edit: article apears to describe a way to provide local level "tankage" rather than bulk storage
down vote protest Re-edit: just be clear, hydrogen is non viable as a primary energy source due to it's essential properties https://en.wikipedia.org/wiki/Hydrogen , gargantuan ifrastructure lag, and other more implimentable alternatives that are way ahead, and deserves it's place along side "self driving" as the winner of the always almost wouldn't it be nice prise for fantasy technological non developement.
> just be clear, hydrogen is non viable as a primary energy source due to it's essential properties [insert generic link here]
That's not how you construct an argument. At the very least, you're expected to show how the Big Words you're using relate to each other.
It feels like they are working slowly and steadily on the tech and have been doing it since many decades although they never planned to scale it like China did with batteries or solar for numerous reasons beyond the tech folk's capacity
It just doesn't seem reasonable. If we actually had a lot of hydrogen gas around, it would be far easier to distribute and use in the form of hydrocarbons, which would allow us to use existing technology rather than invent new ones.
I'd love to be wrong about this, and clearly there are scientists in the domain who disagree. But it just doesn't seem reasonable, and it has a whiff of being used as a deliberate distraction to slow investment in renewables that can be deployed right this instant.
So you can avoid the issue if you can use hydrogen to do useful work directly. The simplest cases are iron reduction from ore and heating via absorption heat pumps. Iron reduction works pretty well, but absorption heat pumps have limited exergy efficiency (a measure of useful energy available in heat) when using a very high temperature source like a hydrogen flame. An alternative is to use the waste heat from a fuel cell to drive an absorption heat pump, effectively converting hydrogen to both heat and electricity, the latter possibly being returned to the grid or a battery. But this creates a complex system of energy distribution, which requires some fancy load balancing on the electrical side. District heating allows you to avoid having a fancy fuel cell in every residence, but it requires infrastructure.
How would this compare?
If you abandon the "smell nice" constraint, you can get an even higher hydrogen mass fraction. For example, n-pentane has a hydrogen mass fraction of about 16.8% and it's liquid at a pressure of 1 atmosphere and a temperature of 25 degrees Celsius, but it evaporates rapidly, so you need to keep it in a container.
If you don't mind pressurizing the container a bit, you could put ammonia in there, and it has a hydrogen mass fraction of about 17.6%.
To work with a circular system you would need carbon collection on all combustion engines. Try fitting one on a plane.
And now we’re down the path of fossil industry talking points where they will ”soon” implement carbon capture and storage.
Another option is ammonia. The maritime industry is particularly interested in that one due to hydrogen taking up too much space if you want to go across oceans.
why not simply centralize the carbon collection and synthesis in some area (preferably where the sun shines a lot), then pipe/transport the resulting hydrocarbon fuel to where it is needed?
On the other hand, the output of a methane-powered fuel cell is 33% CO2 and 66% H2O - with the water being rather trivial to filter out. Even a dirty regular combustion engine outputs about 14% CO2.
Why would you need the carbon collection on planes? Surely a ground station would be equivalent and more sensible.
https://news.ycombinator.com/item?id=45313923
Direct air capture introduces processing massive volumes which causes extra energy usage.
The central point was that syngas, as it stands today, only really works if you have a concentrated carbon source due to the infeasibility of direct air carbon capture.
Meaning, for aviation to be freely able to release its previously captured carbon to the atmosphere we need a source for it. Capturing the exhaust fumes from a coal plant is just fossil emissions with extra steps.
One source could be biofuels and biogas from waste. But is that enough to run all airtravel on? Likely not. And if the carbon source is biofuels then we might as well just skip making syngas and run the airplanes on it directly.
The aviation industry have enormous problems to solve, and for it to work I think direct air capture needs to be solved. Or they need to manage with liquid hydrogen or ammonia. Come to think of it; ammonia and an airplane crash sounds like a terrible recipe...
For maritime shipping they alreay have engines running on hydrogen, methanol, syngas, syndiesel, ammonia and whatever else that is liquid at any temperature and makes a bang. They also have the space to install carbon capture systems if they choose to go down carbon based fuels allowing them to not be reliant on direct air capture.
This is why they truly like ammonia. It is a liquid with similar nastiness properties as methanol which they know how to deal with. Nitrogen is trivial to capture and it makes a bang when ran in an engine.
I know I am just an amateur
In the PicoBalloon hobbyist world, we are generating our own hydrogen. You can buy the equipment for cheap from China and generate it from water. It doesn’t require extreme temperatures to store. Are we generating dirty hydrogen?
Why does this paper suggest storing at extreme temperatures and pressure?
The 300+ psi pressure is needed to achieve similar power density as gasoline/electric. At atmospheric pressure you need about 15 liters of hydrogen gas to match the energy in one small AA battery.
Hydrogen gas also has very low energy density. To store enough of it to be useful, it has to be pressurized/liquified, which requires the expensive storage solutions.
For example, the Hyundai Nexo has a range of 611 km (380 mi), which requires it to store 6.3 kg of hydrogen. At atmospheric temperature and pressure hydrogen has a density of 0.08988 g/L, so that would require a tank with a volume of 70 m3. For reference, a semi-trailer has a volume of about 100 m3.
That's not accurate, storing hydrogen is very difficult. The atoms are so small that they pass into the molecular matrix of storage containers, sometimes even when kept at extreme temperatures and pressures, causing "hydrogen embrittlement", which eventually destroys the container and releases all of the hydrogen.
The only truly reliable way to store hydrogen over appreciable time frames is when it's bound in molecular forms, like fossil fuels or ammonia.
granted this is most real world scenarios. but not always.
You're also getting terrible energy density with gaseous hydrogen. Liquid hydrogen has great energy density but requires active cryogenics to store or it'll blow open even the thickest walled container.
That's said to be even more energy-dense than liquid H2, and it's obviously much safer.
Guessing the answer is that it requires heat to liberate the gas, and/or makes us even more dependent on rare earths.
A hydrogen battery that operates at just 90 °C has been developed by researchers from Japan, overcoming the high-temperature and low-capacity limits of earlier methods. The device works by moving hydride ions through a solid electrolyte, allowing magnesium hydride, which acts as the anode, to repeatedly store and release hydrogen at full capacity.
As methane it's reasonably easily liquified. You also already have a network of natural gas systems that you can utilise this in right now. There's literally fleets of natural gas vehicles today as well as pipelines everywhere. If making hydrogen from electricity was in any way viable we'd already be doing it for the methane networks we have today.
Of course if we start talking like this the myth of hydrogen being green gets blown right out of the water and we realise that storage isn't even the biggest issue of hydrogen. "Hey Toyota why don't we just use your existing CNG cars instead, it'll save us making hydrogen from methane and if we ever do start making it from electricity in bulk couldn't we just make methane similarly?".
By the same token, I've always thought it would be interesting if someone came up with a way to retrofit gas stations with something that could split the hydrocarbon molecules without burning them. Then we'd really be able to reuse existing infrastructure (handwaving away the storage-density problem of course, which the subject of this article might help with.)
But same problem... the carbon and the hydrogen really, really like to hang out together.
You then reform the co2 on combustion.
Fwiw methane to hydrogen and back again is trivial. It’s how hydrogen is predominantly made today. You can indeed make a hydrogen fuel station from methane. It’s just that it’s really really dumb to do that when hydrogen is so inefficient in an engine and so hard to store. You should just use methane all the way.
pkphilip•4mo ago
I do wonder about the efficiency though as that has not been clearly mentioned in the article though they are alluding to it being more efficient than using liquid electrolytes for Hydrogen transport.
randomNumber7•4mo ago
This will highly depend on the insulation and the duration of storage.
Likely not useful for your personal car that stands a week in sunlight but maybe for s. th. Like public transportation
audunw•4mo ago
But for industry, grid energy storage (perhaps longer term, paired with existing gas power plants, to deal with dunkelflaute) and perhaps some roles in sea and air transportation… there are plenty of areas where efficient hydrogen storage would be useful.
pfdietz•4mo ago