Fractional distillation of crude oil

Question 1

Outline the stages involved in fractional distillation

6 stages

Answer 1

1) The crude oil is heated in a furnace
2) A mixture of liquid and vapour passes into a tower that is cooler at the bottom than it is at the top

3) The vapours pass up the tower via a series of trays containing bubble caps until they arrive at a tray that is sufficiently cool (at a lower boiling point than their temperature).
- Then they condense to liquid

3) The mixture of liquids that condenses at each tray is piped off.
3) The shorter chain hydrocarbons condense in the trays nearer to the top because it is cooler and they have low boiling points.

4) The thick residue that collects at the base of the tower is bitumen.
- It can be used for road surfacing