What is crude oil?

Crude oil -.

What is crude oil?

Crude oil -Oil we find underground.

What is crude oil?

Crude oil -Oil we find underground.

It is formed from partially decayed plants and animals, under mud, millions of years ago.

What is crude oil?

Crude oil doesn’t always look the same, it depends where it’s from.

It can vary from black to colourless.

What is crude oil?

…but usually it looks like thin, brown treacle.

Crude Oil formation

Drilling for oil

• In some places, rock traps oil so it cannot escape.

• Oil wells are drilled through the rock and the oil is pumped to the surface.

Drilling for oil

Separating crude oil

• Crude oil is made up of a mixture of hydrocarbons.

• Hydrocarbons are compounds that are made up of hydrogen and carbon atoms only.

• Because crude oil is a mixture, the long chains need to be separated before they are useful.

Separating crude oil

• The hydrocarbons that make up the crude oil mixture vary in size.

• The larger the hydrocarbon the higher it’s boiling point.

Separation of crude oil

• The hydrocarbons in crude oil are separated using fractional distillation.

• This happens at an oil refinery in a tower called a fractionating column.

• In the fractioning column the hydrocarbons in crude oil are separated as they have different boiling points.

Heated Crude Oil

350o

C

40o

C

Liquid petroleum gas

Naphtha

Petrol (gasoline)

Paraffin

Diesel

Fuel oil

Lubricating oil

Bitumen

Fraction Boiling pt.

< 25oC

25 – 60oC

60 – 180oC

180 – 220oC

220 – 250oC

250 – 300oC

300 – 350oC

> 350oC

Average number of C atoms in chain

3

8

10

12

20

40

80

120

The Fractional Distillation of Crude Oil

Properties of the fractions

Use your diagram to help you!