Concentration polarization modelling in the maple sap concentration by reverse osmosis

This research studied the effect of concentration polarization on the efficiency of reverse osmosis to concentrate maple sap. For these purposes, a commercial reverse osmosis spiral wound module was tested. A correlation of the variation of the sucrose mass transfer coefficient with the tangential velocity and temperature was experimentally determined from pure sucrose solution permeation tests. This correlation, together with a set of simple equations describing the reverse osmosis system, predicted the membrane sucrose concentration during maple sap concentration under a wide range of operating conditions. Good agreement was found between the predicted and experimentally determined value of the membrane concentration. Also, it was shown through some parametric studies, how the results of this work are helpful in the design and operation of a reverse osmosis system.