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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

#51

Post by pgrohe »

Detrytus wrote: post #3

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.

A startup from Quebec is using an electrochemical process to produce potassium formate from CO2.

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.

Re: Efficient method to capture carbon dioxide from the atmosphere

#52

Post by netcraft »

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?

I was also a bit skeptical, but chatgpt gave a pretty good answer I think: https://chatgpt.com/share/69553e26-ea28-8011-bc17-8658fbea4e...

Buildings with higher people/sqft could already take advantage of indoor co2 scrubbers today.

Re: Efficient method to capture carbon dioxide from the atmosphere

#53

Post by adrianN »

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…

You can heat definitely heat NaHCO3 to get CO2 and NaOH back. It just takes a lot of energy.

Re: Efficient method to capture carbon dioxide from the atmosphere

#55

Post by comicjk »

elil17 wrote: post #14

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.

Re: Efficient method to capture carbon dioxide from the atmosphere

#56

Post by nephihaha »

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...

Trees have advantages that go beyond bureaucratic aspects of environmentalism.

Re: Efficient method to capture carbon dioxide from the atmosphere

#57

Post by Teever »

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 "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.

Re: Efficient method to capture carbon dioxide from the atmosphere

#58

Post by adrianN »

cjbenedikt wrote: post #28
gus_massa wrote: post #6

Earlier quoted context omitted.

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…

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?

Re: Efficient method to capture carbon dioxide from the atmosphere

#60

Post by condensedcrab »

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…

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.

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