[HN Gopher] New research shows hydrogen-reduced iron has superio...
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New research shows hydrogen-reduced iron has superior properties
Author : tda
Score : 89 points
Date : 2022-10-12 13:36 UTC (9 hours ago)
(HTM) web link (group.vattenfall.com)
(TXT) w3m dump (group.vattenfall.com)
| photochemsyn wrote:
| Here's a good steel production flowchart that shows where this
| process would be used (replace the natural gas-powered direct
| reduction feed-in to the electric arc furnace with a hydrogen-
| powered direct-reduction step). Overall, it's part of the
| electric arc process which avoids the need for coke from coal in
| blast furnaces.
|
| https://www.steel.org/steel-technology/steel-production/
|
| Of course, making this fossil-fuel free requires significant
| hydrogen production from sources like hydropower (or nuclear)
| powered electrolyis, or my favorite, photoelectrochemical
| reduction of water, such as:
|
| https://techxplore.com/news/2017-08-decades-technology-nrel-...
|
| As far as the claims about producing a superior product with
| hydrogen compared to natural gas, that's hard to evaluate without
| more data. I imagine quality of the incoming ore is a major
| factor. If you want a technical paper on it, here's something
| recent from what looks like a China-Germany research
| collaboration:
|
| https://sci-hub.se/10.1016/j.actamat.2021.116933
|
| "(2021) Influence of microstructure and atomic-scale chemistry on
| the direct reduction of iron ore with hydrogen at 700degC"
|
| P.S. The issue of hydrogen embrittlement of steel doesn't apply
| here, although it is a major issue that doesn't bode that well
| for replacing natural gas with hydrogen anywhere other than in
| industrial processes where the hydrogen is being consumed almost
| as fast as it is produced. Making synthetic natural gas from
| atmospheric CO2 and water-sourced hydrogen is a (currently
| expensive) option, however.
| hinkley wrote:
| Methane digesters would probably be more efficient, but I'm not
| sure about the volume.
| ncmncm wrote:
| It is substantially more efficient, by unit of collecting area,
| to produce electricity using a regular solar panel and then
| electrolyse water for hydrogen. But of course collection area
| efficiency is not what matters, cost is. We don't know what the
| electrophotochemical equipment costs, or how that compares. It
| does seem more elegant, at a remove.
|
| In practice, of course, you drive your electrolyser from solar,
| wind, hydro, geo, tidal, numerous forms of storage, or an
| unholy mix of all of them at different times -- whatever comes
| off the grid. At first, it will include NG sometimes, and
| nukes, until those are priced off of the market.
| scythe wrote:
| Can this reasonably be more efficient than the direct
| electrolysis process? There was a major breakthrough in 2013 with
| a ferrochromium anode:
|
| https://europepmc.org/article/med/23657254
|
| which led to an NSF grant:
|
| https://www.nsf.gov/awardsearch/showAward?AWD_ID=1534664
|
| which spawned a startup that is now seeking private investors:
|
| https://www.bostonmetal.com/transforming-metal-production/
| pfdietz wrote:
| It's not just a question of efficiency. How expensive is the
| equipment? And in particular, if it's using intermittently
| available power, how expensive is the part that must be ready
| to absorb that power? For hydrogen it's electrolysers (and
| perhaps compressors); for that scheme it would be the oxide
| electrolysis cells.
| jl6 wrote:
| I recently came across Boston Metal's proposed use of this
| inert anode material but I couldn't find much detail on whether
| the "breakthrough" claim was genuine. It still seems early
| days, though if true it would be a transformative enabler for
| the production of low-carbon steel.
| actionfromafar wrote:
| Maybe not but the hydrogen process is probably a game changer
| regardless, because there is less research and productisation
| needed. It is similar to existing processes.
|
| It's also perfectly positioned to take advantage of wind power.
| The gas storage tanks can make up for variations in electricity
| production. It's all set to be deployed at a large scale
| already.
|
| Watt for watt it might not (I have no idea) be as efficient as
| electrolysis, but as a total solution I see how it could be
| deployed at scale. Combined with the advances in electric
| mining equipment like what Volvo is offering, the industry is
| all set to go fully carbon neutral and electric. (No tech
| hurdles left.)
| arctan wrote:
| FWIW, iron reduced in hydrogen is known to have a very high
| magnetic permeability, surpassed only by one of the Metglas
| alloys.
| steve_john wrote:
| lvxferre wrote:
| What the link is "conveniently forgetting" to mention is that
| most industrial hydrogen production emits CO2 (steam reforming:
| CH4 + 2H2O - 2H2 + CO2). And there's a good reason for that:
| electrolysis consumes a lot of electricity. I won't do the maths
| here but, if the electricity was generated through fossil fuels,
| I wouldn't be surprised if the process actually _increased_ CO2
| emissions instead of reducing them.
|
| But let's say that the hydrogen is from fossil-free electricity.
| You could be plugging that fossil-free electricity elsewhere
| instead. The press and media link does not mention that.
|
| >Hydrogen-reduced carbon-free DRI is highly metallized
|
| That can mean two things:
|
| 1. They're able to retrieve more iron from the oxide. Good, but
| it isn't enough to replace the current processes; at most to add
| hydrogen as the "chef's kiss" to the iron produced through
| another method.
|
| 2. Less cementite aka iron carbide aka the stuff that actually
| makes steel "steel" instead of plain iron. That's great or awful
| depending on application.
|
| >has superior mechanical [...] properties
|
| Again, it depends on application. I expect their iron to be
| rather soft and malleable, but lacking tensile strength.
|
| >This new knowledge is a direct result of close value chain
| cooperation, determined innovative thinking and bold efforts in
| piloting new technology - _a recipe to copy for other industrial
| sectors,"_
|
| > _Hybrit Development AB has filed patent applications describing
| the included inventions to the European Patent Office._
|
| "Guys, we made something to copy for other industrial sectors,
| except that we're smearing patents on it so you can't copy the
| process~".
|
| There's another detail that the press and media link doesn't
| mention: hydrogen makes steel brittle.
|
| ______________________________________________________________
|
| Take this link with a grain of salt.
| danans wrote:
| > I won't do the maths here but, if the electricity was
| generated through fossil fuels, I wouldn't be surprised if the
| process actually increased CO2 emissions instead of reducing
| them. > But let's say that the hydrogen is from fossil-free
| electricity. You could be plugging that fossil-free electricity
| elsewhere instead.
|
| This assumes a zero-sum situation where we have a fixed amount
| of fossil free electricity, but that's unlikely because fossil
| free energy (solar specifically) is the cheapest type of
| electricity generation we can build today.
|
| Furthermore, the hydrogen can be electrolyzed at times when the
| supply of fossil free energy exceeds demand, thereby actually
| improving the economics of intermittent renewables by
| increasing their overall utilization, and hence incentivizing
| building more if it.
| cinntaile wrote:
| Sweden, where this facility is supposed to be built, hardly has
| any fossil fuel electricity production.
|
| Also you should compare the natural gas hydrogen process to the
| currently used coke process.
| hypertele-Xii wrote:
| Correct.
|
| https://en.wikipedia.org/wiki/File:Electricity_production_in.
| ..
| thehappypm wrote:
| Personally, I don't see industrial processes like these as a
| priority for reducing CO2 emissions. If we get to a point where
| all the heavy emitters like cars and power plants are carbon
| neutral, things like steel production will be a tiny
| contributor to climate change, and can probably be better
| managed through capture and sequestration if the world decides
| every molecule of CO2 is harmful.
| heisenbit wrote:
| Concrete production is responsible for 7% of global CO2
| emissions so there are a few key processes and material which
| really are worth a look.
| thehappypm wrote:
| I'd still put it below transit and electricity as far as
| priority.
| kristianp wrote:
| Depending on which source you look at, steel production
| accounts for 8% - 11% of global CO2 emissions. According to
| Gate's 2021 book, 'getting around' (planes, trucks, cargo
| ships) accounts for 16% of CO2 emissions. So steel production
| is definitely a significant contributor.
| metal_am wrote:
| Reading between the lines, it seems like this is intended for
| high quality steels. Think aerospace, not buildings. Actually
| in those applications, you don't really want carbon. The
| strongest steels have virtually no carbon. Hydrogen
| embrittlement and cracking have nothing to do with this.
| JoachimS wrote:
| The press release from Vattenfall relates to a research program
| called Hybrit. Vattenfall (an energy company), together with the
| iron ore company LKAB, the steel manufacturer SSAB, and Lulea
| University of Lulea (LTU) are partners in the project.
|
| For more details about Hybrir see:
| https://www.hybritdevelopment.se/en/a-fossil-free-future/
| https://www.hybritdevelopment.se/en/research-project-1/
|
| The research group list of papers (not all of them related to
| Hybrit):
| https://www.ltu.se/research/subjects/Processmetallurgi/Publi...<
|
| A working paper related to Hybrit: https://cdn.sei.org/wp-
| content/uploads/2020/07/bigger-is-som...
| seunosewa wrote:
| 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 wrote:
| Agreed. This claim is so vague, and it sounds like this is just
| one part of the smelting process.
| ortusdux wrote:
| Yes, there is little value in a press release about research
| that does not include a link or refence to said research.
| ghastmaster wrote:
| 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 wrote:
| 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.
| metal_am wrote:
| Steel is an incredible massive category. For high quality
| steels (duplex, maraging, PH stainless), you actually don't
| want much carbon. Since they talk about "aging properties"
| in the article, I'd imagine they're targeting the nicer
| stuff. This doesn't seem like a process intended for cheap
| steel.
| moron4hire wrote:
| 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 wrote:
| 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.
| ghastmaster wrote:
| 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.
| lazide wrote:
| 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!
| dodobirdlord wrote:
| 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 wrote:
| Do you think that removes the concern? I don't see how it
| would.
| photochemsyn wrote:
| 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 wrote:
| Thanks for the background! So likely due to the complete
| remelt and re-alloying expected, it should work out?
| yborg wrote:
| This process produces direct reduced iron, not steel.
| lazide wrote:
| 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.
| xyzzyz wrote:
| You mean, _cast_ iron is pretty brittle. Pure iron is not
| brittle.
| lazide wrote:
| 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.
| metal_am wrote:
| It produces an intermediate product. You can't use it
| without further processing. In any case, the hydrogen
| won't be a problem.
| jbay808 wrote:
| 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.vac-met.com/hydrogen-annealing/
| halfdeadcat wrote:
| This is just a PR release. I hope their claims prove out. But
| there is no evidence supplied and breathless PR releases seldom
| go anywhere.
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