Fractional distillation is a process to separate the volatile liquids. In the apparatus, a fractionating column is the most important part of the fractional distillation apparatus. This column has glass beads in it which provides a large surface area for the vapours to collide and lose energy so that they can be quickly condensed and distilled. Apart from the presence of bead, if the length of the column is increased, then it would also increase the efficiency. The vapours of high boiling liquid get condensed earlier (at a lower level).

The advantages of a fractionating column are as follows:
(i) The purity of the mixture is the main advantage of fractional distillation.
(ii) This method can separate the liquids with a boiling point difference about or less than 25 K.
(iii) During the process, both evaporation and condensation take place simultaneously.
(iii) A mixture (such as petroleum containing several components) can also be separated by the fractional distillation process.