The mass-transfer performance of hydrophobic PP(polypropylene) microporous membrane and activated MDEA(methyldiethanolamine) solutions in the CO₂ separation from a mixture was evaluated with a membrane based gas absorption coupling.Effects of gas and liquid flowrates as well as absorbent and feed components on overall mass transfer coefficient were investigated.Overall mass transfer coefficient Kov was theoretically calculated based on the model of resistance in series.Results show that,activated MDEA solutions could enhance mass transfer and increase the values of K_ov.The values of the model are in good agreement with those of experiments.