A new paper proposes solid air as a medium for recycling cold energy across the hydrogen liquefaction supply chain:
The world is undergoing an energy transition to reduce CO2 emissions and mitigate climate change. The COVID-19 pandemic and the Russia-Ukraine war have further increased the interest of Europe and Western countries to invest in the hydrogen economy as an alternative to fossil fuels. Hydrogen can significantly reduce geopolitical risks if the diversity of future hydrogen energy suppliers is increased.
Hydrogen is a particularly challenging product to transport safely. One option is to liquefy hydrogen, which requires cooling to 20 Kelvin (-253 °C). This is an expensive process and requires around 30% of the energy stored within the hydrogen.
A pioneering approach developed by IIASA researchers and colleagues proposes solid air (nitrogen or oxygen) as a medium for recycling cooling energy across the hydrogen liquefaction supply chain. At standard temperature and pressure, air is a gas, but under certain conditions, it can become a liquid or solid. Solid Air Hydrogen Liquefaction (SAHL) consists of storing the cooling energy from the regasification of hydrogen, by solidifying air, and transporting the solid air back to where the hydrogen was liquefied. The solid air is then used to reduce the energy consumption for liquefying hydrogen. The process is divided into four main steps: hydrogen regasification, solid air transportation, hydrogen liquefaction, and liquid hydrogen transportation.
[...] In their paper, the authors also address the ongoing debate in industry and academia to find the best alternative to transport hydrogen by sea:
"Compared to ammonia or methanol, liquefied hydrogen is the best option for several reasons. Transporting hydrogen with ammonia and other molecules would require around 30% of the energy transported to extract the hydrogen. The hydrogen is liquefied where electricity is cheap. Also, SAHL can lower energy consumption for hydrogen liquefaction by 25 to 50%," Hunt concludes.
Hunt, J., Montanari, P., Hummes D., et al. (2023). Solid air hydrogen liquefaction, the missing link of the hydrogen economy. International Journal of Hydrogen Energy DOI: https://doi.org/10.1016/j.ijhydene.2023.03.405
(Score: 0) by Anonymous Coward on Tuesday May 23, @01:09PM
Heat exchangers can improve the efficiency of thermal processing.
News at 11.
(Score: 3, Informative) by inertnet on Tuesday May 23, @01:44PM (4 children)
Hydrogen is just an energy carrier, not an energy source.
(Score: 4, Funny) by Rosco P. Coltrane on Tuesday May 23, @02:37PM
Pff... You and your facts. Always getting in the way of truthiness and ill-informed journalism. Good thing AI will soon put an end to all that boring fact-checking, by virtue of the sheer unmanageable deluge of nonsense it will produce.
(Score: 3, Informative) by hendrikboom on Tuesday May 23, @02:41PM
Yes. Hydrogen is an energy carrier.
But there are many situations where fossil fuels are used just because they are transportable.
Example: much of the transportation industry.
(Score: 2) by Unixnut on Wednesday May 24, @09:03AM
> Hydrogen is just an energy carrier, not an energy source.
Same applies to all the current hydrocarbons we use. Apart from radioactive energy, all other sources of energy on earth are nothing more than energy carriers, that originally got their energy from the sun.
As for the article, in fact they could solve all their logistical headaches with Hydrogen if they just bound it with some carbon atoms, and would have an easy to store, transport and handle liquid at room temperature.
However that apparently is too cheap, efficient and obvious for those at the top to contemplate.
(Score: 1) by leromarinvit on Wednesday May 24, @11:56AM
Given conservation of energy, is *anything* an energy source? It's always just a conversion of one form into another.
However, assuming the colloquial definition of "energy source" as something you can dig up and use, hydrogen only isn't one until you find a place to mine it. Since astroid mining seems to be all the rage with technology futurists, how about mining the Sun? It has plenty of hydrogen available I hear!
(Score: 2) by VLM on Tuesday May 23, @03:29PM (1 child)
Instead of shoving protons thru steel pipes, someone should try pushing electrons thru copper pipes. I've heard there's an entire technological infrastructure built around that.
Note that a kilo of hydrogen stores way more energy than a kilo of lithium battery, but the battery requires very little support infrastructure so for uses smaller than a literal spaceship rocket, the battery usually wins now-a-days in terms of overall system mass/volume/density. So for most applications smaller than a moon rocket its better to transport electricity in the form of post-2020 lithium batteries than in the form of liq H2.
Most non-electrical ways to get H2 involve turning about five barrels-equivalent of crude oil (or coal) into about one barrel-equivalent of liq H2 so the carbon energy companies like that greenwashing very very much as theoretically their product would quintuple demand by implementing a "green H2 economy". Most are variations on the classic "steam plus an excess of white hot carbon equals CO2 and H2" followed by lots of processing.
(Score: 0) by Anonymous Coward on Tuesday May 23, @03:34PM
> Instead of shoving protons thru steel pipes,
Besides all your other good reasons, it's also bad for the steel pipes.
(Score: 5, Interesting) by MrGuy on Tuesday May 23, @03:40PM
Let’s ignore the storage vs source of energy debate for a minute, and accept we’re using some renewable source like solar to generate the hydrogen.
Hydrogen still have 2 major weaknesses:
* Production loss
* Energy density
This article addresses some of the first concern. Even then, it doesn’t solve it. There’s a reason flywheels, pumped hydro, and huge batteries are still the tool of choice for storing excess energy in the electric grid vs hydrogen. Hydrogen production is lossy from cooling, and that’s not even taking into account the cost to produce and safely store cryogenic fluids (non-trivial).
The other big concern for hydrogen is energy density, which is hard to get around. Hydrogen has about 1/8th the energy density of octane when burned. This means even if you had cheap liquid hydrogen, and you solved all the thermal issues, you couldn’t just spray it into your V8 engine and burn it. You’d get 1/8th the power from the same engine displacement. You’d need an engine 8x the size, so twice as wide, long, deep. Which would be heavy. Or you’d need to make do with much less power. Or, more likely, you’d devise an alternate drivetrain, where you use a fuel cell to directly power electric motors or charge an EV’s batteries as you go (albeit not as fast as they’re drained by the motors) But one way or another, you’re simply hauling around less “liquid energy,” which would be a problem for most of the ways modern humans use motor vehicles.
I’m skeptical of the “hydrogen economy” simply because I hear it touted as a drop-in replacement for fossil fuels, and it’s not.
(Score: 2) by sjames on Tuesday May 23, @04:32PM (2 children)
We somehow come up with hydrogen that totally isn't being derived from fossil sources, use a bunch of energy to liquify it, burn some of it delivering it elsewhere, re-gassify it and freeze some air. Burn more hydrogen taking most of that air-ice back to the hydrogen plant and use it to help liquifying the hydrogen.
With all of that, the losses from electrical transmission are starting to look attractive.
(Score: 0) by Anonymous Coward on Wednesday May 24, @03:10AM (1 child)
Not enough progress on hydrocarbon or alcohol fuel cells and "prefilters/preprocessors"?
(Score: 2) by sjames on Wednesday May 24, @10:31PM
That's something I'm wondering. Unlike just shipping the hydrogen, synthesized methane is comparatively easy to transport and we have existing infrastructure for it. Combine it into synthetic propane and it becomes fairly simple and inexpensive to convert an existing ICE to use it.
If it's synthesized with CO2 from the air, it will be just as carbon neutral as hydrogen itself.
(Score: 2) by esperto123 on Tuesday May 23, @10:32PM
Unless we discover a (or several) free H2 deposits on earth, the hydrogen economy is a gimmick, it pops up every now and then just as 3D movies and when the backers realize that there is no way to make it feaseable, it dies out again.
Hydrogen, the way it operates now, is only found in molecules that require quite a lot of energy and expensive catalyst to be isolated, it is EXTREMELY hard to keep stored, as it has the nasty habit of going between molecules on solid stuff, leaking out and making it brittle, and liquid nitrogen is a bitch to make and transport.
Fuel cells are not that efficient either, the round trip efficiency for a hydrogen vehicle considering the inefficiencies of spliting water (if you at least care for the environment that should be the method, otherwise to get it from fossil fuels would be better to just burn the fossil fuel directly), compressing, transporting, and using a fuel cell to get the energy out is on the order of 35%, compare to just straight battery (which a hydrogen car still needs because fuel cells can't produce high on demand currents) is on the order or >80%, using the same energy source, and you don't need to create a completly new delivery infrastructure technology.
Hydrogen fuel cells are cool but niche application.