Post ATyFG0VipvaF00fGcK by jonathanharker@cloudisland.nz
(DIR) More posts by jonathanharker@cloudisland.nz
(DIR) Post #ATtZpbGQLK7BIlVQm0 by vik@mastodon.nzoss.nz
2023-03-23T04:04:18Z
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It turns out that hydrogen isn't a benign gas when it comes to global warming. When it leaks (for which estimates vary from 0.1-10%) in manufacture, shipping, and use, it prevents methane from breaking down and increases low-level ozone, both significantly increasing the greenhouse effect.
(DIR) Post #ATtaSTtPgNHZjaHb8a by phlogiston@mastodon.nz
2023-03-23T04:11:18Z
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@vik That's something that should be told to the EU. They seem to see hydrogen to be the silver bullet solution to their natural gas problem with Russia.
(DIR) Post #ATtcOU3xJAQv0mR4V6 by vik@mastodon.nzoss.nz
2023-03-23T04:33:01Z
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@phlogiston It's a great solution - for companies that put fuel in tanks and sell it.
(DIR) Post #ATtcqZON5UEfeGNSXA by phlogiston@mastodon.nz
2023-03-23T04:38:04Z
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@vik Yes, those that are looking for political reasons to weasle out of needing to change their business model.
(DIR) Post #ATth3CMePnFpoIqkme by swansinflight@mastodon.nz
2023-03-23T05:25:10Z
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@vik we should use it in everything. In fuel cells etc.
(DIR) Post #ATts54AyvdG4URU8Bs by vik@mastodon.nzoss.nz
2023-03-23T07:28:23Z
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@swansinflightAirships.
(DIR) Post #ATuBTjOzCYg8QeVgjg by Alisca@mastodon.social
2023-03-23T11:06:05Z
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@vik @swansinflight this.It's super light, abundant and cheap.What could possibly go wrong
(DIR) Post #ATuxUerMN42qQkI03s by vik@mastodon.nzoss.nz
2023-03-23T20:04:03Z
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@AliscaAnd now you've got me wondering if it would be possible to make a shaped charge drone using oxygen/hydrogen mix (detonates at 2,000m/s with density 40% that of air)@swansinflight
(DIR) Post #ATv6AT8d8mHTsAocHw by swansinflight@mastodon.nz
2023-03-23T21:41:17Z
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@vik @Alisca please document your testing for us
(DIR) Post #ATv7eWj8ShTte2mr1E by vik@mastodon.nzoss.nz
2023-03-23T21:57:58Z
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@swansinflight @Alisca Will post surviving footage on Utreon.
(DIR) Post #ATvExHHOonakuuhZWC by vik@mastodon.nzoss.nz
2023-03-23T23:19:49Z
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@swansinflightCurrent theory is that filling the inside of the cone with pure hydrogen will allow the cone liner to achieve higher velocity than it would in air as well as providing more lift.@Alisca
(DIR) Post #ATwAnUCxgsYBSXf5KC by Alisca@mastodon.social
2023-03-24T10:07:53Z
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@vik @swansinflight sounds plausible I cant believe nobody has done thiswe're gonna make a fortunewe should all meet up on the maiden flight!
(DIR) Post #ATyFG0VipvaF00fGcK by jonathanharker@cloudisland.nz
2023-03-25T10:07:18Z
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@vik hydrogen destroys the ozone layer on its way out to space, 3H2 + O3 - 3H2O pretty much all exothermic to the right.
(DIR) Post #ATz1nttqiY3u8qB36O by vik@mastodon.nzoss.nz
2023-03-25T19:11:16Z
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@jonathanharkerWhich is ;interesting as in the troposphere ozone production increases more or less linearly with hydrogen production. Bad news at both ends. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1067144/atmospheric-implications-of-increased-hydrogen-use.pdf
(DIR) Post #ATz1qQZODpz02qoQVc by vik@mastodon.nzoss.nz
2023-03-25T19:11:46Z
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@jonathanharkerWhich is interesting as in the troposphere ozone production increases more or less linearly with hydrogen production. Bad news at both ends. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1067144/atmospheric-implications-of-increased-hydrogen-use.pdf
(DIR) Post #ATztxkLQUebCvYDhY0 by jonathanharker@cloudisland.nz
2023-03-26T05:18:08Z
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@vik H₂ is also a yooge waste of energy, even from renewables-driven electrolysis, which is only 70% efficient at best. Fuel cells are only 50-65% efficient and rely on ludicrously rare platinum-group metals. H₂ has an embarrassing rate of storage and transmission loss, low energy density by volume, and a detonation velocity of 3-4 km/s. By the time you've compressed, stored, transported and powered a FCEV with it, the electricity would have taken a BEV more than twice as far.
(DIR) Post #AU06Fkl8tAjAsNbKk4 by vik@mastodon.nzoss.nz
2023-03-26T07:35:03Z
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@jonathanharkerI can kinda see where they're coming from when it comes to producing hydrogen when you simply have nothing else to do with a glut of renewable power. But using it to do things that we currently can't use electricity for, like producing iron, makes much more sense.
(DIR) Post #AU06QDcORmLzHBV0i0 by vik@mastodon.nzoss.nz
2023-03-26T07:37:14Z
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@jonathanharkerPS Haven't reached a detonation velocity of 2,500m/s yet, but hold my beer...
(DIR) Post #AU0F1EQJDRdW7Z0URk by jonathanharker@cloudisland.nz
2023-03-26T09:14:01Z
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@vikAs usual, to get the article just substitute doi.org for your friendly local sci-hub mirror: https://doi.org/10.1002/aic.690060118
(DIR) Post #AVjRPGM1qGYna0CUTY by strypey@mastodon.nzoss.nz
2023-05-17T02:26:56Z
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@vik> ozone production increases more or less linearly with hydrogen productionIsn't this a good thing, while the ozone hole giving us all higher risk of skin cancer is still closing up?@jonathanharker
(DIR) Post #AVjRYAGnpgMvJe06y0 by vik@mastodon.nzoss.nz
2023-05-17T02:28:33Z
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@strypey @jonathanharker Not at our level, no. Down below it's a pollutant that causes smog etc.
(DIR) Post #AVjRtcyOJJUwPychYe by strypey@mastodon.nzoss.nz
2023-05-17T02:32:26Z
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@jonathanharker> By the time you've compressed, stored, transported and powered a FCEV with [hydrogen], the electricity would have taken a BEV more than twice as farShow me battery-powered cargo ships, trucks, planes, and rescue helicopters and I'll be impressed. Hydrogen can do all those things, using surplus energy from renewables, of which there will be more as they scale up. If it can't be used, the efficiency of that energy is 0%. So anything above that is an improvement.@vik
(DIR) Post #AVjSCvdBAIlbmouABE by strypey@mastodon.nzoss.nz
2023-05-17T02:35:54Z
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@jonathanharker> [hydrogen] Fuel cells... rely on ludicrously rare platinum-group metalsSimilar criticism can be made of batteries. I'm hopeful better tech can be discovered in both cases. But even if it can't niche uses are still uses. We need to throw every form of renewables-based energy tech at the wall and see what sticks.(2/2)@vik
(DIR) Post #AVjc8dJaJxPrMbKXWC by strypey@mastodon.nzoss.nz
2023-05-17T04:27:12Z
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@vik> Not at our level, no. Down below it's a pollutantDoes it not rise to where it's useful? @jonathanharker
(DIR) Post #AVjeFVxsFMqAVEaHp2 by vik@mastodon.nzoss.nz
2023-05-17T04:50:44Z
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@strypeyNope. Denser than air.@jonathanharker
(DIR) Post #AVjgUpxWOH6glYqyWm by vik@mastodon.nzoss.nz
2023-05-17T05:16:00Z
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@strypey Your problem is fuel density. It's a better bet to make something that condenses down more and use lighter, smaller fuel tanks with less cross-sectional area and drag. There are other trade-offs as well, but that's a biggie for long distance. For that you would be better off with an airship by a long way. @jonathanharker
(DIR) Post #AVjjgrXUdnex0L6YZU by jonathanharker@cloudisland.nz
2023-05-17T05:51:48Z
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@strypey @vik that is not true. Batteries use principally lithium, iron, aluminium, manganese, and cobalt, all of which are orders of magnitude more common and cheaper than the platinum group metals needed for fuel cells. Also, I was talking about FCEVs i.e. cars and trucks, not helicopters, ships or trains, which you'd power with different thermally efficient fuel cells designed for CHP, not the electrically efficient designs. H2 is silly in road transport.
(DIR) Post #AVjlI1ciD8rswspXGK by vik@mastodon.nzoss.nz
2023-05-17T06:09:47Z
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@jonathanharker @strypey Also a big part of improving battery technology is the replacement of kludges like cobalt with proper material nanostructuring. Tesla hasn't made batteries using cobalt for nigh on a year.
(DIR) Post #AVjlyvvTGmOnjM44no by jonathanharker@cloudisland.nz
2023-05-17T06:17:27Z
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@strypey @vik what weird logic. If you want to store excess electricity, hydrogen is a terribly wasteful way to do it. If you want to displace fossil fuels, it doesn't really help much because you're diverting energy away from other uses in order to power electrolysis, compression, storage, and transport of a not very energy dense fuel, with losses to the atmosphere which permanently damage the ozone layer, 3H₂ + O₃ → 3H₂O
(DIR) Post #AVkSPnZKe4ArhmCbC4 by strypey@mastodon.nzoss.nz
2023-05-17T14:12:55Z
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@vik> Your problem is fuel density. It's a better bet to make something that condenses down moreWell that's definitely not batteries.> For that you would be better off with an airship by a long wayWell, you're always better off with an airship ; )@jonathanharker
(DIR) Post #AVktBhrRleMWi8BETQ by vik@mastodon.nzoss.nz
2023-05-17T19:12:56Z
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@strypey The low density of hydrogen presents another problem: You have to stuff a lot of it into your power plant very quickly to get enough power out of it. Reaction areas in batteries or combustion zones need to be quite large and thus heavy to react enough hydrogen. This is why more energy dense fuels are preferred. Otherwise you can bet your butt that aircraft carriers would be running their planes on hydrogen already. @jonathanharker