* Biodiesel, which works in any diesel engine, is a clean-burning fuel derived from any fat or vegetable oil. About 90 percent of US biodiesel is made from soybean oil. It takes roughly 7 pounds (about 3.2 kg) of soybean oil to make one gallon (about 3.8 liters) of diesel.

* Ethanol, an alcohol most often made from grains and sugar cane, is blended with gasoline to reduce tailpipe emissions in cars and trucks.

* Biodiesel production capacity in Europe, mainly in Germany and France, has risen sharply as countries try to reduce carbon dioxide emissions and cut the bloc's dependence on fuel imports. The EU in 2004 set a target that fuels should contain 5.75 percent of biofuels in 2010.

* Brazil is the world's leading producer and exporter of ethanol, derived from its huge sugarcane crop. It already blends its domestic gasoline with 25 percent ethanol and is looking to US, Japanese and Indian markets to boost exports.

* In the United States, the second-largest biofuel producer after Brazil, hundreds of major truck fleets use biodiesel including all branches of the US military, NASA, several state departments of transportation and public utility fleets.

* China, the world's second-largest energy consumer, is also the third-largest ethanol producer. The Philippines encourages use of coconut oil for biodiesel.

* The International Energy Agency estimates that under the most optimistic scenario ethanol could make up 10 percent of world gasoline by 2025.