|
Scientific study questions hydrogen use as fuel alternative
The Associated Press
Hydrogen fuel cells may not be the most environmentally friendly answer to America's dependence on foreign oil, according to a recent study led by a Los Alamos National Laboratory scientist.
Los Alamos researcher Thom Rahn headed a team of scientists from California universities and the National Center for Atmospheric Research in Boulder, Colo. Their study of the natural cycle of atmospheric hydrogen was published in a recent edition of the British science journal Nature.
While there are certain benefits to hydrogen power, Rahn said there may also be unforeseen consequences that need to be examined carefully before the energy technology replaces fossil fuels.
The reason scientists were interested in hydrogen's natural cycle was �because there are possibilities of perturbations in the future'' of the element,� Rahn said.
Proponents of a hydrogen-based economy powered by fuel cells argue the technology could reduce smog by replacing traditional fossil fuels and produce more efficient engines. Fuel cells convert hydrogen into electricity and heat.
Production of hydrogen near the Earth's surface could also damage the highest region of the atmosphere, or stratosphere, if escaped hydrogen accumulated, Rahn said. The hydrogen buildup could deplete the ozone layer near the earth's poles and increase global warming, he said.
�It is impossible to manufacture, store and transport hydrogen without at least some fractional loss (to the atmosphere)� because hydrogen molecules are so small and lightweight that they are tough to contain, he said.
Rahn and other Los Alamos researchers are studying how the atmosphere might respond to increased hydrogen and are establishing a baseline for further comparisons. Atmospheric effects similar to chloroflurocarbons The atmospheric effects of hydrogen are similar to those produced by chloroflurocarbons, which have been used as refrigerants and aerosol propellants, he said.
�Everyone thought that chloroflurocarbons were innocuous and nonreactive, and there were in the troposphere, but not in the stratosphere,� he said.
In the stratosphere, chloroflurocarbons contribute to the depletion of the ozone layer that protects the planet against the sun's harmful ultraviolet rays.
Rahn said more hydrogen may make it easier for some chemicals already present in the stratosphere to eat away at the ozone and contribute to global warming by increasing the amount of water vapor in the upper atmosphere.
Los Alamos atmospheric scientist Manvendra Dubey, who heads Rahn's research group at the lab, said hydrogen technology holds great potential for cleaner air and more efficient engines although more study is needed.
�With every new technology you have inadvertent consequences,� Dubey said.
| 