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in reply to Sarah Brown

Mark vW
Mark vW
• •
Why is hydrogen on demand not ever going to be feasible?
in reply to Mark vW

Sarah Brown
Sarah Brown
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@Mark vW Demanding it for what? What do you want to burn this pointless gas for?
@Mark vW
in reply to Sarah Brown

Sarah Brown
Sarah Brown
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@Mark vW if you’re that desperate to make steam, you can just turn the kettle on.
@Mark vW
in reply to Sarah Brown

Mark vW
Mark vW
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Hydrogen that is produced as you need it. NFW people are ever going to drive Hindenburg cars with hydrogen tanks. But if there is a catalyst that can extract hydrogen from water as the car requires, that would be most excellent. I just wondered whether you were up on that technology's future potential.
in reply to Mark vW

Sarah Brown
Sarah Brown
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@Mark vW Water is what you get when you burn hydrogen.

So your “catalyst” is gonna need to procure energy to crack it, so you can then use (40% of) it to produce propulsion in an internal combustion engine.

The second law of thermodynamics wants a word.

@Mark vW
in reply to Mark vW

Sarah Brown
Sarah Brown
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@Mark vW Still, be nice if it worked, because you could capture the steam from the exhaust and pass it back over the catalyst to get the hydrogen back and never have to put fuel in your car!
@Mark vW
in reply to Sarah Brown

David Blue ※
David Blue ※
• •
well that's discouraging but it's nice to finally encounter an explanation for our hyped investment in battery technology, of all things.
in reply to Sarah Brown

Clara Listensprechen {in stickershock}
Clara Listensprechen {in stickershock}
• •
It's useful in terms of combustion byproduct. Combustion byproduct is why we have to stop using fossil fuels.
in reply to Clara Listensprechen {in stickershock}

Sarah Brown
Sarah Brown
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@Clara Listensprechen {in stickershock} that’s why it’s maybe got future in aviation where the weight of batteries is their Achilles’ heel.

But if you aren’t flying, then batteries are superior to hydrogen in every way.

Particularly when you start asking awkward questions like, “where did this hydrogen come from?”

@Clara Listensprechen {in stickershock}
in reply to Sarah Brown

Clara Listensprechen {in stickershock}
Clara Listensprechen {in stickershock}
• •
Oh–Hydrozene has been referred to as a type of kerosene but it isn’t, and the useful part of hydrozene is the hydro part.
in reply to Clara Listensprechen {in stickershock}

Sarah Brown
Sarah Brown
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@Clara Listensprechen {in stickershock} can’t use hydrazine as a fuel on Earth because it’s like, lethally poisonous.

It’s what satellites use in their manoeuvring engines (with nitric acid as an oxidiser) though.

@Clara Listensprechen {in stickershock}
Unknown parent

Sarah Brown
Sarah Brown
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@Alex Holst

reshared this

in reply to Sarah Brown

Clara Listensprechen {in stickershock}
Clara Listensprechen {in stickershock}
• •
Hydrazine shouldn't be used in power plant circulating water for the same reason but it is. And it's already being used (and has been used for decades) as a fuel in large rocketry...so there's that.
in reply to Clara Listensprechen {in stickershock}

Sarah Brown
Sarah Brown
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@Clara Listensprechen {in stickershock} It's used in deep space rocketry because it's a storable. You can coast for years and then when you need to light your engines, it will still be there.

"Ignition" by John Clark is a useful read on this.

Don't use it on Earth. It's repulsive stuff.

@Clara Listensprechen {in stickershock}
in reply to Sarah Brown

Katie Fenn
Katie Fenn
• •

I found this episode of Real Engineering to be pretty inspiring.

Rethinking the air liner using the latest composite materials and advances in aeronautics could transform the internal volume for hydrogen too.

I only wish we had the Boeing that designed the 777, and not the mess that designed the 737 MAX.

https://youtu.be/59A8-rKRs-0?si=Yuq_r1n-1EqNPqK0


The Plane That Will Change Travel Forever

Sign up to Nebula here: https://go.nebula.tv/realengineeringGet a free month of Nebula with any Real Engineering merch: https://store.nebula.app/collections/...
YouTube
in reply to Katie Fenn

Sarah Brown
Sarah Brown
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@Katie Fenn They could make it so much more pleasant than the cramped bus in the sky of today too.
@Katie Fenn
in reply to Sarah Brown

Katie Fenn
Katie Fenn
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They could, but I’m sure they’ll find a way to wring the joy out of it somehow.

Maybe we’ll enjoy a brief renaissance like the dawn of the 747 era, where they had no idea what to do with all the new space before realising “let’s shoehorn more bodies in here”.

This entry was edited (4 months ago)
in reply to Sarah Brown

Richard Barrell
Richard Barrell
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I assume oil companies big it up specifically because it's unworkable, to distract attention from solutions that actually will work. Same gambit as hyperloop being fake technology for the sole purpose of distracting attention from trains and trams.
in reply to Sarah Brown

Sarah Brown
Sarah Brown
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I honestly expected a lot more people arguing strongly back, but I guess the shouty weirdoes are more drawn to Facebook.
in reply to Sarah Brown

Bork
Bork
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Not going to shout back, yr pretty much bang on the money. Only thing I'd add is that there's probably a few more niche uses for it than just air travel. Other than that.. yeah 👍
in reply to Sarah Brown

marlies :tblverified:
marlies :tblverified:
• •
if you want people here to shout at you, you gotta either praise systemd or criticize anything else about linux
in reply to marlies :tblverified:

Sarah Brown
Sarah Brown
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@marlies :tblverified: In space nobody can hear you scream. This is because the flight control computers are running Linux 😉
@marlies :tblverified:

Alexandra Lanes reshared this.

in reply to Sarah Brown

User name cannot be blank 🇪🇺
User name cannot be blank 🇪🇺
• •
Not a lot of point in arguing when you are essentially correct, however if you are really looking for argument I'd say that your potential userbase of just aviation is slightly narrow as there are other areas I can see it being used though I am in full agreement on its not really going to be a mainstream energy source. In terms of other uses I am thinking things like some heavy plant, some heavy haulage (this more to do with max weight limits and current battery tech being heavy).
in reply to User name cannot be blank 🇪🇺

Sarah Brown
Sarah Brown
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@User name cannot be blank 🇪🇺 Weight is it’s one saving grace as far as I can see. This is why it’s not awful as a rocket fuel because it gives high specific impulse, but methane is looking like a better bet for the future there.
@User name cannot be blank 🇪🇺
Unknown parent

Sarah Brown
Sarah Brown
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@Andrew Hickey “but you can get it on a large scale by cracking seawater”

Yeah. You can do a lot of things, but no fucker is going to.

@Andrew Hickey
in reply to Sarah Brown

TeflonTrout
TeflonTrout
• •

TANSTAAFL is a real bitch!

About aviation though: Hydrogen is a shit fuel source for flight for all the reasons it blows everywhere else- especially energy density by volume and weight.

Free space in aircraft is actually incredibly limited, and hydrogen containers are both fuck-off heavy and very constrained in shape. Wing fuel tanks work fine for liquids, but pressure vessels won't fit well between the rigid structures of wings and fuselages.

1/2

in reply to TeflonTrout

TeflonTrout
TeflonTrout
• •

You are 100% correct about the issue of dead battery weight, hydrogen tanks have the same problem to a lesser extent, but lack the flexibility batteries have in form factor-you can wedge those bastards in all sorts of convenient places.

As for gliding? Well, most powered aircraft, particularly all jets that I know of, are *terrible* gliders. The aerodynamic rules that make them efficient at high speed also dictate that they float like rocks, so that's not a major consideration. 2/2

in reply to TeflonTrout

TeflonTrout
TeflonTrout
• •

tl:dr, Batteries aren't currently feasible for flight, but hydrogen has all the drawbacks of batteries plus all the drawbacks of being an awkward and specialized material to handle.

Source: I was an Army Aviation Operations Specialist for 14 years. Def not a pilot, but aviation is Mah Jam

This entry was edited (4 months ago)
in reply to TeflonTrout

Sarah Brown
Sarah Brown
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@TeflonTrout the gliding thing was me being a bit flippant. It’s notable, however, that the safe landing weight of many jetliners is lower than the safe takeoff weight and whereas a plane that’s been aloft 10 hours on kerosene weighs a lot less than when it took off, one that uses batteries weighs exactly the same and has to cope with being just as heavy on landing.
@TeflonTrout
in reply to Sarah Brown

TeflonTrout
TeflonTrout
• •
YUP! Electrifying a plane properly would be best done by designing one from scratch, which is a Big Deal
in reply to Sarah Brown

argv minus one
argv minus one
• •

This is not awesome, because hydrogen is also the fuel for the fusion reactors we're hoping to eventually build…

Energy density would be a fair bit higher, though, at least.

Maybe we can store it as water, and electrolyze it from the reactor's own energy output to feed it more hydrogen?

This entry was edited (4 months ago)
in reply to argv minus one

Sarah Brown
Sarah Brown
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@argv minus one Ok, so when referring to hydrogen as a fuel, I’m talking about burning it.

Fusion is a different beast, and nearly all hydrogen on the planet is useless for it because any feasible design we can build or envisage uses deuterium and tritium. The former it extracts from seawater. The latter it breeds by bombarding lithium with neutrons.

Anyway, different issue. I do happen to think that trying to build fusion reactors is largely pointless too, but for entirely different reasons: the economics will never compete with a shitlaod of solar panels and a big-ass battery.

@argv minus one
in reply to Sarah Brown

argv minus one
argv minus one
• •

Solar has a hard upper limit on how much power it can produce. If you want any more than that, you'll have to look elsewhere. Fusion is an obvious candidate, assuming it can be made economical.

Pretty big assumption, I realize, but note that fusion doesn't have the huge safety and liability problems that make fission power plants obscenely expensive, so it may yet work out.

I know they're using heavy hydrogen, but I assume it has the same storage problems as light hydrogen.

in reply to argv minus one

Sarah Brown
Sarah Brown
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@argv minus one That upper limit is orders of magnitude more than humankind's entire energy use of all forms put together.

We don't need fusion power on earth, and probably never will, and of the people experimenting with it, the only ones making significant process are just using as a cover for thermonuclear weapons research (National Ignition Facility).

@argv minus one
in reply to Sarah Brown

argv minus one
argv minus one
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We already have thermonuclear weapons of apocalyptic power. I very seriously doubt that NIF is a weapons program. It would be pointless.
in reply to argv minus one

Sarah Brown
Sarah Brown
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@argv minus one I mean, the following text literally appears verbatim on their website. It's not like they're trying to hide it.

Because it is the only facility that can create the conditions that are relevant to understanding the operation of modern nuclear weapons, NIF is a crucial element of the National Nuclear Security Administration’s science-based Stockpile Stewardship Program.

NIF can repeatedly simulate those conditions inside the Target Chamber’s controlled environment, giving dedicated teams of scientists and researchers the ability to reconstitute and improve upon the capabilities of underground testing.

NIF’s high energy density and inertial confinement fusion experiments, coupled with the increasingly sophisticated simulations available from some of the world’s most powerful supercomputers, increase our understanding of weapon physics, including the properties and survivability of weapons-relevant materials.

@argv minus one
in reply to argv minus one

Sarah Brown
Sarah Brown
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@argv minus one Their bombs are old as fuck.

And they aren’t allowed to set them off by treaty.

So they do this instead. Even if they don’t know why, it keeps the talent trained, I guess.

@argv minus one
in reply to argv minus one

Sarah Brown
Sarah Brown
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@argv minus one BTW, the Space Shuttle and its stupid obscenely eye waveringly expensive bastard child, the alleged "space launch system" was/is also, in a very large part, nuclear weapons programmes. There's a reason that government "space" programmes use solid rocket boosters and commercial space programmes don't: it gives their ICBM engineers something to do.
@argv minus one
in reply to argv minus one

spmatich :blobcoffee:
spmatich :blobcoffee:
• •
@argv_minus_one the kind of hydrogen used for nuclear fission is tritium and deuterium, heavy isotopes, which are byproducts of nuclear fission power (at present). Fusion Power stations, when they are up and running in 30y time, will only need tiny amounts. They will likely be able to breed their own fuel because fusion produces a lot of neutrons (which aren’t radioactive in the way the byproducts of uranium fission are). The neutrons can be used to make heavy water, which when split gives heavy hydrogen. At least that was the plan 30y ago when I studied plasma physics.
@argv minus one
in reply to argv minus one

Sarah Brown
Sarah Brown
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@argv minus one @spmatich :blobcoffee: The easy way to hang on to deuterium is to burn it. Water is very easy to keep for as long as you want.
@spmatich :blobcoffee: @argv minus one
in reply to Sarah Brown

Tim is wearing a mask 🌈
Tim is wearing a mask 🌈
• •
@holsta
Historical note on domestic cooking in the UK: before gas from the North Sea oil fields became popular, "town gas" was piped around, composed of hydrogen and carbon monoxide.
@Alex Holst
in reply to Sarah Brown

Jono Ferguson
Jono Ferguson
• •

I'm open to there being uses for it, but I'm not seeing any in conventional land transport.

Trains maybe? ( no I haven't thought this through, and am likely in the pocket of big electron)

in reply to Jono Ferguson

Kincaid
Kincaid
• •
@jonoabroad overhead wires, and big bastard batteries where not feasible. Weight is not really an issue for trains
@Jono Ferguson
in reply to Kincaid

Sarah Brown
Sarah Brown
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@Kincaid @Jono Ferguson yeah. Trains are absurdly easy to run on grid electricity.
@Kincaid @Jono Ferguson
in reply to Sarah Brown

Jono Ferguson
Jono Ferguson
• •

@kincaid

look, it was late and I did say I didn't put any thought into it.

I was thinking of the ass end of Australia, but you are, rather cruelly using my own argument against me that electrons are easier to move than explody gas

I'll go back to my previous position of "I'm open to ideas, but cant' think of any" and this time not offer half ass, clearly not thought through ones 😀

@Kincaid
in reply to Sarah Brown

Jan Adriaenssens
Jan Adriaenssens
• •
I always thought especially transcontinental shipping and heavy industry would be the hydrogen users?
in reply to Jan Adriaenssens

Kincaid
Kincaid
• •
ammonia is looking better, easier to store, less explosive, can be made using renewables (but not yet economically at scale). Less energy dense than bunkerfuel tho
This entry was edited (4 months ago)
in reply to Sarah Brown

Hen Gymro Heb Wlad
Hen Gymro Heb Wlad
• •
Am I the only person who hears "hydrogen as fuel for aviation" and thinks "Hindenburg"?
in reply to Sarah Brown

Ed Davies
Ed Davies
• •

99% agree with you - hydrogen for any consumer application is stupid - electricity (via batteries were required) will always make more efficient use assuming the bulk of our energy is coming from renewable electricity in some form or other.

No opinion one way or the other on hydrogen in aviation. Maybe alcohol or ammonia? Dunno.

Hydrogen for grid-scale semi-interseasonal energy storage does seem to make some sense to me, though. L²/L³ is on your side if you're storing enough of the stuff. OK, the round-trip efficiency isn't great but I don't really see any other way of storing multiple TWh over weeks or months.

The Dutch government seems to have big plans in that direction. They must make at least a bit of sense, even if they're over-affected by the proximity of Shell or whoever.

A reminder for me to re-read Chris Goodall's The Switch, I think.

in reply to Ed Davies

Sarah Brown
Sarah Brown
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@Ed Davies for storage, I’m a big fan of pumping water uphill into big lakes. This may be an issue for the Dutch government in particular. They have many lakes, but not doing so well in the hills department!
@Ed Davies
in reply to Sarah Brown

Matthew Malthouse
Matthew Malthouse
• •

Even some of the high temperature industries that 5 years ago I was guessing would want hydrogen have tuned to electricity. There have been electric furnaces for steel recycling for years and recently smelting furnaces have gone into production.

Michael Liebreich's hydrogen ladder makes a nice graphic and even that keeps shifting (away from widespread hydrogen use) and is now on version 5.

in reply to Sarah Brown

Clara Listensprechen {in stickershock}
Clara Listensprechen {in stickershock}
• •
You won't find much intelligence on Diaspora either, like the kind that knows that hydrazine has been in TERRESTRIAL use both in water and in rocketry. Ta ta.
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