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

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

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

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

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

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