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Compared to other fuels, what are the advantages of hydrogen?
by Valgrim 3y ago
Compared to other fuels, what are the advantages of hydrogen?
- goethes_kind 3y agoWhat other fuels? All green/synthetic fuels depend on hydrogen and as such I consider them the same technology.
- ianai 3y agoPulls oxygen in from the atmosphere and outputs energy plus water. Just have to make the hydrogen generation/transport emission free. My question is whether storing hydrogen and the complications therein are mitigated. I just don’t know my modern material science/manufacturing enough.
- funnymony 3y agoIf you have some time: https://youtu.be/Zklo4Z1SqkE https://youtu.be/Zklo4Z1SqkE (Sabine Hossenfelder) If I remember video correctly, summary would be: not yet
- deleted 3y ago[deleted]
- ianai 3y agoSeen it, she’s taking pot shots at hydrogen. I’d be more interested in hearing how it works in established applications now and relevant to the article.
- dmbche 3y agoEasy to produce, doesn't go bad, somewhat light, can be produced on site. You lose quite a bit of energy making the hydrogen (around 50% I think) but the claimed positives make this not that problematic. If it's possible to create a lot of energy somewhere remote, making hydrogen there and shipping the hydrogen out can be a good idea. Also making hydrogen when there is unused electricity and storing it for further use when energy is not available (night, winter) There are many other drawbacks - I'm no expert.
- goethes_kind 3y agoThe drawbacks are as follows. To convert hydrogen back into electricity you need to either use a gas turbine or a fuel cell. Fuel cells are expensive, so you have capital cost problems. Additionally fuel cells have problems providing variable power output. For this reason you often couple the system with a battery. Gas turbines running on hydrogen have some engineering challenges. In particular the gas turbine technology needs to be re-engineered because hydrogen burns differently from natural gas. Secondly NOx emissions are an issue that needs to be addressed. Moreover, if one is to store and transport hydrogen as a gas or a liquid, the infrastructure is more challenging than with a natural gas pipeline. If one is to further convert hydrogen into a synthetic fuel, you get additional conversion losses.
- dmbche 3y agoThanks for the explanation, clear and to the point.
- _aavaa_ 3y agoDon’t forget: - it has an abysmal energy density per unit volume, even as a liquid. E.g. if you used to need 1 tanker or gasoline, you’ll need 18 tankers of compressed hydrogen for the same energy content. - compressing and liquifying it is much more expensive and challanging that natural gas. See this fun little challange [0] - there are currently no odorants available for use in hydrogen (the thing that gives natural gas it’s smell). All the available ones either react with hydrogen or poison your fuel cell - it’s flame is essentially invisible and incredibly hot - it has an explosive range from 4-75% (natural gas for example is 5-17%) [0]: https://en.m.wikipedia.org/wiki/Spin_isomers_of_hydrogen https://en.m.wikipedia.org/wiki/Spin_isomers_of_hydrogen
- dmbche 3y agoI hadn't realised the flame was invisible. It's terrifying to me, after seeing ethanol fires on racecars.
- 3y ago
- _aavaa_ 3y agoWhy do we need fuels? We have electricity that we need to use later. Going electricity -> fuel -> electricity is a necessarily lossy process.
- allannienhuis 3y agoAs an example: transportation. More specifically, airplanes. Energy density is a bigger factor for some uses than others.
- _aavaa_ 3y agoAnything but the longest flights will end up electric, and everything else can go biofuels. No need for a hydrogen-centered Rube Goldberg machine. And if biofuels cost is a concern, synthetic fuels will be out of the question.
- goethes_kind 3y agoYou are betting on a 20x improvement in mass energy density of batteries for that to become realistic. That would probably require entirely new chemistries and while I am not going to rule it out, there is really no good reason to believe that it will happen either. Hydrogen powered flight is on the other hand only a matter of incremental improvements. It is already feasible today.
- _aavaa_ 3y agoDamn straight I am: https://www.energy.gov/eere/vehicles/articles/fotw-1234-april-18-2022-volumetric-energy-density-lithium-ion-batteries https://www.energy.gov/eere/vehicles/articles/fotw-1234-apri... Ain’t no incremental improvement going to improve the density of a gas or a liquid. On top of that you talk of energy per mass, but what kills you for flights is also volume. Hydrogen power flights are not feasible today. Even hydrogen busses are struggling to operate, to say. I thing of trains. For starters you’ll need hydrogen at any and all possible destinations (plus any nearby airports if you’re diverted) since nobody is going to buy a plane that will likely get stranded. Then: 1. Hydrogen’s energy/volume is far too low. 2. You can’t store it in the empty space in the fuselage due to pressure vessel geometry requirements. 3. You need heaters and coolers and all sorts of extra parts to operate something hydrogen power (hint: a hydrogen car is just an electric car with a small battery and a while separate hydrogen system frankesteined ontop). 4. Going back to that volume, you’ll need to store the hydeogren tanks inside the main fuselage, where the volume required is going to either eat into your available volume for cabin or cargo. OR, you’re gonna need a bigger cross-section, which will increase your drag. To top all that off. Nobody is using green hydrogen. They’re using hydrogen made directly from methane (or god help us coal). This hydrogen has more GhG emissions associate with it than the methane it’s made from. Hydrogen itself also has a GHG impact since it will interfere with the processes occurring that remove other GHGs.
- alex_duf 3y agoDoesn't release CO2 or methane during production and use
- Krssst 3y agoDepending on how it is produced. Electrolysis is fine but steam methane reformating is the cheapest method and emits CO2. (https://en.m.wikipedia.org/wiki/Hydrogen_production https://en.m.wikipedia.org/wiki/Hydrogen_production)
- rawgabbit 3y agoFrom https://royalsociety.org/-/media/policy/projects/climate-change-science-solutions/climate-science-solutions-hydrogen-ammonia.pdf https://royalsociety.org/-/media/policy/projects/climate-cha.... "Heavy-duty road vehicles Hydrogen fuel cells or hydrogen-derived fuels offer a low-carbon alternative for heavy-duty vehicles, for which batteries do not currently have the energy density to offer a long-range solution. " "One niche market for hydrogen fuel cells is forklift trucks. These currently outnumber hydrogen cars, with around 30,000 in use. Fuel cell forklifts are suited to warehouse use because refuelling is simple, and the vehicles emit no air pollutants32" "Synthetic fuels. A range of synthetic fuels for multiple uses can be made via the Fischer Tropsch process, reacting captured CO2 with hydrogen. These could potentially provide a lower carbon drop-in fuel alternative for the aviation fleet as well as an option for trucks or ships" "Ammonia is denser and only requires compression to 10 times atmospheric pressure or chilling to -33°C6 . Ammonia storage is mature because of its widespread use as a feedstock for mineral fertilisers. " "For transport, China is aiming to produce one million hydrogen fuelled vehicles and 1,000 refuelling stations by 2030, the same goals as California3, 55. South Korea’s roadmap is aiming to produce six million FCEVs and roll out 1,200 refilling stations by 2040."
- legulere 3y agoAll other fuels depend on hydrogen when producing from electricity and have a lower efficiency. Ammonia as a fuel is difficult to handle. Carbohydrates like natural gas or e-fuels depend on carbon capture which is still very expensive/inefficient and they also burn much more dirty emitting particulate matter. There are also some disadvantages of hydrogen though: Low volumetric density makes transport in anything but pipelines much less efficient compared to carbohydrates. That includes fuel tanks which makes hydrogen for aeroplanes unlikely. Also there's no existing infrastructure compared to existing oil and gas infrastructure.
- analog31 3y agoIn addition to its use as a fuel, it's also a chemical feedstock, perhaps notably for the production of ammonia. In fact, wind-to-ammonia production would be a cool thing. Synthetic ammonia for fertilizer, produced via the Haber-Bosch process, sustains more than half of the world's animal population. A lot of ideas for reducing our carbon footprint depend on the dream of getting methane out of the fertilizer business.
- Gwypaas 3y agoSee the hydrogen ladder for what can use synthetic fuels compared to hydrogen as a feedstock. https://www.linkedin.com/pulse/clean-hydrogen-ladder-v40-michael-liebreich/ https://www.linkedin.com/pulse/clean-hydrogen-ladder-v40-mic...
- credit_guy 3y agoIn the particular case discussed here hydrogen just wins hands down. You can easily generate hydrogen at sea, but you can't bring a floating chemical plant to make other fuels. The alternative to send electricity via cable was also considered: > For offshore wind producers, meanwhile, Lhyfe projects that adding electrolysis and a hydrogen pipeline to shore will reduce the cost of delivering their energy as wind parks move further offshore. “A hydrogen production plant plus pipeline is five to ten times cheaper, as an investment, than an electric substation plus a cable,” says Le Berre.
- _hypx 3y agoThe main advantage is that it is a fuel that doesn't release CO₂ when burned. That solves the major weakness of pretty much all competing fuels. For the huge number of use-cases that need a chemical fuel to work, this alone is a game-changer.