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You will notice that this article is from an icelandic newspaper. The electricity in Iceland is almost exclusively 'sustainable' energy (hydro and geothermal)

You will notice that this article is from an icelandic newspaper. The electricity in Iceland is almost exclusively 'sustainable' energy (hydro and geothermal) and the Icelandic power system is one of the least carbon intensive in the world. At present it is #2 (https://www.electricitymap.org https://www.electricitymap.org) in the world behind Norway at 28 gCO2e/kWh. Smelting aluminium in Iceland instead of say, the USA (~ 400 gCO2e/kWh), is already a great way to reduce the carbon intensity of aluminium products. This article is discussing the CO2 emissions related to some integral processes within the smelter, and it is a big deal. No, it wont save the world, but also no, it is not bullshit. These are the sort of small incermental improvements that we require in ALL industries in order to dent global carbon emissions.

chrisco255 6y ago
Correct me if I'm wrong, but geothermal is only useful in volcanically active regions, right?
- deleted 6y ago
  [deleted]
- TheRealPomax 6y ago
  wrong, but it's worth finding out why that's an incorrect assumption on your own. Don't trust comments on the internet.
  - cwal37 6y ago
    That's a bad response when any comment could easily link to a relevant white paper. GP, MIT+INL had a nice report in 2006[1] covering a lot about that and the resource potential. The GeoVision[2] report and data from DOE is also a good and more recent project. [1] https://energy.mit.edu/wp-content/uploads/2006/11/MITEI-The-Future-of-Geothermal-Energy.pdf https://energy.mit.edu/wp-content/uploads/2006/11/MITEI-The-... [2] https://www.energy.gov/eere/geothermal/geovision https://www.energy.gov/eere/geothermal/geovision
- philwelch 6y ago
  There are other forms of carbon-neutral electricity—hydroelectric, solar, wind, tidal, nuclear; you can even capture carbon emissions from natural gas plants if there was a hard requirement to. Since we have to solve that problem anyway it’s a separate problem. Also, aluminum and bauxite can be shipped to/from where it makes the most sense to process it.
SV_BubbleTime 6y ago
This is all true, Iceland is the worlds aluminum smelting hub. And the CO2 here is for the process. However... what people fail to realize over and over is that the route for most of the worlds aluminum is from China to Iceland to China again. In tankers burning fuel like there is no tomorrow. The biggest gain would be in how to refine the aluminum without shipping across the world twice.
- ClumsyPilot 6y ago
  There are only two options i can think of, bith of them are daynting: massive transmission line across the oceans, or nuclear powered cargo ships.
  - VBprogrammer 6y ago
    Probably not a very popular option but Chinese nuclear power stations would also do the job.
    - ClumsyPilot 6y ago
      Thats actually a reasonable point, and china is on nuclear power builsing -spree.
- sacred_numbers 6y ago
  Tankers are extremely energy efficient. A round trip journey from Reykjavik to Shanghai would consume about 90 kg of fuel per ton transported. Since 2 tons of alumina is converted to about 1 ton of aluminum, the round trip cost for aluminum is 135 kg of fuel, which generates about 420 kg of CO2. If the aluminum were produced using electricity from coal it would generate about 14,000 kg of CO2. Of course, China wouldn't have to use coal if they chose not to, and cargo ship bunker fuel produces some very nasty pollution besides CO2, but in the world we live in it is far better for carbon emissions and probably for the environment in general, to use Iceland as the aluminum smelting hub.
- DavidPeiffer 6y ago
  >The biggest gain would be in how to refine the aluminum without shipping across the world twice. Yes, that'd be nice. People are working on solutions, but the only economically viable way to refine the material is to use a highly intensive electrolysis process. My quick google search is showing 17,000 kWh/ton of aluminum [1]. It's currently economically viable to refine in Iceland, but China is the #1 producer of raw aluminum [1] [2]. Iceland only has 3 smelters, and the combined capacity is less than the 9 largest smelters in the world, 2 of which are in China. Citation [1] also has mentions of how much better the process of smelting has become. >So, within 60 years, by improving the technology, fluoride emissions have been reduced more than 15 times (Table 2) and annual amounts of fluorinated residues have decreased from 1500 ton after WWII to 60 ton today. From a purely energy standpoint, raw aluminum production has become vastly more efficient [4], with kWh/kg dropping from ~27 in 1940 to ~17 in 2000. The theoretical minimum is 5.99 kWh/kg [5] [1] https://www.sciencedirect.com/topics/engineering/aluminum-production https://www.sciencedirect.com/topics/engineering/aluminum-pr... [2] https://en.wikipedia.org/wiki/List_of_countries_by_primary_aluminium_production https://en.wikipedia.org/wiki/List_of_countries_by_primary_a... [3] https://en.wikipedia.org/wiki/List_of_aluminium_smelters https://en.wikipedia.org/wiki/List_of_aluminium_smelters [4] https://www1.eere.energy.gov/manufacturing/resources/aluminum/pdfs/al_theoretical.pdf https://www1.eere.energy.gov/manufacturing/resources/aluminu... (page 40 of the PDF, numbered 25 on the page) [5] https://www.aceee.org/files/proceedings/2003/data/papers/SS03_Panel1_Paper02.pdf https://www.aceee.org/files/proceedings/2003/data/papers/SS0...
twic 6y ago
> This article is discussing the CO2 emissions related to some integral processes within the smelter In slightly more (but still high school level!) detail, the raw material for aluminum refining is Al2O3. That is dissolved in a bath of molten salt, where the ions dissociate. The 2 Al3+ is electroplated out by adding electrons at the cathode. The 3 O2- comes out by withdrawing electrons at the anode; usually, the anode is carbon [1], and the reaction is: 2 O2- + C -> CO2 + 4 e- The innovation here is to use an inert anode, so the reaction is: 2 O2- -> O2 + 4 e- The fundamental chemistry of this is pretty obvious, so presumably there are good practical reasons why everyone was using carbon anode before. EDIT It seems [2] that the process is using the carbon to do some of the energetic work of reducing the oxygen (carbon loves to reduce oxygen even when it doesn't have two extra electrons, a fact exploited in an earlier industrial process [3]), therefore requiring less electrical energy. This is sort of a way to stealthily burn some carbon to produce energy. [1] https://en.wikipedia.org/wiki/Prebaked_Consumable_Carbon_Anodes https://en.wikipedia.org/wiki/Prebaked_Consumable_Carbon_Ano... [2] https://chemistry.stackexchange.com/questions/6774/why-do-they-use-graphite-anodes-in-the-hall-heroult-process https://chemistry.stackexchange.com/questions/6774/why-do-th... [3] https://en.wikipedia.org/wiki/Fire https://en.wikipedia.org/wiki/Fire
- catalogia 6y ago
  Do you know how they might be dealing with the oxygen? I assume it comes out very hot and ready to oxidize stuff. I suppose there are stainless alloys that can cope with it?
- twic 6y ago
  Re-reading this, I realise I've got the bit about carbon reducing oxide ions wrong. The oxide ions are being oxidised here, not reduced. But ending up at CO2 rather than O2 means they don't need to be oxidised as hard - oxygen in CO2 is a bit more reduced than in O2. I think. I probably wouldn't pass A level chemistry if I sat the exams today. When neutral carbon and oxygen react, the carbon reduces the oxygen because it gives it a fractional share of its electrons when they form a bond. But when oxygen is charged, it already has lots of electrons. In this reaction the carbon is helping oxidise the oxide ions.
diroussel 6y ago
Also worth noting that the ore is shipped from Australia and other places to the nordics to get the cheaper smelting. But these large ships are not subject to regulation of emmistions or fuel in international waters. And so they burn bitumen like oil fractions that are very cheap.

chrisco255 6y ago

Correct me if I'm wrong, but geothermal is only useful in volcanically active regions, right?

deleted 6y ago
[deleted]
TheRealPomax 6y ago
wrong, but it's worth finding out why that's an incorrect assumption on your own. Don't trust comments on the internet.
- cwal37 6y ago
  That's a bad response when any comment could easily link to a relevant white paper. GP, MIT+INL had a nice report in 2006[1] covering a lot about that and the resource potential. The GeoVision[2] report and data from DOE is also a good and more recent project. [1] https://energy.mit.edu/wp-content/uploads/2006/11/MITEI-The-Future-of-Geothermal-Energy.pdf https://energy.mit.edu/wp-content/uploads/2006/11/MITEI-The-... [2] https://www.energy.gov/eere/geothermal/geovision https://www.energy.gov/eere/geothermal/geovision
philwelch 6y ago
There are other forms of carbon-neutral electricity—hydroelectric, solar, wind, tidal, nuclear; you can even capture carbon emissions from natural gas plants if there was a hard requirement to. Since we have to solve that problem anyway it’s a separate problem. Also, aluminum and bauxite can be shipped to/from where it makes the most sense to process it.

SV_BubbleTime 6y ago

This is all true, Iceland is the worlds aluminum smelting hub. And the CO2 here is for the process. However... what people fail to realize over and over is that the route for most of the worlds aluminum is from China to Iceland to China again. In tankers burning fuel like there is no tomorrow. The biggest gain would be in how to refine the aluminum without shipping across the world twice.

ClumsyPilot 6y ago
There are only two options i can think of, bith of them are daynting: massive transmission line across the oceans, or nuclear powered cargo ships.
- VBprogrammer 6y ago
  Probably not a very popular option but Chinese nuclear power stations would also do the job.
  - ClumsyPilot 6y ago
    Thats actually a reasonable point, and china is on nuclear power builsing -spree.
sacred_numbers 6y ago
Tankers are extremely energy efficient. A round trip journey from Reykjavik to Shanghai would consume about 90 kg of fuel per ton transported. Since 2 tons of alumina is converted to about 1 ton of aluminum, the round trip cost for aluminum is 135 kg of fuel, which generates about 420 kg of CO2. If the aluminum were produced using electricity from coal it would generate about 14,000 kg of CO2. Of course, China wouldn't have to use coal if they chose not to, and cargo ship bunker fuel produces some very nasty pollution besides CO2, but in the world we live in it is far better for carbon emissions and probably for the environment in general, to use Iceland as the aluminum smelting hub.
DavidPeiffer 6y ago
>The biggest gain would be in how to refine the aluminum without shipping across the world twice. Yes, that'd be nice. People are working on solutions, but the only economically viable way to refine the material is to use a highly intensive electrolysis process. My quick google search is showing 17,000 kWh/ton of aluminum [1]. It's currently economically viable to refine in Iceland, but China is the #1 producer of raw aluminum [1] [2]. Iceland only has 3 smelters, and the combined capacity is less than the 9 largest smelters in the world, 2 of which are in China. Citation [1] also has mentions of how much better the process of smelting has become. >So, within 60 years, by improving the technology, fluoride emissions have been reduced more than 15 times (Table 2) and annual amounts of fluorinated residues have decreased from 1500 ton after WWII to 60 ton today. From a purely energy standpoint, raw aluminum production has become vastly more efficient [4], with kWh/kg dropping from ~27 in 1940 to ~17 in 2000. The theoretical minimum is 5.99 kWh/kg [5] [1] https://www.sciencedirect.com/topics/engineering/aluminum-production https://www.sciencedirect.com/topics/engineering/aluminum-pr... [2] https://en.wikipedia.org/wiki/List_of_countries_by_primary_aluminium_production https://en.wikipedia.org/wiki/List_of_countries_by_primary_a... [3] https://en.wikipedia.org/wiki/List_of_aluminium_smelters https://en.wikipedia.org/wiki/List_of_aluminium_smelters [4] https://www1.eere.energy.gov/manufacturing/resources/aluminum/pdfs/al_theoretical.pdf https://www1.eere.energy.gov/manufacturing/resources/aluminu... (page 40 of the PDF, numbered 25 on the page) [5] https://www.aceee.org/files/proceedings/2003/data/papers/SS03_Panel1_Paper02.pdf https://www.aceee.org/files/proceedings/2003/data/papers/SS0...

twic 6y ago

> This article is discussing the CO2 emissions related to some integral processes within the smelter In slightly more (but still high school level!) detail, the raw material for aluminum refining is Al2O3. That is dissolved in a bath of molten salt, where the ions dissociate. The 2 Al3+ is electroplated out by adding electrons at the cathode. The 3 O2- comes out by withdrawing electrons at the anode; usually, the anode is carbon [1], and the reaction is: 2 O2- + C -> CO2 + 4 e- The innovation here is to use an inert anode, so the reaction is: 2 O2- -> O2 + 4 e- The fundamental chemistry of this is pretty obvious, so presumably there are good practical reasons why everyone was using carbon anode before. EDIT It seems [2] that the process is using the carbon to do some of the energetic work of reducing the oxygen (carbon loves to reduce oxygen even when it doesn't have two extra electrons, a fact exploited in an earlier industrial process [3]), therefore requiring less electrical energy. This is sort of a way to stealthily burn some carbon to produce energy. [1] https://en.wikipedia.org/wiki/Prebaked_Consumable_Carbon_Anodes https://en.wikipedia.org/wiki/Prebaked_Consumable_Carbon_Ano... [2] https://chemistry.stackexchange.com/questions/6774/why-do-they-use-graphite-anodes-in-the-hall-heroult-process https://chemistry.stackexchange.com/questions/6774/why-do-th... [3] https://en.wikipedia.org/wiki/Fire https://en.wikipedia.org/wiki/Fire

catalogia 6y ago
Do you know how they might be dealing with the oxygen? I assume it comes out very hot and ready to oxidize stuff. I suppose there are stainless alloys that can cope with it?
twic 6y ago
Re-reading this, I realise I've got the bit about carbon reducing oxide ions wrong. The oxide ions are being oxidised here, not reduced. But ending up at CO2 rather than O2 means they don't need to be oxidised as hard - oxygen in CO2 is a bit more reduced than in O2. I think. I probably wouldn't pass A level chemistry if I sat the exams today. When neutral carbon and oxygen react, the carbon reduces the oxygen because it gives it a fractional share of its electrons when they form a bond. But when oxygen is charged, it already has lots of electrons. In this reaction the carbon is helping oxidise the oxide ions.

diroussel 6y ago

Also worth noting that the ore is shipped from Australia and other places to the nordics to get the cheaper smelting. But these large ships are not subject to regulation of emmistions or fuel in international waters. And so they burn bitumen like oil fractions that are very cheap.