Distillation-Column

Distillation is one of the most common liquid-vapor separation processes in industry, and can be carried out in a continuous or batch system. Distillation works by the application and removal of heat to exploit differences in relative volatility. The heat causes components with lower boiling points and higher volatility to be vaporized, leaving less volatile components as liquids. Mixtures with high relative volatilities are easier to separate. This makes separations of close-boiling and azeotropic feeds difficult, so special distillation techniques have to be used to separate these mixtures. Distillation can be used to separate binary or multi-component mixtures. Many variables, such as column pressure, temperature, size, and diameter are determined by the properties of the feed and the desired products. Some specialized columns perform other functions, such as reactive distillation columns, which combine reaction and separation of products into a single unit.

What is a distillation column?

A distillation column, or tower, is used to separate liquid mixtures into individual constituents based on their boiling points. The liquid is heated to produce vapours which are then condensed, by cooling, back into liquid form. The liquids are then collected in trays or plates positioned at different heights inside the column, their position based on the boiling point of each separate component. Distillation columns are used in petrochemical, chemical and pharmaceutical industries to purify and separate various chemicals, distillation columns are also used in the production of alcoholic beverages. The design and specific operation of a distillation column can vary greatly depending on the type of liquid mixture being distilled and the desired product specifications.