Environmental Engineering Reference
In-Depth Information
Comparison of Consumption
of Ethanol and Gasoline
cars. Presently, ethanol consumption by Brazilian
cars is as pure ethanol and gasohol, a mixture of
ethanol and gasoline, which can reduce oil con-
sumption by 12 percent. However, all the ethanol
produced is still not enough to replace domestic
oil consumption in Brazil. In 2005, Brazil con-
sumed 2 million barrels of oil per day compared
with 280,000 barrels of ethanol produced each
day (Thurmond, n.d.).
Dr. William Thurmond, author of “Ethanol
2020: A Global Market Survey”, stated his perspec-
tive “The global market for ethanol faces enormous
opportunities and transitional challenges over the
next ten years. A few issues hold the key to under-
standing the transitional nature of these challenges
and identifying the best prospects for long-term
growth opportunities.” (Thurmond, n.d.).
Dr. Thurmond identified three market-based
transitional generations of bio-fuel and ethanol
emerging at present. The first generation is based
on traditional domestic production - normally
grown and sold near geographically agricultural
areas. In this generation, the producers don't
receive many subsidies or commercial privileges
from the government. The production of ethanol
is limited to remote areas by local producers who
produce ethanol and used it locally for agriculture
(Thurmond, n.d.).
The second generation, according to Thur-
mond, is based on the emerging transition of
ethanol production facilities from the traditional
agricultural areas to new areas in coastal regions
in order to take advantage of import, export, multi-
feedstock and refinery co-location advantages.
This generation is also identified by the rapidly-
changing globalization of the ethanol trade and
leading competitive imported ethanol fuel to the
domestic market (Thurmond, n.d.).
The third generation is the transition emerging
from technologies and production processes such
as cellulosic ethanol and bio-diesel. The goal of
this generation is to effectively produce renewable
fuels for lower cost.
The Table 1 summarizes the advantages and disad-
vantages of ethanol and gasoline (Caldwell, n.d.).
The Emerging Technology of
Cellulosic Ethanol
Benefits of Cellulosic Ethanol
over Other Biofuels
Given the fact that we know how to produce ethanol
from sugar and corn, and given the availability of
vegetable oils such as canola and soy bean oils
that can either be burned directly or converted
to biodiesel, what advantage is there in trying to
turn a recalcitrant material like wood or grass into
cellulosic ethanol?
There are several answers to this question. By
looking at the economics of using food crops to
make alternative fuels, as well as the net energy
gained from the fuel after the fossil fuel required to
grow and process it have been taken into account,
a case can be made that corn ethanol and biodiesel
are not the best way to create energy from biomass.
And when the environmental impact of these
biofuels is examined more closely (particularly
their significance in reducing green house gases),
alternatives such as cellulosic ethanol made from
agricultural and forestry residues begin to look
more attractive (Bourne, 2007).
Corn Ethanol
Even though corn ethanol has paved the way
for other biofuels in the United States, and even
though the legislative push for it as an additive
in gasoline has been a boon to American corn
farmers, corn has always been first and foremost
a foodstuff for people and animals. By introducing
another competitive market for corn, the price of
this commodity has started to climb, increasing
production costs for ethanol producers and the
costs for cattle ranchers (Bourne, 2007).
