Separation Science and Technology, Vol.40, No.14, 2889-2908, 2005
Dehydration of 2-butanol by pervaporation through blend membranes of chitosan and hydroxy ethyl cellulose
Blend membranes of chitosan (CS) and hydroxyethylcellulose (HEC) were synthesized and cross-linked with glutaraldehyde for the separation of 2-butanol/water mixtures. The blends were characterized by fourier transform infrared (FTIR) spectroscopy and wide-angled X-ray diffraction (WAXD) to assess the intermolecular interactions and occurrence of cross-linking, respectively. The pervaporation performance was evaluated by varying experimental parameters such as feed composition, membrane thickness, and permeate pressure and found to be promising. Sorption studies were conducted to evaluate affinity and degree of swelling of both the unmodified and cross-linked blend membranes in pure as well as binary mixtures of the two liquids. The blends were found to have good potential for breaking the aqueous azeotrope of 2-butanol (77 wt.%). Upon cross-linking, the blend membranes exhibited a substantial improvement in performance. Amongst the various blend combinations used for the dehydration studies, the membrane constituting 70 wt.% of CS and 30 wt.% HEC yielded a flux of 2.1 kg/m(2) center dot h center dot 10 mu m and a selectivity of 554, which was optimum.
Keywords:pervaporation;chitosan/hydroxyethylcellulose blend;2-butanol/water mixture;membrane characterization