What it is

Biodiesel could be the best option for those heavy duty vehicles that are not likely to run off of electricity anytime in the near future. Everything in this section must be taken with the understanding that this is not nearly as good as plug-in hybrid or full electric vehicles, but we are understanding of the fact that some diesel vehicles will need to be on the road and that we should try to work to get them using the best fuel they can.

Biodiesel is a form of diesel fuel manufactured from vegetable oils, animal fats, or recycled restaurant greases that can be used in most diesel engines on the road today without modification. It is safe, biodegradable, and produces less air pollutants than petroleum-based diesel. Although it can be used in its pure form (B100), it is typically found blended with petroleum diesel in B2, B5, and B20 blends, representing 2, 5, and 20% biodiesel, respectively. It is commonly produced from soybean, corn, cottonseed, canola, flax, sunflower, and peanut oils as well as animal-derived fats and also sometimes from recycled oil and grease, although this requires more pretreatment.

This fuel is not the same as pouring used cooking grease into a vehicle, something that is now referred to as Straight Vegetable Oil (SVO), but requires a strict pretreatment and then conversion process be followed to be certified to be used in diesel engines. Biodiesel must go through a process called transesterification, that converts the vegetable oil or animal fat and an alcohol into something called fatty acid methyl ester (FAME) and glycerin. The FAME is biodiesel and the glycerin is currently being researched to find more valuable uses, although it is already used in the pharmaceutical, cosmetics, or other industries. This website has a flow chart of the process of creating biodiesel.