Asked Questions From Biodiesel.Org
What is biodiesel?
Biodiesel is the name of a clean burning alternative fuel produced from
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.
n—a fuel composed of mono-alkyl esters of long chain fatty acids derived
from vegetable oils or animal fats, designated B100, and meeting the
requirements of ASTM (American Society for Testing & Materials) D 6751.
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
B20 (a blend of 20 percent biodiesel with 80 percent petroleum diesel) has
demonstrated significant environmental benefits with a minimum increase in
fleet operations and other consumers.
Is it approved for use in the
Biodiesel is registered as a fuel and fuel additive with the Environmental
Agency (EPA) and meets clean diesel standards established by the
Resources Board (CARB). Neat (100 percent) biodiesel has been designated
alternative fuel by the Department of Energy (DOE) and the U.S. Department
How do biodiesel emissions
compare to petroleum diesel?
Biodiesel is the only alternative fuel to have fully completed the health
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
protocol 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 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
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.