4 ms·

> at ~3g/kg the uranium only has about 10x as much energy as you'd get by burning the polymer or 5x in the current nuclear fleet (wonder how much it takes to ma

> at ~3g/kg the uranium only has about 10x as much energy as you'd get by burning the polymer or 5x in the current nuclear fleet (wonder how much it takes to make?). There goes the much vaunted EROI unless you get quite a few reuses (hint: you only get a few). Except the polymer is re-usable. > The longer you leave it, the more Uranium gets displaced by Vanadium. At 2 months you get 5x as much. Until it's saturated, then you can leave it out all you want and it won't collect any more. And I had thought you were referring to lithium seawater extraction - you just tossed out vanadium without actually explaining how you'd use it and I assumed you mistyped lithium. Unfortunately vanadium redox batteries are not nearly built at the scale of lithium batteries - which are themselves not built at a scale large enough for grid storage - as well as poorer round trip efficiency.

Schroedingersat 4y ago
> Except the polymer is re-usable. A few times: https://www.ornl.gov/publication/investigations-reusability-amidoxime-based-polymeric-adsorbents-seawater-uranium https://www.ornl.gov/publication/investigations-reusability-... As I said, there goes your eroi. At 10mg/kg you're producing 10,000 tonnes of polymer per year per reactor and harvesting it 3-6 times. This is supposed to be economical? That's 10 million tonnes of plastic waste per year just for one terawatt or 10% of world plastic waste to replace FF electrical generation. > Until it's saturated, then you can leave it out all you want and it won't collect any more. If you leave it in too long the Uranium starts going out because Vanadium has higher concentration and similar affinity. But long before that, your polymer breaks down and becomes microplastic pollution. > Unfortunately vanadium redox batteries are not nearly built at the scale of lithium batteries - which are themselves not built at a scale large enough for grid storage - as well as poorer round trip efficiency. So now we're back to this incoherent dissonance where doing something once on a tiny test platform makes it a definite solution to world energy, but something being produced at GWh scale in the real world is not big enough? That's a truly stellar amount of double think you've got going on there. I'm sure there'll be even more interest when your magic $20/kg unlimited supply vanadium machine running at 20x current total production is up and running.
- Manuel_D 4y ago
  > A few times: https://www.ornl.gov/publication/investigations-reusability- https://www.ornl.gov/publication/investigations-reusability-... The adsorbent loses efficiency after a couple elution cycles, but it is regenerated by an alki wash. Read this [1] if you want a better explanation. No, you do not need to keep producing tons and tons of polymer. You have to treat it with chemicals after a couple cycles, but you don't need to throw the whole polymer away and start anew. Regardless, this whole seawater extraction tangent is only a contingency if no new terrestrial reserves of uranium are found. Unlike intermittent sources which require massive amounts of grid storage, uranium seawater extraction isn't going to be necessary any time soon which is why I'm not super concerned about how seawater extraction isn't being commercialized. On the other hand, renewables are already starting to saturate the market during peak production today. In order to make intermittent sources viable we need storage systems now. It's not dissonance, it's the fact that there are presently functioning alternatives to seawater extraction that will continue to work for the near to mid term future. Whereas there are no storage systems capable of delivering energy at grid scale. 1. https://www.osti.gov/servlets/purl/1423067 https://www.osti.gov/servlets/purl/1423067
  - Schroedingersat 4y ago
    > The adsorbent loses efficiency after a couple elution cycles, but it is regenerated by an alki wash. Read this [1] if you want a better explanation. ..The longest lasting method in that paper is a scale model in idealized conditions of the same method I linked to but the first was in more realistic conditions... they ran one in the ocean but not more than once. > Regardless, this whole seawater extraction tangent is only a contingency if no new terrestrial reserves of uranium are found. Unlike intermittent sources which require massive amounts of grid storage, uranium seawater extraction isn't going to be necessary any time soon which is why I'm not super concerned about how seawater extraction isn't being commercialized. So we're back here. To match the scale of renewable when they start to run into the constraints that require scaling up storage, you need about 3TW by 2030 (before then a mix is viable along with using surplus for replacing non-electrical fossil fuels such as H2). That's 10,000 tonnes of fissile material up front, and another 10,000 every reload. You need to open every mine on the planet today and empty them by 2040. Then your sea mining rig needs to be ready to go (and hilariously has to be installed on a greater net capacity of offshore wind turbines than the capacity of nuclear reactors it supplies). After that you still need just as much storage for variable loads because ramping isn't an option as idle capacity would reduce your fuel runway by 6 years. All this because you think lithium production can't double when the extraction started a year ago? It's actually a comically bad plan. Well done. The bit where it needs the wind turbines was comedy gold.

Schroedingersat 4y ago

> Except the polymer is re-usable. A few times: https://www.ornl.gov/publication/investigations-reusability-amidoxime-based-polymeric-adsorbents-seawater-uranium https://www.ornl.gov/publication/investigations-reusability-... As I said, there goes your eroi. At 10mg/kg you're producing 10,000 tonnes of polymer per year per reactor and harvesting it 3-6 times. This is supposed to be economical? That's 10 million tonnes of plastic waste per year just for one terawatt or 10% of world plastic waste to replace FF electrical generation. > Until it's saturated, then you can leave it out all you want and it won't collect any more. If you leave it in too long the Uranium starts going out because Vanadium has higher concentration and similar affinity. But long before that, your polymer breaks down and becomes microplastic pollution. > Unfortunately vanadium redox batteries are not nearly built at the scale of lithium batteries - which are themselves not built at a scale large enough for grid storage - as well as poorer round trip efficiency. So now we're back to this incoherent dissonance where doing something once on a tiny test platform makes it a definite solution to world energy, but something being produced at GWh scale in the real world is not big enough? That's a truly stellar amount of double think you've got going on there. I'm sure there'll be even more interest when your magic $20/kg unlimited supply vanadium machine running at 20x current total production is up and running.

Manuel_D 4y ago
> A few times: https://www.ornl.gov/publication/investigations-reusability- https://www.ornl.gov/publication/investigations-reusability-... The adsorbent loses efficiency after a couple elution cycles, but it is regenerated by an alki wash. Read this [1] if you want a better explanation. No, you do not need to keep producing tons and tons of polymer. You have to treat it with chemicals after a couple cycles, but you don't need to throw the whole polymer away and start anew. Regardless, this whole seawater extraction tangent is only a contingency if no new terrestrial reserves of uranium are found. Unlike intermittent sources which require massive amounts of grid storage, uranium seawater extraction isn't going to be necessary any time soon which is why I'm not super concerned about how seawater extraction isn't being commercialized. On the other hand, renewables are already starting to saturate the market during peak production today. In order to make intermittent sources viable we need storage systems now. It's not dissonance, it's the fact that there are presently functioning alternatives to seawater extraction that will continue to work for the near to mid term future. Whereas there are no storage systems capable of delivering energy at grid scale. 1. https://www.osti.gov/servlets/purl/1423067 https://www.osti.gov/servlets/purl/1423067
- Schroedingersat 4y ago
  > The adsorbent loses efficiency after a couple elution cycles, but it is regenerated by an alki wash. Read this [1] if you want a better explanation. ..The longest lasting method in that paper is a scale model in idealized conditions of the same method I linked to but the first was in more realistic conditions... they ran one in the ocean but not more than once. > Regardless, this whole seawater extraction tangent is only a contingency if no new terrestrial reserves of uranium are found. Unlike intermittent sources which require massive amounts of grid storage, uranium seawater extraction isn't going to be necessary any time soon which is why I'm not super concerned about how seawater extraction isn't being commercialized. So we're back here. To match the scale of renewable when they start to run into the constraints that require scaling up storage, you need about 3TW by 2030 (before then a mix is viable along with using surplus for replacing non-electrical fossil fuels such as H2). That's 10,000 tonnes of fissile material up front, and another 10,000 every reload. You need to open every mine on the planet today and empty them by 2040. Then your sea mining rig needs to be ready to go (and hilariously has to be installed on a greater net capacity of offshore wind turbines than the capacity of nuclear reactors it supplies). After that you still need just as much storage for variable loads because ramping isn't an option as idle capacity would reduce your fuel runway by 6 years. All this because you think lithium production can't double when the extraction started a year ago? It's actually a comically bad plan. Well done. The bit where it needs the wind turbines was comedy gold.