Here is the Study. Sorry it was Cal Tech instead of MIT. This is an
article published in Nature Magazine.
Hydrogen is NOT the big Answer touted by the Anti-Nuclear Crazies, and
others. 



Hydrogen fuel could widen ozone hole
Likely leaks blot green power's perfect reputation. 
13 June 2003 
PHILIP BALL 
 

A hydrogen economy could create bigger, longer-lasting ozone holes over
the poles, a new study claims.

If hydrogen catches on as a 'non-polluting' fuel for energy production,
leaks from its production and transport could increase the amount of the
gas in the atmosphere. This change would worsen ozone depletion,
calculate Yuk Yung and co-workers at the California Institute of
Technology in Pasadena.

In a world of imperfect technology, their research suggests, hydrogen is
not quite the perfect green fuel it is sometimes made out to be.
Although its environmental benefits would still far outweigh any
drawbacks.

Fuel Cells

Devices called fuel cells convert the energy from burning hydrogen
directly into electricity. Using these in place of internal combustion
engines to power vehicles would drastically reduce emissions of
greenhouse gases, which cause global warming, and cut pollutants such as
nitrogen oxides, carbon monoxide and small carbon particles.

The world's major automobile companies are currently exploring fuel-cell
technology. President George W. Bush has even pledged US$1.2 billion to
develop a commercially viable hydrogen-fuelled vehicle.

The idea of a broader hydrogen economy, with the gas fuelling other
power-generation demands still faces big hurdles - not least the problem
of making hydrogen without relying on fossil-fuel energy - but world
leaders are keen to see it happen.

Gas leaks

Yung's team estimates that around 10% of all hydrogen manufactured will
leak into the atmosphere during production, storage and transport.
Current losses are already greater than this.

If so, and if all fossil-fuel energy generation were to be replaced by
hydrogen fuel cells, around 60 million tonnes of human-made hydrogen
would leak into the atmosphere every year: roughly four times the
current amount. There are natural sources of hydrogen too, so this
increase would roughly double the total hydrogen input into the
atmosphere.

Being so light, hydrogen rises rapidly through the atmosphere. In the
upper reaches, or stratosphere, it reacts with oxygen to form water.

A hydrogen economy, say the researchers, would make the stratosphere
wetter. This would cool the lower stratosphere, particularly in the
polar regions, where most hydrogen is converted to water vapour.

This, they calculate, would disrupt the ozone layer, which protects the
Earth's surface from harmful ultraviolet light. It could bring about up
to 8% more depletion over the North Pole, and up to 7% more over the
South Pole.

Whether this will actually happen greatly depends on how quickly a
hydrogen economy is introduced. The use of ozone-depleting CFC
propellants and refrigerants has been largely discontinued in most
developed countries, and their concentrations in the atmosphere are
declining.

If it takes more than 50 years for hydrogen to become widely used as a
fuel, CFCs will have largely disappeared and ozone depletion will no
longer be a problem. By then, hydrogen transport and production might
also be less leaky.
  
References
NaTrompme, T. K., Shia, R.-L., Allen, M., Eiler, J. M. & Yung, Y. L.
Potential environmental impact of a hydrogen economy on the
stratosphere. Science, 300, 1740 - 1742, (2003). |Homepage| 
 

c Nature News Service / Macmillan Magazines Ltd 2003
 
  
 





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