Effects of water vapor on membrane CO2 capture

Effects of water vapor and mixtures of water vapor/SO2 or water vapor/particles on CO2 capture using polyimide (PI) and polypropylene (PP) membranes were investigated by a lab-made membrane CO2 capture setup.The results show that when studied under 90% relative humidity of flue gas,the CO2/N2 separation factor of the PI separation membrane increases slightly but the penetration rate decreases, and the absorption efficiency of the PP membrane decreases by 7%. The capture efficiencies of PI and PP films restore after N2 back flushing.When studied using SO2 and water vapor mixtures, the CO2/N2 separation factor and permeation rate of the PI membrane reduced by 5.64% and 24.54%, respectively,and the removal efficiency of the PP membrane decreased by 18%.Moreover, when studied using particle and water vapor mixtures, the CO2/N2 separation factor and permeation rate of the PI membrane reduced to 39.79% and 49.82%, respectively,and the removal efficiency of the PP membrane decreased by 18.9%.However,the results of N2 back blowing experiments show that the coexistence of water vapor and SO2 has reversible effects on the PI and PP films, while the effect of the coexistence of water vapor and particles is irreversible. © 2019, Editorial Board of Journal of Chemical Engineering of Chinese Universities. All right reserved.