A comparison of hydrogen and methanol production in a thermally coupled membrane reactor for co-current and counter-current flows

Abstract

This work considers three concentric tube reactors to prepare pure hydrogen, especially applicable in fuel cell technologies, with zero CO2 emission. Hydrogen and methanol production rates are compared in a thermally coupled exothermic and endothermic reactor for co-current and counter-current modes. Synthesis of methanol is coupled with dehydrogenation of cyclohexane as a high content hydrogen carrier (7.1 wt%). The efficient coupling of exothermic and endothermic reactions increases the profitability of operation of the reactor, reduces the size of reactor and decreases the operational and capital costs. By inserting a hydrogen-perm selective membrane into the reactor configuration, hydrogen can permeate selectively into the membrane, and hence, the third tube receives hydrogen. The simulation results are compared with the corresponded results for an industrial methanol fixed-bed reactor, which operates under the same feed conditions. The influence of some operating variables is investigated on methanol and hydrogen yields during the performance of reactor. The results show higher methanol conversion, as the same as conventional reactor, and hydrogen for co-current flow. Copyright © 2010 John Wiley & Sons, Ltd.