Biofuels are renewable fuels made from vegetable oils and animal fats. Their incidence in food prices and their environmental impact have made their use -if only- controversial.

Biofuel made its debut at the Exposition Universelle, the 1900 World’s Fair held in Paris, France, where one of Rudolph Diesel’s engines ran on peanut oil. However, wide scale use wasn’t initiated until 1973 when Brazil responded to the world’s oil crisis by using fuel composed of sugarcane based ethanol.

Today, the biofuel industry is a confusing array of distinct mixes: from the European standard of a 5% biodiesel mix to the very common US “gasohol” (10% ethanol, 90% gasoline), to the 100% mostly sugar-based ethanol that runs 40% of all Brazilian cars (*Renewable Fuels Association). They’re all crop-based fuels, yet they are used in different types of engines.

• Biodiesel: derived from vegetable oils and animal fats, can be used in any diesel engine when mixed with standard diesel fuel.
• Cooking oils, like straight vegetable oils (SVO) or waste vegetable oils (WVO), from restaurant kitchens can be used in modified diesel engines.
• Ethanol: an alcohol produced from vegetables, can only be used in special engines in its pure form. However, when mixed with gasoline it can be used in any standard engine. 70% of the new cars in Brazil are “flex vehicles” which have separate tanks which allow them to run on 100% ethanol or gasoline or a combination of the two.

Europe dominates the biodiesel industry. Incentives like tax breaks and the European Union’s 5.75% biofuel use target by 2010,
encourages greater use of biofuel. The world leader in ethanol
production is Brazil where nearly every fueling station offers 100%
ethanol. Brazil hopes to be completely self-sufficient in fuel
production by the end of 2007.

There is heated debate within the industry regarding crop choices. In a
recent study focused on the United States’ two largest biofuel crops,
the National Academy of Sciences found that soybean-based biodiesel is
more efficient to produce and more cleaner-burning than corn-based
ethanol.

Nonetheless, even if the United States’ corn and soybean production were dedicated solely for fuel usage, neither could really
impact national needs (A finding that has been replicated worldwide).

According to the researchers, the best hope for biofuels are nonfood plants, like switchgrass, diverse prairie grasses and woody plants that can grow on marginal lands with little need for fertilizers and pesticides.

• More information regarding biofuel, in Wikipedia.