A Swedish company figured out how to decarbonize steel

Originally published at: A Swedish company figured out how to decarbonize steel | Boing Boing

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When I read the headline, I thought that they were removing carbon from steel thus turning it into pure iron.

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Misleading headline, it should read “figured out how to make steel without CO2 emissions”.

Steel is an alloy made up of iron with typically a few tenths of a percent of carbon to improve its strength and fracture resistance

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What I’m now wondering is that if they get rid of the carbon from the smelting and refining process, then where are they getting the carbon from to form the alloy? Is there naturally enough in the base ore, or is there another step that the article is missing out? As always, articles about science that leave out the science in order to be more “accessible” leave you with more questions than answers.

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The steel I work with (high-carbon) for knife making is usually closer to 1% carbon.

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(And @Jibareaux )

Yeah - After that headline, I was nearly very disappointed when I read the actual story. :wink:

And the press release is clear that it is about (my emphasis):

Eliminating CO₂ emissions from steelmaking

It does also say:

technical factors make these industries difficult to decarbonize

But that statement is very clearly about the industry, not its product - steel.

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For better worse, this is standard terminology now. “Decarbonize X” means “reduce carbon dioxide emissions associated with X.”

@Purplecat Not sure in this case, but there’s lots of people developing tech for CO2 capture and reuse. Also lots of people working to decarbonize steel, cement, and every other industry from many different angles, with different degrees of cost, likelihood, timeline. So it’s not so much just about being accessible, as about the fact that an article that tried to avoid that problem would quickly balloon to become a novella.

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In the U.S., Joe Manchin would join the Republicans in banning this new process to protect the coal industry.

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I have always thought that it is a curious bit of terminology that “cast iron” has more carbon in it than “high carbon steel.”

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Me too. It’ll never hold an edge, I thought

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You are not alone.

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But - where will I get my high carbon pans?

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I don’t think that even accurately describes it. What they’re producing here is sponge iron. A very high carbon alloy, basically a type of pig iron.

The next step for turning it to steel is melting it, then basically forcing oxygen through it to lower the carbon level. Much of that excess carbon ends up in the atmosphere.

They do seem to be working with a process that doesn’t require coke, since they’re not using it to fuel the process. So they’re cutting out the emissions from burning coal to turn it into more burnable coal too.

I’m betting that’s why they phrased it “fossil fuel free”. There’s no approach to this that’s not going to cause carbon emissions.

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Is that supposed to be “…more burnable coke” ?

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Ditto. I was like, “Depending what you are using it for, you WANT carbon in your steel.”

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From what I understand probably mineral coal.

The two big steps here seem to be a practical scale version of new steel making processes that decouple producing heat from adding carbon. Which lets you use practically any sufficiently pure form of carbon rather than being stuck with coke.

And then they’re using renewables to create the heat rather than fossil fuels. In this case using green electricity to create hydrogen to burn as fuel.

Nope. Was trying to underline that the process traditionally involves burning coal, to partially burn other coal, so you can burn that coal (as coke) for fuel.

It’s kind of a thermal circle jerk. Apparently a huge amount of the emissions and fuel consumption are bound up in the coking process. So if you can skip coke, you’ve already improved things a lot.

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First modern, large-scale steel production, sure. But prior to the 1700’s most iron was smelted with charcoal made from wood, not fossil fuels. If you consider trees to be a renewable resource then that iron and steel could be considered carbon-neutral. And Vikings sometimes used bone charcoal (made from their ancestors!) as the source of carbon in their steel swords.

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Woah! The only thing more metal would be to extract the iron from the blood of their vanquished foes.

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“Hey dudes- if we pull all the carbon out of this rock, something amazing happens”
“WHOA!”
“Wait- now put some of it back in!”
“Why? That makes no sense”
“Just try it!”
“WHOOOOOOA”

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As I understand it, they’re not using the hydrogen as fuel. Instead, they’re going to use electric arc furnaces to heat the iron ore, and blow the electrolytically created hydrogen through the ore, so it reacts with the oxygen in the ore, reducing the ore to pure iron. Normally, you use coke from coal for that, which creates a lot of carbon dioxide.

Anyway, I’ve been following SSAB’s plans with great interest, as their steelworks alone in Sweden and Finland produce a good chunk of both countries’ carbon footprint (as mentioned in the original article). This is big, and if and when other steelmakers follow suit, it’s going to cut the global emissions significantly. :slight_smile:

We’ve got two nuclear reactors coming, too, for more fossil-free energy; the perpetually delayed Olkiluoto III is supposedly going to be finished any year now ( :wink: ) and the Hanhikivi plant is going to start building soon.

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