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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. Characterizing and modeling combustion of mild-gasification chars in pressurized fluidized beds

    SciTech Connect

    Daw, C.S.

    1995-10-01

    Oak Ridge National Laboratory (ORNL) is supported by the Morgantown Energy Technology Center (METC) of the Department of Energy (DOE) under FWP-FEAA310 to characterize the fuel properties of liquid and char coproducts from the mild gasification of coal, Because most of the energy content of coals subjected to mild gasification is retained in the byproduct char, efficient and cost-effective utilization of the char is essential in insuring that candidate gasification processes are commercially viable. One potential use for char of particular interest to DOE is pressurized fluidized bed combustion (PFBC). PFBC is of particular interest because it has the potential for 10 to 30 percent greater overall energy efficiency than atmospheric fluidized bed combustion (AFBC), While bench-scale tools and analytical procedures for characterizing fuels for AFBC have been recently demonstrated, no such tools have been reliably demonstrated for PFBC. This report summarizes the results of joint research collaboration between ORNL and B&W that has been directed at modifying the previously developed AFBC fuel characterization procedures to be applicable for mild-gasification chars and PFBC conditions. The specific objectives were to: (1) characterize the combustion reactivity of a selected set of candidate mild- gasification chars at PFB conditions; (2) compare the measured char characteristics with those of more conventional PFBC fuels; (3) modify an AFBC computer code previously developed by B&W and ORNL for the Electric Power Research Institute (EPRI) to predict PFBC performance; and (4) apply the modified code and measured char combustion characteristics to make performance predictions for the candidate chars relative to more conventional fuels.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Characterizing and modeling combustion of mild-gasification chars in pressurized fluidized beds

    SciTech Connect

    Daw, C.S.

    1993-03-01

    Performance estimates for the UCC2, IGTP1, and IGTP2 chars were made for a typical utility PFBC boiler having nominal characteristics similar to those of the American Electric Power 75 MW(e) Tidd PFBC demonstration facility. Table 2 summarizes the assumed boiler operating conditions input to the PFBC simulation code. Input fuel parameters for the chars and reference fuels were determined from their standard ASTM analyses (Table 1) and the results of the bench-scale characterization tests at B&W`s Alliance Research Center. The required characterization information for the reference fuels was available from the B&W data base, and the combustion reactivity information for the mild-gasification chars was generated in the pressurized bench-scale reactor as described earlier. Note that the combustion reactivity parameters for Beulah lignite are those previously measured at low-pressure conditions. It was necessary to use the previous values as the new parameters could not be accurately measured in the pressurized bench-scale facility. Based on very limited measurements of particle size attrition in paste-type feed systems, it was assumed that all of the fuels (including the chars) would have a very small (essentially negligible) degree of attrition in the feed system. Char devolatilization parameters were assumed to be equal to those of anthracite because of the very low levels of volatiles present in UCC2, IGTP1, and IGTP2. Major fuel input parameters and higher heating values are summarized in Table 3.

  9. Characterizing and modeling combustion of mild-gasification chars in pressurized fluidized beds

    SciTech Connect

    Daw, C.S.

    1993-01-01

    Performance estimates for the UCC2, IGTP1, and IGTP2 chars were made for a typical utility PFBC boiler having nominal characteristics similar to those of the American Electric Power 75 MW(e) Tidd PFBC demonstration facility. Table 2 summarizes the assumed boiler operating conditions input to the PFBC simulation code. Input fuel parameters for the chars and reference fuels were determined from their standard ASTM analyses (Table 1) and the results of the bench-scale characterization tests at B W's Alliance Research Center. The required characterization information for the reference fuels was available from the B W data base, and the combustion reactivity information for the mild-gasification chars was generated in the pressurized bench-scale reactor as described earlier. Note that the combustion reactivity parameters for Beulah lignite are those previously measured at low-pressure conditions. It was necessary to use the previous values as the new parameters could not be accurately measured in the pressurized bench-scale facility. Based on very limited measurements of particle size attrition in paste-type feed systems, it was assumed that all of the fuels (including the chars) would have a very small (essentially negligible) degree of attrition in the feed system. Char devolatilization parameters were assumed to be equal to those of anthracite because of the very low levels of volatiles present in UCC2, IGTP1, and IGTP2. Major fuel input parameters and higher heating values are summarized in Table 3.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Development of an advanced, continuous mild-gasification process for the production of coproducts. Report for Task 4.8, Decontamination and disassembly of the mild-gasification and char-to-carbon PRUs and disposal of products from testing

    SciTech Connect

    Merriam, N.W.; Jha, Mahesh C.

    1991-11-01

    This report contains descriptions of mild-gasification and char-to-carbon process research units (PRUS) used by WRI and AMAX R&D Center to conduct tests under contract AC21-87MC24268. Descriptions of materials produced during those tests are also contained herein. Western Research Institute proposes to dispose of remaining fines and dried coal by combustion and remaining coal liquids by incineration during mid-1992. The mild-gasification PRU will be used for additional tests until 1993, at which time WRI proposes to decontaminate and disassemble the PRU. AMAX R&D Center intends to return the spent char, any remaining feed char, and unusable product carbon to the Eagle Butte Mine near Gillette, Wyoming, from where the coal originally came. The solid products will be added to the mine`s coal product stream. Coal liquids collected from condensers will be concentrated and sent to a local oil and solvent recycling company where the liquids will be burned as fuel. The char-to-carbon PRU will be operated periodically until 1993 when the plant will be decontaminated and disassembled.

  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.; 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.

  18. 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.

  19. 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.

  20. Fundamental research on mild gasification char fuel development: Quarterly report for the period March-May 1987

    SciTech Connect

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

    1987-06-01

    Great Lakes Research Corporation (GLRC) has presented a conceptual design for the bench-scale, fluidized-bed char chlorination unit. The estimated costs for the unit are substantially more than the amount originally allocated for constructing the unit. Ways to reduce the cost of the bench-scale unit are being investigated at this time. An existing rotating ''graphitizer'' at GLRC has been modified for the preliminary char chlorination tests. The results of the first test (2500/sup 0/F, 2 cfh chlorine gas for 1 hour) showed that the ash content of the char was reduced to 6.9% from 12.8%, and the sulfur content was reduced to 0.50% from 1.10%. Additional tests with longer durations and higher reaction temperatures are scheduled.

  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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  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.

  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. Influence of pressure on coal pyrolysis and char gasification

    SciTech Connect

    Haiping Yang; Hanping Chen; Fudong Ju; Rong Yan; Shihong Zhang

    2007-12-15

    Coal char structure varied greatly with pyrolysis pressure, which has a significant influence on the gasification reactivity. In this study, the influence of pressure on the behavior of coal pyrolysis and physicochemical structure and gasification characteristics of the resultant coal char was investigated using a pressurized thermogravimetric analyzer combined with an ambient thermogravimetric analyzer. First, the pyrolysis of Shenfu (SF) bituminous coal was performed in a pressurized thermogravimetric analyzer (TGA) at different pressures (0.1, 0.8, 1.5, 3, and 5 MPa). The volatile mainly evolved out at 400-800{sup o}C. The gas products are mainly CO{sub 2}, CO, CH{sub 4}, and light aliphatics with some water. It was observed that the pyrolysis of coal was shifted to lower temperature (50{sup o}C) with pressure increasing from ambient to 5 MPa, and the devolatilization rate of coal pyrolysis was decreased and the coal char yield was increased slightly. The structure of solid coal char was analyzed using FTIR, ASAP2020, and CNHS. In the solid char, the main organic functional groups are mainly CO, C-C (alkane), C-H ar, C-O-C, and C=C ar. The carbon content was increased while H content decreased. Finally, the gasification of the solid char was preformed at ambient pressure with CO{sub 2} as gasify agent. The gasification process of coal char can be divided into postpyrolysis and char gasification. Higher pressure accelerated the initial stage of char gasification, and higher gasification reactivity was observed for char derived at 5 MPa. 23 refs., 8 figs., 5 tabs.

  5. 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.

  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. 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)

  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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Development of an advanced continuous mild gasification process for the production of coproducts. Task 4, Mild gasification tests

    SciTech Connect

    Merriam, N.W.; Cha, C.Y.; Kang, T.W.; Vaillancourt, M.B.

    1990-12-01

    Western Research Institute (WRI) teamed with the AMAX Research and Development Center and Riley Stoker Corporation on Development of an Advanced, Continuous Mild-Gasification Process for the Production of Coproducts under contract DE-AC21-87MC24268 with the Morgantown Energy Technology of the US Department of Energy. The strategy for this project is to produce electrode binder pitch and diesel fuel blending stock by mild gasification of Wyodak coal. The char is upgraded to produce anode-grade carbon, carbon black, and activated carbon. This report describes results of mild-gasification tests conducted by WRI. Char upgrading tests conducted by AMAX will be described in a separate report.

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

    SciTech Connect

    Merriam, N.W.; Jha, M.C.

    1991-11-01

    This report is a final brief summary of development of a mild-gasification and char conversion process. Morgantown Energy Technology Center developed a concept called mild gasification. In this concept, devolatilization of coal under nonoxidizing and relatively mild temperature and pressure conditions can yield three marketable products: (1) a high-heating-value gas, (2) a high-aromatic coal liquid, and (3) a high-carbon char. The objective of this program is to develop an advanced, continuous, mild-gasification process to produce products that will make the concept economically and environmentally viable. (VC)

  12. Development of an advanced continuous mild gasification process for the production of coproducts. Final report

    SciTech Connect

    Merriam, N.W.; Jha, M.C.

    1991-11-01

    This report is a final brief summary of development of a mild-gasification and char conversion process. Morgantown Energy Technology Center developed a concept called mild gasification. In this concept, devolatilization of coal under nonoxidizing and relatively mild temperature and pressure conditions can yield three marketable products: (1) a high-heating-value gas, (2) a high-aromatic coal liquid, and (3) a high-carbon char. The objective of this program is to develop an advanced, continuous, mild-gasification process to produce products that will make the concept economically and environmentally viable. (VC)

  13. 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.

  14. 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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. 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.

  16. 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)

  17. 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.

  18. 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.

  19. Retention of chromium (VI) on a macroporous char following ChemChar gasification and successive leaching with water and acids.

    PubMed

    Marrero, Thomas W; Manahan, Stanley E

    2005-01-01

    A granular macroporous char, triple-reverse-burn (TRB) char, was loaded with 23.40 mg Cr/g TRB char from an aqueous solution, and the retained metal was leached by water, 0.66 M nitric acid, concentrated nitric acid, and concentrated hydrochloric acid before and after treatment by a reductive thermal gasification process (ChemChar process developed by ChemChar Research, Inc., Columbia, Missouri). The chromium leachate was analyzed by flame atomic adsorption. Reverse- and forward-mode gasifications were performed on the metal-laden char. With the exception of a 10% mass loss of carbon, the reverse mode gasification process does not change the physical characteristics of the granular char, but does increase the retention of the chromium from 16.7 to 24.2%, depending on the leachant. The forward mode gasification process produces a vitrified (or glasslike) ash residue. There was an 11.6 to 13.1% increase in the retention of the chromium by the slag and ash when compared to the nongasified chromium-loaded TRB char. Chromium (VI) was effectively removed from solution by TRB char and found to be retained to a higher degree on the char after a reductive thermal treatment.

  20. 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.

  1. High temperature gasification of high heating-rate chars using a flat-flame reactor

    DOE PAGES

    Li, Tian; Niu, Yanqing; Wang, Liang; ...

    2017-08-25

    The increasing interest in gasification and oxy-fuel combustion of biomass has heightened the need for a detailed understanding of char gasification in industrially relevant environments (i.e., high temperature and high-heating rate). Despite innumerable studies previously conducted on gasification of biomass, very few have focused on such conditions. Consequently, in this study the high-temperature gasification behaviors of biomass-derived chars were investigated using non-intrusive techniques. Two biomass chars produced at a heating rate of approximately 104 K/s were subjected to two gasification environments and one oxidation environment in an entrained flow reactor equipped with an optical particle-sizing pyrometer. A coal char producedmore » from a common U.S. low sulfur subbituminous coal was also studied for comparison. Both char and surrounding gas temperatures were precisely measured along the centerline of the furnace. Despite differences in the physical and chemical properties of the biomass chars, they exhibited rather similar reaction temperatures under all investigated conditions. On the other hand, a slightly lower particle temperature was observed in the case of coal char gasification, suggesting a higher gasification reactivity for the coal char. A comprehensive numerical model was applied to aid the understanding of the conversion of the investigated chars under gasification atmospheres. In addition, a sensitivity analysis was performed on the influence of four parameters (gas temperature, char diameter, char density, and steam concentration) on the carbon conversion rate. Here, the results demonstrate that the gas temperature is the most important single variable influencing the gasification rate.« less

  2. 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.

  3. 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.

  4. 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.

  5. 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.

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

    SciTech Connect

    Merriam, N.W.; Cha, C.Y.; Kang, T.W.; Vaillancourt, M.B.

    1990-12-01

    Western Research Institute (WRI) teamed with the AMAX Research and Development Center and Riley Stoker Corporation on Development of an Advanced, Continuous Mild-Gasification Process for the Production of Coproducts under contract DE-AC21-87MC24268 with the Morgantown Energy Technology of the US Department of Energy. The strategy for this project is to produce electrode binder pitch and diesel fuel blending stock by mild gasification of Wyodak coal. The char is upgraded to produce anode-grade carbon, carbon black, and activated carbon. This report describes results of mild-gasification tests conducted by WRI. Char upgrading tests conducted by AMAX will be described in a separate report.

  7. Gasification reactivity and kinetics of typical Chinese anthracite chars with steam and CO{sub 2}

    SciTech Connect

    Linxian Zhang; Jiejie Huang; Yitian Fang; Yang Wang

    2006-05-15

    The gasification reactivities of six typical Chinese anthracite chars with steam and CO{sub 2} at 0.02-0.1 MPa and 920-1050{sup o}C were investigated by using thermogravimetric analysis (TGA). The reactivities of anthracite chars during steam gasification were found to have a good correlation to the coal volatile matter contents. The higher the coal volatile matter content, the higher the reactivity. The difference in reactivities of anthracite chars during CO{sub 2} gasification seems to be more dependent on the catalytic effect of inherent minerals in anthracite. The results show that the greater the alkali index, the higher the reactivity. The reactivities of demineralized anthracite chars vary very little compared with those the undemineralized chars at higher temperatures, whereas the reactivities of demineralized chars from Jincheng and Rujigou are lower than those of undemineralized ones and the reactivities of demineralized chars from Yangquan, Hunan, Guangdong, and Longyan are higher than those of undemineralized chars at lower temperatures. The homogeneous model and shrinking core model were examined as ways to interpret the experimental data. The experimental results could be well-described by the shrinking core model for anthracite chars during steam and CO{sub 2} gasification. Comparison of the reactivities for anthracite chars during steam and CO{sub 2} gasification shows that the reactivities of anthracite chars during steam gasification are far higher than those during CO{sub 2} gasification. The reactivities of the former are about 10 times higher than those of the latter, and this ratio is far greater than that of the lignite and bituminous coal. The mechanism leading to this difference is discussed. 33 refs., 15 figs., 8 tabs.

  8. Development of an advanced, continuous mild gasification process for the production of co-products. Quarterly report, January 1994--March 1994

    SciTech Connect

    O`Neal, G.W.

    1994-04-01

    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. This program consists of four tasks. Task 1 is a literature survey of mild gasification processes and product upgrading methods and also a market assessment for mild gasification products. Based on the literature survey, a mild gasification process and char upgrading method will be identified for further development. Task 2 is a bench-scale investigation of mild gasification to generate data for a larger scale reactor. Task 3 is a bench-scale study of char upgrading to value added products. Task 4 is being implemented by building and operating a 1000-pound per hour demonstration facility. Task 4 also includes a technical and economic evaluation based on the performance of the mild gasification demonstration facility.

  9. 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.

  10. 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.

  11. 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.

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

    NASA Astrophysics Data System (ADS)

    Tsai, Nancy Ko-Chieh

    2000-11-01

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

  13. 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.

  14. Transient behavior of devolatilization and char reaction during steam gasification of biomass.

    PubMed

    Moon, Jihong; Lee, Jeungwoo; Lee, Uendo; Hwang, Jungho

    2013-04-01

    Steam gasification of biomass is a promising method for producing high quality syngas for polygeneration. During the steam gasification, devolatilization and char reaction are key steps of syngas production and the contributions of the two reactions are highly related to gasification conditions. In this study, the transient characteristics of devolatilization and char reaction in biomass steam gasification were investigated by monitoring cumulative gas production and composition changes in terms of reaction temperature and S/B ratio. Contribution of each reaction stage on the product gas yield was studied in detail. The results provide important insight for understanding the complex nature of biomass gasification and will guide future improvements to the biomass gasification process. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. 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.

    1990-10-23

    Research continued on the production of coproducts from continuous mild gasification. During the third quarter of 1990, work focused on start-up and operation of the 50 pound/hour char-to-carbon (CTC) process research unit (PRU). Start-up procedures have been finalized for the methane production reactor, and the design temperature has been achieved. Flows and pressures for the overall process have been balanced and optimized. We have achieved temperatures above 1500{degree}F in the carbon formation reactor. Upgrading experiments on mild gasification pitch have also continued on a pitch produced in run MG-122. Results of heat treating and catalytic treating tests are reported.

  16. Properties of gasification-derived char and its utilization for catalytic tar reforming

    NASA Astrophysics Data System (ADS)

    Qian, Kezhen

    Char is a low-value byproduct of biomass gasification and pyrolysis with many potential applications, such as soil amendment and the synthesis of activated carbon. The overall goal of the proposed research was to develop novel methods to use char derived from gasification for high-value applications in syngas conditioning. The first objective was to investigate effects of gasification condition and feedstock on properties of char derived from fluidized bed gasification. Results show that the surface areas of most of the char were 1--10 m 2/g and increased as the equivalence ratio increased. Char moisture and fixed carbon contents decreased while ash content increased as equivalence ratio increased. The next objective was to study the properties of sorghum and red cedar char derived from downdraft gasifier. Red cedar char contained more aliphatic carbon and o-alkyl carbon than sorghum char. Char derived from downdraft gasification had higher heating values and lower ash contents than char derived from fluidized bed gasification. The gasification reactivity of red cedar char was higher than that of sorghum char. Then, red cedar char based catalysts were developed with different preparation method to reform toluene and naphthalene as model tars. The catalyst prepared with nickel nitrate was found to be better than that with nickel acetate. The nickel particle size of catalyst impregnated with nickel nitrate was smaller than that of catalyst impregnated with nickel acetate. The particle size of catalyst impregnated with nickel acetate decreased by hydrazine reduction. The catalyst impregnated with nickel nitrate had the highest toluene removal efficiency, which was 70%--100% at 600--800 °C. The presence of naphthalene in tar reduced the catalyst efficiency. The toluene conversion was 36--99% and the naphthalene conversion was 37%--93% at 700--900 °C. Finally, effects of atmosphere and pressure on catalytic reforming of lignin-derived tars over the developed catalyst

  17. Co-gasification of coal and biomass: Synergy, characterization and reactivity of the residual char.

    PubMed

    Hu, Junhao; Shao, Jingai; Yang, Haiping; Lin, Guiying; Chen, Yingquan; Wang, Xianhua; Zhang, Wennan; Chen, Hanping

    2017-11-01

    The synergy effect between coal and biomass in their co-gasification was studied in a vertical fixed bed reactor, and the physic-chemical structural characteristics and gasification reactivity of the residual char obtained from co-gasification were also investigated. The results shows that, conversion of the residual char and tar into gas is enhanced due to the synergy effect between coal and biomass. The physical structure of residual char shows more pore on coal char when more biomass is added in the co-gasification. The migration of inorganic elements between coal and biomass was found, the formation and competitive role of K2SiO3, KAlSiO4, and Ca3Al2(SiO4)3 is a mechanism behind the synergy. The graphization degree is enhanced but size of graphite crystallite in the residual char decreases with biomass blending ratio increasing. TGA results strongly suggest the big difference in the reactivity of chars derived from coal and biomass in spite of influence from co-gasification. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Physicochemical properties and gasification reactivity of the ultrafine semi-char derived from a bench-scale fluidized bed gasifier

    NASA Astrophysics Data System (ADS)

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

    2017-08-01

    Zhundong coalfield is the largest intact coalfield worldwide and fluidized bed gasification has been considered as a promising way to achieve its clean and efficient utilization. The purpose of this study is to investigate the physicochemical properties and gasification reactivity of the ultrafine semi-char, derived from a bench-scale fluidized bed gasifier, using Zhundong coal as fuel. The results obtained are as follows. In comparison to the raw coal, the carbon and ash content of the semi-char increase after partial gasification, but the ash fusion temperatures of them show no significant difference. Particularly, 76.53% of the sodium in the feed coal has released to the gas phase after fluidized bed gasification. The chemical compositions of the semi-char are closely related to its particle size, attributable to the distinctly different natures of diverse elements. The semi-char exhibits a higher graphitization degree, higher BET surface area, and richer meso- and macropores, which results in superior gasification reactivity than the coal char. The chemical reactivity of the semi-char is significantly improved by an increased gasification temperature, which suggests the necessity of regasification of the semi-char at a higher temperature. Consequently, it will be considered feasible that these carbons in the semi-char from fluidized bed gasifiers are reclaimed and reused for the gasification process.

  4. TPD study on SO{sub 2} gasification of coal char

    SciTech Connect

    Takarada, T.; Suzuki, Y.

    1996-10-01

    Elementary sulfur can be recovered from SO{sub 2}-containing gas by a gasification reaction between carbon and SO{sub 2}. Gasification of coal chars ranging from brown coal to anthracite was carried out in SO{sub 2} atmosphere using thermo-balance. The gasification temperature ranged from 923 to 1123 K. The SO{sub 2} concentration was 5.3 vol%. Yallourn coal, Australian brown coal, was impregnated with several catalysts. Potassium carbonate, sodium hydroxide, calcium hydroxide, magnesium hydroxide and iron nitrate were used as the starting materials for catalyst impregnation. The active site for SO{sub 2} gasification of coal char was evaluated with TPD technique. The gasification profile was strongly depended on the coal type. High reactivities were observed for low rank coal chars. The gasification rate was enormously enhanced by the addition of alkaline metal catalyst. TPD pattern was depended on the coal type and the catalyst addition. The amount of CO and CO{sub 2} desorbed during TPD procedure in fairly correlated to the reaction rate of sample.

  5. Gasification of the char derived from distillation of granulated scrap tyres.

    PubMed

    López, Félix A; Centeno, Teresa A; Alguacil, Francisco José; Lobato, Belén; López-Delgado, Aurora; Fermoso, Javier

    2012-04-01

    This work reports the effect of pressure on the steam/oxygen gasification at 1000°C of the char derived from low temperature-pressure distillation of granulated scrap tyres (GST). The study was based on the analysis of gas production, carbon conversion, cold gas efficiency and the high heating value (HHV) of the product. For comparison, similar analyses were carried out for the gasification of coals with different rank. In spite of the relatively high ash (≈12 wt.%) and sulphur (≈3 wt.%) contents, the char produced in GST distillation can be regarded as a reasonable solid fuel with a calorific value of 34MJkg(-1). The combustion properties of the char (E(A)≈50 kJ mol(-1)), its temperature of self-heating (≈264°C), ignition temperature (≈459°C) and burn-out temperature (≈676°C) were found to be similar to those of a semi-anthracite. It is observed that the yield, H(2) and CO contents and HHV of the syngas produced from char gasification increase with pressure. At 0.1 MPa, 4.6 Nm(3)kg(char)(-1) of syngas was produced, containing 28%v/v of H(2) and CO and with a HHV around 3.7 MJ Nm(-3). At 1.5 MPa, the syngas yield achieved 4.9N m(3)kg(char)(-1) with 30%v/v of H(2)-CO and HHV of 4.1 MJ Nm(-3). Carbon conversion significantly increased from 87% at 0.1 MPa to 98% at 1.5 MPa. It is shown that the char derived from distillation of granulated scrap tyres can be further gasified to render a gas of considerable heating value, especially when gasification proceeds at high pressure.

  6. Evolution of char structure during steam gasification of the chars produced from rapid pyrolysis of rice husk.

    PubMed

    Fu, Peng; Hu, Song; Xiang, Jun; Yi, Weiming; Bai, Xueyuan; Sun, Lushi; Su, Sheng

    2012-06-01

    The structural evolution of rice husk char particles during steam gasification was studied by ultimate analysis, inductively coupled plasma atomic emission spectroscopy, scanning electronic microscope, N(2) physisorption method and X-ray diffraction. Drastic changes in char structure occurred even when the char conversion was minimal. The C, H and O content decreased by more than 85%, 67% and 91%, respectively. The H/C atomic ratio always increased, while the O/C exhibited a "∼" shape. The maximum porosity appeared at char conversion of 48.6%. D(s) and d(ave) showed a good linear relationship. Aliphatic structures and smaller aromatic rings tended to be preferentially consumed to left the char more ordered and enriched with larger aromatic ring systems. The presence of steam favored the volatilization of Na. K, Mg and Ca showed a similar behavior and their concentrations reached maxima at 60.3%. Great loss of O-containing structures caused significant volatilization of K, Mg and Ca.

  7. Task 4, Mild gasification technology development system integration studies, April 1989--September 1990

    SciTech Connect

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

    1990-12-01

    The IGT mild gasification process incorporates an integrated fluidized-bed/entrained-bed reactor with heat supplied by a combination of hot char and gas recycle. The use of mild operating conditions (1000 to 1500{degree}F), low pressures (<50 psig), and continuous operation in closed reactors, combined with the potential value-added benefits from the sale of co-products, offer an economical and environmentally sound approach to advanced coal utilization. The tests conducted as Task 4 operated with a full-stream product gas condensate system that was added to the process research unit (PRU). In these tests, the use of recycled char from previous tests mixed with the caking coal feed to the fluidized bed simulated the scale-up process design for the adiabatic process development unit (PDU) using recycled hot char. Also, one test was performed to evaluate the effect of carbon dioxide in the inlet fluidization gas, as would be present in the PDU design using heated recycled product gas for fluidization. Co-product yields and quality were compared with Task 2 data and related to sequential char recycle, fluidization gas, and coal type. Oils/tars yields with Illinois and West Virginia bituminous coals were consistently over 25% by weight of moisture- and ash-free coal, and were not adversely affected either by replacement of coke diluent with mild gasification char or by the use of 19% CO{sub 2} in the fluidization gas. Condensable co-products from the Task 4 PRU tests were evaluated by Reilly Industries for the production of chemicals and pitch binders, and recommendations for liquids upgrading for incorporation into the 24-ton/h PDU design were made. Larger batches of char were generated for preparation of form coke and smokeless fuel briquettes to be tested. 3 refs., 4 figs., 31 tabs.

  8. 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.

  9. 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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Development of an advanced, continuous mild-gasification process for the production of coproducts

    SciTech Connect

    Merriam, N.W. ); Jha, Mahesh C. )

    1991-11-01

    This report contains descriptions of mild-gasification and char-to-carbon process research units (PRUS) used by WRI and AMAX R D Center to conduct tests under contract AC21-87MC24268. Descriptions of materials produced during those tests are also contained herein. Western Research Institute proposes to dispose of remaining fines and dried coal by combustion and remaining coal liquids by incineration during mid-1992. The mild-gasification PRU will be used for additional tests until 1993, at which time WRI proposes to decontaminate and disassemble the PRU. AMAX R D Center intends to return the spent char, any remaining feed char, and unusable product carbon to the Eagle Butte Mine near Gillette, Wyoming, from where the coal originally came. The solid products will be added to the mine's coal product stream. Coal liquids collected from condensers will be concentrated and sent to a local oil and solvent recycling company where the liquids will be burned as fuel. The char-to-carbon PRU will be operated periodically until 1993 when the plant will be decontaminated and disassembled.

  11. The production of high quality coke by the CTC continuous mild gasification process

    SciTech Connect

    Wolfe, R.A.; Wright, R.E.; Im, C.J.; Henkelman, M.R.; McKinney, D.A.

    1994-12-31

    Coal Technology Corporation (CTC) in association with the US Department of Energy has developed, patented, and demonstrated a new process to continuously produce high quality coke in less than two hours without the normal environmental emissions associated with existing by-product coke ovens. This process involves the production of three new marketable products from bituminous caking type coals: (1) continuous coke for foundry and blast furnace applications; (2) char containing less than 10 percent volatiles for use in the ferroalloy smelting furnaces; and (3) coal derived liquids for use in the transportation and chemical industry. The CTC Char, Liquids, and Coke (CLC) Mild Gasification Process utilizes a unique twin screw reaction system to produce a devolatilized char from a wide variety of caking and non-caking coals in an environmentally clean system. The CTC/CLC Process is a two-stage carbonization system with a low temperature mild gasification stage followed by a high temperature calcining stage in a totally enclosed system with condensing of the coal liquids and the utilization of the off-gases as the reactor heat source. The process has been demonstrated in a 10-ton per day pilot plant and is now ready for commercialization. The coke and char products meet or exceed the existing quality specification now used in the industry. The coke can be produced in either uniform or irregular shapes to meet the required porosity of foundry and blast furnaces.

  12. 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.

  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. Synergistic effect on co-gasification reactivity of biomass-petroleum coke blended char.

    PubMed

    Wei, Juntao; Guo, Qinghua; Gong, Yan; Ding, Lu; Yu, Guangsuo

    2017-06-01

    In this work, effects of gasification temperature (900°C-1100°C) and blended ratio (3:1, 1:1, 1:3) on reactivity of petroleum coke and biomass co-gasification were studied in TGA. Quantification analysis of active AAEM transformation and in situ investigation of morphological structure variations in gasification were conducted respectively using inductively coupled plasma optical emission spectrometer and heating stage microscope to explore synergistic effect on co-gasification reactivity. The results indicated that char gasification reactivity was enhanced with increasing biomass proportion and gasification temperature. Synergistic effect on co-gasification reactivity was presented after complete generation of biomass ash, and gradually weakened with increasing temperature from 1000°C to 1100°C after reaching the most significant value at 1000°C. This phenomenon was well related with the appearance of molten biomass ash rich in glassy state potassium and the weakest inhibition effect on active potassium transformation during co-gasification at the temperature higher than 1000°C.

  15. 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.

  16. 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.

  17. Properties of chars from the gasification and pyrolysis of rice waste streams towards their valorisation as adsorbent materials.

    PubMed

    Dias, D; Lapa, N; Bernardo, M; Godinho, D; Fonseca, I; Miranda, M; Pinto, F; Lemos, F

    2017-07-01

    Rice straw (RS), rice husk (RH) and polyethylene (PE) were blended and submitted to gasification and pyrolysis processes. The chars obtained were submitted to textural, chemical, and ecotoxic characterisations, towards their possible valorisation. Gasification chars were mainly composed of ashes (73.4-89.8wt%), while pyrolysis chars were mainly composed of carbon (53.0-57.6wt%). Silicon (Si) was the major mineral element in all chars followed by alkaline and alkaline-earth metal species (AAEMs). In the pyrolysis chars, titanium (Ti) was also a major element, as the feedstock blends contained high fractions of PE which was the main source of Ti. Gasification chars showed higher surface areas (26.9-62.9m(2)g(-1)) and some microporosity, attributed to porous silica. On the contrary, pyrolysis chars did not present a porous matrix, mainly due to their high volatile matter content. The gasification bed char produced with 100% RH, at 850°C, with O2 as gasification agent, was selected for further characterization. This char presented the higher potential to be valorised as adsorbent material (higher surface area, higher content of metal cations with exchangeable capacity, and lowest concentrations of toxic heavy metals). The char was submitted to an aqueous leaching test to assess the mobility of chemical species and the ecotoxic level for V. fischeri. It was observed that metallic elements were significantly retained in the char, which was attributed mainly to its alkaline character. This alkaline condition promoted some ecotoxicity level on the char eluate that was eliminated after the pH correction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Development of an advanced, continuous mild gasification process for the production of co-products. Quarterly report, April--June 1994

    SciTech Connect

    O`Neal, G.W.

    1994-07-01

    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. The program consists of four tasks. Task 1 is a literature survey of mild gasification processes and product upgrading methods and also a market assessment of markets for mild gasification products. Based on the literature survey, a mild gasification process and char upgrading method will be identified for further development. Task 2 is a bench-scale investigation of mild gasification to generate design data for a larger scale reactor. Task 3 is a bench-scale study of char upgrading to value added products. Task 4 is being implemented by building and operating a 1000-pound per hour demonstration facility. Task 4 also includes a technical and economic evaluation based on the performance of the mild gasification demonstration facility. Installation of a continuous coke pilot plant started in the second quarter of 1994. Ten of 14 major components have been set. The remaining four are on order. Startup is scheduled for late September 1994. Eight test runs were completed in the continuous mild gasification unit (CMGU). These were short test runs to evaluate repair work or to demonstrate the PDU. Efforts continued to obtain financing for a commercial unit.

  19. 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.

  20. Adding value to gasification and co-pyrolysis chars as removal agents of Cr(3).

    PubMed

    Godinho, D; Dias, D; Bernardo, M; Lapa, N; Fonseca, I; Lopes, H; Pinto, F

    2017-01-05

    The present work aims to assess the efficiency of chars, obtained from the gasification and co-pyrolysis of rice wastes, as adsorbents of Cr(3+) from aqueous solution. GC and PC chars, produced in the gasification and co-pyrolysis, respectively, of rice husk and polyethylene were studied. Cr(3+) removal assays were optimised for the initial pH value, adsorbent mass, contact time and Cr(3+) initial concentration. GC showed a better performance than PC with about 100% Cr(3+) removal, due to the pH increase that caused Cr precipitation. Under pH conditions in which the adsorption prevailed (pH<5.5), GC presented the highest uptake capacity (21.1mg Cr(3+) g(-1) char) for the following initial conditions: 50mg Cr(3+) L(-1); pH 5; contact time: 24h;L/S ratio: 1000mLg(-1). The pseudo-second order kinetic model showed the best adjustment to GC experimental data. Both the first and second order kinetic models fitted well to PC experimental data. The ion exchange was the dominant phenomenon on the Cr(3+) adsorption by GC sample. Also, this char significantly reduced the ecotoxicity of Cr(3+) solutions for the bacterium Vibrio fischeri. GC char proved to be an efficient material to remove Cr(3+) from aqueous solution, without the need for further activation.

  1. 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).

  2. 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).

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

    SciTech Connect

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

    1990-01-01

    Research continued on the production of co-products from mild gasification. This quarter, 10 mild gasification tests were conducted in the 8-inch-I.D. process research unit (PRU). Modifications to the PRU were made during this period to improve mixing and to overcome the caking tendency of the Illinois No. 6 coal. Six of the tests resulted in satisfactory operation at steady conditions for 2.25 to 3.25 hours. Samples of char, gas, water, and organic condensables were collected over a one-hour period from each of these successful tests and analyzed. The effects of process temperature over the range of 1025{degree} to 1390{degree} was studied during this quarter. Compositional effects on the oils and tars observed with increased temperature are increased light oil content, decreased pitch content, decreased oxygen content, increased nitrogen and sulfur content, and increasing aromaticity. Char upgrading studies continued during the quarter. Briquettes made in a laboratory press, using either a pitch binder or Illinois No. 6 coal to provide an in-situ binder, were calcined and tested for diametral compression strength. Char was also subjected to steam activation at a variety of conditions to determine the potential for use as a low-cost absorbent for water treatment. 2 refs., 15 figs., 11 tabs.

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

    SciTech Connect

    Knight, R.A.; Gissy, J.; Kline, S.; Onischak, M.; Babu, S.P. ); Duthie, R.G. )

    1990-04-01

    A project team consisting of the Institute of Gas Technology, Peabody Holding Company, Inc., and Bechtel National, Inc., is developing a mild gasification process that uses a fluidized/entrained-bed reactor. This reactor is designed to process caking bituminous coals over a wide range of particle sizes without oxidative pretreatment, and also without the use of oxygen or air as reactants. The co-product streams, consisting of char, fuel gas, water, and condensables, would be separated by conventional means such as cyclone, staged condensers, and recycle-oil scrubbers. An isothermal process research unit (PRU) has been built at IGT, consisting of an 8-inch-I.D., 8-foot-long fluidized-bed section and a 4-inch-I.D., 13-foot-long entrained flow section, externally heated by electrical heaters. This quarter, eleven mild gasification tests were conducted in the PRU. Illinois No. 6 coal was used in nine of the tests and a West Virginia metallurgical grade of coal was used in the last two tests. The tests conducted in the PRU this quarter were operated with feed rates about three times higher than those used in the last quarter. Results show the effect of process temperature on the shields of char, oils/tars, and gases. Various compositional effects on the oils/tars were also discovered. Char upgrading studies were completed for the char co-product options of smokeless fuel and adsorbent char. A total condensate collection system was designed for the PRU system. 18 figs., 22 tabs.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Characterization, leachability and valorization through combustion of residual chars from gasification of coals with pine.

    PubMed

    Galhetas, Margarida; Lopes, Helena; Freire, Márcia; Abelha, Pedro; Pinto, Filomena; Gulyurtlu, Ibrahim

    2012-04-01

    This paper presents the study of the combustion of char residues produced during co-gasification of coal with pine with the aim of characterizing them for their potential use for energy. These residues are generally rich in carbon with the presence of other elements, with particular concern for heavy metals and pollutant precursors, depending on the original fuel used. The evaluation of environmental toxicity of the char residues was performed through application of different leaching tests (EN12457-2, US EPA-1311 TCLP and EA NEN 7371:2004). The results showed that the residues present quite low toxicity for some of pollutants. However, depending on the fuel used, possible presence of other pollutants may bring environmental risks. The utilization of these char residues for energy was in this study evaluated, by burning them as a first step pre-treatment prior to landfilling. The thermo-gravimetric analysis and ash fusibility studies revealed an adequate thermochemical behavior, without presenting any major operational risks. Fluidized bed combustion was applied to char residues. Above 700°C, very high carbon conversion ratios were obtained and it seemed that the thermal oxidation of char residues was easier than that of the coals. It was found that the char tendency for releasing SO(2) during its oxidation was lower than for the parent coal, while for NO(X) emissions, the trend was observed to increase NO(X) formation. However, for both pollutants the same control techniques might be applied during char combustion, as for coal. Furthermore, the leachability of ashes resulting from the combustion of char residues appeared to be lower than those produced from direct coal combustion.

  10. 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.

  11. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. 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.

  13. 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.

  14. Development of an advanced, continuous mild gasification process for the production of co-products. Quarterly report, April 1--June 30, 1993

    SciTech Connect

    O`Neal, G.W.

    1993-12-31

    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. The program consists of four tasks. Task 1 is a literature survey of mild gasification processes and product upgrading methods and also a market assessment of markets for mild gasification products. Based on the literature survey, a mild gasification process and char upgrading method will be identified for further development. Task 2 is a bench-scale investigation of mild gasification to generate design data for a larger scale reactor. Task 3 is a bench-scale study of char upgrading to value added products. Task 4 is being implemented by building and operating a 1,000-pound per hour demonstration facility. Task 4 also includes a technical and economic evaluation based on the performance of the mild gasification demonstration facility. Seven briquette tests were made to show the effects of different volatile matter contents of chars on coke quality. Higher char volatiles in the range of 7.52% to 14.14% produced better quality coke. This correlation was determined for a low volatile coal, Pocahontas {number_sign}3, and a mid volatiles coal, Sewell Lady H. Fifteen CMGU test runs were made using low volatile coal, Pocahontas {number_sign}3, and a mid volatile coal, Sewell Lady H. The 1,000 pounds/hour design coal feed rate was exceeded at 1,183 pounds/hour. Improvements to the vapor handling system were made including installation of a packed column demister and a tar trap condenser. Elimination of smoke emissions from the flare is in progress.

  15. 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.

  16. Effect of torrefaction on the properties of rice straw high temperature pyrolysis char: Pore structure, aromaticity and gasification activity.

    PubMed

    Chen, Handing; Chen, Xueli; Qin, Yueqiang; Wei, Juntao; Liu, Haifeng

    2017-03-01

    The influence of torrefaction on the physicochemical characteristics of char during raw and water washed rice straw pyrolysis at 800-1200°C is investigated. Pore structure, aromaticity and gasification activity of pyrolysis chars are compared between raw and torrefied samples. For raw straw, BET specific surface area decreases with the increased torrefaction temperature at the same pyrolysis temperature and it approximately increases linearly with weight loss during pyrolysis. The different pore structure evolutions relate to the different volatile matters and pore structures between raw and torrefied straw. Torrefaction at higher temperature would bring about a lower graphitization degree of char during pyrolysis of raw straw. Pore structure and carbon crystalline structure evolutions of raw and torrefied water washed straw are different from these of raw straw during pyrolysis. For both raw and water washed straw, CO2 gasification activities of pyrolysis chars are different between raw and torrefied samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. 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.

  18. 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.

  19. 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.

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

    SciTech Connect

    Runge, B.D.; Ness, R.O. Jr.; Sharp, L.L.; Shockey, R.E.

    1992-07-01

    The char produced in the 100-lb/hr process development unit has been magnetically cleaned by AMAX and returned to the Energy and Environmental Research Center (EERC). The final calcining step of the process is currently being performed in the 4-lb/hr continuous fluidized-bed reactor (CFBR). The liquid products generated by the PDU have been collected and split into usable fractions and fractions to be discarded. Samples of the coal-derived liquids have been sent to Merichem Corporation of Houston and Koppers Industries of Pittsburgh for determination of their usefulness as chemical feedstock for the production of cresylic acids and anode-grade-binder pitch. The technical and economic assessment performed by Xbi and J.E Sinor Consultants has been completed. The briquette testing being conducted at the EERC has produced high quality briquettes using a number of binder agents. The next step in the test matrix will include the use of coal-derived liquids from the PDU as the binder. An additional coal has been added to the mild gasification test matrix. AMAX recently acquired two eastern low-sulfur bituminous coals and suggested that a limited test schedule be conducted to determine the suitability of these coals for the mild gasification process. The sulfur levels in the raw coals are below the target levels suggested by the steel industry for metallurgical coke use. To date, it has not been possible to reach these goals using the high-sulfur Illinois Basin coals tested.

  2. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. True in situ oil shale retort: the role of intrashale transport and char gasification

    SciTech Connect

    Louvar, J.F.

    1983-01-01

    The theoretical understanding of the true in situ crack retort process for Eastern oil shale was expanded by: establishing the role of intrashale 2-dimensional transport on the performance of the retort; determining the significance of the intrashale char gasification reactions with water and carbon dioxide; and determining the conditions for improving the retort performance. Two computer simulation models were developed, one with 1-D mass transport and another with 2-D mass transport. The 1-D transport model includes: 2-D energy transport; variable physical properties; and instantaneous 1-D transfer of the pyrolysis products to the crack. The 2-D transport model includes; 2-D energy transport; variable physical properties; 2-D species transport within the oil shale; and pyrolysis, gasification, and oxidation reactions within the oil shale. The performance of the two models were studied. The results show that the 2-D transport feature has a significant impact on the performance of a true in situ Eastern oil shale retort. Intrashale pressure profiles were found to be very complex, distributing the pyrolysis and gasification products into the crack over a broad region. Results were used to develop regression equations to establish the functional relationships between the dependent and independent variables. Retort performance varied significantly with only minor changes in the operating variables: crack width, inlet gas moisture, ignition time, and gas inlet rate. The regression equations were also used to determine the optimum retort performance while constraining the gas temperature within a reasonable operating region. This theoretically predicted low optimum performance and variable sensitivity identify new problems which make the successful operation of a true in situ crack retort more difficult than previously anticipated.

  4. 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.

  5. 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.

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

    PubMed

    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/Nm(3) at a gasification temperature of 1500 K and equivalence ratio of 0.15.

  8. 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

  9. 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.

  10. Development of an advanced, continuous mild gasification process for the production of co-products. Quarterly report, April--June 1995

    SciTech Connect

    1995-08-01

    The objective of this research and development effort was to develop an advanced, continuous ``mild gasification`` process. The relative quantities and properties of the products are appropriate for making the concept economically and environmentally viable. In ``mild gasification,`` coal is converted under relatively mild conditions of temperature and pressure in the absence of air into products which include a high heating value gas, high aromatic condensibles, char and coke all with physical and chemical properties suitable for the anticipated end uses. Two tons of CTC/DOE continuous coke of 6 in. {times} 5 in. {times} 4 in. size was produced in the Pilot Demonstration Unit. This coke was tested under actual foundry conditions in a 96 in. diameter commercial cupola. The test was run on the first shift on April 19, 1995. The coke sample was used as a direct replacement for 25 percent of the coke charge. A total of 51 scrap iron charges were run with the CTC/DOE continuous coke. Results of the test were excellent. The two main indicators improved., Tap temperature increased from an average of 2846{degrees}F to 2890{degrees}F. Carbon pickup improved from 3.49 percent C to 3.59 percent C when the CTC coke, hit the bed. These results are very meaningful because they cannot be measured in the lab. ChemChar Research, Inc. in Columbia, Missouri, is evaluating CTC chars as potential agents for removing pollutants from gas streams. Composite CTC char treated with the ChemChar activation process resulted in promising results. A 11.8 percent toluene adsorption and 13.4 percent monochlorobenzene adsorption were achieved with CTC char after activation.

  11. 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.

  12. 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.

  13. Development of an advanced, continuous mild gasification process for the production of co-products. Quarterly technical progress report, April--June 1988

    SciTech Connect

    Ness, R.O. Jr.

    1988-07-01

    The Department of Energy is investigating a process concept called Mild Gasification in which rapid devolatilization of coal under mild conditions of temperature and pressure would yield three product slates: a low- or medium-BTU gas, a valuable hydrocarbon condensate, and a reactive char. The ongoing objective of this program is to develop a continuous mild gasification process which will produce a product mix that optimizes process economics. In order to provide the incentive for private industry to commercialize the process, it is necessary to demonstrate yields and qualities in a versatile continuous process development unit (PDU). This unit must be capable of assessing both coal- and process-specific effects in a cost-effective and timely manner. Based on literature reviews and experimental verification, a data base will be developed correlating coal and process parameters with product characteristics. This will provide process developers with the information necessary to derive site-specific economics which will be crucial for the commercialization of the mild gasification process. The literature review and market assessment has been completed under Task 1 of the program. Under Task 2, coal-specific tests are being conducted on three AMAX coals: Chinook, an Indiana {number_sign}3 bituminous coal; Delta, an Illinois {number_sign}6 bituminous coal; and Eagle Butte, a Wyodak subbituminous coal. Various methods of char upgrading are being conducted by AMAX R&D of Golden, Colorado. The upgraded char is then combined with iron ore and tested for pig iron production under an AMAX subcontract to Pellet Technology Corporation of Marquette, Michigan. In addition to the test program, process development and scaleup information is being developed for a 1 ton/hr pilot plant unit. Plans for Tasks 2 and 3, equipment modifications, and report. Results include: char analysis, condensable analysis, waste water analysis, and gas analysis.

  14. 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.

  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. Physico-chemical properties and gasification reactivity of co-pyrolysis char from different rank of coal blended with lignocellulosic biomass: Effects of the cellulose.

    PubMed

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

    2017-07-01

    In this paper, the influence of cellulose on the physicochemical properties and the gasification reactivity of co-pyrolysis char was investigated. A specific surface area analyzer and an X-ray diffraction system were used to characterize the pore structure and the micro-crystalline structure of char. Fractal theory and deconvolution method were applied to quantitatively investigate the influence of cellulose on the structure of co-pyrolysis char. The results indicate that the improvements in the pore structure due to the presence of cellulose are more pronounced in the case of anthracite char with respect to bituminous char. Cellulose promotes the ordering of micro-scale structure and the uniformity of both anthracite and bituminous char, while the negative synergetic effect was observed during gasification of co-pyrolysis char. The exponential relationships between fractal dimension and specific surface area were determined, along with the relations between the gasification reactivity index and the microcrystalline structure parameter. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. 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

  18. Study on the genotoxicity of 13 mild coal gasification products

    SciTech Connect

    Zhong, B.Z.; Robbins, S.; Bryant, D.; Ong, T.; Ma, J.

    1994-12-31

    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 use of coal can help meet future energy needs. The mutagenicity of 13 gasification product samples from various coal mine sources, with different processing conditions and boiling point ranges, was studied using bacteria. The results show that 9 of the 13 composite samples displayed mutagenic activity in the Ames assay. Six mutagenic samples were further fractionated into basic, acidic nonpolar and polar neutral subfractions. All samples displayed mutagenic activity in the Ames assay with S9 in the nonpolar neutral subfraction. Five mutagenic samples were also tested for genotoxicity in three mammalian cell assays. None of the samples tested caused gene mutations in Chinese hamster lung fibroblast (V79) cells in the HGPRT assay system. However, all five samples were found to induce micronuclei and sister chromatid exchange in V79 cells. Chemical characterization of the subfractions indicates that the nonpolar neutral subfractions contain aromatic hydrocarbons. These compounds may be responsible for the genotoxic activity of samples.

  19. 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. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. True in-situ oil retort: the role of intrashale transport and char gasification and an analysis of retort performance

    SciTech Connect

    Louvar, J.F.; Crowl, D.A.

    1984-01-01

    This study expands the theoretical understanding of the true in situ crack retort process for Eastern oil shale by (a) establishing the role of intrashale 2-dimensional transport on the performance of the retort, (b) determining the significance of the intrashale char gasification reactions with water and carbon dioxide, and (c) analyzing the performance characteristics of a theoretical true in-situ retort process for Eastern oil shale and establishing conditions for improving the retort performance. Two computer simulation models were developed and evaluated, one with 1-D mass transport and another with 2-D mass transport. The 1-D transport model featured instantaneous 1-D transfer of the pyrolysis products to the crack. The 2-D transport model featured 2-D species transport within the oil shale, and pyrolysis, gasification, and oxidation reactions within the oil shale.

  1. 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.

  2. 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.

  3. Scaleup of mild gasification to a process development unit

    SciTech Connect

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

    1992-11-01

    The overall objectives 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. During the first ten months of this project. the NEPA Application for construction and operation of the PDU facility at the SIUC site was written and submitted for approval. In addition, the process design for the PDU was completed, bid packages for the PDU modules were prepared and sent to a slate of prospective bidders, and bids were received from the participating bidders.

  4. Mild coal gasification screw pyrolyzer development and design

    SciTech Connect

    Camp, D.W.

    1990-08-01

    Our objective is to produce information and design recommendations needed for the development of an efficient continuous process for the mild gasification of caking bituminous coals. We have focused on the development of an externally heated pyrolyzer in which the sticky, reacting coal is conveyed by one or more screws. We have taken a multifaceted approach to forwarding the development of the externally-heated screw pyrolyzer. Small scale process experiments on a 38-mm single screw pyrolyzer have been a major part of our effort. Engineering analyses aimed at producing design and scaleup equations have also been important. Process design recommendations follow from these. We critically review our experimental data and experience, and information from the literature and equipment manufactures for the purpose of making qualitative recommendations for improving practical pyrolyzer design and operation. Benchscale experiments are used to supply needed data and test some preliminary concepts. 6 refs., 4 figs., 1 tab.

  5. 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.

  6. 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.

  7. 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.

  8. 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%.

  9. 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%.

  10. ENCOAL mild coal gasification project public design and construction report

    SciTech Connect

    1994-12-01

    This Public Design Report describes the 1000 ton per day ENCOAL mild coal gasification demonstration plant now in operation at the Buckskin Mine near Gillette, Wyoming. The objective of the project is to demonstrate that the proprietary Liquids From Coal (LFC) technology can reliably and economically convert low Btu PRB coal into a superior, high-Btu solid fuel (PDF), and an environmentally attractive low-sulfur liquid fuel (CDL). The Project`s plans also call for the production of sufficient quantities of PDF and CDL to permit utility companies to carry out full scale burn tests. While some process as well as mechanical design was done in 1988, the continuous design effort was started in July 1990. Civil construction was started in October 1990; mechanical erection began in May 1991. Virtually all of the planned design work was completed by July 1991. Most major construction was complete by April 1992 followed by plant testing and commissioning. Plant operation began in late May 1992. This report covers both the detailed design and initial construction aspects of the Project.

  11. 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.

  12. Scale-up of mild gasification to a process development unit. Quarterly report, May--August 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. 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. 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 and it is planned to submit it to the State of Illinois early in the next quarter. Also this quarter, a presentation of the project aims and status were presented during a site visit on August 11, 1993 by DOE personnel and Robert Kripowicz, the Staff Assistant, Subcommittee on the Interior, of the US House Committee on Appropriations.

  13. 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.

  14. 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.

  15. CO{sub 2} and H{sub 2}O gasification kinetics of a coal char in the presence of methane

    SciTech Connect

    Zhi-qiang Sun; Jin-hu Wu; Dongke Zhang

    2008-07-15

    The kinetics of CO{sub 2} and H{sub 2}O gasification of a Chinese coal char in the presence of methane has been studied using a thermogravimetric analyzer (TGA) in the temperature range from 1173 to 1273 K. It was observed that the rate of carbon conversion increased with an increasing temperature and decreased with an increasing CH{sub 4} concentration. The rate of carbon conversion during the gasification of the char experienced a maximum without the presence of methane but decreased continuously with carbon conversion in the presence of methane. Carbon deposition from CH{sub 4} cracking reduced the overall rate of carbon conversion during gasification, but this effect was reduced as the temperature and concentration of CO{sub 2} or H{sub 2}O were increased. A gas-solid reaction shrinking core model was developed and applied to the char-CH{sub 4}-CO{sub 2}/H{sub 2}O systems. The experimental results were used to determine the kinetic parameters. The model predictions compared favorably to the measured data. The overall carbon conversion rate has been shown to be a combination of carbon gasification, by CO{sub 2} or H{sub 2}O, respectively, and methane cracking. 11 refs., 12 figs., 2 tabs.

  16. Characterization and partitioning of the char ash collected after the processing of pine wood chips in a pilot-scale gasification unit

    Treesearch

    Thomas L. Eberhardt; Hui Pan; Leslie H. Groom; Chi-Leung So

    2011-01-01

    Southern yellow pine wood chips were used as the feedstock for a pilot-scale gasification unit coupled with a 25 kW generator. The pulp-grade wood chips were relatively free of bark and low in ash content. Processing this feedstock yielded a black/sooty by-product that upon combustion in a muffle furnace resulted in an ash content of about 48%. The term "char ash...

  17. 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.

  18. [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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Integrated methods for production of clean char and its combustion properties. Technical report, December 1, 1991--February 29, 1992

    SciTech Connect

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

    1992-08-01

    The overall objective of this two-year program is to produce low sulfur char using an integrated process scheme which combines physical coal cleaning, mild gasification and char desulfurization. The goal of the project is to produce chars with 50% or more lower sulfur emissions than that of the parent coal, and at minimum meet 1995 emission standards of 2.5 lbs S0{sub 2}/MMBtu. This project is a cooperative effort between the ISGS, UNDEERC and the US EPA and is cost-shared with the US EPA and the US DOE through UNDEERC. Mild gasification and char desulfurization studies are conducted with six coals selected from the Illinois Basin Coal (IBC) Sample Program in a batch fluidized-bed reactor at the ISGS. Pound quantities of chars for combustion testing are prepared in a continuous rotary kiln reactor under optimized conditions of mild gasification and char desulfurization. Burning characteristics and ash deposition behaviors of desulfurized chars are determined at the US EPA in a 14 kill pilot-scale combustor and at UNDEERC in a drop tube furnace (DTF). In some tests, methane is examined as an auxiliary fuel, and high-surface-area hydrated lime developed at ISGS is used to further reduce S0{sub 2} emissions. Complete analyses of the fuels are obtained to aid char desulfurization studies and help explain combustion and S0{sub 2} emission characteristics of the char.

  4. Development of an advanced, continuous mild gasification process for the production of co-products. Quarterly technical progress report, April--June 1992

    SciTech Connect

    Runge, B.D.; Ness, R.O. Jr.; Sharp, L.L.; Shockey, R.E.

    1992-07-01

    The char produced in the 100-lb/hr process development unit has been magnetically cleaned by AMAX and returned to the Energy and Environmental Research Center (EERC). The final calcining step of the process is currently being performed in the 4-lb/hr continuous fluidized-bed reactor (CFBR). The liquid products generated by the PDU have been collected and split into usable fractions and fractions to be discarded. Samples of the coal-derived liquids have been sent to Merichem Corporation of Houston and Koppers Industries of Pittsburgh for determination of their usefulness as chemical feedstock for the production of cresylic acids and anode-grade-binder pitch. The technical and economic assessment performed by Xbi and J.E Sinor Consultants has been completed. The briquette testing being conducted at the EERC has produced high quality briquettes using a number of binder agents. The next step in the test matrix will include the use of coal-derived liquids from the PDU as the binder. An additional coal has been added to the mild gasification test matrix. AMAX recently acquired two eastern low-sulfur bituminous coals and suggested that a limited test schedule be conducted to determine the suitability of these coals for the mild gasification process. The sulfur levels in the raw coals are below the target levels suggested by the steel industry for metallurgical coke use. To date, it has not been possible to reach these goals using the high-sulfur Illinois Basin coals tested.

  5. 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.

  6. Mutagenicity of six DMSO and Tween 80-solvated mild gasification products in Salmonella typhimurium

    SciTech Connect

    Stamm, S.C.; Zhong, B.Z.; Bryant, E.D.; Ong, T.; Johnson, R.; Sharp, S.

    1992-12-31

    Mild gasification is an emerging coal-conversion process that is being developed by the United States Department of Energy and private industry to meet future energy needs. Products of this process are being submitted to NIOSH in Morgantown, WV, for the evaluation of their genotoxic activity. Six mild gasification products, solvated in both DMSO and Tween 80, have been assayed for mutagenic activity in the preincubation modification of the Ames Salmonella assay system using tester strains TA98 and TA1OO with and without S9 metabolic acbvation. No significant mutagenic activity was detected in these samples when DMSO was used as the solvent vehicle; however, two of the six samples indicated positive mutagenic activity on tester strain TA98 with S9 when solvated in Tween 80. The positive control 2-aminoanthracene, an aromatic amine, demonstrated a significant increase in response when assayed using Tween 80 as a solvent as compared to DMSO. These results suggest that mutagen/solvent interactons may be occurring in the testing of these coal-derived samples and the positive control in the Ames assay. Since past studies have indicated that aromatic amines account for a large percentage of the mutagenic activity of coal-derived materials, the solitary use of DMSO as a solvent for mutagenicity determination must be questioned for these and other chemically related materials.

  7. 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.

  8. [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.

  9. 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.

  10. Mutagenicity of six DMSO and Tween 80-solvated mild gasification products in Salmonella typhimurium

    SciTech Connect

    Stamm, S.C.; Zhong, B.Z.; Bryant, E.D.; Ong, T. . Div. of Respiratory Disease Studies); Johnson, R.; Sharp, S. )

    1992-01-01

    gasification is an emerging coal-conversion process that is being developed by the United States Department of Energy and private industry to meet future energy needs. Products of this process are being submitted to NIOSH in Morgantown, WV, for the evaluation of their genotoxic activity. Six mild gasification products, solvated in both DMSO and Tween 80, have been assayed for mutagenic activity in the preincubation modification of the Ames Salmonella assay system using tester strains TA98 and TA1OO with and without S9 metabolic acbvation. No significant mutagenic activity was detected in these samples when DMSO was used as the solvent vehicle; however, two of the six samples indicated positive mutagenic activity on tester strain TA98 with S9 when solvated in Tween 80. The positive control 2-aminoanthracene, an aromatic amine, demonstrated a significant increase in response when assayed using Tween 80 as a solvent as compared to DMSO. These results suggest that mutagen/solvent interactons may be occurring in the testing of these coal-derived samples and the positive control in the Ames assay. Since past studies have indicated that aromatic amines account for a large percentage of the mutagenic activity of coal-derived materials, the solitary use of DMSO as a solvent for mutagenicity determination must be questioned for these and other chemically related materials.

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

    SciTech Connect

    Knight, R.A.; Babu, S.P.

    1988-09-01

    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 zinc chloride as a potential recirculating catalyst for coal, initiated in the previous quarter, was continued. The design of an all-quartz laboratory-scale isothermal free-fall reactor was completed, and construction was begun. One free-fall experiment was performed in an existing stainless-steel free-fall reactor with methanol-treated Illinois No. 6 high-volatile bituminous coal. 1 ref., 2 figs., 2 tabs.

  12. Scaleup of mild gasification to a process development unit. [MILDGAS Process

    SciTech Connect

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

    1992-01-01

    The overall objectives 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. During the first ten months of this project. the NEPA Application for construction and operation of the PDU facility at the SIUC site was written and submitted for approval. In addition, the process design for the PDU was completed, bid packages for the PDU modules were prepared and sent to a slate of prospective bidders, and bids were received from the participating bidders.

  13. 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.

  14. 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.

  15. Synergistic combination of biomass torrefaction and co-gasification: Reactivity studies.

    PubMed

    Zhang, Yan; Geng, Ping; Liu, Rui

    2017-09-01

    Two typical biomass feedstocks obtained from woody wastes and agricultural residues were torrefied or mildly pyrolized in a fixed-bed reactor. Effects of the torrefaction conditions on product distributions, compositional and energetic properties of the solid products, char gasification reactivity, and co-gasification behavior between coal and torrefied solids were systematically investigated. Torrefaction pretreatment produced high quality bio-solids with not only increased energy density, but also concentrated alkali and alkaline earth metals (AAEM). As a consequence of greater retention of catalytic elements in the solid products, the chars derived from torrefied biomass exhibited a faster conversion than those derived from raw biomass during CO2 gasification. Furthermore, co-gasification of coal/torrefied biomass blends exhibited stronger synergy compared to the coal/raw biomass blends. The results and insights provided by this study filled a gap in understanding synergy during co-gasification of coal and torrefied biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. 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.

  17. 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.

  18. 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)

  19. Mild coal gasification: Product separation, pilot-unit support, twin screw heat transfer, and H sub 2 S evolution

    SciTech Connect

    Camp, D.W.; Wallman, P.H.; Coburn, T.T.

    1991-08-09

    Our general objective is to further the development of efficient continuous mild coal gasification processes. Our efforts this year have been in four main areas. A new thrust has been to identify and develop efficient processes to separate the vapor product stream into particulate-free liquid and mist-free gas. We continued work aimed at predicting heat transfer rates (hence throughput) in externally-heated twin-screw pyrolyzers. We sought to provide technical support for the design, installation, startup, and operation of the DOE-sponsored 500 kg/hr twin-screw mild gasification unit at Coal Technology Corporation (CTC). A smaller laboratory effort had the objective of identifying and testing the reaction mechanisms of sulfur species during coal pyrolysis. Detailed subproject objectives are given in their respective sections. 20 refs., 4 figs., 1 tab.

  20. Literature survey of mild gasification processes, co-products upgrading and utilization, and market assessment: Topical report

    SciTech Connect

    Wootten, J.M.; Nawaz, M.; Duthie, R.G.; Knight, R.A.; Onischak, M.; Babu, S.P.; Bair, W.G.

    1988-01-01

    The primary objective of this DOE-sponsored project is to develop an advanced mild gasification process to produce coal-derived co- products that can readily open new markets for coal in both the utility and nonutility sectors. The study will incorporate novel and innovative concepts for process development and for co-products utilization. The former includes the development of a means to promote the rapid, continuous devolatilization of caking coals, the use of inexpensive reactor additives for capturing sulfur compounds, and the use of inexpensive reaction gases to produce co-products of optimal quality and quantity. It is the ultimate goal of this project to commercialize the advanced mild gasification technology in the next 5 to 10 years. 109 refs., 86 figs., 45 tabs.

  1. 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)

  2. 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.

  3. Upgrading mild gasification liquids to produce electrode binder pitch; [Quarterly] report, September 1--November 30, 1993

    SciTech Connect

    Knight, R.A.

    1994-03-01

    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{degree}--1500{degree}F to produce solid, gas, and liquid co-products. With Illinois coal, the 750{degree}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 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 was constructed for operation at 1200{degree}--1800{degree}F. Reactor design features and process conditions are being examined to optimize the properties of the finished pitch. During the current quarter, the semi-continuous thermocracking unit was updated with several improvements: pressure transducers, a mass flow controller, and a load cell transducer were installed to improve data acquisition and control capabilities. Also, two samples produced in the previous year were evaluated by a commercial tar processing firm for mesophase content, QI particle size, and other carbon types.

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

    SciTech Connect

    Ness, R.O. Jr.; Li, Y.; Heidt, M.

    1992-09-01

    Prior to disassembly of the CFBR, accumulated tar residue must be removed from the reactor, piping and tubing lines, and the condenser vessels. Based on experience from the CFBR mild gasification tests, lacquer thinner must be pumped through the unit for at least one hour to remove the residual tar. The lacquer thinner wash may be followed by a water wash. The CFBR will be disassembled after the system has been thoroughly flushed out. The following equipment must be disassembled and removed for storage: Superheater; Water supply pump; Coal feed system (hopper, auger, ball feeder, valves); Reactor; Cyclone and fines catch pot; Condensers (water lines, glycol bath, condenser pots, valves); and Gas meter. After the process piping and reactor have been disassembled, the equipment will be inspected for tar residues and flushed again with acetone or lacquer thinner, if necessary. All solvent used for cleaning the system will be collected for recycle or proper disposal. Handling and disposal of the solvent will be properly documented. The equipment will be removed and stored for future use. Equipment contaminated externally with tar (Level 4) will be washed piece by piece with lacquer thinner after disassembly of the PRU. Proper health and safety practices must be followed by the personnel involved in the cleanup operation. Care must be taken to avoid ingestion, inhalation, or prolonged skin contact of the coal tars and lacquer thinner. Equipment contaminated internally by accumulation of residual tar or oil (Level 5) will be flushed section by section with lacquer thinner. The equipment will be washed with solvent both before and after disassembly to ensure that all tar has been removed from the piping, pumps, gas quench condensers, light tar condensers, and drain lines. The coal tars wig be separated from the solvent and incinerated.

  6. 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.

  7. Combustion properties of coal-char blends: No{sub x} emission characteristics. Technical report, December 1, 1992--February 28, 1993

    SciTech Connect

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

    1993-05-01

    Tests under pulverized coal combustion conditions suggest that NO{sub x} formed during release of volatile matter far exceed NO{sub x} formed during combustion of the resulting char. This is attributed to char/NO{sub x} interactions by both direct reduction of NO, by carbon and char-catalyzed reduction by CO. This implies combustion of char not only produces substantially lower No{sub x} but the presence of char in the flame during initial stages of combustion may potentially provide catalytic activity for reduction of NO{sub x} produced from volatile nitrogen. The goal of the project is to determine if the concept of NO{sub x} reduction by char/NO{sub x} interactions, while maintaining a high combustion efficiency by co-firing coal with char, is a technically feasible way to reduce NO{sub x} emissions. Char samples will be prepared in a continuous rotary tube kiln under mild gasification conditions. Combustion testing will be conducted with the coal and coal-char blends in a combustor located at BYU. The effect of coal/char ratio, formation characteristics, ignition characteristics, flame stability, and combustion efficiency will be determined. Physical and chemical properties of the fuels will be measured to help explain combustion and emission characteristics of fuels.

  8. 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.

  9. 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.

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

    SciTech Connect

    Knight, R.A.; Babu, S.P.

    1988-09-01

    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 zinc chloride as a potential recirculating catalyst for coal, initiated in the previous quarter, was continued. The design of an all-quartz laboratory-scale isothermal free-fall reactor was completed, and construction was begun. One free-fall experiment was performed in an existing stainless-steel free-fall reactor with methanol-treated Illinois No. 6 high-volatile bituminous coal. 1 ref., 2 figs., 2 tabs.

  11. Work plan for ``Production of mild gasification co-products`` project

    SciTech Connect

    Not Available

    1992-07-01

    The coproducts wig be collected and handled to limit their exposure to air. The aim is to ensure the coproducts are as close as possible to those which would be generated by an LFC Plant at the mine site. The char will be collected in sealed, stainless steel containers. While in the containers the char will be cooled to room temperature and a small amount of water added (5% by weight) to simulate the final processing step, stabilizing the char and converting it to PDF. This SPU-processed PDF will be transferred to nitrogen iffed five gallon polyethylene pads for storage and shipping. During processing the CDL will be collected using a single stage, thermostatically-controlled electrostatic precipitator (ESP). The collected CDL will be trapped in a sealed collection cylinder attached directly to the ESP. The CDL will be transferred from the collection cylinder to replace nitrogen in nitrogen-filled one liter bottles for storage and shipment. The results of the analyses will be collected and included in the project data base to be retrieved as necessary for use in the topical and final reports. Twenty (20) Kg samples of SPU processed PDF will be sent to three government laboratories plus one outside laboratory. The government laboratories will be the same labs which received the fresh coal samples, as indicated in section 4.2, above. The outside laboratory will analyze the SPU processed PDF as was done for the coal. These tests will include the bulk density, particle size distribution, proximate analysis, ultimate analysis (C, H, N, O, S), and heating value.

  12. Work plan for Production of mild gasification co-products'' project

    SciTech Connect

    Not Available

    1992-07-01

    The coproducts wig be collected and handled to limit their exposure to air. The aim is to ensure the coproducts are as close as possible to those which would be generated by an LFC Plant at the mine site. The char will be collected in sealed, stainless steel containers. While in the containers the char will be cooled to room temperature and a small amount of water added (5% by weight) to simulate the final processing step, stabilizing the char and converting it to PDF. This SPU-processed PDF will be transferred to nitrogen iffed five gallon polyethylene pads for storage and shipping. During processing the CDL will be collected using a single stage, thermostatically-controlled electrostatic precipitator (ESP). The collected CDL will be trapped in a sealed collection cylinder attached directly to the ESP. The CDL will be transferred from the collection cylinder to replace nitrogen in nitrogen-filled one liter bottles for storage and shipment. The results of the analyses will be collected and included in the project data base to be retrieved as necessary for use in the topical and final reports. Twenty (20) Kg samples of SPU processed PDF will be sent to three government laboratories plus one outside laboratory. The government laboratories will be the same labs which received the fresh coal samples, as indicated in section 4.2, above. The outside laboratory will analyze the SPU processed PDF as was done for the coal. These tests will include the bulk density, particle size distribution, proximate analysis, ultimate analysis (C, H, N, O, S), and heating value.

  13. Kinetics and Mechanisms of NO(x) - Char Reduction.

    SciTech Connect

    Suurerg, E.M.; Lilly, W.D.; Aarna, I.

    1997-12-31

    Most industrially important carbons are produced from naturally occurring materials such as coal, oil, peat or wood by some form of thermal process. Chars are obtained from those natural materials as a residue after removal of the volatile matter. Chars (prepared from coal or other organic precursors) are non-graphitizable carbons, meaning that they cannot be transformed into graphitic carbon. Chars are comprised of elementary crystallites in parallel layers which are randomly oriented with respect to each other and are crosslinked together through weak bonds. Voids between crystallites determine the porosity of the char, and this plays an important role in char gasification behavior. Chars usually contain a pore size distribution, in which the larger macro- and mesopores play an important role in transport of reactants into the much smaller micropores, in which most gasification and combustion take place. Therefore, the effectiveness of micropores in gasification depends heavily on the numbers of meso- and macropores.

  14. Integrated production/use of ultra low-ash coal, premium liquids and clean char. Technical report, September 1, 1991--November 30, 1991

    SciTech Connect

    Kruse, C.W.

    1991-12-31

    This integrated, multi-product approach for utilizing Illinois coal starts with the production of ultra low-ash coal and then converts it to high-vale, 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.

  15. 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)

  16. 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.

  17. 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.

  18. Upgrading mild gasification liquids to produce electrode binder pitch. [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 production of electrode binder pitch from mild gasification liquids. The IGT MILDGAS process pyrolyzes coal in a 1000{degrees}--1500{degrees}F(538{degrees}--816{degrees}C) fluidized/entrained bed to produce solid, gas, and liquid co-products. With Illinois coal, the 750{degrees}F+ (400{degrees}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 f or electrolytic furnaces. 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{degrees}--1800{degrees}F (650{degrees}--982{degrees}C). Atomization of the pitch at the thermocracker inlet is being examined as a method of optimizing the particle size of polymerized pitch components. Four successful thermocracking tests were performed with a crude Illinois No. 6 pitch from 1110{degrees}F MILDGAS PRU runs. Key pitch properties improved in all cases, with higher temperatures resulting in increased softening point (187--273{degrees}F), QI (1.6--15.7%), TI (18--41%), coking value (38--55%), C/H ratio (1.17--1.57), and density (1.18--1.26).

  19. Development of an advanced, continuous mild gasification process for the production of co-products. Task 4.8, Decontamination and disassembly of the mild gasification process research unit and disposal of co-products

    SciTech Connect

    Ness, R.O. Jr.; Li, Y.; Heidt, M.

    1992-09-01

    Prior to disassembly of the CFBR, accumulated tar residue must be removed from the reactor, piping and tubing lines, and the condenser vessels. Based on experience from the CFBR mild gasification tests, lacquer thinner must be pumped through the unit for at least one hour to remove the residual tar. The lacquer thinner wash may be followed by a water wash. The CFBR will be disassembled after the system has been thoroughly flushed out. The following equipment must be disassembled and removed for storage: Superheater; Water supply pump; Coal feed system (hopper, auger, ball feeder, valves); Reactor; Cyclone and fines catch pot; Condensers (water lines, glycol bath, condenser pots, valves); and Gas meter. After the process piping and reactor have been disassembled, the equipment will be inspected for tar residues and flushed again with acetone or lacquer thinner, if necessary. All solvent used for cleaning the system will be collected for recycle or proper disposal. Handling and disposal of the solvent will be properly documented. The equipment will be removed and stored for future use. Equipment contaminated externally with tar (Level 4) will be washed piece by piece with lacquer thinner after disassembly of the PRU. Proper health and safety practices must be followed by the personnel involved in the cleanup operation. Care must be taken to avoid ingestion, inhalation, or prolonged skin contact of the coal tars and lacquer thinner. Equipment contaminated internally by accumulation of residual tar or oil (Level 5) will be flushed section by section with lacquer thinner. The equipment will be washed with solvent both before and after disassembly to ensure that all tar has been removed from the piping, pumps, gas quench condensers, light tar condensers, and drain lines. The coal tars wig be separated from the solvent and incinerated.

  20. 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.

  1. Upgrading mild gasification liquids to produce electrode binder pitch. Final technical report, 1 September, 1992--31 August, 1993

    SciTech Connect

    Knight, R.A.

    1993-12-31

    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 fluidized/entrained bed to produce solid, gas, and liquid co-products. 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 pitch from the DOE-sponsored MILDGAS process research programs being modified by a flash thermocracking technique to achieve specifications typical of a binder pitch. Atomization of the pitch at the thermocracker inlet is being examined as a method of optimizing the particle size of polymerized pitch components. Six successful thermocracking tests were performed with a crude Illinois No. 6 pitch from 1,110 F MILDGAS PRU runs. The tests were conducted at 1,200--1,500 F with pitch feed rates of 2.6--12.7 g/min and residence times of 2.6--4.5 seconds. Tests were conducted with and without an atomizing nozzle to evaluate the effects of atomization on the primary quinoline- and toluene-insoluble (QI and TI) content of the pitch. Key pitch properties improved in all cases, with higher temperatures resulting in increased softening point (187--273 F), QI (10--16%), TI (18--41%), coking value (38--55%), C:H ratio (1.17--1.57), and density (1.16--1.26). Higher reactor loading appears to promote more coke and gas production, but atomization promotes higher yield of cracked pitch, oil, and gas and less coke. The products of pitch cracking ranged from 26--54 wt% cracked pitch, 13--44 wt% coke, 16--28 wt% oils, and 3--23 wt% high-Btu gas. The pitch cokes had C:H atomic ratios of 1.95--2.93, which could be increased by calcination for use as a carbon anode filler.

  2. 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.

  3. 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%.

  4. Integrated production/use of ultra low-ash coal, premium liquids and clean char. Technical report, March 1, 1992--May 31, 1992

    SciTech Connect

    Kruse, C.W.; Carlson, S.L.; Snoeyink, V.L.; Feizoulof, C.; Assanis, D.N.; Syrimis, M.; Fatemi, S.M.

    1992-10-01

    The first step in the envisioned integrated, multi-product approach for utilizing Illinois coal is the production of ultra low-ash coal. Subsequent steps would convert low-ash coal to high-value products through mild gasification, char activation, and oxidation reactions. Approximately eight pounds of low-ash coal has been obtained from the crude reactor slurry produced for us at the University of North Dakota Energy and Environmental Research Center (UNDEERC). After treatment to remove the remaining meta-cresol, this material will be subjected to mild gasification. Low-ash mild gasification char will be activated and a catalyst surface will be added by oxidation. A 20% coal: 80% diesel fuel slurry was tested in cylinder two of a two-cylinder, diesel engine after the necessary modifications in the engine`s fuel injection system were made. Four tests indicated that the coal successfully substitutes for diesel fuel in the slurry. The fuel burns in the cylinder, with slightly improved thermal and combustion efficiency. The tests were performed at 1800 rpm and 2200 rpm and 75% load. The change in the surface properties of Calgon F-400 commercial activated carbon caused by several treatments were examined by X-ray Photoelectron Spectroscopy (XPS).

  5. 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.

  6. 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.

  7. 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.

  8. 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.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  10. 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.

  11. 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.

  12. 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

  13. Integrated methods for production of clean char and its combustion properties. Quarterly technical report, December 1, 1992--February 28, 1993

    SciTech Connect

    DeBarr, J.A.; Rostam-Abadi, M.; Gullett, B.K.; Benson, S.A.; Toman, D.L.; Honea, F.

    1993-05-01

    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 pilot-scale 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, desulfurized chars with SO{sub 2} emissions 60--71% lower than the parent coals were made in the FBR, 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%. During the reporting period, about 160 pounds of {minus}48 mesh IBC-102 coal were preoxidized in air at 150{degrees}C for 30 minutes in the RTK to minimize agglomeration during MG tests. MG of the preoxidized coal at 600{degrees}C produced about 75 pounds of char. About65 pounds of LTO char were prepared by oxidizing the MG char at 420,,C for about 10 minutes. The amount of sulfur removed in the RTK was less than in the FBR, and gave a char with SO{sub 2} emissions of about 2.4 lbs SO{sub 2}/MmBtu. The greater sulfur removal in the FBR was attributed to a smaller mean particle diameter, better gas-solid contact and/or a decreased partial pressure of SO{sub 2}.

  14. Reactivity of young chars via energetic distribution measurements

    SciTech Connect

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

    1991-01-01

    In this report, we present some preliminary work performed on the effect of CO{sub 2} partial pressure on temperature programmed desorption spectra from CO{sub 2}-oxidized chars. The following was accomplished during the reporting period: Temperature programmed desorption (TPD) experiments were conducted on oxidized resin and Wyodak coal char samples gasified under varying different CO{sub 2} partial pressures. The following observations were made: CO{sub 2} partial pressure can be an important factor affecting TPD spectra. Generally, the total amount of surface oxygen desorbed as CO and CO{sub 2} increases with CO{sub 2} partial pressure during gasification for both resin char and Wyodak coal char. The total amount of oxygen desorbed is also a function of gasification temperature. Apparently, the higher the gasification temperature, the more CO and CO{sub 2} are desorbed. As an example, for 0.33 atm CO{sub 2} partial pressure, the peak CO desorption rates are 0.17 mmole/g/min and 0.13 mmole/g/min, corresponding to gasification temperature 1223K and 1173K. 12 refs., 8 figs.

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

    PubMed

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

    2004-01-01

    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. 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.

  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. Solar coal gasification reactor with pyrolysis gas recycle

    SciTech Connect

    Aiman, W.R.; Gregg, D.W.

    1983-11-15

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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. Characteristics of the microwave pyrolysis and microwave CO2-assisted gasification of dewatered sewage sludge.

    PubMed

    Chun, Young Nam; Jeong, Byeo Ri

    2017-07-28

    Microwave drying-pyrolysis or drying-gasification characteristics were examined to convert sewage sludge into energy and resources. The gasification was carried out with carbon dioxide as a gasifying agent. The examination results were compared with those of the conventional heating-type electric furnace to compare both product characteristics. Through the pyrolysis or gasification, gas, tar, and char were generated as products. The produced gas was the largest component of each process, followed by the sludge char and the tar. During the pyrolysis process, the main components of the produced gas were hydrogen and carbon monoxide, with a small amount of hydrocarbons such as methane and ethylene. In the gasification process, however, the amount of carbon monoxide was greater than the amount of hydrogen. In microwave gasification, a large amount of heavy tar was produced. The largest amount of benzene in light tar was generated from the pyrolysis or gasification. Ammonia and hydrogen cyanide, which are precursors of NOx, were also generated. In the microwave heating method, the sludge char produced by pyrolysis and gasification had pores in the mesopore range. This could be explained that the gas obtained from the microwave pyrolysis or gasification of the wet sewage sludge can be used as an alternative fuel, but the tar and NOx precursors in the produced gas should be treated. Sludge char can be used as a biomass solid fuel or as a tar removal adsorbent if necessary.

  8. Study of the removal mechanism of aquatic emergent pollutants by new bio-based chars.

    PubMed

    Bernardo, Maria Manuel Serrano; Madeira, Catarina Alexandra Catanas; Dos Santos Nunes, Nuno Carlos Lapa; Dias, Diogo André Costa Messias; Godinho, Delfina Maria Barbosa; de Jesus Pinto, Maria Filomena; do Nascimento Matos, Inês Alexandra Morgado; Carvalho, Ana Paula Batista; de Figueiredo Ligeiro Fonseca, Isabel Maria

    2017-08-16

    This work is dedicated to study the potential application of char byproducts obtained in the gasification of rice husk (RG char) and rice husk blended with corn cob (RCG char) as removal agents of two emergent aquatic contaminants: tetracycline and caffeine. The chars presented high ash contents (59.5-81.5%), being their mineral content mainly composed of silicon (as silica) and potassium. The samples presented a strong basic character, which was related to its higher mineral oxides content. RCG char presented better textural properties with a higher apparent surface area (144 m(2) g(-1)) and higher micropore content (V micro = 0.05 cm(3) g(-1)). The alkaline character of both chars promoted high ecotoxicity levels on their aqueous eluates; however, the ecotoxic behaviour was eliminated after pH correction. Adsorption experiments showed that RG char presented higher uptake capacity for both tetracycline (12.9 mg g(-1)) and caffeine (8.0 mg g(-1)), indicating that textural properties did not play a major role in the adsorption process. For tetracycline, the underlying adsorption mechanism was complexation or ion exchange reactions with the mineral elements of chars. The higher affinity of RG char to caffeine was associated with the higher alkaline character presented by this char.

  9. 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. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. 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.

  11. Pressurized pyrolysis and gasification of Chinese typical coal samples

    SciTech Connect

    Hanping Chen; Zhiwu Luo; Haiping Yang; Fudong Ju; Shihong Zhang

    2008-03-15

    This paper aims to understand the pyrolysis and gasification behavior of different Chinese coal samples at different pressures. First, the pyrolysis of four typical Chinese coals samples (Xiaolongtan brown coal, Shenfu bituminous coal, Pingzhai anthracite coal, and Heshan lean coal) were carried out using a pressurized thermogravimetric analyzer at ambient pressure and 3 MPa, respectively. The surface structure and elemental component of the resultant char were measured with an automated gas adsorption apparatus and element analyzer. It was observed that higher pressure suppressed the primary pyrolysis, while the secondary pyrolysis of coal particles was promoted. With respect to the resultant solid char, the carbon content increased while H content decreased; however, the pore structure varied greatly with increasing pressure for different coal samples. For Xiaolongtan brown coal (XLT) char, it decreased greatly, while it increased obviously for the other three char types. Then, the isothermal gasification behavior of solid char particles was investigated using an ambient thermal analyzer with CO{sub 2} as the gasifying agent at 1000{sup o}C. The gasification reactivity of solid char was decreased greatly with increasing pyrolysis pressure. However, the extent of change displayed a vital relation with the characteristics of the original coal sample. 26 refs., 5 figs., 5 tabs.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

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

    USDA-ARS?s Scientific Manuscript database

    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 (...

  17. 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.

  18. 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).

  19. Partitioning of sodium, chlorine and sulfur during coal and char combustion in a fluid bed

    SciTech Connect

    Bhattacharya, S.P.; He, Y.

    1998-12-31

    Advanced power generation technologies (IGCC, Advanced PFBC) using high moisture low-rank coals require gasification of coal followed by combustion of char in a fluid bed. A study was undertaken to investigate the bed behaviour of char during combustion in a fluid bed. Three high moisture Australian low-rank coals, which are currently used in Victorian power stations, were chosen for this study. These were air dried, ground and sieved to 1--4 mm size. Char was prepared from these coals by devolatilising in a 76-mm diameter spouted bed at 700 C in presence of nitrogen. Char samples were combusted in the same spouted bed under hydrodynamic conditions similar to that in an atmospheric circulating fluid bed at temperatures of 800 C and 900 C. The three coal samples were also combusted under similar conditions to compare with the combustion behaviour of the char. No significant agglomeration problems were observed during combustion of these coals for periods of up to four hours. For one char, the bed defluidized 70 minutes after combustion at 900 C, while the two remaining chars didn`t present any significant agglomeration during the test period of four hours. Ultimate and inorganic analyses were carried out for the coal and char samples before the tests. The bed materials and cyclone ash after each combustion test were analyzed for inorganics and phases using chemical analysis, XRD and DTA techniques. A significant separation of the sodium and chlorine in coal was observed during pyrolysis of the coal to char. During combustion of char, most of the sodium (in char) was captured in the bed materials. This information was used to explain the bed behaviour observed during char combustion. This paper discusses the results and suggest strategies for mitigation of defluidization, that are currently under trial.

  20. 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.

  1. Co-gasification of bituminous coal and hydrochar derived from municipal solid waste: Reactivity and synergy.

    PubMed

    Wei, Juntao; Guo, Qinghua; He, Qing; Ding, Lu; Yoshikawa, Kunio; Yu, Guangsuo

    2017-09-01

    In this work, the influences of gasification temperature and blended ratio on co-gasification reactivity and synergy of Shenfu bituminous coal (SF) and municipal solid waste-derived hydrochar (HTC) were investigated using TGA. Additionally, active alkaline and alkaline earth metal (AAEM) transformation during co-gasification was quantitatively analyzed by inductively coupled plasma optical emission spectrometer for correlating synergy on co-gasification reactivity. The results showed that higher char gasification reactivity existed at higher HTC char proportion and gasification temperature, and the main synergy behaviour on co-gasification reactivity was performed as synergistic effect. Enhanced synergistic effect at lower temperature was mainly resulted from more obviously inhibiting the primary AAEM (i.e. active Ca) transformation, and weak synergistic effect still existed at higher temperature since more active K with prominent catalysis was retained. Furthermore, more active HTC-derived AAEM remaining in SF sample during co-gasification would lead to enhanced synergistic effect as HTC char proportion increased. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. 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.

  3. 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.

  4. Fundamental and exploratory studies of catalytic steam gasification of carbonaceous materials. Final report, fiscal years 1985--1994

    SciTech Connect

    Heinemann, H.; Somorjai, G.A.

    1994-03-01

    The major purpose of this project was to find catalysts which will permit steam gasification of carbonaceous material at reasonable rates and at lower temperatures than currently practiced. Rapid catalyst deactivation must be avoided. An understanding of the catalytic mechanism is necessary to provide leads towards this aim. This report describes the gasification of graphite studies and the gasification of coals, chars, and petroleum cokes.

  5. Underground Coal Gasification Program

    SciTech Connect

    Thorsness, C. B.; Britten, J. A.

    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, 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.

  6. Kinetics of petroleum coke/biomass blends during co-gasification

    NASA Astrophysics Data System (ADS)

    Zhang, Jian-liang; Guo, Jian; Wang, Guang-wei; Xu, Tao; Chai, Yi-fan; Zheng, Chang-le; Xu, Run-sheng

    2016-09-01

    The co-gasification behavior and synergistic effect of petroleum coke, biomass, and their blends were studied by thermogravimetric analysis under CO2 atmosphere at different heating rates. The isoconversional method was used to calculate the activation energy. The results showed that the gasification process occurred in two stages: pyrolysis and char gasification. A synergistic effect was observed in the char gasification stage. This effect was caused by alkali and alkaline earth metals in the biomass ash. Kinetics analysis showed that the activation energy in the pyrolysis stage was less than that in the char gasification stage. In the char gasification stage, the activation energy was 129.1-177.8 kJ/mol for petroleum coke, whereas it was 120.3-150.5 kJ/mol for biomass. We also observed that the activation energy calculated by the Flynn-Wall-Ozawa (FWO) method were larger than those calculated by the Kissinger-Akahira-Sunosen (KAS) method. When the conversion was 1.0, the activation energy was 106.2 kJ/mol when calculated by the KAS method, whereas it was 120.3 kJ/mol when calculated by the FWO method.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Mass balances for underground coal gasification in steeply dipping beds

    SciTech Connect

    Lindeman, R.; Ahner, P.; Davis, B.E.

    1980-01-01

    Two different mass balances were used during the recent underground coal gasification tests conducted in steeply dipping coal beds at Rawlins, Wyoming. The combination of both mass balances proved extremely useful in interpreting the test results. One mass balance which assumed char could be formed underground required the solution of 3 simultaneous equations. The assumption of no char decouples the 3 equations in the other mass balance. Both mass balance results are compared to the test data to provide an interpretation of the underground process.

  16. 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

  17. 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)

  18. Gasification Characteristics of Coal/Biomass Mixed Fuels

    SciTech Connect

    Mitchell, Reginald

    2014-09-01

    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

  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. 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.

  1. Development of Kinetics and Mathematical Models for High Pressure Gasification of Lignite-Switchgrass Blends

    SciTech Connect

    Agrawal, Pradeep K.

    2016-12-20

    The overall objective of the current project was to investigate the high pressure gasification characteristics of a feed containing both coal and biomass. The two feed types differ in their ash contents and ash composition, particularly the alkali content. Gasification of a combined feed of coal and biomass has the potential for considerable synergies that might lead to a dramatic improvement in process economics and flexibility. The proposed study aimed to develop a detailed understanding of the chemistry, kinetics, and transport effects during high pressure gasification of coal-biomass blend feed. Specifically, we studied to develop: (a) an understanding of the catalytic effect of alkali and other inorganic species present in the biomass and coal, (b) an understanding of processing conditions under which synergistic effects of the blending of coal and biomass might be observed. This included the role of particle size, residence time, and proximity of the two feed types, (c) kinetics of high pressure gasification of individual feeds as well as the blends, and (d) development of mathematical models that incorporate kinetics and transport models to enable prediction of gasification rate at a given set of operating conditions, and (e) protocols to extend the results to other feed resources. The goal was to provide a fundamental understanding of the gasification process and guide in optimizing the configurations and design of the next generation of gasifiers. The approach undertaken was centered on two basic premises: (1) the gasification for small particles without internal mass transfer limitations can be treated as the sum of two processes in series (pyrolysis and char gasification) , and (2) the reactivity of the char generated during pyrolysis not only depends on the pressure and temperature but is also affected by the heating rates. Thus low heating rates (10-50 °C/min) typical of PTGA fail to produce char that would typically be formed at high heating rates

  2. The effect of model fidelity on prediction of char burnout for single-particle coal combustion

    SciTech Connect

    McConnell, Josh; Sutherland, James C.

    2016-07-09

    In this study, practical simulation of industrial-scale coal combustion relies on the ability to accurately capture the dynamics of coal subprocesses while also ensuring the computational cost remains reasonable. The majority of the residence time occurs post-devolatilization, so it is of great importance that a balance between the computational efficiency and accuracy of char combustion models is carefully considered. In this work, we consider the importance of model fidelity during char combustion by comparing combinations of simple and complex gas and particle-phase chemistry models. Detailed kinetics based on the GRI 3.0 mechanism and infinitely-fast chemistry are considered in the gas-phase. The Char Conversion Kinetics model and nth-Order Langmuir–Hinshelwood model are considered for char consumption. For devolatilization, the Chemical Percolation and Devolatilization and Kobayashi-Sarofim models are employed. The relative importance of gasification versus oxidation reactions in air and oxyfuel environments is also examined for various coal types. Results are compared to previously published experimental data collected under laminar, single-particle conditions. Calculated particle temperature histories are strongly dependent on the choice of gas phase and char chemistry models, but only weakly dependent on the chosen devolatilization model. Particle mass calculations were found to be very sensitive to the choice of devolatilization model, but only somewhat sensitive to the choice of gas chemistry and char chemistry models. High-fidelity models for devolatilization generally resulted in particle temperature and mass calculations that were closer to experimentally observed values.

  3. The effect of model fidelity on prediction of char burnout for single-particle coal combustion

    SciTech Connect

    McConnell, Josh; Sutherland, James C.

    2016-07-09

    In this study, practical simulation of industrial-scale coal combustion relies on the ability to accurately capture the dynamics of coal subprocesses while also ensuring the computational cost remains reasonable. The majority of the residence time occurs post-devolatilization, so it is of great importance that a balance between the computational efficiency and accuracy of char combustion models is carefully considered. In this work, we consider the importance of model fidelity during char combustion by comparing combinations of simple and complex gas and particle-phase chemistry models. Detailed kinetics based on the GRI 3.0 mechanism and infinitely-fast chemistry are considered in the gas-phase. The Char Conversion Kinetics model and nth-Order Langmuir–Hinshelwood model are considered for char consumption. For devolatilization, the Chemical Percolation and Devolatilization and Kobayashi-Sarofim models are employed. The relative importance of gasification versus oxidation reactions in air and oxyfuel environments is also examined for various coal types. Results are compared to previously published experimental data collected under laminar, single-particle conditions. Calculated particle temperature histories are strongly dependent on the choice of gas phase and char chemistry models, but only weakly dependent on the chosen devolatilization model. Particle mass calculations were found to be very sensitive to the choice of devolatilization model, but only somewhat sensitive to the choice of gas chemistry and char chemistry models. High-fidelity models for devolatilization generally resulted in particle temperature and mass calculations that were closer to experimentally observed values.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Gasification at Navy Bases.

    DTIC Science & Technology

    1978-07-01

    Battalion Center at Port Hueneme, CA. The title of the contract was ’ Coal Gasification Feasibility Study.’ Coal gasification is recognized as a way...operated. A conceptual design study comparing coal gasification with central direct coal-fired boilers at five bases was performed.

  11. 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.

  12. 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.

  13. Pyrolysis, combustion and gasification characteristics of Nannochloropsis gaditana microalgae.

    PubMed

    Sanchez-Silva, L; López-González, D; Garcia-Minguillan, A M; Valverde, J L

    2013-02-01

    Pyrolysis, combustion and gasification characteristics of Nannochloropsis gaditana microalgae (NG microalgae) were investigated by thermogravimetric analysis (TGA). NG microalgae pyrolysis and combustion could be divided into three main stages: dehydration, proteins and polysaccharides degradation and char decomposition. The effects of the initial sample mass, particle size and gas flow on the pyrolysis and combustion processes were studied. In addition, gasification operation conditions such as temperature, initial sample mass, particle size, sweep gas flow and steam concentration, were experimentally evaluated. The evolved gases were analyzed online using mass spectroscopy (MS). In pyrolysis and combustion processes, most of the gas products were generated at the second degradation step. N-compounds evolution was associated with the degradation of proteins. Furthermore, SO(2) release from combustion could be related to sulphated polysaccharides decomposition. The main products detected during gasification were CO(2), CO, H(2), indicating that oxidation reactions, water gas and water gas shift reactions, were predominant.

  14. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. 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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Kinetic modeling of the formation and growth of inorganic nano-particles during pulverized coal char combustion in O2/N2 and O2/CO2 atmospheres

    DOE PAGES

    Shaddix, Christopher R.; Niu, Yanqing; Hui, Shi'en; ...

    2016-08-01

    In this formation of nano-particles during coal char combustion, the vaporization of inorganic components in char and the subsequent homogeneous particle nucleation, heterogeneous condensation, coagulation, and coalescence play decisive roles. Furthermore, conventional measurements cannot provide detailed information on the dynamics of nano-particle formation and evolution, In this study, a sophisticated intrinsic char kinetics model that considers ash effects (including ash film formation, ash dilution, and ash vaporization acting in tandem), both oxidation and gasification by CO2 and H2O, homogeneous particle nucleation, heterogeneous vapor condensation, coagulation, and and coalescence mechanisms is developed and used to compare the temporal evolution of themore » number and size of nano-particles during coal char particle combustion as a function of char particle size, ash content, and oxygen content in O2/N2 and O2/CO2 atmospheres .« less

  17. 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.

  18. CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES

    SciTech Connect

    Unknown

    1999-04-01

    at UTSI during this reporting period. Temperature was found to have a significant effect on the rate of gasification of coal. The rate of gasification increased up to 1400 F. Pressure did not have much effect on the gasification rates. The catalyst loading increased the gasification rate and approached complete conversion when 10 wt% of catalyst was added to the coal. Upon further increasing the catalyst amount to 20-wt% and above, there was no significant rise in gasification rate. The rate of gasification was lower for a 2:1 steam to char molar ratio (60%) compared to gasification rates at 3.4:1 molar ratio of steam-to-char where the conversion approached 100%. The characterization results of Georgia Tech are very preliminary and inconclusive and will be made available in the next report.

  19. 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.

  20. Comparison of biomass and coal char reactivities

    SciTech Connect

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

    1995-12-31

    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 change in reactivities with the extent of burnout of both biomass and coal chars were compared using Sandia`s Captive Particle Imaging (CPI) apparatus. This paper summarizes the experimental approach used to examine biomass and coal char reactivities and extinction behaviors and presents results from CPI experiments. The reactivity as a function of extent of burnout for six types of char particles, two high-rank coal chars, two low-rank coal chars, and two biomass chars, was investigated using the CPI 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.

  1. 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.

  2. 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.

  3. 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.

  4. CAVSIM. Underground Coal Gasification Program

    SciTech Connect

    Britten, J.A., Thorsness, C.B. )

    1989-03-03

    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, 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.

  5. 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.

  6. 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.

  7. Sulphur in char and char desulphurization by acid leaching and hydropyrolysis

    USGS Publications Warehouse

    Chou, I.-Ming; Loffredo, D.M.

    1985-01-01

    Sulphur compounds volatilized during pyrolysis of acid-leached char were measured to determine characteristics of char desulphurization reactions. Pyrolysis of char in a hydrogen atmosphere (hydropyrolysis) produced a much higher concentration of thiophenic organics compared with that produced during pyrolysis in a nitrogen atmosphere. Hydrogen sulphide gas evolution, at progressively increasing pyrolysis temperature in a helium atmosphere, was measured on five char samples: untreated char, hydrochloric acid-leached char, and three model chars: a demineralized char and two demineralized chars incorporated with sulphur via reactions with elemental sulphur. Hydrogen sulphide gas evolution in untreated char and acid-leached char was found to peak in three temperature regions; the maxima are thought to relate to sulphur in different bonding environments. The amounts of hydrogen sulphide volatilized were much higher for acid-leached char than for untreated char. The gas evolved from each of the remaining three samples showed a single peak region corresponding closely to one of the three peak regions observed for the first two chars. The results of this study indicate that elemental sulphur was produced during hydrochloric acid leaching of the untreated char and suggested that the improved rate of desulphurization observed in the char that had been acid-leached before hydropyrolysis was due in part to the conversion of strongly bound mineral sulphur forms to more weakly bound sulphur forms that are predominantly elemental sulphur in character, and are more easily removed by hydrogen. ?? 1985.

  8. 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.

  9. 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.

  10. 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.

  11. Advanced automated char image analysis techniques

    SciTech Connect

    Tao Wu; Edward Lester; Michael Cloke

    2006-05-15

    Char morphology is an important characteristic when attempting to understand coal behavior and coal burnout. In this study, an augmented algorithm has been proposed to identify char types using image analysis. On the basis of a series of image processing steps, a char image is singled out from the whole image, which then allows the important major features of the char particle to be measured, including size, porosity, and wall thickness. The techniques for automated char image analysis have been tested against char images taken from ICCP Char Atlas as well as actual char particles derived from pyrolyzed char samples. Thirty different chars were prepared in a drop tube furnace operating at 1300{sup o}C, 1% oxygen, and 100 ms from 15 different world coals sieved into two size fractions (53-75 and 106-125 {mu}m). The results from this automated technique are comparable with those from manual analysis, and the additional detail from the automated sytem has potential use in applications such as combustion modeling systems. Obtaining highly detailed char information with automated methods has traditionally been hampered by the difficulty of automatic recognition of individual char particles. 20 refs., 10 figs., 3 tabs.

  12. 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.

  13. 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.

  14. 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.

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

    PubMed

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

    2012-04-01

    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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. Physicochemical evolution during rice straw and coal co-pyrolysis and its effect on co-gasification reactivity.

    PubMed

    Wei, Juntao; Gong, Yan; Guo, Qinghua; Ding, Lu; Wang, Fuchen; Yu, Guangsuo

    2017-03-01

    Physicochemical evolution (i.e. pore structure variation, carbon structure change and active AAEM transformation) during rice straw (RS) and Shenfu bituminous coal (SF) co-pyrolysis was quantitatively determined in this work. Moreover, the corresponding char gasification was conducted using a thermogravimetric analyzer (TGA) and relative reactivity was proposed to quantify the co-pyrolysis impact on co-gasification reactivity. The results showed that the development of pore structure in co-pyrolyzed chars was first inhibited and then enhanced with the decrease of SF proportion. The promotion effect of co-pyrolysis on order degree of co-pyrolyzed chars gradually weakened with increasing RS proportion. Co-pyrolysis mainly enhanced active K transformation in co-pyrolyzed chars and the promotion effect was alleviated with increasing RS proportion. The inhibition effect of co-pyrolysis on co-gasification reactivity weakened with increasing RS proportion and gasification temperature, which was mainly attributed to the combination of carbon structure evolution and active AAEM transformation in co-pyrolysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Gasification: A Cornerstone Technology

    ScienceCinema

    Gary Stiegel

    2016-07-12

    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

  10. 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

  11. 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.

  12. The role of catalyst precursor anions in coal gasification. Eighth quarterly report, [July--September 1993

    SciTech Connect

    Abotsi, G.M.K.

    1993-12-31

    This project investigates the roles of various aqueous soluble catalyst precursor anions, specifically acetate, chloride, nitrate, sulfate, and carbonate anions on the surface electrical properties of coal and seeks to understand the effects of these anions on the adsorption, dispersion and activities of calcium and potassium. The effects of the various anions on coal char gasification is currently under investigation. The influence of acetate, chloride and nitrate ions, when using the corresponding potassium compounds, are discussed in this report. The thermograms for the char preparation in nitrogen show that rapid devolatilization of moisture and other volatile materials occurs in the first 30 min. The rate of weight loss decreases significantly thereafter up to about 70 min. when char preparation was complete. Introduction of carbon dioxide after this time resulted in only a small amount of carbon gasification of the unloaded, demineralized coal. However, the chars containing the acetate, chloride or nitrate of potassium gave reactivities of 24.8, 30.4 or 24.3 %wt., respectively. The catalysts were ion-exchanged with the salt solutions and the corresponding potassium content were 2.9, 2.6 and 2.3 %wt. The higher reactivities of the catalyzed chars compared to the unloaded char correlates the high degree of demineralization and the resultant low catalytic activity by the inherent inorganic materials. It is observed that the potassium acetate and the potassium nitrate have similar reactivities, while the reactivity in the presence of KCl is higher. This finding contrasts some of the previous literature reports which show that oxygen-containing catalytic salts are more active catalysts due to the formation of carbon-oxygen-metal bonds which have been postulated as pre-requisites to carbon gasification.

  13. Combustion reactivity of low rank coal chars

    SciTech Connect

    Young, B.C.

    1983-08-01

    For many years the CSIRO has been involved in studies on the combustion kinetics of coal chars and related materials. Early work included studies on a char produced from a Victorian brown coal. More recently, the combustion kinetics of chars produced during the flash pyrolysis of sub-bituminous coals have been determined. Data are given for the combustion reactivities of four flash pyrolysis chars. Their reactivities are compared with the results for chars produced from low and high rank coals, and petroleum coke. Reactivity is expressed as the rate of combustion of carbon per unit external surface area of the particle, with due correction being made for the effect of the mass transfer of oxygen to the particle. It has been shown that the reactivities to oxygen of chars produced from Millmerran sub-bituminous coal decrease with increasing pyrolysis temperature but are similar in magnitude to the reactivities of chars derived from a brown and a bituminous coal and to the reactivities of anthracites and semi-anthracites. However, Wandoan char, also of sub-bituminous origin, exhibits about twice the reactivity of Millmerran char and about ten times the reactivity of petroleum coke. On the basis of observed activation energy values, particle size and particle density behaviour it is concluded that the combustion rates of Millmerran and Wandoan chars are controlled by the combined effects of pore diffusion and chemical reaction.

  14. 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.

  15. The effect of model fidelity on prediction of char burnout for single-particle coal combustion

    DOE PAGES

    McConnell, Josh; Sutherland, James C.

    2016-07-09

    In this study, practical simulation of industrial-scale coal combustion relies on the ability to accurately capture the dynamics of coal subprocesses while also ensuring the computational cost remains reasonable. The majority of the residence time occurs post-devolatilization, so it is of great importance that a balance between the computational efficiency and accuracy of char combustion models is carefully considered. In this work, we consider the importance of model fidelity during char combustion by comparing combinations of simple and complex gas and particle-phase chemistry models. Detailed kinetics based on the GRI 3.0 mechanism and infinitely-fast chemistry are considered in the gas-phase.more » The Char Conversion Kinetics model and nth-Order Langmuir–Hinshelwood model are considered for char consumption. For devolatilization, the Chemical Percolation and Devolatilization and Kobayashi-Sarofim models are employed. The relative importance of gasification versus oxidation reactions in air and oxyfuel environments is also examined for various coal types. Results are compared to previously published experimental data collected under laminar, single-particle conditions. Calculated particle temperature histories are strongly dependent on the choice of gas phase and char chemistry models, but only weakly dependent on the chosen devolatilization model. Particle mass calculations were found to be very sensitive to the choice of devolatilization model, but only somewhat sensitive to the choice of gas chemistry and char chemistry models. High-fidelity models for devolatilization generally resulted in particle temperature and mass calculations that were closer to experimentally observed values.« less

  16. Thermal and biological gasification

    SciTech Connect

    Overend, R.P.; Rivard, C.J.

    1993-12-31

    Gasification is being developed to enable a diverse range of biomass resources to meet modern secondary energy uses, especially in the electrical utility sector. Biological or anaerobic gasification in US landfills has resulted in the installation of almost 500 MW(e) of capacity and represents the largest scale application of gasification technology today. The development of integrated gasification combined cycle generation for coal technologies is being paralleled by bagasse and wood thermal gasification systems in Hawaii and Scandinavia, and will lead to significant deployment in the next decade as the current scale-up activities are commercialized. The advantages of highly reactive biomass over coal in the design of process units are being realized as new thermal gasifiers are being scaled up to produce medium-energy-content gas for conversion to synthetic natural gas and transportation fuels and to hydrogen for use in fuel cells. The advent of high solids anaerobic digestion reactors is leading to commercialization of controlled municipal solid waste biological gasification rather than landfill application. In both thermal and biological gasification, high rate process reactors are a necessary development for economic applications that address waste and residue management and the production and use of new crops for energy. The environmental contribution of biomass in reducing greenhouse gas emission will also be improved.

  17. 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

  18. High Pressure Biomass Gasification

    SciTech Connect

    Agrawal, Pradeep K

    2016-07-29

    According to the Billion Ton Report, the U.S. has a large supply of biomass available that can supplement fossil fuels for producing chemicals and transportation fuels. Agricultural waste, forest residue, and energy crops offer potential benefits: renewable feedstock, zero to low CO2 emissions depending on the specific source, and domestic supply availability. Biomass can be converted into chemicals and fuels using one of several approaches: (i) biological platform converts corn into ethanol by using depolymerization of cellulose to form sugars followed by fermentation, (ii) low-temperature pyrolysis to obtain bio-oils which must be treated to reduce oxygen content via HDO hydrodeoxygenation), and (iii) high temperature pyrolysis to produce syngas (CO + H2). This last approach consists of producing syngas using the thermal platform which can be used to produce a variety of chemicals and fuels. The goal of this project was to develop an improved understanding of the gasification of biomass at high pressure conditions and how various gasification parameters might affect the gasification behavior. Since most downstream applications of synags conversion (e.g., alcohol synthesis, Fischer-Tropsch synthesis etc) involve utilizing high pressure catalytic processes, there is an interest in carrying out the biomass gasification at high pressure which can potentially reduce the gasifier size and subsequent downstream cleaning processes. It is traditionally accepted that high pressure should increase the gasification rates (kinetic effect). There is also precedence from coal gasification literature from the 1970s that high pressure gasification would be a beneficial route to consider. Traditional approach of using thermogravimetric analyzer (TGA) or high-pressure themogravimetric analyzer (PTGA) worked well in understanding the gasification kinetics of coal gasification which was useful in designing high pressure coal gasification processes. However

  19. 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.

  20. Kinetic modeling of the formation and growth of inorganic nano-particles during pulverized coal char combustion in O2/N2 and O2/CO2 atmospheres

    SciTech Connect

    Shaddix, Christopher R.; Niu, Yanqing; Hui, Shi'en; Wang, Shuai

    2016-08-01

    In this formation of nano-particles during coal char combustion, the vaporization of inorganic components in char and the subsequent homogeneous particle nucleation, heterogeneous condensation, coagulation, and coalescence play decisive roles. Furthermore, conventional measurements cannot provide detailed information on the dynamics of nano-particle formation and evolution, In this study, a sophisticated intrinsic char kinetics model that considers ash effects (including ash film formation, ash dilution, and ash vaporization acting in tandem), both oxidation and gasification by CO2 and H2O, homogeneous particle nucleation, heterogeneous vapor condensation, coagulation, and and coalescence mechanisms is developed and used to compare the temporal evolution of the number and size of nano-particles during coal char particle combustion as a function of char particle size, ash content, and oxygen content in O2/N2 and O2/CO2 atmospheres .

  1. Kinetic modeling of the formation and growth of inorganic nano-particles during pulverized coal char combustion in O2/N2 and O2/CO2 atmospheres

    SciTech Connect

    Shaddix, Christopher R.; Niu, Yanqing; Hui, Shi'en; Wang, Shuai

    2016-08-01

    In this formation of nano-particles during coal char combustion, the vaporization of inorganic components in char and the subsequent homogeneous particle nucleation, heterogeneous condensation, coagulation, and coalescence play decisive roles. Furthermore, conventional measurements cannot provide detailed information on the dynamics of nano-particle formation and evolution, In this study, a sophisticated intrinsic char kinetics model that considers ash effects (including ash film formation, ash dilution, and ash vaporization acting in tandem), both oxidation and gasification by CO2 and H2O, homogeneous particle nucleation, heterogeneous vapor condensation, coagulation, and and coalescence mechanisms is developed and used to compare the temporal evolution of the number and size of nano-particles during coal char particle combustion as a function of char particle size, ash content, and oxygen content in O2/N2 and O2/CO2 atmospheres .

  2. 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.

  3. CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES

    SciTech Connect

    1999-10-01

    This is the progress report for the DOE grant DE-FG26-97FT97263 entitled, ''Catalytic Gasification of Coal Using Eutectic Salt Mixtures'' for the period April 1999 to October 1999. The project is being conducted jointly by Clark Atlanta University, the University of Tennessee Space Institute and Georgia Institute of Technology. The overall objectives of the project 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 and system pressure) on coal gasification; evaluate the recovery, regeneration and recycle of the spent catalysts; and conduct thorough analysis and modeling of the gasification process to provide better understanding of the fundamental mechanisms and kinetics of the process. During this reporting period, free swelling index measurements of the coal, fixed-bed gasification experiments, kinetic modeling of the catalyzed gasification, and X-ray diffraction analysis of catalyst and gasified char samples were undertaken. The gasification experiments were carried out using two different eutectic salt mixtures of Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} (LNK) system and Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} (NK) system. The gasification process followed a Langmuir-Hinshelwood type model. At 10 wt% of catalyst loading, the activation energy of the ternary catalyst system (LNK) was about half (98kJ/mol) the activation energy of the single catalyst system (K{sub 2}CO{sub 3}), which is about 170 kJ/ mole. The binary catalyst system (NK) showed activation energy of about 201 kJ/mol, which is slightly higher, compared to the K{sub 2}CO{sub 3} catalyst system. The ternary catalyst system was a much better eutectic catalyst system compared to the binary or single catalyst system. In general, a eutectic with a melting point

  4. 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

  5. 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.

  6. 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.

  7. Integrated coal gasification combined cycle

    NASA Astrophysics Data System (ADS)

    Richards, P. C.; Wijffels, J.-B.; Zuideveld, P. L.

    Features of the integrated coal gasification combined cycle power plants are described against the backdrop of the development and first commercial application of the shell coal gasification process. Focus is on the efficiency and excellent environmental performance of the integrated coal gasification combined power plants. Current IGCC projects are given together with an outline of some of the options for integrating coal gasification with combined cycles and also other applications of synthesis gas.

  8. Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 2: Evaluation of ash materials as phosphorus fertilizer.

    PubMed

    Thomsen, Tobias Pape; Hauggaard-Nielsen, Henrik; Gøbel, Benny; Stoholm, Peder; Ahrenfeldt, Jesper; Henriksen, Ulrik B; Müller-Stöver, Dorette Sophie

    2017-08-01

    The study is part 2 of 2 in an investigation of gasification and co-gasification of municipal sewage sludge in low temperature gasifiers. In this work, solid residuals from thermal gasification and co-gasification of municipal sewage sludge were investigated for their potential use as fertilizer. Ashes from five different low temperature circulating fluidized bed (LT-CFB) gasification campaigns including two mono-sludge campaigns, two sludge/straw mixed fuels campaigns and a straw reference campaign were compared. Experiments were conducted on two different LT-CFBs with thermal capacities of 100kW and 6MW, respectively. The assessment included: (i) Elemental composition and recovery of key elements and heavy metals; (ii) content of total carbon (C) and total nitrogen (N); (iii) pH; (iv) water extractability of phosphorus after incubation in soil; and (v) plant phosphorus response measured in a pot experiment with the most promising ash material. Co-gasification of straw and sludge in LT-CFB gasifiers produced ashes with a high content of recalcitrant C, phosphorus (P) and potassium (K), a low content of heavy metals (especially cadmium) and an improved plant P availability compared to the mono-sludge ashes, thereby showing the best fertilizer qualities among all assessed materials. It was also found that bottom ashes from the char reactor contained even less heavy metals than cyclone ashes. It is concluded that LT-CFB gasification and co-gasification is a highly effective way to purify and sanitize sewage sludge for subsequent use in agricultural systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Municipal solid waste gasification: Perspectives

    SciTech Connect

    Bain, R.; Overend, R.P.; Chornet, E.; Craig, K.R.

    1996-12-31

    The paper consists of the transparencies that were used during the presentation. Flowcharts are presented for processing options for municipal solid wastes and refuse derived fuels, and for the gasification of refuse derived fuels. Summaries are presented on gasification and gas conditioning goals, the history of MSW gasification, clean gas requirements for engines, and recent history of several gasification processes (Lurgi CFB, TPS CFB, Thermoselect pilot plant, and Proler pilot plant). Challenges are listed and a flowchart for a typical gasification/gas conditioning process is given.

  14. 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

  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.

  16. 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.

  17. 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

  18. 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.

  19. Temperature Trends in Coal Char Combustion under Oxy-fuel Conditions for the Determination of Kinetics

    SciTech Connect

    Iqbal, Samira; Hecht, Ethan

    2014-08-01

    Oxy-fuel combustion technology with carbon capture and storage could significantly reduce global CO2 emissions, a greenhouse gas. Implementation can be aided by computational fluid dynamics (CFD) simulations, which require an accurate understanding of coal particle kinetics as they go through combustion in a range of environments. To understand the kinetics of pulverized coal char combustion, a heated flow reactor was operated under a wide range of experimental conditions. We varied the environment for combustion by modifying the diluent gas, oxygen concentration, gas flow rate, and temperature of the reactor/reacting gases. Measurements of reacting particle temperatures were made for a sub-bituminous and bituminous coal char, in environments with CO2 or N2 as the diluent gas, with 12, 24, and 36 vol-% oxygen concentration, at 50, 80, 100, and 200 standard liters per minute flowing through the reactor, reactor temperatures of 1200, 1400 K, at pressures slightly above atmospheric. The data shows consistent increasing particle temperature with increased oxygen concentration, reactor temperature and higher particle temperatures for N2 diluent than CO2. We also see the effects of CO2 gasification when different ranks of coal are used, and how the reduction in the temperature due to the CO2 diluent is greater for the coal char that has higher reactivity. Quantitative measurements for temperature are not yet complete due to ongoing calibration of detection systems.

  20. 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.

  1. 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.

  2. 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. © The Author(s) 2015.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Investigation of sewage sludge treatment using air plasma assisted gasification.

    PubMed

    Striūgas, Nerijus; Valinčius, Vitas; Pedišius, Nerijus; Poškas, Robertas; Zakarauskas, Kęstutis

    2017-03-18

    This study presents an experimental investigation of downdraft gasification process coupled with a secondary thermal plasma reactor in order to perform experimental investigations of sewage sludge gasification, and compare process parameters running the system with and without the secondary thermal plasma reactor. The experimental investigation were performed with non-pelletized mixture of dried sewage sludge and wood pellets. To estimate the process performance, the composition of the producer gas, tars, particle matter, producer gas and char yield were measured at the exit of the gasification and plasma reactor. The research revealed the distribution of selected metals and chlorine in the process products and examined a possible formation of hexachlorobenzene. It determined that the plasma assisted processing of gaseous products changes the composition of the tars and the producer gas, mostly by destruction of hydrocarbon species, such as methane, acetylene, ethane or propane. Plasma processing of the producer gas reduces their calorific value but increases the gas yield and the total produced energy amount. The presented technology demonstrated capability both for applying to reduce the accumulation of the sewage sludge and production of substitute gas for drying of sewage sludge and electrical power.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. Mineral matter effects on char structural evolution and oxidation kinetics during coal char combustion

    SciTech Connect

    Lunden, M.; Yang, N.; Headley, T.; Shaddix, C.; Hardesty, D.

    1997-10-01

    The authors report on recent investigations of the evolution of char structure during carbon burnout and the role of mineral matter in determining this structure. Char samples collected in a carefully controlled laminar, flame-supported entrained flow reactor have been characterized using a number of microscopy tools. Observations of the inorganic structure of chars produced at a variety of combustion conditions are coupled with in-situ optical measurements of the char particle population with an eye towards identifying the mechanism of mineral interaction and its effects on carbon burnout kinetics during pulverized coal char combustion. Preliminary results show a surprising amount of inorganic mineral in solid solution with the carbonaceous matrix. This intimate mixing of organic and inorganic constituents may affect reactivity by both blocking oxygen access to active carbon sites and influencing the microscopic carbon structure that evolves during combustion.

  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. 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.

  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. Coke gasification method

    SciTech Connect

    Weber, H.; Dungs, H.; Tippmer, K.

    1983-12-27

    A method for the gasification of coke is disclosed in which coke produced in a coke oven and having a temperature of 900/sup 0/ C. to 1100/sup 0/ C. is forced into a coke bucket, after coking in the coke oven, and fed by means of hot coke conveyors without substantial temperature changes to a gasifier. The coke is gasified in the gasifier while adding at least one of oxygen and air, and steam and carbon dioxide.

  19. 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

  20. Catalytic gasification of biomass

    NASA Astrophysics Data System (ADS)

    Robertus, R. J.; Mudge, L. K.; Sealock, L. J., Jr.; Mitchell, D. H.; Weber, S. L.

    1981-12-01

    Methane and methanol synthesis gas can be produced by steam gasification of biomass in the presence of appropriate catalysts. This concept is to use catalysts in a fluidized bed reactor which is heated indirectly. The objective is to determine the technical and economic feasibility of the concept. Technically the concept has been demonstrated on a 50 lb per hr scale. Potential advantages over conventional processes include: no oxygen plant is needed, little tar is produced so gas and water treatment are simplified, and yields and efficiencies are greater than obtained by conventional gasification. Economic studies for a plant processing 2000 T/per day dry wood show that the cost of methanol from wood by catalytic gasification is competitive with the current price of methanol. Similar studies show the cost of methane from wood is competitive with projected future costs of synthetic natural gas. When the plant capacity is decreased to 200 T per day dry wood, neither product is very attractive in today's market.

  1. 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.

  2. Catalytic gasification fundamentals

    SciTech Connect

    Heinemann, H.; Somorjai, G.A.

    1992-01-01

    Last year it was found that Maya coke gasification could be greatly accelerated if the colting took place in the presence of small amounts (below 1%) of caustic. When the Maya coke thus prepared was impregnated with 1% of CaO-KO[sub x] catalyst, the rate of gasification was doubled. During the past year, this phenomenon has been further investigated and the work has been extended to two other and very different cokes. As shown in Figure 2, a Statfjord Bottoms coke prepared in the presence of 1% NaOH and then impregnated with CaO[sub x]-KO[sub x] catalyst gasified very much faster than the same material coked in the absence of NaOH. The same phenomenon is exhibited in Figure 3 for a Torrance Hondo coke, although in this case the difference between the cokes prepared in the presence and absence of NaOH is somewhat smaller. It is concluded that the preparation method of the coke is of major importance for the rate of gasification and that the phenomenon that presence of alkali during coking is helpful is a generic one.

  3. Catalytic gasification fundamentals

    SciTech Connect

    Heinemann, H.; Somorjai, G.A.

    1992-11-01

    Last year it was found that Maya coke gasification could be greatly accelerated if the coking took place in the presence of small amounts (below 1%) of caustic. When the Maya coke thus prepared was impregnated with 1% of CaO-KO{sub x} catalyst, the rate of gasification was doubled. During the past year, this phenomenon has been further investigated and the work has been extended to two other and very different cokes. As shown in Figure 2, a Statfjord Bottoms coke prepared in the presence of 1% NaOH and then impregnated with CaO{sub x}-KO{sub x} catalyst gasified very much faster than the same material coked in the absence of NaOH. The same phenomenon is exhibited in Figure 3 for a Torrance Hondo coke, although in this case the difference between the cokes prepared in the presence and absence of NaOH is somewhat smaller. It is concluded that the preparation method of the coke is of major importance for the rate of gasification and that the phenomenon that presence of alkali during coking is helpful is a generic one.

  4. 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.

  5. 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.

  6. NH{sub 3} formation and destruction during the gasification of coal in oxygen and steam

    SciTech Connect

    Lachlan J. Mckenzie; Fu-Jun Tian; Chun-Zhu Li

    2007-08-01

    The study was conducted to investigate the formation and destruction of NH{sub 3} during the gasification of coal in atmospheres containing O{sub 2} and steam. A Victorian brown coal was gasified in a novel bench-scale fluidized-bed/fixed-bed reactor at 800{sup o}C in atmospheres containing 2000 ppm O{sub 2}, 15% H{sub 2}O, or 2000 ppm O{sub 2} + 15% H{sub 2}O. A NH{sub 3} standard gas was also used to study the destruction of NH{sub 3} in the gas phase and through gas-solid interactions. Sand, char, and coal ash were all found to enhance the destruction of NH{sub 3}. An atmosphere containing O{sub 2} alone does not favor the conversion of char-N into NH{sub 3} but favors the destruction of NH{sub 3} through various mechanisms. The introduction of H{sub 2}O into the gasification system greatly favors the conversion of char-N into NH{sub 3} and inhibits the destruction of NH{sub 3}. The formation and destruction of NH{sub 3} in an atmosphere containing 15% H{sub 2}O was similar to that in an atmosphere containing 15% H{sub 2}O and 2000 ppm O{sub 2}, indicating the dominant effects of steam in the formation and destruction of NH{sub 3} in a gasifier.

  7. Evaluation of char combustion models: measurement and analysis of variability in char particle size and density

    SciTech Connect

    Maloney, Daniel J; Monazam, Esmail R; Casleton, Kent H; Shaddix, Christopher R

    2008-08-01

    Char samples representing a range of combustion conditions and extents of burnout were obtained from a well-characterized laminar flow combustion experiment. Individual particles from the parent coal and char samples were characterized to determine distributions in particle volume, mass, and density at different extent of burnout. The data were then compared with predictions from a comprehensive char combustion model referred to as the char burnout kinetics model (CBK). The data clearly reflect the particle- to-particle heterogeneity of the parent coal and show a significant broadening in the size and density distributions of the chars resulting from both devolatilization and combustion. Data for chars prepared in a lower oxygen content environment (6% oxygen by vol.) are consistent with zone II type combustion behavior where most of the combustion is occurring near the particle surface. At higher oxygen contents (12% by vol.), the data show indications of more burning occurring in the particle interior. The CBK model does a good job of predicting the general nature of the development of size and density distributions during burning but the input distribution of particle size and density is critical to obtaining good predictions. A significant reduction in particle size was observed to occur as a result of devolatilization. For comprehensive combustion models to provide accurate predictions, this size reduction phenomenon needs to be included in devolatilization models so that representative char distributions are carried through the calculations.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Formation and structure of amorphous carbon char from polymer materials

    NASA Astrophysics Data System (ADS)

    Lawson, John W.; Srivastava, Deepak

    2008-04-01

    Amorphous carbonaceous char produced from burning polymer solids has insulating properties that make it valuable in thermal protection and fire-retardant systems. A pyrolytic molecular dynamics simulation method is devised to study the transformation of the local microstructure from virgin polymer to a dense, disordered char. 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.

  14. 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.

  15. 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...

  16. 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...

  17. Activation of pyrolytic lignite char with CO{sub 2}. Kinetic study

    SciTech Connect

    R. Murillo; M.V. Navarro; J.M. Lopez; T. Garcia; M.S. Callen; E. Aylon; A.M. Mastral

    2006-02-01

    In this paper, an approach to lignite char partial gasification with carbon dioxide in its physical activation is carried out. Four gas-solid kinetic models (the volume reaction model, modified volume reaction model, changing grain size model, and random pore model) are reviewed in order to obtain the most accurate description for the activation reaction. Both structural and nonstructural models have been used to fit the experimental data obtained in thermobalance experiments. Prior to the determination of the kinetic parameters, a thorough study was performed to achieve the required conditions to carry out the experiments under a kinetic control regime. The final equation proposed to describe the reaction accurately is based on the random pore model. This model, in addition to fitting the conversion versus time plots at different temperatures, is able to offer a physical explanation for the maximum observed in the reaction rate for a conversion of around 30%. 27 refs., 11 figs., 3 tabs.

  18. 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

  19. 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.

  20. High temperature deactivation of coal chars

    SciTech Connect

    Beeley, T.J.; Gibbins, J.R.; Man, C.K.

    1994-12-31

    High levels of char burnout, typically to less than 5% by weight of residual carbon in the fly ash, are desirable in large, multi-burner utility boilers fired with pulverised coal in order to optimise plant efficiency and allow the ash to be incorporated in building materials. Achieving high levels of char burnout can be a particular problem with air-staged low-NOx combustors, where air/fuel ratios (and flame temperatures) have to be constrained to give satisfactory emission levels. Switching to imported low-sulphur coals can also be associated with a need to at least assess the potential for burnout problems. In general the levels of carbon in ash required represent very high overall fuel conversion. For example, a coal with 10%w/w ash dry basis giving 5% carbon in ash will still achieve 99.4% conversion. The difference between satisfactory and unsatisfactory burnout thus depends on whether a very small fraction of the coal does or does not burn. This study examined the effect of time and temperature on char reactivity. Fly ash samples containing char were obtained from plant trials.

  1. Modelling the charring behaviour of structural lumber

    Treesearch

    Peter W.C. Lau; Robert White; Ineke Van Zealand

    1999-01-01

    Charring rates for large-section timber based on experimental data have been generally established. The established rates may not be appropriately used for the prediction of failure times of lumber members which are small by comparison. It is questionable whether a constant rate can be safely assumed for lumber members since the rate is likely to increase once the...

  2. Char yield on pyrolysis of cellulose

    Treesearch

    A. Broido; Maxine A. Nelson

    1975-01-01

    Whether the pyrolysis of cellulose is conducted in an inert medium or in air, partial pyrolysis at a lower temperature increases the char yield subsequently obtained after 1 hour at 370°C. The results are consistent with a pyrolysis scheme in which two competing sequences of cellulose pyrolysis reactions are initiated by (1) an intermolecular dehydration leading to...

  3. 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.

  4. 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.

  5. 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.

  6. Intermediates and kinetics for phenol gasification in supercritical water.

    PubMed

    Huelsman, Chad M; Savage, Phillip E

    2012-02-28

    We processed phenol with supercritical water in a series of experiments, which systematically varied the temperature, water density, reactant concentration, and reaction time. Both the gas and liquid phases were analyzed post-reaction using gas chromatographic techniques, which identified and quantified the reaction intermediates and products, including H(2), CO, CH(4), and CO(2) in the gas phase and twenty different compounds--mainly polycyclic aromatic hydrocarbons--in the liquid phase. Many of these liquid phase compounds were identified for the first time and could pose environmental risks. Higher temperatures promoted gasification and resulted in a product gas rich in H(2) and CH(4) (33% and 29%, respectively, at 700 °C), but char yields increased as well. We implicated dibenzofuran and other identified phenolic dimers as precursor molecules for char formation pathways, which can be driven by free radical polymerization at high temperatures. Examination of the trends in conversion as a function of initial water and phenol concentrations revealed competing effects, and these informed the kinetic modeling of phenol disappearance. Two different reaction pathways emerged from the kinetic modeling: one in which rate ∝ [phenol](1.73)[water](-16.60) and the other in which rate ∝ [phenol](0.92)[water](1.39). These pathways may correspond to pyrolysis, which dominates when there is abundant phenol and little water, and hydrothermal reactions, which dominate in excess water. This result confirms that supercritical water gasification of phenol does not simply follow first-order kinetics, as previous efforts to model phenol disappearance had assumed.

  7. 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.

  8. Recent developments in coal gasification

    SciTech Connect

    Schad, M.K.; Hafke, C.F.

    1983-05-01

    This paper reports on how Lurgi, as one of the major engineering companies with extensive experience in coal gasification, has expanded the application of the fixed-bed gasifier. Improvements have been made to the type and size of coal which can be gasified and the quality of gas produced. Lurgi's development efforts are continuous, and are directed not only to search for new process methods but also to reduce the investment, operating and maintenance costs. It is manifested in the achievement of higher specific gasification rates and the layer size of the gasifiers, both of which reduce the complexity of a gasification plant and improve its supervision and controllability.

  9. Gasification kinetics of raw and wet-torrefied microalgae Chlorella vulgaris ESP-31 in carbon dioxide.

    PubMed

    Bach, Quang-Vu; Chen, Wei-Hsin; Sheen, Herng-Kuang; Chang, Jo-Shu

    2017-03-27

    This study aims at investigating the gasification behavior and kinetics of microalga Chlorella vulgaris ESP-31 before and after wet torrefaction. The raw and wet-torrefied microalgae were first gasified in a thermogravimetric analyzer under a continuous CO2 flow. Thereafter, the obtained thermogravimetric data were modeled for kinetic study, employing a seven-parallel-reaction mechanism. The decomposition of the microalgae in CO2 shows two reactive stages: devolatilization with two peaks and gasification with a peak accompanied by a shoulder, and the thermal decomposition of components in the samples can be clearly identified. Increasing wet torrefaction temperature lowers the height of the major devolatilization peak but enhances the height of the minor one. Moreover, the kinetic evaluation reveals that wet torrefaction affects most of the kinetic parameters of the microalgal components. Furthermore, wet torrefaction temperature influences the kinetic parameters of carbohydrate and lipid, but not on those of protein, "others", and chars.

  10. Sorption of organic contaminants by biopolymer-derived chars.

    PubMed

    Wang, Xilong; Xing, Baoshan

    2007-12-15

    Sorption of phenanthrene and naphthalene by chitin and cellulose, as well as these biopolymer-derived chars, was examined. Carbon contents were much higher in the chars than their respective biopolymers, and nitrogen was dramatically accumulated in the chitin-derived chars. After charring, sorption of these two compounds was greatly increased, which was attributed to the newly created surface area, porosity, and aromatic components. The aromatic carbon content of the biopolymer chars increased with an increase in the charring temperature. Sorption of phenanthrene and naphthalene to chitin and cellulose was dominated by partitioning. However, after charring, sorption of these two compounds became much more of an adsorption process, because of the newly created surfaces and micropores. The maximum mass sorption capacity of phenanthrene and naphthalene by the original biopolymers and their chars was positively correlated with their surface areas, suggesting that active sorption sites were largely on the surfaces of chars. At low solute concentrations, sorption of phenanthrene and naphthalene by biopolymer chars was dominated by the micropore-filling mechanism; with an increase in the solute concentration, sorption of these two compounds by biopolymer chars shifted to a surface-sorption-dominant process. The maximum mass sorption capacity and K(ow)-normalized sorption amount of phenanthrene were lower than those of naphthalene by the biopolymers and their chars, showing the influence of molecular dimension on sorption. This study demonstrates the significantly enhanced sorption of hydrophobic organic compounds by highly polar biopolymers through charring and the joint roles of surface area, porosity, and surface functionalities of biopolymer-derived chars in governing sorption.

  11. Simulation of coal gasification in a fluidized bed

    SciTech Connect

    O`Brien, T.J.

    1996-12-31

    In this analysis of coal gasification, a fundamental approach is used where a set of multiphase (Eulerian) fluid dynamic equations, obtained either by a suitable averaging technique (Anderson and Jackson, 1976; Drew, 1971) or the formulations of continuum mechanics (Drew, 1983), is used to describe the conservation of mass, momentum, and energy for three interpenetrating phases. The particles, like the fluidizing gas, are described as interpenetrating continua. Different particle types are treated as distinct phases; in this study, the feed coal and the bed char are represented as separate phases in order to account for their different histories. Constitutive laws account for the exchange of momentum between phases (``drag``) and interphase energy transfer. The stresses within the granular phases are determined by a formulation based on the kinetic theory, characterized by a ``granular temperature``. A computer code, based on this multiphase hydrodynamic model, has been developed at the Morgantown Energy Technology Center for the detailed simulation of gas and particle dynamics in heavily loaded coal conversion processes (Syamlal, Rogers, O`Brien, 1994; Syamlal, 1995). The hydrodynamic simulation showed the reactor operated in a jetting/bubbling mode. A gas jet penetrated a considerable distance into the bed, and then detached as ``bubbles`` which rose to the top of the column. The reaction scheme indicated that the feed coal did not begin to devolatilize until it had traversed this region, because of the time required to heat up. Thus, volatiles were not released in the jetting region of the bed, but higher in the bed. The oxygen fed with the coal, however, reacted immediately with the recirculating hot char. The net effect of the char reaction scheme was to created. CO, which burned in the region where.the jet detached, creating a, fairly stable ``flame``. The tar reaction scheme indicated that none of the tar escaped the bed.

  12. Oxidation/gasification of carbon residue on retorted oil shale. Final report

    SciTech Connect

    Thomson, W. J.

    1984-01-16

    Studies of the oxidation and gasification of oil shale char were extended to an investigation of the effects of mineral catalysis. Six shales with differing mineral compositions were studied, including samples from the saline zone in the Western Colorado and from the Antrim shales of Michigan. Oxidation kinetics data, corrected for mass transfer effects, were compared for all six samples. A high assay shale from Utah and a sample from the saline zone were found to have the highest oxidation rates. By examining the data for shales which were water leached and thermally pretreated, it was concluded that both NaO and CaO act as oxidation catalysts. However, as a result of mineral decomposition experiments conducted with a sample from the C-a lease tract, it appears as though the ankeritic dolomite fraction will not decompose as long as there is a minimal CO/sub 2/ over pressure. Rather, low temperature silication reactions appear to take place once the temperature exceeds 925/sup 0/K. An extensive evaluation was also completed for the gasification of an Antrim shale from Michigan. Both the rates of CO/sub 2/ and steam gasification of the char were found to be markedly lower than that observed for a shale sample from the Parachute Creek member in Colorado. However, unlike the Colorado shale, the make gas resulting from the steam gasification of the Antrim shale produced nearly equal quantities of CO and CO/sub 2/. Thus, despite the high concentration of iron in the Antrim shale, the water gas shift reaction is not catalyzed nearly to the same extent as in western shales.

  13. 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.

  14. Influence of sulfur in coals on char morphology and combustion. [Quarterly] technical report, March 1, 1992--May 31, 1992

    SciTech Connect

    Marsh, H.; Crelling, J.C.

    1992-10-01

    During coal pyrolysis, in applications such as in a utility boiler, sulfur which is present in the original coal is transferred to the resultant char, to be burnt (combusted) subsequently. The effect of sulfur on char reactivity during combustion is poorly understood and this study addresses the problem. Due to the complex nature of coal, initial experiments make use of organic model compounds which can be related to chars from coals. This approach allows for clear identification of the important parameters which influence reactivity, in this instance namely; phenolic resin concentration, sulfur and/or iron content. The addition of iron serves to mimic the effect of catalytic mineral matter in coals. The experimental approach involves the preparation of model compounds and the study of their gasification behavior, including surface characterization by adsorption techniques and microscopy. The equipment necessary to this study has been commissioned and progress has been made. Previous results indicated that increasing phenolic resin (resol) content led to greater yields and that carbons with less than 20 wt.% resol were optically anisotropic, whereas carbons with higher concentrations of resol were isotropic. Due to the high volatility of thiophene it was decided to incorporate sulfur into the model carbon structure by the addition of elemental sulfur and dibenzothiophene sulfone.

  15. 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

  16. Coal gasification and occupational health.

    PubMed

    Young, R J; McKay, W J; Evans, J M

    1978-12-01

    Identification and prevention of health effects due to occupational exposures in coal gasification processes requires a basic knowledge of the technological process by which gasification proceeds. This paper presents an overview of the technology and a rational approach to health hazard identification based upon the concept of the unit operation specific micro environment. A final section is devoted to summarizing current research efforts being carried out under the aegis of the National Institute for Occupational Safety and Health.

  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. 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

  20. 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.

  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. 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

    2015-01-01

    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.

  3. 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.

  4. 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...

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  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. Oil shale ash-layer thickness and char combustion kinetics

    SciTech Connect

    Aldis, D.F.; Singleton, M.F.; Watkins, B.E.; Thorsness, C.B.; Cena, R.J.

    1992-04-15

    A Hot-Recycled-Solids (HRS) oil shale retort is being studied at Lawrence Livermore National Laboratory. In the HRS process, raw shale is heated by mixing it with burnt retorted shale. Retorted shale is oil shale which has been heated in an oxygen deficient atmosphere to pyrolyze organic carbon, as kerogen into oil, gas, and a nonvolatile carbon rich residue, char. In the HRS retort process, the char in the spent shale is subsequently exposed to an oxygen environment. Some of the char, starting on the outer surface of the shale particle, is burned, liberating heat. In the HRS retort, the endothermic pyrolysis step is supported by heat from the exothermic char combustion step. The rate of char combustion is controlled by three resistances; the resistance of oxygen mass transfer through the gas film surrounding the solid particle, resistance to mass transfer through a ash layer which forms on the outside of the solid particles as the char is oxidized and the resistance due to the intrinsic chemical reaction rate of char and oxygen. In order to estimate the rate of combustion of the char in a typical oil shale particle, each of these resistances must be accurately estimated. We begin by modeling the influence of ash layer thickness on the over all combustion rate of oil shale char. We then present our experimental measurements of the ash layer thickness of oil shale which has been processed in the HRS retort.

  13. 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.

  14. Gasification of Gulf Coast Lignites

    SciTech Connect

    Smoller, R.K.

    1983-11-01

    Gulf Coast lignites are examined as a feedstock for a gasification facility making substitute natural gas (SNG). Advantages and disadvantages are explored in the areas of project development factors, gasification technology and physical and chemical characteristics of the lignite. The Texas Gasification Project currently under study at Phillips Coal is used to exemplify these factors. It has been found that the use of Gulf Coast lignite has several natural developmental advantages over fuels from other parts of the U.S. A project is relatively close to markets for all of its products including SNG, carbon dioxide and all by-products. The Gulf Coast has adequate supplies of basic commodities such as water. Most potential gasification plant locations have a good local infrastructure in existence. Labor can be drawn from one or more metropolitan areas within commuting distance. State regulatory agencies interact with energy development projects of all sizes on a regular basis providing a solid working knowledge of energy policies and accepted project development guidelines. Finally, a positive business climate exists at both the state and local levels providing support and encouragement to go forward with projects. The physical and chemical characteristics of the lignite are shown to have a major effect on the operability of the gasification process. Lignite properties examined include moisture content, friability, and ash content.

  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. [Transformation of sulfur forms during coal pyrolysis and partial gasification in a fixed bed reactor].

    PubMed

    Li, Bin; Cao, Yan; Zhang, Jianmin; Huang, Jiejie; Wang, Yang; Chen, Fuyan

    2003-03-01

    The development of various process to the pre-desulfurization of coal was drawn more attention. In present study, the transformation of sulfur forms of three different ranks high sulfur coals during coal pyrolysis and partial gasification were investigated in a fixed bed reactor. The sulfur and carbon content analysis of original coal and coal char produced were determined by LECO SC-444 and wet chemical analysis according to Sugawara's method. The results showed that half of inorganic sulfur and partial of organic sulfur were removed during coal pyrolysis. And the sulfur removal was much more than carbon during pyrolysis process; and the sulfur in the coal char, especially the sulfide sulfur was removed completely during partial gasification process for both Datong coal and Xishan coal, the degree of sulfide sulfur removal could be increased with increasing temperature. At the same time, the results of Yima coal showed that the effect of fixed-sulfur by alkaline metals increased when the temperature was higher than 700 degrees C, which attribute to the increase of the fixed sulfur reaction rate and the decrease of mass-transfer limitation.

  17. 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.

  18. 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.

  19. Hybrid coal gasification

    SciTech Connect

    Moore, K.

    2007-01-15

    Retrofitting gas, oil and coal-fired boilers can reduce operating costs and meet EPA's Clean Air Interstate Rules (CAIR) when firing most Eastern and Midwest bituminous coals. The trademarked Clean Combustion System (CCS) concept, conceived at Rockwell International, evolved from a confluence of advanced combustion modelling know-how, experience in coal gasification and wet-bottom boiler operation and design. The CCS is a high temperature air-feed entrained flow gasifier that replaces a boiler's existing burners. It fires pulverized coal with some limestone added to provide calcium to capture sulfur and provide a clean hot fuel-rich gas to the boiler furnace. Subsequent over-fire air (OFA) staging completes the combustion. A 'sulfur bearing glass' waste product results from the coal ash and the calcium sulfide. The CCS process prevents formation of NOx from fuel-bound nitrogen. The initial commercialisation of CCS is the update and retrofit an industrial stoker design boiler. Steps for the retrofit are described in the article. 2 figs., 1 photo.

  20. 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.

  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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. 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.

  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.

  4. 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.

  5. Charring rate of wood exposed to a constant heat flux

    Treesearch

    R. H. White; H. C. Tran

    1996-01-01

    A critical factor in the fire endurance of a wood member is its rate of charring. Most available charring rate data have been obtained using the time-temperature curves of the standard fire resistance tests (ASTM E 119 and ISO 834) to define the fire exposure. The increased use of heat release calorimeters using exposures of constant heat flux levels has broadened the...

  6. 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.

  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. 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.

  9. Structural evolution of maize stalk/char particles during pyrolysis.

    PubMed

    Fu, Peng; Hu, Song; Sun, Lushi; Xiang, Jun; Yang, Tao; Zhang, Anchao; Zhang, Junying

    2009-10-01

    The structural evolution characteristics of maize stalk/char particles during pyrolysis were investigated. The char was prepared by pyrolyzing at temperatures ranging from 200 to 900 degrees C. Maize stalk and chars were characterized by thermogravimetric analysis, ultimate analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), helium density measurement and N(2) adsorption/desorption method. The char yield decreased rapidly with increasing temperature until 400 degrees C. As temperature increased, the char became progressively more aromatic and carbonaceous. The hydroxyl, aliphatic C-H, carbonyl and olefinic C=C groups were lost at high temperatures. Below 500 degrees C, the removal of volatile matter made pore opening. High temperatures led to the occurrence of softening, melting, fusing and carbon structural ordering. The aromatization process started at approximately 350 degrees C and continued to higher temperatures. The shrinkage of carbon structure occurred above 500 degrees C, which was concurrent with the aromatization process.

  10. Changes imposed by pyrolysis, thermal gasification and incineration on composition and phosphorus fertilizer quality of municipal sewage sludge.

    PubMed

    Thomsen, Tobias Pape; Sárossy, Zsuzsa; Ahrenfeldt, Jesper; Henriksen, Ulrik B; Frandsen, Flemming J; Müller-Stöver, Dorette Sophie

    2017-08-01

    Fertilizer quality of ash and char from incineration, gasification and pyrolysis of a single municipal sewage sludge sample were investigated by comparing composition and phosphorus (P) plant availability. A process for post oxidation of gasification ash and pyrolysis char was developed and the oxidized materials were investigated as well. Sequential extraction with full elemental balances of the extracted pools as well as scanning electron microscopy with energy dispersive X-ray spectroscopy were used to investigate the mechanisms driving the observed differences in composition and P plant availability in a short-term soil incubation study. The compositional changes related mainly to differences in the proximate composition as well as to the release of especially nitrogen, sulfur, cadmium and to some extent, phosphorus (P). The cadmium load per unit of P was reduced with 75-85% in gasification processes and 10-15% in pyrolysis whereas no reduction was observed in incineration processes. The influence on other heavy metals was less pronounced. The plant availability of P in the substrates varied from almost zero to almost 100% of the plant availability of P in the untreated sludge. Post-oxidized slow pyrolysis char was found to be the substrate with the highest P fertilizer value while ash from commercial fluid bed sludge incineration had the lowest P fertilizer quality. The high P fertilizer value in the best substrate is suggested to be a function of several different mechanisms including structural surface changes and improvements in the association of P to especially magnesium, calcium and aluminum. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. 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.

  12. 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...

  13. 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...

  14. Process simulation of ethanol production from biomass gasification and syngas fermentation.

    PubMed

    Pardo-Planas, Oscar; Atiyeh, Hasan K; Phillips, John R; Aichele, Clint P; Mohammad, Sayeed

    2017-09-01

    The hybrid gasification-syngas fermentation platform can produce more bioethanol utilizing all biomass components compared to the biochemical conversion technology. Syngas fermentation operates at mild temperatures and pressures and avoids using expensive pretreatment processes and enzymes. This study presents a new process simulation model developed with Aspen Plus® of a biorefinery based on a hybrid conversion technology for the production of anhydrous ethanol using 1200tons per day (wb) of switchgrass. The simulation model consists of three modules: gasification, fermentation, and product recovery. The results revealed a potential production of about 36.5million gallons of anhydrous ethanol per year. Sensitivity analyses were also performed to investigate the effects of gasification and fermentation parameters that are keys for the development of an efficient process in terms of energy conservation and ethanol production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Artificial neural network based modelling approach for municipal solid waste gasification in a fluidized bed reactor.

    PubMed

    Pandey, Daya Shankar; Das, Saptarshi; Pan, Indranil; Leahy, James J; Kwapinski, Witold

    2016-12-01

    In this paper, multi-layer feed forward neural networks are used to predict the lower heating value of gas (LHV), lower heating value of gasification products including tars and entrained char (LHVp) and syngas yield during gasification of municipal solid waste (MSW) during gasification in a fluidized bed reactor. These artificial neural networks (ANNs) with different architectures are trained using the Levenberg-Marquardt (LM) back-propagation algorithm and a cross validation is also performed to ensure that the results generalise to other unseen datasets. A rigorous study is carried out on optimally choosing the number of hidden layers, number of neurons in the hidden layer and activation function in a network using multiple Monte Carlo runs. Nine input and three output parameters are used to train and test various neural network architectures in both multiple output and single output prediction paradigms using the available experimental datasets. The model selection procedure is carried out to ascertain the best network architecture in terms of predictive accuracy. The simulation results show that the ANN based methodology is a viable alternative which can be used to predict the performance of a fluidized bed gasifier.

  16. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. A novel approach to highly dispersing catalytic materials in coal for gasification

    SciTech Connect

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

    1989-01-01

    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 high 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. The work is focused on the elucidation of coal-catalyst precursor interactions in solution and the variables which control the adsorption and dispersion of coal gasification metal catalysts. In order to optimize coal-metal ion interactions and hence maximize catalyst activity, the study examines the surface electrochemistry of a lignite, a subbituminous, and a bituminous coals and their demineralized and oxidized derivatives prior to loading with the catalytic materials. The surface electrical properties of the coals are investigated with the aid of electrophoresis, while the effects of the surface charge on the adsorption of K{sup +} and Ca{sup 2+} are studied by agitating the coals with aqueous solutions of potassium and calcium. A zeta meter, a tube furnace, and other equipment required for the investigation have been acquired and installed. Preliminary work shows that the lignite (Psoc 1482) is negatively charged between pH 1.8 and pH 11.0 and has an isoelectric point of pH 1.8.

  18. 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.

  19. Non-catalytic co-gasification of sub-bituminous coal and biomass

    NASA Astrophysics Data System (ADS)

    Nyendu, Guevara Che

    Fluidization characteristics and co-gasification of pulverized sub-bituminous coal, hybrid poplar wood, corn stover, switchgrass, and their mixtures were investigated. Co-gasification studies were performed over temperature range from 700°C to 900°C in different media (N2, CO2, steam) using a bubbling fluidized bed reactor. In fluidization experiments, pressure drop (Delta P) observed for coal-biomass mixtures was higher than those of single coal and biomass bed materials in the complete fluidization regime. There was no systematic trend observed for minimum fluidization velocity ( Umf) with increasing biomass content. However, porosity at minimum fluidization (εmf) increased with increasing biomass content. Channeling effects were observed in biomass bed materials and coal bed with 40 wt.% and 50 wt.% biomass content at low gas flowrates. The effect of coal pressure overshoot reduced with increasing biomass content. Co-gasification of coal and corn stover mixtures showed minor interactions. Synergetic effects were observed with 10 wt.% corn stover. Coal mixed with corn stover formed agglomerates during co-gasification experiments and the effect was severe with increase in corn stover content and at 900°C. Syngas (H2 + CO) concentrations obtained using CO2 as co-gasification medium were higher (~78 vol.% at 700°C, ~87 vol.% at 800°C, ~93 vol.% at 900°C) than those obtained with N2 medium (~60 vol.% at 700°C, ~65 vol.% at 800°C, ~75 vol.% at 900°C). Experiments involving co-gasification of coal with poplar showed no synergetic effects. Experimental yields were identical to predicted yields. However, synergetic effects were observed on H2 production when steam was used as the co-gasification medium. Additionally, the presence of steam increased H2/CO ratio up to 2.5 with 10 wt.% hybrid poplar content. Overall, char and tar yields decreased with increasing temperature and increasing biomass content, which led to increase in product gas.

  20. 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.

  1. 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.

  2. 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. 

  3. A burnout prediction model based around char morphology

    SciTech Connect

    Tao Wu; Edward Lester; Michael Cloke

    2006-05-15

    Several combustion models have been developed that can make predictions about coal burnout and burnout potential. Most of these kinetic models require standard parameters such as volatile content and particle size to make a burnout prediction. This article presents a new model called the char burnout (ChB) model, which also uses detailed information about char morphology in its prediction. The input data to the model is based on information derived from two different image analysis techniques. One technique generates characterization data from real char samples, and the other predicts char types based on characterization data from image analysis of coal particles. The pyrolyzed chars in this study were created in a drop tube furnace operating at 1300{sup o}C, 200 ms, and 1% oxygen. Modeling results were compared with a different carbon burnout kinetic model as well as the actual burnout data from refiring the same chars in a drop tube furnace operating at 1300{sup o}C, 5% oxygen, and residence times of 200, 400, and 600 ms. A good agreement between ChB model and experimental data indicates that the inclusion of char morphology in combustion models could well improve model predictions. 38 refs., 5 figs., 6 tabs.

  4. 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.

  5. 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.

  6. 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, October 1--December 31, 1992

    SciTech Connect

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

    1992-12-01

    Work on catalytic steam gasification with chars and coals will be extended from atmospheric to elevated pressures using the newly built pressure unit. The novel finding that coking of petroleum in the presence of small amounts of caustic greatly improves the gasification rates and characteristics of the coke will be extended to chars; in the oxidative coupling of methane over ternary catalysts, emphasis will be placed on low temperature coupling and on the oxidative production of syngas from methane at low temperature. Experimental work will continue on the synthesis of the mixed catalyst, and they will be characterized by a number of techniques, including elemental analyses, x-ray diffraction, and surface area determination.

  7. Formation and structure of amorphous carbon char from polymer materials

    NASA Astrophysics Data System (ADS)

    Lawson, John; Srivastava, Deepak

    2008-03-01

    Amorphous carbonaceous char produced from burning polymer solids has insulating properties that makes it valuable for aerospace thermal protection systems as well as for fire retardants. A pyrolytic molecular dynamics simulation method is devised to study the transformation of the local microstructure from virgin polymer to a dense, disordered char. Release of polymer hydrogen is found to be critical to allow the system to collapse into a highly coordinated structure. Mechanisms of the char formation process and the morphology of the resulting structure are elucidated.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. 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.

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

    SciTech Connect

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

    2008-07-15

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

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Characterizing cytotoxic and estrogenic activity of Arctic char tissue extracts in primary Arctic char hepatocytes.

    PubMed

    Petersen, Karina; Hultman, Maria T; Bytingsvik, Jenny; Harju, Mikael; Evenset, Anita; Tollefsen, Knut Erik

    2017-09-01

    Contaminants from various anthropogenic activities are detected in the Arctic due to long-range atmospheric transport, ocean currents, and living organisms such as migrating fish or seabirds. Although levels of persistent organic pollutants (POPs) in Arctic fish are generally low, local hot spots of contamination were found in freshwater systems such as Lake Ellasjøen at Bjørnøya (Bear Island, Norway). Higher concentrations of organic halogenated compounds (OHC), and higher levels of cytochrome P450 and DNA-double strand breaks were reported in Arctic char (Salvelinus alpinus) from this lake compared to fish from other lakes on Bjørnøya. Although several of the measured contaminants are potential endocrine disrupters, few studies have investigated potential endocrine disruptive effects of the contaminant cocktail in this fish population. The aim of this study was to compare acutely toxic and estrogenic potency of the cocktail of pollutants as evidenced by cytotoxic and/or estrogenic effects in vitro using extracts of Arctic char livers from contaminated Lake Ellasjøen with those from less contaminated Lake Laksvatn at Bjørnøya. This was performed by in situ sampling and contaminant extraction from liver tissue, followed by chemical analysis and in vitro testing of the following contaminated tissue extracts: F1-nonpolar OHC, F2-polar pesticides and metabolites of OHC, and F3-polar OHC. Contaminant levels were highest in extracts from Ellasjøen fish. The F2 and F3 extracts from Lake Laksvatn and Lake Ellasjøen fish reduced in vitro cell viability at a concentration ratio of 0.03-1 relative to tissue concentration in Arctic char. Only the F3 liver extract from Ellasjøen fish increased in vitro vitellogenin protein expression. Although compounds such as estrogenic OH-PCBs were quantified in Ellasjøen F3 extracts, it remains to be determined which compounds were inducing estrogenic effects.

  5. 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.

  6. 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...

  7. 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.

  8. 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...

  9. Updraft gasification of salmon processing waste

    USDA-ARS?s Scientific Manuscript database

    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...

  10. Digested sewage sludge gasification in supercritical water.

    PubMed

    Zhai, Yunbo; Wang, Chang; Chen, Hongmei; Li, Caiting; Zeng, Guangming; Pang, Daoxiong; Lu, Pei

    2013-04-01

    Digested sewage sludge gasification in supercritical water was studied. Influences of main reaction parameters, including temperature (623-698 K), pressure (25-35 Mpa), residence time (10-15 min) and dry matter content (5-25 wt%), were investigated to optimize the gasification process. The main gas products were methane, carbon monoxide, carbon dioxide and traces of ethene, etc. Results showed that 10 wt% dry matter content digested sewage sludge at a temperature of 698 K and residence time of 50 min, with a pressure of 25 MPa, were the most favorable conditions for the sewage sludge gasification and carbon gasification efficiencies. In addition, potassium carbonate (K2CO3) was also employed as the catalyst to make a comparison between gasification with and without catalyst. When 2.6 g K2CO3 was added, a gasification efficiency of 25.26% and a carbon gasification efficiency of 20.02% were achieved, which were almost four times as much as the efficiencies without catalyst. K2CO3 has been proved to be effective in sewage sludge gasification.

  11. Modeling integrated biomass gasification business concepts

    Treesearch

    Peter J. Ince; Ted Bilek; Mark A. Dietenberger

    2011-01-01

    Biomass gasification is an approach to producing energy and/or biofuels that could be integrated into existing forest product production facilities, particularly at pulp mills. Existing process heat and power loads tend to favor integration at existing pulp mills. This paper describes a generic modeling system for evaluating integrated biomass gasification business...

  12. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Gasification technologies 2005. Conference papers and presentations

    SciTech Connect

    2005-07-01

    A total of 43 papers and two keynote addresses were presented at the conference in eight sessions entitled Four perspectives on gasification industry trends and new developments; Federal gasification incentives: opportunities and challenges; Carbon sequestration ready: What does it mean and who can do it?; Experience with gasifying low rank coals (panel discussion); What are current gasification-based offerings in the energy marketplace?; Coal to liquids and chemicals: prospects and challenges; Gasification market drivers panel; and Gasification technologies advancements continue. The CD-ROM contains 43 presentations plus on keynote address, all in slide/overview form as pdfs. In addition, the text of four presentations is included. These have been abstracted separately for the Coal Abstracts database.

  14. 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

  15. Mild Traumatic Brain Injury

    MedlinePlus

    ... Questions Glossary Contact Us Visitor Feedback mild Traumatic Brain Injury mild Traumatic Brain Injury VIDEO STORIES What is TBI Measuring Severity ... most common deployment injuries is a mild Traumatic Brain Injury (TBI). A mild TBI is an injury ...

  16. 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

  17. Two stage coal gasification plant

    SciTech Connect

    Shoebotham, N.M.

    1984-06-26

    This invention relates to a two stage coal gasification plant which comprises a gasifier 1 and a predistillation retort 2. The gasifier has a plurality of gas extraction outlets 4 located in the periphery thereof which feed into a manifold 5 from where a percentage of the gas from the gasifier is extracted. Gas from the predistillation retort is extracted through an outlet near the top of the retort. An agitator 8 is provided for agitation of the coal in the agglomeration zone. The agitator is preferably automatically controlled by means of a temperature sensing device 10 located on an arm thereof.

  18. 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.

  19. Simulation of blast-furnace tuyere and raceway conditions in a wire mesh reactor: extents of combustion and gasification

    SciTech Connect

    Long Wu; N. Paterson; D.R. Dugwell; R. Kandiyoti

    2007-08-15

    A wire mesh reactor has been modified to investigate reactions of coal particles in the tuyeres and raceways of blast furnaces. At temperatures above 1000{sup o}C, pyrolysis reactions are completed within 1 s. The release of organic volatiles is probably completed by 1500{sup o}C, but the volatile yield shows a small increase up to 2000{sup o}C. The additional weight loss at the higher temperature may be due to weight loss from inorganic material. The residence time in the raceway is typically 20 ms, so it is likely that pyrolysis of the coal will continue throughout the passage along the raceway and into the base of the furnace shaft. Combustion reactions were investigated using a trapped air injection system, which admitted a short pulse of air into the wire mesh reactor sweep gas stream. In these experiments, the temperature and partial pressure of O{sub 2} were limited by the oxidation of the molybdenum mesh. However, the tests have provided valid insight into the extent of this reaction at conditions close to those experienced in the raceway. Extents of combustion of the char were low (mostly, less than 5%, daf basis). The work indicates that the extent of this reaction is limited in the raceway by the low residence time and by the effect of released volatiles, which scavenge the O{sub 2} and prevent access to the char. CO{sub 2} gasification has also been studied and high conversions achieved within a residence time of 5-10 s. The latter residence time is far longer than that in the raceway and more typical of small particles travelling upward in the furnace shaft. The results indicate that this reaction is capable of destroying most of the char. However, the extent of the gasification reaction appears limited by the decrease in temperature as the material moves up through the furnace. 44 refs., 12 figs., 6 tabs.

  20. Thermal effects in cellulose pyrolysis: Relationship to char formation processes

    SciTech Connect

    Milosavljevic, I.; Oja, V.; Suuberg, E.M.

    1996-03-01

    The thermochemistry of cellulose pyrolysis has been studied by a combination of differential scanning calorimetry and thermogravimetric analysis. Additionally, the vapor pressure and heat of vaporization of levoglucosan have been determined by an effusion method. The cellulose pyrolysis has been carried out under inert gas at heating rates from 0.1 to 60 K/min. The main cellulose thermal degradation pathway is endothermic, in the absence of mass transfer limitations that promote char formation. The endothermicity is estimated to be about 538 J/g of volatiles evolved. It is concluded that this endothermicity mainly reflects a latent heat requirement for vaporizing the primary tar decomposition products. Pyrolysis can be driven in the exothermic direction by char-forming processes that compete with tar-forming processes. The formation of char is estimated to be exothermic to the extent of about 2 kJ/g of char formed. Low heating rates, in concert with mass transfer limitations, serve to drive the pyrolysis in this direction. The enthalpy of cellulose pyrolysis is thus seen to be a sensitive function of the pyrolysis conditions. Pyrolysis appears to initially follow a common thermal pathway (in terms of enthalpy required per mass of volatile loss), irrespective of heating rate. Only at some finite level of conversion does the thermal trajectory of the process follow a heating rate dependent path, as significant char formation begins to occur.

  1. Arsenate adsorption onto iron oxide amended rice husk char.

    PubMed

    Cope, Christopher O; Webster, Damon S; Sabatini, David A

    2014-08-01

    In this study, rice husks were charred at 550 °C in a partially sealed ceramic vessel for 30minutes to create a high specific surface area (SSA) rice husk char (RHC). The RHC was then amended with iron oxides using dissolved ferric nitrate, Fe(NO3)3⋅9H2O, to provide a surface chemistry conducive to arsenic adsorption. The 550 °C iron oxide amended rice husk char's (550 IOA-RHC's) SSA was nearly 2.5 orders of magnitude higher and the arsenate adsorptive level was nearly 2 orders of magnitude higher than those reported for iron oxide amended sand, thus indicating a positive relationship between post-amendment SSA and arsenate adsorptive levels. Rice husks were then charred at temperatures ranging from 450 °C to 1050 °C to create an even higher SSA material, which might further increase arsenate adsorptive levels. The 950 °C RHC was chosen for amendment due to its high SSA and feasibility of being produced in the field. Once amended, the 950 °C iron oxide amended rice husk char (950 IOA-RHC) improved the arsenate adsorption capacity by thus confirming a positive relationship, though not a linear relationship, between post-amendment SSA and arsenic adsorptive capacity. Further study demonstrated that post-amendment mesoporous volume and mesoporous surface area appear to be better indicators of arsenic adsorptive capacity than SSA or iron content.

  2. 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.

  3. 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.

  4. Fundamental studies of catalytic gasification

    SciTech Connect

    Heinemann, H.; Somorjai, G.A.

    1991-03-01

    Studies of the catalytic steam gasification of carbon solids continued. A considerable number of important findings have been made. Recently limited experimentation has been carried out on the production of C{sub 2} hydrocarbons from methane in the presence of Ca/K/Ni oxide catalysts and of oxygen, carbon and water. The main finding thus far has been that C{sub 2} yields of 10--13% can be obtained at about 600{degrees}C or 150{degrees} lower temperature than described in the literature for similar yields. Yields of 7--10% C{sub 2} hydrocarbons at 99+% selectivity have been obtained. The presence of water and small amounts of oxygen is essential. Yields of this magnitude may be attractive since there is no loss of methane to valueless by-products, no purification of the recycle steam is required and no oxygen is used to burn methane. Further improvement in yields by catalyst and operating conditions modification will be investigated. It is also intended to clarify the chemistry which inhibits burning of methane to carbon oxides. Work is discussed on gasification of petroleum cokes and oxidative methane coupling. 8 figs., 2 tabs.

  5. 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.

  6. Kansas refinery starts up coke gasification unit

    SciTech Connect

    Rhodes, A.K.

    1996-08-05

    Texaco Refining and Marketing Inc. has started up a gasification unit at its El Dorado, Kan., refinery. The unit gasifies delayed coke and other refinery waste products. This is the first refinery to install a coke-fueled gasification unit for power generation. Start-up of the $80-million gasification-based power plant was completed in mid-June. The gasifier produces syngas which, along with natural gas, fuels a combustion turbine. The turbine produces virtually 100% of the refinery`s electricity needs and enough heat to generate 40% of its steam requirements.

  7. 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.

  8. 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.

  9. Charring Rate for Fire Exposed X-Lam

    NASA Astrophysics Data System (ADS)

    Wong, Bernice VY; Fah Tee, Kong

    2017-06-01

    Design of timber structures has been outlined in Eurocode 5. Notional charring rate for softwood and hardwood timber is given. For the performance of X-LAM panels in fire, only little information on charring is available and whether the fire behaviour of X-LAM is similar to homogenous timber panels has not yet been systematically analysed. This paper presents an overview of fire performance of X-LAM and evaluation of its resistance to elevated temperature as an element of structure in comparison to homogeneous timber panels. Numerical study has been carried out based on available experimental results. Charring rates for X-LAM panels obtained from experimental results are compared with those obtained from Eurocode 5 and proposed simplified model.

  10. 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.

  11. [Genetic divergence of mitochondrial DNA in white char Salvelinus albus and northern Dolly Varden char Salvelinus malma malma].

    PubMed

    Oleĭnik, A G; Skurikhina, L A; Brykov, Vl A

    2010-03-01

    Comparative analysis of mitochondrial DNA variation was performed in white char Salvelinus albus and in its putative ancestor species, northern Dolly Varden char Salvelinus malma malma. Highly statistically significant differentiation of S. albus and S. m. malma in the areas of sympatric (Kamchatka River basin) and allopatric (Kronotskoe Lake and Kronotskaya River) residence was demonstrated. The mtDNA divergence between S. albus and S. m. malma did not exceed the range ofintraspecific variation in the populations of northern Dolly Varden char. At the same time, clusterization pattern of the Salvelinus chars provides hypothesis on the common origin of two allopatric populations of white char. Genealogical analysis of haplotypes indicates that S. albus and S. m. malma currently demonstrate incomplete radiation of mitochondrial lineages. The low nucleotide divergence estimates between S. albus and S. m. malma reflect the short time period since the beginning of the radiation of ancestral lineages. These estimates are determined by ancestral polymorphism and haplotype exchange between the diverged phylogenetic groups as a result of introgressive hybridization.

  12. 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.

  13. Catalytic gasification of coal using eutectic salts: recovery, regeneration, and recycle of spent eutectic catalysts.

    PubMed

    Sheth, Atul C; Sastry, Chandramouli; Yeboah, Yaw D; Xu, Yong; Agarwal, Pradeep

    2003-04-01

    Catalyst recovery studies were conducted for gasified chars produced from steam gasification of Illinois #6 coal catalyzed with two different catalyst systems. A ternary (43.5 mol% Li2CO3-31.5 mol% Na2COr-25 mol% K2CO3) and a binary (29 mol% Na2CO3-71 mol% K2CO3) eutectic catalyst system were used for gasifying coal. Various extraction schemes, such as water extraction, H2SO4 extraction, and acetic acid extraction, were evaluated with respect to their extraction efficiencies. Effects of major process variables, such as solvent-to-char ratio, mixing time, temperature, and concentration, on the extraction efficiency were evaluated. A process schematic for the entire catalyst recovery, regeneration, and recycle scheme was developed and the preliminary process economics were determined based on these extraction schemes. H2SO4 extraction was found to be the most desirable. It also turned out to be more attractive than a once-through throwaway system.

  14. Biomass gasification at the focus of the Odeillo (France 1-MW (thermal) solar furnace

    SciTech Connect

    Antal, M.J. Jr.; Royere, C.; Vialaron, A.

    1980-01-01

    Experiments described in this paper were undertaken to explore the use of concentrated solar radiation for the flash pyrolysis of biomass. Biomass materials (powdered, microcrystalline cellulose and ground corn cob material) have been successfully gasified in a windowed chemical reactor operating at the focus of the Odeillo 1 MW/sub th/ solar furnace. The quartz window survived radiant flux levels in excess of 1000 W/cm/sup 2/; however impurities carried by the steam flow into the reactor ultimately clouded the window. Pyrolytic char yields of the Odeillo experimetns were quite low: ranging between one and four percent. Gas yields were also relatively low, but condensible yields were high. These results reflect the important role played by the gas phase chemistry (largely unaffected by the high solar flux) in the production of permanent gases from biomass. A consideration of the characteristic times for chemical kinetic and heat transfer phenomenon within a rapidly pyrolyzing particle indicate that heat transfer (not chemical kinetics) is the rate limiting step. However, the thermochemical and optical properties of biomass materials are poorly understood and much more experimental work must be completed before definitive conclusions in this important area can be made. Because the use of concentrated solar radiation for direct gasification of biomass materials results in the formation of little or no char without reliance on the water gas or Boudourad reactions, solar flash pyrolysis of biomass holds unusual promise for the economical production of liquid and gaseous fuels from renewable resources.

  15. Steam-air blown bubbling fluidized bed biomass gasification (BFBBG): Multi-scale models and experimental validation

    DOE PAGES

    Bates, Richard B.; Ghoniem, Ahmed F.; Jablonski, Whitney S.; ...

    2017-02-02

    During fluidized bed biomass gasification, complex gas-solid mixing patterns and numerous chemical and physical phenomena make identification of optimal operating conditions challenging. In this work, a parametric experimental campaign was carried out alongside the development of a coupled reactor network model which successfully integrates the individually validated sub-models to predict steady-state reactor performance metrics and outputs. The experiments utilized an integrated gasification system consisting of an externally-heated, bench-scale, 4-in., 5 kWth, fluidized bed steam/air blown gasifier fed with woody biomass equipped with a molecular beam mass spectrometer to directly measure tar species. The operating temperature (750-850°C) and air/fuel equivalence ratiomore » (ER = 0-0.157) were independently varied to isolate their effects. Elevating temperature is shown to improve the char gasification rate and reduce tar concentrations. In conclusion, air strongly impacts the composition of tar, accelerating the conversion of lighter polycyclic-aromatic hydrocarbons into soot precursors, while also improving the overall carbon conversion.« less

  16. 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

  17. 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

    2015-11-12

    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.

  18. 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.

  19. 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.

  20. Preparation and gasification of a Thailand coal-water fuel

    SciTech Connect

    Ness, R.O. Jr.; Anderson, C.M.; Musich, M.A.; Richter, J.J.; Dewall, R.A.; Young, B.C.; Nakanart, A.

    1996-12-31

    In response to an inquiry by the Department of Mineral Resources (DMR) in Thailand, the Energy and Environmental Research Center (EERC) prepared a four-task program to assess the responsiveness of Wiang Haeng coal to the temperature and pressure conditions of hot-water drying (HWD). The results indicate that HWD made several improvements in the coal, notably increases in heating value and carbon content and reductions in equilibrium moisture and oxygen content. The equilibrium moisture content decreased from 37.4 wt% for the raw coal to about 20 wt% for the HWD coals. The energy density, determined at 500 cP, indicates an increase from 4450 to 6650 Btu/lb by hydrothermal treatment. Raw and HWD coal were then gasified at various mild gasification conditions of 700 C and 30 psig. The tests indicated that the coal is probably similar to other low-rank coals and will produce high levels of hydrogen and be fairly reactive.

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. Potential of producing hydrogen and high Btu gas from steam gasification of lignins

    SciTech Connect

    Iqbal, M.; Dalai, A.K.; Bakhshi, N.N.; Thring, R.W.

    1998-07-01

    Generally, lignins are considered as a waste product from the pulp and paper industry. In this work, the authors have attempted to convert a number of lignins to hydrogen and high Btu gas by gasifying them with steam. Steam gasification of three lignins, namely, Kraft-1, Kraft-2 and Alcell was carried out in a fixed bed reactor in the temperature range 600--800 C. The steam flow rate was 10 g/h/g of lignin. As expected, lignin conversion was highest at 800 C and followed the order Kraft-1 {gt} Kraft-2 {gt} Alcell. The product gas consisted of H{sub 2}, CO, CO{sub 2}, and CH{sub 4}, C{sub 2} and C{sub 3+} hydrocarbons. The Btu value of the product gas ranged between 450--850 Btu/scf. It was interesting to observe that the H{sub 2} content was fairly high and ranged between 30--50 mol% of the product gas mixture. In addition, the effect of steam flow rate (5--15 g/h/g of lignin) was also studied at a fixed temperature of 800 C. It was interesting to observe that at high steam flow rates, the lignin conversion increased and the process resulted in high selectivity for CH{sub 4}. All these three lignins have been thoroughly characterized. A comparison of these results with results obtained from steam gasification of biomass-derived chars will also be presented.

  6. 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

  7. 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.

  8. Characterization of a Neochlamydia-like Bacterium Associated with Epitheliocystis in Cultured Artic Char Salvelinus alpinus

    USDA-ARS?s Scientific Manuscript database

    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...

  9. [Genetic Connectivity Between Sympatric Populations of Closely Related Char Species, Dolly Varden Salvelinus malma and White Char Salvelinus albus].

    PubMed

    Salmenkova, E A

    2016-01-01

    The closely related chars Salvelinus malma and Salvelinus albus, which sympatrically inhabit the Kamchatka River basin and Kronotsky Lake (Kamchatka), attract the attention of the researchers because of their debated origin and taxonomic status. Previous studies of sympatric populations of these chars revealed small but statistically significant genetic differences between these species at a number of molecular markers, suggesting the presence of the genetic exchange and hybridization. In this study, based on genotypic characterization of nine microsatellite loci, a considerable level of historical and contemporary genetic migration between sympatric populations of these chars was demonstrated. At the individual level a high degree of hybridization was observed, mainly among the Dolly Varden individuals from the studied populations. The obtained evidence on the genetic connectivity between sympatric S. malma and S. albus do not support the separate species status of S. albus.

  10. Synthetic chars for studies of char combustion mechanisms: Quarterly technical progress report, March 1, 1987-May 31, 1987

    SciTech Connect

    Not Available

    1987-01-01

    The physical and chemical properties of synthetic char particles formed by atomization of a solution containing a polymer of furfuryl alcohol and pore formers in acetone were examined in detail. The plain polymer char shows only pores smaller than about 20 nm, while that containing carbon blace includes a small volume of pores as large as 0.5 microns. The former was typical of all but the chars containing carbon black or that formed from tannic acid which formed cenospheres. The surface areas of the glassy carbons increased dramatically during combustion. Combustion experiments were undertaken to map the increase of the surface area with burn-off. To examine the source of this large surface area, small angle X-ray scattering (SAXS) was used as a separate measurement of the porous microstructure. 3 figs., 3 tabs.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Updraft Fixed Bed Gasification Aspen Plus Model

    SciTech Connect

    2007-09-27

    The updraft fixed bed gasification model provides predictive modeling capabilities for updraft fixed bed gasifiers, when devolatilization data is available. The fixed bed model is constructed using Aspen Plus, process modeling software, coupled with a FORTRAN user kinetic subroutine. Current updraft gasification models created in Aspen Plus have limited predictive capabilities and must be "tuned" to reflect a generalized gas composition as specified in literature or by the gasifier manufacturer. This limits the applicability of the process model.

  16. 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.

  17. Sewage sludge gasification: First studies

    SciTech Connect

    Garcia-Bacaicoa, P.; Bilbao, R.; Uson, C.

    1995-11-01

    Wastewater treatment installations produce a large quantity of sewage sludge, the disposal and treatment of which causes several problems because of its volume, its toxic organic constituents and the heavy metals that it contains. Certain methods of treatment and disposal do exist, but they are not entirely satisfactory. Moreover, it is important to develop a technology for the adequate treatment of sewage sludge in order to reduce the environmental problem and the costs of treatment. It can be assumed that gasification is a suitable technology because it reduces the waste volume, destroys the toxic organic compounds and fixes the heavy metals in the resultant solid. In order to gain knowledge of the processes occurring in the gasifier, the results obtained in experiments on the thermal decomposition of sewage sludge at different heating rates are shown.

  18. Dakota Gasification Company - ammonia scrubber

    SciTech Connect

    Wallach, D.L.

    1995-12-31

    Amain stack BACT assessment for sulfur dioxide emissions conducted in 1990 for the Dakota Gasification Company`s (DGC) Great Plains Synfuels Plant identified wet limestone flue gas desulfurization system as BACT. During the development of the design specification for the wet limestone FGD, GE Environmental Systems Inc. and DGC jointly demonstrated a new ammonia-based process for flue gas desulfurization on a large pilot plant located at the Great Plains Synfuels Plant. The production of saleable ammonium sulfate, rather than a waste product, was of interest to DGC as it fit into the plant`s on-going by-product recovery efforts. With the success of the pilot plant, DGC and GEESI entered into an agreement to build the first commercial scale Ammonium Sulfate Forced Oxidation FGD system. Construction of this system is well in progress with an anticipated start-up date of August, 1996.

  19. Charring does not affect wood infestation by subterranean termites

    Treesearch

    C.J. Peterson; P.D. Gerard; T.L. Wagner

    2007-01-01

    Fire is an important part of forest ecosystems, as is the insect fauna. Changes in wood brought aboutby fire may alter the ability of termites to use the wood, interrupting the decay cycle of woody debris.The ability of termites to find, infest, and feed upon wood after it had been charred was evaluated in

  20. Production and characterization of chars from cherry pulp via pyrolysis.

    PubMed

    Pehlivan, E; Özbay, N; Yargıç, A S; Şahin, R Z

    2017-12-01

    Pyrolysis is an eco-friendly process to achieve valuable products like bio-oil, char and gases. In the last decades, biochar production from pyrolysis of a wide variety of industrial and agricultural wastes become popular, which can be utilized as adsorbent instead of the expensive activated carbons. In this study, cherry pulp was pyrolyzed in a fixed bed tubular reactor at five different temperatures (400, 500,550, 600 and 700 °C) and three different heating rates (10, 100 and 200 °C/min) to obtain biochar. Proximate, ultimate, nitrogen adsorption/desorption isotherms, scanning electron microscopy, thermogravimetric analysis, x-ray fluorescence, x-ray diffraction, and Fourier transform infrared spectroscopy were performed on cherry pulp and its chars to examine the chemical alterations after the pyrolysis process. Biochar yields were decreased with increasing pyrolysis temperature and heating rate, based on experimental results. Porous biochars are carbon rich and includes high potassium content. The aromaticity of biochars increased and O/C mass ratio reduced with an increase in the pyrolysis temperature as a result of the development of compact aromatic structure in char. Pyrolysis provides a promising conversion procedure for the production of high energy density char which has promising applications in existing coal-fired boilers without any upgrading. Copyright © 2017 Elsevier Ltd. All rights reserved.