|1.||the process of separating the constituents of a liquid mixture by heating it and condensing separately the components according to their different boiling points|
|2.||a distillation in which the vapour is brought into contact with a countercurrent of condensed liquid to increase the purity of the final products|
A process by which a chemical compound is separated into components by distillation. In fractional distillation the compound is heated and, as each of its constituent components comes to a boil, its vapors are separated and cooled, so it can be removed in its pure form. Fractional distillation is used to refine petroleum. See also distillation.