Improvement of the cyclic stability of high temperature CO2 absorbent by the addition of oxygen vacancy possessing material

Influences of oxygen vacancy possessing additives (CexZr1−xO2, LaAlyMg1−yO3) on the cyclic stability of Ca-based high temperature CO2 absorbent were investigated. Compared to absorbents composed only of CaO, oxygen vacancy possessing materials added absorbents showed significantly improved cyclic stability in repeated CO2 absorption/desorption. It has been also found that the cyclic stability of CO2 absorbent was proportional to the availability of oxygen vacancy in additives. It was presumed that oxygen vacant site behaves as a jump site for facilitating CO2 diffusion through the product layer formed during carbonation.