Biodiesel, an alternative biodegradable diesel fuel, is a renewable fuel that can be produced from vegetable oils, animal fats, and used cooking oil, including triglycerides. It is derived from triglycerides by transesterication with methanol and ethanol. Concerns about the depletion of diesel fuel reserves and the pollution caused by the continuously increasing energy demands make biodiesel an attractive alternative motor fuel for compression ignition engines. There are four different ways of modifying vegetable oils and fats to use them as diesel fuel, such as pyrolysis/cracking, dilution with hydrocarbons blending, emulsication, and transesterication. The most commonly used process is the transesterication of vegetable oils and animal fats.