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Hydrogen is stuff from hell when it comes to engineering challenges. Not as bad as some of the "Things I Won't Work With" chemicals [0], but still. I am almost

Hydrogen is stuff from hell when it comes to engineering challenges. Not as bad as some of the "Things I Won't Work With" chemicals [0], but still. I am almost convinced that whatever direction the future carbonless energy production takes, hydrogen won't be a significant part of it. [0] https://www.science.org/content/blog-post/things-i-won-t-work-dioxygen-difluoride https://www.science.org/content/blog-post/things-i-won-t-wor...

zionic 4y ago
Exactly. This event just makes all the hydrogen car people even more entertaining. At this point I’m fairly convinced hydrogen cars were a coordinated plan by oil companies to delay EVs. It probably would have worked if Tesla hadn’t come out of nowhere.
- microtonal 4y ago
  Could you explain what the problems are? I don't have a strong opinion either way, but you can buy hydrogen cars. In the city where I live there are hydrogen buses and garbage trucks and they seem to do fine?
  - mikepurvis 4y ago
    I think it's an okay fit for fleet vehicles where the headaches are closer to worth it, but the volatility + the difficulties in safely and reliably containing the compressed gas are the main issues.
    - senectus1 4y ago
      >I think it's an okay fit for fleet vehicles This is the thing... there is no "one size fits all" but the nay sayers look at hydrogen and say "nah too hard for anything". They're wrong. Hydrogen will be huge in the NEAR future... it just wont be a silver bullet.
      - panick21_ 4y ago
        > will be huge in the NEAR future. Is what fans of hydrogen have been arguing for 30 years.
        senectus1 4y ago
        while the dominant powers in the world get fat and rich (and sick) off liquid dino's. The world finally has motivation to get out of that rut. Dominant powers will make hydrogen work for them because thats how a corrupt capitalist society works.
      - manholio 4y ago
        You are ignoring economies of scale and the externalities of a mass market technology. Electricity is everywhere and even so, electric cars had and still have a huge barrier to overcome in providing adequate infrastructure. Once a technology takes off, it's virtually impossible for an incumbent to replace it unless it provides drastic improvements, because of the momentum the old technology has. Well, H2 is an "also ran" at this point: it has lower energy efficiency (losing the majority of input energy in the cycle from electrolysis -> compression -> fuel cell -> electric), it requires more expensive and practically non-existent infrastructure, it's theoretical range advantages are negated by the need to have a small COPV bomb on board, forcing the longest range Hidrogen cars have less range than the equivalent electric, they are more expensive and complex, requiring expensive, platinum based catalysts, pushing the prices of H2 models into a multiple over the equivalent BEV. There is nothing that H2 can do that BEV can't do better, with the exception of fast refueling, which is becoming less and less of an issue. For cars the race with BEV is irredeemably lost, and even for trucks the hydrogen industry needs to perform some technological miracle to stay in the game.
      - zionic 4y ago
        Hydrogen vehicles are essentially an oil company scam. They are fraud, at a physics level, vs EVs. They fall apart the second you take a serious, first-principles look at how they work. HN rate limits my replies you can read my sibling comment if you’d like more information.
  - mikeyouse 4y ago
    Mostly hydrogen is the smallest element so molecules of hydrogen (H2) are extremely hard to contain. They leak from everywhere so your entire infrastructure has to be designed with very tight tolerances and even still, you’ll have leaks. In addition, those leaks can prove to be dangerous since it’s so reactive and flammable, so you have a highly leaky flammable gas at high pressure… So you think, well fine, we can just generate it on site via electrolysis — alas, hydrogen actively destroys metal containers via embrittlement. Not so much in hydrogen gas, but any process where you’re running chemical or electrolytic reactions; https://www.wikipedia.org/wiki/Hydrogen_embrittlement https://www.wikipedia.org/wiki/Hydrogen_embrittlement
    - fsh 4y ago
      I have the impression that the problem of hydrogen leakage from vehicles is vastly exaggerated. A study on two commercial hydrogen cars found leakage rates of 2-6 mL/min (Table 4 in [1]). At this rate, it would take over 15 years for the tank content of a Toyota Mirai (5 kg of H2) to leak out. [1] https://link.springer.com/article/10.1007/s42154-020-00096-z https://link.springer.com/article/10.1007/s42154-020-00096-z
      - mikeyouse 4y ago
        The Hydrogen isn't leaking from vehicles since they take so many precautions to ensure they don't, including those tight tolerances and special materials. You just need to replicate that at every step of the supply chain which becomes onerous and expensive.
  - panick21_ 4y ago
    Its not that it doesn't work at all, but while there are some trial uses of hydrogen in automotive. Its the very extreme minority of cases. You can buy one of only a few models of car, and those are only sold in absurdly small numbers. For trucks there are more trials going on but real mass production of hydrogen trucks isn't really a thing for a few more years (and many expect those will be further delayed). There are many reasons for this. Just something as simple as count how many different sub-systems are required between a BEV and a FCEV. In addition that basic disadvantage, the end to end energy in efficiency is worse, so its more expensive. In addition to that, the infrastructure required is about 10-100x more expensive. Tesla as one start up rolled out a global (or lets say in the developed world) EV charging infrastructure. The same amount of money invested in hydrogen infrastructure like not even have resulted in enough locations to charge the whole West coast. And because you can't charge at home, you need many more such locations. So really end to end it makes no sense pretty much from any direction you look at it and has been absolutely destroyed in the market. Some people still have hope for trucks, but there too the trends are pretty clear.
    - Fatnino 4y ago
      Hydrogen has one thing going for it in that it only takes 5 minutes to fill up once you find a pump. Electric takes 4-6 times as long or more. Electric still comes out ahead despite this handicap.
      - microtonal 4y ago
        Hydrogen has one thing going for it in that it only takes 5 minutes to fill up once you find a pump. Electric takes 4-6 times as long or more. Right. This is the main issue for us for going electric. We barely use the car, but when we use it, it is often for longer distances (visiting my in-laws, who live in another country, holidays). Having to 'refuel' longer and more often is very inconvenient.
        panick21_ 4y ago
        Most normal people don't drive many hours without making a 20 min break. Doing a 5-10 min break every couple hours seems reasonable. Even just pieing and stretching the legs. As long as the supercharges are placed well its perfectly fine. I know there are some extreme people who basically push and pie in a bottle if they have to, but most people don't travel that way. Modern EV can refuel large part of the battery in like 15min. There is still an advantage, but it gets smaller with every generation of vehicle.
  - snewman 4y ago
    Part of the issue is that this rocket doesn't just use hydrogen, it uses cryogenic liquid hydrogen, which apparently is even harder to manage. To quote from an excellent writeup [0]: > Because it is so tiny, hydrogen can squeeze through the smallest of gaps. This is not so great a problem at ambient temperatures and pressures, but at super-chilled temperatures and high pressures, hydrogen easily oozes out of any available opening. Elon Musk responded to this article with the following tweet [1], which to my understanding is a pretty reasonable take: > Accurate assessment. Raptor design started out using H2, but switched to CH4. Latter is best combo of high efficiency & ease of operation imo. Delta-v difference between H2 & CH4 is small for most missions, because CH4 tank is much smaller & no insulation is needed. [0] https://arstechnica.com/science/2022/09/years-after-shuttle-nasa-rediscovers-the-perils-of-liquid-hydrogen/ https://arstechnica.com/science/2022/09/years-after-shuttle-... [1] https://twitter.com/elonmusk/status/1566233000458592256 https://twitter.com/elonmusk/status/1566233000458592256
- hotpotamus 4y ago
  I just think of hydrogen cars as electric cars with a competing battery technology. I think li-ion batteries have just come a longer way in energy density, lifecycle, and charging speed than anyone expected 20 years ago.
  - zionic 4y ago
    Hydrogen is an extremely inefficient (200-300% the energy waste of an EV) battery that’s notoriously difficult to handle, contain, and transport safely. Unless we’re mining gas giants hydrogen is not a fuel source, so you have to immediately toss 40-50% of the energy you produce to create it. You lose a ton then transporting it to its point of consumption, and even then converting that (wastefully) stored energy to kinetic energy is STILL less efficient than an EV. Instead, all of that energy used to make hydrogen could have been sent via the grid at 90-95% efficiency to an EV that will store and convert that energy to motion at 85-90% efficiency. A hydrogen economy means tens of PWH of waste energy vs a pure EV economy. The only reason you’d want hydrogen is if you’ve invested trillions in the oil industry and hope to repurpose that infrastructure.
imglorp 4y ago
On the other hand, solving these challenges presents many rewards in space. It seems like a chemistry gift from the universe, if you can transmute between one of the highest energy density fuels to water, electricity, air, and radiation shielding. And water is laying on the ground on many bodies in the solar system. One final gift is you can quit burning hydrocarbons to get to space, if you can figure out how to do this sustainably.
- csours 4y ago
  It's all about trade-offs. It may be worth the trouble for space craft, and that may open up aircraft applications, or we may have hydro-something in airplanes instead of hydro-carbons - Ammonia (hydrogen+nitrogen), Magnesium Hydride, etc.
  - amelius 4y ago
    > or we may have hydro-something in airplanes instead of hydro-carbons - Ammonia (hydrogen+nitrogen) Nitrogen in many forms (including ammonia) is bad news for natural ecosystems. https://news.mongabay.com/2021/09/nitrogen-the-environmental-crisis-you-havent-heard-of-yet/ https://news.mongabay.com/2021/09/nitrogen-the-environmental...
    - csours 4y ago
      So is gasoline, but our main problem with gasoline is the carbon dioxide that is created when you burn it. The products of ammonia hydrolysis (or any other chemical reaction that releases energy) are N2 (same as atmospheric nitrogen) and water. Yes, if we leak ammonia, that is very very bad. Ammonia is also an immediate, serious, and acute irritant. Any significant ammonia leak is dangerous to human health.
      - Valgrim 4y ago
        Using ammonia as fuel doesn't "just" release n2, it also release a lot of nitrogen oxides, which are significantly more powerful greenhouse gases than CO2, contribute to the formation of smog and acid rain, and destroy tropospheric ozone.
Implicated 4y ago
> I am almost convinced that whatever direction the future carbonless energy production takes, hydrogen won't be a significant part of it. Just based on the fact that it's the most abundant element in our 'space' (earth, atmosphere, reasonably accessible), I do really hope that you're wrong with this. I'd feel a lot better about the fate of humanity if we somehow found a way to use Hydrogen as our primary fuel (if we can't otherwise do so with solar/wind/tidal).
- lamontcg 4y ago
  We're not going to be figuring it out in the next few decades fast enough to address the climate crisis. 100 years from now it may be all hydrogen fuel cells, but that doesn't help anything today.
dddddddd111 4y ago

zionic 4y ago

Exactly. This event just makes all the hydrogen car people even more entertaining. At this point I’m fairly convinced hydrogen cars were a coordinated plan by oil companies to delay EVs. It probably would have worked if Tesla hadn’t come out of nowhere.

microtonal 4y ago
Could you explain what the problems are? I don't have a strong opinion either way, but you can buy hydrogen cars. In the city where I live there are hydrogen buses and garbage trucks and they seem to do fine?
- mikepurvis 4y ago
  I think it's an okay fit for fleet vehicles where the headaches are closer to worth it, but the volatility + the difficulties in safely and reliably containing the compressed gas are the main issues.
  - senectus1 4y ago
    >I think it's an okay fit for fleet vehicles This is the thing... there is no "one size fits all" but the nay sayers look at hydrogen and say "nah too hard for anything". They're wrong. Hydrogen will be huge in the NEAR future... it just wont be a silver bullet.
    - panick21_ 4y ago
      > will be huge in the NEAR future. Is what fans of hydrogen have been arguing for 30 years.
      - senectus1 4y ago
        while the dominant powers in the world get fat and rich (and sick) off liquid dino's. The world finally has motivation to get out of that rut. Dominant powers will make hydrogen work for them because thats how a corrupt capitalist society works.
    - manholio 4y ago
      You are ignoring economies of scale and the externalities of a mass market technology. Electricity is everywhere and even so, electric cars had and still have a huge barrier to overcome in providing adequate infrastructure. Once a technology takes off, it's virtually impossible for an incumbent to replace it unless it provides drastic improvements, because of the momentum the old technology has. Well, H2 is an "also ran" at this point: it has lower energy efficiency (losing the majority of input energy in the cycle from electrolysis -> compression -> fuel cell -> electric), it requires more expensive and practically non-existent infrastructure, it's theoretical range advantages are negated by the need to have a small COPV bomb on board, forcing the longest range Hidrogen cars have less range than the equivalent electric, they are more expensive and complex, requiring expensive, platinum based catalysts, pushing the prices of H2 models into a multiple over the equivalent BEV. There is nothing that H2 can do that BEV can't do better, with the exception of fast refueling, which is becoming less and less of an issue. For cars the race with BEV is irredeemably lost, and even for trucks the hydrogen industry needs to perform some technological miracle to stay in the game.
    - zionic 4y ago
      Hydrogen vehicles are essentially an oil company scam. They are fraud, at a physics level, vs EVs. They fall apart the second you take a serious, first-principles look at how they work. HN rate limits my replies you can read my sibling comment if you’d like more information.
- mikeyouse 4y ago
  Mostly hydrogen is the smallest element so molecules of hydrogen (H2) are extremely hard to contain. They leak from everywhere so your entire infrastructure has to be designed with very tight tolerances and even still, you’ll have leaks. In addition, those leaks can prove to be dangerous since it’s so reactive and flammable, so you have a highly leaky flammable gas at high pressure… So you think, well fine, we can just generate it on site via electrolysis — alas, hydrogen actively destroys metal containers via embrittlement. Not so much in hydrogen gas, but any process where you’re running chemical or electrolytic reactions; https://www.wikipedia.org/wiki/Hydrogen_embrittlement https://www.wikipedia.org/wiki/Hydrogen_embrittlement
  - fsh 4y ago
    I have the impression that the problem of hydrogen leakage from vehicles is vastly exaggerated. A study on two commercial hydrogen cars found leakage rates of 2-6 mL/min (Table 4 in [1]). At this rate, it would take over 15 years for the tank content of a Toyota Mirai (5 kg of H2) to leak out. [1] https://link.springer.com/article/10.1007/s42154-020-00096-z https://link.springer.com/article/10.1007/s42154-020-00096-z
    - mikeyouse 4y ago
      The Hydrogen isn't leaking from vehicles since they take so many precautions to ensure they don't, including those tight tolerances and special materials. You just need to replicate that at every step of the supply chain which becomes onerous and expensive.
- panick21_ 4y ago
  Its not that it doesn't work at all, but while there are some trial uses of hydrogen in automotive. Its the very extreme minority of cases. You can buy one of only a few models of car, and those are only sold in absurdly small numbers. For trucks there are more trials going on but real mass production of hydrogen trucks isn't really a thing for a few more years (and many expect those will be further delayed). There are many reasons for this. Just something as simple as count how many different sub-systems are required between a BEV and a FCEV. In addition that basic disadvantage, the end to end energy in efficiency is worse, so its more expensive. In addition to that, the infrastructure required is about 10-100x more expensive. Tesla as one start up rolled out a global (or lets say in the developed world) EV charging infrastructure. The same amount of money invested in hydrogen infrastructure like not even have resulted in enough locations to charge the whole West coast. And because you can't charge at home, you need many more such locations. So really end to end it makes no sense pretty much from any direction you look at it and has been absolutely destroyed in the market. Some people still have hope for trucks, but there too the trends are pretty clear.
  - Fatnino 4y ago
    Hydrogen has one thing going for it in that it only takes 5 minutes to fill up once you find a pump. Electric takes 4-6 times as long or more. Electric still comes out ahead despite this handicap.
    - microtonal 4y ago
      Hydrogen has one thing going for it in that it only takes 5 minutes to fill up once you find a pump. Electric takes 4-6 times as long or more. Right. This is the main issue for us for going electric. We barely use the car, but when we use it, it is often for longer distances (visiting my in-laws, who live in another country, holidays). Having to 'refuel' longer and more often is very inconvenient.
      - panick21_ 4y ago
        Most normal people don't drive many hours without making a 20 min break. Doing a 5-10 min break every couple hours seems reasonable. Even just pieing and stretching the legs. As long as the supercharges are placed well its perfectly fine. I know there are some extreme people who basically push and pie in a bottle if they have to, but most people don't travel that way. Modern EV can refuel large part of the battery in like 15min. There is still an advantage, but it gets smaller with every generation of vehicle.
- snewman 4y ago
  Part of the issue is that this rocket doesn't just use hydrogen, it uses cryogenic liquid hydrogen, which apparently is even harder to manage. To quote from an excellent writeup [0]: > Because it is so tiny, hydrogen can squeeze through the smallest of gaps. This is not so great a problem at ambient temperatures and pressures, but at super-chilled temperatures and high pressures, hydrogen easily oozes out of any available opening. Elon Musk responded to this article with the following tweet [1], which to my understanding is a pretty reasonable take: > Accurate assessment. Raptor design started out using H2, but switched to CH4. Latter is best combo of high efficiency & ease of operation imo. Delta-v difference between H2 & CH4 is small for most missions, because CH4 tank is much smaller & no insulation is needed. [0] https://arstechnica.com/science/2022/09/years-after-shuttle-nasa-rediscovers-the-perils-of-liquid-hydrogen/ https://arstechnica.com/science/2022/09/years-after-shuttle-... [1] https://twitter.com/elonmusk/status/1566233000458592256 https://twitter.com/elonmusk/status/1566233000458592256
hotpotamus 4y ago
I just think of hydrogen cars as electric cars with a competing battery technology. I think li-ion batteries have just come a longer way in energy density, lifecycle, and charging speed than anyone expected 20 years ago.
- zionic 4y ago
  Hydrogen is an extremely inefficient (200-300% the energy waste of an EV) battery that’s notoriously difficult to handle, contain, and transport safely. Unless we’re mining gas giants hydrogen is not a fuel source, so you have to immediately toss 40-50% of the energy you produce to create it. You lose a ton then transporting it to its point of consumption, and even then converting that (wastefully) stored energy to kinetic energy is STILL less efficient than an EV. Instead, all of that energy used to make hydrogen could have been sent via the grid at 90-95% efficiency to an EV that will store and convert that energy to motion at 85-90% efficiency. A hydrogen economy means tens of PWH of waste energy vs a pure EV economy. The only reason you’d want hydrogen is if you’ve invested trillions in the oil industry and hope to repurpose that infrastructure.

imglorp 4y ago

On the other hand, solving these challenges presents many rewards in space. It seems like a chemistry gift from the universe, if you can transmute between one of the highest energy density fuels to water, electricity, air, and radiation shielding. And water is laying on the ground on many bodies in the solar system. One final gift is you can quit burning hydrocarbons to get to space, if you can figure out how to do this sustainably.

csours 4y ago
It's all about trade-offs. It may be worth the trouble for space craft, and that may open up aircraft applications, or we may have hydro-something in airplanes instead of hydro-carbons - Ammonia (hydrogen+nitrogen), Magnesium Hydride, etc.
- amelius 4y ago
  > or we may have hydro-something in airplanes instead of hydro-carbons - Ammonia (hydrogen+nitrogen) Nitrogen in many forms (including ammonia) is bad news for natural ecosystems. https://news.mongabay.com/2021/09/nitrogen-the-environmental-crisis-you-havent-heard-of-yet/ https://news.mongabay.com/2021/09/nitrogen-the-environmental...
  - csours 4y ago
    So is gasoline, but our main problem with gasoline is the carbon dioxide that is created when you burn it. The products of ammonia hydrolysis (or any other chemical reaction that releases energy) are N2 (same as atmospheric nitrogen) and water. Yes, if we leak ammonia, that is very very bad. Ammonia is also an immediate, serious, and acute irritant. Any significant ammonia leak is dangerous to human health.
    - Valgrim 4y ago
      Using ammonia as fuel doesn't "just" release n2, it also release a lot of nitrogen oxides, which are significantly more powerful greenhouse gases than CO2, contribute to the formation of smog and acid rain, and destroy tropospheric ozone.

Implicated 4y ago

> I am almost convinced that whatever direction the future carbonless energy production takes, hydrogen won't be a significant part of it. Just based on the fact that it's the most abundant element in our 'space' (earth, atmosphere, reasonably accessible), I do really hope that you're wrong with this. I'd feel a lot better about the fate of humanity if we somehow found a way to use Hydrogen as our primary fuel (if we can't otherwise do so with solar/wind/tidal).

lamontcg 4y ago
We're not going to be figuring it out in the next few decades fast enough to address the climate crisis. 100 years from now it may be all hydrogen fuel cells, but that doesn't help anything today.

dddddddd111 4y ago