Now, this could actually elp to make hydrogen powered cars practical.
Powering cars from alcohol to hydrogen
Anna Salleh
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
researchers wrote.
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
directly.
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
Wales.
"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
metal.
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 ~
Mike Hunter - 25 Apr 2006 01:02 GMT
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. ;)
mike hunt
Now, this could actually elp to make hydrogen powered cars practical.
Powering cars from alcohol to hydrogen
Anna Salleh
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
researchers wrote.
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
directly.
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
Wales.
"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
metal.
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 ~
Paradox - 25 Apr 2006 02:18 GMT
Its such a joke that the middle east has so much of the worlds oil reserves,
nobody would give a crap about them if they didn't, and the whole area would
be as poor as africa.
> 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
[quoted text clipped - 104 lines]
> remember that the intial objective was to drain the swamp."
> ~ Unknown ~
Spam Hater - 25 Apr 2006 09:29 GMT
> Ethanol, an alcohol derived from grain like corn, has been one of the
> renewable hydrogen sources researchers have explored. It is easy to
[quoted text clipped - 10 lines]
> ethanol to make hydrogen for a fuel cell, you would get 60% efficiency,"
> the researchers wrote.
An engineering friend and I both concluded that it's better to just burn
the hydrogen in an IC engine.
Those fuel cells are still very expensive and present a number of
maintenance problems particularly with extreme weather.
By the way I live 1 km from the industry leading fuel cell research
house- Ballard Power. Unfortunately they are struggling, another top
management change recently.
http://www.ballard.com/
Their promises of a practical working fuel cell engine is always several
years in the future.
http://www.h2fc.com/news/index.shtml
They almost had a BIG BLOWUP a year ago. The truck delivering hydrogen
had the hose come off and they had a serious fire at the hose end. A
0.5 KM radius area was evacuated for about 12 hrs. until the hydrogen
burned off. Firemen were there hosing it down to avoid the whole truck
blowing up.
Mike Hunter - 25 Apr 2006 19:00 GMT
GM exhibited an experimental vehicle, at the NYC International car show, in
2005 that had an 320 HP V6 IC engine, designed to burn hydrogen. The future
standard car will more likely be such a vehicle, with an on board reformer
that will produce hydrogen from gasoline. No new, trillion dollar,
distribution will need to be built. The hydrogen will burn cleaner and far
more efficiently than gasoline. In addition only one type of gasoline will
need to be refined, store or transported. No additive will be needed to
suit the various environuts. Refineries will not need to crack and thus
produce less gasoline and get more of the profitable carbon stock out of the
crude. Overall that should reduce the cost of production dramatically and
lead to lower retail price to consumers
mike hunt
> An engineering friend and I both concluded that it's better to just burn
> the hydrogen in an IC engine.
[quoted text clipped - 16 lines]
> burned off. Firemen were there hosing it down to avoid the whole truck
> blowing up.
Nomen Nescio - 25 Apr 2006 22:50 GMT
The President went before the corn producers today and delivered an awe
inspiring speech touting ethanol. He's a real fan of alternative fuels.
Going one step further by reforming ethanol to yield hydrogen makes an
awful lot of sense, except it leaves a carbon residue. EtOH = H + CO (non
balanced). Somebody should bring Mr. Bush up to date on this latest twist
to break our addiction to oil; it'll give him the goose bumps!
A much better approach is to use the reformer to extract H^2 from H^2O!
Using that process, we could simply fill our fuel tanks with water and
*burn* it in our internal combustion engines! The only residue from this
conversion is pure oxygen, sort of like having an Ionic Breeze inside your
muffler. This technology is not new, having been first demonstrated in the
1949 movie, Free for All. In the movie, Robert Cummings drops a tablet in
a barrel of water and it instantly becomes high-test fuel for his outboard
motor. Folks, we're talking here a penny per gallon gasoline. Somebody
should show Mr. Bush this film while he's hot on gas; it'll give him a
hard-on!