4 de marzo del 2001
Va al Ejemplar actual
PNUMAPNUD
Edición Impresa
MEDIOAMBIENTE Y DESARROLLO
 
Inter Press Service
Buscar Archivo de ejemplares Audio
 
Home Page
Ejemplar actual
Reportajes
  Análisis
  Grandes Plumas
  Acentos
  Entrevista y P&R
  Ecobreves
  ¿Lo sabías?
  Tú puedes
  Libros
  Galería
Ediciones especiales
Gente de Tierramérica
  ¿Quiénes somos?
Geojuvenil
Espacio de debate hecho por jóvenes y para Jóvenes
Geojuvenil
 
Cambio Climático
Proyecto de soporte a negociación ambiental

Cambio Climático

  Inter Press Service
Principal fuente de información
sobre temas globales de seguridad humana
  PNUD
Programa de las Naciones Unidas para el Desarrollo
  PNUMA
Programa de las Naciones Unidas para el Medio Ambiente

 
Report

The Dream of a Clean Car

By Mario Osava*

Enthusiastic scientists in Brazil predict that within 20 years hydrogen will be used to fuel a quarter of all vehicles in the country.

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.


* Mario Osava is an IPS correspondent

 

Copyright © 2001 Tierramérica. Todos los Derechos Reservados

 

Traffic in Sao Paulo, Brazil. Credit: State Agency
  Traffic in Sao Paulo, Brazil. Credit: State Agency