Green methanol synthesis process from carbon dioxide via reverse water gas shift reaction in a membrane reactor

In the present work, carbon dioxide hydrogenation to methanol via reverse water gas shift reaction (CAMERE) in an industrial scale was modeled and optimized. In this process, syn-gas is first produced by CO2 hydrogenation through reverse water gas shift (RWGS) reaction over Ni/Al12O19 catalyst and next the syngas is conveyed to a reactor as the feedstock to produce methanol. The inner tubes of methanol synthesis reactor were coated by a water perm-selective membrane for removal of H2O, as the cause of catalyst poisoning. A precise two-dimensional model solved by finite-difference procedure was employed to evaluate both RWGS and methanol synthesis membrane reactors performance. Also, the operating conditions of the RWGS reactor were optimized by differential evolution (DE) technique to gain a maximum methanol production rate. Moreover, the results of the methanol production reactor from the CAMERE process were compared with the conventional route (CR) in which methanol is produced from coal and natural gas. In the case of methanol synthesis membrane reactor, CAMERE process was superior to CR due to achieving 20.8% increase in methanol production rate. The results of this process modeling provide a good initial insight for green methanol production form indirect CO2 conversion. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.