How Biodiesel Works

Biofuel History

Photo courtesy Bob Allan
Current U.S. biodiesel production is primarily from oil from soybeans such as these or from recycled restaurant cooking oil.

The concept of biofuels is surprisingly old. Rudolf Diesel, whose invention now bears his name, had envisioned vegetable oil as a fuel source for his engine. In fact, much of his early work revolved around the use of biofuel. In 1900, for example, at the World Exhibition in Paris, France, Diesel demonstrated his engine by running it on peanut oil. Similarly, Henry Ford expected his Model T to run on ethanol, a corn product. Eventually, in both Diesel's and Ford's cases, petroleum entered the picture and proved to be the most logical fuel source. This was based on supply, price and efficiency, among other things. Though it wasn't common practice, vegetable oils were also used for diesel fuel during the 1930s and 1940s.

It was in the 1970s and 1980s that the idea of using biofuels was revisited in the United States. One of the most important events occurred in 1970 with the passage of the Clean Air Act by the Environmental Protection Agency (EPA). This allowed the EPA to more closely regulate emissions standards for pollutants like sulfur dioxides, carbon monoxide, ozone and nitrogen oxides (NOx). This set the stage for developing cleaner-burning fuels. This also set standards for fuel additives.

Events overseas such as the 1973-1974 Arab oil embargo and the 1978-1979 Iranian Revolution, coupled with a decrease in domestic oil production, served to drive prices up. According to the U.S. Department of Energy's Energy Information Administration, U.S. crude oil imports were cut by 30% during the embargo, and "the world price of crude oil jumped from around $14 per barrel at the beginning of 1979 to more than $35 per barrel in January 1981 before stabilizing. Prices did not drop appreciably until 1983, when the world price stabilized between $28 and $29 per barrel."

With petroleum prices increasing, researchers began to look elsewhere. In August 1982, the first International Conference on Plant and Vegetable Oils was held in Fargo, N.D. This conference dealt with matters ranging from fuel cost and the effects of vegetable oil to fuel additives and extraction methods.

In 1990, the Clean Air Act was amended and included more stringent restrictions on vehicle emissions. The amendment introduced provisions for such things as increased oxygen content in gasoline (which lowers carbon monoxide emissions) and lower sulfur content in diesel fuels.

In 1992, the EPA passed the Energy Policy Act, or EPACT. This was aimed at increasing the amount of alternative fuel used by the U.S. government transportation fleets in order to reduce dependency on foreign oil. The 1998 EPACT amendment included using biodiesel fuel in existing government diesel vehicles as an acceptable alternative to purchasing alternative fuel vehicles, or AFVs, as stipulated in the original EPACT.

With all of these rules and regulations in place, it's understandable that any viable petroleum alternative would cause a clamor. But biodiesel isn't a perfect substitute for gasoline. We'll look at its pros and cons in the next sections.