Chemical-looping gasification （CLG） is a novel process for syngas generation from solid fuels, sharing the same basic principles as chemical-looping combustion （CLC）. It also uses oxygen carriers （mainly metal ox...Chemical-looping gasification （CLG） is a novel process for syngas generation from solid fuels, sharing the same basic principles as chemical-looping combustion （CLC）. It also uses oxygen carriers （mainly metal oxide and calcium sulfate） to transfer heat and oxygen to the fuel. In this paper, the primary investigation into the CLG process with CaSO4 as oxygen carrier was carried out by thermodynamic analysis and experiments in the tube reactor. Sulfur-contained gas emission was mainly H2S rather than SO2 in the CLG process, showing some different features from the CLC. The mass and heat balance of CLG processes were calculated thermodynamically to determinate the auto-thermal operating conditions with different CaSO4/C and steam/C molar ratios. It was found that the CaSO4/C molar ratio should be higher than 0.2 to reach auto-thermal balance. The effect of temperature on the reactions between oxygen carrier and coal was investigated based on Gibbs free energy minimum method and ex- perimental results. It indicated that high temperature favored the CLG process in the fuel reactor and part of syngas was consumed to compensate for auto-thermal system.展开更多
A solid oxygen carrier is usually applied in a chemical looping conversion process to transfer oxygen from the gaseous oxygen source to the fuel,which can avoid the direct contact of these two reactants and hence decr...A solid oxygen carrier is usually applied in a chemical looping conversion process to transfer oxygen from the gaseous oxygen source to the fuel,which can avoid the direct contact of these two reactants and hence decrease the energy penalty of separation.Among the solid oxygen carriers,iron-based oxygen carrier is an attractive option due to its inherent properties of low cost and environmentally-friendly.Several processes such as chemical looping combustion(CLC),chemical looping gasification(CLG),chemical looping reforming(CLR),and chemical looping hydrogen generation(CLHG)have been proposed and investigated based on the iron-based oxygen carrier.In this review,the relevant researches on the iron-based oxygen carrier are summarized,which include the characteristics of iron oxides,the preparations of the iron-based oxygen carrier based on the iron ores and some other low-cost iron contained materials,and their applications in the continuous operated chemical looping conversion processes.It is expected to provide a better understanding for the development and utilization of iron-based oxygen carrier in the practical chemical looping processes.展开更多
基金Supported by the National~ Natural Science Foundation of China （20876079）, the Natural Science Funds for Distinguished Young Scholar in Shandong Province （JQ200904）, and Shandong Province Key Technologies Research and Development Program of China （2008GG 10006010, 2009GG 10007001）.
文摘Chemical-looping gasification （CLG） is a novel process for syngas generation from solid fuels, sharing the same basic principles as chemical-looping combustion （CLC）. It also uses oxygen carriers （mainly metal oxide and calcium sulfate） to transfer heat and oxygen to the fuel. In this paper, the primary investigation into the CLG process with CaSO4 as oxygen carrier was carried out by thermodynamic analysis and experiments in the tube reactor. Sulfur-contained gas emission was mainly H2S rather than SO2 in the CLG process, showing some different features from the CLC. The mass and heat balance of CLG processes were calculated thermodynamically to determinate the auto-thermal operating conditions with different CaSO4/C and steam/C molar ratios. It was found that the CaSO4/C molar ratio should be higher than 0.2 to reach auto-thermal balance. The effect of temperature on the reactions between oxygen carrier and coal was investigated based on Gibbs free energy minimum method and ex- perimental results. It indicated that high temperature favored the CLG process in the fuel reactor and part of syngas was consumed to compensate for auto-thermal system.
基金This work was financially supported by the National Natural Science Foundation of China(NSFC,no.21506241,U1710101)Key Laboratory of Coal Science and Technology(Taiyuan University of Technology)the China Scholarship Council.
文摘A solid oxygen carrier is usually applied in a chemical looping conversion process to transfer oxygen from the gaseous oxygen source to the fuel,which can avoid the direct contact of these two reactants and hence decrease the energy penalty of separation.Among the solid oxygen carriers,iron-based oxygen carrier is an attractive option due to its inherent properties of low cost and environmentally-friendly.Several processes such as chemical looping combustion(CLC),chemical looping gasification(CLG),chemical looping reforming(CLR),and chemical looping hydrogen generation(CLHG)have been proposed and investigated based on the iron-based oxygen carrier.In this review,the relevant researches on the iron-based oxygen carrier are summarized,which include the characteristics of iron oxides,the preparations of the iron-based oxygen carrier based on the iron ores and some other low-cost iron contained materials,and their applications in the continuous operated chemical looping conversion processes.It is expected to provide a better understanding for the development and utilization of iron-based oxygen carrier in the practical chemical looping processes.
