What is Biodiesel?

Biodiesel is the name for a variety of ester-based oxygenated fuels made from
vegetable oils or animal fats.  The concept of using vegetable oil as a fuel
dates back to 1895 when Dr. Rudolf Diesel developed the first diesel engine to
run on vegetable oil. Diesel demonstrated his engine at the World Exhibition
in Paris in 1900 using peanut oil as fuel.

Emissions

Biodiesel is the first and only alternative fuel to have a complete evaluation
of emission results and potential health effects submitted to the U.S.
Environmental Protection Agency (EPA) under the Clean Air Act Section 211(b).
These programs include the most stringent emissions testing protocols ever
required by EPA for certification of fuels or fuel additives in the US. The
data gathered through these tests complete the most thorough inventory of the
environmental and human health effects attributes that current technology will
allow. A survey of the results is provided in the table below.

BIODIESEL EMISSIONS COMPARED TO CONVENTIONAL DIESEL

The overall ozone (smog) forming potential of biodiesel is less than diesel
fuel. The ozone forming potential of the speculated hydrocarbon emissions was
nearly 50 percent less than that measured for diesel fuel.
Sulphur emissions are essentially eliminated with pure biodiesel. The exhaust
emissions of sulphur oxides and sulfates (major components of acid rain) from
biodiesel were essentially eliminated compared to sulphur oxides and sulphate's
from diesel.

Criteria pollutants are reduced with biodiesel use. The use of biodiesel in an
unmodified Cummins N14 diesel engine resulted in substantial reductions of
unburned hydrocarbons, carbon monoxide, and particulate matter. Emissions of
nitrogen oxides were slightly increased.

Carbon Monoxide -- The exhaust emissions of carbon monoxide (a poisonous
gas) from biodiesel were 50 percent lower than carbon monoxide emissions
from diesel.

Particulate Matter -- Breathing particulate has been shown to be a human
health hazard. The exhaust emissions of particulate matter from biodiesel
were 30 percent lower than overall particulate matter emissions from diesel.

Hydrocarbons –The exhaust emissions of total hydrocarbons (a contributing  factor in the localized formation of smog and ozone) were 93 percent lower for biodiesel than diesel fuel.

Nitrogen Oxides -- NOx emissions from biodiesel increase or decrease
depending on the engine family and testing procedures. NOx emissions (a
contributing factor in the localized formation of smog and ozone) from pure
(100%) biodiesel increased in this test by 13 percent. However, biodiesel’s
lack of sulphur allows the use of NOx control technologies that cannot be
used with conventional diesel. So, biodiesel NOx emissions can be effectively
managed and efficiently eliminated as a concern of the fuel’s use.

Biodiesel reduces the health risks associated with petroleum diesel. Biodiesel
emissions showed decreased levels of PAH and nitrited PAH compounds which
have been identified as potential cancer causing compounds. In the recent testing,
PAH compounds were reduced by 75 to 85 percent, with the exception of
benzo(a)anthracene, which was reduced by roughly 50 percent. Targeted nPAH
compounds were also reduced dramatically with biodiesel fuel, with
2-nitrofluorene and 1-nitropyrene reduced by 90 percent, and the rest of the
nPAH compounds reduced to only trace levels.