Fractional Distillation and Crude Oil

Fractional Distillation

• Crude oil is a fossil fuel. It's formed from the remains of plants and animals, mainly plankton, that died millions of years ago and were buried in mud. Over millions of years, with high temperature and pressure, the remains turn to crude oil, which can be drilled up from the rocks where it's found.
• Fossil fuels like coal, oil and gas are called non-renewable fuels as they take so long to make that they're being used up much faster than their being formed. They're finite resources- one day they'll run out.
• The diffderent compounds in crude oil are separated by fractional distillation. 

1) The oil is heated up until most of it has turned into gas. The gases enter a fractioning column, and the liquid bit is drained off.

2) In the column there's 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, when they're near the bottom. The shorter hydrocarbons have lower boiling points, so they condense and drain much later on, near to the top of the column where it's cooler.

4) You end up with the crude…