Running a car with fuel that has grown on the fields sounds like a safe and attractive option for a climate-conscious citizen. The plants grown for biofuel production absorb CO2 from the atmosphere and combustion of the biofuel releases only the CO2 previously absorbed by the plant. Therefore biofuels typically have far lower well-to-wheel GHG emissions than fossil fuels. With the surge in fossil fuel prices in the recent past and government programmes supporting the production of biofuels, the demand for plant-based energy has risen sharply. In the United States for example, the US Renewable Fuels Standard (RFS) required in 2006 that 1 500 million litres of the US fuel supply be provided by renewable
fuels, and it is supposed to increase to 28 400 million litres in 2012.
With a further surge in demand ahead of us it is worth looking at ways to ensure a sustainable production of energy corps. Whether biofuels are “good” or “bad” is a matter of introducing a number of environmental and social safeguards.
The technical facts
Bioenergy – the use of biomass – has been and in many regions still is one of the most prominent sources of energy, in developing countries often enough ineffi ciently. Bioenergy refers to biomass converted to higher value and more effi cient and convenient energy carriers, such as pellets, gas, or liquids. Most common liquid biofuels used for transportation are ethanol and biodiesel.
Bioethanol is an alcohol thatcan be made from almost anycrop that has a high content of sugar (sugarcane or sugar beet), starch crops (corn) or any cellulosic crops. The alcohol is
mainly produced through a repetitive fermentation process which involves soaking, crushing or chemical extraction using a process similar to that used in