In this paper, an experimental and theoretical study was carried out to evaluate the performance of gas-liquid membrane contactor in benzene/nitrogen separation process by using an aqueous N-Formylmorpholine (NFM) solution as absorbent. The effects of operating parameters such as the gas and liquid flow rates, the feed gas and the initial liquid concentrations, the liquid temperature, the absorbent concentration and the long term operation on the benzene flux and removal efficiency were investigated. A mathematical model was developed to simulate the absorption process in order to gain an insight into the experimental observation. Both simulative and experimental results show that benzene mass transfer flux increases with the gas flow rate and the feed gas concentration, while the liquid flow rate has no significant effect on it. The increase in liquid temperature and initial liquid benzene concentration results in a decrease in benzene flux. Long term performance test shows that the aqueous NFM solution is a suitable absorbent to be applied to the polypropylene (PP) hollow fiber gas-liquid membrane contactor. (C) 2009 Elsevier B.V. All rights reserved.