1. Why do we refine crude oil?
Refining Crude oil
Learning Objectives:
Why do we refine crude oil?
How do we do it?
What do we get from it

2. Local oil refinery

3. What happens at an oil refinery?
Fractional Distillation
Boiling the crude oil at different temperatures so that the different fractions evaporate and can be collected separately. The heavier the fraction the higher the boiling point
Cracking –
Increasing the proportion of the useful smaller hydrocarbons by breaking C-C bonds holding together longer chain molecules.

4. Knocking greatly reduces the performance of engines
What happens contd
Reforming
Turning light gasoline and naphtha from single chain to hydrocarbons to highly branched and aromatic hydrocarbons.
This is done to stop their pre-ignition in combustion engines (known as knocking)
Knocking greatly reduces the performance of engines

5. Crude oil
A soup of different chemicals

6. What it comprises (a barrel)
This varies from different oil fields. Not all crude oils are the same. Light or sweet crude is the best because it has the largest amount of petrol/gasoline. US, North Sea and Libyan known for their high quality.

7. Chemical description of components
Note fractions different for different crude oils

8. Parts of a refinery

9. Fractionating column

10. Cracking

11. How cracking fits in

12. Plenary questions Octane is an important hydrocarbon
Which fraction of crude oil would it be found in?
What would be its likely use?
From what length carbon chains could it be produced by cracking?

13. Complete this fractionating column by adding the uses of the different fractions.