A membrane filtration plant using suitable micro or ultra-filtration membranes has theudpotential to significantly increase pan stage capacity and improve sugar quality.udPrevious investigations by SRI and others have shown that membranes will removeudpolysaccharides, turbidity and colloidal impurities and result in lower viscosity syrupsudand molasses. However, the conclusion from those investigations was that membraneudfiltration was not economically viable. A comprehensive assessment of currentudgeneration membrane technology was undertaken by SRI. With the aid of two pilotudplants provided by Applexion and Koch Membrane Systems, extensive trials wereudconducted at an Australian factory using clarified juice at 80–98°C as feed to each pilotudplant. Conditions were varied during the trials to examine the effect of a range ofudoperating parameters on the filtering characteristics of each of the membranes. Theseudparameters included feed temperature and pressure, flow velocity, soluble solids andudimpurity concentrations. The data were then combined to develop models to predict theudfiltration rate (or flux) that could be expected for nominated operating conditions. Theudmodels demonstrated very good agreement with the data collected during the trials. Theudtrials also identified those membranes that provided the highest flux levels per unit areaudof membrane surface for a nominated set of conditions. Cleaning procedures wereuddeveloped that ensured the water flux level was recovered following a clean-in-placeudprocess. Bulk samples of clarified juice and membrane filtered juice from each pilotudwere evaporated to syrup to quantify the gain in pan stage productivity that results fromudthe removal of high molecular weight impurities by membrane filtration. The results areudin general agreement with those published by other research groups.
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