By SP Times Staff Writer  November 19, 2005

What is biodiesel?

Biodiesel is a renewable diesel replacement fuel that is manufactured from plant oils and animal fats, such as soybean oil and recycled cooking oils. To manufacture biodiesel, these fats and oils are chemically removed to produce biodiesel and a glycerin coproduct. Biodiesel can be used pure (B100 or "neat" biodiesel) or in any concentration with petroleum-based diesel fuel to create a biodiesel blend.

What's the difference between biodiesel and ethanol?

Both are based on agricultural products. Biodiesel is a product based on vegetable oils. Ethanol is alcohol based, derived by distilling the alcohol from the sugars in plants like corn and sugar cane. Like ethanol, biodiesel can be used as a pure fuel or blended with petroleum in any percentage. But beware: whereas any blend of biodiesel can be used in a diesel engine, regular gasoline engines need modifications to run high blends of ethanol.

How much does it cost?

Retail, the national price for diesel in September was $2.81 per gallon. It was $2.90 for B20 biodiesel (20 percent biodiesel, 80 percent petroleum) and $3.40 per gallon for pure biodiesel. Distributor tax incentives could lower the price of B20 to be approximately the same as diesel.

What are the advantages of using biodiesel?

Biodiesel is a safe, biodegradable and cleaner burning alternative to petroleum-based diesel, and it is made from renewable resources grown here in the United States, reducing the country's dependence on imported oil. Effective November 1998, Congress approved the use of biodiesel as a way for company vehicle fleets to comply with the 1992 Energy Policy Act. The legislation allows fleets (federal, state and public utility fleets) to meet their alternative fuel vehicle purchase requirements simply by buying pure biodiesel and burning it in new or existing diesel vehicles in at least a 20 percent blend with diesel fuel.

Where can I get it?

Producers, distributors and retailers are listed on the Web site of the National Biodiesel Board - www.nbb.org - under Guide to Buying Biodiesel, or by calling the board toll-free at 1-800-841-5849. What about emissions? Is biodiesel cleaner than regular diesel?

Tests show the use of biodiesel in diesel engines results in substantial reductions of unburned hydrocarbons (67 percent reduction), carbon monoxide (48 percent reduction) and particulate matter (47 percent reduction) compared with emissions from diesel fuel. Emissions of nitrogen oxides stay the same or are slightly increased. The exhaust emissions of sulfur oxides and sulfates (major components of acid rain) are essentially eliminated compared with diesel.

Do I have to do anything special to my engine?

Blends of 20 percent biodiesel with 80 percent petroleum diesel (B20) can generally be used in unmodified diesel engines; however, users should consult their manufacturer and engine warranty statement. Biodiesel can also be used in its pure form (B100), but it may require certain engine modifications to avoid maintenance and performance problems and may not be suitable for wintertime use.

I hear there are tax credits available. Am I eligible?

The federal tax incentive is taken at the blender level, meaning petroleum distributors. They should pass their savings on to consumers, resulting in lower biodiesel prices.

Energy Department, Alternative Fuels: www.eere.energy.gov/afdc/altfuel/altfuels.html National Biodiesel Board: www.nbb.org or toll-free, 1-800-841-5849.

SOURCES: National Biodiesel Board, Department of Energy