In this study, capture of CO2 and H2S from natural gas mixture using porous polymeric membranes has been investigated numerically to assess the capacity of a novel absorbent, di-isopropanol amine (DIPA), in CO2 removal. Diffusion of acid gases through porous polymeric membranes was simulated by employing CFD techniques and considering a gas feed stream, a porous membrane and a reaction medium. For solving conservation equations, finite element method was applied to calculate the rate of CO2 and H2S absorption in the membrane. The type of membrane in this work is a hollow-fiber module. According to the modeling results, a high H2S removal can be achieved by DIPA absorber. Moreover, CO2 was captured from natural gas in an efficient manner in low gas/liquid flow rates. POLYM. ENG. SCI., 55:598-603, 2015. (c) 2014 Society of Plastics Engineers