Synthesis of ZSM-5 zeolite composite membranes for CO2 separation

摘要

ZSM-5 type zeolites were synthesized by thehydrothermal treatment of the reaction mixture of silica sol,aluminum nitrate, sodium hydroxide, and TPABr at thetemperature range of 150-180℃in the autoclave. The shape ofthe ZSM-5 zeolite calcined at 450250L鎤as spherical or polyhedraland its crystalline size was 0.5-3μm. The synthetic ZSM-5 wasfound to be highly hydrophobic and active for CO2 adsorption.ZSM-5 zeolite composite membranes supported with porous α-alumina tubes have been synthesized by dip coating orpressurized coating of the reaction sol-mixture followed byhydrothermal treatment. The permeation mechanism of CO2through ZSM-5 membranes was a surface diffusion and themembranes prepared by the pressurized-coating hydrothermaltheatment showed a fairly high CO2/N2 separation factor of 9.0and a permeability of 10-8—10-7 mol/m2·s·Pa at room temperature.