CO₂ Capture over K₂CO₃/MgO/Al₂O₃ Dry Sorbent in a Fluidized Bed

Abstract

CO 2 capture was carried out over dry K 2 CO 3 /MgO/Al 2 O 3 sorbent in a fluidized-bed reactor. The result showed that the total CO 2 adsorption capacity of the new sorbent reached 109.6 mg of CO 2 /g of sorbent in the bubbling regime at 60 °C. The X-ray diffraction (XRD) results revealed that there were several kinds of carbonates formed during CO 2 adsorption, such as KHCO 3, KAl(CO 3 ) 2 (OH) 2, K 2 Mg(CO 3 ) 2, K 2 Mg(CO 3 ) 2 ·4H 2 O, and MgCO 3 . The high concentration CO 2 could be obtained by the multi-stage adsorption/desorption cycles. The sorbent could be completely regenerated at 480 °C, and the adsorption capacity remained unchanged after 6 cycles. Furthermore, the application of a conceptual CO 2 -capture process using this sorbent was proposed for an existing coal-fired power plant.