Synthesis and Characterization of ZSM-5 Nano Structure Zeolite Membrane

In the present study, ZSM5 zeolite membranes were synthesized on porous αaluminasupport by secondary growth hydrothermal method. Membranes synthesized were tested by structural characterization and single gas permeation experiments. To prepare zeolite membranes, nanosized silicalite-1 powder was first synthesized as seed with mean diameter of 40 nm from a clear solution. Silicalite nanoparticle slurries were purifiedby repeated centrifugation followed by redispersion by ultra-sound in deionized water. The effects of synthetic parameters such as synthesis time and aluminum content are studied. It was found that the membranes quality was sensitive to the aluminum content. Investigation of different synthesis times showed that the best film was obtained during 36 hours. The permeation properties of the support and membranes were measured over the pressure range of 1-4bar at room temperature. The ZSM-5 membranes were examined by permeation measurements using single CO2, N2, CH4 and H2 gases. Under optimum synthetic conditions, the permselectivity at 300K for H2/CH4, H2/CO2 and H2/N2 were 3.8, 3.5 and 4.4, respectively.