Kinetics and Hydrogen Removal Effect for Methanol Decomposition

Abstract

Methanol decomposition to carbon monoxide in a palladium membrane reactor (PMR) is presented, where a 1 wt % Pd/SiO2 catalyst and a Pd91Ru6In3 alloy membrane tube were employed. Experiments were carried out at relatively low temperatures, 220−250 °C, in a PMR mode as well as a conventional catalytic reactor (CCR) mode. A kinetic analysis for methanol conversion change in the CCR mode revealed that the overall reaction rate was controlled by the desorption process of the resultant carbon monoxide from the active sites of the catalyst surface. In the PMR mode it was shown that the selective separation of produced hydrogen from the reaction to the permeate side led to an increase in methanol conversion. Further, amounts of byproducts such as carbon dioxide, dimethyl ether, and methyl formate were found to be also influenced by the hydrogen separation.

Decline in Hydrogen Permeation Due to Concentration Polarization and CO Hindrance in a Palladium Membrane Reactor

“…8 This reactor consisted of a stainless steel shell tube and a 0.2-mm-thick membrane tube made of Pd 91 Ru 6 In 3 alloy. A 1 / 16 -in.…”

High-temperature steam reforming of methanol over ZnO–Al2O3 catalysts

“…The catalyst was durable at 390 • C, but the CO selectivity was over 10% with the methanol conversion of 35%. It can be seen that the catalysts mentioned above produced fairly high CO, which can reduce the H 2 yield and inhibit the hydrogen permeation of Pd membrane [28]. Therefore, the suppression of CO formation over the high temperature catalyst is still very essential.…”

Synthesis gas production in a novel hydrogen and oxygen perm-selective membranes tri-reformer for methanol production

“…where the pre-exponential factor P 0 above 200 C is reported as 6.33 Â 10 À8 (mol/m 2 s Pa 1/2 ) and activation energy E p is 15.7 kJ/mol (Hara et al, 1999;Shu et al, 1994;Cussler 1984).…”