Separation of non-sucrose compounds from the syrup of sugar-beet processing by ultra- and nanofiltration using polymer membranes

摘要

Sugar, as the final product of the technology of sugar production, has to satisfy rigorous quality demands. Among others, it means low content of non-sucrose compounds, as well as the smallest possible share of coloured matters. Ultrafiltration and nanofiltration can be one of the solutions for a more effective separation of non-sucrose compounds from the intermediate products from which sucrose can directly be crystallized. Applying this procedure energy can be saved and the environment protected. Syrup solution from sugar-beet processing which contains 39.2% d.m. is being ultra- and nanofiltered.Polymer membranes with different MWCO (15-20 kDa, 6-8 kDa and 0.5 kDa) are used. Effects of UF are carried at 30°C and 60°C, with flow rates at 200 and 400 L/h and in the range of transmembrane pressure between 1-4 bar. NF is carried at 30°C and 50°C, with flow rates at 300 and 400 L/h and in the range of pressure between 1-30 bar. The separation of non-sucrose compounds is the most effective on a membrane with MWCO of 0.5 kDa, if the transmembrane pressure is kept at 30 bar and at a flow rate range between 300-400 L/h. Under these conditions colour and turbidity became lower for 76% and 80% respectively, if related to feed.