Preparation of high performance zeolite T membranes by a two-stage temperature-varied synthesis with microsized seeds

Zeolite T membranes were prepared by a two-stage temperature-varied hydrothermal technique with microsized seeds on the surface of the porous mullite supports. Under the typical synthesis solution of n _SiO2: n _Al2O3: n _Na2O: n _K2O: n _H2O=l:0.05:0.3:0.1:30, the zeolite T membranes with high permeation performance were successfully synthesized by the two-stage temperature-varied crystallization process. The results of XRD and SEM showed that a continuous and dense T-type zeolite layer formed on the surface of the support. The two-stage temperature- varied synthesis method leads to shorten crystallization time and improved membrane density. The as-synthesized zeolite membranes exhibited high pervaporation performance and high-reproducibility of preparation procedure. The permeation flux and separation factor of the membrane were obtained over 4.25 kg·m ^-2·h ^-2 and 7 600 for water/i-propanol (10/90, w/w) mixtures at 75 °C, respectively. Moreover, the permeation flux of the membrane up to 2.87 kg·m ^-2·h ^-1 and separation factor over 1900 were achieved for water/ethanol (10/90, w/w) mixtures at the same operation conditions.