Researchers travel back in time for a cheaper hydrogen storage solution

https://newatlas.com/ ^ | August 30, 2024 | Abhimanyu Ghoshal

[Jonty30]

While hydrogen's high energy per mass makes it an excellent fuel, it's awfully hard and expensive to store long-term. That could change, thanks to the work of researchers at Switzerland's ETH Zurich. They've worked out a way to store hydrogen in ordinary steel-walled containers for months without losing it into the atmosphere – using iron.

The research team led by Wendelin Stark, Professor of Functional Materials at ETH Zurich, hit upon this method by drawing from the steam-iron process of producing hydrogen, first invented in 1784.

The group's storage solution is especially suitable in places like Switzerland, where solar power is abundant in the summer, and scarce in the winter.

Surplus solar power is used to split water to produce hydrogen in the summer; it's then streamed into stainless steel reactors filled with iron ore at 752 °F (400 °C). The hydrogen extracts oxygen from the iron oxide, so you're left with iron and water in the reactor, ready to store without expending a lot of energy.

[Jonty30]

If it works as intended, they've solved a big hurdle in the hydrogen economy, storage. Currently, it is impossible to hold hydrogen because it leaks.

[alloysteel]

The chemistry is not clear to me. First inject hydrogen at 400 degrees Centigrade into a retort filled with iron oxide (Fe2O3), forming free metallic iron and water, what steps are taken to reverse this reaction? More heat? Let the iron rust to again form ferric oxide and free hydrogen? How fast does this proceed? Is the hydrogen produced at a rapid enough pace to be a reliable power source?

[Deaf Smith]

“Surplus solar power…”

I do not think there is such a thing.

Solar power is only produced during peak demand and does not meet peak demand.

[Jonty30]

What it sounds like to me is that the steam decomposes water and the free oxygen remixes with the iron to become Iron oxide again.

[Jonty30]

Solar power is not a great primary source of power, because it’s passive in nature and you are dependent upon the sunshine.

However, as a passive source of power to create stored energy seems to be great. If you can store the energy in some form, then the disadvantages of solar power become muted because it becomes less important when the sun shines because the energy is being stored for later use.

[Jonty30]

If I were building my own home or lived on a farm, I would, at least, look at seeing if it was feasible to set up a system of solar power and wind power to charge an e-generator so when it becomes charged, I could disconnect from the electrical grid for a a day and run my house on the power from the generator.

That’s where I see solar and wind being useful. I would not have a system where I was dependent upon them in any way.

[Deaf Smith]

The posted thread states splitting water to make hydrogen and the using iron ore as a catalyst to store the hydrogen as water.

Rinse and repeat.

[Jonty30]

Once you have the primary ingredients, then it’s just back and forth composing and decomposing Iron oxide.

[IndispensableDestiny]

I read the report. Outside heat comes to play twice. First, the reactor holding the iron oxide (rust) is kept at 400 C. Later, steam must be made to oxide the iron and liberate the hydrogen. The reports claims about 11 percent thermal efficiency, which they wave off with plans of better insulation.

Not impressed if the goal is to store, not make, hydrogen.

[Deaf Smith]

Then why is decomposing iron oxide not the primary means to produce hydrogen?

Lots of iron oxide in Texas & US soil.

[cpdiii]

The chemistry is not clear to me. First inject hydrogen at 400 degrees Centigrade into a retort filled with iron oxide (Fe2O3), forming free metallic iron and water, what steps are taken to reverse this reaction? More heat? Let the iron rust to again form ferric oxide and free hydrogen? How fast does this proceed? Is the hydrogen produced at a rapid enough pace to be a reliable power source?

Exactly, I was about to post the same thing but then remembered the real equation shown below:

enthalpy + the magic = more enthalpy and entropy is not a factor. LOL

Gibbs Free Energy will not be denied.

[Navy Patriot]

From the article: "Steam is fed into the reactor to retrieve the stored hydrogen when needed; it can then be converted into electricity or heat easily enough."

I believe the sticking point is that Steam doesn't come free, you have to use energy to make steam unless you have your conversion station in a volcano.

[oldbill]

Let me get this straight -
You split water into H and O and then mix with iron to get water again.

Why not just pour water in the tank and avoid the middleman?

[Jonty30]

It would be a question as to how efficient they can make it when optimized. It has the advantage of the main stock of iron never disappearing once you have it.

[Jonty30]

Maybe it’s more efficient to use a middle man in the process, like Iron oxide.

[BipolarBob]

Hydrogen embrittlement will settle in over time and cause surface fractures. Small at first but this plus temperature changes (expand and contraction) and you’ll have more leakages than Biden Depends.

[catnipman]

"The posted thread states splitting water to make hydrogen and the using iron ore as a catalyst to store the hydrogen as water." that's exactly how i read it too ... my reaction was HUH?

[Jonty30]

I think it’s based on this technology.
https://scienceillustrated.com/technology/welcome-to-the-new-iron-age-iron-can-generate-eternal-energy

[DannyTN]

Are they going back to learn about blimps? Because that didn’t end so well.

[Jonty30]

It wasn’t the hydrogen that set off. Hydrogen won’t ignite because of kinetic action. The blimp’s paint caught fire and that’s what set off the hydrogen.