Environmental Engineering Reference
In-Depth Information
Biofuels
Farmers traditionally grow three Fs: food, feed, and fi ber. Now a
fourth F has been added: fuel. It is hard to scan a newspaper, maga-
zine, or popular science publication today without encountering an
article about biofuels. Global production of ethanol more than doubled
from 2004 to 2008, with the United States leading the way. Biofuel
production in 2008 was 8 billion gallons. The federal government is
pushing it, the agricultural lobby is in favor of it, and even the auto-
mobile industry wants it because it will decrease noxious emissions
from motor vehicles. However, the generation of biofuels is not all
benefi t according to environmentalists.
Ethanol
The energy bill passed by Congress in 2005 mandated that at
least 7.5 billion gallons of renewable fuel (ethanol and biodiesel) be
produced annually by 2012 and 36 billion by 2022. By 2008, annual
production was already almost 10 billion gallons (94 percent of it
ethanol), having risen from 4 billion in 2005. The 10 billion gallons was
7 percent of America's annual gasoline use of 140 billion gallons. Ethanol
plants have mushroomed across the nation like fungi in wet soil, espe-
cially in the Midwest, where most of the nation's corn, the foodstock
currently used in the United States for ethanol, is grown. As of June
2009, 180 ethanol refi neries were operating. This number is the equiva-
lent of 150 operating oil refi neries. When money is to be made, things
move fast.
Corn planting increased from 76 million acres in 2001-2002 to 85
million acres in 2008-2009 even as yields per acre were increasing, with
one-third of the 2009 crop scheduled for ethanol distilleries rather than
as feed for animals and other traditional sources. Corn prices doubled
between 2005 and 2009. The percentage of America's corn crop used
for ethanol was 5 percent in 2001, 14 percent in 2006, and 31 percent
in 2009-2010.
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Dedicating all current corn production to ethanol would
meet 12 percent of America's gasoline demand.
Many Americans wince when they become aware that 70 percent of
the nation's corn is fed to cattle, swine, and chickens rather than humans,
but at least the farm animals are food for humans. However, it appears
that soon farm animals may be relegated to second place as corn consum-
ers, and even less corn will be used for food. To avoid this possibility,
some companies are building ethanol plants next to cattle feeding opera-
tions, so that corn kernels can go through the ethanol distillery, and then
residues from the operation—basically corn minus the starch—can go
