Separation Of Pgme/Water With Pervaporation

Propylene glycol monomethyl ether (PGME) was called the universal solvent because of its low toxicity and excellent performance. It was widely used in coatings, inks, printing, dyeing, pesticide, cellulose, acrylic and other industries. However it was difficult to separate effectively the PGME and water with the traditional methods for it easily formed an isotropic system with water. Pervaporation technology had advantages of low operating temperature, a small device occupies, low energy consumption and environmental friend, and so on. It was mainly used on separating the isotropic system, near boiling, isomeric and heat-sensitive liquid. Polyether block amide (PEBA(2533)) membrane had good priority selection for some organics. Polyving akohol (PVA) membrane was highly hydrophilic and was researched widely in dehydrating from organic/water binary. Zeolite membrane had high permselectivity on organic/water binary, good corrosion resistance, thermostability and chemical resistance. Based on the swelling and adsorbing of membranes in the solution, PGME was recovered from the dilute solution by PEBA(2533) pure membrane, PEBA/PVDF and modified with activated carbon, and water was removed from the mixtures of PGME and water with pervaparation. The effects of the ratio of Si to Al, feed concentration and operating temperature on separating properties were investigated by the experimental methods. The fitting of permeation activation energy was further considered. The results showed that the performance of three hydropholic membrane of PEBA was not so well, because the separation factor was only between1and3. The maximum separation factor of hydrophilic membrane PVA for the feed with90wt.%PGME was7.4. While the maximum separation factor of zeolite membrane was2693and the total permeate flux increased up to9265g·m-2·h-1in the pervaporation experiments. The separation factor of zeolite membrane decreased with increasing the temperatures, but the total and partial permeate flux increased. On the contrary the separation factor increased with increasing the feed concentration, but the total and partial permeate flux increased. The permeation activation energy was up to50.6kJ·mol-1, and the maximum adsorption quantity to water was2.73g·(g zeolite)-1. Zeolite membrane material showed a superior permselectivity on separating PGME/water binary.