Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Efficient method to capture carbon dioxide from the atmosphere

helsinki.fi

Post reply on HN
Print view View original

271–280 of 349 posts

Re: Efficient method to capture carbon dioxide from the atmosphere

#271

Post by nine_k »

mikestorrent wrote: post #241
fodkodrasz wrote: post #236

Earlier quoted context omitted.

I guess Coke. https://en.wikipedia.org/wiki/Coke_(fuel)

How are we getting that out of a tree

https://en.wikipedia.org/wiki/Charcoal

Did you ever do a barbecue? You first burn the light, hydrogen-rich substances of the firewood, with a large beautiful flame; that flame would burn down the meat, but it burns off quickly. What remains is charcoal, the source of most heat in the firewood; it does no produce a visible flame, but emits a lot of heat. It is mostly carbon.

Re: Efficient method to capture carbon dioxide from the atmosphere

#272

Post by BurningFrog »

IshKebab wrote: post #266
PeterHolzwarth wrote: post #84

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 rea…

Also more fundamentally it's always going to be more efficient to not produce CO2 than to unproduce it. Ok maybe in a small number of circumstances there's no other option (e.g. planes), but mostly you're far better off spending your energy making solar, wind, batteries, heat pumps, insulation etc.

It's hard to put my finger on why, but that's a really weird way to frame the situation.

For one thing, most of us don't control any CO₂ production we can turn off.

Also, even if/when we finally produced our last CO₂ molecule, the excess CO₂ will last for many centuries, and we really should get it back to lower levels.

With good capture tech, you can keep keep doing some important CO₂ producing activities.

Sure, it seems very unfeasible with current technology, but that is bound to improve as you work on it.

Re: Efficient method to capture carbon dioxide from the atmosphere

#273

Post by roughly »

rayiner wrote: post #235
teknopaul wrote: post #192

Earlier quoted context omitted.

Covid proved this generalisation is not a truism. USofA was probably the only place that actively resisted the global effort. I think people do want a better world. Greed is not universal. Most countries that grow a middle class find most people prefer to stop work. I.e. there are not that many infinitely greedy humans. And they can be taxed. Despite neocon economic theory, most people aren't selfish. And those that…

COVID didn’t cost anyone anything in terms of improved standard of living. Curbing emissions growth would do that. People aren’t “greedy,” but my family in Bangladesh absolutely wants to live like my family in America, or at the very least like my family in Canada. They don’t consider that “greedy” and if you tell them it is they’ll laugh at you. The country’s CO2 emissions per person have increased by a factor of 5x…

> COVID didn’t cost anyone anything in terms of improved standard of living. Curbing emissions growth would do that.

We live in a horrendously inefficient way. We ship everything from half way around the world in diesel ships, trucks, and trains, we buy shitty single-use plastic items packaged and shipped in single-use plastic packaging, we replace our phones instead of our batteries, our clothing and shoes degrade within a couple years, our restaurants and grocery stores throw away half the food they purchase, our agricultural system spends nitrogen and pesticides like they're free to grow corn as an industrial chemical component. I don't know exactly how much meat there is on that bone, but there's a whole lot of emissions we could remove that wouldn't negatively impact our lives and would probably improve them.

Re: Efficient method to capture carbon dioxide from the atmosphere

#274

Post by petermcneeley »

PeterHolzwarth wrote: post #84

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 rea…

And yet trees do this trivially?

Re: Efficient method to capture carbon dioxide from the atmosphere

#275

Post by petermcneeley »

verytrivial wrote: post #247
PeterHolzwarth wrote: post #84

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 rea…

Indeed. I've always had trouble picturing how to efficiently "unmix the cake" too. CO2 is rare and throughout the whole atmospheric column. What kind of concentration gradient can you get going to meaningfully pull it out from everywhere in human timescales? (Sorry if this nerd-snipes someone stronger with calculus than me.)

Diffusion and convection would do all the work. You dont need to worry. You can see the stuff mix around https://www.youtube.com/watch?v=-aSBfn6_pUY

Re: Efficient method to capture carbon dioxide from the atmosphere

#276

Post by IshKebab »

BurningFrog wrote: post #272
IshKebab wrote: post #266

Earlier quoted context omitted.

Also more fundamentally it's always going to be more efficient to not produce CO2 than to unproduce it. Ok maybe in a small number of circumstances there's no other option (e.g. planes), but mostly you're far better off spending your energy making solar, wind, batteries, heat pumps, insulation etc.

It's hard to put my finger on why, but that's a really weird way to frame the situation. For one thing, most of us don't control any CO₂ production we can turn off. Also, even if/when we finally produced our last CO₂ molecule, the excess CO₂ will last for many centuries, and we really should get it back to lower levels. With good capture tech, you can keep keep doing some important CO₂ producing activities. Sure, it…

> most of us don't control any CO₂ production we can turn off.

Uhm what? Driving? Flying? Heating?

> Sure, it seems very unfeasible with current technology, but that is bound to improve as you work on it.

Improve, yes. Break the laws of thermodynamics? No.

You can improve a perpetual motion machine but it's never going to be useful.

Re: Efficient method to capture carbon dioxide from the atmosphere

#277

Post by jmward01 »

ctoth wrote: post #129
ctoth wrote: post #124

Earlier quoted context omitted.

> If we don't have the political will to reduce the amount going into the air then what makes anyone think we would have the political will to build out some system to capture and sequester? Because political will requires coordination, building systems and turning them on doesn't have to! > We need to focus more on not putting CO2 into the air and less on trying to take it out. What part of the "we" in this coordina…

The implicit model in "just emit less" is that human coordination problems are easier than engineering problems. That's historically backwards. We're extremely good at building things. We're terrible at getting everyone to sacrifice simultaneously for diffuse future benefits. Please generalize this!

I strongly beg to differ. Building is the easy part. It is the political will that isn't. Try to build a train in California and it takes decades and you have a hundred different entities sabotaging you. Put five more lanes on a freeway and no drama, it just happens. We got to the moon when the political will was there but the engineering was still basically science fiction but once the political will dried up, even though the engineering was solved and 'easy', we couldn't get back. History is full of these examples.

Re: Efficient method to capture carbon dioxide from the atmosphere

#278

Post by jmward01 »

rayiner wrote: post #230
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…

> The only solution we have is put less in the air in the first place That’s not a solution either, because the developing world is not going to stop increasing their CO2 output until they fully industrialize. They’re just not. Feel free to seek reductions where you can, but don’t think of it as a solution because it’s not. The technical problems with CO2 capture are far more solvable than the sociological problems w…

Actually, solar and other renewables are making it easy to skip legacy hydrocarbon based infrastructure and the 'developing world' (not the west) is snapping it up [1]. Additionally, the big problem countries aren't really the developing world. China is rapidly hitting its targets and other than a brief moment where they threw up a lot of coal fired generation to meet immediate demand it looks like they will very rapidly decarbonize in the coming years and start having so much excess renewable energy that they will pay people to use it for manufacturing [2][3].

[1] https://www.nytimes.com/2025/12/30/climate/solar-south-afric...

[2] https://energy.economictimes.indiatimes.com/news/renewable/g...

[3]https://www.pv-magazine.com/2025/06/23/china-hits-1-tw-solar...

Re: Efficient method to capture carbon dioxide from the atmosphere

#279

Post by newyankee »

IshKebab wrote: post #266
PeterHolzwarth wrote: post #84

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 rea…

Also more fundamentally it's always going to be more efficient to not produce CO2 than to unproduce it. Ok maybe in a small number of circumstances there's no other option (e.g. planes), but mostly you're far better off spending your energy making solar, wind, batteries, heat pumps, insulation etc.

In today's world there is a roadmap for a However Chinese domination, global geopolitics being changed and fossil fuel industries and countries still being extremely large and powerful make even choosing the obviously cheapest (and incidentally clean) option difficult in many parts of the world.

Nonetheless, it seems much more optimistic today in 2025 than say 2015 speaking purely based on where technology stands

Re: Efficient method to capture carbon dioxide from the atmosphere

#280

Post by MobiusHorizons »

nxpnsv wrote: post #215
teknopaul wrote: post #190

Earlier quoted context omitted.

The is one trick that doesn't require political will. If you can make the microeconomics work it can be made to scale it self. E.G. Make CO2 extraction so cheap it's worth everyone doing it and say, make a market to sell the CO2 to farmers. Then make burying inedible bits of plants so cheap it's done on a large scale. Then you just wait. Microeconomics takes over. They did this with plastic clean up. By building a ma…

Buried plants make methane…

This is true, but can be mitigated if the plant parts are first converted to to charcoal. It’s doable, but not trivial enough for farmers to do it without some other incentive.
Post reply on HN