Transcript IC.29.3 Alcohol as fuel

IC.29.3 Alcohol as fuel
Alcohol as fuel
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IC.29.3 Alcohol as fuel
If you refuel your car in Brazil,
you won’t be adding just petrol
to your tank.
 Brazilian car fuel is a mixture
of petrol and ethanol
 It may even be a mix of 95%
ethanol with 5% water.
 In Brazil, ethanol is made by
fermenting sugar cane.
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IC.29.3 Alcohol as fuel
Drag racers often fuel their cars with methanol.
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IC.29.3 Alcohol as fuel
At Christmas it is a tradition
to pour brandy over the
pudding and set it alight.
The alcohol in brandy
burns with a blue flame.
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IC.29.3 Alcohol as fuel
Alcohols burn in air to make carbon dioxide and water.
For example:
ethanol + oxygen  carbon dioxide + water
CH3CH2OH(l) + 3O2(g)  2CO2(g) + 3H2O(g)
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IC.29.3 Alcohol as fuel
There are advantages and
disadvantages of using ethanol
as a vehicle fuel instead of
fossil fuels such as petrol
and diesel.
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IC.29.3 Alcohol as fuel
Advantages:
• Made from a renewable resource, e.g. sugar cane or
maize.
• The plants from which the fuel is made remove
carbon dioxide from the atmosphere as they grow.
• Some people say this means that ethanol fuel is
carbon neutral – the plants remove the same amount
of carbon dioxide from the atmosphere as burning
the fuel later puts into the atmosphere.
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IC.29.3 Alcohol as fuel
Disadvantages:
• Crops used to make ethanol are grown on land that
could be used to grow food.
• Ethanol produces carbon dioxide, a greenhouse gas,
as it burns.
• Carbon dioxide is also added to the atmosphere as a
result of making fertilisers for the crops, and during
the manufacture of ethanol from the crops.
• Some people say this means ethanol fuel is not
carbon neutral.
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IC.29.3 Alcohol as fuel
1. What is the word equation for the combustion
reaction of propanol?
propanol + oxygen  carbon dioxide + water
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IC.29.3 Alcohol as fuel
2. Why is it important to develop alternatives to fossil
fuels? Do you think ethanol makes a good fuel?
Fossil fuels are a finite resource – one day, they will
run out.
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IC.29.3 Alcohol as fuel
3. Do you think ethanol makes a good fuel?
Discuss this with a partner or in your group.
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