Performance of sodium A zeolite membranes synthesized via microwave and autoclave techniques for water–ethanol separation: Recycle-continuous pervaporation process Original Research Article

The performance of sodium A (NaA) zeolite membranes with a surface area of 4.91 cm2, synthesized on an alumina support via microwaving (MW) and autoclaving (AC, or conventional heating) using the recycle-continuous pervaporation of a water–ethanol mixture (10:90 vol.%), was studied. It was found that the process could produce ethanol having a concentration close to 100% (higher than 99.5%) after passing the mixture through the membrane for 120–140 h. The time-dependence separation factor and the total water flux were 3350–6050 and 0.4–1.0 kg/m2/h, respectively. The time-dependence separation factor of this process was increased to higher than 10,000 when the percentage of ethanol at the retentate side was higher than 98%. The overall results showed good stability of the membranes for the water–ethanol separation.