7 ms·

Ammonia combustion engines: latest research (2021)

63 points by colinprince 4y ago

dendrite9 4y ago
There was a Hackaday post about this recently. Here are a couple links that go into more detail about using Ammonia in engines. https://spectrum.ieee.org/why-the-shipping-industry-is-betting-big-on-ammonia https://spectrum.ieee.org/why-the-shipping-industry-is-betti... https://hackaday.com/2022/09/27/japan-wants-to-decarbonize-with-the-help-of-ammonia/ https://hackaday.com/2022/09/27/japan-wants-to-decarbonize-w...
allenrb 4y ago
Is this really better than producing something like synthetic methane (ie, natural gas?) We have vast experience using this as a fuel already. It does contain carbon (methane is CH4) so you’d need to produce it using carbon from the atmosphere in order to achieve neutrality.
- philipkglass 4y ago
  The atmosphere is approximately 78% nitrogen and 0.04% carbon dioxide. That means that separating pure nitrogen from the atmosphere is relatively simple while separating pure CO2 is more complex and energy intensive. The additional complexity and energy requirements are such that it may be worthwhile developing ways to use ammonia as a fuel, as in this work, even though methane is more well established.
  - Brian_K_White 4y ago
    Did this person lie or something? Why the downvotes? HN is bizarre sometimes.
    - ChrisMarshallNY 4y ago
      There's that "HN Egg Cup" picture someone shows, if the person hits their site from HN. I have a couple of downvote stalkers. It's really cute. One of them even went and wrote a pretty much embarrassingly childish one-star review on one of my Apple App Store apps. It was so bad that Apple hid it. Sometimes, we deal better with machines, than with other people.
      - namecheapTA 4y ago
        I'm sure some people would consider me a troll, while I think I'm just writing honestly when I see things I don't agree with. Yet reading what you just wrote makes me want to quit this site forever. On most sites we know not to reveal enough to get doxxed. Here we reveal a lot thinking we're dealing with serious people. Stupid mistake. Thanks for the warning about the stalkers.
        ChrisMarshallNY 4y ago
        I’m not too concerned about it. I’m a fairly tough old coot (I’m a reformed troll, myself). I’ve dealt with much worse. As you can tell, more folks seem to value what I have to say, than have issues with it. I make a sincere effort not to bring negativity (and boy, oh boy, is that something I can do). I’m pretty sure that the ones that have problems with me, consider me to be an arrogant old “OK boomer.” Maybe they’re right. I don’t think so, but, as they say, if your feet are wet, and you see pyramids, you’re in de Nile (or a fountain in Vegas). I don’t attack folks, or try to intimidate them. My worst crime is to be annoying. This is a professional venue. It may not always seem like it, but people can get and lose careers, by their behavior, hereabouts. I’m done with mine. I don’t really need to impress anyone, but if I fight with someone, it could have severe consequences for them. I know how to draw the worst out in people, and make them show their ass. They may “win” their fight, here, and lose everything else. A pyrric victory. Even if I don’t like someone, I don’t actually want to cause them damage. I would sincerely like to be a positive influence, if at all possible. As I said, I used to be a rather nasty troll, and one of the reasons I participate here, is as recompense. I believe amends need to be made. This site is Disneyland. Maybe it can’t last, but it has, so far. I like it here. Most folks here have some truly great stuff to share, and I learn something every day. I am truly humbled by some of the participants, here. I make a point of hanging out with people smarter than I am. I’ve done that, all my life. I participate, because I want to be a good citizen, and it’s actually kind of an honor to be here. If it gets bad, I can always hightail it outta here. I have done that many times, in the past.
        aliswe 4y ago
        Please don't criticize the downvoting system, you will get in trouble.
    - sbierwagen 4y ago
      It only talks about separating gas from the atmosphere. You then have to split up the molecules to do useful things with the atoms, and nitrogen in the air is triple bonded diatomic N2. N2 gas takes 945 kilojoules per mole to split, while CO2 takes 393 kJ/mol. Since the thermodynamics aren't as favorable, the difference in concentration cost needs to be pretty good. Which it probably would be, (LN2 has been produced at scale for a century via cryogenic air separation and costs about a buck a liter) but green NH4 v green CH4 synthesis is not a slam dunk and it's not clear yet which one will be cheaper at the "replacing all transport oil consumption worldwide" megascale.
      - Brian_K_White 4y ago
        thanks
      - CoastalCoder 4y ago
        I have a very naive assumption that the amount of energy needed to break apart molecules for fuel, is roughly the energy we get back when burning them. Is there any truth to that?
        pencilguin 4y ago
        Approximately. Burning H2, you have to separate the H2 to cram an oxygen in between.
      - namibj 4y ago
        You don't even need to purify N₂ that much, as you can just add air to H₂ and feed that to the reactor, wasting some H₂ on O₂ but AFAIK it's quite cheap to enrich air to low-purity N₂ via pressure-swing adsorption, and it's just O₂ that's cheaper to get high concentration of via cryogenic distillation. [Upon further reading, iron-based catalysts in Haber-Bosch synthesis are fairly sensitive to water as it promotes recrystallization of the high-surface-area needle geometry into more clumpy structures with less surface area and thus less catalytic activity; apparently it's thus preferable to cryogenically distill the oxygen out of the air to get by without a water-condenser-trap between the nitrogen feed and the catalytic reactor (ammonia condensing happens between reactor outlet and re-compressing to reactor inlet pressure).] The bigger issue is that NH₃ (there is the ammonium cation NH₄⁺, but it's charged and thus needs an anion nearby to cancel the charge as coulomb repulsion would otherwise strongly limit the density of your (bulk) substance) is fairly toxic to inhalation when spilled, due to absorbing into water on the surfaces of your mucous membranes, eyes, and lungs. It is technically also slightly toxic once in your bloodstream, but it's hard to experience that toxicity if you follow "GTFO once you smell" as most non-fish (mammals, sharks, amphibians, birds, reptiles, and terrestrial (i.e., non-aquatic) snails) have fairly capable metabolic excretion pathways due to protein "burning" (breaking down protein from old cells and food for energy) having ammonia as a waste product. NH₃ is fairly toxic to fish because most assume they can just dump their own ammonia waste into the surrounding water and therefore rely on the surrounding water having concentrations far enough below what would be toxic inside the fish, as there needs to be some gradient to support the waste production/excretion rate.
  - ajross 4y ago
    > separating pure CO2 [from the atmosphere] is more complex and energy intensive Maybe we could find some kind of existing organism with the right chemistry to do this? Seems like such a beast would be very successful if that trick could be accomplished. No, seriously, this is what plants do. Just ask them for help; we've done it before, we have their number in the rolodex.
    - domtron_vox 4y ago
      Grow plants > feed to goats > collect menure > anerobic decay (aka methane digester) > natural gas (pretty close anyway) + good fertilizer. That's the system I'm interested in. The only real issue is needing to filter out a sulfer based gas (forgetting the exact thing off the top of my head, but it's corrosive to metal)
      - tastyfreeze 4y ago
        Hydrogen sulfide (H2S) is pretty easy to clean from biogas.
    - dendrite9 4y ago
      Have you heard about the (possible) Azolla Event? https://en.wikipedia.org/wiki/Azolla_event https://en.wikipedia.org/wiki/Azolla_event I bought some to grow in an unused tub in my yard until I figure out what to do with it. Not exactly a major CO2 vacuum, but I like the idea. I've wondered if there's something to using such plants as a way to reduce CO2 emissions from various plants. What to do with the plants is not clear since sequestration is the important part. Here is a lab working on something like what you described. https://www.azollahs.com/research https://www.azollahs.com/research
    - namibj 4y ago
      You can use the NaOH/CaO cycle to scrub carbon dioxide at atmospheric conditions and even regenerate the calcium carbonate with a (fairly cheap) methane + pure oxygen lime kiln (electric lime kilns are currently in testing). I'm fact, as long as we still use mined limestone to feed kilns, one can just switch them over to burn with pure oxygen (possibly diluted with it's own exhaust to reduce flame temperatures) and get a pure CO₂/H₂O exhaust. Usage in construction partially reacts back to limestone using atmospheric CO₂. The issue with plants is just that they are really inefficient compared to solar panels, to the point where scientists have some success feeding solar-industrial synthetic acetate to plants [0] and ending up substantially more efficient per solar-capturing area than outdoor plants. [0]: https://news.ycombinator.com/item?id=31957068 https://news.ycombinator.com/item?id=31957068
- sanxiyn 4y ago
  The primary advantage is that ammonia is much easier to liquefy than methane.
  - pfdietz 4y ago
    Ammonia also plays better with alkaline fuel cells, as there is no CO2 to precipitate carbonates (as there would be with methane as the hydrogen source). You still would have to filter CO2 from the air being fed into the fuel cell, though.
    - namibj 4y ago
      I'm not sure about how bad/dangerous the failure modes are (relative to the anhydrous NH₃), but cryogenic O₂ stores quite easily and the purified O₂ should come out of the (solar-powered) production of NH₃, some even already as a liquid.
jayyhu 4y ago
On a related note, the renowned North American X-15[1] was one of the very few rocket/plane powered by a rocket engine[2] that consumed ammonia as fuel. [1] https://en.wikipedia.org/wiki/North_American_X-15 https://en.wikipedia.org/wiki/North_American_X-15 [2] https://en.wikipedia.org/wiki/Reaction_Motors_XLR99 https://en.wikipedia.org/wiki/Reaction_Motors_XLR99
markvdb 4y ago
I am trying to get a good overview of how NH3 would work at scale as an energy carrier versus H2 or CH4. Any reason to speculate that one of them will dominate? Have you read any good overview?
- legulere 4y ago
  NH3 and CH4 both get produced with H2. H2 is difficult to transport in a lot of situations, so the idea is to transform it into NH3. For CH4 you need carbon capture which is energy intensive and only makes sense when you need the carbon like in chemical processes.
  - markvdb 4y ago
    Thank you for your comment. I'm really looking for a more extensive overview, an extensively motivated educated guess. For example, catching CO2 might be done much more cheaply when burning CH4 at a power station. This might change the equation or not. There also seems to be quite a bit of evolution in reducing the price of carbon capture. [0][1] I seem goals of $30/ton for carbon capture and wonder what factors will change the equation... [0] https://www.pnnl.gov/news-media/cheaper-carbon-capture-way https://www.pnnl.gov/news-media/cheaper-carbon-capture-way [1] https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/cssc.202101590 https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10....
    - himinlomax 4y ago
      > For example, catching CO2 might be done much more cheaply when burning CH4 at a power station There's something quite absurd about catching CO₂ at a power station. A more sensible source is at cement factories.
      - pfortuny 4y ago
        I guess he is trying to say: use existent gas stations and/or we might be able to capture all the CO2 therein. But I am not gp, obviously.
danans 4y ago
From a CO2 emissions reduction perspective, it seems far better to use green ammonia as a direct replacement for fossil-derived ammonia used in fertilizers.
- legulere 4y ago
  Certainly, however Europe won’t be able to fulfill all of its energy needs by local production. Hydrogen is too difficult to ship, so probably ammonia will get shipped instead. Also you have the issue of ships that can’t get electrified yet. Green ammonia might be one way to replace fossil fuels.
  - pencilguin 4y ago
    There are already definite plans in play to transition shipping to green ammonia.
  - danans 4y ago
    > Europe won’t be able to fulfill all of its energy needs by local production In the long run, why not? Between overbuilding renewable capacity (needed for green ammonia anyway), using nuclear when it's cost effective and renewable energy is limited, and multi-day storage, Europe should get pretty close. The last couple percent can be bridged with fossil fuels.
  - tpm 4y ago
    Natural gas pipelines can be upgraded to transport hydrogen instead.
    - jillesvangurp 4y ago
      Not that easy. Hydrogen is very hard to contain. Given gas leaks and gas explosions are already a regular thing, pushing hydrogen through the same leaky pipes is not going to improve things. There's this hydrogen fantasy where people think it's a drop in replacement for methane. The reality is that most hydrogen that is currently produced (from vast amounts of methane typically), is used on site. Transporting it around is just very hard. Even in compressed form, it still takes up a lot of space. Diesel has much better energy density by volume than hydrogen compressed at 300 bar. About 18x for the same volume.
franckl 4y ago
I am the cofounder at Airthium (YC S17), we make a seasonal energy storage system based on green ammonia and thermal storage (molten salts or sand). We are currently developing a low NOx ammonia burner in partnership with UC Louvain in Belgium Check us out! https://airthium.com https://airthium.com
- pencilguin 4y ago
  Checking. It seems more likely that most users will prefer to import ammonia from tropical solar farms, and keep local tankage of just a couple of weeks' worth. It is hard to imagine where seasonal storage would be needed.
  - actionfromafar 4y ago
    Global energy supply chain brittleness has come in the foreground recently due to war. I can imagine interest in seasonal storage.
    - pencilguin 4y ago
      Practically everyone imports what they need, at need, today. Only pipelines have lately been considered a problem. "Strategic National Reserves" are a thing, but thus far only used for economic leverage, to my knowledge. Underground storage of NG is pretty common, but again used mainly for price stability. But this is not the only place where I see people honestly believing that seasonal storage would be desirable and important. I hope they are not, in the end, disappointed by slack demand.
      - franckl 4y ago
        The long term goal is to replace NG. What we are building is the functional equivalent to a natural gas fired powerplant, without the CO2 emissions.
        pencilguin 4y ago

63 points by colinprince 4y ago

There was a Hackaday post about this recently. Here are a couple links that go into more detail about using Ammonia in engines. https://spectrum.ieee.org/why-the-shipping-industry-is-betting-big-on-ammonia https://spectrum.ieee.org/why-the-shipping-industry-is-betti... https://hackaday.com/2022/09/27/japan-wants-to-decarbonize-with-the-help-of-ammonia/ https://hackaday.com/2022/09/27/japan-wants-to-decarbonize-w...

allenrb 4y ago

Is this really better than producing something like synthetic methane (ie, natural gas?) We have vast experience using this as a fuel already. It does contain carbon (methane is CH4) so you’d need to produce it using carbon from the atmosphere in order to achieve neutrality.

philipkglass 4y ago
The atmosphere is approximately 78% nitrogen and 0.04% carbon dioxide. That means that separating pure nitrogen from the atmosphere is relatively simple while separating pure CO2 is more complex and energy intensive. The additional complexity and energy requirements are such that it may be worthwhile developing ways to use ammonia as a fuel, as in this work, even though methane is more well established.
- Brian_K_White 4y ago
  Did this person lie or something? Why the downvotes? HN is bizarre sometimes.
  - ChrisMarshallNY 4y ago
    There's that "HN Egg Cup" picture someone shows, if the person hits their site from HN. I have a couple of downvote stalkers. It's really cute. One of them even went and wrote a pretty much embarrassingly childish one-star review on one of my Apple App Store apps. It was so bad that Apple hid it. Sometimes, we deal better with machines, than with other people.
    - namecheapTA 4y ago
      I'm sure some people would consider me a troll, while I think I'm just writing honestly when I see things I don't agree with. Yet reading what you just wrote makes me want to quit this site forever. On most sites we know not to reveal enough to get doxxed. Here we reveal a lot thinking we're dealing with serious people. Stupid mistake. Thanks for the warning about the stalkers.
      - ChrisMarshallNY 4y ago
        I’m not too concerned about it. I’m a fairly tough old coot (I’m a reformed troll, myself). I’ve dealt with much worse. As you can tell, more folks seem to value what I have to say, than have issues with it. I make a sincere effort not to bring negativity (and boy, oh boy, is that something I can do). I’m pretty sure that the ones that have problems with me, consider me to be an arrogant old “OK boomer.” Maybe they’re right. I don’t think so, but, as they say, if your feet are wet, and you see pyramids, you’re in de Nile (or a fountain in Vegas). I don’t attack folks, or try to intimidate them. My worst crime is to be annoying. This is a professional venue. It may not always seem like it, but people can get and lose careers, by their behavior, hereabouts. I’m done with mine. I don’t really need to impress anyone, but if I fight with someone, it could have severe consequences for them. I know how to draw the worst out in people, and make them show their ass. They may “win” their fight, here, and lose everything else. A pyrric victory. Even if I don’t like someone, I don’t actually want to cause them damage. I would sincerely like to be a positive influence, if at all possible. As I said, I used to be a rather nasty troll, and one of the reasons I participate here, is as recompense. I believe amends need to be made. This site is Disneyland. Maybe it can’t last, but it has, so far. I like it here. Most folks here have some truly great stuff to share, and I learn something every day. I am truly humbled by some of the participants, here. I make a point of hanging out with people smarter than I am. I’ve done that, all my life. I participate, because I want to be a good citizen, and it’s actually kind of an honor to be here. If it gets bad, I can always hightail it outta here. I have done that many times, in the past.
      - aliswe 4y ago
        Please don't criticize the downvoting system, you will get in trouble.
  - sbierwagen 4y ago
    It only talks about separating gas from the atmosphere. You then have to split up the molecules to do useful things with the atoms, and nitrogen in the air is triple bonded diatomic N2. N2 gas takes 945 kilojoules per mole to split, while CO2 takes 393 kJ/mol. Since the thermodynamics aren't as favorable, the difference in concentration cost needs to be pretty good. Which it probably would be, (LN2 has been produced at scale for a century via cryogenic air separation and costs about a buck a liter) but green NH4 v green CH4 synthesis is not a slam dunk and it's not clear yet which one will be cheaper at the "replacing all transport oil consumption worldwide" megascale.
    - Brian_K_White 4y ago
      thanks
    - CoastalCoder 4y ago
      I have a very naive assumption that the amount of energy needed to break apart molecules for fuel, is roughly the energy we get back when burning them. Is there any truth to that?
      - pencilguin 4y ago
        Approximately. Burning H2, you have to separate the H2 to cram an oxygen in between.
    - namibj 4y ago
      You don't even need to purify N₂ that much, as you can just add air to H₂ and feed that to the reactor, wasting some H₂ on O₂ but AFAIK it's quite cheap to enrich air to low-purity N₂ via pressure-swing adsorption, and it's just O₂ that's cheaper to get high concentration of via cryogenic distillation. [Upon further reading, iron-based catalysts in Haber-Bosch synthesis are fairly sensitive to water as it promotes recrystallization of the high-surface-area needle geometry into more clumpy structures with less surface area and thus less catalytic activity; apparently it's thus preferable to cryogenically distill the oxygen out of the air to get by without a water-condenser-trap between the nitrogen feed and the catalytic reactor (ammonia condensing happens between reactor outlet and re-compressing to reactor inlet pressure).] The bigger issue is that NH₃ (there is the ammonium cation NH₄⁺, but it's charged and thus needs an anion nearby to cancel the charge as coulomb repulsion would otherwise strongly limit the density of your (bulk) substance) is fairly toxic to inhalation when spilled, due to absorbing into water on the surfaces of your mucous membranes, eyes, and lungs. It is technically also slightly toxic once in your bloodstream, but it's hard to experience that toxicity if you follow "GTFO once you smell" as most non-fish (mammals, sharks, amphibians, birds, reptiles, and terrestrial (i.e., non-aquatic) snails) have fairly capable metabolic excretion pathways due to protein "burning" (breaking down protein from old cells and food for energy) having ammonia as a waste product. NH₃ is fairly toxic to fish because most assume they can just dump their own ammonia waste into the surrounding water and therefore rely on the surrounding water having concentrations far enough below what would be toxic inside the fish, as there needs to be some gradient to support the waste production/excretion rate.
- ajross 4y ago
  > separating pure CO2 [from the atmosphere] is more complex and energy intensive Maybe we could find some kind of existing organism with the right chemistry to do this? Seems like such a beast would be very successful if that trick could be accomplished. No, seriously, this is what plants do. Just ask them for help; we've done it before, we have their number in the rolodex.
  - domtron_vox 4y ago
    Grow plants > feed to goats > collect menure > anerobic decay (aka methane digester) > natural gas (pretty close anyway) + good fertilizer. That's the system I'm interested in. The only real issue is needing to filter out a sulfer based gas (forgetting the exact thing off the top of my head, but it's corrosive to metal)
    - tastyfreeze 4y ago
      Hydrogen sulfide (H2S) is pretty easy to clean from biogas.
  - dendrite9 4y ago
    Have you heard about the (possible) Azolla Event? https://en.wikipedia.org/wiki/Azolla_event https://en.wikipedia.org/wiki/Azolla_event I bought some to grow in an unused tub in my yard until I figure out what to do with it. Not exactly a major CO2 vacuum, but I like the idea. I've wondered if there's something to using such plants as a way to reduce CO2 emissions from various plants. What to do with the plants is not clear since sequestration is the important part. Here is a lab working on something like what you described. https://www.azollahs.com/research https://www.azollahs.com/research
  - namibj 4y ago
    You can use the NaOH/CaO cycle to scrub carbon dioxide at atmospheric conditions and even regenerate the calcium carbonate with a (fairly cheap) methane + pure oxygen lime kiln (electric lime kilns are currently in testing). I'm fact, as long as we still use mined limestone to feed kilns, one can just switch them over to burn with pure oxygen (possibly diluted with it's own exhaust to reduce flame temperatures) and get a pure CO₂/H₂O exhaust. Usage in construction partially reacts back to limestone using atmospheric CO₂. The issue with plants is just that they are really inefficient compared to solar panels, to the point where scientists have some success feeding solar-industrial synthetic acetate to plants [0] and ending up substantially more efficient per solar-capturing area than outdoor plants. [0]: https://news.ycombinator.com/item?id=31957068 https://news.ycombinator.com/item?id=31957068
sanxiyn 4y ago
The primary advantage is that ammonia is much easier to liquefy than methane.
- pfdietz 4y ago
  Ammonia also plays better with alkaline fuel cells, as there is no CO2 to precipitate carbonates (as there would be with methane as the hydrogen source). You still would have to filter CO2 from the air being fed into the fuel cell, though.
  - namibj 4y ago
    I'm not sure about how bad/dangerous the failure modes are (relative to the anhydrous NH₃), but cryogenic O₂ stores quite easily and the purified O₂ should come out of the (solar-powered) production of NH₃, some even already as a liquid.

jayyhu 4y ago

On a related note, the renowned North American X-15[1] was one of the very few rocket/plane powered by a rocket engine[2] that consumed ammonia as fuel. [1] https://en.wikipedia.org/wiki/North_American_X-15 https://en.wikipedia.org/wiki/North_American_X-15 [2] https://en.wikipedia.org/wiki/Reaction_Motors_XLR99 https://en.wikipedia.org/wiki/Reaction_Motors_XLR99

markvdb 4y ago

I am trying to get a good overview of how NH3 would work at scale as an energy carrier versus H2 or CH4. Any reason to speculate that one of them will dominate? Have you read any good overview?

legulere 4y ago
NH3 and CH4 both get produced with H2. H2 is difficult to transport in a lot of situations, so the idea is to transform it into NH3. For CH4 you need carbon capture which is energy intensive and only makes sense when you need the carbon like in chemical processes.
- markvdb 4y ago
  Thank you for your comment. I'm really looking for a more extensive overview, an extensively motivated educated guess. For example, catching CO2 might be done much more cheaply when burning CH4 at a power station. This might change the equation or not. There also seems to be quite a bit of evolution in reducing the price of carbon capture. [0][1] I seem goals of $30/ton for carbon capture and wonder what factors will change the equation... [0] https://www.pnnl.gov/news-media/cheaper-carbon-capture-way https://www.pnnl.gov/news-media/cheaper-carbon-capture-way [1] https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/cssc.202101590 https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10....
  - himinlomax 4y ago
    > For example, catching CO2 might be done much more cheaply when burning CH4 at a power station There's something quite absurd about catching CO₂ at a power station. A more sensible source is at cement factories.
    - pfortuny 4y ago
      I guess he is trying to say: use existent gas stations and/or we might be able to capture all the CO2 therein. But I am not gp, obviously.

danans 4y ago

From a CO2 emissions reduction perspective, it seems far better to use green ammonia as a direct replacement for fossil-derived ammonia used in fertilizers.

legulere 4y ago
Certainly, however Europe won’t be able to fulfill all of its energy needs by local production. Hydrogen is too difficult to ship, so probably ammonia will get shipped instead. Also you have the issue of ships that can’t get electrified yet. Green ammonia might be one way to replace fossil fuels.
- pencilguin 4y ago
  There are already definite plans in play to transition shipping to green ammonia.
- danans 4y ago
  > Europe won’t be able to fulfill all of its energy needs by local production In the long run, why not? Between overbuilding renewable capacity (needed for green ammonia anyway), using nuclear when it's cost effective and renewable energy is limited, and multi-day storage, Europe should get pretty close. The last couple percent can be bridged with fossil fuels.
- tpm 4y ago
  Natural gas pipelines can be upgraded to transport hydrogen instead.
  - jillesvangurp 4y ago
    Not that easy. Hydrogen is very hard to contain. Given gas leaks and gas explosions are already a regular thing, pushing hydrogen through the same leaky pipes is not going to improve things. There's this hydrogen fantasy where people think it's a drop in replacement for methane. The reality is that most hydrogen that is currently produced (from vast amounts of methane typically), is used on site. Transporting it around is just very hard. Even in compressed form, it still takes up a lot of space. Diesel has much better energy density by volume than hydrogen compressed at 300 bar. About 18x for the same volume.

franckl 4y ago

I am the cofounder at Airthium (YC S17), we make a seasonal energy storage system based on green ammonia and thermal storage (molten salts or sand). We are currently developing a low NOx ammonia burner in partnership with UC Louvain in Belgium Check us out! https://airthium.com https://airthium.com

pencilguin 4y ago
Checking. It seems more likely that most users will prefer to import ammonia from tropical solar farms, and keep local tankage of just a couple of weeks' worth. It is hard to imagine where seasonal storage would be needed.
- actionfromafar 4y ago
  Global energy supply chain brittleness has come in the foreground recently due to war. I can imagine interest in seasonal storage.
  - pencilguin 4y ago
    Practically everyone imports what they need, at need, today. Only pipelines have lately been considered a problem. "Strategic National Reserves" are a thing, but thus far only used for economic leverage, to my knowledge. Underground storage of NG is pretty common, but again used mainly for price stability. But this is not the only place where I see people honestly believing that seasonal storage would be desirable and important. I hope they are not, in the end, disappointed by slack demand.
    - franckl 4y ago
      The long term goal is to replace NG. What we are building is the functional equivalent to a natural gas fired powerplant, without the CO2 emissions.
      - pencilguin 4y ago