Biodiesel F.A.Q.

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 no major modifications. Biodiesel is simple to use, biodegradable, nontoxic, and essentially free of sulfur and aromatics.

Is biodiesel used as a pure fuel or is it blended with petroleum diesel?
Biodiesel can be used as a pure fuel or blended with petroleum in any percentage. B20 (a blend of 20 percent by volume biodiesel with 80 percent by volume petroleum diesel) has demonstrated significant environmental benefits with a minimum increase in cost for fleet operations and other consumers.

Can unaltered vegetable oil be used in a diesel engine?
Biodiesel is made from a base stock of vegetable oil and requires no alterations to your vehicle. It is possible to run a diesel vehicle on straight, unaltered, vegetable oil, but a few minor alterations are necessary. Conversion information is available in "From the Fryer to the Fuel Tank: The Complete Guide to Using Vegetable Oil as an Alternative Fuel" by Joshua Tickell (Tickell Energy Consulting, 2000).

How do biodiesel emissions compare to petroleum diesel?
Biodiesel is the only alternative fuel to have fully completed the health effects testing requirements of the Clean Air Act. The use of biodiesel in a conventional diesel engine results in substantial reduction of unburned hydrocarbons, carbon monoxide, and particulate matter compared to emissions from diesel fuel. In addition, the exhaust emissions of sulfur oxides and sulfates (major components of acid rain) from biodiesel are essentially eliminated compared to diesel.

Can biodiesel help mitigate "global warming"?
A 1998 biodiesel lifecycle study, jointly sponsored by the US Department of Energy and the US Department of Agriculture, concluded biodiesel reduces net CO2 emissions by 78 percent compared to petroleum diesel. This is due to biodiesel’s closed carbon cycle. The CO2 released into the atmosphere when biodiesel is burned is recycled by growing plants, which are later processed into fuel.

Where can I buy biodiesel? Does it cost more than conventional diesel?
Biodiesel is available for sale at the Biofuel Oasis in Berkeley (check website for hours). There are a number of bulk biodiesel dealers; contact the National Biodiesel Board for more information. It is also possible to manufacture your own biodiesel (see contacts below). Biodiesel can cost up to twice as much at the pump as petroleum diesel. As demand and commercial production of biodiesel increases, prices are expected to drop dramatically. As an alternative fuel, biodiesel is very competitively priced.

Can I use biodiesel in my existing diesel engine?
Biodiesel can be operated in any diesel engine with little or no modification to the engine or the fuel system. Biodiesel has a solvent effect that may release deposits accumulated on tank walls and pipes from previous diesel fuel storage. The release of deposits may clog filters initially and precautions should be taken. Ensure that only fuel meeting the biodiesel specification is used.

(For a more complete list of frequently asked questions, please contact the National Biodiesel Board. Much of the above information reflects research and writing done by NBB staff.)

BIODIESEL RESOURCES
For more information on purchasing biodiesel, producing your own biodiesel, or converting a vehicle to run on straight vegetable oil, read From the Fryer to the Fuel Tank: The Complete Guide to Using Vegetable Oil as an Alternative Fuel by Joshua Tickell (Tickell Energy Consulting, 2000) or visit the following websites.

There are also several email lists dedicated to small and large scale biodiesel production and use.

For information on local environmentalists involved in the small-scale production of biodiesel, write to biodiesel@ecologycenter.org.