Zeolite membranes: Comparison in the separation of H2O/H2/CO2 mixtures and test of a reactor for CO2 hydrogenation to methanol

A zeolite membrane reactor can be employed for hydrogenation of CO2 to methanol. The removal of water from the reaction environment would increase the reaction rate and the achievable conversion. The separation of water from mixtures containing CO2, hydrogen and water at suitable temperatures for this reaction was tested with several zeolite membranes (zeolite A, mordenite, zeolite T, chabazite and Ti-Chabazite). Zeolite A provided the best H2O/H2 separation factor. Preliminary experiments comparing a traditional reactor and the combination of a traditional reactor with a membrane reactor show that the yield of methanol was improved, in one case being higher than the limit corresponding to the thermodynamic equilibrium in a conventional reactor.