85 comments

[ 3.6 ms ] story [ 239 ms ] thread
Current refrigerants (e.g., R-410) have large global warming potentials (GWP) when they inevitably leak into the atmosphere, so there's a move to other chemicals. On of the leading contenders (at least in the commercial/industrial space) is actually CO2 (R-744):

* https://www.hpacmag.com/features/co2-as-a-refrigerant-yesco2...

* https://www.ohio.edu/mechanical/thermo/Applied/Chapt.7_11/Ch...

* https://blog.isa.org/why-co2-is-the-most-promising-refrigera...

* https://plumbingandhvac.ca/co2-refrigeration/

* https://en.wikipedia.org/wiki/Carbon_dioxide#Refrigerant

CO2 has GWP=1, and just about everything else is higher.

A disadvantage of CO2 as a refrigerant is the operating pressure required, much higher than CFC or HFC type refrigerants. This is probably not a big issue for industrial applications but for home and auto use it will probably affect cost and/or reliability.
Don't forget propane, a historically common refrigerant with a GWP less than 1.
It's a shame it's flammable, or it'd be a no-brainer to use it everywhere.
The real rationale is a few paragraphs down:

> "For now, Denbury’s pipeline network isn’t really low carbon, but instead will function as an extension of Exxon’s normal oil business. Today the CO2 carried in the pipelines is used for “enhanced oil recovery,” a process in which it is injected into oil wells to push out the last few drops."

All the DOE-funded 'clean coal' and similar CCS schemes were all conveniently set up near end-of-life oilfields, and whatever CO2 they produced was used to help get the last few barrels out. Of course the CO2 is carrying the oil so it's mostly lost to the atmosphere during the processing/refining stage.

Carbon capture and storage from fossil fuels has been nothing but a massive fraud; capturing and burying 100% of the carbon from coal would take significantly more energy than you can get from burning that amount of coal. Notably, data about this key ration (energy cost per ton of buried carbon vs. energy cost from burning the source fuel) is hidden on the private side of DOE public-private partnerships and can't be accessed by the public, even by FOIA requests.

CCS is literally one of the biggest scientific frauds perpetrated on the public in the history of the DOE.

(comment deleted)
(comment deleted)
“capturing and burying 100% of the carbon”

What about 50%? Does the cost go up as you try to capture a larger percentage?

From my understanding the cost is in the technology and energy required. Essentially, you burn more fossil fuels trying to inject it at any level than the carbon you put in. And something like this couldn’t be run on renewables as is, you’d need a rather large amount of batteries which is so incredibly expensive at this point in time.

So cost and carbon output make geological sequestration impractical. However, when used for “enhanced oil extraction”, it easily covers the costs and carbon output worries. They wouldn’t do it if it wasn’t profitable, and despite the article’s claims they are not in the business of carbon neutrality.

> Exxon’s vision is that eventually these pipelines will ferry CO2 captured from industrial point sources like cement and steel plants, and potentially from natural gas power plants, and transport it to underground rock formations or old oil wells where it could be buried (Denbury also owns a number of large sites for carbon sequestration).

Color me skeptical. The article offers no supporting evidence that this is Exxon's "vision", and then hits us with this:

> For now, Denbury’s pipeline network isn’t really low carbon, but instead will function as an extension of Exxon’s normal oil business. Today the CO2 carried in the pipelines is used for “enhanced oil recovery,” a process in which it is injected into oil wells to push out the last few drops.

Sounds like they made the acquisition for their current fossil fuel business, not a bet that "carbon will be the new oil."

And as a cherry on top:

> The company plans to double the size of its liquefied natural gas business by 2030, an executive said this week, with a focus on buyers in Asia.

It sounds more like an excuse to continue to output oil while doing absolutely nothing to stop the further degradation of out environment.
It shouldn’t be a surprise. They’re an oil and gas company, with gigantic investments in that space, a culture that supports it, knowledge to do it, politics solved for it, and a crap ton of inertia.

The expectation that they’d pivot is far less likely than likely. This isn’t a sector known for disruption outside of new ways to extract.

The insane thing about this is to me that Exxon did seem to have ideas about pivoting away from oil and gas in the 1970s[0]. They funded research that brought down the cost of solar panels five-fold and started manufacturing and selling their own panels[1], they developed the lithium-ion battery[2], and they created subsidiaries for servicing the nuclear power industry[3], among other things.

I’ve never understood the obstructionist position of these oil execs. If you want to make a shitload of money, why not push for development of some emerging industry like renewables where all the infrastructure has to be built up from nothing? That could be money you are getting paid to build it. Instead, now it’s money going to some other company.

[0] https://www.desmog.com/s1ep1-bell-labs-energy/

[1] https://www.npr.org/2019/09/30/763844598/how-big-oil-of-the-...

[2] https://www.bupipedream.com/news/49390/prof-whittingham/

[3] https://www.nytimes.com/1976/03/14/archives/exxons-innovativ...

The first digital camera was (AFAIK) made by Kodak. The modern desktop computer was largely invented by Xerox. Both companies failed to follow through.
It’s not an either/or situation. Most of the Big Oil companies have significant investments in renewable power. It’s just that oil is insanely profitable, to a point which is hard to grasp so it dwarfs whatever else they do.
The idea is to become so big by selling oil that you are essentially paid/begged to create the new industry that solves the problem, thereby giving you first-mover advantage in the new era. The obstructionist stuff is a little bit performative for shareholders, but there will be an inflection point in their public attitudes. Unfortunately it'll be past the inflection point for favorable living conditions.
Despite having all sorts of advantages (a head start and patents for batteries and renewable energy tech, robust research capabilities, etc.) and a literal roadmap of how climate change would play out, they realized that it was easier and less risky--for them, at least--to maintain the status quo. After all, once you've started a revolution, there's no guarantee that you'll keep control of it.

A long, slow transition that started in the 70s would have been, if not painless, then close enough to it that the pain was easily managed. Worries about stranded assets? By the time the transition was over, they'd have been near the end of their expected lifespans anyways. New, more nimble competitors popping up? They could just acquire them.

Lost revenue? Please. They convinced the world not to take action on climate change, and even managed to hoodwink one of the two major political parties in the US that climate change didn't even exist in the first place. Persuading politicians and the public to support mindbogglingly massive federal subsidies to fund the transition away from fossil fuels would have been easy in comparison. And probably cheaper, for that matter.

I mean, my god. I can just imagine the marketing and PR angle: The industry that chose to end itself to save humanity's future. We'd have shoveled money at them, and thanked them for the privilege.

Had they been willing, they could have pushed for an energy transition that, in the end, would have likely been as profitable or even more profitable than what they managed since they first understood just how catastrophic climate change would be. Instead, they chose to merely delay the inevitable. They'll still face the very consequences that scared them off of acting on climate change, only they'll be worse due to the shortened window of action.

The only difference is that the executives who first made that decision will likely not be around for it.

Private oil companies like Exxon are only about 10% of oil production. The biggies are the state oil companies, on which state wealth depends. They aren't going to give that up.
Related: Revealed: Exxon made ‘breathtakingly’ accurate climate predictions in 1970s and 80s

https://www.theguardian.com/business/2023/jan/12/exxon-clima...

Interesting (I think I've seen here at HN before?)

And replace this:

> while doing absolutely nothing to stop the further degradation of out environment

with:

> doing something to profit from the further degradation of our environment

Eat the cake and have it too

> Eat the cake and have it too

I don't understand how you're using this metaphor here. What's the cake? WRT the environment, they're just eating it.

The environment yes, and after they've eaten it they can continue making money from it, by partly reversing a bit of the damage they did.
Funny but Exxon could become a ‘net zero’ company without fundamentally changing its business.

You see, companies get charged for the carbon they emit, not the carbon that their customers emit.

An oil refinery is an ideal place to implement carbon capture because it is a concentrated source of emissions and is already using technology such as amine strippers that one would use for carbon capture. Refineries burn a lot of fuel to produce hydrogen and process heat and those could be replaced with green hydrogen or pink hydrogen, heat could be derived from resistive heating, nuclear HTGR or adiabatic compression in turbines. What CO2 is produced can be pumped underground into saline aquifers.

The Biden administration is interested in subsidizing such development in the ‘Refinery Row” of the U.S. South and it is something they are equipped to succeed at because they have the geology, industrial concentration, skills and attitude to pull it off.

A net-zero Exxon would still have to decarbonize production and that is harder than the refinery but they could buy some offsets (or themselves implement with direct carbon capture, BECCS, etc.) It would be a lot cheaper than buying offsets for their customers but who knows they might sell those too.

The idea of Exxon becoming “net zero” is a howler and we can’t let them get away with it.

We need to price the carbon emissions at the source. If they want to pass on the external carbon costs to their customers, so be it.

Stop making destruction of the ecosystem an economic externality? What's next, pricing human rights abuses to prevent US companies from profiting off of foreign slave labor?
I think you fail to realize how the profitability of this industry subsidizes a lot of issues that look to be crisises on their own. Plastics being too cheap to make so we don’t really do recycling or reducing to name one.
> The idea of Exxon becoming “net zero” is a howler and we can’t let them get away with it.

Get away with what, a talking point?

> We need to price the carbon emissions at the source. If they want to pass on the external carbon costs to their customers, so be it.

What if a power company buys a bunch of natural gas, with emissions already paid, then captures the burned carbon instead of emitting it?

> then captures the burned carbon instead of emitting it?

Presumably the only reason they would is if they could get paid carbon credits for doing so.

They'd better be able to get credits for it! It would be pretty awful to charge for emissions whether they emit or not, because then they have no incentive to decrease emissions.

But giving them credits seems pointlessly complicated to me, compared to just saying "no emissions, no charge".

Or alternately get charged carbon taxes if they don’t.
I find it interesting that people seem to think that storing CO2 under ground under high pressure for an unlimited amount of time is totally fine. "What could possibly go wrong?"

But at the same time somehow storing nuclear waste in specially designed containers sitting inside granite mountains is somehow extremely irresponsible and not an option?

Do most people actually realize what happens when that stored CO2 comes back up for whatever reason in x amount of years (all the way up to 100's of millions of years). I mean both the short term (everything in a certain radius that doesn't fly dies) as well as long term effects.

The irony is that people are forgetting where all that carbon came from in the first place, before plants captured it from the atmosphere!

Humans are contributing to climate change, but the climate had constantly changed throughout history. During the peak to the Roman empire, parts of the Mediterranean are estimated to have been 2°C hotter than today. The climate cooling is one of the likely contributing factors behind the collapse of the Roman empire, as agricultural output fell as a result.

Climate change is bad for current human settlement and farming, as what is currently primar land for living and farming will change. Such a charge would have dangerous global economic and political consequences.

> parts of the Mediterranean are estimated to have been 2°C hotter than today.

That's not a change in global average tempreture though, that's a local variation.

> but the climate had constantly changed throughout history.

'History' is written history, and no, global climatic parameters haven't changed in written history.

I believe you might be thinking of geological time - and yes, on long time scales climate has changed - and changed with cause just as a stone moves subject to force.

In this particular moment of time climate has started to change within the past century after remaining stable for tens of thousands of years and the root cause of that change is human activity changing the insulation properties of the atmosphere.

There is historical data which suggests that there has been two ice ages in the time of modern humans. The climate only appears to be stable when observed over a short timespan.

I don't think there is any doubt that human activity is contributing to climate change.

It's ironic that modern civilization and population numbers aren't possible without fossil fuels, but their use will ultimately cause it's demise.

Consider that during the first ice age, humans had not left Africa - and during the second ice age, much of North America and Europe were uninhabitable
Why would Exxon need an excuse?
"We're not extracting oil, we're making space for future captured CO2"
I also seriously question the concept of massive investment in CO2 dumping/sequestration alone, as it seems more likely that CO2 will be used as a feedstock to generate more complex and useful molecules.

That said, the endpoints of the pipelines could just route to processing plants instead of underground carbon sinks, so the pipeline part could be valid, if appropriately structured.

It looks like Exxon is pivoting to be an energy provider & owner of piping infrastructure, with petroleum products being a product line. The CO2 pipelines seem similar in infrastructure to oil pipelines. CO2 looks like a great opportunity for companies like Exxon to further consolidate the energy markets & gain entry into the heavily subsidized Carbon Capture market. They will gain tax funded & printed revenue as well as more pipeline infrastructure.

On the PR front, Exxon is now a "Green Company" who is "saving the world from Climate Change". Their ESG score will rise which will attract additional investment in public markets.

I wonder how many Carbon Offset credits this will yield them. Will this make Exxon a "Carbon Neutral Company"? An interesting mix of finance justified by environmentalism & a case example of what happens when environmentalism is reduced to a single metric. Well played Exxon, well played...

Along those lines there was an interesting article on 'white hydrogen' the other day. Apparently there are vast quantities of hydrogen underground which could be drilled for and piped in a manner similar to natural gas. https://archive.ph/3c7Hs
Key points:

"Carbon management is becoming increasingly popular with oil companies, since it plays to their know-how in trading, transporting, and storing molecules (as opposed to electrons from renewable energy, which are an entirely different business). ... It also allows Exxon to tap one of the most lucrative tax credits in the Inflation Reduction Act: $85 per ton of CO2 that is permanently stored underground. "

Isn’t it more likely to be water (and probably more like fresh water ) ?

It’s hard to desalinate already and we have been more and more heat and droughts that keep on being said they are of the century or historic and those words are losing their meaning

Get paid for selling oil for people to burn.

Get paid for capturing carbon from burned oil.

It's not exactly in conflict with their current business model.

I would bet that this is not going to happen unless someone finds an industrial use for all that carbon. I’m not an expert but it seems like it would be much more efficient to invest in low carbon energy and manufacturing tech than to build a ton of infrastructure for sequestration.
If the story of Earth were a novel and the current chapter introduced both global warming and the advent of carbon-based manufacturing, it would almost feel too contrived of a setup.
The issue is that some things are difficult to decarbonize because they emit carbon directly due to chemical processes or use gas for process heat. There is a lot of investigation into whether these can be decarbonized economically, but a lot of it is still fairly early stages. It makes sense to have a variety of solutions available, especially for the short term.
(comment deleted)
When I think about carbon extraction and storage, I get the same feeling as when I read about the ancients discovering oil seeps and surface deposits of hydrocarbons.

They knew that they could be harnessed for keeping fires lit and even sometimes associated them with the supernatural. They just lacked the tech and industrial background to use them.

We know that carbon is essential for life and if we ever engineer useful organisms to build structures or produce macroscale goods (as opposed to pharmaceuticals or food), then clearly carbon will be one of the main limiting factors, along with energy and water. It just feels like we will one day look back at this and think “why didn’t we just try to use it instead of burying it?”

I don't see how "carbon will be one of the main limiting factors". Carbon is abundant in our environment -- it's around 0.03% of it and is spread evenly enough that you can always find it. It's even relatively common in the universe.

What is hard to find - and has always been hard to find is cheap energy. And carbon dioxide is essentially the lowest energy state for carbon. It's a dead end as far as energy goes. That's why it's a waste product.

If you want to build useful structures then you're still subject to thermodynamics, whether you're using "organisms" to do it or not. So using graphite or any other form of carbon would be a better source of carbon than CO2. The only reason to use CO2 is that it is commonly available (which is why plants use it).

And again, no one is proposing removing all the CO2, just enough to keep us in this little ice age we have been enjoying. So there's no reason to worry about running out.

At least it could be unburied if it's needed in the future. Same with many landfills, when the value of non-recycled junk in there is higher than reprocessing it.
oil made those companies rich, but there is no proof that the vision of a rich company will have any value or offer an worthy insight into the future.

important reminder: CO2 is an oxide and requires A LOT OF ENERGY to break down.

so unless they can genetically engineer some kind of moss like in Robinson climate trilogy, it's highly doubtful they will achieve anything worthwhile

“ExxonMobil… [acquired]… a smaller Texas oil and gas company with the U.S.’s largest network of pipelines designed to carry carbon dioxide.”

There was a great episode of the Volts podcast, about a startup aiming to make synthetic shipping fuel (methanol), where waste CO2 was one of the main inputs.

Some good discussion of where they sourced their CO2, and the practicalities of CO2 distribution.

https://podcasts.apple.com/gb/podcast/volts/id1548554104?i=1...

(comment deleted)
They're going to charge us twice. Once for emitting it, second time for sequestering it. The fight for subsidies up here in Canada is insane. The electricity generated is already more expensive then renewables, and soon they can pad their margins with novelty projects that may or may not pan out, while telling us in their annual reports how great they are.
>They're going to charge us twice. Once for emitting it, second time for sequestering it.

The local water utility charges you once for providing the water, and another time for treating it (ie. sewers). Are you similarly outraged?

Did the local water utility know sewage was a problem half a century ago but spend decades denying that, encouraging excessive use, and preventing development of treatment systems or alternatives?

That’s why this analogy doesn’t work: water is a hard requirement. Fossil fuels can be replaced easily in many applications.

Stupid question, can't the CO2 just be dissolved in (deep) sea water?
CO2 dissolving into water is killing the ocean as we speak.
That is just on the surface, right? The mass of CO2 relased into the air per year compared to total sea water on earth is approx 1/35000. Does is really make such a big difference if dissolved in deep sea water?
We know basically nothing about the ocean other than it's where almost all our oxygen comes from, and we have no way to know what the tipping point is. Assuming we're too small to affect the environment is how we got here.

And we know from effects of climate change above the surface that it doesn't have to be cataclysmic to cause trouble. There could be all kinds of nasty things in store that are even harder to predict with how hard it is to explore and study the oceans. We don't even have an accurate map of it.

That sounds like "I just don't want that!". We don't need a map to know how dissolved CO2 influences acidity of sea water. Trust the science, bro.
"Trust the science, bro."

There is much more involved than how dissolved CO2 affects ocean acidity. CO2 has a number of other affects on both biological and chemical systems that shift equilibriums. Understanding how injecting CO2 would affect deep ocean ecosystems (and indirectly upper ocean layers and climate through layer interchange) when we only have a rudimentary understanding of the deep sea ecosystem is not a matter of science. It's the realm of prophecy and hubris.

I'm not saying that deep-water injections of CO2 are dangerous. But that at the current level of science we don't even know what we don't know about the possible affects that would have. And with the large amounts of energy required to sequester and pump carbon dioxide into the sea, it would be best if we understood the costs as well as the benefits of such an approach before we started.

I'm not an expert in this, but this link from NOAA seems to be a definitive explanation. Short answer is yes, but it also leads to more ocean acidity, which causes problems for ocean life.

https://www.noaa.gov/education/resource-collections/ocean-co...

Carbon dioxide, which is naturally in the atmosphere, dissolves into seawater. Water and carbon dioxide combine to form carbonic acid (H2CO3), a weak acid that breaks (or “dissociates”) into hydrogen ions (H+) and bicarbonate ions (HCO3-).

Because of human-driven increased levels of carbon dioxide in the atmosphere, there is more CO2 dissolving into the ocean. The ocean’s average pH is now around 8.1, which is basic (or alkaline), but as the ocean continues to absorb more CO2, the pH decreases and the ocean becomes more acidic.

CO2 can be combined with powdered limestone and the result mixed with/dissolved in water.
Yes. I mean, that's happening. Some of the CO2 automatically ends up in the ocean, which reduces the burden for the atmosphere.

But what you probably meant is if we can artificially increase the CO2 dissolved in sea water. The answer is no. The CO2 in seawater is relative to the concentration in the atmosphere. If you add more to the atmosphere, you add more to the ocean. If you remove it from the atmosphere, you reduce the amount in the ocean.

That is only true for sea water near surface. I am talking about deeper levels of the ocean. If my calculation is correct the mass of CO2 released into the air per year is roughtly 1/35000 the mass of all sea water in the oceans. Sounds not too concentrated to me.
I feel like this title is the definition of "anti-clickbait" to me (i.e. I don't even want to read the article because of the title), because it makes no sense.

Oil is primarily an energy source. When we talk about "carbon" in the context of climate change we're usually talking about carbon dioxide, which is a byproduct of energy generation that itself contains no consumable energy. Saying "carbon will be the new oil" is like saying my poop will be my new food source - it just doesn't make sense.

To be honest, I think "poop will be my new food source" makes perfect sense. But that might just be me.
Remind me to pass on any of your dinner parties...
Haha :) I meant in a grammatical sense.
Too little, too late by the fox guarding the henhouse.

I hope government subsidies and the insurance industry bitch slap manufacturing and petrochem to drive rapid deployment of substantial projects involving oceanic bio-GMO CCS at scale because they won't by so-called "invisible hand" market forces alone until billions are on the move, hypercanes are obliterating continents, and waves are lapping at the NYSE building. It's an emergency, and delay, half-measures, and planting trees isn't going to cut it.

Carbon Capture from industrial point sources is extremely expensive and extremely ineffective. so I doubt that's going to be a thing. The only way I could see CC paying off is if big companies keep lobbying for government grants and taxpayers money to go towards their shite projects so they can abandon them halfway through anyway. This'll keep the prospect of "clean methods" of operating dirty industries in everyone's brain space through political and astroturfed mouthpieces, people will start to believe it and oil companies will once again reap the rewards of mass confusion
It’s still a point source, and thus cheaper and easier than direct air capture. I don’t think it will be as significant as some think it will be (we will likely move toward different processes for the remaining limited petrochemical production), it is likely to still be important for some industries.
It's nonsense like this that makes a more rational debate around carbon capture difficult.

Yes, CCS will likely have to play some role in a future decarbonized society, e.g. for cement production. But it's not a plausible lifeline for fossil fuel companies. The vast bulk of emission reductions need to come from phasing down fossil fuel use, and that is fundamentally incompatible with their business model.

(shameless self plug: I tried to write down my view on the whole CCS issue recently: https://industrydecarbonization.com/news/can-ccs-escape-from... )

> It's nonsense like this that makes a more rational debate around carbon capture difficult.

such a great point and couldn't agree more.

in the US, I'm seeing more ethanol & chemical companies adopting carbon capture right now, not fossil fuel companies. it will be interesting to see how it evolves in the next couple years.

> (shameless self plug: I tried to write down my view on the whole CCS issue recently: https://industrydecarbonization.com/news/can-ccs-escape-from... )

subscribed! and you can follow some of the north america projects at https://decarbonfuse.com

(comment deleted)
Exxon is a behemoth that spreads its money over everything just to catch something - and even that is done poorly over there. They do have a number of legacy fields that if not already on CO2 flooding, may become candidates in their eyes soon. But that is where "being done poorly" comes in again. CO2 flooding, like water flooding, should start sooner than later to catch a certain pressure and oil/water amount/quality regime in the reservoir. Guaranteed, they will try to make it look like they are being sustainable by showing off how they are using the CO2, recycling it and, at some point, sequestering it, but it will be done in the most inefficient manner possible and probably result in losing a good amount of CO2 to the atmosphere due to poor field oversight of the equipment. Challenges that will come up due to whatever stage a reservoir might be in: https://www.mdpi.com/energies/energies-10-00345/article_depl...
Climate Change is the essence of "Intractable Problems".

There is tremendous wealth in oil reserves that is outside the control of the G7 countries: Russia, Iran, Saudi Arabia. There is also demand for this oil from non-G7 nations who simply don't have the money to go carbon free without descent into starvation, poverty and chaos.

Going carbon free on a big enough scale to impact the climate, according to existing models, requires getting these petroleum reserve holders to give up their massive wealth in exchange for little to nothing, and large developing economies to destabilize themselves to go carbon neutral.

IT ISN"T GOING TO HAPPEN.

Poor Indians and Chinese aren't going to give up their opportunity to secure better lives for themselves for the sake of the climate.

We need to be thinking in terms of mitigations and technologies that reduce climate impacts while being economically sensible.

Yes, it's not optimal, but choices made in the real world rarely are, and as adults we must learn to make them.

> Going carbon free on a big enough scale to impact the climate, according to existing models, requires getting these petroleum reserve holders to give up their massive wealth in exchange for little to nothing, and large developing economies to destabilize themselves to go carbon neutral.

The climate will continue to change even if humanity goes carbon free. When it comes to climate, the only constant is change.

> Poor Indians and Chinese aren't going to give up their opportunity to secure better lives for themselves for the sake of the climate.

Or fall for the NeoColonialist trap of paying taxes to financial markets to "save the world". Instead, the producer nations will leverage their positions as commodities become more valuable.

Carbon is definitely not the new oil. My hope is that carbon becomes the feedstock of the future (with a long way to go).

Exxon is an easy target in this but there are many other companies and industries that are working towards carbon capture.

I'm working with ethanol producers, co2 utilization companies, direct air capture, and other capture technology companies to move the carbon management industry forward. Exxon will be a player but not THE player in carbon management.

The article fails to mention that Denbury has several Class VI well permits (these are the wells where CO2 is injected) in areas near Denbury pipelines. Everyone will talk about the Gulf Coast as the strategic reason but Denbury's pipeline in Wyoming will be key to advancing the industry since Wyoming and North Dakota have authority over the Class VI wells today. I've heard estimates of 40 million tons of CO2 storage capacity in one of the Wyoming projects (that's just one of several projects).

Disclosure: I monitor carbon management at https://decarbonfuse.com by tracking the ccus, dac, and beccs projects in North America.