Carbon dioxide capture from open air using covalent organic frameworks | Hacker News Reader

Carbon dioxide capture from open air using covalent organic frameworks

nature.com

Before anyone points out that trees already handle this, let me clarify:

We need to pursue all available options simultaneously to effectively combat climate change. This includes:

    Reducing reliance on carbon-based energy to lower emissions.
    Implementing carbon capture and long-term storage solutions to remove excess CO₂ from the atmosphere.

+ it can be worked out based on photosynthesis efficiency and available surface area that we would need ~4 earths of trees to handle current human CO2 production rate

Planting trees is nice and should be done but isn’t a solution for drawdown

Fully agree. In my college ecology course, my professor stressed that sequestration/capture, while not ideal, will likely be crucial as our production of greenhouse gases outpaces the rate of absorption by plant biomass and ocean algae.

Sequestration underground doesn't really work. It is based on lies. It will just bubble back up when the Earth's plates move. For capture to work, it has to be reacted with a stable absorber, so it cannot bubble back up into the atmosphere.

This.

We have a worked example for geologically stable carbon sequestration without any novel chemical bonding, and that's storing carbon in compounds that are mostly unhydrogenated carbon by mass, deep underground:

Charcoal. If you aim to sequester carbon without some kind of reactant (and most reactants are incredibly energy intensive to make & stage, burning more CO2 than captured), you have to effectively make charcoal. Growing a forest, pyrolyzing it, and burying the charcoal, is the inverse process of coal mining, and is the default comparator on cost, effort, and materials for any sort of carbon sequestration scheme.

There is not nearly enough available space on the surface of Earth to make any dent into the atmospheric carbon dioxide concentration over any relevant time frame. We burnt through millions of years of sequestrated carbon in a century and some, but we do not have millions of years to do the sequestration again.

If we solve fusion, or even if we exploit space solar on a massive scale, we should in principle have all the energy we need to put the carbon back into charcoal.

Sure, with enough energy we can do whatever we want, but we just do not have enough clean energy, that is the very problem carbon capture is supposed to address.

It would be completely disingenuous to use carbon capture as an excuse to continue the use of fossil fuels. Firstly, it will be so price inefficient. Secondly, it delays the inevitable, meaning the transition to clean energy, as some European countries already have accomplished.

The demand for carbon capture makes more sense after we have already transitioned to clean energy, as we can then begin to reverse the damage that excess CO2 and methane have been causing. The financial model for doing this is by a long-acting insurance firm that not only collects insurance but also uses the premium to preemptively take restorative actions.

Carbon capture is of course less efficient than not burning fossil fuels to begin with, so the first goal must be to no longer emit new carbon. Then it may make sense to capture some carbon and turn it into synthetic fuels for certain applications because of the energy density and ease of storage. Maybe even for plastics and similar stuff. After that, undoing a century of emissions, that is a monumental challenge. Depending on how exactly we want to store the carbon, we might need more or less the same amount of energy that we got out of fossil fuels over the last century. Double our renewable energy generation capacity and then use half of it for half a century - roughly taking into account the increase in emissions over the past century - to capture carbon.

So...

No.

That's almost certainly a dumb idea. Always was. A red herring from the fossil fuel companies.

Obviously digging 1000kg of coal out of the ground, burning it to make electricity, and using that electricity to _synthetically create more coal_, and putting that back deep underground, is not going to put away even 100kg of carbon; You're probably lucky if you get 10kg given that CO2 is a trace gas.

You can do it cheaper, if you're willing to tolerate the carbon having less than the geological stability of coal. But then the ground burps and you're back to square one.

The part of carbon sequestration that isn't insultingly is the question of what happens once we've destroyed all the fossil fuel infrastructure and replaced that part of our civilization with renewables and (since it's always going to be advantageous to be a free rider) a good number of bomb craters.

My suspicion is that even when we get to that point, sequestration of 1kg is _so much more difficult_ than emission of 1kg was, that there's still a vast gulf between being at that point, and the point where we have the excess resources sufficient to sequester significant portions of the atmospheric carbon artificially. Probably instead, we end up coasting for a long while to see how much the biosphere can put away on its own; If we have climate change issues, we deal with them via stratospheric sulfur injection and by stochastically just adapting our footprint on the planet.

But I'm willing to be persuaded on this point. Perhaps there's work to be done with some kind of advantageous catalyst, mineral reserve & reaction (olivine maybe?), some way to cheat the system in the long run. I just don't think it's especially relevant to our plight in the short term.

The point is, charcoal production is the default method of carbon sequestration, the reliable null hypothesis by which you have to measure any other method, the denominator of human effort in this venture. No, even charcoaling the entire Earth's forests is nowhere close to sufficient to offset coal production (how the fuck could it be? The Carboniferous epoch was 60 million years long and we're going to run through its detritus in less than 600 years!), but a project to run a country-sized forest through the oven and into the mines every year is the _baseline_ for future meaningful effort.

Burning fossil fuels for energy to then unburn carbon dioxide is of course idiotic, one has to use renewable energy sources. If you could make more synthetic fuel than you put into the process, then you would have a perpetuum mobile. That is also why my comment says clean energy. But even then, read my other comments and you will see that I am extremely sceptical because of the scale of the problem.

CO2 levels over 600 ppm indoors already start to hurt cognitive function and cause drowsiness in me. Due to the cold, I have been managing with 550 ppm in the winter, otherwise with 500 ppm in the summer. A decade ago, the indoor level easily was 100 ppm lower. This is becoming a problem fast as I run up against the 600 ppm threshold. The older you get, the more intolerant you become to high CO2 if you want good cognitive function.

The point is that no, sulfur injections aren't going to fix climate change, nor will a solar shield. The reason is that they leave high CO2 on the ground which harms cognition. One can't really make a living with a deteriorated mental function.

The papers lead author stated that 200g of the material can absorb as much CO2 in a year as a tree.

Optimistically [1] 200 g can capture 250 kg carbon dioxide per year, at the expense of heating the material almost 28,000 times from ambient to 60°C. And that still leaves you with 139 m³ of carbon dioxide gas, what do you do with that?

[1] 2.05 mmol/g at half capacity equals 45 mg/g per cycle, and ignoring heating and cooling times one can fit 27,976.6 cycles into a year. Overall that is 1.262 kg/g/y.

Cool, we only produced 37 000 000 000 tonnes of co2 in the last 100 years

That is last year alone. Over the last 100 years it is probably more like 50 times that.

Indeed, that's per year: https://ourworldindata.org/co2-emissions

What is that supposed to mean?

According to their calculations, they're getting 1-2mmol/g adsorption. That means 44-88g of CO2 captured per kilogram of adsorbent.

My guess is that it means that the material can be reused by capturing/releasing/sequestering multiple times, and that number reflects how much C02 it can capture given how many cycles can be completed in one year.

According to studies about batteries we should have electric planes since 2010 and we should be able to recharge any battery instantly regardless of their size. Ah and these batteries would be very cheap too

And that's if:

- the study can be replicated

- the study wasn't altered to boost publishing metrics

Remember super conductivity at room temperature from a few months back ?

> We need to pursue all available options simultaneously to effectively combat climate change.

lol, all available options as long as we don't actually look at the root cause and just throw more money and tech at it in the hope it automagically stops

hint: infinite growth in a finite system doesn't work

PS: and if you care about results, we've been exploring every solution for quite some time now, you know after all our leaders get together in Paris or other fancy place and talk about clean solutions. Well we've been release more CO2 every year. The only time it dipped was during covid when ... you guessed it ... we had negative growth, aka degrowth. We never had so much sustainable energy production but we also never produced so much co2 and pollution

We can throw about causation arguments till the rivers dry up. Will it get us anywhere? Doing something will always win against doing nothing because we're fighting over who has the most virtuous opinion.

> Doing something will always win against doing nothing

Yeah, like we used to pray our gods for more rain, it certainly doesn't hurt, proving it is useful is much more difficult though.

We focus on co2 because it's the only thing we can pretend to be able to tackle a little bit while ignoring the rest like ocean acidification, massive global collapse of wildlife, including insects, rainwater being unsafe to drink pretty much everywhere in the world, micro plastics polluting the entire planet and virtually every single living organism, PFAs, increase in chances of world wide simultaneous crop failure, &c.

99% of what we're doing is green washing or wishful thinking (or sinking, when it comes to co2), the truth is that we won't be able to sustain the western lifestyle much longer, especially not when China, India, and Africa are coming for their slice of the cake

If you think 3000kg EVs transporting 80kg of meat and niche carbon sinking tech will save us I have a bridge to sell you.

Degrowth doesn't work either, it's not a solution and nobody will ever go for it. From the abstract of Reviewing studies of degrowth: Are claims matched by data, methods and policy analysis?:

> (2) the large majority (almost 90%) of studies are opinions rather than analysis;

> (3) few studies use quantitative or qualitative data, and even fewer ones use formal modelling;

> (4) the first and second type tend to include small samples or focus on non-representative cases;

> (5) most studies offer ad hoc and subjective policy advice, lacking policy evaluation and integration with insights from the literature on environmental/climate policies;

> (6) of the few studies on public support, a majority concludes that degrowth strategies and policies are socially-politically infeasible;

Source: https://www.sciencedirect.com/science/article/pii/S092180092...

> Degrowth doesn't work either

It's literally the only mathematically viable option. Either you choose it and plan for it or you hit the wall and deal with the consequences. Just take a gpd per capita world map, superimpose it over a pollution per capita world map, and extrapole the impact of china+india+africa living like the average american or even the average european, it just doesn't work out, but it's coming very soon

It's not coming very soon because those populations are going to completely skip the phase where every household has 2 or 3 fossil fuel vehicles.

Personal transportation is about 15% of co2 emissions. That hardly explains why the average American lifestyle produces literally 10 times more co2 than the average Indian's

> Either you choose it and plan for it or you hit the wall and deal with the consequences.

That's the problem though, without a sea change in human behavior, nobody will ever choose it. As the paper I linked points out, degrowth is a political self-own. Nobody likes it, nobody wants it, and hardly anybody has even studied it properly. Planning on hitting the wall and dealing with the consequences is our reality, so studies like the OP have a real and practical use.

At this point we need net-zero. Degrowth cannot get us to 0, nor can it get us anywhere close to zero.

See the problem is that we want to continue doing everything in the exact same way without giving up on any single little eccentricity we have no matter how ridiculous and how stupidly unsustainable they are, not a single damn thing

Degrowth is also stopping to eat tomatoes in the middle of January instead of importing them from the other side of the world, or not eating fucking salmon when you live in South Africa, or not using a 3000kg car to move you 80kg ass around the street to go shopping. Or things like not living in the desert and relying on AC and artificial rain to keep you alive because you would physically die if you were to experience the outside world for more than an hour

And by making all of those changes you'll lower carbon emissions by about 10%.

OTOH, switching to zero-carbon electricity and zero-carbon transportation would lower carbon emissions by 60%.

> switching to zero-carbon electricity and zero-carbon transportation would lower carbon emissions by 60%

Is the 0 carbon mining and 0 carbon steel in the room with us right now ?

What about the 0 carbon asphalt ? 0 carbon tires ? 0 carbon cement to build your 0 carbon power plant ? 0 carbon plastic to build your 0 carbon solar panels ?

fyi steel is still made with coke, 1700s century style, and nothing is even close to ready to replace it, and you need it in virtually every car and building

When you actually look into it you will quickly realise it raises way more questions than it brings answers. And then you realise we already mined all the easy shit, now it's getting harder and harder to find the good stuff, harder meaning more energy intensive, it also means more soil to go through which means more chemicals to use (and guess what, most of it is petrol derivates), which means more tailing dams, more pollution, more wild life ecosystems destroyed, &c.

Anyone looking into the problem with an ounce of good faith cannot reach a conclusion as simple as yours. If you're still at the "electric cars " will save us I envy you, life was simpler back then

IMO, my solution is far less simple and hand-wavy than yours is. I can point to several books with solutions on how to get from my 60% solution to a full zero-carbon future.

There is no degrowth based path that gets us to 0 carbon except for degrowth to 0 humans.

Meanwhile, after decades of "we tried everything" we produce, year after year, record levels of co2

You can look at it any way you want it simply doesn't work, it's not enough to wish for it.

There is no 60% solution, not even close, so it doesn't matter if a sci fi books mention a 0 carbon future

CO2 levels have been dropping on a per capita basis for several years and are expected to drop on an absolute basis in 2024 or 2025.

It's worth noting that this lab has a lot of patents: https://yaghi.berkeley.edu/publications.html#patent

It's not clear that this particular chemical is subject to a patent application, but they have applied for a patent on the entire class of chemicals: https://patents.google.com/patent/US20220370981A1

I'm conflicted about this. while I'm skeptical about most patents this is exactly the kind of invention that patents are supposed to incentivise, and this guy obviously deserves a reward if his invention, like, literally saves the world. But - reading between the lines, while it's effective, it sounds like it's not yet cost effective. And making something cost effective is exactly the kind of thing that patents that restrict development to a single lab (which is what a class patent will do) will cause problems with.

Probably the best answer would be for someone rich to buy him out and licence it for free.

News article from Berkley, where it was developed.

https://news.berkeley.edu/2024/10/23/capturing-carbon-from-t...

To counteract the current carbon dioxide emissions, we only have to heat up 30 million metric tons of that stuff from ambient to 60°C every 18.8 minutes. And then figure out what to do with the 1.35 million metric tons carbon dioxide gas cloud we produce every 18.8 minutes.

Related: Half a pound of this powder can remove as much CO2 from the air as a tree (21 points, 40 days ago, 45 comments) https://news.ycombinator.com/item?id=41927684

See also: metal organic frameworks. Cheaper to produce and faster at adsorbing.

https://en.m.wikipedia.org/wiki/Metal%E2%80%93organic_framew...

I think such an appliance had already been invented. They are called "trees".

All they need to do their work is corporations leaving them alone.

Old trees don’t capture much CO2. It’s only young, growing trees that have a meaningful impact. Need a lot more than fewer corps

And any operation of planting and cutting to drawdown CO2 must bury or properly process the biomass to actually put co2 somewhere

Else it is an open cycle where co2 in == co2 out

Great thing about wood is you can build almost-permanent structures with it?

And the remaining biomass (leaves, bark, etc.) is fine to compost and re-enter the carbon cycle.

Also it's clearly not an open cycle, not in temperate climates. The accumulation of carbon in top soils etc. is one of the things that kept CO2 in balance for millions of years prior to us pulling it out of the ground. Peat bogs being another key one.

Yes, it can't keep up with us. But it's not an open cycle. (It is in the tropics, though)

You can build permanent structures from wood, but consider the sheer volume of wood that would be needed to counter current CO2 increase.

Best thing we can do is stop pulling it out of the ground. Best way we can do that is to build out renewables. Best way to do that is to create a profit incentive for an oversupply of power that sucks up carbon.

It's crazy how fast poplars grow in temperate climates. And absorb excess nutrients and contaminants.

Would love to see huge fields of them grown, then harvested, and the product turned to lumber and other longer-term carbon storage. Even composted or biocharred and the carbon amended into top soils (yes it won't stay there forever, but...) Assuming the process can be done without emitting more CO2 than is captured.

2/3 of the CO2 is stored in the soil, cutting "old trees" is the best way to release all that CO2.

Until you do the math, then you see how bad a solution trees are.

It's the same reason biofuels cannot be a general replacement for fossil fuels.

Growing trees is nice for other reasons, of course, and some limited CO2 capture would come along for the ride. This would not eliminate the desirability of other kinds of CO2 capture.

> Until you do the math, then you see how bad a solution trees are.

If you do the math the only sensible solution is hardcore degrowth starting yesterday.

I disagree completely, although degrowth may end up happening eventually due to low birth rates.

If rapid degrowth could be enforced, so could switching to sustainable technologies, which do exist and could be employed.

The level of degrowth needed to avoid warming from fossil fuel use would be extreme, if it's the only knob turned. Even a 90% reduction in the rate of fossil fuel extraction and use would not avoid eventual massive global warming. Degrowth would simply delay that outcome.

> Degrowth would simply delay that outcome.

And growth accelerates it...

Just look into cement, steel, mining, medicine &c. we're not even remotely close to replace fossil fuel, not even a tiny bit, no one even pretends that it's around the corner.

> would not avoid eventual massive global warming

Well nothing will because in a couple of hundred millions years the sun will be too warm anyways

Meanwhile 70% of the wildlife disappeared since 1970, 50% of insects, and we're debating about some shitty tech that would sequester 0.1% of the co2 we emit each day. CO2 isn't even our biggest problem, rain water isn't even safe to drink anywhere on the planet anymore, PFAS, microplastics, chemicals in rivers/lake/aquifers

People who think co2 capture and that replacing 1.4b of ICE by 1.4B of 3000kg EVs are the future are delusional or straight up cognitively impaired

I find the microplastics bit has all the odor of an unhinged panic. There seems to be quite a lot of dubious science being done. For example, a few years ago there was a study that said we eat up to 5g of microplastics a week. This figure was widely quoted in the press, with images of a credit card (about 5g) held in chopsticks as an illustration. But critical examination of the paper and the methodology concluded it overestimated the rate of ingestion by as much as a factor of a million.

Underlying all this is the moral approach being taken. It is not enough that environmental problems (perceived or otherwise) be solved; humanity must be punished. Solutions that do not also punish are rejected on that basis alone.

We find microplastics in foetus brains, if your immediate thought is "meh ok it's probably fine" you're already beyond saving, all of that for what ? Cheap gadgets, some convenience and comfort

> humanity must be punished

We're punishing ourselves right now... look at our food, 75% obese/overweight in the west, 15% of US population on antidepressant, life expectancy going down, testosterone levels dropping 1% per year from the 80s if not before, massive wildlife collapse, nutrients in veggies/fruits massively dropped since the 50s, increasing floods/hurricanes/&c.

> Solutions that do not also punish are rejected on that basis alone

If you're about to get lung cancer because your smoke 1 pack a day you can always tell your doctor you started drinking green tea to get extra antioxidants, as long as you smoke 1 pack a day you're doomed.

> We find microplastics in foetus brains,

That's another study I am skeptical about.

I imagine if you cherry pick everything that goes your way and trash the rest it makes a very nice little fairy tale in which we can continue on our merry way without ever facing any kind of consequences

I harp on this. Unless I biffed my calcs a solar farm produces 25-50 times as much energy per acre as corn. That alone tells you biofuels is a dead technology.

A solar farm doesn't need to be weeded, ploughed, planted, weeded again, topped, and harvested every year like corn does. You also don't need to ferment it to ethanol then burn it at a 70% loss to power a set of wheels.

Possible also that the vegetation growing between and under the panels sequesters carbon.

And the solar farm doesn't transpire quite the enormous quantities of water a field of corn does. So much water goes into the air from a corn field it affects the weather.

I wouldn't say biofuels are a dead technology, but they are niche. They may be useful in a post-fossil fuel age for things that are very difficult to electrify, like long distance air travel and production of organic chemical feedstocks.

Albedo & moisture

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