Pervaporation of aqueous ethanol solution using bacterial cellulose-alginate membrane

Abstract

Modifying bacterial cellulose membrane for the dehydration of ethanol solution by means of adding 0.5-1 (% w/v) of alginate in the culture medium during biosynthesis was studied. To be able to understand the effects on the separation by membrane pervaporation, the developed bacterial cellulose (BC) and the bacterial cellulose with alginate supplement (BCA) membranes were characterized for intermolecular interaction by Fourier transform infrared spectroscopy, mechanical properties by Instron testing machine, degree of swelling and water vapor transmission rate. From the pervaporation experiments, it was found the BCA membrane with 1% alginate added culture medium gave the improved selectivity when compared with the BC membrane. The membrane selectivity was increased with the alginate content in membranes. Furthermore, the increase of membrane thickness strongly enhanced the selectivity. Moreover, the selectivity and total flux could be increased by the reduction of the permeate pressure.