The mathematical model of multicomponent mixture mass transfer in membrane contactor has been developed. The model is based on the calculation of mass balance in absorber and desorber taking into account the recirculation of the liquid carrier flow. Paper presents the results of simulation of recycle membrane contactor system (RMC) for biogas separation and air dehumidification application. The practical recommendations for optimal selection of contactor geometrical parameters and hydrodynamic regime are given. The optimal membrane area ratio in absorber and desorber in recycle system with physical absorbent as liquid carrier is determined. (C) 2006 Elsevier B.V. All rights reserved.