Effect of Cu/Fe Mass Ratio on Chemical Looping Combustion Performance of Bayan Obo Iron Concentrate‐Based Cu‐Fe Composite Oxygen Carriers

In order to explore efficient oxygen carriers (OCs) for chemical looping combustion (CLC), this article investigates Bayan Obo iron concentrate‐based Cu‐Fe composite OCs with varying Cu/Fe mass ratios (1:1, 1:1.5, 1:2) for CLC performance using thermogravimetric analysis (temperature‐programmed reduction (TPR), isothermal reduction, redox cycling) and characterization (Brunauer–Emmett–Teller (BET), X‐ray diffraction (XRD), scanning electron microscopy (SEM)). The TPR tests reveal a three‐stage reduction pathway of CuFe 2 O 4 with CO: CuFe 2 O 4 → Cu + Fe 3 O 4 → FeO → Fe. The 1:1 Cu/Fe ratio OCs exhibit good reducibility, with a 4.32% higher mass loss than raw iron concentrate, lower mass‐loss commencing temperature than other ratios (280°C), higher oxygen release than other ratios above 806°C under N 2 , which intensifies with temperature, and high kinetic activity (always the first to reach equilibrium in isothermal reduction test). In 11 thermogravimetric redox cycles, the 1:1 Cu/Fe ratio sample maintains high reduction conversion, showing a maximum mass loss difference of 5.09% compared to the iron concentrate. Its stable mass loss over the initial seven cycles demonstrates its good cycling stability.