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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

#71

Post by marcosdumay »

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…

> 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.

Re: Efficient method to capture carbon dioxide from the atmosphere

#72

Post by omgJustTest »

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…

citation for the co2 scrubbers in home need?

Re: Efficient method to capture carbon dioxide from the atmosphere

#73

Post by marcosdumay »

yodon wrote: post #48
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…

Do you have a citation for that 20 years estimate?

https://gml.noaa.gov/ccgg/trends/

Extending the current exponential for 20 years, we get into the 500ppm region.

I don't think that's enough to need scrubbers.

Re: Efficient method to capture carbon dioxide from the atmosphere

#74

Post by lokar »

_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…

Really? Wow, I try to keep my place at 500-600, without that much effort.

Re: Efficient method to capture carbon dioxide from the atmosphere

#75

Post by marcosdumay »

condensedcrab wrote: post #13

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.

Re: Efficient method to capture carbon dioxide from the atmosphere

#76

Post by nkmnz »

HPsquared wrote: post #39
cjbenedikt wrote: post #21

Earlier quoted context omitted.

You can combine it with H2 to produce synthetic fuels. Not ideal but could reduce fossil fuel use and hence new CO2 released.

Third ingredient missed out: lots of energy.

The reaction of 3 H2 + CO2 -> CH3OH + H2O is exergonic, so the H2 already brings all the energy needed.

Re: Efficient method to capture carbon dioxide from the atmosphere

#77

Post by fsckboy »

nephihaha wrote: post #56
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...

Trees have advantages that go beyond bureaucratic aspects of environmentalism.

I think that I shall never see a poem lovely as a tree. -- Joyce Kilmer

Re: Efficient method to capture carbon dioxide from the atmosphere

#78

Post by ekianjo »

_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…

> high CO2 levels cause cognitive impairment

Sounds seriously unlikely. How would this work in practice, at the level of bodily functions?

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