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James Madison University Biodiesel

Biodiesel and Ethanol Fuel Use in Vehicles - Clarification on Common Misconceptions

Prior to trying any alternative fuel, consumers need to educate themselves. The large quantity of incomplete, and/or conflicting information circulating can be very confusing.


Biodiesel is an alternative to conventional diesel fuel. Biodiesel is used in a diesel engine. Biodiesel is made from a chemical refining process that is separate from the vehicle. The process includes hazardous chemicals, such as methanol.

Vegetable oil is not biodiesel! Vegetable oil is one of the possible inputs to the chemical process that produces biodiesel. Other common inputs used to make biodiesel are animal fats or oil recovered from crushed agricultural crops.

Only fuel that is ASTM certified is considered biodiesel. JMU purchases commercial biodiesel that meets ASTM standards and runs a blend of 5% biodiesel and 95% diesel fuel. Fuel that does not meet or exceed the specifications detailed in ASTM D-6751 can result in engine damage.

Commercially-available biodiesel is commonly blended with regular diesel fuel. A B5 blend is 5% biodiesel and 95% conventional diesel. A B20 blend is 20% biodiesel and 80% petroleum diesel. B100 is 100% biodiesel.

No vehicle modifications are usually necessary to run commercially-made B20 that meets ASTM standards in modern vehicles. However , some older vehicles may need hoses or seals replaced because of a reaction with the biodiesel.

Even if using ASTM-certified biodiesel, at blends higher than B20, you should also check with your supplier to confirm an additive has been used to support cold weather operation. Blends higher than B20 that are untreated may have cold weather issues.

Vehicle warranties often specify a maximum blend of biodiesel. Consumers need to check with vehicle manufacturers to be sure what blends are approved for a particular vehicle.

If someone is thinking of using vegetable oil without processing it into biodiesel (this is commonly called straight vegetable oil - SVO), or running B100, significant vehicle modifications will be required to the vehicle to process these fuels. Engine issues are very common with long-term use of straight vegetable oil and B100 that does not meet ASTM standards.

Research experiments on making biodiesel are conducted at JMU only by trained students under the supervision of scientists . Although we have come very close to achieving ASTM standards, we run our home-brew fuel only in our test engines as research projects.

When making biodiesel, JMU enforces strict safety in production. Hazardous chemicals are used in the biodiesel production process. This is a complex chemical process that needs to be conducted by trained people in proper facilities.

When making biodiesel, JMU properly disposes of the byproducts. The byproducts, such as glycerin, can contain some of the hazardous substances from the reaction and their handling and disposal is regulated. The Virginia Department of Environmental Quality can be contacted for more information.

For those considering small scale production, production and distribution of biodiesel requires permits to be obtained. As with commercial sale of anything, taxes must be paid. Chemicals used and produced in the process may be regulated in Virginia and the Department of Environmental Quality can be contacted for further information.

While biodiesel and ethanol are both alternative fuels, they are used in entirely different applications. While biodiesel is a substitute for diesel fuel, ethanol is a substitute for gasoline.

Further Information on Biodiesel

A scientific source of information on biodiesel fuel is “Biodiesel Handling and Use Guidelines” available free from the National Renewable Energy Laboratory at http://www.nrel.gov/vehiclesandfuels/npbf/feature_guidelines.html.


Ethanol is fuel is a similar chemical to the alcohol that many people drink, except that ethanol is highly purified and it is usually denatured (made toxic) by the addition of gasoline, nicotine, or other chemicals to prevent human consumption. It is similar to drinking alcohol in that it is made by converting sugars and starches into alcohol via fermentation.

Like biodiesel, ethanol is sold as a blended fuel . E10 is 10% ethanol/90% gasoline and can be used in a gasoline engine without modification. E85 is 85% ethanol/15% gasoline and is only be used in vehicles that are designated as ethanol or flex-fuel compatible. It is possible to retrofit vehicles to run on higher blends of ethanol (>15%) but requires significant vehicle modification. These modifications may affect vehicle warranties.

Ethanol is also subject to ASTM certification. Home-brewing of ethanol in the Commonwealth of Virginia requires distillation permits . Federal fuel distillation permits are also required and sales subject to taxes.

Cellulosic ethanol is different from conventional ethanol in that it is not made from sugar or starch, but rather from any cellulosic material. Cellulose is the most abundant organic molecule on Earth, and is the dominant component found in the roots, stalks, branches, leaves, and flowers of all plants. Cellulosic ethanol provides the potential to make fuel from a wide variety of agricultural waste residues, such as corn stalks and husks, rice hulls, wheat straw, saw dust, leaves, and grass clippings. It can also be used to convert municipal and industrial waste into fuel (construction waste, wood pulp, waste paper, cardboard, waste fabric, etc.) The Department of Energy has recently approved nearly $500 million for the production of the U.S. first Cellulosic Ethanol Production Facilities. Construction of these facilities will begin later in 2007.

For Further Information on Ethanol:

A scientific source of information on ethanol is the Renewable Fuels Association, http://www.ethanolrfa.org/. Safety and handling issues are discussed, as well as descriptions of both conventional and cellulosic ethanol production.

Disclaimer: The information included above is based on JMU’s educational experience and data provided by State and non-profit organizations. As part of our mission, JMU is disseminating information from our experience to the public and is not endorsing use or manufacture of any particular fuel.