Development of hydrogen permselective membranes for propylene production

Silica hybrid membranes were developed for a membrane reactor for propane dehydrogenation reaction using a counter diffusion chemical vapor deposition (CVD) method. The effects of the alkyl chains in the silica precursor were investigated to control the membrane properties. Additionally, a membrane reactor test using a CVD silica membrane for the membrane reactor was performed and compared with only using a catalytic bed reactor. An ethyltrimethoxysilane-derived membrane deposited at 500°C exhibited a high H₂/C₃H₈ selectivity of 650. The C₃H₈ conversion was 53% with C₃H₆ selectivity of 69% for the 600°C reaction in the membrane reactor. The conversion was slightly higher than that at equilibrium.