Separating crude oil
Fran Scott explains fractional distillation - the separation of crude oil into fractions
In fractional distillation a mixture of several substances, such as crude oil, is distilled and the evaporated components are collected as they condense at different temperatures. is used to separate Mixture of hydrocarbons, mainly alkanes, formed over millions of years from the remains of ancient dead marine organisms. into simpler, more useful Two or more substances that are not joined together. The substances can be elements, compounds, or both.. This method can be used because different A compound that contains hydrogen and carbon only. have different The temperature at which a substance rapidly changes from a liquid to a gas..
Fractional distillation
During the fractional distillation of crude oil:
- heated crude oil enters near the bottom of a tall Piece of apparatus in which mixtures separate during fractional distillation., which is hot at the bottom and gets cooler towards the top
- vapours from the oil rise through the column
- vapours Condensation is a change of state in which gas becomes liquid by cooling. when the temperature of the column is cool enough
- liquids are led out of the column at different heights
Some hydrocarbons have low boiling points. They do not condense but leave the column as gases. Some hydrocarbons have high boiling points. They leave the column as hot liquid bitumen.
Crude oil fractions
The different, useful mixtures separated from crude oil are called In fractional distillation, such as that of crude oil, the different parts of the original mixture are called fractions. The substances in each fraction have similar boiling points to each other.. This is because they are only part of the original crude oil.
Non-renewable fuels
Fuels obtained from crude oil or A naturally occurring hydrocarbon gas mixture. are called Natural, finite fuel formed from the remains of living organisms, eg oil, coal and natural gas.. They include:
- petrol, kerosene and diesel oil from crude oil
- methane from natural gas
These fuels are A resource that cannot be replaced when it is used up, such as oil, natural gas or coal. - they are being used up faster than they are being formed. This means that they will run out one day if we carry on using them.
One way to remember the names of the fractions is 'Good Penguins Keep Diving For Bass'.