Understanding coupling effects in pervaporation of multi-component mixtures

The separation performance of four commercial membranes (i.e., PERVAP 1255-30, PERVAP 4155-40, PERVAP 1255-50, PERVAP 4155-80) from Sulzer Chemtech, Switzerland, is evaluated. The effect of the feed concentration and the temperature on the separation performance was studied in terms of permeance and selectivity. Coupling effects were observed when the permeance of pure solvents was compared with that of the components in the mixture. The coupling effects were analyzed by the Hansen solubility approach and by the variation of activities within the membrane.