The Basics of Distillation

Distillation is a process of separating two liquids through differences in their boiling points. A considerable oversimplification of the process is as follows. First a still, a distillation apparatus, must be constructed consisting of at the very least a pot, a condenser, and a receiver. A mixture of two liquids—let's say liquid A and liquid X—is heated in the pot. Liquid A has a lower boiling point and will, therefore, boil from the solution first. The vapor from liquid A boiling off the mixture flows into a condenser, a cooling system designed to reduce the temperature of the vapor A so that it condenses back into liquid A. The condenser conducts the newly condensed liquid A into the receiver, a separate vessel for collecting the purified liquid A. Thus the solution is separated when the last of the liquid A with the lower boil point boils from the solution leaving only liquid X in the pot. A sharp rise in temperature of the liquid X remaining in the pot denotes the completion of the distillation. Ideally, distillation or a series of distillation can completely separate two liquids from a solution. This process has been used since ancient times. Though it is commonly associated with the production of alcohol, distillation has many laboratory and industrial uses.

There are several subcategories of distillation, all of which are variations based on simple distillation:

• Azeotropic distillation
• Dry Distillation
• Extractive distallation
• Fractional distillation
• Freeze distiallation
• Steam distillation
• Vacuum distallation