Synthesis and characterization of T-type zeolite membrane for pervaporation of Water/Isopropanol mixtures

Zeolite membranes have been recently more developed to employ in pervaporation, gas separation, membrane reactors and other chemical industries. In this research, T-type zeolite membranes were prepared by hydrothermal reaction on the outer surface of a tubular porous mullite support seeded with zeolite T crystals. Effects of the most important parameters on flux and porosity of supports and zeolite layers produced by extrusion and hydrothermal methods, respectively, were evaluated. The best results were achieved by calcining for about 3.5 h at a temperature of about 1250 ºC and with a kaolinite percent of about 83 %. These supports exhibited optimum porosity and flux and smooth surfaces. Effects of Silicon module (SiO2/Al2O3), Alkalinity (relative) (OH/SiO2), Crystallization temperature (K) on the zeolite T synthesis were also investigated. Results of these experiments showed that the gel composition of 1SiO2: 0.04Al2O3: 0.26Na2O: 0.09K2O: 14H2O yields formation of the best zeolite T powders. Effects of crystallization time and temperature on membrane characteristics and its morphology were investigated for the zeolite T membranes using SEM, XRD and pervaporation tests. PV experiments were carried out with water/Isopropanol mixtures using synthesized membranes. Composition analysis of the feed and permeate was performed by a refractometer. It was found that the membrane synthesized at a temperature of 393 K for 30 h, shows high permeation flux of 0.7 kg m-2h-1 and selectivity of 10000.