hydrogen storage - Page 1
Forum section: electronics / general

author: m3vuv
author_rank: Super Contributor
timestamp: April 29, 2022, 11:21:06 pm
content: i was reading about hydrogen storage also tritium leaks,from what i gather as hydrogen is one of the smallest atoms it can squeeze inbetween the atoms of whatever is trying to contain it,same with tritium,is that so,if thats the case,how do they plan on keeping hold of it if we change from petrol powered cars to hydrogen?

author: Marco
author_rank: Super Contributor
timestamp: April 30, 2022, 12:01:01 am
content: Round trip efficiency loss is atrocious to begin with, leaking a little hydrogen is not a problem energetically. So assuming it doesn't accumulate significantly in the atmosphere, it's not a problem.

author: coppice
author_rank: Super Contributor
timestamp: April 30, 2022, 12:18:25 am
content: Hydrogen has many problems. It makes many materials brittle over time, as those tiny atoms diffuse into the material. I don't understand the fascination with it. If you are going an create a long term energy store from renewable sources, make something liquid and easy to store. It doesn't matter if its a hydrocarbon, and ends up as CO2, as long as you keep pulling that CO2 back out of the atmosphere to create more liquid fuel.

author: langwadt
author_rank: Super Contributor
timestamp: April 30, 2022, 12:20:58 am
content: Quote from: Marco on April 30, 2022, 12:01:01 ambut hydrogen is explosive in damn near any ratio with air

author: Marco
author_rank: Super Contributor
timestamp: April 30, 2022, 03:01:05 am
content: Quote from: coppice on April 30, 2022, 12:18:25 amThat requires electrolysis, carbon capture and one or more stages of catalytic conversion and the end product can't be used in fuel cells. Round trip efficiency goes from atrocious to ludicrous.

author: Kleinstein
author_rank: Super Contributor
timestamp: April 30, 2022, 04:05:43 am
content: The penetration and diffusion through wall material is mainly a problem with steel/iron with it's somewhat open BCC structure. Most other metalls are OK. There are commercial pressureized containers (similar to those for nitrogen / oxigen) with not problems with leakage.Besides pressurized gas there is also the option of cryogenic (~20 K and thus very cold) liquid and also absorbtion in materials (e.g. magnesium based). The recover the hydrogen from the absorbed state it needs heat - about the waste heat released from a fuel cell. A large part of this is due to the gas form and change in volume and thus no pure conincidence.Storrage in a car is indeed a slight problem, as the storrage is relatively heavy, though still a little less than a battery.

author: Psi
author_rank: Super Contributor
timestamp: April 30, 2022, 04:17:42 am
content: Hydrogen for a transport fuel has already lost.There maybe some very niche applications where it makes sense, but there's just too much momentum built up in battery tech and charging infrastructure.

author: ConKbot
author_rank: Super Contributor
timestamp: May 01, 2022, 05:32:35 am
content: Quote from: Marco on April 30, 2022, 03:01:05 amCorn plants and some yeast : "look what they need to mimic a fraction of our power"Not that commercial ethanol is exactly ideal in terms of longevity of soil not being rotated, and energy intensive distillation, etc.I'd expect any big biofuel source to end up algae sourced just for ease of industrial handling, and hopefully more sustainable long term then crops.

author: Marco
author_rank: Super Contributor
timestamp: May 01, 2022, 01:41:45 pm
content: Quote from: ConKbot on May 01, 2022, 05:32:35 amIn a pinch that's doable just for aviation, but even then the acreage is huge. Biofuel has the same problem as putting trees in old coal power plant, soil exhaustion and not enough land on the planet.QuoteOpen ponds need lots of land and fresh water and has pathetic yields, the algae need to be competitive with whatever comes floating in, sea has unusable yields. Hermetic ponds and more efficient bioreactors can have GM algae and won't necessarily suffer evaporation, depending how you implement cooling, but competing with PV+electrolysis is very hard even if GM algae start becoming energetically competitive per m2.PV is just inert and need a robot to wipe them down occasionally, all the maintenance requiring machinery is centralized. Each bioreactor is maintenance requiring machinery. In the future the PV can likely be made from just polymer and thin film and still last decades. If you make bioreactors out of polymer you will likely have to recycle the polymer on monthly scales. When you start covering square miles, these kinds of costs add up.

author: coppice
author_rank: Super Contributor
timestamp: May 01, 2022, 03:27:17 pm
content: Quote from: Marco on April 30, 2022, 03:01:05 amYou are thinking is a very narrow way. If you want to pass all of humanity's energy through a liquid fuel what you say is true. If you want to use surplus wind, PV and other renewable energy sources to make a long term storable fuel for the potentially long spells when the renewables under perform, efficiency is not your first priority. Storage practicality is.

author: TimFox
author_rank: Super Contributor
timestamp: May 01, 2022, 03:53:51 pm
content: Quote from: langwadt on April 30, 2022, 12:20:58 amTo be quantitative: Hydrogen gas forms combustible or explosive mixtures with the atmospheric oxygen over a wide range of concentrations in the range 4.0%–75% (combustion) and 18%–59% (explosion).A range of 41% is considerable, but not "damn near any".

author: Marco
author_rank: Super Contributor
timestamp: May 01, 2022, 05:07:29 pm
content: Quote from: coppice on May 01, 2022, 03:27:17 pmSynthesis likely starts from hydrogen any way (ignoring someone finding a way to make bioreactors lifetime cost approach PV per m2 by order of magnitude, which I think is unlikely). So any solution will be competing against plain hydrogen, practicality is just another name for cost.Even when PV electricity becomes a negligible cost component, the rest of the chain can still be more expensive for hydrogen alternatives.

author: langwadt
author_rank: Super Contributor
timestamp: May 01, 2022, 05:58:41 pm
content: Quote from: TimFox on May 01, 2022, 03:53:51 pmonly ten times that of gasoline, propane etc.

author: nctnico
author_rank: Super Contributor
timestamp: May 01, 2022, 06:27:32 pm
content: Quote from: langwadt on May 01, 2022, 05:58:41 pmOTOH hydrogen is lighter than air while the stuff you list sinks. Either way the discussion about 'explosiveness' of hydrogen is moot; it has been deemed not a problem already by safety approval agencies. The problems -if any- have been solved. What is left is just FUD.

author: TimFox
author_rank: Super Contributor
timestamp: May 01, 2022, 06:29:33 pm
content: Quote from: nctnico on May 01, 2022, 06:27:32 pmAcetylene's range is 2.5% to 100%, yet we safely store it and use it in practice. Full list:https://www.engineeringtoolbox.com/explosive-concentration-limits-d_423.htmlwith some confusion between flammable and explosive.

author: Gyro
author_rank: Super Contributor
timestamp: May 01, 2022, 06:32:36 pm
content: It's a little known fact that 'Town Gas' (Coal gas), was around 50% Hydrogen. This was distributed for many decades in ductile iron pipes (some of which are almost certainly still in service).https://en.wikipedia.org/wiki/Coal_gas.I was surprised to see this somewhere recently, in connection with the possibility of converting the gas distribution network and appliances to Hydrogen (which of course is no problem for modern MDPE distribution piping).It seems that there is nothing completely new under the Sun [Edit which itself is about 73% Hydrogen by mass].

author: coppice
author_rank: Super Contributor
timestamp: May 01, 2022, 07:09:20 pm
content: Quote from: Gyro on May 01, 2022, 06:32:36 pmLittle known? The only part of what you said that is little known is town gas was only 50% hydrogen. When I was a kid, and town gas was the norm, descriptions of it implied that it was nearly all hydrogen.

author: Gyro
author_rank: Super Contributor
timestamp: May 01, 2022, 07:15:13 pm
content: Well everyone I've told little knew it. Of course, it had to have the obligatory Carbon Monoxide content that made sticking your head in the oven so rewarding... and was part of its calorific value. I still remember the gas board coming around and replacing the jets to convert everything to 'Seagas'.