Pervaporation Recovery of Acetone-Butanol from Aqueous Solution and Fermentation Broth Using HTPB-Based Polyurethaneurea Membranes

In this paper, hydroxyterminated polybutadiene-based polyurethaneurea (HTPB-PU) pervaporation membranes were prepared by phase inversion and used for recovering acetone and n-butanol from dilute aqueous solutions. The effects of the operation temperature and feed composition on the pervaporation performance were investigated. The differences of the separation performance between the ternary mixture and binary mixture were also studied through evaluating the permeability coefficient, the swelling degree of the membrane, and the activity coefficient. The results indicated that a complex ocoupling effecto occurred in the ternary mixture. The pervaporation performance for the ternary mixture was superior to that for the binary mixture because of the permeant-permeant and permeant-membrane interactions. A high selectivity towards acetone and n-butanol was obtained. Acetone and butanol were condensed from 1.5 to 11.9wt% and 3.0 to 43.5wt% at 40 degrees C for the ternary mixtures, respectively. Furthermore, potential of the membrane for separation of organics from fermentation was also studied by testing the pervaporaton performance, and acetone and butanol were condensed from 0.5 to 8.7wt% and 1.1 to 16.4wt% at 45 degrees C, respectively.