Separation of light olefin-paraffin mixtures having the same carbon number is one of the most energy-intensive separation processes in petrochemical industry. Gas-liquid membrane contactors as an alternative to conventional processes have gained increasing interest due to low energy consumption. A 2D comprehensive model was developed to predict the transport and chemical absorption of propylene in a cocurrent microporous membrane contactor. Formations of a complex between propylene and silver ion and dissolution of silver nitrate were considered. With increasing gas flow rate the system efficiency decreases due to the reduction of propylene residence time inside the contactor. As the absorbent amount increases in the tube, both propylene and complex penetrate more deeply into the liquid and a diffusion layer is formed near the gas-liquid interface.