Making steel without emitting CO2

https://www.science.org/content/article/electrifying-new-ironmaking-method-could-slash-carbon-emissions

by ttfkam • 2 years ago

236 117 2 years ago

yesbut• 2 years ago

Can we extract iron ore without releasing CO2 and if so, which countries are mandating this?

sosull• 2 years ago

The article is saying ‘kinda’. The process works in lab conditions with highly purified ore, but produces an equivalent amount of chlorine gas and iron.

sanxiyn3• 2 years ago

The article is about iron smelting without CO2. The question is about iron mining without CO2.

senectus1• 2 years ago

Fortescue (www.fortescue.com) is actively working towards that goal.

To the extent they have stopped taking tax credits for diesel fuel as they start trialing electric/hydrogen/ammonia fueled equipment. (while also researching into green steal production and hydrogen electrolyzer production.)

defrost2• 2 years ago

Fortescue says regenerative “Infinity Train” may be on tracks in two years

https://reneweconomy.com.au/fortescue-says-regenerative-infi...

They're also hiring Software Architects and embedded engineers (along with Engineers)

https://careers.fortescue.com/job/Perth-Senior-Software-Arch...

https://careers.fortescue.com/job/Perth-Embedded-Test-Engine...

Perth, Western Australia based.

selimthegrim• 2 years ago

Their founder/CEO gives some very impressive climate talks.

ZeroGravitas2• 2 years ago

I saw an interesting comment about EV mining equipment recently.

The manufacturer initially sold them as reducing CO2 globally, and also reducing harmful emissions in the mine itself, and saving fuel and fuel transport costs to remote mines.

The miners reported that the key benefit was actually that the machine spit out a lot less heat in a confined space undeground. Previously they'd need to spend an hour using AC to reduce the temperature to a level that humans could cope with before sending workers in for the next stage. With the EVs that time was saved and work could begin immediately.

jaggederest2• 2 years ago

The chlor-alkali process is responsible for something on the order of 80%+ of what we think of when we say "toxic waste" - dioxins and polychlorinated compounds. I don't think it's going to be a panacea for iron refining to switch to electrolysis. That said, it's very interesting research that probably works for a lot of other non-bulk metals that need to be reduced to elemental metals.

roenxi2• 2 years ago

The Oregon group’s setup generates essentially as much chlorine gas as it does iron

I'd much rather be dealing with industrial quantities of CO2 than Cl2, if that stuff gets into the atmosphere in bulk I doubt it'd end well. The article seems to suggest that the chlorine can be solved commercially so the argument seems to be that it is economical to sequester the chlorine rather than the carbon dioxide.

There are some obvious risks of being left with large amounts of Chlorine to try and find a home for, but the idea is at least plausible on face value.

pwarner• 2 years ago

I mean people are intentionally making industrial quantities of chlorine, via electrolysis, and have been for an century.

jszymborski• 2 years ago

I imagine Cl2 being way easier to capture by virtue of its weight. It is also a very useful byproduct for downstream applications.

s0rce• 2 years ago

Isn't Cl gas commercially valuable, people are making it. edit: the article says that this process would make too much...

sharemywin• 2 years ago

but at scale? how much cl2 are we talking about?

wolverine8763• 2 years ago

I'd much rather be dealing with industrial quantities of CO2 than Cl2

The costs of CO2 - the real costs, not the subsidized ones - are extraordinarily high, possibly leading to the worst global catastrophe in human history. What is the cost of Cl2?

photochemsyn• 2 years ago

You can avoid any CO2 production in the iron production process via replacing the natural gas inputs to the Direct Reduced Iron (DRI) method with hydrogen. To compare DRI with carbon vs only hydrogen:

with carbon and hydrogen from natural gas/coal gasification: CH4 + CO2 -> 2CO + 2H2 Fe2O3 + 3CO -> 2Fe + 3CO2 (exothermic in >50% H2 environment)

with water-sourced hydrogen: 2H2O -> O2 + 2H2 Fe2O3 + 3H2 -> 2Fe + 3H2O (endothermic, requires energy input)

There are two issues with using hydrogen, which can be overcome:

"The energy balance of the shaft furnace is affected by the absence of the exothermic carbon monoxide reduction. . . Thus, it is necessary to add energy to the shaft furnace to carry heat in the burden."
"The second issue is the resulting DRI carbon content; the DRI will have 0% carbon with pure hydrogen. The majority of DRI is used in EAFs, and EAF steelmaking practice generally employs carbon addition... Under current melting practices, it will be necessary to add hydrocarbons at some place in the process to achieve the desired carbon level... However, this added carbon will then be converted to CO2 in the EAF... Alternatively, carbon from a renewable source (like biomass) could be used."

https://www.midrex.com/tech-article/ultra-low-co2-ironmaking...

ChatGTP2• 2 years ago

It really seems like any level of CO2 production from fossil fuels is now dangerously toxic too though? Swapping one problem off another yes but we have zero time to waste.

telecuda• 2 years ago

Different method, but related goal: I enjoyed this episode on making carbon-negative portland cement for construction https://wondery.com/shows/how-i-built-this/episode/10386-lit...

jseliger• 2 years ago

Sublime Systems is working in the same field: https://sublime-systems.com/

scythe• 2 years ago

It's a little misleading to suggest that "co-production" of iron and chlorine can meaningfully save energy. Annual production of steel is about 2000 Mt, of Cl2 is about 100 Mt (a similar figure for NaOH). So you'll get many times more chlorine than the economy can presently use. You could neutralize it by a variety of processes[1], but this isn't thrifty.

IIRC there was already a thread some time ago about electrolysis of iron ore in sodium hydroxide (as reusable solvent) where I was wondering about the cost of NaOH and how much would have to be replenished per cycle. But that process easily whoops this one.

1: Cl2 + MgO >> MgCl2 + O2, for one. (Stoichiometry exercise for the reader.)

pfdietz3• 2 years ago

If we release Cl2 into the daytime troposphere, it will be rapidly photolyzed to chlorine radicals, which rapidly react with methane. It would be a way of scrubbing methane out of the atmosphere.

FredPret• 2 years ago

Will we all turn blonde though?

euroderf2• 2 years ago

What are the products of the reaction ?

lkbm• 2 years ago

At what ratio does this process produce steel and Cl2? I'm guessing it's not a ratio of 20:1, but I don't know. The final paragraph of the article suggests it's not an awful ratio:

Even so, scaling production to match industrial chlorine gas needs would still produce tens of millions of tons of CO2-free iron and chlorine annually

sanxiyn3• 2 years ago

The article mentions it's 1:1.

The Oregon group's setup generates essentially as much chlorine gas as it does iron, notes Iryna Zenyuk, a chemical engineer at the University of California, Irvine.

nine_k2• 2 years ago

Chlorine is 1.6 times lighter than iron. Depending on how many atoms of iron are reduced per one atom of chlorine exhausted, the balance may be not as starkly bad.

But likely replacing 100% of steel industry with this process would still produce more chlorine than can be profitably sold currently. Maybe it would do with replacing 30%, for starters.

IHEARTANAL• 2 years ago

Can we extract iron ore while releasing more CO2? Just to piss of these techie armchair expert environmentalists.

jojobas2• 2 years ago

Direct hydrogen reduction has been there for a while.

The only issue is cost.

bigger_cheese• 2 years ago

Energy intensity is an issue with hydrogen steelmaking. To produce hydrogen by electrolysis at the large scale needed for steelmaking requires a massive amount of electricity. Ideally it needs to be green electricity as well.

So if there is a lower energy way of producing green steel it is at least worth exploring.

jojobas2• 2 years ago

What are you suggesting, electrolysis baths in every solar-powered home?

Meaningful solar, hydro, nuke and wind power plants are quite concentrated (100MW-few GW) anyway.

If anything, solar/wind are less suitable due to intermittent output and would require hydrogen buffer storage.

abriggs8• 2 years ago

There is a company called Helios Space that found adding Sodium into the process solves a couple of different issues. And it can work to refine other elements as well.

https://project-helios.space/green-steel/

joshuahaglund• 2 years ago

Could they add H to CL then use the HCL and NAOH to drive a acid-base flow battery* during peak loads? I guess it'd be less efficient because the hydrogen would have to come from electrolysis.

https://www.cetjournal.it/cet/23/100/112.pdf

trompetenaccoun3• 2 years ago

Hydrogen is an indirect greenhouse gas with a Global Warming Potential(100) of around 11.6¹. Meaning it's over 11x worse than CO2 in the atmosphere! The main problem with this is that hydrogen molecules are extremely tiny, light and volatile, thus having a very high diffusivity. So unsurprisingly, hydrogen transport and storage has extremely high leakage rates. It's hard to alleviate because of the fundamental structure of the atom/molecules. Hydrogen can even permeate solid metals. A lot of the "green hydrogen" pitches don't take this into account.

¹https://www.nature.com/articles/s43247-023-00857-8

blharr• 2 years ago

Maybe this is a dumb question, but looking at GWP figures, it seems like there's nothing listed that's below CO2. Are there really no hypothetical gases to put in the air that is better than CO2 for global warming?

Ma8ee• 2 years ago

And how much does it leak? If the amount leaking to the atmosphere is a thousand of the amount of CO2 that would have been released for the same process, it's still a huge net win.

Comparing the effect of one kg of H2 with one kg of CO2 is irrelevant if we don't know how much H2 is released compared to the amount of CO2 for corresponding processes to produce the same amount of goods.

pjc504• 2 years ago

But how long does bare H2 remain in the atmosphere, given that it's pretty reactive and light enough to leave entirely?

rr808• 2 years ago

Interestingly with steel being made with electricity instead of coal, the best places for steel mills are deserts on the equator with lots of solar, like North Africa, the Middle East.

sanxiyn3• 2 years ago

The best place is next to nuclear power plant. Nuclear power is good because it has few restrictions on locations.

bryanlarsen2• 2 years ago

Using expensive electricity for an energy intensive process seems like a good way to lose money.

mdf• 2 years ago

Optimally, next to a source of water that can be split into hydrogen, ready to be used for the chemical process producing the pure iron. (Not the process in TFA.)

An array of SMRs (small modular reactors) located at the steel factory could be used – and would be sufficient – both for heating and producing the electricity without interruptions caused by fluctuating prices or blackouts.

adonovan• 2 years ago

Wouldn't the need for labor, a supply of ore, and a means of delivering the product all argue for a port city? There aren't many railroads in those deserts. Or steelworkers.

lazide2• 2 years ago

There are plenty of ports in those areas.

zjaffee• 2 years ago

Not inherently, nothing is cheaper than hydropower.

ChatGTP2• 2 years ago

How reliable is hydropower now though? I’m living in a place which normally sees huge snow falls each year, this melting snow runs hydro, guess what ? We have about 15% of our usual base and next week it's going to be +10c average.

Alpha3031• 2 years ago

Not necessarily true at this point for new projects. IRENA indicates wind projects commissioned globally in 2022 had a weighted average LCOE of $33 USD/MWh. Hydropower projects over the last decade or so (2010–2021) were around $39 to $48. (2022 average was $61, but obviously recent market conditions were far from normal)

api_or_ipa• 2 years ago

Shipping of raw resources is cheap. Much of the bauxite used in aluminum cans in N America is shipped to Kitimat BC [0] to be smelted. Aluminum is notoriously electrically expensive.

0 https://en.m.wikipedia.org/wiki/Kitimat

euroderf2• 2 years ago

Iceland is a player too IIRC.

logifail• 2 years ago

Shipping of raw resources is cheap

Cheap in terms of money, maybe.

Less so in terms of emissions: https://www.statista.com/statistics/1291468/international-sh...

cyberax2• 2 years ago

One technology that I'd love to see is direct molten oxide electrolysis. It requires some unobtanium materials, but it seems to be possible: https://corporate.arcelormittal.com/media/press-releases/arc...

littlestymaar• 2 years ago

I'm flabbergasted that there is no mention in the article of the H2 direct iron reduction process which today is the contender when it comes to decarbonization of steel making (especially now that we realize that there are tons of white hydrogen everywhere)

Too• 2 years ago

If you are interested in this, check out https://www.hybritdevelopment.se/en/

They are running something similar with goal of larger industrial scale.

beautifulfreak2• 2 years ago

I was more impressed by the Science article from two weeks ago about cost effectively making iron from the toxic residue of aluminum refining: https://www.science.org/content/article/zapping-red-mud-plas...

Gibbon1• 2 years ago

A group in Norway ran a pilot plant producing iron from sulfide ores back in the 1950's. Their paper quotes achieving 85% efficiency and around 4.7kwh/kg. It feels like with eletrowinning you can get the cost down to a few hundred dollars a metric ton. Scrap is around $200/ton. So not grossly uneconomic.

I think the devil is really in pre-processing ore. Whatever process can do that most cheaply is likely to win out. If you can figure out how to use waste like red mud so much that better.

beautifulfreak2• 2 years ago

A phys.org article goes into more detail about its cost effectiveness: https://phys.org/news/2024-02-team-green-steel-toxic-red.htm...

okeuro492• 2 years ago

In the UK we like to pretend to not emit CO2 by closing down our own steel production, and importing it instead.

https://www.theguardian.com/business/2024/jan/18/tata-steel-...

parski• 2 years ago

This is how we will get to net zero and it's so sad.

christkv• 2 years ago

This represents a long term critical security risk for Europe as a whole.

pjc504• 2 years ago

Steel is not magic. People don't get this excited over UK copper and lead production. The UK was a steel leader due to easily accessible iron resources, which are greatly depleted now.

It is worth considering the environmental footprint of our trading partners, but note that they are rapidly improving as well as renewables come down the cost curve.

okeuro492• 2 years ago

Countries like China are just building more coal power stations, while the UK trashes its small remaining industry, pretending to save CO2.

https://energyandcleanair.org/publication/chinas-new-coal-po...

weberer• 2 years ago

Yeah, its the same with most manufacturing in western countries. Then politicians can pat themselves on the back for "doing something to fight climate change" when they probably just lead to a net increase in emissions.

https://upload.wikimedia.org/wikipedia/commons/1/15/World_fo...

Cthulhu_• 2 years ago

Same with plastic recycling, if it's packaged up and exported you get the tickbox. It's a great example of Goodheart's Law being applied, focusing on the local metric (reduced emissions in our neck of the woods! Look at us meeting the Paris agreement!) without solving or even exacerbating the underlying problem (steel production in countries with less carbon emission rules, added emissions due to shipping, and big ships use really shitty bunker fuel anyway)

panick21_• 2 years ago

There is already a method that seems promising:

https://bostonmetal.com/green-steel-solution/

RamblingCTO• 2 years ago

Germany is pushing "green steel" very hard right now: https://www.reuters.com/markets/europe/german-econ-ministry-...

bjornsing2• 2 years ago

Swedish tax payers are already all-in on “green steel”. But it seems we are betting on a different process, using hydrogen gas to strip the oxygen from the iron. Paradoxically, if this new electrolytic process works it’s probably a (financial) disaster for us…

EDIT: For clarity, based on comment below.

alex_duf• 2 years ago

Why would it be a disaster if the hydrogen based "green steel" were a success?

bjornsing2• 2 years ago

No I meant it would be a (financial) disaster if a cheaper way of making “green steel” was discovered. As I understand it this process (the OP) could be such a process.

fransje26• 2 years ago

Well, they also produce hydrogen in the process, so you could ask them kindly for the rest gases, and be on your way. And now, you are not producing one unit of steel thanks to the electrolysis process, but two. Win! ;-)

red_admiral• 2 years ago

As all factorio players know, upgrading your steel production from coal-based to electric smelters is great to keep pollution down, and you also save on coal transport belts this way. Driving the smelters off solar panels is a good choice too.

Qwertious• 2 years ago

As a factorio player, by the time I'm upgrading steel production I'm wondering whether I even care about pollution. The #1 benefit of electric smelters is that I can beaconize and fill it with prod mods, to get 140% the output at only the minor cost of a fuckton of pollution and electricity use.

In fact, the real score for reducing pollution here is efficiency mods - electric smelters plus steam engines apparently produce the exact same amount of pollution as just using lv2 smelters directly so you'll need those efficiency mods anyway (unless you've already switched to solar+nuclear), but you're better off putting your initial efficiency mods into your miners and oil.

Solar and nuclear are both a pain in the ass to switch to, though - nuclear takes stacks and stacks of copper to build and is a PITA to set up centrifuges and pipe down hydrochloric acid to uranium, and solar needs bots to place with any speed. It's just easy to slap down steam engines fed by either coal or solid fuel. So if you prioritize player-time over strict efficiency then the quickest way of reducing pollution is almost certainly efficiency mods into pre-existing buildings (i.e. miners and oil), and building electric furnaces will in-practice force you to build more power plants anyway. At least, in my experience. But maybe that's due to the prod-mods and beacons.

Areading314• 2 years ago

Experimental methods and data analysis are usually scrutinized in peer review, whereas wild, unsubstantiated economic claims such as the above are not. I think we need a higher bar for making claims like the above.

Sticking points for me were, massive chlorine gas production (extremely toxic...) and requiring extremely high purity iron ore, with costs to purify it hand waved away.

Making steel without emitting CO2

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