Stanford Researchers Produce Ammonia Fuel from Thin Air
39 comments
·January 16, 2025chrisbrandow
Assuming the energy input is atmospheric warmth, then the real question is what volume of ammonia can you produce with this device per acre? Then how does that amount of captured energy compare with wind/solar in the same area?
Otherwise, you’re just better off, producing electricity from one of those sources, or producing ammonia, using electricity from one of those sources, after accounting for losses in the various processes of course.
dexwiz
Ammonia is very common in industrial applications.
hammock
So they invented a (chemical) bean plant/rhizobium? Or Nitrobacter. AKA atmospheric nitrogen fixer
blueflow
Take that ammonium, burn it, have heat, power a steam engine, infinite energy?
Where does that energy come from? 1st law of thermodynamics?
pjc50
This is under-explained, isn't it? The reaction has to be endothermic, so it must be taking in ambient heat. Would be useful if someone dug up the actual paper rather than the press release.
One aspect of these miracle solutions to watch out for: the catalyst is often very expensive and has a finite lifespan.
Edit: actual paper https://www.science.org/doi/full/10.1126/sciadv.ads4443
Edit: got to the bit in the paper where they describe the process; "contact electrification". This appears to be an electrostatic phenomenon like tribocharging (the old "rub a balloon on your hair" trick). Water droplets hitting the catalyst generates enough potential at the surface to trigger a reaction. So I suppose the energy input is actually in the spray+pump of the experiment, or wind in the outdoor example.
The resulting output is extremely dilute. Raising the concentration is likely to consume more energy for generating an actually useful output.
blueflow
There is the smoking gun:
> resulting in ammonia concentrations ranging from 25 to 120 μM in 1 hour
Not usable as fuel. You'd need to separate the ammonium from the water using a energy intensive process (cooking or such).
LincolnedList
The energy comes from the sun, without it the atmosphere would freeze and this device wouldn't work.
BobaFloutist
For our purposes solar power is effectively perpetual motion.
PittleyDunkin
I see what you're saying in the sense of passive energy collection, but perpetual motion strikes me as a terrible metaphor. Perpetual motion would imply so many thing about the universe that solar can't deliver.
blueflow
And how does the presented device make use of solar power? Wind movement?
dessimus
If you consider solar only working for 50% of the day on average, "perpetual".
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kurthr
The power could come from anything (solar, wind, wave) other than the dominant current source for all ammonia, the Haber Process. TFA mentions this in the headline? Could this be done before by just using water+air+solar, yes it could. Frankly, this is just a proof of concept and any commercial solution would be different for scaling reasons.
Professor Aldo Rossa started popularizing a lot of this in the 80s. https://patents.google.com/patent/US4107277A/en
Having something other than a fossil fuel source for the most common fertilizer in the world seems useful. Also, it's easier, cheaper and safer to ship ammonia around than Hydrogen since it's a low pressure liquid and more energy dense. People have been talking about using it as a shipping fuel for decades.
blueflow
You didn't read the article? "The process requires no external power" right after the headline.
hansvm
Like you said, the energy comes from somewhere. If I had to guess, it's effectively solar powered (the catalyst lowering the activation energy enough that photons can actually do the work), plus indirectly solar powered in that you need wind to physically move the compounds around.
selimthegrim
Didn’t a group from KAUST falsify Zare’s results about microdroplets a few years ago and show that they weren’t anything special
ada1981
How do we create this right now?
What are the costs for the catalysts and how long do they last?
Those sorts of questions feel important to understand.
Tagbert
Most ammonia is produced via the Haber process. It takes nitrogen from the air and hydrogen from natural gas and combines them into ammonia. It uses an iron catalyst. This process emits significant CO2.
adrian_b
Currently hydrogen made from natural gas is the cheapest, but the Haber process could equally well use hydrogen made from water electrolysis using solar/wind energy.
In that case there will be no production of CO2.
The only reason why this is not done yet is because avoiding the production of CO2 would raise the cost of ammonia, then the costs of fertilizers and various other chemical substances, including explosives, which would trigger a cascade of price increases in food and in many other products.
einpoklum
"Researchers produce NH_3 fuel from N-gas-compound with H_2O vapor"
Doesn't sound so exciting.
But, sniping aside - is there a potential for cheap enough production in abundant enough amounts to use safely in machine engines? Or as grid-level storage medium for solar energy? The very transformation is neat, but the application is what would be interesting.
pjc50
> produce NH_3 fuel from N-gas-compound with H_2O vapor
At room temperature! That's the interesting bit.
adrian_b
In TFA the alternative methods for making ammonia are mentioned.
One such method, which already works at room temperature for combining hydrogen with nitrogen into ammonia, uses electricity together with a platinum-gold catalyst and it has a 13% energetic efficiency.
The methods described here uses cheaper materials and the authors hope that some time in the future it might reach a better energetic efficiency.
bparsons
There are a million ways to turn large amounts of energy into smaller amounts of energy.
BobaFloutist
And many of them are incredibly useful. Take, for example, the burning of fuel. Or eating and digesting.
foxyv
Hopefully, one day they will turn large amounts of cheap energy into valuable chemical feed stock and fuels. When you think about it, aluminum producers are doing something similar.
ThatGuyRaion
Fractional Distillation is nothing new.
0xedd
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_aavaa_
Ammonia as a fuel is an absurdly stupid idea. It is trading the lives and safety of crews and passengers for a bit of money.
ReptileMan
What is so dangerous about it compared to lets say a gasoline engine converted to use LPG or Methane? There are many of those in Europe where I live.
AlotOfReading
Ammonia is much more caustic, toxic, and explosive than LPG and incidents involving it like the Minot derailment tend to be significantly worse.
_aavaa_
You mean aside from being a colorless toxic gas that will kill you in as little as 5 minutes?
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jofer
Yeah, ammonia leaks are much more nasty than methane or hydrogen leaks. Methane, especially in LNG form, is quite safe compared to ammonia. LPG is even more stable than LNG and requires lower pressures. With that said, hydrogen leaks are "fun" because large ones usually self ignite and burn with a hot but mostly invisible flame. But hydrogen itself isn't toxic. Similarly, methane and propane aren't directly toxic.
Basically, an ammonia leak will kill you. By itself. The others are only a problem if they're the right concentrations to ignite. That's a relatively high concentration and a larger leak. Much smaller leaks of ammonia are deadly.
It's still a good solution for some things, but it's a bad solution for consumer vehicles like cars for that reason.
ReptileMan
Just like propane, nitrogen, laughing gas, and methane ... I don't follow?
The article mentions "Traditional methods for ammonia production require high temperatures and pressures" in reference to the existing Haber-Bosch process for producing NH3 from thin air, an interesting historic story on its own.
https://blog.rootsofprogress.org/turning-air-into-bread
https://www.penguinrandomhouse.com/books/73464/the-alchemy-o...