ETYM French distillation, Latin destillatio.
Technique used to purify liquids or to separate mixtures of liquids possessing different boiling points. Simple distillation is used in the purification of liquids (or the separation of substances in solution from their solvents) —for example, in the production of pure water from a salt solution.
The solution is boiled and the vapors of the solvent rise into a separate piece of apparatus (the condenser) where they are cooled and condensed. The liquid produced (the distillate) is the pure solvent; the non-volatile solutes (now in solid form) remain in the distillation vessel to be discarded as impurities or recovered as required. Mixtures of liquids (such as petroleum or aqueous ethanol) are separated by fractional distillation, or fractionation. When the mixture is boiled, the vapors of its most volatile component rise into a vertical fractionating column where they condense to liquid form. However, as this liquid runs back down the column it is reheated to boiling point by the hot rising vapors of the next-most-volatile component and so its vapors ascend the column once more. This boiling-condensing process occurs repeatedly inside the column, eventually bringing about a temperature gradient along its length. The vapors of the more volatile components therefore reach the top of the column and enter the condenser for collection before those of the less volatile components. In the fractional distillation of petroleum, groups of compounds (fractions) possessing similar molecular weights and boiling points are tapped off at different points on the column. The earliest-known reference to the process is to the distillation of wine in the 12th century by Adelard of Bath. The chemical retort used for distillation was invented by Muslims, and was first seen in the West about 1570.
The process of boiling a liquid and condensing its vapors; SYN. distillment. + prikaži više