Formed from the remains of plants and animals that died millions of years ago and through heat and pressure turned into crude oil
Non-renewable fuel
Fractional distillation is used to separate hydrocarbon fractions
Crude oil is a mixture of lots of different hydrocarbons
To separate them:
Heat until most has turned into a gas, bitumen won’t and will drain straight out
Gases enter a fractionating column which has a temperature gradient, hot at the bottom and cooler towards the top
Longer hydrocarbons have higher boiling points, so they condense back to liquids early on when they’re near the bottom, shorter hydrocarbon then take longer
End with crude oil mixture separated into different fractions