CO2 capture and utilization (CCU) technology has been widely adopted to reduce the greenhouse effect. The emerging chemical looping technology applied in the syngas production and gas-solid separation process has attracted widespread attention. In this research, a novel combined chemical looping reforming (CLR) process with CCU is realized in one system with CaO and Fe2O3 as the CO2 and oxygen carriers, respectively. The effects of operating parameters (i.e. Fe2O3/Al2O3 weight ratio, CO2 carrier feed ratio, CH4 feed concentration and reforming temperature) on the reforming performance are investigated through the experiments in a fixed bed reactor. The results show that these operating factors have significant impacts on the reforming reactivity. 2.5 times of CaCO3 simulation amount has the lowest CO2 releasing, 60wt% Fe/Al material obtains the highest H2 and syngas yields, 4.5% CH4 is beneficial for maintaining higher and more stable CH4 conversion and syngas purity, and 850 oC seems to be more suitable for combined CLR. The interaction between oxygen carrier and CO2 carrier is identified and discussed. The optimization for the operating conditions of this combined CLR process would provide an alternate pathway for efficient and clean syngas production.
Keywords CO2 capture and utilization, chemical looping reforming, CO2 carriers, oxygen carriers, syngas production, energy savings