Bauxite-modified oxygen carrier for chemical looping combustion: A possible solution to the heat of combustion compensation

CuO was induced into red mud oxygen carrier materials to balance the temperature difference between the fuel and air reactors in chemical looping combustion. Considering the lower melting point of CuO, surface sintering and agglomeration might be inevitable, and only a low loading was applied in this work. The addition of CuO did not lower the overall redox activity, as demonstrated by both thermogravimetric analysis (TGA) and a bench-scale fluidized bed reactor. Instead, the oxygen transfer capacity was improved. A variety of characterization techniques were used to compare the crystal structure, surface morphology and physical properties before and after long-term reactions. The present results provide a potential strategy for the design and development of oxygen carriers with high stability and reactivity that maintain a lower required circulation rate.