CaSO_4的复合载氧体制备及其反应特性

Preparation and Reactivity Behavior of Compound CaSO_4 Oxygen Carrier

利用浸渍法制备出载氧性能较好及价格低廉的复合型CaSO4载氧体,同时研究其固体燃料化学链燃烧特性。在综合热分析仪中研究复合型载氧体同H2和CO等气体燃料和煤焦固体燃料的反应性能,发现浸渍有微量Fe2O3和NiO的CaSO4复合型载氧体同气体、固体燃料的反应速率加快,反应时间大大缩短,Fe2O3改善载氧体的反应性能方面优于NiO。SEM照片显示复合型载氧体同固体燃料高温下反应前后颗粒形态发生较大变化,并出现颗粒聚团。XRD分析表明循环反应后浸渍的Ni以Ni3S2形式出现,而浸渍的Fe以Fe3O4化合物的形式存在,CaSO4的还原产物只有CaS。加入CaCO3颗粒后,大大改善了复合CaSO4载氧体的循环性能。

In this test,the compound oxygen carrier was prepared by chemical impregnation,characterized with high ability of transferring oxygen,low cost and no secondary pollution.By thermogravimetric analysis（TGA）,the reactivity of the compound oxygen carrier was investigated by reacting with both gaseous fuels including H2 and CO and coal char.The reaction rate for the compound oxygen carrier impregnated with trace Fe2O3 and NiO,reacting with solid fuels was much faster than that for fresh CaSO4 oxygen carrier.The morphology of the oxygen carrier impregnated with NiO changed dramatically after reaction with solid fuels.In particular,the oxygen carrier particles yielded agglomerates.An analysis indicates that Fe2O3 was oxidized into Fe3O4 and NiO into Ni3S2,CaSO4 was reduced into CaS in the compound oxygen carrier particles after a series of cycling reactions.The compound oxygen carrier particles were mixed with CaCO3 to present excellent cycling ability.