Sometimes called clean diesel, biodiesel is a important category of alternative fuels. Its environmental benefits have caused it to grow in popularity in recent years. But how much do you know about this alternative fuel? Here are five takeaways that you should know about this important renewable fuel:
- Biodiesel is derived from oils, whether vegetable oils, animals fats or even used cooking oils. Vegetable oils are sourced from any of a number of plants, the most common being soybeans, but also canola, peanuts, sunflowers--event cottonseed. Biodiesel can be thought of as being especially green when it s made from waste cooking oil, a process that turns a useful leftover substance into a value-added product. Producing biodiesel leaves no waste product afterward. Whatever is leftover can be incorporated into the next batch or sold as a by-product for channels such as animal feed additives.
- To understand why there is no waste product in biodiesel production, it's helpful to have an understanding of the basics of how its produced. Biodiesel production begins with the addition of vegetable oil or animal fat, a catalyst of some sort, and methanol into a reactor. It is the oil and methanol that actually become the biodiesel, along with the production of glycerin, the latter of which has a wide variety of applications. This process is known as transesterification. Further processing is necessary in order to finish with a biodiesel product that can meet government fuel standards and a crude glycerin product ready for manufacture into a value-added product, be it feed, healthcare products, or industrial use.
- Because of its ties to oils sourced from vegetables, many people think biodiesel can be easily made at home from sources such as home cooking oil waste. But before you start digging around the cabinet and hoarding veggie oil in your basement, learn the facts. Begin with the fct that biodiesel is not raw vegetable oil. Proper performance as a fuel is only possible because fuel-grade biodiesel adheres to strict industry specifications (ASTM D6751) after properly going through transesterification and then further processing. Biodiesel becomes legal for sale and distribution as a motor fuels only after it has met the specifications of ASTM D6751 and also has been legally registered with the U.S. Environmental Protection Agency. It isn't possible for raw vegetable oil to meet these rigorous biodiesel fuel specifications. Also, raw vegetable oil isn't registered with the EPA and so cannot be legally used as a motor fuel the way real biodiesel can.
- So, what are the benefits? Well, like many alternative fuels, they vary. From an economic standpoint, one of the overriding benefits of using biodiesel is that it helps to reduce dependency on foreign oil. It's estimated that there is enough existing raw materials to displace at least 5% of the current petroleum-based diesel being consumed in this country. Like its cousin, ethanol, biodiesel also helps to boost ailing rural economies, bringing jobs to the area and helping farmers to rely on the marketplace for income.
- Like most alternative fuels, biodiesel has an environmental advantage over fossil fuels. It improves air quality and has been documented to contain more energy than it took to produce it. Specifically, for each unit of energy that is used to make a gallon of biodiesel, it's known that 3.24 units of energy are stored for future use. This is in contrast to petroleum which provides only 0.83 units of energy for every one unit needed to produce a gallon.