SEPARATION OF TETRAHYDROFURAN FROM AQUEOUS MIXTURES BY PERVAPORATION

Studies on the separation of tetrahydrofuran (THF) and water by pervap oration were conducted. A silicalite-filled silicone composite membran e was used for organic permeation and a polyvinyl alcohol composite me mbrane for dehydration. Effects of feed concentration, feed temperatur e, permeate-side pressure, and type of membrane were studied. The sili cone composite membrane yielded a selectivity of 205 and a THF flux of 1.1 kg/m2.h at benchmark conditions of 50-degrees-C feed temperature, 2 torr permeate-side pressure, and a feed concentration of 4.4% w/w T HF. An increase in temperature increased the flux exponentially in an Arrhenius-type manner, but had little effect on selectivity. These dat a show that the trend agrees with an Arrhenius-type relationship. An i ncrease in feed concentration increased the flux, but the selectivity for THF decreased. As the permeate-side pressure increased, the flux d ecreased in a sigmoidal fashion, but the selectivity for THF increased . Some initial studies on dehydration were also performed, Use of perv aporation in a solvent recovery/reuse system in industry has also been examined.