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Supplies of ethanol have increased
tremendously in the last few years,
mainly for use as a source of renewable
fuel. Use in many countries is expected
to continue to rise at a rapid rate.
Ethanol is usually made by the fermentation
of a carbohydrate (starch, sugar or
cellulose) to the alcohol, followed
by distillation and other processing
to make it suitable for use as fuel,
solvent, chemical feedstock or for
alcoholic beverage consumption. Most
ethanol (approximately 70% of global
production) is derived from the fermentation of sugar crops, including sugarcane,
sugar beets or molasses. Brazil and many tropical countries use sugarcane or
molasses, while France, the largest producer in Europe, uses mainly sugar beets.
The United States and eastern Canada use mainly corn kernels; in western Canada,
wheat is the main feedstock. In China, corn, cassava and sweet potatoes are used.
In France and Italy, ethanol is produced from the waste products of wine manufacture.
Considerable research is being focused on developing processes that can produce
ethanol from low-cost, nonfood feedstocks. The industry is hoping to develop
economical cellulosic ethanol, derived from the fermentation of cheap forms of
biomass.
Any long-term forecast for global supply/demand for ethanol is speculative, as
actual growth will depend on a number of economic and technical factors, as well
as possible changes in legislative and regulatory policy. Governmental mandates
may be changed and/or waivers granted. The United States set goals for long-term
use of ethanol in 2005 and proceeded to revise them upwards in 2007. There is
no assurance that regulations will always be enforced, as there has already been
resistance to mandates in Japan, India, Thailand and other countries, which may
force governments to change policies. Developments in technology will also influence
ethanol demand; if processes can be developed that allow economical production
of cellulosic ethanol, the market will grow strongly. The United States set goals
for use of cellulosic ethanol and other "advanced" biofuels in 2007,
but at the same time, has waivers in place to change the mandates if the technology
cannot be developed economically and without harming the environment.
The following pie chart shows world consumption of ethanol:
Use of ethanol as
a fuel now accounts for 80–90%
of global consumption. The growing
market is use in motor fuels, where
ethanol serves to boost octane levels;
increase combustion efficiency, as
ethanol is an oxygenate that helps
reduces carbon monoxide, volatile
organic compounds, toxics and fine-particulate
emission from automotive exhaust;
extend supplies of gasoline; decrease
emissions of greenhouse gases; and
decrease dependency on imports of
crude oil or gasoline if the country
is not a producer of crude oil but
a producer of ethanol.
Several new projects have been announced
that will use ethanol as a feedstock
for chemical production in Brazil,
where the costs to produce ethanol
are the lowest in the world. In 2007,
Dow Chemical announced that it will
build a 350 thousand metric ton-per-year
polyethylene plant that uses ethylene
derived from ethanol as feedstock.
Braskem is evaluating a similar process
and Solvay will use ethanol to make
ethylene to make ethylene dichloride
(EDC)/vinyl chloride (VCM) and finally
polyvinyl chloride (PVC).
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