Distillation Operations: Methods, Operational and Design Issues

Distillation is one of the oldest and most common methods for the purification of liquids. It has been used for centuries to concentrate dilute alcoholic beverages and to obtain perfumes from fruits and flowers. In this paper various methods of distillation, operating principles, equipment for distillation are discussed in detail. Various design and operating policies for binary distillation columns are discussed with objective of maximizing production rate. Significant increasing in capacity can be realized by optimum design of column-i.e. number of trays, trays hold up, reflux drum hold up etc. and optimum operation- i.e. reflux ratio and start up procedure. Equipment and column size issues discussed here may be useful to practicing engineers in early stage of distillation design. Some issues in the design and operation of a batch and continuous distillation column are addressed. Key words: distillation operations, methods, distillation equipment, operational and design Issues