Abstract: Disclosed is a method and plant for the catalytic dehydrogenation of alkanes, such as propane. The plant is a plant of hybrid architecture wherein one or more membrane-assisted reactor configurations according to open architecture are combined with one or more membrane-containing reactors of closed architecture. Hydrogen remaining in the reaction mixture after separation in the membrane separation unit of a first open architecture configuration, is fed to a first membrane-reactor of the closed architecture type. Also disclosed are methods of modifying plants so as to create the hybrid architecture plant.