Enzyme-enhanced CO2 absorption process in rotating packed bed

Abstract

Carbon dioxide is considered the most important contributor to the global warming effect. To reduce greenhouse gas emissions, CO2 should be separated from the exhaust gas stream in a selective way. The most often applied technology to capture CO2 from exhaust gases is the reactive absorption in aqueous amine solutions, which is currently widely used in different industrial applications. The efficiency of this technology could be improved by applying high-gravity technologies that intensify mass transfer and can enable substantial equipment size reduction compared to the traditionally used packed columns. Rotating packed bed (RPB) technology meets these requirements very well. Applying innovative materials such as the highly efficient enzyme carbonic anhydrase can further improve the efficiency of the CO2 absorption process. This combination of intensified technology together with new solvents is expected to improve the total efficiency of CO2 absorption. In this study, we present our experimental results of CO2 absorption using 30 wt% N-methyldiethanolamine (MDEA) solution in water in an RPB unit with and without carbonic anhydrase for different gas and liquid flow rates. The results indicate significantly improved performance of CO2 absorption, up to 18 times compared to the solvent without enzyme.