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Using energy to free up CO2, so that you can bind CO2 that was produced by using energy - do I have that right? Anybody see any trouble with that plan? If you'r

Using energy to free up CO2, so that you can bind CO2 that was produced by using energy - do I have that right? Anybody see any trouble with that plan? If you're being charitable you can assume the whole thing is 100% efficient like in a physics textbook. Don't worry about the CO2 we freed-up in the first step; we'll just use more energy to drill and pump it underground from where it'll escape, or inject it into one of the most energy-intensive building materials, concrete, which would of course continue to be produced in kilns and used. Speaking of kilns, this one is electric, meaning the fossil fuels are burned elsewhere, not on our premises! What an elaborate arbitrage.

p0w3n3d 3y ago
Most important is to show on paper that your company is green. Other things don't matter
az226 3y ago
You’d hope the kiln is powered by nukes or renewables.
walnutclosefarm 3y ago
There are no energy free ways to resequester atmospheric CO2. If you accept that we will have to do so to meet the world's climate change goals, then the question is really, how energy efficient can you make your process, and where can you get carbon-free energy. This company has a credible approach, although as soon as you look at any of the mechanisms being considered, the scaling problem is daunting.
- natch 3y ago
  The CO2 in the limestone was already sequestered by nature. They are freeing it, which is the opposite of what is needed. Leave the limestone alone and that CO2 remains sequestered, no additional energy needed. This sounds like a way to just capture CO2 on paper.
  - walnutclosefarm 3y ago
    Obviously, you didn't read how it is intended to work. Baking the rock gives them a stream of nearly pure CO2, which can be sequestered underground. The powdered rock then efficiently captures CO2 from the air (where it is of course, very low in concentration). That CO2 can then be baked off, sequestered, and the rock cycled to the air again. In an industrial plant, you'd have a continuous process of rock being baked, exposed, baked again, with a continous stream CO2 being sequestered geologically.
    - aydyn 3y ago
      How can one sequester CO2 “geologically”?
      - ttyprintk 3y ago
        There are two natural geologies I know of: Oil fields often have dissolved CO2 and methane contaminants. Those gasses are captured and pressurized to force more oil out. Those empty caverns are the largest opportunity for capture. At ocean depth, CO2 is trapped under hydrate caps. This is best-known around geothermal “smokers”, but the ocean floor is largely unknown. So, there is significant risk allowing the hydrate caps to melt.
        natch 3y ago
        >Those empty caverns are the largest opportunity for capture How large? We have 42,592 trillion cubic feet of CO2 in the atmosphere, and the projected total natural gas that can be extracted going forward in the US over the next 85 years is 2,973 trillion cubic feet. First, will we even extract that much? I've heard that using that much will create more CO2 than we can handle. And, taking the wild assumption that we do extract that much, how much of that natural gas will come from fracking, and how much from caverns? Let's be generous and say that 50% comes from caverns. So now we have 2973 times 0.5 which gives 1486 trillion cubic feet of space we can eventually use for the plan you describe, if we use more natural gas than we safely can use. And that's making again another overly generous assumption in favor of your plan which is that these caverns are somehow left in a state of vacuum before we start putting in CO2. And let's be fair and assume we only want to sequester say 20% of the CO2, so we want to squeeze 8,518 trillion cubic feet of CO2 into this idealized generously estimated 1,486 trillion cubic feet. Naturally the gas will be injected under pressure. I imagine this gets incredibly complex, and there will be leakage, and it will be the province of huge contracting companies that historically have shown themselves to be mainly interested in getting to a finish line such that they can get paid by the taxpayers, with help from their bought-and-paid-for lawmakers, long term results and consequences be damned (see: oil and gas industry, nuclear industry). I don't feel very good about this plan. But I can envision the ear-to-ear grins at the contracting companies when they found out "the libs" are going to make tax dollars rain on them for continuing to extract oil and gas out of the ground using some paperwork and a variation of a process they were already doing, even though it probably won't achieve the ends those libs want.
- ImPostingOnHN 3y ago
  Honestly, the low tech nature of grinding up rocks, baking them, and setting them out in a pile makes this seem pretty easy to scale, given any money
  - eppp 3y ago
    Isn't this just portland cement at that point?
  - walnutclosefarm 3y ago
    I'm really thinking of the energy scaling. Suppose you want to use such a technology to offset burning oil for some purpose. Even for highly efficient processes, you're going to get generate a ton of CO2 for a MWh of usable energy. You're then going to use 2 MWh of electrical energy to recapture the CO2. So, you've tripled the energy we need to produce for that process. That's really raising the bar on carbon neutral energy production.
    - ImPostingOnHN 3y ago
      energy production is orthogonal to CO2 production, neither requires the other to happen so, imagine you want to absorb a ton of CO2 from the air to prevent the planet from further spiraling into uninhabitability: you could electrically bake the rock with renewable energy, then use it to absorb CO2
anon84873628 3y ago
Presumably the concentrated stream of CO2 output from the kiln is easier to work with than pulling dilute CO2 out of the atmosphere, to the degree that it is worth doing that way. I'd love to hear a more detailed explanation from experts about how the output stream is sequestered. It doesn't sound absurd though; getting gasses in the right place at the right time is not necessarily a trivial task.
Twixes 3y ago
Optimistically (and ostensibly), almost all the energy for the kilns would be free of direct emissions (e.g solar). In that case the plan sounds effective. Let's see if that actually works out.
marssaxman 3y ago
> Using energy to free up CO2, so that you can bind CO2 ...thereby concentrating CO2 which had previously been diffused throughout the atmosphere, so that it can be processed and stored. > Speaking of kilns, this one is electric, meaning ...that fossil fuels need not be involved at all. Solar panels are cheap, and they can choose to build the factory in a sunny place.
- natch 3y ago
  > so that it can be processed and stored it was already processed and stored. In the limestone. By nature. For free. Just leave the CO2 stored in the limestone alone, and find some other way to capture the CO2 from the atmosphere.
  - seti0Cha 3y ago
    I don't think you've properly understood the process. They free the carbon from the limestone, but capture it. They then use the resulting material to capture more carbon. Then they repeat the process. The first batch that was in the limestone originally is obviously of no benefit, but succeeding cycles are using carbon pulled from the air.
    - natch 3y ago
      >but capture it For certain values of “capture” TFA says it could be pumped underground, etc. “could be” in theory if that gets proved out and doesn’t leak. For a period. At least for long enough to collect the tax credit. Meantime, it was already captured in the limestone.
      - seti0Cha 3y ago
        If we reject the idea that captured carbon can remain captured, then no carbon capture mechanism works. I'm not sure your skepticism on that front is warranted, though.
        3y ago

p0w3n3d 3y ago

Most important is to show on paper that your company is green. Other things don't matter

az226 3y ago

You’d hope the kiln is powered by nukes or renewables.

walnutclosefarm 3y ago

There are no energy free ways to resequester atmospheric CO2. If you accept that we will have to do so to meet the world's climate change goals, then the question is really, how energy efficient can you make your process, and where can you get carbon-free energy. This company has a credible approach, although as soon as you look at any of the mechanisms being considered, the scaling problem is daunting.

natch 3y ago
The CO2 in the limestone was already sequestered by nature. They are freeing it, which is the opposite of what is needed. Leave the limestone alone and that CO2 remains sequestered, no additional energy needed. This sounds like a way to just capture CO2 on paper.
- walnutclosefarm 3y ago
  Obviously, you didn't read how it is intended to work. Baking the rock gives them a stream of nearly pure CO2, which can be sequestered underground. The powdered rock then efficiently captures CO2 from the air (where it is of course, very low in concentration). That CO2 can then be baked off, sequestered, and the rock cycled to the air again. In an industrial plant, you'd have a continuous process of rock being baked, exposed, baked again, with a continous stream CO2 being sequestered geologically.
  - aydyn 3y ago
    How can one sequester CO2 “geologically”?
    - ttyprintk 3y ago
      There are two natural geologies I know of: Oil fields often have dissolved CO2 and methane contaminants. Those gasses are captured and pressurized to force more oil out. Those empty caverns are the largest opportunity for capture. At ocean depth, CO2 is trapped under hydrate caps. This is best-known around geothermal “smokers”, but the ocean floor is largely unknown. So, there is significant risk allowing the hydrate caps to melt.
      - natch 3y ago
        >Those empty caverns are the largest opportunity for capture How large? We have 42,592 trillion cubic feet of CO2 in the atmosphere, and the projected total natural gas that can be extracted going forward in the US over the next 85 years is 2,973 trillion cubic feet. First, will we even extract that much? I've heard that using that much will create more CO2 than we can handle. And, taking the wild assumption that we do extract that much, how much of that natural gas will come from fracking, and how much from caverns? Let's be generous and say that 50% comes from caverns. So now we have 2973 times 0.5 which gives 1486 trillion cubic feet of space we can eventually use for the plan you describe, if we use more natural gas than we safely can use. And that's making again another overly generous assumption in favor of your plan which is that these caverns are somehow left in a state of vacuum before we start putting in CO2. And let's be fair and assume we only want to sequester say 20% of the CO2, so we want to squeeze 8,518 trillion cubic feet of CO2 into this idealized generously estimated 1,486 trillion cubic feet. Naturally the gas will be injected under pressure. I imagine this gets incredibly complex, and there will be leakage, and it will be the province of huge contracting companies that historically have shown themselves to be mainly interested in getting to a finish line such that they can get paid by the taxpayers, with help from their bought-and-paid-for lawmakers, long term results and consequences be damned (see: oil and gas industry, nuclear industry). I don't feel very good about this plan. But I can envision the ear-to-ear grins at the contracting companies when they found out "the libs" are going to make tax dollars rain on them for continuing to extract oil and gas out of the ground using some paperwork and a variation of a process they were already doing, even though it probably won't achieve the ends those libs want.
ImPostingOnHN 3y ago
Honestly, the low tech nature of grinding up rocks, baking them, and setting them out in a pile makes this seem pretty easy to scale, given any money
- eppp 3y ago
  Isn't this just portland cement at that point?
- walnutclosefarm 3y ago
  I'm really thinking of the energy scaling. Suppose you want to use such a technology to offset burning oil for some purpose. Even for highly efficient processes, you're going to get generate a ton of CO2 for a MWh of usable energy. You're then going to use 2 MWh of electrical energy to recapture the CO2. So, you've tripled the energy we need to produce for that process. That's really raising the bar on carbon neutral energy production.
  - ImPostingOnHN 3y ago
    energy production is orthogonal to CO2 production, neither requires the other to happen so, imagine you want to absorb a ton of CO2 from the air to prevent the planet from further spiraling into uninhabitability: you could electrically bake the rock with renewable energy, then use it to absorb CO2

anon84873628 3y ago

Presumably the concentrated stream of CO2 output from the kiln is easier to work with than pulling dilute CO2 out of the atmosphere, to the degree that it is worth doing that way. I'd love to hear a more detailed explanation from experts about how the output stream is sequestered. It doesn't sound absurd though; getting gasses in the right place at the right time is not necessarily a trivial task.

Twixes 3y ago

Optimistically (and ostensibly), almost all the energy for the kilns would be free of direct emissions (e.g solar). In that case the plan sounds effective. Let's see if that actually works out.

marssaxman 3y ago

> Using energy to free up CO2, so that you can bind CO2 ...thereby concentrating CO2 which had previously been diffused throughout the atmosphere, so that it can be processed and stored. > Speaking of kilns, this one is electric, meaning ...that fossil fuels need not be involved at all. Solar panels are cheap, and they can choose to build the factory in a sunny place.

natch 3y ago
> so that it can be processed and stored it was already processed and stored. In the limestone. By nature. For free. Just leave the CO2 stored in the limestone alone, and find some other way to capture the CO2 from the atmosphere.
- seti0Cha 3y ago
  I don't think you've properly understood the process. They free the carbon from the limestone, but capture it. They then use the resulting material to capture more carbon. Then they repeat the process. The first batch that was in the limestone originally is obviously of no benefit, but succeeding cycles are using carbon pulled from the air.
  - natch 3y ago
    >but capture it For certain values of “capture” TFA says it could be pumped underground, etc. “could be” in theory if that gets proved out and doesn’t leak. For a period. At least for long enough to collect the tax credit. Meantime, it was already captured in the limestone.
    - seti0Cha 3y ago
      If we reject the idea that captured carbon can remain captured, then no carbon capture mechanism works. I'm not sure your skepticism on that front is warranted, though.
      - 3y ago