Isopropanol dehydration by pervaporation

Abstract

Pervaporation, a membrane process for separation liquid mixtures, is becoming recognized as an energy efficient alternative of distillation and other separation methods. The performance of a pervaporation membrane can be characterized in terms of permeation flux and separation factor, which are determined by feed temperature and feed composition. The influence of these parameters on isopropanol dehydration by pervaporation will be discussed in this study, by using different water permselective membranes (CMC-CE-01, CMC-CA-01, CMC-CE-02). The experiments were carried out in a laboratory pervaporation unit with various operating temperature (45∼65°C) and feed isopropanol concentration (70∼99.48). The permeate flux, isopropanol and water content in the permeate and in the concentrate fractions were measured during the experimental runs. Comparing the separation behavior of the membranes it was found that all the three types of membrane are suitable for isopropanol dehydration by pervaporation and anhydrous isopropanol can be achieved. The permeation characteristics are obviously dependent on the feed concentration and temperature. The permeation rate significantly increases and the selectivity is strongly decreases with increasing temperature.