Biofuels

• What are biofuels?

  Renewable fuels made from recently living organisms.
• Recently living organisms..

  Plants or algae

  Animal waste
• Contrast to fossil fuels..

  Made from organisms which died millions of years ago.
• Plants and algae can trap the suns energy as part of photosynthesis, and this energy is released when we combust the fuel.
• Advantages of biofuels?

  Renewable

  Can be used in cars

  Easy to transport
• Disadvantages of biofuels?

  Require a large area of land to grow.

  Lots energy to harvest, process and transport.
• ‘Biofuels are carbon neutral’

  Absorb the same amount of carbon dioxide while growing, as they release when burned.
• In theory biofuels should be carbon neutral, but they’re not.

  Why?

  Trees may be cut down, so no longer absorb C02.

  Trees will release C02 if burned.