Dehydrogenation of n-butane on the industrial microspherical chromia-alumina catalyst AOK-73-24 in a membrane reactor

The basic features of the catalytic membrane dehydrogenation of n-butane have been studied in a reactor with membrane modules based on Pd/Ag foil of 9.3 and 30 mu m thickness and in the absence of the membrane (temperature, 500-550A degrees C; feed space velocity, 150-1200 h(-1)). It has been shown that in the absence of the membrane, the dehydrogenation of n-butane occurs in the kinetic region. The membrane thickness has a significant effect on the performance of the catalytic membrane reaction, presumably, because of the difference in the rate of H-2 withdrawal from the reaction mixture. In the reactor with the 9.3-mu m thick Pd/Ag-foil, the reaction is controlled by the H-2 formation rate. As the thickness of the palladium foil is increased to 30 mu m, the reaction proceeds to the diffusion region, thereby resulting in both enhancement of selectivity for butenes and a reduction of the yield of hydrocarbon deposits.