Chemical looping reforming for syngas production with co-conversion of CH4 and CO2 by using ilmenite ore as both oxygen carrier and catalyst

Chemical looping CH4 reforming has been accepted as a highly promising solution for sustainable syngas production from gaseous feedstocks, e.g., natural gas, shale gas, biogas, etc., with reduced safety concerns and without the need for purified O2. However, the presence of CO2 in fuel streams severely suppresses syngas generation when using iron-based oxygen carriers. This study has identified the most possible pathway of the reactions among CO2, CH4, and FeTiO3 through density functional theory calculation and isotope analysis. Based on the revealed mechanism, a novel strategy for chemical looping CH4 reforming coupled with CO2 utilization has been demonstrated by using naturally occurring and low-cost ilmenite ore as both an oxygen carrier and a catalyst. With a well-designed solid configuration, not only can the suppressing effect of CO2 on CH4 partial oxidation be mitigated to some extent, but CH4 and CO2 can be simultaneously converted into syngas within the same reactor.