This is the VOA Special English Economics Report.
What happens when a
food crop becomes a fuel crop? This is a question many people are trying to
answer as demand for ethanol increases. The issue is important not just to
farmers and the energy industry.
President Bush began a Latin American trip in Brazil Thursday for talks with
President Luiz Inacio Lula da Silva on subjects including biofuels. One goal is
to increase production of ethanol from sugar cane in Central American and
Caribbean nations.
Together, the United States and Brazil produce more than seventy percent of
the world's ethanol. In the United States, ethanol is produced mostly from corn,
or maize, and is also imported -- with a tariff that critics call protectionist.
Brazilian ethanol production is mainly from sugar
cane.
In Brazil, about forty percent of all motor fuel is ethanol, also known as
ethyl alcohol. Many Brazilians drive flex-fuel vehicles. These can use either
gasoline or ethanol. They are so successful, General Motors has stopped making
cars for the Brazilian market that only use gasoline.
In the United States, vehicles that run on pure ethanol are rare. But most
cars can run on a mixture of gasoline and ten percent ethanol. Some states
require an ethanol-gas mixture to cut pollution.
Yet the use of an important food crop for fuel has led to concerns. Ethanol
now makes up about twelve percent of all corn use in the United States. At
current growth rates, that could nearly double by 2015.
The American Midwest is known as the corn belt -- that is where most of the
nation's corn is grown.
Some people worry that strong demand may push up food prices and reduce
supplies of corn for food aid or farm animals.
Fuel researchers are exploring additional ways to make ethanol. One
possibility is to use the remains of corn plants left in the field after
harvest. This material is known as stover. But stover protects against soil loss
to wind and water.
Researchers are also developing "cellulosic biomass" -- things like grass and
tree bark, which are normally
considered waste.
The Department of Energy says the United States could produce more than one
billion tons of biomass a year. But the technologies to make ethanol from
biomass do not exist yet. The government says developing these new technologies
could take five to ten years.
And that's the VOA Special English Economics Report. I'm Mario Ritter.
sugar cane : 甘蔗
tree
bark
: 樹皮
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