Fractional Distillation

• Crude oil:

  • A fossil fuel
  • Formed from the remains of plants and animals, mainly plankton
  • non- renewable
• Fractional distillation can be used to seperate hydrocarbons:

  1. The oil is heated until most of it has turned into gas. The gases enter a fractionating column
  2. in the column there is a temperature gradient (it's hot at the bottom and gets cooler as you go up )
  3. the longer hydrocarbons have high boiling points. They condense back into liquids and drain out of the column early on. the shorter hydrocarbons have lower boiling points. They condense and drain out much later on, near the top of the column.
• Each fraction contains a mixture of hydrocarbons that all contain a similar number of Carbon Atoms