Preparation and characterization of preferentially oriented continuous MFI-type zeolite membranes from porous glass

Preferentially oriented and continuous B-Al-ZSM-5 zeolite membranes have been prepared from B-containing porous glass disks in a mixed vapor of ethylenediamine, tri-n-propylamine and H2O. The crystals with the orientations of {101}/{011} and (002) planes paralleling to the substrate surfaces predominate in the membranes. The membranes are about 60 mum in thickness. On the calcined zeolite membranes, the ideal selectivity of H-2, He, Ne, Ar, O-2 and CO2 over N-2 is 16.8, 15.5, 12.6, 9.4, 8.6 and 5.3. respectively. The ideal selectivity of CO and SO2 over N-2 is 0.13 and 0.018, respectively. The ideal selectivities of O-2 over CO and SO, reach 65 and 491, respectively. The highest water separation factors appearing at 303 K are 28, 136 and 519 for the solutions of 5 wt.% EtOH/H2O, 50wt.% EtOH/H2O and 95 wt.% EtOH/H2O at different temperatures, respectively, indicating that the prepared membranes are strongly hydrophilic. (C) 2004 Elsevier Inc. All rights reserved.