Performance of Mitsui NaA type zeolite membranes for the dehydration of organic solvents in comparison with commercial polymeric pervaporation membranes

The dehydration performance of a commercial NaA type zeolite membrane (supplied by Mitsui engineering) was investigated for dehydration of the binary mixtures isopropanol/water, acetonitril/water and methylethylketon/water. For each solvent the dehydration performance was compared with alternative commercial polymeric membranes from two different suppliers: Celfa and Sulzer. All experiments were performed at 70 °C. For all the solvents tested, the zeolite membrane shows the best dehydration properties at water concentrations in the azeotropic region and below. For isopropanol dehydration, the polymeric Celfa membrane type CMC-VS-11V also shows very good results. The advantage of the Mitsui zeolite membrane is that it shows a higher temperature and mechanical stability than the polymeric membranes making pervaporation in harsh conditions possible. The higher fluxes and selectivities obtained with the Mitsui membranes even at low feed water concentrations, makes it possible to pervaporate up to low feed water concentrations. The disadvantage of the zeolite membrane is that it cannot withstand low pH values and that it is more expensive than the polymeric membranes, although prices are expected to decrease when more membranes are produced in the future.