Application of a Hydrogen-permselective Membrane in a Two-stage Methanol Synthesis Reactor for Reduction of CO Emission

Carbon monoxide (CO) is a scentless and invisible gas that is quite poisonous and also known to be a major environmental pollutant. One of the most important processesfor controlling the CO content is conversion of CO to methanol by catalytic hydrogenation. The present work investigates enhancement of CO conversion in a conventional two-stagemethanol synthesis reactor using a hydrogen-permselective membrane. For this membrane system, a one-dimensionaldynamic model was proposed in the presence of long-term catalyst deactivation. This model compares CO removal in amembrane two-stage methanol synthesis reactor with a conventional two-stage methanol synthesis reactor. A conventional two-stage reactor is a vertical shell and tube inwhich the first reactor coolant is saturated water and the second one is cooled with synthesis gas. In a membrane two-stagereactor, the wall of the tubes in the gas-cooled reactor is coated with a Pd-Ag membrane, which only permits the diffusion of hydrogen.