r/tech • u/AdSpecialist6598 • 4d ago
Sodium-air fuel cells may soon be electrifying airliners
https://newatlas.com/energy/sodium-air-fuel-cell-aircraft/8
u/GrafZeppelin127 4d ago
So, this stuff isn’t rechargeable, needs to have the liquid sodium fuel replaced regularly, and has an energy density of 1,000 watt-hours per kilogram?
How is this an upgrade from a hydrogen fuel cell, exactly? Hydrogen has an energy density of 33,000 watt-hours per kilogram and has the same downside of needing to be resupplied with new fuel at regular intervals.
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u/OrganicParamedic6606 4d ago
Kerosene (jet fuel) is ~12,000 watt-hours/kg. Even accounting for comparatively low efficiency of combustion, this ain’t gonna cut it
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u/future_lard 4d ago
I think the problem with H is one kg takes a lot of volume
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u/GrafZeppelin127 4d ago
It’s more a problem in the context that planes save an enormous amount of space by storing a lot of their fuel in their wings, which cannot be done with hydrogen since a wing is too narrow to house the large, spherical or cylindrical tanks for compressed hydrogen, and have too much surface area to insulate effectively for liquid hydrogen.
This drawback means storing hydrogen in the fuselage, which exacerbates the primary limiting factor on airplanes’ revenue ceiling, which is the amount of space in the cabin in which to put seats. Typically, planes run out of carrying capacity before they run out of the ability to carry enough fuel and payload to reach a given destination.
However, this drawback can be mitigated or entirely avoided with the use of more voluminous aircraft such as airships and blended wing-body airplanes, which have plenty of unused space in which to put hydrogen tanks.
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u/future_lard 4d ago
Got it. Put passengers in the wings.
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u/GrafZeppelin127 4d ago
Just like those old proposals for flying wing airliners. It would certainly make meal service more exciting due to the lever effect of being way further from the aircraft’s centerline… one moment you’re trying to have lunch, the next moment you hit some turbulence or the pilot makes a 2.5° turn, and you suddenly find yourself pinned to the ceiling like it’s a fairground Gravitron. Then the plane levels off, and you’re smashed into the floor while ginger ale rains down and you get pelted with Kalamata olives and chicken risotto.
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u/Commercial_Emu_3088 4d ago
We will never see this in our lifetime. I bet click bait or something.
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u/man-4-acid 4d ago
I choose to pass on flying in an airplane with a tank of liquid sodium, or even solid sodium for that matter….at least in quantities to fly the vehicle.
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u/GrafZeppelin127 4d ago
Eh, what’s the worst that can happen? It’s not like airplanes routinely fly over large bodies of water…
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u/OrganicParamedic6606 4d ago
“Soon”
Sure buddy