Iron-based oxygen carriers in chemical looping conversions: A review

A solid oxygen carrier is usually applied in a chemical looping conversion process to transfer oxygen from the gaseous oxygen source to the fuel, which can avoid the direct contact of these two reactants and hence decrease the energy penalty of separation. Among the solid oxygen carriers, iron-based oxygen carrier is an attractive option due to its inherent properties of low cost and environmentally-friendly. Several processes such as chemical looping combustion (CLC), chemical looping gasification (CLG), chemical looping reforming (CLR), and chemical looping hydrogen generation (CLHG) have been proposed and investigated based on the iron-based oxygen carrier. In this review, the relevant researches on the iron-based oxygen carrier are summarized, which include the characteristics of iron oxides, the preparations of the iron-based oxygen carrier based on the iron ores and some other low-cost iron contained materials, and their applications in the continuous operated chemical looping conversion processes. It is expected to provide a better understanding for the development and utilization of iron-based oxygen carrier in the practical chemical looping processes.