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About
Ethanol
Ethanol is a distilled alcohol fuel currently made from plant sugars,
such as corn kernels and sugar cane. The two worldwide leaders in
ethanol production are the United States, which produces ethanol
mostly from corn, and Brazil, which produces ethanol from cane.
Much of the excitement about ethanol stems from (a) the potential
to produce very significant volumes of the fuel; and, (b) the potential
to produce ethanol from feedstocks other than corn kernels and cane
sugar. In the latter case, ethanol companies and independent researchers
are working on ways to break down starches into fermentable sugars,
so that almost any starch-based feedstock (wood and paper waste,
switch and other grasses, corn stover) could be used to produce
ethanol.
In 2005, the United States produced about 4 billion gallons of ethanol.
The industry is expected to be close to 6 billion gallons with a
couple years. The United States will surpass Brazil as the largest
producer in 2006.
About Biodiesel
Biodiesel is an ester-based refined vegetable oil. Fuel-grade biodiesel
(i.e. street legal) must be produced to strict industry specifications
(ASTM D6751).
Biodiesel must be refined, in part, to reduce the viscosity of the
oil to comply with today's diesel engines. Biodiesel can be refined
from traditional vegetable oils, such as canola and soy, as well
as waste grease from restaurants and food processing facilities.
One of the primary advantages of biodiesel is that it achieves significant
environmental gains at very low levels of use. A 2 percent biodiesel
blend (with 98 percent diesel) reduces emissions significantly,
while increasing the lubricity of diesel fuel by 30-50 percent.
Lubricity is important for Ultra Low Sulfur Diesel (ULSD) - required
for use in most areas in 2006 - because reducing sulfur content
greatly reduces the lubricity of diesel fuel.
In 2005, 85 biodiesel production facilities reported a cumulative
capacity of 580 million gallons per year. Another 65 companies have
reported plant construction plans, with an additional 13 reporting
upgrade plans. If these targets are met, the production capacity
of the U.S. biodiesel industry could approach 2 billion gallons
per year in 2008.
Other Renewable Fuels
There may be several other "renewable fuels" coming to market.
Ediesel is ethanol-blended diesel fuel. Many of the
benefits of biodiesel blends can be achieved with ethanol-blended
diesel fuel. Ethanol can also be added to biodiesel blends (i.e.
ethanol + biodiesel + diesel fuel) with positive environmental results.
Proponents of eDiesel are working on regulatory and certification
issues.
Renewable diesel is similar to biodiesel, except that
producers do not rely on transesterfication to refine the vegetable
oil into biodiesel. Instead, producers create a chemical reaction
(aided by heat) that allows the raw vegetable oil to blend with
petroleum diesel (the vegetable oil bonds to the hydrocarbon molecule).
Proponents (e.g. Neste Oil) claim that the resultant fuel has all
the benefits of biodiesel.
Biobutanol is butanol made from bio-based products.
Butanol is an alcohol with a 4-carbon structure. BP and Dupont partnered
to conduct research into biobutanol, announcing in 2006 that this
"advanced biofuel" will be made available in 2007. BP claims biobutanol
has the benefits of ethanol (i.e. bio-based, greenhouse gas reductions)
without some of the disbenefits (e.g. attracting water in pipelines,
incompatible with some cars at levels higher than 10 percent).
Please visit the Resource Center for any more technical questions
about renewable fuels. Click here. |
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