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So it acts like a reusable CO2 trap, then releases said CO2 at the cost of heating it up to 140F. Which then releases it. It doesn't really talk about how you

So it acts like a reusable CO2 trap, then releases said CO2 at the cost of heating it up to 140F. Which then releases it. It doesn't really talk about how you would sequester the gaseous CO2 other than "put it underground."... But if you put a gas underground it will eventually leak out. Even a liquid is prone to leak out eventually due to plate techtonics, but a liquid doesn't immediately turn into gaseous CO2. So though a crucial technology, I don't see how effective it would be in a long term solution.

floxy 2y ago
>how you would sequester the gaseous CO2 other than "put it underground." I wonder if there is a reason you couldn't just sequester the powder. Probably too expensive? Or not volume efficient? >to leak out eventually due to plate techtonics This might seem shortsighted, but I'm OK pushing the problem out by 50 million years or so.
- BizarroLand 2y ago
  Since the powder is reusable, it likely wouldn't make sense to sequester it with the CO2 either materially or financially.
  - entropicdrifter 2y ago
    This. The powder is more efficiently used as a way to move the CO2 around than as a means to keep it sequestered.
    - Woodi 2y ago
      Still, tree produce oxygen from that CO_2. And do not need energy from grid for that :) Threating CO_2 like radioactive waste, putting it underground etc - that what I call not self-sustained :>
BizarroLand 2y ago
If you can extract ~100% pure CO2 from the powder, then it might be feasible to develop a process that can convert very dense CO2 into Carbon and Oxygen. Carbon is about 3/8ths of the total weight of a CO2 molecule and is solid and relatively inert at room temperature and pressure. Of course, if there were a convenient way to simply strip carbon off of a CO2 molecule to begin with that would be the ideal system, but I'm sure that can be figured out given enough opportunity. Plants do it, after all. It's not impossible.
- jiggawatts 2y ago
  Plants do it using the energy from the sun. All of these “can’t we just unburn burnt things” forget that the reason we burnt the carbon in the first place was to get that energy. Unburning it would need to return that energy and more because of inefficiencies. If you have energy to spare, you don’t need to burn the carbon in the first place. With global fossil fuel usage still rising, we clearly don’t have any to spare.
  - glial 2y ago
    It's not so clear to me -- the MIT Technology Review is already wringing its hands about energy being so cheap it causes problems with economics. [1] https://www.technologyreview.com/2021/07/14/1028461/solar-value-deflation-california-climate-change/ https://www.technologyreview.com/2021/07/14/1028461/solar-va...
    - doctorwho42 2y ago
      Energy can be economically cheap in the current paradigm, while also being insufficiently cheap or insufficient quantities of clean energy to make the above comments suggestion work.
- gus_massa 2y ago
  > Plants do it, after all. It's not impossible. The problem is that to reverse CO2 -> C + O2 you need the same amount of energy that you get burning coal C + O2 -> CO2. But burning coal, like half of the energy is lost as unuseful heat. The reaction of plants is different, but plants only has a 2% of efficiency. The chemical reaction of plants is more complicated, so let's be optimistic and assume this reaction has a 10% of efficiency. If they use a coal plant to power the CO2 -> C + O2 conversion, they will release like 20 times the amount of CO2 absorbed. If they use a renewable source, it's better to close the absortion plant and also 20 coal plants. Until we close all the coal plants and we get very cheep carbon-free energy, it's bad for the environment to try a CO2 -> C + O2 conversion.
jjk166 2y ago
Many common minerals like olivine react with CO2 at high concentrations to form carbonates which are geologically stable. The issue is getting the high carbon concentrations to make this process fast. Concentrating CO2 is the major technical hurdle of carbon sequestration.
7speter 2y ago
What I'm about to say may sound absurd and an attempt to be funny, but I'm being serious. The other day I was wondering how people always talk about sending undesirable material (garbage, spent radioactive fuel, etc.) on a one way trip to the sun. Why not send things to the surface of Venus? It has an ultra dense atmosphere that pulverizes anything that reaches the surface. In the case of this material, it's just more C02, which is what the atmosphere of Venus is already primarily composed of. We aren't going to ever explore the surface of Venus, or at least we won't for thousands, if not millions of years, barring we can easily convert co2 into energy, so is this a bad idea?
- defrost 2y ago
  Let's take the 2020 figures for annual human carbon dioxide emmissions. 35 billion metric tons. What's your back of the envelope energy figure for extracting that weight of a gas from the atmosphere, pressurising it, and lifting it to orbit and sending it to Venus? Got a rough notion of the number of trips, fuel and resources that would need every single year?

floxy 2y ago

>how you would sequester the gaseous CO2 other than "put it underground." I wonder if there is a reason you couldn't just sequester the powder. Probably too expensive? Or not volume efficient? >to leak out eventually due to plate techtonics This might seem shortsighted, but I'm OK pushing the problem out by 50 million years or so.

BizarroLand 2y ago
Since the powder is reusable, it likely wouldn't make sense to sequester it with the CO2 either materially or financially.
- entropicdrifter 2y ago
  This. The powder is more efficiently used as a way to move the CO2 around than as a means to keep it sequestered.
  - Woodi 2y ago
    Still, tree produce oxygen from that CO_2. And do not need energy from grid for that :) Threating CO_2 like radioactive waste, putting it underground etc - that what I call not self-sustained :>

BizarroLand 2y ago

If you can extract ~100% pure CO2 from the powder, then it might be feasible to develop a process that can convert very dense CO2 into Carbon and Oxygen. Carbon is about 3/8ths of the total weight of a CO2 molecule and is solid and relatively inert at room temperature and pressure. Of course, if there were a convenient way to simply strip carbon off of a CO2 molecule to begin with that would be the ideal system, but I'm sure that can be figured out given enough opportunity. Plants do it, after all. It's not impossible.

jiggawatts 2y ago
Plants do it using the energy from the sun. All of these “can’t we just unburn burnt things” forget that the reason we burnt the carbon in the first place was to get that energy. Unburning it would need to return that energy and more because of inefficiencies. If you have energy to spare, you don’t need to burn the carbon in the first place. With global fossil fuel usage still rising, we clearly don’t have any to spare.
- glial 2y ago
  It's not so clear to me -- the MIT Technology Review is already wringing its hands about energy being so cheap it causes problems with economics. [1] https://www.technologyreview.com/2021/07/14/1028461/solar-value-deflation-california-climate-change/ https://www.technologyreview.com/2021/07/14/1028461/solar-va...
  - doctorwho42 2y ago
    Energy can be economically cheap in the current paradigm, while also being insufficiently cheap or insufficient quantities of clean energy to make the above comments suggestion work.
gus_massa 2y ago
> Plants do it, after all. It's not impossible. The problem is that to reverse CO2 -> C + O2 you need the same amount of energy that you get burning coal C + O2 -> CO2. But burning coal, like half of the energy is lost as unuseful heat. The reaction of plants is different, but plants only has a 2% of efficiency. The chemical reaction of plants is more complicated, so let's be optimistic and assume this reaction has a 10% of efficiency. If they use a coal plant to power the CO2 -> C + O2 conversion, they will release like 20 times the amount of CO2 absorbed. If they use a renewable source, it's better to close the absortion plant and also 20 coal plants. Until we close all the coal plants and we get very cheep carbon-free energy, it's bad for the environment to try a CO2 -> C + O2 conversion.

jjk166 2y ago

Many common minerals like olivine react with CO2 at high concentrations to form carbonates which are geologically stable. The issue is getting the high carbon concentrations to make this process fast. Concentrating CO2 is the major technical hurdle of carbon sequestration.

7speter 2y ago

What I'm about to say may sound absurd and an attempt to be funny, but I'm being serious. The other day I was wondering how people always talk about sending undesirable material (garbage, spent radioactive fuel, etc.) on a one way trip to the sun. Why not send things to the surface of Venus? It has an ultra dense atmosphere that pulverizes anything that reaches the surface. In the case of this material, it's just more C02, which is what the atmosphere of Venus is already primarily composed of. We aren't going to ever explore the surface of Venus, or at least we won't for thousands, if not millions of years, barring we can easily convert co2 into energy, so is this a bad idea?

defrost 2y ago
Let's take the 2020 figures for annual human carbon dioxide emmissions. 35 billion metric tons. What's your back of the envelope energy figure for extracting that weight of a gas from the atmosphere, pressurising it, and lifting it to orbit and sending it to Venus? Got a rough notion of the number of trips, fuel and resources that would need every single year?