Abstract
Faujasite membranes were prepared by hydrothermal synthesis on porous cylindrical stainless steel supports. The starting gel composition was H2O/Na2O=45, Na2O/SiO2=0.88, SiO2/Al2O3=25. The outer-surface of the porous support was completely covered with randomly oriented, well-intergrown zeolite crystals at a one-time-coating. X-ray diffraction patterns of membranes consist of peaks corresponding to the support and the zeolite. The membrane was also characterized by Field Emission Scanning Electron Microscopy, energy dispersive X-ray spectroscopy analysis, and inductively coupled plasma analysis. The membranes showed high alcohol selectivity for several feed mixtures, such as methanol/methyl t-butyl ether, methanol/benzene, methanol/dimethyl carbonate, ethanol/ethyl t-butyl ether, ethanol/benzene and ethanol/cyclohexane systems. In addition, the membrane also showed a high benzene selectivity in benzene/cyclohexane saparation (220 of separation factor and 0.23 kg/m2h in flux at 423K). The separation performances of the membrane were comparable to that of the previously reported membrane prepared on porous mullite support.
