Effects of synthesis parameters on zeolite membrane formation and performance by microwave technique

Recently, zeolite membranes on porous supports have been extensively studied in the ethanol–water separation process for further use for gasohol production. This work focuses on a NaA membrane synthesized on an α‐Al2O3 support via microwave hydrothermal treatment. Synthesis temperature and time, type of substrate, seed amount and seeding time for the layer growth of the membrane are considered. The formation of as‐synthesized membranes is discussed according to observations by SEM and XRD. In addition, a preliminary study of the performance of the synthesized NaA zeolite membrane was conducted using the pervaporation technique. It was found that, for the synthesized continuous NaA membranes prepared using a 0.5 µm NaA crystal seed concentration of 3 g/l via vacuum seeding, the optimum conditions were 363 K synthesis temperature for 15–20 min via microwave heating. The flux and the separation factor obtained were 1.6 kg/m2 h and 1760.5, respectively, for the substrate without an intermediate layer. Interestingly, the substrate with an intermediate layer showed better flux and separation factor at 1.7 kg/m2 h and 6532.7, respectively. Copyright © 2007 John Wiley & Sons, Ltd. Synthesized continuous NaA membranes were prepared using a 0.5 µm NaA crystal seed via vacuum seeding. The optimum conditions were 363 K synthesis temperature for 15–20 min via microwave heating. The flux and separation factor obtained were 1.56 kg/m2 h and 1760.52, respectively, for the substrate without an intermediate layer. Interestingly, the substrate with an intermediate layer showed better flux and separation factor at 1.69 kg/m2 h and 6532.72, respectively.