Skip to content(if available)orjump to list(if available)

Launch HN: AirMyne (YC W22) – Capturing CO2 from air at industrial scale

Launch HN: AirMyne (YC W22) – Capturing CO2 from air at industrial scale


·March 17, 2022

Hi HN, we are Sudip and Mark, founders of AirMyne (, but there’s nothing there yet). We’re building an industrial-scale process/plant to capture and remove CO2 from air, so it can be piped to nearby sequestration facilities and injected underground—a process that requires less energy and capital equipment than other leading solutions.

Companies spent over $1B on CO2 offsets last year, sourced primarily from landowners and project aggregators claiming to protect forested lands. Over the past few years, interest in more permanent forms of CO2 removal have led to the pilot-scale commercialization of novel bio-oil/biochar/biomass, direct air capture, mineralization, and ocean processes, but these are not yet available with sufficient capacity to meet demand. There is no silver bullet, but we believe removing CO2 from air with an industrial chemical process offers the most realistic and scalable path forward.

Capturing and sequestering CO2 from air is a huge engineering challenge. The dilute concentration of CO2 in the atmosphere (~400ppm) means a system operating at 100% capture efficiency would still need to process 2500 tons of air to capture just 1 ton of CO2. Significant energy is then required to release CO2 from the capture medium. On top of that, compressing and injecting CO2 underground requires controlling for gas leakages, dry ice blockages, and the corrosive conditions created when concentrated CO2 comes in contact with trace water vapor.

Our approach goes back to the fundamentals of acid/base chemistry. CO2 acts as an acid and will bind to a base, whether in the liquid phase or on a solid surface. We have developed a process to bring air in contact with a base substrate that captures CO2 molecules while letting N2 and O2 molecules pass through. After energy is applied, CO2 is desorbed from the substrate for downstream treatment and compression. This reversible process allows for a single stage “air in, CO2 out” system where 1 ton of substrate could capture >1000 tons of CO2 over its useful lifetime.

In the lab, we have demonstrated this approach at a gram-level scale and believe the process offers favorable energy use, planned capex/opex costs, and process complexity compared to existing solutions. (We’d love to show you a video but can’t do that yet—the chemistry & physical embodiment of the system are areas where we’re developing core IP and that process still involves some secrecy at this stage.)

As we scale this process, we are initiating discussions with other companies who can help us inject captured CO2 deep underground so it can be sequestered for geologic time scales. Sequestration technologies have improved their compression and injection processes over the years, and an emerging regulatory landscape is starting to take shape to accelerate the deployment of CO2 injection wells and mineralization projects in the US, the EU, and around the world. We intend to colocate our CO2 capture near injection facilities to minimize transport logistics.

Sudip and I both come from industry. At Honeywell, Sudip invented and scaled the low-global-warming refrigerant 1234yf used in automotive air conditioning systems, as well as a variety of products used to make displays, computer chips, sensors, solar modules, and electrical components. I invented formulations at BASF now widely used in the manufacture of silicon carbide power electronics for EVs, solar inverters, and other high power electric devices. We bring a systems engineering perspective to the C02/climate problem—our focus is not only developing, but also derisking and scaling industrial systems/processes into a business case suitable for large industrial stakeholders.

Eliminating existing emissions is the most urgent and important challenge we face to keep the climate habitable, but removing CO2 from the atmosphere will likely be needed too. Tackling this problem head-on opens up other fascinating possibilities. By focusing on the “extreme user” case of removing dilute CO2 from air, we might develop unique innovations or insights applicable to the point-source capture of more concentrated CO2 streams such as industrial flue gases. And just as natural gas (methane) was a commercially useless molecule until oil companies started capturing it and finding a use case, we believe that if CO2 can be captured from air and made useful, it could become the feedstock for an industry of similar scope and scale.

We are thrilled to launch as a YC W22 company - we couldn’t ask for a more forward-looking community of folks open to buying, supporting, or otherwise engaging with climate solutions like ours. Grateful for your time and happy to take your questions! We are at if you want to reach out.

p.s. dang took out all our footnotes but if you want references for any of the above, please ask!


I want to be excited about this, but it's capturing CO2 as CO2 gas, not sequestering CO2 in a form that keeps it out of the atmosphere.

If you pay a lot of money in process and power to pull CO2 out of the atmosphere or out of exhaust gases and then use it in chemical processes other than ones which sink the carbon into long lasting solid, liquid, or oceanic absorption form you're just burning money and power to make yourself feel good, you aren't actually denting the global climate change problem because all that CO2 will just end up back in the atmosphere once it's been used in the industrial processes.

You also can't use storage of gaseous (or liquid) CO2 as a way to sequester climatically meaningful amounts of CO2. We've added around 600 billion tons of CO2 to that atmosphere since 2000. If we want to use sequestration to roll back the changes we've done to the atmosphere, we almost certainly need to sequester at least that much, if not more out of the atmosphere. Do a quick calculation on how big a set of storage tanks you need to hold that amount of gaseous or liquid CO2, and compare that volume to the volume of a mountain (or mountain range) near you. Then think about maintaining those tanks in perpetuity and you'll see why you have to get the CO2 stashed in solid or room temperature stable liquid form.

I'm by no means critical or dismissive of this tech, it sounds great, but we're still a long way from pulling off the sequestration that's actually needed at the scale that's needed.


Huge amounts of CO2 can be injected into Saline Aquifers

Capturing CO2 from a power plant, biofuel factory, oil refinery, petrochemical plant or other point source and disposing of it underground is a developed technology. Very little of that is happening because the financial incentives aren't there and the financial incentives that do exist go to carbon sequestration schemes which are low-cost, low-quality and generally not measurable (pay us $ and we won't cut down these trees... for now, let's crush some rocks and apply sand to the beach and hope for the best, ...)

With aquifer injection you can measure the gas going in but there are also questions such as: how long does the CO2 stay there? do you have seismic problems?

This scheme is similar to aquifer injection but is more secure at the expense of requiring unusual rock formations and 25 tons of water for every ton of CO2 captured.

I think it gets way too much press but assuming energy is available you can build a direct air capture in a place where you have reactive rocks and water.


We agree that saline aquifers are be a compelling strategy given the huge volumes available & measurement capabilities you mentioned. As verification standards emerge in the (currently nascent & somewhat fragmented) CO2 removal ecosystem, precise & accurate quantification is going to be a huge driver to differentiate the highest-quality CO2 removal solutions.


Thats only 6,250 gallons of water.. less than a single 10K water truck you've seen everywhere.

THe question is how many tons does this plan to produce over what period?


If you want to delay the impact of climate change by 1 year by sequestering one year of of CO2 added to the environment through saline sequestration, that's about 40 billion 10K water trucks worth of storage, or about 40 Lake Tahoes turned into saline storage ponds, and you need to add that much storage capacity every year just to keep atmospheric CO2 from getting worse than it is (you're not yet to the scale of reducing atmospheric CO2 at this rate). The oceans have enough volume for this, but most other containers are too small to be meaningful.


> We're still a long way from pulling off the sequestration that's actually needed at the scale that's needed.

How so? The simple fact that natural gas and oil still exists, when it comes from 100 million year old biomass, proves beyond a shadow of doubt that geological sequestration holds its integrity at geological timescales.

We have also been injecting CO2 at a rate of 1 million tonnes per year at the Sleipner field in the North Sea since 1996, and extensive 3D timelapse seismography shows the CO2 is permanently trapped.

Think about that - we have been demonstrating CO2 storage at scale since before the launch of the first Palm Pilot.


The existence of oil shows CO2 can be stored in solid or liquid form, but doesn't show we know how to convert CO2 into that stored form at scale or keep our hands off it once it's stored that way. It's easy to burn oil, it's hard to make it, and it's harder still to not burn it when you know it's readily available.


CO2 is in the dense supercritical state at the temperature and pressure conditions in storage reservoirs. It's density is between 750 and 850 kg/m3 then (water is 1000). You just have to compress it and pump it down there, and it will stay like that.

Honestly, the storage part is a solved problem from the feasibility side. The remaining challenges are mainly cost optimization, across all of capture, transport and storage.

And the biggest hurdle is forcing businesses to actually pay for the currently externalized cost of CO2 emissions.


Inject CO2 into basalt formations, and over the course of a year or so it will turn into rock. There are already several pilot programs doing this, and it's very scalable.

Other projects apply energy to turn the CO2 into liquid fuel. Of course that returns the CO2 to the atmosphere, but it'll be a long time before we electrify long-haul jets so it'd be great if their fuel were carbon-neutral.


>Inject CO2 into basalt formations...

Thanks for this comment - the calculations I'd been doing in the GP comment and elsewhere where pretty darn depressing and this approach you're mentioning is very exciting in that it bypasses the fundamental storage volume problems most other sequestration methods face by leveraging the interstitial spaces inside existing rock volumes, and also exciting in that it leverages undersea rock formations for even lower impact. Thanks for pointing me to this.

For others interested in learning more you might hit [0] or [1].




There are a few startups exploring this and also PNNL is doing great public work on this topic as well.


Thanks, Mark - do you (or anyone else reading this) happen to know offhand any of the startups targeting this approach?


This is sort of crazy. Presumably industry will use liquid CO2 for the foreseeable future. Pulling it from the atmosphere instead of ground is a huge net benefit.


Most of the gasses we pull from the ground are byproducts of oil and natural gas production. We don't pull them from the ground because we want them on their own, we just go ahead and capture them because they are coming up with the stuff we want for fuel - they'll still continue to be captured (or worse vented to the atmosphere) as long as we're pulling those fuel sources from the ground.

Industrial CO2 also mostly comes not from the ground but from other industrial processes.


We use so much CO2 (on beverages, inert atmospheres, cooling devices, fire extinguishers, etc). Does all of it come as side-product of some industrial process? Or do we burn extra fuels to get it?


> use it in chemical processes other than ones which sink the carbon into long lasting solid

There are not many chemical reactions that 'fix' CO2. The compound is pretty low energy. Kind of a analogous to 'feed' bacteria with plastics.

The Swiss start-up Climeworks [1] has a business model built around actually already is in operational mode when it comes to pumping CO2 into the ground in Iceland.



Capturing CO2 should be just that, capturing. Capturing and transforming is just costing more problem that other people have to deal with (creating more byproducts, consuming energy and other resources in the process). If it turns out that there is a market for CO2 gas then the product can be used as is, as opposed to burning coal back to CO2. If not, then you will have other companies solving the problem of turning it back to carbon. That's always been how problems are solved, divide an conquer




Isn't the idea to pump the captured co2 underground, where the proper reactions take place to turn this more or less into rock ? I'm not sure anyone was suggesting to actually store the co2 long term as a gas or liquid


It should be much more cost-effective to float wind turbines to pump surface water to benthic depths. Then, the whole ocean is your CO2 collection surface. You might also pump water from (lesser) depths to the surface to distribute over coral reefs to relieve both heat and pH. (Picture a line of these some miles seaward, all up and down the Great Barrier Reef.)

The wind turbine nacelle could be substantially cheaper than in the typical electrical generating turbine, instead coupling mechanically or hydraulically to the water pump.

Some people worry that this would saturate the deep ocean with CO2. A bit of calculation shows this is an idle concern: the shallow ocean is already being saturated with CO2, with immediately dire consequences, and there is overwhelmingly more deep ocean water than surface water. So long as atmospheric CO2 falls off over the coming century, there would no long-term problem.

Geoengineering that tackles the root problem, CO2, is fundamentally different from schemes that only (e.g.) try to block insolation. Other engineering is going on to tackle upstream CO2 emission, but we have a huge stock of CO2 already built up in the atmosphere that will need to be drawn down.


I think the problem with that approach is that it would be harder to establish a regulatory framework were you can get "I sequestered CO2 credits" if your pumps are out in the ocean and pumping the CO2 into deeper waters. The capturing facilities inland are easier to audit and regulate.

So yeah maybe it's better for the planet but since it's harder to regulate it would be tricky to get funding to build that if the potential profit comes from the government intervening to set a price for the CO2 removal you are doing.


Pumped water volume and pH are easy to measure, precisely identifying how much CO2 is being sequestered. These could be reported continuously via satellite link.

It doesn't cost any less to keep a wind turbine and pump still than to leave it running, so there will be no incentive to cheat.


I was not thinking it was a technological challenge, I was more concerned about how useless governments in general are at regulating stuff that happens in the sea. There's no civil arm of the government that runs around in boats inspecting and certifying stuff.


I don't know anything specifically about wind turbine maintenance, but if its anything like everything else I know about, it probably does cost more to have 99% uptime than it does to have 80% uptime.


You should build this! This is one of those "all of the above" moments.


Today we see a moment when popular interest, need, capital, and talent are converging on a willingness to to try new things with a path to success. Who knows how long the window will last. We must try to advance any path that has some chance of succeeding and has a technically/commercially viable path forward.


This is really well said. As a person who lived through the first dot-com boom, this feels a lot like the 90's. There are way more ideas than there are viable paths forward. But among these ideas, there's at least a handful of future giants.


It could be profitable if you sold carbon credits. The pH and water volume may be measured accurately on the way through, precisely identifying exactly how much CO2 is being sequestered.

I don't know how the carbon credit economy works. I would welcome enlightenment.


As I know there are some standards like and . They audit the projects that claim to remove CO2 from the atmosphere worldwide and issue CO2 credits. These credits then can be sold to companies that want to offset their emissions. Usually OTC deals, sometimes involving brokers as well. There's also , which is one of the big marketplaces where such deals are happening.

I've heard deals with prices in the range of $0.5 to $5 per tonne CO2 equivalent. There's also a decentralized protocol that aims to move these credits onchain (, their BCT (Base Carbon Tonne) token price is currently around $3.1.

As stated in the post, last year ~$1B worth of credits are sold. One McKinsey report expects it to be around $50B at 2030.

There are much more details of course, but these are the basics as I know.


Churning ocean water is a terrific idea. Especially the added benefit protecting habitats. Thanks for sharing.


I also have no clue about the economics of carbon capture. Maybe ask David Roberts? He has always answered my emails. (Note he's currently on vacation.)

Roberts is my current primary source for climate and energy policy news. He definitely talks to all the right people, eg Saul Griffins.

Here's a sample of his articles which may be relevant to your question:

These uses of CO2 could cut emissions — and make trillions of dollars [2019]

A simpler, more useful way to tax carbon [2020]

Volts podcast: Sen. Tina Smith on the promise of a Clean Electricity Payment Program [2021]

Volts podcast: Rebecca Dell on decarbonizing heavy industry [2022]


Where did you learn about this idea? I've been trying to get up to speed on climate change solutions and I thought I heard just about everything but this is the first I've heard this solution and it sounds like it might make total sense. Are there companies developing these pump mills?


Also, wouldn't it be even nicer to pump up the cold water? That way you decrease the acidity of the surface water more strongly, increasing the acidic uptake of the surface water, and you also cool it down more.

If we did that for example in the East Australian Current north of Vanuatu, we might help out the Great Barrier Reef a little, moderating both the temperature and the acidity. It's like 3 birds with one stone.

I guess pumping up has the additional complexity of having the intake all the way down at 2KM, which is also where you'd need to do the maintenance. But maybe you could float up the entire pipe for maintenance.

Seems a similar idea has been proposed, but from a depth of a mere 40m:


Yes, there is lots of room for development, and connected ideas.

Where waves are available, the wind turbine might not be needed. Waves tend to happen mostly where water is shallow. Anyway, idea is that you have a big, floating, anchored fabric tube with rim held above mean surface level, that waves slop into. Once water is in, the only exit is way down deep. So more water slops in all the time, and moves down under the weight of what comes in after it.

Then, you need no wind turbine, no pumps, no moving parts at all; just anchors, floats, a surface frame, and a few thousand square yards of very tough fabric.

The tube doesn't need to go straight down. It could collect water in (relative) shallows and exhaust it some distance off, at cost of just more fabric.


A proposal showed up here on HN, maybe a month ago. I will try to find it. It seems like a good place to invest.


I'm not a marine or ocean expert, but won't pumping large amounts of surface water to benthic depths have a huge impact on the marine life, currents and so on?


We are already making a huge impact on marine life, today, with increasingly disastrous consequences. This reduces that impact.


This doesn't remove CO2 from the ocean, right? It instead mixes the ocean better to increase the total CO2 absorbed in the ocean, reducing atmospheric CO2?

It sounds like a cool idea but is not really related to what AirMyne is trying to do! Lots of ideas are promising and people need to be working on all of them


AirMyne is trying to remove CO2 from the atmosphere and sequester it attached to rocks underground. Pumping surface water down sequesters surface water down deep that recently collected CO2 from the atmosphere, and exposes incrementally less-saturated surface water to collect more.

The important difference is not how the CO2 is collected, or where it ends up. Ultimately, what matters is how much mass of CO2 is collected per unit cost, and how much CO2 is collected in total. I.e., how profitable is it, and how much difference does it really make? We need methods that can move CO2 out of the atmosphere by, ultimately, billions of tons per week.


Not to derail the OP discussion; but, how does one go about pumping water to great depths? That sounds like it would require immense energy to do on any large scale. Also thinking of the maintenance on the presumably narrow vertical pipe going miles(?) below the ocean.


It does take energy to pump water. How much is easy to calculate. But if the energy is provided by capturing wind, the cost is just the fixed capital expenditure to buy the wind turbine and pump, plus (as always) maintenance on the turbine, pump, and plumbing.

Maintaining a pipe, even one a half-mile long, is pretty cheap. (It has floats along its length, so it doesn't need to be especially strong.) Probably the biggest maintenance chore is keeping the intake from being fouled with barnacles, something most easily handled by replacing linings periodically.


Hmm, off the top of my head I think that it takes as much energy to pump water down a 1-foot tube as it would for a 1000-foot tube. It's like rotating a long loop of chain on a pulley, but in three dimensions. One liter of water goes down the tube, one liter of water comes up around the tube. Both sides weigh equal amounts so there's no net force. Of course, overcoming inertia to get the water moving and keeping it moving despite friction might be significant. Ironically, a consequence of the oil industry is that we have powerful pumps that are proven to be economical in moving large amounts of liquids long distances through pipes :)


> Both sides weigh equal amounts so there's no net force.

Water at 40m depth has a different pressure than at the surface level. Pumping at the surface and releasing at depth will have significant water pressure difference.

(A quick Google later). At 40m, it's 5atm or roughly 75psi pressure.

(Another quick Google). Oil pipelines run at a higher order of magnitude as that, so it's doable but would return energy, increasing as you go deeper.


There is significant friction between the water and the tube that needs to be accounted for. The longer the tube, the more friction there is.


Sounds like it would also directly cool surface water, by replacing it with very cold deep water.

That cooling would directly reduce current average earth temperatures, in addition to the CO2 impact on long term heating / cooling.


Not sure in which measure this "cooling" (of oceans only) would have any impact on other parameters of global climate, but that's a project I'd be eager to work on anyways.


The ocean surface, when colder, absorbs heat from the atmosphere. But the effect of removing CO2 is much more important because CO2 blocks heat that comes in every day from space from escaping back to space. And, acidifies the ocean top, damaging the food chain at its roots.


"CO2 acts as an acid and will bind to a base, whether in the liquid phase or on a solid surface. We have developed a process to bring air in contact with a base substrate that captures CO2 molecules while letting N2 and O2 molecules pass through"

Interesting, and of course worth noting that many geological events have done exactly this when calcium bearing rock (chemically basic) is exposed and weathered, capturing carbon as calcium carbonate. See, e.g. the hypothesis that the uplift of the Himalayas contributed to a past ice age[1].

One way to grasp the scale of the problem of sequestering our current level industrial emissions is to imagine assembling a calcium surface comparable to that of the Tibetan plateau. That's not to minimize the value of potential sequestration solutions here, which as you note will definitely need to be coupled with emissions reductions. Just that we need to, in effect "move mountains" to get this to work.



Great point. Cheers.


As I understand it, the most efficient, scalable, and long-term effective climate solution remains olivine carbonation as proposed by efforts like Project Vesta [0]. I take the point that any and all solutions should be explored at this time of critical importance, but there's a risk that sexier, more high tech approaches gain disproportionate momentum for reasons separate from the science. Is there an obvious explanation for why this or other geoengineering schemes haven't taken a leading role either in the discourse or implementation of carbon capture and sequestration?



Why bother with 400ppm when there are so many, well, "burning sites" untapped?

The intuitive counter-argument is that long term there shouldn't be any "burning sites" left and that capturing all burning sites would only ever get us to zero but not to negative emissions, but that's not true when you include burning sites that run on biological sources. Let plants deal with the 400ppm problem, use those plants as fuel, sequester where those plants are burnt. Negative emissions.


Thanks for the question, copying from an earlier comment which touches on similar point --

"Great question. We'd love to capture point-source CO2 from factory flue gas where it is orders of magnitude more concentrated (often >10%) than in air (~400ppm). And fundamentally, there is no reason our process cannot be applied for this type of CO2 capture. For now, we are choosing to focus on air for 2 reasons:

1) Market. Early buyers of CO2 credits are primarily looking to get very clean accounting of who gets credit for the CO2 removed, and will pay a premium for anyone who can do it. If a buyer (say, a software company) pays for a polluting chemical factory or power plant to capture some of its emissions, it requires complex multi-party contracts & the incentives between the parties are often conflicting. That being said, point-source CO2 removal is absolutely needed & a huge opportunity/problem and more work is needed from a technology/policy side.

2) The "extreme user" case. If we give 100% focus to solving the more challenging problem of removing CO2 from air, we may gain learnings & knowledge that will translate to an improved point-source capture process, whether from an energy/efficiency/cost perspective."


Ah, ok.

"We try to tackle the crazy problem because if we can almost do that we should be quite good at the reasonable ones" sounds like a communication problem unnecessarily attached to the physical one.


Given the dilution problem, I’ve been wondering if a decentralized approach is ultimately better. Can we build some cheap system that people could just simply put on top of their homes and let the wind do the movement? Individually each system would remove little, but if enough participants were involved (perhaps it’s even government mandated to have), then the costs would be shared as would be the scale.

Would love thoughts.


Great question. We believe it becomes an issue of storage, logistics, supply chains, transport, and so on. We approach it this way: if we build & install 1,000,000 decentralized car-sized capture systems that capture, say, 1 ton of CO2 a year, that is going to require 1,000,000 CO2 absorption/desorption systems (cost/energy/embedded CO2), 1,000,000 high-pressure compression systems (cost/energy/embedded CO2), as well as installation, delivery, system maintanance & repair, etc. Then we have to collect the CO2 when the decentralized units are full - again, not easy, since CO2 likes to leak when stored/transported under pressure. When deployed over a large geographic area, the problem gets more complex since it must be monitored & managed with many nodes in the system.

That's not to say a decentralized system can't be done. If someone can do it & it costs less than us, that's good for the world. But coming from years in the chemical manufacturing world, we believe that humans have learned a lot, especially over the past 2-3 centuries, how to build huge chemical production facilities that make (relatively) efficient use of power & resources to process ton-scale quantities of materials. We have experience in bulk-scale chemical facilities for other chemical processes, and know that when they work, they can work really well. So we believe that bulk industrial scale is the fastest/cheapest way for CO2 removal from air in a way that can be deployed fast enough & in an economically-sustainable way to meet existing/forecast demand for voluntary CO2 credits & eventually to tip the needle through large-scale deployment.


There was an art project a couple of years ago to clean up smog.


This would be equivalent to trees, where you then store the tree forever before it dies, and even assuming you can plant and then store those trees using 0 energy it really doesn't make much of a dent.


I would love to see a page on your website where you compare yourselves (in a fair and transparent way) to the best plant that does the same thing. I am not knowledgeable in the field. But there will be some algae or mangroves that get CO2 out of the air.

I would love to see that comparison. Incl. the aspect that the plant does not need to be repaired, multiplies on its own, etc.


The problem with plant based sequestration is that it is a net neutral proposition unless you can bury the plants. All the talk about forests being so great(and they are, just not as carbon sinks) ignores the complete lifecycle, which is only as negative as the sustained volume of the forest, assuming you started from just dirt. If that forest ever burns, it's all back in the atmosphere again.


This might be true of conventional crops like corn or soy but this article [1] implies kelp farming in oceans could sequester carbon from the atmosphere for a long time.

"So the kelp will sink to the ocean bottom in the sediment, and become, essentially, part of the ocean floor..."



Of course there is always the possibility that things could burn but forests that burn do grow back eventually. Plant-based sequestration should not be written off. A planet covered by X% of forest vs Y% where X%>Y% has more sequestered carbon. If that X% is long-term stable, i.e. if the forests are preserved and curated on a long-term basis, then so is that carbon. Forests are also an enjoyable natural environment for humans, which is an added bonus.


When we say "plant based sequestration" we are (I for one am) not talking forests. Carbon sequestration in forests is wilfully ignoring the economic and practical drawbacks:

Forests only sequester carbon as they grow. After that they are carbon neutral. You end up with land that cannot be used for any economic purpose. (The creatures and plants that live in it have a value too, but that is not part of this argument).

After that, at some point, in a year, ten years, a hundred years, the forest burns. And all the carbon is released.

A pointless waste of time. We do it because we are obsessed with things we can count (one tree, two trees....) and fixated on the short term.

There is a better way:

Increase depth of top soil all over our agricultural land. It increases productivity and sequesters carbon. But it has no profit centre and is hard to measure, and given our "big man" capitalist culture that is the problem.

We really must stop producing CO2. That is the only answer that does not steal the future from our children


burn or decompose same thing, trees are a buffer not a solution, unless you cut down, bury deep, then regrow.


> unless you can bury the plants.

Maybe this is a naive question: but why not bury plants? We got into this mess by digging up long-buried plants, so why not literally reverse the process? With intentional effort, maybe this could be a viable solution? (Probably not -- but I'm curious why.)


No need to. Trees bury about half their biomass as roots. Then leaves and branches fall on the ground and bury older leaves and branches. Of course it's long and inefficient (because of fungus, bugs...) but plants do it without our input so we need to let them do their thing. Calling this process net neutral is a falsehood.

Of course it's not enough to balance human emissions. Sequestering carbon in fields, as pointed out, is a win-win solution which may do a large part in canceling emissions.


What about building houses and furniture with the wood?


That is typically only sequestering the carbon for 20-50 years. In the end, the house is torn down, or the furniture burned. Very little lasts for more then a century, and basically nothing lasts for more than a millennia.

Deep underground sequestration is the only viable strategy if your goal is total CO2 reduction in the atmosphere.


It's not a terrible solution, but you need specific trees of specific thicknesses for it to be possible at all (and these aren't always the same trees best suited for rapid growth). Selecting the most carbon-intensive plants and then turning them into biochar is probably better for long-term sequestration.


Sorry to get to this question late. There is some good discussion below on the possibilities of bio-based and nature-based solutions. We see bio-based solutions as having a great advantage in the short term since the feedstocks are concentrated & the collection is fairly straightforward. But we believe that these technologies may have a hard time getting to bulk scale as land & logistics become a concern.

Most likely, industrial/engineered solutions and nature-based/bio-based/ocean-based solutions will need several years to evaluate which paths are most viable. We wish everyone luck in this challenge for the world's sake!


Have you looked into technology to turn CO2 into a solid? Like here:

Also could the process be adapted to use sources of waste heat like from nuclear power, solar or geothermal?


We are exploring a number of conversion pathways, but our right now our focus is on capture, removal, and sequestration underground.

The process could potentially use waste heat & that is something we are thinking about as we think about plant design, potential locations, and partners.


Whats the energy cost per ton of CO2 removed?


Right now, it's >5MWh/ton using lab scale equipment. At 1 million ton per year scale, we expect closer to 1-2MWh/ton.


To put that in perspective, pure graphite or carbon (basically equivalent to anthracite) releases about 2.5 MWh of heat per ton of CO2 produced.

Pure methane (if fully combusted) releases about 5.6 MWh of heat her ton of CO2 emitted.

Oil is somewhere in between.

In terms of electrical or mechanical (ie useful, low-entropy) energy produced per tonne of CO2 emitted, HHV efficiency typically 25-50%, so between 0.625 and 1.25 MWh/tonne of CO2 per tonne of coal and 1.4-2.8MWh/tonneCO2 for methane.




That's >18 GJ/tonne, with a goal of 3.6 to 7.2 GJ/tonne, making it much less efficient than post-combustion capture (which I think tends to aim for <2 GJ/tonne now).

Why not just do post-combustion capture if it's cheaper and more effective?


It should be done more but stronger tax & regulatory incentives are needed to encourage point-source polluters to adopt CO2 capture for emissions from industrial processes & energy production. It is very difficult to convince, say, a software company to pay for/subsidize the cleanup of another company's/utility's dirty process, because of the complex incentives & liabilities involved.

(Would love for an entrepreneur to come up with a way to find a market solution to this matching problem -- AirMyne might want to bid to be the technology platform on which such a CO2 capture system is built!)


Does that exclude the energy cost involved in injecting CO2 into a reservoir? Also, what would be the energy cost of converting captured CO2 to a more stable form (CaCO3, aka limestone), or a commodity such as methanol?


The energy estimate includes the costs of compression & injection using some figures in publicly available resources that look at CO2 removal end-to-end. Co-locating the capture as close as possible to removal/injection site (e.g. minimizing transit logistics) helps to keep the energy & financial costs low.

However at this stage, we are more focused on scaling our capture process so it can be integrated to injection/sequestration later on at a pilot plant scale.


Where do you envision this energy to come from and in which timescale? would that be electricity only or a mix? Thank you.


so ~40 PWh just to keep up with the carbon emitted each year. a mere 1000x more than the global electrical output.

and we're still arguing about whether fission is good in the year of our lord 2022


As you mentioned, I'd love to see the carbon that's captured from the air turned into something valuable like building materials. Or do something wild and have a worldwide monument building contest where captured carbon is used to make incredible sculptures and artworks.

Injecting it underground is just turning waste into waste, which depends entirely on regulatory controls to become sustainable; though of course, developing an efficient process for capture is a hugely important step.

I'm curious what the latest developments are on finding a use case for captured CO2?


> Or do something wild and have a worldwide monument building contest where captured carbon is used to make incredible sculptures and artworks.

I wondered about the scale here. In 2020 we emitted 34.81 billion tons of CO2 from fossil fuels[1]. Now that's much more than what I can lift, or even imagine. So let's say we want to build Pyramid of Giza sized monuments out of that. The Pyramid of Giza weigh about 5.75 million tons[2].

That means that if we want to soak all the yearly emission into monuments we need to find place for about 6000 Pyramid of Giza sized ones. That's a lot of monuments to go around. And then next year we repeat again. I'm not sure this will scale.

> Injecting it underground is just turning waste into waste, [...]

Yes? That's where the carbon was stored for hundreds of millions of years and it was fine there until one day humans figured out a way to get it out and spread it into the atmosphere. The problem is not that we have a moral objection to CO2 on principle. The problem is that it's screwing up the atmosphere.

1: 2:


Right now we're focused on getting our capture/removal process working at scale, but we are keeping a close eye on the use cases since that is a big part of the conversation. There are many great teams working on the usage problem right now & are excited to see where they take things.


The numbers seem to indicate some challenges. This is just back of the envelope and this isn't my field so I may be misinterpreting the data, but it looks like extracting 1 million tons of CO2 per year has the following costs (at lab scale values):

* > 1 Billion dollars

* > 5 Million MWhr

Assuming 200 Kg/MWhr of CO2 emissions produced by electrical generation (I believe the average carbon intensity in the USA is over 400 Kg/MWhr) the emissions produced (just for the electricity to do the extraction) is 1 Million Tons of CO2.

Thus, it looks like with the current estimates the process costs 1 Billion dollars and doesn't reduce CO2 at all. Like ethanol, I wonder if this process will be worth it in the end. I don't know what raw materials it requires and how much CO2 is generated in their extraction and production. It's possible that your belief that at industrial scale the CO2 intensity and dollar cost will go down, but are you even accounting for the CO2 cost of manufacturing the facility, transportation of raw materials, etc.


Great points. We are using lab scale equipment today, and as trained engineers we want to be conservative to any forecasts we share publicly since unrealistic claims will not help us or anyone in this space get to where we want to go. We have spent many months building models, demonstrating at a lab scale, & talking to experts to get their feedback, and now we see the most value will come from actually building our pilot plant to get a much clearer sense on the real financial/energy costs & to identify which process parameters need the most focus.

Coming from the chemical manufacturing world, we have (painful) experience modeling & planning for new processes & know that cost/energy models of new processes can only get us so far.

That being said, we see a path forward for our process at scale and are motivated to make it a reality.


If you're setting this up at enough scale to matter, you're going to need more power than is available today anyway. As long as you're building new, it would make sense to build renewable or nuclear.


Yes, but wouldn’t it be better to simply replace dirty power generation with this new renewable electricity rather than expending all of the renewable power on this hypothetical CO2 extraction facility. At some point, I suppose, the overall carbon footprint of our world’s electrical generation will come down to the point where CO2 extraction will be a net win. Right now it’s not clear to me.


Ideally, sure, but then when we replace electricity sources we still have all the things we weren't able to electrify, and we're faced with scaling up something like this from scratch. We need the fastest path to net zero including things like cement and ships and long-haul jets and agriculture, and all that adds up to more than our emissions from electricity. Fastest path probably includes getting a head start on negative emissions.


Probably stupid idea, but why don’t you put your system at the end of a factory co2 output There you ll have more than 400ppm ?


Great question. We'd love to capture point-source CO2 from factory flue gas where it is orders of magnitude more concentrated (often >10%) than in air (~400ppm). And fundamentally, there is no reason our process cannot be applied for this type of CO2 capture. For now, we are choosing to focus on air for 2 reasons:

1) Market. Early buyers of CO2 credits are primarily looking to get very clean accounting of who gets credit for the CO2 removed, and will pay a premium for anyone who can do it. If a buyer (say, a software company) pays for a polluting chemical factory or power plant to capture some of its emissions, it requires complex multi-party contracts & the incentives between the parties are often conflicting. That being said, point-source CO2 removal is absolutely needed & a huge opportunity/problem and more work is needed from a technology/policy side.

2) The "extreme user" case. If we give 100% focus to solving the more challenging problem of removing CO2 from air, we may gain learnings & knowledge that will translate to an improved point-source capture process, whether from an energy/efficiency/cost perspective.


That's what most carbon capture tech seeks to do, this would be direct carbon capture from the air. You are completely correct in assuming this is highly inefficient. As long as we are still blasting new CO2 into the atmosphere, it will always be easier to capture it at the source. Direct air capture only becomes significant when we get access to enough clean energy to power the absurdly inefficient technology. Thermodynamically, even if you are capturing at max efficiency, it still sucks (something like 250kwh+ minimum to extract 1ton of CO2, not even close to reality). We need either abundant renewables or fusion/fission energy to make it viable.