Biodiesel refers to a vegetable oil - or animal fat-based diesel fuel consisting of long-chainalkyl (methyl, ethyl, or propyl) esters. Biodiesel is typically made by chemically reactinglipids (e.g., vegetable oil, soybean oil, animal fat) with an alcohol producingfatty acid esters.
Biodiesel is meant to be used in standard diesel engines and is thus distinct from the vegetable and waste oils used to fuel converted diesel engines. Biodiesel can be used alone, or blended with petrodiesel in any proportions.Biodiesel blends can also be used as heating oil.