Ultrafiltration of sugarcane juice with spiral wound modules: on-site pilot trials

This work investigates the performance of spiral wound membrane modules for the ultrafiltration (UF) of sugarcane juice. In on-site trials carried out in an Indian sugar mill, different modules with varying channel sizes employing 20 kDa polyethersulphone and polysulphone membranes were evaluated. Two juice streams viz. raw juice and clarified juice were selected in the sugar manufacturing process and the effect of such operating parameters as transmembrane pressure, operating time and feed temperature on the permeate flux and quality were examined. It was observed that a narrow channel size resulted in a higher flux with a corresponding lower membrane fouling. The flux could be further improved by increasing the operating temperature. With both the feed streams, the permeate was observed to be consistently superior in terms of higher clarity, lower color and reduced calcium oxide content as compared to the clarified juice produced by the conventional double sulphitation process.