Catalyst with Shayle Kann - The good and bad of carbon capture

Episode Date: July 20, 2023

Carbon capture and storage. It’s a controversial tool in the energy transition that we don’t want to use, but probably have to. Most of the scenarios in the IPCC’s Sixth Assessment Report include capturing and storing hundreds of gigatons of carbon dioxide between now and 2100.  When people say carbon capture and storage, or CCS, they often mean different things. It’s a term that covers multiple technologies used to capture CO2—such as point-source and direct-air capture— and different approaches to using that CO2.  With the CCS industry is in its infancy, tackling some big questions now could save us headaches down the road. Questions about CCS infrastructure use, where we’ll build it, and who will control it. In this episode, Shayle talks to Dr. Emily Grubert, associate professor of sustainable energy policy at the University of Notre Dame. She posted a Twitter thread recently about how the same CCS infrastructure actually has four different use cases: Avoiding emissions to extend the life of fossil-fuel infrastructure Avoiding emissions where we don’t have zero-carbon alternatives yet, like cement production Removing carbon to compensate for other emissions, i.e. offsets Removing carbon to draw down legacy emissions and avoid overshooting 1.5 degrees Celsius targets They walk through each categories and cover topics like: Which categories to prioritize over others Avoiding the double-counting problem Where we should use CCS vs. zero-carbon alternatives The resource constraints on CCS, including water, land and energy Whether we have the luxury to prioritize when we need to deploy CCS so quickly Whether CCS customers or regulatory bodies should determine the type of CCS infrastructure we have and where we build it Recommended Resources: Catalyst: Carbon capture and storage is making a comeback Bloomberg: Big Money Rushes Into Carbon Capture. Can It Deliver This Time? US DOE: Strategic Vision: The Role of FECM in Achieving Net-Zero Greenhouse Gas Emissions Catalyst is a co-production of Post Script Media and Canary Media. Catalyst is supported by Antenna Group. For 25 years, Antenna has partnered with leading clean-economy innovators to build their brands and accelerate business growth. If you're a startup, investor, enterprise, or innovation ecosystem that's creating positive change, Antenna is ready to power your impact. Visit antennagroup.com to learn more. Catalyst is supported by RE+. RE+ is more than just the largest clean energy event, it’s a catalyst for industry innovation designed to supercharge business growth in the clean energy economy. Learn more: re-plus.com.

from the studios of PostScript Media and Canary Media. I'm Shayle Khan, and this is Catalyst. Is adding carbon capture to that natural gas plant extending the life or the use of fossil fuels unnecessarily, or is it best available alternative? And so I feel like there's just a lot of gray area in the specific cases for this one. Yeah, it's always a classic thing, too,

because necessary is always necessary to do what kind of a question? necessary to reduce costs versus necessary to keep the lights on versus necessary to continue existing. These are very, very different spaces. And I think that's also partially why this gray area gets so confusing. Time to untangle the knotty knot that is understanding what exactly is carbon capture, where should we do it, when should we do it, and when should we avoid it. When utilities need flexible capacity they can count on, they turn to Energy Hub. Energy Hub works with more than 170 utilities, coordinating,

over 2.5 million devices to manage 3.4 gigawatts of flexibility built for the moments when utilities can't afford uncertainty. Energy Hub builds and operates virtual power plants that utilities actually stake their grid planning on, coordinating EVs, batteries, thermostats, and more through a single platform built for utility scale. Predictive, verifiable, and designed to perform when it counts. Learn more at energy hub.com. Trillions of dollars are flowing into clean and critical infrastructure, but those investments aren't driven by technology alone. They're shaped by markets, by policy, by capital, and by the institutions that connect them. I'm Alfred Johnson, CEO of Crux, and host of a brand new podcast, Critical Capital. Each episode, I talk with people deploying capital, shaping policy

and building the clean economy. Tune in as we unpack how progress is actually made. Listen to Critical Capital on Spotify, Apple, or wherever you get your podcasts. I'm Shail Khan. I invest in revolutionary climate technologies at energy impact partners. Welcome. Well, whether we like it or not, we are probably going to have to use carbon capture and sequestration, or CCS, and lots of it in this world, if we want to achieve any of our reasonable climate goals. Most of the scenarios in the IPCC's sixth assessment report, which is the most recent one, include capturing and storing literally hundreds of gigatons cumulatively of CO2 between now and the end of the end of the end of the data. the century. Just to be clear what we're talking about here, I mean CCS in the broadest sense. It's an umbrella term here for direct air capture with storage or sequestration, bioenergy with carbon capture and storage, point source carbon capture, basically capturing CO2

from any source, ambient air or exhaust flus, and then storing it away somehow for thousands of years, we hope. It's the net in net zero. And it's sort of controversial because using CCS will be a tricky balancing act. On one hand, true decarbonization needs to do most of the work of cutting emissions. It's just going to be way too expensive if we rely too much on CCS. We don't want it crowding out or competing with the resources that should go toward that kind of true decarbonization. On the other hand, we do need CCS or we will need it for a lot of the hardest to abate emissions that decarbonization can't get to,

what we often call residual emissions, not to mention the fact that we are going to get to net zero and then probably need to go even further and become net negative globally because we will have overshot our carbon budget. So whether you're thinking about process emissions from steel or cement, where there are fewer zero-carbon alternatives,

or whether you're thinking about just getting to negative through things like direct air capture. CCS is definitely going to be a part of the mix here. But there's a lot of debate around it because I think some people think of CCS and particularly certain parts of CCS world as being a potential crutch or a way to extend the lifetime of infrastructure

that they want to end the lifetime of as quickly as possible. So it can be either thing, right? It can be a crutch or it can be a way to accelerate our path to net zero. So how do we think? about for any given application or any given use of CCS, how do we understand, is it a good use, is it a bad use, what category does it fall into? I think there's a very small group of nerds, most of whom probably listen to this podcast, who intuitively get the differences amongst

these different ways to capture CO2 and where they sit in this pecking order. But I think many, many more people do not. And that's a challenge because there are real political and economic forces that are pushing for various forms of carbon capture that can totally muddy these waters. So to try to tease some of this out, I spoke to someone who thinks a lot about these questions, Dr. Emily Grubert. She's an associate professor of sustainable energy policy at Notre Dame, and she posted a really good Twitter thread recently, probably the last Twitter thread that we're going to reference before we start referencing Threads threads, about how the same CCS infrastructure actually has a bunch of different use cases. She put it in four different categories, which we talked about,

And I think they're illuminating and a good frame for how to think about this broad category and make sure that when we're talking about CCS, we are talking about the same thing. So, before I get to Emily, as always, you can leave us a voicemail if you want to suggest topics or ask questions. Our number is 911-808-5832, or you can email us at Catalyst at PostScript Audio.com. You can also tag us on Twitter. I'm sure we're on threads by the time this gets released. And for now, here's my conversation with Emily. Emily, welcome. Thanks for having me.

Let's talk about CCS. I want to start with talking about terminology a little bit because we're probably going to use a bunch of terms and we should be clear on what we are talking about. So I guess when we talk about CCS, carbon capture and sequestration or carbon capture in storage, people sometimes use them interchangeably, I think. Do you think of that as being an umbrella term that encompasses all the different ways to capture CO2,

whether from a point source or the app, or whatever, or do you think of there being that is one category and some other stuff falls into a different category? Yeah, it's interesting. I think about it as an umbrella term for a set of technologies, but not everything that falls under sort of mitigative carbon capture and storage or carbon removal specifically. I think about it kind of in any situation where you're using a chemical or physical process to get CO2 out of something. So it probably wouldn't ever refer to biomass absorption of CO2 as carbon capture and storage, even though you could make that argument. When I talk about it, it's mostly kind of the chemical and physical

storage capture mechanisms, whether that's applied to mitigation or removal. Okay. And then there's obviously like nuance within that. So like what if you take biogenic CO2 and run a Bex plant where you're doing bioenergy plus CCS? Then there's, then you're in CCS world, right? But you're saying the process of the plant capturing the CO2 from the atmosphere is not itself CCS, at least to the way we're defining it. Yeah, exactly. Like the tree is not capture. The giant capture unit you put on the power plant is capture in the CCS terminology zone, I think. But yeah, the whole thing where CCS is kind of a set of technologies and it doesn't really map that well to an atmospheric function, I think is partially what's so confusing about a lot of this. Totally.

And that's, I think, why we want to have this conversation because I thought what you did when you laid out this sort of framework, it was sort of starting to answer a question I hadn't fully articulated, which is that I feel like in the discourse, whether that is in policy circles or even in investment circles and things like that, we often conflate various subcategories of CCS or we confuse them with each other. And it's only going to get worse, not better,

in part because we're doing more of it of all these different kinds, and there's like now a policy overlay with tax credits that vary for different things. And I think it is important to separate all that stuff out. And then as you did, start to answer the question of, okay, like, we're probably going to do some limited amount of

all of this stuff. How should we be thinking about prioritization? What are good uses of CCS and bad? And so on. So I want to tease that out together. And we can maybe start by, I thought your frame of the four different uses of CCS is a good way to start. So why don't you walk us through sort of like one of the four things you can do when you are capturing and sequestering CO2? Yeah, absolutely. And I think one of the things that gets exciting about this is that I can even convince myself that there are different categories or subcategories, but broadly speaking, I think the first category and the one that we talk about the most is CCS applied to things where we really do have other solutions. And for the most part, that's basically fossil CCS. There's some things I think you can argue that are maybe not super well suited to alternatives at this point, but for the most part, fossil CCS applied to a power plant that's using a fossil fuel or. a refinery or something like that is kind of a way to deploy CCS to mitigate emissions in a way that could be substituted by something different. In practice, because this is mostly fossil stuff, I think that ends up looking a lot like lifespan extension or some way to keep using fossil fuels

into a decarbonized future, that sounds, I think, maybe a little bit more aggressively judgy than I intended because I do come down pretty hard on the notion that we need to phase out fossil fuels, but it doesn't necessarily mean that there are no circumstances where we would want to be able to use fossil fuels for a transition or for providing basic energy services or something like that. So it's a preservationist approach that's not necessarily always 100% of the time bad, but the net effect is to enable us to keep using fossil fuels. Now, yeah, I always struggle with that framing, the sort of preservationist way to think about it too, because so let's just like give an imaginary example. So you've got a, let's just say a

natural gas power plant, right? Now, to your point, the thing that you're sort of using to distinguish this category is that there are alternatives. So you theoretically, you could shut down the natural gas plant tomorrow and put together a suite of alternatives to replace it. Now, if you wanted to replace it one for one, all the generation from that natural gas plant, that might actually end up being kind of expensive if you did it today. And it'd be doubly expensive if you're shutting natural gas plant down before the end of its useful life. And so, you know, there's this, there's the, like, microversion of it. Like, in this specific case, is adding carbon capture to that natural gas plant extending

the life or the use of fossil fuels unnecessarily, or is it best available alternative? And so I feel like there's just a lot of gray area in the specific cases for this one. Yeah, it's always a classic thing, too, because necessary is always necessary to do what, kind of a question. I think I drive my students insane when they use these kinds of words and papers and such because it's a multi-criteria and very value-based evaluation of what you're trying to accomplish, right? So necessary to reduce costs versus necessary to keep the lights on versus necessary to continue existing. Like these are very, very different spaces. And I think that's also partially why this gray area gets so confusing. Because one person saying, like, yep, I agree with you.

Like, we need to do this when it's necessary. It might have a very, very different viewpoint of when that is. Yeah. Okay, but so the thing that distinguishes this category from the other three that we are going to talk about is you're saying, this is adding carbon capture where generally on the combustion of fossil fuels where we have a readily available alternative that let's set aside the nuances of, you know, the tradeoffs that that alternative presents, but like there is an alternative.

There is an alternative, exactly. Okay. All right. So then what's the second category? The second category, I think, is mitigative CCS, so you're avoiding emissions rather than removing them from the atmosphere, but on processes that we don't have other alternatives for. This is also one of these places where you can have a lot of arguments about what constitutes an alternative. But I think things like mitigating process emissions from cement plants fall into this category. You can reduce the amount of cement that you're using. We can come up with slightly different formulations for concrete that are less cement intensive, those types of things. But fundamentally, we're going to keep using. cement in ways that are very, very difficult to imagine moving beyond and cement, just the process of making it fundamentally results in CO2 emissions, even if you did full energy switching, efficiency, all that kind of thing. Basically, you're cooking limestone that drives off CO2. You've got to do something

with that CO2. So this is one of those cases where unless you really get rid of cement or come up with something completely different that fulfills the same societal function, there's not really an alternative to having CO2 emissions from that process. And therefore, it's really hard to think about something alternative to a carbon capture and storage process. People talk about alternative chemistries, those kinds of things. But I'm a civil engineer, and I sometimes get a little bit of flack for following my disciplines. Conservatism on this maybe, but there are a lot of good reasons that we are a little worried about moving to different concrete formulations, things like that. When you need a building to stay up, you probably are going to be using concrete.

So it's one of these places where it's really hard to think about what an alternative might be. It's interesting because I think with regard to this category of CCS, I sometimes can convince myself that cement might be the only thing in this category where you need CCS to mitigate emissions from something. You could argue that maybe the same applies to iron and steel. There's some technological development that's actually kind of moving beyond that, but it is indeed true that you need some amount of carbon to make steel out of iron at some level. And so potentially there's kind of an ongoing carbon emission there.

There are potentially other ways you could do it, but that's kind of the other example people bring up and then maybe a couple of other chemical processes but cement's kind of the huge one right so here you're saying these are basically industrial processes that produce a lot of CO2 emissions in most cases at least in the cement case and maybe to some extent in the steel case like CO2 is inherent to the process not just a result of the combustion to get the heat or whatever but it may be that as well and the key point the distinction here between this and the first category is like, because I want to make an important distinction here too. It's not that there are no alternatives. It's that the alternatives are earlier stage, I would say. Whereas like replace a natural gas plant with something, yeah, you kind of

know what your option suite is and there's a bunch of technologies that are proven to do that. Again, there could be some cost and other challenges. But like in the case of cement and steel, yeah, there are actually emerging alternatives, but they're way earlier. in the technology maturity cycle. So you couldn't realistically say today, I'm going to shut down every single cement plant in the world, replace it one for one with X and keep building all the buildings that we need to build. We might be able to do that in 10 or 20 years, but we're not there today.

That's interesting. I agree with the distinction in your drawing. I'm actually not sure I agree that there is an obvious, even emerging technology to replace cement, to reduce the amount of cement, absolutely. But to replace it, not sure I'm entirely on board that point. But yeah, I do think that this point about technological development can move things across categories to, like you come up with some

process that eliminates CO2 emissions from steel production that kind of moves it to this category of CCS, even though there is an alternative for mitigation versus CSCS where there's not an alternative for mitigation. Right. Okay. So back to our category. So category one is basically add carbon capture to things that have alternatives where you might not need to to do carbon capture in the first place. Category 2 is add carbon capture on-point sources where it's just really difficult today to imagine a realistic alternative.

What's Category 3? So Category 3 moves to a different atmospheric function, the way that I laid out. So categories 1 and 2 are both mitigation. Basically, you have CO2 that you would otherwise be adding to the atmosphere, and now you are avoiding that actually reaching the atmosphere or staying there.

Category 3 moves into the carbon dioxide removal space, And this, in my categorization, at least, is basically around removing CO2 emissions from the atmosphere as compensation for ongoing emissions elsewhere. So compensatory carbon dioxide removal. Okay. And so this is an important. So, as you said, we shifted now from point source sort of avoided emissions world into carbon removal world. And this is where I think a lot of the like discourse gets confused because I think there's a small group of people who are like all in on carbon removal and totally understand the distinction here. and then there's a much, much bigger group of people who think CCS is one big thing,

and it doesn't, they don't really think about the distinction between atmospheric CO2 and CO2 that otherwise is coming off of a flu stack. So we've moved over into... Which is an interesting space too, because I think we haven't helped ourselves with that by kind of repeatedly emphasizing that any unit of the CO2 is kind of the same.

A ton is a ton. You know, we should be calling them different things. I totally agree with that. It would actually simplify this a bit. But actually, the core thing that you're just describing in this category, which I also think is really important, is this is carbon removal. So this is removing CO2 from the atmosphere, one way or another, but as compensation for somebody else's continued emissions. So this is in the world of carbon offsets or people purchasing

carbon removals and crediting them against their ongoing emissions. And that's a specific category here, which I think is actually kind of important, because we'll distinguish it against the fourth category, which you can now describe. Yeah, and I think also the thing about the third category that's interesting is that this is basically what net zero means. So when people talk about removals and so forth, like we're talking about net zero, no change to the atmosphere. So yeah, the fourth category then is how we get to net negative. And this is basically what I refer to as draw down CO2 removal, essentially taking CO2 out of the atmosphere that's not being counterbalanced by an ongoing emission. I think IPCC refers to this category as net negative CDR, which is actually extra confusing,

because when we look at an individual unit of CDR, we talk about whether that in itself is or is not net negative. But same general idea. It's basically you're taking legacy emissions out of the atmosphere. And so any removal that you're doing is being credited against prior emissions that are already there. You cannot avoid them getting into the atmosphere. This one's also really interesting because depending on how you structure a CDR sector, this is either something, that you can do before you've reached net zero in just like a pure liability metric where you kind of purchase a unit of CDR

and decide what you're applying it to, whether an ongoing emission or a legacy emission, or from a totally atmospheric perspective, this is something that doesn't happen until after you've reached net zero because up until that point, you're always going to be compensating for something, even though it's possible that like the purchaser of the CDR

might not be doing it for a liability that they own. So let me see if I can offer another frame on this distinction. Right. So from a global perspective to just like first order, you know, we emit 50 gigatons of CO2 annually now. Part of the reason that so much interest has emerged in carbon removal is that there's an expectation it's going to be really difficult to get to true zero. And so we're going to have, let's just say, 10 gigatons of residual emissions in 2040 or 2050 that are going to be really hard to mitigate. and so we compensate for that with carbon removals, removing CO2 from the atmosphere. So maybe we'll need 10 gigatons just to put a number on it of carbon removal. That actually won't get us all the way there because then the expectation is that we are going to need to go negative.

We're going to end up just from a global standpoint needing to go negative emissions to deal with the residual emissions already in the atmosphere that you described because we're probably going to overshoot. So then we're going to need even more than that 10 gigatons that comes in the form of the truly net negative. stuff. Now, what's confusing about all of that is that what's happening today is that people are starting to build CDR. We're building the first direct air capture plants, for example. And the way that they're being monetized is that somebody is purchasing a credit. And a credit is a one ton, it's represented of one ton of carbon removed from the atmosphere. But the question is, what is the buyer doing with that credit? Right. And I don't think this actually gets like all that much attention. So if you're, you know, I don't

remember one of the big airlines signed a big purchase, right? No, it was one of the year maybe it was Boeing or something. I think it was one of the Europeans. Anyway, the point being, you're an airline and you sign up for 100,000 tons of carbon removal from direct air capture plant.

What is it that you're doing? Are you crediting that 100,000 tons against your ongoing emissions? And if so, it falls into one of these categories and not the other, right? And I think that's actually like a not a well-understood distinction at this point. No, for sure. And it's interesting, too, because I think the more that, so to back up a little bit,

CDR is something that kind of doesn't exist yet as an industry or as a sector. And I think one of the things that starts to get really important is how we actually think about institutionalizing a lot of this stuff and what we decide about some of the governance questions here. Because, yeah, in a situation where it's entirely a liability model, so I can purchase a unit of CDR and apply that to whatever I choose to, and maybe that's setting myself up to be in a regulated context at some point where I'm going to be told I have to actually show up with a certain number of credits or something like that. That fundamentally gives me, as a buyer, the right to prioritize CDR applications, which is, I think, extra interesting in the context of CDR as a pretty limited

resource. This is an incredibly energy-intensive thing to do, for the most part, across different ways that you do it. It's land-intensive in many cases. It's potentially pretty water-intensive in some cases. So there's a huge amount of resource allocation that goes into this that means that you can't actually just do infinite CDR, even if it were cheap. And so by saying, like, I get to buy a CDR and apply it to something that lets me decide what's important. And like you're saying, if we do actually end up in a situation where we have 10 gigatons of emissions associated with like agriculture, keeping people in enough modern energy services and emergencies to kind of get by, whether that looks like diesel generators or whatever, like those kinds of things where you actually really would probably at a societal scale say we need CDR to compensate for these kinds of things, those don't get prioritized in a world where I can essentially decide I'm allowed to keep emitting something because I purchase some CDR. where that CDR goes is something that I get to choose to do. In a world where you look at it from a much more system level of just deciding that we have a certain number of residual emissions that are going to be allowed to continue, and then kind of having CDR scale to that volume, essentially, that's a really different structure of governments and prioritization for how this limited resource gets allocated.

Yeah. Now, to be fair, I think that in a lot of the emerging standards and a lot of these net zero commitments and stuff, you know, people are thinking about some of these challenges. And for example, there's a lot of a big movement toward the reduce first, then offset the rest or remove the rest or whatever. And so it's not, I fear, you know, the part of the problem with this market, this emerging market in general is that's kind of the Wild West. So everything is happening, all the good stuff, all the bad stuff. But, but I, you know, I have some hope that at least the like using carbon removals

to make up for the easy to mitigate emissions thing isn't really going to happen in part just for economic reasons. It's like way more expensive to remove CO2 from the atmosphere than it is to take your low-hanging fruit emissions if you're, let's just say, a corporate. But nonetheless, I do think it's a, that creates a complication in this market for sure. And I wonder how you think about the sort of crediting component of it as a result of this. Because I've been accused, so I'm generally pretty sensitive to like the messiness of the carbon market. I've talked about on this show before. I just think it's, I think it's problematic. And I've been accused of, especially in the context of CDR, like, look, realistically, we're, we need to scale this market

at a pace. If you believe we're going to try to get to 10 gigatons by 2050 or whatever the number is, the slope of the curve of scaling for CDR as an overall market needs to be incredibly steep. And so we can't really afford at this point to be perfect with regard to what these credits count toward. And so, for example, in this distinction between your third and fourth category of like offsetting somebody's emissions versus getting rid of residual emissions in the atmosphere, like, is that not just a luxury distinction that we should have in 2040? Or does it have, do you think it has like real utility today? No, I think it has really utility today. I'm sympathetic to that argument. I mean, I've been buying CDR credits for four or five years at this point.

point. And like I'm not saying that I'm net zero or anything like that. It's purely just sort of an investment in scaling some of the stuff to see how it goes. But I think it is actually incredibly important to think about these things now as opposed to later. Because right now, basically, the CDR industry doesn't exist as such. There are emerging companies. There are some tax credit structures, those kinds of things. But what we decide about governance now, I think, is what we have as governance in 2040, where it really starts to become important. I agree with you that we're not going to get anywhere close to these distinctions actually mattering physically for a long time, but in terms of what we set up, what kinds of liabilities we're creating, and what kinds of

investments, capital structures, you know, basically power structures that we're creating at this point, it's really easy to adjust those before they exist. Once you've created something that is incredibly, incredibly predicated on a specific market structure, it's really hard to change that. I think where it becomes incredibly important, actually, is just in this in this context of having something that's purely for profit and purely potentially based on compensatory CDR that's selected by an actor as opposed to kind of being the net impact of a bunch of decisions that we've made regulatory or otherwise in terms of who's actually allowed to keep emitting under these different circumstances, mostly because you can end up in a world where

basically you increase that level of residual emissions by opening up a declaration by buyers, essentially to say that my residual emission matters. And yeah, in terms of just creating the capital infrastructure, all that kind of stuff, it's going to look the same either way. But you basically extend the amount of CDR you have to do if you provide license for some of that compensatory CDR to be applied in places where you don't really need it. Virtual power plants are becoming a reliable way for utilities to manage capacity. But enrolling devices is just the start.

What really matters is confidence. Knowing those resources will perform when dispatched and being able to prove it from the control room to the living room. Energy Hub's platform handles the full picture, from near real-time forecasting, locational dispatch, and the kind of rigorous verification that holds up when regulators, grid operators, or leadership, ask, did it deliver? Easy enrollment creates momentum, proven performance builds trust. That's why more than 170 utilities rely on Energy Hub to manage over 2.5 million devices delivering 3.4 gig. of flexible capacity. See what that looks like at energy hub.com.

We're living through a profound economic shift, and energy sits at the center of all of it. Trillions of dollars are flowing into power plants, transmission lines, battery factories, data centers, but the future of energy isn't shaped by technology alone. It's shaped by markets, by policy, by capital, and by the institutions that connect them. I'm Alfred Johnson, CEO of Crux, the capital platform for the clean economy. me. Join me for my brand new show, Critical Capital, as I talk with people deploying capital, shaping policy and building projects. Together, we unpack how risk is priced, how incentives are structured, and how progress

is actually made. Listen to Critical Capital on Spotify, Apple, or wherever you get your podcasts. Okay, so the point of, part of the point, anyway, of this categorization is to then ask the question of, okay, does this help us prioritize a little bit? So back to the four categories. is just as a reminder. Number one, add carbon cap point source carbon capture where there's an alternative. Category two, add point source capture where there's probably, there's not currently a good alternative. Category three, do carbon removal use it to compensate for somebody's continued emissions? Category four, do carbon removal, period, and don't use it to compensate, right? So how do you think about how much of each of these things we kind of want to be doing and how do we think about

prioritizing them? No, I think it's a really good question. This is also an interesting question in the context of the compensatory removals, where I think there are some things that you do kind of have to do and some things that you don't have to do. So there's probably a sub-distinction there, too. Nitrous oxide emissions from agriculture are kind of the classic one of really, really hard to get rid of, and kind of the basis of a lot of the food system that allows us to have a population the size that it is. So getting rid of that is not super probable.

Their compensatory emissions actually do probably fall into a kind of higher priority, category than like, you know, compensatory emissions because I feel like not upgrading my natural gas fired furnace or something like that. And so I think when we think about priorities, really recognizing that there's not just social license questions about a lot of this, but actually resource constraint questions starts to guide how that conversation goes. With CDR in particular, I think we would do well to really recognize this as essentially a depletable resource in some ways. You know, there's an amount of CO2 in the atmosphere that means we're not going to run out anytime, you know, in the foreseeable future. Yeah, exactly. But because it's energy-intensive,

land-intensive, those types of things. Like, you actually can use it up. And so I think that that's a really important frame on the removal side. On the mitigation side, I think really recognizing how infrastructurally intensive some of the stuff is and kind of the fact that you are hitching your wagon, so to speak, to some industries continuing to exist if you end up investing a ton of money and effort into certain of these pathways also helps kind of point to prioritization. So, like, one thing that I think about a lot on the mitigation side is basically how many technology generations might you expect if you do assume that we're going to reach deep decarbonization by the middle of the century. So for power, that probably looks like one

generation, if you assume a power plant lives kind of 30 to 50 years. And then, hypothetically, you move on. And the fossil fuel industries that are supplying those kinds of infrastructures probably are a lot smaller or don't exist, but there's other reasons that you would expect that to kind of phase out over time. With stuff like cement, you might actually expect that we have some small amount of mitigative CCS kind of indefinitely.

So maybe that's, you know, three or four technology generations before you see really something coming up to replace that. But then with something like CDR, this is potentially as many technology generations as you could project out because after you kind of move past the stuff that you need to compensate for, some of which will happen indefinitely, some of which will kind of phase out over time,

you still have this drawdown pool. And so in terms of prioritization, when we think about technology investments, I think really focusing on the stuff that we know we're probably going to need for a specific atmospheric application for a long time is a better move. In terms of actually what we're applying the various CCS-CDR technologies to, then, yeah, I think thinking about how to, what would a, CCS or CDR minimal system look like, what do we not like about that? And then what do we maybe want to add to that in addition to the kind of absolutely

necessary pieces of it? How do you think about one of the odd things about all this is that at the end of the day, with basically all of these options, with the exception of some versions of CDR that are like mineralization or something like that. But in basically every other one of these options, you get the same thing, which is a stream of CO2 gas that you've got from somewhere. And then there's a bunch of infrastructure that has to get built to do something with that, right? There are CO2 pipelines that are getting built permitted right now in the Midwest and sort of the corn belt around ethanol plants. And then obviously

there's sequestration, you've got to do something with it and let it stay there for tens of thousands of years, hopefully. So now we're permitting poor space and class six wells and so on. All that midstream and downstream stuff, or by the way, you could also utilize it, like turn it into jet fuel or whatever you're going to do. All that stuff is common across all these approaches, right? It's not unique to one or the other. So there's also, I think, an argument to be made that, like, if we're going to build a carbon management industry, it is to the benefit of the entirety of that industry and all of the things that we do agree that we need to do, to just kind of, within some limits, kind of maximize how much of it we capture now, because that is going to get

us to the point where we have all the midstream and downstream infrastructure we are definitely going to need no matter what? You know what I mean? Like is there an argument that, um, look, it's okay to do more of the category one, which is clearly the least valuable carbon capture category. That is what's going to spur the development of CO2 pipelines and classics wells or- Yeah, I'm, I'm glad to bring this up because I hear this argument all the time and I disagree with a lot of the way that it gets framed for a couple of reasons. So I think one of the things we haven't really talked about is just there are a lot of justice implications for the way that this stuff gets worked out, particularly with the category one types of things where you're generally preserving fossil

infrastructure. Like there are other emissions. There are other reasons why people want to move away from fossil fuels other than CO2. And so by having a situation where you are actually expanding the amount of fossil fuels you're using because, you know, CCS is energy intensive, all that type of thing. That has an extraction burden. It has an upstream. like transportation burden, those types of things. There are other emissions other than CO2. But that all aside, I think even if you're just looking at this from a CO2 perspective, the idea of maximizing now because you're going to need the infrastructure anyway fails,

I think, in one major way, which is that it's not conscious of where that infrastructure needs to go. And in a situation where you're designing linear infrastructure like pipelines, storage resources and such, around where old fossil plants are now, rather than on where ideal locations for like a DAX facility might be or something along those lines, I think you end up with the pipelines in the wrong places, basically, and that is not necessarily something where even the same amount of infrastructure built under one paradigm or the other is kind of going to ultimately get you to where you need to go.

I think it does fundamentally change what this buildout looks like in ways that are probably inefficient for the longer term. But yeah, because linear infrastructure lasts a lot longer than point source infrastructure even, like a pipeline you're going to rebuild in the same place probably many times, if you need to because it's really hard to cite new ones, those types of things, and that's probably going to be true for a long time. That kind of stuff lasts maybe 100 years, 200 years, as opposed to 30 to 50. You really want your pipelines to be in the right place in this sort of situation.

And, yeah, I think the paradigm for what this looks like, if you're really fundamentally orienting around CDR, which maybe means a lot of co-location of plants with storage resources, so you can minimize the transport infrastructure, maybe means you have some spur lines to some mitigative stuff that's a little less efficient for them, but is really optimized around that CDR. Maybe you don't need quite as much networking as you do with something that's mitigative. Maybe you don't need quite as much redundancy, those types of things.

So I think you do actually end up in a really different place. This point on redundancy, just to kind of tie that one out, I think one of the other really big infrastructure distinctions between mitigation CCS and removal CCS is basically that it matters if the CO2 is re-released in a very different way. for something that's mitigative versus removal. This even maybe applies to compensatory CDR a little bit, but it's a real big problem in kind of a net zero circumstance if you have a mitigative CCS project releasing CO2 by accident.

That means you need pipeline redundancy. It means you need ways to manage that CO2. Otherwise, with a removal situation, it's not good if you re-release that CO2, but if you have to shut down a pipeline for a couple of months to repair it, it's not necessarily going to be creating a giant atmospheric problem to stop the CDR for a couple of months. And so you might actually be able to get away

with a much lower intensity of pipeline infrastructure if you're oriented that way than you are around mitigation for the same kind of assurances atmospherically. How do you think about utilization? So let's just take synthetic jet fuel

as an example. So there's, you know, in order to make synthetic jet fuel, you basically need CO2 and hydrogen. That CO2 is going to have to come from somewhere. Could come from any one of these four categories, Well, I guess it can't come from the fourth one because the fourth category is removing residual emissions. It doesn't do that because the end of the day you're still going to combust your jet fuel and it's going to get re-released.

So any of the first three categories, does the scale of the need for some alternative to today's jet fuel affect your thinking a little bit about how we capture, how what kind of CO2 we capture and from where? Not really, because I think mitigative CO2 capture. still ends up having an atmospheric burden, even if it's used in sin fuels. Like, who gets the benefit of having captured it in the first place is maybe an open question in some of these. There's some really interesting concerns about double counting and so on in those circumstances. But, like, that CO2 ultimately is still a contribution to atmospheric levels at the end of the day, whether it's because of the plant or because of the jet fuel, you know.

So it actually is kind of a, it's a one plus zero instead of a zero plus zero kind of equation. if you're looking at something like direct air capture for utilization that results in re-release. So I think that it does actually matter quite a bit. We don't really have the structures in place to ensure that that accounting is really happening. And looking at some of the project announcements or ideas that I've seen where both ends of the spectrum are kind of claiming the mitigation is challenging, especially because then you start to get into people saying, well, this is also an avoidance offset credit because otherwise it would have been fossil jet fuel in addition. You end up sometimes with like three credits for, you know, not having actually prevented that CO2 from reaching the atmosphere. So those kinds of things, I think, do actually really matter when we talk about utilization that results in re-release.

Yeah, to me in that scenario, actually it is an avoidance credit. It's an avoidance or whatever credit, but it's an avoidance of emissions from what otherwise would have been traditional jet fuel. But in being that, it is nothing else. Like the direct air capture that led to that is actually not. removing CO2 from the atmosphere. You can't count it as that. But this is the problem with these markets. And yeah, which is also kind of interesting because like what we're actually talking about when we think about avoidance credits depends on a counterfactual. And having the possibility of avoidance credits kind of forces people to thinking about the counterfactual being

business as usual as opposed to like, well, we have to do something else other than this. So what's that going to look like? And I think you end up crediting against a counterfactual that is maybe higher emissions than it would be absent that opportunity. Yeah. Okay. So to draw it all back then, how do you think about prioritization? What should we be doing of these four categories? How should we be incentivizing each of them and help me rank order the importance of each of them? Yeah. So in my view, I think we need to at least try to get to a world that minimizes the amount of CCS that we're doing, whether that is for mitigation or removal. And basically just because it's infrastructurally intensive. it's energy intensive, all of these kinds of things. We would rather do less waste management than more waste management, kind of all else equal.

All else equal gets a little tricky sometimes because we actually do need to decide what we're trying to accomplish, and more waste management sometimes helps you manage wastes than that's not a bad thing. But I think doing the stuff that we have to do in order to reach net zero and then net negative needs to be the priority in my view. So really figuring out what does CCS look like in the cement industry

and what are the residual emissions that we really don't see being able to manage any other way than compensatory CDR. Having those answers and seeing what that looks like, thinking about what those infrastructure buildouts look like, I think really needs to be where we start. And then the faster you can get to the point where you're actually able to be doing drawdown CDR, the better off you are. All right, this is a lot. And we didn't even get into, like, we listed the four categories. We didn't list the subcategories of the four categories that you originally came up with. but there's only so much we can do. So I think we did as well as we could.

And I appreciate you helping me think through all these complex nuances of the emerging CCS world. Yeah, thanks for the conversation. Dr. Emily Grubert is an associate professor of sustainable energy policy at Notre Dame's Keogh School of Global Affairs. This show is a co-production of PostScript Media and Canary Media. You can head over to canarymedia.com for links to topics on today's show. And PostScript, as always, is supported by Prelude Ventures. venture capital firm that partners with entrepreneurs to address climate change across a range of sectors, including advanced energy, food and ag, transportation and logistics, advanced materials in manufacturing,

and advanced computing. This episode was produced by Daniel Waldorf, mixing by Roy Campanella and Sean Marquan, theme song by Sean Marquan. I'm Shail Khan, and this is Catalyst.