Biodiesel is a fuel that is made from materials such as vegetable oil,animal fat,and waste matter.In the case of waste matter,a year's worth of Europe's used cooking oil could produce more than a billion liters of biodiesel fuel.In order to convert starchy and oily plants like rapeseed and soybean fats into biodiesel,they have to be heated.After processing,unlike regular vegetable oil,biodiesel has combustible properties very similar to petroleum diesel,and can replace it in most cases.Biodiesel is a good possibility to replace fossil fuels as the world's primary energy source for vehicles.There are two reasons for this:biodiesel can be used in current car engines,and it can be transported and sold using existing infrastructures.