Propane dehydrogenation over a hydrogen permselective membrane reactor

The dehydrogenation of propane to propylene has been studied in an isothermal high-temperature shell-and-tube membrane reactor containing a Pd-coated γ-Al₂O₃ membrane and a Pt/K/Sn/Al₂O₃ packed catalyst. A tubular Pd-coated γ-Al₂O₃ membrane was prepared by an electroless plating method. This membrane showed high hydrogen to nitrogen permselectivities (P_H2/N2 = 10-50) at 400°C and 500°C with various transmembrane pressure drops. The employment of a membrane reactor in the dehydrogenation reaction, which selectively separates hydrogen from the reaction mixture along the reaction path, can greatly increase the conversion and enable operation of the reactor at lower temperatures. High hydrogen permselectivity has been confirmed as a key factor in determining the reactor performance of conversion enhancement.