Increase the Quality of Sugar by Ultrafiltration Process

Abstract

Interest in membrane filtration in the sugar industry is increasing. Sugar, as the final product of technology of sugar production, has to satisfy rigorous quality demands. Among others, it means low content of nonsucrose compounds, as well as the smallest possible share of colored matter. This work aimed to investigate the performance of ultrafiltration in purification of thin sugar beet juice. Thin juice was processed using polysulfonamide spiral wound membrane module of 20 kDa molecular weight cutoff on a pilot plant under different operating conditions including; temperature at three levels of 30, 40 and 50C, transmembrane pressure at three levels of 1, 2 and 3 bar and operation time at levels of 15, 30 and 45 min. The trials displayed satisfactory separation with an average purity rise of 0.72 unit, 7% lower CaO content, 86.9% lower turbidity and 10% lower color in the permeate on a 45-min operation and at different TMP and temperature. The average flux was 21.84 kg/m2h. Practical Applications This study has demonstrated that ultrafiltration of thin sugar syrup can increasing the purity ratio of permeates and decrease the turbidity, colorants and CaO content of permeate. Increasing the purity and decreasing the nonsugar compounds leads to increase the efficiency of sugar factory. Additionally, this will increase the quality of sugar production, especially in terms of color. Also, fouling of the evaporators decrease with decreasing thin sugar beet CaO content. With increasing purity syrup, evaporators need less time and energy to thicken thin syrup.