A process is disclosed for the catalytic dehydrogenation of C.sub.3 -C.sub.4 hydrocarbons wherein an integrated scheme comprising a cold box unit and a pressure swing adsorption unit is employed to reject methane produced in the dehydrogenation reaction from the hydrogen-rich recycle stream. The process results in a significant improvement in the efficiency of the separation of the reaction by-products and a corresponding increase in the overall feed capacity of the process.