Biofuels

Question 1

What are biofuels?

Answer 1

Fuels produced from plant material, rather than fossil fuels.

Question 2

What is biodiesel?

Answer 2

Biodiesel is made from rapeseed oil and other plant oils. It can be used in diesel-powered vehicles without needing any modifications to the engine.

Question 3

What is bioethanol?

Answer 3

Bioethanol is made by fermenting sugars from sugar cane, wheat and other plants. It cannot be used on its own unless the engine is modified. However, modern petrol engines can use petrol containing up to 10 percent ethanol without needing any modifications, and most petrol sold in the UK contains ethanol.

Question 4

What are some advantages to biofuels? (7)

Answer 4

Less expensive than fossil fuels
Efficient step in recycling, as is made from waste materials
Renewable, as new crops are always grown and waste material collected
Can be produced locally, means energy does not have to be bought from other countries
Can provide many jobs in rural areas
Increase demand for suitable crops, and provide economic stimulation to the agriculture industry
Carbon neutral, the amount of carbon dioxide they release when they are combusted is equal to the amount they absorbed when they grew

Question 5

What are some disadvantages to biofuels? (5)

Answer 5

Not fully carbon neutral, as fossil fuels are used in their production, e.g for making fertilisers, powering the machinery necessary to cultivate the crops
Lower energy output than fossil fuels, so more will need to be consumed
Using crops that could have been used to feed people are used to provide the raw materials for biofuels instead. This could cause food shortages or increases in the price of food
Large quantities are necessary for the proper irrigation of biofuel crops as well as to manufacture the fuel, which could strain local and regional water resources
More people are needed to produce biofuels than are needed for petrol and diesel.