Mass-transfer studies of solid-base catalyst-aided CO2 absorption and solid-acid catalyst-aided CO2 desorption for CO2 capture in a pilot plant using aqueous solutions of MEA and blends of MEA-MDEA and BEA-AMP
Abstract Mass-transfer studies of catalyst-aided CO2 absorption and desorption were performed in a full-cycle, bench-scale pilot plant to improve CO2 absorption using 5M MEA, 5M MEA-2M MDEA and 2M BEA-2M AMP. A solid-base catalyst, K/MgO, and an acid catalyst, HZSM-5, were used to facilitate absorption and desorption, respectively. Absorption and desorption mass-transfer performance was presented in terms of the overall mass-transfer coefficient of the gas side (KGav) and liquid side (KLav), respectively. For non-catalytic runs, the highest KGaV and KLaV were 0.086 Kmolm3.kPa.hr and 0.785 1hr for 2M BEA-2M AMP solvent. The results showed 38.7% KGav and 23.6% KLav increase for 2M BEA-2M AMP with only HZSM-5 catalyst in desorber and a 95% KGaV and 45% KLaV increase for both K/MgO catalyst and HZSM-5 catalyst. This was attributed to the role of K/MgO in bonding loosely with CO2 and making it available for the amine reaction.