15. Mass Transfer Operations

Distillation is the process in which the separation of components in a mixture is achieved due to differences in volatility, that is differences in vapour pressure, of the components in the mixture to be separated. The simplest kind of batch distillation process results in only a limited increase in the concentration of the more volatile component (MVC) in the distillate; a greater degree of separation can be obtained by using a fractionating column. In the food industry, distillation is used in the purification of raw alcohol and the production of beverage alcohol from wheat; the separation of flavour components, for example from the condensed vapour resulting from evaporation of fruit juices; as an important step in the production of bioethanol from sugar beet; and in the production of food grade white oils which are used as binders or coating materials. Other applications of distillation are the recovery, concentration and fractionation of aromas; the recovery of solvents from miscella; and the concentration and recovery of solvents used in extraction process such as the recovery of isopropanol used in the extraction of pectin from fruit peel.