What is Fractional Distillation ?

Fractional distillation is the technique to separate different components present in the crude oil on the basis of their boiling points. Crude oil is a mixture of many useful hydrocarbons and it is very important to separate them. Different hydrocarbons differs in chain length and hence have different boiling points This property is used in separating them by the technique called fractional distillation. Fractional distillation is carried out in a fractionating column where the lowest temperature is at the top and the highest is at the bottom. The crude oil is fed into the column from the bottom. As it rise up the column, the components of crude oil that correspond to that temperature boils off. The vapours are then collected at each fraction and condensed. In this way crude oil is separated into different components. Shorter carbon chains are collected at the top as they have a lower boiling point and the heavier carbon chains are collected at the bottom.