Them proplem is of cource where are you going to get enough corn to produce
enough Ethanol to replace the 220,000,000 barrels of gasoline that is
consumed in the US every day? Where will the reformer be, in the vehicle or
in the fueling station. How will all the Ethanol get to the fueling
station, particcurly when one will need more Ethanol to produce the energy
of gasoline? Even if we answer all of those questions, who can afford the
car that has a $25,000 worth the fuel cels under the hood?
Teh best we car expect for ANY of the renewable fuels is that they will help
to slow the growth in the need for crude oil over the next fifty years. ;)
Now, this could actually elp to make hydrogen powered cars practical.
Powering cars from alcohol to hydrogen
ABC Science Online
Monday, 16 February 2004
Hydrogen-powered cars could be one step closer following the development
of a new compact reactor that produces hydrogen from a renewable energy
source, according to new U.S. research.
Gregg Deluga and fellow chemical engineers from the University of
Minnesota report how they generated hydrogen from alcohol in the current
issue of the journal Science.
"This process has great potential for low-cost H2 generation in fuel
cells for small portable applications where liquid fuel storage is
essential and where systems must be small, simple, and robust," the
Efficient production of hydrogen gas from renewable resources is one of
the key factors holding back the much mooted green 'hydrogen economy',
which includes cars running on hydrogen fuel cells.
Ethanol, an alcohol derived from grain like corn, has been one of the
renewable hydrogen sources researchers have explored. It is easy to
transport, relatively non-toxic and some vehicle engines already burn it
But Deluga's team used ethanol indirectly, to produce hydrogen for a
fuel cell the researchers said would be three times as efficient as
burning ethanol directly.
"Ethanol in car engines is burned with 20% efficiency, but if you used
ethanol to make hydrogen for a fuel cell, you would get 60% efficiency,"
the researchers wrote.
So far, the process used to convert ethanol to hydrogen, steam
reforming, is slower and takes up more space than the method Deluga
proposed, which is called partial oxidation, said Australian chemical
engineer Professor David Trimm from Sydney's University of New South
"A partial oxidation unit is much smaller than a steam reforming unit,"
he told ABC Science Online. "That's a definite advantage. And partial
oxidation is very much faster than steam reforming."
Deluga's method relies on rapid burning of an ethanol and water mixture
in the presence of a catalyst made from the metal rhodium. An automotive
fuel injector vapourises and mixes the ethanol-water fuel. This then
passes through a porous plug containing the catalyst and emerges mainly
as hydrogen gas and carbon dioxide.
The whole process generates heat and temperatures more than 700°C keep
the process going.
The reaction takes only 50 milliseconds and has none of the flames or
soot usually involved in ethanol combustion, the researchers said. When
coupled with a hydrogen fuel cell, the researchers said the new reactor
could generate enough hydrogen from 46 grams of ethanol for 350
watt-hours of electricity.
But they said that the final hydrogen gas produced was not yet pure
enough to be used in a car engine since it was contaminated with water.
The hydrogen was also contaminated with carbon monoxide, which presents
an environmental problem and can damage car engines.
"We believe that simple changes in the experimental conditions and
catalysts should be capable of reducing these undesired species by
factors of at least two," they said.
But Trimm argued that even such a reduction they would still have a long
way to go to meet environmental standards. "And what would happen to
hydrogen yield?" he asks. He also said that rhodium was a very expensive
Another way of producing hydrogen is by solar-powered hydrolysis of
water, a method Professor Charles Sorrell of the University of New South
Wales is investigating.
Sorrell believes the water hydrolysis method has the advantage over the
Deluga method by not producing greenhouse gases.
Nevertheless, he said it was "nice to see rapid advance to apparently
successful levels" and there were "no front runners" in terms of which
technology was ahead.
Sorrell has been involved in negotiations to develop a Co-operative
Research Centre for Hydrogen based at the University of New South Wales.
The production of renewable hydrogen is one area it would examine.
"Sometimes, when you're up to your butt in alligators, it's hard to
remember that the intial objective was to drain the swamp."
~ Unknown ~