Comparison of SiO2-ZrO2-50% and commercial SiO2 membranes on the pervaporative dehydration of organic solvents

In this work several SiO2-ZrO2-50% tubular pervaporation (PV) membranes were prepared by the sol–gel and hot coating method. Their PV performance was investigated regarding the separation of water/isopropanol and water/acetone mixtures in terms of water flux and selectivity. The behaviour of these membranes was compared to the performance of two commercially available silica membranes (Pervatech BV, The Netherlands, and Pervap SMS, Sulzer, Germany) on the PV of water/isopropanol mixtures and a residual water/acetone mixture coming from the manufacture process of rubber antioxidants. An exponential dependence of the water flux with respect to the water activity in the feed was confirmed for both types of membranes. The value of the mass transfer parameter that describes the interaction of the permeating component, i.e. water, with the membrane has a very similar value for the commercial silica membranes and the prepared silica–zirconia membranes.