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Sample records for mild gasification char

  1. Investigation of a sulfur reduction technique for mild gasification char

    SciTech Connect

    Knight, R.A.

    1991-01-01

    The object of this program is to investigate the desulfurization of mild gasification char using hydrogen/methane mixtures in a laboratory-scale experimental study. In the first year of the two- year program, char is being treated with mixtures of H{sub 2} and CH{sub 4} at temperatures of 1100{degrees}C to 1550{degrees}F and pressures of 50 to 100 psig. The effects of temperature, pressure, residence time, gas velocity, and gas composition on sulfur removal and carbon gasification are being determined. The batch experiments are being performed in a nominal 2-inch-ID stainless-steel, batch, fluidized-bed reactor. The char to be desulfurized was produced by the IGT mild gasification process research unit (PRU) in a recently completed DOE/METC-sponsored technology development program. The parent coal was Illinois No. 6 from a preparation plant, and the char from the selected test contains 4.58 wt% sulfur. In the first quarter, we have obtained and prepared a char for the desulfurization tests. Ultimate and proximate analyses were performed on this char, and its pore size distribution and surface area were determined. Also this quarter, the fluidized-bed reactor system was constructed and equipped with high pressure mass flow controllers and a high pressure sintered metal filter to remove fines from the effluent gas stream.

  2. Bench-scale development of mild gasification char desulfurization. Technical report, 1 March--31 May 1994

    SciTech Connect

    Knight, R.A.

    1994-09-01

    The goal of this project is to scale up a process, developed under a previous ICCI grant, for desulfurization of mild gasification char by treatment with hydrogen-rich process-derived fuel gas at 650--760 C and 7--15 atm. The char can be converted into a low-sulfur metallurgical form coke. In the prior study, IBC-105 coal with 4.0 wt% sulfur was converted to chars with less than 1.0 wt% sulfur in a laboratory-scale batch reactor. The susceptibility of the char to desulfurization was correlated with physicochemical char properties and mild gasification conditions. Acid pretreatment of the coal prior to mild gasification was also shown to significantly enhance subsequent sulfur removal. In this study, IGT is conducting continuous bench-scale tests in a 1-lb/h fluidized-bed reactor to determine the preferred process conditions and obtain steady-state data necessary for process design and scale-up. The desulfurized chars are to be used to produce low-sulfur form coke, which will be evaluated for density, reactivity, and strength properties relevant to utilization in blast furnaces. This quarter, 2,500 g of mild gasification char was produced from untreated IBC-105 coal in the bench-scale reactor. Half of this char will be subjected to sulfuric acid treatment to enhance subsequent desulfurization. Char-producing runs were also initiated with acid-pretreated coal, which will produce about 1,250 g of char.

  3. Bench-scale development of mild gasification char desulfurization; [Quarterly] report, September 1--November 30, 1993

    SciTech Connect

    Knight, R.A.

    1994-03-01

    This goal of this project is to scale up a process, developed under a previous ICCI grant, for desulfurization of mild gasification char by treatment with hydrogen-rich process-derived fuel gas at 650{degree}--760{degree}C and 7-15 atm. The char can be converted into a low-sulfur metallurgical form coke. In the prior study, IBC-105 coal with 4.0 wt % sulfur was converted to chars with less than 1.0 wt % sulfur in a laboratory-scale batch reactor. The susceptibility of the char to desulfurization was correlated with physicochemical char properties and mild gasification conditions. Acid pretreatment of the coal prior to mild gasification was also shown to significantly enhance subsequent sulfur removal. In this study, IGT is conducting continuous bench-scale tests in a 1-lb/h fluidized-bed reactor to determine the preferred process conditions and obtain steady-state data necessary for process design and scale-up. The desulfurized chars are to be used to produce low-sulfur form coke, which will be evaluated for density, reactivity, and strength properties relevant to utilization in blast furnaces. During the first quarter, 180 lb (82 kg) of IBC-105 coal was obtained and subjected to crushing, and sizing to prepare 49 lb (22 kg) of material for test operation.

  4. Investigation of a technique for sulfur reduction of mild gasification char. [Quarterly] report, December 1, 1991--February 29, 1992

    SciTech Connect

    Knight, R.A.

    1992-08-01

    The object of this program is to investigate the desulfurization of mild gasification char using H{sub 2}CH{sub 4} mixtures in a laboratory-scale experimental study. Mild gasification is a coal conversion technique which produces solid, liquid, and gaseous co-products. Char is the major co-product, about 60% of the dry coal yield. Form coke for steelmaking and foundries presents the best potential high-value markets for chars from eastern bituminous coals. Conventional metallurgical cokes generally contain about 1 wt% or less sulfur. Mild gasification char from high-sulfur Illinois coals must be upgraded to meet these criteria. One method to accomplish this is desulfurization with reducing gases derived from the mild gasification co-product gases. Because form coke has a market value up to $200/ton, it can accommodate desulfurization costs and still be economically attractive. The desulfurization can be performed either on the granular char or on formed-briquettes.

  5. Investigation of a sulfur reduction technique for mild gasification char. [Quarterly] technical report, March 1--May 31, 1993

    SciTech Connect

    Knight, R.A.

    1993-09-01

    The objective of this program is to investigate the desulfurization of mild gasification char using H{sub 2}:CH{sub 4} mixtures. Mild gasification of coal produces char, liquids, and gases at 1000{degrees}--1500{degrees}F and near-ambient pressure. Char, comprising 60--70% of the product, can be used to make high-value form coke for steel making and foundries. However, a sulfur content below 1 wt% is desirable, and char from high-sulfur Illinois coals must be upgraded to meet this criterion. Illinois No. 6 chars were treated in a batch fluidized bed with H{sub 2}:CH{sub 4} blends containing 9--24 vol% CH{sub 4} at 1100{degrees}--1600{degrees}F and 50--200 psig. Sulfur removal up to 92.5 wt% were obtainer, and the char desulfurization susceptibility was related to porosity, density, and crystallite size. The relationships among mild gasification parameters, char properties, and char desulfurization susceptibility are being studied. Acid washing of coal to remove Ca and Fe is being explored for its effect on subsequent sulfur removal, and secondary desulfurization of form coke produced from the desulfurized chars is also being studied. Desulfurization tests of entrained and fluidized-bed reactor chars from IBC-105 coal (4.1--4.3 wt% sulfur) were completed. Desulfurization conditions were 1400{degrees}F, 100--200 psig and reactant gas compositions of 15-49 vol% CH{sub 4} in H{sub 2}. Sulfur removal ranged from 28 to 95%, with carbon losses from 5 to 29%. Acid-washing of the coal prior to mild gasification or the char prior to desulfurization increased its susceptibility to desulfurization, with sulfur content reduced to as low as 0.10 wt% dry char. Fluidized-bed chars were easier to desulfurize than entrained chars, and were less affected by acid-washing.

  6. Investigation of a sulfur reduction technique for mild gasification char. Final technical report, September 1, 1992--August 31, 1993

    SciTech Connect

    Knight, R.A.

    1993-12-31

    The objective of this program is to investigate the desulfurization of mild gasification char using H{sub 2}:CH{sub 4} mixtures. Mild gasification of coal produces char, liquids, and gases at 1000{degrees}--1500{degrees}F and near-ambient pressure. Char, comprising 60--70% of the product, can be used to make high-value form coke for steel making and foundries. A sulfur content below 1 wt% is desirable, and char from high-sulfur Illinois coals must be upgraded to meet this criterion. In the first year of the program, Illinois No. 6 chars were treated in a batch fluidized bed with H{sub 2}:CH{sub 4} blends containing 9--24 vol% CH{sub 4} at 1100{degrees}--1600{degrees}F and 50--200 psig. Sulfur removals up to 92.5 wt% were obtained, and the char desulfurization susceptibility was related to porosity, density, and carbon crystallite size. During the second year, the relationships among mild gasification parameters, char properties, char desulfurization susceptibility, and form coke properties were studied. Acid washing of coal to remove Ca and Fe was explored for its effect on subsequent sulfur removal, and secondary desulfurization of form coke produced from the desulfurized chars was studied. Desulfurization tests of entrained and fluidized-bed reactor chars from IBC-105 coal were completed. Acid-washing of the coal prior to mild gasification or the char prior to desulfurization increased its susceptibility to desulfurization, with sulfur content reduced to as low as 0.10 wt % dry char. Fluidized-bed chars were easier to desulfurize than entrained chars, with or without acid-washing. Form coke briquettes were prepared from selected chars and mild gasification pitch binder, and then carbonized under both N{sub 2} and H{sub 2}:CH{sub 4} atmospheres. carbonization in H{sub 2}:CH{sub 4} removed additional sulfur from the form coke. Adequate tensile strength (837 psi) was achieved in briquettes with 1.2 wt% sulfur made from desulfurized char.

  7. Investigation of a sulfur reduction technique for mild gasification char. Technical report, December 1, 1992--February 28, 1993

    SciTech Connect

    Knight, R.A.; Banerjee, D.

    1993-05-01

    The objective of this program is to investigate the desulfurization of mild gasification char using H{sub 2}:CH{sub 4} mixtures. Mild gasification of coal produces char, liquids, and gases at 1000{degrees}--1500{degrees}F (538{degrees}-816{degrees}C) and near-ambient pressure. Char, comprising 60--70% of the product, can be used to make high-value form coke for steelmaking and foundries. However, a sulfur content below 1 wt% is desirable, and char from high-sulfur Illinois coals must be upgraded to meet this criterion. Illinois No. 6 chars were treated in a 2-inch batch fluidized-bed reactor with H{sub 2}:CH{sub 4} blends containing 9--24 vol % CH{sub 4} at 1100{degrees}-1600{degrees}F (538{degrees}-871{degrees}C) and 50--200 psig (0.35--1.38 Mpa). The data from these tests show sulfur removal of 6.0--92.5 wt % and carbon losses of 0.0--25.6 wt %, with the desulfurization susceptibility of char related to porosity, density, and crystallite size. The relationships among mild gasification parameters, char properties, and char desulfurization susceptibility are being studied. Acid washing of char to remove Ca and Fe is being explored for its effect on subsequent sulfur removal. Secondary desulfurization of form coke produced from the desulfurized chars is also being studied, and a final recommendation will be made for integration of char desulfurization into the IGT MILDGAS process.

  8. Bench-scale development of mild gasification char desulfurization. Technical report, 1 December 1993--28 February 1994

    SciTech Connect

    Knight, R.A.

    1994-06-01

    The goal of this project is to scale up a process, developed under a previous ICCI grant, for desulfurization of mild gasification char by treatment with hydrogen-rich process-derived fuel gas at 650--760 C and 7-15 atm. The char can be converted into a low-sulfur metallurgical form coke. In the prior study, IBC-105 coal with 4.0 wt % sulfur was converted to chars with less than 1.0 wt% sulfur was converted to chars with less than 1.0 wt % sulfur in a laboratory-scale batch reactor. The susceptibility of the char to desulfurization was correlated with physicochemical char properties and mild gasification conditions. Acid pretreatment of the coal prior to mild gasification was also shown to significantly enhance subsequent sulfur removal. In this study, IGT is conducting continuous bench-scale tests in a 1-lb/h fluidized-bed reactor to determine the preferred process conditions and obtain steady-state data necessary for process conditions and obtain steady-state data necessary for process design and scale-up. The desulfurized chars are to be used to produce low-sulfur form coke, which will be evaluated for density, reactivity, and strength properties relevant to utilization in blast furnaces. During the second quarter, the authors completed the acid pretreatment of 25 lb (11 kg) of the 40 x 80-mesh IBC-105 coal and 7 lb (3 kg) of carbonizer char. Modifications of the bench-scale fluidized-bed reactor were completed, permitting extended-duration char-producing runs with caking coal. Char-producing runs were initiated at 1100 F and 20 psig in nitrogen, and will continue into the third quarter.

  9. Investigation of a sulfur reduction technique for mild gasification char. Technical report, September 1, 1991--November 30, 1991

    SciTech Connect

    Knight, R.A.

    1991-12-31

    The object of this program is to investigate the desulfurization of mild gasification char using hydrogen/methane mixtures in a laboratory-scale experimental study. In the first year of the two- year program, char is being treated with mixtures of H{sub 2} and CH{sub 4} at temperatures of 1100{degrees}C to 1550{degrees}F and pressures of 50 to 100 psig. The effects of temperature, pressure, residence time, gas velocity, and gas composition on sulfur removal and carbon gasification are being determined. The batch experiments are being performed in a nominal 2-inch-ID stainless-steel, batch, fluidized-bed reactor. The char to be desulfurized was produced by the IGT mild gasification process research unit (PRU) in a recently completed DOE/METC-sponsored technology development program. The parent coal was Illinois No. 6 from a preparation plant, and the char from the selected test contains 4.58 wt% sulfur. In the first quarter, we have obtained and prepared a char for the desulfurization tests. Ultimate and proximate analyses were performed on this char, and its pore size distribution and surface area were determined. Also this quarter, the fluidized-bed reactor system was constructed and equipped with high pressure mass flow controllers and a high pressure sintered metal filter to remove fines from the effluent gas stream.

  10. Investigation of a technique for sulfur reduction of mild gasification char. Technical report, March 1--May 31, 1992

    SciTech Connect

    Knight, R.A.

    1992-10-01

    The object of this program is to investigate the desulfurization of mild gasification char using H{sub 2}:CH{sub 4} mixtures at the laboratory scale. Mild gasification is a coal conversion technique which produces solid, liquid, and gaseous co-products at 1100{degrees}--1500{degrees}F and near-ambient pressure. Char comprises about 60 to 70% of the dry coal yield. Form coke for steelmaking and foundries presents potential high-value markets for chars from eastern bituminous coals. Conventional metallurgical cokes generally contain less than 1 wt% sulfur, and mild gasification char from high-sulfur Illinois coals must be upgraded to meet these criteria. One method to accomplish this is desulfurization with reducing gases derived from the co-product gases. Because form coke has a market value up to $200/ton, it can accommodate desulfurization costs and still be economically attractive. In the first year of the two-year program, granular char is being treated with H{sub 2}:CH{sub 4} blends at temperatures of 1100{degrees}--1600{degrees}F and pressures of 50--200 psig. The effects of temperature, pressure, residence time, gas velocity, and gas composition on sulfur removal and carbon gasification are being determined. During the third quarter, 10 tests were performed with four chars. Fluidized-bed tests were conducted at 1400--1600{degrees}F, 50--200 psig, and 120--240 min residence time. Future tests will focus on determining the key properties that determine the susceptibility of char to hydrodesulfurization with minimal carbon conversion.

  11. Investigation of a technique for sulfur reduction of mild gasification char. Final technical report, September 1, 1991--August 31, 1992

    SciTech Connect

    Knight, R.A.

    1992-12-31

    The objective of this program is to investigate the desulfurization of mild gasification char using H{sub 2}:CH{sub 4}, mixtures at the laboratory scale. Mild gasification produces solid, liquid, and gaseous co-products at 1000{degree} to 1500{degree}F and near-ambient pressure. Char comprises about 60 to 70% of the dry coal yield. Form coke for steelmaking and foundries presents potential high-value markets for chars from eastern bituminous coals, Metallurgical cokes generally contain less than 1 wt% sulfur, and mild gasification char from high-sulfur Illinois coals must be upgraded to meet these criteria. One method to accomplish this is desulfurization with reducing gases derived from the.co-product gases. In the first year of the two-year program, granular chars were treated with H{sub 2}:CH{sub 4}, blends at temperatures of 1100{degree} to 1600{degree}F and pressures of 50 to 200 psig. During the year, 23 tests were performed with 10 chars. Fluidized-bed tests were conducted for 120 to 240 minutes with superficial gas velocities from 0.067 to 0.150 ft/s. The desulfurization medium was H{sub 2} gas containing 9 to 24 vol% CH{sub 4}. The data from these tests show sulfur conversions ranging from 6.0 to 92.5 wt%, with carbon conversions from zero to 35.3 wt%. The maximum sulfur conversion was 92.5 wt% at 1400{degree}F and 200 psig in 76% H, for 120 minutes residence time, using IFFR char produced from IBC-106 coal at 1200{degree}F in helium. The sulfur content of the char in that test was reduced from 3.78 to 0.39 wt%.

  12. Mild gasification technology development process: Task 3, Bench-scale char upgrading study, February 1988--November 1990

    SciTech Connect

    Carty, R.H.; Onischak, M.; Babu, S.P.; Knight, R.A.; Wootten, J.M.; Duthie, R.G.

    1990-12-01

    The overall objective of this program is to develop mild gasification technology and co-product utilization. The objective of Task 3 was to investigate the necessary steps for upgrading the mild gasification char into potential high-market-value solid products. Recommendations of the Task 1 market survey section formed the basis for selecting three value-added solid products from mild gasification char: form coke, smokeless fuel, and activated adsorbent char. The formation and testing for the form coke co-product involved an evaluation of its briquette strength and reactivity. The measured tensile strength and reactivity of the form coke sample briquettes were in the range of commercial coke, and development tests on a larger scale are recommended. The reaction rate of the form coke carbon with carbon dioxide at 1825{degree}F was measured using a standard procedure. A smokeless fuel briquette with limestone added to control sulfur can be made from mild gasification char in a simple manner. Test results have shown that briquettes with limestone have a heating value comparable to other solid fuels and the limestone can retain up to 88% of the sulfur during combustion in a simple bench-scale combustion test, almost all of it as a stable calcium sulfate. Adsorbent chars were prepared with a standard steam activation procedure and tested for a variety of pertinent property and performance values. Such adsorbents may be better suited for use in some areas, such as the adsorption of low-molecular-weight substances, because of the smaller pore sizes measured in the char. 5 refs., 17 figs., 6 tabs.

  13. Analyzing organic sulfur in coal/char: Integrated mild gasification/XANES methods. Technical report, 1 March--31 May 1994

    SciTech Connect

    Palmer, S.R.; Huffman, G.P.

    1994-09-01

    The overall goal of this study is to improve the understanding of sulfur in coals/chars via the use of combined advanced non-destructive and advanced destructive methods of sulfur analysis. This study combines selective oxidation, analytical pyrolysis, and sulfur X-ray Absorption Near Edge Structure Spectroscopy (XANES) analysis. Samples with a wide variety of sulfur contents, (0.63% to 4.40%) have been prepared for use in this study. This includes steam gasification chars, oxidized coals and desulfurized coals as well of the original unaltered coals. Mild pyrolysis and preliminary XANES data shows that the sulfur chemistry of gasification chars is significantly different from that of the original coals. Mild pyrolysis of the samples that were oxidized with peroxyacetic acid showed that the level of simple thiophene structures observed in the pyrolysis products declines with increasing levels of oxidation. Sulfur XANES spectra of treated samples showed various effects depending on the treatment severity. For the less severely treated samples (demineralization and solvent extraction), the XANES spectra were similar, although not identical, to the untreated coal spectra, whereas the more severe treatments (steam at 450 C; peroxyacetic acid at 25 C) showed preferential oxidation of one or more sulfur-bearing phases in the original coal. Additional samples have recently been examined by XANES and W-band EPR and the data is currently being processed and evaluated.

  14. Development of an advanced continuous mild gasification process for the production of coproducts. Task 4, System integration studies: Char upgrading

    SciTech Connect

    Jha, M.C.; McCormick, R.L.; Hogsett, R.F.; Rowe, R.M.; Anast, K.R.

    1991-12-01

    This document describes the results of Task 4 under which a 50 pound/hour char-to-carbon (CTC) process research unit (PRU) was designed in the second half of 1989, with construction completed in June 1990. The CTC PRU at Golden was operated for nearly one year during which 35 runs were completed for a total of nearly 800 hours of operation. Char methanation and carbon production reactor development activities are detailed in this report, as well as the results of integrated runs of the CTC process. Evaluation of the process and the carbon product produced is also included. It was concluded that carbon could be produced from mild gasification char utilizing the CTC process. Char methanation and membrane separation steps performed reasonably well and can scaled up with confidence. However, the novel directly heated reactor system for methane cracking did not work satisfactorily due to materials of construction and heat transfer problems, which adversely affected the quantity and quality of the carbon product. Alternative reactor designs are recommended.

  15. Development of mild gasification process

    SciTech Connect

    Chu, C.I.C.; Derting, T.M.

    1988-07-01

    Under a previous contract with Morgantown Energy Technology Center (METC), Department of Energy (DOE) Contract No. AC21-84MC21108, UCC Research Corporation (UCCRC) built and tested a 1500 lb/day Mild Gasification Process Development Unit (MGU). The MGU, as tested under the previous contract, is shown in Figure 1. Testing completed under the previous contract showed that good quality hydrocarbon liquids and good quality char can be produced in the MGU. However, the MGU is not optimized. The primary objectives of the current project are to optimize the MGU and determine the suitability of char for several commercial applications. The program consists of four tasks; Task 1 -- Test Plan; Task 2 -- Optimization of Mild Gasification Process; Task 3 -- Evaluation of Char and Char/Coal Blends as a Boiler/Blast Furnace Fuel; and Task 4 -- Analysis of Data and Preparation of Final Report. Task 1 has been completed while work continued on Task 2.

  16. Development of mild gasification process

    SciTech Connect

    Chu, C.I.C.; Gillespie, B.L.

    1988-02-01

    Under a previous contract with Morgantown Energy Technology Center (METC), Department of Energy (DOE) Contract No. DE-AC21-84MC21108, UCC Research Corporation (UCCRC) built and tested a 1500 lb/day Mild Gasification Process Development Unit (MGU). The MGU, as tested under the previous contract, is shown in Figure 1. Testing completed under the previous contract showed that good quality hydrocarbon liquids and good quality char can be produced in the MGU. However, the MGU is not optimized. The primary objectives of the current project are to optimize the MGU and determine the suitability of char for several commercial applications. The program consists of four tasks; Task 1-Test Plan; Task 2-Optimization of Mild Gasification Process; Task 3-Evaluation of Char and Char/Coal Blends as a Boiler/Blast Furnace Fuel; and Task 4-Analysis of Data and Preparation of Final Report. Task 1 has been completed while work continued on Task 2.

  17. Development of mild gasification process

    SciTech Connect

    Chu, C.I.C.; Williams, S.W.

    1989-01-01

    Under a previous contract with Morgantown Energy Technology Center (METC), Department of Energy (DOE) Contract No. AC21-84MC21108, UCC Research Corporation (UCCRC) built and tested a 1500 lb/day Mild Gasification Process Development Unit (MGU). The MGU, as tested under the previous contract, is shown in Figure 1. Testing completed under the previous contract showed that good quality hydrocarbon liquids and good quality char can be produced in the MGU. However, the MGU is not optimized. The primary objectives of the current project are to optimize the MGU and determine the suitability of char for several commercial applications. The program consists of four tasks; Task 1 -- Test Plan; Task 2 -- Optimization of Mild Gasification Process; Task 3 -- Evaluation of Char and Char/Coal Blends as a Boiler/Blast Furnace Fuel; and Task 4 -- Analysis of Data and Preparation of Final Report. Task 1 has been completed while work continued on Task 2.

  18. Development of mild gasification process

    SciTech Connect

    Chu, C.I.C.; Gillespie, B.L.

    1987-11-01

    Under a previous contract with Morgantown Energy Technology Center (METC), Department of Energy (DOE) Contract No. AC21-84MC21108, UCC Research Corporation (UCCRC) built and tested a 1500 lb/day Mild Gasification Process Development Unit (MGU). The MGU, as tested under the previous contract, is shown in Figure 1. Testing completed under the previous contract showed that good quality hydrocarbon liquids and good quality char can be produced in the MGU. However, the MGU is not optimized. The primary objectives of the current project are to optimize the MGU and determine the suitability of char for several commercial applications. The program consists of four tasks; Task 1 -- Test Plan; Task 2 -- Optimization of Mild Gasification Process; Task 3 -- Evaluation of Char and Char/Coal Blends as a Boiler/Blast Furnace Fuel; and Task 4 -- Analysis of Data and Preparation of Final Report. Task 1 has been completed while work continued on Task 2.

  19. Study of char gasification reactions

    SciTech Connect

    Ballal, G.D.

    1986-01-01

    A Texas lignite, an anthracite and two bituminous coals, Pittsburgh number8 and Illinois number6, were pyrolyzed in a nitrogen atmosphere to prepare chars. Optical microscopy, mercury porosimetry and gas adsorption techniques using nitrogen, CO/sub 2/ and CO, were employed for pore structure characterization. The lignite char exhibited the fastest rates of gaseous diffusion, followed in order of decreasing diffusivities by the Illinois number6, Pittsburgh number8 and anthracite chars. The changes in reactivities and pore structures of chars were measured experimentally during their reaction with oxygen (400-550C) and CO/sub 2/ (800-1000C). For a particular char-gas system, the normalized rate-conversion pattern was invariant with respect to temperature and gaseous concentration. In the case of lignite and Pittsburgh number8 chars, the rate-conversion pattern was similar during reaction with oxygen and CO/sub 2/. Adsorption experiments on partially reacted chars indicated that the micropores in the lignite char were accessible to both reactants. The micropores in the Illinois number6 char were, however, not accessible during its reaction with oxygen. The evolution of pore structure during reaction was modeled by using a probabilistic approach which accounts for overlapping pores with different shapes and sizes. The kinetics of gasification of the lignite and the Pittsburgh number8 chars was studied using a Langmuir-Hinshelwood type kinetic expression to correlate the experimental data. CO was found to inhibit the reaction substantially. The effect of a potassium carbonate catalyst on the reaction of these two chars was also investigated. Substantial increases in reaction rates were observed, and the enhancement was approximately proportional to the catalyst loading.

  20. Fundamental aspects of catalysed coal char gasification

    NASA Astrophysics Data System (ADS)

    Gangwal, S. K.; Truesdale, R. S.

    1980-06-01

    A brief review of the basic aspects of catalysed coal char gasification is presented. Kinetics and mechanisms of catalysed and uncatalysed gasification reactions of coal char with steam, carbon dioxide and hydrogen are discussed. Mass transport effects and internal structure of coals are shown to be important in determining rates of these reactions. The importance of the type of catalyst used is also discussed. Such factors as catalyst cations and anions, the method by which the catalyst is contacted with the coal char, and physical and chemical states of the catalyst both prior to and during reaction are shown to be important in the gasification process. Finally, research instruments and equipment used recently for studies in catalysed gasification are reviewed. These include various types of reactor systems for following the course of these reactions and analytical instruments for assessing the physical and/or chemical state of the catalysts and/or coal char both prior to and during the gasification reactions.

  1. Study on CO₂ gasification properties and kinetics of biomass chars and anthracite char.

    PubMed

    Wang, Guangwei; Zhang, Jianliang; Hou, Xinmei; Shao, Jiugang; Geng, Weiwei

    2015-02-01

    The CO2 gasification properties and kinetics of three biomass chars (WS-char, RL-char and PS-char) and anthracite char (AC-char) were investigated by thermogravimetric analysis method. Three nth-order representative gas-solid reaction models, random pore model (RPM), volume reaction model (VM) and unreacted core model (URCM) were employed to describe the reactive behavior of chars. Results show that gasification reactivity order of different chars from high to low was WS-char, PS-char, RL-char and AC-char. In addition, the chemical components as well as physical structures of four chars were systematically tested. It was found that gasification properties of char were determined by carbonaceous structure. It was concluded from kinetics analysis that RPM model was the best model for describing the reactivities of biomass chars and VM was the model that best fitted the gasification process of anthracite char. The activation energies obtained for the biomass and anthracite char samples lie in the range of 236.4-284.9 kJ/mol. PMID:25479395

  2. Interaction and its induced inhibiting or synergistic effects during co-gasification of coal char and biomass char.

    PubMed

    Ding, Liang; Zhang, Yongqi; Wang, Zhiqing; Huang, Jiejie; Fang, Yitian

    2014-12-01

    Co-gasification of coal char and biomass char was conducted to investigate the interactions between them. And random pore model (RPM) and modified random pore model (MRPM) were applied to describe the gasification behaviors of the samples. The results show that inhibiting effect was observed during co-gasification of corn stalk char with Hulunbeier lignite coal char, while synergistic effects were observed during co-gasification of corn stalk char with Shenmu bituminous coal char and Jincheng anthracite coal char. The inhibiting effect was attributed to the intimate contact and comparable gasification rate between biomass char and coal char, and the loss of the active form of potassium caused by the formation of KAlSiO4, which was proved to be inactive during gasification. While the synergistic effect was caused by the high potassium content of biomass char and the significant difference of reaction rate between coal char and biomass char during gasification. PMID:25280109

  3. Combustion and gasification characteristics of chars from four commercially significant coals of different rank. Final report

    SciTech Connect

    Nsakala, N.Y.; Patel, R.L.; Lao, T.C.

    1982-09-01

    The combustion and gasification kinetics of four size graded coal chars were investigated experimentally in Combustion Engineering's Drop Tube Furnace System (DTFS). The chars were prepared in the DTFS from commercially significant coals representing a wide range of rank; these included a Pittsburgh No. 8 Seam hvAb coal, an Illinois No. 6 Seam hvCb coal, a Wyoming Sub C, and a Texas Lignite A. Additionally, a number of standard ASTM and special bench scale tests were performed on the coals and chars to characterize their physicochemical properties. Results showed that the lower rank coal chars were more reactive than the higher rank coal chars and that combustion reactions of chars were much faster than the corresponding gasification reactions. Fuel properties, temperature, and reactant gas partial pressure had a significant influence on both combustion and gasification, and particle size had a mild but discernible influence on gasification. Fuel reactivities were closely related to pore structure. Computer simulation of the combustion and gasification performances of the subject samples in the DTFS supported the experimental findings.

  4. Development of an advanced, continuous mild gasification process for the production of co-products: Topical report

    SciTech Connect

    Cha, C.Y.; Merriam, N.W.; Jha, M.C.; Breault, R.W.

    1988-06-01

    Research on mild gasification is discussed. The report is divided into three sections: literature survey of mild gasification processes; literature survey of char, condensibles, and gas upgrading and utilization methods; and industrial market assessment of products of mild gasification. Recommendations are included in each section. (CBS) 248 refs., 58 figs., 62 tabs.

  5. Development of an advanced, continuous mild gasification process for the production of co-products (Tasks 2, 3, and 4. 1 to 4. 6), Volume 2

    SciTech Connect

    Knight, R.A.; Gissy, J.L.; Onischak, M.; Babu, S.P.; Carty, R.H. ); Duthie, R.G. ); Wootten, J.M. )

    1991-09-01

    Volume 2 contains information on the following topics: (1) Mild Gasification Technology Development: Process Research Unit Tests Using Slipstream Sampling; (2) Bench-Scale Char Upgrading Study; (3) Mild Gasification Technology Development: System Integration Studies. (VC)

  6. Active sites in char gasification: Final technical report

    SciTech Connect

    Wojtowicz, M.; Lilly, W.D.; Perkins, M.T.; Hradil, G.; Calo, J.M.; Suuberg, E.M.

    1987-09-01

    Among the key variables in the design of gasifiers and combustors is the reactivity of the chars which must be gasified or combusted. Significant loss of unburned char is unacceptable in virtually any process; the provision of sufficient residence time for complete conversion is essential. A very wide range of reactivities are observed, depending upon the nature of the char in a process. The current work focuses on furthering the understanding of gasification reactivities of chars. It has been well established that the reactivity of char to gasification generally depends upon three principal factors: (1) the concentration of ''active sites'' in the char; (2) mass transfer within the char; and (3) the type and concentration of catalytic impurities in the char. The present study primarily addresses the first factor. The subject of this research is the origin, nature, and fate of active sites in chars derived from parent hydrocarbons with coal-like structure. The nature and number of the active sites and their reactivity towards oxygen are examined in ''model'' chars derived from phenol-formaldehyde type resins. How the active sites are lost by the process of thermal annealing during heat treatment of chars are studied, and actual rate for the annealing process is derived. Since intrinsic char reactivities are of primary interest in the present study, a fair amount of attention was given to the model char synthesis and handling so that the effect of catalytic impurities and oxygen-containing functional groups in the chemical structure of the material were minimized, if not completely eliminated. The project would not be considered complete without comparing characteristic features of synthetic chars with kinetic behavior exhibited by natural chars, including coal chars.

  7. Mild coal gasification: Product separation

    SciTech Connect

    Wallman, P.H.; Singleton, M.F.

    1992-08-04

    Our general objective is to further the development of efficient continuous mild coal gasification processes. The research this year has been focused on product separation problems and particularly the problem of separating entrained ultra-fine particles from the chemically reactive environment of the product gas stream. Specifically, the objective of the present work has been to study candidate barrier filters for application to mild coal gasification processes. Our approach has been to select the most promising existing designs, to develop a design of our own and to test the designs in our bench-scale gasification apparatus. As a first step towards selection of the most promising barrier filter we have determined coking rates on several candidate filter media.

  8. Study on CO2 gasification reactivity and physical characteristics of biomass, petroleum coke and coal chars.

    PubMed

    Huo, Wei; Zhou, Zhijie; Chen, Xueli; Dai, Zhenghua; Yu, Guangsuo

    2014-05-01

    Gasification reactivities of six different carbonaceous material chars with CO2 were determined by a Thermogravimetric Analyzer (TGA). Gasification reactivities of biomass chars are higher than those of coke and coal chars. In addition, physical structures and chemical components of these chars were systematically tested. It is found that the crystalline structure is an important factor to evaluate gasification reactivities of different chars and the crystalline structures of biomass chars are less order than those of coke and coal chars. Moreover, initial gasification rates of these chars were measured at high temperatures and with relatively large particle sizes. The method of calculating the effectiveness factor η was used to quantify the effect of pore diffusion on gasification. The results show that differences in pore diffusion effects among gasification with various chars are prominent and can be attributed to different intrinsic gasification reactivities and physical characteristics of different chars. PMID:24642484

  9. Development of an advanced, continuous mild gasification process for the production of co-products

    SciTech Connect

    Wolfe, R.A.; Wright, R.E.; Im, C.J.; Henkelman, M.R.; O`Neal, G.W.

    1992-11-01

    The objective of this project is to develop a continuous mild gasification process to convert highly caking coals to coal liquids, char and coke for near term commercial application. Task 3, Bench-Scale Char Upgrading Study, has been underway since September 1989. In char upgrading studies, ``green`` uncured char briquettes have been prepared and calcined in 20-pound batches to evaluate the effects of char, binders, and heating conditions on final coke properties. A total of 150. formulations have been tested thus far in this work. Work on Task 4, Process Development Unit (PDU) Mild Gasification Study, has been in progress since February 1991, with the completion of a Continuous Mild Gasification Unit (CMGU) with a design rate of 1000 lb./hr. Since start-up of the CMGU, there have been 72 runs with a variety of operating conditions and coal types.

  10. Comparison of kinetic models for isothermal CO2 gasification of coal char-biomass char blended char

    NASA Astrophysics Data System (ADS)

    Zuo, Hai-bin; Geng, Wei-wei; Zhang, Jian-liang; Wang, Guang-wei

    2015-04-01

    This study investigated the isothermal gasification reactivity of biomass char (BC) and coal char (CC) blended at mass ratios of 1:3, 1:1, and 3:1 via isothermal thermogravimetric analysis (TGA) at 900, 950, and 1000°C under CO2. With an increase in BC blending ratio, there were an increase in gasification rate and a shortening of gasification time. This could be attributed to the high specific surface area of BC and the high uniformity of carbon structures in CC when compared to those in BC. Three representative gas-solid kinetic models, namely, the volumetric model (VM), grain model (GM), and random pore model (RPM), were applied to describe the reaction behavior of the char. Among them, the RPM model was considered the best model to describe the reactivity of the char gasification reaction. The activation energy of BC and CC isothermal gasification as determined using the RPM model was found to be 126.7 kJ/mol and 210.2 kJ/mol, respectively. The activation energy was minimum (123.1 kJ/mol) for the BC blending ratio of 75%. Synergistic effect manifested at all mass ratios of the blended char, which increased with the gasification temperature.

  11. Effects of volatile-char interactions on char during pyrolysis of rice husk at mild temperatures.

    PubMed

    Liu, Peng; Zhao, Yijun; Guo, Yangzhou; Feng, Dongdong; Wu, Jiangquan; Wang, Pengxiang; Sun, Shaozeng

    2016-11-01

    In order to understand the sensitivity of volatile-char interactions to mild temperatures (600-800°C), in-situ rice husk char was prepared from fast pyrolysis (>10(3)Ks(-1)) on a fixed-bed reactor. Retention of K in char, changes in char structure and char reactivity were determined. The results showed that volatile-char interactions did not cause obvious effect on the char yield but showed an inhibitory effect on char reactivity. The inhibition began only above 650°C and intensified with temperature rise, but kept almost unchanged at 700-800°C. Char structure and retention of K have a combined effect on char reactivity. The decreased reactivity was caused by additional volatilization of K from char matrix and transformation of relatively smaller aromatic ring systems to large ring systems (>6 benzene rings) above 650°C. PMID:27544921

  12. Pressure passivation of mild pyrolysis char

    SciTech Connect

    Ochs, T.; Summers, C.; Schroeder, K.; Sands, W.

    1999-07-01

    Low-rank coals that have been thermally dried in the mild pyrolysis process have a tendency to spontaneously combust. The spontaneous combustion of coals and chars has been linked to their affinity for oxygen. The USDOE has developed a method for the passivation of mild pyrolysis char derived from a low-rank coal using pressure differentials to control the oxidation of the active sites in the char rapidly and safely. Initial experiments performed by the USDOE show that the affinity of the coal for oxygen uptake (residual oxygen demand, ROD) is reduced by exposure of the coal-char to high-pressure gas mixtures including air or oxygen-enriched air. Laboratory-scale tests have shown that the ROD can be rapidly reduced by cycling the active coals between low-pressure (atmospheric pressure or less) and high-pressure (500 psi to 1,500 psi) regimes. Cycling the pressure of the treatment gas provides rapid passivation resulting from two effects: The high-pressure cycle forces fresh oxygen into the pores which have been purged of adsorbed gases and reaction products. The pores of coal are small enough to prohibit free convection and force oxygen exchange to take place by way of diffusion under ambient conditions. The forced introduction of fresh process gas under high pressure overcomes the restrictions due to diffusion limits while the removal of adsorbed products clears the way to active surface sites. The high pressure increases the number of oxygen molecules with sufficient energy to overcome the activation barrier of the passivation reaction, due to the increased number of molecules per unit volume of the high-pressure gas. Combined, the two effects rapidly produce a coal with a significantly reduced ROD.

  13. Combustion and gasification characteristics of chars from raw and torrefied biomass.

    PubMed

    Fisher, E M; Dupont, C; Darvell, L I; Commandré, J-M; Saddawi, A; Jones, J M; Grateau, M; Nocquet, T; Salvador, S

    2012-09-01

    Torrefaction is a mild thermal pretreatment (T<300°C) that improves biomass milling and storage properties. The impact of torrefaction on the gasification and oxidation reactivity of chars from torrefied and raw biomass was investigated. Thermogravimetric analysis was used to study the differences in O(2) and steam reactivity, between chars prepared from torrefied and raw willow, under both high- and low-heating-rate conditions. High-heating-rate chars were prepared at 900°C with a residence time of 2s. Low-heating-rate chars were prepared with a heating rate of 33°C/min, a maximum temperature of 850 or 1000°C, and a residence time of 30 min or 1h, respectively, at the maximum temperature. Pretreatment by torrefaction consistently reduced char reactivity. Torrefaction's impact was greatest for high-heating-rate chars, reducing reactivity by a factor of two to three. The effect of torrefaction on a residence time requirements for char burnout and gasification was estimated. PMID:22728196

  14. Development of an advanced, continuous mild gasification process for the production of co-products (Tasks 2, 3, and 4.1 to 4.6), Volume 2. Final report

    SciTech Connect

    Knight, R.A.; Gissy, J.L.; Onischak, M.; Babu, S.P.; Carty, R.H.; Duthie, R.G.; Wootten, J.M.

    1991-09-01

    Volume 2 contains information on the following topics: (1) Mild Gasification Technology Development: Process Research Unit Tests Using Slipstream Sampling; (2) Bench-Scale Char Upgrading Study; (3) Mild Gasification Technology Development: System Integration Studies. (VC)

  15. Kinetics of gasification of black liquor char by steam

    SciTech Connect

    Li, J.; van Heiningen, A.R.P. )

    1991-07-01

    This paper reports on the steam gasification kinetics of kraft black liquor char that were studied in a thermogravimetric analysis reactor. The effect of steam and hydrogen concentration on gasification rate can be described by Langmuir-Hinshelwood type kinetics. An activation energy of 210 kJ/mol was obtained. Methane formation was negligible, and H{sub 2}S was the major gaseous sulfur-containing product obtained over the temperature range studied, 873-973 K. The CO{sub 2} concentration was higher than calculated for the water-shift reaction at equilibrium. A gasification mechanism is proposed whereby CO{sub 2} is one of the primary gasification products.

  16. Development of an advanced, continuous mild gasification process for the production of co-products

    SciTech Connect

    Ness, R.O. Jr.; Aulich, T.R.

    1990-10-01

    The primary objective of the EERC/AMAX Mild Gasification project is to commercialize a process that will produce several value-added products from a high-sulfur midwestern bituminous or a low-sulfur subbituminous coal. Indiana No. 3 and Wyodak coals are being tested in a 100-lb/hr process development unit (PDU) that has undergone shakedown testing and is undergoing parametric testing. This unit will provide the engineering data for use in determining the technical and economic data required for the design of a commercial-scale mild gasification plant. This report discusses results of carbonizer tests, char upgrading and char separations. 12 figs., 16 tabs.

  17. Development of mild gasification process. Quarterly report, April--June 1988

    SciTech Connect

    Chu, C.I.C.; Derting, T.M.

    1988-07-01

    Under a previous contract with Morgantown Energy Technology Center (METC), Department of Energy (DOE) Contract No. AC21-84MC21108, UCC Research Corporation (UCCRC) built and tested a 1500 lb/day Mild Gasification Process Development Unit (MGU). The MGU, as tested under the previous contract, is shown in Figure 1. Testing completed under the previous contract showed that good quality hydrocarbon liquids and good quality char can be produced in the MGU. However, the MGU is not optimized. The primary objectives of the current project are to optimize the MGU and determine the suitability of char for several commercial applications. The program consists of four tasks; Task 1 -- Test Plan; Task 2 -- Optimization of Mild Gasification Process; Task 3 -- Evaluation of Char and Char/Coal Blends as a Boiler/Blast Furnace Fuel; and Task 4 -- Analysis of Data and Preparation of Final Report. Task 1 has been completed while work continued on Task 2.

  18. Development of mild gasification process. Quarterly report, July--September 1987

    SciTech Connect

    Chu, C.I.C.; Gillespie, B.L.

    1987-11-01

    Under a previous contract with Morgantown Energy Technology Center (METC), Department of Energy (DOE) Contract No. AC21-84MC21108, UCC Research Corporation (UCCRC) built and tested a 1500 lb/day Mild Gasification Process Development Unit (MGU). The MGU, as tested under the previous contract, is shown in Figure 1. Testing completed under the previous contract showed that good quality hydrocarbon liquids and good quality char can be produced in the MGU. However, the MGU is not optimized. The primary objectives of the current project are to optimize the MGU and determine the suitability of char for several commercial applications. The program consists of four tasks; Task 1 -- Test Plan; Task 2 -- Optimization of Mild Gasification Process; Task 3 -- Evaluation of Char and Char/Coal Blends as a Boiler/Blast Furnace Fuel; and Task 4 -- Analysis of Data and Preparation of Final Report. Task 1 has been completed while work continued on Task 2.

  19. Development of mild gasification process. Quarterly report, October--December 1988

    SciTech Connect

    Chu, C.I.C.; Williams, S.W.

    1989-01-01

    Under a previous contract with Morgantown Energy Technology Center (METC), Department of Energy (DOE) Contract No. AC21-84MC21108, UCC Research Corporation (UCCRC) built and tested a 1500 lb/day Mild Gasification Process Development Unit (MGU). The MGU, as tested under the previous contract, is shown in Figure 1. Testing completed under the previous contract showed that good quality hydrocarbon liquids and good quality char can be produced in the MGU. However, the MGU is not optimized. The primary objectives of the current project are to optimize the MGU and determine the suitability of char for several commercial applications. The program consists of four tasks; Task 1 -- Test Plan; Task 2 -- Optimization of Mild Gasification Process; Task 3 -- Evaluation of Char and Char/Coal Blends as a Boiler/Blast Furnace Fuel; and Task 4 -- Analysis of Data and Preparation of Final Report. Task 1 has been completed while work continued on Task 2.

  20. Development of mild gasification process. Quarterly report, October--December, 1987

    SciTech Connect

    Chu, C.I.C.; Gillespie, B.L.

    1988-02-01

    Under a previous contract with Morgantown Energy Technology Center (METC), Department of Energy (DOE) Contract No. DE-AC21-84MC21108, UCC Research Corporation (UCCRC) built and tested a 1500 lb/day Mild Gasification Process Development Unit (MGU). The MGU, as tested under the previous contract, is shown in Figure 1. Testing completed under the previous contract showed that good quality hydrocarbon liquids and good quality char can be produced in the MGU. However, the MGU is not optimized. The primary objectives of the current project are to optimize the MGU and determine the suitability of char for several commercial applications. The program consists of four tasks; Task 1-Test Plan; Task 2-Optimization of Mild Gasification Process; Task 3-Evaluation of Char and Char/Coal Blends as a Boiler/Blast Furnace Fuel; and Task 4-Analysis of Data and Preparation of Final Report. Task 1 has been completed while work continued on Task 2.

  1. Transient kinetics study of catalytic char gasification in carbon dioxide

    SciTech Connect

    Lizzio, A.A.; Radovic, L.R. . Dept. of Materials Science and Engineering)

    1991-08-01

    In this paper, the deactivation behavior of K, Ca, and Ni catalysts during carbon (char) gasification in CO{sub 2} is investigated. Correlations were sought between gasification rates and reactive surface areas (RSA) of the chars. In addition, the results allowed some speculation on recently proposed mechanisms of catalysis. An excellent correlation was found in the case of K catalysis, suggesting the rate-determining step in the overall mechanism to be the same as in the uncatalyzed reaction, i.e., desorption of the reactive C(O) intermediate. For the Ca-catalyzed reaction, the quality of the correlation depended on catalyst dispersion, suggesting that an additional process, besides the direct decomposition of the reactive C(O) intermediate, contributed to the transient evolution of CO (e.g., oxygen spillover). No correlation was found for Ni-catalyzed gasification; an oxygen-transfer mechanism is proposed to explain these findings. Mixed catalyst systems (Ca/K, K/Ni, Ca/Ni) were also studied. An excellent correlation between reactivity and RSA was observed in cases where the K-catalyzed reaction was dominant.

  2. Co-gasification of tire and biomass for enhancement of tire-char reactivity in CO2 gasification process.

    PubMed

    Lahijani, Pooya; Zainal, Zainal Alimuddin; Mohamed, Abdul Rahman; Mohammadi, Maedeh

    2013-06-01

    In this investigation, palm empty fruit bunch (EFB) and almond shell (AS) were implemented as two natural catalysts rich in alkali metals, especially potassium, to enhance the reactivity of tire-char through co-gasification process. Co-gasification experiments were conducted at several blending ratios using isothermal Thermogravimetric analysis (TGA) under CO2. The pronounced effect of inherent alkali content of biomass-chars on promoting the reactivity of tire-char was proven when acid-treated biomass-chars did not exert any catalytic effect on improving the reactivity of tire-char in co-gasification experiments. In kinetic studies of the co-gasified samples in chemically-controlled regime, modified random pore model (M-RPM) was adopted to describe the reactive behavior of the tire-char/biomass-char blends. By virtue of the catalytic effect of biomass, the activation energy for tire-char gasification was lowered from 250 kJ/mol in pure form 203 to 187 kJ/mol for AS-char and EFB-char co-gasified samples, respectively. PMID:23612170

  3. Effects of metal catalysts on CO2 gasification reactivity of biomass char.

    PubMed

    Huang, Yanqin; Yin, Xiuli; Wu, Chuangzhi; Wang, Congwei; Xie, Jianjun; Zhou, Zhaoqiu; Ma, Longlong; Li, Haibin

    2009-01-01

    The effects of five metal catalysts (K, Na, Ca, Mg, and Fe) on CO(2) gasification reactivity of fir char were studied using thermal gravimetric analysis. The degree of carbonization, crystal structure and morphology of char samples was characterized by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The CO(2) gasification reactivity of fir char was improved through the addition of metal catalysts, in the order K>Na>Ca>Fe>Mg. XRD analysis indicated that Na and Ca improved the formation of crystal structure, and that Mg enhanced the degree of carbon structure ordering. SEM analysis showed that spotted activation centers were distributed on the surface of char samples impregnated with catalysts. Moreover, a loose flake structure was observed on the surface of both K-char and Na-char. Finally, the kinetic parameters of CO(2) gasification of char samples were calculated mathematically. PMID:19393736

  4. Development of an advanced, continuous mild gasification process for the production of co-products (Task 1), Volume 1

    SciTech Connect

    Knight, R.A.; Gissy, J.L.; Onischak, M.; Babu, S.P.; Carty, R.H. ); Duthie, R.G. ); Wootten, J.M. )

    1991-09-01

    Under US DOE sponsorship, a project team consisting of the Institute of Gas Technology, Peabody Holding Company, and Bechtel Group, Inc. has been developing an advanced, mild gasification process to process all types of coal and to produce solid and condensable liquid co-products that can open new markets for coal. The three and a half year program (September 1987 to June 1991) consisted of investigations in four main areas. These areas are: (1) Literature Survey of Mild Gasification Processes, Co-Product Upgrading and Utilization, and Market Assessment; (2) Mild Gasification Technology Development: Process Research Unit Tests Using Slipstream Sampling; (3) Bench-Scale Char Upgrading Study; (4) Mild Gasification Technology Development: System Integration Studies. In this report, the literature and market assessment of mild gasification processes are discussed.

  5. Kinetics characteristics of straw semi-char gasification with carbon dioxide.

    PubMed

    Xiao, Ruirui; Yang, Wei

    2016-05-01

    The gasification process has promising potential as a solution for the current global energy problem. Kinetics characteristics of straw semi-char gasification were investigated. The main influence factors of gasification, which include bio-char particle size, pyrolysis temperature and pyrolysis atmosphere, were studied. The smaller the particle size is, the higher is the conversion rate. The gasification reactivity of semi-chars increases with pyrolysis temperature and reaches its maximum at approximately 400°C. The straw semi-char obtained in an H2 pyrolysis atmosphere has the best gasification reactivity, while the semi-char obtained in a CO2 atmosphere has the worst reactivity. In addition, characteristics of semi-char were systematically tested. A random pore model, unreacted core shrinking model and integrated model were employed to describe the reactive behavior of semi-chars. Gasification kinetics parameters were calculated. The random pore model fitting result is in better agreement with the experiments than that of the other two models. PMID:26890792

  6. Considerations Based on Reaction Rate on Char Gasification Behavior in Two-stage Gasifier for Biomass

    NASA Astrophysics Data System (ADS)

    Taniguchi, Miki; Nishiyama, Akio; Sasauchi, Kenichi; Ito, Yusuke; Akamatsu, Fumiteru

    In order to develop a small-scale gasifier in which biomass can be converted to energy with high efficiency, we planned a gasification process that consists of two parts: pyrolysis part (rotary kiln) and gasification part (downdraft gasifier). We performed fundamental experiments on gasification part and discussed the appropriate conditions such as air supply location, air ratio, air temperature and hearth load. We considered the results by calculating reaction rates of representative reactions on char gasification part and found that water gas reaction is dominant in the reduction area and its behavior gives important information to decide the adequate length of the char layer.

  7. Behaviors of Char Gasification Based on Two-stage Gasifier of Biomass

    NASA Astrophysics Data System (ADS)

    Taniguchi, Miki; Sasauchi, Kenichi; Ahn, Chulju; Ito, Yusuke; Hayashi, Toshiaki; Akamatsu, Fumiteru

    In order to develop a small-scale gasifier in which biomass can be converted to energy with high efficiency, we planed a gasification process that consists of two parts: pyrolysis part (rotary kiln) and gasification part (downdraft gasifier). We performed fundamental experiments on gasification part and discussed the apropriate conditions such as air supply location, air ratio, air temperature and hearth load. The following results was found: 1) the air supply into the char bed is more effective than that into the gas phase, 2) we can have the maximum cold gas efficiency of 80% on the following conditions: air supply location: char layer, air temperature: 20°C, air ratio: 0.2. 3) As air temperature is higher, the cold gas efficiency is larger. As for the hearth load, the cold gas efficiency becomes higher and reaches the constant level. It is expected from the results that high temperature in the char layer is effective on the char gasification.

  8. The ENCOAL Mild Gasification Demonstration Project

    SciTech Connect

    Not Available

    1990-07-01

    The DOE plans to enter into a Cooperative Agreement with ENCOAL Corporation, a wholly owned subsidiary of Shell Mining Company, for the cost-shared design, construction and operation of a mild gasification facility based on Liquids-from-Coal (LFC) technology. The facility is planned to be located at the Triton Coal Company's Buckskin Mine near Gillette, Wyoming. The mild gasification process to be demonstrated will produce two new, low-sulfur fuel forms (a solid and a liquid) from subbituminous coal. The new fuel forms would be suitable for combustion in commercial, industrial, and utility boilers. This environmental assessment has been prepared by the DOE to comply with the requirements of the NEPA. Pollutant emissions, land use, water, and waste management are briefly discussed. 3 figs., 5 tabs.

  9. Microwave-enhanced CO2 gasification of oil palm shell char.

    PubMed

    Lahijani, Pooya; Zainal, Zainal Alimuddin; Mohamed, Abdul Rahman; Mohammadi, Maedeh

    2014-04-01

    CO2 gasification of oil palm shell (OPS) char to produce CO through the Boudouard reaction (C + CO2 ↔ 2CO) was investigated under microwave irradiation. A microwave heating system was developed to carry out the CO2 gasification in a packed bed of OPS char. The influence of char particle size, temperature and gas flow rate on CO2 conversion and CO evolution was considered. It was attempted to improve the reactivity of OPS char in gasification reaction through incorporation of Fe catalyst into the char skeleton. Very promising results were achieved in our experiments, where a CO2 conversion of 99% could be maintained during 60 min microwave-induced gasification of iron-catalyzed char. When similar gasification experiments were performed in conventional electric furnace, the superior performance of microwave over thermal driven reaction was elucidated. The activation energies of 36.0, 74.2 and 247.2 kJ/mol were obtained for catalytic and non-catalytic microwave and thermal heating, respectively. PMID:24607454

  10. Effect of CO2 gasification reaction on oxycombustion of pulverized coal char.

    SciTech Connect

    Molina, Alejandro; Hecht, Ethan S.; Shaddix, Christopher R.; Haynes, Brian S.

    2010-07-01

    For oxy-combustion with flue gas recirculation, as is commonly employed, it is recognized that elevated CO{sub 2} levels affect radiant transport, the heat capacity of the gas, and other gas transport properties. A topic of widespread speculation has concerned the effect of the CO{sub 2} gasification reaction with coal char on the char burning rate. To give clarity to the likely impact of this reaction on the oxy-fuel combustion of pulverized coal char, the Surface Kinetics in Porous Particles (SKIPPY) code was employed for a range of potential CO{sub 2} reaction rates for a high-volatile bituminous coal char particle (130 {micro}m diameter) reacting in several O{sub 2} concentration environments. The effects of boundary layer chemistry are also examined in this analysis. Under oxygen-enriched conditions, boundary layer reactions (converting CO to CO{sub 2}, with concomitant heat release) are shown to increase the char particle temperature and burning rate, while decreasing the O{sub 2} concentration at the particle surface. The CO{sub 2} gasification reaction acts to reduce the char particle temperature (because of the reaction endothermicity) and thereby reduces the rate of char oxidation. Interestingly, the presence of the CO{sub 2} gasification reaction increases the char conversion rate for combustion at low O{sub 2} concentrations, but decreases char conversion for combustion at high O{sub 2} concentrations. These calculations give new insight into the complexity of the effects from the CO{sub 2} gasification reaction and should help improve the understanding of experimentally measured oxy-fuel char combustion and burnout trends in the literature.

  11. ENCOAL mild coal gasification project. Annual report

    SciTech Connect

    Not Available

    1993-10-01

    This document is the combination of the fourth quarter report (July--September 1993) and the 1993 annual report for the ENCOAL project. The following pages include the background and process description for the project, brief summaries of the accomplishments for the first three quarters, and a detailed fourth quarter report. Its purpose is to convey the accomplishments and current progress of the project. ENCOAL Corporation, has completed the construction of a mild gasification demonstration plant at Triton Coal Company`s Buckskin Mine near Gillette, Wyoming. The process, using Liquids From Coal (LFC) technology developed by SMC and SGI International, utilizes low-sulfur Powder River Basin coal to produce two new fuels, Process Derived Fuel (PDF) and Coal Derived Liquids (CDL). ENCOAL submitted an application to the US Department of Energy (DOE) in August 1989, soliciting joint funding of the project in the third round of the Clean Coal Technology Program. The project was selected by DOE in December, 1989 and the Cooperative Agreement approved in September, 1990. Construction, commissioning, and start-up of the ENCOAL mild coal gasification facility was completed in June of 1992, and the project is currently in the operations phase. Some plant modifications have been required and are discussed in this report.

  12. Ash of palm empty fruit bunch as a natural catalyst for promoting the CO₂ gasification reactivity of biomass char.

    PubMed

    Lahijani, Pooya; Zainal, Zainal Alimuddin; Mohamed, Abdul Rahman; Mohammadi, Maedeh

    2013-03-01

    Palm empty fruit bunch ash (EFB-ash) was used as a natural catalyst, rich in potassium to enhance the CO2 gasification reactivity of palm shell char (PS-char). Various EFB-ash loadings (ranging from 0 to 12.5wt.%) were implemented to improve the reactivity of PS-char during CO2 gasification studies using thermogravimetric analysis. The achieved results explored that the highest gasification reactivity was devoted to 10% EFB-ash loaded char. The SEM-EDS and XRD analyses further confirmed the successful loading of EFB-ash on PS-char which contributed to promoting the gasification reactivity of char. Random pore model was applied to determine the kinetic parameters in catalytic gasification of char at various temperatures of 800-900°C. The dependence of char reaction rate on gasification temperature resulted in a straight line in Arrhenius-type plot, from which the activation energy of 158.75kJ/mol was obtained for the catalytic char gasification. PMID:23195653

  13. Addendum to industrial market assessment of the products of mild gasification

    SciTech Connect

    Not Available

    1992-05-01

    The objective of this report is to review and update the 1988 report by J. E. Sinor Consultants Inc., Industrial Market Assessment of the Products of Mild Gasification, and to more fully present market opportunities for two char-based products from the mild gasification process (MGP): Formcoke for the iron and steel industry, and activated carbon for wastewater cleanup and flue gas scrubbing. Please refer to the original report for additional details. In the past, coal conversion projects have and liquids produced, and the value of the residual char was limited to its fuel value. Some projects had limited success until gas and oil competition overwhelmed them. The strategy adopted for this assessment is to seek first a premium value for the char in a market that has advantages over gas and oil, and then to find the highest values possible for gases, liquids, and tars, either on-site or sold into existing markets. During the intervening years since the 1988 report, there have been many changes in the national economy, industrial production, international competition, and environmental regulations. The Clean Air Act Amendments of 1990 (CAAA) will have a large impact on industry. There is considerable uncertainty about how the Act will be implemented, but it specifically addresses coke-oven batteries. This may encourage industry to consider formcoke produced via mild gasification as a low-pollution substitute for conventional coke. The chemistry and technology of coke making steel were reviewed in the 1988 market assessment and will not be repeated here. The CAAA require additional pollution control measures for most industrial facilities, but this creates new opportunities for the mild gasification process.

  14. Addendum to industrial market assessment of the products of mild gasification

    SciTech Connect

    Not Available

    1992-05-01

    The objective of this report is to review and update the 1988 report by J. E. Sinor Consultants Inc., ``Industrial Market Assessment of the Products of Mild Gasification, and to more fully present market opportunities for two char-based products from the mild gasification process (MGP): Formcoke for the iron and steel industry, and activated carbon for wastewater cleanup and flue gas scrubbing. Please refer to the original report for additional details. In the past, coal conversion projects have and liquids produced, and the value of the residual char was limited to its fuel value. Some projects had limited success until gas and oil competition overwhelmed them. The strategy adopted for this assessment is to seek first a premium value for the char in a market that has advantages over gas and oil, and then to find the highest values possible for gases, liquids, and tars, either on-site or sold into existing markets. During the intervening years since the 1988 report, there have been many changes in the national economy, industrial production, international competition, and environmental regulations. The Clean Air Act Amendments of 1990 (CAAA) will have a large impact on industry. There is considerable uncertainty about how the Act will be implemented, but it specifically addresses coke-oven batteries. This may encourage industry to consider formcoke produced via mild gasification as a low-pollution substitute for conventional coke. The chemistry and technology of coke making steel were reviewed in the 1988 market assessment and will not be repeated here. The CAAA require additional pollution control measures for most industrial facilities, but this creates new opportunities for the mild gasification process.

  15. CO2 gasification reactivity of biomass char: catalytic influence of alkali, alkaline earth and transition metal salts.

    PubMed

    Lahijani, Pooya; Zainal, Zainal Alimuddin; Mohamed, Abdul Rahman; Mohammadi, Maedeh

    2013-09-01

    This study investigates the influence of alkali (Na, K), alkaline earth (Ca, Mg) and transition (Fe) metal nitrates on CO2 gasification reactivity of pistachio nut shell (PNS) char. The preliminary gasification experiments were performed in thermogravimetric analyzer (TGA) and the results showed considerable improvement in carbon conversion; Na-char>Ca-char>Fe-char>K-char>Mg-char>raw char. Based on TGA studies, NaNO3 (with loadings of 3-7 wt%) was selected as the superior catalyst for further gasification studies in bench-scale reactor; the highest reactivity was devoted to 5 wt% Na loaded char. The data acquired for gasification rate of catalyzed char were fitted with several kinetic models, among which, random pore model was adopted as the best model. Based on obtained gasification rate constant and using the Arrhenius plot, activation energy of 5 wt% Na loaded char was calculated as 151.46 kJ/mol which was 53 kJ/mol lower than that of un-catalyzed char. PMID:23880130

  16. Study of char gasification in a differential fixed-bed reactor

    SciTech Connect

    Sotirchos, S.Y.; Crowley, J.A.

    1985-01-01

    The reaction of a low-ash coconut char with CO/sub 2/ was studied in a flow-type reaction/adsorption apparatus equipped with a thermal conductivity detector. The gaseous reactant (CO/sub 2/) is used as carrier gas. The concentration of CO in the product stream and hence the reaction rate, is monitored continuously by the TC detector. The experimental data obtained in this study are compared with the predictions of models for char gasification.

  17. Pyrolysis of pine and gasification of pine chars--influence of organically bound metals.

    PubMed

    Aho, A; DeMartini, N; Pranovich, A; Krogell, J; Kumar, N; Eränen, K; Holmbom, B; Salmi, T; Hupa, M; Murzin, D Yu

    2013-01-01

    Pyrolysis of pine and gasification of pine chars was studied in this work, focusing on the influence of organically bound metals. Selective leaching of the major ash-forming elements in pine wood was performed with different acids, namely, nitric, sulfuric, hydrochloric and oxalic acids. No other major changes in the chemical composition of the biomass were observed except the removal of the metals. The effect of organically bound sodium, potassium, magnesium and calcium was studied in both pyrolysis and gasification. Removal of the metals had a positive effect on the pyrolysis, resulting in higher bio-oil, lower char and gas yields. PMID:23196217

  18. Development of an advanced, continuous mild gasification process for the production of co-products (Task 1), Volume 1. Final report

    SciTech Connect

    Knight, R.A.; Gissy, J.L.; Onischak, M.; Babu, S.P.; Carty, R.H.; Duthie, R.G.; Wootten, J.M.

    1991-09-01

    Under US DOE sponsorship, a project team consisting of the Institute of Gas Technology, Peabody Holding Company, and Bechtel Group, Inc. has been developing an advanced, mild gasification process to process all types of coal and to produce solid and condensable liquid co-products that can open new markets for coal. The three and a half year program (September 1987 to June 1991) consisted of investigations in four main areas. These areas are: (1) Literature Survey of Mild Gasification Processes, Co-Product Upgrading and Utilization, and Market Assessment; (2) Mild Gasification Technology Development: Process Research Unit Tests Using Slipstream Sampling; (3) Bench-Scale Char Upgrading Study; (4) Mild Gasification Technology Development: System Integration Studies. In this report, the literature and market assessment of mild gasification processes are discussed.

  19. Effects of rank and calcium catalysis on oxygen chemisorption and gasification reactivity of coal chars

    NASA Astrophysics Data System (ADS)

    Piotrowski, Andrzej

    The effects of coal rank and calcium catalysis on oxygen gasification of coal chars have been investigated. Five different coals, from lignite to anthracite were used. Coals were demineralized and a calcium catalyst was deposited on the carbon in different amounts, by ion exchange for lignite and subbituminous coals and by impregnation for the others. Chars from all coals were obtained by both slow and rapid pyrolysis. Oxygen chemisorption studies conducted under conditions far away from gasification and measured oxygen uptakes during gasification revealed that large amounts of oxygen are chemisorbed. The lower the coal rank, the greater the amount of chemisorbed oxygen in both cases. The presence of a calcium catalyst additionally increased the oxygen uptake by solid carbons. The chemisorption tests also showed the influence of diffusion inside the smallest micropores on the kinetics of the process. Reactivity profiles were investigated in detail. Demineralized coal chars showed monotonic, linear increases with burn-off for a broad range of conversion (20-80%). The higher the coal rank, the greater the reactivity increase per unit burn-off. A comparison of reactivities of the demineralized form of coal chars confirmed that the reactivity is affected by diffusion inside the smallest micropores for experiments in the intermediate temperature range, usually 700-800 K. A comparison of reactivities of the calcium-loaded and demineralized coal chars prepared and subsequently reacted at the same conditions has confirmed that the catalytic effect of calcium is the greatest for lower-rank coals, and that it decreases with increasing coal rank. Comparable reactivities for as-received and calcium-loaded lignite and subbituminous char were about two orders of magnitude greater than for a corresponding demineralized char. For higher ranks of coal the effect of calcium loading is smaller than one order of magnitude. For the lower ranks of coal, where calcium is very well

  20. Differences in gasification behaviors and related properties between entrained gasifier fly ash and coal char

    SciTech Connect

    Jing Gu; Shiyong Wu; Youqing Wu; Ye Li; Jinsheng Gao

    2008-11-15

    In the study, two fly ash samples from Texaco gasifiers were compared to coal char and the physical and chemical properties and reactivity of samples were investigated by scanning electron microscopy (SEM), SEM-energy-dispersive spectrometry (EDS), X-ray diffraction (XRD), N{sub 2} and CO{sub 2} adsorption method, and isothermal thermogravimetric analysis. The main results were obtained. The carbon content of gasified fly ashes exhibited 31-37%, which was less than the carbon content of 58-59% in the feed coal. The fly ashes exhibited higher Brunauer-Emmett-Teller (BET) surface area, richer meso- and micropores, more disordered carbon crystalline structure, and better CO{sub 2} gasification reactivity than coal char. Ashes in fly ashes occurred to agglomerate into larger spherical grains, while those in coal char do not agglomerate. The minerals in fly ashes, especial alkali and alkaline-earth metals, had a catalytic effect on gasification reactivity of fly ash carbon. In the low-temperature range, the gasification process of fly ashes is mainly in chemical control, while in the high-temperature range, it is mainly in gas diffusion control, which was similar to coal char. In addition, the carbon in fly ashes was partially gasified and activated by water vapor and exhibited higher BET surface area and better gasification activity. Consequently, the fact that these carbons in fly ashes from entrained flow gasifiers are reclaimed and reused will be considered to be feasible. 15 refs., 7 figs., 5 tabs.

  1. Biomass gasification chars for mercury capture from a simulated flue gas of coal combustion.

    PubMed

    Fuente-Cuesta, A; Diaz-Somoano, M; Lopez-Anton, M A; Cieplik, M; Fierro, J L G; Martínez-Tarazona, M R

    2012-05-15

    The combustion of coal can result in trace elements, such as mercury, being released from power stations with potentially harmful effects for both human health and the environment. Research is ongoing to develop cost-effective and efficient control technologies for mercury removal from coal-fired power plants, the largest source of anthropogenic mercury emissions. A number of activated carbon sorbents have been demonstrated to be effective for mercury retention in coal combustion power plants. However, more economic alternatives need to be developed. Raw biomass gasification chars could serve as low-cost sorbents for capturing mercury since they are sub-products generated during a thermal conversion process. The aim of this study was to evaluate different biomass gasification chars as mercury sorbents in a simulated coal combustion flue gas. The results were compared with those obtained using a commercial activated carbon. Chars from a mixture of paper and plastic waste showed the highest retention capacity. It was found that not only a high carbon content and a well developed microporosity but also a high chlorine content and a high aluminium content improved the mercury retention capacity of biomass gasification chars. No relationship could be inferred between the surface oxygen functional groups and mercury retention in the char samples evaluated. PMID:22325640

  2. Toxicity studies of mild gasification products

    SciTech Connect

    Ong, T.M.; Whong, W.Z.; Ma, J.; Zhong, B.Z.; Bryant, D.

    1992-01-01

    The objectives of this project are: (1) to perform mutagenicity studies with the Ames Salmonella/microsomal assay system on coal liquids produced by mild gasification from different coals and/or processing conditions, (2) to determine whether coal liquids which are mutagenic to bacteria are also genotoxic to mammalian cells, (3) to establish correlations between mutagenicity, aromaticity, and boiling point range of coal liquids, and (4) to identify the chemical classes which are likely to be responsible for the mutagenic activity of gasification products. Four of the seven samples tested so far failed to demonstrate any mutagenic activity under any conditions tested. Those samples were SHELL[number sign]830331, MG-122IBP-420[degree]F, MG-122 420--720[degree]F, and MG-122 720[degree]F+. Table 1 summarizes the results from all samples tested in DMSO and Tween 80. When solvated in DMSO, MG-119 and MG-120 composite materials displayed slight, but ultimately insignificant, genotoxic activity on TA98 and TA1OO in the presence of S9. When Tween 80 was used as the solvent, MG-119 and MG-120 displayed slight, but significant, geno-toxic activity on TA98 with S9 (Figure 4). CTC[number sign]11 in DMSO displayed significant genotoxic activity on both TA98 and TA1OO with and without S9. The activity was higher on TA98 than TA100, and higher with S9 than without, primarily indicating the presence of indirect-acting frameshift mutagen. The results of the testing on CTC[number sign]11 were similar for both solvents, DMSO and Tween 80 (Table 2).

  3. Toxicity studies of mild gasification products

    SciTech Connect

    Ong, T.M.; Whong, W.Z.; Ma, J.; Zhong, B.Z.; Bryant, D.

    1992-11-01

    The objectives of this project are: (1) to perform mutagenicity studies with the Ames Salmonella/microsomal assay system on coal liquids produced by mild gasification from different coals and/or processing conditions, (2) to determine whether coal liquids which are mutagenic to bacteria are also genotoxic to mammalian cells, (3) to establish correlations between mutagenicity, aromaticity, and boiling point range of coal liquids, and (4) to identify the chemical classes which are likely to be responsible for the mutagenic activity of gasification products. Four of the seven samples tested so far failed to demonstrate any mutagenic activity under any conditions tested. Those samples were SHELL{number_sign}830331, MG-122IBP-420{degree}F, MG-122 420--720{degree}F, and MG-122 720{degree}F+. Table 1 summarizes the results from all samples tested in DMSO and Tween 80. When solvated in DMSO, MG-119 and MG-120 composite materials displayed slight, but ultimately insignificant, genotoxic activity on TA98 and TA1OO in the presence of S9. When Tween 80 was used as the solvent, MG-119 and MG-120 displayed slight, but significant, geno-toxic activity on TA98 with S9 (Figure 4). CTC{number_sign}11 in DMSO displayed significant genotoxic activity on both TA98 and TA1OO with and without S9. The activity was higher on TA98 than TA100, and higher with S9 than without, primarily indicating the presence of indirect-acting frameshift mutagen. The results of the testing on CTC{number_sign}11 were similar for both solvents, DMSO and Tween 80 (Table 2).

  4. Development of an advanced, continuous mild gasification process for the production of co-products

    SciTech Connect

    Wright, R.E.; Wolfe, R.A.; Im, C.J.; Henkelman, M.R.; O`Neal, G.W.; McKinney, D.A.

    1993-12-31

    The objective of this project is to develop a continuous mild gasification process to convert highly caking coals to coal liquids, char and coke for near term commercial application. Coal liquids after fractionation can be blended with petroleum and used interchangeably with conventional fuels without modifications in gasoline and diesel engines. Char can be used as a carbon source in the production of ferroalloys and in mini-mills. Coke can be produced by upgrading char through briquetting and calcining and for use in the steel industry foundries and blast furnaces. In a step beyond the scope of the project, the plan is to finance, design and construct, in a partnership with others, a plant to produce coal liquid, char and coke in the initial range of 250,000 tons/year. In the Coal Technology Corporation CTC/CLC{reg_sign} Process, coal is continuously moved by interfolded twin screws through a heated retort in the absence of air. The residence time of the coal in the Continuous Mild Gasification Unit (CMGU) is in the range of 20--30 minutes. The coal is heated to controlled temperatures between 800{degree} and 1400{degree}F and is converted into char, condensible hydrocarbon liquids, small quantities of water, and non-condensible fuel gases. The coal derived fuel gases could supply all the required process heat, but for convenience, natural gas is used in the experimental unit. The process concept particularly suitable for highly caking coals which cannot be processed in fluidized bed or moving bed furnaces.

  5. Thermal decomposition and gasification of biomass pyrolysis gases using a hot bed of waste derived pyrolysis char.

    PubMed

    Al-Rahbi, Amal S; Onwudili, Jude A; Williams, Paul T

    2016-03-01

    Chars produced from the pyrolysis of different waste materials have been investigated in terms of their use as a catalyst for the catalytic cracking of biomass pyrolysis gases during the two-stage pyrolysis-gasification of biomass. The chars were produced from the pyrolysis of waste tyres, refused derived fuel and biomass in the form of date stones. The results showed that the hydrocarbon tar yields decreased significantly with all the char materials used in comparison to the non-char catalytic experiments. For example, at a cracking temperature of 800°C, the total product hydrocarbon tar yield decreased by 70% with tyre char, 50% with RDF char and 9% with biomass date stones char compared to that without char. There was a consequent increase in total gas yield. Analysis of the tar composition showed that the content of phenolic compounds decreased and polycyclic aromatic hydrocarbons increased in the product tar at higher char temperatures. PMID:26773946

  6. Scale-up of mild gasification to a process development unit

    SciTech Connect

    Campbell, J.A.L.; Carty, R.H.; Saladin, N.; Foster, H.

    1992-06-01

    The work performed during the second quarterly reporting period (February 21 through May 20, 1992) on the research program, Scale-Up of Mild Gasification to a Process Development Unit'' is presented in this report. The overall objective of this project is to develop the IGT Mild-Gasification (MILDGAS) process for near-term commercialization. The specific objectives of the program are to: (1) design, construct, and operate a 24-tons/day adiabatic process development unit (PDU) to obtain process performance data suitable for further design scaleup. (2) obtain large batches of coal-derived co-products for industrial evaluation. (3) prepare a detailed design of a demonstration unit. (4) develop technical and economic plans for commercialization of the MILDGAS process. The MILDGAS process is a continuous closed system for producing liquid and solid (char) co-products at mild operating conditions up to 50 psig and 1300[degrees]F. It is capable of processing a wide range of both eastern caking and western noncaking coals. The PDU to be constructed is comprised of a 2.5-ft ID adiabatic gasifier for the production of char, coal liquids, and gases; a thermal cracker for upgrading of the coal liquids; and a hot briquetting unit for the production of form coke and smokeless fuel briquettes. The facility will also incorporate support equipment for environmentally acceptable disposal of process waste.

  7. Changes in char structure during the gasification of a Victorian brown coal in steam and oxygen at 800{degree}C

    SciTech Connect

    Xin Guo; Hui Ling Tay; Shu Zhang; Chun-Zhu Li

    2008-11-15

    Char structure is an important factor influencing its reactivity during gasification. This study aims to investigate the changes in char structure during the gasification of brown coal. A Victorian brown coal was gasified in a fluidized-bed/fixed-bed reactor at 800{degree}C in atmospheres containing 15% H{sub 2}O, 2000 ppm O{sub 2}, or 15% H{sub 2}O and 2000 ppm O{sub 2}, respectively. Although the char gasification in 2000 ppm O{sub 2} was mainly rate-limited by the external diffusion of O{sub 2}, the char-H{sub 2}O reaction was mainly rate-limited by the chemical reactions. The structural features of char at different levels of char gasification conversion were examined with FT-Raman spectroscopy. Our results show that the chars from the gasification in the mixture of 2000 ppm O{sub 2} and 15% H{sub 2}O had almost the same features as the chars from the gasification in 15% H{sub 2}O alone when the same levels of char conversion were achieved. Both the thermal decomposition of char and the char gasification reactions could result in changes in char structure during gasification. 29 refs., 5 figs., 1 tab.

  8. Active sites in char gasification. Quarterly technical progress report, 1 January 1984-31 March 1984. [Polymers of phenol-formaldehyde family; chars produced from model compounds

    SciTech Connect

    Calo, J.M.; Suubers, E.M.; Wojtowicz, M.; Lilly, W.

    1984-05-01

    This project is concerned with the study of the nature and behavior of active sites in gasification of chars produced from synthesized model compounds, primarily of the phenol-formaldehyde family of resins. The current technical progress report presents further developments on resin synthesis and characterization and the design of a pyro-gasifier reactor for transient kinetic studies of the chars produced from the model compounds. 7 references, 12 figures, 2 tables.

  9. Study of char gasification in a reaction/adsorption apparatus

    SciTech Connect

    Sotirchos, S.V.; Crowley, J.A.

    1987-09-01

    The reaction of an activated carbon (coconut char) with CO/sub 2/ was studied in a reaction/adsorption apparatus which allows successive reactivity and physical adsorption measurements to be made on the same solid sample. Reaction and surface area evolution data were obtained in the temperature range from 800 to 900/sup 0/C. All reaction rate trajectories obtained in this study showed a maximum in the reaction rate, 2-3 times higher than the initial rate, at about 85% conversion. There was no correlation between these results and the evolution of the internal surface area although the reaction appeared to take place initially in the kinetically controlled regime.

  10. A simple expression for the apparent reaction rate of large wood char gasification with steam.

    PubMed

    Umeki, Kentaro; Roh, Seon-Ah; Min, Tai-Jin; Namioka, Tomoaki; Yoshikawa, Kunio

    2010-06-01

    A simple expression for the apparent reaction rate of large wood char gasification with steam is proposed. Large char samples were gasified under steam atmosphere using a thermo-balance reactor. The apparent reaction rate was expressed as the product of the intrinsic rate and the effective factor. The effective factor was modified to include the effect of change in char diameter and intrinsic reaction rate during the reaction. Assuming uniform conversion ratio throughout a particle, the simplified reaction scheme was divided into three stages. In the initial stage, the local conversion ratio increases without particle shrinkage. In the middle stage, the particle shrinks following the shrinking core model without change in the local conversion ratio. In the final stage, the local conversion ratio increases without particle shrinkage. The validity of the modified effective value was confirmed by comparison with experimental results. PMID:20144863

  11. Mild gasification of Usibelli coal in an inclined fluidized-bed reactor

    SciTech Connect

    Merriam, N.W.; Thomas, K.P.; Cha, C.Y.

    1991-02-01

    Results of mild gasification tests of minus 16-mesh Usibelli coal in an inclined fluidized-bed reactor are described in this report. The minus 16-mesh fraction was separated from the coal by screening. The coal was dried to zero moisture content, and about 2 wt % of the volatiles was removed as gas by partial decarboxylation using a 100-lb/hr inclined fluidized-bed dryer. The dried coal was subjected to mild gasification at maximum temperatures of 1050 to 1250{degrees}F (566 to 677{degrees}C) and feed rates of 7.5 lb/hr while using a once-through flow of carbon dioxide as fluidizing gas in a 1-inch-wide, inclined fluidized-bed reactor. Mild gasification of the dried coal resulted in production of 44 to 56 wt % of the dried coal as char, 10 to 13 wt % as liquids, 17 to 28 wt % as gas, and 8 to 21 wt % as fines. The yield of moisture- and ash-free (MAF) liquids varied from 11.4 to 14.2 wt % of the dried coal feed. Chemical analysis was carried out on these products.

  12. Analyzing organic sulfur in coal/char: Integrated mild degradation/XANES methods. Final technical report, September 1, 1993--November 30, 1994

    SciTech Connect

    Palmer, S.R.; Huffman, G.P.

    1994-12-31

    The overall goal of this study is to improve the understanding of sulfur in coals/chars via the use of combined advanced nondestructive and advanced destructive methods of sulfur analysis. This study combines selective oxidation, analytical pyrolysis, and sulfur X-ray Absorption Near Edge Structure Spectroscopy (XANES) analysis. Samples with a wide variety of sulfur contents, (0.63%--4.40%) have been prepared for use in this study. This includes steam gasification chars, oxidized coals and desulfurized coals as well of the original unaltered coals. Mild pyrolysis and XANES data shows that the sulfur chemistry of gasification chars is significantly different from that of the original coals. Mild pyrolysis of the samples that were oxidized with peroxyacetic acid showed that the level of simple thiophene structures observed in the pyrolysis products declines with increasing levels of oxidation. Sulfur XANES spectra of treated samples showed various effects depending on the treatment severity. The XANES spectra of less severely treated samples were similar, although not identical, to the untreated coal spectra. XANES of gasification chars indicated conversion of pyrite to pyrrhotite, removal of organic sulfide sulfur and dissolution of soluble inorganic sulfur species during gasification. Mild oxidation with peroxyacetic acid results in preferential oxidation of sulfide forms before thiophene forms but increasing oxidation severity leads to virtually all sulfur species being oxidized. Good agreement between W-band EPR and XANES data for aromatic sulfur contents were obtained. The TPR analysis of coal indicated that organic sulfur was present as alkyl-aryl sulfide, aryl-aryl sulfides, simple thiophenes and condensed thiophenes. TPR shows that non-thiophenic compounds are removed by PAA oxidation, and that the longer the oxidation is performed the greater is the removal of non-thiophenic sulfur structures.

  13. Development of an advanced continuous mild gasification process for the production of coproducts

    SciTech Connect

    Jha, M.C.; McCormick, R.L.; Hogsett, R.F.; Rowe, R.M.; Anast, K.R.

    1991-12-01

    This document describes the results of Task 4 under which a 50 pound/hour char-to-carbon (CTC) process research unit (PRU) was designed in the second half of 1989, with construction completed in June 1990. The CTC PRU at Golden was operated for nearly one year during which 35 runs were completed for a total of nearly 800 hours of operation. Char methanation and carbon production reactor development activities are detailed in this report, as well as the results of integrated runs of the CTC process. Evaluation of the process and the carbon product produced is also included. It was concluded that carbon could be produced from mild gasification char utilizing the CTC process. Char methanation and membrane separation steps performed reasonably well and can scaled up with confidence. However, the novel directly heated reactor system for methane cracking did not work satisfactorily due to materials of construction and heat transfer problems, which adversely affected the quantity and quality of the carbon product. Alternative reactor designs are recommended.

  14. Scaleup of mild gasification to be a process development. Quarterly report, February 1995--May 1995

    SciTech Connect

    Doane, E.P.; Carty, R.H.; Foster, H.

    1995-06-01

    The work performed during the Fourteenth quarterly reporting period (February 21 through May 20, 1995) on the research program, {open_quotes}Scale-Up of Mild Gasification to a Process Development Unit{close_quotes} is presented in this report. The overall objective of this project is to develop the IGT Mild-Gasification (MILDGAS) process for near-term commercialization. The specific objectives of the program are to: (1) design, construct, and operate a 24-tons/day adiabatic process development unit (PDU) to obtain process performance data suitable for further design scaleup; (2) obtain large batches of coal-derived co-products for industrial evaluation; (3) prepare a detailed design of a demonstration unit; and (4) develop technical and economic plans for commercialization of the MILDGAS process. The project team that is performing the initial phases of the PDU development are: Kerr-McGee Coal Corporation (K-M Coal), the Institute of Gas Technology (IGT), Bechtel Corporation (Bechtel), and Southern Illinois University at Carbondale (SIUC). The MILDGAS process is a continuous closed system for producing liquid and solid (char) co-products at mild operating conditions up to 50 psig and 1300{degrees}F. It is capable of processing a wide range of both eastern caking and western noncaking coals. The 1 ton/hr PDU facility that is to be constructed is comprised of a 2.5-ft ID adiabatic gasifier for the production of gases, coal liquids, and char; a three-stage condensation train to condense and store the liquid products; and coal feeding and char handling equipment. The facility will also incorporate support equipment for environmentally acceptable disposal of process waste. This quarter, the formal HAZOP review was completed and a report detailing action items for resolution by the parties responsible was prepared.

  15. Development of an advanced continuous mild gasification process for the production of coproducts: Task 4. 6, Technical and economic evaluation

    SciTech Connect

    Hogsett, R.F.; Jha, M.C.

    1991-12-01

    Morgantown Energy Technology Center (METC) of DOE has sponsored, and continues to sponsor, programs for the development of technology and market strategies which will lead to the commercialization of processes for the production of coproducts from mild gasification of coal. It has been recognized by DOE and industry that mild gasification is a promising technology with potential to economically convert coal into marketable products, thereby increasing domestic coal utilization. In this process, coal is devolatilized under non- oxidizing conditions at mild temperature (900--1100{degrees}F) and pressure (1--15psig). Condensation of the vapor will yield a liquid product that can be upgraded to a petroleum substitute, and the remaining gas can provide the fuel for the process. The residual char can be burned in a power plant. Thus, in a long-term national scenario, implementation of this process will result in significant decrease of imported oil and increase in coal utilization.

  16. Determination of the intrinsic reactivities for carbon dioxide gasification of rice husk chars through using random pore model.

    PubMed

    Gao, Xiaoyan; Zhang, Yaning; Li, Bingxi; Zhao, Yijun; Jiang, Baocheng

    2016-10-01

    Rice husk is abundantly available and environmentally friendly, and char-CO2 gasification is of great importance for the biomass gasification process. The intrinsic reaction rates of carbon dioxide gasification with rice husk chars derived from different pyrolysis temperatures were investigated in this study by conducting thermogravimetric analysis (TGA) measurements. The effects of gasification temperature and reactant partial pressure on the char-CO2 gasification were investigated and the random pore model (RPM) was used to determine the intrinsic kinetic parameters based on the experimental data. The results obtained from this study show that the activation energy, reaction order and pre-exponential factor varied in the ranges of 226.65-232.28kJ/mol, 0.288-0.346 and 2.38×10(5)-2.82×10(5)1/sPa(n) for the rice husk chars pyrolyzed at 700-900°C, respectively. All the determination coefficients between the RPM predictions and experimental results were higher than 0.906, indicating the RPM is reliable for determining and evaluating the intrinsic reactivities of rice husk chars. PMID:27459684

  17. Behavior of chars from Bursa Mustafa Kemal Pasa Alpagut and Balkesir Dursunbey Cakiirca Lignite (Turkey) during non-catalytic and catalytic gasification

    SciTech Connect

    Bozkurt, Y.; Misirlioglu, Z.; Sinag, A.; Tekes, A.T.; Canel, M.

    2008-07-01

    The reactivities of chars obtained by pyrolysis of Bursa Mustafa Kemal Pasa Alpagut lignite and Balkesir Dursunbey Cakiirca lignite (Turkey) at different temperatures were determined by CO{sub 2} gasification and by combustion with O{sub 2}. Catalytic effect of Na{sub 2}CO{sub 3} on the CO{sub 2} and O{sub 2} gasification reactivity of chars was investigated. Gasification tests were performed in the fixed bed reactors operating at ambient pressure. Reactivity of chars during the CO{sub 2} gasification reactions was determined by calculating the reaction rate constants and reactivity of chars during the O{sub 2} gasification was determined by using ignition temperatures of the samples. Activation energies and Arrhenius constants of the chars on the CO{sub 2} gasification reactions were also calculated by the help of Arrhenius curves. The activation energy for CO{sub 2} gasification was generally decreased with pyrolysis temperature, due to the different surface characteristics and different nature of carbon atoms gasified as the gasification reactions proceed. Generally, the increase in pyrolysis temperature leads to an increase in gasification reactivity with CO{sub 2}. The reactivity of chars in catalytic gasification was higher than the corresponding non-catalytic reactivity of the same chars. Ignition temperature increased with increasing pyrolysis temperature.

  18. Kinetic modelling of steam gasification of various woody biomass chars: influence of inorganic elements.

    PubMed

    Dupont, Capucine; Nocquet, Timothée; Da Costa, José Augusto; Verne-Tournon, Christèle

    2011-10-01

    A study was performed on the influence of wood variability on char steam gasification kinetics. Isothermal experiments were carried out in a thermobalance in chemical regime on various wood chars produced under the same conditions. The samples exhibited large differences of average reaction rate. These differences were linked neither with the biomass species nor age and may be related to the biomass inorganic elements. A modelling approach was developed to give a quantitative insight to these observations. The grain model was used on one biomass of reference for temperatures between 750 and 900 °C and steam partial pressures between 0 and 0.27 bar. The model was applied to the other samples through the addition of an integral parameter specific to each sample. A satisfactory correlation was found between this parameter and the ratio potassium/silicium. This result highlighted the catalytic effect of potassium and inhibitor effect of silicium on the reaction. PMID:21862327

  19. Reduction of iron oxide as an oxygen carrier by coal pyrolysis and steam char gasification intermediate products

    SciTech Connect

    Jing-biao Yang; Ning-sheng Cai; Zhen-shan Li

    2007-12-15

    The feasibility of the reduction of oxygen carrier Fe{sub 2}O{sub 3} in chemical-looping combustion using solid fuel (lignite) provided a gasifying agent like steam was introduced into the reactor was investigated with a fixed-bed reactor. The X-ray diffractometer and scanning electron microscope were used for the characterization of the Fe{sub 2}O{sub 3} and its reduction residue. Results strongly supported the feasibility of Fe{sub 2}O{sub 3} reduction by lignite and obtaining pure CO{sub 2} from the off-gases. Fe{sub 2}O{sub 3} can be fully converted to Fe{sub 3}O{sub 4} by pyrolysis and gasification intermediates primarily H{sub 2} and CO, which was confirmed by both the off-gas concentrations and X-ray diffractometer analysis. A 0.75 g portion of Fe{sub 2}O{sub 3} can be completely reduced to Fe{sub 3}O{sub 4} by the volatile matter released from 0.1 g coal, and Fe{sub 2}O{sub 3} can be fully reduced to Fe{sub 3}O{sub 4} by steam char gasification products provided that the molar ratio of carbon in char to Fe{sub 2}O{sub 3} is 1:6. The purity of CO{sub 2} in the outlet gases was higher than 85% when Fe{sub 2}O{sub 3} was reduced by intermediate products during coal pyrolysis, and the purity of CO{sub 2} in the off-gases was higher than 95% when Fe{sub 2}O{sub 3} was reduced by intermediate products resulting from steam char gasification, making CO{sub 2} sequestration disposal desirable for high purity CO{sub 2}. The char gasification reaction rate was slow compared with the reactivity of the iron oxide with the char gasified intermediates, indicating that char gasification was the rate-limiting step in the reduction process. In the steam char gasification process, the times it took to reach 90% carbon conversion for K-10-char and Ca-10-char were 15 and 30 min, respectively, at 1123 K, but the time for the raw char was 50 min at 1173 K. 40 refs., 15 figs., 3 tabs.

  20. Separation of products from mild coal gasification processes

    SciTech Connect

    Wallman, P.H.

    1991-09-11

    The primary mild coal gasification product mixture containing noncondensible gas, high-boiling hydrocarbon vapors and entrained fines is difficult to process into the desired pure products: gas, liquids, and dry solids. This challenge for mild coal gasification process development has been studied by surveying the technical literature for suitable separations processes and for similar issues in related processes. The choice for a first-stage solids separation step is standard cyclones, arranged in parallel trains for large-volume applications in order to take advantage of the higher separation efficiency of smaller cyclones. However, mild gasification pilot-plant data show entrainment of ultrafine particles for which standard cyclones have poor separation efficiency. A hot secondary solids separation step is needed for the ultrafine entrainment in order to protect the liquid product from excessive amounts of contaminating solids. The secondary solids separation step is similar to many high-temperature flue-gas applications with an important complicating condition: Mild gasifier vapors form coke on surfaces in contact with the vapors. Plugging of the filter medium by coke deposition is concluded to be the main product separation problem for mild gasification. Three approaches to solution of this problem are discussed in the order of preference: (1) a barrier filter medium made of a perforated foil that is easy to regenerate, (2) a high-efficiency cyclone coupled with recycle of a solids-containing tar fraction for coking/cracking in the gasifier, and (3) a granular moving bed filter with regeneration of the bed material. The condensation of oil vapors diluted by noncondensible gas is analyzed thermodynamically, and the conclusion is that existing commercial oil fractionator designs are adequate as long as the vapor stream does not contain excessive amounts of solids. 34 refs., 4 figs.

  1. The concept of reactive surface area applied to uncatalyzed and catalyzed carbon (char) gasification in carbon dioxide and oxygen

    SciTech Connect

    Lizzio, A.A.

    1990-01-01

    The virtues of, and/or problems with, utilizing the concepts of total and active surface area to explain the reactivity profiles were evaluated and discussed. An alternative approach, involving the concept of reactive surface area (RSA), was introduced and results based on the direct measurement of RSA were presented. Here, reactive surface area is defined as the concentration of carbon atoms on which the carbon-oxygen C(O) surface intermediate forms and subsequently decomposes to give gaseous products. The transient kinetics (TK) approach gave a direct measurement of RSA for chars gasified in CO{sub 2} and O{sub 2}. A temperature-programmed desorption technique was also used to determine the amount of reactive surface intermediate formed on these chars during gasification. A comparison of turnover frequencies for different chars gasified in 1 atm CO{sub 2} suggested that char gasification mat be a structure sensitive reaction. The concept of RSA was also used to achieve a better quantitative understanding of catalyzed char reactivity variations with conversion in CO{sub 2}. For a calcium-exchanged lignite char gasified in 1 atm CO{sub 2}, a poor correlation was found between RSA and reactivity, suggesting that in addition to the direct decomposition of the reactive C(O) intermediate, other processes, e.g., oxygen spillover, contributed to the transient evolution of CO. An extensive study of Saran char loaded with calcium, potassium or nickel by impregnation to incipient wetness (IW) or ion exchange (IE) was undertaken. An excellent correlation was found between reactivity and RSA variations with conversion for both IW and IE K-catalyzed chars, suggesting that TK indeed titrates the reactive K-O-C complexes formed during gasification in CO{sub 2}.

  2. Supercritical water gasification of Eucalyptus grandis and related pyrolysis char: Effect of feedstock composition.

    PubMed

    Louw, Jeanne; Schwarz, Cara E; Burger, Andries J

    2016-09-01

    Eucalyptus grandis (E. grandis) wood and char products derived from pyrolysis of E. grandis wood, were gasified in supercritical water at 450°C - with and without the use of a homogeneous (K2CO3) and heterogeneous (Ni/Al2O3-SiO2) catalyst. Gas yields and gasification efficiencies were measured experimentally and compared to calculated thermodynamic equilibrium values, specifically considering the effects of the O/C ratio and volatile matter content of the feed material. Thermodynamically, feed material with lower O/C ratios (0.22) typically resulted in higher CH4 yields (30mol/kgfeed,dry) and gasification efficiencies (188%). However, experimentally, feed material with lower O/C ratios and lower volatile matter resulted in the lowest CH4 yields and gasification efficiencies. Furthermore, a linear relationship between the carbon efficiency (CE) and both the volatile matter content and O/C ratio of the feed material was found to hold true in both catalytic and non-catalytic experiments. PMID:27343456

  3. Scale-up of mild gasification to a process development unit. Progress report, February 21, 1992--May 20, 1992

    SciTech Connect

    Campbell, J.A.L.; Carty, R.H.; Saladin, N.; Foster, H.

    1992-06-01

    The work performed during the second quarterly reporting period (February 21 through May 20, 1992) on the research program, ``Scale-Up of Mild Gasification to a Process Development Unit`` is presented in this report. The overall objective of this project is to develop the IGT Mild-Gasification (MILDGAS) process for near-term commercialization. The specific objectives of the program are to: (1) design, construct, and operate a 24-tons/day adiabatic process development unit (PDU) to obtain process performance data suitable for further design scaleup. (2) obtain large batches of coal-derived co-products for industrial evaluation. (3) prepare a detailed design of a demonstration unit. (4) develop technical and economic plans for commercialization of the MILDGAS process. The MILDGAS process is a continuous closed system for producing liquid and solid (char) co-products at mild operating conditions up to 50 psig and 1300{degrees}F. It is capable of processing a wide range of both eastern caking and western noncaking coals. The PDU to be constructed is comprised of a 2.5-ft ID adiabatic gasifier for the production of char, coal liquids, and gases; a thermal cracker for upgrading of the coal liquids; and a hot briquetting unit for the production of form coke and smokeless fuel briquettes. The facility will also incorporate support equipment for environmentally acceptable disposal of process waste.

  4. The fate of sulfur in mild gasification liquids

    SciTech Connect

    Knight, R.A.; Koncar, G.J.; Babu, S.P.

    1991-01-01

    This investigation addresses the determination of sulfur distribution in mild gasification liquids produced from untreated coal and from modified in two ways to reduce sulfur in the products: (a) physical mixing with a sulfur scavenger (CaO), and (b) pretreatment with aqueous alkali followed by mixing with CaO. Coal pyrolysis in the presence of CaO has previously been investigated, (3,5) showing that CaO can be effective in reducing the sulfur content of the fuel gas, and possibly that of the product liquids. Pretreatment of coals with alkaline chemicals has also been studied,(6,7) showing reduced sulfur and other changes in the liquid products.(8) Data on sulfur distribution in the liquid products could be useful for understanding the chemistry of alkali pretreatment and CaO interaction with coal sulfur during pyrolysis. In this work, a pyrolysis-gas chromatography (Py-GC) technique that simulates mild gasification on a milligram scale was used in conjunction with a carbon-specific flame ionization detector (FID) and a sulfur-specific flame photometric detector (FPD) to determine the sulfur distribution in oils/tars from Illinois No. 6 coal. A low-resolution packed GC column was employed to resolve oils/tars by carbon number, with ranges selected to approximate distillation fractions which might be recovered from a commercial mild gasification process. Oils/tars up to C{sub 18} were also collected from the pyro-probe effluent into dichloromethane for off-line study using a high-resolution GC with atomic emission detector (GC/AED) and with GC-mass spectrometry (GC/MS) to measure specific sulfur compounds. 9 refs., 1 tab.

  5. Kinetic models comparison for steam gasification of coal/biomass blend chars.

    PubMed

    Xu, Chaofen; Hu, Song; Xiang, Jun; Yang, Haiping; Sun, Lushi; Su, Sheng; Wang, Baowen; Chen, Qindong; He, Limo

    2014-11-01

    The non-isothermal thermogravimetric method (TGA) was applied to different chars produced from lignite (LN), sawdust (SD) and their blends at the different mass ratios in order to investigate their thermal reactivity under steam atmosphere. Through TGA analysis, it was determined that the most prominent interaction between sawdust and lignite occurred at the mass ratio of sawdust/lignite as 1:4, but with further dose of more sawdust into its blends with lignite, the positive interaction deteriorated due to the agglomeration and deactivation of the alkali mineral involved in sawdust at high steam gasification temperature. Through systematic comparison, it could be observed that the random pore model was the most suitable among the three gas-solid reaction models adopted in this research. Finally, rational kinetic parameters were reached from these gas-solid reaction models, which provided a basis for design and operation of the realistic system of co-gasification of lignite and sawdust in this research. PMID:25203234

  6. Development of an advanced continuous mild gasification process for the production of co-products. Final report, September 1987--September 1996

    SciTech Connect

    1996-12-31

    Char, the major co-product of mild coal gasification, represents about 70 percent of the total product yield. The only viable use for the char is in the production of formed coke. Early work to develop formed coke used char from a pilot plant sized mild gasification unit (MGU), which was based on commercial units of the COALITE plant in England. Formed coke was made at a bench-scale production level using MGU chars from different coals. An evolutionary formed coke development process over a two-year period resulted in formed coke production at bench-scale levels that met metallurgical industries` specifications. In an ASTM D5341 reactivity test by a certified lab, the coke tested CRI 30.4 and CSR 67.0 which is excellent. The standard is CRI < 32 and CSR > 55. In 1991, a continuous 1000 pounds per hour coal feed mild coal gasification pilot plant (CMGU) was completed. The gasification unit is a heated unique screw conveyor designed to continuously process plastic coal, vent volatiles generated by pyrolysis of coal, and convert the plastic coal to free flowing char. The screw reactor auxiliary components are basic solids materials handling equipment. The screw reactor will convert coal to char and volatile co-products at a rate greater than 1000 pounds per hour of coal feed. Formed coke from CMGU char is comparable to that from the MGU char. In pilot-plant test runs, up to 20 tons of foundry coke were produced. Three formed coke tests at commercial foundries were successful. In all of the cupola tests, the iron temperature and composition data indicated that the formed coke performed satisfactorily. No negative change in the way the cupola performed was noticed. The last 20-ton test was 100 percent CTC/DOE coke. With conventional coke in this cupola charging rates were 10 charges per hour. The formed coke charges were 11 to 12 charges per hour. This equates to a higher melt rate. A 10 percent increase in cupola production would be a major advantage. 13 figs., 13 tabs.

  7. Scale-up of mild gasification to a process development unit. Progress report, November 21, 1992--February 20, 1993

    SciTech Connect

    Campbell, J.A.L.; Carty, R.H.; Saladin, N.; Foster, H.

    1993-03-01

    The overall objective of this project is to develop the IGT Mild-Gasification (MILDGAS) process for near-term commercialization. The specific objectives of the program are to: design, construct, and operate a 24-tons/day adiabatic process development unit (PDU) to obtain process performance data suitable for further design scaleup obtain large batches of coal-derived co-products for industrial evaluation prepare a detailed design of a demonstration unit develop technical and economic plans for commercialization of the MILDGAS process. The MILDGAS process is a continuous closed system for producing liquid and solid (char) co-products at mild operating conditions up to 50 psig and 1300{degree}F. It is capable of processing a wide range of both eastern caking and western noncaking coals. The 1 ton/hr PDU facility that is to be constructed is comprised of a 2.5-ft ID adiabatic gasifier for the production of gases, coal liquids, and char; a thermal cracker for upgrading of the coal liquids; a three-stage condensation train to condense and store the liquid products; and coal feeding and char handling equipment. The facility will also incorporate support equipment for environmentally acceptable disposal of process waste.

  8. Biodesulfurization of mild gasification liquid products. Technical report, December 1, 1992--February 28, 1993

    SciTech Connect

    Kilbanes, J.J. II; Ho, K.

    1993-05-01

    The mild gasification of coal, as being developed at IGT and elsewhere, is a promising new technology that can convert coal to multiple products: gas, solid, and liquids. Mild gasification liquids can be used as feedstock to make transportation fuels and chemicals. However, the sulfur content and aromaticity of mild gasification liquids limits their usefulness and biodesulfurization can potentially decrease both sulfur content and aromaticity. The objective of this project is to investigate the feasibility of using biodesulfurization to upgrade the quality of mild gasification liquids. During the current quarter a laboratory-scale mild gasification reactor was used to produce additional liquid derived from IBC-105 coal. The liquid has an organic sulfur content of 2.88%. The biocatalyst is apparently inhibited by chemical constituents in the light oil fraction of mild coal gasification liquids, but functions quite well in other liquid fractions or in unfractionated mild coal gasification liquid. Even when excess biocatalyst is used, approximately 12% of the organosulfur compounds appear to be recalcitrant to biodesulfurization. Biodesulfurization tests utilizing membrane fragments purified from IGTS8 and freeze-dried IGTS8 cell preparations added directly to mild coal gasification liquids have been performed. The processing and analysis of those samples is currently under way.

  9. Biodesulfurization of mild gasification liquid products. Final technical report, 1 September, 1992--31 August, 1993

    SciTech Connect

    Kilbane, J.J. II

    1993-12-31

    The mild gasification of coal, as being developed at IGT and elsewhere, is a promising new technology that can convert coal to multiple products: gas, solid, and liquids. Mild gasification liquids can be used as feedstock to make transportation fuels and chemicals. However, the sulfur content and aromaticity of mild gasification liquids limits their usefulness and biodesulfurization can potentially decrease both sulfur content and aromaticity. The objective of this project is to investigate and feasibility of using biodesulfurization to upgrade the quality of mild gasification liquids. During this project, it was shown that the middle distillate (360--440 F) fraction of liquids derived from the mild gasification of coal, and unfractionated liquids can be biodesulfurized. Moreover, it was demonstrated that lysed cell preparations and freeze-dried cells can be used to biodesulfurize mild coal gasification liquids. The importance of the finding that freeze-dried biocatalysts can be used to biodesulfurize mild coal gasification liquids is that freeze-dried cells can be produced at one location, stored indefinitely, and then shipped (at reduced weight, volume, and cost) to another location for coal biodesulfurization. Moreover, freeze-dried biocatalysts can be added directly to mild coal gasification liquids with only minimal additions of water so that reactor volumes can be minimized.

  10. Steam Gasification Rates of Three Bituminous Coal Chars in an Entrained-Flow Reactor at Pressurized Conditions

    SciTech Connect

    Lewis, Aaron D.; Holland, Troy M.; Marchant, Nathaniel R.; Fletcher, Emmett G.; Henley, Daniel J.; Fuller, Eric G.; Fletcher, Thomas H.

    2015-02-26

    Three bituminous coal chars (Illinois #6, Utah Skyline, and Pittsburgh #8) were gasified separately at total pressures of 10 and 15 atm in an entrained-flow reactor using gas temperatures up to 1830 K and particle residence times <240 ms. The experiments were performed at conditions where the majority of particle mass release was due to H2O gasification, although select experiments were performed at conditions where significant mass release was due to gasification by both H2O and CO2. The measured coal data we recorded were fit to three char gasification models including a simple first-order global model, as well as the CCKNand CCK models that stem from the CBK model. The optimal kinetic parameters for each of the three models are reported, and the steam reactivity of the coal chars at the studied conditions is as follows: Pittsburgh #8 > Utah Skyline > Illinois #6.

  11. Development of an advanced continuous mild gasification process for the production of coproducts: Task 4.6, Technical and economic evaluation

    SciTech Connect

    Hogsett, R.F.; Jha, M.C.

    1991-12-01

    Morgantown Energy Technology Center (METC) of DOE has sponsored, and continues to sponsor, programs for the development of technology and market strategies which will lead to the commercialization of processes for the production of coproducts from mild gasification of coal. It has been recognized by DOE and industry that mild gasification is a promising technology with potential to economically convert coal into marketable products, thereby increasing domestic coal utilization. In this process, coal is devolatilized under non- oxidizing conditions at mild temperature (900--1100{degrees}F) and pressure (1--15psig). Condensation of the vapor will yield a liquid product that can be upgraded to a petroleum substitute, and the remaining gas can provide the fuel for the process. The residual char can be burned in a power plant. Thus, in a long-term national scenario, implementation of this process will result in significant decrease of imported oil and increase in coal utilization.

  12. The ENCOAL Mild Coal Gasification Project, A DOE Assessment

    SciTech Connect

    National Energy Technology Laboratory

    2002-03-15

    This report is a post-project assessment of the ENCOAL{reg_sign} Mild Coal Gasification Project, which was selected under Round III of the U.S. Department of Energy (DOE) Clean Coal Technology (CCT) Demonstration Program. The CCT Demonstration Program is a government and industry cofunded technology development effort to demonstrate a new generation of innovative coal utilization processes in a series of commercial-scale facilities. The ENCOAL{reg_sign} Corporation, a wholly-owned subsidiary of Bluegrass Coal Development Company (formerly SMC Mining Company), which is a subsidiary of Ziegler Coal Holding Company, submitted an application to the DOE in August 1989, soliciting joint funding of the project in the third round of the CCT Program. The project was selected by DOE in December 1989, and the Cooperative Agreement (CA) was approved in September 1990. Construction, commissioning, and start-up of the ENCOAL{reg_sign} mild coal gasification facility was completed in June 1992. In October 1994, ENCOAL{reg_sign} was granted a two-year extension of the CA with the DOE, that carried through to September 17, 1996. ENCOAL{reg_sign} was then granted a six-month, no-cost extension through March 17, 1997. Overall, DOE provided 50 percent of the total project cost of $90,664,000. ENCOAL{reg_sign} operated the 1,000-ton-per-day mild gasification demonstration plant at Triton Coal Company's Buckskin Mine near Gillette, Wyoming, for over four years. The process, using Liquids From Coal (LFC{trademark}) technology originally developed by SMC Mining Company and SGI International, utilizes low-sulfur Powder River Basin (PRB) coal to produce two new fuels, Process-Derived Fuel (PDF{trademark}) and Coal-Derived Liquids (CDL{trademark}). The products, as alternative fuel sources, are capable of significantly lowering current sulfur emissions at industrial and utility boiler sites throughout the nation thus reducing pollutants causing acid rain. In support of this overall objective

  13. Scale-up of mild gasification to a process development unit. Progress report, November 21, 1994--February 20, 1995

    SciTech Connect

    Doane, E.P.; Carty, R.H.; Foster, H.

    1995-03-01

    The overall objective of this project is to develop the IGT Mild-Gasification (MILDGAS) process for near-term commercialization. The specific objectives of the program are to: design, construct, and operate a 24-tons/day adiabatic process development unit (PDU) to obtain process performance data suitable for further design scaleup; obtain large batches of coal-derived co-products for industrial evaluation; prepare a detailed design of a demonstration unit; develop technical and economic plans for commercialization of the MILDGAS process. The project team that is performing the initial phases of the PDU development are: Kerr-McGee Coal Corporation (K-M Coal), the Institute of Gas Technology (IGT), Bechtel Corporation (Bechtel), and Southern Illinois University at Carbondale (SIUC). The MILDGAS process is a continuous closed system for producing liquid and solid (char) co-products at mild operating conditions up to 50 psig and 1300{degrees}F. It is capable of processing a wide range of both eastern caking and western noncaking coals. The 1 ton/hr PDU facility that is to be constructed is comprised of a 2.5-ft ID adiabatic gasifier for the production of gases, coal liquids, and char; a three-stage condensation train to condense and store the liquid products; and coal feeding and char handling equipment. The facility will also incorporate support equipment for environmentally acceptable disposal of process waste. This quarter, Roberts and Schaefer (R&S) of Salt Lake City, Utah was awarded the contract to perform the detailed design for the gasification, liquids recovery and overall plant design coordination. They began work in December of 1994 and a meeting was held between R&S, Bechtel, and IGT to discuss control methods, detailed equipment design, the heavy liquids filter, and possible modifications to the first and second stage cyclones.

  14. Analysis of Hydrogen Generation through Thermochemical Gasification of Coconut Shell Using Thermodynamic Equilibrium Model Considering Char and Tar

    PubMed Central

    Rupesh, Shanmughom; Muraleedharan, Chandrasekharan; Arun, Palatel

    2014-01-01

    This work investigates the potential of coconut shell for air-steam gasification using thermodynamic equilibrium model. A thermodynamic equilibrium model considering tar and realistic char conversion was developed using MATLAB software to predict the product gas composition. After comparing it with experimental results the prediction capability of the model is enhanced by multiplying equilibrium constants with suitable coefficients. The modified model is used to study the effect of key process parameters like temperature, steam to biomass ratio, and equivalence ratio on product gas yield, composition, and heating value of syngas along with gasification efficiency. For a steam to biomass ratio of unity, the maximum mole fraction of hydrogen in the product gas is found to be 36.14% with a lower heating value of 7.49 MJ/Nm3 at a gasification temperature of 1500 K and equivalence ratio of 0.15. PMID:27433487

  15. Encoal mild coal gasification project: Final design modifications report

    SciTech Connect

    1997-07-01

    The design, construction and operation Phases of the Encoal Mild Coal Gasification Project have been completed. The plant, designed to process 1,000 ton/day of subbituminous Power River Basin (PRB) low-sulfur coal feed and to produce two environmentally friendly products, a solid fuel and a liquid fuel, has been operational for nearly five years. The solid product, Process Derived Fuel (PDF), is a stable, low-sulfur, high-Btu fuel similar in composition and handling properties to bituminous coal. The liquid product, Coal Derived Liquid (CDL), is a heavy, low-sulfur, liquid fuel similar in properties to heavy industrial fuel oil. Opportunities for upgrading the CDL to higher value chemicals and fuels have been identified. Significant quantities of both PDF and CDL have been delivered and successfully burned in utility and industrial boilers. A summary of the Project is given.

  16. Encoal mild coal gasification project: Commercial plant feasibility study

    SciTech Connect

    1997-07-01

    In order to determine the viability of any Liquids from Coal (LFC) commercial venture, TEK-KOL and its partner, Mitsubishi Heavy Industries (MHI), have put together a technical and economic feasibility study for a commercial-size LFC Plant located at Zeigler Coal Holding Company`s North Rochelle Mine site. This resulting document, the ENCOAL Mild Coal Gasification Plant: Commercial Plant Feasibility Study, includes basic plant design, capital estimates, market assessment for coproducts, operating cost assessments, and overall financial evaluation for a generic Powder River Basin based plant. This document and format closely resembles a typical Phase II study as assembled by the TEK-KOL Partnership to evaluate potential sites for LFC commercial facilities around the world.

  17. Leaching of major and trace elements from paper-plastic gasification chars: an experimental and modelling study.

    PubMed

    Fuente-Cuesta, A; Lopez-Anton, M A; Diaz-Somoano, M; Zomeren, A van; Cieplik, M; Martínez-Tarazona, M R

    2013-01-15

    The control of soluble metal species in the sub-product leachate generated in electricity production processes is of great concern from an environmental and health point of view. Unlike fly ash, the leaching behaviour of char materials has received little attention. Yet, these solids are captured together with fly ashes in the particle control devices of power plants and are emitted in the same way as by-products. The present study was carried out using two char samples: (i) a raw char and (ii) the same type of char employed in a previous study so that it could serve as a sorbent for mercury species in gas phase. The char samples were by-products (residues) that had been generated during the gasification of plastic and paper waste. The leachates were analyzed for the following elements: Al, Ca, Si, Mg, Ba, Cu, Ni, Pb, Zn, Mo and Hg. In addition, geochemical modelling of the leaching test results was employed to identify the underlying chemical processes that led to the release of toxic elements. The results showed that at alkaline pH values, sorption on the solid surfaces of the char was negligible due to the inorganic complexation of cations in the solution. When the char was used as mercury sorbent slight changes occurred on the reactive surface resulting in the modification of the binding of some elements. As the pH increased, complexation with dissolved organic matter played a more important role in the case of some elements such as Cu because of the greater concentration of dissolved organic matter in solution. PMID:23246942

  18. Biodesulfurization of mild gasification liquid products. [Quarterly] technical report, March 1, 1993--May 31, 1993

    SciTech Connect

    Kilbane, J.J. II

    1993-09-01

    The mild gasification of coal is a promising new technology that can convert coal to multiple products: gas, solid, and liquids. However, the sulfur content and aromaticity of mild gasification liquids limits their usefulness. Biodesulfurization can potentially decrease both sulfur content and aromaticity. The objective of this project is to investigate the feasibility of using biodesulfurization to upgrade the quality of mild gasification liquids. Previously it was shown that the middle distillate (360--440{degrees}F) fraction of liquids derived from the mild gasification of coal could be biodesulfurized. During this quarter it was demonstrated that unfractionated liquids can be biodesulfurized. Moreover, it was demonstrated that lysed cell preparations and freeze-dried cells can be used to biodesulfurize mild coal gasification liquids. The importance of the finding that freeze-dried biocatalysts can be used to biodesulfurize mild coal gasification liquids is that freezedried cells can be produced at one location, stored indefinitely, and then shipped to another location for coal biodesulfurization. Moreover, freeze-dried biocatalysts can be added directly to mild coal gasification liquids with only minimal additions of water so that reactor volumes can be minimized.

  19. Mild temperature gasification: Partitioning sulfur to gas as H{sub 2}S. Technical report, December 1, 1992--February 28, 1993

    SciTech Connect

    Stencel, J.M.; Neathery, J.K.; Schaefer, J.L.; Yang, J.; Banerjee, D.

    1993-05-01

    Bench-scale, mild-temperature fluidized bed gasification (MTFBG) of three high sulfur Illinois basin coals (IBC) mixed with phosphoric acid will be performed to initiate development of an advanced processing technology which partitions coal sulfur to the gas phase as H{sub 2}S. The influence of coal type, coal agglomeration, and steam injection on the properties of the solid, condensible and gaseous products produced during MTFBG will be examined. Analytical measurements of the products will be obtained and are designed to provide product quality and quantity. Combustion reactivity testing of the char, and pressurized, hot water extraction of H{sub 3}PO{sub 4} from the char, will be performed to provide information for design of a continuous and integrated process for the removal and recovery of coal sulfur. During this quarter, the acquisition and construction of equipment to be used for MTFBG of Illinois coals and hot water, pressurized filtration of chars were completed. IBC 106 was subjected to fluidized bed gasification testing under nitrogen and steam/nitrogen atmospheres. The percentage of total sulfur removed from the parent coal using physical cleaning followed by MTFBG of coal/phosphoric acid mixtures was as high as 94% at a gasification temperature of 500{degrees}C.

  20. Development of advanced, continuous mild gasification process for the production of co-products

    SciTech Connect

    Ness, R.O. Jr.; Aulich, T.R.

    1991-05-01

    The current objective of the University of North Dakota Energy and Environmental Research Center (EERC) mild gasification project is to optimize reaction char and marketable liquids production on a 100-lb/hr scale using Wyodak subbituminous and Indiana No. 3 bituminous coals. Tests performed using the EERC 100-lb/hr process development unit (PDU) include a refractory-cure (Test P001), a test using petroleum coke (Test P002), and tests using Wyodak and Indiana coals. The reactor system used for the 11 PDU tests conducted to date consists of a spouted, fluid-bed carbonizer equipped with an on-line condensation train that yields three boiling point fractions of coal liquids ranging in volatility from about (77{degrees}--750{degrees}F) (25{degrees}--400{degrees}C). The September--December 1990 quarterly report described reaction conditions and the bulk of the analytical results for Tests P010 and P011. This report describes further P010 and P011 analytical work, including the generation of simulated distillation curves for liquid samples on the basis of sulfur content, using gas chromatography coupled with atomic emission detection (GC/AED) analysis. 13 figs., 3 tabs.

  1. Structural characteristics and gasification reactivity of chars prepared from K{sub 2}CO{sub 3} mixed HyperCoals and coals

    SciTech Connect

    Atul Sharma; Hiroyuki Kawashima; Ikuo Saito; Toshimasa Takanohashi

    2009-04-15

    HyperCoal is a clean coal with mineral matter content <0.05 wt %. Oaky Creek (C = 82%), and Pasir (C = 68%) coals were subjected to solvent extraction method to prepare Oaky Creek HyperCoal, and Pasir HyperCoal. Experiments were carried out to compare the gasification reactivity of HyperCoals and parent raw coals with 20, 40, 50 and 60% K{sub 2}CO{sub 3} as a catalyst at 600, 650, 700, and 775{sup o}C with steam. Gasification rates of coals and HyperCoals were strongly influenced by the temperature and catalyst loading. Catalytic steam gasification of HyperCoal chars was found to be chemical reaction controlled in the 600-700{sup o}C temperature range for all catalyst loadings. Gasification rates of HyperCoal chars were found to be always higher than parent coals at any given temperature for all catalyst loadings. However, X-ray diffraction results showed that the microstructures of chars prepared from coals and HyperCoals were similar. Results from nuclear magnetic resonance spectroscopy show no significant difference between the chemical compositions of the chars. Significant differences were observed from scanning electron microscopy images, which showed that the chars from HyperCoals had coral-reef like structures whereas dense chars were observed for coals. 26 refs., 8 figs., 2 tabs.

  2. Chars from gasification of coal and pine activated with K2CO3: acetaminophen and caffeine adsorption from aqueous solutions.

    PubMed

    Galhetas, Margarida; Mestre, Ana S; Pinto, Moisés L; Gulyurtlu, Ibrahim; Lopes, Helena; Carvalho, Ana P

    2014-11-01

    The high carbon contents and low toxicity levels of chars from coal and pine gasification provide an incentive to consider their use as precursors of porous carbons obtained by chemical activation with K2CO3. Given the chars characteristics, previous demineralization and thermal treatments were made, but no improvement on the solids properties was observed. The highest porosity development was obtained with the biomass derived char (Pi). This char sample produced porous materials with preparation yields near 50% along with high porosity development (ABET≈1500m(2)g(-1)). For calcinations at 800°C, the control of the experimental conditions allowed the preparation of samples with a micropore system formed almost exclusively by larger micropores. A mesopore network was developed only for samples calcined at 900°C. Kinetic and equilibrium acetaminophen and caffeine adsorption data, showed that the processes obey to a pseudo-second order kinetic equation and to the Langmuir model, respectively. The results of sample Pi/1:3/800/2 outperformed those of the commercial carbons. Acetaminophen adsorption process was ruled by the micropore size distribution of the carbons. The caffeine monolayer capacities suggest a very efficient packing of this molecule in samples presenting monomodal micropore size distribution. The surface chemistry seems to be the determinant factor that controls the affinity of caffeine towards the carbons. PMID:25112917

  3. Mild temperature gasification: Partitioning sulfur to gas as H{sub 2}S. Interim final technical report, 1 September, 1992--31 August, 1993

    SciTech Connect

    Stencel, J.M.; Neathery, J.K.; Schaefer, J.L.; Yang, Jidong

    1993-12-31

    Bench-scale, mild-temperature fluidized bed gasification (MTFBG) was performed on three high sulfur Illinois basin coals after mixing with phosphoric acid. The research initiated development of an advanced processing technology which partitions coal sulfur to the gas phase as H{sub 2}S. The MTFBG experiments were performed on Illinois coals IBC-101, IBC-106 and IBC-110. Product yields were between 60--85% char, 0.4--1.3% tar and 15--43% gases. Gas yields were sensitive to the coal/acid mixing ratios and the residence time of the coal within the gasifier. Tar and gas yields were significantly lower for coal/acid feeds than for coal-only feeds. At 500 C, the sulfur removal was as high as 82% for IBC-106; sulfur emissions during combustion of this char would be 1.10 lbs SO{sub 2}/MMBtu. Emissions levels from the IBC-110 char would be 1.15 lbs SO{sub 2}/MMBtu whereas it would be 2.15 lb SO{sub 2}/MMBtu from the IBC-101 char. In comparison, the emission levels from chars produced during gasification of coal using no acid would be 4.35 (IBC-110) and 4.81 (IBC-101), whereas the emission levels of the parent coals would be between 5--6 lb SO{sub 2}/MMBtu. Gas product analysis confirmed that the coal sulfur was removed as H{sub 2}S. Pressurized hot-water filtration of the chars removed nearly 80% of the phosphorus. Its removal rate should be near 95% to restrain the reagent cost to less than $25/Ton of SO{sub 2}.

  4. Mild temperature gasification: Partitioning sulfur to gas as H{sub 2}S. Final technical report, September 1, 1992--November 30, 1993

    SciTech Connect

    Stencel, J.M.; Neathery, J.K.; Schaefer, J.L.; Yang, Jidong

    1993-12-31

    Bench-scale, mild-temperature fluidized bed gasification (MTFBG) was performed on three high sulfur Illinois basin coals after mixing with phosphoric-acid. The research initiated development of an advanced processing technology which partitions coal sulfur to the gas phase as H{sub 2}s. The MTFBG experiments were performed on Illinois coals IBC-101, IBC-106 and IBC-110. Product yields were between 60--80% char, 0.41.3% tar and 20--40% gases. Gas yields were sensitive to the coal/acid mixing ratios and the residence time of the coal within the gasifier. Tar and gas yields were significantly lower for coal/acid feeds than for coal-only feeds. At 500{degrees}C, the sulfur removal was as high as 82% for IBC-106; sulfur emissions during combustion of this char would be 1.10 lbs SO{sub 2}/MMBtu. Emission levels from the IBC-110 char would be 1.15 lbs SO{sub 2}/MMBtu whereas it would be 2.15 lb SO,/MmBtu from the IBC-101 char. In comparison, the emission levels from chars produced during gasification of coal using no acid would be 4.35 (IBC-110) and 4.81 (IBC-101), whereas the emission levels of the parent coals would be between 5--6 lb SO{sub 2}/MMBtu. Gas product analysis confirmed that the coal sulfur was removed as H{sub 2}s. Pressurized hot-water filtration of the chars removed nearly 80% of the phosphorus. Its removal rate should be near 95% to restrain the reagent cost to less than $25/Ton of SO{sub 2}.

  5. Development of advanced, continuous mild gasification process for the production of co-products addendum to technical evaluation. Final report

    SciTech Connect

    Not Available

    1992-11-01

    This report contains the material balance data for Wyodak, Indiana No. 3, and Cannelton coals that were tested in the mild gasification program. Data include tests conducted using the 1- to 4-lb/hr continuous fluid-bed reactor (CFBR) and the 100-lb/hr Process Research Unit (PRU). All raw analysis data were reduced to calculate product yields as a percentage of the product mass divided by the maf coal feed. The material closure was then determined, and losses were assigned to one or a combination of the three product streams: char, condensate (includes condensed steam), and gas. Mass was added proportionally to each constituent of the stream until the closure was 100%.

  6. Development of advanced, continuous mild gasification process for the production of co-products addendum to technical evaluation

    SciTech Connect

    Not Available

    1992-11-01

    This report contains the material balance data for Wyodak, Indiana No. 3, and Cannelton coals that were tested in the mild gasification program. Data include tests conducted using the 1- to 4-lb/hr continuous fluid-bed reactor (CFBR) and the 100-lb/hr Process Research Unit (PRU). All raw analysis data were reduced to calculate product yields as a percentage of the product mass divided by the maf coal feed. The material closure was then determined, and losses were assigned to one or a combination of the three product streams: char, condensate (includes condensed steam), and gas. Mass was added proportionally to each constituent of the stream until the closure was 100%.

  7. Final report for {open_quotes}Production of mild gasification co-products{close_quotes} project

    SciTech Connect

    Horne, D.A.; Castro, J.C.

    1994-12-04

    The SGI International Liquids From Coal (LFC) Process is a mild pyrolysis, or mild gasification, treatment that upgrades low-rank coals by removing almost all of the moisture and a substantial portion of the volatile matter. The process produces two value-added co-products: a Coal Derived Liquid (CDL) and a solid Process Derived Fuel (PDF). A third co-product, a low-heating-value non-condensible gas, is recirculated and combusted in a commercial sized plant to provide drying and pyrolysis process heat. The LFC Process consists of three basic steps. The first step, drying, involves essentially inert gas convectively raising the coal temperature and removing most of the moisture. The drying temperature is limited to ensure that no hydrocarbon gases evolve, and the flow rate is limited below fluidization levels for most of the coal particles. The second step, pyrolysis, consists of additional inert gas heating that raises the temperature of the dried coal so that more than half of the volatile matter is removed under a controlled temperature history that is characteristic for each particular coal and customer demand. The third step, finishing or conditioning, consists of exposure to a cooling inert gas that quenches the pyrolysis reaction, followed by controlled exposure to oxygen for the purposes of stabilization. The processed solid char is then brought to moisture equilibrium (much less than the parent coal`s equilibrium level), and, if necessary, a dust suppressant is added to the PDF. The PDF co-product is environmentally more attractive than the parent coal because a large fraction of the organic sulfur is removed with the volatile matter, and the heating value of the fuel is increased with a concurrent increase in combustion efficiency. When subjected to appropriate finishing steps, the PDF represents a stable, economically transportable, high-heat-value reactive combustion fuel with stable flame characteristics similar to natural gas.

  8. Behavior of mineral matters in Chinese coal ash melting during char-CO{sub 2}/H{sub 2}O gasification reaction

    SciTech Connect

    Xiaojiang Wu; Zhongxiao Zhang; Guilin Piao; Xiang He; Yushuang Chen; Nobusuke Kobayashi; Shigekatsu Mori; Yoshinori Itaya

    2009-05-15

    The typical Chinese coal ash melting behavior during char-CO{sub 2}/H{sub 2}O gasification reaction was studied by using TGA, XRD, and SEM-EDX analysis. It was found that ash melting behavior during char gasification reaction is quite different from that during coal combustion process. Far from the simultaneously ash melting behavior during coal combustion, the initial melting behavior of ash usually occurs at a middle or later stage of char-CO{sub 2}/H{sub 2}O reaction because of endothermic reaction and more reactivity of char gasification reaction as compared with that of mineral melting reactions in ash. In general, the initial melting temperature of ash is as low as 200-300 K below the deformation temperature (T{sub def}) of ash with ASTM test. The initial molten parts in ash are mainly caused by iron bearing minerals such as wustite and iron-rich ferrite phases under gasification condition. Along with the proceeding of ash melting, the melting behavior appears to be accelerated by the presence of calcium to form eutectic mixtures in the FeO-SiO{sub 2}-Al{sub 2}O{sub 3} and CaO-SiO{sub 2}-Al{sub 2}O{sub 3} system. The different states of iron are the dominant reason for different melting behaviors under gasification and combustion conditions. Even under both reducing conditions, the ash fusion temperature (AFT) of coal under char-CO{sub 2} reaction is about 50-100 K lower than that under char-H{sub 2}O reaction condition. The main reason of that is the higher content of CO under char-CO{sub 2} reaction, which can get a lower ratio of Fe{sup 3+}/{Sigma}Fe in NaO-Al{sub 2}O{sub 3}-SiO{sub 2}-FeO melts. 38 refs., 8 figs., 4 tabs.

  9. Scale-up of mild gasification to a process development unit. Quarterly report, August--November 1993

    SciTech Connect

    Campbell, J.A.L.; Carty, R.H.; Foster, H.

    1994-03-01

    The overall objective of this project is to develop the IGT Mild-Gasification (MILDGAS) process for near-term commercialization. The specific objectives of the program are to: design, construct, and operate a 24-tons/day adiabatic process development unit (PDU) to obtain process performance data suitable for further design scaleup; obtain large batches of coal-derived co-products for industrial evaluation; prepare a detailed design of a demonstration unit; and develop technical and economic plans for commercialization of the MILDGAS process. The MILDGAS process is a continuous closed system for producing liquid and solid (char) co-products at mild operating conditions up to 50 psig and 1300 F. The 1 ton/hr PDU facility that is to be constructed is comprised of a 2.5-ft ID adiabatic gasifier for the production of gases, coal liquids, and char; a thermal cracker for upgrading of the coal liquids; a three-stage condensation train to condense and store the liquid products; and coal feeding and char handling equipment. The facility will also incorporate support equipment for environmentally acceptable disposal of process waste. This quarter, the authors completed preparation of the draft of the permitting documentation that will be required by the Illinois EPA for the permit to construct the PDU. SIUC`s comments are currently being incorporated into the version of the permitting document that will be submitted to the Illinois EPA. The Environmental Assessment (EA) was prepared by DOE and submitted in September, 1993 to the State of Illinois and the Crab Orchard Wildlife Refuge for comments. Neither organization found any issue with the EA that would prevent construction of the PDU at the proposed site. They did submit comments which are being taken into consideration in revising the EA.

  10. The effect of char {open_quotes}age{close_quotes} on gasification reactivity

    SciTech Connect

    Calo, J.M.; Zhang, L.; Lu, W.

    1996-10-01

    It is well known that {open_quotes}age{close_quotes} (i.e., the degree of pyrolysis severity) can significantly affect char reactivity, generally with {open_quotes}younger{close_quotes} chars being more reactive than {open_quotes}older{close_quotes} chars. In the current work we investigate this issue via the analysis of post-reaction thermal desorption data for a few different char samples (coal chars and a resin char), that were prepared under different conditions of pyrolysis severity, in both CO{sub 2} and steam. It is observed that the total amount of desorbed oxygen increases with char {open_quotes}age,{close_quotes} in both CO{sub 2} and steam, while the reactivity decreases significantly. The CO TPD spectra for the samples gasified in one atmosphere of CO{sub 2} are analyzed using a kinetic model based on energetic heterogeneity of the char surface. It is demonstrated that this model correlates the variation in reactivity with {open_quotes}age{close_quotes} very well. These results support a conclusion that reactivity decrease with age is dependent on a decrease in the active site population in addition to a shift in the energetic distributions to higher values.

  11. Integrated mild gasification processing at the Homer City Electric Power Generating Station site. Final report, July 1989--June 1993

    SciTech Connect

    Battista, J.J.; Zawadzki, E.A.

    1993-07-01

    A new process for the production of commercial grade coke, char, and carbon products has been evaluated by Penelec/NYSEG. The process, developed by Coal Technology Corporation, CTC, utilizes a unique screw reactor to produce a devolatilized char from a wide variety of coals for the production of commercial grade coke for use in blast furnaces, foundries, and other processes requiring high quality coke. This process is called the CTC Mild Gasification Process (MGP). The process economics are significantly enhanced by integrating the new technology into an existing power generating complex. Cost savings are realized by the coke producer, the coke user, and the electric utility company. Site specific economic studies involving the Homer City Generating Station site in Western Pennsylvania, confirmed that an integrated MGP at the Homer City site, using coal fines produced at the Homer City Coal Preparation Plant, would reduce capital and operating costs significantly and would enable the HC Owners to eliminate thermal dryers, obtain low cost fuel in the form of combustible gases and liquids, and obtain lower cost replacement coal on the spot market. A previous report, identified as the Interim Report on the Project, details the technical and economic studies.

  12. Scale-up of mild gasification to a process development unit. Progress report for August 21--November 20, 1994

    SciTech Connect

    Doane, E.P.; Carty, R.H.; Foster, H.

    1995-02-01

    The overall objective of this project is to develop the IGT Mild-Gasification (MILDGAS) process for near-term commercialization. The specific objectives of the program are to: design, construct, and operate a 24-tons/day adiabatic process development unit (PDU) to obtain process performance data suitable for further design scaleup; obtain large batches of coal-derived co-products for industrial evaluation; prepare a detailed design of a demonstration unit; and develop technical and economic plans for commercialization of the MILDGAS process. The 1 ton/hr PDU facility that is to be constructed is comprised of a 2.5-ft ID adiabatic gasifier for the production of gases, coal liquids, and char; a three-stage condensation train to condense and store the liquid products; and coal feeding and char handling equipment. The facility will also incorporate support equipment for environmentally acceptable disposal of process waste. This quarter work included clearing, grubbing, grading and backfilling of the site, installation of culverts and fencing, placing of the main structure foundation and truck pad, and installation of gravel on the areas that will later be blacktopped. Also this quarter, a contract for the emissions and control package was awarded to Calidus Technologies. In addition, agreement with Central Illinois Power Service on the electrical supply scope and the natural gas delivery pressure was made and the FAA waived any requirement for aircraft warning devices on the top of the structure.

  13. Scale-up of mild gasification to a process development unit. Quarterly report, November 1993--February 1994

    SciTech Connect

    Campbell, J.A.L.; Carty, R.H.; Foster, H.

    1994-05-01

    The work performed during the ninth quarterly reporting period (November 21, 1993 through February 20, 1994) is presented in this report. The overall objective of this project is to develop the IGT Mid-Gasification MILDGAS) process for near-term commercialization. The specific objectives of the program are to: design, construct, and operate a 24-tons/day adiabatic process development unit (PDU) to obtain process performance data suitable for further design scaleup; obtain large batches of coal-derived co-products for industrial evaluation; prepare a detailed design of a demonstration unit; and develop technical and economic plans for commercialization of the MILDGAS process. The project team that is performing the initial phases of the PDU development are: Kerr-McGee Coal Corporation (K-M Coal), the Institute of Gas Technology (IGT), Bechtel Corporation (Bechtel), and Southern Illinois University at Carbondale (SIUC). The MILDGAS process is a continuous closed system for producing liquid and solid (char) co-products at mild operating conditions up to 50 psig and 1300F. It is capable of processing a wide range of both eastern caking and western noncaking coals. The 1 ton/hr PDU facility that is to be constructed is comprised of a 2.5-ft ID adiabatic gasifier for the production of gases, coal liquids, and char; a three-stage condensation train to condense and store the liquid products; and coal feeding and char handling equipment. The facility will also incorporate support equipment for environmentally acceptable disposal of process waste. A Finding of No Significant Impact (FONSI) was obtained on our NEPA submittal on February 10, 1994, allowing us to proceed with the project. The permitting documentation for the authority to construct was submitted to the Illinois EPA this quarter. Work to finalize the process design and obtain updated bids on the PDU was begun after the FONSI was obtained.

  14. Mechanism of catalytic gasification of coal char. Quarterly technical report No. 5, October 1 to December 31, 1981

    SciTech Connect

    Wood, B. J.; Sancier, K. M.; Sheridan, D. R.; Chan, B. L.; Wise, H.

    1982-02-26

    The purpose of this study is to determine the mechanisms involved in the catalytic reactions of coal char and to identify the specific reaction steps and the parameters that control the catalytic process. The mode of action of the catalyst can be viewed in two ways. In one view, the catalyst participates in a reduction/oxidation cycle. The initial reaction between the carbon and the catalyst reduces the KOH to potassium accompanied by the gaseous reactant (H/sub 2/O or CO/sub 2/), producing further gaseous products (CO and H/sub 2/) and regenerating the initial state of the catalyst. In an alternative view, the catalyst initially forms an alkali metal addition compound with the carbon network of the char. The carbon-carbon bonds are altered by the formation of the metal-carbon linkage, possibly by electron transfer from the alkali metal atom to the carbon structure. As a result, the carbon structure is more readily attacked by the gaseous reactant (CO or H/sub 2/O) to produce the products of gasification. The following areas were investigated to provide experimental evidence for these catalytic modes of action: chemical kinetic measurements; thermodynamic measurements; free radicals in reacting carbon; electrical conductivity measurements. A detailed discussion on the catalyst-carbon interaction and on the reaction intermediate is provided.

  15. Rapid co-pyrolysis of rice straw and a bituminous coal in a high-frequency furnace and gasification of the residual char.

    PubMed

    Yuan, Shuai; Dai, Zheng-hua; Zhou, Zhi-jie; Chen, Xue-li; Yu, Guang-suo; Wang, Fu-chen

    2012-04-01

    Rapid pyrolysis of rice straw (RS) and Shenfu bituminous coal (SB) separately, and rapid co-pyrolysis of RS/SB blends (mass ratio 1:4, 1:4, and 4:1), were carried out in a high-frequency furnace which can ensure both high heating rate and satisfying contact of fuel particles. Synergies between RS and SB during rapid co-pyrolysis were investigated. Intrinsic and morphological structures of residual char from co-pyrolysis, and their effects on gasification characteristics were also studied. Synergies occurred during rapid co-pyrolysis of RS and SB (RS/SB=1:4) resulting in decreasing char yields and increasing volatile yields. Synergies also happened during gasification of the char derived from co-pyrolysis of RS and SB with mass ratio of 1:4. The increased mass ratio of RS to SB did not only weaken synergies during co-pyrolysis, but significantly reduced the gasification rates of the co-pyrolysis char compared to the calculated values. Results can help to optimize co-conversion process of biomass/coal. PMID:22305541

  16. [Toxicity studies of mild gasification products]. [Quarterly report, October 1, 1992--December 31, 1992

    SciTech Connect

    Not Available

    1992-12-31

    Mild gasification of coal is a technology being developed by the United States Department of Energy and private industry with the hope that a cleaner method of coal use can help meet future energy needs. As the technology develops and its commercial use becomes a more viable possibility, efforts are being made to study the safety or possible toxicity of the mild gasification products. DOE and the National Institute for occupational Safety and Health (NIOSH) are cooperating through an interagency agreement to examine some of these products for their genotoxic potential. NIOSH has studied the mutagenicity of several mild gasification product samples using the Ames Salmonella/microsomal assay. As reported earlier PSIS{number_sign}830331 failed to demonstrate genotoxic activity in the Ames assay under all conditions tested. Since the mild gasification products are complex mixtures, interactions between various components are likely to occur. Such interactions between various components of complex mixtures may increase or decrease genotoxic activity in short-term assays like the Ames test. Although all synergistic interactions may not be detailed, the separate analysis of those components in several classes provides a more accurate view of the genotoxicity of each component and better allows for chemical characterization of the possible mutagens in the mixture. NIOSH has performed mutagenicity studies on the subfractions of PSIS{number_sign}830331. The results of those studies are detailed in this report.

  17. Rapid gasification of nascent char in steam atmosphere during the pyrolysis of Na- and Ca-ion-exchanged brown coals in a drop-tube reactor

    SciTech Connect

    Ondej Maek; Sou Hosokai; Koyo Norinaga; Chun-Zhu Li; Jun-ichiro Hayashi

    2009-09-15

    Several recent studies on in situ steam gasification of coal suggest a possibility of extremely fast steam gasification of char from rapid pyrolysis of pulverized brown coal. The unprecedented rate of char steam gasification can be achieved by exposing nascent char, that is, after tar evolution (temperature range >600{sup o}C), but before devolatilization (<900{sup o}C), to steam in the presence of Na and/or Ca dispersed in/on the char. In this study, we conducted rapid pyrolysis experiments using ion-exchanged Loy Yang brown coal samples, that is, H-form coal with Na/Ca contents <0.001 wt %, Na-form coal with Na content = 2.8 wt % and Ca-form coal with Ca content = 3.2 wt %. These samples were pyrolyzed in an atmospheric drop-tube reactor at a temperature of 900{sup o}C, inlet steam concentration of 50 vol. %, and a particle residence times of 2.8 s. The char yields from the pyrolysis of Na-form and Ca-form coals were as low as 12 and 33% on the respective coal carbon bases, and accounted for only 18 and 53% of the char yields from the full devolatilization of the respective coals at 900{sup o}C. In addition, the pyrolysis also consumed as much as 0.7-1.1 mol of H{sub 2}O per mol of coal C. On the other hand, the nascent char from the H-form coal allowed carbon deposition from the nascent tar, resulting in a char yield as high as 115% of that from the full devolatilization. The chars from the Na-form and Ca-form coals also acted as catalysts for steam reforming of tar, which was evidenced by significant negative synergistic effects of blending of H-form coal with Na-form coal or Ca-form coal on the tar and soot yields. 57 refs., 6 figs.

  18. Clean, premium-quality chars: Demineralized and carbon enriched

    SciTech Connect

    Smith, G.V.

    1992-01-03

    The goal of this project is to develop a bench-scale procedure to produce clean, desulfurized, premium-quality chars from the Illinois basin coals. This goal is achieved by utilizing the effective capabilty of smectites in combination with methane to manipulate the char yields. The major objectives are: to determine the optimum water- ground particle size for the maximum reduction of pyrite and minerals by the selective-bitumen agglomeration process; to evaluate the type of smectite and its interlamellar cation which enhances the premium-quality char yields; to find the mode of dispersion of smectites in clean coal which retards the agglomeration of char during mild gasification; to probe the conditions that maximize the desulfurized clean-char yields under a combination of methane+oxygen or helium+oxygen; to characterize and accomplish a material balance of chars, liquids, and gases produced during mild gasification; to identify the conditions which reject dehydrated smectites from char by the gravitational separation technique; and to determine the optimum seeding of chars with polymerized maltene for flammability and transportation.

  19. Study on the effect of heat treatment and gasification on the carbon structure of coal chars and metallurgical cokes using fourier transform Raman spectroscopy

    SciTech Connect

    S. Dong; P. Alvarez; N. Paterson; D.R. Dugwell; R. Kandiyoti

    2009-03-15

    Differences in the development of carbon structures between coal chars and metallurgical cokes during high-temperature reactions have been investigated using Raman spectroscopy. These are important to differentiate between different types of carbons in dust recovered from the top gas of the blast furnace. Coal chars have been prepared from a typical injectant coal under different heat-treatment conditions. These chars reflected the effect of peak temperature, residence time at peak temperature, heating rate and pressure on the evolution of their carbon structures. The independent effect of gasification on the development of the carbon structure of a representative coal char has also been studied. A similar investigation has also been carried out to study the effect of heat-treatment temperature (from 1300 to 2000{sup o}C) and gasification on the carbon structure of a typical metallurgical coke. Two Raman spectral parameters, the intensity ratio of the D band to the G band (I{sub D}/I{sub G}) and the intensity ratio of the valley between D and G bands to the G band (I{sub V}/I{sub G}), have been found useful in assessing changes in carbon structure. An increase in I{sub D}/I{sub G} indicates the growth of basic graphene structural units across the temperature range studied. A decrease in I{sub V}/I{sub G} appears to suggest the elimination of amorphous carbonaceous materials and ordering of the overall carbon structure. The Raman spectral differences observed between coal chars and metallurgical cokes are considered to result from the difference in the time-temperature history between the raw injectant coal and the metallurgical coke and may lay the basis for differentiation between metallurgical coke fines and coal char residues present in the dust carried over the top of the blast furnace. 41 refs., 17 figs., 3 tabs.

  20. Development of an advanced, continuous mild gasification process for the production of co-products technical evaluation

    SciTech Connect

    Ness, R.O. Jr.; Runge, B.; Sharp, L.

    1992-11-01

    The University of North Dakota Energy and Environmental Research Center (EERC) and the AMAX Research and Development Center are cooperating in the development of a Mild Gasification process that will rapidly devolatilize coals of all ranks at relatively low temperatures between 930[degree] and 1470[degree]F (500[degree]and 800[degree]C) and near atmospheric pressure to produce primary products that include a reactive char, a hydrocarbon condensate, and a low-Btu gas. These will be upgraded in a coal refinery'' system having the flexibility to optimize products based on market demand. Task 2 of the four-task development sequence primarily covered bench-scale testing on a 10-gram thermogravimetric analyzer (TGA) and a 1 to 4-lb/hr continuous fluidized-bed reactor (CFBR). Tests were performed to determine product yields and qualities for the two major test coals-one a high-sulfur bituminous coal from the Illinois Basin (Indiana No. 3) and the other a low-sulfur subbituminous coal from the Powder River Basin (Wyodak). Results from Task 3, on product upgrading tests performed by AMAX Research and Development (R D), are also reported. Task 4 included the construction, operation of a Process Research Unit (PRU), and the upgrading of the products. An economic evaluation of a commercial facility was made, based on the data produced in the PRU, CFBR, and the physical cleaning steps.

  1. Development of an advanced, continuous mild gasification process for the production of co-products technical evaluation. Final report

    SciTech Connect

    Ness, R.O. Jr.; Runge, B.; Sharp, L.

    1992-11-01

    The University of North Dakota Energy and Environmental Research Center (EERC) and the AMAX Research and Development Center are cooperating in the development of a Mild Gasification process that will rapidly devolatilize coals of all ranks at relatively low temperatures between 930{degree} and 1470{degree}F (500{degree}and 800{degree}C) and near atmospheric pressure to produce primary products that include a reactive char, a hydrocarbon condensate, and a low-Btu gas. These will be upgraded in a ``coal refinery`` system having the flexibility to optimize products based on market demand. Task 2 of the four-task development sequence primarily covered bench-scale testing on a 10-gram thermogravimetric analyzer (TGA) and a 1 to 4-lb/hr continuous fluidized-bed reactor (CFBR). Tests were performed to determine product yields and qualities for the two major test coals-one a high-sulfur bituminous coal from the Illinois Basin (Indiana No. 3) and the other a low-sulfur subbituminous coal from the Powder River Basin (Wyodak). Results from Task 3, on product upgrading tests performed by AMAX Research and Development (R&D), are also reported. Task 4 included the construction, operation of a Process Research Unit (PRU), and the upgrading of the products. An economic evaluation of a commercial facility was made, based on the data produced in the PRU, CFBR, and the physical cleaning steps.

  2. Effect of the chemical heat treatment in a semianthracite char on the textural properties and the gasification in air

    SciTech Connect

    Dominguez, M.A.

    2009-08-15

    The effects of the chemical heat treatments of a semianthracite char (AC) on the textural properties and the gasification in air are investigated. Sample AC first was treated with the LiCl/KCl mixture or the mixture formed by LiCl/IKCl and a metallic oxide, M{sub n=1,2}O (MgO, CaO, FeO, CoO, NiO, Cu{sub 2}O or ZnO) at 743, 873 or 1173 K and products obtained they were then washed carefully with water distilled. The information on the textural modifications was deduced of isotherms of CO{sub 2} adsorption to 273 K. The reactivity tests were taken to the temperature 808, 823 and 838 K. As resulting from the AC treatments, on developed the microporosity and on increase the air reactivity, in particular, the first effect is greater when the used mixture went LiCl/KCl/CoO at 1173 K and the second effect are greater when the used mixture went LiCl/KCl/Cu{sub 2}O at 1173 K.

  3. Reactivity of young chars via energetic distribution measurements

    SciTech Connect

    Calo, J.M.; Zhang, L.H.; Lu, W.; Lilly, W.D.

    1992-06-10

    We have developed what we believe to be the very first a priori prediction technique for the gasification reactivity of coal char. With this method the gasification reactivity of a coal char as function of temperature can be predicted from a single temperature programmed desorption (TPD) experiment following mild gasification at a single temperature (Calo et al., 1989; Hall and Calo, 1990a). This approach has been demonstrated for C0{sub 2} gasification of coal chars where the gasification reactivity is controlled by the thermal desorption of oxygen surface complexes formed during gasification. This approach may be extended to other oxidant species, such as steam, and carbon-hydrogen complexes for hydrogen gasification as well. In the current report, we present a summary of the work that has been conducted to date in constructing a new TGA/TPD-MS experimental system which provides us with the capability of simultaneous monitoring of transient sample mass data, as well as gas phase composition during thermal desorption experiments. In addition, we present some steam reactivity data obtained with another TGA (Cahn 113 system) which has been modified for steam gasification experiments.

  4. Mild temperature gasification: Partitioning sulfur to gas as H{sub 2}S. [Quarterly] technical report, March 1--May 31, 1993

    SciTech Connect

    Stencel, J.M.; Neathery, J.K.; Schaefer, J.L.; Yang, Jidong

    1993-09-01

    Bench-scale, mild temperature fluidized bed gasification (MTFBG) will be performed on three high sulfur Illinois basin coals after mixing with phosphoric acid. The research initiates development of an advanced processing technology which partitions coal sulfur to the gas phase as H{sub 2}S. Influences of coal type, coal agglomeration, and steam injection on the properties of the solid, condensible and gaseous products produced during MTFBG will be examined. Analytical measurements of the products will be obtained and are designed to provide product quality and quantity data. Combustion reactivity testing of the char, and pressurized, hot water extraction of H{sub 3}PO{sub 4} from the char, will be performed to provide information for design of a continuous and integrated process for the removal and recovery of coal sulfur. MTFBG experiments were performed on Illinois coals IBC-101, -106 and -110. The yields of char, tar and gaseous products varied between 60--85% char, 0.4--1.3% tar, and 15--43% gas for IBC-101 and -106. Gas yields were sensitive to the coal/phosphoric acid mixing ratio and also dependent on the residence time within the gasifier. The mean residence time was low ({approximately}6 seconds), and was influenced by the mean particle size of the coals. The total sulfur removal was as high as 83% for IBC-106 at a temperature of 500{degrees}C. In comparison with previous fixed bed testing, it is believed that the sulfur is removed as H{sub 2}S. Experiments planned for the next quarter should define the concentration and type of sulfur in the gas.

  5. Task 3 -- Bench-scale char upgrading and utilization study

    SciTech Connect

    Jha, M.C.; McCormick, R.L.

    1989-08-02

    This report describes the results of the bench-scale char upgrading study conducted as Task 3 of Development of an Advanced, Continuous Mild Gasification Process for the Production of Coproducts. A process where the char is gasified to produce methane in a first stage reactor was investigated. This methane is then decomposed to produce carbon and hydrogen for recycle in a second stage. The results indicate that both reaction steps are feasible using mild gasification char as the starting feedstock. Conditions for methanation are 700 to 800 C and 200 to 400 psig. Carbon formation conditions are 1,200 to 1,400 C at atmospheric pressure. The carbon produced has properties similar to those of carbons which are commercially marketed as carbon black.

  6. ENCOAL Mild Coal Gasification Demonstration Project. Annual report, October 1993--September 1994

    SciTech Connect

    1995-03-01

    ENCOAL Corporation, a wholly-owned subsidiary of SMC Mining Company (formerly Shell Mining Company, now owned by Zeigler Coal Holding Company), has completed the construction and start-up of a mild gasification demonstration plant at Triton Coal Company`s Buckskin Mine near Gillette, Wyoming. The process, using Liquids From Coal (LFC) technology developed by SMC and SGI International, utilizes low-sulfur Powder River Basin coal to produce two new fuels, Process Derived Fuel (PDF) and Coal Derived Liquids (CDL). The LFC technology uses a mild pyrolysis or mild gasification process which involves heating the coal under carefully controlled conditions. The process causes chemical changes in the feed coal in contrast to conventional drying, which leads only to physical changes. Wet subbituminous coal contains considerable water, and conventional drying processes physically remove some of this moisture, causing the heating value to increase. The deeper the coal is physically dried, the higher the heating value and the more the pore structure permanently collapses, preventing resorption of moisture. However, deeply dried Powder River Basin coals exhibit significant stability problems when dried by conventional thermal processes. The LFC process overcomes these stability problems by thermally altering the solid to create PDF and CDL. Several of the major objectives of the ENCOAL Project have now been achieved. The LFC Technology has been essentially demonstrated. Significant quantities of specification CDL have been produced from Buckskin coal. Plant operation in a production mode with respectable availability (approaching 90%) has been demonstrated.

  7. Industrial market assessment of the products of mild gasification: Final report

    SciTech Connect

    Sinor, J.E.

    1988-01-01

    The goal of this study is to determine the best available conditions, in terms of market volumes and prices, for the products from a mild gasification facility. A process feasibility study will then have to determine the cost of building and operating a facility to make those products. The study is presented as a summary of the options available to a coal producer for creating added product value. For this reason, three specific coal mines owned by AMAX Inc. were chosen, and the options were analyzed from the viewpoint of increasing the total revenue derived from those coals. No specific mild gasification, or mild devolatilization technology was assumed during the assessment. The analysis considers only product prices, volumes, and specifications. It does not assign any intangible value or national benefit to substituting coal for oil or to producing a cleaner fuel. Although it would be desirable to conceive of a product slate which would be immune from energy price fluctuations, such a goal is probably unattainable and no particular emphasis was placed on it. 76 figs., 75 tabs.

  8. Ames test mutagenicity studies of the subfractions of the mild gasification composite material, CTC No. 11

    SciTech Connect

    Not Available

    1992-12-31

    The results of the Ames testing of subfractions of a mild gasification product with a liquid/tar consistency obtained from coal technology corporation, CTC{number_sign}11 subfractions indicates significant genotoxic activity in each of the four fractions. CTC{number_sign}11 is quite genotoxic to bacteria and apparently contains a wide variety of mutagens. Since mutation is generally accepted as one of the first steps in carcinogenesis, CTC{number_sign}11 has displayed potential carcinogenicity. The evidence collected from this study and testing of the whole sample is sufficient to suggest further testing of CTC{number_sign}11 as a possible carcinogen.

  9. Pyrolysis and gasification of coal at high temperatures

    SciTech Connect

    Zygourakis, K.

    1992-02-10

    The macropore structure of chars is a major factor in determining their reactivity during the gasification stage. The major objectives of this contract were to (a) quantify by direct measurements the effect of pyrolysis conditions of the macropore structure, and (b) establish how the macropores affected the reactivity pattern, the ignition behavior and the fragmentation of the char particles during gasification in the regime of strong diffusional limitations. Results from this project provide much needed information on the factors that affect the quality of the solid products (chars) of coal utilization processes (for example, mild gasification processes). The reactivity data will also provide essential parameters for the optimal design of coal gasification processes. (VC)

  10. An integrated process for hydrogen-rich gas production from cotton stalks: The simultaneous gasification of pyrolysis gases and char in an entrained flow bed reactor.

    PubMed

    Chen, Zhiyuan; Zhang, Suping; Chen, Zhenqi; Ding, Ding

    2015-12-01

    An integrated process (pyrolysis, gas-solid simultaneous gasification and catalytic steam reforming) was utilized to produce hydrogen-rich gas from cotton stalks. The simultaneous conversion of the pyrolysis products (char and pyrolysis gases) was emphatically investigated using an entrained flow bed reactor. More carbon of char is converted into hydrogen-rich gas in the simultaneous conversion process and the carbon conversion is increased from 78.84% to 92.06% compared with the two stages process (pyrolysis and catalytic steam reforming). The distribution of tar components is also changed in this process. The polycyclic aromatic compounds (PACs) of tar are converted into low-ring compounds or even chain compounds due to the catalysis of char. In addition, the carbon deposition yield over NiO/MgO catalyst in the steam reforming process is approximately 4 times higher without the simultaneous process. The potential H2 yield increases from 47.71 to 78.19g/kg cotton stalks due to the simultaneous conversion process. PMID:26433156

  11. Toxicity studies of mild gasification products. Quarterly report, October--December 1993

    SciTech Connect

    Not Available

    1994-03-01

    The major hypothesis of carcinogenesis is that malignancy is due to an alteration (mutation) of the genetic material in a somatic cell. Reactive electrophilic metabolites are generated from many chemicals by the action of endogenous mixed-function oxidases. These reactive metabolites may bind to cellular macromolecules, such as DNA, and can, therefore, initiate a mutagenic or carcinogenic event. Prokaryotes and non-mammalian eukaryotes are used in mutation assays, while cultured mammalian cells are generally used for mutagenic as well as clastogenic tests examining alterations and damage to the DNA and/or chromosomes of somatic cells. One of the first mammalian cell lines used in genotoxicity studies is V79, which was derived from Chinese hamster lung cells. According to the test plan on toxicity studies of mild gasification products, mammalian cell in vitro assays are to be performed on selected samples displaying mutagenic activity in the Ames assay. The results of the Ames testing of the mild gasification sample Shell Oil PSIS{number_sign}330331 were negative. However, fractionation of the sample and Ames testing of the subfractions were performed per DOE request. None of the subfractions was mutagenic in the Ames assay, as has been previously reported. Assays for the induction of gene mutation, sister chromatid exchange and micronucleus formation in V79 cells have also been carried out for the sample. This paper reports the results of the mammalian cell assay.

  12. [Toxicity studies of mild gasification products: Quarterly technical progress report, April--June 1993

    SciTech Connect

    Not Available

    1993-12-31

    The major hypothesis of carcinogenesis is that malignancy is due to an alteration (mutation) of the genetic material in a somatic cell. Reactive electrophilic metabolites are generated from many chemicals by the action of endogenous mixed function oxidases. These reactive metabolites may bind to cellular macromolecules, such as DNA, and can, therefore, initiate a mutagenic or carcinogenic event. Prokaryotes and non-mammalian eukaryotes are used in mutation assays, while cultured mammalian cells are generally used for mutagenic as well as clastogenic tests examining alterations and damage to the DNA and/or chromosomes of somatic cells. One of the first mammalian cell lines used in genotoxicity studies is V79, which was derived from Chinese hamster lung cells. According to the test plan on toxicity studies of mild gasification products, mammalian cell in vitro assays are to be performed on selected samples displaying mutagenic activity in the Ames assay. The results of the Ames testing of the mild gasification sample IST {number_sign}10 indicate significant mutagenic activity. Hence, assays for the induction of gene mutation, sister chromatid exchange and micronucleus formation in V79 cells have been carried out for the sample. This paper reports the results of these assays.

  13. Encoal mild coal gasification project: Encoal project final report, July 1, 1997--July 31, 1997

    SciTech Connect

    1997-07-01

    This document is the summative report on the ENCOAL Mild Coal Gasification Project. It covers the time period from September 17, 1990, the approval date of the Cooperative Agreement between ENCOAL and the US Department of Energy (DOE), to July 17, 1997, the formal end of DOE participation in the Project. The Cooperative Agreement was the result of an application by ENCOAL to the DOE soliciting joint funding under Round III of the Clean Coal Technology Program. By June 1992, the ENCOAL Plant had been built, commissioned and started up, and in October 1994, ENCOAL was granted a two-year extension, carrying the project through to September 17, 1996. No-cost extensions have moved the Cooperative Agreement end date to July 17, 1997 to allow for completion of final reporting requirements. At its inception, ENCOAL was a subsidiary of Shell Mining Company. In November 1992, Shell Mining Company changed ownership, becoming a subsidiary of Zeigler Coal Holding Company (Zeigler) of Fairview Heights, Illinois. Renamed successively as SMC Mining Company and then Bluegrass Coal Development Company, it remained the parent entity for ENCOAL, which has operated a 1,000-ton/day mild coal gasification demonstration plant near Gillette, Wyoming for nearly 5 years. ENCOAL operates at the Buckskin Mine owned by Triton Coal Company (Triton), another Zeigler subsidiary.

  14. Ames test mutagenicity studies of the subfractions of the mild gasification composite material, MG-120

    SciTech Connect

    Not Available

    1992-04-17

    Mutagenicity of six mild gasification product samples was studied using the Ames Salmonella/microsomal assay system. The results of the Ames testing of the MG-119 and MG-120 subfractions indicate significant mutagenic activity only in the nonpolar neutral fraction. The activity was evident on bacterial strains, TA98 and TA100, with and without metabolic activation for MG-120, and with metabolic activation for MG-119. Previous testing of MG-119 and MG-120 when solvated in DMSO had shown possible, but unconfirmable, mutagenic activity. Tween 80-solvated MG-119 and MG-120 showed low, but significant, mutagenic activity only on TA98 with metabolic activation. Comparison of these results indicate an inhibition of the mutagenic components by nonmutagenic components in the complex mixture. 4 refs., 2 tabs.

  15. ENCOAL mild coal gasification demonstration project. Annual report, October 1994--September 1995

    SciTech Connect

    1996-01-01

    This document is the combination of the fourth quarter report (July - September 1995) and the 1995 annual report for the ENCOAL project. The following pages include the background and process description for the project, brief summaries of the accomplishments for the first three quarters, and a detailed fourth quarter report. Its purpose is to convey the accomplishments and current progress of the project. ENCOAL Corporation, a wholly-owned subsidiary of SMC Mining Company (formerly Shell Mining company, now owned by Zeigler Coal Holding Company), has completed the construction and start-up of a mild gasification demonstration plant at Triton Coal Company`s Buckskin Mine near Gillette, Wyoming. The process, using Liquids From Coal (LFC) technology developed by SMC and SGI International, utilizes low-sulfur Powder River Basis coal to produce two new fuels, Process Derived Fuel (PDF) and Coal Derived Liquids (CDL). The products, as alternative fuels sources, are expected to significantly lower current sulfur emissions at industrial and utility boiler sites throughout the nation, thereby reducing pollutants causing acid rain. In the LFC technology, coal is first deeply dried to remove water physically. The temperature is further raised in a second stage which results in decomposition reactions that form the new products. This chemical decomposition (mild gasification) creates gases by cracking reactions from the feed coal. The chemically altered solids are cooled and further processed to make PDF. The gases are cooled, condensing liquids as CDL, and the residual gases are burned in the process for heat. The process release for the ENCOAL plant predicted that one ton of feed coal would yield roughly {1/2} ton of PDF and {1/2} barrel of CDL. By varying plant running conditions, however, it has since been learned that the actual CDL recovery rate may be as much as 15% to 20% above the projections.

  16. Clean, premium-quality chars: Demineralized and carbon enriched. Quarterly report, September 1, 1991--Novemer 30, 1991

    SciTech Connect

    Smith, G.V.

    1992-01-03

    The goal of this project is to develop a bench-scale procedure to produce clean, desulfurized, premium-quality chars from the Illinois basin coals. This goal is achieved by utilizing the effective capabilty of smectites in combination with methane to manipulate the char yields. The major objectives are: to determine the optimum water- ground particle size for the maximum reduction of pyrite and minerals by the selective-bitumen agglomeration process; to evaluate the type of smectite and its interlamellar cation which enhances the premium-quality char yields; to find the mode of dispersion of smectites in clean coal which retards the agglomeration of char during mild gasification; to probe the conditions that maximize the desulfurized clean-char yields under a combination of methane+oxygen or helium+oxygen; to characterize and accomplish a material balance of chars, liquids, and gases produced during mild gasification; to identify the conditions which reject dehydrated smectites from char by the gravitational separation technique; and to determine the optimum seeding of chars with polymerized maltene for flammability and transportation.

  17. Reactivity of young chars via energetic distribution measurements. Quarterly technical progress report, 15 December 1991--15 March 1992

    SciTech Connect

    Calo, J.M.; Zhang, L.H.; Lu, W.; Lilly, W.D.

    1992-06-10

    We have developed what we believe to be the very first a priori prediction technique for the gasification reactivity of coal char. With this method the gasification reactivity of a coal char as function of temperature can be predicted from a single temperature programmed desorption (TPD) experiment following mild gasification at a single temperature (Calo et al., 1989; Hall and Calo, 1990a). This approach has been demonstrated for C0{sub 2} gasification of coal chars where the gasification reactivity is controlled by the thermal desorption of oxygen surface complexes formed during gasification. This approach may be extended to other oxidant species, such as steam, and carbon-hydrogen complexes for hydrogen gasification as well. In the current report, we present a summary of the work that has been conducted to date in constructing a new TGA/TPD-MS experimental system which provides us with the capability of simultaneous monitoring of transient sample mass data, as well as gas phase composition during thermal desorption experiments. In addition, we present some steam reactivity data obtained with another TGA (Cahn 113 system) which has been modified for steam gasification experiments.

  18. Development of an advanced, continuous mild gasification process for the production of co-products (Task 4. 7), Volume 3

    SciTech Connect

    Knight, R.A.; Gissy, J.L.; Onischak, M.; Babu, S.P.; Carty, R.H. ); Duthie, R.G. ); Wootten, J.M. )

    1991-09-01

    The focus of this task is the preparation of (1) preliminary piping and instrument diagrams (P IDs) and single line electrical diagrams for a site-specific conceptual design and (2) a factored cost estimate for a 24 ton/day (tpd) capacity mild gasification process development unit (PDU) and an associated form coke preparation PDU. The intended site for this facility is the Illinois Coal Development Park at Carterville, Illinois, which is operated by Southern Illinois University at Carbondale. (VC)

  19. Radioactive waste forms stabilized by ChemChar gasification: characterization and leaching behavior of cerium, thorium, protactinium, uranium, and neptunium.

    PubMed

    Marrero, T W; Morris, J S; Manahan, S E

    2004-02-01

    The uses of a thermally reductive gasification process in conjunction with vitrification and cementation for the long-term disposal of low level radioactive materials have been investigated. gamma-ray spectroscopy was used for analysis of carrier-free protactinium-233 and neptunium-239 and a stoichiometric amount of cerium (observed cerium-141) subsequent to gasification and leaching, up to 48 days. High resolution ICP-MS was used to analyze the cerium, thorium, and uranium from 46 to 438 days of leaching. Leaching procedures followed the guidance of ASTM Procedure C 1220-92, Standard Test Method for Static Leaching of Monolithic Waste Forms for Disposal of Radioactive Waste. The combination of the thermally reductive pretreatment, vitrification and cementation produced a highly non-leachable form suitable for long-term disposal of cerium, thorium, protactinium, uranium, and neptunium. PMID:14637345

  20. Novel concept development of an internal recirculation catalyst for mild gasification

    SciTech Connect

    Knight, R.A.; Babu, S.P.; Martin, K.A.; Chao, S.C.

    1988-10-01

    The objective of this program is to provide an overall evaluation of a novel process concept for mild gasification by completing work in three major tasks: (1) Laboratory-Scale Experiments, (2) Bench-Scale Tests, and (3) Proof-of-Concept Tests and Evaluation (optional). During this quarter, experimental work involving potential recirculating catalysts for coal, initiated in the previous quarter, was continued. The construction and shakedown of an all quartz laboratory-scale isothermal free-fall reactor was completed. Three free-fall experiments were performed in an existing stainless-steel free-fall reactor with untreated and ammonia treated Illinois No. 6 high-voltatile bituminous coal, and the analyzed data are presented herein. A survey of available literature on catalyzed devolatilization of coal, coal pretreatment methods, and related topics was made. Based on the results of this survey, two potential recirculating catalysts, in addition to the already selected zinc chloride, were selected for study: ferrous chloride (FeCl{sub 2}) and ferric chloride (FeCl{sub 3}). Also, based on the survey, two coal pretreatment/chemical comminution methods were selected for study, in addition to methanol treatment: ammonia and n-butylamine pretreatment. A matrix of experiments was formulated to study the three catalysts and three pretreatment methods selected. 2 refs., 2 tabs.

  1. Mutagenicity of Tween 80-solvated mild gasification products in the Ames salmonella microsomal assay system

    SciTech Connect

    Not Available

    1992-01-13

    The results of the Tween 80-solvated Ames testing of six mild gasification samples indicate significant mutagenic activity only in the composite materials (MG-119 and MG-120), previously suspected from the DMSO-solvated assays, which had shown some variable but ultimately insignificant mutagenic responses. The activity of these samples from the Tween 80-solvated assays was quite low when compared to either the positive controls or the SRC-II HD coal-liquefaction reference material. The class of mutagenic activity expressed by these samples solvated in Tween 80 was that of an indirect-acting, frameshift mutagen(s) since significant activity was found only on tester strain TA98 in the presence of the metabolic activation fraction (S9). Because DMSO and other solvents have been shown to affect the mutagenic activity of certain pure chemicals, the possibility of solvent/mutagen interactions in complex mixtures such as coal-derived liquids exists. Thus, the testing of the genotoxic activity of undefined, chemically complex compounds may require the use of at least two solvent systems to reduce the possibility of artifactual findings. 10 refs., 4 tabs.

  2. Analysis of char-slag interaction and near-wall particle segregation in entrained-flow gasification of coal

    SciTech Connect

    Montagnaro, Fabio; Salatino, Piero

    2010-05-15

    The fate of carbon particles during entrained-flow gasification of coal in the slagging regime is analyzed. More specifically, the study addresses the relevance of segregation of carbon particles in a near-wall region of the gasifier to coal conversion. Segregation of carbon particles is analyzed considering the effects of turbulence- and swirl-promoted particle migration toward the wall, interaction of the impinging particles with the wall ash layer, coverage of the slag layer by refractory carbon particles, accumulation of carbon particles in a dense-dispersed phase near the wall of the gasifier. Operating conditions of the gasifier and slag properties may be combined so as to give rise to a variety of conversion regimes characterized by distinctively different patterns of carbon particles segregation. A simple 1D model of an entrained-flow gasifier has been developed based on the conceptual framework of carbon particle segregation. The model aims at providing a general assessment of the impact of the different patterns of carbon particle segregation on the course and extent of carbon gasification. A sensitivity analysis with reference to selected model parameters is performed to identify key processes controlling carbon segregation and their impact on the gasifier performance. (author)

  3. Pyrolysis and gasification of coal at high temperatures. Final technical report, September 15, 1987--September 14, 1991

    SciTech Connect

    Zygourakis, K.

    1992-02-10

    The macropore structure of chars is a major factor in determining their reactivity during the gasification stage. The major objectives of this contract were to (a) quantify by direct measurements the effect of pyrolysis conditions of the macropore structure, and (b) establish how the macropores affected the reactivity pattern, the ignition behavior and the fragmentation of the char particles during gasification in the regime of strong diffusional limitations. Results from this project provide much needed information on the factors that affect the quality of the solid products (chars) of coal utilization processes (for example, mild gasification processes). The reactivity data will also provide essential parameters for the optimal design of coal gasification processes. (VC)

  4. Upgrading mild gasification liquids to produce electrode binder pitch. Technical report, 1 March--31 May 1994

    SciTech Connect

    Knight, R.A.

    1994-09-01

    The objective of this program is to investigate the production of electrode binder pitch, valued at $250--$300/ton, from mild gasification liquids. The IGT MILDGAS process pyrolyzes coal at 650--760 C and, with Illinois coal, the 400 C+ distillation residue (crude pitch) comprises 40--70% of the MILDGAS liquids, representing up to 20 wt% of maf feed coal. The largest market for pitch made from coal liquids is the aluminum industry, which uses it to make carbon anodes for electrolytic furnaces. In this project, crude MILDGAS pitch is being modified by a flash thermocracking technique to achieve specifications typical of a binder pitch. Last year, a pitch thermocracking unit was constructed for operation at 650--900 F. Process conditions are being examined to optimize the properties of the finished pitch and coke. In the current year, improvements to the thermocracker were made for better gas and pitch flow control, continuous electronic monitoring of feed rate and pressures, and improvements to allow longer tests. During the current quarter, five thermocracking tests were conducted in 100% N{sub 2}, 50% H{sub 2}/N{sub 2}, and 100% H{sub 2}. Test temperatures were 758--873 C with residence times of 1.86--2.42 s and pitch:gas ratios of 0.90--1.10 {times} 10{sup {minus}4}. Product analyses showed that there was no significant effect of H{sub 2} on the pitch sulfur content, but the pitch sulfur content was significantly reduced at higher temperature.

  5. Upgrading mild gasification liquids to produce electrode binder pitch: Final technical report, September 1, 1993--October 31, 1994

    SciTech Connect

    Knight, R.A.

    1994-12-31

    The objective of this program is to investigate the production of electrode binder pitch, valued at $250--$300/ton, from mild gasification liquids. In the IGT MILDGAS process, the 400 C+ distillation residue (crude pitch) comprises up to 20 wt% of maf feed coal. The largest market for pitch made from coal liquids is the aluminum industry, which uses it to make carbon anodes for electrolytic furnaces. In this project, crude MILDGAS pitch is being modified by flash thermocracking to achieve binder pitch specifications. A 1-kg/h continuous unit has been built for operation up to 900 C at 2.5 atm, and parametric tests were conducted in N{sub 2}, H{sub 2} and 50% H{sub 2}/N{sub 2}. In general, thermocracking at 750--850 C in N{sub 2} resulted in a pitch which meets binder pitch requirements for QI, TI, softening point, and C:H ratio. Further improvements in density and sulfur content are required. Test anodes were prepared by Alcoa using the upgraded mild gasification pitch. All of the key anode properties (density, strength, resistivity, thermal properties, permeability, and reactivity) compared very favorably with those of electrodes made from a standard pitch binder.

  6. Development of high energy density fuels from mild gasification of coal. Final report

    SciTech Connect

    Not Available

    1991-12-01

    METC has concluded that MCG technology has the potential to simultaneously satisfy the transportation and power generation fuel needs in the most cost-effective manner. MCG is based on low temperature pyrolysis, a technique known to the coal community for over a century. Most past pyrolysis developments were aimed at maximizing the liquids yield which results in a low quality tarry product requiring significant and capital intensive upgrading. By properly tailoring the pyrolysis severity to control the liquid yield-liquid quality relationship, it has been found that a higher quality distillate-boiling liquid can be readily ``skimmed`` from the coal. The resultant liquids have a much higher H/C ratio than conventional pyrolytic tars and therefore can be hydroprocessed at lower cost. These liquids are also extremely enriched in l-, 2-, and 3-ring aromatics. The co-product char material can be used in place of coal as a pulverized fuel (pf) for power generation in a coal combustor. In this situation where the original coal has a high sulfur content, the MCG process can be practiced with a coal-lime mixture and the calcium values retained on the char can tie up the unconverted coal sulfur upon pf combustion of the char. Lime has also been shown to improve the yield and quality of the MCG liquids.

  7. Development of high energy density fuels from mild gasification of coal

    SciTech Connect

    Greene, Marvin

    1991-12-01

    METC has concluded that MCG technology has the potential to simultaneously satisfy the transportation and power generation fuel needs in the most cost-effective manner. MCG is based on low temperature pyrolysis, a technique known to the coal community for over a century. Most past pyrolysis developments were aimed at maximizing the liquids yield which results in a low quality tarry product requiring significant and capital intensive upgrading. By properly tailoring the pyrolysis severity to control the liquid yield-liquid quality relationship, it has been found that a higher quality distillate-boiling liquid can be readily skimmed'' from the coal. The resultant liquids have a much higher H/C ratio than conventional pyrolytic tars and therefore can be hydroprocessed at lower cost. These liquids are also extremely enriched in l-, 2-, and 3-ring aromatics. The co-product char material can be used in place of coal as a pulverized fuel (pf) for power generation in a coal combustor. In this situation where the original coal has a high sulfur content, the MCG process can be practiced with a coal-lime mixture and the calcium values retained on the char can tie up the unconverted coal sulfur upon pf combustion of the char. Lime has also been shown to improve the yield and quality of the MCG liquids.

  8. Development of an advanced, continuous mild gasification process for the production of co-products

    SciTech Connect

    Cohen, L.R. ); Hogsett, R.F. ); Sinor, J.E. Consultants, Inc., Niwot, CO ); Ness, R.O. Jr.; Runge, B.D. . Energy and Environmental Research Center)

    1992-10-01

    The principal finding of this study was the high capital cost and poor financial performance predicted for the size and configuration of the plant design presented. The XBi financial assessment gave a disappointingly low base-case discounted cash flow rate of return (DCFRR) of only 8.1% based on a unit capital cost of $900 per ton year (tpy) for their 129,000 tpy design. This plant cost is in reasonable agreement with the preliminary estimates developed by J.E. Sinor Associates for a 117,000 tpy plant based on the FMC process with similar auxiliaries (Sinor, 1989), for which a unit capital costs of $938 tpy was predicted for a design that included char beneficiation and coal liquids upgrading--or about $779 tpy without the liquid upgrading facilities. The XBi assessment points out that a unit plant cost of $900 tpy is about three times the cost for a conventional coke oven, and therefore, outside the competitive range for commercialization. Modifications to improve process economics could involve increasing plant size, expanding the product slate that XBi has restricted to form coke and electricity, and simplifying the plant flow sheet by eliminating marginally effective cleaning steps and changing other key design parameters. Improving the financial performance of the proposed formed coke design to the level of a 20% DCFRR based on increased plant size alone would require a twenty-fold increase to a coal input of 20,000 tpd and a coke production of about 2.6 minion tpy--a scaling exponent of 0.70 to correct plant cost in relation to plant size.

  9. Development of an advanced, continuous mild gasification process for the production of co-products (Task 4.7), Volume 3. Final report

    SciTech Connect

    Knight, R.A.; Gissy, J.L.; Onischak, M.; Babu, S.P.; Carty, R.H.; Duthie, R.G.; Wootten, J.M.

    1991-09-01

    The focus of this task is the preparation of (1) preliminary piping and instrument diagrams (P&IDs) and single line electrical diagrams for a site-specific conceptual design and (2) a factored cost estimate for a 24 ton/day (tpd) capacity mild gasification process development unit (PDU) and an associated form coke preparation PDU. The intended site for this facility is the Illinois Coal Development Park at Carterville, Illinois, which is operated by Southern Illinois University at Carbondale. (VC)

  10. Novel concept development of an internal recirculation catalyst for mild gasification. Progress report, June 1, 1988--August 31, 1988

    SciTech Connect

    Knight, R.A.; Babu, S.P.; Martin, K.A.; Chao, S.C.

    1988-10-01

    The objective of this program is to provide an overall evaluation of a novel process concept for mild gasification by completing work in three major tasks: (1) Laboratory-Scale Experiments, (2) Bench-Scale Tests, and (3) Proof-of-Concept Tests and Evaluation (optional). During this quarter, experimental work involving potential recirculating catalysts for coal, initiated in the previous quarter, was continued. The construction and shakedown of an all quartz laboratory-scale isothermal free-fall reactor was completed. Three free-fall experiments were performed in an existing stainless-steel free-fall reactor with untreated and ammonia treated Illinois No. 6 high-voltatile bituminous coal, and the analyzed data are presented herein. A survey of available literature on catalyzed devolatilization of coal, coal pretreatment methods, and related topics was made. Based on the results of this survey, two potential recirculating catalysts, in addition to the already selected zinc chloride, were selected for study: ferrous chloride (FeCl{sub 2}) and ferric chloride (FeCl{sub 3}). Also, based on the survey, two coal pretreatment/chemical comminution methods were selected for study, in addition to methanol treatment: ammonia and n-butylamine pretreatment. A matrix of experiments was formulated to study the three catalysts and three pretreatment methods selected. 2 refs., 2 tabs.

  11. Upgrading mild gasification liquids to produce electrode binder pitch. Technical report, December 1, 1992--February 28, 1993

    SciTech Connect

    Knight, R.A.; Banerjee, D.

    1993-05-01

    The objective of this program is to investigate the production of electrode binder pitch from mild gasification liquids. The IGT MILDGAS process pyrolyzes coal in a 1000{degree}--1500{degree}F (538{degree}--816{degree}C) fluidized/entrained bed to produce solid, gas, and liquid co-products. With Illinois coal, the 750{degree} F+ (400{degree}C+) distillation residue (crude pitch) comprises 40--70% of the MILDGAS liquids, representing up to 20 wt % of feed coal. The largest market for pitch made from coal liquids is the aluminum industry, which uses it to make carbon anodes for electrolytic furnaces. Traditionally, binder pitches have only been made from high-temperature coke-oven tars. In this project, crude pitch from the DOE-sponsored MILDGAS process research program is being modified by a flash thermocracking technique to achieve specifications typical of a binder pitch. A pitch thermocracking unit has been constructed for operation at 1200{degree}--1800{degree}F (650{degree}--982{degree}C). Atomization of the pitch at the thermocracker inlet is being examined as a method of optimizing the particle size of polymerized pitch components. With the production of cracked pitch samples, test electrodes will be fabricated using the best performing pitch samples and petroleum coke or calcined pitch coke filler.

  12. Integrated production/use of ultra low-ash coal, premium liquids and clean char. [Quarterly] report, December 1, 1991--February 29, 1992

    SciTech Connect

    Kruse, C.W.

    1992-08-01

    The first step in the integrated, mufti-product approach for utilizing Illinois coal is the production of ultra low-ash coal. Subsequent steps convert low-ash coal to high-value, coal-derived, products. The ultra low-ash coal is produced by solubilizing coal in a phenolic solvent under ChemCoal{trademark} process conditions, separating the coal solution from insoluble ash, and then precipitating the clean coal by dilution of the solvent with methanol. Two major products, liquids and low-ash char, are then produced by mild gasification of the low-ash coal. The low ash-char is further upgraded to activated char, and/or an oxidized activated char which has catalytic properties. Characterization of products at each stage is part of this project.

  13. Upgrading mild gasification liquids to produce electrode binder pitch. [Quarterly] technical report, December 1, 1993--February 28, 1994

    SciTech Connect

    Knight, R.A.

    1994-06-01

    The objective of this program is to investigate the production of electrode binder pitch, valued at $250--$300/ton, from mild gasification liquids. The IGT MILDGAS process pyrolyzes coal at 1000{degrees}--1500{degrees}F and, with Illinois coal, the 750{degrees}F+ distillation residue (crude pitch) comprises 40--70% of the MILDGAS liquids, representing up to 20 wt% of maf feed coal. The largest market for pitch made from coal liquids is the aluminum industry, which uses it to make carbon anodes for electrolytic furnaces. In this project, crude MILDGAS pitch is being modified by a flash thermocracking technique to achieve specifications typical of a binder pitch. Last year, a pitch thermocracking unit was constructed for operation at 1200{degrees}--1600{degrees}F. Reactor design features and process conditions are being examined to optimize the properties of the finished pitch. In the current year, improvements to the thermocracker are being made for better gas and pitch flow control, continuous electronic monitoring of feed rate and pressures, and improvements to allow longer tests. Tests are being conducted under both inert and reducing gases. During the current quarter, equipment modifications, calibrations, and shakedown were completed, and thermocracking tests were resumed. One test was completed at 1600{degrees}F in N{sub 2} with a pitch rate of 11 g/min. Data from this and following tests will be presented in the next quarterly report. During the next quarter, thermocracking tests will be completed and selected products (pitch and/or pitch coke) will be submitted to an aluminum company testing lab for production and evaluation of test electrodes.

  14. Development of an advanced, continuous mild gasification process for the production of co-products. Quarterly technical progress report, October--December 1991

    SciTech Connect

    Runge, B.D.; Ness, R.O. Jr.

    1992-01-01

    On November 6, 1991, a meeting was held at the AMAX Research and Development Center in Golden, Colorado. Those in attendance at the meeting included Brian Runge and Robert Ness of the EERC, Scott McFeely of Xoi, Frank Hogsett and Mahesh Jha of AMAX, and Jerry Sinor and Trevor Ellis of J.E- Sinor Consultants. Items on the agenda included framing the scope of work to be conducted by Sinor on the market assessment for mild gasification products. An attempt was made to draft an integrated time line for the completion of all subcontracts issued under the project. The commercial process flowsheet under development by XBi was presented for review. The goals to be achieved by the technical and economic assessment to be performed by XBi were outlined. Frank Hogsett reported on the progress of the coal cleaning being conducted by AMAX. As soon as sufficient coal has been cleaned, the mild gasification reactors at the EERC will be run to generate sufficient quantities of products to allow testing of product upgrading and utilization methods. The next project review meeting was held on December 12, 1991, in the Houston, Texas, offices of XBi. The major work conducted during this meeting focused on review of the preliminary process flow diagrams (PFOS) prepared by XBi. Several modifications were discussed and will be reflected in the updated PFDs.

  15. The genotoxicity studies of mild gasification product, MRE{number_sign}1, in mammalian cells. [Quarterly technical progress report, July 1, 1993--September 30, 1993

    SciTech Connect

    Not Available

    1993-12-31

    The major hypothesis of carcinogenesis is that malignancy is due to an alteration (mutation) of the genetic material in a somatic cell. Reactive electrophilic metabolites are generated from many chemicals by the action of endogenous mixed function oxidases. These reactive metabolites may bind to cellular macromolecules such as DNA, and can, therefore, initiate a mutagenic or carcinogenic event. Prokaryotes and non-mammalian eukaryotes are used in mutation assays, while cultured mammalian cells are generally used for mutagenic as well as clastogenic tests examining alterations and damage to the DNA and/or chromosomes of somatic cells. One of the first mammalian cell lines used in genotoxicity studies is V79, which was derived from Chinese hamster lung cans. According to the test plan on toxicity studies of mild gasification products, mammalian cell in vitro assays are to be performed on selected samples displaying mutagenic activity in the Ames assay. The results of the Ames testing of the mild gasification sample MRE{number_sign}1 indicate weak, but significant mutagenic activity. Hence, assays for the induction of gene mutation, sister chromated exchange and micronucleus formation in V79 cells have been carried out for the sample. This paper reports the results of these assays.

  16. Adding value to coal conversion`s char: A strategy for lower-priced fuels

    SciTech Connect

    Kruse, C.W.; Fatemi, M.; Feizoulof, C.

    1994-12-31

    Coal`s low hydrogen to carbon ratio gives coal physical properties that are not the most desired in fuel markets. The problem is dealt with in conversion technologies designed to upgrade coal to more desirable fuels by either: (1) chemically adding hydrogen, as in liquefaction or high-BTU gasification, or (2) the production of char, as in mild gasification. The first option is neither cost-effective nor environmentally sound. Liquefaction results in the production of one mole of carbon dioxide for each mole of hydrogen needed. The result is that despite the preferred hydrogen to carbon ratio in the fuel, carbon dioxide is produced in greater quantities than it would be by simply burning the coal. The depressed market value of char is the primary drawback of coal utilization technologies exercising the second option. Making value-added, non-fuel products from char could significantly improve the economics of overall operations and result in competitively-priced premium hydrocarbon fuels. The research goal of a growing number of groups, including ours, is to produce and describe carbon products which will command higher prices than the carbon (coal) from which they were produced.

  17. Integrated methods for production of clean char and its combustion properties. [Quarterly] technical report, March 1, 1993--May 31, 1993

    SciTech Connect

    DeBarr, J.A.; Rostam-Abadi, M.; Gullett, B.K.; Benson, S.A.

    1993-09-01

    An integrated method consisting of physical coal cleaning, mild gasification (MG) and low temperature oxidation (LTO) is proposed to produce chars with SO{sub 2} emissions at least 50% lower than those of their parent coals. MG and char desulfurization studies are conducted in both a batch fluidized-bed reactor (FBR) and in a continuous rotary tube kiln (RTK). Combustion properties and ash deposition behaviors of desulfurized chars are determined at the US EPA in a 14 kill pilotscale combustor and at UNDEERC in a drop tube furnace (DTF). This project is cost-shared with the US EPA and the US DOE through UNDEERC. During the first year of this two year project, six coals from the IBC sample program (IBC-101, 102, 104, 105, 106 and 109) were studied. Under non-optimized conditions in the FBR, desulfurized chars were made with SO{sub 2} emissions 60--71% lower than the parent coals, depending on the coal. Chars prepared from four of the six coals had SO{sub 2} emissions less than 2.5 lbs SO{sub 2}/MMBtu. Under optimum conditions, SO{sub 2} emissions of one of the coals were reduced nearly 67%, from 4.60 to 1.49 lbs SO{sub 2}/MMBtu. MG reduced the chlorine content of one coal 93%.

  18. Combustion properties of coal-char blends: NO{sub x} emission characteristics. Interim final technical report, September 1, 1992--August 31, 1993

    SciTech Connect

    Rostam-Abadi, M.; Khan, L.; Khan, S.; Smoot, L.D.; Germane, G.J.; Eatough, C.N.

    1993-12-31

    Under pulverized coal combustion conditions, NO{sub x} formed during the release of volatile matter far exceed NO{sub x} formed from combustion of the resulting char. It is believed that interactions of NO{sub x} with char is responsible for the reduced NO{sub x} formation from the combustion of char. The goal of this research is to assess the potential technical and economical benefits of co-firing coal-char blends in pulverized coal boilers to reduce NO{sub x}. The rationale for the proposed research is that the presence of char in the flame during the initial stages of combustion may provide catalytic activity for reduction of NO{sub x} produced from volatile nitrogen. This project is a cooperative effort between the Illinois State Geological Survey (ISGS) and BYU/ACERC. Seven hundred and fifty pounds of three coal-char blends containing 12.5%, 25%, and 50% char and 125 pounds of a coal-activated carbon blend containing 12.5% activated carbon were prepared. The volatile matter contents of the blends ranged from 27.3 to 35.6% (dry basis). Char (16.2 wt% volatile matter) was made from an Illinois No. 6 coal (Peabody Coal Company) in a continuous feed charring oven under mild gasification conditions. Nine combustion tests will be performed with the coal and blends in a 0.5--1.0 MBtu/hr combustor located at BYU. Combustion data will be analyzed to determine the effect of blend type, stoichiometry, and flame temperature on NO{sub x} formation, ignition characteristics, flame stability, and combustion efficiency. A four month no-cost extension has been requested for the project. The results of the combustion tests will be reported in the final technical report in December 1993.

  19. Char separator

    DOEpatents

    Matthews, Francis T.

    1979-01-01

    Particulates removed from the flue gases produced in a fluidized-bed furnace are separated into high-and low-density portions. The low-density portion is predominantly char, and it is returned to the furnace or burned in a separate carbon burnup cell. The high-density portion, which is predominantly limestone products and ash, is discarded or reprocessed. According to another version, the material drained from the bed is separated, the resulting high-and low-density portions being treated in a manner similar to that in which the flue-gas particulates are treated.

  20. Scale-up of mild gasification to be a process development unit mildgas 24 ton/day PDU design report. Final report, November 1991--July 1996

    SciTech Connect

    1996-03-01

    From November 1991 to April 1996, Kerr McGee Coal Corporation (K-M Coal) led a project to develop the Institute of Gas Technology (IGT) Mild Gasification (MILDGAS) process for near-term commercialization. The specific objectives of the program were to: design, construct, and operate a 24-tons/day adiabatic process development unit (PDU) to obtain process performance data suitable for further design scale-up; obtain large batches of coal-derived co-products for industrial evaluation; prepare a detailed design of a demonstration unit; and develop technical and economic plans for commercialization of the MILDGAS process. The project team for the PDU development program consisted of: K-M Coal, IGT, Bechtel Corporation, Southern Illinois University at Carbondale (SIUC), General Motors (GM), Pellet Technology Corporation (PTC), LTV Steel, Armco Steel, Reilly Industries, and Auto Research.

  1. Ames test mutagenicity studies of the subfractions of the mild gasification composite material, MG-120. [Quarterly report, January--March 1992

    SciTech Connect

    Not Available

    1992-04-17

    Mutagenicity of six mild gasification product samples was studied using the Ames Salmonella/microsomal assay system. The results of the Ames testing of the MG-119 and MG-120 subfractions indicate significant mutagenic activity only in the nonpolar neutral fraction. The activity was evident on bacterial strains, TA98 and TA100, with and without metabolic activation for MG-120, and with metabolic activation for MG-119. Previous testing of MG-119 and MG-120 when solvated in DMSO had shown possible, but unconfirmable, mutagenic activity. Tween 80-solvated MG-119 and MG-120 showed low, but significant, mutagenic activity only on TA98 with metabolic activation. Comparison of these results indicate an inhibition of the mutagenic components by nonmutagenic components in the complex mixture. 4 refs., 2 tabs.

  2. Analyzing organic sulfur in coal/char: Integrated mild degradation/XANES methods. [Quarterly] technical report, December 1, 1993--February 28, 1994

    SciTech Connect

    Palmer, S.R.; Huffman, G.P.

    1994-06-01

    The cost effective removal of sulfur from coal has been very difficult to accomplish. Perhaps the single most important reason for this is the fact that the organic sulfur in coal remains very poorly characterized. The overall goal of this study is to improve our understanding of sulfur in coals/chars via the use of combined advanced non-destructive and advanced destructive methods of sulfur analysis. This study combines selective oxidation, analytical pyrolysis, and sulfur X-ray Absorption Near Edge Structure Spectroscopy (XANES) analysis. Examination of samples that were oxidized with peroxyacetic acid using the analytical pyrolysis technique showed that the level of simple thiophene structures observed in the pyrolysis products declines with increasing levels of oxidation. Sulfur XANES spectra of treated samples showed various effects depending on the treatment severity. For the less severely treated samples (demineralization and solvent extraction), the XANES spectra were similar, although not identical, to the untreated coal spectra, whereas the more severe treatments (steam at 450{degree}C; peroxyacetic acid at 25{degree}C) showed preferential oxidation of one or more sulfur-bearing phases in the original coal.

  3. Development of an advanced continuous mild gasification process for the production of co-products. Quarterly report, October--December 1995

    SciTech Connect

    O`Neal, G.W.

    1996-01-01

    Efforts continued to obtain financing for a commercial continuous formed coke plant. Discussions were held with two steel companies that are interested in producing coke for their use in steel production and foundry operations. Planning for production of 40 tons of foundry formed coke is underway. This coke will be used in two 20-ton tests at General Motors` foundries. During this production, it is planned to determine if a tunnel kiln can be used as a coking furnace as an alternative for a rotary hearth. A rotary hearth is about three times more costly than a competitive-sized tunnel kiln. Work continued on using Western non-caking coals to produce formed coke. Successful tests were made by using Eastern caking coals and other binders to permit using up to 50% of the cheaper Western non-caking coals in formed coke production. The primary objective of this project is to develop an advanced continuous mild gasification process and product upgrading processes which will be capable of eventual commercialization.

  4. Mutagenicity of Tween 80-solvated mild gasification products in the Ames salmonella microsomal assay system. [Quarterly report, October--December 1991

    SciTech Connect

    Not Available

    1992-01-13

    The results of the Tween 80-solvated Ames testing of six mild gasification samples indicate significant mutagenic activity only in the composite materials (MG-119 and MG-120), previously suspected from the DMSO-solvated assays, which had shown some variable but ultimately insignificant mutagenic responses. The activity of these samples from the Tween 80-solvated assays was quite low when compared to either the positive controls or the SRC-II HD coal-liquefaction reference material. The class of mutagenic activity expressed by these samples solvated in Tween 80 was that of an indirect-acting, frameshift mutagen(s) since significant activity was found only on tester strain TA98 in the presence of the metabolic activation fraction (S9). Because DMSO and other solvents have been shown to affect the mutagenic activity of certain pure chemicals, the possibility of solvent/mutagen interactions in complex mixtures such as coal-derived liquids exists. Thus, the testing of the genotoxic activity of undefined, chemically complex compounds may require the use of at least two solvent systems to reduce the possibility of artifactual findings. 10 refs., 4 tabs.

  5. Reactivity of young chars via energetic distribution measurements. Final report, 1 September 1990--31 December 1994

    SciTech Connect

    Calo, J.M.; Zhang, L.; Lu, W.; Lilly, W.D.

    1996-01-01

    We have developed what we believe to be the very first, a priori, correlation/prediction technique for the gasification reactivity of coal char. With this method the gasification reactivity of a coal char as a function of temperature can be correlated using the data from a temperature programmed desorption (TPD) experiment following gasification under conditions where the reactivity is controlled by the thermal desorption of oxygen surface complexes formed during gasification. The current project was directed at extending and developing related techniques for the characterization and prediction/correlation of the reactivity of the ``young`` chars to CO{sub 2} and steam. Of particular interest was mapping of the reactivity behavior of the resultant chars, as revealed by the energetic heterogeneity of the complexes with char preparation conditions.

  6. Chemical characterization of chars developed from thermochemical treatment of Kentucky bluegrass seed screenings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Char produced from the gasification of post-seed harvest Kentucky bluegrass residues could be recycled to a cropping system as a soil amendment if chemical characterization determined that the gasification process had not produced or concentrated deleterious chemical or physical factors that might h...

  7. Coal gasification cogeneration process

    SciTech Connect

    Marten, J.H.

    1990-10-16

    This patent describes a process for the coproduction of a combustible first gas stream usable as an energy source, a sulfur-dioxide-containing second gas stream usable as a source for oxidant in the gasification of coal and a sulfur-dioxide-containing third gas stream usable as a feedstock for the production of sulfuric acid. It comprises: reacting coal in a coal gasification zone in the presence of an oxidant under partial coal-gasifying conditions to produce carbonaceous char and a crude gas stream; separating sulfur-containing compounds from the crude gas stream in a sulfur recovery zone to produce a combustible first gas stream and elemental sulfur; reacting the carbonaceous char and gypsum in a reaction zone in proportions such that the non-gypsum portion of the carbonaceous char and gypsum mixture contains sufficient reducing potential to reduce sulfur in the gypsum to gaseous compounds of sulfur in a +4 or lower oxidation state under reducing conditions to produce first a sulfur-dioxide-containing second gas stream which contains weaker SO{sub 2} produced in an early stage of the reaction zone and removed from the reaction zone, and then a sulfur-dioxide-containing third gas stream which contains concentrated SO{sub 2} recovered from a later stage of the reaction zone.

  8. Physical beneficiation of char and chemically conditioned coal

    SciTech Connect

    Warzinski, R.P.; Cavallaro, J.A.

    1986-04-01

    Demineralization of coals and coal-derived chars is part of an effort to develop alternative fuels from coal. Pyrolysis and some gasification processes yield chars containing a large fraction of the calorific value of the feed coal and essentially all of its mineral matter. In the work reported here, three gasification chars produced from anthracite, bituminous, and subbituminous coals have been subjected to specific gravity separation to determine their yield-ash relationships. Either low yields or high ash levels in the float products were observed. Also reported is preliminary work concerning the use of chemical conditioning to enhance the cleanability of coal prior to physical beneficiation. Conditioning of an Illinois No. 6 River King Mine coal with either supercritical methanol or cyclohexane resulted in an improved yield-ash relationship, whereas similar treatment with supercritical toluene had a negative effect.

  9. Influence of sulfur in coals on char morphology and combustion

    SciTech Connect

    Marsh, H.

    1991-01-01

    During coal carbonization (pyrolysis), as during the combustion process of pulverized coal in a combustor, not all of the sulfur is released. Significant proportions become pat of the structure of the resultant coke and char. The combustion process of the char within the flames of the combustor in influenced dominantly by char morphology. This, in turn, controls the accessibility of oxidizing gases to the surfaces of the carbonaceous substance of the char. Mineral matter content, its extent and state of distribution, also exerts an influence on char morphology created during pyrolysis/carbonization. This complexity of coal renders it a very difficult material to study, systematically, to distinguish and separate out the contributing factors which influence combustion characteristics. Therefore, in such circumstances, it is necessary to simplify the systems by making use of model chars/cokes/carbons which can be made progressively more complex, but in a controlled way. In this way complicating influence in chars from coals can be eliminated, so enabling specific influences to be studied independently. It is important to note that preliminary work by Marsh and Gryglewicz (1990) indicated that levels of sulfur of about 3 to 5 wt % can reduce reactivities by 10 to 25%. The overall purpose of the study is to provide meaningful kinetic data to establish, quantitatively, the influence of organically-bound sulfur on the reactivity of carbons, and to ascertain if gasification catalysts are effective in the preferential removal of sulfur from the chars.

  10. Clean, premium-quality chars: Demineralized and carbon enriched. Final technical report, 1 September, 1992--31 August, 1993

    SciTech Connect

    Smith, G.V.; Malhotra, V.M.; Wiltowski, T.

    1993-12-31

    The overall objective of this two-year project was to evaluate methods of preparing demineralized and carbon enriched chars from Illinois Basin coals. The two processing steps, physical cleaning and devolatilization under different environments, led to the following results. Cleaning coal incompletely removes mineral matter which decreases catalytic activity and increases micropore structure. Water forms hydrogen bonds to oxygen functional groups in coal, and during drying, coals undergo structural changes which affect mild gasification. When methane reacts wit coal, devolatilization and carbon deposition occur, the rates of which depend on temperature and amount of ash. Thermal decomposition of IBC-101 coal starts at 300 C, which is much lower than previously believed, but maximum yields of liquids occur at 500 C for IBC-101 coal and at 550 C for IBC-102 coal. Aliphatic-to-aromatic ratios increase with increasing pyrolysis temperatures to 300 C and then decrease; therefore, liquids formed during gasification of 550 C or higher contain mainly aromatic compounds. Btu values of chars are higher after methane treatment than after helium treatment.

  11. Effect of temperature and pressure on characteristics and reactivity of biomass-derived chars.

    PubMed

    Recari, J; Berrueco, C; Abelló, S; Montané, D; Farriol, X

    2014-10-01

    This study evaluates the influence of pyrolysis temperature (350-450°C) and pressure (0.1-2.0MPa) on product yields and char properties. Spruce chars were produced under slow pyrolysis conditions in a fixed bed reactor. Special attention was devoted to the study of the oxidation reactivity of the produced chars, and its relationship with the evaluated char properties. The obtained results showed that the effect of the pyrolysis condition on char production and in particular on the mechanism of secondary char formation strongly influenced the char reactivity. Additionally it has been observed that the interval of temperature between 350 and 450°C may be key in the mechanism of tar repolymerization. The information provided in this study is of great interest for the determination of optimal operation conditions and the design of new gasification concepts or the development of bioenergy carriers via pyrolysis technologies. PMID:25146312

  12. Combustion Characteristics of Lignite Char in a Laboratory-scale Pressurized Fluidized Bed Combustor

    NASA Astrophysics Data System (ADS)

    Murakami, Takahiro; Suzuki, Yoshizo

    In a dual fluidized bed gasifier, the residual char after steam gasification is burnt in riser. The objectives of this work are to clarify the effect of parameters (temperature, pressure, and particle size of lignite char) of char combustion using a laboratory-scale pressurized fluidized bed combustor (PFBC). As a result, the burnout time of lignite char can be improved with increasing operating pressure, and temperature. In addition, the decrease in the particle size of char enhanced the effect on burnout time. The initial combustion rate of the char can be increased with increasing operating pressure. The effect was decreased with increasing operating temperature. However, the effect of operating pressure was slightly changed in small particle size, such as 0.5-1.0 mm. It takes about 20 sec to burn 50% of char in the operating pressure of 0.5 MPa and the particle size of 0.5-1.0 mm.

  13. Treatment of Mixed Wastes via Fixed Bed Gasification

    SciTech Connect

    1998-10-28

    This report outlines the details of research performed under USDOE Cooperative Agreement DE-FC21-96MC33258 to evaluate the ChemChar hazardous waste system for the destruction of mixed wastes, defined as those that contain both RCRA-regulated haz- ardous constituents and radionuclides. The ChemChar gasification system uses a granular carbonaceous char matrix to immobilize wastes and feed them into the gasifier. In the gasifier wastes are subjected to high temperature reducing conditions, which destroy the organic constituents and immobilize radionuclides on the regenerated char. Only about 10 percent of the char is consumed on each pass through the gasifier, and the regenerated char can be used to treat additional wastes. When tested on a 4-inch diameter scale with a continuous feed unit as part of this research, the ChemChar gasification system was found to be effective in destroying RCRA surrogate organic wastes (chlorobenzene, dichloroben- zene, and napht.halene) while retaining on the char RCRA heavy metals (chromium, nickel, lead, and cadmium) as well as a fission product surrogate (cesium) and a plutonium surrogate (cerium). No generation of harmful byproducts was observed. This report describes the design and testing of the ChemChar gasification system and gives the operating procedures to be followed in using the system safely and effectively for mixed waste treatment.

  14. High temperature steam gasification of solid wastes: Characteristics and kinetics

    NASA Astrophysics Data System (ADS)

    Gomaa, Islam Ahmed

    Greater use of renewable energy sources is of pinnacle importance especially with the limited reserves of fossil fuels. It is expected that future energy use will have increased utilization of different energy sources, including biomass, municipal solid wastes, industrial wastes, agricultural wastes and other low grade fuels. Gasification is a good practical solution to solve the growing problem of landfills, with simultaneous energy extraction and nonleachable minimum residue. Gasification also provides good solution to the problem of plastics and rubber in to useful fuel. The characteristics and kinetics of syngas evolution from the gasification of different samples is examined here. The characteristics of syngas based on its quality, distribution of chemical species, carbon conversion efficiency, thermal efficiency and hydrogen concentration has been examined. Modeling the kinetics of syngas evolution from the process is also examined. Models are compared with the experimental results. Experimental results on the gasification and pyrolysis of several solid wastes, such as, biomass, plastics and mixture of char based and plastic fuels have been provided. Differences and similarities in the behavior of char based fuel and a plastic sample has been discussed. Global reaction mechanisms of char based fuel as well polystyrene gasification are presented based on the characteristic of syngas evolution. The mixture of polyethylene and woodchips gasification provided superior results in terms of syngas yield, hydrogen yield, total hydrocarbons yield, energy yield and apparent thermal efficiency from polyethylene-woodchips blends as compared to expected weighed average yields from gasification of the individual components. A possible interaction mechanism has been established to explain the synergetic effect of co-gasification of woodchips and polyethylene. Kinetics of char gasification is presented with special consideration of sample temperature, catalytic effect of ash

  15. Fate of heavy metals and radioactive metals in gasification of sewage sludge

    SciTech Connect

    Marrero, Thomas W.; McAuley, Brendan P.; Sutterlin, William R.; Steven Morris, J.; Manahan, Stanley E

    2004-07-01

    The fates of radioactive cadmium, strontium, cesium, cobalt, arsenic, mercury, zinc, and copper spiked into sewage sludge were determined when the sludge was gasified by a process that maximizes production of char from the sludge (ChemChar process). For the most part the metals were retained in the char product in the gasifier. Small, but measurable quantities of arsenic were mobilized by gasification and slightly more than 1% of the arsenic was detected in the effluent gas. Mercury was largely mobilized from the solids in the gasifier, but most of the mercury was retained in a filter composed of char prepared from the sludge. The small amounts of mercury leaving the gasification system were found to be associated with an aerosol product generated during gasification. The metals retained in the char product of gasification were only partially leachable with 50% concentrated nitric acid.

  16. Production of mild gasification coproducts

    SciTech Connect

    1994-12-01

    In summary, the co-product production runs performed by the SGI Development Center yielded sufficient simulated PDF (process derived fuel) and CDL (coal derived liquid) to meet the production needs for each of the four coals. The LFC Process appears to be an attractive method for upgrading all of the coals except for the Knife River Coal because of its limited yield and difficulty in processing. The Buckskin coal appears to be a slightly stronger candidate for upgrading than the other three coals because it has the greatest CDL yield and a more than 50% increase in heating value from ROM to PDF. (LFC processing of Usibelli and Sarpy Creek coal produces more PDF, but the heating value increase is less and the oil yields are low. Processing Knife River coal produces much less PDF but a greater heating value increase because of its higher moisture content). Finally, in all cases, the LFC Process removed significant percentage of the organic sulfur, clearly demonstrating its coal cleaning potential.

  17. Solar coal gasification reactor with pyrolysis gas recycle

    DOEpatents

    Aiman, William R.; Gregg, David W.

    1983-01-01

    Coal (or other carbonaceous matter, such as biomass) is converted into a duct gas that is substantially free from hydrocarbons. The coal is fed into a solar reactor (10), and solar energy (20) is directed into the reactor onto coal char, creating a gasification front (16) and a pyrolysis front (12). A gasification zone (32) is produced well above the coal level within the reactor. A pyrolysis zone (34) is produced immediately above the coal level. Steam (18), injected into the reactor adjacent to the gasification zone (32), reacts with char to generate product gases. Solar energy supplies the energy for the endothermic steam-char reaction. The hot product gases (38) flow from the gasification zone (32) to the pyrolysis zone (34) to generate hot char. Gases (38) are withdrawn from the pyrolysis zone (34) and reinjected into the region of the reactor adjacent the gasification zone (32). This eliminates hydrocarbons in the gas by steam reformation on the hot char. The product gas (14) is withdrawn from a region of the reactor between the gasification zone (32) and the pyrolysis zone (34). The product gas will be free of tar and other hydrocarbons, and thus be suitable for use in many processes.

  18. Computer molecular models of low-rank coal and char containing inorganic complexes.

    PubMed

    Domazetis, George; James, Bruce D; Liesegang, John

    2008-07-01

    Molecular models of low-rank coal containing water, aqua-ionic species, and transition metal aqua-complexes, were optimised using semi-empirical (SE) quantum mechanics; the model was constructed with properties similar to brown coal; 10-20 wt% water was hydrogen bonded to coal oxygen groups, and the remainder was bulk water. Single point self-consistent field (1scf) computations of coal models provided octahedral mono-, and di-nuclear complexes of Cr, Fe, Co, and Ni, but SE computations often provided distorted structures. Models of char were developed by transforming the coal model containing multi-nuclear metal species into char according to pyrolysis chemistry; the composition of char models containing iron oxides was similar to char samples obtained over 250-800 degrees C. Density functional theory (DFT) optimisation of char models with metal clusters provided low energy configurations of disordered structures with a shallow energy minimum. SE and DFT calculations of char models containing metal clusters were conducted for mechanisms for H2 and CO formation from pyrolysis and iron-catalysed steam gasification; the active site for gasification was [Fe-C] and its accessibility to H2O was related to the configuration of the char model. The major steps in iron-catalysed steam gasification were chemi-adsorption of water on [Fe-C], hydrogen abstraction, and oxygen transfer. PMID:18478281

  19. Chemisorption, reaction and desorption studies of coal chars in steam, oxygen and carbon dioxide. Final report, January 1986-December 1989

    SciTech Connect

    Radovic, L.R.; Lizzio, A.A.; Jiang, H.

    1990-09-01

    The use of a transient kinetics (TK) technique allowed a direct measurement of reactive surface area (RSA) for chars gasified in both CO{sub 2} and O{sub 2}, i.e., gasification rates normalized with respect to RSA were essentially constant over the entire conversion range. A temperature-programmed desorption (TPD) technique was also used to determine the amount of reactive surface intermediate formed on the chars during gasification in CO{sub 2} and O{sub 2}; the results were in good agreement with those obtained by TK. In addition, TPD allowed an important distinction to be made between the stable C-O complexes and reactive C(O) intermediates residing on the char surface during gasification in CO{sub 2} and O{sub 2}. The application of the two independent but complementary techniques provided a satisfactory quantitative understanding of char reactivity variations with conversion in CO{sub 2} and O{sub 2}. Both techniques possess the unique capability of separately determining the reaction rate constant (site reactivity or turnover frequency) and the number of active sites participating in the reaction (RSA). A comparison of turnover frequencies for different chars gasified in 1 atm CO{sub 2} suggested that char gasification may be a structure sensitive reaction. The concept of reactive surface area was also used to achieve a better quantitative understanding of catalyzed char reactivity variations with conversion in carbon dioxide.

  20. Conversion of microwave pyrolysed ASR's char using high temperature agents.

    PubMed

    Donaj, Pawel; Blasiak, Wlodzimierz; Yang, Weihong; Forsgren, Christer

    2011-01-15

    Pyrolysis enables to recover metals and organic feedstock from waste conglomerates such as: automotive shredder residue (ASR). ASR as well as its pyrolysis solid products, is a morphologically and chemically varied mixture, containing mineral materials, including hazardous heavy metals. The aim of the work is to generate fundamental knowledge on the conversion of the organic residues of the solid products after ASR's microwave pyrolysis, treated at various temperatures and with two different types of gasifying agent: pure steam or 3% (v/v) of oxygen. The research is conducted using a lab-scale, plug-flow gasifier, with an integrated scale for analysing mass loss changes over time of experiment, serving as macro TG at 950, 850 and 760 °C. The reaction rate of char decomposition was investigated, based on carbon conversion during gasification and pyrolysis stage. It was found in both fractions that char conversion rate decreases with the rise of external gas temperature, regardless of the gasifying agent. No significant differences between the reaction rates undergoing with steam and oxygen for char decomposition has been observed. This abnormal char behaviour might have been caused by the inhibiting effects of ash, especially alkali metals on char activity or due to deformation of char structure during microwave heating. PMID:20940079

  1. Method and apparatus for removing coarse unentrained char particles from the second stage of a two-stage coal gasifier

    DOEpatents

    Donath, Ernest E.

    1976-01-01

    A method and apparatus for removing oversized, unentrained char particles from a two-stage coal gasification process so as to prevent clogging or plugging of the communicating passage between the two gasification stages. In the first stage of the process, recycled process char passes upwardly while reacting with steam and oxygen to yield a first stage synthesis gas containing hydrogen and oxides of carbon. In the second stage, the synthesis gas passes upwardly with coal and steam which react to yield partially gasified char entrained in a second stage product gas containing methane, hydrogen, and oxides of carbon. Agglomerated char particles, which result from caking coal particles in the second stage and are too heavy to be entrained in the second stage product gas, are removed through an outlet in the bottom of the second stage, the particles being separated from smaller char particles by a counter-current of steam injected into the outlet.

  2. A new mathematical solution for predicting char activation reactions

    USGS Publications Warehouse

    Rafsanjani, H.H.; Jamshidi, E.; Rostam-Abadi, M.

    2002-01-01

    The differential conservation equations that describe typical gas-solid reactions, such as activation of coal chars, yield a set of coupled second-order partial differential equations. The solution of these coupled equations by exact analytical methods is impossible. In addition, an approximate or exact solution only provides predictions for either reaction- or diffusion-controlling cases. A new mathematical solution, the quantize method (QM), was applied to predict the gasification rates of coal char when both chemical reaction and diffusion through the porous char are present. Carbon conversion rates predicted by the QM were in closer agreement with the experimental data than those predicted by the random pore model and the simple particle model. ?? 2002 Elsevier Science Ltd. All rights reserved.

  3. Investigating the morphology and reactivity of chars from Triplochiton scleroxylon pyrolysed under varied conditions.

    PubMed

    Oluoti, Kehinde; Pettersson, Anita; Richards, Tobias

    2016-05-01

    A gasifier may be optimised via a good understanding of the char formation, morphology and reactivity. The effects of varying the pyrolysis pressure and heating rate on the morphology of the char were investigated using a thermogravimetric analyser (TGA), scanning electron microscope (SEM) and micrograph spot analyser. The gasified chars were produced at heating rates of 5, 10 and 20°C/min and pressures of 0.1, 0.4 and 0.6 MPa. All the chars have different degrees of apparent gasification reactivity. The random pore model (RPM) provided a better description of the experiment, with low average error values, θ, in all of the cases considered. The alkaline and alkaline earth metals (AAEM) in the tropical wood biomass Arere (Triplochiton scleroxylon) consist predominantly of calcium and could altogether be partly responsible for the noticeably high reactivity nature of the tropical Arere chars. PMID:26926201

  4. Char from sugarcane bagasse

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unused sugarcane bagasse represents an underutilized resource in sugarcane growing regions of the world. This is a renewable resource that can be used in a thermochemical process to create chars, which could be incorporated back into agricultural activities. The practice is likely to improve soil ...

  5. Experimental investigations of biomass gasification with carbon-dioxide

    NASA Astrophysics Data System (ADS)

    Sircar, Indraneel

    A sustainable energy cycle may include enhanced utilization of solar energy and atmospheric CO2 to produce biomass and enhanced utilization of exhaust CO2 from power plants for synthetic gas production. The reaction of carbon with CO2 is potentially one of the important processes in a future sustainable carbon cycle. Reactions involving carbon and CO2 are also relevant to the chemical process and metal industries. Biomass char has been recognized as a present and future alternative to fossil-fuels for energy production and fuel synthesis. Therefore, biomass char gasification with CO2 recycling is proposed as a sustainable and carbon-neutral energy technology. Biomass char is a complex porous solid and its gasification involves heat and mass transfer processes within pores of multiple sizes from nanometer to millimeter scales. These processes are coupled with heterogeneous chemistry at the internal and external surfaces. Rates for the heterogeneous carbon gasification reactions are affected by inorganic content of the char. Furthermore, pore structure of the char develops with conversion and influences apparent gasification rates. Effective modeling of the gasification reactions has relied on the best available understanding of diffusion processes and kinetic rate property constants from state of the art experiments. Improvement of the influences of inorganic composition, and process parameters, such as pressure and temperature on the gasification reaction rates has been a continuous process. Economic viability of gasification relies on use of optimum catalysts. These aspects of the current status of gasification technologies have motivated the work reported in this dissertation. The reactions between biomass chars and CO2 are investigated to determine the effects of temperature and pressure on the reaction rates for large char particles of relevance to practical gasification technologies. An experimental apparatus consisting of a high-pressure fixed-bed reactor

  6. Gasification of agricultural residues (biomass): Influence of inorganic constituents

    SciTech Connect

    DeGroot, W.F.; Kannan, M.P.; Richards, G.N. ); Theander, O. )

    1990-01-01

    Four different biomass samples are included in this study, viz., sphagnum peat, wheat straw, sugar beet pulp, and potato pulp. They were chosen to represent a wide range of plant origin and inorganic content. This paper represents a preliminary investigation of an approach based on pyrolysis of biomass to produce volatile products and chars, followed by gasification of the chars. The particular interest lies in the investigation of the influence of the indigenous metal ions on the rate of gasification. Carbon dioxide has been used for the gasification, and the biomass was analyzed for nine metals, uronic acids (which are implicated in the binding of inorganic counterions), protein, and Klason lignin. The highest individual metal ion content was 13,964 ppm of potassium in potato pulp, and the gasification rates, under constant conditions, covered up to a 20-fold range, with char from potato pulp being the most readily gasified and char from peat the most resistant. The correlation of gasification rates with content of the major metal ions (alkali metals and alkaline earths) was poor. However, a high level of correlation was observed when wheat straw was omitted. It is speculated that the latter biomass may be anomalous with respect to the other three because of its high silica content.

  7. Pyrolysis and gasification of lignocellulosic solid wastes for activated-carbon production

    SciTech Connect

    Mackay, D.M.

    1981-01-01

    The production process under consideration was pyrolysis of raw solid-waste material (precursor) to form a carbonaceous char followed by activation, or expansion of the pore system of the char by gasification with carbon dioxide at 900/sup 0/C. Char yield was found to be determined by precursor composition (percent lignin, holocellulose, etc.) and pyrolysis heating rate. Both factors were found to exert their main influence on char yield during pyrolysis below 500/sup 0/C. Selected chars prepared by pyrolysis at the lower heating rates (1 and 15/sup 0/C/min) to 500/sup 0/, 700/sup 0/, and 900/sup 0/C were gasified for various lengths of time in a CO/sub 2/ atmosphere at 900/sup 0/C. Pore-volume analysis of the final products was performed by nitrogen adsorption 77K and mercury porosimetry. The rate of mass loss and development of the pore system during gasification was found to vary with prior pyrolysis conditions: e.g., low heating rate or longer exposure to high temperature during pyrolysis led to lower rate of gasification. However, the pore volume developed for a given mass loss due to gasification reactions was independent of prior pyrolysis conditions. The latter result was apparently due to the similarity of the pore systems present in the chars immediately prior to the onset of the gasification reactions, i.e. after the char had heated to the gasification temperature. Because the heating rate during pyrolysis below 500/sup 0/C was the critical factor controlling char yield at 900/sup 0/C, the final yield of activated carbon (i.e. gasified char) of a specified pore volume was also influenced mainly by the pyrolysis heating rate below 500/sup 0/C.

  8. Role of char during reburning of nitrogen oxides. Eighth quarterly report, July 1, 1995--September 30, 1995

    SciTech Connect

    Chen, Wei-Yin; Lu, Te-Chang; Fan, L.T.; Yashima, Mutsuo

    1995-11-05

    The investigation of this quarter focuses on the rates of NO reactions with chars in various gaseous environments. The results have revealed significant insights into the NO reduction mechanisms on char surface, particularly when the oxidants, O{sub 2} and CO{sub 2}, are introduced into the feed. Indeed, evidences suggest that the formation of stable oxygen complexes is the major cause of differences in NO reactivity on chars of different origins. The oxidants retard the reactivity of char derived fro the bituminous coal more seriously than they affect the char derived from lignite. Furthermore, additions of these oxidants into the reacting stream produce additional yields of CO and CO{sub 2} during NO reaction with lignite char, suggesting gasification of carbon from lignite char. No excess CO and CO{sub 2} were observed when the bituminous coal char was used. These yields of CO and CO{sub 2} also imply that desorption of stable surface oxygen complex is a rate-limiting step which may be catalyzed by the mineral matters during reactions involving lignite char. Surface area evaluated by CO{sub 2} and Dubinin-Radushkevich (D-R) equation is not a normalization factor of char reactivity during reburning. In the absence of oxidants, the bituminous coal char shows drastic increase in activation energy at about 950 {degrees}C indicating transition of desorption to adsorption controlled mechanisms. When CO{sub 2} is introduced, the transition temperature increases. When oxygen is also added, no such transition is observed up to 1100 {degrees}C. Lignite char reactivity increases smoothly over the temperature range 800 to 1100 {degrees}C. It is also observed that char reactivity decreases with increasing pyrolysis temperature which may be caused by closure of pores due to graphitization. The rate of NO reduction on the Pittsburgh {number_sign}8 coal char is then in good accord with that of a West Virginia coal char reported by De Soete (1980).

  9. Solar coal gasification - Plant design and economics

    NASA Astrophysics Data System (ADS)

    Aiman, W. R.; Thorsness, C. B.; Gregg, D. W.

    A plant design and economic analysis is presented for solar coal gasification (SCG). Coal pyrolysis and char gasification to form the gasified product are reviewed, noting that the endothermic gasification reactions occur only at temperatures exceeding 1000 K, an energy input of 101-136 kJ/mol of char reformed. Use of solar heat offers the possibility of replacing fuels needed to perform the gasification and the oxygen necessary in order to produce a nitrogen-free product. Reactions, energetics, and byproducts from the gasification of subbituminous coal are modeled for a process analysis code used for the SCG plant. Gas generation is designed to occur in a unit exposed to the solar flux focus from a heliostat field. The SCG gas would have an H2 content of 88%, compared to the 55% offered by the Lurgi process. Initial capital costs for the SCG plant are projected to be 4 times those with the Lurgi process, with equality being achieved when coal costs $4/gJ.

  10. Development of an advanced continuous mild gasification process for the production of co-products. Quarterly report, January--March, 1996

    SciTech Connect

    O`Neal, G.W.

    1996-04-01

    Determination of the best furnace for a commercial coke plant is underway. A shuttle or tunnel kiln has economic advantage over a rotary hearth design. Production of 20 tons of coke in a small shuttle kiln is near completion which will provide experience for this design. Twenty tons of CTC continuous coke are being produced for testing at a General Motors` foundry. The production is approximately 75 percent complete. During this production, variables of the process are being studied to aid in design of a commercial coke plant. Raw material composition, blending, briquetting variables, and calcining heat profile are the major areas of interest. Western SynCoal Company produces a dried coal product from sub-bituminous coal. This upgraded product was evaluated for producing coke products by blending char from this coal product with the coal product along with suitable binders. The green briquettes were then calcined to produce coke. The resulting coke was judged to be usable as part of a cupola coke charge or as a fuel in cement kilns and sugar beet furnaces.

  11. Char-amended farm soils – effects on soil chemistry and wheat growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    On-farm gasification of agricultural residues, the non-food byproducts from crop harvests, could provide a means to generate value-added income from the production of fuel or electrical generation. Char produced during the process also has potential value as a soil amendment to adjust acid soil pH (...

  12. Distribution of nitrogen species during vitrinite pyrolysis and gasification

    SciTech Connect

    Lin, J.Y.; Li, W.Y.; Chang, L.P.; Feng, J.; Zhao, W.; Xie, K.C.

    2006-08-15

    The formation of HCN and NH3 during pyrolysis in Ar and gasification in CO{sub 2} and steam/Ar was investigated. Vitrinites were separated and purified from different rank coal from lignite to anthracite. Pyrolysis and gasification were carried out in the drop-tube/fixed-bed reactor at temperatures of 600-900{sup o}C. Results showed that with increase of reaction temperature the yield of HCN increased significantly during pyrolysis and gasification. Decrease of coal rank also increased the yield of HCN. Vitrinite from lower rank of coal with high volatile content released more HCN. The yield of NH3 was the highest at 800 {sup o}C during pyrolysis and gasification. And the yield of NH3 from gasification in steam/Ar was far higher than that from gasification in CO{sub 2}, where the hydrogen radicals play a key role. Nitrogen retained in char was also investigated. The yield of char-N decreased with an increase of pyrolysis temperature. Vitrinite from lower rank coal had lower yield of char-N than that from the high rank coal.

  13. Role of char during reburning of nitrogen oxides. First quarterly report, October 1, 1993--December 31, 1993

    SciTech Connect

    Chen, Wei-Yin

    1993-12-31

    Customarily, coal and lignite have not been considered viable reburning fuels for a number of reasons. NO reduction through homogeneous gas phase mechanisms is generally believed more important than the heterogeneous NO reduction on char; and coal devolatilization in the fuel rich environment generates only about 50% of the volatile hydrocarbon radicals than gaseous hydrocarbons under the same fuel-to-oxidant stoichiometry. In addition, the fuel nitrogen could result in additional nitrogen oxide emissions in the burnout stage. What has not been anticipated is the highly active nature of lignite char surface. First, it has been demonstrated in the literature that lignite char can be gasified by nitrogen oxide; second, the minerals in lignite char can catalyze the CO + NO and gasification reaction; and third, lignite char has a highly porous structure which is desirable for gas/solid reactions. The unique NO activity on char surface is expected to benefit the utilities which are involved in coal combustion and have to meet the stringent Clean Air Act Amendments of 1990. This program is aimed at a better understanding of the chemical and physical mechanisms involved in the reburning with chars. Char gasification rates will be measured with and without the presence of CO. Further, the rate of the char catalyzed CO + NO reaction will also be measured. Experiments have been conducted with a flow reactor which simulates the reburning stage. One bituminous coal and two lignites, one from North Dakota and the other from Mississippi, are used in these tasks. A unique component of this program is the use of the fractal concept in the estimations of these gas/solid reaction rates. The proposed program is designed to investigate the relative importance of these two reactions (char gasification and ash catalyzed CO + NO reactions) under reburning conditions.

  14. Air blown gasification cycle

    SciTech Connect

    Dawes, S.G.; Mordecai, M.; Brown, D.; Burnard, G.K.

    1995-12-31

    The Air Blown Gasification Cycle (ABGC) is a hybrid partial gasification cycle based on a novel, air blown pressurized fluidized bed gasifier (PFBG) with a circulating fluidized bed combustor (CFBC) to burn the residual char from the PFBG. The ABGC has been developed primarily as a clean coal generation system and embodies a sulfur capture mechanism based on the addition of limestone, or other sorbent, to the PFBG where it is sulfided in the reducing atmosphere, followed by oxidation to a stable sulfate residue in the CFBC. In order to achieve commercialization, certain key technological issues needed to be addressed and an industry-led consortium was established to develop the components of the system through the prototype plant to commercial exploitation. The consortium, known as the Clean Coal Power Generation Group (CCPGG), is undertaking a program of activity aimed at achieving a design specification for a 75 MWe prototype integrated plant by March, 1996. Component development consists of both the establishment of new components, such as the PFBG and the hot gas clean up system, and specific development of already established components, such as the CFBC, raw gas cooler, heat recovery steam generator (HRSG) and gas turbine. This paper discusses the component development activities and indicates the expected performance and economics of both the prototype and commercial plants. In addition, the strategy for component development and achievement of the specification for a 75 MWe prototype integrated plant is described.

  15. Laboratory support for in situ gasification: reaction kinetics. Annual report October 1977-September 1978

    SciTech Connect

    Young, J.E.; Wong, S.H.; Johnson, J.E.; Sikand, N.; Jonke, A.A.

    1980-02-01

    This work is directed toward support studies for the national program for the development and demonstration of in situ coal gasification processes. The objective of this work is to determine the reaction-controlling variables and reaction kinetics for the gasification of chars obtained by pyrolyzing coal in simulated underground gasification conditions. The reactions being studied and to be studied include steam-char, CO/sub 2/-char, H/sub 2/-char, the water-gas shift reaction, and the methanation reaction. In this report are presented data regarding the kinetics of the reaction of steam with chars prepared from Pittsburgh seam high-volatile bituminous coal. In addition, a reaction model is described correlating the steam-char reaction rates measured earlier for Hanna subbituminous coal with operating conditions including temperature, partial pressures of steam and hydrogen, and extent of carbon gasification. Partial results are presented and discussed for an investigation of structural parameters of Hanna char as a function of pyrolysis conditions and extent of carbon gasified.

  16. Catalysis in biomass gasification

    SciTech Connect

    Baker, E.G.; Mudge, L.K.

    1984-06-01

    The objective of these studies is to evaluate the technical and economic feasibility of producing specific gas products by catalytic gasification of biomass. Catalyst performance is a key factor in the feasibility of catalytic gasification processes. The results of studies designed to gain a fundamental understanding of catalytic mechanisms and causes of deactivation, and discussion of the state-of-the-art of related catalytic processes are presented. Experiments with primary and secondary catalysts were conducted in a 5-cm-diameter, continuous-wood-feed, fixed-catalyst-bed reactor. The primary catalysts used in the experiments were alkali carbonates mixed with the biomass feed; the secondary catalysts included nickel or other transition metals on supports such as alumina, silica, or silica-alumina. The primary catalysts were found to influence wood pyrolysis as well as the char/steam reaction. Secondary catalysts were used in a fixed-bed configuration to direct gas phase reactions. Results of the performance of these catalysts are presented. Secondary catalysts were found to be highly effective for conversion of biomass to specific gas products: synthesis gases and methane-rich gas. With an active catalyst, equilibrium gas composition are obtained, and all liquid pyrolysis products are converted to gases. The major cause of catalyst deactivation was carbon deposition, or coking. Loss of surface area by sintering was also inportant. Catalyst deactivation by sulfur poisoning was observed when bagasse was used as the feedstock for catalytic gasification. Mechanisms of catalyst activity and deactivation are discussed. Model compounds (methane, ethylene, and phenol) were used to determine coking behavior of catalysts. Carbon deposition is more prevalent with ethylene and phenol than with methane. Catalyst formulations that are resistant to carbon deposition are presented. 60 references, 10 figures, 21 tables.

  17. Development of an advanced, continuous mild gasification process for the production of co-products. Task 4.6, Economic evaluation

    SciTech Connect

    Cohen, L.R.; Hogsett, R.F.; Sinor, J.E.; Ness, R.O. Jr.; Runge, B.D.

    1992-10-01

    The principal finding of this study was the high capital cost and poor financial performance predicted for the size and configuration of the plant design presented. The XBi financial assessment gave a disappointingly low base-case discounted cash flow rate of return (DCFRR) of only 8.1% based on a unit capital cost of $900 per ton year (tpy) for their 129,000 tpy design. This plant cost is in reasonable agreement with the preliminary estimates developed by J.E. Sinor Associates for a 117,000 tpy plant based on the FMC process with similar auxiliaries (Sinor, 1989), for which a unit capital costs of $938 tpy was predicted for a design that included char beneficiation and coal liquids upgrading--or about $779 tpy without the liquid upgrading facilities. The XBi assessment points out that a unit plant cost of $900 tpy is about three times the cost for a conventional coke oven, and therefore, outside the competitive range for commercialization. Modifications to improve process economics could involve increasing plant size, expanding the product slate that XBi has restricted to form coke and electricity, and simplifying the plant flow sheet by eliminating marginally effective cleaning steps and changing other key design parameters. Improving the financial performance of the proposed formed coke design to the level of a 20% DCFRR based on increased plant size alone would require a twenty-fold increase to a coal input of 20,000 tpd and a coke production of about 2.6 minion tpy--a scaling exponent of 0.70 to correct plant cost in relation to plant size.

  18. Overview of the CHarring Ablator Response (CHAR) Code

    NASA Technical Reports Server (NTRS)

    Amar, Adam J.; Oliver, A. Brandon; Kirk, Benjamin S.; Salazar, Giovanni; Droba, Justin

    2016-01-01

    An overview of the capabilities of the CHarring Ablator Response (CHAR) code is presented. CHAR is a one-, two-, and three-dimensional unstructured continuous Galerkin finite-element heat conduction and ablation solver with both direct and inverse modes. Additionally, CHAR includes a coupled linear thermoelastic solver for determination of internal stresses induced from the temperature field and surface loading. Background on the development process, governing equations, material models, discretization techniques, and numerical methods is provided. Special focus is put on the available boundary conditions including thermochemical ablation, surface-to-surface radiation exchange, and flowfield coupling. Finally, a discussion of ongoing development efforts is presented.

  19. Overview of the CHarring Ablator Response (CHAR) Code

    NASA Technical Reports Server (NTRS)

    Amar, Adam J.; Oliver, A. Brandon; Kirk, Benjamin S.; Salazar, Giovanni; Droba, Justin

    2016-01-01

    An overview of the capabilities of the CHarring Ablator Response (CHAR) code is presented. CHAR is a one-, two-, and three-dimensional unstructured continuous Galerkin finite-element heat conduction and ablation solver with both direct and inverse modes. Additionally, CHAR includes a coupled linear thermoelastic solver for determination of internal stresses induced from the temperature field and surface loading. Background on the development process, governing equations, material models, discretization techniques, and numerical methods is provided. Special focus is put on the available boundary conditions including thermochemical ablation and contact interfaces, and example simulations are included. Finally, a discussion of ongoing development efforts is presented.

  20. Chemical characterization of chars developed from thermochemical treatment of Kentucky bluegrass seed screenings.

    PubMed

    Griffith, Stephen M; Banowetz, Gary M; Gady, David

    2013-08-01

    Seed mill screenings would be a considerable biofeedstock source for bioenergy and char production. Char produced from the gasification of residues resulting from cleaning of grass seed and small grains could be recycled to a cropping system as a soil amendment if chemical characterization determined that the gasification process had not produced or concentrated deleterious chemical or physical factors that might harm the environment, crop growth or yield. Previous reports have shown that char derived from the pyrolysis of a variety of biomass feedstocks has potential to enhance soil quality by pH adjustment, mineral amendment, and improved soil porosity. The objective of this research was to characterize char produced from Kentucky bluegrass seed mill screenings (KBss) by a small-scale gasification unit, operated at temperatures between 600 and 650°C, with respect to polycyclic aromatic hydrocarbons, selected heavy metals, as well as other physical and chemical characteristics, and determine its suitability for agricultural application as a soil amendment. We utilized KBss as a model for seed and grain-cleaning residues with the understanding that chemical and physical characteristics of char produced by gasification or other cleaning residues may differ based on soil and environmental conditions under which the crops were produced. Our results support the hypothesis that KBss char could be applied in a cropping system without toxic environmental consequences and serve multiple purposes, such as; recycling critical plant macro- and micro-nutrients back to existing cropland, enhancing soil carbon sequestration, managing soil pH, and improving water holding capacity. Crop field trails need to be implemented to further test these hypotheses. PMID:23591135

  1. Effect of fuel origin on synergy during co-gasification of biomass and coal in CO2.

    PubMed

    Zhang, Yan; Zheng, Yan; Yang, Mingjun; Song, Yongchen

    2016-01-01

    The effect of fuel origin on synergy in coal/biomass blends during co-gasification has been assessed using a congruent-mass thermogravimetry analysis (TGA) method. Results revealed that synergy occurs when ash residuals are formed, followed by an almost complete gasification of biomass. Potassium species in biomass ash play a catalytic role in promoting gasification reactivity of coal char, which is a direct consequence of synergy during co-gasification. The SEM-EDS spectra provided conclusive evidence that the transfer of potassium from biomass to the surface of coal char occurs during co-pyrolysis/gasification. Biomass ash rich in silica eliminated synergy in coal/biomass blends but not to the extent of inhibiting the reaction rate of the blended chars to make it slower than that of separated ones. The best result in terms of synergy was concluded to be the combination of low-ash coal and K-rich biomass. PMID:26580896

  2. POLLUTANTS FROM SYNTHETIC FUELS PRODUCTION: COAL GASIFICATION SCREENING TEST RESULTS

    EPA Science Inventory

    Coal gasification test runs have been conducted in a semibatch, fixed-bed laboratory gasifier in order to evaluate various coals and operating conditions for pollutant generation. Thirty-eight tests have been completed using char, coal, lignite, and peat. Extensive analyses were ...

  3. Method for using fast fluidized bed dry bottom coal gasification

    DOEpatents

    Snell, George J.; Kydd, Paul H.

    1983-01-01

    Carbonaceous solid material such as coal is gasified in a fast fluidized bed gasification system utilizing dual fluidized beds of hot char. The coal in particulate form is introduced along with oxygen-containing gas and steam into the fast fluidized bed gasification zone of a gasifier assembly wherein the upward superficial gas velocity exceeds about 5.0 ft/sec and temperature is 1500.degree.-1850.degree. F. The resulting effluent gas and substantial char are passed through a primary cyclone separator, from which char solids are returned to the fluidized bed. Gas from the primary cyclone separator is passed to a secondary cyclone separator, from which remaining fine char solids are returned through an injection nozzle together with additional steam and oxygen-containing gas to an oxidation zone located at the bottom of the gasifier, wherein the upward gas velocity ranges from about 3-15 ft/sec and is maintained at 1600.degree.-200.degree. F. temperature. This gasification arrangement provides for increased utilization of the secondary char material to produce higher overall carbon conversion and product yields in the process.

  4. Dual Fluidized Bed Biomass Gasification

    SciTech Connect

    2005-09-30

    The dual fluidized bed reactor is a recirculating system in which one half of the unit operates as a steam pyrolysis device for biomass. The pyrolysis occurs by introducing biomass and steam to a hot fluidized bed of inert material such as coarse sand. Syngas is produced during the pyrolysis and exits the top of the reactor with the steam. A crossover arm, fed by gravity, moves sand and char from the pyrolyzer to the second fluidized bed. This sand bed uses blown air to combust the char. The exit stream from this side of the reactor is carbon dioxide, water and ash. There is a second gravity fed crossover arm to return sand to the pyrolysis side. The recirculating action of the sand and the char is the key to the operation of the dual fluidized bed reactor. The objective of the project was to design and construct a dual fluidized bed prototype reactor from literature information and in discussion with established experts in the field. That would be appropriate in scale and operation to measure the relative performance of the gasification of biomass and low ranked coals to produce a high quality synthesis gas with no dilution from nitrogen or combustion products.

  5. Fundamental studies of catalytic gasification: Quarterly report, October 1, 1986-December 31, 1986

    SciTech Connect

    Heinemann, H.

    1986-12-01

    This program studies the basic chemistry of the reaction of carbonaceous materials with water in the presence of catalysts to produce hydrogen and/or synthesis gas. Relatively low temperatures are being used. The catalysts under investigation are compounds of potassium and a transition metal oxide. Major objectives are the extension of the work from chars to coke; the effect of H/sub 2/, CO and CO/sub 2/ partial pressure on the gaseous product distribution; and the inhibition of catalyst poisoning by ash components. Some of the highlights are: (1) Activation energies for K/Ni catalyzed steam gasification of graphite and of chars are identical, indicating the same mechanism prevails though rates are much higher for chars. This permits extrapolation of findings in high vacuum equipment from graphite to chars. (2) The CO/CO/sub 2/ ratio of gases produced along with hydrogen varies with different chars. The ratio is 0.8 for Illinois No. 6 char and 0.08 for North Dakota char. Methane production is several orders of magnitude smaller and ceases after about 2 hours. (3) Comparison of K/Ni catalyst for steam gasification of Illinois No. 6 char with K or Ni alone indicates: (a) K alone produces much higher CO/CO/sub 2/ ratios than K/Ni. (b) Ni alone is almost inactive for the steam gasification of Illinois No. 6 except for the short first period of operation. (4) Montana char treated with aqua regia to remove ash components prior to impregnation with K/Ni has 75% of the activity of untreated char but exhibits little deactivation with time so that it gasifies better than untreated char after a few hours. (5) Controlled atmosphere electron microscopy studies have been extended to wet hydrogen and wet oxygen treatments of K/Ni impregnated graphite 3 refs., 8 figs., 2 tabs.

  6. Numerical simulation of waste tyres gasification.

    PubMed

    Janajreh, Isam; Raza, Syed Shabbar

    2015-05-01

    Gasification is a thermochemical pathway used to convert carbonaceous feedstock into syngas (CO and H2) in a deprived oxygen environment. The process can accommodate conventional feedstock such as coal, discarded waste including plastics, rubber, and mixed waste owing to the high reactor temperature (1000 °C-1600 °C). Pyrolysis is another conversion pathway, yet it is more selective to the feedstock owing to the low process temperature (350 °C-550 °C). Discarded tyres can be subjected to pyrolysis, however, the yield involves the formation of intermediate radicals additional to unconverted char. Gasification, however, owing to the higher temperature and shorter residence time, is more opted to follow quasi-equilibrium and being predictive. In this work, tyre crumbs are subjected to two levels of gasification modelling, i.e. equilibrium zero dimension and reactive multi-dimensional flow. The objective is to investigate the effect of the amount of oxidising agent on the conversion of tyre granules and syngas composition in a small 20 kW cylindrical gasifier. Initially the chemical compositions of several tyre samples are measured following the ASTM procedures for proximate and ultimate analysis as well as the heating value. The measured data are used to carry out equilibrium-based and reactive flow gasification. The result shows that both models are reasonably predictive averaging 50% gasification efficiency, the devolatilisation is less sensitive than the char conversion to the equivalence ratio as devolatilisation is always complete. In view of the high attained efficiency, it is suggested that the investigated tyre gasification system is economically viable. PMID:25755167

  7. Underground Coal Gasification Program

    Energy Science and Technology Software Center (ESTSC)

    1994-12-01

    CAVSIM is a three-dimensional, axisymmetric model for resource recovery and cavity growth during underground coal gasification (UCG). CAVSIM is capable of following the evolution of the cavity from near startup to exhaustion, and couples explicitly wall and roof surface growth to material and energy balances in the underlying rubble zones. Growth mechanisms are allowed to change smoothly as the system evolves from a small, relatively empty cavity low in the coal seam to a large,more » almost completely rubble-filled cavity extending high into the overburden rock. The model is applicable to nonswelling coals of arbitrary seam thickness and can handle a variety of gas injection flow schedules or compositions. Water influx from the coal aquifer is calculated by a gravity drainage-permeation submodel which is integrated into the general solution. The cavity is considered to consist of up to three distinct rubble zones and a void space at the top. Resistance to gas flow injected from a stationary source at the cavity floor is assumed to be concentrated in the ash pile, which builds up around the source, and also the overburden rubble which accumulates on top of this ash once overburden rock is exposed at the cavity top. Char rubble zones at the cavity side and edges are assumed to be highly permeable. Flow of injected gas through the ash to char rubble piles and the void space is coupled by material and energy balances to cavity growth at the rubble/coal, void/coal and void/rock interfaces. One preprocessor and two postprocessor programs are included - SPALL calculates one-dimensional mean spalling rates of coal or rock surfaces exposed to high temperatures and generates CAVSIM input: TAB reads CAVSIM binary output files and generates ASCII tables of selected data for display; and PLOT produces dot matrix printer or HP printer plots from TAB output.« less

  8. STUDY OF ACTIVATION OF COAL CHAR

    SciTech Connect

    E.M. Suuberg; I. Kulaots; I Aarna; M. Callejo; A. Hsu

    2003-12-31

    This is the final report on a project whose aim is to explore in a fundamental manner the factors that influence the development of porosity in coal chars during the process of activation. It is known that choices of starting coal, activating agent and conditions can strongly influence the nature of an activated carbon produced from a coal. This project has been concerned mainly with the process of physical activation, which in fact involves the gasification of a char produced from a coal by oxidizing gases. This is of interest for two reasons. One is that there is commercial interest in production of activated carbons from coal, and therefore, in the conditions that can best be used in producing these materials. Much is already known about this, but there is a great deal that is in the realm of ''trade secret'' or just ''industry lore''. The second reason for interest in these processes is that they shed light on how porosity develops during any gasification process involving oxidizing gases. This has implications for understanding the kinetics and the role that ''surface area'' may play in determining kinetics. In earlier reports from this project, several conclusions had been reached upon which the present results rest. There is an often-cited difference in use of nitrogen and carbon dioxide as molecular probes of carbon porosity when using vapor adsorption techniques. Carbon dioxide is often ''preferred'' since it is argued that it offers greater access to fine microporosity, due to the higher temperature of carbon dioxide as opposed to nitrogen measurements. The early phases of this work revealed that the extreme differences are observed only in chars which are not much activated, and that by a few weight percent burnoff, the difference was negligible, provided a consistent theoretical equation was used in calculating uptake or ''surface area''. In another phase of this study, it was noted in a preliminary way how the use of different oxidizing environments

  9. Gasification process

    SciTech Connect

    Woldy, P.N.; Kaufman, H.C.; Dach, M.M.; Beall, J.F.

    1981-02-03

    This version of Texaco's gasification process for high-ash-content solids is not extended to include the production of superheated steam, as described in US Patent 4,247,302. The hot, raw gas stream passes through fewer coolers, producing a high-pressure steam instead of a superheated steam.

  10. Industrial uses of wood char

    SciTech Connect

    Kumar, M.; Gupta, R.C.

    1998-08-01

    The quality and feasibility of wood char utilization in various industries are reported. Wood char provides fuel not only for cooking and domestic heating but also for many industrial purposes, such as manufacture of iron and some ferro-alloys, recovery of gold and other nonferrous metals from their leached solutions, manufacture of chemicals and medicines, burning of bricks and glass, and removal of toxic substances from their solutions. The selection of wood char for these purposes is made on the basis of its properties, such as chemical composition, reactivity, heating value, electrical resistivity, adsorption capacity, and strength.

  11. Role of char during reburning of nitrogen oxides. Seventh quarterly progress report, April 1, 1995--June 30, 1995

    SciTech Connect

    Wei-Yin Chen; Te-Chang Lu; Fan, L.T.; Yashima, M.

    1995-08-11

    The progress in this quarter includes four parts. In the first segment, the implications of our data reported in the List quarter are discussed further. BET N{sub 2} surface area does not seems to be the only contributing factor to the remarkable activity of lignite char during reburning, and chars of different origins probably have different controlling steps in the overall surface reaction mechanisms. Unlike NO reduction in the gas phase, oxygen inhibits the heterogeneous mechanisms. The second part of this report justifies the use of our laminar flow reactor system for the measurement of reaction rate. Dispersion model is used in the analysis. An expression relating the rate constant with the experimentally obtainable NO conversion for our flow reactor have been derived. Rates of NO/char reaction for six series of experiments have been measured over the temperature range 800 to 1100{degrees}C. These six series of experiments have been conducted with two different chars, one bituminous coal char and one lignite char, and three different levels of feed NO concentrations, 200, 400 and 1000 ppm. Results from the comparison of char activities suggest that, in the absence of O{sub 2} and CO{sub 2}, the origin of char is not a significant factor for NO reduction. The CO/CO{sub 2} ratio in the products is higher than one under all test conditions, but the ratio increases with increasing feed NO concentrations. Recoveries of oxygen form the lignite char at temperatures above 1050{degrees}C is higher than 1 indicating gasification of organic oxygen in the char. Surface areas of selected chars after devolatilization and after reburning have been analyzed by BET in N{sub 2}. Results indicated char surface area changes after reburning, which is caused either by the higher temperature of reburning or by surface reaction.

  12. Fundamental studies of the mechanism of catalytic reactions with catalysts effective in the gasification of carbon solids and the oxidative coupling of methane. Quarterly report, July 1, 1993--September 30, 1993

    SciTech Connect

    Heinemann, H.; Somorjai, G.A.; Perry, D.L.

    1993-11-01

    During the fourth quarter of FY93, additional studies were undertaken to quantify the effect of adding alkali to coal during charring. Figure 1 shows that the rate of gasification of Ill{number_sign}6 char prepared by charring the coal in the presence of different amounts of NAOH increases with the amount of NAOH used between 0 and 2 wt %. However, most of the improvement occurs with the addition of small amounts of alkali, while doubling the proportion of alkali from 0.9 to 1.7% gives a small additional improvement. In fact it appears that 0.8 to 1% alkali during charring is optimal. This is demonstrated in Figure 2. The chars prepared in the presence of NAOH were water washed and extracted at room temperature until the water was alkali free, dried and then gasified. Figure 2 presents the same data as Figure 1 but additionally shows the gasification rate at 640{degree}C for the water washed chars. The water washed char originally prepared with .85% NAOH had the same gasification rate as before water washing, while the gasification rate of the char originally prepared with 1.7% NAOH dropped to the level of the .85% NAOH containing char after water washing. This may be interpreted as an indication of about 1% alkali being incorporated into the char in a water insoluble form.

  13. Oxy-combustion of pulverized coal : modeling of char-combustion kinetics.

    SciTech Connect

    Shaddix, Christopher R.; Haynes, Brian S.; Geier, Manfred

    2010-09-01

    In this study, char combustion of pulverized coal under oxy-fuel combustion conditions was investigated on the basis of experimentally observed temperature-size characteristics and corresponding predictions of numerical simulations. Using a combustion-driven entrained flow reactor equipped with an optical particle-sizing pyrometer, combustion characteristics (particle temperatures and apparent size) of pulverized coal char particles was determined for combustion in both reduced oxygen and oxygen-enriched atmospheres with either a N{sub 2} or CO{sub 2} bath gas. The two coals investigated were a low-sulfur, high-volatile bituminous coal (Utah Skyline) and a low-sulfur subbituminous coal (North Antelope), both size-classified to 75-106 {micro}m. A particular focus of this study lies in the analysis of the predictive modeling capabilities of simplified models that capture char combustion characteristics but exhibit the lowest possible complexity and thus facilitate incorporation in existing computational fluid dynamics (CFD) simulation codes. For this purpose, char consumption characteristics were calculated for char particles in the size range 10-200 {micro}m using (1) single-film, apparent kinetic models with a chemically 'frozen' boundary layer, and (2) a reacting porous particle model with detailed gas-phase kinetics and three separate heterogeneous reaction mechanisms of char-oxidation and gasification. A comparison of model results with experimental data suggests that single-film models with reaction orders between 0.5 and 1 with respect to the surface oxygen partial pressure may be capable of adequately predicting the temperature-size characteristics of char consumption, provided heterogeneous (steam and CO{sub 2}) gasification reactions are accounted for.

  14. Oxy-combustion of pulverized coal : modeling of char combustion kinetics.

    SciTech Connect

    Shaddix, Christopher R.; Haynes, Brian S.; Geier, Manfred

    2010-09-01

    In this study, char combustion of pulverized coal under oxy-fuel combustion conditions was investigated on the basis of experimentally observed temperature-size characteristics and corresponding predictions of numerical simulations. Using a combustion-driven entrained flow reactor equipped with an optical particle-sizing pyrometer, combustion characteristics (particle temperatures and apparent size) of pulverized coal char particles was determined for combustion in both reduced oxygen and oxygen-enriched atmospheres with either a N{sub 2} or CO{sub 2} bath gas. The two coals investigated were a low-sulfur, high-volatile bituminous coal (Utah Skyline) and a low-sulfur subbituminous coal (North Antelope), both size-classified to 75-106 {micro}m. A particular focus of this study lies in the analysis of the predictive modeling capabilities of simplified models that capture char combustion characteristics but exhibit the lowest possible complexity and thus facilitate incorporation in existing computational fluid dynamics (CFD) simulation codes. For this purpose, char consumption characteristics were calculated for char particles in the size range 10-200 {micro}m using (1) single-film, apparent kinetic models with a chemically 'frozen' boundary layer, and (2) a reacting porous particle model with detailed gas-phase kinetics and three separate heterogeneous reaction mechanisms of char-oxidation and gasification. A comparison of model results with experimental data suggests that single-film models with reaction orders between 0.5 and 1 with respect to the surface oxygen partial pressure may be capable of adequately predicting the temperature-size characteristics of char consumption, provided heterogeneous (steam and CO{sub 2}) gasification reactions are accounted for.

  15. Gasification system

    DOEpatents

    Haldipur, Gaurang B.; Anderson, Richard G.; Cherish, Peter

    1985-01-01

    A method and system for injecting coal and process fluids into a fluidized bed gasification reactor. Three concentric tubes extend vertically upward into the fluidized bed. Coal particulates in a transport gas are injected through an inner tube, and an oxygen rich mixture of oxygen and steam are injected through an inner annulus about the inner tube. A gaseous medium relatively lean in oxygen content, such as steam, is injected through an annulus surrounding the inner annulus.

  16. Gasification system

    DOEpatents

    Haldipur, Gaurang B.; Anderson, Richard G.; Cherish, Peter

    1983-01-01

    A method and system for injecting coal and process fluids into a fluidized bed gasification reactor. Three concentric tubes extend vertically upward into the fluidized bed. Coal particulates in a transport gas are injected through an inner tube, and an oxygen rich mixture of oxygen and steam are injected through an inner annulus about the inner tube. A gaseous medium relatively lean in oxygen content, such as steam, is injected through an annulus surrounding the inner annulus.

  17. Characteristics of rice husk gasification in an entrained flow reactor.

    PubMed

    Zhao, Yijun; Sun, Shaozeng; Tian, Hongming; Qian, Juan; Su, Fengming; Ling, Feng

    2009-12-01

    Experiments were performed in an entrained flow reactor to better understand the characteristics of biomass gasification. Rice husk was used in this study. Effects of the gasification temperature (700, 800, 900 and 1000 degrees C) and the equivalence ratio in the range of 0.22-0.34 on the biomass gasification and the axial gas distribution in the reactor were studied. The results showed that reactions of CnHm were less important in the gasification process except cracking reactions which occurred at higher temperature. In the oxidization zone, reactions between char and oxygen had a more prevailing role. The optimal gasification temperature of the rice husk could be above 900 degrees C, and the optimal value of ER was 0.25. The gasification process was finished in 1.42 s when the gasification temperature was above 800 degrees C. A first order kinetic model was developed for describing rice husk air gasification characteristics and the relevant kinetic parameters were determined. PMID:19589673

  18. Influence of sulfur in coals on char morphology and combustion. Technical report, 1 September 1991--30 November 1991

    SciTech Connect

    Marsh, H.

    1991-12-31

    During coal carbonization (pyrolysis), as during the combustion process of pulverized coal in a combustor, not all of the sulfur is released. Significant proportions become pat of the structure of the resultant coke and char. The combustion process of the char within the flames of the combustor in influenced dominantly by char morphology. This, in turn, controls the accessibility of oxidizing gases to the surfaces of the carbonaceous substance of the char. Mineral matter content, its extent and state of distribution, also exerts an influence on char morphology created during pyrolysis/carbonization. This complexity of coal renders it a very difficult material to study, systematically, to distinguish and separate out the contributing factors which influence combustion characteristics. Therefore, in such circumstances, it is necessary to simplify the systems by making use of model chars/cokes/carbons which can be made progressively more complex, but in a controlled way. In this way complicating influence in chars from coals can be eliminated, so enabling specific influences to be studied independently. It is important to note that preliminary work by Marsh and Gryglewicz (1990) indicated that levels of sulfur of about 3 to 5 wt % can reduce reactivities by 10 to 25%. The overall purpose of the study is to provide meaningful kinetic data to establish, quantitatively, the influence of organically-bound sulfur on the reactivity of carbons, and to ascertain if gasification catalysts are effective in the preferential removal of sulfur from the chars.

  19. Micropore diffusion in coal chars under reactive conditions: Annual topical report, 15 September 1987--15 September 1988

    SciTech Connect

    Calo, J.M.; Perkins, M.T.; Lilly, W.D.

    1988-01-01

    The current project is concerned with the development and application of a new technique to measure micropore diffusion under actual gasification conditions. The method is an outgrowth of and related to the transient kinetics approach to the measurement of kinetic rate parameters for char-gas reactions that has been developed in our laboratory. It can be shown that the initial transient behavior of a species introduced as a step-function into a ''gradientless'' reactor in which char is present, is controlled by the transport resistance offered by the char micropores. Therefore, this data can be analyzed for micropore diffusion time constants. In addition, due to the time-resolved nature of the process in the reactor, the initial diffusion step is separated (in time) from any subsequent gas-solid reaction steps. Therefore, diffusion measurements can be performed under gasification conditions. Diffusion time constant data have been obtained for a few microporous carbonaceous materials, including a Sigma (pine wood) char, a Fischer coconut char and PSOC-467 (Deadman No. 2) subbituminous coal char, in addition to the previously reported (DOE/PC/90529-Annual-1) 5A zeolite data. These data have been compared to other results, where possible, and, for the most part, they behave as expected. 65 refs., 12 figs.

  20. NO sub x -char reactions: Kinetics and transport aspects

    SciTech Connect

    Calo, J.M.; Suuberg, E.M.

    1990-01-01

    The present project is motivated by the need to reduce NO{sub x} emissions from combustors, especially coal combustors. Reactions with carbon are known to be effective at reducing No to N{sub 2}, and remain interesting candidates in a wide variety of possible applications. These reactions are known to be important in reducing NO{sub x} emissions from fluidized bed coal combustors, in which the coal char itself serves as the reducing agent. The principal goal of this project is to develop a mechanistic understanding of the processes by which carbons reduce NO to N{sub 2}. The carbon was a char derived from phenol-formaldehyde resin. This material has been noted to be a reasonable model for coal chars in most respects, expect that its gasification behavior is not complicated by catalytic processes due to minerals. In the first phases of the project, the global kinetics of the process were established. In more recent work, attention has been turned to the individual steps in the mechanism. Recent quarterly reports have detailed the role of both chemisorption and desorption processes in determining the course and kinetics of the process. This report continues the reporting of results obtained along these lines, and draws an important new conclusion concerning the number of separate processes involved in determining the kinetics. 40 refs., 3 figs., 2 tabs.

  1. Influence of sulfur in coals on char morphology and combustion. Final report, September 1, 1991--August 31, 1992

    SciTech Connect

    Marsh, H.; Crelling, J.C.

    1992-12-31

    The experimental approach involves the preparation of 34 model compounds and the study of their gasification behavior, including surface characterization by adsorption techniques and microscopy. Sulfur was incorporated into the model carbon structures by co- carbonization of the acenaphthylene and resol with elemental sulfur and dibenzothiophene sulfone, heating at 5{degrees}C min {sup {minus}1}, under argon to 900{degrees}C. Total surface areas were measured by adsorption of carbon dioxide at 195 K.The use of a CAHN microbalance allows for active surface area measurements to be made. Gasifications in oxygen, using a microbalance to 25 wt.% bum-off generate intemal surface areas dependent on the carbon being studied, varying from 35 to {approximately}900 m{sup 2} g{sup {minus}1}. Similarly, as seen from the scanning electron micrographs there are differences in the topographies developed during gasification. This must reflect differences in structures. Conclusions of the study are summarized as follows. Sulfur within chars from coals influences the mode of gasification of the char. Oxides of sulfur are evolved ahead of the main carbon oxide peaks. This indicates preferential oxidation of sulfur atoms from the carbon lattice. This preferential removal appears to enhance the reactivity of the internal carbon surface. The reactivity of these internal surfaces is sensitive to new structures generated within the carbons/chars by the incorporation of sulfur in some way within the surface during carbonizations. Incorporation of sulfur within chars may be a significant parameter in terms of methods of gasification of char particles, generation of cenospheres, etc.

  2. Second stage gasifier in staged gasification and integrated process

    DOEpatents

    Liu, Guohai; Vimalchand, Pannalal; Peng, Wan Wang

    2015-10-06

    A second stage gasification unit in a staged gasification integrated process flow scheme and operating methods are disclosed to gasify a wide range of low reactivity fuels. The inclusion of second stage gasification unit operating at high temperatures closer to ash fusion temperatures in the bed provides sufficient flexibility in unit configurations, operating conditions and methods to achieve an overall carbon conversion of over 95% for low reactivity materials such as bituminous and anthracite coals, petroleum residues and coke. The second stage gasification unit includes a stationary fluidized bed gasifier operating with a sufficiently turbulent bed of predefined inert bed material with lean char carbon content. The second stage gasifier fluidized bed is operated at relatively high temperatures up to 1400.degree. C. Steam and oxidant mixture can be injected to further increase the freeboard region operating temperature in the range of approximately from 50 to 100.degree. C. above the bed temperature.

  3. 2007 gasification technologies conference papers

    SciTech Connect

    2007-07-01

    Sessions covered: gasification industry roundtable; the gasification market in China; gasification for power generation; the gasification challenge: carbon capture and use storage; industrial and polygeneration applications; gasification advantage in refinery applications; addressing plant performance; reliability and availability; gasification's contribution to supplementing gaseous and liquid fuels supplies; biomass gasification for fuel and power markets; and advances in technology-research and development

  4. Gasification Characteristics of Coal/Biomass Mixed Fuels

    SciTech Connect

    Mitchell, Reginald

    2013-09-30

    A research project was undertaken that had the overall objective of developing the models needed to accurately predict conversion rates of coal/biomass mixtures to synthesis gas under conditions relevant to a commercially-available coal gasification system configured to co- produce electric power as well as chemicals and liquid fuels. In our efforts to accomplish this goal, experiments were performed in an entrained flow reactor in order to produce coal and biomass chars at high heating rates and temperatures, typical of the heating rates and temperatures fuel particles experience in real systems. Mixed chars derived from coal/biomass mixtures containing up to 50% biomass and the chars of the pure coal and biomass components were subjected to a matrix of reactivity tests in a pressurized thermogravimetric analyzer (TGA) in order to obtain data on mass loss rates as functions of gas temperature, pressure and composition as well as to obtain information on the variations in mass specific surface area during char conversion under kinetically-limited conditions. The experimental data were used as targets when determining the unknown parameters in the chemical reactivity and specific surface area models developed. These parameters included rate coefficients for the reactions in the reaction mechanism, enthalpies of formation and absolute entropies of adsorbed species formed on the carbonaceous surfaces, and pore structure coefficients in the model used to describe how the mass specific surface area of the char varies with conversion. So that the reactivity models can be used at high temperatures when mass transport processes impact char conversion rates, Thiele modulus – effectiveness factor relations were also derived for the reaction mechanisms developed. In addition, the reactivity model and a mode of conversion model were combined in a char-particle gasification model that includes the effects of chemical reaction and diffusion of reactive gases through particle

  5. A model approach to highly dispersing catalytic materials in coal for gasification

    SciTech Connect

    Abotsi, G.M.K.; Bota, K.B.

    1992-01-01

    This project seeks to develop a technique, based on coal surface properties, for highly dispersing catalysts in coal for gasification and to investigate the potential of using potassium carbonate and calcium acetate mixtures as catalysts for coal gasification. The lower cost and higher catalytic activity of the latter compound will produce economic benefits by reducing the amount of K[sub 2]CO[sub 3] required for high coal char reactivities. As was shown in previous reports, coal loading with potassium or calcium at different pHs produced CO[sub 2] gasification activities which increased in the order pH 6 > pH 10 >>pH 1. A similar trend was obtained when calcium and potassium were simultaneously loaded and char reaction times were less than about 75 min. In the last quarter, the potential application of ammonia as a reactive medium for coal gasification has been investigated. This gas has not been previously applied to coal gasification. However, related work suggests that the potential chemical feedstock base can be broadened by using ammonia to generate hydrogen cyanide and cyanogen from coal. The current report shows that the reactivity of a demineralized lignite in ammonia is significantly higher in the presence of calcium or potassium catalyst than that for the char without added catalyst and suggests that ammonia is a potentially reactive gas for catalyzed coal gasification.

  6. Coal char fragmentation during pulverized coal combustion

    SciTech Connect

    Baxter, L.L.

    1995-07-01

    A series of investigations of coal and char fragmentation during pulverized coal combustion is reported for a suite of coals ranging in rank from lignite to low-volatile (lv) bituminous coal under combustion conditions similar to those found in commercial-scale boilers. Experimental measurements are described that utilize identical particle sizing characteristics to determine initial and final size distributions. Mechanistic interpretation of the data suggest that coal fragmentation is an insignificant event and that char fragmentation is controlled by char structure. Chars forming cenospheres fragment more extensively than solid chars. Among the chars that fragment, large particles produce more fine material than small particles. In all cases, coal and char fragmentation are seen to be sufficiently minor as to be relatively insignificant factors influencing fly ash size distribution, particle loading, and char burnout.

  7. Pyrolysis and gasification of coal at high temperatures

    SciTech Connect

    Zygourakis, K.

    1990-01-01

    We made considerable progress towards developing a thermogravimetric reactor with in-situ video imaging capability (TGA/IVIM). Such a reactor will allow us to observe macroscopic changes in the morphology of pyrolyzing particles and thermal ignitions while monitoring at the time the weight of pyrolyzing or reacting samples. The systematic investigation on the effects of pyrolysis conditions and char macropore structure on char reactivity continued. Pyrolysis and gasification experiments were performed consecutively in our TGA reactor and the char reactivity patterns were measured for a wide range of temperatures (400 to 600[degrees]C). These conditions cover both the kinetic and the diffusion limited regimes. Our results show conclusively that chars produced at high pyrolysis heating rates (and, therefore, having a more open cellular macropore structure) are more reactive and ignite more easily than chars pyrolyzed at low heating rates. These results have been explained using available predictions from theoretical models. We also investigated for the first time the effect of coal particle size and external mass transfer limitations on the reactivity patterns and ignition behavior of char particles combusted in air. Finally, we used our hot stage reactor to monitor the structural transformations occurring during pyrolysis via a video microscopy system. Pyrolysis experiments were videotaped and particle swelling and the particle ignitions were determined and analyzed using digitized images from these experiments.

  8. Advanced coal gasification system for electric power generation. Third quarterly progress report, April 1-June 30, 1980

    SciTech Connect

    1980-07-25

    The operation, maintenance and modifications to the Westinghouse gasification process development unit during the quarter are reviewed. The tests of the gasifier-agglomerator included direct coal feed as well as oxygen-blown gasification of a char or coal bed. Then the whole system was tested in single and double stage operation. Laboratory support involved fluidized bed test facilities at ambient temperature and at design temperature for devolatilization and gasification studies. Other laboratory systems were related to thermal analysis and pressurized high temperature studies of gasification and gas cleaning. (LTN)

  9. Comparison of biomass and coal char reactivities

    SciTech Connect

    Huey, S.P.; Davis, K.A.; Hurt, R.H.

    1995-08-01

    Char combustion is typically the rate limiting step during the combustion of solid fuels. The magnitude and variation of char reactivity during combustion are, therefore, of primary concern when comparing solid fuels such as coal and biomass. In an effort to evaluate biomass` potential as a sustainable and renewable energy source, the reactivities of both biomass and coal chars were compared using Sandia`s Captive Particle Imaging (CPI) apparatus. This paper summarizes the experimental approach used to determine biomass and coal reactivities and presents results from CPT experiments. The reactivity of six types of char particles, two high-rank coal chars, two low-rank coal chars, and two biomass chars, were investigated using the CPT apparatus. Results indicate that both of the high-rank coal chars have relatively low reactivities when compared with the higher reactivities measured for the low-rank coal and the biomass chars. In addition, extinction behavior of the chars support related investigations that suggest carbonaceous structural ordering is an important consideration in understanding particle reactivity as a function of extent of burnout. High-rank coal chars were found to have highly ordered carbon structures, where as, both low-rank coal and biomass chars were found to have highly disordered carbon structures.

  10. Char binder for fluidized beds

    DOEpatents

    Borio, Richard W.; Accortt, Joseph I.

    1981-01-01

    An arrangement that utilizes agglomerating coal as a binder to bond coal fines and recycled char into an agglomerate mass that will have suitable retention time when introduced into a fluidized bed 14 for combustion. The simultaneous use of coal for a primary fuel and as a binder effects significant savings in the elimination of non-essential materials and processing steps.

  11. Process for reducing sulfur in coal char

    DOEpatents

    Gasior, Stanley J.; Forney, Albert J.; Haynes, William P.; Kenny, Richard F.

    1976-07-20

    Coal is gasified in the presence of a small but effective amount of alkaline earth oxide, hydroxide or carbonate to yield a char fraction depleted in sulfur. Gases produced during the reaction are enriched in sulfur compounds and the alkaline earth compound remains in the char fraction as an alkaline earth oxide. The char is suitable for fuel use, as in a power plant, and during combustion of the char the alkaline earth oxide reacts with at least a portion of the sulfur oxides produced from the residual sulfur contained in the char to further lower the sulfur content of the combustion gases.

  12. Pyrolysis and gasification of coal at high temperatures

    SciTech Connect

    Zygourakis, K.

    1988-01-01

    Particles from two parent coals (Illinois [number sign]6 and lignite) were pyrolyzed in a nitrogen atmosphere using a captive sample microreactor capable of achieving heating rates as high as 1000[degrees]C/s. Direct measurements on digitized image of char particle cross-sections and a stereological model were used to characterize the macropore structure of chars. Macroporosites, pore size distributions and surface areas were accurately measured allowing us to quantify the effects of pyrolysis heating rates and coal particle size. We have paid particular attention to the development of image analysis software that has allowed us to analyze for the first time the shape or bounary tortuosity of the macropores. Tortuous pore boundaries result in higher values for the true macropore surface areas and should enhance the reactivity of the char samples. Another contribution of the current research program is the development of probabilisitic gasification models that work on computational grids obtained from digitized images of actual cross-sections of char particles. These digital images are accurate discrete approximations of a slice of the actual reacting solid. The incorporation of sophisticated image processing technique is perhaps the most attractive feature of the new simulation approach. Preliminary results indicate that the probabilistic models can accurately account for the opening of closed porosity and fragmentation phenomena occurring during gasification at high temperatures.

  13. Biomass waste gasification - Can be the two stage process suitable for tar reduction and power generation?

    SciTech Connect

    Sulc, Jindrich; Stojdl, Jiri; Richter, Miroslav; Popelka, Jan; Svoboda, Karel; Smetana, Jiri; Vacek, Jiri; Skoblja, Siarhei; Buryan, Petr

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Comparison of one stage (co-current) and two stage gasification of wood pellets. Black-Right-Pointing-Pointer Original arrangement with grate-less reactor and upward moving bed of the pellets. Black-Right-Pointing-Pointer Two stage gasification leads to drastic reduction of tar content in gas. Black-Right-Pointing-Pointer One stage gasification produces gas with higher LHV at lower overall ER. Black-Right-Pointing-Pointer Content of ammonia in gas is lower in two stage moving bed gasification. - Abstract: A pilot scale gasification unit with novel co-current, updraft arrangement in the first stage and counter-current downdraft in the second stage was developed and exploited for studying effects of two stage gasification in comparison with one stage gasification of biomass (wood pellets) on fuel gas composition and attainable gas purity. Significant producer gas parameters (gas composition, heating value, content of tar compounds, content of inorganic gas impurities) were compared for the two stage and the one stage method of the gasification arrangement with only the upward moving bed (co-current updraft). The main novel features of the gasifier conception include grate-less reactor, upward moving bed of biomass particles (e.g. pellets) by means of a screw elevator with changeable rotational speed and gradual expanding diameter of the cylindrical reactor in the part above the upper end of the screw. The gasifier concept and arrangement are considered convenient for thermal power range 100-350 kW{sub th}. The second stage of the gasifier served mainly for tar compounds destruction/reforming by increased temperature (around 950 Degree-Sign C) and for gasification reaction of the fuel gas with char. The second stage used additional combustion of the fuel gas by preheated secondary air for attaining higher temperature and faster gasification of the remaining char from the first stage. The measurements of gas composition and tar

  14. Combustion of char-coal waste pellets for high efficiency and low NO{sub x}. Technical report, September 1--November 30, 1994

    SciTech Connect

    Rajan, S.

    1994-12-31

    Illinois coals are prime candidates for use in Integrated Gasification Combined Cycle (IGCC) plants because of their high volatility and good char reactivity. In these plants, partial gasification of the coal in the presence of limestone eliminates the major portion of the sulfur species in the product gases, which are used as fuel for the topping cycle. The char produced is high in ash content, the major portion of which is calcium sulfide. It is also low in volatiles and of low density, compared to the parent coal. The economic success of the gasification route depends on the subsequent utilization of the residual char for raising steam for use in a Rankine cycle bottoming plant and/or preheating the air to the gasifier. Fluidized bed combustion of the char appears an attractive way of utilizing the char. Areas of concern in the fluidized bed combustion of the high ash, low volatility char are: attainment of high carbon conversion efficiencies; reduction of oxides of nitrogen emissions; reduction/elimination of corrosive chlorine species; reduction/elimination of sodium and other alkali species; and efficient usage of the calcium present in the ash to reduce sulfur compounds. The aim of the present project is to investigate ways of improving the carbon conversion efficiency, sulfur capture efficiency and NO{sub x} reduction during the fluidized bed combustion by pelletizing the low density char with coal and coal wastes using cornstarch or wood lignin as binder. During this first quarter, the parent coals and the chars to be tested have been analyzed. Particle size distributions have been measured. Sample pellets have been made evaluation of their properties.

  15. Gasification: redefining clean energy

    SciTech Connect

    2008-05-15

    This booklet gives a comprehensive overview of how gasification is redefining clean energy, now and in the future. It informs the general public about gasification in a straight-forward, non-technical manner.

  16. TRP0033 - PCI Coal Combustion Behavior and Residual Coal Char Carryover in the Blast Furnace of 3 American Steel Companies during Pulverized Coal Injection (PCI) at High Rates

    SciTech Connect

    Veena Sahajwalla; Sushil Gupta

    2005-04-15

    Combustion behavior of pulverized coals (PC), gasification and thermal annealing of cokes were investigated under controlled environments. Physical and chemical properties of PCI, coke and carbon residues of blast furnace dust/sludge samples were characterized. The strong influence of carbon structure and minerals on PCI reactivity was demonstrated. A technique to characterize char carryover in off gas emissions was established.

  17. Release characteristics of alkali and alkaline earth metallic species during biomass pyrolysis and steam gasification process.

    PubMed

    Long, Jiang; Song, Hu; Jun, Xiang; Sheng, Su; Lun-Shi, Sun; Kai, Xu; Yao, Yao

    2012-07-01

    Investigating the release characteristics of alkali and alkaline earth metallic species (AAEMs) is of potential interest because of AAEM's possible useful service as catalysts in biomass thermal conversion. In this study, three kinds of typical Chinese biomass were selected to pyrolyse and their chars were subsequently steam gasified in a designed quartz fixed-bed reactor to investigate the release characteristics of alkali and alkaline earth metallic species (AAEMs). The results indicate that 53-76% of alkali metal and 27-40% of alkaline earth metal release in pyrolysis process, as well as 12-34% of alkali metal and 12-16% of alkaline earth metal evaporate in char gasification process, and temperature is not the only factor to impact AAEMs emission. The releasing characteristics of AAEMs during pyrolysis and char gasification process of three kinds of biomass were discussed in this paper. PMID:22525260

  18. The effect of chars and their water extractable organic carbon (WEOC) fractions on atrazine adsorption-desorption processes

    NASA Astrophysics Data System (ADS)

    Cavoski, I.; Jablonowski, N.; Burauel, P.; Miano, T.

    2012-04-01

    Chars are carbonaceous material produced from different type of biomass by pyrolysis. They are known as highly effective adsorbents for atrazine therefore limiting its degradation and its diffusion into the aqueous phase. The aim of the present work is to study the effects of different chars and char's derived WEOC on atrazine sorption-desorption processes. The five chars been used in this study derived from: 1) fast pyrolysis from hard wood (FP1); 2) flash pyrolysis from soft wood (FP2); 3) slow pyrolysis from deciduous wood (CC); 4) gasification from deciduous wood (GC) and 5) the market, purchased as activated charcoal standard (AC). Short-term batch equilibration tests were conducted to assess the sorption-desorption behavior of 14C-labeled atrazine on the chars, with a special focus on the desorption behavior using successive dilution method with six consecutive desorption step. Chars and their WEOC were physically and chemically characterized. Results demonstrate that biomass and pyrolysis process used to produce chars affect their physical and chemical properties, and atrazine adsorption-desorption behavior. Atrazine desorption resulted from the positive and competitive interactions between WEOC and chars surfaces. WEOC pool play important role in atrazine adsorption-desorption behavior. FP1 and FP2 with higher concentration of WEOC showed higher desorption rates, whereas GC, CC and AC with insignificant WEOC concentration strongly adsorb atrazine with low desorption rates. According to our results, when high WEOC pools chars are concerned, an increase in atrazine desorption can be observed but further studies would help in confirming the present results.

  19. 2010 Worldwide Gasification Database

    DOE Data Explorer

    The 2010 Worldwide Gasification Database describes the current world gasification industry and identifies near-term planned capacity additions. The database lists gasification projects and includes information (e.g., plant location, number and type of gasifiers, syngas capacity, feedstock, and products). The database reveals that the worldwide gasification capacity has continued to grow for the past several decades and is now at 70,817 megawatts thermal (MWth) of syngas output at 144 operating plants with a total of 412 gasifiers.

  20. Computational fluid dynamics modeling of coal gasification in a pressurized spout-fluid bed

    SciTech Connect

    Zhongyi Deng; Rui Xiao; Baosheng Jin; He Huang; Laihong Shen; Qilei Song; Qianjun Li

    2008-05-15

    Computational fluid dynamics (CFD) modeling, which has recently proven to be an effective means of analysis and optimization of energy-conversion processes, has been extended to coal gasification in this paper. A 3D mathematical model has been developed to simulate the coal gasification process in a pressurized spout-fluid bed. This CFD model is composed of gas-solid hydrodynamics, coal pyrolysis, char gasification, and gas phase reaction submodels. The rates of heterogeneous reactions are determined by combining Arrhenius rate and diffusion rate. The homogeneous reactions of gas phase can be treated as secondary reactions. A comparison of the calculated and experimental data shows that most gasification performance parameters can be predicted accurately. This good agreement indicates that CFD modeling can be used for complex fluidized beds coal gasification processes. 37 refs., 7 figs., 5 tabs.

  1. Considerations on coal gasification

    NASA Technical Reports Server (NTRS)

    Franzen, J. E.

    1978-01-01

    Commercial processes for the gasification of coal with oxygen are discussed. The Koppers-Totzek process for the gasification of coal dust entrained in a stream of gasifying agents is described in particular detail. The outlook for future applications of coal gasification is presented.

  2. Hydrogen production from biomass gasification using biochar as a catalyst/support.

    PubMed

    Yao, Dingding; Hu, Qiang; Wang, Daqian; Yang, Haiping; Wu, Chunfei; Wang, Xianhua; Chen, Hanping

    2016-09-01

    Biochar is a promising catalyst/support for biomass gasification. Hydrogen production from biomass steam gasification with biochar or Ni-based biochar has been investigated using a two stage fixed bed reactor. Commercial activated carbon was also studied as a comparison. Catalyst was prepared with an impregnation method and characterized by X-ray diffraction, specific surface and porosity analysis, X-ray fluorescence and scanning electron micrograph. The effects of gasification temperature, steam to biomass ratio, Ni loading and bio-char properties on catalyst activity in terms of hydrogen production were explored. The Ni/AC catalyst showed the best performance at gasification temperature of 800°C, S/B=4, Ni loading of 15wt.%. Texture and composition characterization of the catalysts suggested the interaction between volatiles and biochar promoted the reforming of pyrolysis volatiles. Cotton-char supported Ni exhibited the highest activity of H2 production (64.02vol.%, 92.08mgg(-1) biomass) from biomass gasification, while rice-char showed the lowest H2 production. PMID:27240230

  3. The effect of Jatropha torrified biomass and coal preparation on steam co-gasification in a fixed bed reactor

    NASA Astrophysics Data System (ADS)

    Aloqaili, Mashal Mohammed

    Coal fired power stations produce vast amounts of harmful products that may affect our health and environment. Co-gasification of coal and biomass could be a solution to this issue as an emerging technology. Biomass may reduce emissions significantly and it may contribute to reducing capital operational cost while providing high gas yields. This research tests the co-gasification of coal and biomass blended chars. Coal and biomass were both prepared. Coal Illinois No #6 was prepared as coal semi-char and coal-char while Jatropha biomass was torrefied at six different temperatures ranging from [200-300] ºC. The co-gasification experiments was conducted in a fixed-bed reactor. A gasification temperature was 900 ºC and a constant flow rate of 100 mL/min. Carbon conversion, maximum char reactivity, products yield and amount of hydrogen produced were evaluated and studied based on data obtained from the G.C. Additionally, weight of bed material and ash leftover weight from gasification process were significantly contributed in calculating the carbon conversion percentages.

  4. Fundamental studies of catalytic gasification: Quarterly report, April 1, 1987-June 30, 1987

    SciTech Connect

    Heinemann, H.

    1987-07-01

    Our results indicate that there is a strong interaction between nickel and potassium in the steam gasification of carbon solids leading to a ternary oxide compound formation. Nickel and potassium, however, can potentially also interact with other components present in the char, mainly calcium and alumino-silicate compounds. We have previously reported that the nickel/calcium mixed catalysts are much less active than the nickel/potassium mixture for steam gasification of graphite. The nickel/calcium interaction may therefore be a reason for the loss of catalyst activity. Most of the ash components in the char can be extracted by treatment in aqua regia, and this treatment does prevent the loss of catalyst activity with carbon conversion. The same treatment, however, may also affect the char structure and composition, which in turn can be responsible for the results observed. For example, this treatment strongly oxidizes the carbon surface, and the resulting surface oxygen groups may interact with the catalysts, changing their spreading characteristics and thereby the deactivation process. To distinguish between these two possibilities for catalyst deactivation, that is, interaction with the indigenous components of the char, or change of carbon-catalyst contact, further experiments are being performed. First, pretreatment of the char in HF, instead of aqua regia, can extract the mineral content of the char without oxidizing the carbon surface. Comparison of the results obtained after these two pretreatments can distinguish between these two possible explanations for the catalyst deactivation.

  5. Heterogeneous kinetics of coal gasification. Quarterly technical progress report, 1 April 1983-30 June 1983

    SciTech Connect

    Calo, J.M.; Ganapathi, R.

    1983-01-01

    In the current quarterly technical progress report we present data and results on transient kinetic studies of the steam-char reaction system for activated coconut and lignite chars. These experiments were conducted in a fashion similar to the previous char-CO/sub 2/ studies, under approximately the same experimental conditions. The two principal product species, H/sub 2/ and CO, were monitored using the automatic mass programming system developed especially for this project. In order to perform the steam-char experiments, the original apparatus was modified by the addition of a steam generation/condensate removal system. The steam-char reaction system, being somewhat more complex than the CO/sub 2/-char reaction system, was modeled with a six-parameter, elementary kinetic scheme. The ''effective'' active site concentrations determined from the steam gasification data were of the same order of magnitude, and behaved in a similar fashion, to those obtained for the CO/sub 2/ gasification studies. The implications of this result are briefly discussed. 21 refs., 23 figs., 2 tabs.

  6. Catalytic effects in coal gasification. Quarterly report, April-June 1980

    SciTech Connect

    Padrick, T D

    1980-11-01

    This quarterly report, for the period April through June 1980, summarizes the activities of Sandia National Laboratories' program on mineral matter effects in coal gasification. The objective is to determine the effects of mineral matter on the devolatilization of coal and on the subsequent char gasification. We have selected a basis set of Eastern bituminous coals whose mineral matter content, as determined by x-ray analysis of low-temperature ash, ranged from less than 5% to more than 20%. Chemical and physical characterization revealed that these coals had similar rank and petrographic content. Baseline thermal gravimetric experiments, in which the coals were heated from ambient to 1000/sup 0/C at 5/sup 0/C/min under nitrogen or hydrogen, have been completed. Work has been initiated to measure the composition of the gas evolved during both the devolatilization regime and the subsequent period of slower char gasification.

  7. Characterization of cellulosic wastes and gasification products from chicken farms

    SciTech Connect

    Joseph, Paul; Tretsiakova-McNally, Svetlana; McKenna, Siobhan

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer The gas chromatography indicated the variable quality of the producer gas. Black-Right-Pointing-Pointer The char had appreciable NPK values, and can be used as a fertiliser. Black-Right-Pointing-Pointer The bio-oil produced was of poor quality, having high moisture content and low pH. Black-Right-Pointing-Pointer Mass and energy balances showed inadequate level energy recovery from the process. Black-Right-Pointing-Pointer Future work includes changing the operating parameters of the gasification unit. - Abstract: The current article focuses on gasification as a primary disposal solution for cellulosic wastes derived from chicken farms, and the possibility to recover energy from this process. Wood shavings and chicken litter were characterized with a view to establishing their thermal parameters, compositional natures and calorific values. The main products obtained from the gasification of chicken litter, namely, producer gas, bio-oil and char, were also analysed in order to establish their potential as energy sources. The experimental protocol included bomb calorimetry, pyrolysis combustion flow calorimetry (PCFC), thermo-gravimetric analyses (TGA), differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, elemental analyses, X-ray diffraction (XRD), mineral content analyses and gas chromatography. The mass and energy balances of the gasification unit were also estimated. The results obtained confirmed that gasification is a viable method of chicken litter disposal. In addition to this, it is also possible to recover some energy from the process. However, energy content in the gas-phase was relatively low. This might be due to the low energy efficiency (19.6%) of the gasification unit, which could be improved by changing the operation parameters.

  8. Coal combustion: Effect of process conditions on char reactivity. Final technical report, September 1, 1991--May 31, 1995

    SciTech Connect

    Zygourakis, K.

    1996-02-01

    Coal utilization involves two major stages: coal pyrolysis and char combustion. Figure 1.1 summarizes the steps of these processes. During the pyrolysis stage, heated particles from plastic coals soften, swell and release their volatiles before resolidifying again. During the combustion or gasification stage, char particles may ignite and fragment as the carbon is consumed leaving behind a solid ash residue. Process conditions such as pyrolysis heating rate, heat treatment temperature, pyrolysis atmosphere, and particle size are shown to chemically and physically affect the coal during pyrolysis and the resulting char. Consequently, these pyrolysis conditions as well as the combustion conditions such as the oxygen concentration and combustion temperature affect the char reactivity and ignition phenomena during the combustion stage. Better understanding of the fundamental mechanisms of coal pyrolysis and char combustion is needed to achieve greater and more efficient utilization of coal. Furthermore, this knowledge also contributes to the development of more accurate models that describe the transient processes involved in coal combustion. The project objectives were to investigate the effect of pyrolysis conditions on the macropore structure and subsequent reactivity of chars.

  9. Coal Gasification (chapter only)

    SciTech Connect

    Shadle, L.J.; Berry, D.A.; Syamlal, Madhava

    2002-11-15

    Coal gasification is presented in terms of the chemistry of coal conversion and the product gas characteristics, the historical development of coal gasifiers, variations in the types and performance of coal gasifiers, the configuration of gasification systems, and the status and economics of coal gasification. In many ways, coal gasification processes have been tailored to adapt to the different types of coal feedstocks available. Gasification technology is presented from a historical perspective considering early uses of coal, the first practical demonstration and utilization of coal gasification, and the evolution of the various processes used for coal gasification. The development of the gasification industry is traced from its inception to its current status in the world economy. Each type of gasifier is considered focusing on the process innovations required to meet the changing market needs. Complete gasification systems are described including typical system configurations, required system attributes, and aspects of the industry's environmental and performance demands. The current status, economics of gasification technology, and future of gasification are also discussed.

  10. Assessment of Advanced Coal Gasification Processes

    NASA Technical Reports Server (NTRS)

    McCarthy, John; Ferrall, Joseph; Charng, Thomas; Houseman, John

    1981-01-01

    This report represents a technical assessment of the following advanced coal gasification processes: AVCO High Throughput Gasification (HTG) Process; Bell Single-Stage High Mass Flux (HMF) Process; Cities Service/Rockwell (CS/R) Hydrogasification Process; Exxon Catalytic Coal Gasification (CCG) Process. Each process is evaluated for its potential to produce SNG from a bituminous coal. In addition to identifying the new technology these processes represent, key similarities/differences, strengths/weaknesses, and potential improvements to each process are identified. The AVCO HTG and the Bell HMF gasifiers share similarities with respect to: short residence time (SRT), high throughput rate, slagging and syngas as the initial raw product gas. The CS/R Hydrogasifier is also SRT but is non-slagging and produces a raw gas high in methane content. The Exxon CCG gasifier is a long residence time, catalytic, fluidbed reactor producing all of the raw product methane in the gasifier. The report makes the following assessments: 1) while each process has significant potential as coal gasifiers, the CS/R and Exxon processes are better suited for SNG production; 2) the Exxon process is the closest to a commercial level for near-term SNG production; and 3) the SRT processes require significant development including scale-up and turndown demonstration, char processing and/or utilization demonstration, and reactor control and safety features development.

  11. Circulating fluidized bed gasification of low rank coal: Influence of O2/C molar ratio on gasification performance and sulphur transformation

    NASA Astrophysics Data System (ADS)

    Zhang, Haixia; Zhang, Yukui; Zhu, Zhiping; Lu, Qinggang

    2016-08-01

    To promote the utilization efficiency of coal resources, and to assist with the control of sulphur during gasification and/or downstream processes, it is essential to gain basic knowledge of sulphur transformation associated with gasification performance. In this research we investigated the influence of O2/C molar ratio both on gasification performance and sulphur transformation of a low rank coal, and the sulphur transformation mechanism was also discussed. Experiments were performed in a circulating fluidized bed gasifier with O2/C molar ratio ranging from 0.39 to 0.78 mol/mol. The results showed that increasing the O2/C molar ratio from 0.39 to 0.78 mol/mol can increase carbon conversion from 57.65% to 91.92%, and increase sulphur release ratio from 29.66% to 63.11%. The increase of O2/C molar ratio favors the formation of H2S, and also favors the retained sulphur transforming to more stable forms. Due to the reducing conditions of coal gasification, H2S is the main form of the released sulphur, which could be formed by decomposition of pyrite and by secondary reactions. Bottom char shows lower sulphur content than fly ash, and mainly exist as sulphates. X-ray photoelectron spectroscopy (XPS) measurements also show that the intensity of pyrite declines and the intensity of sulphates increases for fly ash and bottom char, and the change is more obvious for bottom char. During CFB gasification process, bigger char particles circulate in the system and have longer residence time for further reaction, which favors the release of sulphur species and can enhance the retained sulphur transforming to more stable forms.

  12. Heat capacity of coal chars

    SciTech Connect

    Wang, W.Y.

    1982-01-01

    The selected starting materials were, a North Dakota lignite, an Illinois No. 6 bituminous and a Virginia coking coal. The carbon content of these coals ranged from 59 to 75 wt% (mineral matter included). Half of each of the received coal sample was demineralized using a standard procedure. Chars were prepared from the received and demineralized pulverized coals by pyrolysis. Heating rate of 5/sup 0/C/minute was employed for the pyrolysis under dry nitrogen gas atmosphere. The pyrolysis temperatures were 700, 900 and 1100/sup 0/C for periods of 0.1, 1 and 24. The char samples were characterized by chemical composition analysis, x-ray diffraction and porosimetry. Heat capacity data were collected over 75 to 300/sup 0/K temperature range using an adiabatic calorimeter. The heat capacity of these samples increases, with increasing temperature and moisture content, and its behavior and order of magnitude are similar to that of carbon when compared on a moisture free basis. Due to the uncertainties of the chemical forms of the mineral matter and the water phase below room temperature, all the heat capacity data are analyzed on a dry mineral matter free basis.

  13. Evaluating phenanthrene sorption on various wood chars

    USGS Publications Warehouse

    James, G.; Sabatini, D.A.; Chiou, C.T.; Rutherford, D.; Scott, A.C.; Karapanagioti, H.K.

    2005-01-01

    A certain amount of wood char or soot in a soil or sediment sample may cause the sorption of organic compounds to deviate significantly from the linear partitioning commonly observed with soil organic matter (SOM). Laboratory produced and field wood chars have been obtained and analyzed for their sorption isotherms of a model solute (phenanthrene) from water solution. The uptake capacities and nonlinear sorption effects with the laboratory wood chars are similar to those with the field wood chars. For phenanthrene aqueous concentrations of 1 ??gl-1, the organic carbon-normalized sorption coefficients (log Koc) ranging from 5.0 to 6.4 for field chars and 5.4-7.3 for laboratory wood chars, which is consistent with literature values (5.6-7.1). Data with artificial chars suggest that the variation in sorption potential can be attributed to heating temperature and starting material, and both the quantity and heterogeneity of surface-area impacts the sorption capacity. These results thus help to corroborate and explain the range of log Koc values reported in previous research for aquifer materials containing wood chars. ?? 2004 Elsevier Ltd. All rights reserved.

  14. Heterogeneous kinetics of coal gasification. Quarterly technical progress report, 1 February-30 April 1982. [680 to 770/sup 0/C; 8 to 30 atm

    SciTech Connect

    Calo, J.M.

    1982-05-01

    The operation of the gradientless reactor system designed to study heterogeneous gas-char reactions under transient conditions was successfully demonstrated. CO/sub 2/ char gasification was studied at temperatures from 680 to 770/sup 0/C and at pressures from 8 to 30 atm. The transient response of the reactor resulting from a step change from inert gas (Ar) to pure CO/sub 2/ is adequately described by a simple, two-step mechanism. The determination of the rate parameters from the transient data was accomplished with the Marquardt optimization code developed for this purpose. For what is believed to be the first time in the same experiment, the active site concentration was uncoupled from the intrinsic rate constants. The active site concentration of the coconut char exhibits an Arrhenius type temperature dependence with an apparent negative activation energy. A preliminary design has been developed for a steam addition system to be used for steam-char gasification studies. This system will be constructed during the next reporting period. Various chars have been generated in a high temperature furnace system from fresh coals. These chars are to be used in the gradientless reactor system to determine the effects of char type on the intrinsic rate parameters and char reactivity.

  15. Gasification of Woody Biomass.

    PubMed

    Dai, Jianjun; Saayman, Jean; Grace, John R; Ellis, Naoko

    2015-01-01

    Interest in biomass to produce heat, power, liquid fuels, hydrogen, and value-added chemicals with reduced greenhouse gas emissions is increasing worldwide. Gasification is becoming a promising technology for biomass utilization with a positive environmental impact. This review focuses specifically on woody biomass gasification and recent advances in the field. The physical properties, chemical structure, and composition of biomass greatly affect gasification performance, pretreatment, and handling. Primary and secondary catalysts are of key importance to improve the conversion and cracking of tars, and lime-enhanced gasification advantageously combines CO2 capture with gasification. These topics are covered here, including the reaction mechanisms and biomass characterization. Experimental research and industrial experience are investigated to elucidate concepts, processes, and characteristics of woody biomass gasification and to identify challenges. PMID:26247289

  16. Gasification. 2nd. ed.

    SciTech Connect

    Christopher Higman; Maarten van der Burgt

    2008-02-15

    This book covers gasification as a comprehensive topic, covering its many uses, from refining, to natural gas, to coal. It provides an overview of commercial processes and covers applications relevant to today's demands. The new edition is expanded and provides more detail on the integration issues for current generation, state-of-the-art Integrated Gasification Combined Cycles (IGCC); CO{sub 2} capture in the IGCC context addressing the issues of pre-investment and retrofitting as well as defining what the term 'CO{sub 2} capture ready' might mean in practice; issues of plant reliability, availability and maintainability (RAM) including as evaluation of feedback from existing plants; implementation of fuel cell technology in IGCC concepts. Contents are: Introduction; The Thermodynamics of Gasification; The Kinetics of Gasification and Reactor Theory; Feedstocks and Feedstock Characteristics; Gasification Processes; Practical Issues; Applications; Auxiliary Technologies; Economics, environmental, and Safety Issues; Gasification and the Future. 5 apps.

  17. Fluidized bed reactor apparatus and related gasification system

    SciTech Connect

    Fernandez, J.M.; Hoffert, F.D.; Marina, J.M.; Milligan, J.D.

    1982-11-16

    A process and pressurized, gasification reactor apparatus are claimed for converting combustible carbon containing materials such as coal char and other carbonaceous solids or carbonaceous solids/heavy oil combinations to an intermediate heating value fuel gas. The gasification reactor includes an insulated fluidized bed reactor chamber, an upper reactor housing for a freely suspended bayonet bundle type heat exchanger for (A) superheating incoming saturated steam and (B) cooling outgoing high temperature product gas, and a lower reactor housing structure which includes a freefloating, conically-shaped perforated plenum chamber. The superheated steam and oxygen are premixed with the plenum chamber before being pressure directed into the fluidized bed reactor chamber for mixture and combustion with the incoming combustible carbon containing materials such as coal char. After reaction of the superheated steam, oxygen and coal char in the fluidized bed reactor at temperatures ranging from 900/sup 0/ F to 1750/sup 0/ F, the product fuel gases and associated particulate matter are cooled by steam flowing through the bayonet heat exchanger, the steam being superheated by this exchange. After discharge from the heat exchanger, the fuel gas product containing particulate matter is pressure directed into a conventional cyclone separator for (A) separation of the desired product gases and (B) return of the particulate matter for further recycling in the reactor chamber. Undesirable ash clinkers are gravitationally and pressure directed out of the reactor chamber through a central ash withdrawal pipe.

  18. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUIDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    SciTech Connect

    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.

  19. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUIDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    SciTech Connect

    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.

  20. Development of Pressurized Circulating Fluidized Bed Partial Gasification Module (PGM)

    SciTech Connect

    A. Robertson

    2002-09-30

    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 July 1-September 30, 2002 time period.

  1. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    SciTech Connect

    Archie Robertson

    2002-07-10

    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, 2002 time period.

  2. Development of Pressurized Circulating Fluidized Bed Partial Gasification Module (PGM)

    SciTech Connect

    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.

  3. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUIDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    SciTech Connect

    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.

  4. Solar coal gasification

    NASA Astrophysics Data System (ADS)

    Gregg, D. W.; Aiman, W. R.; Otsuki, H. H.; Thorsness, C. B.

    1980-01-01

    A preliminary evaluation of the technical and economic feasibility of solar coal gasification has been performed. The analysis indicates that the medium-Btu product gas from a solar coal-gasification plant would not only be less expensive than that from a Lurgi coal-gasification plant but also would need considerably less coal to produce the same amount of gas. A number of possible designs for solar coal-gasification reactors are presented. These designs allow solar energy to be chemically stored while at the same time coal is converted to a clean-burning medium-Btu gas.

  5. Gasification-based biomass

    SciTech Connect

    None, None

    2009-01-18

    The gasification-based biomass section of the Renewable Energy Technology Characterizations describes the technical and economic status of this emerging renewable energy option for electricity supply.

  6. Calderon coal gasification Process Development Unit design and test program

    SciTech Connect

    Calderon, A.; Madison, E.; Probert, P.

    1992-01-01

    The Process Development Unit (PDU) was designed and constructed to demonstrate the novel Calderon gasification/hot gas cleanup process. in the process, run-of-mine high sulfur coal is first pyrolyzed to recover a rich gas (medium Btu gas), after which the resulting char is subjected to airblown gasification to yield a lean gas (low Btu gas). The process incorporates a proprietary integrated system for the conversion of coal to gases and for the hot cleanup of the gases which removes both particulate and sulfur components of the gaseous products. The yields are: a syngas (CO and H[sub 2] mix) suitable for further conversion to liquid fuel (e.g. methanol/gasoline), and a lean gas suitable to fuel the combustion turbine of a combined cycle power generation plant with very low levels of NO[sub x] (15 ppmv). The fused slag (from the gasified char ash content) and the sulfur recovered during the hot gas cleanup will be sold as by-products. The small quantity of spent sorbent generated will be combined with the coal feed as a fluxing agent for the slag. The small quantity of wastewater from slag drainings and steam generation blowdown will be mixed with the coal feed for disposal. The Calderon gasification/hot gas cleanup, which is a completely closed system, operates at a pressure suitable for combined cycle power generation.

  7. Calderon coal gasification Process Development Unit design and test program

    SciTech Connect

    Calderon, A.; Madison, E.; Probert, P.

    1992-11-01

    The Process Development Unit (PDU) was designed and constructed to demonstrate the novel Calderon gasification/hot gas cleanup process. in the process, run-of-mine high sulfur coal is first pyrolyzed to recover a rich gas (medium Btu gas), after which the resulting char is subjected to airblown gasification to yield a lean gas (low Btu gas). The process incorporates a proprietary integrated system for the conversion of coal to gases and for the hot cleanup of the gases which removes both particulate and sulfur components of the gaseous products. The yields are: a syngas (CO and H{sub 2} mix) suitable for further conversion to liquid fuel (e.g. methanol/gasoline), and a lean gas suitable to fuel the combustion turbine of a combined cycle power generation plant with very low levels of NO{sub x} (15 ppmv). The fused slag (from the gasified char ash content) and the sulfur recovered during the hot gas cleanup will be sold as by-products. The small quantity of spent sorbent generated will be combined with the coal feed as a fluxing agent for the slag. The small quantity of wastewater from slag drainings and steam generation blowdown will be mixed with the coal feed for disposal. The Calderon gasification/hot gas cleanup, which is a completely closed system, operates at a pressure suitable for combined cycle power generation.

  8. The influence of thermal annealing on oxygen uptake and combustion rates of a bituminous coal char

    SciTech Connect

    Osvalda Senneca; Piero Salatino; Daniela Menghini

    2007-07-01

    The effect of thermal annealing on the combustion reactivity of a bituminous coal char has been investigated with a focus on the role of the formation of surface oxides by oxygen chemisorption. The combined use of thermogravimetric analysis and of analysis of the off-gas during isothermal combustion of char samples enabled the determination of the rate and extent of oxygen uptake along burn-off. Combustion was carried out at temperatures between 350 and 510{sup o}C. Char samples were prepared by controlled isothermal heat treatment of coal for different times (in the range between 1 s and 30 min) at different temperatures (in the range 900-2000{sup o}C). Results indicate that oxygen uptake is extensive along burn-off of chars prepared under mild heat treatment conditions. The maximum oxygen uptake is barely affected by the combustion temperature within the range of combustion conditions investigated. The severity of heat treatment has a pronounced effect on char combustion rate as well as on the extent and rate at which surface oxides are built up by oxygen chemisorption. Chars prepared under severe heat treatment conditions show negligible oxygen uptake and strongly reduced combustion rates. Altogether it appears that a close correlation can be established between the extent and the accessibility of active sites on the carbon surface and the combustion rate. Despite the investigation has been carried out at temperatures well below those of practical interest, results provide useful insight into the relationship existing between thermal annealing, formation of surface oxide and combustion reactivity which is relevant to the proper formulation of detailed kinetic models of char combustion. 31 refs., 6 figs., 1 tab.

  9. Catalytic Gasification of Coal using Eutectic Salt Mixtures

    SciTech Connect

    Atul Sheth; Pradeep Agrawal; Yaw D. Yeboah

    1998-12-04

    The objectives of this study are to: identify appropriate eutectic salt mixture catalysts for coal gasification; assess agglomeration tendency of catalyzed coal; evaluate various catalyst impregnation techniques to improve initial catalyst dispersion; evaluate effects of major process variables (such as temperature, system pressure, etc.) on coal gasification; evaluate the recovery, regeneration and recycle of the spent catalysts; and conduct an analysis and modeling of the gasification process to provide better understanding of the fundamental mechanisms and kinetics of the process. A review of the collected literature was carried out. The catalysts which have been used for gasification can be roughly classified under the following five groups: alkali metal salts; alkaline earth metal oxides and salts; mineral substances or ash in coal; transition metals and their oxides and salts; and eutectic salt mixtures. Studies involving the use of gasification catalysts have been conducted. However, most of the studies focused on the application of individual catalysts. Only two publications have reported the study of gasification of coal char in CO2 and steam catalyzed by eutectic salt mixture catalysts. By using the eutectic mixtures of salts that show good activity as individual compounds, the gasification temperature can be reduced possibly with still better activity and gasification rates due to improved dispersion of the molten catalyst on the coal particles. For similar metal/carbon atomic ratios, eutectic catalysts were found to be consistently more active than their respective single salts. But the exact roles that the eutectic salt mixtures play in these are not well understood and details of the mechanisms remain unclear. The effects of the surface property of coals and the application methods of eutectic salt mixture catalysts with coal chars on the reactivity of gasification will be studied. Based on our preliminary evaluation of the literature, a ternary

  10. Sugarcane vinasse CO2 gasification and release of ash-forming matters in CO2 and N2 atmospheres.

    PubMed

    Dirbeba, Meheretu Jaleta; Brink, Anders; DeMartini, Nikolai; Lindberg, Daniel; Hupa, Mikko

    2016-10-01

    Gasification of sugarcane vinasse in CO2 and the release of ash-forming matters in CO2 and N2 atmospheres were investigated using a differential scanning calorimetry and thermogravimetric analyzer (DSC-TGA) at temperatures between 600 and 800°C. The results showed that pyrolysis is the main mechanism for the release of the organics from vinasse. Release of ash-forming matters in the vinasse is the main cause for vinasse char weight losses in the TGA above 700°C. The losses are higher in N2 than in CO2, and increase considerably with temperature. CO2 gasification also consumes the carbon in the vinasse chars while suppressing alkali release. Alkali release was also significant due to volatilization of KCl and reduction of alkali sulfate and carbonate by carbon. The DSC measured thermal events during heating up in N2 atmosphere that correspond to predicted melting temperatures of alkali salts in the char. PMID:27403861

  11. Complete study of the pyrolysis and gasification of scrap tires in a pilot plant reactor.

    PubMed

    Conesa, Juan A; Martín-Gullón, I; Font, R; Jauhiainen, J

    2004-06-01

    The pyrolysis and gasification of tires was studied in a pilot plant reactor provided with a system for condensation of semivolatile matter. The study comprises experiments at 450, 750, and 1000 degrees C both in nitrogen and 10% oxygen atmospheres. Analysis of all the products obtained (gases, liquids, char, and soot) are presented. In the gas phase only methane and benzene yields increase with temperature until 1000 degrees C. In the liquids the main components are styrene, limonene, and isoprene. The solid fraction (including soot) increases with temperature. Zinc content of the char decreases with increasing temperature. PMID:15224754

  12. Combustion of char from plastic wastes pyrolysis

    NASA Astrophysics Data System (ADS)

    Saptoadi, Harwin; Rohmat, Tri Agung; Sutoyo

    2016-06-01

    A popular method to recycle plastic wastes is pyrolysis, where oil, gas and char can be produced. These products can be utilized as fuels because they are basically hydrocarbons. The research investigates char properties, including their performance as fuel briquettes. There are 13 char samples from PE (Polyethylene) pyrolyzed at temperatures of around 450 °C, with and without a catalyst. Some of the samples were obtained from PE mixed with other types, such as Polystyrene (PS), Polypropylene (PP), Polyethylene Terephthalate (PET), and Others. Char properties, such as moisture, ash, volatile matter, and fixed carbon contents, are revealed from the proximate analysis, whereas calorific values were measured with a bomb calorimeter. Briquettes are made by mixing 4 g of char with 0.5 - 1 g binder. Briquettes are hollow cylinders with an outer and inner diameter of around 1.75 cm and 0.25 cm, respectively. Combustion is carried out in a furnace with wall temperatures of about 230°C and a constant air velocity of 0.7 m/s. Five out of 13 char briquettes are not feasible because they melt during combustion. Briquettes made from 100% PE wastes burn in substantially shorter duration than those from mixed plastic wastes. Char #1 and #5 are excellent due to their highest energy release, whereas #10 show the worst performance.

  13. Gasification: A Cornerstone Technology

    ScienceCinema

    Gary Stiegel

    2010-01-08

    NETL is a leader in the science and technology of gasification - a process for the conversion of carbon-based materials such as coal into synthesis gas (syngas) that can be used to produce clean electrical energy, transportation fuels, and chemicals efficiently and cost-effectively using domestic fuel resources. Gasification is a cornerstone technology of 21st century zero emissions powerplants

  14. Gasification: A Cornerstone Technology

    SciTech Connect

    Gary Stiegel

    2008-03-26

    NETL is a leader in the science and technology of gasification - a process for the conversion of carbon-based materials such as coal into synthesis gas (syngas) that can be used to produce clean electrical energy, transportation fuels, and chemicals efficiently and cost-effectively using domestic fuel resources. Gasification is a cornerstone technology of 21st century zero emissions powerplants

  15. 2006 gasification technologies conference papers

    SciTech Connect

    2006-07-01

    Sessions covered: business overview, industry trends and new developments; gasification projects progress reports; industrial applications and opportunities; Canadian oil sands; China/Asia gasification markets - status and projects; carbon management with gasification technologies; gasification economics and performance issues addressed; and research and development, and new technologies initiatives.

  16. Biomass waste gasification - can be the two stage process suitable for tar reduction and power generation?

    PubMed

    Sulc, Jindřich; Stojdl, Jiří; Richter, Miroslav; Popelka, Jan; Svoboda, Karel; Smetana, Jiří; Vacek, Jiří; Skoblja, Siarhei; Buryan, Petr

    2012-04-01

    A pilot scale gasification unit with novel co-current, updraft arrangement in the first stage and counter-current downdraft in the second stage was developed and exploited for studying effects of two stage gasification in comparison with one stage gasification of biomass (wood pellets) on fuel gas composition and attainable gas purity. Significant producer gas parameters (gas composition, heating value, content of tar compounds, content of inorganic gas impurities) were compared for the two stage and the one stage method of the gasification arrangement with only the upward moving bed (co-current updraft). The main novel features of the gasifier conception include grate-less reactor, upward moving bed of biomass particles (e.g. pellets) by means of a screw elevator with changeable rotational speed and gradual expanding diameter of the cylindrical reactor in the part above the upper end of the screw. The gasifier concept and arrangement are considered convenient for thermal power range 100-350 kW(th). The second stage of the gasifier served mainly for tar compounds destruction/reforming by increased temperature (around 950°C) and for gasification reaction of the fuel gas with char. The second stage used additional combustion of the fuel gas by preheated secondary air for attaining higher temperature and faster gasification of the remaining char from the first stage. The measurements of gas composition and tar compound contents confirmed superiority of the two stage gasification system, drastic decrease of aromatic compounds with two and higher number of benzene rings by 1-2 orders. On the other hand the two stage gasification (with overall ER=0.71) led to substantial reduction of gas heating value (LHV=3.15 MJ/Nm(3)), elevation of gas volume and increase of nitrogen content in fuel gas. The increased temperature (>950°C) at the entrance to the char bed caused also substantial decrease of ammonia content in fuel gas. The char with higher content of ash leaving the

  17. Flexible Ablators Char Depths LHMEL Test Results

    NASA Technical Reports Server (NTRS)

    White, Susan; Qu, Vince; Fan, Wendy; Stackpoole, Mairead; Thornton, Jeremy

    2012-01-01

    Char and pyrolysis zone depths give physical evidence of peak temperature reached in depth: The pyrolyzing material acts as a temperature indicator within its characteristic thermal decomposition range. A matrix of novel flexible ablators were laser tested in one component of material screening for NASA Entry, Descent and Landing research for future Mars missions. LHMEL tests were run both on virgin materials, and on previously charred materials for a dual pulse simulation of the heating due to aerocapture followed by atmospheric entry. The test models were machined to expose the cross-sections. Char measurements were made at three locations near the center of the exposed area. Data are presented showing the char depths developed in these flexible materials, grouped by reinforcing fiber and pyrolyzing material type.

  18. A model approach to highly dispersing catalytic materials in coal for gasification. Eleventh quarterly report, April 1, 1992--June 30, 1992

    SciTech Connect

    Abotsi, G.M.K.; Bota, K.B.

    1992-10-01

    This project seeks to develop a technique, based on coal surface properties, for highly dispersing catalysts in coal for gasification and to investigate the potential of using potassium carbonate and calcium acetate mixtures as catalysts for coal gasification. The lower cost and higher catalytic activity of the latter compound will produce economic benefits by reducing the amount of K{sub 2}CO{sub 3} required for high coal char reactivities. As was shown in previous reports, coal loading with potassium or calcium at different pHs produced CO{sub 2} gasification activities which increased in the order pH 6 > pH 10 >>pH 1. A similar trend was obtained when calcium and potassium were simultaneously loaded and char reaction times were less than about 75 min. In the last quarter, the potential application of ammonia as a reactive medium for coal gasification has been investigated. This gas has not been previously applied to coal gasification. However, related work suggests that the potential chemical feedstock base can be broadened by using ammonia to generate hydrogen cyanide and cyanogen from coal. The current report shows that the reactivity of a demineralized lignite in ammonia is significantly higher in the presence of calcium or potassium catalyst than that for the char without added catalyst and suggests that ammonia is a potentially reactive gas for catalyzed coal gasification.

  19. Microbial oxidation of pyrrhotites in coal chars

    USGS Publications Warehouse

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

    1988-01-01

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

  20. In Situ Causticizing for Black Liquor Gasification

    SciTech Connect

    Scott Alan Sinquefield

    2005-10-01

    Black liquor gasification offers a number of attractive incentives to replace Tomlinson boilers but it also leads to an increase in the causticizing load. Reasons for this have been described in previous reports (FY04 ERC, et.al.). The chemistries have also been covered but will be reviewed here briefly. Experimental results of the causticizing reactions with black liquor are presented here. Results of the modeling work were presented in detail in the Phase 1 report. They are included in Table 2 for comparison but will not be discussed in detail. The causticizing agents were added to black liquor in the ratios shown in Table 1, mixed, and then spray-dried. The mixture ratios (doping levels) reflect amount calculated from the stoichiometry above to achieve specified conversions shown in the table. The solids were sieved to 63-90 microns for use in the entrained flow reactors. The firing conditions are shown in Table 2. Pictures and descriptions of the reactors can be found in the Phase 1 annual report. Following gasification, the solids (char) was collected and analyzed by coulometric titration (for carbonate and total carbon), and by inductively coupled plasma emission spectroscopy (ICP) for a wide array of metals.

  1. Fuel Flexibility in Gasification

    SciTech Connect

    McLendon, T. Robert; Pineault, Richard L.; Richardson, Steven W.; Rockey, John M.; Beer, Stephen K.; Lui, Alain P.; Batton, William A.

    2001-11-06

    coal to percent by weight sawdust. The mixtures of interest were: 65/35 subbituminous, 75/25 subbituminous, 85/15 subbituminous, and 75/25 bituminous. Steady state was achieved quickly when going from one subbituminous mixture to another, but longer when going from subbituminous to bituminous coal. The most apparent observation when comparing the base case to subbituminous coal/sawdust mixtures is that operating conditions are nearly the same. Product gas does not change much in composition and temperatures remain nearly the same. Comparisons of identical weight ratios of sawdust and subbituminous and bituminous mixtures show considerable changes in operating conditions and gas composition. The highly caking bituminous coal used in this test swelled up and became about half as dense as the comparable subbituminous coal char. Some adjustments were required in accommodating changes in solids removal during the test. Nearly all the solids in the bituminous coal sawdust were conveyed into the upper freeboard section and removed at the mid-level of the reactor. This is in marked contrast to the ash-agglomerating condition where most solids are removed at the very bottom of the gasifier. Temperatures in the bottom of the reactor during the bituminous test were very high and difficult to control. The most significant discovery of the tests was that the addition of sawdust allowed gasification of a coal type that had previously resulted in nearly instant clinkering of the gasifier. Several previous attempts at using Pittsburgh No. 8 were done only at the end of the tests when shutdown was imminent anyway. It is speculated that the fine wood dust somehow coats the pyrolyzed sticky bituminous coal particles and prevents them from agglomerating quickly. As the bituminous coal char particles swell, they are carried to the cooler upper regions of the reactor where they re-solidify. Other interesting phenomena were revealed regarding the transport (rheological) properties of the

  2. Gasification Technologie: Opportunities & Challenges

    SciTech Connect

    Breault, R.

    2012-01-01

    This course has been put together to provide a single source document that not only reviews the historical development of gasification but also compares the process to combustion. It also provides a short discussion on integrated gasification and combined cycle processes. The major focus of the course is to describe the twelve major gasifiers being developed today. The hydrodynamics and kinetics of each are reviewed along with the most likely gas composition from each of the technologies when using a variety of fuels under different conditions from air blown to oxygen blown and atmospheric pressure to several atmospheres. If time permits, a more detailed discussion of low temperature gasification will be included.

  3. Supercritical droplet gasification experiments with forced convection

    NASA Technical Reports Server (NTRS)

    Litchford, Ron; Parigger, Chris; Jeng, San-Mou

    1992-01-01

    Preliminary results of a comprehensive experimental program are presented which offer the first direct observations of suspended n-heptane droplet gasifications in pure nitrogen with forced convection without the interference to optical probing associated with a flame. Measurements show attainment of a wet-bulb temperature until reduced pressures exceed about 1.0 under supercritical gas temperatures. Thereafter, temperature measurements indicate fully transient heat-up through the critical temperature. The surface is found to regress in a continuous manner with the measured temperature approaching the critical value at the end of the droplet lifetime under supercritical conditions with very mild level of convection. At increased level of convection for the same ambient conditions, similar sized droplets will undergo significant deformation during the gasification process until partially convected away as a dense vapor cloud as the critical temperature is approached.

  4. Combustion of Illinois coals and chars with natural gas

    SciTech Connect

    Buckius, R.O.

    1991-01-01

    There are applications where the combined combustion of coal and natural gas offers potential advantages over the use of either coal or natural gas alone. For example, low volatile coals or low volatile chars derived from treatment or gasification processes can be of limited use during to their poor flammability characteristics. However, the use of natural gas in conjunction with the solid fuel can provide the necessary volatiles'' to enhance the combustion. In addition, natural gas provides a clean fuel source of fuel which, in cofiring situations, can extend the usefulness of coals with high sulfur content. The addition of natural gas may reduce SO{sub x} emission through increased sulfur retention in the ash and reduce NO{sub x} emissions by varying local stoichiometry and temperature levels. In this research program, studies of combined coal and natural gas combustion will provide particle ignition, burnout rates and ash characterization, that will help clarify the effect of coal and natural gas and identify the controlling parameters and mechanisms.

  5. Study on product distributions and char morphology during rapid co-pyrolysis of platanus wood and lignite in a drop tube fixed-bed reactor.

    PubMed

    Meng, Haiyu; Wang, Shuzhong; Chen, Lin; Wu, Zhiqiang; Zhao, Jun

    2016-06-01

    The rapid co-pyrolytic behavior of platanus wood and Pingzhuang lignite was explored in a drop tube fixed-bed reactor under nitrogen atmosphere. Synergistic effects were evaluated using the deviations between experimental and predicted values of product yields and gas components. Surface morphology of residual chars were also investigated applying the scanning electron microscopy technique (SEM). This study found that the experimental values of gas volume yields were greater than the predicted, and the maximum gas volume yield exhibited with 50% biomass blending ratio at 1000°C. Positive or negative synergistic effects happened in gas components at different blending ratios and temperatures. The SEM results indicated that the differences of char surface morphology were evident. The fractal dimensions of residual chars increased with increasing biomass blending ratio, which may improve their gasification or combustion reactivity. The change in product yields and gas components was attributed to the secondary reactions and tar cracking. PMID:26985627

  6. Novel approach to coal gasification using chemically incorporated catalysts (Phase II). Appendix A-F. Final report, May 1978-June 1981

    SciTech Connect

    Feldmann, H.F.; Conkle, H.N.; Appelbaum, H.R.; Chauhan, S.P.

    1981-01-01

    This volume contains six appendices: experimental apparatus, test conditions, and results of catalytic coal treatment; direct hydrogasification; summary of test runs for hydrogasification of BTC; summary of test runs for hydrogasification of char; summary of steam/O/sub 2/ gasification runs; and process analysis. Forty tables and nine figures are also included.

  7. Experimental study of the reforming of methane with carbon dioxide over coal char - article no. A16

    SciTech Connect

    Li, Y.B.; Xiao, R.; Jin, B.S.; Zhang, H.Y.

    2008-07-01

    As one of the fundamental issues of the new poly-generation system on the basis of gasification gas and coke oven gas, carbon dioxide reforming of methane experiments have been performed over coal chars derived from different parent coals in a lab-scale fixed-bed reactor (internal diameter 12 mm, length 700 mm). The char derived from TongChuan coal exhibited higher activity than other samples employed under the same conditions. After the reforming reaction, the char samples were covered with different amounts of carbon deposition which resulted in the surface areas decrease. As the flow rate of feed gas increased from 200 ml/min to 600 ml/min over the Xuzhou char sample at 1050{sup o}C, the conversion of methane decreased from 52.7% to 17.5% and the H{sub 2}/CO dropped from 0.75 to 0.55. While maintaining the flow rate of CO{sub 2} at 20ml/min at 1050{sup o}C, the mole ratio of reactants CH{sub 4}/CO{sub 2} was varied from 1 to 1.75 which led to the H{sub 2}/CO ratio increase from 0.75 to 1.2.

  8. Role of char during reburning of nitrogen oxides. Sixth quarterly report, January 1, 1995--March 31, 1995

    SciTech Connect

    Chen, W.Y.; Ma, L.; Fan, L.T.

    1995-04-30

    The regulations established by the Clean Air Act Amendments of 1990 in the United States mean that a single NO{sub x} control technology is not likely to be sufficient for boilers in the ozone non-attainment areas. Reburning is an emerging three-stage combustion technology designed for the reduction of NO by introducing a small amount of reburning fuel above the primary flame where the majority of NO is chemically reduced to nitrogen. While coal, in general, has not been considered an effective reburning fuel, our recent research suggested that lignite has a reburning efficiency even higher than that of methane. The objectives of this research are to investigate (1) the relative importance of heterogeneous and homogeneous phase reactions, and (2) the role of CaO in the catalysis of char gasification by NO in reburning environment. Experiments have been performed with a flow reactor with a simulated flue gas at a stoichiometric ratio (SR). Reburning fuels in this study include methane, Pittsburgh No. 8 bituminous coal, Mississippi lignite, North Dakota lignite, chars derived from the coal and lignites, and the bituminous coal char impregnated with Can. Chars were produced in N{sub 2} by suspending a sample basket in a 3{double_prime} tube furnace. The impregnation technique follows that developed for the catalysis of carbon oxidation.

  9. A novel approach to highly dispersing catalytic materials in coal for gasification. Final technical report, September 1989--November 1992

    SciTech Connect

    Abotsi, G.M.K.; Bota, K.B.

    1992-12-01

    The objectives of this project were to investigate the effects of coal surface charge on the uptake of aqueous soluble metal catalysts from solution and to determine the influence of the interfacial interaction on char reactivity. Another goal is to assess the potential of using potassium carbonate, potassium acetate or their mixtures as catalysts for char gasification. The lower cost and the high catalytic activity of the latter compound will produce economic benefits by reducing the amount of potassium carbonate required for efficient char reactivities on a commercial scale. To minimize the interference of the coals` inherent inorganic materials with the added calcium or potassium, the gasification studies were restricted to the demineralized coals. In a manner similar to the effect of pH on the surface electrochemistry of the coals, the reactivities of the calcium- or potassium-loaded chars in bon dioxide at 800{degree}C were dependent upon the pH at which the catalysts were ion-exchanged onto the coals. For the calcium-containing chars, the reactivities increased in the order: pH 6 > pH 10 > pH 1. In contrast, the variation of the gasification rates with potassium loading pH was: pH 6 {approximately} pH 10 {much_gt} pH 1. However, simultaneous adsorption of the metals at {approximately} pH 1 enhanced char reactivity relative to metals loading at pH 6 or 10. These findings are attributed to the differences in the extent of electrostatic interaction between the calcium or potassium ions and the charged coal surface during catalyst loading from solution.

  10. On the combustion of bituminous coal chars

    SciTech Connect

    Sahu, R.

    1988-01-01

    The chars were made by pyrolyzing size-graded PSOC 1451 coal particles in nitrogen at 1000-1600K. Sized char particles were then used in subsequent experiments. Low temperature reactivities of such cenospheric chars were measured at 800K in a TGA. The effects of initial coal size, char size, pyrolysis temperature, and oxygen concentration were investigated. Single particle combustion experiments were done in both air and 50 percent oxygen ambients at 1000-1500K wall temperatures in a drop-tube laminar-flow reactor. The ignition transients of single burning particles were explained using a simple thermal model. Char samples were also partially oxidized at 1200-1500K and then physically characterized using optical and electron microscopy, gas adsorption methods, and mercury porosimetry. Results of characterization were compared to those done at 800K. Single particle combustion was numerically modeled. At first, a continuum model for asymptotic shrinking-core combustion was developed using apparent reaction rate and temperature-dependent properties. Later, a more general continuum model was developed that treated the internal morphology of the particles more realistically, as inferred from experiments. The steady-state diffusion equation was solved inside the particle to determine its theoretical temperature-time history. Good agreement with experimental results was found. The model was extended to include the effect of nonlinear kinetics. A discrete model for a cenospheric char particle was also developed, in which spherical voids were randomly placed in a spherical particle. Connectivity of the internal pore structure was accounted for.

  11. The Effect of Polymer Char on Nitridation Kinetics of Silicon

    NASA Technical Reports Server (NTRS)

    Chan, Rickmond C.; Bhatt, Ramakrishna T.

    1994-01-01

    Effects of polymer char on nitridation kinetics of attrition milled silicon powder have been investigated from 1200 to 1350 C. Results indicate that at and above 1250 C, the silicon compacts containing 3.5 wt percent polymer char were fully converted to Si3N4 after 24 hr exposure in nitrogen. In contrast, the silicon compacts without polymer char could not be fully converted to Si3N4 at 1350 C under similar exposure conditions. At 1250 and 1350 C, the silicon compacts with polymer char showed faster nitridation kinetics than those without the polymer char. As the polymer char content is increased, the amount of SiC in the nitrided material is also increased. By adding small amounts (approx. 2.5 wt percent) of NiO, the silicon compacts containing polymer char can be completely nitrided at 1200 C. The probable mechanism for the accelerated nitridation of silicon containing polymer char is discussed.

  12. Development of Foster Wheeler's Vision 21 Partial Gasification Module

    SciTech Connect

    Robertson, A.

    2001-11-06

    The US Department of Energy (DOE) has awarded Foster Wheeler Development Corporation a contract 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

  13. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUIDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    SciTech Connect

    Archie Robertson

    2004-07-01

    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. Under this contract a series of pilot plant tests are being conducted to ascertain PGM performance with a variety of fuels. The performance and economics of a PGM based plant designed for the co-production of hydrogen and electricity will also be determined. This report describes the work performed during the April-June 30, 2004 time period.

  14. OXIDATION AND DEVOLATILIZATION OF NITROGEN IN COAL CHAR

    EPA Science Inventory

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

  15. Characterization of products obtained from pyrolysis and steam gasification of wood waste, RDF, and RPF.

    PubMed

    Hwang, In-Hee; Kobayashi, Jun; Kawamoto, Katsuya

    2014-02-01

    Pyrolysis and steam gasification of woody biomass chip (WBC) obtained from construction and demolition wastes, refuse-derived fuel (RDF), and refuse paper and plastic fuel (RPF) were performed at various temperatures using a lab-scale instrument. The gas, liquid, and solid products were examined to determine their generation amounts, properties, and the carbon balance between raw material and products. The amount of product gas and its hydrogen concentration showed a considerable difference depending on pyrolysis and steam gasification at higher temperature. The reaction of steam and solid product, char, contributed to an increase in gas amount and hydrogen concentration. The amount of liquid products generated greatly depended on temperature rather than pyrolysis or steam gasification. The compositions of liquid product varied relying on raw materials used at 500°C but the polycyclic aromatic hydrocarbons became the major compounds at 900°C irrespective of the raw materials used. Almost fixed carbon (FC) of raw materials remained as solid products under pyrolysis condition whereas FC started to decompose at 700°C under steam gasification condition. For WBC, both char utilization by pyrolysis at low temperature (500°C) and syngas recovery by steam gasification at higher temperature (900°C) might be practical options. From the results of carbon balance of RDF and RPF, it was confirmed that the carbon conversion to liquid products conspicuously increased as the amount of plastic increased in the raw material. To recover feedstock from RPF, pyrolysis for oil recovery at low temperature (500°C) might be one of viable options. Steam gasification at 900°C could be an option but the method of tar reforming (e.g. catalyst utilization) should be considered. PMID:24246576

  16. Resin char oxidation retardant for composites

    NASA Technical Reports Server (NTRS)

    Bowles, K. J.; Gluyas, R. E.

    1981-01-01

    Boron powder stabilizes char, so burned substances are shiny, smooth, and free of loose graphite fibers. Resin weight loss of laminates during burning in air is identical for the first three minutes for unfilled and boron-filled samples, then boron samples stabilize.

  17. CO2 co-gasification of lower sulphur petroleum coke and sugar cane bagasse via TG-FTIR analysis technique.

    PubMed

    Edreis, Elbager M A; Luo, Guangqian; Li, Aijun; Chao, Chen; Hu, Hongyun; Zhang, Sen; Gui, Ben; Xiao, Li; Xu, Kai; Zhang, Pingan; Yao, Hong

    2013-05-01

    This study investigates the non-isothermal mechanism and kinetic behaviour of gasification of a lower sulphur petroleum coke, sugar cane bagasse and blends under carbon dioxide atmosphere conditions using the thermogravimetric analyser (TGA). The gas products were measured online with coupled Fourier transform infrared spectroscopy (FTIR). The achieved results explored that the sugar cane bagasse and blend gasification happened in two steps: at (<500 °C) the volatiles are released, and at (>700 °C) char gasification occurred, whereas the lower sulphur petroleum coke presented only one char gasification stage at (>800 °C). Significant interactions were observed in the whole process. Some solid-state mechanisms were studied by the Coats-Redfern method in order to observe the mechanisms responsible for the gasification of samples. The results show that the chemical first order reaction is the best responsible mechanism for whole process. The main released gases are CO2, CO, CH4, HCOOH, C6H5OH and CH3COOH. PMID:23567736

  18. Combustion front propagation in underground coal gasification

    SciTech Connect

    Dobbs, R.L. II; Krantz, W.B.

    1990-10-01

    Reverse Combustion (RC) enhances coal seam permeability prior to Underground Coal Gasification. Understanding RC is necessary to improve its reliability and economics. A curved RC front propagation model is developed, then solved by high activation energy asymptotics. It explicitly incorporates extinction (stoichiometric and thermal) and tangential heat transport (THT) (convection and conduction). THT arises from variation in combustion front temperature caused by tangential variation in the oxidant gas flux to the channel surface. Front temperature depends only weakly on THT; front velocity is strongly affected, with heat loss slowing propagation. The front propagation speed displays a maximum with respect to gas flux. Combustion promoters speed front propagation; inhibitors slow front propagation. The propagation model is incorporated into 2-D simulations of RC channel evolution utilizing the boundary element method with cubic hermetian elements to solve the flow from gas injection wells through the coal to the convoluted, temporally evolving, channel surface, and through the channel to a gas production well. RC channel propagation is studied using 17 cm diameter subbituminous horizontally drilled coal cores. Sixteen experiments at pressures between 2000 and 3600 kPa, injected gas oxygen contents between 21% and 75%, and flows between 1 and 4 standard liters per minute are described. Similarity analysis led to scaling-down of large RC ({approx}1 m) to laboratory scale ({approx}5 cm). Propagation velocity shows a strong synergistic increase at high levels of oxygen, pressure, and gas flow. Char combustion is observed, leaving ash-filled, irregularly shaped channels. Cracks are observed to penetrate the char zone surrounding the channel cores. 69 refs., 54 figs., 4 tabs.

  19. GASIFICATION FOR DISTRIBUTED GENERATION

    SciTech Connect

    Ronald C. Timpe; Michael D. Mann; Darren D. Schmidt

    2000-05-01

    A recent emphasis in gasification technology development has been directed toward reduced-scale gasifier systems for distributed generation at remote sites. The domestic distributed power generation market over the next decade is expected to be 5-6 gigawatts per year. The global increase is expected at 20 gigawatts over the next decade. The economics of gasification for distributed power generation are significantly improved when fuel transport is minimized. Until recently, gasification technology has been synonymous with coal conversion. Presently, however, interest centers on providing clean-burning fuel to remote sites that are not necessarily near coal supplies but have sufficient alternative carbonaceous material to feed a small gasifier. Gasifiers up to 50 MW are of current interest, with emphasis on those of 5-MW generating capacity. Internal combustion engines offer a more robust system for utilizing the fuel gas, while fuel cells and microturbines offer higher electric conversion efficiencies. The initial focus of this multiyear effort was on internal combustion engines and microturbines as more realistic near-term options for distributed generation. In this project, we studied emerging gasification technologies that can provide gas from regionally available feedstock as fuel to power generators under 30 MW in a distributed generation setting. Larger-scale gasification, primarily coal-fed, has been used commercially for more than 50 years to produce clean synthesis gas for the refining, chemical, and power industries. Commercial-scale gasification activities are under way at 113 sites in 22 countries in North and South America, Europe, Asia, Africa, and Australia, according to the Gasification Technologies Council. Gasification studies were carried out on alfalfa, black liquor (a high-sodium waste from the pulp industry), cow manure, and willow on the laboratory scale and on alfalfa, black liquor, and willow on the bench scale. Initial parametric tests

  20. Utilization of CO2 and biomass char derived from pyrolysis of Dunaliella salina: the effects of steam and catalyst on CO and H2 gas production.

    PubMed

    Yang, Chao; Jia, Lishan; Su, Shuai; Tian, Zhongbiao; Song, Qianqian; Fang, Weiping; Chen, Changping; Liu, Guangfa

    2012-04-01

    Biomass char, by-product of Dunaliella salina pyrolysis at a final pyrolysis temperature of 500°C, was used as feedstock material in this study. The reactions of biomass char with CO(2) were performed in a fixed-bed reactor to evaluate the effect of temperature and steam on the CO(2) conversion, CO yield and gas composition. The CO(2) conversion and CO yield without steam and catalyst reached about 61.84% and 0.99mol/(mol CO(2)) at 800°C, respectively. Steam and high temperature led to high CO(2) conversion. A new approach for improving H(2) was carried out by using biomass char and Au/Al(2)O(3) catalyst, which combined steam gasification of biomass char and water gas shift reaction, and the H(2) concentration was 1.8 times higher than without catalyst. The process not only mitigated CO(2) emission and made use of residual biomass char, but also created renewable source. PMID:22336747

  1. Advanced Gasification By-Product Utilization

    SciTech Connect

    Rodney Andrews; Aurora Rubel; Jack Groppo; Brock Marrs; Ari Geertsema; Frank Huggins; M. Mercedes Maroto-Valer; Brandie M. Markley; Zhe Lu; Harold Schobert

    2006-08-31

    collaborative effort between the University of Kentucky Center for Applied Energy Research (CAER), The Pennsylvania State University Energy Institute, and industry collaborators supplying gasifier char samples were to investigate the potential use of gasifier slag carbons as a source of low cost sorbent for Hg and NOX capture from combustion flue gas, concrete applications, polymer fillers and as a source of activated carbons. Primary objectives were to determine the relationship of surface area, pore size, pore size distribution, and mineral content on Hg storage of gasifier carbons and to define the site of Hg capture. The ability of gasifier slag carbon to capture NOX and the effect of NOX on Hg adsorption were goals. Secondary goals were the determination of the potential for use of the slags for cement and filler applications. Since gasifier chars have already gone through a devolatilization process in a reducing atmosphere in the gasifier, they only required to be activated to be used as activated carbons. Therefore, the principal objective of the work at PSU was to characterize and utilize gasification slag carbons for the production of activated carbons and other carbon fillers. Tests for the Hg and NOX adsorption potential of these activated gasifier carbons were performed at the CAER. During the course of this project, gasifier slag samples chemically and physically characterized at UK were supplied to PSU who also characterized the samples for sorption characteristics and independently tested for Hg-capture. At the CAER as-received slags were tested for Hg and NOX adsorption. The most promising of these were activated chemically. The PSU group applied thermal and steam activation to a representative group of the gasifier slag samples separated by particle sizes. The activated samples were tested at UK for Hg-sorption and NOX capture and the most promising Hg adsorbers were tested for Hg capture in a simulated flue gas. Both UK and PSU tested the use of the gasifier

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

    DOEpatents

    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.

  3. Variable capacity gasification burner

    SciTech Connect

    Saxon, D.I.

    1985-03-05

    A variable capacity burner that may be used in gasification processes, the burner being adjustable when operating in its intended operating environment to operate at two different flow capacities, with the adjustable parts being dynamically sealed within a statically sealed structural arrangement to prevent dangerous blow-outs of the reactants to the atmosphere.

  4. Advanced hybrid gasification facility

    SciTech Connect

    Sadowski, R.S.; Skinner, W.H.; Johnson, S.A.; Dixit, V.B.

    1993-08-01

    The objective of this procurement is to provide a test facility to support early commercialization of advanced fixed-bed coal gasification technology for electric power generation applications. The proprietary CRS Sirrine Engineers, Inc. PyGas{trademark} staged gasifier has been selected as the initial gasifier to be developed under this program. The gasifier is expected to avoid agglomeration when used on caking coals. It is also being designed to crack tar vapors and ammonia, and to provide an environment in which volatilized alkali may react with aluminosilicates in the coal ash thereby minimizing their concentration in the hot raw coal gas passing through the system to the gas turbine. This paper describes a novel, staged, airblown, fixed-bed gasifier designed to solve both through the incorporation of pyrolysis (carbonization) with gasification. It employs a pyrolyzer (carbonizer) to avoid sticky coal agglomeration which occurs in a fixed-bed process when coal is gradually heated through the 400{degrees}F to 900{degrees}F range. In a pyrolyzer, the coal is rapidly heated such that coal tar is immediately vaporized. Gaseous tars are then thermally cracked prior to the completion of the gasification process. During the subsequent endothermic gasification reactions, volatilized alkali can be chemically bound to aluminosilicates in (or added to) the ash. To reduce NOx from fuel home nitrogen, moisture is minimized to control ammonia generation, and HCN in the upper gasifier region is partially oxidized to NO which reacts with NH3/HCN to form N2.

  5. Gasification of black liquor

    DOEpatents

    Kohl, Arthur L.

    1987-07-28

    A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediatley above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone.

  6. Gasification of black liquor

    DOEpatents

    Kohl, A.L.

    1987-07-28

    A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediately above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone. 2 figs.

  7. Pyrolysis and gasification of coal at high temperatures. Quarterly progress report No. 10, December 15, 1989--March 15, 1990

    SciTech Connect

    Zygourakis, K.

    1990-12-31

    We made considerable progress towards developing a thermogravimetric reactor with in-situ video imaging capability (TGA/IVIM). Such a reactor will allow us to observe macroscopic changes in the morphology of pyrolyzing particles and thermal ignitions while monitoring at the time the weight of pyrolyzing or reacting samples. The systematic investigation on the effects of pyrolysis conditions and char macropore structure on char reactivity continued. Pyrolysis and gasification experiments were performed consecutively in our TGA reactor and the char reactivity patterns were measured for a wide range of temperatures (400 to 600{degrees}C). These conditions cover both the kinetic and the diffusion limited regimes. Our results show conclusively that chars produced at high pyrolysis heating rates (and, therefore, having a more open cellular macropore structure) are more reactive and ignite more easily than chars pyrolyzed at low heating rates. These results have been explained using available predictions from theoretical models. We also investigated for the first time the effect of coal particle size and external mass transfer limitations on the reactivity patterns and ignition behavior of char particles combusted in air. Finally, we used our hot stage reactor to monitor the structural transformations occurring during pyrolysis via a video microscopy system. Pyrolysis experiments were videotaped and particle swelling and the particle ignitions were determined and analyzed using digitized images from these experiments.

  8. The assessment of sewage sludge gasification by-products toxicity by ecotoxicologial test.

    PubMed

    Werle, Sebastian; Dudziak, Mariusz

    2015-08-01

    The process of gasification of sewage sludge generates by-products, which may be contaminated with toxic and hazardous substances, both organic and inorganic. It is therefore important to assess the environmental risk associated with this type of waste. The feasibility of using an ecotoxicological tests for this purpose was determined in the presented study. The applied tests contained indicator organisms belonging to various biological groups (bacteria, crustaceans, plants). The subject of the study were solid (ash, char) and liquid (tar) by-products generated during gasification (in a fixed bed reactor) of dried sewage sludge from various wastewater treatment systems. The tested samples were classified based on their toxic effect. The sensitivity of the indicator organisms to the tested material was determined. In-house procedures for the preparation for toxicity analysis of both sewage sludge and by-products generated during the gasification were presented. The scope of work also included the determination of the effect of selected process parameters (temperature, amount of gasifying agent) on the toxicity of gasification by-products depending on the sewage sludge source. It was shown that both the type of sewage sludge and the parameters of the gasification process affects the toxicity of the by-products of gasification. However, the results of toxicity studies also depend on the type of ecotoxicological test used, which is associated with a different sensitivity of the indicator organisms. Nevertheless, it may be concluded that the by-products formed during the gasification of the low toxicity sewage sludge can be regarded as non-toxic or low toxic. However, the results analysis of the gasification of the toxic sludge were not conclusive, which leads to further research needs in this area. PMID:25827844

  9. Gasification Studies Task 4 Topical Report

    SciTech Connect

    Whitty, Kevin; Fletcher, Thomas; Pugmire, Ronald; Smith, Philip; Sutherland, James; Thornock, Jeremy; Boshayeshi, Babak; Hunsacker, Isaac; Lewis, Aaron; Waind, Travis; Kelly, Kerry

    2014-02-01

    A key objective of the Task 4 activities has been to develop simulation tools to support development, troubleshooting and optimization of pressurized entrained-flow coal gasifiers. The overall gasifier models (Subtask 4.1) combine submodels for fluid flow (Subtask 4.2) and heat transfer (Subtask 4.3) with fundamental understanding of the chemical processes (Subtask 4.4) processes that take place as coal particles are converted to synthesis gas and slag. However, it is important to be able to compare predictions from the models against data obtained from actual operating coal gasifiers, and Subtask 4.6 aims to provide an accessible, non-proprietary system, which can be operated over a wide range of conditions to provide well-characterized data for model validation. Highlights of this work include: • Verification and validation activities performed with the Arches coal gasification simulation tool on experimental data from the CANMET gasifier (Subtask 4.1). • The simulation of multiphase reacting flows with coal particles including detailed gas-phase chemistry calculations using an extension of the one-dimensional turbulence model’s capability (Subtask 4.2). • The demonstration and implementation of the Reverse Monte Carlo ray tracing (RMCRT) radiation algorithm in the ARCHES code (Subtask 4.3). • Determination of steam and CO{sub 2} gasification kinetics of bituminous coal chars at high temperature and elevated pressure under entrained-flow conditions (Subtask 4.4). In addition, attempts were made to gain insight into the chemical structure differences between young and mature coal soot, but both NMR and TEM characterization efforts were hampered by the highly reacted nature of the soot. • The development, operation, and demonstration of in-situ gas phase measurements from the University of Utah’s pilot-scale entrained-flow coal gasifier (EFG) (Subtask 4.6). This subtask aimed at acquiring predictable, consistent performance and characterizing the

  10. Evaluation of a Combined Cyclone and Gas Filtration System for Particulate Removal in the Gasification Process

    SciTech Connect

    Rizzo, Jeffrey J.

    2010-04-30

    The Wabash gasification facility, owned and operated by sgSolutions LLC, is one of the largest single train solid fuel gasification facilities in the world capable of transforming 2,000 tons per day of petroleum coke or 2,600 tons per day of bituminous coal into synthetic gas for electrical power generation. The Wabash plant utilizes Phillips66 proprietary E-Gas (TM) Gasification Process to convert solid fuels such as petroleum coke or coal into synthetic gas that is fed to a combined cycle combustion turbine power generation facility. During plant startup in 1995, reliability issues were realized in the gas filtration portion of the gasification process. To address these issues, a slipstream test unit was constructed at the Wabash facility to test various filter designs, materials and process conditions for potential reliability improvement. The char filtration slipstream unit provided a way of testing new materials, maintenance procedures, and process changes without the risk of stopping commercial production in the facility. It also greatly reduced maintenance expenditures associated with full scale testing in the commercial plant. This char filtration slipstream unit was installed with assistance from the United States Department of Energy (built under DOE Contract No. DE-FC26-97FT34158) and began initial testing in November of 1997. It has proven to be extremely beneficial in the advancement of the E-Gas (TM) char removal technology by accurately predicting filter behavior and potential failure mechanisms that would occur in the commercial process. After completing four (4) years of testing various filter types and configurations on numerous gasification feed stocks, a decision was made to investigate the economic and reliability effects of using a particulate removal gas cyclone upstream of the current gas filtration unit. A paper study had indicated that there was a real potential to lower both installed capital and operating costs by implementing a char

  11. Effects of impregnated metal ions on air/CO2-gasification of woody biomass.

    PubMed

    Hurley, Scott; Li, Hanning; Xu, Chunbao Charles

    2010-12-01

    Several impregnated metal ions (Fe (III), Co (II), Ni (II), and Ru (IV)) and a raw iron ore (natural limonite) were examined as catalysts for gasification of pine sawdust in air/CO(2) at 700 and 800 degrees C. The yields of char and tar both increased with increasing CO(2) content in the feed gas. All the impregnated metal ions, in particular Ni (II), Co (II) and Ru (IV), were very effective for promoting biomass gasification in CO(2), leading to greatly reduced yields of tar and char accompanied by significantly enhanced formation of CO and H(2). At 800 degrees C, the impregnation of Fe (III), Ni (II), Co (II) or Ru (IV) led to almost complete conversion of the solid biomass into gas/liquid products, producing an extremely low char yield (<1-4 wt.%), and a very high yield of combustible gas (from 51.7 wt.% for Fe to 84 wt.% for Ru). The tar yield reduced from 32.1 wt.% without catalyst to 19-27 wt.% with the impregnated metal ions. PMID:20667716

  12. DEVELOPMENT OF PRESSURIZED CIRCULATIONG FLUIDIZED BED PARTIAL GASIFICATION MODULE(PGM)

    SciTech Connect

    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.

  13. Synergetic and inhibition effects in carbon dioxide gasification of blends of coals and biomass fuels of Indian origin.

    PubMed

    Satyam Naidu, V; Aghalayam, P; Jayanti, S

    2016-06-01

    The present study investigates the enhancement of CO2 gasification reactivity of coals due to the presence of catalytic elements in biomass such as K2O, CaO, Na2O and MgO. Co-gasification of three Indian coal chars with two biomass chars has been studied using isothermal thermogravimetric analysis (TGA) in CO2 environment at 900, 1000 and 1100°C. The conversion profiles have been used to establish synergetic or inhibitory effect on coal char reactivity by the presence of catalytic elements in biomass char by comparing the 90% conversion time with and without biomass. It is concluded that both biomasses exhibit synergistic behavior when blended with the three coals with casuarina being more synergetic than empty fruit bunch. Some inhibitory effect has been noted for the high ash coal at the highest temperature with higher 90% conversion time for the blend over pure coal, presumably due to diffusional control of the conversion rate. PMID:26967339

  14. Pyrolysis and gasification of coal at high temperatures. Annual progress report No. 1, September 15, 1987--September 15, 1988

    SciTech Connect

    Zygourakis, K.

    1988-12-31

    Particles from two parent coals (Illinois {number_sign}6 and lignite) were pyrolyzed in a nitrogen atmosphere using a captive sample microreactor capable of achieving heating rates as high as 1000{degrees}C/s. Direct measurements on digitized image of char particle cross-sections and a stereological model were used to characterize the macropore structure of chars. Macroporosites, pore size distributions and surface areas were accurately measured allowing us to quantify the effects of pyrolysis heating rates and coal particle size. We have paid particular attention to the development of image analysis software that has allowed us to analyze for the first time the shape or bounary tortuosity of the macropores. Tortuous pore boundaries result in higher values for the true macropore surface areas and should enhance the reactivity of the char samples. Another contribution of the current research program is the development of probabilisitic gasification models that work on computational grids obtained from digitized images of actual cross-sections of char particles. These digital images are accurate discrete approximations of a slice of the actual reacting solid. The incorporation of sophisticated image processing technique is perhaps the most attractive feature of the new simulation approach. Preliminary results indicate that the probabilistic models can accurately account for the opening of closed porosity and fragmentation phenomena occurring during gasification at high temperatures.

  15. Fundamental research on novel process alternatives for coal gasification: Final report

    SciTech Connect

    Hill, A H; Knight, R A; Anderson, G L; Feldkirchner, H L; Babu, S P

    1986-10-01

    The Institute of Gas Technology has conducted a fundamental research program to determine the technical feasibility of and to prepare preliminary process evaluations for two new approaches to coal gasification. These two concepts were assessed under two major project tasks: Task 1. CO/sub 2/-Coal Gasification Process Concept; Task 2. Internal Recirculation Catalysts Coal Gasification Process Concept. The first process concept involves CO/sub 2/-O/sub 2/ gasification of coal followed by CO/sub 2/ removal from the hot product gas by a solid MgO-containing sorbent. The sorbent is regenerated by either a thermal- or a pressure-swing step and the CO/sub 2/ released is recycled back to the gasifier. The product is a medium-Btu gas. The second process concept involves the use of novel ''semivolatile'' materials as internal recirculating catalysts for coal gasification. These materials remain in the gasifier because their vapor pressure-temperature behavior is such that they will be in the vapor state at the hotter, char exit part of the reactor and will condense in the colder, coal-inlet part of the reactor. 21 refs., 43 figs., 43 tabs.

  16. Calcium silicate cement sorbent for H/sub 2/S removal and improved gasification processes. Final report

    SciTech Connect

    Yoo, H.J.; Steinberg, M.

    1983-10-01

    Based on the studies performed on the agglomerated cement sorbent (ACS) pellet for in-situ desulfurization of gases and for improved gasification, in low and medium Btu fluidized bed coal gasifier (FBG) systems, the following conclusions can be drawn: (1) The pelletization method by a drum pelletizer is a good way of agglomerating large sized (>20 US mesh) ACS pellets having high sorbent performance. (2) The ACS pellets have a sulfur capture capacity of about 60% at 950/sup 0/C, are 100% regenerable, and so not lose reactivity during cyclic use. (3) The rate of sulfidation increases linearly with H/sub 2/S concentration in the feed gas stream up to 1.0%. (4) The rate of sulfidation first increases with temperature in an Arrhenius fashion in the temperature range of 800/sup 0/C to 1000/sup 0/C and then decreases with further increase in temperatures, giving rise to an optimum sulfidation temperature of about 1000/sup 0/C. (5) The gasification of coal or coal char either with CO/sub 2/ gas or by partial oxidation in a 40 mm ID FBG shows that the gasification efficiency of coal (or coal char) is very much enhanced with the ACS pellets and with Greer limestone over the coal (or coal char) alone. There is, however, not much difference between the ACS pellets and Greer limestone in the degree of enhancement. (6) The gasification of coal by partial oxidation with air to low Btu gas in a 1-inch coal-fired FBG unit shows that in the temperature range of 800/sup 0/ to 900/sup 0/C the efficiency of coal gasification is improved by as much as 40% when ACS pellets are used compared to the use of Greer limestone. At the same time the sulfur removal efficiency is increased from 50 to 65% with Greer limestone to over 95% with the ACS pellets.

  17. Development of biomass gasification to produce substitute fuels

    SciTech Connect

    Evans, R.J.; Knight, R.A.; Onischak, M.; Babu, S.P.

    1988-03-01

    The development of an efficient pressurized, medium-Btu steam-oxygen-blown fluidized-bed biomass gasification process was conducted. The overall program included initial stages of design-support research before the 12-ton-per-day (TPD) process research unit (PRU) was built. These stages involved the characterization of test-specific biomass species and the characteristics and limits of fluidization control. Also obtained for the design of the adiabatic PRU was information from studies with bench-scale equipment on the rapid rates of biomass devolatilization and on kinetics of the rate-controlling step of biomass char and steam gasification. The development program culminated with the sucessful operation of the PRU through 19 parametric-variation tests and extended steady-state process-proving tests. the program investigated the effect of gasifier temperature, pressure, biomass throughput rate, steam-to-biomass ratio, type of feedstock, feedstock moisture, and fludized-bed height on gasification performance. A long-duration gasification test of 3 days steady-state operation was conducted with the whole tree chips to indentify long-term effects of fluidized process conditions; to establish gasifier material and energy balances; to determine the possible breakthrough of low concentration organic species; and to evaluate the mechanical performance of the system components. Results indicate that the pressurized fludizied-bed process, can achieve carbon conversions of about 95% with cold gas thermal efficiences about 75% and with low and tar production. New information was collected on the oil and tar fraction, which relate to the process operating conditions and feedstock type. The different feedstocks studied were very similar in elemental compositions, and produced similar product gas compositions, but each has a different distribution and character of the oil and tar fractions. 11 refs., 45 figs., 18 tabs.

  18. Biomass Gasification Combined Cycle

    SciTech Connect

    Judith A. Kieffer

    2000-07-01

    Gasification combined cycle continues to represent an important defining technology area for the forest products industry. The ''Forest Products Gasification Initiative'', organized under the Industry's Agenda 2020 technology vision and supported by the DOE ''Industries of the Future'' program, is well positioned to guide these technologies to commercial success within a five-to ten-year timeframe given supportive federal budgets and public policy. Commercial success will result in significant environmental and renewable energy goals that are shared by the Industry and the Nation. The Battelle/FERCO LIVG technology, which is the technology of choice for the application reported here, remains of high interest due to characteristics that make it well suited for integration with the infrastructure of a pulp production facility. The capital cost, operating economics and long-term demonstration of this technology area key input to future economically sustainable projects and must be verified by the 200 BDT/day demonstration facility currently operating in Burlington, Vermont. The New Bern application that was the initial objective of this project is not currently economically viable and will not be implemented at this time due to several changes at and around the mill which have occurred since the inception of the project in 1995. The analysis shows that for this technology, and likely other gasification technologies as well, the first few installations will require unique circumstances, or supportive public policies, or both to attract host sites and investors.

  19. Study on tar generated from downdraft gasification of oil palm fronds.

    PubMed

    Atnaw, Samson Mekbib; Kueh, Soo Chuan; Sulaiman, Shaharin Anwar

    2014-01-01

    One of the most challenging issues concerning the gasification of oil palm fronds (OPF) is the presence of tar and particulates formed during the process considering its high volatile matter content. In this study, a tar sampling train custom built based on standard tar sampling protocols was used to quantify the gravimetric concentration of tar (g/Nm3) in syngas produced from downdraft gasification of OPF. The amount of char, ash, and solid tar produced from the gasification process was measured in order to account for the mass and carbon conversion efficiency. Elemental analysis of the char and solid tar samples was done using ultimate analysis machine, while the relative concentration of the different compounds in the liquid tar was determined making use of a liquid gas chromatography (GC) unit. Average tar concentration of 4.928 g/Nm3 and 1.923 g/Nm3 was obtained for raw gas and cleaned gas samples, respectively. Tar concentration in the raw gas sample was found to be higher compared to results for other biomass materials, which could be attributed to the higher volatile matter percentage of OPF. Average cleaning efficiency of 61% which is comparable to that of sand bed filter and venturi scrubber cleaning systems reported in the literature was obtained for the cleaning system proposed in the current study. PMID:24526899

  20. Theoretical and experimental studies of fixed-bed coal gasification reactors. Final report

    SciTech Connect

    Joseph, B.; Bhattacharya, A.; Salam, L.; Dudukovic, M.P.

    1983-09-01

    A laboratory fixed-bed gasification reactor was designed and built with the objective of collecting operational data for model validation and parameter estimation. The reactor consists of a 4 inch stainless steel tube filled with coal or char. Air and steam is fed at one end of the reactor and the dynamic progress of gasification in the coal or char bed is observed through thermocouples mounted at various radial and axial locations. Product gas compositions are also monitored as a function of time. Results of gasification runs using Wyoming coal are included in this report. In parallel with the experimental study, a two-dimensional model of moving bed gasifiers was developed, coded into a computer program and tested. This model was used to study the laboratory gasifier by setting the coal feed rate equal to zero. The model is based on prior work on steady state and dynamic modeling done at Washington University and published elsewhere in the literature. Comparisons are made between model predictions and experimental results. These are also included in this report. 23 references, 18 figures, 6 tables.

  1. Study on Tar Generated from Downdraft Gasification of Oil Palm Fronds

    PubMed Central

    Atnaw, Samson Mekbib; Kueh, Soo Chuan; Sulaiman, Shaharin Anwar

    2014-01-01

    One of the most challenging issues concerning the gasification of oil palm fronds (OPF) is the presence of tar and particulates formed during the process considering its high volatile matter content. In this study, a tar sampling train custom built based on standard tar sampling protocols was used to quantify the gravimetric concentration of tar (g/Nm3) in syngas produced from downdraft gasification of OPF. The amount of char, ash, and solid tar produced from the gasification process was measured in order to account for the mass and carbon conversion efficiency. Elemental analysis of the char and solid tar samples was done using ultimate analysis machine, while the relative concentration of the different compounds in the liquid tar was determined making use of a liquid gas chromatography (GC) unit. Average tar concentration of 4.928 g/Nm3 and 1.923 g/Nm3 was obtained for raw gas and cleaned gas samples, respectively. Tar concentration in the raw gas sample was found to be higher compared to results for other biomass materials, which could be attributed to the higher volatile matter percentage of OPF. Average cleaning efficiency of 61% which is comparable to that of sand bed filter and venturi scrubber cleaning systems reported in the literature was obtained for the cleaning system proposed in the current study. PMID:24526899

  2. Two-stage high temperature sludge gasification using the waste heat from hot blast furnace slags.

    PubMed

    Sun, Yongqi; Zhang, Zuotai; Liu, Lili; Wang, Xidong

    2015-12-01

    Nowadays, disposal of sewage sludge from wastewater treatment plants and recovery of waste heat from steel industry, become two important environmental issues and to integrate these two problems, a two-stage high temperature sludge gasification approach was investigated using the waste heat in hot slags herein. The whole process was divided into two stages, i.e., the low temperature sludge pyrolysis at ⩽ 900°C in argon agent and the high temperature char gasification at ⩾ 900°C in CO2 agent, during which the heat required was supplied by hot slags in different temperature ranges. Both the thermodynamic and kinetic mechanisms were identified and it was indicated that an Avrami-Erofeev model could best interpret the stage of char gasification. Furthermore, a schematic concept of this strategy was portrayed, based on which the potential CO yield and CO2 emission reduction achieved in China could be ∼1.92∗10(9)m(3) and 1.93∗10(6)t, respectively. PMID:26409106

  3. Syngas production by two-stage method of biomass catalytic pyrolysis and gasification.

    PubMed

    Xie, Qinglong; Kong, Sifang; Liu, Yangsheng; Zeng, Hui

    2012-04-01

    A two-stage technology integrated with biomass catalytic pyrolysis and gasification processes was utilized to produce syngas (H(2)+CO). In the presence of different nickel based catalysts, effects of pyrolysis temperature and gasification temperature on gas production were investigated. Experimental results showed that more syngas and char of high quality could be obtained at a temperature of 750°C in the stage of pyrolysis, and in the stage of gasification, pyrolysis char (produced at 750°C) reacted with steam and the maximum yield of syngas was obtained at 850°C. Syngas yield in this study was greatly increased compared with previous studies, up to 3.29Nm(3)/kg biomass. The pyrolysis process could be well explained by Arrhenius kinetic first-order rate equation. XRD analyses suggested that formation of Mg(0.4)Ni(0.6)O and increase of Ni(0) crystallite size were two main reasons for the deactivation of nickel based catalysts at higher temperature. PMID:22342084

  4. Development, Verification and Validation of Enclosure Radiation Capabilities in the CHarring Ablator Response (CHAR) Code

    NASA Technical Reports Server (NTRS)

    Salazar, Giovanni; Droba, Justin C.; Oliver, Brandon; Amar, Adam J.

    2016-01-01

    With the recent development of multi-dimensional thermal protection system (TPS) material response codes including the capabilities to account for radiative heating is a requirement. This paper presents the recent efforts to implement such capabilities in the CHarring Ablator Response (CHAR) code developed at NASA's Johnson Space Center. This work also describes the different numerical methods implemented in the code to compute view factors for radiation problems involving multiple surfaces. Furthermore, verification and validation of the code's radiation capabilities are demonstrated by comparing solutions to analytical results, to other codes, and to radiant test data.

  5. Mild balanoposthitis.

    PubMed Central

    Fornasa, C V; Calabrŏ, A; Miglietta, A; Tarantello, M; Biasinutto, C; Peserico, A

    1994-01-01

    AIM--To identify and study cases of mild balanoposthitis (MBP) with penile pathology among patients observed at a dermatology clinic over an 18-month period. MATERIALS--The study included 321 patients with penile pathology. The term MBP was used to describe balanoposthitis of a localised, inflammatory nature with few, non-specific symptoms and a tendency to become chronic or recur. Two hundred and seventy had diseases clearly identifiable by clinical examination or laboratory tests; 51 cases were diagnosed as MBP and these patients had blood tests (to evaluate immune status) and microbiological examination; when these proved negative, a series of patch tests was also used. RESULTS--Of the 51 patients diagnosed as having MBP, the cause was ascertained in 34 cases (infection, mechanical trauma, contact irritation, contact allergy, etc.), whereas no specific aetiological factor was detected to explain the symptoms in the remaining 17 cases. PMID:8001949

  6. Coal and char studies by advanced EMR techniques

    SciTech Connect

    Belford, R.L.; Clarkson, R.B.; Odintsov, B.M.

    1998-09-30

    Advanced magnetic resonance (EMR) methods are used to examine properties of coals, chars, and molecular species related to constituents of coal. During this grant period, further progress was made on proton NMR and low-frequency dynamic nuclear polarization (DNP) to examine the interaction between fluids such as water and the surface of suspended char particles. Effects of char particle size on water nuclear spin relaxation, T2, were measured.

  7. Coal and char studies by advanced EMR techniques

    SciTech Connect

    Belford, R.L.; Clarkson, R.B.; Odintsov, B.M.

    1999-03-31

    Advanced magnetic resonance (EMR) methods are used to examine properties of coals, chars, and molecular species related to constituents of coal. During this grant period, further progress was made on proton NMR and low-frequency dynamic nuclear polarization (DNP) to examine the interaction between fluids such as water and the surface of suspended char particles. Effects of char particle size and type on water nuclear spin relaxation, T2, were measured and modeled.

  8. Combustion characteristics of a solid propellant with a charring binder

    NASA Technical Reports Server (NTRS)

    Udlock, D. E.; Strand, L. D.

    1973-01-01

    A brief investigation of the combustion characteristics of a solid propellant containing a binder which chars, as opposed to melting or volatizing, has been made. The burning rate of the propellant with the charring binder was significantly higher than similar propellants containing non-charring binders. High speed motion pictures of the burning propellant showed that the aluminum burned on the regressing surface, rather than a short distance from it as is typical with composite propellants.

  9. Energy efficient production of hydrogen and syngas from biomass: development of low-temperature catalytic process for cellulose gasification.

    PubMed

    Asadullah, Mohammad; Ito, Shin-ichi; Kunimori, Kimio; Yamada, Muneyoshi; Tomishige, Keiichi

    2002-10-15

    The Rh/CeO2/M (M = SiO2, Al2O3, and ZrO2) type catalysts with various compositions have been prepared and investigated in the gasification of cellulose, a model compound of biomass, in a fluidized bed reactor at 500-700 degrees C. The conventional nickel and dolomite catalysts have also been investigated. Among the catalysts, Rh/CeO2/SiO2 with 35% CeO2 has been found to be the best catalyst with respect to the carbon conversion to gas and product distribution. The steam addition contributed to the complete conversion of cellulose to gas even at 600 degrees C. Lower steam supply gave the syngas and higher steam supply gave the hydrogen as the major product. Hydrogen and syngas from cellulose or cellulosic biomass gasification are environmentally super clean gaseous fuels for power generation. Moreover, the syngas derived liquid fuels such as methanol, dimethyl ether, and synthetic diesels are also super clean transportation fuels. However, the use of cellulose or cellulosic biomass for energy source through the gasification is challenging because of the formation of tar and char during the gasification process. It is interesting that no tar or char was finally formed in the effluent gas at as low as 500-600 degrees C using Rh/CeO2/SiO2(35) catalyst in this process. PMID:12387426

  10. Influence of particle size on pyrolysis and gasification performance of municipal solid waste in a fixed bed reactor.

    PubMed

    Luo, Siyi; Xiao, Bo; Hu, Zhiquan; Liu, Shiming; Guan, Yanwen; Cai, Lei

    2010-08-01

    Pyrolysis and gasification of municipal solid waste (MSW) were carried out in a lab-scale fixed bed reactor in order to evaluate the effects of particle size at different bed temperatures on product yield and composition. The bed temperature was varied from 600 to 900 degrees C and the MSW was separated into three different size fractions (below 5 mm, 50-10 mm and above 10 mm). Particle size and temperature had integrated effects on product yield and composition: higher temperature resulted in higher gas yield with less tar and char, and, at the same temperature, dry gas yield increased with a decrease in particle size, and char and tar yield decreased. The differences due to particle sizes in pyrolysis and gasification performance practically disappeared at the highest temperatures tested. Smaller particle sizes resulted in higher H(2) and CO contents for both pyrolysis and gasification of MSW. Minimizing the size of raw materials is an alternative method to improve the gas quality of MSW pyrolysis and gasification. PMID:20363619

  11. Compositions and sorptive properties of crop residue-derived chars

    USGS Publications Warehouse

    Chun, Y.; Sheng, G.; Chiou, G.T.; Xing, B.

    2004-01-01

    Chars originating from the burning or pyrolysis of vegetation may significantly sorb neutral organic contaminants (NOCs). To evaluate the relationship between the char composition and NOC sorption, a series of char samples were generated by pyrolyzing a wheat residue (Triticum aestivum L) for 6 h at temperatures between 300 ??C and 700 ??C and analyzed for their elemental compositions, surface areas, and surface functional groups. The samples were then studied for their abilities to sorb benzene and nitrobenzene from water. A commercial activated carbon was used as a reference carbonaceous sample. The char samples produced at high pyrolytic temperatures (500-700 ??C) were well carbonized and exhibited a relatively high surface area (>300 m2/g), little organic matter (20% oxygen). The char samples exhibited a significant range of surface acidity/basicity because of their different surface polar-group contents, as characterized by the Boehm titration data and the NMR and FTIR spectra. The NOC sorption by high-temperature chars occurred almost exclusively by surface adsorption on carbonized surfaces, whereas the sorption by low-temperature chars resulted from the surface adsorption and the concurrent smaller partition into the residual organic-matter phase. The chars appeared to have a higher surface affinity for a polar solute (nitrobenzene) than for a nonpolar solute (benzene), the difference being related to the surface acidity/basicity of the char samples.

  12. Lock hopper values for coal gasification plant service

    NASA Technical Reports Server (NTRS)

    Schoeneweis, E. F.

    1977-01-01

    Although the operating principle of the lock hopper system is extremely simple, valve applications involving this service for coal gasification plants are likewise extremely difficult. The difficulties center on the requirement of handling highly erosive pulverized coal or char (either in dry or slurry form) combined with the requirement of providing tight sealing against high-pressure (possibly very hot) gas. Operating pressures and temperatures in these applications typically range up to 1600 psi (110bar) and 600F (316C), with certain process requirements going even higher. In addition, and of primary concern, is the need for reliable operation over long service periods with the provision for practical and economical maintenance. Currently available data indicate the requirement for something in the order of 20,000 to 30,000 open-close cycles per year and a desire to operate at least that long without valve failure.

  13. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUIDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    SciTech Connect

    Unknown

    2001-07-10

    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

  14. Allothermal steam gasification of biomass in cyclic multi-compartment bubbling fluidized-bed gasifier/combustor - new reactor concept.

    PubMed

    Iliuta, Ion; Leclerc, Arnaud; Larachi, Faïçal

    2010-05-01

    A new reactor concept of allothermal cyclic multi-compartment fluidized bed steam biomass gasification is proposed and analyzed numerically. The concept combines space and time delocalization to approach an ideal allothermal gasifier. Thermochemical conversion of biomass in periodic time and space sequences of steam biomass gasification and char/biomass combustion is simulated in which the exothermic combustion compartments provide heat into an array of interspersed endothermic steam gasification compartments. This should enhance unit heat integration and thermal efficiency and procure N(2)-free biosyngas with recourse neither to oxygen addition in steam gasification nor contact between flue and syngas. The dynamic, one-dimensional, multi-component, non-isothermal model developed for this concept accounts for detailed solid and gas flow dynamics whereupon gasification/combustion reaction kinetics, thermal effects and freeboard-zone reactions were tied. Simulations suggest that allothermal operation could be achieved with switch periods in the range of a minute supporting practical feasibility for portable small-scale gasification units. PMID:20060289

  15. Production of activated carbon from TCR char

    NASA Astrophysics Data System (ADS)

    Stenzel, Fabian; Heberlein, Markus; Klinner, Tobias; Hornung, Andreas

    2016-04-01

    The utilization of char for adsorptive purposes is known since the 18th century. At that time the char was made of wood or bones and used for decoloration of fluids. In the 20th century the production of activated carbon in an industrial scale was started. The today's raw materials for activated carbon production are hard coal, peat, wood or coconut shells. All these materials entail costs especially the latter. Thus, the utilization of carbon rich residues (biomass) is an interesting economic opportunity because it is available for no costs or even can create income. The char is produced by thermo-catalytic reforming (TCR®). This process is a combination of an intermediate pyrolysis and subsequently a reforming step. During the pyrolysis step the material is decomposed in a vapor and a solid carbon enriched phase. In the second step the vapor and the solid phase get in an intensive contact and the quality of both materials is improved via the reforming process. Subsequently, the condensables are precipitated from the vapor phase and a permanent gas as well as oil is obtained. Both are suitable for heat and power production which is a clear advantage of the TCR® process. The obtained biochar from the TCR® process has special properties. This material has a very low hydrogen and oxygen content. Its stability is comparable to hard coal or anthracite. Therefore it consists almost only of carbon and ash. The latter depends from input material. Furthermore the surface structure and area can be influenced during the reforming step. Depending from temperature and residence time the number of micro pores and the surface area can be increased. Preliminary investigations with methylene blue solution have shown that a TCR® char made of digestate from anaerobic digestion has adsorptive properties. The decoloration of the solution was achieved. A further influencing factor of the adsorption performance is the particle size. Based on the results of the preliminary tests a

  16. Hydrogen production from the steam-iron process with direct reduction of iron oxide by chemical looping combustion of coal char

    SciTech Connect

    Jing-biao Yang; Ning-sheng Cai; Zhen-shan Li

    2008-07-15

    Experimental results performed with a fluidized-bed reactor supported the feasibility of the three processes including direct reduction of iron oxide by char, H{sub 2} production by the steam-iron process, and the oxidation of Fe{sub 3}O{sub 4} resulting from the steam-iron process to the original Fe{sub 2}O{sub 3} by air. Chars resulting from a Chinese lignite loaded with K{sub 2}CO{sub 3} were used successfully as a reducing material, leading to the reduction of Fe{sub 2}O{sub 3} to FeO and Fe for the steam-iron process, which was confirmed by both the off-gases concentrations and X-ray diffractometer analysis. The reduction of Fe{sub 2}O{sub 3} by K-10-char at 1073 K is desirable from the perspective of the carbon conversion rate and high concentration of CO{sub 2}. The carbon in char was completely converted to CO{sub 2} when the mass ratio of Fe{sub 2}O{sub 3}/K-10-char was increased to 10/0.3. The oxidation rate of K-10-char by Fe{sub 2}O{sub 3} without a gasifying agent was comparable to the K-10-char steam gasification rate. The fractions of FeO and Fe in the reduced residue were 43 and 57%, respectively, in the case of 3 g of Fe{sub 2}O{sub 3} and 0.5 g of K-10-char, which was verified by the total H{sub 2} yield equaling 1000 mL/g K-10-char from the steam-iron process. The time that it took to achieve complete oxidation of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} by air with an 8.7% O{sub 2} concentration at 1073 K was about 15 min. 53 refs., 19 figs., 5 tabs.

  17. Gasification reactivities of solid biomass fuels

    SciTech Connect

    Moilanen, A.; Kurkela, E.

    1995-12-31

    The design and operation of the biomass based gasification processes require knowledge about the biomass feedstocks characteristics and their typical gasification behaviour in the process. In this study, the gasification reactivities of various biomasses were investigated in laboratory scale Pressurized Thermogravimetric apparatus (PTG) and in the PDU-scale (Process Development Unit) Pressurized Fluidized-Bed (PFB) gasification test facility of VTT.

  18. Pyrolysis and gasification of coal at high temperatures. Quarterly progress report No. 2, December 15, 1987--March 15, 1988

    SciTech Connect

    Zygourakis, K.

    1988-12-31

    The effects of particle size on the macropore structure of chars produced from an Illinois No. 6 coal were investigated. Three size fractions (100--120, 50--60 and 25--28 mesh) of coal particles were pyrolyzed in our captive-sample reactor at 10{degrees}C/s. By analyzing digitized particle cross-sections, we obtained the macropore volume distributions and surface areas, and determined that all three char samples had almost equal macroporosities. we have also analyzed for the first time the shape or boundary tortuosity of the macropores. As the size of the pyrolyzed coal particles increased, the produced chars exhibited macropores with more tortuous boundaries. Tortuous pore boundaries result in higher values for the true macropore surface areas and should enhance the reactivity of the char samples. A systematic procedure was developed for analyzing and averaging the simulation results obtained with our erosion models. Such a procedure is necessary for comparing statistical model predictions to experimental data. Several simulations were carried out to investigate the gasification behavior of the three char samples mentioned above and the predicted reactivity patterns are presented. Finally, a thermogravimetric analyzer (TGS-2) was ordered and will soon be delivered to our laboratory.

  19. Underground gasification of coal

    DOEpatents

    Pasini, III, Joseph; Overbey, Jr., William K.; Komar, Charles A.

    1976-01-20

    There is disclosed a method for the gasification of coal in situ which comprises drilling at least one well or borehole from the earth's surface so that the well or borehole enters the coalbed or seam horizontally and intersects the coalbed in a direction normal to its major natural fracture system, initiating burning of the coal with the introduction of a combustion-supporting gas such as air to convert the coal in situ to a heating gas of relatively high calorific value and recovering the gas. In a further embodiment the recovered gas may be used to drive one or more generators for the production of electricity.

  20. PNNL Coal Gasification Research

    SciTech Connect

    Reid, Douglas J.; Cabe, James E.; Bearden, Mark D.

    2010-07-28

    This report explains the goals of PNNL in relation to coal gasification research. The long-term intent of this effort is to produce a syngas product for use by internal Pacific Northwest National Laboratory (PNNL) researchers in materials, catalysts, and instrumentation development. Future work on the project will focus on improving the reliability and performance of the gasifier, with a goal of continuous operation for 4 hours using coal feedstock. In addition, system modifications to increase operational flexibility and reliability or accommodate other fuel sources that can be used for syngas production could be useful.

  1. NO/CHAR REACTIONS AT PULVERIZED COAL FLAME CONDITIONS

    EPA Science Inventory

    The paper discusses nitrogen oxide (NO)/char reactions at pulverized-coal flame conditions. he effective rate of the NO/char reaction, measured over the temperature range 1250 to 1750 K, was found to be retarded by water vapor and enhanced by carbon monoxide (CO) by amounts that ...

  2. Apparatus for mixing char-ash into coal stream

    DOEpatents

    Blaskowski, Henry J.

    1982-03-16

    Apparatus for obtaining complete mixing of char with coal prior to the introduction of the mixture into the combustor (30) of a coal gasifier (10). The coal is carried in one air stream (22), and the char in another air stream (54), to a riffle plate arrangement (26), where the streams of solid are intimately mixed or blended.

  3. Evaluation of solid fuel char briquettes from human waste.

    PubMed

    Ward, Barbara J; Yacob, Tesfayohanes W; Montoya, Lupita D

    2014-08-19

    The developing world faces dual crises of escalating energy demand and lack of urban sanitation infrastructure that pose significant burdens on the environment. This article presents results of a study evaluating the feasibility of using human feces-derived char as a solid fuel for heating and cooking and a potential way to address both crises. The study determined the energy content and the elemental composition of chars pyrolyzed at 300, 450, and 750 °C. Fecal chars made at 300 °C were found to be similar in energy content to wood chars and bituminous coal, having a heating value of 25.6 ± 0.08 MJ/kg, while fecal chars made at 750 °C had an energy content of 13.8 ± 0.48 MJ/kg. The higher heating values of the studied chars were evaluated using their elemental composition and a published predictive model; results found good agreement between the measured and predicted values. Fecal chars made at low temperatures were briquetted with molasses/lime and starch binders. Briquettes made with 10% starch had an average impact resistance index of 79 and a higher heating value of 25 MJ/kg. These values are comparable to those of commercial charcoal briquettes, making fecal char briquettes a potential substitute that also contributes to the preservation of the environment. PMID:25020243

  4. Catalytic Hydrothermal Gasification

    SciTech Connect

    Elliott, Douglas C.

    2015-05-31

    The term “hydrothermal” used here refers to the processing of biomass in water slurries at elevated temperature and pressure to facilitate the chemical conversion of the organic structures in biomass into useful fuels. The process is meant to provide a means for treating wet biomass materials without drying and to access ionic reaction conditions by maintaining a liquid water processing medium. Typical hydrothermal processing conditions are 523-647K of temperature and operating pressures from 4-22 MPa of pressure. The temperature is sufficient to initiate pyrolytic mechanisms in the biopolymers while the pressure is sufficient to maintain a liquid water processing phase. Hydrothermal gasification is accomplished at the upper end of the process temperature range. It can be considered an extension of the hydrothermal liquefaction mechanisms that begin at the lowest hydrothermal conditions with subsequent decomposition of biopolymer fragments formed in liquefaction to smaller molecules and eventually to gas. Typically, hydrothermal gasification requires an active catalyst to accomplish reasonable rates of gas formation from biomass.

  5. Fluid-Bed Testing of Greatpoint Energy's Direct Oxygen Injection Catalytic Gasification Process for Synthetic Natural Gas and Hydrogen Coproduction Year 6 - Activity 1.14 - Development of a National Center for Hydrogen Technology

    SciTech Connect

    Swanson, Michael; Henderson, Ann

    2012-04-01

    The GreatPoint Energy (GPE) concept for producing synthetic natural gas and hydrogen from coal involves the catalytic gasification of coal and carbon. GPE’s technology “refines” coal by employing a novel catalyst to “crack” the carbon bonds and transform the coal into cleanburning methane (natural gas) and hydrogen. The GPE mild “catalytic” gasifier design and operating conditions result in reactor components that are less expensive and produce pipeline-grade methane and relatively high purity hydrogen. The system operates extremely efficiently on very low cost carbon sources such as lignites, subbituminous coals, tar sands, petcoke, and petroleum residual oil. In addition, GPE’s catalytic coal gasification process eliminates troublesome ash removal and slagging problems, reduces maintenance requirements, and increases thermal efficiency, significantly reducing the size of the air separation plant (a system that alone accounts for 20% of the capital cost of most gasification systems) in the catalytic gasification process. Energy & Environmental Research Center (EERC) pilot-scale gasification facilities were used to demonstrate how coal and catalyst are fed into a fluid-bed reactor with pressurized steam and a small amount of oxygen to “fluidize” the mixture and ensure constant contact between the catalyst and the carbon particles. In this environment, the catalyst facilitates multiple chemical reactions between the carbon and the steam on the surface of the coal. These reactions generate a mixture of predominantly methane, hydrogen, and carbon dioxide. Product gases from the process are sent to a gas-cleaning system where CO{sub 2} and other contaminants are removed. In a full-scale system, catalyst would be recovered from the bottom of the gasifier and recycled back into the fluid-bed reactor. The by-products (such as sulfur, nitrogen, and CO{sub 2}) would be captured and could be sold to the chemicals and petroleum industries, resulting in

  6. Chars pyrolyzed from oil palm wastes for activated carbon preparation

    SciTech Connect

    Lua, A.C.; Guo, J.

    1999-01-01

    Chars pyrolyzed from extracted oil palm fibers for the preparation of activated carbons were studied. The effects of pyrolysis temperature and hold time on density, porosity, yield, BET and micropore surface areas, total pore volume, and pore size distributions of chars were investigated. The optimum conditions for pyrolysis were found to be at a pyrolysis temperature of 850 C for a hold time of 3.5 h. Scanning electron micrographs of the char surfaces verified the presence of porosities. The experimental results showed that it was feasible to produce chars with high BET and micropore surface areas from extracted oil palm fibers. The resulting chars will be subjected to steam or carbon dioxide activation to prepare activated carbons for use as gas adsorbents for air pollution control.

  7. Compilation of Sandia coal char combustion data and kinetic analyses

    SciTech Connect

    Mitchell, R.E.; Hurt, R.H.; Baxter, L.L.; Hardesty, D.R.

    1992-06-01

    An experimental project was undertaken to characterize the physical and chemical processes that govern the combustion of pulverized coal chars. The experimental endeavor establishes a database on the reactivities of coal chars as a function of coal type, particle size, particle temperature, gas temperature, and gas and composition. The project also provides a better understanding of the mechanism of char oxidation, and yields quantitative information on the release rates of nitrogen- and sulfur-containing species during char combustion. An accurate predictive engineering model of the overall char combustion process under technologically relevant conditions in a primary product of this experimental effort. This document summarizes the experimental effort, the approach used to analyze the data, and individual compilations of data and kinetic analyses for each of the parent coals investigates.

  8. Simulation of carbon gasification kinetics using an edge recession model

    SciTech Connect

    Takashi Kyotani; Leon y Leon, C.A.L.; Radovic, L.R. )

    1993-07-01

    An edge recession modeling method is proposed as a new approach to the prediction of carbon gasification kinetics. Using this method, the variations in reactive surface area (RSA) and specific reactivity (R) with conversion were simulated for several polynuclear aromatic molecules adopted as models of carbon crystallites. The effects of crystallite size and shape, edge site reactivity and vacancies on the changes in RSA and R with conversion were investigated. As a result, RSA and R were found to be essentially independent of crystallite shape, but to depend on crystallite size and the presence of vacancies. Good agreement was obtained between model predictions and experimental data for several kinds of model carbon crystallites. In the case of structurally disordered carbons (such as chars), simultaneous gasification of model crystallites of two different sizes gave better predictions than that of single-size crystallites. The edge recession model is proposed as an alternative, or at least complementary, approach to the more conventional (and, arguably, less physically meaningful) pore structure development models.

  9. The effects of the conditions of char formation on the physical properties of charred phenolic-nylon

    NASA Technical Reports Server (NTRS)

    Smyly, E. D.; Pears, C. D.

    1972-01-01

    A study was made of the effects of the conditions of char formation on the physical properties of charred phenolic nylon of 0.577 gm/cu cm density. It was found that the thermal conductivity and several of the monitors correlate well with degradation conditions. The monitors included electrical resistivity, sonic velocity, porosity, lattice spacing and crystallite size.

  10. Process characteristics and products of olive kernel high temperature steam gasification (HTSG).

    PubMed

    Skoulou, V; Swiderski, A; Yang, W; Zabaniotou, A

    2009-04-01

    Exploitation of olive kernel for bioenergy production, with respect to the green house gases (GHGs) mitigation, is the main aim of this work. In this study, olive kernels were used as a solid biofuel, and high temperature steam gasification (HTSG) was investigated, in the fixed bed unit at KTH Sweden, with regard to hydrogen maximization in the produced gasification gas. Experiments were carried out in a temperature range of 750-1050 degrees C, with steam as the gasifying agent. The behaviour of olive kernels, under residence times from 120 up to 960 s, has been studied. At 1050 degrees C, a medium to high calorific value gas was obtained (LHVgas=13.62 MJ/Nm3), while an acquired H2/CO molar ratio equal to four proved that olive kernel HTSG gasification could be an effective technology for a hydrogen-rich gas production (approximately 40%vv H2 in the produced gasification gas at 1050 degrees C). The produced char contained 79%ww of fixed carbon, low chlorine and sulphur content, which enables it for further re-use for energetic purposes. Tar content in the produced gas at 750 degrees C was 124.07 g/Nm3, while a 1050 degrees C at 79.64% reduction was observed and reached the value of 25.26 g/Nm3. PMID:19117753

  11. Development and Verification of Enclosure Radiation Capabilities in the CHarring Ablator Response (CHAR) Code

    NASA Technical Reports Server (NTRS)

    Salazar, Giovanni; Droba, Justin C.; Oliver, Brandon; Amar, Adam J.

    2016-01-01

    With the recent development of multi-dimensional thermal protection system (TPS) material response codes, the capability to account for surface-to-surface radiation exchange in complex geometries is critical. This paper presents recent efforts to implement such capabilities in the CHarring Ablator Response (CHAR) code developed at NASA's Johnson Space Center. This work also describes the different numerical methods implemented in the code to compute geometric view factors for radiation problems involving multiple surfaces. Verification of the code's radiation capabilities and results of a code-to-code comparison are presented. Finally, a demonstration case of a two-dimensional ablating cavity with enclosure radiation accounting for a changing geometry is shown.

  12. Clean, premium-quality chars: Demineralized and carbon enriched. [Quarterly] technical report, March 1, 1993--May 31, 1993

    SciTech Connect

    Smith, G.V.; Malhotra, V.M.; Wiltowski, T.; Myszka, E.

    1993-09-01

    The overall objective of this two-year project is to evaluate methods of preparing demineralized and carbon enriched chars from Illinois Basin coals. There are two processing steps: physical cleaning of the coal and devolatilization under different environments to form chars. Two differents techniques were used, in-situ Diffuse Reflectance FTIR measurements and BTU measurements. Experiments were performed with coals IBC-101, 102, and 104 as received and after cleaning. DR-FTIR spectrums helped to explain the possible existing chemical bonds in the coal structure as well as their changes during drying and mild pyrolysis. Drying coal causes hydrogen bonds between water and coal to be broken. Liquids produced above 500{degrees}C are much higher in aromatic content, thus, effectively reducing the concentration of aliphatic groups in the overall liquid yield. BTU values of coals after methane treatment are higher than after helium treatment.

  13. Clean, premium-quality chars: Demineralized and carbon enriched. Technical report, December 1, 1992--February 28, 1993

    SciTech Connect

    Smith, G.V.; Malhotra, V.M.; Wiltowski, T.; Myszka, E.; Banerjee, D.

    1993-05-01

    The overall objective of this two-year project is to evaluate methods of preparing demineralized and carbon enriched chars from Illinois Basin coals. There are two processing steps: physical cleaning of the coal and devolatilization under different environments to form chars. Two different techniques were used: BET surface area analyzer and in-situ Diffuse Reflectance FTIR. Experiments were performed with coals IBC-101, 102, and 104 as received and after cleaning. It was found that the cleaning not only removes the minerals but has changed also the porous structure of the coals. DR-FTIR spectrums helped to explain the possible existing chemical bonds in the coal structure as well as their changes during drying and mild pyrolysis.

  14. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUIDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    SciTech Connect

    Unknown

    2002-03-29

    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 2800 F) 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

  15. Dwarf char, a new form of chars (the genus Salvelinus) in Lake Kronotskoe

    USGS Publications Warehouse

    Pavlov, S.D.; Pivovarov, E.A.; Ostberg, C.O.

    2012-01-01

    Lake Kronotskoe is situated in the Kronotskii State Nature Reserve and is a unique natural heritage of Kamchatka. The lake–river system of the reserve includes numerous springs and small streams and three large inflowing rivers, Listvennichnaya, Unana, and Uzon, which form the main bays of Lake Kronotskoe; one river (Kronotskaya) flows from the lake. This river is characterized by several rapids, which are assumed to be unsurmountable barriers for fish migration. The ichthyofauna of the lake has been isolated for a long time, and some endemic fishes appeared, including char of the genus Salvelinus and the residential form of red salmon Oncorhynchus nerka (the local name is kokanee). These species are perfect model objects to study microevolution processes. Char of Lake Kronotskoe are characterized by significant polymorphism and plasticity [1–3]; therefore, they are extremely valuable for studying the processes of speciation and form development. That is why the populations of char in Lake Kronotskoe are unique and attract special attention of researchers. 

  16. Catalytic Hydrothermal Gasification of Biomass

    SciTech Connect

    Elliott, Douglas C.

    2008-05-06

    A recent development in biomass gasification is the use of a pressurized water processing environment in order that drying of the biomass can be avoided. This paper reviews the research undertaken developing this new option for biomass gasification. This review does not cover wet oxidation or near-atmospheric-pressure steam-gasification of biomass. Laboratory research on hydrothermal gasification of biomass focusing on the use of catalysts is reviewed here, and a companion review focuses on non-catalytic processing. Research includes liquid-phase, sub-critical processing as well as super-critical water processing. The use of heterogeneous catalysts in such a system allows effective operation at lower temperatures, and the issues around the use of catalysts are presented. This review attempts to show the potential of this new processing concept by comparing the various options under development and the results of the research.

  17. Synthesis gas production with an adjustable H{sub 2}/CO ratio through the coal gasification process: effects of coal ranks and methane addition

    SciTech Connect

    Yan Cao; Zhengyang Gao; Jing Jin; Hongchang Zhou; Marten Cohron; Houying Zhao; Hongying Liu; Weiping Pan

    2008-05-15

    Direct production of synthesis gas using coal as a cheap feedstock is attractive but challenging due to its low H{sub 2}/CO ratio of generated synthesis gas. Three typical U.S. coals of different ranks were tested in a 2.5 in. coal gasifier to investigate their gasification reactivity and adjustability on H{sub 2}/CO ratio of generated synthesis gas with or without the addition of methane. Tests indicated that lower-rank coals (lignite and sub-bituminous) have higher gasification reactivity than bituminous coals. The coal gasification reactivity is correlated to its synthesis-gas yield and the total percentage of H{sub 2} and CO in the synthesis gas, but not to the H{sub 2}/CO ratio. The H{sub 2}/CO ratio of coal gasification was found to be correlated to the rank of coals, especially the H/C ratio of coals. Methane addition into the dense phase of the pyrolysis and gasification zone of the cogasification reactor could make the best use of methane in adjusting the H{sub 2}/CO ratio of the generated synthesis gas. The maximum methane conversion efficiency, which was likely correlated to its gasification reactivity, could be achieved by 70% on average for all tested coals. The actual catalytic effect of generated coal chars on methane conversion seemed coal-dependent. The coal-gasification process benefits from methane addition and subsequent conversion on the adjustment of the H{sub 2}/CO ratio of synthesis gas. The methane conversion process benefits from the use of coal chars due to their catalytic effects. This implies that there were likely synergistic effects on both. 25 refs., 3 figs., 3

  18. Coal gasification vessel

    DOEpatents

    Loo, Billy W.

    1982-01-01

    A vessel system (10) comprises an outer shell (14) of carbon fibers held in a binder, a coolant circulation mechanism (16) and control mechanism (42) and an inner shell (46) comprised of a refractory material and is of light weight and capable of withstanding the extreme temperature and pressure environment of, for example, a coal gasification process. The control mechanism (42) can be computer controlled and can be used to monitor and modulate the coolant which is provided through the circulation mechanism (16) for cooling and protecting the carbon fiber and outer shell (14). The control mechanism (42) is also used to locate any isolated hot spots which may occur through the local disintegration of the inner refractory shell (46).

  19. Materials of Gasification

    SciTech Connect

    2005-09-15

    The objective of this project was to accumulate and establish a database of construction materials, coatings, refractory liners, and transitional materials that are appropriate for the hardware and scale-up facilities for atmospheric biomass and coal gasification processes. Cost, fabricability, survivability, contamination, modes of corrosion, failure modes, operational temperatures, strength, and compatibility are all areas of materials science for which relevant data would be appropriate. The goal will be an established expertise of materials for the fossil energy area within WRI. This would be an effort to narrow down the overwhelming array of materials information sources to the relevant set which provides current and accurate data for materials selection for fossil fuels processing plant. A significant amount of reference material on materials has been located, examined and compiled. The report that describes these resources is well under way. The reference material is in many forms including texts, periodicals, websites, software and expert systems. The most important part of the labor is to refine the vast array of available resources to information appropriate in content, size and reliability for the tasks conducted by WRI and its clients within the energy field. A significant has been made to collate and capture the best and most up to date references. The resources of the University of Wyoming have been used extensively as a local and assessable location of information. As such, the distribution of materials within the UW library has been added as a portion of the growing document. Literature from recent journals has been combed for all pertinent references to high temperature energy based applications. Several software packages have been examined for relevance and usefulness towards applications in coal gasification and coal fired plant. Collation of the many located resources has been ongoing. Some web-based resources have been examined.

  20. Mechanical properties of acacia and eucalyptus wood chars

    SciTech Connect

    Kumar, M.; Verma, B.B.; Gupta, R.C.

    1999-10-01

    In the present investigation the effects of carbonization conditions (temperature and heating rate) on the mechanical properties (such as crushing and impact strengths and shatter index) of acacia and eucalyptus wood chars have been determined. The crushing and impact strengths of both the acacia and eucalyptus wood chars (made by slow carbonization) decreased with increase of preparation temperature up to 600 C, followed by an increase thereafter. These wood chars showed a continuous increase in shatter index values with carbonization temperature. In contrast to slow carbonization (heating rate 4 C min{sup {minus}1}), rapid carbonization (heating rate 30 C min{sup {minus}1}) yielded chars of lower crushing strengths. Slowly carbonized eucalyptus wood gave chars of superior crushing and impact strengths than those produced from acacia wood under the same carbonization conditions. The crushing and impact strengths of these wood chars, in general, have shown an increase with increase in their apparent density. The crushing strength of cubic-shaped wood char decreased with increase in size.

  1. Product Chemistry and Process Efficiency of Biomass Torrefaction, Pyrolysis and Gasification Studied by High-Throughput Techniques and Multivariate Analysis

    NASA Astrophysics Data System (ADS)

    Xiao, Li

    ), fast growing energy crops (switchgrass), and popular forage crop (alfalfa), as well as biochar derived from those materials and their mixtures. It demonstrated that Py-MBMS coupled with MVA could be used as fast analytical tools for the study of not only biomass composition but also its thermal decomposition behaviors. It found that the impact of biomass composition heavily depends on the thermal decomposition temperature because at different temperature, the composition of biomass decomposed and the impact of minerals on the decomposition reaction varies. At low temperature (200-500°C), organic compounds attribute to the majority of variation in thermal decomposition products. At higher temperature, inorganics dramatically changed the pyrolysis pathway of carbohydrates and possibly lignin. In gasification, gasification tar formation is also observed to be impacted by ash content in vapor and char. In real reactor, biochar structure also has interactions with other fractions to make the final pyrolysis and gasification product. Based on the evaluation of process efficiencies during torrefaction, temperature ranging from 275°C to 300°C with short residence time (<10min) are proposed to be optimal torrefaction conditions. 500°C is preferred to 700°C as primary pyrolysis temperature in two stage gasification because higher primary pyrolysis temperature resulted in more tar and less gasification char. Also, in terms of carbon yield, more carbon is lost in tar while less carbon is retained in gas product using 700°C as primary pyrolysis temperature. In addition, pyrolysis char is found to produce less tar and more gas during steam gasification compared with gasification of pyrolysis vapor. Thus it is suggested that torrefaction might be an efficient pretreatment for biomass gasification because it can largely improve the yield of pyrolysis char during the primary pyrolysis step of gasification thus reduce the total tar of the overall gasification products. Future work

  2. Variation of char structure during anthracite pyrolysis catalyzed by Fe{sub 2}O{sub 3} and its influence on char combustion reactivity

    SciTech Connect

    Xuzhong Gong; Zhancheng Guo; Zhi Wang

    2009-09-15

    Effects of Fe{sub 2}O{sub 3} on the pyrolysis reactivity of demineralized anthracite were investigated by a thermo-gravimetric analyzer, indicating that pyrolysis reactivity of Fe{sub 2}O{sub 3}-loaded demineralized anthracite was higher than that of raw demineralized anthracite when temperature is over 500{sup o}C. Chars were prepared from the two coal samples in muffle with heating progress, and their structures were analyzed using SEM, FTIR, XRD, and Raman. FTIR results showed that absorption peaks of functional groups on the surface of char from catalytic pyrolysis at 700{sup o}C were more than that of char from noncatalytic pyrolysis. Raman results demonstrated values of (I{sub D3} + I{sub D4})/IG of chars from catalytic pyrolysis and noncatalytic pyrolysis were 4.76 and 3.86, respectively, indicating that ordering of the char was decreased by Fe{sub 2}O{sub 3}. XRD analysis revealed that diffraction angle of the 002 peak did not shift; however, L{sub a} and L{sub c} decreased, indicating degree of graphitization for microcrystalline structure of char from catalytic pyrolysis was decreased. The results of FTIR, XRD, and Raman of the char showed that catalytic pyrolysis improved the formation of free radicals, while hindered polymerization and forming of basic structure units. Finally, combustion reactivity of the three chars, including char of raw demineralized anthracite (char-A), char of Fe{sub 2}O{sub 3}-loaded demineralized anthracite (char-B), and char of Fe{sub 2}O{sub 3}-loaded demineralized anthracite washed by HCl (char-C), was investigated using TG and indicated that their active order was char-B > char-C > char-A. The results corroborated that Fe{sub 2}O{sub 3} changed structure of anthracite char and improved combustion reactivity.

  3. Rate inhibition of steam gasification by adsorbed hydrogen. Technical progress report, December 1, 1993--February 28, 1994

    SciTech Connect

    Miller, D.J.

    1994-05-01

    Our efforts over the past three months have emphasized the following: (1) the continued construction and assembly of the gasification reactors and associated hardware; and (2) preparation and characterization of the chars to be used in the gasification studies. The construction of the experimental system is progressing smoothly and should be completed within one month. Modifications to the old high-pressure reactor are now complete, and the Inconel sample holder has been fabricated and assembled. The ceramic tubes which make up the high-temperature, low pressure reactor have been assembled, including cementing of the required quartz frits into place. All components of the reaction systems, including fittings, are now in hand and final assembly of all components is nearing completion. The final design of the system is somewhat more complex than originally proposed, but offers in return greater flexibility of operation, more precise flow control and switching of flows, and greater operator safety. Preparation of the Saran and coal chars to be used in the experimental studies is progressing well. Saran char is prepared by pyrolysis of Dow MA 127 Saran resin in nitrogen at 900{degrees}C for 30 min (heatup rate of 10{degrees}C/min). We conduct the pyrolysis in a horizontal quartz tube reactor enclosed in a Lindberg tube furnace which is controlled by an Omega 2010 linear temperature controller. The Saran resin is placed in shallow alumina boats.

  4. Co-gasification of biosolids with biomass: Thermogravimetric analysis and pilot scale study in a bubbling fluidized bed reactor.

    PubMed

    Yu, Ming Ming; Masnadi, Mohammad S; Grace, John R; Bi, Xiaotao T; Lim, C Jim; Li, Yonghua

    2014-10-17

    This work studied the feasibility of co-gasification of biosolids with biomass as a means of disposal with energy recovery. The kinetics study at 800°C showed that biomass, such as switchgrass, could catalyze the reactions because switchgrass ash contained a high proportion of potassium, an excellent catalyst for gasification. However, biosolids could also inhibit gasification due to interaction between biomass alkali/alkaline earth metals and biosolids clay minerals. In the pilot scale experiments, increasing the proportion of biosolids in the feedstock affected gasification performance negatively. Syngas yield and char conversion decreased from 1.38 to 0.47m(3)/kg and 82-36% respectively as the biosolids proportion in the fuel increased from 0% to 100%. Over the same range, the tar content increased from 10.3 to 200g/m(3), while the ammonia concentration increased from 1660 to 19,200ppmv. No more than 25% biosolids in the fuel feed is recommended to maintain a reasonable gasification. PMID:25459803

  5. Combustion of Illinois coals and chars with natural gas. Final technical report, September 1, 1991--August 31, 1992

    SciTech Connect

    Buckius, R.O.; Peters, J.E.; Krier, H.

    1992-12-31

    Combined combustion of coal and natural gas offers advantages compared to burning coal or natural gas alone. For example, low volatile coals (or chars) derived from treatment or gasification processes can be of limited use due to their poor flammability characteristics. However, the use of natural gas in conjunction with the solid fuel can provide the necessary ``volatiles`` to enhance the combustion. Also, natural gas provides a clean cofiring fuel source which can enhance the usefulness of coals with high sulfur content. Addition of natural gas may reduce SO{sub x} emissions through increased sulfur retention in the ash and reduce NO{sub x} emissions by varying local stoichiometry and temperature levels. This research program addresses the contributions and the mechanisms of cofiring natural gas with Illinois coal through studies of particle ignition, burning rates and ash characterization.

  6. Visualizing the Stability of Char: Molecular- to Micron-scale Observations of Char Incubated in a Tropical Soil

    NASA Astrophysics Data System (ADS)

    Heckman, K. A.; Ramon, C.; Weber, P. K.; Torn, M. S.; Pett-Ridge, J.; Nico, P. S.

    2014-12-01

    The persistence of pyrogenic materials (hereafter referred to as char) in terrestrial ecosystems is of interest both from a carbon cycle modelling perspective and a climate change mitigation standpoint. However, the fate of newly introduced char in soils remains unclear. Recent reviews attempting to summarize trends in char decomposition have come to differing conclusions, further stressing the complexity of factors dictating char stability in soils. The current dataset specifically addresses the stability of char additions to a tropical clay-rich soil, possible priming effects, and interactions among char, microbial communities and the mineral matrix. 13C- and 15N-labeled Acer rubrum(red maple) wood was combusted at 400°C and added to surface (0-10 cm) and subsurface (20-30 cm) soils from the Luquillo Experimental Forest, Puerto Rico. Soils were incubated for 13 and 345 days at 26°C. Following incubation, intact microaggregates were frozen and cryosectioned into thin sections of approximately 5 μm thickness and mounted on gold-coated quartz slides. Thin sections were examined by synchrotron-based Fourier transform infrared spectroscopy (SR-FTIR), scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), and high resolution secondary ion mass spectrometry (nanoSIMS). The combination of these μm to nm scale techniques allowed us to create corresponding spatial maps of native organic matter, char, and mineral phase distribution, track spatial variability in organic matter molecular structure, and dispersion of 13C and 15N isotopic labels. We present preliminary results indicating a high degree of stability of char in these wet tropical soils throughout the incubation period, suggesting that applied char may persist for long periods of time in similar soils.

  7. FUNDAMENTAL INVESTIGATION OF FUEL TRANSFORMATIONS IN PULVERIZED COAL COMBUSTION AND GASIFICATION TECHNOLOGIES

    SciTech Connect

    Robert Hurt; Joseph Calo; Thomas H. Fletcher; Alan Sayre

    2005-04-29

    The goal of this project was to carry out the necessary experiments and analyses to extend current capabilities for modeling fuel transformations to the new conditions anticipated in next-generation coal-based, fuel-flexible combustion and gasification processes. This multi-organization, multi-investigator project has produced data, correlations, and submodels that extend present capabilities in pressure, temperature, and fuel type. The combined experimental and theoretical/computational results are documented in detail in Chapters 1-8 of this report, with Chapter 9 serving as a brief summary of the main conclusions. Chapters 1-3 deal with the effect of elevated pressure on devolatilization, char formation, and char properties. Chapters 4 and 5 deal with advanced combustion kinetic models needed to cover the extended ranges of pressure and temperature expected in next-generation furnaces. Chapter 6 deals with the extension of kinetic data to a variety of alternative solid fuels. Chapter 7 focuses on the kinetics of gasification (rather than combustion) at elevated pressure. Finally, Chapter 8 describes the integration, testing, and use of new fuel transformation submodels into a comprehensive CFD framework. Overall, the effects of elevated pressure, temperature, heating rate, and alternative fuel use are all complex and much more work could be further undertaken in this area. Nevertheless, the current project with its new data, correlations, and computer models provides a much improved basis for model-based design of next generation systems operating under these new conditions.

  8. Experimental Study of Hydrogasification of Lignite and Subbituminous Coal Chars

    PubMed Central

    Gil, Stanisław

    2015-01-01

    The experimental facility for pressure hydrogasification research was adapted to the pressure of 10 MPa and temperature of 1300 K, which ensured repeatability of results and hydrogen heating to the process temperature. A hydrogasification reaction of chars produced from two rank coals was investigated at temperatures up to 1173 K, pressures up to 8 MPa, and the gas flow rates of 0.5–5 dmn3/min. Reactivity of the “Szczerców” lignite char was found to be slightly higher than that of the subbituminous “Janina” coal char produced under the same conditions. A high value of the char reactivity was observed to a certain carbon conversion degree, above which a sharp drop took place. It was shown that, to achieve proper carbon conversion, the hydrogasification reaction must proceed at a temperature above 1200 K. PMID:26065028

  9. Direct reduction of iron ore by biomass char

    NASA Astrophysics Data System (ADS)

    Zuo, Hai-bin; Hu, Zheng-wen; Zhang, Jian-liang; Li, Jing; Liu, Zheng-jian

    2013-06-01

    By using thermogravimetric analysis the process and mechanism of iron ore reduced by biomass char were investigated and compared with those reduced by coal and coke. It is found that biomass char has a higher reactivity. The increase of carbon-to-oxygen mole ratio (C/O) can lead to the enhancement of reaction rate and reduction fraction, but cannot change the temperature and trend of each reaction. The reaction temperature of hematite reduced by biomass char is at least 100 K lower than that reduced by coal and coke, the maximum reaction rate is 1.57 times as high as that of coal, and the final reaction fraction is much higher. Model calculation indicates that the use of burden composed of biomass char and iron ore for blast furnaces can probably decrease the temperature of the thermal reserve zone and reduce the CO equilibrium concentration.

  10. Char reactivities and their relationship to pore characteristics

    SciTech Connect

    Kata, S.; Keairns, D.L.

    1980-01-01

    Relative reactivities of chars in a H/sub 2/O-N/sub 2/-H/sub 2/ atmosphere were measured in a laboratory fluidized bed. Results were analyzed on the basis of Ergun's rate equation, and the relative reactivities were calculated with reference to coke breeze. Surface areas of chars were obtained by means of CO/sub 2/ adsorption, and pore volumes were measured by means of mercury penetration porosimetry. A correlation can be identified between the relative reactivity versus the surface areas and the mean pore diameter for the limited number of chars investigated in the present study. Additional studies should be conducted to establish the range of validity with additional chars and drawbacks of this approach.

  11. System for recycling char in iron oxide reducing kilns

    SciTech Connect

    Baker, A.C.; Keran, V.P.

    1983-03-08

    A method and means for improving the efficiency of the process for directly reducing ore containing iron oxide in a rotary kiln using a solid carbonaceous reducing agent, such as coal, introduced from the ore feed and discharge ends of the kiln, as both fuel and reductant, is disclosed wherein the charred coal or char found in the discharge product is recycled into the process at the discharge end of the kiln rather than the feed end as in the prior art. In particular, the recovered char, both coarse and finer particles, are transported to a recycle bin from which they are returned at a preselected rate to the kiln process by being injected along with the coal blown into the discharge end of the kiln. Alternatively, the recycle char alone may be fed without any coal at the discharge end of the kiln.

  12. Technology Assessment Report: Aqueous Sludge Gasification Technologies

    EPA Science Inventory

    The study reveals that sludge gasification is a potentially suitable alternative to conventional sludge handling and disposal methods. However, very few commercial operations are in existence. The limited pilot, demonstration or commercial application of gasification technology t...

  13. June 2007 gasification technologies workshop papers

    SciTech Connect

    2007-06-15

    Topics covered in this workshop are fundamentals of gasification, carbon capture and sequestration, reviews of financial and regulatory incentives, co-production, and focus on gasification in the Western US.

  14. Structural and compositional transformations of biomass chars during combustion

    SciTech Connect

    Wornat, M.J.; Hurt, R.H.; Yang, N.Y.C. ); Headley, T.J. )

    1995-01-01

    In an investigation of the physical and chemical transformations of biomass chars during combustion, the authors have subjected two chars, produced from the pyrolysis of pine and switchgrass, to combustion at 1,600 K in a laminar flow reactor. In order to obtain time-resolved data on the structural and compositional transformations of the biomass chars, samples are extracted from the reactor at different residence times and subjected to a variety of analytical techniques: elemental analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, and high-resolution transmission electron microscopy. The results point to several changes in both the organic and inorganic constituents of the chars. The early stages of conversion are characterized by devolatilization, which leads to the removal of amorphous material and the release of oxygen- and hydrogen-rich gases. After devolatilization, combustion is accompanied by: vaporization of some metals (particularly Na and K), surface migration and coalescence of inorganic material, and the incorporation of metals (particularly Ca) into silicate structures. The latest stages of combustion reveal the transformation of inorganic constituents from amorphous phases to crystalline forms. Some short-range order appears in the carbon-rich portions of the chars as combustion proceeds, but the high levels of oxygen originally present in these chars foster cross-linking, which limits the extent of order ultimately attained. The transformation of the biomass chars are compared with those of coal chars, and the implications of these observations--with respect to reactivity and ash behavior--are discussed.

  15. Biothermal gasification of biomass

    SciTech Connect

    Chynoweth, D.P.; Srivastava, V.J.; Henry, M.P.; Tarman, P.B.

    1980-01-01

    The BIOTHERMGAS Process is described for conversion of biomass, organic residues, and peat to substitute natural gas (SNG). This new process, under development at IGT, combines biological and thermal processes for total conversion of a broad variety of organic feeds (regardless of water or nutrient content). The process employs thermal gasification for conversion of refractory digester residues. Ammonia and other inorganic nutrients are recycled from the thermal process effluent to the bioconversion unit. Biomethanation and catalytic methanation are presented as alternative processes for methanation of thermal conversion product gases. Waste heat from the thermal component is used to supply the digester heat requirements of the bioconversion component. The results of a preliminary systems analysis of three possible applications of this process are presented: (1) 10,000 ton/day Bermuda grass plant with catalytic methanation; (2) 10,000 ton/day Bermuda grass plant with biomethanation; and (3) 1000 ton/day municipal solid waste (MSW) sewage sludge plant with biomethanation. The results indicate that for these examples, performance is superior to that expected for biological or thermal processes used separately. The results of laboratory studies presented suggest that effective conversion of thermal product gases can be accomplished by biomethanation.

  16. Beluga Coal Gasification - ISER

    SciTech Connect

    Steve Colt

    2008-12-31

    ISER was requested to conduct an economic analysis of a possible 'Cook Inlet Syngas Pipeline'. The economic analysis was incorporated as section 7.4 of the larger report titled: 'Beluga Coal Gasification Feasibility Study, DOE/NETL-2006/1248, Phase 2 Final Report, October 2006, for Subtask 41817.333.01.01'. The pipeline would carry CO{sub 2} and N{sub 2}-H{sub 2} from a synthetic gas plant on the western side of Cook Inlet to Agrium's facility. The economic analysis determined that the net present value of the total capital and operating lifecycle costs for the pipeline ranges from $318 to $588 million. The greatest contributor to this spread is the cost of electricity, which ranges from $0.05 to $0.10/kWh in this analysis. The financial analysis shows that the delivery cost of gas may range from $0.33 to $0.55/Mcf in the first year depending primarily on the price for electricity.

  17. Environmental benefits of underground coal gasification.

    PubMed

    Liu, Shu-qin; Liu, Jun-hua; Yu, Li

    2002-04-01

    Environmental benefits of underground coal gasification are evaluated. The results showed that through underground coal gasification, gangue discharge is eliminated, sulfur emission is reduced, and the amount of ash, mercury, and tar discharge are decreased. Moreover, effect of underground gasification on underground water is analyzed and CO2 disposal method is put forward. PMID:12046301

  18. Resinous binders for coal and chars

    SciTech Connect

    Olson, E.S.; Sharma, R.K.; Young, B.C.

    1995-12-31

    Binder development and application to the briquetting or pelleting of coal fines has been extensive. The search for low-cost, effective binders for making strong and durable briquettes or pellets continues unabated. Strong, durable compacts are required, not only for handling, transport, and storage of the product but also to withstand the rigors of application such as flue gas treatment sorbents and catalytic supports. Many kinds of binders, organic and inorganic, have been used to gain the desired strength. Synthetic polymers have been investigated because they promote good strength and water insolubility, but these features are generally outweighed by the polymer cost. Promising earlier developments of biomass-derived binders have received slow market acceptance, mainly because of the cost resulting from the high concentrations required. However, recent advances in processing lignocellulosic materials have generated potentially low-cost polymeric binding agents for making coal briquettes. Phenol novolaks were previously used with lignites to make activated carbons. Recently, binders were prepared from mixtures of phenol, lignin, and formaldehyde and used for wood flour molding and friction materials. The goal of our work was to investigate the characteristics of resinous binders from lignocellulosic as well as coal-derived materials when used with dried or beneficiated coals and chars.

  19. Experimental and modeling study on char combustion

    SciTech Connect

    J. Yu; M.C. Zhang

    2009-05-15

    In this study, on the basis of experimental verifications with an FTIR online measurement system, theoretical calculations by using the strict continuous-film model were first compared with those by the simple single-film model that is still widely used in mathematical modeling of pulverized coal flames. The results indicated that the single-film model has some significant errors in its predictions of the ignition temperature and the combustion following ignition and hence should have some restrictions on its application. Then an improved char combustion model has been presented, taking into consideration the influence of the finite-rate heterogeneous reduction and oxidation reactions. This model gives the explicit algebraic expressions for the overall rate of combustion, the surface temperature of the particle, and the gas temperature at the flame sheet. Compared with the single-film model, predictions by the present model were in much better agreement with those predicted by the continuous-film model and the experimental data. The novel model is also much easier to be integrated into the comprehensive computing codes for industrial pulverized coal flame than the continuous-film model. 21 refs., 14 figs.

  20. CO{sub 2}-gasification reactivity of different carbonaceous materials at elevated temperatures

    SciTech Connect

    Gu, J.; Wu, S.; Wu, Y.; Gao, J.

    2009-07-01

    At the atmospheric pressure and at the temperatures between 1,223 and 1,673 K, the CO{sub 2} gasification reactivity of seven different carbonaceous materials comprising coal tar pitch coke, petroleum coke, natural graphite, carbon black and three coal chars was investigated by using thermogravimetric analysis. Their crystalline structures were analyzed by X-ray diffraction (XRD). It is found that the reactivity of the chars, pitch coke and petroleum coke produced from liquid phase carbonization, is several times poorer than that of the coal chars produced from solid phase carbonization and even lower than that of natural graphite. At the same time, it is obtained that under the condition of the chemical reaction control, the apparent activation energies of the former are in the range of 135.82-174.92 kJ/mol, while those of the latter are between 89.95 kJ/mol and 110.05 kJ/mol. Besides, the reactivity of the sample has a certain correlation with the crystalline structure of the sample, i.e., the larger the fraction of the relatively better crystalline structure is, the poorer the reactivity of the sample is.

  1. Comparative study on combined co-pyrolysis/gasification of walnut shell and bituminous coal by conventional and congruent-mass thermogravimetric analysis (TGA) methods.

    PubMed

    Zhang, Yan; Fan, Di; Zheng, Yan

    2016-01-01

    Combined co-pyrolysis/gasification of bituminous coal (BC) and walnut shell (WS) are comparatively studied with both conventional and congruent-mass thermogravimertric analysis (TGA) methods. The results indicate that BC and WS exhibit additivity in the co-pyrolysis step. However, the gasification reactivity of chars in subsequent gasification step exhibits remarkable sample-mass dependence, which causes the illusions in synergy and inhibition effects when conventional TGA tests are conducted. A congruent-mass TGA method has been developed to overcome the limitations of the conventional TGA mode. One of the advantages of this method is that it can reduce to a minimum the effect of sample mass on reactivity. Thus, the degree of synergy or inhibition can be directly estimated from the deviation of the experimental TG curves between the two separated and blended samples. We recommend this method in studying the co-processing behavior between coal and biomass. PMID:26306847

  2. Integrated Biomass Gasification with Catalytic Partial Oxidation for Selective Tar Conversion

    SciTech Connect

    Zhang, Lingzhi; Wei, Wei; Manke, Jeff; Vazquez, Arturo; Thompson, Jeff; Thompson, Mark

    2011-05-28

    Biomass gasification is a flexible and efficient way of utilizing widely available domestic renewable resources. Syngas from biomass has the potential for biofuels production, which will enhance energy security and environmental benefits. Additionally, with the successful development of low Btu fuel engines (e.g. GE Jenbacher engines), syngas from biomass can be efficiently used for power/heat co-generation. However, biomass gasification has not been widely commercialized because of a number of technical/economic issues related to gasifier design and syngas cleanup. Biomass gasification, due to its scale limitation, cannot afford to use pure oxygen as the gasification agent that used in coal gasification. Because, it uses air instead of oxygen, the biomass gasification temperature is much lower than well-understood coal gasification. The low temperature leads to a lot of tar formation and the tar can gum up the downstream equipment. Thus, the biomass gasification tar removal is a critical technology challenge for all types of biomass gasifiers. This USDA/DOE funded program (award number: DE-FG36-O8GO18085) aims to develop an advanced catalytic tar conversion system that can economically and efficiently convert tar into useful light gases (such as syngas) for downstream fuel synthesis or power generation. This program has been executed by GE Global Research in Irvine, CA, in collaboration with Professor Lanny Schmidt's group at the University of Minnesota (UoMn). Biomass gasification produces a raw syngas stream containing H2, CO, CO2, H2O, CH4 and other hydrocarbons, tars, char, and ash. Tars are defined as organic compounds that are condensable at room temperature and are assumed to be largely aromatic. Downstream units in biomass gasification such as gas engine, turbine or fuel synthesis reactors require stringent control in syngas quality, especially tar content to avoid plugging (gum) of downstream equipment. Tar- and ash-free syngas streams are a critical

  3. An investigation into the impact of CO2 co-feed on pyrolysis and gasification.

    PubMed

    Kwon, Eilhan; Kim, Sungpyo

    2010-08-01

    This paper presents experimental results of the impact of CO(2) co-feed on a gasification/pyrolysis process for various feedstocks (biomass, coal, and municipal solid waste (MSW)). Various feedstocks were thermo-gravimetrically characterized under various atmospheric conditions and heating rates. A substantial amount of char burn out was identified in the presence of CO(2) via a series of thermo-gravimetric analysis tests, which enabled high conversion of final mass (approximately 99%) to be achieved. The impact of CO(2) co-feed on the volatilization regime during the pyrolysis/gasification process was not apparent at a heating rate of 10-40 degrees C min(-1). However, the impact of CO(2) on the volatilization regime at a fast heating rate (950 degrees C min(-1)) was substantial. For example, significant enhancement in the generation of CO, by a factor of approximately 2, was observed in the presence of CO(2). The generation of major chemical species, such as CH(4) and C(2)H(4), were enhanced, but this was not as apparent as in the case with CO. In addition, introducing CO(2) to the pyrolysis/gasification process enabled the amount of condensable liquid hydrocarbons, such as tar (approximately 30-40%) to be significantly reduced in the presence of CO(2), in that injecting CO(2) into the pyrolysis/gasification process expedites cracking the volatilized chemical species. Experimental work confirmed that biomass and MSW could be feasible and desirable feedstocks for the pyrolysis/gasification process as these feedstocks can be easily treated compared to coal. To extend this understanding to a more practical level, various feedstocks were tested in a tubular reactor and drop tube reactor under various experimental conditions. PMID:20546843

  4. The shell coal gasification process

    SciTech Connect

    Koenders, L.O.M.; Zuideveld, P.O.

    1995-12-01

    Future Integrated Coal Gasification Combined Cycle (ICGCC) power plants will have superior environmental performance and efficiency. The Shell Coal Gasification Process (SCGP) is a clean coal technology, which can convert a wide range of coals into clean syngas for high efficiency electricity generation in an ICGCC plant. SCGP flexibility has been demonstrated for high-rank bituminous coals to low rank lignites and petroleum coke, and the process is well suited for combined cycle power generation, resulting in efficiencies of 42 to 46% (LHV), depending on choice of coal and gas turbine efficiency. In the Netherlands, a 250 MWe coal gasification combined cycle plant based on Shell technology has been built by Demkolec, a development partnership of the Dutch Electricity Generating Board (N.V. Sep). The construction of the unit was completed end 1993 and is now followed by start-up and a 3 year demonstration period, after that the plant will be part of the Dutch electricity generating system.

  5. Combustion of char-coal waste pellets for high efficiency and low NO{sub x}. Technical report, March 1--May 31, 1995

    SciTech Connect

    Rajan, S.

    1995-12-31

    To maintain market share, new uses must be found for Illinois coals in the largest end use area, namely power generation. To this end, the suitability of Illinois coal for high efficiency power plants like combined cycles must be investigated. This approach involves partial gasification of the coal to produce fuel gas for the topping cycle gas turbines, while the residual char is burnt in the gas turbine exhaust to produce steam for the Rankine bottoming cycle. This project seeks to improve the combustion characteristics of the residual char by pelletizing it with waste coal in order to improve its combustor residence time and carbon conversion efficiency. At the same time, attempts are made to reduce pollutant emissions. During this quarter, the residual char produced by Foster Wheeler Development Corporation in their pyrolyzer has been pelletized with Illinois gob coal in various proportions. Combustion tests have been performed in a laboratory scale circulating fluidized bed combustor. Preliminary results show that the pellets are much easier to burn and exhibit high carbon conversion efficiencies. Further combustion tests are in progress.

  6. Coal Gasification for Power Generation, 3. edition

    SciTech Connect

    2007-11-15

    The report provides a concise look at the challenges faced by coal-fired generation, the ability of coal gasification to address these challenges, and the current state of IGCC power generation. Topics covered include: an overview of Coal Generation including its history, the current market environment, and the status of coal gasification; a description of gasification technology including processes and systems; an analysis of the key business factors that are driving increased interest in coal gasification; an analysis of the barriers that are hindering the implementation of coal gasification projects; a discussion of Integrated Gasification Combined Cycle (IGCC) technology; an evaluation of IGCC versus other generation technologies; a discussion of IGCC project development options; a discussion of the key government initiatives supporting IGCC development; profiles of the key gasification technology companies participating in the IGCC market; and, a detailed description of existing and planned coal IGCC projects.

  7. Coal gasification 2006: roadmap to commercialization

    SciTech Connect

    2006-05-15

    Surging oil and gas prices, combined with supply security and environmental concerns, are prompting power generators and industrial firms to further develop coal gasification technologies. Coal gasification, the process of breaking down coal into its constituent chemical components prior to combustion, will permit the US to more effectively utilize its enormous, low cost coal reserves. The process facilitates lower environmental impact power generation and is becoming an increasingly attractive alternative to traditional generation techniques. The study is designed to inform the reader as to this rapidly evolving technology, its market penetration prospects and likely development. Contents include: Clear explanations of different coal gasification technologies; Emissions and efficiency comparisons with other fuels and technologies; Examples of US and global gasification projects - successes and failures; Commercial development and forecast data; Gasification projects by syngas output; Recommendations for greater market penetration and commercialization; Current and projected gasification technology market shares; and Recent developments including proposals for underground gasification process. 1 app.

  8. Measurement and modeling the coefficient of restitution of char particles under simulated entrained flow gasifier conditions

    NASA Astrophysics Data System (ADS)

    Gibson, LaTosha M.

    Inefficiencies in plant operations due to carbon loss in flyash, necessitate control of ash deposition and the handling of the slag disposal. Excessive char/ash deposition in convective coolers causes reduction in the heat transfer, both in the radiative (slagging) section and in the low-temperature convective (fouling) heating section. This can lead to unplanned shutdowns and result in an increased cost of electricity generation. CFD models for entrained flow gasification have used the average bulk coal composition to simulate slagging and ash deposition with a narrow particle size distribution (PSD). However, the variations in mineral (inorganic) and macerals (organic) components in coal have led to particles with a variation in their inorganic and organic composition after grinding as governed by their Particle Size Distribution (PSD) and mineral liberation kinetics. As a result, each particle in a PSD of coal exhibits differences in its conversion, particle trajectory within the gasifier, fragmentation, swelling, and slagging probability depending on the gasifier conditions (such as the temperature, coal to oxygen ratio, and swirling capacity of the coal injector). Given the heterogeneous behavior of char particles within a gasifier, the main objective of this work was to determine boundary conditions of char particle adhering and/or rebounding from the refractory wall or a layer of previously adhered particles. In the past, viscosity models based on the influence of ash composition have been used as the method to characterize sticking. It is well documented that carbon contributes to the non-wettability of particles. Therefore, it has been hypothesized that viscosity models would not be adequate to accurately predict the adhesion behavior of char. Certain particle wall impact models have incorporated surface tension which can account the contributions of the carbon content to the adhesive properties of a char particle. These particle wall impact models also

  9. Advanced development of a pressurized ash agglomerating fluidized-bed coal gasification system: Topical report, Process analysis, FY 1983

    SciTech Connect

    1987-07-31

    KRW Energy Systems, Inc., is engaged in the continuing development of a pressurized, fluidized-bed gasification process at its Waltz Mill Site in Madison, Pennsylvania. The overall objective of the program is to demonstrate the viability of the KRW process for the environmentally-acceptable production of low- and medium-Btu fuel gas from a variety of fossilized carbonaceous feedstocks and industrial fuels. This report presents process analysis of the 24 ton-per-day Process Development Unit (PDU) operations and is a continuation of the process analysis work performed in 1980 and 1981. Included is work performed on PDU process data; gasification; char-ash separation; ash agglomeration; fines carryover, recycle, and consumption; deposit formation; materials; and environmental, health, and safety issues. 63 figs., 43 tabs.

  10. Updraft gasification of poultry litter at farm-scale--A case study.

    PubMed

    Taupe, N C; Lynch, D; Wnetrzak, R; Kwapinska, M; Kwapinski, W; Leahy, J J

    2016-04-01

    Farm and animal wastes are increasingly being investigated for thermochemical conversion, such as gasification, due to the urgent necessity of finding new waste treatment options. We report on an investigation of the use of a farm-scale, auto-thermal gasification system for the production of a heating gas using poultry litter (PL) as a feedstock. The gasification process was robust and reliable. The PL's ash melting temperature was 639°C, therefore the reactor temperature was kept around this value. As a result of the low reactor temperature the process performance parameters were low, with a cold gas efficiency (CGE) of 0.26 and a carbon conversion efficiency (CCE) of 0.44. The calorific value of the clean product gas was 3.39 MJ m(-3)N (LHV). The tar was collected as an emulsion containing 87 wt.% water and the extracted organic compounds were identified. The residual char exceeds thresholds for Zn and Cu to obtain European biochar certification; however, has potential to be classified as a pyrogenic carbonaceous material (PCM), which resembles a high nutrient biochar. PMID:26948170

  11. The role of pore structure on char reactivity

    SciTech Connect

    Sarofim, A.F.

    1992-06-01

    The Wyoming lignite raw coal was size classified to 38--45 [mu]m, first by air-classification to remove the fine panicles, and then by sieving with a standard Ro-tap sieving machine. The size-classified Wyoming lignite was then pyrolyzed in a laboratory-scale laminar flow furnace at 1650K, 100% N[sub 2]. About one gram of pyrolyzed char was collected with Millipore membrane filters (teflon/polyethylene). The char sample thus collected was carefully poured into an cylindrical mold filled with epoxy resin and thoroughly mixed with epoxy resin. In order to remove the air bubbles trapped during mixing in the mixture, the sample-filled mold was placed in a dessicator connected to a vacuum pump. By periodically evacuating the dessicator, trapped air bubbles could be removed. The mold with the char sample and epoxy resin was placed in a cool area for 24 hours until it hardened. One end of the hardened cylindrical plug was carefully polished with alumina paste so that char particles embedded could also be cross-sectioned. The polished end of the sample plug thus prepared was observed under a Wetzlar optical microscope with a built-in camera. Pictures of fifty cross-sections of char particles were taken. The magnification was in the range of [times] l00 and [times] 650. Figure 1 shows cross-sections of char particles shown in black and white images. (The carbonaceous matrix is shown in black). Characterization of the pore structure of the char was carried out by digital image processing on cross-sections of the char particles. Pictures of cross-sections were scanned in, digitized in 600 [times] 5l2-pixel, 256-grayscale images using an Apple Scanner. Grayscale images were first converted to binary black-and-white images by setting a grayscale threshold that gives the best images of pores and char. Editing, i.e., sharpening and noise reduction, was performed to the binary images using Image v 1.17, a public domain program.

  12. Bio-char from treated and untreated oil palm fronds

    NASA Astrophysics Data System (ADS)

    Sulaiman, Fauziah; Abdullah, Nurhayati; Rahman, Aizuddin Abdul

    2013-05-01

    The palm oil industry generates almost 94% of biomass in Malaysia, while other agricultural and forestry by-products contribute the remaining of 6%. Oil palm fronds (OPF) are estimated to be the highest available biomass amounting to 44.84 million tonnes in Malaysia. However, studies on OPF for thermochemical conversion technology which has good potential for energy conversion are still lacking. In this work, pyrolysis of OPF is conducted by using a fixed bed reactor. Samples were carbonized at slow pyrolysis temperature of around 300 to 500°C with heating rate of 10°C min-1. In addition, samples were treated for 20 min with distilled water at ambient temperature to reduce the ash content. Effectiveness of pre-treatment can be determined by observing the percentage of ash content reduction of each sample after undergoing washing pre-treatment. At 300°C, the char yields of the untreated OPF were slightly higher at 50.95% compared to the treated sample at 49.77%. Approximately all bio-char from the treated samples have better high heating value (HHV) of around 18-20 MJ kg-1 compared to the untreated samples. Besides that, all treated OPF char is more carbon rich and considered to be environmental friendly due to its low nitrogen content compared to the untreated OPF char. In this work, microscopic analysis of OPF bio-char were also studied by observing and evaluating their structure surface and morphology.

  13. Characterization of char from slow pyrolysis of sewage sludge.

    PubMed

    Xu, Wen-Ying; Wu, Di

    2016-01-01

    The effects of final pyrolysis temperature Tend from 300 ºC to 550 ºC, heating rates β of 2 ºC/min, 3 ºC/min and 5 ºC/min, retention time RT from 45 min to 90 min, and the moisture content MC from 0 to 70% on characteristics of the pyrolysis char from sewage sludge were investigated using a tube furnace in this study. The resulting chars were characterized by sorption of nitrogen (surface area and pore volume). Their adsorption characteristics were evaluated via iodine value and methylene blue value. Either the pore structures or adsorption characteristics depend on the pyrolysis processing and moisture content of the sludge precursors. In terms of iodine value and surface area of the char, Tend of 450 ºC, RT of 75 min and β of 3 ºC/min proved the optimum combination of pyrolysis parameters. The chars have an undeveloped mesopore and macropore structure and a developed micropore structure. The sodium phenoxide adsorption equilibrium data fit well with the Langmuir model of adsorption, suggesting monolayer coverage of sodium phenoxide molecules at the surface of the char. Its adsorption mechanism is mainly physical in nature, enhanced by chemisorption. PMID:27191557

  14. Preparation and characterization of activated carbon from demineralized tyre char

    NASA Astrophysics Data System (ADS)

    Manocha, S.; Prasad, Guddu R.; Joshi, Parth.; Zala, Ranjitsingh S.; Gokhale, Siddharth S.; Manocha, L. M.

    2013-06-01

    Activated carbon is the most adsorbing material for industrial waste water treatment. For wider applications, the main consideration is to manufacture activated carbon from low cost precursors, which are easily available and cost effective. One such source is scrap tyres. Recently much effort has been devoted to the thermal degradation of tyres into gaseous and liquid hydrocarbons and solid char residue, all of which have the potential to be processed into valuable products. As for solid residue, char can be used either as low-grade reinforcing filler or as activated carbon. The product recovered by a typical pyrolysis of tyres are usually, 33-38 wt% pyrolytic char, 38-55 wt% oil and 10-30 wt% solid fractions. In the present work activated carbon was prepared from pyrolyzed tyre char (PC). Demineralization involves the dissolution of metal into acids i.e. HCl, HNO3 and H2SO4 and in base i.e. NaOH. Different concentration of acid and base were used. Sodium hydroxide showed maximum amount of metal oxide removal. Further the concentration of sodium hydroxide was varied from 1N to 6N. As the concentration of acid are increased demineralization increases. 6N Sodium hydroxide is found to be more effective demineralising agent of tyre char.

  15. BIMOMASS GASIFICATION PILOT PLANT STUDY

    EPA Science Inventory

    The report gives results of a gasification pilot program using two biomass feedstocks: bagasse pellets and wood chips. he object of the program was to determine the properties of biomass product gas and its suitability as a fuel for gas-turbine-based power generation cycles. he f...

  16. Catalytic gasification of bagasse for the production of methanol

    SciTech Connect

    Baker, E.G.; Brown, M.D.; Robertus, R.J.

    1985-10-01

    The purpose of the study was to evaluate the technical and economic feasibility of catalytic gasification of bagasse to produce methanol. In previous studies, a catalytic steam gasification process was developed which converted wood to methanol synthesis gas in one step using nickel based catalysts in a fluid-bed gasifier. Tests in a nominal 1 ton/day process development unit (PDU) gasifier with these same catalysts showed bagasse to be a good feedstock for fluid-bed gasifiers, but the catalysts deactivated quite rapidly in the presence of bagasse. Laboratory catalyst screening tests showed K/sub 2/CO/sub 3/ doped on the bagasse to be a promising catalyst for converting bagasse to methanol synthesis gas. PDU tests with 10 wt % K/sub 2/CO/sub 3/ doped on bagasse showed the technical feasibility of this type of catalyst on a larger scale. A high quality synthesis gas was produced and carbon conversion to gas was high. The gasifier was successfully operated without forming agglomerates of catalyst, ash, and char in the gasifier. There was no loss of activity throughout the runs because catalysts is continually added with the bagasse. Laboratory tests showed about 80% of the potassium carbonate could be recovered and recycled with a simple water wash. An economic evaluation of the process for converting bagasse to methanol showed the required selling price of methanol to be significantly higher than the current market price of methanol. Several factors make this current evaluaton using bagasse as a feedstock less favorable: (1) capital costs are higher due to inflation and some extra costs required to use bagasse, (2) smaller plant sizes were considered so economies of scale are lost, and (3) the market price of methanol in the US has fallen 44% in the last six months. 24 refs., 14 figs., 16 tabs.

  17. Reactivity of young chars via energetic distribution measurements

    SciTech Connect

    Calo, J.M.; Lilly, W.D.

    1991-01-01

    The current project is directed at developing related techniques for the characterization and prediction/correlation of the reactivity of young'' chars to steam and oxygen. Of particular interest is mapping of the reactivity behavior of the resultant chars, as revealed by the energetic heterogeneity of the complexes with char preparation conditions; i.e., heating rate and ultimate temperature. In this first quarterly technical progress report we present the background of the project and the research program for the proposed investigations. The following work was accomplished on the experimental apparatus: a new set of electronics for the UTi quadrupole mass spectrometer head was purchased and delivered. The Temperature Programmed Desorption (TPD) System was moved to another laboratory and interfaced with the mass spectrometer system. A Polycold{trademark} freon refrigeration system was repaired and interfaced with the vacuum system for the TPD apparatus. It will be used to cool the diffusion pump trap. 60 refs.

  18. COAL AND CHAR STUDIES BY ADVANCED EMR TECHNIQUES

    SciTech Connect

    R. Linn Belford; Robert B. Clarkson; Mark J. Nilges; Boris M. Odintsov; Alex I. Smirnov

    2001-04-30

    Advanced electronic magnetic resonance (EMR) as well as nuclear magnetic resonance (NMR) methods have been used to examine properties of coals, chars, and molecular species related to constituents of coal. During the span of this grant, progress was made on construction and applications to coals and chars of two high frequency EMR systems particularly appropriate for such studies--48 GHz and 95 GHz electron magnetic resonance spectrometer, on new low-frequency dynamic nuclear polarization (DNP) experiments to examine the interaction between water and the surfaces of suspended char particulates in slurries, and on a variety of proton nuclear magnetic resonance (NMR) techniques to measure characteristics of the water directly in contact with the surfaces and pore spaces of carbonaceous particulates.

  19. Studying the specific features pertinent to combustion of chars obtained from coals having different degrees of metamorphism and biomass chars

    NASA Astrophysics Data System (ADS)

    Bestsennyi, I. V.; Shchudlo, T. S.; Dunaevskaya, N. I.; Topal, A. I.

    2013-12-01

    Better conditions for igniting low-reaction coal (anthracite) can be obtained, higher fuel burnout ratio can be achieved, and the problem of shortage of a certain grade of coal can be solved by firing coal mixtures and by combusting coal jointly with solid biomass in coal-fired boilers. Results from studying the synergetic effect that had been revealed previously during the combustion of coal mixtures in flames are presented. A similar effect was also obtained during joint combustion of coal and wood in a flame. The kinetics pertinent to combustion of char mixtures obtained from coals characterized by different degrees of metamorphism and the kinetics pertinent to combustion of wood chars were studied on the RSK-1D laboratory setup. It was found from the experiments that the combustion rate of char mixtures obtained from coals having close degrees of metamorphism is equal to the value determined as a weighted mean rate with respect to the content of carbon. The combustion rate of char mixtures obtained from coals having essentially different degrees of metamorphism is close to the combustion rate of more reactive coal initially in the process and to the combustion rate of less reactive coal at the end of the process. A dependence of the specific burnout rate of carbon contained in the char of two wood fractions on reciprocal temperature in the range 663—833 K is obtained. The combustion mode of an experimental sample is determined together with the reaction rate constant and activation energy.

  20. Correlation for the total sulfur content in char after devolatilization

    SciTech Connect

    Vasilije Manovic; Borislav Grubor

    2006-02-01

    The overall process of coal combustion takes place in two successive steps: devolatilization and char combustion. The fate of sulfur during the devolatilization of coal of different rank was investigated. The significance of the investigation is in fact that a major part of sulfur release occurs during devolatilization of coal, (i.e., emission of sulfur oxides during combustion of coal largely depends on sulfur release during devolatilization). The experimental investigations were conducted to obtain the data about the quantitative relation between sulfur content in the coal and sulfur content in the char. Standard procedures were used for obtaining the chars in a laboratory oven and determining the sulfur forms in the coal and char samples. The experiments were done with ground coal samples ({lt}0.2 mm), at the temperatures in the range of 500-1000{sup o}C. We showed that the amount of sulfur remaining in the char decreases, but not significantly in the temperature range 600-900{sup o}C. On the basis of the theoretical consideration of behavior of sulfur forms during devolatilization, certain simplifying assumptions, and obtained experimental data, we propose two correlations to associate the content of sulfur in the coal and in the char. The correlations are based on the results of the proximate analysis and sulfur forms in coal. Good agreement was found when the proposed correlations were compared with the experimental results obtained for investigated coals. Moreover, the correlations were verified by results found in the literature for numerous Polish, Albanian, and Turkish coals. Significant correlations (P {lt}0.05) between observed and calculated data with correlation coefficient, R {gt}0.9, were noticed in the case of all coals. 25 refs., 3 figs., 2 tabs.

  1. Characterization of a Neochlamydia-like Bacterium Associated with Epitheliocystis in Cultured Artic Char Salvelinus alpinus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infections of branchial epithelium by intracellular gram-negative bacteria, termed epitheliocystis, have limited culture of Arctic char (Salvelinus alpinus). To characterize a bacterium associated with epitheliocystis in cultured char, gills were sampled for histopathologic examination, conventional...

  2. Formation, Structure and Properties of Amorphous Carbon Char from Polymer Materials in Extreme Atmospheric Reentry Environments

    NASA Technical Reports Server (NTRS)

    Lawson, John W.

    2010-01-01

    Amorphous carbonaceous char produced from the pyrolysis of polymer solids has many desirable properties for ablative heat shields for space vehicles. Molecular dynamics simulations are presented to study the transformation of the local atomic structure from virgin polymer to a dense, disordered char [1]. Release of polymer hydrogen is found to be critical to allow the system to collapse into a highly coordinated char structure. Mechanisms of the char formation process and the morphology of the resulting structures are elucidated. Thermal conductivity and mechanical response of the resulting char are evaluated [2]. During reenty, the optical response and oxidative reactivity of char are also important properties. Results of ab initio computations of char optical functions [3] and char reactivity [4] are also presented.

  3. KINETICS AND MECHANISMS OF NOx - CHAR REDUCTION

    SciTech Connect

    Suuberg, E.M.

    1998-06-19

    This study was undertaken in order to improve understanding of several aspects of the NO-carbon reaction. This reaction is of practical importance in combustion systems, but its close examination also provides some fundamental insight into oxidizing gas-carbon reactions. As part of this study, a comprehensive literature review of earlier work on this reaction has been published (Aarna and Suuberg, Fuel, 1997, 76, 475-491). It has been thought for some time that the kinetics of the NO-carbon reaction are unusual, in that they often show a two-regime Arrhenius behavior. It has, however, turned out during this work that NO is not alone in this regard. In this laboratory, we also uncovered evidence of two kinetic regime behavior in CO{sub 2} gasification. In another laboratory, a former colleague has identified the same behavior in N{sub 2}O. The low temperature reaction regime always shows an activation energy which is lower than that in the high temperature regime, leaving little doubt that a shift in mechanism, as opposed to transport limitations, dictates the behavior. The activation energy of the low temperature regime of these reactions is typically less than 100 kJ/mol, and the activation energy of the high temperature regime is generally considerably in excess of this value. In this study, we have resolved some apparent inconsistencies in the explanation of the low temperature regime, whose rate has generally been ascribed to desorption-controlled processes. Part of the problem in characterization of the different temperature regimes is that they overlap to a high degree. It is difficult to probe the low temperature regime experimentally, because of slow relaxation of the surface oxides in that regime. Using careful experimental techniques, we were able to demonstrate that the low temperature regime is indeed characterized by zero order in NO, as it must be. A separate study is being carried out to model the behavior in this regime in NO and in other gases, and

  4. Evaluation of current techniques for isolation of chars as natural adsorbents.

    PubMed

    Chun, Yuan; Sheng, Guangyao; Chiou, Cary T

    2004-08-01

    Chars in soils or sediments may potentially influence the soil/sediment sorption behavior. Current techniques for the isolation of black carbon including chars rely often on acid demineralization, base extraction, and chemical oxidation to remove salts and minerals, humic acid, and refractory kerogen, respectively. Little is known about the potential effects of these chemical processes on the char surface and adsorptive properties. This study examined the effects of acid demineralization, base extraction, and acidic Cr2O7 2- oxidation on the surface areas, surface acidity, and benzene adsorption characteristics of laboratory-produced pinewood and wheat-residue chars, pure or mixed with soils, and a commercial activated carbon. Demineralization resulted in a small reduction in the char surface area, whereas base extraction showed no obvious effect. Neither demineralization nor base extraction caused an appreciable variation in benzene adsorption and presumably the char surface properties. By contrast, the Cr2O7 2- oxidation caused a >31% reduction in char surface area. The Boehm titration, supplemented by FTIR spectra, indicated that the surface acidity of oxidized chars increased by a factor between 2.3 and 12 compared to non-oxidized chars. Benzene adsorption with the oxidized chars was lower than that with the non-oxidized chars by a factor of >8.9; both the decrease in char surface area and the increase in char surface acidity contributed to the reduction in char adsorptive power. Although the Cr2O7 2-oxidation effectively removes resistant kerogen, it is not well suited for the isolation of chars as contaminant adsorbents because of its destructive nature. Alternative nondestructive techniques that preserve the char surface properties and effectively remove kerogen must be sought. PMID:15352465

  5. Evaluation of current techniques for isolation of chars as natural adsorbents

    USGS Publications Warehouse

    Chun, Y.; Sheng, G.; Chiou, C.T.

    2004-01-01

    Chars in soils or sediments may potentially influence the soil/sediment sorption behavior. Current techniques for the isolation of black carbon including chars rely often on acid demineralization, base extraction, and chemical oxidation to remove salts and minerals, humic acid, and refractory kerogen, respectively. Little is known about the potential effects of these chemical processes on the char surface and adsorptive properties. This study examined the effects of acid demineralization, base extraction, and acidic Cr2O72- oxidation on the surface areas, surface acidity, and benzene adsorption characteristics of laboratory-produced pinewood and wheat-residue chars, pure or mixed with soils, and a commercial activated carbon. Demineralization resulted in a small reduction in the char surface area, whereas base extraction showed no obvious effect. Neither demineralization nor base extraction caused an appreciable variation in benzene adsorption and presumably the char surface properties. By contrast, the Cr2O 72- oxidation caused a >31% reduction in char surface area. The Boehm titration, supplemented by FTIR spectra, indicated that the surface acidity of oxidized chars increased by a factor between 2.3 and 12 compared to nonoxidized chars. Benzene adsorption with the oxidized chars was lower than that with the non-oxidized chars by a factor of >8.9; both the decrease in char surface area and the increase in char surface acidity contributed to the reduction in char adsorptive power. Although the Cr 2O72- oxidation effectively removes resistant kerogen, it is not well suited for the isolation of chars as contaminant adsorbents because of its destructive nature. Alternative nondestructive techniques that preserve the char surface properties and effectively remove kerogen must be sought.

  6. Corrosion and mechanical behavior of materials for coal gasification applications

    SciTech Connect

    Natesan, K.

    1980-05-01

    A state-of-the-art review is presented on the corrosion and mechanical behavior of materials at elevated temperatures in coal-gasification environments. The gas atmosphere in coal-conversion processes are, in general, complex mixtures which contain sulfur-bearing components (H/sub 2/S, SO/sub 2/, and COS) as well as oxidants (CO/sub 2//CO and H/sub 2/O/H/sub 2/). The information developed over the last five years clearly shows sulfidation to be the major mode of material degradation in these environments. The corrosion behavior of structural materials in complex gas environments is examined to evaluate the interrelationships between gas chemistry, alloy chemistry, temperature, and pressure. Thermodynamic aspects of high-temperature corrosion processes that pertain to coal conversion are discussed, and kinetic data are used to compare the behavior of different commercial materials of interest. The influence of complex gas environments on the mechanical properties such as tensile, stress-rupture, and impact on selected alloys is presented. The data have been analyzed, wherever possible, to examine the role of environment on the property variation. The results from ongoing programs on char effects on corrosion and on alloy protection via coatings, cladding, and weld overlay are presented. Areas of additional research with particular emphasis on the development of a better understanding of corrosion processes in complex environments and on alloy design for improved corrosion resistance are discussed. 54 references, 65 figures, 24 tables.

  7. A continuous two stage solar coal gasification system

    NASA Astrophysics Data System (ADS)

    Mathur, V. K.; Breault, R. W.; Lakshmanan, S.; Manasse, F. K.; Venkataramanan, V.

    The characteristics of a two-stage fluidized-bed hybrid coal gasification system to produce syngas from coal, lignite, and peat are described. Devolatilization heat of 823 K is supplied by recirculating gas heated by a solar receiver/coal heater. A second-stage gasifier maintained at 1227 K serves to crack remaining tar and light oil to yield a product free from tar and other condensables, and sulfur can be removed by hot clean-up processes. CO is minimized because the coal is not burned with oxygen, and the product gas contains 50% H2. Bench scale reactors consist of a stage I unit 0.1 m in diam which is fed coal 200 microns in size. A stage II reactor has an inner diam of 0.36 m and serves to gasify the char from stage I. A solar power source of 10 kWt is required for the bench model, and will be obtained from a central receiver with quartz or heat pipe configurations for heat transfer.

  8. Influence of the reactant carbon-hydrogen-oxygen composition on the key products of the direct gasification of dewatered sewage sludge in supercritical water.

    PubMed

    Gong, Miao; Zhu, Wei; Fan, Yujie; Zhang, Huiwen; Su, Ying

    2016-05-01

    The supercritical water gasification of ten different types of dewatered sewage sludges was investigated to understand the relationship between sludge properties and gasification products. Experiments were performed in a high-pressure autoclave at 400°C for 60 min. Results showed that gasification of sewage sludge in supercritical water consists mainly of a gasification reaction, a carbonization reaction and a persistent organic pollutants synthesis reaction. Changes in the reactant C/H/O composition have significant effects on the key gasification products. Total gas production increased with increasing C/H2O of the reactant. The char/coke content increased with increasing C/H ratio of the reactant. A decrease in the C/O ratio of the reactant led to a reduction in polycyclic aromatic hydrocarbon formation. This means that we can adjust the reactant C/H/O composition by adding carbon-, hydrogen-, and oxygen-containing substances such as coal, algae and H2O2 to optimize hydrogen production and to inhibit an undesired by-product formation. PMID:26922316

  9. System study on partial gasification combined cycle with CO{sub 2} recovery - article no. 051801

    SciTech Connect

    Xu, Y.J.; Jin, H.G.; Lin, R.M.; Han, W.

    2008-09-15

    S partial gasification combined cycle with CO{sub 2} recovery is proposed in this paper. Partial gasification adopts cascade conversion of the composition of coal. Active composition of coal is simply gasified, while inactive composition, that is char, is burnt in a boiler. Oxy-fuel combustion of syngas produces only CO{sub 2} and H{sub 2}O, so the CO{sub 2} can be separated through cooling the working fluid. This decreases the amount of energy consumption to separate CO{sub 2} compared with conventional methods. The novel system integrates the above two key technologies by injecting steam from a steam turbine into the combustion chamber of a gas turbine to combine the Rankine cycle with the Brayton cycle. The thermal efficiency of this system will be higher based on the cascade utilization of energy level. Compared with the conventional integrated gasification combined cycle (IGCC), the compressor of the gas turbine, heat recovery steam generator (HRSG) and gasifier are substituted for a pump, reheater, and partial gasifier, so the system is simplified. Furthermore, the novel system is investigated by means of energy-utilization diagram methodology and provides a simple analysis of their economic and environmental performance. As a result, the thermal efficiency of this system may be expected to be 45%, with CO{sub 2} recovery of 41.2%, which is 1.5-3.5% higher than that of an IGCC system. At the same time, the total investment cost of the new system is about 16% lower than that of an IGCC. The comparison between the partial gasification technology and the IGCC technology is based on the two representative cases to identify the specific feature of the proposed system.

  10. 40 CFR 454.10 - Applicability; description of the manufacture of char and charcoal briquets subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... manufacture of char and charcoal briquets subcategory. 454.10 Section 454.10 Protection of Environment... MANUFACTURING POINT SOURCE CATEGORY Char and Charcoal Briquets Subcategory § 454.10 Applicability; description of the manufacture of char and charcoal briquets subcategory. The provisions of this subpart...

  11. 40 CFR 454.10 - Applicability; description of the manufacture of char and charcoal briquets subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... manufacture of char and charcoal briquets subcategory. 454.10 Section 454.10 Protection of Environment... MANUFACTURING POINT SOURCE CATEGORY Char and Charcoal Briquets Subcategory § 454.10 Applicability; description of the manufacture of char and charcoal briquets subcategory. The provisions of this subpart...

  12. 40 CFR 454.10 - Applicability; description of the manufacture of char and charcoal briquets subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... manufacture of char and charcoal briquets subcategory. 454.10 Section 454.10 Protection of Environment... MANUFACTURING POINT SOURCE CATEGORY Char and Charcoal Briquets Subcategory § 454.10 Applicability; description of the manufacture of char and charcoal briquets subcategory. The provisions of this subpart...

  13. 40 CFR 454.10 - Applicability; description of the manufacture of char and charcoal briquets subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... manufacture of char and charcoal briquets subcategory. 454.10 Section 454.10 Protection of Environment... MANUFACTURING POINT SOURCE CATEGORY Char and Charcoal Briquets Subcategory § 454.10 Applicability; description of the manufacture of char and charcoal briquets subcategory. The provisions of this subpart...

  14. 40 CFR 454.10 - Applicability; description of the manufacture of char and charcoal briquets subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... manufacture of char and charcoal briquets subcategory. 454.10 Section 454.10 Protection of Environment... MANUFACTURING POINT SOURCE CATEGORY Char and Charcoal Briquets Subcategory § 454.10 Applicability; description of the manufacture of char and charcoal briquets subcategory. The provisions of this subpart...

  15. Low-energy and chemical-free activation of pyrolytic tire char and its adsorption characteristics.

    PubMed

    Quek, Augustine; Balasubramanian, Rajasekhar

    2009-06-01

    It is generally known that the solid char obtained from pyrolysis of scrap rubber tires can be used as an adsorbent for several applications such as wastewater treatment. In this study, scrap tires were first pyrolyzed under nitrogen (N2) or carbon dioxide (CO2) gas under various temperatures to produce char. The char was activated in situ by post-pyrolysis oxygenation (PPO) at different temperature ranges as soon as the pyrolysis process was completed. Elemental and spectroscopic analyses showed significant zinc content in the char after PPO. Batch-mode removal of aqueous copper (Cu) using the chars revealed that, for N2 and CO2, the optimum condition for pyrolysis was at 550 degrees C and for activation was from 550 to 250 degrees C. Although CO2-pyrolyzed char had lower Cu and lead (Pb) removal than N2-pyrolyzed char, it had higher char yields. For both N2- and CO2-pyrolyzed char, activation with PPO improved their heavy metal removal efficiencies significantly compared with unactivated char. PPO chars had much faster removal rates and higher Cu removal compared with both pyrolyzed, unactivated char and commercial activated carbons. PMID:19603742

  16. Apparatus for solar coal gasification

    DOEpatents

    Gregg, D.W.

    Apparatus for using focused solar radiation to gasify coal and other carbonaceous materials is described. Incident solar radiation is focused from an array of heliostats onto a tower-mounted secondary mirror which redirects the focused solar radiation down through a window onto the surface of a vertically-moving bed of coal, or a fluidized bed of coal, contained within a gasification reactor. The reactor is designed to minimize contact between the window and solids in the reactor. Steam introduced into the gasification reactor reacts with the heated coal to produce gas consisting mainly of carbon monoxide and hydrogen, commonly called synthesis gas, which can be converted to methane, methanol, gasoline, and other useful products. One of the novel features of the invention is the generation of process steam at the rear surface of the secondary mirror.

  17. Plasma gasification of coal in different oxidants

    SciTech Connect

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

    2008-12-15

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

  18. Underground coal gasification using oxygen and steam

    SciTech Connect

    Yang, L.H.; Zhang, X.; Liu, S.

    2009-07-01

    In this paper, through model experiment of the underground coal gasification, the effects of pure oxygen gasification, oxygen-steam gasification, and moving-point gasification methods on the underground gasification process and gas quality were studied. Experiments showed that H{sub 2} and CO volume fraction in product gas during the pure oxygen gasification was 23.63-30.24% and 35.22-46.32%, respectively, with the gas heating value exceeding 11.00 MJ/m{sup 3}; under the oxygen-steam gasification, when the steam/oxygen ratio stood at 2: 1, gas compositions remained virtually stable and CO + H{sub 2} was basically between 61.66 and 71.29%. Moving-point gasification could effectively improve the changes in the cavity in the coal seams or the effects of roof inbreak on gas quality; the ratio of gas flowing quantity to oxygen supplying quantity was between 3.1:1 and 3.5:1 and took on the linear changes; on the basis of the test data, the reasons for gas quality changes under different gasification conditions were analyzed.

  19. EMERY BIOMASS GASIFICATION POWER SYSTEM

    SciTech Connect

    Benjamin Phillips; Scott Hassett; Harry Gatley

    2002-11-27

    Emery Recycling Corporation (now Emery Energy Company, LLC) evaluated the technical and economical feasibility of the Emery Biomass Gasification Power System (EBGPS). The gasifier technology is owned and being developed by Emery. The Emery Gasifier for this project was an oxygen-blown, pressurized, non-slagging gasification process that novelly integrates both fixed-bed and entrained-flow gasification processes into a single vessel. This unique internal geometry of the gasifier vessel will allow for tar and oil destruction within the gasifier. Additionally, the use of novel syngas cleaning processes using sorbents is proposed with the potential to displace traditional amine-based and other syngas cleaning processes. The work scope within this project included: one-dimensional gasifier modeling, overall plant process modeling (ASPEN), feedstock assessment, additional analyses on the proposed syngas cleaning process, plant cost estimating, and, market analysis to determine overall feasibility and applicability of the technology for further development and commercial deployment opportunities. Additionally, the project included the development of a detailed technology development roadmap necessary to commercialize the Emery Gasification technology. Process modeling was used to evaluate both combined cycle and solid oxide fuel cell power configurations. Ten (10) cases were evaluated in an ASPEN model wherein nine (9) cases were IGCC configurations with fuel-to-electricity efficiencies ranging from 38-42% and one (1) case was an IGFC solid oxide case where 53.5% overall plant efficiency was projected. The cost of electricity was determined to be very competitive at scales from 35-71 MWe. Market analysis of feedstock availability showed numerous market opportunities for commercial deployment of the technology with modular capabilities for various plant sizes based on feedstock availability and power demand.

  20. Coal gasification players, projects, prospects

    SciTech Connect

    Blankinship, S.

    2006-07-15

    Integrated gasification combined cycle (IGCC) technology has been running refineries and chemical plants for decades. Power applications have dotted the globe. Two major IGCC demonstration plants operating in the United States since the mid-1900s have helped set the stage for prime time, which is now approaching. Two major reference plant designs are in the wings and at least two major US utilities are poised to build their own IGCC power plants. 2 figs.

  1. Environmental Impacts of the Production and Application of Biochar - EuroChar Project

    NASA Astrophysics Data System (ADS)

    Rack, Mireille; Woods, Jeremy

    2014-05-01

    One of the potential benefits of biochar is carbon sequestration. To determine the overall net sequestration potential it is important to analyse the full supply chain, assessing both the direct and indirect emissions associated with the production and application of biochar. However, it is essential to also incorporate additional environmental impact categories to ensure the assessment of a more complete environmental impact profile. This paper uses a full life-cycle assessment (LCA) methodology to evaluate the results from the EuroChar, 'biochar for carbon sequestration and large-scale removal of GHG from the atmosphere', project. This EU Seventh Framework Programme project aims to investigate and reduce uncertainties around the impacts of, and opportunities for, biochar, and in particular explore possible pathways for its introduction into modern agricultural systems in Europe. The LCA methodology, according to the ISO standards, is applied to the project-specific supply chains to analyse the environmental impacts of biochar production and application. Two conversion technologies for the production of biochar are assessed, gasification and hydrothermal carbonization (HTC), in order to provide conversion efficiencies and emission factors for the biochar production component of the supply chain. The selected feedstocks include those derived from waste residues and dedicated crops. For the end use stage, various forms and methods for biochar application are considered. In addition to the Global Warming Potential category, other environmental impact categories are also included in the analysis. The resulting 'feedstock * conversion technology' matrix provides nine pathways for the production and application of biochar, which are applied as a representative basis for the scenario modelling. These scenarios have been developed in order to assess the feedstock and land availability in Europe for the production and application of biochar and to give an order of

  2. Recovery of a Charred Painting Using Atomic Oxygen Treatment

    NASA Technical Reports Server (NTRS)

    Rutledge, Sharon K.; Banks, Bruce A.; Chichernea, Virgil A.

    1999-01-01

    A noncontact method is described which uses atomic oxygen to remove soot and char from the surface of a painting. The atomic oxygen was generated by the dissociation of oxygen in low pressure air using radio frequency energy. The treatment, which is an oxidation process, allows control of the amount of material to be removed. The effectiveness of char removal from half of a fire-damaged oil painting was studied using reflected light measurements from selected areas of the painting and by visual and photographic observation. The atomic oxygen was able to effectively remove char and soot from the treated half of the painting. The remaining loosely bound pigment was lightly sprayed with a mist to replace the binder and then varnish was reapplied. Caution should he used when treating an untested paint medium using atomic oxygen. A representative edge or corner should he tested first in order to determine if the process would be safe for the pigments present. As more testing occurs, a greater knowledge base will be developed as to what types of paints and varnishes can or cannot be treated using this technique. With the proper precautions, atomic oxygen treatment does appear to be a technique with great potential for allowing very charred, previously unrestorable art to be salvaged.

  3. Trace metal transformations in gasification

    SciTech Connect

    Erickson, T.A.; Zygarlicke, C.J.; O`Keefe, C.A.

    1995-08-01

    The Energy & Environmental Research Center (EERC) is carrying out an investigation that will provide methods to predict the fate of selected trace elements in integrated gasification combined cycle (IGCC) and integrated gasification fuel cell (IGFC) systems to aid in the development of methods to control the emission of trace elements determined to be air toxics. The goal of this project is to identify the effects of critical chemical and physical transformations associated with trace element behavior in IGCC and IGFC systems. The trace elements included in this project are arsenic, chromium, cadmium, mercury, nickel, selenium, and lead. The research seeks to identify and fill, experimentally and/or theoretically, data gaps that currently exist on the fate and composition of trace elements. The specific objectives are to (1) review the existing literature to identify the type and quantity of trace elements from coal gasification systems, (2) perform laboratory-scale experimentation and computer modeling to enable prediction of trace element emissions, and (3) identify methods to control trace element emissions.

  4. Trace metal transformations in gasification

    SciTech Connect

    Benson, S.A.; Erickson, T.A.; O`Keefe, C.A.; Katrinak, K.; Allan, S.E.; Hassett, D.J.; Hauserman, W.B.; Zygarlicke, C.J.

    1995-11-01

    The Energy and Environmental Research Center (EERC) is carrying out an investigation that will provide methods to predict the fate of selected trace elements in integrated gasification combined cycle (IGCC) and integrated gasification fuel cell (IGFC) systems to aid in the development of methods to control the emission of trace elements determined to be air toxics. The goal of this project is to identify the effects of critical chemical and physical transformations associated with trace element behavior in IGCC and IGFC systems. The trace elements included in this project are arsenic, chromium, cadmium, mercury, nickel, selenium, and lead. The research seeks to identify and fill, experimentally and/or theoretically, data gaps that currently exist on the fate and composition of trace elements. The specific objectives are to (1) review the existing literature to identify the type and quantity of trace elements from coal gasification systems; (2) perform laboratory-scale experimentation and computer modeling to enable prediction of trace element emissions; and (3) identify methods to control trace element emissions. Results are presented and discussed on the partitioning of trace metals and the model design for predicting trace metals behavior.

  5. Trace metal transformations in gasification

    SciTech Connect

    Benson, S.; Erickson, T.A.; Zygarlicke, C.J.

    1995-12-01

    The Energy & Environmental Research Center (EERC) is carrying out an investigation that will provide methods to predict the fate of selected trace elements in integrated gasification combined cycle (IGCC) and integrated gasification fuel cell (IGFC) systems to aid in the development of methods to control the emission of trace elements determined to be air toxics. The goal of this project is to identify the effects of critical chemical and physical transformations associated with trace element behavior in IGCC and IGFC systems. The trace elements included in this project are arsenic, chromium, cadmium, mercury, nickel, selenium, and lead. The research seeks to identify and fill, experimentally and/or theoretically, data gaps that currently exist on the fate and composition of trace elements. The specific objectives are to (1) review the existing literature to identify the type and quantity of trace elements from coal gasification systems, (2) perform laboratory-scale experimentation and computer modeling to enable prediction of trace element emissions, and (3) identify methods to control trace element emissions.

  6. Trace metal transformation in gasification

    SciTech Connect

    Benson, S.A.; Erickson, T.A.; Zygarlicke, C.J.; O`Keefe, C.A.; Katrinak, K.A.; Allen, S.E.; Hassett, D.J.; Hauserman, W.B.; Holcombe, N.T.

    1996-12-31

    The Energy & Environmental Research Center (EERC) is carrying out an investigation that will provide methods to predict the fate of selected trace elements in integrated gasification combined cycle (IGCC) and integrated gasification fuel cell (IGFC) systems to aid in the development of methods to control the emission of trace elements determined to be air toxics. The goal of this project is to identify the effects of critical chemical and physical transformations associated with trace element behavior in IGCC and IGFC systems. The trace elements included in this project are arsenic, chromium, cadmium, mercury, nickel, selenium, and lead. The research seeks to identify and fill, experimentally and/or theoretically, data gaps that currently exist on the fate and composition of trace elements. The specific objectives are to 1) review the existing literature to identify the type and quantity of trace elements from coal gasification systems, 2) perform laboratory-scale experimentation and computer modeling to enable prediction of trace element emissions, and 3) identify methods to control trace element emissions.

  7. Co-gasification of biomass and plastics: pyrolysis kinetics studies, experiments on 100 kW dual fluidized bed pilot plant and development of thermodynamic equilibrium model and balances.

    PubMed

    Narobe, M; Golob, J; Klinar, D; Francetič, V; Likozar, B

    2014-06-01

    Thermo-gravimetric analysis (TGA) of volatilization reaction kinetics for 50 wt.% mixtures of plastics (PE) and biomass (wood pellets) as well as for 100 wt.% plastics was conducted to predict decomposition times at 850°C and 900°C using iso-conversional model method. For mixtures, agreement with residence time of dual fluidized bed (DFB) reactor, treated as continuous stirred-tank reactor (CSTR), was obtained at large conversions. Mono-gasification of plastics and its co-gasification with biomass were performed in DFB pilot plant, using olivine as heterogeneous catalyst and heat transfer agent. It was found that co-gasification led to successful thermochemical conversion of plastics as opposed to mono-gasification. Unknown flow rates were determined applying nonlinear regression to energy and mass balances acknowledging combustion fuel, air, steam, feedstock, but also exiting char, tar, steam and other components in DFB gasification unit. Water-gas shift equilibrium and methanol synthesis requirements were incorporated into gasification model, based on measurements. PMID:24736208

  8. Structure Based Predictive Model for Coal Char Combustion

    SciTech Connect

    Robert Hurt; Joseph Calo; Robert Essenhigh; Christopher Hadad

    2000-12-30

    This unique collaborative project has taken a very fundamental look at the origin of structure, and combustion reactivity of coal chars. It was a combined experimental and theoretical effort involving three universities and collaborators from universities outside the U.S. and from U.S. National Laboratories and contract research companies. The project goal was to improve our understanding of char structure and behavior by examining the fundamental chemistry of its polyaromatic building blocks. The project team investigated the elementary oxidative attack on polyaromatic systems, and coupled with a study of the assembly processes that convert these polyaromatic clusters to mature carbon materials (or chars). We believe that the work done in this project has defined a powerful new science-based approach to the understanding of char behavior. The work on aromatic oxidation pathways made extensive use of computational chemistry, and was led by Professor Christopher Hadad in the Department of Chemistry at Ohio State University. Laboratory experiments on char structure, properties, and combustion reactivity were carried out at both OSU and Brown, led by Principle Investigators Joseph Calo, Robert Essenhigh, and Robert Hurt. Modeling activities were divided into two parts: first unique models of crystal structure development were formulated by the team at Brown (PI'S Hurt and Calo) with input from Boston University and significant collaboration with Dr. Alan Kerstein at Sandia and with Dr. Zhong-Ying chen at SAIC. Secondly, new combustion models were developed and tested, led by Professor Essenhigh at OSU, Dieter Foertsch (a collaborator at the University of Stuttgart), and Professor Hurt at Brown. One product of this work is the CBK8 model of carbon burnout, which has already found practical use in CFD codes and in other numerical models of pulverized fuel combustion processes, such as EPRI's NOxLOI Predictor. The remainder of the report consists of detailed technical

  9. TEXACO GASIFICATION PROCESS - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    This report summarizes the evaluation of the Texaco Gasification Process (TGP) conducted under the U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation (SITE) Program. The Texaco Gasification Process was developed by Texaco Inc. The TGP is a comm...

  10. COAL GASIFICATION ENVIRONMENTAL DATA SUMMARY: TRACE ELEMENTS

    EPA Science Inventory

    The report summarizes trace element measurements made at several coal gasification facilities. Most of the measurements were made as part of EPA's source testing and evaluation program on low- and medium-Btu gasification. The behavior of trace elements is discussed in light of th...

  11. Updraft gasification of salmon processing waste

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this research is to judge the feasibility of gasification for the disposal of waste streams generated through salmon harvesting. Gasification is the process of converting carbonaceous materials into combustible “syngas” in a high temperature (above 700 °C), oxygen deficient environmen...

  12. Improved catalysts for carbon and coal gasification

    DOEpatents

    McKee, D.W.; Spiro, C.L.; Kosky, P.G.

    1984-05-25

    This invention relates to improved catalysts for carbon and coal gasification and improved processes for catalytic coal gasification for the production of methane. The catalyst is composed of at least two alkali metal salts and a particulate carbonaceous substrate or carrier is used. 10 figures, 2 tables.

  13. The effects of pre-oxidation of cellulose on the properties of chars for methane storage

    SciTech Connect

    Norton, F.J.; Love, G.D.; Hall, P.J.

    1994-12-31

    In the present economic climate and with ecological awareness at a high, the need for cheaper more environmentally friendly fuels has never been greater. Natural gas is an abundant and relatively clean burning fuel. It is conventionally stored at high pressures for transportation and for use as an alternative vehicle fuel, (Compressed Natural Gas (CNG) pressure is 3000 psi). Adsorbed Natural Gas (ANG) systems, which involve adsorption of gas onto porous media, (operating pressure, 500 psi), have emerged as a viable alternative to CNG for use as a storage system for natural gas as a vehicle fuel. The methane is stored in the micropores (<20 {Angstrom}) of the adsorbent where the physical forces are such that the methane is at a higher density than that of liquid methane. Weaker forces in the meso (20-200 {Angstrom}) and macro-pores (>200 {Angstrom}) mean that compressed gas at 500 psi only is stored in them. Since a finite volume (i.e. storage vessel) of adsorbent can be utilised, it is important that the adsorbent not only possesses high levels of microporosity, but that it is also of a high enough density. Activated Carbons contain high levels of microporosity and can be produced with satisfactorily high densities to be good adsorbents for methane storage. However, the process of creating an activated carbon generally involves gasification of the char with CO{sub 2}, O{sub 2} or H{sub 2}O in order to increase the overall surface area. This treatment tends to widen the porosity and thus produce higher levels of meso- and macro-pores. By paying more attention to the precursor and the effects of altering its structure on the carbon produced, it may be possible to produce a more uniform microporosity. It was therefore decided to take pure cellulose and change its structure through air oxidation, observing any changes in the porosity of the resultant carbon produced.

  14. Steam gasification of waste tyre: Influence of process temperature on yield and product composition

    SciTech Connect

    Portofino, Sabrina; Donatelli, Antonio; Iovane, Pierpaolo; Innella, Carolina; Civita, Rocco; Martino, Maria; Matera, Domenico Antonio; Russo, Antonio; Cornacchia, Giacinto; Galvagno, Sergio

    2013-03-15

    Highlights: ► Steam gasification of waste tyre as matter and energy recovery treatment. ► Process temperature affects products yield and gas composition. ► High temperature promotes hydrogen production. ► Char exploitation as activated carbon or carbon source. - Abstract: An experimental survey of waste tyre gasification with steam as oxidizing agent has been conducted in a continuous bench scale reactor, with the aim of studying the influence of the process temperature on the yield and the composition of the products; the tests have been performed at three different temperatures, in the range of 850–1000 °C, holding all the other operational parameters (pressure, carrier gas flow, solid residence time). The experimental results show that the process seems promising in view of obtaining a good quality syngas, indicating that a higher temperature results in a higher syngas production (86 wt%) and a lower char yield, due to an enhancement of the solid–gas phase reactions with the temperature. Higher temperatures clearly result in higher hydrogen concentrations: the hydrogen content rapidly increases, attaining values higher than 65% v/v, while methane and ethylene gradually decrease over the range of the temperatures; carbon monoxide and dioxide instead, after an initial increase, show a nearly constant concentration at 1000 °C. Furthermore, in regards to the elemental composition of the synthesis gas, as the temperature increases, the carbon content continuously decreases, while the oxygen content increases; the hydrogen, being the main component of the gas fraction and having a small atomic weight, is responsible for the progressive reduction of the gas density at higher temperature.

  15. STRUCTURE-BASED PREDICTIVE MODEL FOR COAL CHAR COMBUSTION

    SciTech Connect

    CHRISTOPHER M. HADAD; JOSEPH M. CALO; ROBERT H. ESSENHIGH; ROBERT H. HURT

    1999-01-13

    Significant progress continued to be made during the past reporting quarter on both major technical tasks. During the reporting period at OSU, computational investigations were conducted of addition vs. abstraction reactions of H, O(3 P), and OH with monocyclic aromatic hydrocarbons. The potential energy surface for more than 80 unique reactions of H, O ( 3 P), and OH with aromatic hydrocarbons were determined at the B3LYP/6-31G(d) level of theory. The calculated transition state barriers and reaction free energies indicate that the addition channel is preferred at 298K, but that the abstraction channel becomes dominant at high temperatures. The thermodynamic preference for reactivity with aromatic hydrocarbons increases in the order O(3 P) < H < OH. Abstraction from six-membered aromatic rings is more facile than abstraction from five-membered aromatic rings. However, addition to five-membered rings is thermodynamically more favorable than addition to six-membered rings. The free energies for the abstraction and addition reactions of H, O, and OH with aromatic hydrocarbons and the characteristics of the respective transition states can be used to calculate the reaction rate constants for these important combustion reactions. Experimental work at Brown University on the effect of reaction on the structural evolution of different chars (i.e., phenolic resin char and chars produced from three different coals) have been investigated in a TGA/TPD-MS system. It has been found that samples of different age of these chars appeared to lose their "memory" concerning their initial structures at high burn-offs. During the reporting period, thermal desorption experiments of selected samples were conducted. These spectra show that the population of low temperature oxygen surface complexes, which are primarily responsible for reactivity, are more similar for the high burn-off than for the low burn-off samples of different ages; i.e., the population of active sites are more

  16. Life Cycle Assessment of Biochar - EuroChar Project

    NASA Astrophysics Data System (ADS)

    Rack, M.; Woods, J.

    2012-04-01

    One of the most significant challenges faced by modern-day society is that of global warming. An exclusive focus on reducing the greenhouse gas (GHG) emissions will not suffice and therefore technologies capable of removing CO2 directly from the atmosphere at low or minimal cost are gaining increased attention. The production and use of biochar is an example of such an emerging mitigation strategy. However, as with any novel product, process and technology it is vital to conduct an assessment of the entire life cycle in order to determine the environmental impacts of the new concept in addition to analysing the other sustainability criteria. Life Cycle Assessment (LCA), standardized by ISO (2006a), is an example of a tool used to calculate the environmental impacts of a product or process. Imperial College London will follow the guidelines and recommendations of the ISO 14040 series (ISO 2002, ISO 2006a-b) and the International Life Cycle Data System (ILCD) Handbook (EC JRC IES, 2010a-e), and will use the SimaPro software to conduct a LCA of the biochar supply chains for the EuroChar project. EuroChar ('biochar for Carbon sequestration and large-scale removal of GHG from the atmosphere') is a project funded by the European Commission under its Seventh Framework Programme (FP7). EuroChar aims to investigate and reduce uncertainties around the impacts of, and opportunities for, biochar and, in particular, explore a possible introduction into modern agricultural systems in Europe, thereby moving closer to the determination of the true potential of biochar. EuroChar will use various feedstocks, ranging from wheat straw to olive residues and poplar, as feedstocks for biochar production and will focus on two conversion technologies, Hydrothermal Carbonization (HTC) and Thermochemical Carbonization (TC), followed by the application of the biochar in crop-growth field trials in England, France and Italy. In April 2012, the EuroChar project will be at its halfway mark and

  17. Gasification Product Improvement Facility (GPIF)

    SciTech Connect

    Sadowski, R.S.; Brooks, K.S.; Skinner, W.H.; Brown, M.J.

    1992-11-01

    The objective is to provide a test facility to support early commercialization of advanced fixed-bed coal gasification technology electric power generation applications. The proprietary CRS Sirrine Engineers, Inc. PyGas{trademark} staged gasifier has been selected as the initial gasifier to be developed under this program. The gasifier is expected to avoid agglomeration when used on caking coals. It is also being designed to crack tar vapors and ammonia, and to provide an environment in which volatilized alkali may condense onto aluminosilicates in the coal ash thereby minimizing their exiting with the hot raw coal gas and passing through the system to the gas turbine. The management plan calls for a three phased program. The initial phase (Phase 1), includes the CRS Sinine Engineers, Inc. proprietary gasification invention called PyGas{trademark}, necessary coal and limestone receiving/storage/reclaim systems to allow closely metered coal and limestone to be fed into the gasifier for testing. The coal gas is subsequently piped to and combusted in an existing burner of the Monongahela Power Fort Martin Generating Station Unit No. 2. Continuous gasification process steam is generated by a small GPIF packaged boiler using light oil fuel at startup, and by switching from light oil to coal gas after startup. The major peripheral equipment such as foundations, process water system, ash handling, ash storage silo, emergency vent pipe, building, lavatory, electrical interconnect, control room, provisions for Phases II & III, and control system are all included in Phase I. A future hot gas cleanup unit conceptualized to be a zinc ferrite based fluidized bed process constitutes the following phase (Phase H). The final phase (Phase III) contemplates the addition of a combustion turbine and generator set sized to accommodate the parasitic load of the entire system.

  18. Gasification Product Improvement Facility (GPIF)

    SciTech Connect

    Sadowski, R.S.; Brooks, K.S.; Skinner, W.H.; Brown, M.J.

    1992-01-01

    The objective is to provide a test facility to support early commercialization of advanced fixed-bed coal gasification technology electric power generation applications. The proprietary CRS Sirrine Engineers, Inc. PyGas[trademark] staged gasifier has been selected as the initial gasifier to be developed under this program. The gasifier is expected to avoid agglomeration when used on caking coals. It is also being designed to crack tar vapors and ammonia, and to provide an environment in which volatilized alkali may condense onto aluminosilicates in the coal ash thereby minimizing their exiting with the hot raw coal gas and passing through the system to the gas turbine. The management plan calls for a three phased program. The initial phase (Phase 1), includes the CRS Sinine Engineers, Inc. proprietary gasification invention called PyGas[trademark], necessary coal and limestone receiving/storage/reclaim systems to allow closely metered coal and limestone to be fed into the gasifier for testing. The coal gas is subsequently piped to and combusted in an existing burner of the Monongahela Power Fort Martin Generating Station Unit No. 2. Continuous gasification process steam is generated by a small GPIF packaged boiler using light oil fuel at startup, and by switching from light oil to coal gas after startup. The major peripheral equipment such as foundations, process water system, ash handling, ash storage silo, emergency vent pipe, building, lavatory, electrical interconnect, control room, provisions for Phases II III, and control system are all included in Phase I. A future hot gas cleanup unit conceptualized to be a zinc ferrite based fluidized bed process constitutes the following phase (Phase H). The final phase (Phase III) contemplates the addition of a combustion turbine and generator set sized to accommodate the parasitic load of the entire system.

  19. Synfuels environmental research program for high-Btu coal gasification: health effects summary report

    SciTech Connect

    Reilly, C.A. Jr.; Wilzbach, K.E.; Stetter, J.R.; Haugen, D.A.; Kirchner, F.R.; Stamoudis, V.C.; Peak, M.J.; Matsushita, T.; Boparai, A.S.; Jones, R.E.

    1986-10-01

    Process materials from two coal gasification pilot plants were evaluated for their toxicologic potential by investigators in the Synfuels Environmental Research Program at Argonne National Laboratory. The process samples were collected at the HYGAS fluidized-bed gasifier operated by the Institute of Gas Technology (Chicago, IL) and at a slagging fixed-bed gasifier at the University of North Dakota Energy Research Center (UNDERC; Grand Forks, ND). A tiered approach was used or the toxicologic evaluation. The cytotoxicity and genotoxicity of the materials were first assessed with a battery of short-term cellular screening assays. Selected toxic materials were then studied in a number of acute and chronic whole-animal toxicity assays, including tests of carcinogenicity. In the screening assays, a number of materials from both gasifiers were found to be genotoxic and cytotoxic. All HYGAS materials except quench waters yielded nonvolatile organic (NVO) fractions containing mutagenic components as determined in the Ames Salmonella assay. Fewer materials were tested in whole-animal assays. HYGAS recycle oil was slightly toxic in an acute oral toxicity assay (LD/sub 50/ was 1.3 g/kg). HYGAS recycle oil and char slurry oil caused dermal response in rabbits. NVO fractions of a HYGAS LTR gas condensate, pretreater quench water, char slurry oil, cyclone slurry, and recycle oil were eye irritants. HYGAS recycle oil and UNDERC tar were dermal carcinogens in mice.

  20. Mild Cognitive Impairment

    MedlinePlus

    ... Research Portfolio (IADRP) AMP-AD Detecting Cognitive Impairment Database ... Mild cognitive impairment (MCI) is a condition in which people have more memory or other thinking problems than normal for their ...

  1. Mild Cognitive Impairment

    MedlinePlus

    ... other people their age. This condition is called mild cognitive impairment, or MCI. People with MCI can take care of themselves and do their normal activities. MCI memory problems may include Losing things often Forgetting ...

  2. Formation of hydrothermal biochar and char stability in soils

    NASA Astrophysics Data System (ADS)

    Baumert, Julia; Gleixner, Gerd

    2010-05-01

    The use of charcoal as an artificial soil additive is suggested to beneficially modify degraded soil, reduce greenhouse gas emission and improve crop yields. So far research has been mainly done using pyrolysis chars which are produced by dry pyrolysis of biomass. Here we used hydrothermal carbonisation (HTC). In this process wet biomass is converted to char at moderate temperatures (~200°C). Due to the exothermal carbonisation reaction this process is almost energy neutral, i.e. the energy needed to start the carbonisation equals the energy released during carbonisation. Different process parameters have been used to modify the properties of the produced chars. We examined the chemical and morphological properties of hydrothermally synthesized biochar. Cellulose, yeast and sucrose were used as model substances for a range of parent material types like organic and garden waste as well as residues from biogas production. By modifying the process conditions of hydrothermal carbonisation concerning temperature (180°C to 220°C) and duration (6 hours to 24 hours) we produced a variety of different biochars. Our findings suggest that the elemental composition and the thermal stability of resulting chars depend on the feedstock and production conditions. Functional group chemistry determined by NMR shows that the aromaticity of the product increases as a function of temperature whereas the amount of O-alkylic compounds declines, concurrently. Our results show that the properties of the biochar can be manipulated by the modification of process conditions. This opens the opportunity to adjust the charcoal to a given soil type.

  3. Environmentally Safe, Large Volume Utilization Applications for Gasification Byproducts

    SciTech Connect

    J.G. Groppo; R. Rathbone

    2008-06-30

    Samples of gasification by-products produced at Polk Station and Eastman Chemical were obtained and characterized. Bulk samples were prepared for utilization studies by screening at the appropriate size fractions where char and vitreous frit distinctly partitioned. Vitreous frit was concentrated in the +20 mesh fraction while char predominated in the -20+100 mesh fraction. The vitreous frit component derived from each gasifier slag source was evaluated for use as a pozzolan and as aggregate. Pozzolan testing required grinding the frit to very fine sizes which required a minimum of 60 kwhr/ton. Grinding studies showed that the energy requirement for grinding the Polk slag were slightly higher than for the Eastman slag. Fine-ground slag from both gasifiers showed pozzoalnic activity in mortar cube testing and met the ASTM C618 strength requirements after only 3 days. Pozzolanic activity was further examined using British Standard 196-5, and results suggest that the Polk slag was more reactive than the Eastman slag. Neither aggregate showed significant potential for undergoing alkali-silica reactions when used as concrete aggregate with ASTM test method 1260. Testing was conducted to evaluate the use of the frit product as a component of cement kiln feed. The clinker produced was comprised primarily of the desirable components Ca{sub 3}SiO{sub 5} and Ca{sub 2}SiO{sub 4} after raw ingredient proportions were adjusted to reduce the amount of free lime present in the clinker. A mobile processing plant was designed to produce 100 tons of carbon from the Eastman slag to conduct evaluations for use as recycle fuel. The processing plant was mounted on a trailer and hauled to the site for use. Two product stockpiles were generated; the frit stockpile contained 5% LOI while the carbon stockpile contained 62% LOI. The products were used to conduct recycle fuel tests. A processing plant was designed to separate the slag produced at Eastman into 3 usable products. The coarse frit

  4. Structure-Based Predictive model for Coal Char Combustion.

    SciTech Connect

    Hurt, R.; Colo, J; Essenhigh, R.; Hadad, C; Stanley, E.

    1997-09-24

    During the third quarter of this project, progress was made on both major technical tasks. Progress was made in the chemistry department at OSU on the calculation of thermodynamic properties for a number of model organic compounds. Modelling work was carried out at Brown to adapt a thermodynamic model of carbonaceous mesophase formation, originally applied to pitch carbonization, to the prediction of coke texture in coal combustion. This latter work makes use of the FG-DVC model of coal pyrolysis developed by Advanced Fuel Research to specify the pool of aromatic clusters that participate in the order/disorder transition. This modelling approach shows promise for the mechanistic prediction of the rank dependence of char structure and will therefore be pursued further. Crystalline ordering phenomena were also observed in a model char prepared from phenol-formaldehyde carbonized at 900{degrees}C and 1300{degrees}C using high-resolution TEM fringe imaging. Dramatic changes occur in the structure between 900 and 1300{degrees}C, making this char a suitable candidate for upcoming in situ work on the hot stage TEM. Work also proceeded on molecular dynamics simulations at Boston University and on equipment modification and testing for the combustion experiments with widely varying flame types at Ohio State.

  5. Microstructural evolution of char under oxidation induced by uneven heating

    SciTech Connect

    Kantorovich, I.I.; Bar-Ziv, E. |

    1996-04-01

    Single spherical char particles were intentionally irradiated nonuniformly in an electrodynamic chamber, in the temperature range 600--1,000 K. The char particles were irradiated from one side (bottom) and consequently heated unevenly. Nonuniform shrinkage of an initially spherical char particle has been observed during oxidation. The features of nonuniform shrinkage are rather peculiar: (1) up to 40%--60% conversion, the particle shrank uniformly. Then spatial preferential consumption initiated, indicating the threshold nature of the phenomenon; (2) preferential consumption, in most experiments, was observed to start from the top of the particle; (3) above the threshold conversion, a disk structure became clear; (4) at very high conversion the particle became like a center-hole doughnut. A model was developed to explain these features by nonuniform transformation of the micropore structure due to oxidation of the unevenly heated particle. The threshold nature of the phenomenon was also explained in terms of the dynamic stability of a particle. The threshold of nonuniform shrinkage corresponds to the transition of the particle to a stable position. After initiation of nonuniform shrinkage, the macroporosity distribution inside the particle becomes nonuniform. Macroporosity was shown to increase near the particle`s center; this eventually creates a hole at high conversion. The good agreement of modeling results with experimental observation confirms the notion that nonuniform shrinkage in regime 1 (kinetically controlled) is an indication of the fundamental microstructural transformations in the course of oxidation.

  6. Improving the quality of waste-derived char by removing ash.

    PubMed

    Hwang, I H; Nakajima, D; Matsuto, T; Sugimoto, T

    2008-01-01

    This study characterized and removed ash from waste-derived char to improve the quality of char as fuel. Municipal solid waste (MSW) and automobile shredder residue (ASR) were carbonized at 450 degrees C and at 500 degrees C, respectively, in a rotary kiln with a nitrogen atmosphere for 1h. MSW and ASR char were subjected to sieving and pulverization-sieving to screen incombustibles and the ash-rich fraction, after which float-sink separation, froth floatation, and oil agglomeration were applied to remove ash from the char. The established target quality was (1) less than 30% ash content and (2) more than 20,000 kJ/kg heating value. However, the rate of combustibles recovery had to be lowered to produce a good quality of char along with a high heating value. MSW char attained the targeted quality level using froth floatation or oil agglomeration, whereas, neither separation method was able to make ASR-derived char satisfy the target. Based on the assumption that particle properties of char are determined by the weight ratio of combustibles and ash, the densities of combustibles and ash in char were estimated using the results of float-sink separation, X-ray diffraction (XRD) analysis, and elemental content. To verify the above assumption, an energy dispersive X-ray/scanning electron microscope (EDX/SEM) analyzer was used to observe char particles. PMID:17317141

  7. Apparatus for solar coal gasification

    DOEpatents

    Gregg, D.W.

    1980-08-04

    Apparatus for using focused solar radiation to gasify coal and other carbonaceous materials is described. Incident solar radiation is focused from an array of heliostats through a window onto the surface of a moving bed of coal, contained within a gasification reactor. The reactor is designed to minimize contact between the window and solids in the reactor. Steam introduced into the gasification reactor reacts with the heated coal to produce gas consisting mainly of carbon monoxide and hydrogen, commonly called synthesis gas, which can be converted to methane, methanol, gasoline, and other useful products. One of the novel features of the invention is the generation of process steam in one embodiment at the rear surface of a secondary mirror used to redirect the focused sunlight. Another novel feature of the invention is the location and arrangement of the array of mirrors on an inclined surface (e.g., a hillside) to provide for direct optical communication of said mirrors and the carbonaceous feed without a secondary redirecting mirror.

  8. Integration of coal gasification and waste heat recovery from high temperature steel slags: an emerging strategy to emission reduction

    NASA Astrophysics Data System (ADS)

    Sun, Yongqi; Sridhar, Seetharaman; Liu, Lili; Wang, Xidong; Zhang, Zuotai

    2015-11-01

    With the continuous urbanization and industrialization in the world, energy saving and greenhouse gas (GHG) emission reduction have been serious issues to be addressed, for which heat recovery from traditional energy-intensive industries makes up a significant strategy. Here we report a novel approach to extract the waste heat and iron from high temperature steel slags (1450-1650 oC) produced in the steel industry, i.e., integration of coal gasification and steel slag treatment. Both the thermodynamics and kinetics of the pertinent reactions were identified. It was clarified that the kinetic mechanism for gasification varied from A2 model to A4 model (Avrami-Erofeev) in the presence of slags. Most importantly, the steel slags acted not only as good heat carriers but also as effective catalysts where the apparent activation energy for char gasification got remarkably reduced from 95.7 kJ/mol to 12.1 kJ/mol (A2 model). Furthermore, the FeO in the slags was found to be oxidized into Fe3O4, with an extra energy release, which offered a potential for magnetic separation. Moreover, based on the present research results, an emerging concept, composed of multiple industrial sectors, was proposed, which could serve as an important route to deal with the severe environmental problems in modern society.

  9. Integration of coal gasification and waste heat recovery from high temperature steel slags: an emerging strategy to emission reduction

    PubMed Central

    Sun, Yongqi; Sridhar, Seetharaman; Liu, Lili; Wang, Xidong; Zhang, Zuotai

    2015-01-01

    With the continuous urbanization and industrialization in the world, energy saving and greenhouse gas (GHG) emission reduction have been serious issues to be addressed, for which heat recovery from traditional energy-intensive industries makes up a significant strategy. Here we report a novel approach to extract the waste heat and iron from high temperature steel slags (1450–1650 oC) produced in the steel industry, i.e., integration of coal gasification and steel slag treatment. Both the thermodynamics and kinetics of the pertinent reactions were identified. It was clarified that the kinetic mechanism for gasification varied from A2 model to A4 model (Avrami-Erofeev) in the presence of slags. Most importantly, the steel slags acted not only as good heat carriers but also as effective catalysts where the apparent activation energy for char gasification got remarkably reduced from 95.7 kJ/mol to 12.1 kJ/mol (A2 model). Furthermore, the FeO in the slags was found to be oxidized into Fe3O4, with an extra energy release, which offered a potential for magnetic separation. Moreover, based on the present research results, an emerging concept, composed of multiple industrial sectors, was proposed, which could serve as an important route to deal with the severe environmental problems in modern society. PMID:26558350

  10. Integration of coal gasification and waste heat recovery from high temperature steel slags: an emerging strategy to emission reduction.

    PubMed

    Sun, Yongqi; Sridhar, Seetharaman; Liu, Lili; Wang, Xidong; Zhang, Zuotai

    2015-01-01

    With the continuous urbanization and industrialization in the world, energy saving and greenhouse gas (GHG) emission reduction have been serious issues to be addressed, for which heat recovery from traditional energy-intensive industries makes up a significant strategy. Here we report a novel approach to extract the waste heat and iron from high temperature steel slags (1450-1650 (o)C) produced in the steel industry, i.e., integration of coal gasification and steel slag treatment. Both the thermodynamics and kinetics of the pertinent reactions were identified. It was clarified that the kinetic mechanism for gasification varied from A2 model to A4 model (Avrami-Erofeev) in the presence of slags. Most importantly, the steel slags acted not only as good heat carriers but also as effective catalysts where the apparent activation energy for char gasification got remarkably reduced from 95.7 kJ/mol to 12.1 kJ/mol (A2 model). Furthermore, the FeO in the slags was found to be oxidized into Fe3O4, with an extra energy release, which offered a potential for magnetic separation. Moreover, based on the present research results, an emerging concept, composed of multiple industrial sectors, was proposed, which could serve as an important route to deal with the severe environmental problems in modern society. PMID:26558350

  11. The role of catalyst precursor anions in coal gasification. Final technical report, September 1991--June 1994

    SciTech Connect

    Abotsi, G.M.K.

    1995-01-01

    The utilization of coal is currently limited by several factors, including the environmental impacts of coal use and the lack of cost-effective technologies to convert coal into useful gaseous and liquid products. Several catalysts have been evaluated for coal gasification and liquefaction. The activities of the catalysts are dependent on many factors such as the method of catalyst addition to the coal and the catalyst precursor type. Since catalyst addition to coal is frequently conducted in aqueous solution, the surface chemistry of colloidal coal particles will be expected to exert an influence on catalyst uptake. However, the effects of the various coal gasification catalyst precursors on the interfacial properties of coal during catalyst loading from solution has received little attention. The aim of this study is to ascertain the influence of the metal salts (i): calcium acetate (Ca(OOCCH{sub 3}){sub 2}), calcium chloride (CaCl{sub 2}) or calcium nitrate (Ca(NO{sub 3}){sub 2}) and (ii): potassium acetate (KOOCCH{sub 3}), potassium chloride (KCl), potassium nitrate (KNO{sub 3}), potassium carbonate (K{sub 2}CO{sub 3}) and potassium sulfate (K{sub 2}SO{sub 4}) on the electrokinetic and adsorptive properties of coal and determine the relationship, if any, between coal surface electrokinetic properties, and catalyst loading and eventually its effects on the reactivities of coal chars.

  12. Utilisation of biomass gasification by-products for onsite energy production.

    PubMed

    Vakalis, S; Sotiropoulos, A; Moustakas, K; Malamis, D; Baratieri, M

    2016-06-01

    Small scale biomass gasification is a sector with growth and increasing applications owing to the environmental goals of the European Union and the incentivised policies of most European countries. This study addresses two aspects, which are at the centre of attention concerning the operation and development of small scale gasifiers; reuse of waste and increase of energy efficiency. Several authors have denoted that the low electrical efficiency of these systems is the main barrier for further commercial development. In addition, gasification has several by-products that have no further use and are discarded as waste. In the framework of this manuscript, a secondary reactor is introduced and modelled. The main operating principle is the utilisation of char and flue gases for further energy production. These by-products are reformed into secondary producer gas by means of a secondary reactor. In addition, a set of heat exchangers capture the waste heat and optimise the process. This case study is modelled in a MATLAB-Cantera environment. The model is non-stoichiometric and applies the Gibbs minimisation principle. The simulations show that some of the thermal energy is depleted during the process owing to the preheating of flue gases. Nonetheless, the addition of a secondary reactor results in an increase of the electrical power production efficiency and the combined heat and power (CHP) efficiency. PMID:27118736

  13. Method of producing synthesis gas by underground gasification of coal using specific well configuration

    SciTech Connect

    Gash, B.W.; Arri, L.E.; Hunt, E.B. Jr.; Parrish, D.R.

    1987-03-10

    A method is described of producing synthesis gas by the underground gasification of coal in individual noninteracting cavities formed by the gasification of the coal in a thick coal seam which is generally horizontal under an overburden and wherein loose coal and char formed from the combustion of the coal in the seam have a known angle of repose. The seam is provided with an injection well positioned at an angle with respect to the horizontal of less than the angle of repose and with a production well positioned at an angle with respect to the horizontal of greater than the angle of repose but less than 90/sup 0/. The distance between the wells decreases toward the bottom of the seam. The method comprises linking the wells, initiating combustion near the bottom of the seam and thereby producing a cavity in the seam, introducing an oxygen-containing gas mixture into the seam through the injection well, and removing combustion products through the production well.

  14. Fluidized bed catalytic coal gasification process

    DOEpatents

    Euker, Jr., Charles A.; Wesselhoft, Robert D.; Dunkleman, John J.; Aquino, Dolores C.; Gouker, Toby R.

    1984-01-01

    Coal or similar carbonaceous solids impregnated with gasification catalyst constituents (16) are oxidized by contact with a gas containing between 2 volume percent and 21 volume percent oxygen at a temperature between 50.degree. C. and 250.degree. C. in an oxidation zone (24) and the resultant oxidized, catalyst impregnated solids are then gasified in a fluidized bed gasification zone (44) at an elevated pressure. The oxidation of the catalyst impregnated solids under these conditions insures that the bed density in the fluidized bed gasification zone will be relatively high even though the solids are gasified at elevated pressure and temperature.

  15. Fixed-bed gasification research using US coals. Volume 10. Gasification of Benton lignite

    SciTech Connect

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-05-01

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a cooperative effort by private industrial participants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) Group. This report is the tenth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of Benton lignite. The period of gasification test was November 1-8, 1983. 16 refs., 22 figs., 19 tabs.

  16. Adsorption of Cu(2+) and methyl orange from aqueous solutions by activated carbons of corncob-derived char wastes.

    PubMed

    Hou, Xiao-Xu; Deng, Qing-Fang; Ren, Tie-Zhen; Yuan, Zhong-Yong

    2013-12-01

    Corncob-derived char wastes (CCW) obtained from biomass conversion to syngas production through corncob steam gasification, which were often discarded, were utilized for preparation of activated carbon by calcination, and KOH and HNO3 activation treatments, on the view of environment protection and waste recycling. Their adsorption performance in the removal of heavy metal ions and dye molecules from wastewater was evaluated by using Cu(2+) and methyl orange (MO) as the model pollutant. The surface and structure characteristics of the CCW-based activated carbons (CACs) were investigated by N2 adsorption, CO2 adsorption, FT-IR, and He-TPD. The adsorption capacity varied with the activation methods of CACs and different initial solution concentrations, indicating that the adsorption behavior was influenced by not only the surface area and porosity but also the oxygen functional groups on the surface of the CACs. The equilibrium adsorption data were analyzed with the Langmuir, Freundlich, and Temkin isotherm models, and the adsorption kinetics was evaluated by the pseudo-first-order and pseudo-second-order models. PMID:23666685

  17. Combustion of Illinois coals and chars with natural gas. [Quarterly] technical report, March 1, 1992--May 31, 1992

    SciTech Connect

    Buckius, R.O.; Peters, J.E.; Krier, H.

    1992-10-01

    Combined combustion of coal and natural gas offers advantages compared to burning coal or natural gas alone. For example, low volatile coals or low volatile chars derived from treatment or gasification processes can be of limited use due to their poor flammability characteristics. However, the use of natural gas in conjunction with the solid fuel can provide the necessary ``volatiles`` to enhance the combustion. Additionally, natural gas provides a clean cofiring fuel source which can enhance the usefulness of coals with high sulfur content. Addition of natural gas may reduce SO{sub x} emissions through increased sulfur retention in the ash and reduce NO{sub x} emissions by varying local stoichiometry and temperature levels. This research program seeks to clarify the contributions and to identify the controlling mechanisms of coining natural gas with Illinois coal through studies of particle ignition, burning rates and ash characterization. The first two quarters focused on the ignition delay measurements and their analysis, along with the incorporation of particle porosity into the burning rate model. The emphasis of the third quarter was on a more detailed understanding of the burning rate process, as well as understanding of cofiring`s effects on sulfur retention. The contributions of particle burning area to the quantification of the particle burning mechanisms have been shown to be important and continue to be investigated. Ash samples for various methane concentrations under similar other conditions have shown positive trends in reducing S0{sub 2} emission through increased sulfur capture in the ash.

  18. Combustion of Illinois coals and chars with natural gas. Technical report, December 1, 1991--February 29, 1992

    SciTech Connect

    Buckinus, R.O.; Peters, J.E.; Krier, H.

    1992-08-01

    The combined combustion of coal and natural gas offers advantageous compared to burning coal or natural gas alone. For example, low volatile coals or low volatile chars derived from treatment or gasification processes can be of limited use due to their poor flammability characteristics. However, the use of natural gas in conjunction with the solid fuel can provide the necessary ``volatiles`` to enhance the combustion. Additionally, natural gas provides a clean cofiring fuel source which can enhance the usefulness of coals with high sulfur content. Addition of natural gas may reduce SO{sub x} emissions through increased sulfur retention in the ash and reduce NO{sub x} emissions by varying local stoichiometry and temperature levels. In this research program, studies of combined Illinois coal and natural gas combustion provide particle ignition, burnout rates and ash characterization, helping clarify the effect of coal and natural gas and identify the controlling parameters and mechanisms. The Drop Tube Furnace Facility allows detailed measurements of coal particle combustion under well-controlled conditions. The combustion characteristics of single coal particles are determined through a novel set of diagnostic techniques including in situ simultaneous measurements of particle morphology, temperature and velocity. The emphasis of the effort in the second quarter of this project was on the understanding of the ignition enhancement, burning rate processes during cofiring, and sulfur retention in the ash.

  19. Combustion of Illinois coals and chars with natural gas. Technical report, September 1, 1991--November 30, 1991

    SciTech Connect

    Buckius, R.O.

    1991-12-31

    There are applications where the combined combustion of coal and natural gas offers potential advantages over the use of either coal or natural gas alone. For example, low volatile coals or low volatile chars derived from treatment or gasification processes can be of limited use during to their poor flammability characteristics. However, the use of natural gas in conjunction with the solid fuel can provide the necessary ``volatiles`` to enhance the combustion. In addition, natural gas provides a clean fuel source of fuel which, in cofiring situations, can extend the usefulness of coals with high sulfur content. The addition of natural gas may reduce SO{sub x} emission through increased sulfur retention in the ash and reduce NO{sub x} emissions by varying local stoichiometry and temperature levels. In this research program, studies of combined coal and natural gas combustion will provide particle ignition, burnout rates and ash characterization, that will help clarify the effect of coal and natural gas and identify the controlling parameters and mechanisms.

  20. Toxicity of char residues produced in the co-pyrolysis of different wastes.

    PubMed

    Bernardo, Maria; Lapa, N; Gonçalves, M; Barbosa, R; Mendes, B; Pinto, F; Gulyurtlu, I

    2010-04-01

    Char residues produced in the co-pyrolysis of different wastes (plastics, pine biomass and used tyres) were characterized using chemical and toxicity assays. One part of the solid chars was submitted to extraction with dichloromethane (DCM) in order to reduce the toxicity of the char residues by removing organic contaminants. The different volatility fractions present in the extracted char (Char A) and in the raw char (Char B) were determined by progressive weight loss combustion. A selected group of heavy metals (Cd, Pb, Zn, Cu, Hg and As) was determined in both chars. The chars were subjected to the leaching test ISO/TS 21268 - 2, 2007 and the resulting eluates were further characterized by determining a group of inorganic parameters (pH, conductivity, Cd, Pb, Zn, Cu, Hg and As contents) and the concentrations of several organic contaminants (volatile aromatic hydrocarbons and alkyl phenols). An ecotoxicological characterization was also performed by using the bio-indicator Vibrio fischeri. The chemical and ecotoxicological results were analyzed according to the Council Decision 2003/33/CE and the criteria on the evaluation methods of waste ecotoxicity (CEMWE). The results obtained in this work indicated that the extraction with DCM is an effective method for the removal of organic contaminants of high to medium volatility from pyrolysis solid residues, thus decreasing their toxicity potential. Zn can be leached from the chars even after the DCM extraction treatment and can contribute to the ecotoxicity of the eluates obtained from chars. Both chars (treated and non treated with DCM) were classified as hazardous and ecotoxic wastes. PMID:19932606

  1. Advances in the shell coal gasification process

    SciTech Connect

    Doering, E.L.; Cremer, G.A.

    1995-12-31

    The Shell Coal Gasification Process (SCGP) is a dry-feed, oxygen-blown, entrained flow coal gasification process which has the capability to convert virtually any coal or petroleum coke into a clean medium Btu synthesis gas, or syngas, consisting predominantly of carbon monoxide and hydrogen. In SCGP, high pressure nitrogen or recycled syngas is used to pneumatically convey dried, pulverized coal to the gasifier. The coal enters the gasifier through diametrically opposed burners where it reacts with oxygen at temperatures in excess of 2500{degrees}F. The gasification temperature is maintained to ensure that the mineral matter in the coal is molten and will flow smoothly down the gasifier wall and out the slag tap. Gasification conditions are optimized, depending on coal properties, to achieve the highest coal to gas conversion efficiency, with minimum formation of undesirable byproducts.

  2. Catalysts for carbon and coal gasification

    DOEpatents

    McKee, Douglas W.; Spiro, Clifford L.; Kosky, Philip G.

    1985-01-01

    Catalyst for the production of methane from carbon and/or coal by means of catalytic gasification. The catalyst compostion containing at least two alkali metal salts. A particulate carbonaceous substrate or carrier is used.

  3. UTILIZATION OF LIGHTWEIGHT MATERIALS MADE FROM COAL GASIFICATION SLAGS

    SciTech Connect

    Unknown

    2000-04-24

    The integrated-gasification combined-cycle (IGCC) process is an emerging technology that utilizes coal for power generation and production of chemical feedstocks. However, the process generates large amounts of solid waste, consisting of vitrified ash (slag) and some unconverted carbon. In previous projects, Praxis investigated the utilization of ''as-generated'' slags for a wide variety of applications in road construction, cement and concrete production, agricultural applications, and as a landfill material. From these studies, we found that it would be extremely difficult for ''as-generated'' slag to find large-scale acceptance in the marketplace even at no cost because the materials it could replace were abundantly available at very low cost. It was further determined that the unconverted carbon, or char, in the slag is detrimental to its utilization as sand or fine aggregate. It became apparent that a more promising approach would be to develop a variety of value-added products from slag that meet specific industry requirements. This approach was made feasible by the discovery that slag undergoes expansion and forms a lightweight material when subjected to controlled heating in a kiln at temperatures between 1400 and 1700 F. These results confirmed the potential for using expanded slag as a substitute for conventional lightweight aggregates (LWA). The technology to produce lightweight and ultra-lightweight aggregates (ULWA) from slag was subsequently developed by Praxis with funding from the Electric Power Research Institute (EPRI), Illinois Clean Coal Institute (ICCI), and internal resources. The major objectives of the subject project are to demonstrate the technical and economic viability of commercial production of LWA and ULWA from slag and to test the suitability of these aggregates for, various applications. The project goals are to be accomplished in two phases Phase I, comprising the production of LWA and ULWA from slag at the large pilot scale, and

  4. UTILIZATION OF LIGHTWEIGHT MATERIALS MADE FROM COAL GASIFICATION SLAGS

    SciTech Connect

    1999-03-29

    The integrated-gasification combined-cycle (IGCC) process is an emerging technology that utilizes coal for power generation and production of chemical feedstocks. However, the process generates large amounts of solid waste, consisting of vitrified ash (slag) and some unconverted carbon. In previous projects, Praxis investigated the utilization of ''as-generated'' slags for a wide variety of applications in road construction, cement and concrete production, agricultural applications, and as a landfill material. From these studies, we found that it would be extremely difficult for ''as-generated'' slag to find large-scale acceptance in the marketplace even at no cost because the materials it could replace were abundantly available at very low cost. It was further determined that the unconverted carbon, or char, in the slag is detrimental to its utilization as sand or fine aggregate. It became apparent that a more promising approach would be to develop a variety of value-added products from slag that meet specific industry requirements. This approach was made feasible by the discovery that slag undergoes expansion and forms a lightweight material when subjected to controlled heating in a kiln at temperatures between 1400 and 1700 F. These results confirmed the potential for using expanded slag as a substitute for conventional lightweight aggregates (LWA). The technology to produce lightweight and ultra-lightweight aggregates (ULWA) from slag was subsequently developed by Praxis with funding from the Electric Power Research Institute (EPRI), Illinois Clean Coal Institute (ICCI), and internal resources. The major objectives of the subject project are to demonstrate the technical and economic viability of commercial production of LWA and ULWA from slag and to test the suitability of these aggregates for various applications. The project goals are to be accomplished in two phases: Phase I, comprising the production of LWA and ULWA from slag at the large pilot scale, and

  5. Utilization of lightweight materials made from coal gasification slags

    SciTech Connect

    1999-09-30

    The integrated-gasification combined-cycle (IGCC) process is an emerging technology that utilizes coal for power generation and production of chemical feedstocks. However, the process generates large amounts of solid waste, consisting of vitrified ash (slag) and some unconverted carbon. In previous projects, Praxis investigated the utilization of as-generated slags for a wide variety of applications in road construction, cement and concrete production, agricultural applications, and as a landfill material. From these studies, the authors found that it would be extremely difficult for as-generated slag to find large-scale acceptance in the marketplace even at no cost because the materials it could replace were abundantly available at very low cost. It was further determined that the unconverted carbon, or char, in the slag is detrimental to its utilization as sand or fine aggregate. It became apparent that a more promising approach would be to develop a variety of value-added products from slag that meet specific industry requirements. This approach was made feasible by the discovery that slag undergoes expansion and forms a lightweight material when subjected to controlled heating in a kiln at temperatures between 1,400 and 1,700 F. These results confirmed the potential for using expanded slag as a substitute for conventional lightweight aggregates (LWA). The technology to produce lightweight and ultra-lightweight aggregates (ULWA) from slag was subsequently developed by Praxis with funding from the Electric Power Research Institute (EPRI), Illinois Clean Coal Institute (ICCI), and internal resources. The major objectives of the subject project are to demonstrate the technical and economic viability of commercial production of LWA and ULWA from slag and to test the suitability of these aggregates for various applications. The project goals are to be accomplished in two phases: Phase 1, comprising the production of LWA and ULWA from slag at the large pilot scale

  6. CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES

    SciTech Connect

    Atul Sheth; Chandramouli Sastry

    2001-03-31

    Most of the tasks on the project have successfully been completed and reported. A 12 month no-cost extension has been requested to complete the remaining tasks. This report summarizes the accomplishments of the first six months of the no-cost extensions period. The acetic acid extraction showed that acetic acid has more effect on the extraction of the ternary catalyst (LNK) ions than water. Based on the extraction results, the order of the recovery capability of Na{sub 2}CO{sub 3} using acetic acid, sulfuric acid and water extractions is sulfuric acid {ge} acetic acid > water; the order for K{sub 2}CO{sub 3} is sulfuric acid > water >acetic acid; and the order for Li{sub 2}CO{sub 3} is acetic acid > sulfuric acid >water. A process flowsheet for the catalyst recovery process was proposed based on the results. Scanning electron microscopy (SEM) studies showed most of the particles (coal) appear amorphous. Some coal particles are as large as 50-60 {micro}m, but most are smaller. One can also easily see a few crystalline particles (10-20 {micro}m) with sharp facets and corners. The electron micrographs of gasified char samples (reactor-aged) of the LNKcoal mixture showed that a dramatic change is obvious in the morphology and crystallinity of the sample and is consistent with the results obtained from the x-ray diffraction studies. XRD studies of reactor-aged samples showed a substantial increase in the sample crystallinity (due to the gasification of amorphous carbon). The eutectic salt presumably mostly converted to sulfates.

  7. Sorption studies of Cr(VI) from aqueous solution using bio-char as an adsorbent.

    PubMed

    Hyder, A H M G; Begum, Shamim A; Egiebor, Nosa O

    2014-01-01

    The characteristics of sorption of hexavalent chromium (Cr(VI)) onto bio-char derived from wood chips (spruce, pine, and fir) were evaluated as a function of pH, initial Cr(VI) concentration and bio-char dosage using synthetic wastewater in batch tests. The initial Cr(VI) concentrations were varied between 10 and 500 mg/L to investigate equilibrium, kinetics, and isotherms of the sorption process. About 100% of Cr(VI) was removed at pH 2 with initial Cr(VI) concentration of 10 mg/L using 4 g of bio-char after 5 hours of sorption reaction. The maximum sorption capacity of the bio-char was 1.717 mg/g for an initial Cr(VI) concentration of 500 mg/L after 5 hours. The sorption kinetics of total Cr onto bio-char followed the second-order kinetic model. The Langmuir isotherm model provided the best fit for total Cr sorption onto bio-char. The bio-char used is a co-product of a down draft gasifier that uses the derived syngas to produce electricity. Bio-char as a low cost adsorbent demonstrated promising results for removal of Cr(VI) from aqueous solution. The findings of this study would be useful in designing a filtration unit with bio-char in a full-scale water and wastewater treatment plant for the Cr(VI) removal from contaminated waters. PMID:24901621

  8. [Genetic divergence of chars of the genus Salvelinus from Kronotsky Lake (Kamchatka Peninsula)].

    PubMed

    Salmenkova, E A; Omel'chenko, V T; Radchenko, O A; Gordeeva, N V; Rubtsova, G a; Romanov, N S

    2005-08-01

    Chars from the genus Salvelinus, inhabiting lakes and lake-river systems, belong to morphologically and ecologically different forms whose taxonomic status is under dispute. In the present work, we have examined genetic variation and divergence in various chars from the Kronotsky lake basin: the lacustrine chars (white, nose, and long-head) and Dolly Varden char Salvelinus malma. The study was conducted using analysis of allozyme and microsatellite loci, myogens, RAPD, and restriction analysis of two mtDNA segments. The estimates of heterozygoisty at allozyme and microsatellite loci were similar to the corresponding parameters in populations of northern Dolly Varden and Arctic char. Heterozygote deficit was recorded in both samples of individual forms, and in the combined sample of all chars from Kronotsky Lake. For both markers, appreciable genetic differentiation among the samples of different char forms was found, which was comparable to that among the spatially isolated populations of northern Dolly Varden. This result indicates reproductive isolation among the char forms examined. However, this isolation is not complete, because no fixed differences between the forms by any of the genetic systems analyzed was found. The genetic differentiation among different forms of lacustrine chars, which corresponds to the interpopulation rather than interspecies level, is thought to be explained by their comparatively recent divergence. PMID:16161631

  9. Production of activated char from Illinois coal for flue gas cleanup

    USGS Publications Warehouse

    Lizzio, A.A.; DeBarr, J.A.; Kruse, C.W.

    1997-01-01

    Activated chars were produced from Illinois coal and tested in several flue gas cleanup applications. High-activity chars that showed excellent potential for both SO2 and NOx removal were prepared from an Illinois No. 2 bituminous coal. The SO2 (120 ??C) and NOx (25 ??C) removal performance of one char compared favorably with that of a commercial activated carbon (Calgon Centaur). The NOx removal performance of the same char at 120 ??C exceeded that of the Centaur carbon by more than 1 order of magnitude. Novel char preparation methods were developed including oxidation/thermal desorption and hydrogen treatments, which increased and preserved, respectively, the active sites for SO2 and NOx adsorption. The results of combined SO2/NOx removal tests, however, suggest that SO2 and NOx compete for similar adsorption sites and SO2 seems to be more strongly adsorbed than NO. A low-activity, low-cost char was also developed for cleanup of incinerator flue gas. A three-step method involving coal preoxidation, pyrolysis, and CO2 activation was used to produce the char from Illinois coal. Five hundred pounds of the char was tested on a slipstream of flue gas from a commercial incinerator in Germany. The char was effective in removing >97% of the dioxins and furans present in the flue gas; mercury levels were below detectable limits.

  10. Kinetic modeling of inherent mineral catalyzed NO reduction by biomass char.

    PubMed

    Wu, X Y; Song, Q; Zhao, H B; Zhang, Z H; Yao, Q

    2014-04-01

    The evolution of rice straw char reactivity during reaction with NO was examined in differential reactor at 900 and 1000 °C. Original and acid-washed rice straw chars were used. Surface area and mineral content of char samples with different conversion were analyzed. The reactivity of the acid-washed char increased until conversion Xchar = 20%, remained constant, and then decreased continuously to zero. The reactivity of the original char decreased continuously to zero throughout the reaction, with a faster decrease at 1000 °C. Mineral transformation during original char reaction was obvious. Concentration of acid-soluble K decreased about 56% and 90% at 900 and 1000 °C. Ca and Mg released little to gas phase, but reacted with SiO2 in a small amount. The evolution of the acid-washed char reactivity correlated well with the development of surface area and was well predicted by random pore model. The reactivity of the original char depended not only on the development of surface area, but also on transformation of inherent minerals, mainly K. A two-reaction model was built which well predicted inherent K transformation. A modified random pore model was developed, which successfully simulated inherent mineral catalyzed char-NO reaction. PMID:24588459

  11. Activated carbon from char obtained from vacuum pyrolysis of teak sawdust: pore structure development and characterization.

    PubMed

    Ismadji, S; Sudaryanto, Y; Hartono, S B; Setiawan, L E K; Ayucitra, A

    2005-08-01

    The preparation of activated carbon from vacuum pyrolysis char of teak sawdust was studied and the results are presented in this paper. The effects of process variables such as temperature and activation time on the pore structure of activated carbons were studied. The activated carbon prepared from char obtained by vacuum pyrolysis has higher surface area and pore volume than that from atmospheric pyrolysis char. The BET surface area and pore volume of activated carbon prepared from vacuum pyrolysis char were 1150 m2/g and 0.43 cm3/g, respectively. PMID:15792584

  12. Influence of carbonization conditions on the pyrolytic carbon deposition in acacia and eucalyptus wood chars

    SciTech Connect

    Kumar, M.; Gupta, R.C.

    1997-04-01

    The amount of deposited pyrolytic carbon (resulting from the cracking of volatile matter) was found to depend on wood species and carbonization conditions, such as temperature and heating rate. Maximum pyrolytic carbon deposition in both the acacia and eucalyptus wood chars has been observed at a carbonization temperature of 800 C. Rapid carbonization (higher heating rate) of wood significantly reduces the amount of deposited pyrolytic carbon in resulting chars. Results also indicate that the amount of deposited pyrolytic carbon in acacia wood char is less than that in eucalyptus wood char.

  13. Coal gasification for electric power generation.

    PubMed

    Spencer, D F; Gluckman, M J; Alpert, S B

    1982-03-26

    The electric utility industry is being severely affected by rapidly escalating gas and oil prices, restrictive environmental and licensing regulations, and an extremely tight money market. Integrated coal gasification combined cycle (IGCC) power plants have the potential to be economically competitive with present commercial coal-fired power plants while satisfying stringent emission control requirements. The current status of gasification technology is discussed and the critical importance of the 100-megawatt Cool Water IGCC demonstration program is emphasized. PMID:17788466

  14. Investigation of plasma-aided bituminous coal gasification

    SciTech Connect

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

    2009-04-15

    This paper presents thermodynamic and kinetic modeling of plasma-aided bituminous coal gasification. Distributions of concentrations, temperatures, and velocities of the gasification products along the gasifier are calculated. Carbon gasification degree, specific power consumptions, and heat engineering characteristics of synthesis gas at the outlet of the gasifier are determined at plasma air/steam and oxygen/steam gasification of Powder River Basin bituminous coal. Numerical simulation showed that the plasma oxygen/steam gasification of coal is a more preferable process in comparison with the plasma air/steam coal gasification. On the numerical experiments, a plasma vortex fuel reformer is designed.

  15. On the burning behavior of pulverized coal chars

    SciTech Connect

    Mitchell, Reginald E.; Ma, Liqiang; Kim, BumJick

    2007-11-15

    A model that predicts the physical changes that pulverized coal char particles undergo during combustion has been developed. In the model, a burning particle is divided into a number of concentric annular volume elements. The mass loss rate, specific surface area, and apparent density in each volume element depend upon the local particle conditions, which vary as a consequence of the adsorbed oxygen and gas-phase oxygen concentration gradients inside the particle. The model predicts the particle's burning rate, temperature, diameter, apparent density, and specific surface area as combustion proceeds, given ambient conditions and initial char properties. A six-step heterogeneous reaction mechanism is used to describe carbon reactivity to oxygen. A distributed activation energy approach is used to account for the variation in desorption energies of adsorbed O-atoms on the carbonaceous surface. Model calculations support the three burning zones established for the oxidation of pulverized coal chars. The model indicates two types of zone II behavior, however. Under weak zone II burning conditions, constant-diameter burning occurs up to 30% to 50% conversion before burning commences with reductions in both size and apparent density. Under strong zone II conditions, particles burn with reductions in both size and apparent density after an initial short period (conversion) of constant-diameter burning. Model predictions reveal that early in the oxidation process, there is mass loss at constant diameter under all zone II burning conditions. Such weak and strong burning behavior cannot be predicted with the commonly used power-law model for the mode of burning employing a single value for the burning mode parameter. Model calculations also reveal how specific surface area evolves when oxidation occurs in the zone II burning regime. Based on the calculated results, a surface area submodel that accounts for the effects of pore growth and coalescence during combustion under

  16. Preparation of porous bio-char and activated carbon from rice husk by leaching ash and chemical activation.

    PubMed

    Ahiduzzaman, Md; Sadrul Islam, A K M

    2016-01-01

    Preparation porous bio-char and activated carbon from rice husk char study has been conducted in this study. Rice husk char contains high amount silica that retards the porousness of bio-char. Porousness of rice husk char could be enhanced by removing the silica from char and applying heat at high temperature. Furthermore, the char is activated by using chemical activation under high temperature. In this study no inert media is used. The study is conducted at low oxygen environment by applying biomass for consuming oxygen inside reactor and double crucible method (one crucible inside another) is applied to prevent intrusion of oxygen into the char. The study results shows that porous carbon is prepared successfully without using any inert media. The adsorption capacity of material increased due to removal of silica and due to the activation with zinc chloride compared to using raw rice husk char. The surface area of porous carbon and activated carbon are found to be 28, 331 and 645 m(2) g(-1) for raw rice husk char, silica removed rice husk char and zinc chloride activated rice husk char, respectively. It is concluded from this study that porous bio-char and activated carbon could be prepared in normal environmental conditions instead of inert media. This study shows a method and possibility of activated carbon from agro-waste, and it could be scaled up for commercial production. PMID:27536531

  17. Advanced High-Temperature, High-Pressure Transport Reactor Gasification

    SciTech Connect

    Michael L. Swanson

    2005-08-30

    50 hours of gasification on a petroleum coke from the Hunt Oil Refinery and an additional 73 hours of operation on a high-ash coal from India. Data from these tests indicate that while acceptable fuel gas heating value was achieved with these fuels, the transport gasifier performs better on the lower-rank feedstocks because of their higher char reactivity. Comparable carbon conversions have been achieved at similar oxygen/coal ratios for both air-blown and oxygen-blown operation for each fuel; however, carbon conversion was lower for the less reactive feedstocks. While separation of fines from the feed coals is not needed with this technology, some testing has suggested that feedstocks with higher levels of fines have resulted in reduced carbon conversion, presumably due to the inability of the finer carbon particles to be captured by the cyclones. These data show that these low-rank feedstocks provided similar fuel gas heating values; however, even among the high-reactivity low-rank coals, the carbon conversion did appear to be lower for the fuels (brown coal in particular) that contained a significant amount of fines. The fuel gas under oxygen-blown operation has been higher in hydrogen and carbon dioxide concentration since the higher steam injection rate promotes the water-gas shift reaction to produce more CO{sub 2} and H{sub 2} at the expense of the CO and water vapor. However, the high water and CO{sub 2} partial pressures have also significantly reduced the reaction of (Abstract truncated)

  18. WABASH RIVER COAL GASIFICATION REPOWERING PROJECT

    SciTech Connect

    Unknown

    2000-09-01

    The close of 1999 marked the completion of the Demonstration Period of the Wabash River Coal Gasification Repowering Project. This Final Report summarizes the engineering and construction phases and details the learning experiences from the first four years of commercial operation that made up the Demonstration Period under Department of Energy (DOE) Cooperative Agreement DE-FC21-92MC29310. This 262 MWe project is a joint venture of Global Energy Inc. (Global acquired Destec Energy's gasification assets from Dynegy in 1999) and PSI Energy, a part of Cinergy Corp. The Joint Venture was formed to participate in the Department of Energy's Clean Coal Technology (CCT) program and to demonstrate coal gasification repowering of an existing generating unit impacted by the Clean Air Act Amendments. The participants jointly developed, separately designed, constructed, own, and are now operating an integrated coal gasification combined-cycle power plant, using Global Energy's E-Gas{trademark} technology (E-Gas{trademark} is the name given to the former Destec technology developed by Dow, Destec, and Dynegy). The E-Gas{trademark} process is integrated with a new General Electric 7FA combustion turbine generator and a heat recovery steam generator in the repowering of a 1950's-vintage Westinghouse steam turbine generator using some pre-existing coal handling facilities, interconnections, and other auxiliaries. The gasification facility utilizes local high sulfur coals (up to 5.9% sulfur) and produces synthetic gas (syngas), sulfur and slag by-products. The Project has the distinction of being the largest single train coal gasification combined-cycle plant in the Western Hemisphere and is the cleanest coal-fired plant of any type in the world. The Project was the first of the CCT integrated gasification combined-cycle (IGCC) projects to achieve commercial operation.

  19. Digital image processing applications in the ignition and combustion of char/coal particles

    SciTech Connect

    Annamalai, K.; Kharbat, E.; Goplakrishnan, C.

    1992-12-01

    Digital image processing, is employed in this remarch study in order to visually investigate the ignition and combustion characteristics of isolated char/coal particles as well as the effect of interactivecombustion in two-particle char/coal arrays. Preliminary experiments are conducted on miniature isolated candles as well as two-candle arrays.

  20. CE IGCC Repowering Project char filters. Topical report, November 1990--May 1993

    SciTech Connect

    Krawczyk, P.D.

    1993-05-01

    The char filters are required to operate at 1000 degrees at a nominal internal pressure range of 256 to 294 psia. In the design used for estimating the demonstration plant, product gas and entrained char leave the gasifier heat exchanger at 1000{degrees}F and enter a char cyclone that separates a nominal 65% of the char from the product gas. The product gas and remaining char discharge the cyclone to two parallel char filters each sized to handle 50% of the gas and char load. The char filters resemble conventional cylindrical bag filter modules use for gas filtration. The 12-ft. diameter vessels are constructed of carbon steel with insulating refractory linings. The refractory in the cones is lined with stainless steel to promote flow. The filters are designed to use any of three different high temperature filter media. Each type of filter is available in common diameters, and the tube sheet is arranged for a single filter diameter. The tube sheet is designed to accommodate movement and stress due to thermal expansion and differential pressure excursions.

  1. Compositional and thermal evaluation of lignocellulosic and poultry litter chars via high and low temperature pyrolysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inorganic elements in biomass feedstocks can influence thermochemical reactions as well as the resultant chars elemental, compositional, and thermal characteristics. Chars were produced using slow pyrolysis at less than 400 and at higher than 500 degree Celsius from sugarcane bagasse, peanut hulls,...

  2. Removal of lead (Pb2+) from aqueous medium by using chars from co-pyrolysis.

    PubMed

    Bernardo, Maria; Mendes, Sandra; Lapa, Nuno; Gonçalves, Margarida; Mendes, Benilde; Pinto, Filomena; Lopes, Helena; Fonseca, Isabel

    2013-11-01

    The effectiveness of chars from the co-pyrolysis of pine, used tires and plastic wastes for the removal of lead (Pb(2+)) from aqueous medium, was investigated. The chars were predominantly of macroporous nature, but the introduction of tires in the pyrolysis feedstock enhanced their mesoporous content as well as surface area. Pb(2+) sorption with the chars was a slow and unstable process in which sorption-desorption seems to be competing. The highest Pb(2+) removal (88%) was attained by the char resulting from the pyrolysis of a mixture composed by equal mass ratios of used tires and plastics, at 48 h of contact time. This char was also the one with the overall better performance for Pb(2+) sorption, achieving almost 100% of Pb(2+) removal on the study of the effect of adsorbent dose. Mixing the three raw materials for pyrolysis had no advantage for the resulting char concerning the removal efficiency of Pb(2+). The sorption mechanisms varied according to the pyrolysis feedstock: in chars from feedstock with pine, chemisorption involving complexation with oxygenated surface functional groups followed by cation exchange was the presumable mechanism. In tire rubber derived chars, cation exchange with Ca(2+), K(+), and Zn(2+) played the major role on Pb(2+) sorption. PMID:23972502

  3. Studies of NO-char reaction kinetics obtained from drop-tube furnace and thermogravimetric experiments

    SciTech Connect

    Shaozeng Sun; Juwei Zhang; Xidong Hu; Shaohua Wu; Jiancheng Yang; Yang Wang; Yukun Qin

    2009-01-15

    Four coal chars were prepared in a flat flame flow reactor (FFR), which can simulate the temperature and gas composition of a real pulverized coal combustion environment. The pore structure of chars was measured by mercury porosimetry and nitrogen adsorption, and the Hg and Brunauer-Emmett-Teller (BET) surface areas were obtained. The kinetics of NO-char was studied in a drop-tube furnace (DTF) and thermogravimetric analyzer (TGA). In the TGA experiments, the random pore model (RPM) was applied to describe the NO-char reactions and obtain the intrinsic kinetics. By presenting the data of DTF and TGA experiments on the same Arrhenius plot, it can be concluded that TGA is an available tool to study the kinetics of a high-temperature NO-char reaction. With respect to the DTF experiments, in comparison to the BET surface area, the Hg surface area is a better basis for normalizing the reactivity of different coal chars because of less scatter in the measured values, better agreement with TGA experimental data, and more stable values during the process of reaction. Moreover, by comparing the Hg surface area of chars before and after reactions, it is believed that the Hg surface area basis is more appropriate for high-rank coal chars. The determined kinetic rate constants are in good agreement with other data in the literature, and a new rate constant expression is proposed. 30 refs., 8 figs., 7 tabs.

  4. Mercury adsorption of modified mulberry twig chars in a simulated flue gas.

    PubMed

    Shu, Tong; Lu, Ping; He, Nan

    2013-05-01

    Mulberry twig chars were prepared by pyrolysis, steam activation and impregnation with H2O2, ZnCl2 and NaCl. Textural characteristics and surface functional groups were performed using nitrogen adsorption and FTIR, respectively. Mercury adsorption of different modified MT chars was investigated in a quartz fixed-bed absorber. The results indicated that steam activation and H2O2-impregnation can improve pore structure significantly and H2O2-impregnation and chloride-impregnation promote surface functional groups. However, chloride-impregnation has adverse effect on pore structure. Mercury adsorption capacities of impregnated MT chars with 10% or 30% H2O2 are 2.02 and 1.77 times of steam activated MT char, respectively. Mercury adsorption capacity of ZnCl2-impregnated MT char increase with increasing ZnCl2 content and is better than that of NaCl-impregnated MT char at the same chloride content. The modified MT char (MT873-A-Z5) prepared by steam activation following impregnation with 5% ZnCl2 exhibits a higher mercury adsorption capacity (29.55 μg g(-1)) than any other MT chars. PMID:23567680

  5. Pathways for conversion of char nitrogen to nitric oxide during pulverized coal combustion

    SciTech Connect

    Molina, A.; Murphy, J.J.; Blevins, L.G.; Shaddix, C.R.; Winter, F.; Haynes, B.S.

    2009-03-15

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

  6. Influence of post-treatment strategies on the properties of activated chars from broiler manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are a myriad of carbonaceous precursors that can be used advantageously to produce activated carbons or chars, due to their low cost, availability and intrinsic properties. Because of the nature of the raw material, production of granular activated chars from broiler manure results in a signif...

  7. Effects and characterization of an environmentally-friendly, inexpensive composite Iron-Sodium catalyst on coal gasification

    NASA Astrophysics Data System (ADS)

    Monterroso, Rodolfo

    were studied through characterization tests. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Mossbauer spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), gas chromatography (GC-MS) and nuclear magnetic resonance spectroscopy (NMR) were used to perform the analyses. The XRD results are consistent with interactive mechanisms or the formation of Na-Fe oxides as the catalytic pathway. Activity of the iron catalyst during late stages of the gasification process was confirmed through XPS. Mossbauer spectroscopy also indicated the presence of metallic iron and cementite in the char at different stages. The Fe catalysts were better at tar decomposition than the Na catalysts, as indicated by GC-MS analyses. NMR spectra confirmed that tar compositions vary with the catalytic mechanism. FTIR analysis confirmed the presence of high yields of aromatic components and long aliphatic chains in the tar. Composite Fe-Na catalysts provide a method to tailor the amounts and composition of product generated during gasification.

  8. Solid fuel gasification in the global energy sector (a review)

    NASA Astrophysics Data System (ADS)

    Ol'khovskii, G. G.

    2015-07-01

    In the review of the Conference on Gasification of Solid Fuels, which was held on October 2013 by the United States, the commercial use of the most advanced coal gasification systems in the chemical and power industry is considered. Data on the projects of integrated solid fuel gasification combined-cycle plants, either being developed or exploited in the United States, as well as the nature and results performed in specialized organizations to improve the existing gasification equipment and systems, are presented.

  9. Influence of pressure on pyrolysis of black liquor: 2. Char yields and component release.

    PubMed

    Whitty, Kevin; Kullberg, Mika; Sorvari, Vesa; Backman, Rainer; Hupa, Mikko

    2008-02-01

    This is the second in a series of papers concerning the behavior of black liquor during pyrolysis at elevated pressures. Two industrial black liquors were pyrolyzed under pressurized conditions in two laboratory-scale devices, a pressurized single-particle reactor and a pressurized grid heater. Temperatures ranging between 650 and 1100 degrees C and pressures in the range 1-20 bar were studied. Char yields were calculated and based on analysis of some of the chars the fate of carbon, sodium, potassium and sulfur was determined as a function of pyrolysis pressure. At temperatures below 800 degrees C little variation in char yield was observed at different pressures. At higher temperatures char yield increased with pressure due to slower decomposition of sodium carbonate. For the same reason, sodium release decreased with pressure. Sulfur release, however, increased with pressure primarily because there was less opportunity for its capture in the less-swollen chars. PMID:17349787

  10. Fast pyrolysis char - Assessment of alternative uses within the bioliq® concept.

    PubMed

    Funke, A; Niebel, A; Richter, D; Abbas, M M; Müller, A-K; Radloff, S; Paneru, M; Maier, J; Dahmen, N; Sauer, J

    2016-01-01

    Experiments with a process development unit for fast pyrolysis of biomass residues of 10kgh(-1) have been performed to quantify the impact of two different product recovery options. Wheat straw, miscanthus and scrap wood have been used as feedstock. A separate recovery of char increases the organic oil yield as compared to a combined recovery of char and organic condensate (OC). Furthermore, it allows for an alternative use of the byproduct char which represents an important product fraction for the high ash biomass residues under consideration. The char produced shows little advantage over its biomass precursor when considered as energy carrier due to its high ash content. Significant value can be added by demineralizing and activating the char. The potential to increase the economic feasibility of fast pyrolysis is shown by an assessment of the bioliq® process chain. PMID:26609947

  11. Characterizations of Bio-char from Fast Pyrolysis of Meranti Wood Sawdust

    NASA Astrophysics Data System (ADS)

    Mazlan, M. A. F.; Uemura, Y.; Osman, N. B.; Yusup, S.

    2015-06-01

    In this research, Meranti wood sawdust (MWS) was pyrolyzed in a fixed bed drop- type pyrolyzer under an inert condition. The first part of the study is to determine the influence of pyrolysis temperature (450, 500 and 550 °C) on the yield of pyrolysis products. Pyrolysis of the waste MWS material generated the highest amount of bio-char with approximately 38 wt.% at pyrolysis temperature of 450 °C. Next, the char product (from pyrolysis at 450 °C) was analyzed to compare its characteristics with the raw MWS feedstock. The major component of the char is carbon element, significantly contributed to its high calorific value. TGA profile shows the MWS char could withstand high temperature of up to 400 °C. Under extensive heating, particle size of the bio-char from SEM images decreased due to breakage and shrinkage processes.

  12. Uses found for gasification slag

    SciTech Connect

    Not Available

    1986-12-01

    A study carried out for the Electric Power Research Institute by Praxis Engineers, Inc. has examined possible uses for the gasifier slag produced during coal gasification. After describing some of the problems foreseen to market development, seven categories of uses are listed and briefly discussed. The possible uses for slag identified are: (1) Agriculture (soil conditioner, lime substitute, low analysis fertilizer, carrier for insecticides); (2) Industrial material (abrasive grit, catalyst and adsorbent, roofing granules, industrial filler, mineral wool production, filter media); (3) Cement and Concrete (concrete aggregate, mortar/grouting material, pozzolanic admixture, raw materials for Portland cement production, masonary unit production); (4) Road Construction and Maintenance (de-icing grit, fine aggregate for bituminous pavement, base aggregate, sub-base aggregate, seal-cost aggregate); (5) Synthetic Aggregate (lightweight construction aggregate, landscaping material, sand substitute); (6) Land Fill and Soil Stabilization (soil conditioner for improving stability, structural fill, embankment material); (7) Resource Recovery (source of carbon, magnetite, iron, aluminium, and other metals). 2 tables.

  13. Solar gasification of carbonaceous materials

    NASA Astrophysics Data System (ADS)

    Taylor, R. W.; Berjoan, R.; Coutures, J. P.

    1983-01-01

    Charcoal, wood and paper have ben gasified in a packed-bed reactor using steam and solar energy. The steam was generated by spraying water directly on to the surface of the fuel and, at the same time, heating the fuel at the focus of a solar furnace. Half of the steam reacted with carbon and 30 pct of the incident solar energy was stored as chemical enthalpy. The performance of a fluidized-bed reactor was compared to that of a packed-bed reactor using charcoal and CO2. The fraction of the incident solar energy utilized to produce CO (stored) was 10 pct in the case of the fluidized-bed reactor and 40 pct for the packed-bed reactor. The fuel value of the gas produced from the steam-gasification of wood and paper was 65 kcal/mole (320 Btu/lb). On an ash free basis the volume yield of the gas was within 0.1 of 1 cu m/kq.

  14. Coal gasification using solar energy

    NASA Astrophysics Data System (ADS)

    Mathur, V. K.; Breault, R. W.; Lakshmanan, S.

    1983-01-01

    An economic evaluation of conventional and solar thermal coal gasification processes is presented, together with laboratory bench scale tests of a solar carbonization unit. The solar design consists of a heliostat field, a central tower receiver, a gasifier, and a recirculation loop. The synthetic gas is produced in the gasifier, with part of the gas upgraded to CH4 and another redirected through the receiver with steam to form CO and H2. Carbonaceous fuels are burned whenever sunlight is not available. Comparisons are made for costs of Lurgi, Bi-gas, Hygas, CO2 Acceptor, and Peat Gas processes and hybrid units for each. Solar thermal systems are projected to become economical with 350 MWt output and production of 1,420,000 cu m of gas per day. The laboratory bench scale unit was tested with Montana rosebud coal to derive a heat balance assessment and analyse the product gas. Successful heat transfer through a carrier gas was demonstrated, with most of the energy being stored in the product gas.

  15. Plasma Treatments and Biomass Gasification

    NASA Astrophysics Data System (ADS)

    Luche, J.; Falcoz, Q.; Bastien, T.; Leninger, J. P.; Arabi, K.; Aubry, O.; Khacef, A.; Cormier, J. M.; Lédé, J.

    2012-02-01

    Exploitation of forest resources for energy production includes various methods of biomass processing. Gasification is one of the ways to recover energy from biomass. Syngas produced from biomass can be used to power internal combustion engines or, after purification, to supply fuel cells. Recent studies have shown the potential to improve conventional biomass processing by coupling a plasma reactor to a pyrolysis cyclone reactor. The role of the plasma is twofold: it acts as a purification stage by reducing production of tars and aerosols, and simultaneously produces a rich hydrogen syngas. In a first part of the paper we present results obtained from plasma treatment of pyrolysis oils. The outlet gas composition is given for various types of oils obtained at different experimental conditions with a pyrolysis reactor. Given the complexity of the mixtures from processing of biomass, we present a study with methanol considered as a model molecule. This experimental method allows a first modeling approach based on a combustion kinetic model suitable to validate the coupling of plasma with conventional biomass process. The second part of the paper is summarizing results obtained through a plasma-pyrolysis reactor arrangement. The goal is to show the feasibility of this plasma-pyrolysis coupling and emphasize more fundamental studies to understand the role of the plasma in the biomass treatment processes.

  16. Apparatus for fixed bed coal gasification

    DOEpatents

    Sadowski, Richard S.

    1992-01-01

    An apparatus for fixed-bed coal gasification is described in which coal such as caking coal is continuously pyrolyzed with clump formation inhibited, by combining the coal with a combustible gas and an oxidant, and then continually feeding the pyrolyzed coal under pressure and elevated temperature into the gasification region of a pressure vessel. The materials in the pressure vessel are allowed to react with the gasifying agents in order to allow the carbon contents of the pyrolyzed coal to be completely oxidized. The combustion of gas produced from the combination of coal pyrolysis and gasification involves combining a combustible gas coal and an oxidant in a pyrolysis chamber and heating the components to a temperature of at least 1600.degree. F. The products of coal pyrolysis are dispersed from the pyrolyzer directly into the high temperature gasification region of a pressure vessel. Steam and air needed for gasification are introduced in the pressure vessel and the materials exiting the pyrolyzer flow down through the pressure vessel by gravity with sufficient residence time to allow any carbon to form carbon monoxide. Gas produced from these reactions are then released from the pressure vessel and ash is disposed of.

  17. Chicken-Bio Nuggets Gasification process

    SciTech Connect

    Sheth, A.C.

    1996-12-31

    With the cost of landfill disposal skyrocketing and land availability becoming scarce, better options are required for managing our nation`s biomass waste. In response to this need, the University of Tennessee Space Institute (UTSI) is evaluating an innovative idea (described as Chicken-Bio Nuggets Gasification process) to gasify waste products from the poultry industry and industrial wood/biomass-based residues in {open_quotes}as-is{close_quotes} or aggregate form. The presence of potassium salts in the poultry waste as well as in the biomass can act as a catalyst in reducing the severity of the thermal gasification. As a result, the mixture of these waste products can be gasified at a much lower temperature (1,300-1,400{degrees}F versus 1,800-2,000{degrees}F for conventional thermal gasification). Also, these potassium salts act as a catalyst by accelerating the gasification reaction and enhancing the mediation reaction. Hence, the product gas from this UTSI concept can be richer in methane and probably can be used as a source of fuel (to replace propane in hard reach remote places) or as a chemical feed stock. Exxon Research and Engineering Company has tested a similar catalytic gasification concept in a fluid-bed gasifier using coal in a one ton/day pilot plant in Baytown, Texas. If found technically and economically feasible, this concept can be later on extended to include other kinds of waste products such as cow manure and wastes from swine, etc.

  18. Hydrothermal Gasification for Waste to Energy

    NASA Astrophysics Data System (ADS)

    Epps, Brenden; Laser, Mark; Choo, Yeunun

    2014-11-01

    Hydrothermal gasification is a promising technology for harvesting energy from waste streams. Applications range from straightforward waste-to-energy conversion (e.g. municipal waste processing, industrial waste processing), to water purification (e.g. oil spill cleanup, wastewater treatment), to biofuel energy systems (e.g. using algae as feedstock). Products of the gasification process are electricity, bottled syngas (H2 + CO), sequestered CO2, clean water, and inorganic solids; further chemical reactions can be used to create biofuels such as ethanol and biodiesel. We present a comparison of gasification system architectures, focusing on efficiency and economic performance metrics. Various system architectures are modeled computationally, using a model developed by the coauthors. The physical model tracks the mass of each chemical species, as well as energy conversions and transfers throughout the gasification process. The generic system model includes the feedstock, gasification reactor, heat recovery system, pressure reducing mechanical expanders, and electricity generation system. Sensitivity analysis of system performance to various process parameters is presented. A discussion of the key technological barriers and necessary innovations is also presented.

  19. Evaluating paint-sludge chars for adsorption of selected paint solvents

    SciTech Connect

    Kim, B.R.; Kalis, E.M.; Salmeen, I.T.; Kruse, C.W.; Demir, I.; Rostam-Abadi, M.; Carlson, S.L.

    1996-06-01

    At Ford, a study had been carried out to investigate the technical feasibility of converting paint sludge to activated char and reusing the char in paint spray-booth water to capture paint solvents from spray-booth air. As part of the study, several chars were made from a paint sludge and six dried paints to evaluate their effectiveness as adsorbents by conducting a series of liquid-phase adsorption experiments. Three commonly-used paint solvents and p-nitrophenol were selected as adsorbates. The three paint solvents were toluene, 2-methyl-1-propanol (iso-butanol), and 2-butoxyethanol (butylcellosolve). In this paper, the results of the pyrolysis and adsorption experiments are presented along with practical implications. The primary findings include the following: (1) Black-paint chars showed substantially larger surface area and higher adsorption capacity (based on total weight) than white-paint chars which had high ash contents due to the white pigment, titanium dioxide; (2) the adsorption capacity of the paint-sludge char was between those of black-paint and white-paint chars, and was 5--20% that of a commercial activated carbon; (3) titanium dioxide in white-paint chars did not improve the chars` affinity for hydrophilic compounds such as 2-methyl-1-propanol and 2-butoxyethanol; (4) coal could be added to paint sludge to improve the quality of the resulting char and to reduce ash content; and (5) the pyrolysis of paint sludge could present an attractive opportunity for reusing and recycling a waste product for pollution abatement and as a vehicle component.

  20. STRUCTURE-BASED PREDICTIVE MODEL FOR COAL CHAR COMBUSTION

    SciTech Connect

    CHRISTOPHER M. HADAD; JOSEPH M. CALO; ROBERT H. ESSENHIGH; ROBERT H. HURT

    1998-09-11

    Progress was made this period on a number of tasks. A significant advance was made in the incorporation of macrostructural ideas into high temperature combustion models. Work at OSU by R. Essenhigh in collaboration with the University of Stuttgart has led to a theory that the zone I / II transition in char combustion lies within the range of conditions of interest for pulverized char combustion. The group has presented evidence that some combustion data, previously interpreted with zone II models, in fact takes place in the transition from zone II to zone 1. This idea was used at Brown to make modifications to the CBK model (a char kinetics package specially designed for carbon burnout prediction, currently used by a number of research and furnace modeling groups in academia and industry). The resulting new model version, CBK8, shows improved ability to predict extinction behavior in the late stages of combustion, especially for particles with low ash content. The full development and release of CBK8, along with detailed descriptions of the role of the zone 1/2 transition will be reported on in subsequent reports. ABB-CE is currently implementing CBK7 into a special version of the CFD code Fluent for use in the modeling and design of their boilers. They have been appraised of the development, and have expressed interest in incorporating the new feature, realizing full CBK8 capabilities into their combustion codes. The computational chemistry task at OSU continued to study oxidative pathways for PAH, with emphasis this period on heteroatom containing ring compounds. Preliminary XPS studies were also carried out. Combustion experiments were also carried out at OSU this period, leading to the acquisition of samples at various residence times and the measurement of their oxidation reactivity by nonisothermal TGA techniques. Several members of the project team attended the Carbon Conference this period and made contacts with representatives from the new FETC Consortium