Fig. 1. Schematic of the pervaporation equipment: (1) feed tank; (2) thermometer;
(3) recirculation pump; (4) valve; (5) membrane cell; (6) three-way valve;
(7) cold trap immersed in brine solution (15 1C); (8) cold trap immersed in liquid
nitrogen; (9) vacuum gauge; and (10) vacuum pump.