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C1 Crude Oil and Fuels
A compound made of only carbon and hydrogen atoms.
When the amount of carbon released when a fuel burns is balanced by the amount absorbed as the plant used to make the fuel grows (through photosynthesis).
A saturated hydrocarbon contains only single bonds, and is called 'saturated' as no more hydrogen atoms can 'fit in'.
A mixture of hydrocarbons. This mixture contains many useful compounds that need to be separated using a process called fractional distillation. Some of these fractions can be used as fuels.
Alkanes are a family of hydrocarbons. They contain only single bonds between all hydrogen and carbon atoms, making them 'saturated'. The general formula means that the number of hydrogen atoms is double the number of carbon atoms, plus two.
This is a separating technique used to separate liquid mixtures.
- Crude oil is heated until it boils.
- The different fractions will vaporise (turn to gas) between different ranges of temperatures.
- The vapours can be collected by condensing them into different containers.
Below is a video showing how anothor mixture can be separated using distillation.
To separate the different hydrocarbons, the crude oil mixture must be passed through a fractionating column.
There are many uses for the different fractions, but most are used for fuel.
When fuels burn they are reacting with the oxygen in the air. If there is an abundance of air, then complete combustion will take place. This means carbon dioxide is produced. If they isn't enough air, then carbon monoxide is made. We say the carbon has been oxidised.
- Carbon dioxide is a greenhouse gas, and high concentrations of it in the atmosphere lead to global warming.
- Carbon monoxide is a toxic gas, so enough ventilation is important when burning fuels.
When burning fuels solid particles are also released. These particulates contain carbon and appear as 'soot'. They reduce the amount of light reaching Earth from the Sun - causing global dimming.
hydrocarbon + oxygen (abundant) --> carbon dioxide + water
hydrocarbon + oxygen (low concentration) --> carbon monoxide + water
When carbon dioxide dissolves in water is makes a slightly acidic solution. Other chemicals released from burning fuels makes rainwater even more acidic still. This acid rain reacts with metals and building materials, such as limestone, causing damage to buildings. Damage is also caused to living organisms such as plants, and makes rivers and lakes too acidic for some life to survive.
The two main causes are sulfur dioxide and nitrogen oxides.
Biofuels are fuels created from plant material, and can be used as a renewable fuel source, rather than non-renewable fossil fuels (like coal and oil).
Extracted oils from plants. Breaks down much quicker than normal diesel, burns much cleaner (produces less sulfur dioxide) and can be considered as 'carbon neutral'. A problem is that large amounts of farmland are needed to grow fuel instead of food.
We can ferment sugar to make ethanol, and unless an engine has been modified it must be mixed with other fuels. Like biodiesel - it could be considered carbon neutral.
Page last updated: 16/04/2017