A triacetate cellulose membrane for the separation of methyl tert-butyl ether/methanol mixtures by pervaporation

Sorption and pervaporation experiments were carried out with cellulose tria cetate membranes for the separation of methyl tert-butyl ether and methanol mixtures. The sorption experiments show that with an increase of MeOH conc entration in the feed, the membrane swelling ratio increases first until a maximum value is reached and then remains constant, On the other hand, the MeOH concentration in the sorped phase first decreases to a minimum value a nd then increases with the transition occurring near the azeotropic point. In the pervaporation experiments, the total and MeOH permeation fluxes were found to increase with the increase of MeOH concentration in the feed whil e the MTBE permeation flux first increases and then decreases. The total pe rmeation fluxes are significantly enhanced with an increase in temperature. This temperature dependence is more pronounced at low MeOH concentration, but the extent of increase of the total permeate flux is relatively constan t when MeOH concentrations are greater than 10%,, and it can be described b y the Arrhenius law. Selectivity decreases with the increase of MeOH concen tration and becomes more or less constant at high MeOH concentrations. (C) 2001 Published by Elsevier Science B.V.