Biodiesel is composed of monoalkyl esters (methyl/ethyl esters), a long chain of fatty acids derived from renewable lipid sources. It is an ester based, renewable fuel made from vegetable oils, recycled fryer oils, tallow and other biological products which have had their viscosity reduced using a process called tranestrification, by which glycerin (thick component of vegetable oil) is removed. Biodiesel is biodegradable, non-toxic, and essentially free of sulfur and aromatics. Originally biodiesel was considered a by-product of glycerin soap production.
Biodiesel is a clean-burning, alternative fuel that traditionally is made by processing renewable resources such as vegetable oils, waste cooking oils and animal fats with alcohol through a simple refining process. One of the primary agricultural sources for biodiesel is soybeans. Smithfield Foodsâ€™ version of biodiesel fuel combines biomethanol produced from swine waste with vegetable oils and rendered animal fats.