This is Open Access, and mentions how that is also a leap forward in Nitrogen fixation
“Abstract:
For decarbonization of ammonia production in industry, alternative methods by exploiting renewable energy sources have recently been explored. Nonetheless, they still lack yield and efficiency to be industrially relevant. Here, we demonstrate an advanced approach of nitrogen fixation to synthesize ammonia at ambient conditions via laser–induced multiphoton dissociation of lithium oxide. Lithium oxide is dissociated under non–equilibrium multiphoton absorption and high temperatures under focused infrared light, and the generated zero–valent metal spontaneously fixes nitrogen and forms a lithium nitride, which upon subsequent hydrolysis generates ammonia. The highest ammonia yield rate of 30.9 micromoles per second per square centimeter is achieved at 25 °C and 1.0 bar nitrogen. This is two orders of magnitude higher than state–of–the–art ammonia synthesis at ambient conditions. The focused infrared light here is produced by a commercial simple CO2 laser, serving as a demonstration of potentially solar pumped lasers for nitrogen fixation and other high excitation chemistry. We anticipate such laser-involved technology will bring unprecedented opportunities to realize not only local ammonia production but also other new chemistries.”
"The corresponding lowest energy consumption of ammonia synthesis based on the light power can be calculated to be approximately 322 kWh kg−1 NH3 (Fig. 3b). This value is significantly higher than that (10 to 13 kWh kg−1 NH3) of the H–B process at an industrial scale" still way to go. found nothing about the "subsequent hydrolysis" step, skimming the article
> (10 to 13 kWh kg−1 NH3) of the H–B process at an industrial scale"
It isn't clear to me how they're pricing the H-B process there, industrial HB uses hydrogen from hydrocarbons. An apples to apples comparison would at least add the energy you could get from burning the hydrogen instead, but arguably should compare with H-B where the hydrogen comes from electrolysis of water.
> "subsequent hydrolysis"
As far as I can tell, you just add water. zap rinse repeat. I'm a little skeptical that their yield figures were for Li2O though the repeated process has you cycling through LiOH after the first pass.
There’s that, but I meant just turning electrical energy into photons. Diode lasers are pretty decent at 50ish percent efficient. Everything else is way, way worse.
This could enable fertilizer production with no CO2 emissions. The numbers in the paper suggest that it might prove cheaper than natural gas based production which is common today. Fertilizer production is 2.1% of all CO2 emissions right now.
"In addition to its use in the fertilizer and chemical industries, ammonia is currently seen as a potential replacement for carbon-based fuels and as a carrier for worldwide transportation of renewable energy."
Long-term grid storage?
Publication: 22 July 2022
Anyone know if maybe some pilot / small scale production facility has been set up in the mean time?
I've read about a farm that produced its own fertilizer, but dunno whether that uses this or some older / unrelated process.
Where are all the people that complain about the dangers and impracticality of hydrogen when the topic of using a corrosive gas that poses an immediate danger to life and health at concentrations as low as 300 ppm as a fuel comes up?
They're trying to avoid using the stuff in industrial refrigeration it's so nasty, and yet here we are gleefully considering rolling down the highway with it in the cheapest vessel industry can lobby for strapped to our bum.
I guess the notion has passed so quickly we haven't had time for the media to program us with corporate agendas...
I don't think it's realistic as a fuel for cars, but "worldwide transportation" means more than that. I suspect they're talking about container ships, tankers, and such.
Ammonia is easier to liquify than hydrogen, and is in many respects easier to handle. However, it's definitely not something you want to have a spill of at a gas station or in your garage, and for that reason, it probably won't have "consumer" uses.
As far as industrial gasses go, it's certainly nowhere near the worst, and there's plenty of ammonia tankers on the roads today, but large spills do kill people every now and then.
It is important to note that hydrogen, due to the small size of the molecule, is really hard to contain as a gas. Moreover, leaked hydrogen gas is an indirect but potent greenhouse gas via interfering with the degradation of existing methane in the atmosphere. If we leak enough hydrogen, we might not be helping the climate very much.
I was once in a presentation which claimed formic acid to be a better alternative, but I'm not an expert in that field, so I can't comment on its merits.
There were some recent articles suggesting that there may be enough natural hydrogen seeping out of the ground to supply all of humanity’s energy needs. It seems a bit unlikely that leakage of hydrogen from fuel systems would matter much in comparison.
No, it gives off alpha particles and gamma rays. Hypothetically, you could build a device to harvest that energy (along the lines of an RTG), but the energy density and conversion efficiency would be laughable, given the 3.8 day half-life and gaseous state.
Use compressed air or NOx as oxidizers for delayed combustion in engines. Not only would it provide a means of storing energy for ICEs, but it would also eliminate pumping losses on the intake stroke.
I wonder if this process would be easy enough that “ammonia battery” plants would just synthesize on site when solar power is high. Like charging up a battery with no need to move anything.
They can keep making claims to cover up their complete bungling of their market position.
As for the idea itself. Ammonia as fuel fails the first principle of safe design. It’s a poisonous gas. Using it as a fuel is a willingness to trade the safety of people for a cheaper fuel.
The move from cars to SUVs in America was so car manufacturers could skip emissions and safety requirements of cars on the technicality that SUVs are “light truck” chassis[1]. Dan Luu shows that those safety regulations are often a box ticking exercise for manufacturers except Volvo[2]. American stroad design is a particularly bad mix of street and road which is more dangerous for drivers and pedestrians than other designs. And the diesel emissions scandal so many car manufacturers were caught defrauding.
“willingness to trade the safety of people for a cheaper X” is exactly what we should expect car companies (and companies in general) to do, because that’s what they’ve done so often though history.
In my limited understanding, neither one really explodes. The petrol one would look like a huge impressive fireball that launches a big black mushroom cloud and then just burns like crazy. The hydrogen one, if the hydrogen is fairly pure, would be like a big faint blue wispy fireball, not all that impressive.
If there were an oxidizer in the mix somehow, it would be rather more explosive.
The issue with hydrogen is that it has a fairly wide combustion range (meaning the ratio of fuel/air that can burn), I can't remember the numbers but it's several times greater than other common fuels.
The other issue with hydrogen is that the combustion happens VERY fast... if you ignite gasoline vapor/air in an open 5-gallon jug, you have a nice rocket that'll fly 50 feet or so.
If you ignite hydrogen/air in the same jug, you have permanent hearing damage and shards of plastic embedded in you.
If the hydrogen is fairly pure and the amount is question is small, then sure: combustion will happen at the hydrogen-air interface. If it mixes with air before ignition, then it can burn all a once, and Wikipedia informs me that “the limits of detonability of hydrogen in air are 18.3% to 59% by volume.”. Yes, it will literally detonate with supersonic flame velocity.
I once got to watch some moderately crazy students fill an ordinary party balloon with a stoichiometric mix of hydrogen and oxygen at ambient temperature and pressure. When it was ignited, the result was extremely impressive. No one was injured (because we were all warned to protect our ears and open our mouths and balloons don’t produce significant shrapnel), but the shock wave was not at all subtle.
My dad did this once. He drained the acid from a car battery and put it in a container with a narrow opening, then dropped in a bunch of zinc galvanized nails. Sulfuric acid + zinc = hydrogen gas. He then stretched balloons over the mouth of the container to inflate them, tied them up, and attached a strip of newspaper to the bottom. Finally, he lit the bottom of the newspaper on fire and let it go. Balloon floats up, makes pretty fireball.
We ran into two problems. First, a number of the flames blew out on their way up. No fireball.
Second, we ran out of balloons pretty fast. So he cast around for ideas, and decided to fall back on a box of condoms. They held a lot more hydrogen than the balloons.
They were also equally likely to go out before blowing up. I always imagined them coming down on someone's lawn, causing no end of confusion.
That’s not the same thing, though — your dad forgot the oxygen! A balloon full of approximately pure hydrogen makes a nice fireball but doesn’t really explode — the same group that made the exploding balloon I watched also did one of those.
The stoichiometric premixed balloon is only 2/3 H2 by volume, so it releases 1/3 less energy, but it’s a whole different experience when the energy is released essentially all at once. Interestingly, there was no noticeable fireball from the premixed balloon.
A premixed H2+air balloon probably makes a fine explosion, too :)
> That’s not the same thing, though — your dad forgot the oxygen!
Oh, I'm quite aware. The other fun game we played was with his acetylene welding torch and balloons. It has separately controlled tanks of acetylene and oxygen. Acetylene only = nice big fireball. Acetylene + oxygen = no fireball at all, instead a very loud boom + a bit of a shockwave.
A quick search for higher heating values suggests that acetylene and hydrogen gasses have fairly similar HHV per mole of oxidizer. (H2 needs 1/2 equivalent or O2; acetylene needs 5/2 equivalents, so H2 wins by a bit.)
But H2 takes up most of the space in the balloon, and acetylene is nice and compact, so considerably more total energy should be available with acetylene!
I don’t know whether oxyacetylene will detonate nicely, though, or whether a balloon-sized oxyacetylene mix will merely combust subsonically.
Hydrogen is way worse than gasoline or any hydrocarbon. It has to be stored at very high pressures and there’s no practical situation in which it doesn’t explode.
At atmospheric pressure Ammonia liquifies at −28 °F (−33.3 °C), Hydrogen −423.17 °F (−252.87 °C). That alone is a vast improvement. You can build a car/boat/aircraft that keeps its Ammonia fuel tank cool with minimal effort however it’s wildly impractical with hydrogen.
Add the issues with hydrogen embrittlement and Ammonia starts to look trivial by comparison. People deal with industrial quantities of Ammonia on a regular basis without significant issues. Hell even gasoline and diesel are toxic and can be quite dangerous
My primary point here is that if you see an ammonia spill you're going to die whether or not it explodes.
I suppose it's worth noting in your second link, the fatalities were from the kinetics of the impact, which is a hazard that belongs to "things with velocity" rather than "things containing fuels".
We can assume that uncontained fire and explosion are categorical hazards with fuels.
Ammonia has significant risks that few other proposed fuels present and I believe it's worth considering whether this is something we want moving outside of hazmat routes between industrial zones.
Except the risk of fire / explosion is lower. NFPA 704 for gasoline is 1 Health, 3 fire, 0 Instability where Ammonia is 3 Health, 1 fire, 0 Instability
Major spills of either are dangerous but rare compared to how much is being created and transported. We’re only ~5x as much gasoline vs Ammonia today. Considering most cars would be EV’s I suspect the total amount of Ammonia produced even with widespread adoption isn’t going to change by that much. Say Long haul trucks, heavy equipment, aircraft etc.
PS: Which isn’t to say Ammonia is actually a good fuel, the only thing I can think that actually used the stuff was the X-15. So it would need significant economic advantages to end up adopted.
You don’t have to keep it cool. Ammonia has similar profile to propane. It is liquid at 7-14 bar. We build pressure tanks like that all the time for propane.
Ammonia is probably too unsafe for cars and boats. But anything filled by professionals like trains or ships would work. But might work to have tank exchange system like with propane.
I was thinking about that but it's only a liquid at those pressures if you can keep it from getting too hot--say, a tank sitting there under the desert sun. And if your pressure relief triggers on ammonia it's a lot more of an issue than if it happens with propane.
Especially frustrating when considering that decarbonising a large part of transportation is easy, but boring: it's trains, light rail, it's cycling infrastructure. Not as sexy as futuristic energy sources, but it's what will save us in this sector: viable alternatives to the horrendously inefficient automobile
This is not to mention everything else. The immense death toll directly (crashes) and indirectly (pollution, particulates, etc). The waste of space in cities. The waste of time in traffic that is unfixable if everyone is driving in an individual car. Etc etc. I wish people would stop trying to save the auto industry and start looking at the root of the problem.
Replace highway infrastructure with train infrastructure that is powered by overhead lines. Build out the power grid to support that, and blanket the country with new rail lines that are nationalized and run as a public utility.
Result, reduces carbon footprint of travel - land shipping - ability to build out modern towns - etc
Toss in a bill to require all train lines to also install national fiber. You now have enabled the revitalization of large swaths of the county.
The Haber Bosch reaction does not produce any CO2:
N2 + 3H2 -> 2NH3
The challenge is getting the zero emission Hydrogen. The process presented here is somewhat better than using electricity for the electrolysis split water, but still substantially more expensive than the gray Hydrogen obtain by cracking Methane gas and releasing the CO2.
I took the author's claim of 100% electrolytic efficiency at face value and contrasted with typical water electrolysis efficiencies, followed by a Haber-Bosch step.
This method of direct electroreduction should not confused with the Laser-induced method discussed elsewhere in the thread, which has abysmal numbers.
While not in mass production, there is strong interest from the marine shipping industry. It can be produced near ports, and meets the storage and combustion engine constraints (similar to diesel) of the use case.
A sibling comment mentions scrubbing NOx emissions as a significant issue, and it strikes me that the shipping/cruise industry is already a major polluter in that area. (Unlike cars, which must have catalytic converters because of local landlubber laws.)
I guess my point is that cleaner technology is already being avoided by those companies, because they can save a buck by polluting in international waters.
Generally speaking modern hydrogen pressure vessels are not metal for this reason, they are composite and not affected by embrittlement.
The Toyota Mirai, a production hydrogen car, uses a type IV carbon fiber pressure vessel rated for 70 MPa / 10,000 psi.
Type V are rated for 15,000 psi.
It is not necessary to liquefy hydrogen for adequate range in ground transport applications: The Mirai yields a 402 mile EPA rated range on gaseous hydrogen.
The tanks weigh 93kg filled with 5.65kg hydrogen, yielding an approximately 190 kWh of stored energy.
All without corroding flesh in trace concentrations.
By comparison the Tesla Roadster's 450kg battery pack yields a 200 kWh capacity.
Ammonia is and would likely continue to be stored in metal pressure vessels as an obvious cost optimization and thus would compare unfavorably to hydrogen pressure vessels' effective energy density where that area of the performance versus cost optimization space is not available due to embrittlement.
Direct propane fuel cells have some thermal issues, but recently there was a breakthrough in propane synthesis that would make it efficient to produce. Are ammonia fuelcells efficient?
Not sure if they are today, but Toyota is putting a lot of effort into ammonia turbines. Also ammonia can be fired with coal or natural gas in existing setups. The main issue is neutralization of NOx exhaust.
I think many (most?) combined cycle plants use ammonia to destroy NOx in the exhaust (selective catalytic reduction). Some diesel cars use this technology as well (using urea instead of ammonia).
which I just can't imagine being clean when I consider that nitrogen oxides are also a concern with combustion fuels, not to mention it being an inefficient "battery" if you're making ammonia from green hydrogen and then burning it and spinning a turbine.
Well, we don't necessarily need as much storage if we can just shift a good amount of demand.
Fertilizer production via this method might be a good fit for times when rates are low or even negative due to wind energy overproduction during off peak.
They sometimes use weird techniques to produce electrodes with specific area on the orders of thousands of square meters per gram.
Even if it has to be flat, there's little holding you back from stacking 10k layers as long as you can manage the heat.
CO2 production with current processes isn’t necessary. They could use renewable electricity to hydrolyze water and power the plant, it’s just cheaper to use the grid and methane as a source of hydrogen.
Switching to carbon free ammonia would be no great task, just a price hike and some minor retrofitting.
Working past their fake news headlines like 100%. Hydrogen is almost 100% and that's not big if true.
We are decades away for renewable electricity only for our electric needs.
Then you have oil and many other things electric can replace which are worse than gas.
What about this is big? In a dream world of unlimited electricity everything is easy, like synth fuel and fertilizer and climate control. Today, burning coal to make fertilizer doesn't seem good, if this is true.
California produces about half of its electricity from renewables, mostly solar.
We’re decades away from 100%, but how long away are we nationally from 50%, 65%, 90%, 99%?
As solar production ramps up to higher percentages there is going to be more and more peak power in excess of demand. Industrial scale electrochemistry is going to be one of the alternatives to batteries that’s going to be developed.
Already nitrogen fixation requires a huge amount of energy, this process at scale could very well require less energy than the modern haber process.
What factory that produces X is so cheap to build in relation to the cost of energy on a daily basis that it is worth producing less X at different times of day due to the price of energy? The cost of the energy is usually such a small component of total costs it is not worth altering behavior for daily small energy price fluctuations, and nobody is advocating for energy prices to change by 10x throughout the day.
Before markets figured out how to take advantage, there have been several situations where electricity prices were regularly negative… they would pay for you to consume energy.
When solar hits a certain ratio of production there will be a daily peak where electricity will be very cheap because there’s too much of it, regardless of what people “advocate”.
Electrochemistry things are where it’s at, metal refining specifically.
Aluminum production from ore has one step where you literally just make what is effectively an enormous battery out of aluminum ore and “charge” it, when it’s fully charged you’ve turned aluminum oxide into pure aluminum. It can even be run backwards to produce electricity because it’s literally a battery (a really shitty one). So there’s not a huge capital investment or complex process and electric input is actually a significant portion of the cost.
Other simple electrochemistry things that do have a major portion of the cost in electricity can do the same when costs get low enough. There’s a lot of recycling that becomes possible with cheap clean energy that you would never do with fossil fuel electricity.
Sometimes they’re built next to hydroelectric dams and use the entire power output of the dam. Usually with long term power contracts that are more about constant load than consuming excess peaks (having a larger base load is more of an old school energy efficiency benefit, having users for variable loads is the future)
They don’t shut down entirely because the aluminum has to stay molten at a thousand degrees, but they can scale the energy usage significantly, this is becoming more of an interest in the last decade.
We are decades away from needing this. But we need to generate ammonia without fossil fuels for fertilizer and feed stock.
Also, we need a fuel for long distance transport like ships when batteries won’t work. Ammonia will always be cheaper than synthetic fuel because no carbon doesn’t have to come from air, and it stores better than hydrogen.
There may be lots of surplus electricity in the future but there will also be a lot of demands for carbon capture, hydrogen, long term storage, and chemical processes.
At current costs, a price-optimal solar/wind/battery mix for handling existing electricity needs would have on the order of 400% overcapacity. All that extra electricity is what will power the hydrogen-generation.
The main challenge is building cheap electrolysers without so much regard to efficiency, in order to use all the power when available. Most commercially available electrolysers today are expensive and cannot ramp up and down quickly.
Not until you can generate electricity at grid scale without CO2 emissions. That includes building the infrastructure to do so. Even nuclear doesn't get you there.
What does the term "current-to-ammonia efficiency" mean here? I imagine it would refer to the specificity of the reaction, i.e. that 99% of the electrons passing through the system are used in the main reaction, and <1% on side reactions.
The abstract doesn't go into detail on energy efficiency and a comparison to the old method using gas. For instance, would this method result in less CO2 emissions using regular grid electricity, or would it need to be 100% low-carbon electricity? If, say, the electricity came from a CCGT plant, how would that compare? Etc etc
>> ... would this method result in less CO2 emissions using regular grid
>> electricity, or would it need to be 100% low-carbon electricity? ...
Who cares? This is about electricity to ammonia.
Given: a very efficient way to make ammonia (as an energy store) using electricity, this becomes a storage mechanism. So then, make ammonia and money whenever the grid is in a 'pay to take power' state, and (up to a point) even if you have to pay. End source is irrelevant.
Alternate process: run a solar farm, produce ammonia whenever that's cheaper than paying someone to take the power (or curtail), then sell the stored power when prices are high. Or, sell the ammonia directly.
Not 100% of the energy, because even if no current is wasted, the voltage applied to the electrolysis cell is higher than the minimum value that corresponds to 100% energy efficiency.
To know the energy efficiency, besides the current efficiency, which is close to 100%, we need to know how big is the overvoltage needed for electrolysis.
Probably refers to "Coulombic efficiency." Ie, it takes 4 electron transfers to turn 2 H2 + N -> NH4, so that gives you a conversion factor between Coulombs of electrons (1 Amp of current is 1 Coulomb per second) and number of NH4 molecules produced.
Yeah, someone would have to get access to the paper to see if they state the energy efficiency. I assume that b/c they don't mention it, it is abysmal. There's pressure to put good results into the abstract.
Bear in mind that grid electricity is getting cleaner over time. We need to skate to where the puck is going, which is 100% clean electricity. Now is an excellent time to be developing and preparing to scale technologies that work well with clean electricity.
Yes - in theory, it's probably pretty efficient. Just would be interesting to see how it compares. We know it has good Coulombic efficiency, but that's only half the picture - at least for energy storage / synfuel applications.
This would be a gigantic breakthrough if true and scalable, correct? Most ammonia production for fertilizer currently uses natural gas, and of clean sources of electricity with such a high yield of ammonia production would have a huge worldwide impact. So is there something I'm missing?
The scalable part is going to be difficult though.
This is not all that different from the production of hydrogen. Hydrogen is most economically produced from natural gas nowadays. You can produce it from water, with (just like here) an almost 100% current-to-hydrogen efficiency. But it's still twice as expensive, if not more.
Current/Faraday efficiency is an entirely different thing. 100% current efficiency means you won't get a buildup of side products or erosion of your electrodes due to stray electrons. In isolation it is not a measure of power efficiency.
Not if the energy efficiency were poor, compared to electrolytic hydrogen into a conventional Haber-Bosch process. And remember hydrogen is very storable, so that process could buffer renewable intermittency and keep the H-B plant running continuously. Electrolyzers are getting cheap.
Actually storing and transporting hydrogen are technical challenges. It takes up a lot of space and hydrogen molecules are so small they leak through a lot of materials. Not impossible but you need a lot of expensive infrastructure to handle it.
Most hydrogen produced today is consumed very close to where it is produced. Also energy storage and fuel type use cases rank very low on Michael Liebreich's hydrogen ladder. That's a nice tool that ranks different uses of hydrogen by their economic feasibility and overhead. Chemically binding it to something else to store it works of course. Ammonia (NH3) is common for this; and in fact the biggest use case for hydrogen. People have speculated about using that as a fuel. It's much easier to store and transport. And of course these chemical transformations also have an energy cost.
Actually, storage and transportation are positives for hydrogen. It's easier to transport and store hydrogen than it is to transport and store electricity. Hydrogen can be stored underground in caverns very cheaply (this is a demonstrated technology already in use for buffering hydrogen produced from fossil fuels), compared to the cost of equipment for storing electrical energy. Hydrogen is a viable for seasonal storage of renewable energy, unlike batteries.
The negative for hydrogen is poor round trip efficiency of electricity -> hydrogen -> electricity. But for sufficiently long storage times the lower cost of storage capacity vs. batteries overwhelms that, and hydrogen becomes cheaper for grid storage.
Probably not just yet. I calculated downthread that the productivity is something like 16x less per unit area than a hydrogen electrolyzer, so that would need to be improved to make it cost-effective probably. Also they don't mention the energy efficiency, only the "current efficiency" so I would assume the energy efficiency is also poor. Sounds like there's much to be done still.
One downside of ammonia is its toxicity (with an IDLH threshold of 300 ppm). I doubt we'll ever see cars running on it, and storing large amounts as energy storage sounds risky.
Do we know if this process is burstable (i.e. the devices for running it are likely cheap enough compared to the energy requirement that they don't need to run 24/7, and could use excess renewable energy when available)?
I agree, it's kind of a different class of threat for everyday people.
Not assuming it would be the same, but picturing a spill at a gas station. Spilling gas is a problem, but at least it's just sort of there.
If you get an ammonia leak and it forms a vapor cloud, I don't think most people would know how to deal with that.
I'll bet your spilled gas likely won't migrate into the intersection.
But on the plus side, we already see what handling/transportation of large amounts looks like for agriculture, even if rail carriers etc. dislike dealing with it.
Correction: Ammonia is not flammable since the flash point is significantly above room temperature. It would only be explosive if you consider the pressure vessel exploding, but we also have natural gas powered cars which also have pressurized cylinders. The main real issue is the toxicity.
It does have a higher ignition point than gas. But one a spark can definitely reach. It’s been a common problem in industry where ammonia gets used a lot (refrigeration in particular).
BLEVE’s are also a problem too of course. And the toxic nature of breathing it in! Haha.
Anhydrous ammonia’s ‘flash point’ (producing flammable/explosive vapors) is well below room temperature at STP? It boils at -28F. That’s why it is so commonly used for refrigeration.
It does have a specific LEL and UEL that makes it less dangerous than gasoline. It also has a much higher auto ignition temp.
Yeah, anhydrous ammonia is less dangerous than gasoline (1 instead of 4) on the fire diamond due to it being less easy to ignite.
But flash point doesn’t help you here?
electrical sparks or open flame can still definitely do it. And have, multiple times.
Some pretty amazing clips in industrial accident videos from it, actually. My favorite part is when the chunk of roof almost makes it to the highway.
Flash point and boiling points are different. The flashpoint of ammonia is 270F. Below this temperature at 1 atm, ammonia will not catch fire no matter what.
That video took place in an engine room, so any combination of heat, flame, or spark is possible.
“Flash point is the temperature a liquid (usually a petroleum product) will form a vapour in the air near its surface that will “flash,” or briefly ignite, on exposure to an open flame”
If ammonia is boiling (and producing a fog) of concentrated vapor which then burns/explodes in exposure to an open flame, which it will definitely do at even OF, that is an entirely academic point no?
If it is cheap, that will beat out a lot of other concerns. Not sufficient for consumer use, but power plants are already hazardous places that can engineer significant safety controls.
Well... there's hydrazine (N2H4) which is the stuff they use as monopropellant rocket fuel. It burns even without the presence of oxygen and it's even more toxic and explosive than ammonia. It's the reason the capture crews for returning spacecrafts wear hazmat suits.
However hydrazine is liquid at room temperature and it can be converted to hydrazone (also being considered for fuel cells) which is solid at room temperature and non-reactive... until it comes into contact with water at which point it all turns back into hydrazine.
But yeah no there's really not a "nicer" fuel. Generally, if it has nitrogen in it and it isn't literally just nitrogen with itself, it's dangerous. And the more nitrogens it has the more dangerous it is.
Diesel's flash point is above ambient temperature (unless you live in the Sahara). It has a lower autoignition point than gasoline, which is one of the reasons it's preferred in compression ignition engines.
If you dump gasoline on a fire, it will go ‘fwoomp’ and try to climb back into whatever container you poured it out of. If it succeeds, that container may even explode. Which is bad, and why people die or get terrible burns from pouring gasoline on fires.
If you pour diesel on a fire, the fire will get bigger and none of those things will happen. Unless, apparently, like the poster above, you pour so much on it so fast it drowns it before the diesel can get up to temp. Apparently. I’ve personally never tried that.
Diesel is basically cooking oil in many ways, and you can do the same thing with cooking oil too if you want.
This is well known by every redneck I’ve ever met, and I’ve personally done it numerous times.
P.S. also, putting gasoline on cold fuel in warm climates makes a pretty cool fireball due to said flashpoint. Just, you know, don’t light it from close up. Cold climates? No problem.
This could be a game changer for seasonal energy storage if it allows round trip efficiencies of even say 60%. Ammonia has been demonstrated as a fuel in existing natural gas turbines [1] at combustion efficiencies up to 99%.
First you want to displace natural gas for fertilizer production. But yes, if the energy efficiency is good enough and the electrolyzer costs are very low, it would make more sense than electrolyzing hydrogen and then running that through Haber-Bosch. Remains to be seen if either of those criteria can be met.
Undoubtedly, at the scales needed for seasonal energy storage, containment systems with multiple fail-safes would be needed. But if we can do that for nuclear reactors, it's got to be strictly simpler for ammonia.
The paper says that this is only half of a solution: "Our investigation here has focussed [sic] on the fundamental Li-NRR performance at the cathode. Further developments towards a complete ammonia electrosynthesis system will require investigations of appropriate anode reactions while eliminating sacrificial solvent oxidation. A feasible initial strategy is to couple the Li-NRR with the H2 oxidation reaction, which has already been demonstrated but requires improvements in stability and activity. A more-desirable anode process is H2O oxidation, which presents larger challenges because of the potential interference of water with the Li-mediated process and vice versa."
This system involves ethanol as a sacrificial hydrogen donor: "The amount of ammonia produced in the 96 h experiments (3.9 ± 0.1 mmol) was around four times higher than the amount of ethanol present (1 mmol), indicating that it is not a completely sacrificial reactant but can also operate as a proton carrier."
I need to ask this question for any chemical engineers currently reading this. I'm seeing people in the comments talking about how this could be applied to consumer vehicles, not just industry like cargo ships and agriculture.
If I, the consumer, had unlimited access to cheap, unregulated liquid ammonia (as common as gasoline), how many precursor-steps am I away from having access to like... a LOT of high explosives?
-asking for your friendly neighborhood crazy person with a vendetta against... whoever.
As far as I can see, it's a very similar problem to hydrogen. It doesn't matter how safe you can make it, it matters how dangerous a random nutjob can make it.
It only needs to be as safe as fossil fuels, or even slightly less safe, if the benefits are higher.
This always bothers me. People freak out about LiIon battery failures, or hydrogen, or ammonia, or nuclear power. But here we are with an entire economy riding on an explosive, firey, dirty fuel that is already causing global climate problems.
Safety concerns should be kept on-par with what we have today. Let’s not throw out a good solution because it can be dangerous in some cases. Any high-energy-dense thing we switch to after fossil fuels is going to release that energy if handled improperly. That concern should be quite low on the list.
Fueling up with ammonia is roughly as dangerous as fueling up with concentrated pesticide, on the health risk scale. It’s much more toxic than gasoline.
Synthesizing high explosives from anhydrous ammonia is not trivial and no random person would ever bother. There are easier precursors to work with and much easier ways to acquire high explosives than trying to bootstrap from ammonia.
And if someone really was bent on mayhem, well, anhydrous ammonia is nasty toxic stuff as is. You don’t need to do anything chemically to it to kill or injure a lot of people. On the other hand, it isn’t a chemical that sneaks up on you. If you are being exposed to dangerous levels, you’ll know it.
Yes, the difference is tannerite (by yield) is many times more expensive, and much easier to trace when someone buys hundreds of pounds of it from a sporting goods store. Similarly, a random individual buying a half ton of AN would probably trip some kind of alarm bells somewhere.
half ton? If I was headed to a friend's house who owns a farm and they asked me to pick up half a ton of farm supplies I would think nothing of it. Even my truck with its tiny payload can carry that around
If somebody asks you to buy half a ton of fertilizer on their behalf, I suggest you think twice about it. Why do they want you to buy it for them? Even if he's a farmer, with a rational use for that much fertilizer, why is he making such an unusual arrangement to receive fertilizer through his friend instead of buying it himself normally?
Who knows man, maybe feds caught him with some pot plants and now he's setting you up in some sort of bullshit anti-terror sting to cut a deal. Regardless of what kind of truck you have, casually buying half a ton of fertilizer for somebody else is an odd request that warrants some explaining.
You can buy ammonium nitrate in bulk. Much easier to turn into an explosive if that’s the point you’re making. Just say you’re opening a farm and off you go.
Well of course, but that only works once before you get traced and caught, might still be acceptable for the aforementioned crazy guy but I assume most others would rather blend in with the 50 million people buying gas on any given day.
I heard something about this too, though I omitted it for the sake of brevity. Don't know the specifics, but yes I think it's also a drug precursor. I remember some CCTV footage of people stealing ammonia from large tanks on a farm, not sure what other reason they would have other than drug production.
Incorrect in multiple respects. The molar mass of N is 14.006747 g/mol, while ammonia is 17.03052 g/mol. Gas expands to fill the container, so it's only worth discussing in mass terms.
It's rate of production over the area of the catalyst. Put another way, that's 1.5 ± 0.2 mmol/m²s or 25.5 ± 3.4 mg/m²s.
24 hours of production over a catalyst with an area of 1000 m² would create 25 ± 3.4 t. That's about the product weight of a typical full cold / cool towed trailer tank sent to large-scale customers. A commercial ammonia refinery would need many multiples of this area to be economically viable.
For hydrogen electrolysis they typically quote around 1 A/cm^2 current. One Coulomb is ~6e18 charges, whereas one mole is 6e23 molecules, so that makes about 1e-5 H atoms per cm per second. Of course making one molecule of ammonia needs 4 H atoms, so it works out to something like 16x lower productivity. I assume it's not competitive as is.
> ammonia production is energy-intensive, accounting for 1% to 2% of global energy consumption, 3% of global carbon emissions,[23] and 3% to 5% of natural gas consumption
Big if we can improve this.
For more on the Haber process and its impact on the world, I highly recommend this book: "The Alchemy of Air: A Jewish Genius, a Doomed Tycoon, and the Scientific Discovery That Fed the World but Fueled the Rise of Hitler" by Thomas Hager.
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And I’d suggest you to be this rude somewhere else. You are entitled to ignore my question or downvote it. A bit of negative karma is way more didactic than your comment. Acting with this level of arrogance, no matter how out of touch my comment may be, isn’t good for anyone.
“Laser-induced nitrogen fixation” https://www.nature.com/articles/s41467-023-41441-0
This is Open Access, and mentions how that is also a leap forward in Nitrogen fixation
“Abstract: For decarbonization of ammonia production in industry, alternative methods by exploiting renewable energy sources have recently been explored. Nonetheless, they still lack yield and efficiency to be industrially relevant. Here, we demonstrate an advanced approach of nitrogen fixation to synthesize ammonia at ambient conditions via laser–induced multiphoton dissociation of lithium oxide. Lithium oxide is dissociated under non–equilibrium multiphoton absorption and high temperatures under focused infrared light, and the generated zero–valent metal spontaneously fixes nitrogen and forms a lithium nitride, which upon subsequent hydrolysis generates ammonia. The highest ammonia yield rate of 30.9 micromoles per second per square centimeter is achieved at 25 °C and 1.0 bar nitrogen. This is two orders of magnitude higher than state–of–the–art ammonia synthesis at ambient conditions. The focused infrared light here is produced by a commercial simple CO2 laser, serving as a demonstration of potentially solar pumped lasers for nitrogen fixation and other high excitation chemistry. We anticipate such laser-involved technology will bring unprecedented opportunities to realize not only local ammonia production but also other new chemistries.”