An extractor-type CMR, including a Pt-based fixed-bed catalyst, was combined with two different membranes, either a Pd membrane, obtained by electroless plating, or an MFI zeolite membrane, obtained by hydrothermal synthesis. These two configurations were compared in isobutane dehydrogenation. Both CMRs give better results than conventional reactors. However, though the two membranes presented different separative properties, the two CMRs showed very similar yields. This has been attributed to the limitation of both CMRs by the catalyst lack of efficiency, when compared to the membrane performance. A modeling approach that combines catalyst kinetic law and membrane gas transfer equations also contributes to the description of the CMRs performance. (C) 2003 Elsevier B.V. All rights reserved.