Investigation into Syngas Generation from Solid Fuel Using CaSO4-based Chemical Looping Gasification Process

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.

化学循环的气化(CLG ) 是为从固体的燃料的 syngas 产生的一个新奇过程，分享象化学循环的燃烧(CLC ) 的一样的基本原则。它也使用氧搬运人(主要金属氧化物和钙硫酸盐) 把热和氧转移到燃料。在这份报纸，进有 CaSO4 的 CLG 过程的主要调查被热力学的分析和实验在试管反应堆作为氧搬运人执行。包含硫的煤气的排放主要在 CLG 过程是 H2S 而非 SO2，显示出从 CLC 的一些不同特征。团和 CLG 过程的热平衡热力学地被计算到确定有不同 CaSO4/C 和 steam/C 的汽车热的操作条件臼齿的比率。CaSO4/C 臼齿的比率应该比 0.2 高到达汽车热的平衡，这被发现。在氧搬运人和煤之间的反应上的温度的效果基于吉布斯被调查免费精力最小方法和试验性的结果。它显示高温度在燃料反应堆赞成了 CLG 进程， syngas 的部分被消费补偿汽车热的系统。