Cycling performance of composite hematite and copper ore oxygen carrier in chemical looping combustion

A single natural ore oxygen carrier (OC) has a limited industrial application due to its weak reactivity and cyclic stability. For the composite hematite and copper ore OC prepared by spray drying granulation, long-term chemical looping combustion (CLC) cycle tests were performed on a fluidized bed thermogravimetric analyzer (FB-TGA). The results showed that a substantial mechanical stress and the presence of partially enriched fine particles on the surface of new OC particles caused a high attrition rate of OC at the early stage of fluidization. After 6 min, the attrition rate of the particle was stabilized at 0.28 %/h. The OC was subjected to chemical and thermal stresses during the redox cycle reaction, which decreased the mechanical strength and increased particle attrition and sintering. The particle sintering also hindered the oxidation stage, which led to a deep reduction of OC to a lower valence state, which drove particle agglomeration and eventual defluidization. Therefore, lowering the oxygen transfer capacity and residence time in the fuel reactor is beneficial for the safe operation of OC in industry.