Abstract

The present paper reports the in situ hydrothermal synthesis of a composite mordenite membrane. In this process, mordenite forms at the surface and within the pores of a porous ceramic alumina support by nucleation and crystallization from a mixture containing alumina and silica species. The structure and texture of the composite membrane were identified by XRD and SEM, as well as by single gas permeation at room temperature with H₂, N₂, O₂, Ar, CO, He and CH₄. The permeation resulting as a function of transmembrane pressure revealed a small viscous flow contribution for gas transport through the MOR composite membrane. Furthermore, these preliminary results (order of gas permeance and ideal selectivities) suggest that Knudsen diffusion is the dominant transport mechanism for the investigated series of gases, although an ideal selectivity slightly higher than the Knudsen selectivity was obtained, namely α = 1.6 at Δp = 0.6 bar for CH₄/N₂.