4 ms·

Don’t we use coal for two main things? Energy and steel? Do we have a replacement for coal in the steel industry?

germinalphrase 5y ago
I don’t know if he is right, but Bill Gates has been saying that we should basically accept that certain kinds of steel will never be made with a net zero process. We need steel though, so we will have to offset those carbon costs.
pengaru 5y ago
Cement production is another big one.
- tuatoru 5y ago
  It's relatively easy to capture the carbon dioxide produced by cement production, though. Relatively few, relatively large, point sources where the CO2 is in pipes already. Low-carbon alternatives to Portland cement are being researched and piloted, too. Just a matter of money and the learning curve, the same as with electric power production.
- BuyMyBitcoins 5y ago
  I wish we could engineer a way to use all the heat from nuclear reactors for this purpose.
  - jjk166 5y ago
    Unfortunately about 60% of CO2 emissions from cement production is simply the CO2 released from the conversion of Calcium Carbonate (CaCO3) to lime (CaO). You need carbon capture no matter what, so capturing emissions from the heat production as well is likely far more economical than modifying a plant to use a totally different process heat source. Further, nuclear is simply not a good option for this application. Cement kilns need to reach 1,450 C, while reactor temperatures are limited to about 950 C.
    - pengaru 5y ago
      > Unfortunately about 60% of CO2 emissions from cement production is simply the CO2 released from the conversion of Calcium Carbonate (CaCO3) to lime (CaO). Isn't this irrelevant? It's not like we just produce cement to stockpile it indefinitely. When it's mixed with water and used to construct useful things, that CO2 comes back out of the atmosphere as it "cures". What am I missing here?
      - jjk166 5y ago
        Cement curing only absorbs about 30% of the CO2 released. The cement doesn't turn 100% back into calcium carbonate. Only the surface of the grains get exposed to the water and CO2 necessary to cure.
kleton 5y ago
And cement
gus_massa 5y ago
We had a very big steel mill here in Argentina that had it's own forest to grow eucalyptus, and make coal with them and use that in the steel production. From https://es.wikipedia.org/wiki/Aceros_Zapla_S.A https://es.wikipedia.org/wiki/Aceros_Zapla_S.A. translation> It had 15,000 ha of forest with 30 million eucalyptus trees to extract the coal necessary in the process, for which the town of "Centro Forestal" was build.
ph0rque 5y ago
> Do we have a replacement for coal in the steel industry? Still in R&D admittedly, but micronuclear should do the job well.
- QuercusMax 5y ago
  how does micronuclear replace coal for producing carbon steels?
  - ph0rque 5y ago
    Here's an example research article: https://www.sciencedirect.com/science/article/abs/pii/S0360544212000527 https://www.sciencedirect.com/science/article/abs/pii/S03605...
    - 6nf 5y ago
      Ah I think you're misunderstanding the question about the steel. Steel contains quite a bit of carbon (the element carbon) dissolved in the iron, on the order of 1% of the steel bulk is elemental carbon. You need to get that carbon from somewhere and coal is good source of carbon. No research is going to replace the carbon in steel with something clean, your article is about the energy used in steel production and not the elemental carbon going into the steel itself.
      - ph0rque 5y ago
        I see, thanks for the clarification. Yes, I was thinking of coal solely as a source of energy (heat, specifically) to melt steel.
      - stavros 5y ago
        But carbon in steel is in steel, not the atmosphere, so we don't mind, no?
      - Dylan16807 5y ago
        > No research is going to replace the carbon in steel with something clean Is that what you meant to say? How is carbon in steel not "clean"?
Gibbon1 5y ago
I read an old paper from the 60's on electrowinning iron from a sulfate solution. They claimed around 4.5kwh/kg. Read a more recent paper (2019) reporting on same process with modern separators[1] got energy requirements down to 3.5kwh/kg. 3.5 kwh/kg is probably 20 cents worth of electricity. [1] Separators are used to isolate the anode and cathode in electrolytic cells in order to suppress side reactions. Modern separators allow specific ions to pass while blocking others.
- SECProto 5y ago
  > 3.5 kwh/kg is probably 20 cents worth of electricity. Your phrasing implies this is a small number - but 20 cents per kg is 20000c/tonne or $200 per tonne. The current spot price for iron ore is $200, which itself is twice as much as it was a year ago. So the additional cost of electricity could take the spot price as high as $400, four times as much as it was in July 2020. It's still an important for the environment to do this & remove carbon from the industry, but need to acknowledge the costs.
  - jjk166 5y ago
    You're ignoring the current price of fuel. For context, in 2019 the cost of coke was $143 per ton of steel produced. Also it takes about 1.6 tons of iron ore per ton of steel, so that's currently about $320 in iron ore costs. Combined, that means 3.5 kwh/kg is roughly 12% more expensive raw material-wise than the current process. So it's an increase, but a drop in the bucket compared to the 200% increase in cost that happened over the past year; in fact its smaller than any YOY price change since 2015. Assuming it is phased in over the course of a few years, we likely wouldn't even notice the price increase.
    - Gibbon1 5y ago
      What tantalizing to me is solar and wind are unique in that the marginal cost of production is near zero. Meaning very unlike coal and natural gas energy sources. That leads to a energy grid characterized by frequent over supply. My thinking is electrowinning iron and mini-mills could easily absorb excess capacity. Aqueous electrolytic cells should be able to just sit idle for hours to days. And electric furnaces draw easily 10-100MW. That makes them a good match for a renewable grid.
tialaramex 5y ago
You need carbon to make steel, but it doesn't necessarily have to be from coal. So we definitely could replace coal, but that may be very expensive at today's scale. Even if we can use trees rather than coal, we are avoiding the release of carbon which was previously locked away underground. Also, coal we dig up is much more suitable for one or the other purpose. If you mine thermal coal, the steel plant doesn't want it, they want metallurgical coal. If your country has a steel plant, and a thermal coal mine, you will export thermal coal from the mine and import metallurgical coal to run the steel plant. Well, if nobody buys your thermal coal, the coal mine shuts, even if you still have a steel plant.
- socialdemocrat 5y ago
  Not sure how much coal you really need. Sure steel is an iron alloy with carbon, but most coal in a steel mill is used as a reducing agent. Hydrogen can be used instead. Or you can use electrolysis to reduce which is even more efficient.
  - visiblink 5y ago
    It must take a lot of coal to make steel. The mine I used to work for shipped 3-4 million tonnes of metallurgical coal to Japan every year.
    - dredmorbius 5y ago
      It's about 14-15% of global coal consumption last I checked. That shifts around a bit as use in electrical generation and alternate steelmaking technologies vary. (Electric minimills processing scrap and not requiring coking are a significant source of steel.)
socialdemocrat 5y ago
You can use charcoal, hydrogen or use electrolysis. The latter is not as well developed yet.

I don’t know if he is right, but Bill Gates has been saying that we should basically accept that certain kinds of steel will never be made with a net zero process. We need steel though, so we will have to offset those carbon costs.

pengaru 5y ago

Cement production is another big one.

tuatoru 5y ago
It's relatively easy to capture the carbon dioxide produced by cement production, though. Relatively few, relatively large, point sources where the CO2 is in pipes already. Low-carbon alternatives to Portland cement are being researched and piloted, too. Just a matter of money and the learning curve, the same as with electric power production.
BuyMyBitcoins 5y ago
I wish we could engineer a way to use all the heat from nuclear reactors for this purpose.
- jjk166 5y ago
  Unfortunately about 60% of CO2 emissions from cement production is simply the CO2 released from the conversion of Calcium Carbonate (CaCO3) to lime (CaO). You need carbon capture no matter what, so capturing emissions from the heat production as well is likely far more economical than modifying a plant to use a totally different process heat source. Further, nuclear is simply not a good option for this application. Cement kilns need to reach 1,450 C, while reactor temperatures are limited to about 950 C.
  - pengaru 5y ago
    > Unfortunately about 60% of CO2 emissions from cement production is simply the CO2 released from the conversion of Calcium Carbonate (CaCO3) to lime (CaO). Isn't this irrelevant? It's not like we just produce cement to stockpile it indefinitely. When it's mixed with water and used to construct useful things, that CO2 comes back out of the atmosphere as it "cures". What am I missing here?
    - jjk166 5y ago
      Cement curing only absorbs about 30% of the CO2 released. The cement doesn't turn 100% back into calcium carbonate. Only the surface of the grains get exposed to the water and CO2 necessary to cure.

kleton 5y ago

And cement

gus_massa 5y ago

We had a very big steel mill here in Argentina that had it's own forest to grow eucalyptus, and make coal with them and use that in the steel production. From https://es.wikipedia.org/wiki/Aceros_Zapla_S.A https://es.wikipedia.org/wiki/Aceros_Zapla_S.A. translation> It had 15,000 ha of forest with 30 million eucalyptus trees to extract the coal necessary in the process, for which the town of "Centro Forestal" was build.

ph0rque 5y ago

> Do we have a replacement for coal in the steel industry? Still in R&D admittedly, but micronuclear should do the job well.

QuercusMax 5y ago
how does micronuclear replace coal for producing carbon steels?
- ph0rque 5y ago
  Here's an example research article: https://www.sciencedirect.com/science/article/abs/pii/S0360544212000527 https://www.sciencedirect.com/science/article/abs/pii/S03605...
  - 6nf 5y ago
    Ah I think you're misunderstanding the question about the steel. Steel contains quite a bit of carbon (the element carbon) dissolved in the iron, on the order of 1% of the steel bulk is elemental carbon. You need to get that carbon from somewhere and coal is good source of carbon. No research is going to replace the carbon in steel with something clean, your article is about the energy used in steel production and not the elemental carbon going into the steel itself.
    - ph0rque 5y ago
      I see, thanks for the clarification. Yes, I was thinking of coal solely as a source of energy (heat, specifically) to melt steel.
    - stavros 5y ago
      But carbon in steel is in steel, not the atmosphere, so we don't mind, no?
    - Dylan16807 5y ago
      > No research is going to replace the carbon in steel with something clean Is that what you meant to say? How is carbon in steel not "clean"?

Gibbon1 5y ago

I read an old paper from the 60's on electrowinning iron from a sulfate solution. They claimed around 4.5kwh/kg. Read a more recent paper (2019) reporting on same process with modern separators[1] got energy requirements down to 3.5kwh/kg. 3.5 kwh/kg is probably 20 cents worth of electricity. [1] Separators are used to isolate the anode and cathode in electrolytic cells in order to suppress side reactions. Modern separators allow specific ions to pass while blocking others.

SECProto 5y ago
> 3.5 kwh/kg is probably 20 cents worth of electricity. Your phrasing implies this is a small number - but 20 cents per kg is 20000c/tonne or $200 per tonne. The current spot price for iron ore is $200, which itself is twice as much as it was a year ago. So the additional cost of electricity could take the spot price as high as $400, four times as much as it was in July 2020. It's still an important for the environment to do this & remove carbon from the industry, but need to acknowledge the costs.
- jjk166 5y ago
  You're ignoring the current price of fuel. For context, in 2019 the cost of coke was $143 per ton of steel produced. Also it takes about 1.6 tons of iron ore per ton of steel, so that's currently about $320 in iron ore costs. Combined, that means 3.5 kwh/kg is roughly 12% more expensive raw material-wise than the current process. So it's an increase, but a drop in the bucket compared to the 200% increase in cost that happened over the past year; in fact its smaller than any YOY price change since 2015. Assuming it is phased in over the course of a few years, we likely wouldn't even notice the price increase.
  - Gibbon1 5y ago
    What tantalizing to me is solar and wind are unique in that the marginal cost of production is near zero. Meaning very unlike coal and natural gas energy sources. That leads to a energy grid characterized by frequent over supply. My thinking is electrowinning iron and mini-mills could easily absorb excess capacity. Aqueous electrolytic cells should be able to just sit idle for hours to days. And electric furnaces draw easily 10-100MW. That makes them a good match for a renewable grid.

tialaramex 5y ago

You need carbon to make steel, but it doesn't necessarily have to be from coal. So we definitely could replace coal, but that may be very expensive at today's scale. Even if we can use trees rather than coal, we are avoiding the release of carbon which was previously locked away underground. Also, coal we dig up is much more suitable for one or the other purpose. If you mine thermal coal, the steel plant doesn't want it, they want metallurgical coal. If your country has a steel plant, and a thermal coal mine, you will export thermal coal from the mine and import metallurgical coal to run the steel plant. Well, if nobody buys your thermal coal, the coal mine shuts, even if you still have a steel plant.

socialdemocrat 5y ago
Not sure how much coal you really need. Sure steel is an iron alloy with carbon, but most coal in a steel mill is used as a reducing agent. Hydrogen can be used instead. Or you can use electrolysis to reduce which is even more efficient.
- visiblink 5y ago
  It must take a lot of coal to make steel. The mine I used to work for shipped 3-4 million tonnes of metallurgical coal to Japan every year.
  - dredmorbius 5y ago
    It's about 14-15% of global coal consumption last I checked. That shifts around a bit as use in electrical generation and alternate steelmaking technologies vary. (Electric minimills processing scrap and not requiring coking are a significant source of steel.)

socialdemocrat 5y ago

You can use charcoal, hydrogen or use electrolysis. The latter is not as well developed yet.