[HN Gopher] Green steel without green hydrogen - can it work?
___________________________________________________________________
Green steel without green hydrogen - can it work?
Author : orangebanana1
Score : 55 points
Date : 2022-02-15 14:44 UTC (8 hours ago)
(HTM) web link (www.canarymedia.com)
(TXT) w3m dump (www.canarymedia.com)
| greesil wrote:
| Ah yes this is Professor Sadoway's work.
| tofof wrote:
| 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.
| baybal2 wrote:
| 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 wrote:
| 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/
|
| So, that's why MOE wasn't around before 2013.
| baybal2 wrote:
| MOE wasn't, but colocating blast furnaces with steel
| converters is a very old idea.
| kragen wrote:
| Aluminum and calcium have substantially stronger affinities for
| oxygen than iron does, so they'll tend to stay in oxide form
| even when you're successfully reducing the oxygen.
|
| This is mentioned in the article:
|
| > _All of these oxides are more stable than iron oxide, so the
| iron oxide is the first to separate when exposed to electric
| charge, breaking down into pure oxygen and iron. The iron,
| still liquified, sinks to the bottom where it can be tapped out
| and turned to steel._
|
| There are other elements in ore that will tend to reduce before
| the iron, like nickel, cobalt, lead, and copper, but they're a
| lot less abundant than iron and may not be harmful to the iron
| produced.
| rocqua wrote:
| 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.
| londons_explore wrote:
| The higher temperature doesn't consume more energy
| _theoretically_ as long as there is some way to use the heat of
| the produced iron and oxygen to help heat up the incoming iron
| oxide.
|
| Not many heat exchangers can survive 1100 degrees C, but even a
| rudimentary 'fan blows air over the produced iron and then
| directs that through a ceramic pipe and through the incoming
| iron ore' heat recovery system should extract a large
| percentage of the thermal energy.
| philipkglass wrote:
| 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/20...
| kragen wrote:
| 1600deg 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 1600deg 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 wrote:
| I think carbon electrodes would dissolve in iron. If I recall
| correctly, it's some sort of oxide-coated metal electrodes.
| rocqua wrote:
| 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 wrote:
| 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 wrote:
| 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.
| pfdietz wrote:
| Yes, in underground caverns, like natural gas is stored. This
| is a demonstrated technology.
| baybal2 wrote:
| > 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 wrote:
| 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.
| ZeroGravitas wrote:
| 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 wrote:
| 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.
| hannob wrote:
| 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/ I recently covered this in an
| article (though German, in case you understand that:
| https://www.golem.de/news/eisenoxid-elektrolyse-stahlherstel...
| ).
|
| Main difference between this and Boston Metal: They use a
| relatively cold process (~100degC) while Boston Metal uses a hot
| process.
|
| I guess it's good to try to make this work in different ways.
| aaronbrethorst wrote:
| 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-decarb...
| ZeroGravitas wrote:
| That was an excellent listen, thank you for recommending it.
| ZeroGravitas wrote:
| 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.
| Animats wrote:
| 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.
| pfdietz wrote:
| 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.
| jillesvangurp wrote:
| So, all you need is a bunch of batteries or other storage plus
| some links to back up power supply from the grid (wind, hydro,
| geothermal, etc.).
|
| Hydrogen is basically just a really inefficient battery. Nice
| if you really need it for e.g. energy density reasons but
| basically sub-optimal for other things.
|
| The challenge with hydrogen hydrogen is energy losses in
| producing it are about 3-4x (so use 4 kwh of electricity to
| produce 1kwh of hydrogen). And then you lose more actually
| burning it. And storing and transporting it add to those
| losses. Using the electricity directly for heating the
| iron/steel is much more efficient and potentially a lot more
| cost effective since you effectively use at least 3-4x less
| MWH. That's a lot of cost savings. And those can finance a lot
| of batteries and other solutions.
| ncmncm wrote:
| Hydrogen has many other uses than for energy storage. And,
| when top-line energy production gets cheap enough, round-trip
| losses come to matter less than other things, such as raw
| usefulness.
|
| Hydrogen is directly useful in electrical synthethis of
| methane and ammonia, besides myriad current industrial uses,
| and, as LH2, is disruptive as an aviation fuel: LH2 aircraft
| will be impossible to compete with, wherever they are
| available.
| sbierwagen wrote:
| I've seen a couple articles which push hydrogen but with
| economics that don't make sense for "green" hydrogen.
| (Produced by electrolytic cracking of water with solar power)
|
| Instead these are advertisements for "blue" hydrogen--
| cracking natural gas and then injecting the CO2 back into the
| ground. It's a campaign by fossil fuel companies to preserve
| some of the value of their capital base, rather than just
| being shut down entirely. Blue hydrogen will be a lot
| cheaper, at the cost of fossil emissions from methane and CO2
| that escape from the equipment or leak from the wellhead.
| ZeroGravitas wrote:
| There's no economics in which blue hydrogen is cheaper than
| green hydrogen.
|
| So it's basically just good old fashioned lies.
| rocqua wrote:
| 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 wrote:
| 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).
| scythe wrote:
| I think the bigger problem right now is that the pilot scale
| reactor didn't work. Cf:
|
| https://www.nsf.gov/awardsearch/showAward?AWD_ID=1534664
|
| >Bench scale experiments made use of an externally heated
| reactor while pilot scale experiments conducted under this
| grant used a reactor that was self-heating.
|
| >At the bench scale, oxygen was produced with minimal corrosion
| of the anode material. At the pilot scale experiments in the
| self-heated reactor were not able to demonstrate oxygen
| production at the anode, or the production of iron as measured
| by tracer dilution. Further work is necessary to elucidate the
| difference between bench and pilot scale results.
| DennisP wrote:
| So maybe the intermittent sources of clean electric power
| aren't the best way to go for absolutely everything.
| pfdietz wrote:
| That depends on how cheap they are. Intermittency is a
| negative, but it's not an infinitely costly negative. Here,
| the question is how expensive the electrolysers would be --
| and they are quickly falling in price now, due to China.
|
| https://www.rechargenews.com/energy-transition/will-us-
| and-e...
| djmips wrote:
| Anyone know if this process could also help with copper
| contaminated iron scrap?
| gostsamo wrote:
| 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.
| boringg wrote:
| 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.
| barney54 wrote:
| 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.
| pornel wrote:
| 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 wrote:
| 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 wrote:
| 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)
| ZeroGravitas wrote:
| 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.
| boplicity wrote:
| 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.
| baybal2 wrote:
| > For example, we are seeing large electricity prices increases
| in Europe.
|
| Which is very good. New capacity will most likely be non-gas.
| afarrell wrote:
| Iceland has solved the cheap electricity problem and has easy
| access to iron ore from the port of Narvik.
| jillesvangurp wrote:
| 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.
| user-the-name wrote:
| Anything that relies on cheap electricity is not going to
| actually be very green.
| cinntaile wrote:
| Wind energy counts as green and will be used for this
| purpose.
| Bronze_Colossus wrote:
| 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 wrote:
| 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.
| dbodin11 wrote:
| TLDR - Article Highlights
| https://www.kontxt.io/document/d/EhrawY-veGAyWlYU8-98OI5FKC3...
| londons_explore wrote:
| 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 wrote:
___________________________________________________________________
(page generated 2022-02-15 23:02 UTC)