Alternative Fuel Sources - Hydrogen and Fuel Cells: Advances in Transportation and Power - page 82

duced is generally mixed in a ratio of 1-to-10 with gasoline to produce gas-
ohol. The mash, or debris, that is left behind contains all the original pro-
tein and is used as a livestock feed supplement. A bushel of corn provides
two and a half gallons of alcohol plus byproducts that can almost double
the corn's value. Ethanol is a renewable source of energy, but critics ques-
tion turning food-producing land into energy production. Cellulose etha-
nol eliminates the diversion of food crops to fuel. It can be produced from
agricultural residues which are often destroyed by burning.
Ethanol is a healthy industry in some parts of the United States and
the rest of the world. It is an alternative as an automobile fuel. Brazil has
a large ethanol industry, producing about three billion gallons each year
from sugar cane.
RENEWABLE FUEL STANDARD
The U.S. Environmental Protection Agency (EPA) has established the
Renewable Fuel Standard (RFS). The RFS was mandated by the Energy
Policy Act of 2005. It requires that by 2012, at least 7.5 billion gallons of re-
newable fuel be blended into motor vehicle fuel sold in the U.S.
The program is based on a credit trading system that provides a flex-
ible way to comply with the annual standard by allowing renewable fuels
to be used where they are most economical. By 2012, the program may cut
petroleum use by almost 4 billion gallons and reduce annual greenhouse
gas emissions by 13 million metric tons. This would be the equivalent of
removing about 2.4 million cars from the road.
By 2007, about 4% of all the fuel sold or dispensed to U.S. motorists
came from renewable sources, which is almost 5 billion gallons of renew-
able fuels. New and expanded plants now under construction are expect-
ed to push the annual production of ethanol well above this level.
The EPA will no longer require facilities that use carbohydrate feed-
stocks in producing ethanol to count fugitive emissions of regulated pol-
lutants. These are emissions that do not come from process stacks or vents.
This may allow some plants to expand production. It will also allow new
ethanol facilities to emit up to 250 tons of regulated pollutants per year
in areas that are not exceeding EPA's air quality standards and not in an
Ozone Transport Region, where ground-level ozone is a problem.
One source of ethanol is sugar cane or the molasses remaining after
the juice has been extracted. Other plants such as potatoes, corn and other