Fuels

• A fuel is a substance which when burned, releases heat energy which can be transferred into electricity, which we use in our daily lives.

• Fossil fuels include coal, natural gas and hydrocarbons such as methane and propane.

Petroleum

• Petroleum is also called crude oil and is a complex mixture of hydrocarbons which also contains natural gas.

• It is a thick, sticky, black liquid that is found under porous rock.

• The fractions in petroleum are separated from each other in a process called fractional distillation.

Fractional distillation of Petroleum

• Fractional distillation is carried out in a fractionating column.

• The fractionating column is hot at the bottom and cools at the top.

• Crude oil enters the fractionating column and is heated so vapours rise.

• Vapours of hydrocarbons with very high boiling points will immediately turn into liquid and are tapped off at the bottom of the column,

• Vapours of hydrocarbons with low boiling points will rise up the column and condense at the top to be tapped off.

Properties of fraction

• Viscocity

• Melting and boiling points

• Colour

• Volatility

Products and uses

1. Refinery gas: heating and cooking

2. Gasoline: fuel for cars (petrol)

3. Naphtha: raw product for producing chemicals

4. Kerosene: for making jet fuel (paraffin)

5. Diesel: fuel for diesel engines (gas oil)

6. Fuel oil: fuel for ships and for home heating

7. Lubricating oil: for lubricants, polishes, waxes

8. Bitumen: for surfacing roads