A brief review for chemical looping combustion as a promising CO2 capture technology: Fundamentals and progress

Chemical looping combustion (CLC) is a promising CO₂ capture technology; which expected to achieve 100% capture efficiency with a low energy penalty. The principle of CLC is utilizing metal particles (known as an oxygen carrier) as a medium for transport oxygen between two reactors, aiming to avoid nitrogen in combustion exhaust. Oxygen carrier is considered a key parameter in CLC, so it received particular interest in this study. CLC is an emerging technology; it received sensible attention at the beginning of this century, whether in analytical studies, TGA tests, or else. However, the first test in continuous operation was carried out in 2004 for gaseous fuel and followed by many experiments. Solid fuel was tested after gaseous ones and then received significant attention due to their high contribution to CO₂ emissions. Besides, it could accomplish negative emissions in the case of biomass-based fuel. In contrast, liquid fuels have not received considerable interest for not enough justified reasons, despite their negative emission options; whatever, the feasibility of liquid CLC has also proved in continuous tests. Up to date, the realism of CLC has shown in over 10,000 test hours worldwide on 40 test units, in an ultimate power 4 MW_th. An acceptable performance has been obtained via these tests, which encourages passing to larger-scale units, considering some difficulties associated with present experiences. This review has presented the fundamentals of CLC and a brief discussion of a comprehensive survey; concerning the status of development, obstacles that face a shift to higher scales, and future perspectives.