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

Abstract

CO2 capture was carried out over dry K2CO3/MgO/Al2O3 sorbent in a fluidized-bed reactor. The result showed that the total CO2 adsorption capacity of the new sorbent reached 109.6 mg of CO2/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 CO2 adsorption, such as KHCO3, KAl(CO3)2(OH)2, K2Mg(CO3)2, K2Mg(CO3)2·4H2O, and MgCO3. The high concentration CO2 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 CO2-capture process using this sorbent was proposed for an existing coal-fired power plant.