Steam reforming of methane in a hydrogen-permeable membrane reactor

Steam reforming of methane was carried out in a reactor incorporating a hydrogen-permeable membrane, which consisted of a thin palladium film supported on a porous glass cylinder. It was shown that the supported palladium membrane promoted the hydrogen production reaction more effectively than a porous Vycor glass membrane. The level of methane conversion exceeded the equilibrium attainable in a closed system in the temperature range of 623–773 K as a result of selective removal of hydrogen from the reaction system. Under the same conditions the porous Vycor glass membrane exhibited little effect on the shift of equilibrium. The difference between these two types of membranes is attributed to their hydrogen permeabilities. Although high reaction pressures are thermodynamically unfavorable for steam reforming, the level of methane conversion in the palladium membrane reactor increased with increasing pressure on the reaction side, as a result of accelerated hydrogen flow to the permeation side.