Fractional distillation - Purification of organic compounds

This method is used to separate a mixture of two or more miscible liquids that have boiling points close to each other. As in this process, the distillate is collected in fractions within different temperatures, it is termed as fractional distillation. This process is performed by using fractionating columns.  Fractionating column is a unique type of long glass tube given with obstructions to the passage of the vapour upwards and that of liquid downwards.

This process may be employed to separate a mixture of acetone (b. p. 330 K) and methyl alcohol (b. p. 338 K) or a mixture of benzene and toluene.  Just One of the technological applications of fractional distillation is to separate dissimilar fractions of crude oil in petroleum industry into several helpful fractions such as gasoline, diesel oil, kerosene oil, lubricating oil etc.