3 ms·

> Probably you will want liquified H2. More likely to use solid adsorbed hydrogen. Room temperature, room pressure, less mass in the tanks. Adsorption has bee

> Probably you will want liquified H2. More likely to use solid adsorbed hydrogen. Room temperature, room pressure, less mass in the tanks. Adsorption has been experimented with for several decades at least. But modern computer power and modern processes for controlling material surface properties make it more likely than ever before. https://en.wikipedia.org/wiki/Adsorption https://en.wikipedia.org/wiki/Adsorption - not specific to hydrogen Random PDF of study: https://www.cambridge.org/core/services/aop-cambridge-core/content/view/10F54D8F0E3E0ACB12D0083DF1C91672/S0883769400053458a.pdf/hydrogen_adsorption_in_carbon_materials.pdf https://www.cambridge.org/core/services/aop-cambridge-core/c... https://www.youtube.com/watch?v=U7CCq4oBgw4&t=464s https://www.youtube.com/watch?v=U7CCq4oBgw4&t=464s - latest "breakthrough". One day, one of these will be real.

ncmncm 5y ago
Less mass than what? I promise you, adsorbed hydrogen along with whatever it is adsorbed onto will not weigh less than the same hydrogen, liquified. LH2 at atmospheric pressure does not need a heavy tank. If they can get it to adsorb to an aerogel, they might have something, but you still have to get the H2 back out.
- ddek 5y ago
  The best solid adsorbed hydrogen is currently running about 5% the density of liquid hydrogen. Most solutions use either graphene or heavy metals too rare to meet mass demand. It's not a promising technology.
ddek 5y ago
As you say, we've been working on solid adsorption for a long time now. Nothing has left the lab. The video presents an optimistic future, but we don't even have the basics yet. Firstly, there is a fundamental issue - H² doesn't really give you anything to work with. The vast majority of compounds have two protons, two neutrons (rare isotopes have more protons). [They're distributed in the most boring orbitals, just spheres with no real edge to gain leverage.](https://winter.group.shef.ac.uk/orbitron/atomic_orbitals/1s/index.html https://winter.group.shef.ac.uk/orbitron/atomic_orbitals/1s/...) This lack of leverage makes surface adsorption tricky. The molecule gives us nothing to grab. You won't carefully craft a surface that can hold H². I think right now there's a focus on activated carbon. That's become a bit of a synonym for 'graphene', with it's well known limitations. When I studied the subject, metal-organic complexes were the focus. These would be extremely customisable, but if they worked we'd probably have seen by now. They tended to use heavy metals. I wasn't optimistic at the time, I thought anything using materials past the 4th row of the periodic table was unrealistic. As the metals get heavier they get expensive and sometimes rare. If we want to solve a common problem, we need common components. If your solution has lanthanoid, it won't scale. I was right btw. The research group closed when funding was reallocated. Each experiment ran the research budget of another group. MoC's don't really get much love any more. Anyway, we should probably think about what makes a good hydrogen adsorption material. I think it's pretty simple, you want a material that: stores a high density of hydrogen, is reusable, quickly picks up hydrogen, and quickly releases hydrogen. The latter 2 categories is the 'kinetics'. Of the materials we know, all (literally all) that have 'good' kinetics are either single use or low density. Conversely, all that are both multi use and relatively high density have poor kinetics. Additionally, most of those with good kinetics have unrealistic conditions, like requiring 400˚C temperature to release the hydrogen.
- zoomablemind 5y ago
  From a realm of sustainability, it'd be cool to dream up a way for having bioships [1], so that the energy would be accumulated in the structure while still on the ground, then metabolised while in-flight. Well, SkyMoos [2] would also be nice to have around. [1]:https://en.m.wikipedia.org/wiki/Bioship https://en.m.wikipedia.org/wiki/Bioship [2]:https://aliens.fandom.com/wiki/Skymoo https://aliens.fandom.com/wiki/Skymoo
- drran 5y ago
  LENR scientists are using palladium and nickel to compress hydrogen up to 100k atmospheres (90 hydrogen atoms per 1 atom of palladium) at room temperature and pressure.
  - ddek 5y ago
    No? LENR is not a particularly active field of research. The most recent noteworthy paper is a well funded, failed, replication. It is a pipedream. There are almost no LENR scientists. I can't see any noteworthy papers for PdNi as a hydrogen storage mechanism. It's capability to absorb (hold within its structure; not adsorb, to hold on surface) hydrogen has been known for a century, if it had utility we would know by now.
    - drran 5y ago
      https://patents.google.com/patent/US10507452B2/en https://patents.google.com/patent/US10507452B2/en
- tuatoru 5y ago
  I'm glad I prompted an expert to comment! Thanks.

ncmncm 5y ago

Less mass than what? I promise you, adsorbed hydrogen along with whatever it is adsorbed onto will not weigh less than the same hydrogen, liquified. LH2 at atmospheric pressure does not need a heavy tank. If they can get it to adsorb to an aerogel, they might have something, but you still have to get the H2 back out.

ddek 5y ago
The best solid adsorbed hydrogen is currently running about 5% the density of liquid hydrogen. Most solutions use either graphene or heavy metals too rare to meet mass demand. It's not a promising technology.

ddek 5y ago

As you say, we've been working on solid adsorption for a long time now. Nothing has left the lab. The video presents an optimistic future, but we don't even have the basics yet. Firstly, there is a fundamental issue - H² doesn't really give you anything to work with. The vast majority of compounds have two protons, two neutrons (rare isotopes have more protons). [They're distributed in the most boring orbitals, just spheres with no real edge to gain leverage.](https://winter.group.shef.ac.uk/orbitron/atomic_orbitals/1s/index.html https://winter.group.shef.ac.uk/orbitron/atomic_orbitals/1s/...) This lack of leverage makes surface adsorption tricky. The molecule gives us nothing to grab. You won't carefully craft a surface that can hold H². I think right now there's a focus on activated carbon. That's become a bit of a synonym for 'graphene', with it's well known limitations. When I studied the subject, metal-organic complexes were the focus. These would be extremely customisable, but if they worked we'd probably have seen by now. They tended to use heavy metals. I wasn't optimistic at the time, I thought anything using materials past the 4th row of the periodic table was unrealistic. As the metals get heavier they get expensive and sometimes rare. If we want to solve a common problem, we need common components. If your solution has lanthanoid, it won't scale. I was right btw. The research group closed when funding was reallocated. Each experiment ran the research budget of another group. MoC's don't really get much love any more. Anyway, we should probably think about what makes a good hydrogen adsorption material. I think it's pretty simple, you want a material that: stores a high density of hydrogen, is reusable, quickly picks up hydrogen, and quickly releases hydrogen. The latter 2 categories is the 'kinetics'. Of the materials we know, all (literally all) that have 'good' kinetics are either single use or low density. Conversely, all that are both multi use and relatively high density have poor kinetics. Additionally, most of those with good kinetics have unrealistic conditions, like requiring 400˚C temperature to release the hydrogen.

zoomablemind 5y ago
From a realm of sustainability, it'd be cool to dream up a way for having bioships [1], so that the energy would be accumulated in the structure while still on the ground, then metabolised while in-flight. Well, SkyMoos [2] would also be nice to have around. [1]:https://en.m.wikipedia.org/wiki/Bioship https://en.m.wikipedia.org/wiki/Bioship [2]:https://aliens.fandom.com/wiki/Skymoo https://aliens.fandom.com/wiki/Skymoo
drran 5y ago
LENR scientists are using palladium and nickel to compress hydrogen up to 100k atmospheres (90 hydrogen atoms per 1 atom of palladium) at room temperature and pressure.
- ddek 5y ago
  No? LENR is not a particularly active field of research. The most recent noteworthy paper is a well funded, failed, replication. It is a pipedream. There are almost no LENR scientists. I can't see any noteworthy papers for PdNi as a hydrogen storage mechanism. It's capability to absorb (hold within its structure; not adsorb, to hold on surface) hydrogen has been known for a century, if it had utility we would know by now.
  - drran 5y ago
    https://patents.google.com/patent/US10507452B2/en https://patents.google.com/patent/US10507452B2/en
tuatoru 5y ago
I'm glad I prompted an expert to comment! Thanks.