http://dailynews.yahoo.com/h/nm/20000315/sc/science_energy_1.html
Wednesday March 15 2:20 PM ET
Cell Generates Electricity From Ordinary Fuels
By David Morgan
PHILADELPHIA (Reuters) - A tiny experimental fuel cell could lead to a
gleaming new horizon of clean energy that relies on fuels no more exotic than
the gasoline that runs the family car, researchers said Wednesday.
While policy-makers worldwide struggle to cope with pollution problems caused
by dirty and wasteful methods of energy production using combustion,
scientists at the University of Pennsylvania, who invented the device, say
their creation could be lighting homes within 10 years.
Their ultimate aim is to construct a prototype for fuel cells that can be
used to power buses, trucks and automobiles in coming decades.
The Penn fuel cell, less than a square centimeter (0.4 square inch) in size
and constructed from inexpensive materials, has proven capable of converting
the hydrocarbon molecules of diesel, gasoline, methane and butane into
electricity without producing dangerous fumes.
No Smoking
Aside from electricity and heat, the experimental cell produced only water
and carbon dioxide. Details of the breakthrough appeared in the journal
Nature.
``Until now, it has been said that any fuel will work in a fuel cell as long
as the fuel is hydrogen,'' said Raymond Gorte, a chemical engineering
professor at Penn who helped construct the device as part of a study funded
by the Chicago-based Gas Research Institute.
Hydrogen has proven too costly and too dangerous for widespread use. While
earlier studies have successfully generated electricity from methane, the
Penn project has developed an energy cell far more versatile and effective
than anything seen up to now.
Scientists view the electrochemical conversion process used by fuel cells as
the latest and most sophisticated juncture in an evolution of energy
technology that has led humankind from wood to coal to oil.
``By the end of the century, these fiery combustion processes may be
banned,'' warned Kevin Kendall of Britain's University of Birmingham, who
wrote an article in Nature accompanying the Penn team's results.
``Even now the trend is apparent: smoking is frowned upon; fires in forests
are not permitted; dirty vehicles are penalized; and a new regulation has
appeared in (Germany) defining ten parts per million of nitrogen oxides as
the upper level of effluent from fossil-fuel burners.''
High-Tech Battery
The Penn fuel cell is a kind of high-tech battery that combines oxygen and
hydrocarbon molecules to produce enough free electrons to generate
electricity. Unlike a battery, however, it does not run down or need
recharging as long as it is supplied with fuel.
Earlier versions ran into trouble because the electrochemical process caused
a buildup of carbon that soon ruined the cell. But the Penn team overcame the
problem by substituting different materials, for example, using a Cu-ceria
composite instead of zirconia for the cell's anode.
As a result, the cell was able to generate one-tenth of a kilowatt of
electricity and remain in operation for four days. The process occurred at a
temperature of 700 degrees C (1,292 F). Gorte said that equaled only half the
amount of heat used in combustion.
Gorte also said it would be some time before the fuel cell could be made
small enough and cheap enough for use in the automotive world.
But a portable generator for vacation cottages could be envisioned over the
next five to 10 years, he said, with larger units capable of powering
individual homes following shortly thereafter.
``It's much more efficient to produce the electricity on-site than it is to
make it miles away,'' he said.
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