CO2 capture using hollow fiber membrane under wet ammonia-based desulfurization flue gas conditions

Abstract

The fine particulates and coexistent gaseous components, i.e., SO2 and water vapor in desulfurized flue gas, may severely impact the performance of membrane gas absorption in the long term. In order to gain a better understanding on the effects of the impurities on the membrane performance, the process of membrane absorption for CO2 capture under wet ammonia-based desulfurization flue gas conditions was investigated. Using monoethanolamine (MEA) aqueous solution as absorbent, the operating conditions of polypropylene (PP) hollow fiber membrane for CO2 absorption were optimized firstly, and the best ones were 0.5 mol/L as the concentration of MEA, 1 m3/h as the feed gas flow rate, and 24 L/h as the absorbent flow rate. Then, the PP hollow fiber membrane performance on CO2 capture from desulfurized flue gas was studied. The results revealed that the residual SO2 and water vapor slightly influence the CO2 absorption performance. However, the aerosol particulates formed during desulfurization process deteriorated the absorption properties of microporous membrane leading to the decrease of the CO2 removal efficiency.