Separation of methanol–benzene and methanol–toluene mixtures by pervaporation: effects of thermodynamics and structural phenomenon

Pervaporative separation of methanol–benzene and methanol–toluene mixtures over the entire range of concentration was studied using regenerated cellulose (cellophane), poly(vinyl alcohol) (PVA), cellulose acetate (CA), cellulose tri-acetate (CTA), two blends of CTA (B1 and B2) with acrylic acid, poly(dimethylsiloxane) (PDMS) and linear low density polyethylene (LLDPE) membrane. For selective separation of aromatic PDMS and LLDPE was used. Among these two PDMS is better in terms of flux and selectivity than LLDPE. Rests of the membranes are methanol selective. Regenerated cellulose membrane gave highest selectivity and flux. Other hydrophilic membranes obeyed the following trend in methanol selectivity PVA>CA>CTA>B1>B2. The influence of the membrane material with varying solubility parameter, starting from cellophane (32.24 MPa1/2) to PDMS (14.9 MPa1/2) is investigated through the analysis of experimental data.