Well, instead of repeating myself manually, I'll paste in a comment of mine here from a past discussion on carbon capture:
It's easy to forget why there is a bit of a challenge to getting C02 out of the air: there's so little of it, comparatively.
In order, air is, broadly, made up of the following:
Nitrogen: %78.084
Oxygen: %20.946
Argon: %00.934
CO2: %00.042
The stuff is essentially beyond a rounding error - it really gives one an appreciation of the "either don't release it, or capture it at the point of release" sentiment, and for the difficulties in making carbon capture outside of these scenarios be even slightly cost-effective.
At current rates of emissions, we’re only about 20 years away from people needing to install CO2 scrubbers in their homes.
Soda lime, or calcium hydroxide, is the current state of the art. We use that in an anesthesia and in saltwater aquariums and in scuba rebreathers. An idealized system can capture 500 mg per gram, but in practice you only capture around 250mg/g. This outperforms the method in the article but it’s one-shot. There are interesting proposals to use this for direct capture at industrial facilities and to turn the waste material into bricks for building.
The key advantage of this new material appears to be that it can be heated and reused. That would be very valuable in an interior direct air capture use case. Think about filtering the CO2 from an office or a home to get us back to pre-industrial levels indoors.
I think it’s little appreciated that high CO2 levels cause cognitive impairment, and with the same amount of (often very poor) air exchange, higher outdoor concentrations can push indoor spaces to levels that cause impaired cognition and poor sleep. I’ve already been seeing this in my home, and will often open windows even when cold just to keep co2 levels reasonable. One solution that can help is an external air heat exchanger, which can exchange air with the outdoors without compromising your homes heating and cooling like an open window will do.
Noticeable cognitive impairment starts in the 700-1000ppm range, whereas it is very common for homes to reach 2000-3000ppm, especially when in a closed bedroom.
> The ease of releasing CO2 is the key advantage of the new compound.
I have no idea why the journalist that wrote this article choose to highlight the carbon density of the sub-header. It's almost completely irrelevant for carbon capture plants.
Another clear benefit is that it's a liquid.
Today people mostly use the substances that you called non-reversible in research plants (AFAIK, all plants are research right now). They are perfectly reversible, but that uses a lot of energy.
160F, non toxic, this already sounds like something that could feasibly be used in the home. I would already be interested in installing one. And would absolutely love to see what it would do to school performance.
Indoor is always higher ppm (how much depends on many parameters) without proper ventilation. „Proper“ should include a „Heat exchanger“ thus you don’t need to reheat fresh air.
Direct air capture imo can’t escape the scaling problem - when the feedstock has CO2 at ~400 ppm the economics simply won’t work out despite various oil companies backing one off systems around the globe.
Capturing CO2 at the source (power plant, etc) would be simpler to reach economic viability but without incentives it’s dead on arrival. I believe the IRA infra bill had put a price ~$50/ton of CO2 captured.
Capturing CO2 at the source will always be worse than removing the source. At the same time, capturing CO2 from the air will stay necessary until we do it.
But we still need to remove all the excess co2 that we released into the atmosphere since the start of the industrial revolution if we want to reduce the temperature back to what it was before we started disrupting the natural state of the plane.
We and previous generations took out a loan and the payment is coming due.
Because of the framing about degrees in celcius change people are thinking in small numbers, like "oh, it's just 1.5'C over normal. oops, we missed that, well maybe we'll get it at 2.0'C. They don't realize that if we want normal we ahve to reduce the temperaure and to do that we need to take that c02 blanket off that we've been tightly wrapping around our collective bodies for decades.
And that endeavor is nearly unfathomable. Think of all the energy used by humanity since the industrial revolution and the energy we're going to be producing in the time period that we attempt to sequester the previously poduced C02. All of that needs to be accounted for.
And then there's the surplus energy roiling around in the system now, and the collapse of food webs.
I don't see how we get our way out of this in the next 50 years.
That’s true. It’s more of a policy issue that’s like carbon credits… nice on paper but a big nothing burger. Look at F1 and Porsche talking about sustainable synthetic fuels.
When you compare round trip efficiencies and economics it makes sense to just not burn the hydrocarbons to begin with.
If stored near a populated area, hundreds of thousands could be kill, including all animals and insects, in a matter of minutes if the "vault" has a catastrophic failure. I would rather live near a nuclear waste site than a CO2 Site.
Well as far as storing it goes, if you can capture it, turn it into a solid and stick it in the ground.
Imagine you were growing a huge biomass that you harvest, dry out, and then store. We know how the bacteria and processes that stripped co2 from the atmosphere in the past, we just need to do that in a big way. Good thing we have places on earth that are huge and flat and growing algae won't be a problem.
And then we complement that with green energy and an attempt at net zero.
A better title would be "More efficient method to capture CO2 from the atmosphere." The method is not objectively efficient, but may be more efficient than other methods (solvents/sorbents) used for DAC.
I gave my engineering students a CO2 removal design problem once, and at the end, asked why the theoretical efficiency had increased in the time since the textbook was written. The answer was that the concentration of CO2 in the atmosphere was higher.
Economics rules everything. How much does this cost vs simply planting trees, when the value of harvesting the trees is included? Since tree farms are generally profitable, and wood is expensive, it seems this method is likely to be economically less efficient.
The problem is you cannot plant enough trees around the globe to offset our CO2 emissions.
Also, a forest only absorbs CO2 while alive. Once it dies, it emits CO2 too.
You would need to permanently store the wood somewhere (submerging in water, etc).
If these forests are planted by humans, why do we think the dead trees would just be left to rot like you suggest vs being harvested for wood? The logic does not compute other than trying to make a ridiculous point.
One little appreciated fact is that trees also respirate CO2 when they are cracking their stored sugars produced via photosynthesis. So they don’t sequester all of the CO2 that they consume.
I suppose I’m pointing it out to highlight the trade offs with any of these solutions.
What is unsaid is that we need to sequester CO2 for hundreds of years—often far beyond the lifespan of the trees. Trees are short term storage, and sometimes the storage is a lot shorter than popular imagination purports.
It's a hugely underappreciated option. I'm not sure how accurate it is (or how legitimate the companies doing biochar carbon removal are), but cdr.fyi shows biochar as the top carbon sequestration method that's actually happening.
Physics rules everything, once you start trying to run at scale.
The density of carbon per unit volume in solid materials of interest doesn't vary that much, whether you sink it in trees or in exotic materials like diamonds. That means you can calculate the volume of material required so sink a desired amount of atmospheric carbon.
If you want to have a measurable impact on the atmosphere, say dialing it back to 1980 CO2 levels, you're talking not about making a pile of stuff but about making a mountain range that's a mile high and hundreds of miles long.
Now figure out how many trucks you're going to need to move that much material from where your sequestering machine is to where your pile of stuff is.
Or if you want to dump that material in the ocean (which someone else will certainly object to), extend your calculation to figure out how many container trucks worth of material you need to dump into the ocean every hour to accomplish your atmospheric cleanup in whatever amount of time you choose (a decade? If it takes a century, that's not fast enough).
And finally think about surface to volume ratios. You're trying to sink it into a volume, but you can only get the gas into the volume through its surface, so the speed of your process is limited by surface area.
If you want to do it with trees,
my personal spitball estimates are that you probably need to plant somewhere between the entire state of Connecticut and the entire state of Colorado to have the kind of impact one would want (there's more subtlety to tree calculations than one generally likes to admit, so feel free to come in with way higher numbers than I did).
Which brings us back to economics. If you have a well-managed forest of that size and scale, someone is eventually going to come along, maybe in 100 years, maybe in 500 years, and say "hey if we cut this down, we could burn the wood to heat our homes" and all that carbon goes back into the atmosphere, so you actually need to sink it into something that is energetically unfavorable for recovery, which means you also need to expand a huge amount of energy to sink the carbon into that energetically unfavorable state.
> you're talking not about making a pile of stuff but about making a mountain range that's a mile high and hundreds of miles long.
Just to put it into numbers, wikipedia has the total amount of CO2 on the global warming page, if we assume it's in a 2 g/l substance it totals to around 180 km^3.
1. Even if we do magic and emit nothing, we still need to remove CO2 from the atmosphere or it will cook us over time, just longer.
2. We would need an enormous area for forests (which i great), which would mean a lot of intervention, like resettling people, demolishing and constructing new buildings, a lot of machinery time to move people to and from the new forests, a lot of planting and forest maintenance involved. And add he work to cut and bury resulting wood. If you would sum all the incidental emissions from this process it would rapidly become much less efficient (if at all).
Without either CO2 capture or a sun shade of some sort, the CO2 levels and temperature will only ever increase, just like now.
I agree. Plants are not very efficient (1% or 2%) but they include packaging the CO2 in a stable form. You can store the grain or wood for long periods of times.
In this case, it looks like they get CO2 as a gas. It's cheaper because you don't have to use energy to undo the burning, but it's difficult to store for a long time.
(I'm not sure if someone tried to make a fake underground bog in abandoned mine. Just fill with wood and water to keep the oxygen low and make the wood decompose slowly.)
Take a look at "wood vault".
'Wood vaulting': A simple climate solution you’ve probably never heard of | Grist https://share.google/lS8xnMGEd1pMzlNg2
Economically not attractive but apparently very efficient in locking up CO2.
The problem with any scheme to capture and store carbon from the atmosphere is the incredible amount of carbon we've blown into the air in the last 150 years. Just look at the size of the machines we use to harvest coal. Essentially you'd need to have machines of similar size working for many decades to re-bury the carbon we extracted and burned. Who's gonna pay for that?
Planting trees is not effective since it takes decades to capture the carbon, but the next years are crucial for determining long term climate developments.
There is no carbon capture technology on earth that can be rolled out at a scale over the next few years that can compete with planting trees. Especially not one that has just been invented in one university. Ash grows 90cm per year, that's all carbon. Scale that to millions and billions.
The thing people don't think about with regards to CO2 capture is that you have to get the atmosphere in order to capture CO2 from it. You essentially have to suck the entire atmosphere into these carbon capture facilities.
Using something like this to capture carbon from an exhaust pipe might be viable, but scrubbing CO2 out of the atmosphere is not even remotely viable. There's just too much air out there.
You can actually capture CO2 from sea water thereby reducing ocean acidification and improving its capability to continue as our planets biggest CO2 sink.
You're right, it's expensive and hard, so it's better to not do anything and... migrate all humanity onto space stations so we don't die with the earth, I guess is the alternative you're suggesting?
This solves only part of the problem: it captures CO2 and can release it later. But you still need to figure out what to do with this CO2, how to turn it into something useful.
you can inject it into peridotites and let it mineralize. there is enough exposed peridotite outcrops in the world that we could inject all the co2 produced and store it there indefinitely. this process also produces elemental hydrogen.
Someone proposed to make giant beaches of malachite and let the sea break the rocks. Malachite has two -OH that can be replaced by a CO3= and so capture the CO2.
I can't find a good link now, but at least it's the only method I know where it's not obvious that requires a huge amount of energy that makes the whole process net negative.
Their process for generating potassium formate is greener than standard methods. It does require electricity as an input but that can come from renewable, green sources.
Potassium formate is used in de-icing products, fertilizer, heat transfer fluids, drilling fluid, etc... so a useful, monetizeable output comes out of the process.
Disclosure - Know the founders personally. Wanted to shoutout their work. No financial ties to the company.Chemistry is not at all my expertise & I don't have details on their process beyond what's on the website.
I'm fine with keeping it inside something brick-shaped and chucking it down an abandoned mine from where it can be retrieved at a later time. It would definitely be a storage improvement over "the atmosphere and our lungs".
Stable storage would be limestone. To bring it down to pre-industrial levels it would mean that each person on earth would get a cube of 5 meters a side.
IDK, build houses out of limestone like we have been doing for ages.
The answer is obvious: create a cryptocurrency-based economy where countries and citizens are incentivized to pull CO2 out of the atmosphere and ship it into space in exchange for crypto.
/s
One of the subplots from the excellent Delta-V series by Daniel Suarez.
It's easy to forget why there is a bit of a challenge to getting C02 out of the air: there's so little of it, comparatively.
In order, air is, broadly, made up of the following:
Nitrogen: %78.084
Oxygen: %20.946
Argon: %00.934
CO2: %00.042
The stuff is essentially beyond a rounding error - it really gives one an appreciation of the "either don't release it, or capture it at the point of release" sentiment, and for the difficulties in making carbon capture outside of these scenarios be even slightly cost-effective.
Soda lime, or calcium hydroxide, is the current state of the art. We use that in an anesthesia and in saltwater aquariums and in scuba rebreathers. An idealized system can capture 500 mg per gram, but in practice you only capture around 250mg/g. This outperforms the method in the article but it’s one-shot. There are interesting proposals to use this for direct capture at industrial facilities and to turn the waste material into bricks for building.
The key advantage of this new material appears to be that it can be heated and reused. That would be very valuable in an interior direct air capture use case. Think about filtering the CO2 from an office or a home to get us back to pre-industrial levels indoors.
Noticeable cognitive impairment starts in the 700-1000ppm range, whereas it is very common for homes to reach 2000-3000ppm, especially when in a closed bedroom.
Sounds seriously unlikely. How would this work in practice, at the level of bodily functions?
I have no idea why the journalist that wrote this article choose to highlight the carbon density of the sub-header. It's almost completely irrelevant for carbon capture plants.
Another clear benefit is that it's a liquid.
Today people mostly use the substances that you called non-reversible in research plants (AFAIK, all plants are research right now). They are perfectly reversible, but that uses a lot of energy.
The hard part is capture and disposal.
Imagine capturing CO2 to turn it into cement, used for constructions.
Pardon my ignorance, though.
Extending the current exponential for 20 years, we get into the 500ppm region.
I don't think that's enough to need scrubbers.
Just extrapolate.
Buildings with higher people/sqft could already take advantage of indoor co2 scrubbers today.
Capturing CO2 at the source (power plant, etc) would be simpler to reach economic viability but without incentives it’s dead on arrival. I believe the IRA infra bill had put a price ~$50/ton of CO2 captured.
We and previous generations took out a loan and the payment is coming due.
Because of the framing about degrees in celcius change people are thinking in small numbers, like "oh, it's just 1.5'C over normal. oops, we missed that, well maybe we'll get it at 2.0'C. They don't realize that if we want normal we ahve to reduce the temperaure and to do that we need to take that c02 blanket off that we've been tightly wrapping around our collective bodies for decades.
And that endeavor is nearly unfathomable. Think of all the energy used by humanity since the industrial revolution and the energy we're going to be producing in the time period that we attempt to sequester the previously poduced C02. All of that needs to be accounted for.
And then there's the surplus energy roiling around in the system now, and the collapse of food webs.
I don't see how we get our way out of this in the next 50 years.
For the atmospheric one, grow trees and algae
When you compare round trip efficiencies and economics it makes sense to just not burn the hydrocarbons to begin with.
Another concern, who will pay for maintenance ? See this for why you cannot let CO2 escape from underground storage:
https://en.wikipedia.org/wiki/Lake_Nyos_disaster
If stored near a populated area, hundreds of thousands could be kill, including all animals and insects, in a matter of minutes if the "vault" has a catastrophic failure. I would rather live near a nuclear waste site than a CO2 Site.
Imagine you were growing a huge biomass that you harvest, dry out, and then store. We know how the bacteria and processes that stripped co2 from the atmosphere in the past, we just need to do that in a big way. Good thing we have places on earth that are huge and flat and growing algae won't be a problem.
And then we complement that with green energy and an attempt at net zero.
Recent article: https://www.theguardian.com/environment/2025/nov/28/africa-f...
But left out to rot and yeah, the fungus and bacteria will ultimately consume the wood and release CO2 as a byproduct.
What is unsaid is that we need to sequester CO2 for hundreds of years—often far beyond the lifespan of the trees. Trees are short term storage, and sometimes the storage is a lot shorter than popular imagination purports.
Physics rules everything, once you start trying to run at scale.
The density of carbon per unit volume in solid materials of interest doesn't vary that much, whether you sink it in trees or in exotic materials like diamonds. That means you can calculate the volume of material required so sink a desired amount of atmospheric carbon.
If you want to have a measurable impact on the atmosphere, say dialing it back to 1980 CO2 levels, you're talking not about making a pile of stuff but about making a mountain range that's a mile high and hundreds of miles long.
Now figure out how many trucks you're going to need to move that much material from where your sequestering machine is to where your pile of stuff is.
Or if you want to dump that material in the ocean (which someone else will certainly object to), extend your calculation to figure out how many container trucks worth of material you need to dump into the ocean every hour to accomplish your atmospheric cleanup in whatever amount of time you choose (a decade? If it takes a century, that's not fast enough).
And finally think about surface to volume ratios. You're trying to sink it into a volume, but you can only get the gas into the volume through its surface, so the speed of your process is limited by surface area.
If you want to do it with trees, my personal spitball estimates are that you probably need to plant somewhere between the entire state of Connecticut and the entire state of Colorado to have the kind of impact one would want (there's more subtlety to tree calculations than one generally likes to admit, so feel free to come in with way higher numbers than I did).
Which brings us back to economics. If you have a well-managed forest of that size and scale, someone is eventually going to come along, maybe in 100 years, maybe in 500 years, and say "hey if we cut this down, we could burn the wood to heat our homes" and all that carbon goes back into the atmosphere, so you actually need to sink it into something that is energetically unfavorable for recovery, which means you also need to expand a huge amount of energy to sink the carbon into that energetically unfavorable state.
Just to put it into numbers, wikipedia has the total amount of CO2 on the global warming page, if we assume it's in a 2 g/l substance it totals to around 180 km^3.
1. Even if we do magic and emit nothing, we still need to remove CO2 from the atmosphere or it will cook us over time, just longer.
2. We would need an enormous area for forests (which i great), which would mean a lot of intervention, like resettling people, demolishing and constructing new buildings, a lot of machinery time to move people to and from the new forests, a lot of planting and forest maintenance involved. And add he work to cut and bury resulting wood. If you would sum all the incidental emissions from this process it would rapidly become much less efficient (if at all).
Without either CO2 capture or a sun shade of some sort, the CO2 levels and temperature will only ever increase, just like now.
The largest sous-vide cooking pot ever...
In this case, it looks like they get CO2 as a gas. It's cheaper because you don't have to use energy to undo the burning, but it's difficult to store for a long time.
(I'm not sure if someone tried to make a fake underground bog in abandoned mine. Just fill with wood and water to keep the oxygen low and make the wood decompose slowly.)
Not really, forest fires happen and then a few hundred of years of sequestered CO2 gets released back in an instant.
Organic material with oxygen gas floating around is not stable.
Sequestering carbon into the ocean might be a better strategy. Not flammable and not subject to stupid capitalism effects around land prices.
Using something like this to capture carbon from an exhaust pipe might be viable, but scrubbing CO2 out of the atmosphere is not even remotely viable. There's just too much air out there.
The problem is the same, the relative concentration of oxygen in air is less than 0.05% (~450pars per million). In water much less.
How long and how many terawatts of power do you think it'll take to suck a significant fraction of the earth's seawater through a capture facility?
One application I think is neat is that it’s a pretty robust refrigerant in a heat pump application.
I can't find a good link now, but at least it's the only method I know where it's not obvious that requires a huge amount of energy that makes the whole process net negative.
Electro Carbon https://www.electrocarbon.ca/en
https://sustainablebiz.ca/clear-the-runway-electro-carbon-be...
Their process for generating potassium formate is greener than standard methods. It does require electricity as an input but that can come from renewable, green sources.
Potassium formate is used in de-icing products, fertilizer, heat transfer fluids, drilling fluid, etc... so a useful, monetizeable output comes out of the process.
Disclosure - Know the founders personally. Wanted to shoutout their work. No financial ties to the company.Chemistry is not at all my expertise & I don't have details on their process beyond what's on the website.
IDK, build houses out of limestone like we have been doing for ages.
/s
One of the subplots from the excellent Delta-V series by Daniel Suarez.