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Green steel without green hydrogen – can it work?

62 points by orangebanana1 5y ago

djmips 5y ago
Anyone know if this process could also help with copper contaminated iron scrap?
- gostsamo 5y ago
  The melting temperature of copper is lower than that of iron. Most likely it will be possible, but instead of letting the iron flow out of the bath, you do it with the copper.
barney54 5y ago
The challenge here is cheap electricity. We can do amazing things with cheap electricity (green steel, green hydrogen, etc), but we are moving backwards on electricity prices. For example, we are seeing large electricity prices increases in Europe.
- afarrell 5y ago
  Iceland has solved the cheap electricity problem and has easy access to iron ore from the port of Narvik.
- user-the-name 5y ago
  Anything that relies on cheap electricity is not going to actually be very green.
  - Bronze_Colossus 5y ago
    Not necessarily. Northern most part of Scandinavia have among the lowest prices for electricity in Northern and Central Europe. Most of the electricity there comes from Hydropower. It's also the same area where Sweden makes it green steel. Cheap and green electricity is not an oxymoron or impossibility.
    - cinntaile 5y ago
      I'm pretty sure they're mostly counting on wind energy to provide the cheap electricity since 0 marginal cost while hydro serves as a reliable backup.
      - jabl 5y ago
        Traditionally Swedish electricity has been about equal parts nuclear and hydro. Nuclear usually running full out, with hydro used to regulate for daily and seasonal variation. In recent years they have built a lot of wind, as of 2019 providing 12% of electricity, today almost certainly more. But yes, like you said, hydro is used as the backup for wind.
  - cinntaile 5y ago
    Wind energy counts as green and will be used for this purpose.
- pornel 5y ago
  Currently we have a "problem" of solar energy being too cheap (even negative price) at peak. Could a steel production still be viable if it could only run during daylight, or adjust to intermittent availability of wind+solar? I know currently production is typically designed to run at maximum utilization 24/7, but maybe the solution is to rethink that assumption.
  - rocqua 5y ago
    I recently heard that, even in Germany where there is lots of solar, there were only 9 days in the last year where spot prices were negative. Sadly my source is just "someone said". As for intermittent steel production, from what I know about aluminum it is essentially impossible to turn the process off, because the molten stuff solidifies and is impossible to melt again.
  - Milner08 5y ago
    Steel plants sometimes have deals to operate at certain times for load shedding anyway, but how about they use the times when we have an excess of solar/wind and its not well suited to steel production (maybe due to shift patterns) to generate onsite Hydrogen using that excess power? Then they have readily available onsite green hydrogen. I think things like this will become an absolute necessity soon, using green power at its peaks to store resources for use later. (Obviously batteries will also be essential, although I would rather see gravity storage with big reservoirs like they have in Wales)
  - jabl 5y ago
    Largely the negative prices are a side-effect of feed-in tariffs, where (some) renewable projects get paid a fixed price/kWh regardless of what the actual spot market price is. So when there's an oversupply of these subsidized renewables it pushes the spot price to negative. I think newer renewable support schemes have been designed to avoid this problem, either by cutting off the feed-in tariff when the spot price goes to zero, or then by restructuring the subsidies as some kind of investment support (state guaranteed very low interest loans or such) rather than paying for the generated electricity. That of course doesn't change the fundamental issue, in that in a grid with increasing amounts of variable production renewables and the price determined by marginal cost of the most expensive producer, the price swings will be larger than what we previously were used to.
- boplicity 5y ago
  European electricity still depends on natural gas -- which is largely controlled by Russia in large swaths of Europe. (This is also why Russia might think it can get away with invading Ukraine.) The cost of electricity once we've transitioned from fossil fuels is ultimately what counts -- and there is a lot of progress being made there, albeit slowly. Russia's influence, frankly, should be another really big motivator for Europe to transition away from fossil fuels as quickly as possible.
  - theshrike79 5y ago
    Germany is especially linked to Russian gas for their electricity production, as they shut down all of their nuclear plants in some kind of attempt to be "more green" or something.
- baybal2 5y ago
  > For example, we are seeing large electricity prices increases in Europe. Which is very good. New capacity will most likely be non-gas.
- ZeroGravitas 5y ago
  The electricity price is set by the most expensive marginal cost. This made sense when renewables were more expensive on average than fossil fuels (which we want to discourage) but the rules probably need rewritten now that renewables are cheaper and continuing to get cheaper and fossils relegated to peaked roles. At the moment it just means that renewable providers are getting a lot of extra cash for not doing anything different and then on occasions when we go 100% renewable the price will crash suddenly to near zero.
  - jabl 5y ago
    Dispatch based on marginal cost makes sense, as that ensures that the lowest marginal cost generators will be used to provide the demand. But yes, increasing penetration of variable renewable energy like wind and solar will mean that the price will vary wildly. That means that players in the market will need to be hedged to insure them against too high/low prices. Also it wouldn't surprise me if various capacity market type mechanisms were to become more popular and constitute a bigger share of the money flows in the electricity market as a whole.
    - ZeroGravitas 5y ago
      Recent article on this topic, summarizing a paper they co-wrote (linked at the end): https://theconversation.com/renewables-are-cheaper-than-ever-so-why-are-household-energy-bills-only-going-up-174795 https://theconversation.com/renewables-are-cheaper-than-ever...
- jillesvangurp 5y ago
  Grid prices and cost are two things. EU and US grid pricing is dominated by the most expensive things in the market (gas, coal, and nuclear) because once you use up all the cheap supply, people end up bidding for the expensive stuff. So whenever there's a shortage of that, prices go up. Burning gas costs money. Shutting down or restarting a gas plant costs money too. And a gas plant that is not running still needs upkeep, maintenance, staffing, etc so it costs money. Some operators actually use negative rates to stimulate demand so they can keep their gas plants running and avoid shutting them down. Negative rates of course cost money, so that is added to the overall grid pricing. None of that has anything to do with the cost of renewables. That same dynamic is also what makes renewable power very lucrative for operators. A low cost and a high market price just means a lot of profit. That's why world+dog is putting up windmills and solar parks as fast as they can. It's just that good of a deal. And of course the subsidies and positive press help. If you are consuming a lot of power, that difference means investing in your own power generation makes a lot of sense. Which is why many plans for green steel plants involve plans for e.g. wind turbines and other solutions. So, they only buy from the grid when that supply is inadequate and actually supply to the grid when there is enough supply. Yes that's intermittent. But the connection to the grid isn't and the difference is just cost.
tofof 5y ago
So, the process used in the article is molten oxide electrolysis - using a raw iron oxide ore in molten form in a bath with its other (oxygen-bound) impurities - aluminum oxide, burnt lime (CaO), etc. The neat thing here is that the impurities stay behind in the electrolyte bath after the iron is removed (unsure if it's a gravity mechanism or a cathode attraction, but the molten iron ends up on the bottom of the electrolytic cell). As the article explains, this means that even cheap, low-grade ore with lots of impurities can be used with this technique. The other advantage is that the direct chemical reduction of iron eliminates the multi step (ore in a blast furnace to get pig iron, pig iron + coke, etc) procedure in traditional production. Among other benefits, you're now only heating the material once instead of 2-3 times, and as a result, you actually consume less total energy in this process even though you have to reach a higher temperature in the single heating.
- rocqua 5y ago
  I imagine the carbon content of the final steal output might still be hard to control. In which case further treatment would be required, though perhaps that could be done directly with the molten output from the cell (e.g. by blowing CO or O2 through the molten iron depending on whether carbon should be added or removed.
- baybal2 5y ago
  You don't target cheap steel market with this, you go after VAR, and ESR steel. > Among other benefits, you're now only heating the material once instead of 2-3 times, and as a result, you actually consume less total energy in this process even though you have to reach a higher temperature in the single heating. Combined steel+iron plants were around 60+ years
  - scythe 5y ago
    The key development that allowed this was the 2013 development of chromium anodes that tolerate the insane conditions of the process: https://pubmed.ncbi.nlm.nih.gov/23657254/ https://pubmed.ncbi.nlm.nih.gov/23657254/ So, that's why MOE wasn't around before 2013.
aaronbrethorst 5y ago
I happened across a great, long-form podcast that touches on this subject the other day. It offers a great survey of broad trends around decarbonizing heavy industry. https://www.volts.wtf/p/volts-podcast-rebecca-dell-on-decarbonizing https://www.volts.wtf/p/volts-podcast-rebecca-dell-on-decarb...
- ZeroGravitas 5y ago
  off-topic aside: whats the audio based equivalent to pocket or other "bookmark this to read it later" services. I dont want to figure out specific audio hosting things for each site, I want to hit a button that means, I want to listen to this audio later and have some code figure out all the BS and put it in a list for me when I have time to listen to something.
- ZeroGravitas 5y ago
  That was an excellent listen, thank you for recommending it.
  - aaronbrethorst 5y ago
    Glad you liked!
pfdietz 5y ago
The problem with this is that it doesn't work as well with intermittent source of electric power. The pot has to be kept hot. Contrast this with production of hydrogen. A hydrogen electrolyser can ramp up and down very quickly and is not damaged by long periods in an off state. The hydrogen can then be cheaply stored for a very long time, even seasonally, allowing the direct iron production facility to be operated continuously.
- rocqua 5y ago
  I was thinking the same thing. Though I am surprised to hear that seasonal storage of hydrogen is doable. I imagined that the size of pressure vessels required, as well as the leakage losses of hydrogen in general, would make that infeasible.
  - pfdietz 5y ago
    Hydrogen can be stored underground just like natural gas. The cost is very low, particularly if there are salt domes available where large cavities can be solution mined. For example, the salt formation at Delta, Utah has room for 100 such cavities that could store enough hydrogen that (if burned in combined cycle power plants) could power the entire US grid for 30 hours. The estimated storage cost is as little as $1/kWh of storage capacity (power related costs are extra).
    - flumpmaster 5y ago
      Here is a commercial example of underground hydrogen storage that has been in service since 2007. It is a salt cavern in Texas. It is part of extensive hydrogen infrastructure connecting many industrial users (600 miles of pipeline) https://investors.linde.com/archive/praxair/news/2007/praxair-commercializes-industrys-only-hydrogen-storage https://investors.linde.com/archive/praxair/news/2007/praxai...
    - prpl 5y ago
      Would not have expected to see Delta, UT on HN. I spent a significant amount of time there as an undergrad.
rocqua 5y ago
One upside I see with hydrogen is that it is easier to store on the scale of days. Hence you can be more opportunistic with your hydrogen production. Whereas an electricity based process will require a constant supply of electricity, putting more strain on the grid, and on prices in moments where wind and solar are low in production. In fact, I imagine the hydrogen production could help level out daily fluctuations in power availability.
- elric 5y ago
  Is hydrogen easy to store? I was under the impression that it had the tendency to leak out of whatever you store it in, due to its very small size.
  - usrusr 5y ago
    Easier at a scale of "national grid for n hours" and beyond than batteries. Much harder than piling up unused coal for a decade or two, noticeably harder than the equivalent stash of hydrocarbon gases or liquids.
    - smileysteve 5y ago
      For these energy quantities and consistencies, wouldn't a flywheel or localized hydro storage solve for n hours? (Next to a local reactor obv)
      - rocqua 5y ago
        Flywheels are quite limited in their storage capabilities. Because there is a limit to their RPM before they tear themselves apart from centrifugal forces. They are really interesting for energy storage on the scale of seconds, to smooth out spikes over that range. Much less interesting for storage on the scale of hours to days. Where batteries and hydrogen become more interesting. Pumped hydro is also quite nice on those scales, but cannot be implemented everywhere. Hydrogen is much less efficient that batteries, but much more scalable. That makes it attractive for taking in large amounts of over-produced electricity, and for use-cases where you need hydrogen anyway rather than meaning to turn the hydrogen back into electricity.
boringg 5y ago
Worth noting that today Green Steel investment at a facility that is already running (that will convert it to green steel) just happened. It is a $1.8B plan at the Steel facility in Hamilton, Canada. $400M kicked in by the Feds which should be operational by 2028. Electric arc furnace for the moment is the plan and maybe in the future bringing in Hydrogen. So this is a project in the wild.
baybal2 5y ago
> then refine it from iron oxide into pure iron and fortify it with small amounts of carbon. It’s a complex process that emits carbon at different stages. Some emissions come from the heating process, which usually involves burning a heat-refined form of coal called coke. A bit of the carbon from the coke gets dissolved into the iron, turning it into steel. Very incorrect. It's not even a highschooler level mistake.
- etskinner 5y ago
  I worked in a steel mill a while back. While I agree it's incorrect, I would say that the average high school student knows next to nothing about making steel. Here's how we made it: Take pig iron, put it into a Basic Oxygen Furnace. Add flux and inject supersonic oxygen. This removes impurities and carbon from the pig iron turning it into steel. Transfer to a huge crucible. Add any alloying elements, and cast it into slabs using a continuous slab caster.
  - baybal2 5y ago
    > I worked in a steel mill a while back. While I agree it's incorrect, I would say that the average high school student knows next to nothing about making steel. What country you are in?
philipkglass 5y ago
Others have mentioned that molten oxide electrolysis isn't as flexible with electricity consumption as hydrogen based processes. The even bigger problem, IMO, is the incredibly demanding chemical and thermal environment. There are not many combinations of vessel/electrode materials that are stable toward these high temperatures, dissolution by the lava-like electrolyte, and oxidation at the anode. According to the article their molten bath sounds like it is made of silicates. Electrolyzing molten silicates sounds a lot like NASA's "molten regolith electrolysis" [1] concept for in-situ resource utilization on the moon. The NASA concept valued the oxygen product while the produced metal is much more interesting here on Earth. Although conceptually simple, it has been a tremendous challenge finding materials that endure under these operating conditions. If Boston Metal has really cracked the problem, it bodes well for the future of terrestrial and off-planet resource extraction. [1] e.g. https://ntrs.nasa.gov/api/citations/20120003037/downloads/20120003037.pdf https://ntrs.nasa.gov/api/citations/20120003037/downloads/20...
- kragen 5y ago
  1600° is really about the same temperature as an ordinary blast furnace, and silicates have been commonly used as fluxes and refractories in steelmaking, even if basic oxygen steelmaking is more popular nowadays. If I understand correctly, Bessemer converters commonly used silicates. So I don't think the challenges you're pointing at, even if they have to be solved, are anything new for steelmaking. However, the article suggests that actually the electrolyte might be neutral, containing both calcium and silicon oxides. That can't possibly be right if they're talking about only 1600° because larnite would precipitate out. Electrodes would surely be carbon, just as they are in any old arc furnace. This does result in carbon dioxide emissions, as it does in the making of aluminum. Can they keep this down to an acceptable level? Is there an alternative electrode material, such as zirconia or carborundum? I'd like to know, but the article doesn't say.
  - pfdietz 5y ago
    I think carbon electrodes would dissolve in iron. If I recall correctly, it's some sort of oxide-coated metal electrodes.
greesil 5y ago
Ah yes this is Professor Sadoway's work.
ZeroGravitas 5y ago
It seems likely that almost any process that uses fossil inputs can be done reasonably well by simply subbing in electricity to fake the original process (e.g in this case making green hydrogen) but that there's a lot of synergies to be unlocked by revisiting from first principles. It's like TV going from radio with pictures to its own thing, or horseless carriages becoming automobiles etc. A new paradigm for looking at things afresh.
- HPsquared 5y ago
  You could even make a "fake internal combustion" engine that uses high-power electric arcs or lasers to super-heat the compressed air in the cylinders at the right moment, instead of combustion. Super inefficient and would likely spew out ozone and/or nitrogen oxides, but fun.
dbodin11 5y ago
TLDR - Article Highlights https://www.kontxt.io/document/d/EhrawY-veGAyWlYU8-98OI5FKC31modDcV3yB5krPzpE3/summary?kontxt_user=d https://www.kontxt.io/document/d/EhrawY-veGAyWlYU8-98OI5FKC3...
londons_explore 5y ago
This is entirely going to depend on how governments treat 'blue hydrogen' (ie. hydrogen produced from natural gas where the carbon is injected back underground). If blue hydrogen is treated as carbon-free by treaties and taxation schemes, then it will be a cheaper energy source than electricity, so it will be used to power steel, concrete, glass, and all the other heat and energy heavy industries. If however blue hydrogen is put in the bin of dirty fossil power, then steelmaking via hydrogen will prove to be more expensive than direct electrolysis.
- splitstud 5y ago
Animats 5y ago
So what does Nucor think of this? Nucor, which started as a steel recycler, is the US's largest steelmaker. They use huge electric furnaces to melt down scrap. Scrap is 71% of their input. They now have some basic oxygen furnace operations, too, making new steel, but mostly it's the same steel going round and round. If anybody is going to make basic steel with electric furnaces, it's likely to be Nucor. When they take this seriously, it's real.
hannob 5y ago
The article doesn't mention it: there is actually a research project in France doing iron oxide electrolysis, but in a different way than what Boston Metal does. It's called Siderwin and steel company ArcelorMittal is involved: https://www.siderwin-spire.eu/ https://www.siderwin-spire.eu/ I recently covered this in an article (though German, in case you understand that: https://www.golem.de/news/eisenoxid-elektrolyse-stahlherstellung-mit-strom-statt-kohle-2112-161461.html https://www.golem.de/news/eisenoxid-elektrolyse-stahlherstel... ). Main difference between this and Boston Metal: They use a relatively cold process (~100°C) while Boston Metal uses a hot process. I guess it's good to try to make this work in different ways.

62 points by orangebanana1 5y ago

djmips 5y ago

Anyone know if this process could also help with copper contaminated iron scrap?

gostsamo 5y ago
The melting temperature of copper is lower than that of iron. Most likely it will be possible, but instead of letting the iron flow out of the bath, you do it with the copper.

barney54 5y ago

The challenge here is cheap electricity. We can do amazing things with cheap electricity (green steel, green hydrogen, etc), but we are moving backwards on electricity prices. For example, we are seeing large electricity prices increases in Europe.

afarrell 5y ago
Iceland has solved the cheap electricity problem and has easy access to iron ore from the port of Narvik.
user-the-name 5y ago
Anything that relies on cheap electricity is not going to actually be very green.
- Bronze_Colossus 5y ago
  Not necessarily. Northern most part of Scandinavia have among the lowest prices for electricity in Northern and Central Europe. Most of the electricity there comes from Hydropower. It's also the same area where Sweden makes it green steel. Cheap and green electricity is not an oxymoron or impossibility.
  - cinntaile 5y ago
    I'm pretty sure they're mostly counting on wind energy to provide the cheap electricity since 0 marginal cost while hydro serves as a reliable backup.
    - jabl 5y ago
      Traditionally Swedish electricity has been about equal parts nuclear and hydro. Nuclear usually running full out, with hydro used to regulate for daily and seasonal variation. In recent years they have built a lot of wind, as of 2019 providing 12% of electricity, today almost certainly more. But yes, like you said, hydro is used as the backup for wind.
- cinntaile 5y ago
  Wind energy counts as green and will be used for this purpose.
pornel 5y ago
Currently we have a "problem" of solar energy being too cheap (even negative price) at peak. Could a steel production still be viable if it could only run during daylight, or adjust to intermittent availability of wind+solar? I know currently production is typically designed to run at maximum utilization 24/7, but maybe the solution is to rethink that assumption.
- rocqua 5y ago
  I recently heard that, even in Germany where there is lots of solar, there were only 9 days in the last year where spot prices were negative. Sadly my source is just "someone said". As for intermittent steel production, from what I know about aluminum it is essentially impossible to turn the process off, because the molten stuff solidifies and is impossible to melt again.
- Milner08 5y ago
  Steel plants sometimes have deals to operate at certain times for load shedding anyway, but how about they use the times when we have an excess of solar/wind and its not well suited to steel production (maybe due to shift patterns) to generate onsite Hydrogen using that excess power? Then they have readily available onsite green hydrogen. I think things like this will become an absolute necessity soon, using green power at its peaks to store resources for use later. (Obviously batteries will also be essential, although I would rather see gravity storage with big reservoirs like they have in Wales)
- jabl 5y ago
  Largely the negative prices are a side-effect of feed-in tariffs, where (some) renewable projects get paid a fixed price/kWh regardless of what the actual spot market price is. So when there's an oversupply of these subsidized renewables it pushes the spot price to negative. I think newer renewable support schemes have been designed to avoid this problem, either by cutting off the feed-in tariff when the spot price goes to zero, or then by restructuring the subsidies as some kind of investment support (state guaranteed very low interest loans or such) rather than paying for the generated electricity. That of course doesn't change the fundamental issue, in that in a grid with increasing amounts of variable production renewables and the price determined by marginal cost of the most expensive producer, the price swings will be larger than what we previously were used to.
boplicity 5y ago
European electricity still depends on natural gas -- which is largely controlled by Russia in large swaths of Europe. (This is also why Russia might think it can get away with invading Ukraine.) The cost of electricity once we've transitioned from fossil fuels is ultimately what counts -- and there is a lot of progress being made there, albeit slowly. Russia's influence, frankly, should be another really big motivator for Europe to transition away from fossil fuels as quickly as possible.
- theshrike79 5y ago
  Germany is especially linked to Russian gas for their electricity production, as they shut down all of their nuclear plants in some kind of attempt to be "more green" or something.
baybal2 5y ago
> For example, we are seeing large electricity prices increases in Europe. Which is very good. New capacity will most likely be non-gas.
ZeroGravitas 5y ago
The electricity price is set by the most expensive marginal cost. This made sense when renewables were more expensive on average than fossil fuels (which we want to discourage) but the rules probably need rewritten now that renewables are cheaper and continuing to get cheaper and fossils relegated to peaked roles. At the moment it just means that renewable providers are getting a lot of extra cash for not doing anything different and then on occasions when we go 100% renewable the price will crash suddenly to near zero.
- jabl 5y ago
  Dispatch based on marginal cost makes sense, as that ensures that the lowest marginal cost generators will be used to provide the demand. But yes, increasing penetration of variable renewable energy like wind and solar will mean that the price will vary wildly. That means that players in the market will need to be hedged to insure them against too high/low prices. Also it wouldn't surprise me if various capacity market type mechanisms were to become more popular and constitute a bigger share of the money flows in the electricity market as a whole.
  - ZeroGravitas 5y ago
    Recent article on this topic, summarizing a paper they co-wrote (linked at the end): https://theconversation.com/renewables-are-cheaper-than-ever-so-why-are-household-energy-bills-only-going-up-174795 https://theconversation.com/renewables-are-cheaper-than-ever...
jillesvangurp 5y ago
Grid prices and cost are two things. EU and US grid pricing is dominated by the most expensive things in the market (gas, coal, and nuclear) because once you use up all the cheap supply, people end up bidding for the expensive stuff. So whenever there's a shortage of that, prices go up. Burning gas costs money. Shutting down or restarting a gas plant costs money too. And a gas plant that is not running still needs upkeep, maintenance, staffing, etc so it costs money. Some operators actually use negative rates to stimulate demand so they can keep their gas plants running and avoid shutting them down. Negative rates of course cost money, so that is added to the overall grid pricing. None of that has anything to do with the cost of renewables. That same dynamic is also what makes renewable power very lucrative for operators. A low cost and a high market price just means a lot of profit. That's why world+dog is putting up windmills and solar parks as fast as they can. It's just that good of a deal. And of course the subsidies and positive press help. If you are consuming a lot of power, that difference means investing in your own power generation makes a lot of sense. Which is why many plans for green steel plants involve plans for e.g. wind turbines and other solutions. So, they only buy from the grid when that supply is inadequate and actually supply to the grid when there is enough supply. Yes that's intermittent. But the connection to the grid isn't and the difference is just cost.

tofof 5y ago

So, the process used in the article is molten oxide electrolysis - using a raw iron oxide ore in molten form in a bath with its other (oxygen-bound) impurities - aluminum oxide, burnt lime (CaO), etc. The neat thing here is that the impurities stay behind in the electrolyte bath after the iron is removed (unsure if it's a gravity mechanism or a cathode attraction, but the molten iron ends up on the bottom of the electrolytic cell). As the article explains, this means that even cheap, low-grade ore with lots of impurities can be used with this technique. The other advantage is that the direct chemical reduction of iron eliminates the multi step (ore in a blast furnace to get pig iron, pig iron + coke, etc) procedure in traditional production. Among other benefits, you're now only heating the material once instead of 2-3 times, and as a result, you actually consume less total energy in this process even though you have to reach a higher temperature in the single heating.

rocqua 5y ago
I imagine the carbon content of the final steal output might still be hard to control. In which case further treatment would be required, though perhaps that could be done directly with the molten output from the cell (e.g. by blowing CO or O2 through the molten iron depending on whether carbon should be added or removed.
baybal2 5y ago
You don't target cheap steel market with this, you go after VAR, and ESR steel. > Among other benefits, you're now only heating the material once instead of 2-3 times, and as a result, you actually consume less total energy in this process even though you have to reach a higher temperature in the single heating. Combined steel+iron plants were around 60+ years
- scythe 5y ago
  The key development that allowed this was the 2013 development of chromium anodes that tolerate the insane conditions of the process: https://pubmed.ncbi.nlm.nih.gov/23657254/ https://pubmed.ncbi.nlm.nih.gov/23657254/ So, that's why MOE wasn't around before 2013.

aaronbrethorst 5y ago

I happened across a great, long-form podcast that touches on this subject the other day. It offers a great survey of broad trends around decarbonizing heavy industry. https://www.volts.wtf/p/volts-podcast-rebecca-dell-on-decarbonizing https://www.volts.wtf/p/volts-podcast-rebecca-dell-on-decarb...

ZeroGravitas 5y ago
off-topic aside: whats the audio based equivalent to pocket or other "bookmark this to read it later" services. I dont want to figure out specific audio hosting things for each site, I want to hit a button that means, I want to listen to this audio later and have some code figure out all the BS and put it in a list for me when I have time to listen to something.
ZeroGravitas 5y ago
That was an excellent listen, thank you for recommending it.
- aaronbrethorst 5y ago
  Glad you liked!

pfdietz 5y ago

The problem with this is that it doesn't work as well with intermittent source of electric power. The pot has to be kept hot. Contrast this with production of hydrogen. A hydrogen electrolyser can ramp up and down very quickly and is not damaged by long periods in an off state. The hydrogen can then be cheaply stored for a very long time, even seasonally, allowing the direct iron production facility to be operated continuously.

rocqua 5y ago
I was thinking the same thing. Though I am surprised to hear that seasonal storage of hydrogen is doable. I imagined that the size of pressure vessels required, as well as the leakage losses of hydrogen in general, would make that infeasible.
- pfdietz 5y ago
  Hydrogen can be stored underground just like natural gas. The cost is very low, particularly if there are salt domes available where large cavities can be solution mined. For example, the salt formation at Delta, Utah has room for 100 such cavities that could store enough hydrogen that (if burned in combined cycle power plants) could power the entire US grid for 30 hours. The estimated storage cost is as little as $1/kWh of storage capacity (power related costs are extra).
  - flumpmaster 5y ago
    Here is a commercial example of underground hydrogen storage that has been in service since 2007. It is a salt cavern in Texas. It is part of extensive hydrogen infrastructure connecting many industrial users (600 miles of pipeline) https://investors.linde.com/archive/praxair/news/2007/praxair-commercializes-industrys-only-hydrogen-storage https://investors.linde.com/archive/praxair/news/2007/praxai...
  - prpl 5y ago
    Would not have expected to see Delta, UT on HN. I spent a significant amount of time there as an undergrad.

rocqua 5y ago

One upside I see with hydrogen is that it is easier to store on the scale of days. Hence you can be more opportunistic with your hydrogen production. Whereas an electricity based process will require a constant supply of electricity, putting more strain on the grid, and on prices in moments where wind and solar are low in production. In fact, I imagine the hydrogen production could help level out daily fluctuations in power availability.

elric 5y ago
Is hydrogen easy to store? I was under the impression that it had the tendency to leak out of whatever you store it in, due to its very small size.
- usrusr 5y ago
  Easier at a scale of "national grid for n hours" and beyond than batteries. Much harder than piling up unused coal for a decade or two, noticeably harder than the equivalent stash of hydrocarbon gases or liquids.
  - smileysteve 5y ago
    For these energy quantities and consistencies, wouldn't a flywheel or localized hydro storage solve for n hours? (Next to a local reactor obv)
    - rocqua 5y ago
      Flywheels are quite limited in their storage capabilities. Because there is a limit to their RPM before they tear themselves apart from centrifugal forces. They are really interesting for energy storage on the scale of seconds, to smooth out spikes over that range. Much less interesting for storage on the scale of hours to days. Where batteries and hydrogen become more interesting. Pumped hydro is also quite nice on those scales, but cannot be implemented everywhere. Hydrogen is much less efficient that batteries, but much more scalable. That makes it attractive for taking in large amounts of over-produced electricity, and for use-cases where you need hydrogen anyway rather than meaning to turn the hydrogen back into electricity.

boringg 5y ago

Worth noting that today Green Steel investment at a facility that is already running (that will convert it to green steel) just happened. It is a $1.8B plan at the Steel facility in Hamilton, Canada. $400M kicked in by the Feds which should be operational by 2028. Electric arc furnace for the moment is the plan and maybe in the future bringing in Hydrogen. So this is a project in the wild.

baybal2 5y ago

> then refine it from iron oxide into pure iron and fortify it with small amounts of carbon. It’s a complex process that emits carbon at different stages. Some emissions come from the heating process, which usually involves burning a heat-refined form of coal called coke. A bit of the carbon from the coke gets dissolved into the iron, turning it into steel. Very incorrect. It's not even a highschooler level mistake.

etskinner 5y ago
I worked in a steel mill a while back. While I agree it's incorrect, I would say that the average high school student knows next to nothing about making steel. Here's how we made it: Take pig iron, put it into a Basic Oxygen Furnace. Add flux and inject supersonic oxygen. This removes impurities and carbon from the pig iron turning it into steel. Transfer to a huge crucible. Add any alloying elements, and cast it into slabs using a continuous slab caster.
- baybal2 5y ago
  > I worked in a steel mill a while back. While I agree it's incorrect, I would say that the average high school student knows next to nothing about making steel. What country you are in?

philipkglass 5y ago

Others have mentioned that molten oxide electrolysis isn't as flexible with electricity consumption as hydrogen based processes. The even bigger problem, IMO, is the incredibly demanding chemical and thermal environment. There are not many combinations of vessel/electrode materials that are stable toward these high temperatures, dissolution by the lava-like electrolyte, and oxidation at the anode. According to the article their molten bath sounds like it is made of silicates. Electrolyzing molten silicates sounds a lot like NASA's "molten regolith electrolysis" [1] concept for in-situ resource utilization on the moon. The NASA concept valued the oxygen product while the produced metal is much more interesting here on Earth. Although conceptually simple, it has been a tremendous challenge finding materials that endure under these operating conditions. If Boston Metal has really cracked the problem, it bodes well for the future of terrestrial and off-planet resource extraction. [1] e.g. https://ntrs.nasa.gov/api/citations/20120003037/downloads/20120003037.pdf https://ntrs.nasa.gov/api/citations/20120003037/downloads/20...

kragen 5y ago
1600° is really about the same temperature as an ordinary blast furnace, and silicates have been commonly used as fluxes and refractories in steelmaking, even if basic oxygen steelmaking is more popular nowadays. If I understand correctly, Bessemer converters commonly used silicates. So I don't think the challenges you're pointing at, even if they have to be solved, are anything new for steelmaking. However, the article suggests that actually the electrolyte might be neutral, containing both calcium and silicon oxides. That can't possibly be right if they're talking about only 1600° because larnite would precipitate out. Electrodes would surely be carbon, just as they are in any old arc furnace. This does result in carbon dioxide emissions, as it does in the making of aluminum. Can they keep this down to an acceptable level? Is there an alternative electrode material, such as zirconia or carborundum? I'd like to know, but the article doesn't say.
- pfdietz 5y ago
  I think carbon electrodes would dissolve in iron. If I recall correctly, it's some sort of oxide-coated metal electrodes.

greesil 5y ago

Ah yes this is Professor Sadoway's work.

ZeroGravitas 5y ago

It seems likely that almost any process that uses fossil inputs can be done reasonably well by simply subbing in electricity to fake the original process (e.g in this case making green hydrogen) but that there's a lot of synergies to be unlocked by revisiting from first principles. It's like TV going from radio with pictures to its own thing, or horseless carriages becoming automobiles etc. A new paradigm for looking at things afresh.

HPsquared 5y ago
You could even make a "fake internal combustion" engine that uses high-power electric arcs or lasers to super-heat the compressed air in the cylinders at the right moment, instead of combustion. Super inefficient and would likely spew out ozone and/or nitrogen oxides, but fun.

dbodin11 5y ago

TLDR - Article Highlights https://www.kontxt.io/document/d/EhrawY-veGAyWlYU8-98OI5FKC31modDcV3yB5krPzpE3/summary?kontxt_user=d https://www.kontxt.io/document/d/EhrawY-veGAyWlYU8-98OI5FKC3...

londons_explore 5y ago

This is entirely going to depend on how governments treat 'blue hydrogen' (ie. hydrogen produced from natural gas where the carbon is injected back underground). If blue hydrogen is treated as carbon-free by treaties and taxation schemes, then it will be a cheaper energy source than electricity, so it will be used to power steel, concrete, glass, and all the other heat and energy heavy industries. If however blue hydrogen is put in the bin of dirty fossil power, then steelmaking via hydrogen will prove to be more expensive than direct electrolysis.

splitstud 5y ago

Animats 5y ago

So what does Nucor think of this? Nucor, which started as a steel recycler, is the US's largest steelmaker. They use huge electric furnaces to melt down scrap. Scrap is 71% of their input. They now have some basic oxygen furnace operations, too, making new steel, but mostly it's the same steel going round and round. If anybody is going to make basic steel with electric furnaces, it's likely to be Nucor. When they take this seriously, it's real.

hannob 5y ago

The article doesn't mention it: there is actually a research project in France doing iron oxide electrolysis, but in a different way than what Boston Metal does. It's called Siderwin and steel company ArcelorMittal is involved: https://www.siderwin-spire.eu/ https://www.siderwin-spire.eu/ I recently covered this in an article (though German, in case you understand that: https://www.golem.de/news/eisenoxid-elektrolyse-stahlherstellung-mit-strom-statt-kohle-2112-161461.html https://www.golem.de/news/eisenoxid-elektrolyse-stahlherstel... ). Main difference between this and Boston Metal: They use a relatively cold process (~100°C) while Boston Metal uses a hot process. I guess it's good to try to make this work in different ways.