Effective methanol production by CO2 hydrogenation using water-permeable NaA zeolite membrane
In recent years,the production of methanol by CO2 hydrogenation with green hydrogen produced from renewable energy sources has received a lot of attention.However,the CO2 conversion and methanol selectivity of the reaction are limited by the thermodynamic equilibrium of CO2 catalytic hydrogenation reaction.Moreover,the presence of water as a byproduct usually leads to catalyst deactivation.In this study,a mother liquid seeding method was used to prepare defect-free single-channel NaA zeolite membrane.Then Cu-based catalysts were filled on the membrane to create a zeolite membrane-catalyst bifunctional reaction system that allowed for the simultaneous hydrogenation of CO2 to produce methanol and the on-line selective removal of water.XRD,SEM,N2 isothermal adsorption-desorption,and H2-TPR were used to characterize the physical and chemical properties of the NaA zeolite membranes and the catalysts.The catalysts performance for CO2 hydrogenation were evaluated by the membrane reactor.The results showed that the reaction system can significantly increase the CO2 conversion and effectively drive the reaction equilibrium forward compared with the conventional fixed-bed reactor.The CO2 conversion was increased from 3.34%to 28.78%and the methanol yield was promoted from 3.28%to 27.62%at 250℃and 3MPa.