C7: Fractional Distillation Flashcards
How is crude oil made?
It’s a fossil fuel. Formed from the remains of plants and animals, mainly plankton, that died millions of years ago and were buried in mid. Over time with high temperature and pressure the remains turn to crude oil which can be drilled up from the rocks where it’s found.
What does it mean when crude oil is called a finite resource?
It’s non-renewable - they take so long to make that they’re being used up much faster than they’re being formed.
What is crude oil?
It’s a mixture of lots of different hydrocarbons, most of which are alkanes. The different compound are separated by fractional distillation.
How does fractional distillation work?
1) Oil is heated until most has turned to gas. The gases enter a fractionating column (& the liquid bit is drained off)
2) There’s a temperature gradient in the column (hot at bottom, cool at top)
3) Longer hydrocarbons have high boiling points - condensed to liquids & drain out of column early on when they’re near the bottom.
4) End up with crude oil mixture separated into different fractions.
What’s the order of the different fractions of crude oil in fractional distillation and what are their uses?
Refinery Gas/LPG (Liquid Petroleum Gas, contains mostly propane and butane) - BBQs, heaters
Gasoline/Petrol -transport
Naphtha - to make alkanes -> plastic
Keeps on/Paraffin - lamps, planes
Diesel Oil - transport
Heavy Fuel Oil (can be heating oil, fuel oil or lubricating oil) - ships
Bitumen - roads, rooves
