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Army researchers develop novel nanogalvanic alloys for on-demand hydrogen generation; plans to license

Army researchers have developed a novel, structurally-stable, aluminum-based nanogalvanic alloy powder that, when combined with water or any water-based liquid, reacts to produce on-demand hydrogen for power generation at room temperature without chemicals, catalysts or externally supplied power.

These patent-pending powders produce hydrogen at a rate that currently is one of the fastest reported for Al and water reactions without the need of hazardous and costly materials or additional processes. The reaction results in the production of hydrogen and heat with only inert residual materials; i.e., no toxic by-products. ARL has demonstrated that hydrolysis will occur with virtually any water containing liquid.

It has long been known that aluminum (Al) reacts with water to produce hydrogen gas and aluminum oxide via a hydrolysis reaction. Aluminum metal oxidizes when in contact with water, rapidly producing a passivating oxide layer which prevents the hydrolysis reaction (H2). Further, hydrolysis to evolve H2 can only occur if the native oxide layer is actively removed. This is usually achieved by adding hazardous corrosive compounds (caustic soda, hydrochloric acid, etc.) which dissolve in water, toxic and expensive metals (such as gallium, platinum, etc.), or by forcing the reaction by additional external energy (electric current and/or superheated steam).

Arl1

Source: ARL.

This powder-based alloy includes material that disrupts the formation of an encapsulating aluminum oxide layer, allowing for the continuous production of hydrogen that can be used at the point of need to power a wide range of devices via fuel cells and internal combustion.

The powder can be easily manufactured to scale, and can be conveniently and safely transported via tablets or vacuum pouches, thus eliminating reliance on high-pressure hydrogen cylinders.

—Dr. Anit Giri, a scientist with the lab‘s Weapons and Materials Research Directorate

ARL will post a Federal Register Notice and launch a supporting website inviting companies to submit their ideas on how best to commercialize this technology. The laboratory will then select the most appropriate partners and collaborators. Officials said license exclusivity will then be determined.

The researchers said the powders has many advantages, such as:

  • Energy and Power Source
  • Stable Alloy Powder
  • Non-Toxic
  • Environmentally Friendly
  • Hydrogen Emitting
  • Manufacture to Scale
  • Easily Transportable

Army researchers discovered the unique properties of the nanopowder while investigating aluminum alloy compositions for other purposes. The researchers, from the lab’s Lightweight and Specialty Metals Branch, made the serendipitous discovery that at least one of these compositions can, in the presence of water, spontaneously generate hydrogen, rapidly and efficiently.

The researchers have since demonstrated rapid hydrogen generation rates using powder and tablet forms of the alloy. The hydrogen has been shown to be useful for powering fuel cells and is expected to power internal combustion engines.

—Branch Chief Robert Dowding

The researchers are currently taking advantage of the innovation by characterizing the hydrogen generation rates and purity of the gas generated, Dowding said.

They are also examining the effects of compositional changes to the alloy and systematic changes in the microstructure of the powders, he said.

Giri said the discovery has many benefits and applications, such as simple manufacturing.

The powder can be made using current manufacturing techniques from either pure or alloyed aluminum. The manufacturing process is easily scalable and it is also very fast—with a 75% theoretical hydrogen yield in one minute at standard temperature and pressure, and 100% theoretical yield in three minutes.

—Dr. Giri

The nanopowder is also extremely efficient. Giri said 1 kg of powder can generate 4.4 kWh of energy. The material can be in powder or tablet form and be combined with any available water-based liquid to provide hydrogen on demand, at the point of need.

The discovery eliminates reliance on high-pressure cylinders, Giri said.

It’s easy to transport and store via tablets or vacuum-sealed pouches with no inherent inhalation risk. The powder is also environmentally friendly. Its by-products are stable and non-toxic. Finally it’s a versatile hydrogen source with direct combustion for vehicular power, to use in fuel cells to power any electronic device, and could potentially be used in 3-D printing/additive manufacturing to create self-cannibalizing robots/drones.

—Dr. Giri

In order to support a better understanding of the material, the laboratory established a website to showcase details on the technology and a review the process that will culminate in the granting of a patent license(s) around September 2018.

On this website, visitors can register their interest to be contacted about further developments, post general questions and download background technical information, as well as templates for all the required documents that will be used throughout the process.

Comments

Davemart

Stunning.

Here is a direct link to the technical paper:
https://www.arl.army.mil/www/pages/3337/TechnicalOverview.pdf

Sewage and empty drinks cans are apparently all that is needed to make the material.

I was looking for cost information, but could not spot any direct mention of them, although simple processes always help.

My other big reservation would be that it is developed by the US army, who are considering licensing it only to one company, and may not allow the leaders in fuel cells access or foreign companies on national security grounds.

Engineer-Poet

Reaction:  2 Al + 3 H2O -> Al2O3 + 3 H2

Heat of formation:
Al2O3 -1675.7 kJ/mol
H2O -241.82 kJ/mol

More than 55% of the chemical energy of aluminum is released as heat.  This is grossly inefficient, making it unsuitable for any large-scale use.  One might consider it for things like laptop computers, but you wouldn't even be able to use it on e.g. airplanes because hydrogen gas is an explosion hazard if it leaks.

mahonj

You could probably use it in ground and sea vehicles, however.
Electric cars in winter would be a good application (!)
Or combined heat and electrcity fuel cells.
You could use it on planes as long as it was properly vented.
I wonder can you recycle the spent fuel back to Al metal or is it just easier to dump it?
Interesting, either way. Whether it is the fuel of the future is another matter altogether.

Davemart

Since the technical paper specifically illustrates its use in the ZM2, it is apparent that the scientists involved think that you can indeed use it in ground vehicles.

Davemart

Good point about the waste heat, but the compactness is still attractive.

Heat recovery systems could presumably reduce that, at the expense of more weight and complexity, but on the plus side they would further increase the mileage etc for the weight.

HarveyD

Unless excess heat and residues can be used/recycled, the process may not be economical (with the exception of/for army vehicles) due to the high Al/energy produced cost?

Engineer-Poet

I'm sure the product can be recycled.  Depending on the alloying metals, you might even be able to separate them using wet chemistry like the way ferric chloride etchant solution is regenerated electrolytically with recovery of dissolved copper.  That would give you essentially pure aluminum oxide, which is the starting point for aluminum production (itself an electrolytic process).

The description of feedstock in tablets or sealed bags doesn't sound like anyone is aiming at recycling, though.  What you'd probably want for that is replaceable cartridges which are swapped out when exhausted, and reprocessed and refilled elsewhere.  Sort of like ink cartridges, but designed for re-use.

sd

This is not a new miracle power source. It take a lot of electrical energy to make aluminum from aluminum ore. So what you are doing is storing the energy in powdered aluminum and the releasing some of it in the form of hydrogen. This is not going tobe an economic power source for most applications but it might be a stable compact source of power for the military.

Davemart

By a weird coincidence in the next article here:

'Researchers from Hokkaido University and their colleagues in Japan and Taiwan have more than doubled the ability of a material to transform wasted heat into usable electricity by significantly narrowing the space through which spread electrons move'
http://www.greencarcongress.com/2018/06/20180624-hokkaido.html

Dunno how much of the heat could be made into electricity that way, as how great the temperature differential is would control that, but I would have though 20% absolute tops.

Engineer-Poet

Thermoelectrics are subject to the Carnot limit (and IIUC typically get single-digit percentages thereof), so unless that reaction goes at a very high temperature, you're not going to get much.

gryf

The military has been looking at fuel cell tech for over a decade in 4 applications. This may be the solution to make this viable for wearable power systems and UAV power sources.Today a soldier carries 16 lbs of batteries for electronics and communications so anything to lighten the load or extend endurance is important.
Also for small UAV fuel cell applications check out Protonex (a Ballard company).

Unmanned Undersea Vehicles (UUVS) are using another variation of this aluminum-based nanogalvanic alloy powder using a aluminum-water battery . The original MIT research is now being developed at L3 Open Water Power.

For light duty vehicles this is still a long shot since this will require a larger supply of the aluminum alloy. However, a vehicle smaller than the ZH2 might work. Something like the optionally manned Polaris MRZR X which is being used by SOCOM.

gryf

And that excess heat from generating H2 and fuel cell use could be used to warm MREs and your sleeping bag when recharging batteries. This might even have a commercial use for campers.

Jason Burr

In automotive applications the waste heat can be used in similar manner as the ICE currently do - providing cabin heat for cold weather. Also there are projects to capture waste heat for energy savings and production that I'm sure can be applied as well.

I wonder if there would be any part of the process, such as running fuel cell at high temperature for efficiency, that could use that waste heat to improve overall system efficiency?

Also how would this compare in overall efficiency compared to traditional compressed storage of H2? How would the 55% lost through waste heat trade off for pumping loss, alternative methods of H2 production, loss of H2 through seepage, etc.? Also how does this look from the safety POV?

I think when this is designed into a complete system it will be better than current options.

Engineer-Poet

Do the math:  45% conversion to H2 times 60% conversion to electricity is 27% metal-to-inverter (and much less overall).  The Prius engine hit 38% a couple generations ago, and I'll bet the fuel is lighter than the metal plus water.

This thing is a battery-replacement.

Paroway

Home energy/heating may be a great use and keep pop and beer cans out of landfills.

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