Recovery of ethanol via vapor phase by polydimethylsiloxane membrane with excellent performance

To improve the selectivity of recovering bioethanol from fermentation broth, prevent membrane fouling by the components in fermentation, and enhance market competitiveness of bioethanol, the application of gas stripping assisted vapor permeation (GSVP) in bioethanol recovery and its potential in the integrated fermentation-separation processes were investigated in this work. As a result, a separation factor of 48, with the total flux of 866 g/m2 h, was obtained in separating model solution that contained 6 wt.% of ethanol at 65 °C. In the case of recovering bioethanol from the realistic fermentation broth, GSVP process showed long-time stability, no membrane fouling and no reduction of performance. Moreover, the evaporation energy requirement for GSVP process was at least 54% and 57% less than that of the conventional distillation and pervaporation processes.