The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Jesús Arauzo - One of the best experts on this subject based on the ideXlab platform.
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Kinetics of CO2 Gasification of alkaline black liquor from wheat straw. 2. Evolution of CO2 reactivity with the solid conversion and influence of temperature on the Gasification Rate
Industrial & Engineering Chemistry Research, 2005Co-Authors: Gloria Gea, José Sánchez, M.b. Murillo, Jesús ArauzoAbstract:Results obtained in recent studies have shown that black liquor (BL) Gasification can be considered as an attractive recovery system. However, limited information has been published on the Gasification kinetics of alkaline BL char (ABLC). Part 1 of this work (Gea, G.; Sanchez, J. L.; Murillo, M. B.; Arauzo, J. Ind. Eng. Chem. Res. 2004, 43, 3233) studied the CO 2 Gasification of ABLC, specifically the influence of [CO] and [CO 2 ] on the Gasification Rate at different temperatures. The present work is focused on the variation of this reaction Rate with solid conversion during the Gasification process. The results obtained show that the Gasification Rate increases with the solid conversion up to a maximum value and then decreases. The effect of various factors such as pyrolysis operating conditions on this variation has also been analyzed. Furthermore, the dependence of the ABLC Gasification Rate on the temperature has been evaluated, and the apparent average activation energy over the range 170-234 kJ/mol has been determined for the temperature range 750-850 °C.
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Kinetics of CO2 Gasification of alkaline black liquor from wheat straw. Influence of co and CO2 concentrations on the Gasification Rate
Industrial & Engineering Chemistry Research, 2004Co-Authors: Gloria Gea, José Sánchez, M.b. Murillo, Jesús ArauzoAbstract:Interest in the use of nonwoody biomass as a raw material for pulp and paper production is growing worldwide. Moreover, new technologies are being developed to solve the problems caused by the silica present in alkaline black liquor (ABL) from straw in heat recovery systems. Because, among the various possible technologies, Gasification is becoming attractive as a new alternative recovery system for ABL, in-depth studies of ABL Gasification are therefore required. The present work is focused on the study of CO2 Gasification of a char obtained from the ABL pyrolysis. Specifically, the influence of [CO] and [CO2] on the Gasification Rate at different Gasification temperatures has been studied. The process may be described by a Langmuir−Hinshelwood equation for a specific range of operating conditions. The data obtained suggest that this operational range could be broader if the number of catalytic sites is considered as a function of [CO] and the final pyrolysis temperature rather than as constant.
Wei Lei - One of the best experts on this subject based on the ideXlab platform.
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co2 Gasification Rate analysis of coal in molten blast furnace slag for heat recovery from molten slag by using a chemical reaction
International Journal of Hydrogen Energy, 2015Co-Authors: Wei LeiAbstract:Abstract The coal Gasification Rate of Datong coal in molten blast furnace slag using carbon dioxide as gasifying agent was studied at the temperature ranging from 1473 to 1723 K. The kinetic model was developed. The influence of reaction temperature and coal/slag mass ratio in the reaction Rate was analyzed. The reaction Rate has a strong dependence on reaction temperature and coal/slag ratio. The peak value of reaction Rate increases firstly, and then levels off, or even decreases a little as temperature increases. Within the same reaction time, the carbon conversion and peak value of reaction Rate increase with increasing coal/slag ratio. Molten BF slag is active catalyst for carbon Gasification. The volume reaction model A 1 has the best fit on coal Gasification in molten BF slag. The kinetic parameters applicable to volume reaction model at high temperature with different coal/slag ratios were obtained. The value of intrinsic activation energy is between 50 kJ/mol and 90 kJ/mol. The global Rate equation that includes these parameters was developed. Rate = ⅆ x ⅆ t = k 0 i exp ( − E a i R T ) ( 1 − x )
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CO2 Gasification Rate analysis of coal in molten blast furnace slag—For heat recovery from molten slag by using a chemical reaction
International Journal of Hydrogen Energy, 2015Co-Authors: Wei LeiAbstract:Abstract The coal Gasification Rate of Datong coal in molten blast furnace slag using carbon dioxide as gasifying agent was studied at the temperature ranging from 1473 to 1723 K. The kinetic model was developed. The influence of reaction temperature and coal/slag mass ratio in the reaction Rate was analyzed. The reaction Rate has a strong dependence on reaction temperature and coal/slag ratio. The peak value of reaction Rate increases firstly, and then levels off, or even decreases a little as temperature increases. Within the same reaction time, the carbon conversion and peak value of reaction Rate increase with increasing coal/slag ratio. Molten BF slag is active catalyst for carbon Gasification. The volume reaction model A 1 has the best fit on coal Gasification in molten BF slag. The kinetic parameters applicable to volume reaction model at high temperature with different coal/slag ratios were obtained. The value of intrinsic activation energy is between 50 kJ/mol and 90 kJ/mol. The global Rate equation that includes these parameters was developed. Rate = ⅆ x ⅆ t = k 0 i exp ( − E a i R T ) ( 1 − x )
J. R. Goss - One of the best experts on this subject based on the ideXlab platform.
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Determination of reactor scaling factors for throatless rice husk gasifier
Biomass and Bioenergy, 2000Co-Authors: A.k. Jain, J. R. GossAbstract:Abstract Four open core throatless batch fed rice husk gasifier reactors having internal diameters of 15.2, 20.3, 24.4 and 34.3 cm were designed and fabricated. Each reactor connected with gas cleaning unit was tested for its performance characteristics. On each reactor ten trial runs were conducted varying the air flow Rate or specific Gasification Rate. Gas quality, gas production Rate, Gasification efficiency specific Gasification Rate, and equivalence ratio were determined for every run on each of the four reactors. It was found that for each reactor the gasifier performance was the best at a specific Gasification Rate of around 192.5 kg/h-m 2 . Under the best operating conditions, the equivalence ratio was 0.40 and the Gasification efficiency was around 65%. These parameters may be used for designing rice husk opeRated throatless gasifiers in the capacity range of 3–15 kW.
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Optimum specific Gasification Rate for static bed rice hull gasifiers
Biomass and Bioenergy, 1996Co-Authors: Valentino M. Tiangco, Bryan M. Jenkins, J. R. GossAbstract:Abstract An experimental determination of the optimum specific Gasification Rate for static bed rice hull gas producers was conducted for reactor diameters of 16–30 cm. All experiments were performed with reactors under suction from a throttled centrifugal blower. Cold-gas efficiency was observed to increase as specific Gasification Rate increased from 100 to about 200 kg m −2 h −1 , and then begin to decline as Gasification Rate was increased further. The decline in efficiency at higher Gasification Rates was due to decreasing gas heating value which could not be compensated by increasing gas flow. An empirical relationship derived between specific Gasification Rate and cold gas efficiency was found to be independent of reactor area, although further work is needed at larger scale to assess the validity of the relationship beyond the experimental range evaluated.
Gloria Gea - One of the best experts on this subject based on the ideXlab platform.
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Kinetics of CO2 Gasification of alkaline black liquor from wheat straw. 2. Evolution of CO2 reactivity with the solid conversion and influence of temperature on the Gasification Rate
Industrial & Engineering Chemistry Research, 2005Co-Authors: Gloria Gea, José Sánchez, M.b. Murillo, Jesús ArauzoAbstract:Results obtained in recent studies have shown that black liquor (BL) Gasification can be considered as an attractive recovery system. However, limited information has been published on the Gasification kinetics of alkaline BL char (ABLC). Part 1 of this work (Gea, G.; Sanchez, J. L.; Murillo, M. B.; Arauzo, J. Ind. Eng. Chem. Res. 2004, 43, 3233) studied the CO 2 Gasification of ABLC, specifically the influence of [CO] and [CO 2 ] on the Gasification Rate at different temperatures. The present work is focused on the variation of this reaction Rate with solid conversion during the Gasification process. The results obtained show that the Gasification Rate increases with the solid conversion up to a maximum value and then decreases. The effect of various factors such as pyrolysis operating conditions on this variation has also been analyzed. Furthermore, the dependence of the ABLC Gasification Rate on the temperature has been evaluated, and the apparent average activation energy over the range 170-234 kJ/mol has been determined for the temperature range 750-850 °C.
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Kinetics of CO2 Gasification of alkaline black liquor from wheat straw. Influence of co and CO2 concentrations on the Gasification Rate
Industrial & Engineering Chemistry Research, 2004Co-Authors: Gloria Gea, José Sánchez, M.b. Murillo, Jesús ArauzoAbstract:Interest in the use of nonwoody biomass as a raw material for pulp and paper production is growing worldwide. Moreover, new technologies are being developed to solve the problems caused by the silica present in alkaline black liquor (ABL) from straw in heat recovery systems. Because, among the various possible technologies, Gasification is becoming attractive as a new alternative recovery system for ABL, in-depth studies of ABL Gasification are therefore required. The present work is focused on the study of CO2 Gasification of a char obtained from the ABL pyrolysis. Specifically, the influence of [CO] and [CO2] on the Gasification Rate at different Gasification temperatures has been studied. The process may be described by a Langmuir−Hinshelwood equation for a specific range of operating conditions. The data obtained suggest that this operational range could be broader if the number of catalytic sites is considered as a function of [CO] and the final pyrolysis temperature rather than as constant.
Atul Sharma - One of the best experts on this subject based on the ideXlab platform.
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Effect of Steam Partial Pressure on Gasification Rate and Gas Composition of Product Gas from Catalytic Steam Gasification of HyperCoal
Energy & Fuels, 2009Co-Authors: Atul Sharma, Ikuo Saito, Toshimasa TakanohashiAbstract:HyperCoal was produced from coal by a solvent extraction method. The effect of the partial pressure of steam on the Gasification Rate and gas composition at temperatures of 600, 650, 700, and 750 °C was examined. The Gasification Rate decreased with decreasing steam partial pressure. The reaction order with respect to steam partial pressure was between 0.2 and 0.5. The activation energy for the K2CO3-catalyzed HyperCoal Gasification was independent of the steam partial pressure and was about 108 kJ/mol. The gas composition changed with steam partial pressure and H2 and CO2 decreased and CO increased with decreasing steam partial pressure. By changing the partial pressure of the steam, the H2/CO ratio of the synthesis gas can be controlled.
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Factors affecting steam Gasification Rate of low rank coal char in a pressurized fluidized bed
Fuel Processing Technology, 2009Co-Authors: Koichi Matsuoka, Atul Sharma, Daisuke Kajiwara, Koji Kuramoto, Yoshizo SuzukiAbstract:Abstract A high-pressure bubbling fluidized bed reactor was used to study the steam Gasification of coal char under pressure. Indonesian sub-bituminous coal char (Adaro) and Australian lignite char (Loy Yang) were gasified with steam in the reactor at temperatures below 1173 K and at total pressures ranging from 0.1 to 0.5 MPa. The steam Gasification Rates of the coal chars were determined by analysis of the gaseous products. Activation energies for the steam Gasification of the chars were as high as about 250 kJ/mol, which suggests that the temperature dependence of the Gasification was substantial. The apparent Gasification Rates under the study conditions were described by a Langmuir–Hinshelwood (L–H)-type equation. Analysis of the reaction kinetics on the basis of the L–H equation indicated that increasing steam pressure effectively increased the Gasification Rate.
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low temperature catalytic steam Gasification of hypercoal to produce h2 and synthesis gas
Fuel, 2008Co-Authors: Atul Sharma, Kayoko Morishita, Takayuki Takarada, Toshimasa Takanohashi, Ikuo SaitoAbstract:HyperCoal is an ultra clean coal with ash content <0.05 wt%. Catalytic steam Gasification of HyperCoal was carried out with K 2 CO 3 at 775-650 °C for production of H 2 rich gas and synthesis gas. The catalytic Gasification of HyperCoal showed nearly four times higher Gasification Rate than raw coal. The major gases evolved were H 2 : 63 vol%, CO: 6 vol% and CO 2 : 30 vol%. Catalyst was recycled for four times without any significant Rate loss. The partial pressure of steam was varied from 0.5 atm to 0.05 atm in order to investigate the effect of steam pressure on H 2 /CO ratio. The H 2 /CO ratio decreased from 9.5 at 0.5 atm to 1.9 at 0.05 atm. No significant decrease in Gasification Rate was observed due to change in partial pressure of steam. Gasification Rate decreased with decreasing temperature and become very slow at 650 °C. The preliminary results showed that HyperCoal, an ash less coal, could be a potential hydrocarbon resource for H 2 and synthesis gas production at low temperature by catalytic steam Gasification process.