Journals (Sweden)

    Sufang He

    2015-01-01

    Full Text Available The performance of Ni/SiO2 catalyst in the process of combination of CO2 reforming and partial oxidation of methane to produce syngas was studied. The Ni/SiO2 catalysts were prepared by using incipient wetness impregnation method with nickel nitrate as a precursor and characterized by FT-IR, TG-DTA, UV-Raman, XRD, TEM, and H2-TPR. The metal nickel particles with the average size of 37.5 nm were highly dispersed over the catalyst, while the interaction between nickel particles and SiO2 support is relatively weak. The weak NiO-SiO2 interaction disappeared after repeating oxidation-reduction-oxidation in the fluidized bed reactor at 700°C, which resulted in the sintering of metal nickel particles. As a result, a rapid deactivation of the Ni/SiO2 catalysts was observed in 2.5 h reaction on stream.

  4. Anchoring Tri(8-QuinolinolatoIron Onto Sba-15 for Partial Oxidation of Benzyl Alcohol Using Water as the Solvent

    Directory of Open Access Journals (Sweden)

    Yang Xiaoyuan

    2014-09-01

    Full Text Available Tri(8-quinolinolatoiron complex immobilized onto SBA-15 catalyst has been synthesized through a stepwise procedure. The characterization results indicated that the BET surface area, total pore volume and average pore width decrease after stepwise modification of SBA-15, while the structure keeps intact. Catalytic tests showed that FeQ3-SBA-15 catalyzes the oxidation reaction well with 34.8% conversion of benzyl alcohol and 74.7% selectivity to benzaldehyde when water is used as the solvent after 1 h reaction. In addition, homogeneous catalyst tri(8-quinolinolatoiron exhibits very bad catalytic behavior using water as the solvent.

  5. Quarterly coal report, April--June 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-26

    In the second quarter of 1993, the United States produced 235 million short tons of coal. This brought the total for the first half of 1993 to 477 million short tons, a decrease of 4 percent (21 million short tons) from the amount produced during the first half of 1992. The decrease was due to a 26-million-short-ton decline in production east of the Mississippi River, which was partially offset by a 5-million-short-ton increase in coal production west of the Mississippi River. Compared with the first 6 months of 1992, all States east of the Mississippi River had lower coal production levels, led by West Virginia and Illinois, which produced 9 million short tons and 7 million short tons less coal, respectively. The principal reasons for the drop in coal output for the first 6 months of 1993 compared to a year earlier were: a decrease in demand for US coal in foreign markets, particularly the steam coal markets; a draw-down of electric utility coal stocks to meet the increase in demand for coal-fired electricity generation; and a lower producer/distributor stock build-up. Distribution of US coal in the first half of 1993 was 15 million short tons lower than in the first half of 1992, with 13 million short tons less distributed to overseas markets and 2 million short tons less distributed to domestic markets.

  6. Coal-related research, organic chemistry, and catalysis

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Coal chemistry research topics included: H exchange at 400 0 C, breaking C-C bonds in coal, molecular weight estimation using small-angle neutron scattering, 13 C NMR spectra of coals, and tunneling during H/D isotope effects. Studies of coal conversion chemistry included thermolysis of bibenzyl and 1-naphthol, heating of coals in phenol, advanced indirect liquefaction based on Koelbel slurry Fischer-Tropsch reactor, and plasma oxidation of coal minerals. Reactions of PAHs in molten SbCl 3 , a hydrocracking catalyst, were studied. Finally, heterogeneous catalysis (desulfurization etc.) was studied using Cu, Au, and Ni surfaces. 7 figures, 6 tables

  7. Distilling coal

    Energy Technology Data Exchange (ETDEWEB)

    Blythe, F C

    1914-09-14

    In the destructive distillation of bituminous coal, heavy hydrocarbon oil, such as petroleum, kerosine, shale oil, and heavy tar oil, obtained in some cases during the process, is added to the coal, which is then distilled under pressure and at a comparatively low temperature regulated so as to produce a large proportion of hydrocarbon oils and a small proportion of permanent gas. In one method, about 5 to 10 parts of hydrocarbon oil are mixed with 100 parts of crushed or ground coal, and the mixture is heated in a closed vessel, provided in some cases with an agitator, under a pressure of about 60 lb/in/sup 2/, and the temperature may be gradually raised to 350/sup 0/C and then to about 500/sup 0/C. The heating may be by means of superheated steam with or without external heat.

  8. Coal and recycling mark the way forward

    Energy Technology Data Exchange (ETDEWEB)

    Bignell, E.

    2000-11-01

    A report is given of this year's Mineral Engineering Society's annual conference held in Scarborough, UK. The themes of recycling and coal were chosen for the two days of technical presentations. Topics included the cleaning up of brown field sites; the use of recycled waste oxide to replace iron ore pellets for cooling furnaces in steel making; high pressure filtration of industrial mineral effluent; iron ore mining in Australia; screen development; the status of coal preparation technology, by RJB Mining; study of movement of material (to simulate coal) in a hopper; and a UK-Chinese project on reduction of sulphur in coal.

  9. Mine Water Treatment in Hongai Coal Mines

    Science.gov (United States)

    Dang, Phuong Thao; Dang, Vu Chi

    2018-03-01

    Acid mine drainage (AMD) is recognized as one of the most serious environmental problem associated with mining industry. Acid water, also known as acid mine drainage forms when iron sulfide minerals found in the rock of coal seams are exposed to oxidizing conditions in coal mining. Until 2009, mine drainage in Hongai coal mines was not treated, leading to harmful effects on humans, animals and aquatic ecosystem. This report has examined acid mine drainage problem and techniques for acid mine drainage treatment in Hongai coal mines. In addition, selection and criteria for the design of the treatment systems have been presented.

  10. Mine Water Treatment in Hongai Coal Mines

    Directory of Open Access Journals (Sweden)

    Dang Phuong Thao

    2018-01-01

    Full Text Available Acid mine drainage (AMD is recognized as one of the most serious environmental problem associated with mining industry. Acid water, also known as acid mine drainage forms when iron sulfide minerals found in the rock of coal seams are exposed to oxidizing conditions in coal mining. Until 2009, mine drainage in Hongai coal mines was not treated, leading to harmful effects on humans, animals and aquatic ecosystem. This report has examined acid mine drainage problem and techniques for acid mine drainage treatment in Hongai coal mines. In addition, selection and criteria for the design of the treatment systems have been presented.

  11. The erosion/corrosion of small superalloy turbine rotors operating in the effluent of a PFB coal combustor

    Science.gov (United States)

    Zellars, G. R.; Benford, S. M.; Rowe, A. P.; Lowell, C. E.

    1979-01-01

    The operation of a turbine in the effluent of a pressurized fluidized bed (PFB) coal combustor presents serious materials problems. Synergistic erosion/corrosion and deposition/corrosion interactions may favor the growth of erosion-resistant oxides on blade surfaces, but brittle cracking of these oxides may be an important source of damage along heavy particle paths. Integrally cast alloy 713LC and IN792 + Hf superalloy turbine rotors in a single-stage turbine with 6% partial admittance have been operated in the effluent of a PFB coal combustor for up to 164 hr. The rotor erosion pattern exhibits heavy particle separation with severe erosion at the leading edge, pressure side center, and suction side trailing edge at the tip. The erosion distribution pattern gives a spectrum of erosion/oxidation/deposition as a function of blade position. The data suggest that preferential degradation paths may exist even under the targeted lower loadings (less than 20 ppm).

  12. Rf-sputtered vanadium oxide thin films: effect of oxygen partial pressure on structural and electrochemical properties

    CERN Document Server

    Park, Y J; Ryu, K S; Chang, S H; Park, S C; Yoon, S M; Kim, D K

    2001-01-01

    Vanadium oxide thin films with thickness of about 2000 A have been prepared by radio frequency sputter deposition using a V sub 2 O sub 5 target in a mixed argon and oxygen atmosphere with different Ar/O sub 2 ratio ranging from 99/1 to 90/10. X-ray diffraction and X-ray absorption near edge structure spectroscopic studies show that the oxygen content higher than 5% crystallizes a stoichiometric V sub O sub 5 phase, while oxygen deficient phase is formed in the lower oxygen content. The oxygen content in the mixed Ar + O sub 2 has a significant influence on electrochemical lithium insertion/deinsertion property. The discharge-charge capacity of vanadium oxide film increases with increasing the reactive oxygen content. The V sub O sub 5 film deposited at the Ar/O sub 2 ratio of 90/10 exhibits high discharge capacity of 100 mu Ah/cm sup 2 -mu m along with good cycle performance.

  13. The impact of partial manganese superoxide dismutase (SOD2)-deficiency on mitochondrial oxidant stress, DNA fragmentation and liver injury during acetaminophen hepatotoxicity

    International Nuclear Information System (INIS)

    Ramachandran, Anup; Lebofsky, Margitta; Weinman, Steven A.; Jaeschke, Hartmut

    2011-01-01

    Acetaminophen (APAP) hepatotoxicity is the most frequent cause of acute liver failure in many countries. The mechanism of cell death is initiated by formation of a reactive metabolite that binds to mitochondrial proteins and promotes mitochondrial dysfunction and oxidant stress. Manganese superoxide dismutase (SOD2) is a critical defense enzyme located in the mitochondrial matrix. The objective of this investigation was to evaluate the functional consequences of partial SOD2-deficiency (SOD2+/-) on intracellular signaling mechanisms of necrotic cell death after APAP overdose. Treatment of C57Bl/6J wild type animals with 200 mg/kg APAP resulted in liver injury as indicated by elevated plasma alanine aminotransferase activities (2870 ± 180 U/L) and centrilobular necrosis at 6 h. In addition, increased tissue glutathione disulfide (GSSG) levels and GSSG-to-GSH ratios, delayed mitochondrial GSH recovery, and increased mitochondrial protein carbonyls and nitrotyrosine protein adducts indicated mitochondrial oxidant stress. In addition, nuclear DNA fragmentation (TUNEL assay) correlated with translocation of Bax to the mitochondria and release of apoptosis-inducing factor (AIF). Furthermore, activation of c-jun-N-terminal kinase (JNK) was documented by the mitochondrial translocation of phospho-JNK. SOD2+/- mice showed 4-fold higher ALT activities and necrosis, an enhancement of all parameters of the mitochondrial oxidant stress, more AIF release and more extensive DNA fragmentation and more prolonged JNK activation. Conclusions: the impaired defense against mitochondrial superoxide formation in SOD2+/- mice prolongs JNK activation after APAP overdose and consequently further enhances the mitochondrial oxidant stress leading to exaggerated mitochondrial dysfunction, release of intermembrane proteins with nuclear DNA fragmentation and more necrosis.

  14. Structural evidence for the partially oxidized dipyrromethene and dipyrromethanone forms of the cofactor of porphobilinogen deaminase: structures of the Bacillus megaterium enzyme at near-atomic resolution

    International Nuclear Information System (INIS)

    Azim, N.; Deery, E.; Warren, M. J.; Wolfenden, B. A. A.; Erskine, P.; Cooper, J. B.; Coker, A.; Wood, S. P.; Akhtar, M.

    2014-01-01

    The enzyme porphobilinogen deaminase (PBGD; hydroxymethylbilane synthase; EC 2.5.1.61) catalyses a key early step in the biosynthesis of tetrapyrroles in which four molecules of the monopyrrole porphobilinogen are condensed to form a linear tetrapyrrole. Two near-atomic resolution structures of PBGD from B. megaterium are reported that demonstrate the time-dependent accumulation of partially oxidized forms of the cofactor, including one that possesses a tetrahedral C atom in the terminal pyrrole ring. The enzyme porphobilinogen deaminase (PBGD; hydroxymethylbilane synthase; EC 2.5.1.61) catalyses an early step of the tetrapyrrole-biosynthesis pathway in which four molecules of the monopyrrole porphobilinogen are condensed to form a linear tetrapyrrole. The enzyme possesses a dipyrromethane cofactor, which is covalently linked by a thioether bridge to an invariant cysteine residue (Cys241 in the Bacillus megaterium enzyme). The cofactor is extended during the reaction by the sequential addition of the four substrate molecules, which are released as a linear tetrapyrrole product. Expression in Escherichia coli of a His-tagged form of B. megaterium PBGD has permitted the X-ray analysis of the enzyme from this species at high resolution, showing that the cofactor becomes progressively oxidized to the dipyrromethene and dipyrromethanone forms. In previously solved PBGD structures, the oxidized cofactor is in the dipyromethenone form, in which both pyrrole rings are approximately coplanar. In contrast, the oxidized cofactor in the B. megaterium enzyme appears to be in the dipyrromethanone form, in which the C atom at the bridging α-position of the outer pyrrole ring is very clearly in a tetrahedral configuration. It is suggested that the pink colour of the freshly purified protein is owing to the presence of the dipyrromethene form of the cofactor which, in the structure reported here, adopts the same conformation as the fully reduced dipyrromethane form

  15. Spectral characterization of superficial coal groups

    International Nuclear Information System (INIS)

    Ahmad, I.; Khan, M.A.; Ishaq, M.; Shakirullah; Bahadur, A.

    2004-01-01

    Spectral characterization of superficial coal groups was performed in KBr pellets. KBr Pellets were prepared for virgin and variously pretreated coal samples. Spectra of satisfactory resolution were obtained in wave number range-4000-400 cm /sup -1/. Presence of broad absorption bands corresponds to hydroxyl, carbonyl, carboxyl and phenolic functionalities in the spectra clearly define their presence in all samples understudy. Forced oxidation proved effective for oxidation of both aliphatic and aromatic configurations, which can be revealed from the respective spectra. (author)

  16. Habitual Coffee Consumption Does Not Correlate with Blood Pressure, Inflammation and Endothelial Dysfunction but Partially Correlates with Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Erizal Sugiono

    2013-04-01

    Full Text Available BACKGROUND: Coffee is the most widely consumed beverage in the world and has been known to have effects on cardiovascular system. Many researchers have examined the effects of coffee consumption on blood pressure (BP and risk of cardiovascular disease (CVD, but their results were inconsistent and still remain a subject of controversy. Oxidative stress, inflammation, and endothelial dysfunction have been known as risk factors of hypertension and CVD. Those factors are also known to be affected by coffee consumption. The aim of this study was to examine the relationship between the effects of habitual coffee consumption on BP and to examine the role of oxidative stress (F2 isoprostane, inflammation (high sensitive C-reactive protein (hsCRP and endothelial dysfunction (asymmetric dimethylarginine (ADMA. METHODS: This was a cross-sectional study in which 47 healthy, non-smoking men aged 30-60 years with varying coffee-drinking habits were enrolled. BP and blood/urine analysis of biomarkers were measured in the morning before activity. Coffee consumption was assessed using a questionnaire. The differences among variables were analyzed using ANOVA and the correlations between variables were analyzed using Kendall’s Tau correlation analysis. RESULTS: Habitual coffee consumption did not correlate with systolic/diastolic BP (r=-0.02; p=0.856 and r=0.15; p=0.230, respectively. Concentrations of ADMA and hsCRP were also not correlated with coffee consumption (r=0.03; p=0.764 and r=0.04; p=0.701, respectively. Coffee consumption only showed significant correlation with F2 isoprostane (r=0.34; p=0.004. CONCLUSIONS: BP was not affected by coffee consumption although coffee consumption has a significant correlation with F2 isoprostane. These findings suggest that correlation between coffee consumption and BP might be explained by other factors that were not included in this study. KEYWORDS: coffee, caffeine, cardiovascular disease, blood pressure, oxidative

  17. The future of coal-fired generation

    Energy Technology Data Exchange (ETDEWEB)

    White, G. [Sherritt International Corp., Calgary, AB (Canada)

    2004-07-01

    The 3 features that will ensure coal's place as a primary energy source are its affordability, availability and its abundance. Coal reserves represent more than 200 years of supply. Graphs depicting coal consumption in North America, Central and South America, Western Europe, Easter Europe, Middle East, Africa, and Asia show that coal use is expected to grow 1.5 per cent annually. Asia is the greatest consumer of coal, while the consumption of coal in Eastern Europe is steadily declining. About half of the electricity supply in the United States will continue to be generated by coal and non-electrical utilization is also expected to grow. Emerging technologies that are promoting efficiency of coal utilization include combustion technology, clean coal technology, conversion technology and emissions technology. These technologies also address environmental concerns regarding coal combustion, such as removal of carbon dioxide through sequestration and reduction in nitrogen oxides, sulphur dioxide and particulates. Mercury mitigation technologies are also being developed. It was noted that the use of coal is mitigated by other available supply such as nuclear, natural gas and hydro which provide the base load generation. Renewable energy supply can meet up to 20 per cent of the base load, while coal can fill be gap between base load and peak loads. It was noted that the use of coal in direct industrial processes allows for synergies such as syngas for bitumen upgrading, coal as a chemical feedstock with electricity as a by-product, combined heat and power and cogeneration. tabs., figs.

  18. Microbiological desulfurization and conversion of coal

    International Nuclear Information System (INIS)

    Quigley, D.R.; Stoner, D.L.; Dugan, P.R.

    1991-01-01

    Bio processing of coal is a young and emerging technology. Until the early 1980's it consisted primarily of coal depyritization using Thiobacillus ferro oxidans to either oxidize pyritic sulfur or to alter particle wettability or floatation properties by binding to exposed pyrite inclusions. Since then, other major avenues of research have been pursued. One of these is the microbiologically mediated liquefaction of coal. Initial work indicated that microorganisms were able to transform low rank coal into a black liquid that was later identified as water solubilized by alkaline substances produced by the microbes and could be enhanced by the removal of multi valent cations from coal. Current work at the INEL involves of the identification and characterization of microorganisms that are able to alter the structure of polymeric desulfurization of coal. This work initially focused on the ability of microorganisms to oxidatively remove organic sulfur from model compounds that were representative of those sulfur containing moieties identified as being in coals (e.g., dibenzo thiophene). The work also focused on those organisms that were could remove the organic sulfur without degrading the carbon structure. While some organisms that are able to perform such these reactions will effectively remove organo sulfur from coal. These concerns stem from steric hindrance considerations and the thermodynamically unfavourable nature of reaction. Current work at the INEL involves the isolation and biochemical characterization of microorganisms that are able to desulfurize and solubilized coals that have high organic sulfur contents. (author)

  19. Oxygen Partial Pressure Impact on Characteristics of Indium Titanium Zinc Oxide Thin Film Transistor Fabricated via RF Sputtering.

    Science.gov (United States)

    Hsu, Ming-Hung; Chang, Sheng-Po; Chang, Shoou-Jinn; Wu, Wei-Ting; Li, Jyun-Yi

    2017-06-26

    Indium titanium zinc oxide (InTiZnO) as the channel layer in thin film transistor (TFT) grown by RF sputtering system is proposed in this work. Optical and electrical properties were investigated. By changing the oxygen flow ratio, we can suppress excess and undesirable oxygen-related defects to some extent, making it possible to fabricate the optimized device. XPS patterns for O 1s of InTiZnO thin films indicated that the amount of oxygen vacancy was apparently declined with the increasing oxygen flow ratio. The fabricated TFTs showed a threshold voltage of -0.9 V, mobility of 0.884 cm²/Vs, on-off ratio of 5.5 × 10⁵, and subthreshold swing of 0.41 V/dec.

  20. Briquetting and coking behavior of Bobov-Dol coal

    Energy Technology Data Exchange (ETDEWEB)

    Naundorf, W.

    1987-01-01

    Hard Bulgarian glance brown coal (23.2% ash content, 16% coal moisture 2.39% sulfur) was studied for its general suitability for partial black coal coke substitution in coking plants and for the possibility of producing pyrolysis briquets for coking purposes. Laboratory briquetting variants include coal briquetting without binders, with sulfite lye as binder, briquetting after partial demineralization by wet classification, briquetting of different screening fractions (0 to 4 mm), briquetting as a mixture with type 35 caking black coal as well as mixed with type 34 less caking black coal under addition of black coal tar, pitch or bitumen. Coking of the briquets produced was carried at with and without charge compacting. Graphs and tables provide briquetting and coking results. It is concluded that high strength coke can be produced from this brown coal, but it can only be used commercially as heating coke due to its high ash and sulfur content. Briquetting and coking of partially demineralized brown coal in a mixture with black coal and binders resulted in suitable metallurgical coke. Maximum percentage of brown coal in the briquetting mixture was 30%. 4 refs.

  1. Nitrous oxide reduction genetic potential from the microbial community of an intermittently aerated partial nitritation SBR treating mature landfill leachate.

    Science.gov (United States)

    Gabarró, J; Hernández-Del Amo, E; Gich, F; Ruscalleda, M; Balaguer, M D; Colprim, J

    2013-12-01

    This study investigates the microbial community dynamics in an intermittently aerated partial nitritation (PN) SBR treating landfill leachate, with emphasis to the nosZ encoding gene. PN was successfully achieved and high effluent stability and suitability for a later anammox reactor was ensured. Anoxic feedings allowed denitrifying activity in the reactor. The influent composition influenced the mixed liquor suspended solids concentration leading to variations of specific operational rates. The bacterial community was low diverse due to the stringent conditions in the reactor, and was mostly enriched by members of Betaproteobacteria and Bacteroidetes as determined by 16S rRNA sequencing from excised DGGE melting types. The qPCR analysis for nitrogen cycle-related enzymes (amoA, nirS, nirK and nosZ) demonstrated high amoA enrichment but being nirS the most relatively abundant gene. nosZ was also enriched from the seed sludge. Linear correlation was found mostly between nirS and the organic specific rates. Finally, Bacteroidetes sequenced in this study by 16S rRNA DGGE were not sequenced for nosZ DGGE, indicating that not all denitrifiers deal with complete denitrification. However, nosZ encoding gene bacteria was found during the whole experiment indicating the genetic potential to reduce N2O. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Novel Fuel Cells for Coal Based Systems

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Tao

    2011-12-31

    The goal of this project was to acquire experimental data required to assess the feasibility of a Direct Coal power plant based upon an Electrochemical Looping (ECL) of Liquid Tin Anode Solid Oxide Fuel Cell (LTA-SOFC). The objective of Phase 1 was to experimentally characterize the interaction between the tin anode, coal fuel and cell component electrolyte, the fate of coal contaminants in a molten tin reactor (via chemistry) and their impact upon the YSZ electrolyte (via electrochemistry). The results of this work will provided the basis for further study in Phase 2. The objective of Phase 2 was to extend the study of coal impurities impact on fuel cell components other than electrolyte, more specifically to the anode current collector which is made of an electrically conducting ceramic jacket and broad based coal tin reduction. This work provided a basic proof-of-concept feasibility demonstration of the direct coal concept.

  3. Methane in German hard coal mining

    International Nuclear Information System (INIS)

    Martens, P.N.; Den Drijver, J.

    1995-01-01

    Worldwide, hard coal mining is being carried out at ever increasing depth, and has, therefore, to cope with correspondingly increasing methane emissions are caused by coal mining. Beside carbon dioxide, chloro-fluoro-carbons (CFCs) and nitrogen oxides, methane is one of the most significant 'greenhouse' gases. It is mainly through the release of such trace gases that the greenhouse effect is brought about. Reducing methane emissions is therefore an important problem to be solved by the coal mining industry. This paper begins by highlighting some of the fundamental principles of methane in hard coal mining. The methane problem in German hard coal mining and the industry's efforts to reduce methane emissions are presented. The future development in German hard coal mining is illustrated by an example which shows how large methane volumes can be managed, while still maintaining high outputs at increasing depth. (author). 7 tabs., 10 figs., 20 refs

  4. Coal-packed methane biofilter for mitigation of green house gas emissions from coal mine ventilation air.

    Science.gov (United States)

    Limbri, Hendy; Gunawan, Cindy; Thomas, Torsten; Smith, Andrew; Scott, Jason; Rosche, Bettina

    2014-01-01

    Methane emitted by coal mine ventilation air (MVA) is a significant greenhouse gas. A mitigation strategy is the oxidation of methane to carbon dioxide, which is approximately twenty-one times less effective at global warming than methane on a mass-basis. The low non-combustible methane concentrations at high MVA flow rates call for a catalytic strategy of oxidation. A laboratory-scale coal-packed biofilter was designed and partially removed methane from humidified air at flow rates between 0.2 and 2.4 L min-1 at 30°C with nutrient solution added every three days. Methane oxidation was catalysed by a complex community of naturally-occurring microorganisms, with the most abundant member being identified by 16S rRNA gene sequence as belonging to the methanotrophic genus Methylocystis. Additional inoculation with a laboratory-grown culture of Methylosinus sporium, as investigated in a parallel run, only enhanced methane consumption during the initial 12 weeks. The greatest level of methane removal of 27.2±0.66 g methane m-3 empty bed h-1 was attained for the non-inoculated system, which was equivalent to removing 19.7±2.9% methane from an inlet concentration of 1% v/v at an inlet gas flow rate of 1.6 L min-1 (2.4 min empty bed residence time). These results show that low-cost coal packing holds promising potential as a suitable growth surface and contains methanotrophic microorganisms for the catalytic oxidative removal of methane.

  5. Coal-Packed Methane Biofilter for Mitigation of Green House Gas Emissions from Coal Mine Ventilation Air

    Science.gov (United States)

    Limbri, Hendy; Gunawan, Cindy; Thomas, Torsten; Smith, Andrew; Scott, Jason; Rosche, Bettina

    2014-01-01

    Methane emitted by coal mine ventilation air (MVA) is a significant greenhouse gas. A mitigation strategy is the oxidation of methane to carbon dioxide, which is approximately twenty-one times less effective at global warming than methane on a mass-basis. The low non-combustible methane concentrations at high MVA flow rates call for a catalytic strategy of oxidation. A laboratory-scale coal-packed biofilter was designed and partially removed methane from humidified air at flow rates between 0.2 and 2.4 L min−1 at 30°C with nutrient solution added every three days. Methane oxidation was catalysed by a complex community of naturally-occurring microorganisms, with the most abundant member being identified by 16S rRNA gene sequence as belonging to the methanotrophic genus Methylocystis. Additional inoculation with a laboratory-grown culture of Methylosinus sporium, as investigated in a parallel run, only enhanced methane consumption during the initial 12 weeks. The greatest level of methane removal of 27.2±0.66 g methane m−3 empty bed h−1 was attained for the non-inoculated system, which was equivalent to removing 19.7±2.9% methane from an inlet concentration of 1% v/v at an inlet gas flow rate of 1.6 L min−1 (2.4 min empty bed residence time). These results show that low-cost coal packing holds promising potential as a suitable growth surface and contains methanotrophic microorganisms for the catalytic oxidative removal of methane. PMID:24743729

  6. A study of the evolution of nitrogen compounds during coal devolatilisation

    Energy Technology Data Exchange (ETDEWEB)

    Arenillas, A.; Rubiera, F.; Moreno, A.H.; Pevida, C.; Pis, J.J. [CSIC, Instituto Nacional del Carbon, Oviedo (Spain). Dept. of Energy and Environment

    2001-07-01

    Emissions of nitrogen oxides during combustion are a major environmental problem. The chemically bound nitrogen in fuel accounts for up to 80% of total NOx emissions. In this respect, fundamental studies are needed to clarify the mechanisms and to identify the different species that are precursors in the formation of the NOx. In this work, two methodologies were employed. Simultaneous thermogravimetric-mass spectrometric (TG-MS) analysis was used to study the pyrolysis behaviour of three coals of varying rank. The release of different nitrogen compounds was followed by means of temperature-programmed pyrolysis experiments. The influence of coal rank on the evolution of volatile compounds was also considered. In addition, a series of coal chars with different burn-off degrees were obtained in a bench scale fluidised bed reactor, using the same parent coal. The evolution of gaseous compounds arising from the thermal treatment of the partially burned chars was studied in the TG-MS system. It was found that the different chemical structure of the chars exerted some influence on the evolution of the gaseous compounds during the devolatilisation process. Finally, the evolution of the volatile compounds was also studied in the bench scale fluidised bed reactor. Special attention was given to the formation of N{sub 2}O during the pyrolysis of the coals used. 27 refs., 8 figs., 3 tabs.

  7. Clean coal technology and advanced coal-based power plants

    International Nuclear Information System (INIS)

    Alpert, S.B.

    1991-01-01

    Clean Coal Technology is an arbitrary terminology that has gained increased use since the 1980s when the debate over acid raid issues intensified over emissions of sulfur dioxide and nitrogen oxides. In response to political discussions between Prime Minister Brian Mulroney of Canada and President Ronald Reagan in 1985, the US government initiated a demonstration program by the Department of Energy (DOE) on Clean Coal Technologies, which can be categorized as: 1. precombustion technologies wherein sulfur and nitrogen are removed before combustion, combustion technologies that prevent or lower emissions as coal is burned, and postcombustion technologies wherein flue gas from a boiler is treated to remove pollutants, usually transforming them into solids that are disposed of. The DOE Clean Coal Technology (CCT) program is being carried out with $2.5 billion of federal funds and additional private sector funds. By the end of 1989, 38 projects were under way or in negotiation. These projects were solicited in three rounds, known as Clean Coal I, II, and III, and two additional solicitations are planned by DOE. Worldwide about 100 clean coal demonstration projects are being carried out. This paper lists important requirements of demonstration plants based on experience with such plants. These requirements need to be met to allow a technology to proceed to commercial application with ordinary risk, and represent the principal reasons that a demonstration project is necessary when introducing new technology

  8. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUIDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    International Nuclear Information System (INIS)

    Unknown

    2001-01-01

    Foster Wheeler Development Corporation is working under DOE contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% while producing near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The unique aspect of the process is that it utilizes a pressurized circulating fluidized bed partial gasifier and does not attempt to consume the coal in a single step. To convert all the coal to syngas in a single step requires extremely high temperatures ((approx)2500 to 2800F) that melt and vaporize the coal and essentially drive all coal ash contaminants into the syngas. Since these contaminants can be corrosive to power generating equipment, the syngas must be cooled to near room temperature to enable a series of chemical processes to clean the syngas. Foster Wheeler's process operates at much lower temperatures that control/minimize the release of contaminants; this eliminates/minimizes the need for the expensive, complicated syngas heat exchangers and chemical cleanup systems typical of high temperature gasification. By performing the gasification in a circulating bed, a significant amount of syngas can still be produced despite the reduced temperature and the circulating bed allows easy scale up to large size plants. Rather than air, it can also operate with oxygen to facilitate

  9. Vascular ATP-sensitive potassium channels are over-expressed and partially regulated by nitric oxide in experimental septic shock.

    Science.gov (United States)

    Collin, Solène; Sennoun, Nacira; Dron, Anne-Gaëlle; de la Bourdonnaye, Mathilde; Montemont, Chantal; Asfar, Pierre; Lacolley, Patrick; Meziani, Ferhat; Levy, Bruno

    2011-05-01

    To study the activation and expression of vascular (aorta and small mesenteric arteries) potassium channels during septic shock with or without modulation of the NO pathway. Septic shock was induced in rats by peritonitis. Selective inhibitors of vascular K(ATP) (PNU-37883A) or BK(Ca) [iberiotoxin (IbTX)] channels were used to demonstrate their involvement in vascular hyporeactivity. Vascular response to phenylephrine was measured on aorta and small mesenteric arteries mounted on a wire myograph. Vascular expression of potassium channels was studied by PCR and Western blot, in the presence or absence of 1400W, an inducible NO synthase (iNOS) inhibitor. Aortic activation of the transcriptional factor nuclear factor-kappaB (NF-κB) was assessed by electrophoretic mobility shift assay. Arterial pressure as well as in vivo and ex vivo vascular reactivity were reduced by sepsis and improved by PNU-37883A but not by IbTX. Sepsis was associated with an up-regulation of mRNA and protein expression of vascular K(ATP) channels, while expression of vascular BK(Ca) channels remained unchanged. Selective iNOS inhibition blunted the sepsis-induced increase in aortic NO, decreased NF-κB activation, and down-regulated vascular K(ATP) channel expression. Vascular K(ATP) but not BK(Ca) channels are activated, over-expressed, and partially regulated by NO via NF-κB activation during septic shock. Their selective inhibition restores arterial pressure and vascular reactivity and decreases lactate concentration. The present data suggest that selective vascular K(ATP) channel inhibitors offer potential therapeutic perspectives for septic shock.

  10. BL153 Partially Prevents High-Fat Diet Induced Liver Damage Probably via Inhibition of Lipid Accumulation, Inflammation, and Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2014-01-01

    Full Text Available The present study was to investigate whether a magnolia extract, named BL153, can prevent obesity-induced liver damage and identify the possible protective mechanism. To this end, obese mice were induced by feeding with high fat diet (HFD, 60% kcal as fat and the age-matched control mice were fed with control diet (10% kcal as fat for 6 months. Simultaneously these mice were treated with or without BL153 daily at 3 dose levels (2.5, 5, and 10 mg/kg by gavage. HFD feeding significantly increased the body weight and the liver weight. Administration of BL153 significantly reduced the liver weight but without effects on body weight. As a critical step of the development of NAFLD, hepatic fibrosis was induced in the mice fed with HFD, shown by upregulating the expression of connective tissue growth factor and transforming growth factor beta 1, which were significantly attenuated by BL153 in a dose-dependent manner. Mechanism study revealed that BL153 significantly suppressed HFD induced hepatic lipid accumulation and oxidative stress and slightly prevented liver inflammation. These results suggest that HFD induced fibrosis in the liver can be prevented partially by BL153, probably due to reduction of hepatic lipid accumulation, inflammation and oxidative stress.

  11. Evaluation of thermodynamic and kinetic stability of P-type transparent conducting oxide, SrCu2O2 under various oxygen partial pressures

    International Nuclear Information System (INIS)

    Sugimoto, Takayuki; Yanagawa, Atsumi; Hashimoto, Takuya

    2012-01-01

    Highlights: ▶ Thermodynamic and kinetic stabilities of SrCu 2 O 2 under various P(O 2 ) was estimated. ▶ The reaction rate for decomposition decreased with decreasing temperature and P(O 2 ). ▶ The activation energy for decomposition of SrCu 2 O 2 was estimated to be 66 kJ/mol. ▶ SrCu 2 O 2 showed less stability than those of other transparent p-type semiconductors. - Abstract: Kinetic stability of transparent p-type conducting oxide, SrCu 2 O 2 , has been evaluated by using X-ray diffraction measurement and thermogravimetry. It was revealed that SrCu 2 O 2 decomposed to mixture of CuO and Sr 14 Cu 24 O 41 in air at temperatures above 300 °C. The decomposition reaction rate can be successfully explained by kinetic model assuming first-order chemical reaction. The rate constant can be suppressed with decreasing temperature and oxygen partial pressure. The activation energy for decomposition reaction of SrCu 2 O 2 calculated from Arrhenius plot was 66 kJ/mol, which was lower than those of other transparent p-type semiconductors such as CuAlO 2 and CuGaO 2 . The low decomposition temperature and activation energy for decomposition indicate that chemical stability of SrCu 2 O 2 is far lower than those of other p-type conducting oxides.

  12. Coal Mines Security System

    OpenAIRE

    Ankita Guhe; Shruti Deshmukh; Bhagyashree Borekar; Apoorva Kailaswar; Milind E.Rane

    2012-01-01

    Geological circumstances of mine seem to be extremely complicated and there are many hidden troubles. Coal is wrongly lifted by the musclemen from coal stocks, coal washeries, coal transfer and loading points and also in the transport routes by malfunctioning the weighing of trucks. CIL —Coal India Ltd is under the control of mafia and a large number of irregularities can be contributed to coal mafia. An Intelligent Coal Mine Security System using data acquisition method utilizes sensor, auto...

  13. Coal at the crossroads

    International Nuclear Information System (INIS)

    Scaroni, A.W.; Davis, A.; Schobert, H.; Gordon, R.L.; Ramani, R.V.; Frantz, R.L.

    1992-01-01

    Worldwide coal reserves are very large but coal suffers from an image of being an environmentally unfriendly and inconvenient fuel. Aspects discussed in the article include: coal's poor image; techniques for coal analysis, in particular instrumented techniques; developments in clean coal technology e.g. coal liquefaction, fluidized bed combustion, co-generation and fuel slurries; the environmental impact of mining and land reclamation; and health aspects. It is considered that coal's future depends on overcoming its poor image. 6 photos

  14. DEVELOPMENT OF PRESSURIZED CIRCULATIONG FLUIDIZED BED PARTIAL GASIFICATION MODULE(PGM)

    Energy Technology Data Exchange (ETDEWEB)

    Archie Robertson

    2003-04-17

    Foster Wheeler Power Group, Inc. is working under US Department of Energy contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% and produce near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines, or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The amount of syngas and char produced by the PGM can be tailored to fit the production objectives of the overall plant, i.e., power generation, clean liquid fuel production, chemicals production, etc. Hence, PGM is a robust building block that offers all the advantages of coal gasification but in a more user-friendly form; it is also fuel flexible in that it can use alternative fuels such as biomass, sewerage sludge, etc. This report describes the work performed during the January 1--March 31, 2003 time period.

  15. β-Naphthoflavone enhances oxidative stress responses and the induction of preneoplastic lesions in a diethylnitrosamine-initiated hepatocarcinogenesis model in partially hepatectomized rats

    International Nuclear Information System (INIS)

    Dewa, Yasuaki; Nishimura, Jihei; Muguruma, Masako; Jin, Meilan; Saegusa, Yukie; Okamura, Toshiya; Tasaki, Masako; Umemura, Takashi; Mitsumori, Kunitoshi

    2008-01-01

    The tumour-promoting effects of β-naphthoflavone (BNF), a novel aryl hydrocarbon receptor (AhR) agonist, were investigated using a medium-term hepatocarcinogenesis model in rats. Six-week-old male F344 rats received an intraperitoneal injection of N-diethylnitrosamine (DEN) at a dose of 200 mg/kg body weight and were fed a diet containing 0% (basal diet), 0.5% or 1% BNF for 6 weeks from 2 weeks after DEN treatment. All animals were subjected to two-thirds partial hepatectomy 1 week after the BNF treatment. The number and area of glutathione S-transferase placental form (GST-P) positive foci significantly increased in the livers of rats treated with BNF with concomitantly increased cell proliferation compared to those in the livers of the DEN alone group. Global gene expression analysis and subsequent quantitative real-time reverse transcription-polymerase chain reaction revealed that BNF induced not only the 'AhR gene battery'Cyp1a1, Cyp1a2, Cyp1b1, Nqo1, Aldh3a1 and Ugt1a6 but also the transcription factor NF-E2-related factor 2 (Nrf2)-regulated genes such as Gstm1, Gpx2, Akr7a3 and Yc2 (and also Nqo1), presumably due to the adaptive response against BNF-triggered oxidative stress responses. Reactive oxygen species production increased in microsomes isolated from the livers of BNF-treated rats, and this enhancement was suppressed by the P450 inhibitor SKF-525A. Furthermore, BNF enhanced oxidative DNA damage and lipid peroxidation, estimated by the levels of 8-hydroxydeoxyguanosine (8-OHdG) and thiobarbituric acid-reactive substances. These results suggest that the administration of BNF at a high dose and over a long-term enhance oxidative stress responses which may contribute to its hepatocarcinogenic potential in rats

  16. Conversion of metallurgical coke and coal using a Coal Direct Chemical Looping (CDCL) moving bed reactor

    International Nuclear Information System (INIS)

    Luo, Siwei; Bayham, Samuel; Zeng, Liang; McGiveron, Omar; Chung, Elena; Majumder, Ankita; Fan, Liang-Shih

    2014-01-01

    Highlights: • Accumulated more than 300 operation hours were accomplished for the moving bed reducer reactor. • Different reactor operation variables were investigated with optimal conditions identified. • High conversions of sub-bituminous coal and bituminous coal were achieved without flow problems. • Co-current and counter-current contact modes were tested and their applicability was discussed. - Abstract: The CLC process has the potential to be a transformative commercial technology for a carbon-constrained economy. The Ohio State University Coal Direct Chemical Looping (CDCL) process directly converts coal, eliminating the need for a coal gasifier oran air separation unit (ASU). Compared to other solid-fuel CLC processes, the CDCL process is unique in that it consists of a countercurrent moving bed reducer reactor. In the proposed process, coal is injected into the middle of the moving bed, whereby the coal quickly heats up and devolatilizes, splitting the reactor roughly into two sections with no axial mixing. The top section consists of gaseous fuel produced from the coal volatiles, and the bottom section consists of the coal char mixed with the oxygen carrier. A bench-scale moving bed reactor was used to study the coal conversion with CO 2 as the enhancing gas. Initial tests using metallurgical cokefines as feedstock were conducted to test the effects of operational variables in the bottom section of the moving bed reducer, e.g., reactor temperature, oxygen carrier to char ratio, enhancer gas CO 2 flow rate, and oxygen carrier flow rates. Experiments directly using coal as the feedstock were subsequently carried out based on these test results. Powder River Basin (PRB) coal and Illinois #6 coal were tested as representative sub-bituminous and bituminous coals, respectively. Nearly complete coal conversion was achieved using composite iron oxide particles as the oxygen carriers without any flow problems. The operational results demonstrated that a

  17. Mercury and halogens in coal: Chapter 2

    Science.gov (United States)

    Kolker, Allan; Quick, Jeffrey C.; Granite, Evan J.; Pennline, Henry W.; Senior, Constance L.

    2014-01-01

    Apart from mercury itself, coal rank and halogen content are among the most important factors inherent in coal that determine the proportion of mercury captured by conventional controls during coal combustion. This chapter reviews how mercury in coal occurs, gives available concentration data for mercury in U.S. and international commercial coals, and provides an overview of the natural variation in halogens that influence mercury capture. Three databases, the U.S. Geological Survey coal quality (USGS COALQUAL) database for in-ground coals, and the 1999 and 2010 U.S. Environmental Protection Agency (EPA) Information Collection Request (ICR) databases for coals delivered to power stations, provide extensive results for mercury and other parameters that are compared in this chapter. In addition to the United States, detailed characterization of mercury is available on a nationwide basis for China, whose mean values in recent compilations are very similar to the United States in-ground mean of 0.17 ppm mercury. Available data for the next five largest producers (India, Australia, South Africa, the Russian Federation, and Indonesia) are more limited and with the possible exceptions of Australia and the Russian Federation, do not allow nationwide means for mercury in coal to be calculated. Chlorine in coal varies as a function of rank and correspondingly, depth of burial. As discussed elsewhere in this volume, on a proportional basis, bromine is more effective than chlorine in promoting mercury oxidation in flue gas and capture by conventional controls. The ratio of bromine to chlorine in coal is indicative of the proportion of halogens present in formation waters within a coal basin. This ratio is relatively constant except in coals that have interacted with deep-basin brines that have reached halite saturation, enriching residual fluids in bromine. Results presented here help optimize mercury capture by conventional controls and provide a starting point for

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

    Science.gov (United States)

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

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

  19. Coal industry annual 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    Coal Industry Annual 1997 provides comprehensive information about US coal production, number of mines, prices, productivity, employment, productive capacity, and recoverable reserves. US Coal production for 1997 and previous years is based on the annual survey EIA-7A, Coal Production Report. This report presents data on coal consumption, coal distribution, coal stocks, coal prices, and coal quality for Congress, Federal and State agencies, the coal industry, and the general public. Appendix A contains a compilation of coal statistics for the major coal-producing States. This report includes a national total coal consumption for nonutility power producers that are not in the manufacturing, agriculture, mining, construction, or commercial sectors. 14 figs., 145 tabs.

  20. Coal industry annual 1997

    International Nuclear Information System (INIS)

    1998-12-01

    Coal Industry Annual 1997 provides comprehensive information about US coal production, number of mines, prices, productivity, employment, productive capacity, and recoverable reserves. US Coal production for 1997 and previous years is based on the annual survey EIA-7A, Coal Production Report. This report presents data on coal consumption, coal distribution, coal stocks, coal prices, and coal quality for Congress, Federal and State agencies, the coal industry, and the general public. Appendix A contains a compilation of coal statistics for the major coal-producing States. This report includes a national total coal consumption for nonutility power producers that are not in the manufacturing, agriculture, mining, construction, or commercial sectors. 14 figs., 145 tabs

  1. PETROBRAS green petroleum coke used as partial replacement for coal injected mixtures in blast furnaces; Utilizacao do coque verde de petroleo da PETROBRAS em substituicao parcial ao carvao mineral das misturas injetadas em altos fornos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Agenor Medrado da; Medrado, Swami Botelho; Noblat, Sebastiao Jorge Xavier [Companhia Siderurgia Nacional. CSN. Gerencia Geral de Processos Siderurgicos. RJ (Brazil)], e-mails: ams@csn.com.br, swami@csn.com.br, s.noblat@csn.com.br; Carvalho Junior, Joao Andrade de [Universidade Estadual Paulista Julio de Mesquita Filho. Faculdade de Engenharia de Guaratingueta. Departamento de Energia, SP (Brazil)], e-mail: joao@feg.unesp.br

    2010-04-15

    The PETROBRAS produced green petroleum coke (GPC) is a carbon rich fuel, virtually ash-free, with low sulfur content and is a fuel suitable to replace metallurgical coke in blast furnaces. The GPC was tested in a pulverized coal injection simulator built in the Volta Redonda research center. It presented a low burning efficiency due to low volatile material content and high substitution rate by the carbon content. The industrial-scale tests were carried out in blast furnaces with up to 50% PETROBRAS GPC in the coal blends, which has never been done before in the steel industry. The injected coal/CVP mixtures produced no negative side effects in the blast furnace grinding systems, pneumatic conveying or operating process. The mixture burning process inside the blast furnace, showed a decrease in fuel consumption, with a significant reduction in metallurgical coke consumption. The industrial-scale tests of the GPC mixtures did not reach the 70% maximum for lack of the GPC feedstock, it being necessary to continue with standard coal mixtures. (author)

  2. Coal marketing manual 1987

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    This manual provides information on the international coal market in tabulated format. Statistics are presented for the Australian coal industry, exports, currency movements, world coal production, coal and coke imports and exports. Detailed information is provided on the Australian coal industry including mine specific summaries. Pricing summaries for thermal and coking coal in 1987, coal quality standards and specifications, trends in coal prices and stocks. Imports and exports for World coal and coke, details of shipping, international ports and iron and steel production. An exporters index of Australian and overseas companies with industry and government contacts is included. 15 figs., 67 tabs.

  3. Coal industry annual 1996

    International Nuclear Information System (INIS)

    1997-11-01

    This report presents data on coal consumption, coal distribution, coal stocks, coal prices, and coal quality, and emissions for Congress, Federal and State agencies, the coal industry, and the general public. Appendix A contains a compilation of coal statistics for the major coal-producing States.This report does not include coal consumption data for nonutility power producers that are not in the manufacturing, agriculture, mining, construction, or commercial sectors. Consumption for nonutility power producers not included in this report is estimated to be 24 million short tons for 1996. 14 figs., 145 tabs

  4. Coal industry annual 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    This report presents data on coal consumption, coal distribution, coal stocks, coal prices, and coal quality, and emissions for Congress, Federal and State agencies, the coal industry, and the general public. Appendix A contains a compilation of coal statistics for the major coal-producing States.This report does not include coal consumption data for nonutility power producers that are not in the manufacturing, agriculture, mining, construction, or commercial sectors. Consumption for nonutility power producers not included in this report is estimated to be 24 million short tons for 1996. 14 figs., 145 tabs.

  5. Coal Industry Annual 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    This report presents data on coal consumption, coal distribution, coal stocks, coal prices, coal quality, and emissions for Congress, Federal and State agencies, the coal industry, and the general public. Appendix A contains a compilation of coal statistics for the major coal-producing States. This report does not include coal consumption data for nonutility power producers that are not in the manufacturing, agriculture, mining, construction, or commercial sectors. Consumption for nonutility power producers not included in this report is estimated to be 21 million short tons for 1995.

  6. Coal Industry Annual 1995

    International Nuclear Information System (INIS)

    1996-10-01

    This report presents data on coal consumption, coal distribution, coal stocks, coal prices, coal quality, and emissions for Congress, Federal and State agencies, the coal industry, and the general public. Appendix A contains a compilation of coal statistics for the major coal-producing States. This report does not include coal consumption data for nonutility power producers that are not in the manufacturing, agriculture, mining, construction, or commercial sectors. Consumption for nonutility power producers not included in this report is estimated to be 21 million short tons for 1995

  7. Sixth annual coal preparation, utilization, and environmental control contractors conference

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    A conference was held on coal preparation, utilization and environmental control. Topics included: combustion of fuel slurries; combustor performance; desulfurization chemically and by biodegradation; coal cleaning; pollution control of sulfur oxides and nitrogen oxides; particulate control; and flue gas desulfurization. Individual projects are processed separately for the databases. (CBS).

  8. Experimental and numerical investigation of the catalytic partial oxidation of methane to synthesis gas for power generation applications[Dissertation 17183

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, A.

    2007-07-01

    The present work addresses the catalytic partial oxidation (CPO) of methane to synthesis gas, with particular emphasis on power generation applications. A combined experimental and numerical investigation of methane partial oxidation to synthesis gas (H{sub 2}, CO) over rhodium-based catalysts has been carried out at pressures of up to 10 bar. The reactivity of the produced hydrogen and the suitably-low light-off temperatures of the CPO reactor, greatly facilitate operation of power generation gas turbines with reduced NO{sub x} emissions, stable operation with low calorific value fuels, and new combustion strategies for efficient CO{sub 2} capture. Those strategies utilize CPO of methane with oxygen (separated from air) and large exhaust gas recycle (H{sub 2}O and CO{sub 2}). An optically accessible catalytic channel-flow reactor was used to carry out Raman spectroscopy of major gas-phase species and laser induced fluorescence (LIF) of formaldehyde, in order to gain fundamental information on the catalytic and gas-phase chemical pathways. Transverse concentration profiles measured by the spontaneous Raman scattering technique determined the catalytic reactivity, while the LIF provided flame shapes and anchoring positions that, in turn, characterized the gaseous reactivity. Comparison between measurements and 2-D CFD computations, led to the validation of detailed catalytic and gas-phase reaction mechanisms. Experiments in a subscale gas-turbine honeycomb catalytic reactor have shown that the foregoing reaction mechanisms were also appropriate under gas-turbine relevant conditions with short reactant residence times. The light-off behavior of the subscale honeycomb reactor was reproduced by transient 2-D CFD computations. Ignition and extinction in CPO was studied. It was shown that, despite the chemical impact of the H{sub 2}O diluent during the transient catalytic ignition event, the light-off times themselves were largely unaffected by the exhaust gas dilution

  9. Coal and Energy.

    Science.gov (United States)

    Bryant, Reba; And Others

    This teaching unit explores coal as an energy resource. Goals, student objectives, background information, and activity options are presented for each major section. The sections are: (1) an introduction to coal (which describes how and where coal was formed and explains the types of coal); (2) the mining of coal (including the methods and ways of…

  10. Partial oxidation of jet fuels over Rh/Al_2O_3. Design and reaction kinetics of sulfur-containing surrogates

    International Nuclear Information System (INIS)

    Baer, Julian Nicolaas

    2016-01-01

    The conversion of logistic fuels via catalytic partial oxidation (CPOX) on Rh/Al_2O_3 at short contact times is an efficient method for generating hydrogen-rich synthesis gas. Depending on the inlet conditions, fuel, and catalyst, high syngas yields, low by-product formation, and rates of high fuel conversion can be achieved. CPOX is relevant for mobile hydrogen generation, e.g., on board of airplanes in order to increase the fuel efficiency via fuel cell-based auxiliary power units. Jet fuels contain hundreds of different hydrocarbons and a significant amount of sulfur. The hydrocarbon composition and sulfur content of a jet fuel vary depending on distributor, origin, and refinement of the crude oil. Little is known about the influence of the various compounds on the synthesis-gas yield and the impact of sulfur on the product yield. In this work, the influence of three main chemical compounds of a jet fuel (aromatics, alkanes, and sulfur compounds) on syngas selectivity, the catalyst deactivation process, and reaction sequence is unraveled. As representative components of alkanes and aromatics, n-dodecane and 1,2,4-trimethylbenzene were chosen for ex-situ and in-situ investigations on the CPOX over Rh/Al_2O_3, respectively. Additionally, for a fixed paraffin-to-aromatics ratio, benzothiophene or dibenzothiophene were added as a sulfur component in three different concentrations. The knowledge gained about the catalytic partial oxidation of jet fuels and their surrogates is used to identify requirements for jet fuels in mobile applications based on CPOX and to optimize the overall system efficiency. The results show an influence of the surrogate composition on syngas selectivity. The tendency for syngas formation increases with higher paraffin contents. A growing tendency for by-product formation can be observed with increasing aromatics contents in the fuel. The impact of sulfur on the reaction system shows an immediate change in the product distribution. An

  11. Partial oxidation of jet fuels over Rh/Al{sub 2}O{sub 3}. Design and reaction kinetics of sulfur-containing surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Julian Nicolaas

    2016-07-01

    The conversion of logistic fuels via catalytic partial oxidation (CPOX) on Rh/Al{sub 2}O{sub 3} at short contact times is an efficient method for generating hydrogen-rich synthesis gas. Depending on the inlet conditions, fuel, and catalyst, high syngas yields, low by-product formation, and rates of high fuel conversion can be achieved. CPOX is relevant for mobile hydrogen generation, e.g., on board of airplanes in order to increase the fuel efficiency via fuel cell-based auxiliary power units. Jet fuels contain hundreds of different hydrocarbons and a significant amount of sulfur. The hydrocarbon composition and sulfur content of a jet fuel vary depending on distributor, origin, and refinement of the crude oil. Little is known about the influence of the various compounds on the synthesis-gas yield and the impact of sulfur on the product yield. In this work, the influence of three main chemical compounds of a jet fuel (aromatics, alkanes, and sulfur compounds) on syngas selectivity, the catalyst deactivation process, and reaction sequence is unraveled. As representative components of alkanes and aromatics, n-dodecane and 1,2,4-trimethylbenzene were chosen for ex-situ and in-situ investigations on the CPOX over Rh/Al{sub 2}O{sub 3}, respectively. Additionally, for a fixed paraffin-to-aromatics ratio, benzothiophene or dibenzothiophene were added as a sulfur component in three different concentrations. The knowledge gained about the catalytic partial oxidation of jet fuels and their surrogates is used to identify requirements for jet fuels in mobile applications based on CPOX and to optimize the overall system efficiency. The results show an influence of the surrogate composition on syngas selectivity. The tendency for syngas formation increases with higher paraffin contents. A growing tendency for by-product formation can be observed with increasing aromatics contents in the fuel. The impact of sulfur on the reaction system shows an immediate change in the product

  12. Coal -94

    International Nuclear Information System (INIS)

    Sparre, C.

    1994-05-01

    This report deals with use of coal and coke during 1993; information about techniques, environmental questions and markets are also given. Use of steamcoal for heating purposes has been reduced about 3 % during 1993 to 1,0 mill tons. This is the case especially for the heat generating boilers. Production in co-generation plants has been constant and has increased for electricity production. Minor plants have increased their use of forest fuels, LPG and NG. Use of steamcoal will probably go down in the immediate years both in heat generating and co-generating plants. Coal-based electricity has been imported from Denmark during 1993 corresponding to about 400 000 tons of coal, when several of our nuclear plants were stopped. Use of steamcoal in the industry has been constant at 700 000 tons. This level is supposed to be constant or to vary with business cycles. The import of metallurgical coal in 1993 was 1,6 mill tons like the year before. 1,2 mill tons coke were produced. Coke consumption in industry was 1,4 mill tons. 0,2 mill tons of coke were imported. Average price of steamcoal imported to Sweden in 1993 was 308 SEK/ton or 13 % higher than in 1992; this can be explained by the dollar price level increasing 34% in 1993. For the world, the average import price was 50,0 USD/ton, a decrease of 6 %. The coal market during 1993 was affected by less consumption in Europe, shut downs of European mines and decreasing prices. High freight price raises in Russia has affected the Russian export and the market in northern Europe. The prices have been stabilized recently. All Swedish plants meet emission limits of dust, SO 2 and NO x . Co-generation plants all have some sort of SO 2 -removal system; the wet-dry method is mostly used. A positive effect of the recently introduced NO x -duties is a 40% reduction

  13. Coal statistics 1977

    Energy Technology Data Exchange (ETDEWEB)

    Statistical Office of the European Communities

    1978-01-01

    Presents tables of data relating to the coal market in the European Community in 1977. The tables cover hard coal production, supply and trade; briquettes; cokes; lignite, brown coal briquettes and peat; and mines and coke ovens.

  14. Australian coal yearbook 1989

    Energy Technology Data Exchange (ETDEWEB)

    Aylward, A [ed.

    1989-01-01

    This yearbook contains a mine directory; details of coal export facilities and ports; annual coal statistics; a buyers' guide; names and addresses of industry organisations and an index of coal mine owners.

  15. Coal industry annual 1993

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-06

    Coal Industry Annual 1993 replaces the publication Coal Production (DOE/FIA-0125). This report presents additional tables and expanded versions of tables previously presented in Coal Production, including production, number of mines, Productivity, employment, productive capacity, and recoverable reserves. This report also presents data on coal consumption, coal distribution, coal stocks, coal prices, coal quality, and emissions for a wide audience including the Congress, Federal and State agencies, the coal industry, and the general public. In addition, Appendix A contains a compilation of coal statistics for the major coal-producing States. This report does not include coal consumption data for nonutility Power Producers who are not in the manufacturing, agriculture, mining, construction, or commercial sectors. This consumption is estimated to be 5 million short tons in 1993.

  16. Coal industry annual 1993

    International Nuclear Information System (INIS)

    1994-01-01

    Coal Industry Annual 1993 replaces the publication Coal Production (DOE/FIA-0125). This report presents additional tables and expanded versions of tables previously presented in Coal Production, including production, number of mines, Productivity, employment, productive capacity, and recoverable reserves. This report also presents data on coal consumption, coal distribution, coal stocks, coal prices, coal quality, and emissions for a wide audience including the Congress, Federal and State agencies, the coal industry, and the general public. In addition, Appendix A contains a compilation of coal statistics for the major coal-producing States. This report does not include coal consumption data for nonutility Power Producers who are not in the manufacturing, agriculture, mining, construction, or commercial sectors. This consumption is estimated to be 5 million short tons in 1993

  17. Australian black coal statistics 1990

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    This second edition of Australian black coal statistics replaces the Joint Coal Board's publication 'Black coal in Australia'. It includes an expanded international coal trade supplement. Sections cover resources of black coal, coal supply and demand, coal production, employment and productivity of mines, export data, coal consumption and a directory of producers.

  18. Mercury in coal and the impact of coal quality on mercury emissions from combustion systems

    International Nuclear Information System (INIS)

    Kolker, Allan; Senior, Constance L.; Quick, Jeffrey C.

    2006-01-01

    The proportion of Hg in coal feedstock that is emitted by stack gases of utility power stations is a complex function of coal chemistry and properties, combustion conditions, and the positioning and type of air pollution control devices employed. Mercury in bituminous coal is found primarily within Fe-sulfides, whereas lower rank coal tends to have a greater proportion of organic-bound Hg. Preparation of bituminous coal to reduce S generally reduces input Hg relative to in-ground concentrations, but the amount of this reduction varies according to the fraction of Hg in sulfides and the efficiency of sulfide removal. The mode of occurrence of Hg in coal does not directly affect the speciation of Hg in the combustion flue gas. However, other constituents in the coal, notably Cl and S, and the combustion characteristics of the coal, influence the species of Hg that are formed in the flue gas and enter air pollution control devices. The formation of gaseous oxidized Hg or particulate-bound Hg occurs post-combustion; these forms of Hg can be in part captured in the air pollution control devices that exist on coal-fired boilers, without modification. For a given coal type, the capture efficiency of Hg by pollution control systems varies according to type of device and the conditions of its deployment. For bituminous coal, on average, more than 60% of Hg in flue gas is captured by fabric filter (FF) and flue-gas desulfurization (FGD) systems. Key variables affecting performance for Hg control include Cl and S content of the coal, the positioning (hot side vs. cold side) of the system, and the amount of unburned C in coal ash. Knowledge of coal quality parameters and their effect on the performance of air pollution control devices allows optimization of Hg capture co-benefit

  19. 1982 Australian coal conference papers

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    This third Australian coal conference included papers discussing the market for coal, finance and investment, use of computers, mining, coal research, coal preparation and waste disposal, marketing and trade, and the transport of coal. All papers have been individually abstracted.

  20. A theoretical study on the mechanism of hydrogen evolution on non-precious partially oxidized nickel-based heterostructures for fuel cells.

    Science.gov (United States)

    Pan, Xinju; Zhou, Gang

    2018-03-28

    It is desirable, yet challenging, to utilize non-precious metals instead of noble-metals as efficient catalysts in the renewable energy manufacturing industry. Using first principles calculations, we study the structural characteristics of partially oxidized nickel-based nanoheterostructures (NiO/Ni NHSs), and the interfacial effects on hydrogen evolution. The origin of the enhanced hydrogen evolution performance is discussed at the microscopic level. This study identifies two types of active sites of the exposed Ni surface available for the hydrogen evolution reaction (HER). One is the hcp-hollow sites near the perimeter boundary that exhibit a more excellent HER performance than platinum (Pt), and the other the second nearest neighbor fcc-hollow sites away from the boundary that exhibit a similar performance to Pt. The interfacial effects result from the competitive charge transfer between NiO and Ni surfaces in NHSs, and enhance the reactivity of NiO/Ni NHSs by shifting the d-states of surface atoms down in energy. The illumination of the mechanism would be helpful for the design of more efficient and cheap transition metal-based catalysts.

  1. Experimental and modeling study of hydrogen/syngas production and particulate emissions from a natural gas-fueled partial oxidation engine

    International Nuclear Information System (INIS)

    McMillian, Michael H.; Lawson, Seth A.

    2006-01-01

    In this study, a combustion model was first applied to conditions representing varying compression ratios and equivalence ratios to investigate engine exhaust composition from partial oxidation (POX) of natural gas in reciprocating engines. The model was experimentally validated over a range of equivalence ratios from 1.3 to 1.6 with a spark-ignited single cylinder engine fueled by natural gas. The modeling results matched well with engine gaseous emission data over the experimental range. The model was also extended to higher equivalence ratios to predict H 2 and CO production at engine conditions and stoichiometries representative of homogeneous charge compression ignition (HCCI) engine operation. Secondly, over the same experimental range of equivalence ratios, particulate samples were taken to determine both total particulate mass production (g/hph) via gravimetric measurement as well as particle size distribution and loading via a scanning mobility particle sizer (SMPS). While experiments indicate hydrogen yields up to 11% using spark ignition (SI), modeling results indicate that greater than 20% H 2 yield may be possible in HCCI operation. Over the experimental range, rich-burn particulate matter (PM) production is no greater than that from typical lean-burn operation. Finally, an energy balance was performed over the range of engine experimental operation. (author)

  2. Proceedings of the 11th international conference on coal science

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The theme of the conference was 'Exploring the horizons of coal'. The proceedings include 370 papers dealing with coal petrography, physical structure and properties, advanced characterization, oxidation and weathering, coal preparation and beneficiation, liquefaction and pyrolysis reactivity and products, combustion and combustion modeling, NOx, SO{sub x} and particulate emissions and controls, gasification fundamentals and processing, coal in iron making processes, chemistry of S, N, and Cl, mineral matter, trace elements and HAPS, chemicals, carbons and carbon products, coal combustion byproducts and ash chemistry, and greenhouse gases and sequestration. Although 'proceedings' are published, the conference was cancelled.

  3. Research on mechanism of and catalysts for extraction liquefaction of coal using coal-based solvents; Sekitankei yozai ni yoru sekitan no chushutsu ekika kiko to shokubai no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1981-07-01

    Papers of Professor Yoshio Kamiya of Tokyo University are compiled into this report. The list of the papers includes (1) Synthesis of heavy fuel oils from coal; (2) Research and development of coal liquefaction; (3) Dissolution reaction of coal by hydrogen-donating aromatic solvents (I); (4) Effect of hydrogen-donor solvent on the liquefaction of coal; (5) Recent studies on the chemical structure of solvent refined coal; (6) Dissolution reaction of coal by hydrogen-donating aromatic solvents (II); (7) Future of coal as energy material; (8), (9), (10) same as (6) in the subject discussed; (11) Recent studies on coal liquefaction catalysts; (12) Environmental problems and drain treatment to accompany processes of converting fossil resources into fuels; (13) Chemistry of coal oxidation; (14) Fractionation and analysis of solvent refined coal by gel permeation chromatography; (15) Current state of research and development of coal liquefaction; (16) Properties and components of coal oils from coal liquefaction processes under development; (17) Solvent effect of coal derived aromatic compounds on the liquefaction of Akabira coal; (18) Chemistry of coal liquefaction; (19) Research and development of coal liquefaction in the U.S.; (20) Thermal treatment of coal-related aromatic ethers in tetralin solution; (21) Recent technology of utilizing heavy carbon resources; (22) Chemical properties and reactivity of coal; (23) Current state and future of development of coal liquefaction processes; and (24) Development of overseas coal liquefaction projects. (NEDO)

  4. Automated mineralogical logging of coal and coal measure core

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Fraser; Joan Esterle; Colin Ward; Ruth Henwood; Peter Mason; Jon Huntington; Phil Connor; Reneta Sliwa; Dave Coward; Lew Whitbourn [CSIRO Exploration & Mining (Australia)

    2006-06-15

    A mineralogical core logging system based on spectral reflectance (HyLogger{trademark}) has been used to detect and quantify mineralogies in coal and coal measure sediments. The HyLogger{trademark} system, as tested, operates in the visible-to-shortwave infrared spectral region, where iron oxides, sulphates, hydroxyl-bearing and carbonate minerals have characteristic spectral responses. Specialized software assists with mineral identification and data display. Three Phases of activity were undertaken. In Phase I, carbonates (siderite, ankerite, calcite) and clays (halloysite, dickite) were successfully detected and mapped in coal. Repeat measurements taken from one of the cores after three months demonstrated the reproducibility of the spectral approach, with some spectral differences being attributed to variations in moisture content and oxidation. Also, investigated was HyLogger{trademark} ability to create a 'brightness-profile' on coal materials, and these results were encouraging. In Phase II, geotechnically significant smectitic clays (montmorillonite) were detected and mapped in cores of clastic roof and floor materials. Such knowledge would be useful for mine planning and design purposes. In Phase III, our attempts at determining whether phosphorus-bearing minerals such as apatite could be spectrally detected were less than conclusive. A spectral index could only be created for apatite, and the relationships between the spectrally-derived apatite-index, the XRD results and the analytically-derived phosphorus measurements were ambiguous.

  5. Ultravitrinite coals from Chukotka

    Energy Technology Data Exchange (ETDEWEB)

    Lapo, A.V.; Letushova, I.A.

    1979-03-01

    Chemical and petrographic analysis was conducted on coals from the Anadyrya and Bukhti Ugol'noi deposits. Characteristics of the most prevalent type of vitrinite coals in both regions are presented here. Anadyrya coals belong to a transitional phase between brown coal and long flame. Ultravitrinite coals predominate. Gas coals from Bukti Ugol'noi have a higher carbon content than Anadyrya coals. They also have a higher hydrogen content and yield of initial resin. In several cases there was also a higher yield of volatile substances. Chukotka coals are characterized by a 10 percent higher initial resin yield than equally coalified Donetsk coals, other indicators were equal to those of Donetsk coals. Because of this, Chukotka coals are suitable for fuel in power plants and as raw materials in the chemical industry. (15 refs.) (In Russian)

  6. Coal, energy of the future

    International Nuclear Information System (INIS)

    Lepetit, V.; Guezel, J.Ch.

    2006-01-01

    Coal is no longer considered as a 'has been' energy source. The production and demand of coal is growing up everywhere in the world because it has some strategic and technological advantages with respect to other energy sources: cheap, abundant, available everywhere over the world, in particular in countries with no geopolitical problems, and it is independent of supplying infrastructures (pipelines, terminals). Its main drawback is its polluting impact (dusts, nitrogen and sulfur oxides, mercury and CO 2 ). The challenge is to develop clean and high efficiency coal technologies like supercritical steam power plants or combined cycle coal gasification plants with a 50% efficiency, and CO 2 capture and sequestration techniques (post-combustion, oxy-combustion, chemical loop, integrated gasification gas combined cycle (pre-combustion)). Germany, who will abandon nuclear energy by 2021, is massively investing in the construction of high efficiency coal- and lignite-fired power plants with pollution control systems (denitrification and desulfurization processes, dust precipitators). (J.S.)

  7. Coal Tar and Coal-Tar Pitch

    Science.gov (United States)

    Learn about coal-tar products, which can raise your risk of skin cancer, lung cancer, and other types of cancer. Examples of coal-tar products include creosote, coal-tar pitch, and certain preparations used to treat skin conditions such as eczema, psoriasis, and dandruff.

  8. Carbon formation and metal dusting in hot-gas cleanup systems of coal gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Judkins, R.R.; Tortorelli, P.F.; Judkins, R.R.; DeVan, J.H.; Wright, I.G. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1995-11-01

    The product gas resulting from the partial oxidation of Carboniferous materials in a gasifier is typically characterized by high carbon and sulfur, but low oxygen, activities and, consequently, severe degradation of the structural and functional materials can occur. The objective of this task was to establish the potential risks of carbon deposition and metal dusting in advanced coal gasification processes by examining the current state of knowledge regarding these phenomena, making appropriate thermochemical calculations for representative coal gasifiers, and addressing possible mitigation methods. The paper discusses carbon activities, iron-based phase stabilities, steam injection, conditions that influence kinetics of carbon deposition, and influence of system operating parameters on carbon deposition and metal dusting.

  9. Material balance in coal. 2. Oxygen determination and stoichiometry of 33 coals

    International Nuclear Information System (INIS)

    Volborth, A.; Miller, G.E.; Garner, C.K.; Jerabek, P.A.

    1977-01-01

    The chemical analysis of coal can be supplemented by the determination of oxygen in high and low temperature ash, in coal as received and in coal dried at 105 0 C. The rapid method utilizes fast-neutron activation. The reaction 16 O(n,p) 16 N and counting of the 6.1 and 7.1 MeV gammas of 7.3 second half-life are used. A specially designed dual transfer and simultaneous counting system gives very accurate results. Oxygen in 33 coals ranging from lignite to low volatile bituminous coal is determined and compared with ''oxygen by difference.'' Considerable discrepancies are observed. Better stoichiometric results are obtained if oxygen in coal ash, in wet coal and in the dried coal is determined. This permits the estimation of the true material balances using data of the ultimate and the proximate coal analysis. The oxygen determination provides the coal chemist with an accurate basis and can be used to rank coal. The summation of the percent of carbon, nitrogen, hydrogen, sulfur, and oxygen becomes more meaningful and some errors can be detected and the state of completeness of coal analysis thus evaluated. Total sulfur can be estimated and oxidation effects during drying can be detected. These affect the moisture determination. It appears that after more data are collected, the interpretation of solid fuel analyses may be facilitated and will be stoichiometrically more meaningful. It is shown that it may be possible to simplify the present time-consuming methods of coal analysis

  10. Advanced coal-fueled gas turbine systems

    Energy Technology Data Exchange (ETDEWEB)

    Wenglarz, R.A.

    1994-08-01

    Several technology advances since the early coal-fueled turbine programs that address technical issues of coal as a turbine fuel have been developed in the early 1980s: Coal-water suspensions as fuel form, improved methods for removing ash and contaminants from coal, staged combustion for reducing NO{sub x} emissions from fuel-bound nitrogen, and greater understanding of deposition/erosion/corrosion and their control. Several Advanced Coal-Fueled Gas Turbine Systems programs were awarded to gas turbine manufacturers for for components development and proof of concept tests; one of these was Allison. Tests were conducted in a subscale coal combustion facility and a full-scale facility operating a coal combustor sized to the Allison Model 501-K industrial turbine. A rich-quench-lean (RQL), low nitrogen oxide combustor design incorporating hot gas cleanup was developed for coal fuels; this should also be applicable to biomass, etc. The combustor tests showed NO{sub x} and CO emissions {le} levels for turbines operating with natural gas. Water washing of vanes from the turbine removed the deposits. Systems and economic evaluations identified two possible applications for RQL turbines: Cogeneration plants based on Allison 501-K turbine (output 3.7 MW(e), 23,000 lbs/hr steam) and combined cycle power plants based on 50 MW or larger gas turbines. Coal-fueled cogeneration plant configurations were defined and evaluated for site specific factors. A coal-fueled turbine combined cycle plant design was identified which is simple, compact, and results in lower capital cost, with comparable efficiency and low emissions relative to other coal technologies (gasification, advanced PFBC).

  11. Record coking coal settlements

    Energy Technology Data Exchange (ETDEWEB)

    Macdonald, C.

    2005-02-01

    The US$100/tonne psychological barrier in coking coal prices has been well and truly smashed. The article examines developments in coal pricing. It includes quotes from many senior executives in the coal industry as collected at McCloskey's Australian Coal.04 conference held in Sydney, 18-19 November 2004. 2 photos.

  12. COAL Conference Poster

    OpenAIRE

    Brown, Taylor Alexander; McGibbney, Lewis John

    2017-01-01

    COAL Conference Poster This archive contains the COAL conference poster for the AGU Fall Meeting 2017 by Taylor Alexander Brown. The Inkscape SVG source is available at https://github.com/capstone-coal/coal-conference-poster/ under the Creative Commons Attribution-ShareAlike 4.0 International license.

  13. Coal option. [Shell Co

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    This paper notes the necessity of developing an international coal trade on a very large scale. The role of Shell in the coal industry is examined; the regions in which Shell companies are most active are Australia, Southern Africa, Indonesia; Europe and North America. Research is being carried out on marketing and transportation, especially via slurry pipelines; coal-oil emulsions; briquets; fluidized-bed combustion; recovery of coal from potential waste material; upgrading of low-rank coals; unconventional forms of mining; coal conversion (the Shell/Koppers high-pressure coal gasification process). Techniques for cleaning flue gas (the Shell Flue Gas Desulfurization process) are being examined.

  14. Concerning coal: an anthology

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, M.; Hawse, M.L.; Maloney, P.J. [eds.

    1997-12-31

    The anthology takes a humanistic look at coal mining in Illinois. One of its goals is to increase public awareness of coal in American society; it also seeks to enhance understanding of the historical aspects of coal and to study the impact of coal on mining families. Many of the 25 selections in the anthology come from Coal Research Center publications, `Concerning coal` and `Mineral matters`. Articles are arranged in three parts entitled: life in the mining community; mining in folklore, story telling, literature, art and music; and technology as it affected the people of the coal fields. 117 refs., 25 photos. 1 map.

  15. Coal information 1995

    International Nuclear Information System (INIS)

    1996-01-01

    This volume is a comprehensive reference book on current world coal market trends and long-term prospects to 2010. It contains an in-depth analysis of the 1995 international coal market covering prices, demand, trade, supply and production capacity as well as over 450 pages of country specific statistics on OECD and key non-OECD coal producing and consuming countries. The book also includes a summary of environmental policies on climate change and on coal-related air quality issues as well as essential facts on coal-fired power stations in coal-importing regions, on coal ports world-wide and on emission standards for coal-fired boilers in OECD countries. Coal Information is one of a series of annual IEA statistical publications on major energy sources; other reports are Oil and Gas Information and Electricity Information. Coal Information 1995 is published in July 1996. (author)

  16. Coal yearbook 1993

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    This book is the first coal yearbook published by ATIC (France). In a first chapter, economical context of coal worldwide market is analyzed: comparative evaluations on coal exports and imports, coal industry, prices, production in USA, Australia, South Africa, China, former USSR, Poland, Colombia, Venezuela and Indonesia are given. The second chapter describes the french energy context: national coal production, imports, sectorial analysis, maritime transport. The third chapter describes briefly the technologies of clean coal and energy saving developed by Charbonnages de France: fossil-fuel power plants with combined cycles and cogeneration, fluidized beds for the recovery of coal residues, recycling of agricultural wastes (sugar cane wastes) in thermal power plant, coal desulfurization for air pollution abatement. In the last chapter, statistical data on coal, natural gas and crude oil are offered: world production, world imports, world exports, french imports, deliveries to France, coal balance, french consumption of primary energy, power generation by fuel type

  17. Hydrogen production with short contact time. Catalytic partial oxidation of hydrocarbons and oxygenated compounds: Recent advances in pilot- and bench-scale testing and process design

    Energy Technology Data Exchange (ETDEWEB)

    Guarinoni, A.; Ponzo, R.; Basini, L. [ENI Refining and Marketing Div., San Donato Milanese (Italy)

    2010-12-30

    ENI R and D has been active for fifteen years in the development of Short Contact Time - Catalytic Partial Oxidation (SCT-CPO) technologies for producing Hydrogen/Synthesis Gas. From the beginning the experimental work addressed either at defining the fundamental principles or the technical and economical potential of the technology. Good experimental responses, technical solutions' simplicity and flexibility, favourable techno-economical evaluations promoted the progressive widening of the field of the investigations. From Natural Gas (NG) the range of ''processable'' Hydrocarbons extended to Liquefied Petroleum Gas (LPG) and Gasoils, including those characterised by high levels of unsaturated and sulphurated molecules and, lately, to other compounds with biological origin. The extensive work led to the definition of different technological solutions, grouped as follows: Technology 1: Air Blown SCT-CPO of Gaseous Hydrocarbons and/or Light Compounds with biological origin Technology 2: Enriched Air/Oxygen Blown SCT-CPO of Gaseous Hydrocarbons and/or Light Compounds with biological origin Technology 3: Enriched Air/Oxygen Blown SCT-CPO of Liquid Hydrocarbons and/or Compounds with biological origin Recently, the licence rights on a non-exclusive basis for the commercialisation of SCT-CPO based processes for H{sub 2}/Synthesis gas production from light hydrocarbons with production capacity lower than 5,000 Nm{sup 3}/h of H{sub 2} or 7,500 Nm3/h of syngas have been assigned to two external companies. In parallel, development of medium- and large-scale plant solutions is progressing within the ENI group framework. These last activities are addressed to the utilisation of SCT-CPO for matching the variable Hydrogen demand in several contexts of oil refining operation. This paper will report on the current status of SCT-CPO with a focus on experimental results obtained, either at pilot- and bench- scale level. (orig.)

  18. Mesoporous activated carbons with metal-oxide particles prepared from Morwell coal; Morwell tan wo genryo to shita kinzoku sankabutsu tanji kasseitan no saiko kozo

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizawa, N.; Yamada, Y.; Shiraishi, M. [National Institute for Resources and Environment, Tsukuba (Japan); Kojima, S.; Tamai, H.; Yasuda, H. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

    1996-10-28

    The metal dependence of mesoporous activated carbons with various metal acetylacetonate (acac) particles prepared from Morwell coal was studied. In experiment, the mixture of Morwell coal and acac metal complexes were dissipated into tetrahydrofuran, and after agitation in Ar atmosphere, the solvent was removed by vacuum distillation. Coal specimens with Fe(acac)3, Ni(acac)2 and Co(acac)2 as acac complexes were activated by exchanging flow gas with water vapor after heat treatment in N2 gas flow at 900{degree}C. The pore sizes of the specimens were obtained from N2 adsorption isotherms by BET method and BJH method. Conditions of pores and metals in the specimens were examined by XRD measurement and TEM observation. The relation between the above conditions and pore characteristics obtained from adsorption experiment was also examined. As a result, the difference in mesopore ratio between the specimens and blank specimens was larger in the order of Fe, Co and Ni, and the effect of added metal complexes was also larger in this order. 3 refs., 3 figs., 3 tabs.

  19. ACR coal 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    This publication is a comprehensive reference document on production, exports, prices and demand of coal in world markets. A forecast of demand by coal type and country up to the year 2000 is provided. Statistics of the Australian export industry are complemented by those of South Africa, USA, Canada, Indonesia, China, C.I.S. and Colombia. A very comprehensive coal quality specification for nearly all the coal brands exported from Australia, as well as leading non-Australian coal brands, is included.

  20. Assessing coal burnout

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, A. [Pacific Power, Sydney, NSW (Australia)

    1999-11-01

    Recent research has allowed a quantitative description of the basic process of burnout for pulverized coals to be made. The Cooperative Research Centre for Black Coal Utilization has built on this work to develop a coal combustion model which will allow plant engineers and coal company representatives to assess their coals for combustion performance. The paper describes the model and its validation and outlines how it is run. 2 figs.

  1. Quantitative Modelling of Trace Elements in Hard Coal.

    Science.gov (United States)

    Smoliński, Adam; Howaniec, Natalia

    2016-01-01

    The significance of coal in the world economy remains unquestionable for decades. It is also expected to be the dominant fossil fuel in the foreseeable future. The increased awareness of sustainable development reflected in the relevant regulations implies, however, the need for the development and implementation of clean coal technologies on the one hand, and adequate analytical tools on the other. The paper presents the application of the quantitative Partial Least Squares method in modeling the concentrations of trace elements (As, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Rb, Sr, V and Zn) in hard coal based on the physical and chemical parameters of coal, and coal ash components. The study was focused on trace elements potentially hazardous to the environment when emitted from coal processing systems. The studied data included 24 parameters determined for 132 coal samples provided by 17 coal mines of the Upper Silesian Coal Basin, Poland. Since the data set contained outliers, the construction of robust Partial Least Squares models for contaminated data set and the correct identification of outlying objects based on the robust scales were required. These enabled the development of the correct Partial Least Squares models, characterized by good fit and prediction abilities. The root mean square error was below 10% for all except for one the final Partial Least Squares models constructed, and the prediction error (root mean square error of cross-validation) exceeded 10% only for three models constructed. The study is of both cognitive and applicative importance. It presents the unique application of the chemometric methods of data exploration in modeling the content of trace elements in coal. In this way it contributes to the development of useful tools of coal quality assessment.

  2. Aromatic chemical feedstocks from coal

    Energy Technology Data Exchange (ETDEWEB)

    Collin, G

    1982-06-01

    Liquid byproducts of coal carbonization meet some 25% of the world demand for aromatic chemicals, currently at approx. 30 million t/a, in particular 15% of the demand for benzene and over 95% of the demand for condensed aromatics and heteroaromatics. Industrial processing of the aromatic byproducts of coal pressure gasification is carried out to only a minor extent. Other methods that may be employed in future to obtain carbochemical aromatic compounds are solvolysis and supercritical gas extraction, the catalytic liquid-phase hydrogenation and hydropyrolysis of coal, which also permit recovery of benzene and homologues, phenols, and condensed and partially hydrogenated aromatics, and the synthesis of aromatics using methanol as the key compound. As with the present means of obtaining aromatic chemicals from coal, the processes that may in the future be applied on an industrial scale to obtain pure aromatics will only be economically feasible if linked with the manufacture of other mass products and combined with the present production of carbochemical aromatics.

  3. Aromatic raw materials from coal

    Energy Technology Data Exchange (ETDEWEB)

    Collin, G

    1982-06-01

    Liquid byproducts of coal carbonization meet some 25% of the world demand for aromatic chemicals, currently at approx. 30 million t/a, in particular 15% of the demand for benzene and over 95% of the demand for condensed aromatics and heteroaromatics. Industrial processing of the aromatic byproducts of coal pressure gasification is carried out to only a minor extent. Other methods that may be employed in future to obtain carbochemical aromatic compounds are solvolysis and supercritical gas extraction, the catalytic liquid-phase hydrogenation and hydropyrolysis of coal, which also permit recovery of benzene and homologues, phenols, and condensed and partially hydrogenated aromatics, and the synthesis of aromatics using methanol as the key compound. As with the present means of obtaining aromatic chemicals from coal, the processes that may in future be applied on an industrial scale to obtain pure aromatics will only be economically feasible if linked with the manufacture of other mass products and combined with the present production of carbochemical aromatics. (In German)

  4. Continuous bench-scale slurry catalyst testing direct coal liquefaction rawhide sub-bituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, R.F.; Coless, L.A.; Davis, S.M. [and others

    1995-12-31

    In 1992, the Department of Energy (DOE) sponsored research to demonstrate a dispersed catalyst system using a combination of molybdenum and iron precursors for direct coal liquefaction. This dispersed catalyst system was successfully demonstrated using Black Thunder sub-bituminous coal at Wilsonville, Alabama by Southern Electric International, Inc. The DOE sponsored research continues at Exxon Research and Development Laboratories (ERDL). A six month continuous bench-scale program using ERDL`s Recycle Coal Liquefaction Unit (RCLU) is planned, three months in 1994 and three months in 1995. The initial conditions in RCLU reflect experience gained from the Wilsonville facility in their Test Run 263. Rawhide sub-bituminous coal which is similar to the Black Thunder coal tested at Wilsonville was used as the feed coal. A slate of five dispersed catalysts for direct coal liquefaction of Rawhide sub-bituminous coal has been tested. Throughout the experiments, the molybdenum addition rate was held constant at 100 wppm while the iron oxide addition rate was varied from 0.25 to 1.0 weight percent (dry coal basis). This report covers the 1994 operations and accomplishments.

  5. Hydrogen Production by Catalytic Partial Oxidation of Coke Oven Gas in BaCo0.7Fe0.3-xZrxO3-δ Ceramic Membrane Reactors

    Directory of Open Access Journals (Sweden)

    Yao Weilin

    2016-01-01

    Full Text Available The BaCo0.7Fe0.3-xZrxO3-δ (BCFZ, x = 0.04–0.12 mixed ionic–electronic conducting (MIEC membranes were synthesized with a sol–gel method and evaluated as potential membrane reactor materials for the partial oxidation of coke oven gas (COG. The effect of zirconium content on the phase structure, microstructure and performance of the BCFZ membrane under He or COG atmosphere were systemically investigated. The BaCo0.7Fe0.24Zr0.06O3-δ membrane exhibited the best oxygen permeability and good operation stability, which could be a potential candidate of the membrane materials for hydrogen production through the partial oxidation of COG.

  6. Fiscal 1995 survey report on the feasibility study of the environmentally friendly type coal utilization system. Feasibility study of the environmentally friendly type coal utilization system in Thailand; Kankyo chowagata sekitan riyo system kanosei chosa. Tai ni okeru kankyo chowagata sekitan riyo system kanosei chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-01

    The paper surveyed the present situation and future trend of economy, energy supply/demand, coal production/distribution/utilization and the environmental effects in Thailand. The survey on the coal utilization and its environmental effects was partially requested of the environmental research institute in Thailand. The amount of coal utilization in Thailand rapidly increased to nearly four times as large as that ten years ago mainly in terms of domestic lignite under the government`s policy on expansion of the domestic energy use. However, most of this domestic lignite is low-grade coal with low calories and high sulfur content, and the use of it was rapidly increased mostly in power generation sector without no adequate environmental measures taken. This caused an environmental problem on air pollution due to sulfur oxides at Mae Moh power plant in the north several years ago, and the damages to the regional residents, etc. were given much publicity by journalism and developed the social problem. Accordingly, Thai people are now critical of the coal resource exploration and the coal use expansion. Under the circumstances, the Ministry of Industry and the energy related ministries/offices are obliged to review their development/promotion plans. 84 figs., 99 tabs.

  7. Experimental and theoretical investigation on unburned coal char burnout in a pilot-scale rotary kiln

    Energy Technology Data Exchange (ETDEWEB)

    Federico Cangialosi; Francesco Di Canio; Gianluca Intini; Michele Notarnicola; Lorenzo Liberti; Giulio Belz; Pompilio Caramuscio [Technical University of Bari, Taranto (Italy). Department of Environmental Engineering and Sustainable Development

    2006-11-15

    Oxidation reactivity studies are imperative for improving carbon re-burn technologies and valuing the heat content of unburned carbon within coal combustion ashes. Non-isothermal, thermal gravimetric analysis (TGA) was used to examine the oxidation kinetics of unburned carbon in coal combustion fly ashes having different particle size distributions; TGA results were related to combustion efficiencies as measured in a bench-scale rotary kiln. The activation energy and pre-exponential factor were determined for the chemically-controlled reaction regime; the transition temperatures between chemically-controlled and partially diffusion-controlled combustion regimes were obtained for unburned carbon particles of different sizes. After the oxidation reaction rates were evaluated, the residence time distribution (RTD) of fly ashes in the rotary kiln were experimentally measured and the mean residence times related to process parameters, including the rotating velocity and kiln inclination. By comparing these results with an advective-dispersive model, the axial dispersion coefficient of fly ashes was determined. The reaction rates obtained by thermal analyses and the RTDs were used to predict combustion efficiencies within the kiln and oxidation conditions of unburned carbon using various processing options. 21 refs., 6 figs., 4 tabs.

  8. Seventh symposium on coal mine drainage research. NCA/BCR coal conference and Expo IV

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-01-01

    The Seventh Symposium on Coal Mine Drainage Research, sponsored by the National Coal Association and Bituminous Coal Research, Inc., was held at the Kentucky Fair and Exposition Center, Louisville, Kentucky, October 18-20, 1977. Seventeen papers from the proceedings have been entered individually into EDB and ERA. Topics covered include chemical reactions of pyrite oxidation and acid formation in spoil banks, abandoned mines, etc., formation of small acid lakes from the drainage and their neutralization by natural and other neutralization measures, trace elements in acid mine drainage, ground water contamination, limnology, effects of surface mined ground reclamation and neutralization, water purification and treatment, mining and coal preparation plant waste disposal, ash and fly ash disposal (to minimize leaching from the wastes), runoff from large coal storage stockpiles during storms (prevention of environmental effects by collection and neutralization by passing through an ash pond). (LTN)

  9. Coal information 1996

    International Nuclear Information System (INIS)

    1997-01-01

    Coal Information (1997 edition) is the latest edition of a publication that has been produced annually by the IEA since 1983. The report is intended to provide both Member countries of the OECD and those employed in all sectors of the coal industry with information on current world coal market trends and long-term prospects. It includes information on coal prices, demand, trade, supply, production capacity, transport, environmental issues (including emission standards for coal-fired boilers), coal ports, coal-fired power stations and coal used in non -OECD countries. Part I of the publication contains a wide ranging review of world coal market developments in 1996 and current prospects to 2010. The review is based on historical data of OECD energy supply and demand, data on other world regions, projections of OECD coal supply, demand and trade and information provided by the CIAB. Part II provides, in tabular and graphical form, a more detailed and comprehensive statistical picture of coal developments and future prospects for coal in the OECD, by region and for individual Member countries. Readers interested in projections are strongly advised to read the notes for individual countries in Principles and Definitions in Part II. Coal statistics for non-OECD countries are presented in Part III of the book. Summary data are available on hard coal supply and end-use statistics for about 40 countries and regions world-wide. Data are based on official national submissions to the United Nations in Geneva and New York, national energy publications, information provided to the IEA Secretariat by national statistical offices as well as other unofficial Secretariat sources. Further information on coal used in non-OECD countries is published annually by the IEA in Energy Statistics and Balances of Non-OECD Countries. Also included in Part III are the Survey of Coal Ports world-wide and the Survey of Coal-fired Power Stations in coal-importing countries

  10. Coal fired flue gas mercury emission controls

    CERN Document Server

    Wu, Jiang; Pan, Weiguo; Pan, Weiping

    2015-01-01

    Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of

  11. The chemical composition of tertiary Indian coal ash and its

    Indian Academy of Sciences (India)

    In Part 1 of the present investigation, 37 representative Eocene coal samples of Meghalaya, India were analyzed and their physico-chemical characteristics and the major oxides and minerals present in ash samples were studied for assessing the genesis of these coals. Various statistical tools were also applied to study ...

  12. Partial baroreceptor dysfunction and low plasma nitric oxide bioavailability as determinants of salt-sensitive hypertension: a reverse translational rat study

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Pérez, A.S.; López-Rodríguez, J.F.; Calvo-Turrubiartes, M.Z. [Integrative Physiology Laboratory, Department of Physiology and Biophysics, San Luis Potosí (Mexico); Saavedra-Alanís, V.M. [Molecular Biology Laboratory, Department of Biochemistry, San Luis Potosí (Mexico); Llamazares-Azuara, L. [Autonomous University of San Luis Potosí, Renal Laboratory, Faculty of Medicine, San Luis Potosí (Mexico); Rodríguez-Martínez, M. [Integrative Physiology Laboratory, Department of Physiology and Biophysics, San Luis Potosí (Mexico)

    2013-10-02

    This study determined whether clinical salt-sensitive hypertension (cSSHT) results from the interaction between partial arterial baroreceptor impairment and a high-sodium (HNa) diet. In three series (S-I, S-II, S-III), mean arterial pressure (MAP) of conscious male Wistar ChR003 rats was measured once before (pdMAP) and twice after either sham (SHM) or bilateral aortic denervation (AD), following 7 days on a low-sodium (LNa) diet (LNaMAP) and then 21 days on a HNa diet (HNaMAP). The roles of plasma nitric oxide bioavailability (pNOB), renal medullary superoxide anion production (RMSAP), and mRNA expression of NAD(P)H oxidase and superoxide dismutase were also assessed. In SHM (n=11) and AD (n=15) groups of S-I, LNaMAP-pdMAP was 10.5±2.1 vs 23±2.1 mmHg (P<0.001), and the salt-sensitivity index (SSi; HNaMAP−LNaMAP) was 6.0±1.9 vs 12.7±1.9 mmHg (P=0.03), respectively. In the SHM group, all rats were normotensive, and 36% were salt sensitive (SSi≥10 mmHg), whereas in the AD group ∼50% showed cSSHT. A 45% reduction in pNOB (P≤0.004) was observed in both groups in dietary transit. RMSAP increased in the AD group on both diets but more so on the HNa diet (S-II, P<0.03) than on the LNa diet (S-III, P<0.04). MAP modeling in rats without a renal hypertensive genotype indicated that the AD*HNa diet interaction (P=0.008) increases the likelihood of developing cSSHT. Translationally, these findings help to explain why subjects with clinical salt-sensitive normotension may transition to cSSHT.

  13. Synthesis gas generation by high pressure partial oxidation (HP POX {sup registered}); Synthesegaserzeugung durch Hochdruck-Partialoxidation (HP POX {sup registered})

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, B.; Seifert, P.; Zeissler, R. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Energieverfahrenstechnik und Chemieingenieurwesen; Walter, St. [Lurgi AG, Frankfurt/Main (Germany)

    2005-05-01

    The high pressure synthesis gas process HP POX (High Pressure Partial Oxidation) is a thermal conversion process, which converts e.g. natural gas or heavy residue oil with oxygen to fuel or synthesis gas. Innovative burner technologies allow autothermal catalytic or non-catalytic reforming of gaseous feedstock and gasification of liquid feed streams. Hydrogen and carbon monoxide rich synthesis gases with low methane content (particularly suitable as feed gas for methanol synthesis) can be generated. The technology represents a new generation of entrained flow gasification characterized by the new developed equipment and a design pressure of 100 bar. According to the feeds, the HP POX gasification process is the link between the downstream synthesis chemistry (use of gaseous and liquid feeds) and the power plant process (liquid or solid fuels as suspension or slurry). The HP POX development is carried out together with the Lurgi AG at the Institute for Energy Process Engineering and Chemical Engineering (IEC). The 5 MW HP POX test plant built in Freiberg by Lurgi is core of the joint research project, which is supported by the German Federal Ministry of Economics and Labour (BMWA), the Saxon Ministry of Science and the Fine Arts (SMWK), and the mg technologies ag (parent company of Lurgi). The conducted sets of experiments indicate that the unit can be operated in a safe, smooth and stable manner. During this periods of operation, which included nine test campaigns for autothermal reforming (ATR), the maximum pressure for ATR amounted to 70 bar which exceeds the current benchmark in industry for 30 bar. Main objective of R and D work is the development of modelling tools for extreme gasification conditions and different gasification principles of up to 100 bar. These tools are supposed to improve the understanding of the entire gasification process. Their development requires a systematic investigation of the reaction mechanisms and the interactions with the process

  14. Changes in brown coal structure caused by coal-solubilizing microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Schmiers, H.; Koepsel, R.; Weber, A.; Winkelhoefer, M.; Grosse, S. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Energieverfahrenstechnik und Chemieingenieurwesen

    1997-12-31

    The phenomenon of coal solubilization caused by microorganisms has been explained by various mechanisms: extraction of non-covalently bonded polar components of the coal substance by biogenic agents (chelating agents, alkaline substances) and enzyme-catalyzed cleavage of covalent bonds by extracellular enzyme systems. For this it is assumed that bond cleavage occurs on the aliphatic carbon (methylene groups, aliphatic bridges or on ester groups). As the coal has usually been treated with oxidizing agents such as H{sub 2}O{sub 2} or HNO{sub 3} before bioconversion, there is a possibility that the result of bioconversion is overlaid with the effect of the chemical treatment. We therefore studied the structural changes in the organic coal substance during pre-oxidation with H{sub 2}O{sub 2}, treatment with MnP and conversion using the fungal strains of Trichoderma and Fusarium oxysporum. (orig.)

  15. Molecular accessibility in solvent swelled coals. Quarterly report, [April--June 1993

    Energy Technology Data Exchange (ETDEWEB)

    Kispert, L.D.

    1993-08-01

    The effect of weathering (oxidation and dehydration upon exposure to air) on the molecular accessibility of potential catalysts was studied by the EPR spin probe technique. Fresh samples of all 8 APCS coals were exposed to air for periods up to 36 days. Weathering produced significant effects on the retention of spin probes in most of the APCS coals under 91 % carbon (dmmf). It was determined that the lower ranked coal (Beulah Zap and Wyodak) under went a structural collapse which precluded retention of even spin probe VIII. However, medium ranked coals exhibited improved retention upon weathering when swelled in toluene. Swelling with pyridine opened up small pores for 81--86% carbon which is not observed for swelling with toluene. Changes in coal structure were successfully followed by the EPR spin probe method. A detailed analysis of the data collected from the swelling of coals oxidized in a moisture free environment was completed to differentiate between weathering and oxidation. Eight vacuum dried APCS coals were oxidized in an enclosed, pure oxygen, moisture free environment, and the effects of oxidation alone on coal structure were studied by the intercalation of EPR spin probes. The data shows a factor of 5 increase in spin probe retention for some coals oxidized in O{sub 2} versus air., suggesting a large increase in oxidized material. Particular care was taken during the swelling procedures to avoid exposure of the coal samples to air or moisture. EPR spectra were then obtained for these 300 samples.

  16. T