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Efficient method to capture carbon dioxide from the atmosphere

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Re: Efficient method to capture carbon dioxide from the atmosphere

#171

Post by teiferer »

Teever wrote: post #134
teiferer wrote: post #88

Earlier quoted context omitted.

With ice caps melted off, just removing all the excess CO2 isn't even enough since with that reflective surface gone, more energy from sunlight stays in the atmosphere than previously when more of it was reflected back into space instead of nowadays being absorbed by the ocean.

Absolutely. People seem to think that we just need to recycle more, seal some cracks in the house with foam, install some solar panels, and buy an electric car. They underestimate the scale of the intervention that will be required to stave off the potential end of human civilization as we know it. If we have any hope of continuing to live at something resembling the quality of life that we've grown up in it will req…

> If we have any hope of continuing to live at something resembling the quality of life that we've grown up in

Chances are, developed countries won't be hit that hard, at least for a generation or two.

Re: Efficient method to capture carbon dioxide from the atmosphere

#172

Post by tzs »

yodon wrote: post #37
cyphertruck wrote: post #2

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.

>Economics rules everything 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,…

If we took all the CO2 out of the atmosphere and converted the C into graphite and spread that uniformly over the top 10 subtropical deserts it would be around 2 cm deep.

This suggests a long term approach of building solar powered carbon capture plants in subtropical deserts, they capture it and convert to graphite, which is then spread out under the solar panels.

I once did the math on this, using the specs for currently available solar powered carbon capture, and it came out to something like if we used 100 years worth of the current production annual production of solar panels for this we could carbon capture at a rate that could drop the atmosphere from current levels of CO2 to pre-industrial levels in a few years even if we do not reduce emission rates.

So...not practical now, but might be feasible as a very long term project that over many decades builds out enough capacity to get things under control as long as we can keep everything from going to hell over that time.

Re: Efficient method to capture carbon dioxide from the atmosphere

#173

Post by DivingForGold »

condiment wrote: post #45

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…

"outperform" by only one metric too often fails usefulness. It's a one shot unless you heat the calcium carbonate to 900C, the compound in the article only requires 70C, and has quite a bit of ability to re-process CO2 absorption multiple times. Although solar ovens could reach over 900C, probably too dangerous for residential use.

Re: Efficient method to capture carbon dioxide from the atmosphere

#174

Post by sfn42 »

j_maffe wrote: post #63
sfn42 wrote: post #20

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.

Gasses diffuse through the air very quickly. Having a few high-volume extraction points would be enough long-term.

Yeah except the highest volume facility in the world is called mammoth and in order to offset our current emissions we would need a million mammoths.

Even if you could make it a thousand times more efficient it would be a stretch.

Re: Efficient method to capture carbon dioxide from the atmosphere

#175

Post by bilsbie »

condiment wrote: post #45

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…

Just to counter your extreme prediction, if co2 levels halve from here all life on earth goes extinct.

https://www.researchgate.net/post/Minimum_necessary_concentr...

Re: Efficient method to capture carbon dioxide from the atmosphere

#176

Post by arkensaw »

dylan604 wrote: post #49
roflmaostc wrote: post #4

Earlier quoted context omitted.

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). Recent article: https://www.theguardian.com/environment/2025/nov/28/africa-f...

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.

using the wood for heating also releases the CO2. I do think planting trees is a good idea, but it's worth pointing out they can be a carbon source even after harvesting, depending on the usage.

On the other hand if the wood is used for construction or furniture it will not emit.

Re: Efficient method to capture carbon dioxide from the atmosphere

#177

Post by moktonar »

I read somewhere that electrolysis of marine water could emit enough oxygen, while also harvesting hydrogen, to counter CO2 emissions, but I can’t find the source, has anyone heard of it before or am I filling the gaps of my memory with generated garbage?

Re: Efficient method to capture carbon dioxide from the atmosphere

#178

Post by manoDev »

roflmaostc wrote: post #4
cyphertruck wrote: post #2

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). Recent article: https://www.theguardian.com/environment/2025/nov/28/africa-f...

Planting trees solves both the carbon capture and the emissions issue from different angles. Some examples are:

- With more wood available it’s more economical to use it as a building/manufacturing material over other emissive sources (concrete, steel, plastic)

- We can replant the same area multiple times

- Even if we plant crops for biofuels, it’s closer to carbon neutral than burning fossil anyway

Every move we can make towards planting (and managing) more of the surface of the Earth is an improvement, without waiting for miraculous new technology.

Re: Efficient method to capture carbon dioxide from the atmosphere

#179

Post by thangalin »

_yb2s wrote: post #67
condiment wrote: post #45

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…

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 hea…

> I think it’s little appreciated that high CO2 levels cause cognitive impairment

Have you been telling representatives? Here's a letter I wrote to mine:

https://pdfhost.io/v/bRJEGptatL_climate-change

Re: Efficient method to capture carbon dioxide from the atmosphere

#180

Post by wincy »

vasco wrote: post #133
jmward01 wrote: post #114

I am not against doing research in this area, please do, it is interesting and likely has many applications but global CO2 removal isn't one of them. Nothing proposed, including this, is within any orders of magnitude of a viable solution. The only solution we have is put less in the air in the first place. This tech looks interesting for transporting CO2 but that doesn't mean it sequesters it and even if sequestrati…

There's no general will, it's not specifically political will. Emitting less CO2 means doing less things or doing them for much more money due to high taxes to discourage it (and also disproportionately affect poor people). Other than some luddites I've never met anyone that genuinely was willing to sacrifice eating a nice steak or going on vacation unless they are millionaires, and that's only because those people k…

I grew up in a trailer, and last month I flew halfway across the country and ate at a Michelin star restaurant that fed me truffles flown from Italy.

I am definitely part of this group you describe.

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