Effect of H ₂ O impurity in marine exhaust on the CO ₂ capture performance of novel composite CaO–Al ₂ O ₃ –Fe ₂ O ₃ absorbents

Abstract The CaO‐based absorbent recycling carbon capture technology is an effective way to reduce CO 2 emissions from marine exhaust gas. Inert supports (MgO, Al 2 O 3 ) and active additives (Fe 2 O 3 ) were used to obtain economical and efficient CaO‐based absorbents. The experiment results show that CaO–Al 2 O 3 –Fe 2 O 3 (CAF) absorbent has the best CO 2 adsorption performance. Compare with the initial adsorption capacity of 0.64 g/g, the adsorption capacity after 20th cycle can still achieve 0.62 g/g. The characterizing results show that CAF absorbent has the largest pore size and specific surface area. The absorbents doped with active additives Fe 2 O 3 can effectively improve the CO 2 adsorption capacity and cycle stability. In addition, the influence of H 2 O impurity on the cycle performance of the developed CAF absorbent was studied deeply. Results show that the cyclic adsorption performance of CAF absorbent decreases with the increase of the H 2 O concentration. With the increase of the cycle numbers, the existence of H 2 O will reduce the anti‐sintering performance of absorbents, which will lead to the aggregation of absorbents particles, thus reducing their adsorption performance. Therefore, the CAF absorbent developed in this study has excellent adsorption capacity and cycle stability.