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This is a simplification, think about this: You can manufacture hydrogen anywhere as long as you have water, an electrolyzer, and a power source. Oil can only

This is a simplification, think about this: You can manufacture hydrogen anywhere as long as you have water, an electrolyzer, and a power source. Oil can only be pumped out of the ground in certain places, water is technically _much_ more abundant everywhere. Hydrogen storage tech has improved in the last twenty years. It's becoming affordable and "as safe" to store hydrogen at fuel densities similar to that of petroleum based fuels. Obviously the devil's in the details, but shouldn't we attempt to engineer huge carbon emitters like container shipping or aircraft to run on hydrogen + solar?

xoa 6y ago
>You can manufacture hydrogen anywhere as long as you have water, an electrolyzer, and a power source. I don't understand what you're arguing with here? You can manufacture synthetic hydrocarbons anywhere so long as you have water, carbon dioxide, and a power source too. So I'm not sure why you see this as an advantage for hydrogen. >but shouldn't we attempt to engineer huge carbon emitters like container shipping or aircraft to run on hydrogen + solar? Again, why hydrogen from solar vs hydrocarbons from solar? From a global warming perspective what matters is net GHG.
- mayama 6y ago
  > You can manufacture synthetic hydrocarbons anywhere so long as you have water, carbon dioxide You need coal or some biomass to manufacture synthetic hydrocarbons. And tail emission is still a concern.
  - kolinko 6y ago
    You can extract carbon from atmosphere.
    - gus_massa 6y ago
      Organic reactions to produce complex molecules have an horrible efficiency. (For example, photosynthesis in plants has a 1% or 2% of efficiency.) Perhaps the efficiency to produce methane is not so bad, but a chain with 6 or 7 carbons like gasoline is very complicated. It is not equivalent if they are aligned or they form a ramified structure like a tree, and it is very difficult to choose which one they will form unless you have a very complex process. There are some graphics in https://en.wikipedia.org/wiki/Octane_rating#Isooctane_as_a_reference_standard https://en.wikipedia.org/wiki/Octane_rating#Isooctane_as_a_r...
      - jabl 6y ago
        > Perhaps the efficiency to produce methane is not so bad, but a chain with 6 or 7 carbons like gasoline is very complicated. The Fischer-Tropsch process is almost a hundred years old, and has been used on an industrial scale. E.g. Nazi Germany used it to produce a non-trivial fraction of their liquid fuels during WWII. Similarly South Africa used it during Apartheid. Now FT itself is better suited for producing mostly straight hydrocarbon chains like diesel or jet fuel rather than the branched ones seen in high octane gasoline. The efficiency of traditional FT is around 40%, but by adding extra hydrogen to the process it can be increased by around a factor of 3 (the efficiency meaning the energy content of the carbon carrying feedstock vs the output, so over 100% is possible as hydrogen provides some of the energy in the final product). The problem is to get the CO needed for FT in a carbon-neutral manner. Biomass is limited, capturing and reducing CO2 is expensive and requires a lot of energy.
        Qwertious 6y ago
        "The Fischer-Tropsch process is almost a hundred years old, and has been used on an industrial scale. E.g. Nazi Germany used it to produce a non-trivial fraction of their liquid fuels during WWII." I know it's not an argument against, but the Nazis lost WW2 because they ran out of oil. They invaded Russia at the last moment they could before they wouldn't have the oil to invade, and when they invaded they made a beeline for Russia's oil fields. They were desperate for fuel from anywhere, because their tanks are useless and they either have to fight to the death wherever their tanks run out of fuel, or abandon their tanks. ...also, the main non-fossil fuel the nazis used was probably hay. For their horses. It's just a super weird example.
        jabl 6y ago
        > I know it's not an argument against, but the Nazis lost WW2 because they ran out of oil. Well, they would most likely have lost anyway, but failing to capture the Caucasian oil fields as well as the Allies attacking their fuel infrastructure certainly hastened their demise. One can make a good argument that the strategic bombing on the western front in WWII was largely ineffective, but there were parts that were wildly successful, like attacking the fuel infrastructure. As for why they didn't just use synthetic fuel all the way instead of just a fraction of the total use, I don't know. I guess they just couldn't scale it up fast enough. And certainly getting oil from the ground is much cheaper than creating synthetic fuel from coal in huge industrial parks. > ...also, the main non-fossil fuel the nazis used was probably hay. For their horses. It's just a super weird example. Sure. Blitzkrieg captured the public imagination, but in reality only a small fraction of the German army were these mechanized shock troops. Most were infantry that moved by train or marched with horses carrying equipment.
outworlder 6y ago
> It's becoming affordable and "as safe" to store hydrogen at fuel densities similar to that of petroleum based fuels. Have we solved hydrogen embrittlement issues? What about hydrogen leaking out of containers?
- JAlexoid 6y ago
  Hydrogen leaking is an issue for longer term storage, not particularly an issue for liquid hydrogen that is going to run an airplane for a very specific number of hours.
  - liability 6y ago
    > for a very specific number of hours Unless you plan on throwing away the planes after one or two flights, those tanks will be filled with hydrogen for tens of thousands of hours over their lifespan. Perhaps they have light weight alloys that can cope with this though, I'm no metallurgist..
    - JAlexoid 6y ago
      I never addressed the lifespan of containers, that's not same as hydrogen leakage.
      - rbanffy 6y ago
        Still embrittlement is an issue. How long until the hydrogen tank needs replacement? Liquid per liquid, why not liquid methane that's far easier to work with and can be manufactured at zero carbon emissions.
      - liability 6y ago
        Hydrogen embrittlement leads to hydrogen leaks. Unless there are advanced alloys that resist it, any aircraft part that comes into contact with the hydrogen will be subject to accelerated 'wear'. Frankly hydrogen planes are nonsense. Even if it works on paper, it's not realistic to expect all the extant planes to be rapidly phased out with brand new planes with exotic designs that aircraft manufacturers, pilots, and airlines don't have any experience with. On the other hand, old planes can be retrofitted to burn biofuel and new production planes of old proven designs can be made to burn biofuel from the get-go. 'Concept planes' like the ZEROe are basically just science fiction meant to wow shareholders and give the public the impression that legislative reform isn't necessary because corporations are already taking the problem seriously. I don't think these are serious proposals, it's just corporate propaganda. Car companies pushed hydrogen cars for years for the same reason. Hydrogen fuel cell cars were never going to happen for a myriad of practical reasons and car manufacturers knew it but promoted the concept anyway for PR reasons. ZEROe is Airbus doing the same.
Aperocky 6y ago
> engineer huge carbon emitters like container shipping or aircraft to run on hydrogen + solar? Why hydrogen at all then? The source is solar so let's keep it at that, why the middle state?
- ncmncm 6y ago
  Really? You think solar panels on the wings would provide enough power to fly? Aircraft need concentrated energy. Batteries are nowhere near enough for anything big. Liquid H2 is the best possible fuel for aircraft, once certain practicalities are worked out, and can be produced from solar and wind.
  - Aperocky 6y ago
    OK So this is just about conversion. H2 doesn't need solar, it needs power, it doesn't care where that power came from. It's essentially a disconnected system, to sell it as if H2 somehow means solar (which I get from earlier threads) is a little bit disingenuous.
    - ncmncm 6y ago
      Not even a little bit. Wind and solar are the cheapest source of power, with their usability reduced only by surge demands. Liquifying H2 would absorb peak production and be unaffected by temporary lulls. Unless you think it would be natural to use the more expensive power instead?
      - Aperocky 6y ago
        That makes much more sense, was not thinking in terms of surges.

xoa 6y ago

>You can manufacture hydrogen anywhere as long as you have water, an electrolyzer, and a power source. I don't understand what you're arguing with here? You can manufacture synthetic hydrocarbons anywhere so long as you have water, carbon dioxide, and a power source too. So I'm not sure why you see this as an advantage for hydrogen. >but shouldn't we attempt to engineer huge carbon emitters like container shipping or aircraft to run on hydrogen + solar? Again, why hydrogen from solar vs hydrocarbons from solar? From a global warming perspective what matters is net GHG.

mayama 6y ago
> You can manufacture synthetic hydrocarbons anywhere so long as you have water, carbon dioxide You need coal or some biomass to manufacture synthetic hydrocarbons. And tail emission is still a concern.
- kolinko 6y ago
  You can extract carbon from atmosphere.
  - gus_massa 6y ago
    Organic reactions to produce complex molecules have an horrible efficiency. (For example, photosynthesis in plants has a 1% or 2% of efficiency.) Perhaps the efficiency to produce methane is not so bad, but a chain with 6 or 7 carbons like gasoline is very complicated. It is not equivalent if they are aligned or they form a ramified structure like a tree, and it is very difficult to choose which one they will form unless you have a very complex process. There are some graphics in https://en.wikipedia.org/wiki/Octane_rating#Isooctane_as_a_reference_standard https://en.wikipedia.org/wiki/Octane_rating#Isooctane_as_a_r...
    - jabl 6y ago
      > Perhaps the efficiency to produce methane is not so bad, but a chain with 6 or 7 carbons like gasoline is very complicated. The Fischer-Tropsch process is almost a hundred years old, and has been used on an industrial scale. E.g. Nazi Germany used it to produce a non-trivial fraction of their liquid fuels during WWII. Similarly South Africa used it during Apartheid. Now FT itself is better suited for producing mostly straight hydrocarbon chains like diesel or jet fuel rather than the branched ones seen in high octane gasoline. The efficiency of traditional FT is around 40%, but by adding extra hydrogen to the process it can be increased by around a factor of 3 (the efficiency meaning the energy content of the carbon carrying feedstock vs the output, so over 100% is possible as hydrogen provides some of the energy in the final product). The problem is to get the CO needed for FT in a carbon-neutral manner. Biomass is limited, capturing and reducing CO2 is expensive and requires a lot of energy.
      - Qwertious 6y ago
        "The Fischer-Tropsch process is almost a hundred years old, and has been used on an industrial scale. E.g. Nazi Germany used it to produce a non-trivial fraction of their liquid fuels during WWII." I know it's not an argument against, but the Nazis lost WW2 because they ran out of oil. They invaded Russia at the last moment they could before they wouldn't have the oil to invade, and when they invaded they made a beeline for Russia's oil fields. They were desperate for fuel from anywhere, because their tanks are useless and they either have to fight to the death wherever their tanks run out of fuel, or abandon their tanks. ...also, the main non-fossil fuel the nazis used was probably hay. For their horses. It's just a super weird example.
        jabl 6y ago
        > I know it's not an argument against, but the Nazis lost WW2 because they ran out of oil. Well, they would most likely have lost anyway, but failing to capture the Caucasian oil fields as well as the Allies attacking their fuel infrastructure certainly hastened their demise. One can make a good argument that the strategic bombing on the western front in WWII was largely ineffective, but there were parts that were wildly successful, like attacking the fuel infrastructure. As for why they didn't just use synthetic fuel all the way instead of just a fraction of the total use, I don't know. I guess they just couldn't scale it up fast enough. And certainly getting oil from the ground is much cheaper than creating synthetic fuel from coal in huge industrial parks. > ...also, the main non-fossil fuel the nazis used was probably hay. For their horses. It's just a super weird example. Sure. Blitzkrieg captured the public imagination, but in reality only a small fraction of the German army were these mechanized shock troops. Most were infantry that moved by train or marched with horses carrying equipment.

outworlder 6y ago

> It's becoming affordable and "as safe" to store hydrogen at fuel densities similar to that of petroleum based fuels. Have we solved hydrogen embrittlement issues? What about hydrogen leaking out of containers?

JAlexoid 6y ago
Hydrogen leaking is an issue for longer term storage, not particularly an issue for liquid hydrogen that is going to run an airplane for a very specific number of hours.
- liability 6y ago
  > for a very specific number of hours Unless you plan on throwing away the planes after one or two flights, those tanks will be filled with hydrogen for tens of thousands of hours over their lifespan. Perhaps they have light weight alloys that can cope with this though, I'm no metallurgist..
  - JAlexoid 6y ago
    I never addressed the lifespan of containers, that's not same as hydrogen leakage.
    - rbanffy 6y ago
      Still embrittlement is an issue. How long until the hydrogen tank needs replacement? Liquid per liquid, why not liquid methane that's far easier to work with and can be manufactured at zero carbon emissions.
    - liability 6y ago
      Hydrogen embrittlement leads to hydrogen leaks. Unless there are advanced alloys that resist it, any aircraft part that comes into contact with the hydrogen will be subject to accelerated 'wear'. Frankly hydrogen planes are nonsense. Even if it works on paper, it's not realistic to expect all the extant planes to be rapidly phased out with brand new planes with exotic designs that aircraft manufacturers, pilots, and airlines don't have any experience with. On the other hand, old planes can be retrofitted to burn biofuel and new production planes of old proven designs can be made to burn biofuel from the get-go. 'Concept planes' like the ZEROe are basically just science fiction meant to wow shareholders and give the public the impression that legislative reform isn't necessary because corporations are already taking the problem seriously. I don't think these are serious proposals, it's just corporate propaganda. Car companies pushed hydrogen cars for years for the same reason. Hydrogen fuel cell cars were never going to happen for a myriad of practical reasons and car manufacturers knew it but promoted the concept anyway for PR reasons. ZEROe is Airbus doing the same.

Aperocky 6y ago

> engineer huge carbon emitters like container shipping or aircraft to run on hydrogen + solar? Why hydrogen at all then? The source is solar so let's keep it at that, why the middle state?

ncmncm 6y ago
Really? You think solar panels on the wings would provide enough power to fly? Aircraft need concentrated energy. Batteries are nowhere near enough for anything big. Liquid H2 is the best possible fuel for aircraft, once certain practicalities are worked out, and can be produced from solar and wind.
- Aperocky 6y ago
  OK So this is just about conversion. H2 doesn't need solar, it needs power, it doesn't care where that power came from. It's essentially a disconnected system, to sell it as if H2 somehow means solar (which I get from earlier threads) is a little bit disingenuous.
  - ncmncm 6y ago
    Not even a little bit. Wind and solar are the cheapest source of power, with their usability reduced only by surge demands. Liquifying H2 would absorb peak production and be unaffected by temporary lulls. Unless you think it would be natural to use the more expensive power instead?
    - Aperocky 6y ago
      That makes much more sense, was not thinking in terms of surges.