13 ms·

Nitrogen electroreduction with almost 100% current-to-ammonia efficiency (2022)

266 points by gorpovitch 3y ago

londons_explore 3y ago
Big if true... 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.
- RetroTechie 3y ago
  Not just fertilizer: "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. Would be a huge breakthrough in any case.
  - fbdab103 3y ago
    Are there power plants today that burn ammonia directly? If not, is it a simple/cheap enough conversion?
    - praveen9920 3y ago
      It is actually cheaper because of existing infrastructure that exists for fertilisers manufacturing. But the main concern is that ammonia burns slowly. It might work in power plants but not in EVs
      - thfuran 3y ago
        Why would you want to burn ammonia in an electric vehicle?
    - dexwiz 3y ago
      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.
      - ForgedEngine 3y ago
        Filter the exhaust through a caustic solution to neutralize NOxs.
    - toomuchtodo 3y ago
      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. https://spectrum.ieee.org/why-the-shipping-industry-is-betting-big-on-ammonia https://spectrum.ieee.org/why-the-shipping-industry-is-betti... https://www.wartsila.com/media/news/30-06-2020-world-s-first-full-scale-ammonia-engine-test---an-important-step-towards-carbon-free-shipping-2737809 https://www.wartsila.com/media/news/30-06-2020-world-s-first... https://www.lr.org/en/about-us/press-listing/press-release/industry-leaders-join-forces-on-ammonia-fuelled-tanker-project/ https://www.lr.org/en/about-us/press-listing/press-release/i... https://www.ammoniaenergy.org/articles/maritime-fuel-mix-could-be-25-ammonia-by-2050/ https://www.ammoniaenergy.org/articles/maritime-fuel-mix-cou...
      - Terr_ 3y ago
        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.)
        toomuchtodo 3y ago
        High efficiency scrubbing appears to be feasible. https://pubs.acs.org/doi/10.1021/acs.energyfuels.3c01419 https://pubs.acs.org/doi/10.1021/acs.energyfuels.3c01419
        Terr_ 3y ago
        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.
        ForgedEngine 3y ago
        NOxs are practically zero with HCCI at a stoichiometric ratio.
    - adrian_b 3y ago
      There has been a lot of research in fuel cells that generate electricity from ammonia, with much simpler storage problems than for hydrogen.
      - Projectiboga 3y ago
        Yes, fuel cells need more usage as we move away from oil & unnatural gas.
        galangalalgol 3y ago
        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?
      - aifooh7Keew6xoo 3y ago
        I'm not sure I'd leap to "much simpler storage problems than for hydrogen" for a highly corrosive gas. The lower explosive limit of hydrogen is ~4%. By comparison the 300 ppm immediate danger to life and health threshold of ammonia is .03%. It is intrinsically dangerous, i.e. without a source of ignition, at concentrations 2 orders of magnitude lower than the LEL of hydrogen. Not every hydrogen leak is a concern, but just about every ammonia leak is. The established OSHA 15 minute exposure limit for ammonia is 35 ppm, 8 hours is 25 ppm.
        thfuran 3y ago
        But hydrogen likes to make invisible fires and leak through solid steel, and it needs to be ludicrously cold to liquify.
        aifooh7Keew6xoo 3y ago
        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.
    - ZeroGravitas 3y ago
      In Japan they're looking at adding Ammonia co-firing to coal plants: https://about.bnef.com/blog/japans-ammonia-coal-co-firing-strategy-a-costly-approach-to-decarbonization-renewables-present-more-economic-alternative/ https://about.bnef.com/blog/japans-ammonia-coal-co-firing-st...
    - pfdietz 3y ago
      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).
  - jtbayly 3y ago
    Farms have been producing their own fertilizer for centuries. ;-)
    - multiplegeorges 3y ago
      Millenia, even.
    - RetroTechie 3y ago
      Yeah I know. Wasn't talking about that. https://phys.org/news/2021-02-plasma-technology-world.html https://phys.org/news/2021-02-plasma-technology-world.html https://portal.nifa.usda.gov/web/crisprojectpages/1025777-low-cost-plasma-reactors-for-on-farm-nitrogen-fixation.html https://portal.nifa.usda.gov/web/crisprojectpages/1025777-lo... https://pubs.acs.org/doi/10.1021/acssuschemeng.2c06357 https://pubs.acs.org/doi/10.1021/acssuschemeng.2c06357 (paywalled) "plasma" and "NOx" seem to be the keywords here (so other process than discussed here). Not at scale (yet), cost unclear. But the technology exists, and being improved upon.
    - eternauta3k 3y ago
      Yes, and yields were crap back then. Guano and then synthetic fertilizer changed everything.
  - bequanna 3y ago
    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.
  - aifooh7Keew6xoo 3y ago
    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...
    - PumpkinSpice 3y ago
      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.
      - aifooh7Keew6xoo 3y ago
        It is certainly easier to liquefy, I can't argue that point.
      - justinclift 3y ago
        Hmmm, "gas station filled with petrol that explodes" vs "gas station filled with hydrogen that explodes". Being near either one as it explodes would be bad, but I wonder which one looks more impressive movie-effects-wise? :)
        sfink 3y ago
        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.
  - deleted 3y ago
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  - cornholio 3y ago
    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.
    - pfdietz 3y ago
      Where did you conclude it was somewhat better than using electricity for electrolysis?
      - cornholio 3y ago
        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.
        pfdietz 3y ago
        The 100% efficiency is faradaic efficiency, not energy efficiency, I believe.
  - PaulHoule 3y ago
    The strangest thing is that Japan is thinking about burning ammonia together with coal https://about.bnef.com/blog/japans-ammonia-coal-co-firing-strategy-a-costly-approach-to-decarbonization-renewables-present-more-economic-alternative/ https://about.bnef.com/blog/japans-ammonia-coal-co-firing-st... 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.
- conradev 3y ago
  It’s big enough and true enough for entrepreneurs – Nitricity is building shipping container-sized fertilizer factories
- aaron695 3y ago
  > Big if true... Could you explain exactly why you would say this? 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.
  - colechristensen 3y ago
    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.
    - applied_heat 3y ago
      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.
      - gofhwgwidi 3y ago
        Aluminum
        applied_heat 3y ago
        Do aluminum factories shut down daily due to fluctuating prices or are they located in areas with cheap and plentiful reliable electricity supply?
- colechristensen 3y ago
  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.
- Paul-Craft 3y ago
  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.
- scythe 3y ago
  Oh it's true. But as the paper states, they produced 3.9 millimoles — 0.068 grams — of ammonia in 96 hours. So I'm not exactly holding my breath. It's a big improvement over previous methods, but there's still a long way to go.
  - hinkley 3y ago
    Definitely hold your breath around people trying to produce ammonia.
  - jojobas 3y ago
    That's for a 1cm^2 electrode, as far as I remember not precious-metal rich either.
    - thfuran 3y ago
      So you only need an electrode about the size of Monaco to get 1 kg per second. Hopefully you can use some kind of foam or something.
      - jojobas 3y ago
        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.
HPsquared 3y ago
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
- tgsovlerkhgsel 3y ago
  My naive interpretation would be "almost 100% of the energy put into the process gets chemically stored in the ammonia".
  - adrian_b 3y ago
    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.
- cranky908canuck 3y ago
  >> ... 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.
- snewman 3y ago
  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.
hn_throwaway_99 3y ago
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?
- hiddencost 3y ago
  If you can start/stop the process easily, it could be a great sink for excess solar capacity.
- credit_guy 3y ago
  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.
  - Superfluidity 3y ago
    Electrolysis of water is 70–80% efficient (a 20–30% conversion loss) while steam reforming of natural gas has a thermal efficiency between 70 and 85%. https://en.m.wikipedia.org/wiki/Hydrogen_production#:~:text=Water%20electrolysis%20is%20using%20electricity,efficiency%20between%2070%20and%2085%25 https://en.m.wikipedia.org/wiki/Hydrogen_production#:~:text=....
    - ororroro 3y ago
      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.
- pfdietz 3y ago
  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.
marcodiego 3y ago
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- ilyt 3y ago
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  - marcodiego 3y ago
    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.
    - ilyt 3y ago
      "I didn't bother to read, please shorten it up for me peasants" is the most arrogant thing you can do in online forums You have no right to call anyone else "arrogant" Mr. main character complex
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DarkmSparks 3y ago
Nice. Think it was Toyota recently got themselves an ammonia combustion engine prototype running as well.
tgsovlerkhgsel 3y ago
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)?
- ilyt 3y ago
  Well, petrol or diesel isn't that nice either
  - lazide 3y ago
    Anhydrous ammonia is much worse, creating rolling clouds of ground level deadly gas for long distances. And being very flammable. And explosive. Gas doing 2 of those 3, and diesel only 1.
    - fbdab103 3y ago
      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.
    - TheSpiceIsLife 3y ago
      Diesel is none of those things. I have extinguished a fire with diesel.
      - lazide 3y ago
        Diesel is definitely flammable. I works great as an accelerant. It isn’t as easily flammable as gas, and doesn’t have easily autoignitable vapor like gas. I’m guessing you dumped a lot of it on something without a lot of thermal mass? If you did the same on a bonfire, you’d have a different story.
zeristor 3y ago
Looking at the paper, in similar papers reference is made to this paper published 13th September 2023: “Laser-induced nitrogen fixation” https://www.nature.com/articles/s41467-023-41441-0 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.”
- deleted 3y ago
  [deleted]
- wolfi1 3y ago
  "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
  - nullc 3y ago
    > (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.
shrubble 3y ago
Interesting paper from 2019 if you are thinking about burning ammonia for e.g. power plants etc. https://www.sciencedirect.com/science/article/pii/S1540748918306345 https://www.sciencedirect.com/science/article/pii/S154074891...
rational_indian 3y ago
>150 ± 20 nmol s−1 cm−2 Isn't this miniscule? Is this commercially viable? Edit: The molecular mass of nitrogen is 28, so 1 mol is 28 grams, so 150 nmol is 28 x150 nano grams = 4.2 micro grams. How much gas is this?
- oldbbsnickname 3y ago
  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. https://alliancetruckandtank.com/products/transport-trailers/ https://alliancetruckandtank.com/products/transport-trailers...
  - gpm 3y ago
    Any idea how tightly can these cells likely be packed in 3d? Is 1000 m² likely to be 1 m³ or 1000 m³?
- lambdatronics 3y ago
  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.
keep_reading 3y ago
Toyota has an engine that runs on ammonia https://www.enginelabs.com/engine-tech/engine/corrosion-of-conformity-toyota-takes-aim-at-evs-with-ammonia-engine/ https://www.enginelabs.com/engine-tech/engine/corrosion-of-c...
Taiwan_No_1 3y ago
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anon_cow1111 3y ago
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.
- sidewndr46 3y ago
  What would it matter? I can go buy as much materials to make explosives as I want today. Or I could just purchase actual explosives at the sporting good store, like tannerite.
  - anon_cow1111 3y ago
    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.
    - sidewndr46 3y ago
      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
      - mcpackieh 3y ago
        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.
eternauta3k 3y ago
From https://en.wikipedia.org/wiki/Haber_process#Process https://en.wikipedia.org/wiki/Haber_process#Process: > 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.
danans 3y ago
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%. 1. https://nh3fuelassociation.org/2018/12/07/performance-of-ammonia-natural-gas-co-fired-gas-turbine-for-power-generation/#:~:text=Performance%20of%20the%20gas%20turbine,1000%20ppm%4016%25O2 https://nh3fuelassociation.org/2018/12/07/performance-of-amm....
- hinkley 3y ago
  Highly caustic to delicate tissues however, such as lung tissue.
  - danans 3y ago
    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.
    - hinkley 3y ago
      Some early fridges ran on ammonia as the refrigerant. Didn’t survive scaling up to mass production. Neither has nuclear.
- lambdatronics 3y ago
  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.
lambdatronics 3y ago
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."

266 points by gorpovitch 3y ago

Big if true... 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.

RetroTechie 3y ago
Not just fertilizer: "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. Would be a huge breakthrough in any case.
- fbdab103 3y ago
  Are there power plants today that burn ammonia directly? If not, is it a simple/cheap enough conversion?
  - praveen9920 3y ago
    It is actually cheaper because of existing infrastructure that exists for fertilisers manufacturing. But the main concern is that ammonia burns slowly. It might work in power plants but not in EVs
    - thfuran 3y ago
      Why would you want to burn ammonia in an electric vehicle?
  - dexwiz 3y ago
    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.
    - ForgedEngine 3y ago
      Filter the exhaust through a caustic solution to neutralize NOxs.
  - toomuchtodo 3y ago
    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. https://spectrum.ieee.org/why-the-shipping-industry-is-betting-big-on-ammonia https://spectrum.ieee.org/why-the-shipping-industry-is-betti... https://www.wartsila.com/media/news/30-06-2020-world-s-first-full-scale-ammonia-engine-test---an-important-step-towards-carbon-free-shipping-2737809 https://www.wartsila.com/media/news/30-06-2020-world-s-first... https://www.lr.org/en/about-us/press-listing/press-release/industry-leaders-join-forces-on-ammonia-fuelled-tanker-project/ https://www.lr.org/en/about-us/press-listing/press-release/i... https://www.ammoniaenergy.org/articles/maritime-fuel-mix-could-be-25-ammonia-by-2050/ https://www.ammoniaenergy.org/articles/maritime-fuel-mix-cou...
    - Terr_ 3y ago
      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.)
      - toomuchtodo 3y ago
        High efficiency scrubbing appears to be feasible. https://pubs.acs.org/doi/10.1021/acs.energyfuels.3c01419 https://pubs.acs.org/doi/10.1021/acs.energyfuels.3c01419
        Terr_ 3y ago
        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.
      - ForgedEngine 3y ago
        NOxs are practically zero with HCCI at a stoichiometric ratio.
  - adrian_b 3y ago
    There has been a lot of research in fuel cells that generate electricity from ammonia, with much simpler storage problems than for hydrogen.
    - Projectiboga 3y ago
      Yes, fuel cells need more usage as we move away from oil & unnatural gas.
      - galangalalgol 3y ago
        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?
    - aifooh7Keew6xoo 3y ago
      I'm not sure I'd leap to "much simpler storage problems than for hydrogen" for a highly corrosive gas. The lower explosive limit of hydrogen is ~4%. By comparison the 300 ppm immediate danger to life and health threshold of ammonia is .03%. It is intrinsically dangerous, i.e. without a source of ignition, at concentrations 2 orders of magnitude lower than the LEL of hydrogen. Not every hydrogen leak is a concern, but just about every ammonia leak is. The established OSHA 15 minute exposure limit for ammonia is 35 ppm, 8 hours is 25 ppm.
      - thfuran 3y ago
        But hydrogen likes to make invisible fires and leak through solid steel, and it needs to be ludicrously cold to liquify.
        aifooh7Keew6xoo 3y ago
        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.
  - ZeroGravitas 3y ago
    In Japan they're looking at adding Ammonia co-firing to coal plants: https://about.bnef.com/blog/japans-ammonia-coal-co-firing-strategy-a-costly-approach-to-decarbonization-renewables-present-more-economic-alternative/ https://about.bnef.com/blog/japans-ammonia-coal-co-firing-st...
  - pfdietz 3y ago
    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).
- jtbayly 3y ago
  Farms have been producing their own fertilizer for centuries. ;-)
  - multiplegeorges 3y ago
    Millenia, even.
  - RetroTechie 3y ago
    Yeah I know. Wasn't talking about that. https://phys.org/news/2021-02-plasma-technology-world.html https://phys.org/news/2021-02-plasma-technology-world.html https://portal.nifa.usda.gov/web/crisprojectpages/1025777-low-cost-plasma-reactors-for-on-farm-nitrogen-fixation.html https://portal.nifa.usda.gov/web/crisprojectpages/1025777-lo... https://pubs.acs.org/doi/10.1021/acssuschemeng.2c06357 https://pubs.acs.org/doi/10.1021/acssuschemeng.2c06357 (paywalled) "plasma" and "NOx" seem to be the keywords here (so other process than discussed here). Not at scale (yet), cost unclear. But the technology exists, and being improved upon.
  - eternauta3k 3y ago
    Yes, and yields were crap back then. Guano and then synthetic fertilizer changed everything.
- bequanna 3y ago
  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.
- aifooh7Keew6xoo 3y ago
  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...
  - PumpkinSpice 3y ago
    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.
    - aifooh7Keew6xoo 3y ago
      It is certainly easier to liquefy, I can't argue that point.
    - justinclift 3y ago
      Hmmm, "gas station filled with petrol that explodes" vs "gas station filled with hydrogen that explodes". Being near either one as it explodes would be bad, but I wonder which one looks more impressive movie-effects-wise? :)
      - sfink 3y ago
        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.
- deleted 3y ago
  [deleted]
- cornholio 3y ago
  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.
  - pfdietz 3y ago
    Where did you conclude it was somewhat better than using electricity for electrolysis?
    - cornholio 3y ago
      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.
      - pfdietz 3y ago
        The 100% efficiency is faradaic efficiency, not energy efficiency, I believe.
- PaulHoule 3y ago
  The strangest thing is that Japan is thinking about burning ammonia together with coal https://about.bnef.com/blog/japans-ammonia-coal-co-firing-strategy-a-costly-approach-to-decarbonization-renewables-present-more-economic-alternative/ https://about.bnef.com/blog/japans-ammonia-coal-co-firing-st... 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.
conradev 3y ago
It’s big enough and true enough for entrepreneurs – Nitricity is building shipping container-sized fertilizer factories
aaron695 3y ago
> Big if true... Could you explain exactly why you would say this? 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.
- colechristensen 3y ago
  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.
  - applied_heat 3y ago
    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.
    - gofhwgwidi 3y ago
      Aluminum
      - applied_heat 3y ago
        Do aluminum factories shut down daily due to fluctuating prices or are they located in areas with cheap and plentiful reliable electricity supply?
colechristensen 3y ago
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.
Paul-Craft 3y ago
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.
scythe 3y ago
Oh it's true. But as the paper states, they produced 3.9 millimoles — 0.068 grams — of ammonia in 96 hours. So I'm not exactly holding my breath. It's a big improvement over previous methods, but there's still a long way to go.
- hinkley 3y ago
  Definitely hold your breath around people trying to produce ammonia.
- jojobas 3y ago
  That's for a 1cm^2 electrode, as far as I remember not precious-metal rich either.
  - thfuran 3y ago
    So you only need an electrode about the size of Monaco to get 1 kg per second. Hopefully you can use some kind of foam or something.
    - jojobas 3y ago
      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.

HPsquared 3y ago

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

tgsovlerkhgsel 3y ago
My naive interpretation would be "almost 100% of the energy put into the process gets chemically stored in the ammonia".
- adrian_b 3y ago
  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.
cranky908canuck 3y ago
>> ... 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.
snewman 3y ago
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.

hn_throwaway_99 3y ago

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?

hiddencost 3y ago
If you can start/stop the process easily, it could be a great sink for excess solar capacity.
credit_guy 3y ago
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.
- Superfluidity 3y ago
  Electrolysis of water is 70–80% efficient (a 20–30% conversion loss) while steam reforming of natural gas has a thermal efficiency between 70 and 85%. https://en.m.wikipedia.org/wiki/Hydrogen_production#:~:text=Water%20electrolysis%20is%20using%20electricity,efficiency%20between%2070%20and%2085%25 https://en.m.wikipedia.org/wiki/Hydrogen_production#:~:text=....
  - ororroro 3y ago
    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.
pfdietz 3y ago
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.

marcodiego 3y ago

[flagged]

ilyt 3y ago
[flagged]
- marcodiego 3y ago
  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.
  - ilyt 3y ago
    "I didn't bother to read, please shorten it up for me peasants" is the most arrogant thing you can do in online forums You have no right to call anyone else "arrogant" Mr. main character complex
  - dang 3y ago
    Please don't respond to a bad comment by breaking the site guidelines yourself. That only makes things worse. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
- dang 3y ago
  We've banned this account for repeatedly breaking the site guidelines and ignoring our request to stop. If you don't want to be banned, you're welcome to email hn@ycombinator.com and give us reason to believe that you'll follow the rules in the future. They're here: https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html.

DarkmSparks 3y ago

Nice. Think it was Toyota recently got themselves an ammonia combustion engine prototype running as well.

tgsovlerkhgsel 3y ago

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)?

ilyt 3y ago
Well, petrol or diesel isn't that nice either
- lazide 3y ago
  Anhydrous ammonia is much worse, creating rolling clouds of ground level deadly gas for long distances. And being very flammable. And explosive. Gas doing 2 of those 3, and diesel only 1.
  - fbdab103 3y ago
    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.
  - TheSpiceIsLife 3y ago
    Diesel is none of those things. I have extinguished a fire with diesel.
    - lazide 3y ago
      Diesel is definitely flammable. I works great as an accelerant. It isn’t as easily flammable as gas, and doesn’t have easily autoignitable vapor like gas. I’m guessing you dumped a lot of it on something without a lot of thermal mass? If you did the same on a bonfire, you’d have a different story.

zeristor 3y ago

Looking at the paper, in similar papers reference is made to this paper published 13th September 2023: “Laser-induced nitrogen fixation” https://www.nature.com/articles/s41467-023-41441-0 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.”

deleted 3y ago
[deleted]
wolfi1 3y ago
"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
- nullc 3y ago
  > (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.

shrubble 3y ago

Interesting paper from 2019 if you are thinking about burning ammonia for e.g. power plants etc. https://www.sciencedirect.com/science/article/pii/S1540748918306345 https://www.sciencedirect.com/science/article/pii/S154074891...

rational_indian 3y ago

>150 ± 20 nmol s−1 cm−2 Isn't this miniscule? Is this commercially viable? Edit: The molecular mass of nitrogen is 28, so 1 mol is 28 grams, so 150 nmol is 28 x150 nano grams = 4.2 micro grams. How much gas is this?

oldbbsnickname 3y ago
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. https://alliancetruckandtank.com/products/transport-trailers/ https://alliancetruckandtank.com/products/transport-trailers...
- gpm 3y ago
  Any idea how tightly can these cells likely be packed in 3d? Is 1000 m² likely to be 1 m³ or 1000 m³?
lambdatronics 3y ago
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.

keep_reading 3y ago

Toyota has an engine that runs on ammonia https://www.enginelabs.com/engine-tech/engine/corrosion-of-conformity-toyota-takes-aim-at-evs-with-ammonia-engine/ https://www.enginelabs.com/engine-tech/engine/corrosion-of-c...

Taiwan_No_1 3y ago

[dead]

anon_cow1111 3y ago

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.

sidewndr46 3y ago
What would it matter? I can go buy as much materials to make explosives as I want today. Or I could just purchase actual explosives at the sporting good store, like tannerite.
- anon_cow1111 3y ago
  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.
  - sidewndr46 3y ago
    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
    - mcpackieh 3y ago
      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.

eternauta3k 3y ago

From https://en.wikipedia.org/wiki/Haber_process#Process https://en.wikipedia.org/wiki/Haber_process#Process: > 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.

danans 3y ago

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%. 1. https://nh3fuelassociation.org/2018/12/07/performance-of-ammonia-natural-gas-co-fired-gas-turbine-for-power-generation/#:~:text=Performance%20of%20the%20gas%20turbine,1000%20ppm%4016%25O2 https://nh3fuelassociation.org/2018/12/07/performance-of-amm....

hinkley 3y ago
Highly caustic to delicate tissues however, such as lung tissue.
- danans 3y ago
  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.
  - hinkley 3y ago
    Some early fridges ran on ammonia as the refrigerant. Didn’t survive scaling up to mass production. Neither has nuclear.
lambdatronics 3y ago
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.

lambdatronics 3y ago

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."