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Jerry Woodall, a professor at Purdue University invented the new alloy production process, promising affordable, easy hydrogen.  (Source: Purdue University)

Pictures of the alloy in water, reacting to produce hydrogen, as evidenced by bubbling.  (Source: Purdue University)

The byproduct of the process is a recyclable mix of aluminum and gallium-indium-tin ores.  (Source: Purdue University)

Here a Purdue researcher uses the hydrogen produced by the process to power an internal combustion engine.  (Source: Purdue University)
While some hydrogen research focuses on simulating nature, a new metal reagent developed by Purdue University promises economic viability

Jerry Woodall, a distinguished professor of electrical and computer engineering at Purdue University, is firmly ground in the world of commercial production.  When he began researching ways to improve hydrogen production using aluminum reagents, his goal was simple -- if it wasn't commercially viable, it wasn't a success.

While recent researchers have reported significant breakthroughs in fields such as synthetic photosynthesis and microbial hydrogen production, these methods currently are too inefficient to currently be feasible as a non-subsidized fuel alternative.  While these methods are exciting in that they may one day lead to cleaner and more effective energy production, many agree that the time for hydrogen is now, and waiting for theoretical methods is simply impractical.

Fortunately Purdue's Woodall developed a more down to Earth method of hydrogen production that promises a feasible infrastructure and short term commercial viability.  Woodall states, "We now have an economically viable process for producing hydrogen on-demand for vehicles, electrical generating stations and other applications."

The key to the method is a new aluminum reagent, which Woodall invented.  The new reagent is composed of 95 percent aluminum and then a critical 5 percent mixture of gallium, indium and tin to improve its reactive character.  Previous similar alloys used far more gallium, which is very expensive.  By cutting down the gallium, Woodall greatly reduced the costs of hydrogen production.

When the new alloy is exposed to water, it reacts to create hydrogen gas and oxygen.  The oxygen then bonds to the aluminum to form aluminum oxide, also known as alumina.  It is cheaper to recycle alumina back to aluminum than it is to refine aluminum from bauxite ore, which is another element contributing to its efficiency.  Woodall illuminates, "After recycling both the aluminum oxide back to aluminum and the inert gallium-indium-tin alloy only 60 times, the cost of producing energy both as hydrogen and heat using the technology would be reduced to 10 cents per kilowatt hour, making it competitive with other energy technologies."

Control of the microscopic structure of the solid aluminum and the gallium-indium-tin alloy mixture is critical to the technology's success.   The mixture is a "two-phase" mixture, meaning that it features abrupt changes in composition between one constituent to another.  Woodall explains this challenge stating, "This is because the mixture tends to resist forming entirely as a homogeneous solid due to the different crystal structures of the elements in the alloy and the low   melting point of the gallium-indium-tin alloy.  I can form a one-phase melt of liquid aluminum and the gallium-indium-tin alloy by heating it. But when I cool it down, most of the gallium-indium-tin alloy is not homogeneously incorporated into the solid aluminum, but remains a separate phase of liquid.  The constituents separate into two phases just like ice and liquid water."

Researchers had two options -- fast cooling to leave separate alloys or slow cooling to yield a single solid alloy brick.  At first they tried fast cooling, which required a puddle of gallium-indium-tin to initiate the reaction.  However, when they turned to the slow-cooled alloy, they were impressed to discover that it reacted just as well, or better, eliminating the need for the liquid gallium-indium-tin alloy.  Woodall adds, "That was a fantastic discovery.  What used to be a curiosity is now a real alternative energy technology."

The Purdue team is currently completing work on developing a production method to produce briquettes of the alloy.  These briquettes could be dropped into a tank of water, producing pure hydrogen.  This would eliminate both the need for hydrogen storage and hydrogen transportation, two critical obstacles for the hydrogen industry. 

The gallium-indium-tin alloy in the process is inert and is able to be recovered with almost 100 percent efficiency.  Woodall says even the less efficient aluminum recycling produces much less carbon emissions than traditional fuel.  He states, "The aluminum oxide is recycled back into aluminum using the currently preferred industrial process called the Hall-Héroult process, which produces one-third as much carbon dioxide as combusting gasoline in an engine."

In order to fully realize the technology on a national scale for fuel use, alumina recycling infrastructure would need to be dramatically expanded.  Additionally, gallium-indium-tin recycling would need to be added.  This infrastructure would be expensive, but according to Woodall "the economic risk is large, but the potential payoff is also large."

Woodall won the 2001 National Medal of Technology, the highest award for technological achievement in the U.S.  Woodall his fellow researchers will present their findings on Feb. 26, 2008 at the Materials Innovations in an Emerging Hydrogen Economy conference in Cocoa Beach, Fla.  The alloy production process's primary patent title is owned by the Purdue Research Foundation.  Purdue has licensed the technology to an Indiana startup company, AlGalCo LLC., which Purdue hopes will be the first company to implement the technology commercially.

Purdue's solution is similar to the University of Leeds' new method of producing hydrogen from biofuel waste sludge, in that both solutions are economically feasible, but require the development of production infrastructures.  However the new method from Purdue can make hydrogen from a far more plentiful source -- pure water.


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RE: unsure
By geddarkstorm on 2/21/2008 3:21:11 PM , Rating: 2
We have to mine aluminum anyways for cans, cars, planes, etc. It's also the most abundant metal in the earth's crust, so what metal would be better, and why would this process affect the economy that much? As with any new tech, you have to have to invest a lot to get it started, how is that different from anything else?

Alumina has the formula of Al2O3, so that for every 2 aluminum atoms, you'll make 3 molecules of hydrogen gas (H2). That being, 2 tons of aluminum should make 3 tons of hydrogen gas. You still need a relatively small amount of that inert catalyst in the alloy too, and that actually will be the most expensive part according to what they say.

Still, after 60 recycles, it comes out to 10 cents per kilowatt hour to pay for this technology, and recycling is almost 100% efficient? It's pretty dang good, better than most things, and thus it is commercially viable.


RE: unsure
By geddarkstorm on 2/21/2008 3:32:40 PM , Rating: 2
I goofed. Aluminum atomically weighs more than hydrogen, so you can't compare tons. Instead, 2 moles of aluminum should make 3 moles of hydrogen gas when using this process.


RE: unsure
By Chernobyl68 on 2/21/2008 3:40:46 PM , Rating: 2
yeah, I saw that...no big deal...:)


RE: unsure
By Chernobyl68 on 2/21/2008 3:38:31 PM , Rating: 2
assuming it is AL2O3, I'll take your word for that

2 Al + 3 H2O -> Al2O3 + 3 H2

Atomic Weights (rounded)
Al=27
H=1
O=16

2(27) + 3(18) = 102 + 3(2)

so it takes 54 tons of aluminum to make 6 tons of hydrogen gas (9 truckloads of aluminum to make 1 truckload of Hydrogen, roughly) and that's discounting the weight of the catalyst material.

seems its much cheaper to ship the gas than the new alloy.
and the AL2O3 is about twice the weight of the original allow by adding the oxygen. So you're creating roughly 18 truckloads of used material to be recycled, assuming a closed loop system where only the aluminum oxide from the fuel station is used to make the alloy down the line. If its isn't, then you add a third leg to the transport loop where the refined aluminum is taken somewhere to be made into the alloy. It seems far easier to ship the hydrogen by truck or pipe, on the surface. As I said, there may be some unknowns in piping hydrogen gas I'm unaware of.


RE: unsure
By SolarHydrogen on 2/21/2008 4:22:29 PM , Rating: 2
Hydrogen and our existing piping infrustructure do not mix well because the hydrogen reacts with metal, turning it brittle, and susceptible to cracking.


RE: unsure
By geddarkstorm on 2/21/2008 4:36:46 PM , Rating: 2
http://en.wikipedia.org/wiki/Alumina now you don't have to just take my word for it :).

Shipping the gas is actually rather difficult. You have to pressurize it into a liquid as H2's gas volume is 0.08988 g/L (the greatest there is, after all). Furthermore, H2 only goes into liquid form at around 2-4 kelvin (or -271 to -269 degrees C). The new honda fuel cell car has to pressurize to 5,000 psi for 171 liters I believe it was. On top of this, being that hydrogen is just two protons and two electrons, it can pass through most materials, including metal, which can lead to steel becoming brittle and failing.

Now, how much hydrogen do you actually need to produce a certain amount of power via a fuel cell? If the new honda really does use 171 liters for... was it 270 miles? Since liquid hydrogen is 0.070 kg/L, you have 13.2 kg of hydrogen in one of those cars and 1 metric ton = 1000 kg, so 1 ton of liquid H2 could fuel 75 of those cars for 270 miles (if I got the car's figures right). Doesn't seem like too much for 1 ton? If there's "About 450 million passenger cars travel the streets and roads of the world" as of 2001 ( http://hypertextbook.com/facts/2001/MarinaStasenko... ), you'd need 6,000,000 tons of H2 (or 54,000,000 ons of aluminum) to power them for 270 miles (if they were all that honda fuel cell car). That seems like a lot, except cars output 6.9 billion metric tons in of CO2 in 2004 ( http://64.233.167.104/search?q=cache:56cevd1CGJgJ:... ) into the air per year, so you can imagine how many tons of oil and gas we consume. So it seems roughly on par then. I don't have time to really finish the calculations (how much gas do we consume? How far does the average car drive per year? etc) as I have to go.

I think that puts things in perspective? Should check my work to make sure. But, it will certainly take a TON (haha) of aluminum to fuel such an economy--but shouldn't be anything more than what we have to spend on gas?, and thankfully aluminum is the most abundant metal in the crust. No one said making energy to fuel our life styles would be a cake walk ;)


RE: unsure
By Chernobyl68 on 2/21/2008 5:41:08 PM , Rating: 2
I estimate the average driver's personal car is about 14-15,000 miles a year. Possibly more than that for business ues.
assuing
13.2 kg = 270 miles, 15,000 a year, that's 733 kg per vehicle, per year. If you assume it takes 2 weeks to complete a circuit in the recycling loop (just a wild guess) you need 1/26 of that in kg to power that car, or about 28kg per car. multiply that by 450million, you get 12,692,307,692 kg or about 12.7 million metric tons of the worlds aluminum wrapped up in the loop., which according to world-aluminum,org, is a little more than the total amount scrap recycled in 1998.

http://www.world-aluminum.org/production/recycling...

so maybe I'm worrying for nothing, but its interesting to find out this information.


RE: unsure
By geddarkstorm on 2/21/2008 7:12:17 PM , Rating: 3
This is very interesting. At least to me as well.

Another way of looking at it is that if the 11.6 million tons of aluminum recycled in 1998 fulfilled 40% of the world's demand for aluminum, then that demand was 29 million tons for the year. Cars using 12.7 million tons would make the 1998 levels of world demand for aluminum increase by 70% to 41.7 million tons. Quite the jump in world demand, if this was done for all cars, instantly, overnight. Fortunately, the switch would obviously be gradual. However, one thing to consider is how much new aluminum would have to be added to the system per year, over what would be recycled (loss in conversion, increase in cars, how much we can expand our recycling abilities by)? That I can't begin to speculate on, but it would certainly be less and less with each year, so the picture only gets better as time goes on.

Gasoline has an average density of about 737.22 kg/m³ ( http://en.wikipedia.org/wiki/Gasoline ), or 0.737 kg/l, or 2.79 kg/gallon. "Therefore, in the United States, something like 400 million gallons (1.51 billion liters) of gasoline gets consumed every day" ( http://auto.howstuffworks.com/question417.htm ) which then comes to 1.1 million tons of gasoline used by the US alone per day!

So, on the one hand, based on 1998's standards, our aluminum infrastructure would be strained a bit by the demand if all the cars in the world switched to hydrogen produced by this aluminum alloy reagent right at this moment. Sure, we could put all our recycled amounts immediately into it, but that'd leave all the other sectors needing mined aluminum, meaning an increase of 40% in mining would have to be done. By 1998's standards. However, on the other hand, this isn't going to happen over night for all the cars of the world instantly.

But then, compared to how much gasoline we consume, the amount of aluminum it would take to run our cars on hydrogen via this method would be nothing. Nothing at all, in comparison. By the time this method became wide spread, our infrastructure would be more than capable of handling it (recycling is what would go up mostly, after the initial load of raw aluminum gradually leaked into the hydrogen production pool). Again, none of this would happen over night.

Our figures are probably pretty far off from reality, but they give a good perspective and picture. Just looking at that gasoline consumption.. always leaves me shaking my head in awe. Still, the biggest cost factor, especially initially, will be that 5 percent mixture of gallium, indium and tin. If we use 12.7 million tons of aluminum, that'd be 635,000 tons of that stuff (it can be nearly 100% recycled too, thankfully).

In any case, this has been very interesting to research. Thank you for getting me on this kick. Ultimately, we'll just have to see what comes in the future--if this stuff gets commercialized well, if it is presented to the market in a competitive way against gasoline (i.e. how it's priced and how that changes over time), and how the technology matures.


RE: unsure
By SoCalBoomer on 2/21/2008 6:49:49 PM , Rating: 2
And, as the aluminum in this system would not actually be consumed, but could be relatively easily recycled back into this catalyst, it's radically different than burning a limited resource.

The numbers you're giving seem right - but have you compared it to the amount of hydrocarbons we're presently using?


RE: unsure
By geddarkstorm on 2/21/2008 7:18:11 PM , Rating: 2
Very true, which I am unable to take into consideration in my calculations, unfortunately. But that is an extremely important point, and why this tech is so very cool. Reusable and renewable in almost every sense.

From the post I just made: "Therefore, in the United States, something like 400 million gallons (1.51 billion liters) of gasoline gets consumed every day" ( http://auto.howstuffworks.com/question417.htm ) which then comes to 1.1 million tons of gasoline used by the US alone per day. Quite a bit more than the aluminum we'd need, even if we couldn't recycle it!


RE: unsure
By Chernobyl68 on 2/21/2008 10:03:01 PM , Rating: 2
Well, gas and diesel aren't known for their density... :)


RE: unsure
By Chernobyl68 on 2/21/2008 10:11:56 PM , Rating: 2
well, since the end product is alumina (and not aluminum), technically I guess we shouldn't be calling it recycling, but resmelting. You're almost making bauxite over again.


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