Matrimid®5218 dense membrane for the separation of azeotropic MeOH-MTBE mixtures by pervaporation

Matrimid (R) 5218 dense membranes were produced using NMP by solvent evaporation. The membranes have been used, for the first time, in pervaporation (PV) separation of azeotropic methanol (MeOH)-methyl tert-butyl ether (MTBE) mixtures (14.3 and 85.7 wt%, respectively). The membranes were characterized by TGA, SEM, DSC, contact angle and swelling tests. The PV experiments were carried out at different feed temperatures (25-45 degrees C) and vacuum pressures (0.0538, 0.2400, 2.1000 mbar). Moreover, an analysis of the PV process through the Arrhenius relationship has been provided. The feed temperature (in the range of 25-45 degrees C) affected mainly the MeOH permeation producing an increasing on its partial permeate flux and separation factor as well. Indeed, the best performances of Matrimid were found at 45 degrees C and 0.054 mbar, where a permeate flux and a separation factor of about 0.073 kg m(-2) h(-1) and 21.16, respectively, were obtained. Finally, the Matrimid PV performance was compared with other polymeric membranes at the azeotropic conditions.