PERVAPORATION OF ALCOHOLS FROM HYDROCARBON MIXTURES

In this work, the characteristics and enhancement of pervaporation for the separation of various alcohols from hydrocarbon mixtures are demo nstrated. Experiments were performed through a composite plate-and-fra me type hydrophilic PVA (polyvinyl alcohol) membrane at a constant per meate vacuum pressure of 6.5 mmHg and at temperatures of 30, 45 and 60 degrees C. The Wilson equation was used to describe the activity coef ficients for the system. The analysis is presented in terms of the var iations in permeation flux, permeability and selectivity. The results show that as the concentration of alcohols in the feed increases, the permeability, selectivity and total flux also increase. By increasing the temperature, the permeabilities increase while selectivity decreas es. However, the experimental results show that at temperatures of 30 and 45 degrees C a good degree of separation of alcohols from a hydroc arbon mixture is possible by the pervaporation technique using a PVA m embrane with a selectivity of greater than 10. (C) 1997 Published by E lsevier Science B.V.