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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

#61

Post by nilamo »

sfn42 wrote: post #30
cjbenedikt wrote: post #23

Earlier quoted context omitted.

You can actually capture CO2 from sea water thereby reducing ocean acidification and improving its capability to continue as our planets biggest CO2 sink.

Well here's the thing - there's quite a lot of water out there too. 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?

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?

Re: Efficient method to capture carbon dioxide from the atmosphere

#62

Post by 29athrowaway »

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…

Maybe we just need to make cyanobacteria that multiplies faster.

Re: Efficient method to capture carbon dioxide from the atmosphere

#63

Post by j_maffe »

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.

Re: Efficient method to capture carbon dioxide from the atmosphere

#64

Post by idiotsecant »

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://en.wikipedia.org/wiki/Carbon_dioxide_in_the_atmosphe...

Just extrapolate.

Re: Efficient method to capture carbon dioxide from the atmosphere

#66

Post by raverbashing »

Teever wrote: post #57
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.

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…

Yes

For the atmospheric one, grow trees and algae

Re: Efficient method to capture carbon dioxide from the atmosphere

#67

Post by _yb2s »

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 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.

Re: Efficient method to capture carbon dioxide from the atmosphere

#68

Post by jiehong »

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…

Could something like this be used to make cement?

Imagine capturing CO2 to turn it into cement, used for constructions.

Pardon my ignorance, though.

Re: Efficient method to capture carbon dioxide from the atmosphere

#69

Post by umeshunni »

nilamo wrote: post #61
sfn42 wrote: post #30

Earlier quoted context omitted.

Well here's the thing - there's quite a lot of water out there too. 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?

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?

The earth doesn't die because CO2 levels increase. There have been multiple epoch with higher CO2 concentrations than we have now.

Re: Efficient method to capture carbon dioxide from the atmosphere

#70

Post by adregan »

OsrsNeedsf2P wrote: post #35
adregan wrote: post #26

Earlier quoted context omitted.

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.

It's little appreciated since tree growth still consumes CO2

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.

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