Synthesis and characterization of a mordenite membrane on an alpha-Al2O3 tubular support

The present paper reports the in situ hydrothermal synthesis of a composite mordenite membrane. In this process, mordenite forms at the surface and wi thin the pores of a porous ceramic alumina support by nucleation and crysta llization from a mixture containing alumina and silica species. The structu re and texture of the composite membrane were identified by XRD and SEM, as well as by single gas permeation at room temperature with H-2, N-2, O-2, A r, CO, He and CH4. The permeation resulting as a function of transmembrane pressure revealed a small viscous flow contribution for gas transport throu gh the MOR composite membrane. Furthermore, these preliminary results (orde r of gas permeance and ideal selectivities) suggest that Knudsen diffusion is the dominant transport mechanism for the investigated series of gases, a lthough an ideal selectivity slightly higher than the Knudsen selectivity w as obtained, namely alpha = 1.6 at Delta p = 0.6 bar for CH4/N-2.