采用化学链燃烧技术对化石燃料利用,可显著降低二氧化碳的分离成本.由于硫酸钙与硫化钙之间的转化可实现氧的高效传递,因而使之成为化学链燃烧技术中潜在的氧载体之一.为提高硫酸钙的氧传递能力及还原活性,探索了掺杂有过渡金属氧化物的硫酸钙所制备的复合载氧体的性能.在不同温度下对载氧体的反应活性进行实验研究,重点考察了燃料甲烷的转化率,并对燃料反应器出口的一氧化碳和二氧化硫浓度进行了检测.借助于TPR及XPS分析技术,对所涉及的协同作用机制进行了探讨,结果表明负载锰或者铁的复合载氧体在以上性能方面均较单纯硫酸钙有显著提高.在900℃时,两种复合载氧体实现的甲烷转化率均比单纯硫酸钙高出20％,而出口一氧化碳浓度却相应降低了60％,并且没有观察到二氧化硫的浓度的增加.%Considering the efficient oxygen transfer between CaSO4 and CaS, CaSO4 is regarded as a potential oxygen carrier in the chemical-looping combustion for CO2 capture. In order to improve its oxygen transfer ability and reduction activity, several transition metal oxides were tentitavely added into CaSO4 to form the mixed oxygen carriers and their performances were investigated. Experiments were conducted at a series of temperatures, the transform efficiency of methane was intensively investigated and the concentrations of CO and SO2 were also monitored. By means of the analysis technologies of TPR and XPS, the synergy effect involved was explored. The results prove that the mixed oxygen carriers with manganese oxides or ferric oxides added show better performance than that of the pure CaSO4. At 900"C, compared with the pure CaSO4, using the mixed oxygen carriers the methane conversion efficiency is about 20 percentage higher, the concentration of CO in the outlet gas is 60% lower, and the concentration of SO2 produced by the side reaction is very low. The addtiton of iron oxide apprears to be a promising method to improve the performance of CaSO4 used as the oxygen carrier.
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