A2. Fractional distillation of crude oil

2. Describe how the process of fractional distillation can be used to separate the hydrocarbons in crude oil.


The oil is heated up until it vaporises.
It then passes through a fractionating column with a high temperature at the base, and a much lower temperature at the top
As the vapours pass up the tower they cool, and the larger molecules condense to liquid and are collected
And the smaller ones rise until they condense
Separating the crude oil into many useful oils.