The influence of membrane gas separation in the maleic anhydride production cycle by direct oxidation Of n-C4H10 was analysed. The CO2/CO ratio in the purge stream can be controlled by a two-stage system equipped with polymeric membranes in order to improve the reaction yield and the plant productivity, reducing, at the same time, the n-C4H10 loss in the purge stream. The recovery of the not reacted n-C4H10 and the reduction of the CO2 release are further advantages due to the introduction of membrane unit in the production cycle with consequential economic and environmental benefits. The effect of driving force on the membrane system performance was investigated by a simulation study and by experimental tests on three different types of commercial and semi-commercial membranes. For its general character, the concept developed in this work can be extended to other selective oxidative processes.