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RIO DE JANEIRO - The challenge
of finding an environmentally healthy and economically
viable fuel is almost an obsession among experts in
Brazil. In addition to sugarcane alcohol, which has
been used in cars here since the 1970s, hydrogen,
methane gas, vegetable oils and various combinations
are being tested or can already be found in vehicle
fuel tanks.
The most important project
under development involves hydrogen, a ''clean'' fuel
that has for over a century been considered the energy
source of the future. Its time has come, as it is
increasingly needed in this world that is being poisoned
by emissions from petroleum-derived fuels.
Appropriate technology
exists for using hydrogen as a fuel for cars, at a
cost greater than diesel but less than the electricity
used by a trolley, according to studies conducted
between 1997 and 2000, says Marcio Schettino, superintendent
of development for Sao Paulo's Metropolitan Urban
Transport Enterprise (EMTU).
In a second phase, to begin
in the coming months, the technology will be tested
for commercial use. Eight city buses fueled by hydrogen
will circulate throughout Sao Paulo for four years,
until traveling a combined total of one million kilometers.
The number of vehicles
involved in the test could later expand to 100 or
200, if the system proves efficient. That is, if the
technology obtained in the laboratory functions in
the streets and confirms the predicted costs.
The Ministry of Mining
and Energy project being conducted by EMTU is one
of the most advanced in the world, Schettino told
Tierramérica. It is funded by resources from the Brazilian
government and the Global Environment Facility, and
has technical cooperation from the United Nations
Development Program (UNDP).
The new bus is electric,
but obtains energy from fuel cells, a generator installed
in the vehicle that transforms hydrogen into electricity.
The greatest challenge
is producing hydrogen, which is not found in nature
in its free state. It must be obtained from water
through a process of electrolysis, which itself consumes
a great deal of energy and complicates the economic
and environmental viability of the project.
The Brazilian experts propose
conducting the electrolysis process in the early mornings
when energy consumption and prices are at their lowest.
Hydrogen will be at a
competitive price by 2007, and within 20 years will
be used by 25 percent of all cars, predict the specialists.
''Ecological diesel''
Curitiba, capital of the
southern state of Paraná, is seeking immediate alternatives
to improve the urban environment. Since December 30
buses propelled by ''ecological diesel'' have been
circulating in this city of 1.3 million people.
This special fuel is a
mixture of traditional diesel with 11.2 percent anhydrous
alcohol and 2.6 percent of an additive called AEP-102,
derived from soy.
Previous tests with two
buses, which traveled some 100,000 km using this mixture,
emitted 43 percent less particulate mass than vehicles
fueled by conventional diesel, reports Elcio Luiz
Karaz, head of Curitiba Urbanization, the firm in
charge of city transport.
The goal is to gradually
expand the use of the mixture to 2,600 passenger transport
buses in Curitiba, he told Tierramérica.
But ''ecological diesel''
damages the electronic fuel injection system in the
vehicles, admits Karaz. In addition, it only reduces
carbon dioxide emissions by 0.7 percent, the gas scientists
agree is most responsible for what is known as the
greenhouse effect.
In Rio de Janeiro, nearly
all taxis use methane gas, a more economical fuel
than gasoline. But the environmental advantages of
it are lost because the improper adaptation of the
vehicle for methane gas renders the electronic control
of the engine useless, which is itself a mechanism
intended to reduce gas emissions, explained Manuel
Paulo de Toledo, head of the Sao Paulo State Company
of Environmental Technology.
Some 250 buses use methane
in Sao Paulo, a metropolis of 10 million that suffers
high levels of air pollution. There are automobiles
manufactured especially to use this gas, but their
additional cost is double that of adapting a car at
a mechanic's shop that uses inexpensive and anti-environmental
parts, Toledo complained.
Sugarcane alcohol, meanwhile,
by the 1980s had become the fuel of more than 90 percent
of the cars manufactured in Brazil. But the program,
initiated following the oil crisis of 1973, is in
danger of disappearing because the subsidies that
maintain it are drying up and because of unstable
fuel supplies and, as a result, unstable prices.
When sugar prices rise,
the companies in the industry abandon fuel production
because the raw material, the sugarcane itself, is
the common denominator of both products.
But the fuel alcohol program
could be reactivated and return to the level of the
1980s, driven by the need to reduce emissions of greenhouse
gases, which are causing global warming, commented
Suzana Kahn Ribeiro, researcher at the Federal University
of Rio de Janeiro.
Cane alcohol releases some
greenhouse gases, but the sugarcane fields also absorb
them. The fuel production could therefore be financed
by the Clean Development Mechanism (CDM) of the Kyoto
Protocol (1997), under the Framework Convention on
Climate Change, according to a project co-authored
by Kahn Ribeiro. Though it has not yet been completely
defined, the CDM is a channel through which an industrialized
country can meet its emissions-reduction targets by
financing a ''clean'' project in the developing South.
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