BIOFUELS AND BIOGAS

By Imasha

Page 274 to 277 on AQA biology Textbook - B3 4.6 and 4.7

BIOFUEL

Biofuel is an alternative to fossil fuels

They are two types of biofuel : ethanol based fuels and biogas.

Biogas

Biofuel

Ethanol

ETHANOL

Sugar canes are grown with yeast to ferment it aerobically and then ethanol is extracted by distillation.

This ethanol based fuel is carbon neutral since fermentation removes CO2 then gives it back and can also be used as an alternative to petrol.

Sugar cane

Used for fuel

Advantages & Disadvantages

• Biofuels are carbon neutral

• Are more in demand now than ever before since we are looking for a way to preserve resources for the future.

• No toxic gases are released into the atmosphere when burnt

• Ethanol can be mixed with petrol to reduce toxic gases and make gasohol.

• However a lot of plant material is needed to produce ethanol. Scientists are trying to find ways to grow sugar canes as fast as possible.

• We need at least 7.5 billion litres of ethanol a year but unfortunately don’t have enough plant material for this.

• Production of Ethanol takes away edible food which reduces resources.

BIOGAS

Biogas is another alternative to fossil fuels that can be used.

Biogas is a mixture of gases formed in anaerobic conditions when bacteria break down plant material and animal waste. It is mainly made up of methane but also other gases.

Methane is a flammable gas which can be used as fuel for heating, cooking and even electricity.

Biogas production occurs in a biogas generator at 30 degrees in hot countries.

The End