Chapter 3 Pressure-activated membrane processes M. J. LEWIS, Department of Food Science and Technology, The University of Reading, Reading RG6 6AP 3.1 INTRODUCTION Over the last 30 years, a number of membrane processes have evolved, which make use of a pressure driving force and a semi-permeable membrane in order to effect a separa- tion of components in a solution or colloidal dispersion. The separation is based mainly on molecular size, but to a lesser extent on shape and charge. The three main processes
