Oklahoma State University


Canola Quality Feed Stock for Biodiesel   
Answering Questions about Biodiesel
Canola Biodiesel and the Environment Basic Biofuels Information Guide
Canola Lifecycle Biodiesel Analysis  


What is biodiesel?
Biodiesel is the name of a clean burning alternative fuel, produced from domestic, renewable resources. Biodiesel contains no petroleum, but it can be blended at any level with petroleum diesel to create a biodiesel blend. It can be used in compression-ignition (diesel) engines with little or no modifications. Biodiesel is simple to use, biodegradable, nontoxic, and essentially free of sulfur and aromatics. Soybean oil is currently the leading source of virgin vegetable oil used for biodiesel feedstock in the United States.

How is biodiesel made?
Biodiesel is made through a chemical process called transesterification whereby the glycerin is separated from the fat or vegetable oil. The process leaves behind two products -- methyl esters (the chemical name for biodiesel) and glycerin (a valuable byproduct usually sold to be used in soaps and other products).

Is Biodiesel the same thing as raw vegetable oil?
Fuel-grade biodiesel must be produced to strict industry specifications (ASTM D6751) in order to insure proper performance. Biodiesel is the only alternative fuel to have fully completed the health effects testing requirements of the 1990 Clean Air Act Amendments. Biodiesel that meets ASTM D6751 and is legally registered with the Environmental Protection Agency is a legal motor fuel for sale and distribution. Raw vegetable oil cannot meet biodiesel fuel specifications, it is not registered with the EPA, and it is not a legal motor fuel.

What are Biodiesel blends?

Biodiesel blends refer to a fuel that is composed of part pure biodiesel and part petroleum diesel. For example, B100 is pure biodiesel and B20 is a blend of 20% biodiesel and 80% diesel fuel. It is recommended that biodiesel be used in a blend of 20% biodiesel and 80% #2 diesel (B20) for warm weather operation. In cold weather operation the diesel portion would include #1 diesel fuel and possibly cold flow fuel additive enhancers. The B20 blend provides a superior diesel fuel because it has a higher cetane rating, superior lubricity, significant emission reductions, virtually eliminates visible soot emissions, less toxic emissions, and similar fuel consumption, horsepower, and torque -- and the fuel smells cleaner.

Why should I use biodiesel?
Biodiesel is better for the environment because it is made from renewable resources and has lower emissions compared to petroleum diesel. It is less toxic than table salt and biodegrades as fast as sugar. Since it is made in the USA from renewable resources its use decreases our dependence on foreign oil and contributes to our own economy.

Where do I get biodiesel?
Biodiesel is available nationwide. It can be purchased directly from biodiesel producers and marketers, distributors, or at a handful of public pumps throughout the nation.

Bio-Diesel versus Petroleum Diesel

A similar study was co-sponsored by the United States Department of Energy and the USDA, entitled, "Life Cycle Inventory of Biodiesel and Petroleum Diesel for Use in an Urban Bus."

The study, published in May 1998, states; "Biodiesel yields 3.2 units of fuel product energy for every unit of fossil energy consumed in its life cycle." The report continues, "By contrast, Petroleum diesel's life cycle yields only 0.83 units of fuel energy per unit of fossil energy consumed." According to this analysis, the energy yield of biodiesel is (3.2/0.83) 280 percent greater than petroleum diesel fuel.


 Energy Balance/Energy Life Cycle Inventory 


* Energy yield

Net Energy (loss) or gain



(19.5 percent)



(15.7 percent)



34 percent



220 percent

* Life cycle yield in liquid fuel Btus for each Btu of fossil fuel energy consumed.


The positive energy ratio displayed by ethanol and biodiesel is accounted for by the contribution of solar energy collected by the crop from which the fuel is made. This energy is considered "renewable" because a new crop is raised each year. Fossil fuels, on the other hand, originate from fossilized plants and animals stored beneath the earth's surface in a process that took millions of years.

The U. S. economy relies heavily on diesel-powered vehicles for transportation and industry.

  • Diesel represents 20% of all US transportation fuel consumption, or 56 billion gallons per year.
  • Diesel engines provide the power to move 94% of all freight in the U.S.
  • Diesel is used in 95% of all transit buses and heavy construction machinery.
  • Every day, diesel power transports 14 million children to school, moves 18 million tons of freight and moves 14 million U.S. commuters via bus.

Biodiesel offers similar power to diesel fuel.
One of the major advantages of biodiesel is the fact that it can be used in existing engines and fuel injection equipment with little impact on operating performance. Biodiesel has a higher cetane number than U.S. diesel fuel, which makes it ignite faster, with less engine noise. In over 15 million miles of in-field testing, biodiesel showed similar fuel consumption, horsepower, torque, and haulage rates as conventional diesel fuel.

Biodiesel provides more lubricity than petroleum diesel.
Lubricity - or the ability to reduce friction -- reduces wear and tear on the engine, and ultimately the cost of maintaining diesel fleets. Even biodiesel levels below 1% can provide up to a 65 percent increase in lubricity in distillate fuels. Mandated EPA reductions of sulfur by the year 2006 will reduce the lubricity of petroleum diesel fuels and require an additive; biodiesel can fill that role, even at very low percentages, such as B2, or 2% biodiesel.

Biodiesel in cold weather.

Cold weather can cloud and even gel any diesel fuel, including biodiesel. Users of a 20 percent biodiesel blend will experience an increase of the cold flow properties (cold filter plugging point, cloud point, pour point) of approximately 3 to 5° Fahrenheit. Users implement the same solutions as they would with Number 2 diesel fuel: blend with Number 1 diesel (kerosene), use cold flow enhancing additives, turn on fuel filter or fuel line heaters, or store vehicles in or near a building.

Engine Warranties
Most major engine companies have stated formally that use of blends up to B20 will not void their parts and workmanship warranties.

Biodiesel potential to reduce foreign oil consumption.
The National Renewable Energy Laboratory, which studies the technology and market potential of alternative fuels, estimates the total market potential of biodiesel -- using current technology and agricultural capacity -- to be 1.5 billion gallons. A biodiesel market at this level could replace 10% of current on-road U.S. diesel consumption.

It is estimated that 53% of US dollars spent on crude oil leave the country, contributing to huge trade deficits and jeopardizing our national security through the vulnerability of critical energy supplies.

The National Biodiesel Board has published the following rationale for biodiesel:

"With agricultural commodity prices approaching record lows, and petroleum prices approaching record highs, it is clear that more can be done to utilize domestic surpluses of vegetable oils while enhancing our energy security. Because biodiesel can be manufactured using existing industrial production capacity, and used with conventional equipment, it provides substantial opportunity for immediately addressing our energy security issues. If the true cost of using foreign oil were imposed on the price of imported fuel, renewable fuels, such as biodiesel, probably would be the most viable option. For instance, in 1996, it was estimated that the military costs of securing foreign oil was $57 billion annually. Foreign tax credits accounted for another estimated $4 billion annually and environmental costs were estimated at $45 per barrel. For every billion dollars spent on foreign oil, America lost 10,000 - 25,000 jobs."

Are there any negatives?
Of course. There is no perfect fuel.
1) Primarily that it's not readily available in much of the nation. Yet consumption continues to increase, so hopefully availability will change soon.

2) Biodiesel will clean your injectors and fuel lines. If you have an old diesel vehicle, there's a chance that your first tank or two of biodiesel could free up all the accumulated crud and clog your fuel filter.

3) It has a higher gel point. B100 (100% biodiesel) gets slushy a little under 32°F. But B20 (20% biodiesel, 80% regular diesel - more commonly available than B100) has a gel point of -15°F. Like regular diesel, the gel point can be lowered further with additives such as kerosene (blended into winter diesel in cold-weather areas).

4) Old vehicles (older than mid-90s) might require upgrades of fuel lines (a cheap, easy upgrade), as biodiesel can eat through certain types of rubber. Almost all new vehicles should have no problem with biodiesel.

5) The one emission that goes up with biodiesel is NOx. NOx contributes to smog. A increase (up to 15%) in NOx is greatly offset by the reduction in all other emissions and the major reduction in greenhouse gasses.


Thanks to blue sun BIODIESEL, biodiesel.org and other government publications.


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