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Electrified thermochemical systems with high-frequency metamaterial reactors (cell.com)
34 points by PaulHoule 68 days ago | hide | past | favorite | 12 comments



Lotsa big words here.

The key sentence: "Low intrinsic electrical conductivities are obtained by utilizing electrically conductive ceramics made from reaction-bonded silicon carbide."

The basic idea seems to be to make some kind of mesh/foam that will survive high temperatures, is conductive, and contains the catalyst for the desired reaction. Then the mesh/foam can be heated inductively, and you get good contact between the hot catalyst and the reactants.

I'd never heard of silicon carbide ceramic foams before, but they are apparently a common industrial product.[1] Alibaba has many suppliers. They're useful for filters that have to survive high temperatures. The process by which they're made allows adding other materials to the foam, so you can get a material with your catalyst and a nice big surface to volume ratio. That, too, is a known idea.[2] Now somebody has to try it at pilot plant scale for various processes that use catalysts and heat. Which someone did, back in 2016.[3] Even electrically heated silicon carbide ceramic catalytic foams are known.[4] That one used resistive heating, not induction heating.

So the new thing here is induction heating. May be a win. Uniform heating, even if the mesh has some breaks or shorts.

This is a reasonable idea hidden under way too many big words. Amusingly, the articles from people who are doing this sort of thing in production don't use the term "metamaterial". And they write better. This is in "Cell", and not "Process Engineering" or "Chemical & Engineering News". What's it doing in Cell?

[1] https://www.sefunm.com/info/how-do-you-make-a-ceramic-foam-f...

[2] https://www.samaterials.com/content/what-is-the-silicon-carb...

[3] https://www.researchgate.net/profile/Cuong-Duong-Viet/public...

[4] https://www.sciencedirect.com/science/article/abs/pii/S09205...


I think if you want to write papers that use the word "Metamaterial" your choices are Science, Nature and Cell. Like those other two Cell seems to be a molbio journal that publishes an occasional paper in another field, like physics, if it has "Hey Martha" potential but couldn't pass peer review at The National Enquirer. (But even they don't seem to publish exobiology papers by Avi Loeb)


It's in "Joule", one of dozens of less prominent publications on the same platform as Cell.


According to the IEA "Heat accounted for almost half of total final energy consumption and 38% of energy-related CO2 emissions in 2022" so finding ways to create process heat that can reach hot enough temperatures efficiently from electricity is a big deal for industry.


How do you get an electric furnace hot enough to make various molten metals without all the heating equipment melting? Elon was saying that they would use hydrogen for carbon free high temperature metallurgy. Does this technology replace that?


Already

https://en.wikipedia.org/wiki/Induction_furnace

https://en.wikipedia.org/wiki/Electric_arc_furnace

https://en.wikipedia.org/wiki/Zone_melting

Their thing is a fancy version of the induction furnace.

Also there is refractory and then there is refractory

https://chemistry.fandom.com/wiki/List_of_elements_by_meltin...

For instance Tungsten melts at 3407 °C, Platinum at 1772 °C, Iron at 1535 °C, Aluminum at 660 °C and there are all sorts of refractory oxides, carbides and nitrides so you can find something to make a vessel out of to hold most metals, if it is hard it is usually not the temperature but the chemical reactivity, e.g. Titanium wants to dissolve almost anything you try to melt it in which is more of a problem for keeping your Ti pure than it is maintaining the container's integrity.

If you look in a chemistry book you'll see most metals can be reduced from oxide ores easily with hydrogen in the lab, the other reagent that commonly works is carbon monoxide, which is what is used in a blast furnace for reduction of iron. Another approach to "green" iron refining is to use carbon monoxide like a conventional blast furnace but capture the carbon dioxide in the exhaust and recycle it by cracking it down into carbon monoxide again.


Good overview of a modern steel plant in Korea.[1] Useful for seeing how molten steel is handled at scale. Some good views of the refractory bricks inside a cold ladle. It's all about managed heat transfer, getting the heat out of the machinery before damage occurs. Water cooling of everything close to hot metal.

Anybody doing "green" processing of ore at this scale yet?

[1] https://www.youtube.com/watch?v=MfaqrVFnQBQ


Funny the technological breakthrough that made steel affordable was the recycling of heat in firebricks in

https://en.wikipedia.org/wiki/Open-hearth_furnace

invented by

https://en.wikipedia.org/wiki/Carl_Wilhelm_Siemens

whose younger brother

https://en.wikipedia.org/wiki/Werner_von_Siemens

started the famous electrical equipment conglomerate. Previous to that the bit for a horse cost more than the horse and steel was expensive enough that a historical "sword" seemed more like a "knife" by our standards.


We were made to study this in numerical analysis classes. I regret not paying more attention, I failed the subject. The university was close to british steel, and so it made sense to the lecturer to use a subject he had some affinity to. Now, if they'd organised a tour of the steel plant...


There are plenty of electrical high heat technologies available already. Mostly companies have stuck with gas mainly because it's cheap and avoided exploring alternatives for quite long for that reason.

But there's plasma heating, arc furnaces, induction heating, infrared, resistive heating, heat pumps, etc. You can cover anything from thousands of degrees to (more commonly) hundreds of degree with these. Some steel plants already use arc furnaces or induction heating to melt the steel.

I'm not sure where this technology sits but it all boils down to cost and effectiveness. If it works as advertised, companies will use it.

The thing with green hydrogen is that you need even more electricity to generate it. Which makes some of these alternatives more economical because you can use the electricity directly at a higher efficiency.


> Some steel plants already use arc furnaces or induction heating to melt the steel.

Electric arc furnaces are used for around 30% of global steel production

https://en.wikipedia.org/wiki/Steelmaking#/media/File:Evolut...


Electric arc furnaces use scrap steel as input - Nucor has been doing this in the US since the 70's. They don't reduce iron ore directly.




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