1. LO: I know some examples of biofuels.
5.7 Alternative Fuels
5.7.1 Biofuels
LO: I know some examples of biofuels.

2. Biofuels are produced by .
living
organisms
Methane:
Produced by micro-organisms from material.
decaying
Can be burned to produce and
heat
electricity
Is a stronger gas than carbon dioxide.
greenhouse
Ethanol:
Produced from the fermentation of
sugar
Methanol:
Produced from the reaction of and
steam
methane
Both methanol and ethanol have high numbers.
octane
LO: I know some examples of biofuels.

3. LO: I understand what is meant by the hydrogen economy.

4. renewable source of electricity
The hydrogen economy is an economic system built upon the use of hydrogen as a
fuel
renewable source of electricity
water
hydrogen gas
electrolysis
Advantages:
Disadvantages:
Cheap raw material.
Difficult to store.
Very little pollution.
Risk of explosion.
LO: I understand what is meant by the hydrogen economy.

5. LO: I understand what is meant by a fuel cell.
5.7.3 Fuel Cells
LO: I understand what is meant by a fuel cell.

6. Fuel cells produce electrical energy directly from energy.
chemical
Hydrogen/oxygen fuel cell:
Advantages:
No energy is wasted as heat.
Produces no pollution at all.
LO: I understand what is meant by a fuel cell.