PERVAPORATION CHARACTERISTICS OF A BENZOYLCHITOSAN MEMBRANE FOR BENZENE-CYCLOHEXANE MIXTURES

A benzoylchitosan was synthesized as a membrane material for separatio n of benzene/cyclohexane mixtures. When the benzoylchitosan membrane w as applied to the permeation and separation of benzene/cyclohexane mix tures in pervaporation, both the permeation rate and benzene concentra tion in the permeate increased with increasing benzene concentration i n the feed, and thus this membrane showed benzene permselectivity. Cha racteristics of permeation and separation of benzene/cyclohexane mixtu res through the benzoylchitosan membrane were analyzed by the solution -diffusion model. It was found that the benzene permselectivity was de pendent on both the sorption selectivity and diffusion selectivity but was significantly governed by the latter. Also a tentative model for the benzene permselectivity is discussed.