12.5

Question 1

Biofuels are..

Answer 1

renewable energy sources

Question 2

Biofuels include:

Answer 2

Biomass - from fast growing plants, used as fuel for burning

Vegetable oils - can be used as biodiesel

Ethanol - from the fermentation of plant material, used as petrol substitute or as bioethanol

Question 3

The use of biodiesel and bioethanol as transport fuels could…

Answer 3

reduce emissions from greenhouse gases when compared to the emissions from conventional transport fossil fuels

Question 4

Burning the biofuels releases carbon dioxide, but the growing biofuel crop plants absorb a comparable amount of the gas from the..

Answer 4

atmosphere during their lifetime

Question 5

However, energy is used in growing and processing the crops and this can make greenhouse gas emissions from biofuels as…

Answer 5

great as those from petroleum based fuels

Question 6

To produce significant reductions in the use of fossil fuels, the plants used have to be…

Answer 6

grown on a very large scale

Question 7

Growing plants on a large scale have impacts on the environment:

Answer 7

reducing the available habitats for wild animals and plants

affecting the availability of food for human consumption

Question 8

Advantages of biofuels:

Answer 8

• Absorb a comparable amount of the gas from the atmosphere during their lifetime (photosynthesis)
• Could reduce emissions of greenhouse gases, when compared to the emissions from conventional transport fossil fuels
• Reduces the use of fossil fuels
• Can come from various sources

Question 9

Disadvantages of biofuels:

Answer 9

• Reduced availability of habitats for wild animals and plants
• Destruction of habitats
• Loss of biodiversity as land is cleared for biofuel crop cultivation
• Reduced availability of food/water for human consumption - leading to starvation/decline in health/civil unrest/political instability/possible environmental damage
• Energy in growing biofuels crops can be as great as those from petroleum based fuels