Alane: Using Aluminum Hydride as Fuel | Hacker News Reader

Alane: Using Aluminum Hydride as Fuel

ardica.com

So, what's the energy per liter and per kilogram? If these are genuinely good, they need to be front and center. Their absence from the front page makes me immediately skeptical.

Seems to be about twice the energy density of lithium ion batteries. Nice for battery-type applications, but nothing spectacular--an order of magnitude or so less than gasoline.

Maybe not that great for battery-type applications. After all, you still need to turn that hydrogen into useful work, and it's much harder to recharge than a battery.

And to boot it requires heating up the alane to +80C so you're going to need some sort of priming battery in addition to the tank.

It doesn’t lose energy density in cold weather. Batteries have all kinds fo thermal issues too.

Sounds like a scam.

Alane is not a friendly chemical, it's pyrophoric and incompatible with water. It can be produced by hydrogenation of aluminum at 10GPa and 600C, rather hellish conditions, or by electrolysis of sodium-aluminum-hydride using a mercury cathode, two more easily handled chemicals.

They do not quote any details, no numbers, and we are supposed to believe they made this process safe and cheap?

Energy storage technologies are all about nasty chemistry. Nasty chemistry is where the energy is. Commercializing the chemistry isn’t easy or everyone would do it.

So what are their substantiated claims for being able to commercialize this successfully and in a safe manner? The website graphics are nice tho.

What is nasty about the way the human body stores its energy?

A healthy human diet is 8700 kJ/ day. A gallon of gasoline has 120,000 kJ.

So, we are very energy efficient. But no so awesome in terms of energy storage density.

Have you ever smelled one of those things?

But they say they’re developing a patented next generation process to create it efficiently and cheaply so it must be true.

Based on my expert knowledge (As acquired from Wikipedia just now) I agree, it sounds at least as bad as lithium (in terms of exposure to almost anything) and I’m not sure it is more than just a high density hydrogen carrier. It isn’t a “rechargeable” carrier either - so it’s closer to a regular single use battery, with the combustible potential of lithium.

I’m assuming you’re a chemist, so you can tell me how far off the mark I am :)

The US government tried something similar in the 1950s: https://www.amazon.com/-/dp/0841218579

They built a plant in Malta, NY to prepare pentaborane and higher boranes for use in missiles, or something. The project got nowhere far because the combustion residues are solid. At least alane is only pyrophoric but not neurotoxic.

There's a ton of coverage of the borane work in John D. Clark's "Ignition!":

https://library.sciencemadness.org/library/books/ignition.pd...

Finally back in print after 40 years!

https://www.amazon.com/Ignition-Informal-Propellants-Univers...

Oooh I need to buy a hard copy! Do we know how much (if any) goes back to him or his family?

I'm uncertain about any relatives, but it is published by Rutgers University Press, which is a non-profit publisher.

Get the softcover one though, the hardcover version is a complete ripoff.

Alane has a rude habit of going boom.

Soviets had it made in few dozen tons per year for use in ICBMs motors

Ammonium dinitramide + energetic binder + alane

Such fuel lasted for around 7 to 8 years in cold storage, and had to be discarded afterwards as alane decomposition embrittles the grain.

And closer to second half of eighties, Soviet chemical industry effectively kicked the bucket

Putting greek fire or wootz to one side, the truly great thing about scienting is we don't forget how to scient something. So, if Soviet chemists worked something out, and wrote it up, then.. we can carry it on.

So Soviet chemical industry effectively kicked the bucket just means a lot of immigrant soviet chemists are now in other economies, pursuing their ideas.

Keep scienting. It works.

For scient!

The skeptic in me says "Yeah and the by products of burning hydrocarbons are just water and co2" .

Aluminum dust sounds like it would be a disaster if in the air we breathe.

None of this is an educated position, just thoughts of a software engineer.

Aluminium dust would indeed be pretty bad, but as I understand it, this would be closed system like a battery where the Aluminium would be recycled.

Um, CO2 is the problem. Also, no actual fuel you can buy just produces water and CO2.

That's exactly the OP's point.

No numbers. So they are trying to fool someone.

https://www.osti.gov/servlets/purl/1398788

It looks like it's only going to be useful for replacing primary cells in weight-sensitive applications, as even their own (presumably optimistic) research indicates a per-gram-of-hydrogen cost of more than $1, which would be a maximum 33Wh for a primary cell.

That translates to $30/kWh which I think is considerably cheaper than the (also explosive) LiSO2 batteries it would be replacing.

Of course their costs today are 40x higher or $1200/kWh.

They are claiming current energy densities of 1.1kWh/kg of actual built packs which seems high to me (it would imply it's 3% hydrogen by weight). If accurate that blows-away the lithium primary cells they would be replacing.

They predict up to 1.8kWh/kg for larger packs.

Bingo. And even numbers can be made up.

Hydrogen's Achilles heel is its crappy volumetric energy density. Even if you get the hydrogen to the point where you literally can't compress it anymore and it liquefies, it takes up 4x the space of the equivalent energy amount of gasoline. This doesn't include added weights from tanks, bigger engines, etc.

So the people behind this are not wrong that if we're going to have a hydrogen economy we have to confront this volumetric density problem for motor fuels. Even if somehow they lived up to their billing, a vehicle designed to run on alane would suffer the same shortcomings as ethanol- still inferior to gasoline in multiple ways.

Are we going to have a hydrogen economy? No. Even if this alane wasn't snake oil and completely lived up to its promises, hydrogen would still be more expensive to fill your car with, and it wouldn't work as well as, gasoline.

"But, but, but.. what about when we run out of oil?" This won't solve that problem either. We can and will make gasoline from natural gas and/or coal if that ever happens, which it won't.

No clue if these guys are viable but the science is solid.

You do understand that the whole point of hydrides is addressing hydrogen’s storage issues (energy density and need to store under pressure). Using hydrides with fuel cells was what everyone expected electric cars to use before lithium ion batteries took off.

Better just use natural gas (like methane) straight in such case. It's cheaper than making gasoline from it.

While this is largely true (and in fact today natural gas is already cheaper than making gasoline from other sources), sometimes you can't substitute natural gas for gasoline, and some people will still want to buy gasoline (with its commensurate energy density, ease of transport, and worse pollution) and pay a premium to do so.

In fact, I suspect the amount of natural gas burned to produce a gallon of gasoline is already substantial, with electrically-powered catalytic reforming necessary for us to drive around with octane rating numbers over "50", and by and large the cheapest source of that electricity being from burning natural gas.

We will have to find a way to stop using fossil fuels because of climate change.

It is neither explosive nor toxic – the byproducts are a small amount of water vapor and aluminum powder, which can be recycled.

Ardica appears to be ultimately searching for a rechargeable hydrogen storage medium. Fill a cell with aluminum. Add hydrogen to generate alane in situ. (or charge cell with alane to begin with) Discharge to re-form aluminum. Repeat.

There are many technical challenges on the way to this vision.

Alane as fuel would only be practical if it could be economically regenerated from the waste aluminum in situ.

Otherwise the waste aluminum would need to be purged from the system somehow. Waste liquids are easy to work with through pumps, but waste solids (and potentially pyrophoric powders) are very difficult to move.

The company claims that alane does not spontaneously combust. In its alpha form, this is true. But these materials are passivated through the addition of an oxide coating. Doing so could also render the material inert as a fuel.

From Ardica's issued patents, these challenges haven't yet been addressed.

From wikipedia:

"Aluminium hydride decomposes in air and water. Violent reactions occur with both."

"It is a potential additive to rocket fuel and in explosive and pyrotechnic compositions."

So perhaps not ideal as a battery, and in fact the website doesn't appear to explain how it is used as a battery at all - is it by releasing H2 for a fuel cell?

Where is the marketing page for chemists? The reaction

  Feedstocks + Green Energy --> Reaction --> Large Quantities of Alane

is lacking in detail.

Running an engine on alane seems like a spectacularly bad idea. USAF experiments with borane didn't go anywhere, I don't expect this idea to fare any better.

Here's a good video on the experiments for those who are unfamiliar: https://www.youtube.com/watch?v=gdeybNPLpZU

Phinergy a startup from Israel has a prototype car running on Aluminium. So it should be possible to use Aluminum as energy storage. http://www.phinergy.com/

Perhaps the same principle as why we recycle aluminum cans? It takes lots of energy to melt the aluminum can.

It takes less energy to melt the can than to smelt the bauxite ore and create an electrolyte with lots of electricity. That's why we recycle aluminum cans.

"It is neither explosive nor toxic – the byproducts are a small amount of water vapor and aluminum powder, which can be recycled.".

Well. I think aluminium power is cancerogen if enter human body. I hope the solution prevent alumium to be dumped on air.

There is a mention of cartridges, so presumably the intention is that the Al never gets out.

What's the Energy Return on Energy Input? My guess is more energy in than out, making it a a global burden instead of a global asset. Not to mention all the other comments in the thread....

Does any storage medium have an equal in->out balance? I think that is impossible...

Correct, it is impossible (ye olde laws of thermodynamics).

Generally it’s a question of what the efficiency of the charge/draw process is, and how you can get. The advantage of hydrocarbons isn’t that they’re energy efficient to create, but rather that it’s mostly happened already over millions of years, or it’s from power derived from the sun (plants, etc)

Anyone know if Daniel Braithwaite has any relation to Reginald?

Alane is like electricity in that it's not a primary form of energy, if I understand well. Maybe it could be used to make intermittent energy production controllable.

It's solid pellets, and can't be recharged as easily as a battery or (flow) fuel cell.

Aluminium (air) batteries are potentially very promising though.

Sure it might be a great fuel but how much energy is required to make the aluminum "feed stock" a few years ago during the ENRON caused power shortage in California, aluminum smelters were shutting down, paying all their employees full wages and selling the electricity that would have been used make their aluminum to California at a greater profit. Unless there is a new way to produce the aluminum and liquid hydrogen for that matter, I don't see how this will save energy.

https://www.theglobeandmail.com/report-on-business/alcan-bc-...

Incase you don't believe it happened

This is Theranos level quackery. Come back in one year and tell me I'm wrong.

Right? I can’t tell if it’s a deliberate scam or simply self delusion.

How does its production impact enviorement?

Reply on news.ycombinator.com