The oxidative dehydrogenation of propane to propylene catalysed by vanadium supported by oxide, was carried out on a catalytic membrane reactor (CMR) in a reaction temperature range of 380-500degreesC. Two different species of the internal layer (gamma-Al2O3, ZSM-5) that supported the catalyst, were taken in consideration and two possible ways (premixed or separate) of feeding the reactants in the CMR were studied. The chief goal was to validate on an experimental basis, a simple phenomenological model to interpret the CMR performance. It has been found that the use of a thicker catalytic layer can enhance the selectivity to propylene when propane and oxygen are differentiated at the tube and the shell with respect to the premixed feed and when there is a sufficient thickness of the catalytic layer.