Steel slag derived oxygen carriers and solid sorbents for chemical looping CO2 capture: A mini review

• Steel slag derived solid materials for chemical looping CO 2 capture are reviewed. • Synthesis parameters affect the reactivity of steel slag derived oxygen carriers. • Steel slag derived calcium-based sorbents show superior CO 2 sorption performance. • Chemical looping CO 2 capture and steel slag utilization are coupled in one system. Steel slag is a solid waste in iron and steel industry, which shows a harmful effect on the environment as its high valuable reutilization ratio is quite low. Since it possesses high calcium and iron concentrations, it can be potentially used as oxygen carrier and solid sorbent for chemical looping CO 2 capture processes to reduce the material manufacturing cost. To promote the understanding of how to derive oxygen carriers and solid sorbents from steel slags efficiently, this review gives a state-of-the-art on this research area. Two chemical looping CO 2 capture process configurations are firstly introduced to address the application scenarios of steel slags and their derivatives. By clarifying the effect of synthesis parameters, reaction conditions and component interactions on the redox reactivity and CO 2 sorption performance, the oxygen transport capacity and CO 2 sorption capacity of steel slag derived oxygen carriers and solid sorbents can achieve to 10.63 % and 370 mg CO2 ·g -1 with a low material manufacturing cost, respectively. Several integrations of chemical looping CO 2 capture and steel slag reutilization are proposed to realize green and low-carbon iron and steel industry. Challenges and perspectives focus on reaction mechanism, impurity effect and large-scale application for steel slag derived oxygen carriers and solid sorbents.