Chemical looping combustion of coke oven gas by using Fe₂O ₃/CuO with MgAl₂O₄ as oxygen carrier

Chemical looping combustion (CLC) is a new combustion technology that is clean and highly efficienct. The reactivity of four potential oxygen carrier particles composed of Fe₂O₃/CuO and MgAl₂O ₄ have been investigated using thermogravimetric analysis (TGA) and a laboratory pressurized circulating fluidized bed system. According to the research, the following findings can be made: first, oxygen carrier particles consisting of 45% Fe₂O₃ and 15% CuO supported on 40% MgAl₂O₄ (F45C15M40) were found to be the best oxygen carrier for CLC of coke oven gas (COG). Secondly, results of multicycle reduction-oxidation tests in TGA showed that the reactivity of F45C15M40 oxygen carrier remained high and stable after 15 reduction-oxidation reaction cycles. Thirdly, the reaction temperature and cycle number showed a great effect on the reactivity of the oxygen carrier and this was attributed to the high chemical reaction rate of oxygen carrier and morphological change in CuO at high temperature. The pressurized CLC unit was in continuous operation with fuel for a duration of 15 h. The pressurized circulating fluidized bed system for CLC was found to work well with F45C15M40 oxygen carriers. It showed high reactivity in a fluidized bed reactor and gave a high conversion of the fuel, as well as reasonable crushing strength and resistance toward agglomeration and fragmentation. The maximum fuel conversion reached 92.33%.