Calcium looping sorbents incorporated with MgO, Ca₃Al₂O₆, and MgAl₂O₄ supports were prepared by wet-mixing synthesis and analyzed for their CO₂ capture performances during the 30 cycles of carbonation/calcination reactions. At a 7:3 mass ratio of CaO to support oxides, the MgAl₂O₄ mixed support showed the best CO₂ capture performance.

Abstract

Calcium looping is one of the effective methods for post-combustion CO₂ capture. A key issue is choosing the appropriate supports to synthesize effective calcium-based sorbents. In this study, calcium looping sorbents incorporated with MgO, Ca₃Al₂O₆, and MgAl₂O₄ supports were prepared by wet-mixing synthesis. Characterizations were made to determine the cyclic CO₂ capture capacity, crystalline structure, porosity, and morphological changes of the sorbents over multiple cycles. The results showed that, at the mass ratio of CaO to support oxides of 7:3, the MgAl₂O₄ mixed support showed better CO₂ capture performance than the MgO and Ca₃Al₂O₆ supports. Moreover, the sorbent showed a porous and fluffy microstructure with a high specific surface area, making it a suitable candidate for cyclic CO₂ capture.