backtop


Print 65 comment(s) - last by damncrackmonke.. on Feb 22 at 10:49 PM


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.


Comments     Threshold


This article is over a month old, voting and posting comments is disabled

RE: unsure
By geddarkstorm on 2/21/2008 3:51:21 PM , Rating: 2
Do you even begin to realize how much aluminum it would take to "boil away" (react with) even a small lake of water? To react with just 50 tons of water (45,359,237 grams, or 2,519,957.6 moles) you'd need about 50 tons of aluminum (since very 2 moles of aluminum react with 3 moles of water). Now, 50 tons of water is the amount an adult blue whale swallows in a single gulp--not much at all in the grand scheme of things. Consider it takes about 1000 tons of water to grow 1 ton of grain and you'll begin to see you'd need so much raw, refined aluminum to even begin to affect the amount of water in this world substantially that it's not even funny.

But then, you do realize that the hydrogen will (if not captured and put to work as in say a fuel cell) just react with oxygen to form water all over again? It's because hydrogen and oxygen have such a low free energy for forming water that you don't find raw hydrogen naturally occurring anywhere on the globe.

Also, reacting water in a bottle into hydrogen would make a nice loud "boom" with the bottle finally burst, but that's it. It wouldn't be enough to take out a plane.


"Google fired a shot heard 'round the world, and now a second American company has answered the call to defend the rights of the Chinese people." -- Rep. Christopher H. Smith (R-N.J.)














botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki