Theoretical and experimental analysis of diffusion and polarization phenomena in sugar solutions in spiral-wound modules

Abstract

Reverse osmosis experiments have been carried out in a pilot plant equipped with a commercial high rejection spiral-wound module for glucose-water and sucrose-water systems at different feed concentrations in the range 0–14% and 0–25%, respectively, at pressures between 0 and 60 atm and at a temperature of 30°C. Rejections higher than 99% and fluxes of 30–40 l/m 2 h have been obtained at operating conditions of industrial interest. The data collected have been used to derive the characteristic parameters of the membrane and module, with special emphasis on polarization on the high pressure side and on diffusion through the membrane. Comparison of theoretical calculations with the experimental data indicates that a single set of parameters can be used over the whole range of concentrations and pressures for the two systems.