Fuels
Introduced| English | Meaning |
|---|---|
| fuels/ˈfjuːəlz/ | fuels |
| crude oil/kruːd ɔɪl/ | A naturally occurring liquid mixture containing many hydrocarbons and smaller amounts of other substances. |
| hydrocarbons/ˈhaɪdrəkɑːbənz/ | A compound containing only carbon and hydrogen atoms. |
| fractional distillation/ˈfrækʃənl dɪstɪˈleɪʃn/ | Separating components of a liquid mixture through repeated evaporation and condensation based on differences in volatility. |
| incomplete combustion/ɪŋkəmˈpliːt kəmˈbʌstʃn/ | Burning with insufficient oxygen for complete oxidation, often producing carbon monoxide or carbon as well as other products. |
| complete combustion/kəmˈpliːt kəmˈbʌstʃn/ | Burning in sufficient oxygen to fully oxidise the fuel; a hydrocarbon produces carbon dioxide and water. |
| non-renewable/nɒn rɪˈnjuːəbl/ | Describing a resource used faster than natural processes replace it on a human timescale. |
Burning for energy
- Most of the world's energy comes from burning fuels 燃料 — substances that release energy when they burn.
- The most important come from crude oil 原油.
Fuel chain lab
Follow a fuel from source to combustion products.
A hydrocarbon is a compound of:
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Hydrocarbons contain only hydrogen and carbon.
Crude oil is separated into fractions by:
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Fractional distillation separates by boiling point.
Crude oil and fractions
- Crude oil is a mixture of hydrocarbons 碳氢化合物 (compounds of hydrogen and carbon).
- It is separated by fractional distillation 分馏 into useful fractions (petrol, diesel, etc.).
An oil refinery separates crude oil into useful fuels
Fractions separate by boiling point: small molecules leave the cool top, thick bitumen stays at the hot bottom
Complete combustion of a hydrocarbon produces:
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With enough oxygen: CO₂ + water.
Incomplete combustion produces only carbon dioxide and water.
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False. That is complete combustion. With too little oxygen, incomplete combustion also produces toxic carbon monoxide and soot.
Complete and incomplete combustion 不完全燃烧
- Complete combustion 完全燃烧 (plenty of oxygen): fuel + oxygen → carbon dioxide + water.
- Incomplete combustion (too little oxygen): produces carbon monoxide and soot.
Fossil fuels will eventually run out because they are ______.
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They cannot be replaced on a human timescale.
Problems with fossil fuels
- Burning fossil fuels releases carbon dioxide (greenhouse gas) and pollutants.
- They are also non-renewable 不可再生的 — they will run out.
Incomplete combustion is dangerous and wasteful. With too little oxygen, fuels make toxic carbon monoxide and sooty particles, and release less energy. Good ventilation ensures complete combustion.
You've got it
- crude oil is a mixture of hydrocarbons, separated by fractional distillation
- complete combustion → CO₂ + water; incomplete → carbon monoxide + soot
- fossil fuels release CO₂ and are non-renewable
Write from complete combustion making carbon dioxide
- Methane burns in plenty of air.
- A limited air supply is a different case.
What are the carbon-containing and hydrogen-containing products?
Complete combustion of a hydrocarbon gives carbon dioxide and water.
What carbon-containing product forms when methane burns in plenty of air?
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Enough oxygen takes the carbon all the way to carbon dioxide.