Frequently Asked Questions
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.
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 such as soybeans, its use decreases our dependence on foreign oil and contributes to our own economy.
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).
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 a 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.
Of the major exhaust pollutants, both unburned hydrocarbons and nitrogen oxides are
ozone or smog forming precursors. The use of biodiesel results in a substantial reduction
of unburned hydrocarbons. Emissions of nitrogen oxides are either slightly reduced or
slightly increased depending on the duty cycle of the engine and testing methods
used. Based on engine testing, using the most stringent emissions testing protocols
required by EPA for certification of fuels or fuel additives in the U.S., the overall ozone
(smog) forming potential of the hydrocarbon exhaust emissions from biodiesel is nearly
50 percent less than that measured for diesel fuel.
Can biodiesel help mitigate “global warming”?
Biodiesel is the best greenhouse gas mitigation strategy for today’s medium and heavy
duty vehicles. A 1998 biodiesel lifecycle study, jointly sponsored by the U.S. Department
of Energy and the U.S. Department of Agriculture, concluded biodiesel reduces net
carbon dioxide emissions by 78 percent compared to petroleum diesel. This is due to
biodiesel’s closed carbon cycle. The CO˛ released into the atmosphere when biodiesel
is burned is recycled by growing plants, which are later processed into fuel.
Does biodiesel cost more than other alternative fuels?
A federal tax incentive is expected to help lower the cost of biodiesel blends in both
taxable and tax exempt markets.
Additionally, when reviewing the high costs
associated with other alternative fuel systems, many fleet managers determine
biodiesel is their least-cost-strategy to comply with state and federal regulations. Use of
biodiesel does not require major engine modifications. That means operators keep
their same fleets, spare parts inventories, refueling stations and skilled mechanics
Do I need special storage facilities?
In general, the standard storage and handling procedures used for petroleum diesel
can be used for biodiesel. The fuel should be stored in a clean, dry, dark environment.
Acceptable storage tank materials include aluminum, steel, fluorinated polyethylene,
fluorinated polypropylene and teflon. Copper, brass, lead, tin, and zinc should be
avoided.
Can I use biodiesel in my existing diesel engine?
Biodiesel works in any diesel engine with few or no modifications 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 usage. The release of deposits may end
up in fuel filters initially, so fuel filters should be checked more frequently at first. Ensure
that only fuel meeting the biodiesel specification (D 6751) is used.
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 biodiesel with 80 percent petroleum diesel) has
demonstrated significant environmental benefits with a minimum increase in cost for
fleet operations and other consumers.
Is it approved for use in the U.S.?
Biodiesel is registered as a fuel and fuel additive with the Environmental Protection
Agency (EPA) and meets clean diesel standards established by the California Air
Resources Board (CARB). Neat (100 percent) biodiesel has been designated as an
alternative fuel by the Department of Energy (DOE) and the U.S. Department of
Transportation (DOT).
How much biodiesel has been sold in the US?
The National Biodiesel Board has released the following sales volumn estimates for the US:
2005 - 75 million gallons
2004 - 25 million gallons
2003 - 20 million gallons
2002 - 15 million gallons
2001 - 5 million gallons
2000 - 2 million gallons
1999 - 500,000 million gallons