1. Prepared by the EPSRC CDT in Sustainable Chemistry
How clean is your car?
Prepared by the EPSRC CDT in Sustainable Chemistry

2. Biofuels
Renewable source of energy – can be made from plants e.g. sugar cane
Carbon neutral – when the plant grows it uses up carbon dioxide and the same amount is released when the biofuel is burned
Switching to biofuels would be difficult as most cars would not be able to run without modification
Fossil fuels are needed for the growth, production and transport of biofuels therefore, they are not completely carbon neutral
A large amount of land is required to grow the plants for biofuels, this land may be better used to grow food

3. Fossil Fuels
The technology used for producing/burning fossil fuels is well developed, cheap and easy to use
Very energy efficient - generates a large amount of energy through breaking of strong C-C bonds
Finite supply – non-renewable source of energy
When burned, harmful gasses and particles are released e.g. unburnt hydrocarbons, CO2, CO, SOx and NOx
Cause harm to the environment and human health through air, water and soil pollution

4. Electric
No harmful gases or particles are released when used in cars therefore, it is a “clean” form of energy
Very energy efficient – converting most of the energy from electrical to kinetic
The electricity used to power the car may be generated through burning fossil fuels
The cars cannot be driven for very long distances as the battery will run out
Compared to cars with an internal combustion engine, electric cars are very expensive

5. Hybrid Use less fuel than a car with an internal combustion engine
Release fewer toxic gases when compared with fossil fuel-only cars
Does not need to be recharged – the battery is charged through burning the fuel
Are expensive and require frequent maintenance
Are less powerful than cars with internal combustion engines

6. Fuel Cells
No toxic gases are produced - use hydrogen and oxygen as fuels to produce water
More efficient than internal combustion engines – they convert more energy into kinetic energy to move the car
They don’t need to be recharged, just need a continuous supply of hydrogen and oxygen
The production, storage and transport of hydrogen is expensive and complex
The infrastructure for providing hydrogen as a fuel on a large scale does not exist – very few refuelling stations