Permeation properties of a thin silicalite-1 (MFI) membrane

A thin MFI zeolite membrane was synthesised on a porous -Al2O3 tubular support by in situ nucleation and secondary growth. Single gas permeances (CH4, H2, N2, CO,CO2) were measured through the MFI membrane according to the pressure drop method, from room temperature to 280 oC, with pressure differences between 0.1 and 0.4 bar. The membrane combines high permeances (1.6-8.0molm-2 s-1 Pa-1) and also good separation properties (the H2/SF6 permselectivity value is equal to 24 at room temperature). The membrane has been tested also in the pervaporation of an ethanol/water mixture, showing high fluxes (2.1 kgm-2 h-1) and low selectivity.