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Coal
Posted: Wed Feb 10, 2021 9:17 am
by El Pollo Diablo
We can stop using coal for electricity generation, which is nice. But coal is a pretty important raw material for other things, such as production of steel & cement, rare metal extraction, and so on. Even in a zero-carbon energy future, we will still likely need coal for some industrial uses, I would think.
Or would we? Is there any alternative at all to coal in these industries? Hard to see, for instance, how one could have a zero-carbon steel industry. And if there is no alternative, are cases like
this likely to keep cropping up? Should we just be leaving coal mining to the Aussies?
Re: Coal
Posted: Wed Feb 10, 2021 10:21 am
by Grumble
Coal will not be necessary for steel production in the future:
https://www.h2-international.com/2020/1 ... ing/?amp=1
I suspect other use cases for coal may also be successfully challenged, but I admit that’s wishful thinking.
Re: Coal
Posted: Wed Feb 10, 2021 11:16 am
by bjn
El Pollo Diablo wrote: Wed Feb 10, 2021 9:17 am
We can stop using coal for electricity generation, which is nice. But coal is a pretty important raw material for other things, such as production of steel & cement, rare metal extraction, and so on. Even in a zero-carbon energy future, we will still likely need coal for some industrial uses, I would think.
Or would we? Is there any alternative at all to coal in these industries? Hard to see, for instance, how one could have a zero-carbon steel industry. And if there is no alternative, are cases like
this likely to keep cropping up? Should we just be leaving coal mining to the Aussies?
Because I'm meant to be working, I've only had a very quick google (but I did test the sums in the software I'm working on). The
IEA has figures on what the world used coal for. Running some rough stats over it I get world wide figures of (by summing OECD and Non-OECD in 2018),
- Electricity and heat 67.413%
- Iron and steel 15.121%
- Other 14.937%
- Residential, commercial and public services 2.529%
So the majority of it can be hit on the head in the short term, iron and steel production is a bit harder, "Other" is probably a bunch of chemical processes, but no idea what they would be.
We should just ship in met-coal until we can scale up reducing iron ore into iron with H2 or via direct electrical reduction.
Re: Coal
Posted: Wed Feb 10, 2021 11:23 am
by bjn
The 2019 figures for the UK are
here. So making iron and steel consumes more coal than power generation in the UK, the gap will only get bigger over time. The rest are rounding errors. Figures are in 1000s of tonnes.
Re: Coal
Posted: Thu Feb 11, 2021 4:45 pm
by El Pollo Diablo
I'm not seeing in that link how, with the new process, the carbon gets into the mix to turn it from iron into steel, or where that carbon comes from. Is there any information on that?
Re: Coal
Posted: Thu Feb 11, 2021 4:58 pm
by Gfamily
El Pollo Diablo wrote: Thu Feb 11, 2021 4:45 pm
I'm not seeing in that link how, with the new process, the carbon gets into the mix to turn it from iron into steel, or where that carbon comes from. Is there any information on that?
I think other sources of carbon would be used (biochar, or old tyres for example)
https://leard.frontlineaction.org/cokin ... ernatives/
Re: Coal
Posted: Thu Feb 11, 2021 5:57 pm
by bjn
El Pollo Diablo wrote: Thu Feb 11, 2021 4:45 pm
I'm not seeing in that link how, with the new process, the carbon gets into the mix to turn it from iron into steel, or where that carbon comes from. Is there any information on that?
The maximum amount of carbon that iron can absorb is just under 4%, which is stupidly brittle. Typical hard steels are somewhere around 1%. "Mild steels" as used in car doors and so on, don't have enough carbon in them to be hardened are up to about 0.3% carbon. Compared to the carbon needed to reduce iron ore to iron, it's trivial. To make 1 tonne of pig iron you need 1 tonne of carbon + 0.5 tonnes of carbon bearing limestone. The 100:1 iron to carbon chemical content ratio needed for most steels is meh in comparison. Bio char or even met-coal if needs be.
Re: Coal
Posted: Thu Feb 11, 2021 6:13 pm
by Grumble
El Pollo Diablo wrote: Thu Feb 11, 2021 4:45 pm
I'm not seeing in that link how, with the new process, the carbon gets into the mix to turn it from iron into steel, or where that carbon comes from. Is there any information on that?
Good question, and I don’t know, but it’s important to note that normally you spend a lot of effort getting all the excess carbon back out of the iron before you can call it steel. Modern steel has very little carbon in it. Even 1% is quite high.
Re: Coal
Posted: Thu Feb 11, 2021 7:17 pm
by bjn
Grumble wrote: Thu Feb 11, 2021 6:13 pm
El Pollo Diablo wrote: Thu Feb 11, 2021 4:45 pm
I'm not seeing in that link how, with the new process, the carbon gets into the mix to turn it from iron into steel, or where that carbon comes from. Is there any information on that?
Good question, and I don’t know, but it’s important to note that normally you spend a lot of effort getting all the excess carbon back out of the iron before you can call it steel. Modern steel has very little carbon in it. Even 1% is quite high.
AIUI
liquid iron quite happily alloys with carbon, saturating at around 7% carbon (I told a lie above). When making iron in a blast furnace, it's surrounded by the carbon being used to reduce the iron ore to iron, which carries off the oxygen that was bound to the iron as CO2. During that process, the molten iron will alloy with some of that carbon and saturate, forming very brittle cast iron. So after making the cast iron they pump oxygen through the molten cast iron to burn off some carbon to get it to a usable concentration. Which is very spectacular, having seen it up close at the Port Kembla iron works on a school excursion in 1978. Sparks and flames everywhere.
For the H2 reduction of iron ore to iron, I imagine once it's molten, they just chuck in the right amount of carbon to get the grade of steel they want without the need to burn off excess carbon.
Re: Coal
Posted: Thu Feb 11, 2021 7:41 pm
by Grumble
bjn wrote: Thu Feb 11, 2021 7:17 pm
Grumble wrote: Thu Feb 11, 2021 6:13 pm
Good question, and I don’t know, but it’s important to note that normally you spend a lot of effort getting all the excess carbon back out of the iron before you can call it steel. Modern steel has very little carbon in it. Even 1% is quite high.
AIUI
liquid iron quite happily alloys with carbon, saturating at around 7% carbon (I told a lie above). When making iron in a blast furnace, it's surrounded by the carbon being used to reduce the iron ore to iron, which carries off the oxygen that was bound to the iron as CO2. During that process, the molten iron will alloy with some of that carbon and saturate, forming very brittle cast iron. So after making the cast iron they pump oxygen through the molten cast iron to burn off some carbon to get it to a usable concentration. Which is very spectacular, having seen it up close at the Port Kembla iron works on a school excursion in 1978. Sparks and flames everywhere.
For the H2 reduction of iron ore to iron, I imagine once it's molten, they just chuck in the right amount of carbon to get the grade of steel they want without the need to burn off excess carbon.
Quite possibly, but also it might be more complicated than that. There is mention of non-fossil fuels at the top of the diagram.
When I was taught about the blast furnace in A-level chemistry there were about 5-6 reactions we went through. I was then taught it at undergraduate level and there were more like 25 reactions! I was shocked at how oversimplified the A-level version was. So I’m definitely not going to speculate too much about the hydrogen version in any detail without reading the actual paper, which I can’t access.
(Don’t know what’s gone wrong with quotes)
Re: Coal
Posted: Thu Feb 11, 2021 8:32 pm
by plodder
Recycling scrap steel is also a thing. For some reason I can’t quite grasp there’s also this stuff called Greensteel that appears to be slightly different:
https://www.themanufacturer.com/article ... all-about/
Re: Coal
Posted: Fri Feb 12, 2021 10:13 am
by bjn
"Green Steel" just seems to be corporate rebranding of recycling scrap in an arc-furnace.
Re: Coal
Posted: Fri Feb 12, 2021 1:51 pm
by plodder
That's what I initially thought, but perhaps that's a more efficient way of doing it?
Re: Coal
Posted: Fri Feb 12, 2021 2:08 pm
by Herainestold
plodder wrote: Fri Feb 12, 2021 1:51 pm
That's what I initially thought, but perhaps that's a more efficient way of doing it?
We should have a moratorium on coal fired steel making until scrap is used up. By that time it is likely that new methods of producing steel without coal will be common.
Re: Coal
Posted: Fri Feb 12, 2021 2:19 pm
by Grumble
Herainestold wrote: Fri Feb 12, 2021 2:08 pm
plodder wrote: Fri Feb 12, 2021 1:51 pm
That's what I initially thought, but perhaps that's a more efficient way of doing it?
We should have a moratorium on coal fired steel making until scrap is used up. By that time it is likely that new methods of producing steel without coal will be common.
No we shouldn’t. You seem to have the illusion that there is something called steel which is more or less one thing. In reality steel is a class of alloys with a massive range of properties. Where we can recycle we do, and that’s great, but unless you’re simply remaking the same alloy in a different form you can’t easily use scrap in the new steel.
Re: Coal
Posted: Fri Feb 12, 2021 2:45 pm
by Herainestold
Grumble wrote: Fri Feb 12, 2021 2:19 pm
Herainestold wrote: Fri Feb 12, 2021 2:08 pm
plodder wrote: Fri Feb 12, 2021 1:51 pm
That's what I initially thought, but perhaps that's a more efficient way of doing it?
We should have a moratorium on coal fired steel making until scrap is used up. By that time it is likely that new methods of producing steel without coal will be common.
No we shouldn’t. You seem to have the illusion that there is something called steel which is more or less one thing. In reality steel is a class of alloys with a massive range of properties. Where we can recycle we do, and that’s great, but unless you’re simply remaking the same alloy in a different form you can’t easily use scrap in the new steel.
Isn't steel just iron with various (small) amounts of carbon?
We can adjust the carbon content of scrap steel withjout resorting to coal.
Re: Coal
Posted: Fri Feb 12, 2021 3:46 pm
by JQH
Re: Coal
Posted: Fri Feb 12, 2021 3:58 pm
by Grumble
Herainestold wrote: Fri Feb 12, 2021 2:45 pm
Grumble wrote: Fri Feb 12, 2021 2:19 pm
Herainestold wrote: Fri Feb 12, 2021 2:08 pm
We should have a moratorium on coal fired steel making until scrap is used up. By that time it is likely that new methods of producing steel without coal will be common.
No we shouldn’t. You seem to have the illusion that there is something called steel which is more or less one thing. In reality steel is a class of alloys with a massive range of properties. Where we can recycle we do, and that’s great, but unless you’re simply remaking the same alloy in a different form you can’t easily use scrap in the new steel.
Isn't steel just iron with various (small) amounts of carbon?
We can adjust the carbon content of scrap steel withjout resorting to coal.
Mild steel can be more or less described like that, but there are literally hundreds of types and grades of steels. The steel you make rails out of is not the same as the steel used to make paper cutting guillotines is not the same as that used for the crash protection cell in a car is not the same as that used for oil pipelines. And so on.
Re: Coal
Posted: Fri Feb 12, 2021 4:12 pm
by bjn
Grumble wrote: Fri Feb 12, 2021 3:58 pm
Herainestold wrote: Fri Feb 12, 2021 2:45 pm
Grumble wrote: Fri Feb 12, 2021 2:19 pm
No we shouldn’t. You seem to have the illusion that there is something called steel which is more or less one thing. In reality steel is a class of alloys with a massive range of properties. Where we can recycle we do, and that’s great, but unless you’re simply remaking the same alloy in a different form you can’t easily use scrap in the new steel.
Isn't steel just iron with various (small) amounts of carbon?
We can adjust the carbon content of scrap steel withjout resorting to coal.
Mild steel can be more or less described like that, but there are literally hundreds of types and grades of steels. The steel you make rails out of is not the same as the steel used to make paper cutting guillotines is not the same as that used for the crash protection cell in a car is not the same as that used for oil pipelines. And so on.
100% recycled scrap is great for low quality steels like re-bar, for which there is quite a demand and the quality control needed much lower. Some recycled steel goes into a virgin steel melts, again depending on what the use of the final steel is. British Steel says up to ~20% of their melts consists of recycled iron and steel. I gather that for more specialist steels, like tool steels as opposed to mild steels, you'll want more control over the contents, and have much less scrap in it.
Re: Coal
Posted: Fri Feb 12, 2021 6:17 pm
by Herainestold
Steel is more complicated than I thought. Can we not substitute other metals that don't require coal in their processing?
Re: Coal
Posted: Fri Feb 12, 2021 6:19 pm
by shpalman
Quite a lot of ores are oxides so need to be reduced somehow. Silicon* is also reduced with carbon.
* - not a metal and not intended as a replacement for steel, but an important material anyway, especially for photovoltaics.
Re: Coal
Posted: Fri Feb 12, 2021 7:02 pm
by Grumble
Herainestold wrote: Fri Feb 12, 2021 6:17 pm
Steel is more complicated than I thought. Can we not substitute other metals that don't require coal in their processing?
Aluminium doesn’t require coal, if I remember correctly, although it does require mega amounts of electricity - and uses graphite electrodes. It’s not suitable for everything though - aluminium knives would be a bit pants. The steel industry worked hard to head off aluminium as a material of choice for cars by improving their product. Aluminium’s problem is that it doesn’t have as wide a range of properties or potential alloying elements as steel. It’s great for some things though, and the limited numbers of alloys means that it’s much easier to recycle too.
Re: Coal
Posted: Fri Feb 12, 2021 7:05 pm
by shpalman
I vaguely remember there being something on
No Such Thing As A Fish (would have been an episode from about a year ago) about spoons made of different metals contributing to the taste of the food.
https://www.theguardian.com/technology/ ... -aluminium
Re: Coal
Posted: Fri Feb 12, 2021 7:51 pm
by Herainestold
So we need to think of a variety of non fossil fuel derived materials that we can substitute for metals.
Re: Coal
Posted: Fri Feb 12, 2021 8:07 pm
by nekomatic
(didn’t read the post properly, please ignore)