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The claim is that "Hydrogen-reduced carbon-free DRI is highly metallized and has superior mechanical and aging properties compared to direct reduced iron using

The claim is that "Hydrogen-reduced carbon-free DRI is highly metallized and has superior mechanical and aging properties compared to direct reduced iron using fossil-based reducing gas such as natural gas." I wish there were more details.

aardvarkr 4y ago
Agreed. This claim is so vague, and it sounds like this is just one part of the smelting process.
ortusdux 4y ago
Yes, there is little value in a press release about research that does not include a link or refence to said research.
lazide 4y ago
Hydrogen is well known and studied to cause many issues with steel, generally brittleness and crystal structure defects. In situations where it’s important that cracking doesn’t occur, it’s common for low/no hydrogen electrodes in welding be required, for instance. That using a method of production that naturally exposes it hydrogen would produce higher quality steel is surprising! We should still definitely have a link to the study!
- yborg 4y ago
  This process produces direct reduced iron, not steel.
  - lazide 4y ago
    What do you think Steel is, but reduced Iron (to a specific level)? Cast Iron is also impacted by hydrogen embrittlement, albeit iron is usually already pretty brittle so folks don’t use it where that kind of failure matters as much.
    - metal_am 4y ago
      It produces an intermediate product. You can't use it without further processing. In any case, the hydrogen won't be a problem.
    - xyzzyz 4y ago
      You mean, cast iron is pretty brittle. Pure iron is not brittle.
      - lazide 4y ago
        If you're talking pure iron, then yes - it's very ductile and malleable. However, the low end of carbon allowed while still calling something steel is .3%, so with a few exceptions (wrought iron, which is arguably very soft steel), it's rare to run across it. There are of course ways to treat cast iron so it's decently durable (ductile iron), but it's still pretty brittle compared to 99% of steel in the real world.
        robocat 4y ago
        > low end of carbon allowed while still calling something steel is .3% Incorrect. That is the maximum for low carbon steel (also called mild steel - the most common form of steel). Wikipedia says “The carbon content of steel is between 0.002% and 2.14% by weight for plain carbon steel”. “Plain carbon-iron alloys with a higher than 2.1% carbon content are known as cast iron.” https://en.m.wikipedia.org/wiki/Steel https://en.m.wikipedia.org/wiki/Steel https://en.m.wikipedia.org/wiki/Pig_iron https://en.m.wikipedia.org/wiki/Pig_iron https://en.m.wikipedia.org/wiki/Cast_iron https://en.m.wikipedia.org/wiki/Cast_iron https://en.m.wikipedia.org/wiki/Carbon_steel https://en.m.wikipedia.org/wiki/Carbon_steel https://en.m.wikipedia.org/wiki/Alloy_steel https://en.m.wikipedia.org/wiki/Alloy_steel https://en.m.wikipedia.org/wiki/Iron https://en.m.wikipedia.org/wiki/Iron
- dodobirdlord 4y ago
  This is a process for refining iron ore, as opposed to using a blast furnace, or using the same process with decomposed natural gas instead of just hydrogen. In steel production it would be subsequently smelted.
  - lazide 4y ago
    Do you think that removes the concern? I don’t see how it would.
    - photochemsyn 4y ago
      This process produces sponge iron, which is then fed into an electric arc furnace. There is no free hydrogen around at that point. Whatcomes out of an electric arc furnace is carbon steel. The issue with hydrogen, which was first noted IIRC in the high-pressure Haber-Bosch ammonia production process, in which H2 and N2 at high pressure over a catalyst in a steel chamber forms NH3, is that free hydrogen reacts with the carbon in the steel under these conditions, which caused the pressure chambers to regularly explode (solution was a sacrificial lining of the chambers which was regularly replaced). For low-pressure H2 it may not be much of a problem, but that's not very efficient for transport.
      - lazide 4y ago
        Thanks for the background! So likely due to the complete remelt and re-alloying expected, it should work out?
      - pstuart 4y ago
        Speaking of ammonia, any thoughts to share on an ammonia economy vs hydrogen economy? The former seems a lot more practical.
        photochemsyn 4y ago
        Ammonia as fertilizer is the only ammonia economy that makes sense; hydrogen economy doesn't make much sense either. Methane economy is the optional long-term solution for chemical energy sources, just CO2(atm) + H2 (water) -> CH4. Ammonia combustion generates NOx smog, and ammonia is pretty toxic to store and transport as a gas. For fertilizer it's stored as (NH4)(NO3) or similar. Hydrogen production has a few major use cases, but replacing natural gas is not one of them. Iron reduction, nitrogen reduction, carbon reduction, in industrial settings, is about it.
- jbay808 4y ago
  For what it's worth to reduce surprise/skepticism, a hydrogen atmosphere is already commonly used for annealing electrical steels (eg. motor laminations or magnetic parts). https://www.tlclam.net/annealing-process/ https://www.tlclam.net/annealing-process/ https://www.vac-met.com/hydrogen-annealing/ https://www.vac-met.com/hydrogen-annealing/
ghastmaster 4y ago
Using natural gas introduces carbon. After the DRI stage, further treatments would be required to remove the carbon as it oxidizes. With less carbon there should be more consistent oxidizing of the iron, especially since it looks like carbon monoxide(from the natural gas) is not required which would introduce unwanted oxygen. I wish there were more details as well.
- LarsAlereon 4y ago
  The thing is you usually WANT Carbon in your Iron, so if you use Hydrogen DRI you have to further process the Iron to add the Carbon back in. There's a lot of potential for using mixtures of Hydrogen and Natural Gas to produce Iron with the exact desired Carbon content.
  - moron4hire 4y ago
    It seems to me that, when you want carbon in your iron (to make steel), you want a lot of control over how much carbon is in that steel. To start from a base iron that has no carbon in it whatsoever seems like it would be better for being more precise in your steel production.
    - LarsAlereon 4y ago
      While you certainly can add or remove Carbon during processing, you get the lowest costs if your input Iron is as close as possible to the desired Carbon content for your application.
      - moron4hire 4y ago
        Again, it seems to me that, if you care about extreme precision in your steel-making process, cost is the least of your worries.
  - ghastmaster 4y ago
    Carbon is wanted for steel production, but at specific levels. DRI is further worked to oxidize carbon and remove it before processing. Eliminating the carbon/oxygen from natural gas reduction allows a more controlled introduction of carbon and or less processing to make ready for steel production.
deleted 4y ago
[deleted]

aardvarkr 4y ago

Agreed. This claim is so vague, and it sounds like this is just one part of the smelting process.

ortusdux 4y ago

Yes, there is little value in a press release about research that does not include a link or refence to said research.

lazide 4y ago

Hydrogen is well known and studied to cause many issues with steel, generally brittleness and crystal structure defects. In situations where it’s important that cracking doesn’t occur, it’s common for low/no hydrogen electrodes in welding be required, for instance. That using a method of production that naturally exposes it hydrogen would produce higher quality steel is surprising! We should still definitely have a link to the study!

yborg 4y ago
This process produces direct reduced iron, not steel.
- lazide 4y ago
  What do you think Steel is, but reduced Iron (to a specific level)? Cast Iron is also impacted by hydrogen embrittlement, albeit iron is usually already pretty brittle so folks don’t use it where that kind of failure matters as much.
  - metal_am 4y ago
    It produces an intermediate product. You can't use it without further processing. In any case, the hydrogen won't be a problem.
  - xyzzyz 4y ago
    You mean, cast iron is pretty brittle. Pure iron is not brittle.
    - lazide 4y ago
      If you're talking pure iron, then yes - it's very ductile and malleable. However, the low end of carbon allowed while still calling something steel is .3%, so with a few exceptions (wrought iron, which is arguably very soft steel), it's rare to run across it. There are of course ways to treat cast iron so it's decently durable (ductile iron), but it's still pretty brittle compared to 99% of steel in the real world.
      - robocat 4y ago
        > low end of carbon allowed while still calling something steel is .3% Incorrect. That is the maximum for low carbon steel (also called mild steel - the most common form of steel). Wikipedia says “The carbon content of steel is between 0.002% and 2.14% by weight for plain carbon steel”. “Plain carbon-iron alloys with a higher than 2.1% carbon content are known as cast iron.” https://en.m.wikipedia.org/wiki/Steel https://en.m.wikipedia.org/wiki/Steel https://en.m.wikipedia.org/wiki/Pig_iron https://en.m.wikipedia.org/wiki/Pig_iron https://en.m.wikipedia.org/wiki/Cast_iron https://en.m.wikipedia.org/wiki/Cast_iron https://en.m.wikipedia.org/wiki/Carbon_steel https://en.m.wikipedia.org/wiki/Carbon_steel https://en.m.wikipedia.org/wiki/Alloy_steel https://en.m.wikipedia.org/wiki/Alloy_steel https://en.m.wikipedia.org/wiki/Iron https://en.m.wikipedia.org/wiki/Iron
dodobirdlord 4y ago
This is a process for refining iron ore, as opposed to using a blast furnace, or using the same process with decomposed natural gas instead of just hydrogen. In steel production it would be subsequently smelted.
- lazide 4y ago
  Do you think that removes the concern? I don’t see how it would.
  - photochemsyn 4y ago
    This process produces sponge iron, which is then fed into an electric arc furnace. There is no free hydrogen around at that point. Whatcomes out of an electric arc furnace is carbon steel. The issue with hydrogen, which was first noted IIRC in the high-pressure Haber-Bosch ammonia production process, in which H2 and N2 at high pressure over a catalyst in a steel chamber forms NH3, is that free hydrogen reacts with the carbon in the steel under these conditions, which caused the pressure chambers to regularly explode (solution was a sacrificial lining of the chambers which was regularly replaced). For low-pressure H2 it may not be much of a problem, but that's not very efficient for transport.
    - lazide 4y ago
      Thanks for the background! So likely due to the complete remelt and re-alloying expected, it should work out?
    - pstuart 4y ago
      Speaking of ammonia, any thoughts to share on an ammonia economy vs hydrogen economy? The former seems a lot more practical.
      - photochemsyn 4y ago
        Ammonia as fertilizer is the only ammonia economy that makes sense; hydrogen economy doesn't make much sense either. Methane economy is the optional long-term solution for chemical energy sources, just CO2(atm) + H2 (water) -> CH4. Ammonia combustion generates NOx smog, and ammonia is pretty toxic to store and transport as a gas. For fertilizer it's stored as (NH4)(NO3) or similar. Hydrogen production has a few major use cases, but replacing natural gas is not one of them. Iron reduction, nitrogen reduction, carbon reduction, in industrial settings, is about it.
jbay808 4y ago
For what it's worth to reduce surprise/skepticism, a hydrogen atmosphere is already commonly used for annealing electrical steels (eg. motor laminations or magnetic parts). https://www.tlclam.net/annealing-process/ https://www.tlclam.net/annealing-process/ https://www.vac-met.com/hydrogen-annealing/ https://www.vac-met.com/hydrogen-annealing/

ghastmaster 4y ago

Using natural gas introduces carbon. After the DRI stage, further treatments would be required to remove the carbon as it oxidizes. With less carbon there should be more consistent oxidizing of the iron, especially since it looks like carbon monoxide(from the natural gas) is not required which would introduce unwanted oxygen. I wish there were more details as well.

LarsAlereon 4y ago
The thing is you usually WANT Carbon in your Iron, so if you use Hydrogen DRI you have to further process the Iron to add the Carbon back in. There's a lot of potential for using mixtures of Hydrogen and Natural Gas to produce Iron with the exact desired Carbon content.
- moron4hire 4y ago
  It seems to me that, when you want carbon in your iron (to make steel), you want a lot of control over how much carbon is in that steel. To start from a base iron that has no carbon in it whatsoever seems like it would be better for being more precise in your steel production.
  - LarsAlereon 4y ago
    While you certainly can add or remove Carbon during processing, you get the lowest costs if your input Iron is as close as possible to the desired Carbon content for your application.
    - moron4hire 4y ago
      Again, it seems to me that, if you care about extreme precision in your steel-making process, cost is the least of your worries.
- ghastmaster 4y ago
  Carbon is wanted for steel production, but at specific levels. DRI is further worked to oxidize carbon and remove it before processing. Eliminating the carbon/oxygen from natural gas reduction allows a more controlled introduction of carbon and or less processing to make ready for steel production.

deleted 4y ago

[deleted]