Posted on 05/17/2007 4:09:52 AM PDT by saganite
WEST LAFAYETTE, INDIANA, USA -- A Purdue University engineer has developed a method that uses an aluminum alloy to extract hydrogen from water for running fuel cells or internal combustion engines. The technique could be used to replace gasoline, though it is not quite cost-competitive yet.
The method makes it unnecessary to store or transport hydrogen - two major challenges in creating a hydrogen economy, said Jerry Woodall, a distinguished professor of electrical and computer engineering at Purdue who invented the process.
"The hydrogen is generated on demand, so you only produce as much as you need when you need it," said Woodall, who presented research findings detailing how the system works during a recent energy symposium at Purdue.
The technology could be used to drive small internal combustion engines in various applications, including portable emergency generators, lawn mowers and chain saws. The process could, in theory, also be used to replace gasoline for cars and trucks, he said.
Hydrogen is generated spontaneously when water is added to pellets of the alloy, which is made of aluminum and a metal called gallium. The researchers have shown how hydrogen is produced when water is added to a small tank containing the pellets. Hydrogen produced in such a system could be fed directly to an engine, such as those on lawn mowers.
"When water is added to the pellets, the aluminum in the solid alloy reacts because it has a strong attraction to the oxygen in the water," Woodall said.
This reaction splits the oxygen and hydrogen contained in water, releasing hydrogen in the process.
The gallium is critical to the process because it hinders the formation of a skin normally created on aluminum's surface after oxidation. This skin usually prevents oxygen from reacting with aluminum, acting as a barrier. Preventing the skin's formation allows the reaction to continue until all of the aluminum is used.
The waste products are gallium and aluminum oxide, also called alumina. Combusting hydrogen in an engine produces only water as waste.
As a catalyst, the gallium is not consumed, and hence does not need to be replenished. The alumina can be recharged in a separate process, preferably using renewable energy.
The Purdue Research Foundation holds title to the primary patent, which has been filed with the U.S. Patent and Trademark Office and is pending. An Indiana startup company, AlGalCo LLC., has received a license for the exclusive right to commercialize the process.
Woodall discovered that liquid alloys of aluminum and gallium spontaneously produce hydrogen if mixed with water while he was working as a researcher in the semiconductor industry in 1967. The research, which focused on developing new semiconductors for computers and electronics, led to advances in optical-fiber communications and light-emitting diodes, making them practical for everything from DVD players to automotive dashboard displays. That work also led to development of advanced transistors for cell phones and components in solar cells powering space modules like those used on the Mars rover, earning Woodall the 2001 National Medal of Technology from President George W. Bush.
"I was cleaning a crucible containing liquid alloys of gallium and aluminum," Woodall said. "When I added water to this alloy - talk about a discovery - there was a violent poof. I went to my office and worked out the reaction in a couple of hours to figure out what had happened. When aluminum atoms in the liquid alloy come into contact with water, they react, splitting the water and producing hydrogen and aluminum oxide.
"Gallium is critical because it melts at low temperature and readily dissolves aluminum, and it renders the aluminum in the solid pellets reactive with water. This was a totally surprising discovery, since it is well known that pure solid aluminum does not readily react with water."
"No toxic fumes are produced," Woodall said. "It's important to note that the gallium doesn't react, so it doesn't get used up and can be recycled over and over again. The reason this is so important is because gallium is currently a lot more expensive than aluminum. Hopefully, if this process is widely adopted, the gallium industry will respond by producing large quantities of the low-grade gallium required for our process. Currently, nearly all gallium is of high purity and used almost exclusively by the semiconductor industry."
Woodall said that because the technology makes it possible to use hydrogen instead of gasoline to run internal combustion engines it could be used for cars and trucks. In order for the technology to be economically competitive with gasoline, however, the cost of recycling aluminum oxide must be reduced, he said.
"Right now it costs more than $1 a pound to buy aluminum, and, at that price, you can't deliver a product at the equivalent of $3 per gallon of gasoline," Woodall said.
However, the cost of aluminum could be reduced by recycling it from the alumina using a process called fused salt electrolysis. The aluminum could be produced at competitive prices if the recycling process were carried out with electricity generated by a nuclear power plant or windmills. Because the electricity would not need to be distributed on the power grid, it would be less costly than power produced by plants connected to the grid, and the generators could be located in remote locations, which would be particularly important for a nuclear reactor to ease political and social concerns, Woodall said.
"The cost of making on-site electricity is much lower if you don't have to distribute it," Woodall said.
The approach could enable the United States to replace gasoline for transportation purposes, reducing pollution and the nation's dependence on foreign oil. If hydrogen fuel cells are perfected for cars and trucks in the future, the same hydrogen-producing method could be used to power them, he said.
"We call this the aluminum-enabling hydrogen economy," Woodall said. "It's a simple matter to convert ordinary internal combustion engines to run on hydrogen. All you have to do is replace the gasoline fuel injector with a hydrogen injector."
Even at the current cost of aluminum, however, the method would be economically competitive with gasoline if the hydrogen were used to run future fuel cells.
"Using pure hydrogen, fuel cell systems run at an overall efficiency of 75 percent, compared to 40 percent using hydrogen extracted from fossil fuels and with 25 percent for internal combustion engines," Woodall said. "Therefore, when and if fuel cells become economically viable, our method would compete with gasoline at $3 per gallon even if aluminum costs more than a dollar per pound."
The hydrogen-generating technology paired with advanced fuel cells also represents a potential future method for replacing lead-acid batteries in applications such as golf carts, electric wheel chairs and hybrid cars, he said.
The technology underscores aluminum's value for energy production.
"Most people don't realize how energy intensive aluminum is," Woodall said. "For every pound of aluminum you get more than two kilowatt hours of energy in the form of hydrogen combustion and more than two kilowatt hours of heat from the reaction of aluminum with water. A midsize car with a full tank of aluminum-gallium pellets, which amounts to about 350 pounds of aluminum, could take a 350-mile trip and it would cost $60, assuming the alumina is converted back to aluminum on-site at a nuclear power plant.
"How does this compare with conventional technology? Well, if I put gasoline in a tank, I get six kilowatt hours per pound, or about two and a half times the energy than I get for a pound of aluminum. So I need about two and a half times the weight of aluminum to get the same energy output, but I eliminate gasoline entirely, and I am using a resource that is cheap and abundant in the United States. If only the energy of the generated hydrogen is used, then the aluminum-gallium alloy would require about the same space as a tank of gasoline, so no extra room would be needed, and the added weight would be the equivalent of an extra passenger, albeit a pretty large extra passenger."
The concept could eliminate major hurdles related to developing a hydrogen economy. Replacing gasoline with hydrogen for transportation purposes would require the production of huge quantities of hydrogen, and the hydrogen gas would then have to be transported to filling stations. Transporting hydrogen is expensive because it is a "non-ideal gas," meaning storage tanks contain less hydrogen than other gases.
"If I can economically make hydrogen on demand, however, I don't have to store and transport it, which solves a significant problem," Woodall said.
self-ping for later
More like $1.5 - $2 Billion and 5-6 years. A coal fired plant the same size cost around $1 billion and takes 4-5 years to build. Coal or nuclear are to only real options for large baseload power plants.
Yes, but Liquid Plummer is rarer than gasoline.
Gasoline would have to cost $9 a gallon for solar power to make sense... And that $9 would be spent on a manufacturing and maintenance project that itself is polluting. So for now, solar power wastes money and destroys the environment faster than gasoline.
Actually I don't think it sounds all that great.
but people should think things entirely through instead of being so casual about nuclear power....
My point too. The energy has to come from someplace. The likelihood of getting even 2 or 3 nucs approved and financed in the next few years is about zilch. Ga Power's Plant Vogel (PWR) was one of the last to go on line, and it cost in excess of $10 billion and ran over time due to the constantly changing nuclear regulations.
Aluminum is just an energy carrier. You could run a car on Calcium carbide and water too. BFD in this case the calcium carbide is the energy carrier.
If you just built a solar field around this "recycling" plant, the plant operates when the sun shines. When the sun does not shine, the plant does not operate.
The problem with solar and wind on the electric grid is twofold. One, they can't be called on demand so other conventional plants have to be kept on stand-by for times when the sun does not shine or the wind does not blow. There capacity is less than 40%. The second problem is connecting them to the grid. These plants are very land intensive and are generally built in remote areas. It costs over $1 million per mile to build transmission lines to hook these facilities to the grid.
With a processing plant with it's own dedicated solar or wind farm, the 40% capacity might not be a problem and there is no issue with long distance transmission lines.
Please Freep Mail me if you'd like on/off
Personally, I love renewables. I save about $1K per year by heating with wood. Unfortunately, a large scale switch to renewables is a recipe for raping the planet.
This is not an indictment, per se...it's true of all fuels. We're just not used to having to manufacture fuels, instead of pumping them out of the ground.
Great analogy. Like all change-the-basis-of-competition ideas, it's very existence (if successful) will change lots of things. Think of the poor carbon paper manufacturers after copy machines were invented.
At this point, this is nothing more than an intriguing idea that should be investigated and developed as far as feasible. It sounds to me as if it has great potential. Just the prospect of becoming independent from oil imports is exciting.
It may or may not work. We can't decide that today. My best wishes to the inventors and developers. May they live long and prosper.
First, I think the “350 pounds” was a typo. Since the article several times said with recycling, the aluminum would cost one dollar a pount, 350 pounds would cost $350 rather than $60.
And 350 pounds of aluminum wouldn’t fit in a tank either. And since 350 was also the number of miles listed that they would travel, I’m guessing the 350 was replicated by mistake.
So let’s assume instead that it was 60 pounds of aluminum — that would fit in a tank, and would cost about $60.
Comparing things using a car driving 350 miles isn’t useful though, because we all think about different vehicles. For example, my car would do 350 miles with about 8 gallons of gas, costing me about $24 bucks.
The real way to compare is to compare the amount of energy in the hydrogen vs the energy in the gasoline, and then feed that into the efficiency of the hydrogen-to-wheel power transfer vs gasoline-to-wheel transfer.
We probably wouldn’t “burn” the hydrogen, usually we convert it to electricity in a fuel cell and then run an electric motor. The question is, can we incorporate that into this hydrogen generator directly? There’s apparently a lot of waste heat in the process, which maybe you could capture as well.
The real question is, does a “battery” using flow-through water and replaceable pellets cost less, and work better, than actual battery packs that are replaceable, or rechargeable?
I mean if you are pulling 60 pounds out of your car and putting 60 pounds (plus water) into the car, why not swap a charged battery instead?
It sounds like the 60 pounds of material has to be swapped every 350 miles.
Actually it is more like $200 B. Also, that capital is rasied and expended over the life of the construction of the plant, so it is more like $20B per year out of a $13 T per year economy. That is a lot of money, still, but not beyond the pale.
Furthermore, long term nuclear power is profitable because, though the capital cost is high, the operating costs (especially fuel) are low. The principal issue is the haphazard regulatory environment, which puts the capital investment at risk, though the government is putting in place a system of loan guarantees to overcome this problem.
Personally, I think the US has lost control of its own future because of politics and greed accumulating over the years. Importing millions of illegal immigrants will not help us in the near future.
I think this article is a must read for everyone on FR.
Foreign investment in our nations refineries owners explains why we are getting gouged at the pump because at this time, the US is the largest economy in the world and foreign investors want/need our cash. Globalization is here to stay. Power shifts in global oil business
From the article:
As oil prices tripled over the last four years, a new group of oil and gas companies rose to prominence. They have consolidated their power as resource holders and pushed the world's biggest publicly traded energy companies, which emerged out of the original Seven Sisters ExxonMobil Corp. and Chevron Corp. of the U.S. and Europe's BP and Royal Dutch Shell onto the sidelines and into an existential crisis.
The "new seven sisters," or the most influential energy companies from countries outside the Organization for Economic Cooperation and Development, have been identified by the Financial Times in consultation with numerous industry executives. They are Saudi Aramco, Russia's Gazprom, CNPC of China, NIOC of Iran, Venezuela's PDVSA, Brazil's Petrobras and Petronas of Malaysia.
Good point. If you have to “swap” something that heavy, might as well make it all electrice from the get go. That 60 pounds of Al sounds more likely than 350 pounds, unless he was talking about the weight of the water PLUS the Al needed to produce the H. Either way, that’s a lot of mass to haul around. What is the weight of a 20 gallon tank of gasoline or diesel fuel? Plus, can you imagine the “filling station” there would have to be to implement this system? The storage area would have to be huge! Cars would have to line up for hours while forklifts ferried container after container of these “pellets” to the next car, or conveyor belts. WHile this seems a nice lab curiosity, I cannot see it being a practical way of delivering fuel to billions of drivers all over the world..............
Even at $3.00/ gallon, its actually only a little more than $2.00/gallon for gasoline (And this is the highest prices EVER).
The rest is taxes.
This is a cool science project, nothing more.
I don't know of any such facilities in the US. I suspect that there aren't any because they're not cost justified
Go Boiler Makers!
In the not too distant past, the aluminum industry consumed closed to 10% of the electric power produced in this country. Aluminum’s high chemical reactivity manifests itself by requiring more electric energy to produced its elemental form.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.