Crude oil and fuels Flashcards
Crude oil
A mixture of a very large number of compounds that comes for reserves in the ground
Mixture
Two or more elements or compounds that are not chemically joined together.
Hydrocarbon
A molecule made of hydrogen and carbon atoms only.
Alkanes
A group of saturated hydrocarbons with the general formula CnH2n+2
Saturated
When a hydrocarbon contains as many hydrogen atoms as possible
No double bonds
Fractional distillation
A method of separating the different hydrocarbons in crude oil by using the fact that they different boiling points. • Highest temperature is at the bottom. • Lowest temperature is at the top. • Largest molecules at the bottom. • Smallest molecules at top.
Fraction
A mixture of molecules that will be of similar sized and similar boiling point.
Boiling point
How does boiling point change up a fractional distillation tower?
The temperature at which the liquid boils and evaporates or the gas condenses.
Decrease up the tower
Volatility
How does volatility change up a fractional distillation tower?
The tendency of a liquid to turn into a gas.
• Smaller Hydrocarbons will be more volatile
• Larger hydrocarbons will be less volatile
Increase up the tower.
Viscosity
How does viscosity change up a fractional distillation tower?
How easily a liquid flows.
• Smaller Hydrocarbons will be less viscous
• Larger hydrocarbons will be more viscous
Decrease up the tower.
Flammability
How does flammability change up a fractional distillation tower?
How easily a fuel burns.
• Smaller Hydrocarbons will be more flammable
• Larger hydrocarbons will be less flammable
Increase up the tower.
Combustion
When a hydrocarbon fuel is oxidised and energy is released. The carbon and hydrogen are oxidised, producing carbon dioxide and water.
Acid rain
When sulphur dioxide and nitrogen oxides dissolve in droplets of water in the air and react with oxygen, and then fall as acid rain.
Global warming
When carbon dioxide, produced from burning fuels, absorbs energy which is radiated from the earth’s surface and causes a rise in global temperatures.
Biofuels
Renewable fuels that are made from animal or plant products.
