Biodiesel, defined as the monoalkyl esters of long chain fatty acids, is produced from plant oil, animal fat or microbial oil by transesterification with short-chain alcohols (methanol or ethanol).

　　Biodiesel has been regarded as one of the most attractive alternatives to traditional fossil diesel due to its well recognized advantages.

　　Biodiesel is widely used in U.S. and many European countries, and has also been one of the national key industrial projects in China.