Recent progress in calcium looping integrated with chemical looping combustion (CaL-CLC) using bifunctional CaO/CuO composites for CO2 capture: A state-of-the-art review

Calcium looping integrated with chemical looping combustion (CaL-CLC) process is an efficient and cost-effective CO2 capture technology. In this technique, the heat generated by chemical looping combustion of CuO is used insitu to calcine CaCO3, thus avoiding the implementation of the energy-intensive air separation unit (ASU) in the conventional calcium looping (CaL) process for postcombustion CO2 capture. Many studies, including simulation works and material development, have been carried out on the CaL-CLC process. It is thus imperative to present the recent progress in the CaL-CLC process whilst providing a research prospects framework and direction for future research. First, fundamental understandings of the CaL-CLC process are discussed, including its concept and potential applications. Then, simulation work is reviewed, emphasizing process design and analysis, as well as modeling of the reactor and main reactions involved in the CaL-CLC process. Due to the fast reactivity decay of bifunctional CaO/CuO composites, various strategies have been developed to overcome this issue, which are summarized in detail. Last, future research directions for the CaL-CLC process are proposed.