ABSTRACT
Selective separation of one or a mixture of components from a bulk liquid or mass is one of the most common operations encountered in the food industry. This chapter illustrates the principles of mathematical models describing three selected separation processes: filtration, extraction/leaching, and pressure-driven membrane processes. Filtration can be defined as the separation of solids from a suspension in a liquid by means of a porous medium or screen that retains the solids and allows the liquid to pass. The common assumption made in developing theories for cake filtration is that the solid particles deposited on the cake remain without migration. The theories developed have almost exclusively been concerned with deep-bed sand filtration. In supercritical fluid extraction, the solvent is used at temperatures and pressures above the vapor-liquid critical point. By integrating phenomenological models with control equipment, the efficiency of separation processes can be vastly improved.
