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I am doubtful, but if true and if this can be deployed on a large scale hydrogen cars could be a viable alternative to battery powered EVs.

by janmo 6y ago

_ph_ 6y ago
Unfortunately, splitting water into hydrogen and oxygen are only a part of the process. A lot of energy is wasted when the hydrogen has to be compressed for transport, storage and in the car. That makes hydrogen less attractive than batteries, even if we solve the inefficiencies of the hydrogen production. However, it would be great news for many other fields. One way to make hydrogen more storable is to produce methane. And of course use hydrogen directly for industrial applications, like steel production.
- JorgeGT 6y ago
  It would be specially interesting for aviation, since the energy density of batteries is still too low for commercial aircraft. Airbus is pushing for zero emissions H2-powered planes: https://www.airbus.com/innovation/zero-emission/hydrogen/zeroe.html https://www.airbus.com/innovation/zero-emission/hydrogen/zer...
  - jillesvangurp 6y ago
    What makes hydrogen interesting in aviation is that it is possible to convert existing engine designs to burn hydrogen apparently. There have been a few tests with this recently. Mid term, hydrogen is the obvious way to clean up the aviation industry. Basically as soon as hydrogen prices drop below kerosene prices, companies will start doing this by themselves because it makes economical sense. Right now it's more of an investment for the long term. Airbus is clearly betting that this is going to happen in the next two decades or so. If you look at clean energy cost dropping over time, they might be right about that. Battery powered planes also make sense; just not for the bigger planes any time soon. But with another decade of battery improvements, GA planes & battery is going to be a no brainer-solution for a lot of use cases. Basically, this will be driven by cost. At some point battery powered is going to be cheap and good enough that the added advantage of low energy cost and vastly simpler/cheaper maintenance is going to be a killer argument. E.g. flight schools are already switching because it makes economical sense. If you look at the R&D pipelines of companies in this space, ten years could solve a lot of issues. Think double/triple the range of current electrical planes at half the cost. Small planes are expensive to operate currently and fuel & maintenance are big factors here.
    - JorgeGT 6y ago
      Completely correct, H2 either in fuel cells or burnt in turbines and battery-powered hybridization are two of the pillars of the EU's Clean Aviation R&D programme: https://clean-aviation.eu/files/Clean%20Aviation%20-%20Shared%20Vision%2014%20Jan%20FINAL.pdf https://clean-aviation.eu/files/Clean%20Aviation%20-%20Share...
- hef19898 6y ago
  For transportation, hydrogen can be absorbed by a carrier oil. That way it is basically inert, doesn't even count as dangerous goods for transportation purposes. No compression needed. In cars it is different, so.
  - runeks 6y ago
    What’s the density of hydrogen using this method versus compression?
    - hef19898 6y ago
      I'd have to look up the numbers. Cost wise, a pure hydrogen pipeline is cheaper for sure. At scale at least. Until that scale is reached, using carrier oil is much cheaper, but still competitive enough to get it going. EDIT: The oil is called marlotherm something, if memory serves well.
- stewbrew 6y ago
  When there is wind or sun, it's not entirely impossible to produce hydrogen on site - within limits of course. Then the question is what kind of energy storage is more cost efficient on the long run.
  - AnHonestComment 6y ago
    It also needs to beat growing corn and burning it as alcohol on total process efficiency. We can be carbon neutral by using plant based fuels, so anything exotic needs to perform better than burning plant/algae alcohol or gas.
  - ummwhat 6y ago
    If there is sun why not skip the middle man and use an array of mirrors for direct heating?
    - stewbrew 6y ago
      Oh come on. Anyway, the sun doesn't shine at night. In the winter, the situation is difficult too. You need storage but you don't necessarily have to move the storage across countries.
- thysultan 6y ago
  The idea is to use water as the fuel and convert to hydrogen just in time for combustion.
  - bawolff 6y ago
    How would that work? That sounds like a perpetual motion machine.
    - thysultan 6y ago
      Like how a gun works, essentially a battery for the initial motion, using the subsequent motion storing some for the next initial motion.
      - bawolff 6y ago
        Guns work by having chemical explosives in them. Which is also how gasoline powered cars work. They definitely do not work by using a depleted battery to charge a second battery to create energy out of nothing.
        thysultan 6y ago
        gasoline cars also use a battery to initiate the engine.
        bawolff 6y ago
        Yes. However they don't use it to both power the car and charge the battery. Kickstarting the engine with a battery is very different from only having a battery and also using that battery to charge itself and the car at the same time. The original poster was proposing a closed system where you would turn water into hydrogen (a very energy intensive process) and then turn it back into water (an energy releasing process) inside the car to provide all the energy. This is not how physics works. You cannot use your energy source to create more of your energy source without an external energy source. It just doesn't work that way.
- tankenmate 6y ago
  It is going to be very costly (energy and capital investment) to convert steel making to use hydrogen. A blast furnace is a well balanced chemical reaction where the coke serves two purposes; a source of carbon monoxide for turning ore in iron (Fe2O3(s) + 3 CO(g) => 2 Fe(s) + 3 CO2(g), very exothermic, good for turning the iron / steel into a liquid alloy), and a source of carbon for turning the iron into steel. All in one vessel and in one process no less. I guess you could do the first step using peroxide to strip the oxygen from the iron, but the second step in the same vessel at the same time? Fe2o3 + 3H2O2 => 2 Fe + 3 H2O, somewhat exothermic (if my rusty memory of enthalpy calculations are correct), not sure of the activation energy or need for catalysts). [EDIT] also forgot the peroxide reaction would probably require external heat to over come the latent energy required to turn the H2O into super heated steam so that you could melt the iron / steel. This would probably boil off a large chunk of the peroxide as well, so it might need to be done in a contained pressure vessel, which would probably affect the speed of the iron ore reduction.
  - ClumsyPilot 6y ago
    There is a steel mill that uses hydrogen, but it appears to be a recycling kind, rather than one that makes iron from ore with a blast furnace. https://www.rechargenews.com/transition/-world-first-as-hydrogen-used-to-power-commercial-steel-production/2-1-799308 https://www.rechargenews.com/transition/-world-first-as-hydr...
    - tankenmate 6y ago
      Yes, I suspect this is much easier as you don't need to alloy as the steel is already alloyed with carbon.
  - _ph_ 6y ago
    I am not a steel expert, but the steel industry is constantly talking about converting to hydrogen. Your sum formula has a bit lot of oxygen, shouldn't it be Fe2O3+3H2 => 2 Fe + 2 H2O? In any case, they could use additional hydrogen for heating and burning it with ambient air.
hannob 6y ago
I find it amazing (in a bad way) that whenever you talk about hydrogen someone comes up and wants to talk about cars. There's a number of use cases where clean hydrogen will be desperately needed. This starts with areas where hydrogen is already used today - but it's hydrogen made from fossil fuels - like ammonia production and includes areas like steel production where hydrogen really is the only game in town for a low-carbon production. We'll need all the clean hydrogen we can get, and probably more than that. There's no plausible scenario where we'll have excess hydrogen that we can waste in an area where it's just vastly less efficient than the available alternative.
- marcosdumay 6y ago
  On the specific case of steel production, it's way more likely that people will settle on synthetic carbon based fuels. Of course, producing those uses hydrogen too, so no big change.
  - paledot 6y ago
    Yeah, I really don't see a case where large amounts of hydrogen are being transported commercially. Anything you don't need on site makes much more sense to convert to synfuel.
  - hannob 6y ago
    Why would that make any sense? (Synfuels are really, really inefficient, you basically only want them in places where you need the high energy density and can't avoid them, like aviation.)
    - marcosdumay 6y ago
      Because the carbon has an important role on the chemistry of making steel.
- Triv888 6y ago
  > I find it amazing (in a bad way) that whenever you talk about hydrogen someone comes up and wants to talk about cars. It would solve the battery charging problem that electric cars have (for long trips) while not polluting like conventional cars.

I am doubtful, but if true and if this can be deployed on a large scale hydrogen cars could be a viable alternative to battery powered EVs.

by janmo 6y ago

I am doubtful, but if true and if this can be deployed on a large scale hydrogen cars could be a viable alternative to battery powered EVs.

_ph_ 6y ago

Unfortunately, splitting water into hydrogen and oxygen are only a part of the process. A lot of energy is wasted when the hydrogen has to be compressed for transport, storage and in the car. That makes hydrogen less attractive than batteries, even if we solve the inefficiencies of the hydrogen production. However, it would be great news for many other fields. One way to make hydrogen more storable is to produce methane. And of course use hydrogen directly for industrial applications, like steel production.

JorgeGT 6y ago
It would be specially interesting for aviation, since the energy density of batteries is still too low for commercial aircraft. Airbus is pushing for zero emissions H2-powered planes: https://www.airbus.com/innovation/zero-emission/hydrogen/zeroe.html https://www.airbus.com/innovation/zero-emission/hydrogen/zer...
- jillesvangurp 6y ago
  What makes hydrogen interesting in aviation is that it is possible to convert existing engine designs to burn hydrogen apparently. There have been a few tests with this recently. Mid term, hydrogen is the obvious way to clean up the aviation industry. Basically as soon as hydrogen prices drop below kerosene prices, companies will start doing this by themselves because it makes economical sense. Right now it's more of an investment for the long term. Airbus is clearly betting that this is going to happen in the next two decades or so. If you look at clean energy cost dropping over time, they might be right about that. Battery powered planes also make sense; just not for the bigger planes any time soon. But with another decade of battery improvements, GA planes & battery is going to be a no brainer-solution for a lot of use cases. Basically, this will be driven by cost. At some point battery powered is going to be cheap and good enough that the added advantage of low energy cost and vastly simpler/cheaper maintenance is going to be a killer argument. E.g. flight schools are already switching because it makes economical sense. If you look at the R&D pipelines of companies in this space, ten years could solve a lot of issues. Think double/triple the range of current electrical planes at half the cost. Small planes are expensive to operate currently and fuel & maintenance are big factors here.
  - JorgeGT 6y ago
    Completely correct, H2 either in fuel cells or burnt in turbines and battery-powered hybridization are two of the pillars of the EU's Clean Aviation R&D programme: https://clean-aviation.eu/files/Clean%20Aviation%20-%20Shared%20Vision%2014%20Jan%20FINAL.pdf https://clean-aviation.eu/files/Clean%20Aviation%20-%20Share...
hef19898 6y ago
For transportation, hydrogen can be absorbed by a carrier oil. That way it is basically inert, doesn't even count as dangerous goods for transportation purposes. No compression needed. In cars it is different, so.
- runeks 6y ago
  What’s the density of hydrogen using this method versus compression?
  - hef19898 6y ago
    I'd have to look up the numbers. Cost wise, a pure hydrogen pipeline is cheaper for sure. At scale at least. Until that scale is reached, using carrier oil is much cheaper, but still competitive enough to get it going. EDIT: The oil is called marlotherm something, if memory serves well.
stewbrew 6y ago
When there is wind or sun, it's not entirely impossible to produce hydrogen on site - within limits of course. Then the question is what kind of energy storage is more cost efficient on the long run.
- AnHonestComment 6y ago
  It also needs to beat growing corn and burning it as alcohol on total process efficiency. We can be carbon neutral by using plant based fuels, so anything exotic needs to perform better than burning plant/algae alcohol or gas.
- ummwhat 6y ago
  If there is sun why not skip the middle man and use an array of mirrors for direct heating?
  - stewbrew 6y ago
    Oh come on. Anyway, the sun doesn't shine at night. In the winter, the situation is difficult too. You need storage but you don't necessarily have to move the storage across countries.
thysultan 6y ago
The idea is to use water as the fuel and convert to hydrogen just in time for combustion.
- bawolff 6y ago
  How would that work? That sounds like a perpetual motion machine.
  - thysultan 6y ago
    Like how a gun works, essentially a battery for the initial motion, using the subsequent motion storing some for the next initial motion.
    - bawolff 6y ago
      Guns work by having chemical explosives in them. Which is also how gasoline powered cars work. They definitely do not work by using a depleted battery to charge a second battery to create energy out of nothing.
      - thysultan 6y ago
        gasoline cars also use a battery to initiate the engine.
        bawolff 6y ago
        Yes. However they don't use it to both power the car and charge the battery. Kickstarting the engine with a battery is very different from only having a battery and also using that battery to charge itself and the car at the same time. The original poster was proposing a closed system where you would turn water into hydrogen (a very energy intensive process) and then turn it back into water (an energy releasing process) inside the car to provide all the energy. This is not how physics works. You cannot use your energy source to create more of your energy source without an external energy source. It just doesn't work that way.
tankenmate 6y ago
It is going to be very costly (energy and capital investment) to convert steel making to use hydrogen. A blast furnace is a well balanced chemical reaction where the coke serves two purposes; a source of carbon monoxide for turning ore in iron (Fe2O3(s) + 3 CO(g) => 2 Fe(s) + 3 CO2(g), very exothermic, good for turning the iron / steel into a liquid alloy), and a source of carbon for turning the iron into steel. All in one vessel and in one process no less. I guess you could do the first step using peroxide to strip the oxygen from the iron, but the second step in the same vessel at the same time? Fe2o3 + 3H2O2 => 2 Fe + 3 H2O, somewhat exothermic (if my rusty memory of enthalpy calculations are correct), not sure of the activation energy or need for catalysts). [EDIT] also forgot the peroxide reaction would probably require external heat to over come the latent energy required to turn the H2O into super heated steam so that you could melt the iron / steel. This would probably boil off a large chunk of the peroxide as well, so it might need to be done in a contained pressure vessel, which would probably affect the speed of the iron ore reduction.
- ClumsyPilot 6y ago
  There is a steel mill that uses hydrogen, but it appears to be a recycling kind, rather than one that makes iron from ore with a blast furnace. https://www.rechargenews.com/transition/-world-first-as-hydrogen-used-to-power-commercial-steel-production/2-1-799308 https://www.rechargenews.com/transition/-world-first-as-hydr...
  - tankenmate 6y ago
    Yes, I suspect this is much easier as you don't need to alloy as the steel is already alloyed with carbon.
- _ph_ 6y ago
  I am not a steel expert, but the steel industry is constantly talking about converting to hydrogen. Your sum formula has a bit lot of oxygen, shouldn't it be Fe2O3+3H2 => 2 Fe + 2 H2O? In any case, they could use additional hydrogen for heating and burning it with ambient air.

hannob 6y ago

I find it amazing (in a bad way) that whenever you talk about hydrogen someone comes up and wants to talk about cars. There's a number of use cases where clean hydrogen will be desperately needed. This starts with areas where hydrogen is already used today - but it's hydrogen made from fossil fuels - like ammonia production and includes areas like steel production where hydrogen really is the only game in town for a low-carbon production. We'll need all the clean hydrogen we can get, and probably more than that. There's no plausible scenario where we'll have excess hydrogen that we can waste in an area where it's just vastly less efficient than the available alternative.

marcosdumay 6y ago
On the specific case of steel production, it's way more likely that people will settle on synthetic carbon based fuels. Of course, producing those uses hydrogen too, so no big change.
- paledot 6y ago
  Yeah, I really don't see a case where large amounts of hydrogen are being transported commercially. Anything you don't need on site makes much more sense to convert to synfuel.
- hannob 6y ago
  Why would that make any sense? (Synfuels are really, really inefficient, you basically only want them in places where you need the high energy density and can't avoid them, like aviation.)
  - marcosdumay 6y ago
    Because the carbon has an important role on the chemistry of making steel.
Triv888 6y ago
> I find it amazing (in a bad way) that whenever you talk about hydrogen someone comes up and wants to talk about cars. It would solve the battery charging problem that electric cars have (for long trips) while not polluting like conventional cars.