Planeteers’ Frank Rattey and Dr. Thorben Amann on closed-system, alkalinity-based carbon removal

In this edition of Plan Sea, hosts Anna Madlener and Wil Burns are joined by Frank Rattey and Dr. Thorben Amann of Planeteers — a Hamburg-based carbon removal startup researching alkalinity-based carbon dioxide removal (CDR) approaches — to discuss the science behind their closed-system pathway, their first field tests, and the national regulations guiding ocean-climate research.

Dr. Thorben Amann is the Research and Development Lead at Planeteers and a geochemical CDR specialist. In this episode, Thorben explains how Planeteers’ closed-system approach differs from other ocean alkalinity enhancement (OAE) strategies. Rather than dissolving alkalinity directly in the ocean to drive carbon dioxide uptake, Planeteers combines carbon dioxide from point sources and alkaline feedstock in a closed reactor where it forms stable alkalinity and is then discharged into rivers or oceans. 

Thorben walks through the chemistry behind this process and explains how this approach offers advantages for monitoring, reporting, and verification (MRV). Because inputs and outputs are in a controlled reactor, Thorben asserts it’s easier to conduct monitoring and initial reporting. At the same time, Thorben highlights a key challenge for the field: ensuring the stability of the alkalinity after discharge. For carbon storage to be durable, he explains that the alkalinity must remain equilibrated and stable. 

Frank Rattey, Co-Founder and Managing Director of Planeteers, then discusses Project Helix, Planeteers’ first field deployment located at a wastewater treatment plant in Hetlingen, Germany. Validated through the registry Isometric, this first-of-its-kind research project discharges alkalinity-enriched water into the treatment plant’s aquatic system to provide long-term carbon storage. 

Noting that Germany is the only country in the world that has translated the London Convention London Protocol into national law, Frank also offers insight into how Planeteers is operating under Germany’s regulatory environment. In order to conduct their field research safely and responsibly, Planeteers cooperates with wastewater treatment plants, construction permits, and regional water authorities in the country.

To learn more about Planeteers’ closed-system, alkalinity-based CDR approach, listen to the episode above, subscribe with your favorite podcast service, or find the entire series here. 

Plan Sea is a semi-weekly podcast exploring ocean-based climate solutions, brought to you by the Carbon to Sea Initiative and the American University Institute for Responsible Carbon Removal.

ACRONYMS/CONCEPTS:

• MRV: monitoring, reporting, verification
• CO2: carbon dioxide 
• R&D: research and development
• CDR: carbon dioxide removal
• OAE: ocean alkalinity enhancement
• LCA: life cycle analysis
• EU: European Union
• London Convention (LC): Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter 1972
• London Protocol: 1996 Protocol to the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, 1972

Plan Sea is a semi-weekly podcast exploring ocean-based climate solutions, brought to you by the Carbon to Sea Initiative & the American University Institute for Responsible Carbon Removal.

Transcript

00:00 - Introduction and Meet Planeteers

Anna (00:13): Hello and welcome to a new episode of Plan Sea: Ocean Interventions to Address Climate Change. I'm your host, Anna Madlenor, Senior Manager for MRV at the Carbon to Sea Initiative, and with me is, as always, my co-host Wil Burns, who's the Co-Executive Director of the Institute for Responsible Carbon Removal at American University. Hi Wil!

Wil (00:30): Hi Anna. 

Anna (00:31): Good morning. Today we're welcoming two members of the German startup Planeteers. Frank Rattey is the co-founder and managing director and Thorben Amann is the R&D lead of the Hamburg-based startup. Planeteers is developing alkalinity-based carbon dioxide removal approaches. The main one is currently operationally ready as a CO2 point source capturing module that uses alkalinity to transform captured CO2 into bicarbonate, which is a stable form of carbon, and releases that into local waters where it is stored in the ocean. Planeteers is also exploring a method using calcium carbonate, which is a major component of limestone, as a feedstock for the more open system ocean alkalinity enhancement approach. Here, they're researching how to transform that calcium carbonate into a patented feedstock called ikaite, which is a slower dissolving stable mineral, which would then dissolve in marine environments and lead to air-sea gas exchange in the so to say quote traditional OAE sense. So yeah, we're discussing a company, similarly to our previous episode with Limenet, that is implementing an alkalinity based carbon removal pathway as a closed system approach, first with a research focus, also on the open system implementation in the future. Wil, what are you looking forward to discussing today? 

Wil (1:55): Yeah, I mean, even though, as you suggest, one of these approaches is similar to Limenet, there's always differences in technologies, business models, and so forth. So I always think that's interesting. And I think that the second method, the one that's in the earlier stages, is interesting and one that gets discussed a lot less. I'll be interested to hear what they have to say about it. 

Anna (2:22): Yeah, I agree. I think generally shedding some light on these approaches that are, I guess, breaking up the big bucket of ocean alkalinity enhancement into these sort of step-wise implementations is important to highlight and it's almost a bit of a philosophical question in carbon accounting as well, I think, because really they're using the ocean purely, so to say, as the storage reservoir, not the removal reservoir. And it's interesting to think about the differences there and what that means for accounting, et cetera. All right, shall we bring them in? 

Wil (2:56): That'd be great. 

Anna (2:59): Hello hello, hi Frank, hi Thorben, nice to see you. 

Frank (3:03): Hello, hello. 

Thorben (3:04): Hi.

Anna (3:05): We're excited to talk with you both today about Planeteers. To start off, would you mind both briefly introducing yourselves? 

Thorben (3:12): Sure. Maybe I’ll kick it off. Thanks first of all, of course, for having us on the show. It's a great honor. My name is Thorben Amann and I started my career as a scientist at the University of Hamburg investigating the effects of climate change on the carbonate and the silicate cycles of large estuaries and in particular the Elbe estuary, the tidally influenced river part between here in Hamburg and northern Germany where we are based and the North Sea. This was already in the working group of Professor Jens Hartmann, who would later become one of the founders of the Planeteers. I finished my PhD around the time when the first German research priority program on geoengineering, as it was called at the time, was started, and that was in 2013. And it was very new and I was very curious about geoengineering. And what it meant sounded new and exciting and also a little bit dangerous. And yeah, I totally dove into the topic and since then I learned so much about the topic and I specialized in enhanced weathering on land. And later also I tackled the topics around ocean alkalinity enhancement as they are both very related as geochemical carbon dioxide removal methods. I totally love this research field and I totally loved the network that grew over the years as well. There are many talented folks out there thinking about all the different directions in which one can approach the topic, especially the interdisciplinarity of course, from the fundamental physics or chemistry to the philosophical considerations as well, that was very intriguing to me. However, at some point it was feeling a little bit like more of the same and there was a lot of theory and it was also paired up, of course, with the pain of seeing that very little steps were taken against the problem, the climate change that was still going on and for which we were looking into the topic of geoengineering or carbon dioxide removal as it was then later. Called when it was better differentiated. Was when the planet years came around and I was first a little bit skeptical about stepping out of my academic comfort zone, I would say. But then it struck me and I became involved and I was able to provide my geochemical knowledge for his part-time and I tagged along when the first prototype was built in the garage. And yeah, it was really a little bit like a dream. It was hands-on work connected to academic knowledge, to academic background. And the science that I learned so much about, we could bring to life here in the garage where we built the first prototype. That was really cool. And yeah, everything that follows was pretty amazing as well, so it was a really great journey in the last, what is it, two years. Yeah, and now I'm here. I took over the research and development responsibility at the Planeteers. And being a Planeteer makes me really proud to be able…we work on real life solutions. It was a mere theory in the beginning and a few years ago it was a lot of theoretical research and very little practical deployment of ideas. Now I'm here and I'm happy to be also with one of the founders of the Planeteers, Frank, who took me with him to this journey. 

Anna (7:06): Great. You listened to the Limenet episode and took up the garage story. 

Frank (7:12): It's true. We have just one and we still operate it. Thanks, Thorben. Yeah, thanks for very kind words, Thorben. But before that, Anna, Wil, I'm really pleased to be here. For me, it's really is somehow a strange universe I've entered a couple of years ago. When I was a little boy, I dreamt of either becoming a politician one day or leading a company. I couldn't imagine that it's a company like Planeteers though, because it was so far from what I used to see when I was a little boy and therefore I started something different. I studied industrial engineering, moved into consulting for several years and then found my life for quite a while in industry. So I moved into the aerospace industry, working and connecting people globally and them. Been doing this for 12 years prior to the 10 years in consulting. And what came over time was somehow the realization that large companies are wonderful to move things, but it's not wonderful if you want to find your place within and then see what remains when you leave one day. And it struck me more and more. And about five years ago when Corona hit the world and also the industry, there was restructuring going on and I decided to step out. And do something completely different. And founding a business was always somewhere, something I dreamed of. And I started to explore this. And about four years ago, we kicked off the discussions on Planeteers. We met Jens, who was our co-founder at the university in Hamburg. And he had some wonderful ideas and we felt it's so easy. Everything is there. It just needs to be a bit bigger. And maybe it was a bit naïveté, also some background. So there was a founder's team that has some experience from industrial operations and also from scaling things. And yeah, we felt it's feasible and we also had the feeling it matched on a personal level. And this is how it all kicked off. That's also when I met Thorben, one of the first times when he was still at the university. He was obviously one of the core experts in this topic. And we started acting and about three years ago, we then founded the company, which is now a little small company with 25 people. We're in the midst of Hamburg. We have actually a garage, which is now a workshop. It took some, some time to leave this also as a working space. 

Anna (9:30): Was it your grandmother’s? Sorry. 

Frank (9:32): I know it wasn't a grandmother, neither the other one, so it's a building. 

Anna (9:38): Warm greetings to Stefano. 

Frank (9:41): We were lucky to find an office space next to it. So now we live there and work from there. And I'm really grateful for people like Thorben and others that put all their passion into this. And that's probably what it's all about. I have little kids, my daughter is seven, my son is 11, and I seriously wonder in what world they will be able to grow up. And I look back on my childhood, which was also not only easy. I mean, we had acidic rains and all of this. So we had nuclear wars popping up or at least some dangers coming out of it and fears coming out of it, all this passed by. We had wonderful decades of peaceful life and forgot a bit about what it all carries, nature. And it feels good to be in this space now and bring the experience and the ideas we have coming out of leading scientific research into an application. And this is what we're doing and what we are fighting for. 

10:32 - How the Closed-System Alkalinity Reactor Works

Anna (10:32): Cool. So let's dive in. You already alluded to it, that a certain portion of naivety maybe is needed in this space. I think as with every startup, right? You have a nice idea and you think, ah, it just needs to be scaled up. But let's talk about the idea. So how does Planeteers approach fit into alkalinity-based carbon removal pathways? And yeah, what's the story? 

Thorben (10:57): Yeah, it looks so easy and maybe you even have a reactor in the lab at the university and it still looks easy. It looks a little bit more complicated but still doable and then you translate this into the next big thing and then it becomes way more complicated and then, you put it into the field and then there are the next problems and yeah, but it's great fun. So anyways, I would always do it again. So how does it fit in? We produce alkalinity with our solution. We use a CO2 stream, we use alkaline feedstock, we put them in contact and by this we create alkalinity, we convert CO2 into this alkalinity and then in a very controlled way in our closed reactor and the created alkalinity the converted CO2 is then stored in this form and is then discharged, released into rivers and/or oceans. So as such, it is an alkalinity-based carbon removal approach, right? It is, if we would look at it from the perspective of isometric modules or protocols, it is engineered enhanced weathering. So basically, and that's what I said in the beginning. 

Anna (12:18): Isometric being the leading carbon removal registry for those who maybe don't know. 

Thorben (12:23): Exactly. Coming from the research of enhanced weathering on land is actually quite similar in a way of what reactions of what chemical processes we use in our reactor. At the same time while on land we would spread the material and then leave it there in the open nature to be weathered by rain and whatever temperature is there, we can control all of this, all the outside parameters and speed up the process. So everything is done in a matter of seconds to minutes. It is not necessarily marine carbon dioxide removal in the stricter sense, obviously, but the method itself uses the ocean not as the medium to take CO2 out of, but as a medium to store the CO2 that we converted into alkalinity beforehand on land. And for this, we are using point sources of biogenic carbon dioxide that can be biomass power plants or any other point source that produces biogenic or any kind of feedstock. So the method itself is very agnostic to the origin of the CO2. So the process just takes care of the CO2, no matter where it comes from. Yeah, and then in the wider sense, we would call it a geochemical CDR method, I guess. 

Anna (13:59): The emphasis lying on the fact that it does need to be biogenic though, right? Like it cannot be CO2 streamed from fossil fuel, for example, then it would not be considered CDR. 

Thorben (14:07): It will not be considered CDR, right, but it's still the removal that would then probably be considered decarbonization. 

Anna (14:14): Exactly. 

Wil (14:15): So what do you see as some of the advantages of this kind of closed system approach, and maybe what are some of the disadvantages as opposed to the open system ones that we've often talked about?

Thorben (14:29): One of the big advantages compared to methods like enhanced weathering on land or even ocean organization is the measurability. So as we have a closed system with very defined inputs and outputs which we can very closely monitor and measure, that makes our process very controllable and makes our reporting, at least our initial reporting, very easy, because we really know what is going in and what is coming out. So from a sense of monitoring, that is a big advantage that we really don't have to guess at all. The second point is that we can apply this technology to any point source of CO2 that we find. And very often those point sources are within an industrial setting. So all the infrastructure may be already there and we can just attach our unit to the existing infrastructure and leverage whatever infrastructure is already on site and good for us. At the same point, we have to say it's relatively easy to take a bag of mineral dust or rock dust and spread it somewhere. So the disadvantage of our approach may be that we have relatively high energy demand for the process and also very high capital expenditure in the beginning. So it's an industrial process. There's still a lot of components involved and this of course means that we have relatively higher costs for energy but also for building the whole unit. 

Wil (16:25): Okay, great, thanks. We'll talk a bit more about cost and energy later. I was curious, what are you using for alkalinity feedstock? 

Thorben (16:34): In our first approach, in the unit that we all have running right now already in northern Germany in a wastewater treatment plant in Hetlingen, we use limestone as our feedstock. 

Frank (16:47): We have been intensively collaborating with the limestone industry and lime industry in Germany and Europe and globally, we are associated with the International Lime Association.  That was probably also one of the striking elements for us that this approach is so close to what they are doing. Burning lime is producing a lot of CO2 and you can't avoid this because it's process related. On the other side, you still can add one CO2 molecule to calcium carbonate and turn it into bicarbonate. And that was really eye-opening also for this industry. And that leads, for us, a strategic direction to, on the one side, source material from this industry, and we have partnerships with several of these companies, and on the other side, also discuss potential ways to decarbonize or mix models where they turn to biomass incineration and then producing misprocess-related emissions. 

17:35 - Science Challenges: Stability, MRV & Ecosystem Impacts

Wil (17:35): Yeah, I think that's really interesting. I suspect that a lot of the economic viability of this industry is going to hinge on that kind of model in the future. One other question was, what are some of your key research questions that you had to solve in kind of the initial iteration and what else are you working on that's challenging at this point? 

Thorben (17:59): Yeah, I mean we can address this question from many perspectives, I guess. There's chemical components, biological components, physical, technical. I’ll try to address some of them here maybe. I think from the perspective of, and that is our final goal of storing CO2, one of the most important issues or questions that we had to solve and I think still an ongoing topic of research is the stability of the alkalinity that we produce. So we have to make sure that the alkaline that we discharge in an equilibrated and stable way into the ocean, that this alkalinity in which we store the CO2 actually remains as this kind of alkalinity for a very long time so that qualifies as a storage. And there are some studies out there about the stability of alkalinity and the dos and don'ts about it. For now we can, with our approach, make sure that we stay within the limits, very well within the limit actually, of having this alkalinity stable. So we don't expect with our approaches that we will go into areas where we actually would have to expect that the alkalinity becomes unstable and that we would see precipitation again and during this precipitation, the re-release of the CO2 that we initially captured. 

Anna (19:45): Maybe if I can very quickly interject, just from a perspective of, I'm going to get the science right, but I want to give you an opportunity to clarify what you mean with the stability of the alkalinity and what type of alkalinity you are adding to the ocean. You know, the way we often talk about alkalinity enhancement on the podcast is you add alkalinity that then allows the removal of CO2, which turns it into dissolved inorganic carbon. And that's how you store the carbon. You are now saying that the alkalinity is the storage of the carbon, which is because you're specifically adding bicarbonate, is that correct? And do you want to say a little bit about which component of alkalinity you're really adding and storing? 

Thorben (20:25): Yeah, that's a very good point. Thanks for pointing that out. Sometimes it's not really easy to explain because it's very technical, I would say, but generally the process that traditional, classical, so to speak, ocean alkalinity enhancement is done is that you add alkaline materials into the ocean that then dissolve, take up the CO2 from the water column And in that sense, take up the atmospheric CO2 that was going over into the water due to the exchange between water and atmosphere and stores the CO2, making room for more CO2 to be taken up. And what we essentially do is we take this process but lead it into our reactor and we do the whole dissolution process there and we don't take, obviously, water from the water, CO2 from the water column, but we take external CO2. We mix this into some kind of a supply water. We create a carbonic acid solution, and this carbonic acid solution which is also a lot stronger than the carbonic acid that is in seawater, we dissolve then, or we encounter this with an alkaline feedstock like the limestone, for instance, and we do the whole conversion process before leading or discharging the water into the ocean. So we take the whole process of ocean alkalization and do it in our reactor and then only we discharge the final product that will also exist from OAE or classical OAE approaches and we discharge this into the ocean. And that way we consider this as an equilibrated alkalinity discharge, which has no potential to take up further CO2. So that's why I'm saying. The ocean is merely considered a storage tank rather than the reactor tank where actual reactions take place. So actually we don't want to see any reactions ideally. And that is then going back to the stability of alkalinity. So we did all the initial reaction, the forward reaction towards the alkalinity and we want to avoid the backwards reaction in which the CO2 would be released again. Does it make it clear somehow? 

Anna (22:53): Yes, absolutely. I mean, total alkalinity is, you know, an oceanographic nightmare to some, but yeah, I just wanted to emphasize that, that was great. So I think you wanted to touch on some more research questions. 

Thorben (23:07): Some questions. Yeah. So from that end, maybe the chemical part is somewhat like the major part is covered. Of course, there's the biological component. We want to make sure that ecosystem impacts are ideally not happening. So we discharge something and there are no impacts or ideally some positive impacts maybe from increasing alkalinity. But we have to make sure that we don't have any negative impacts, of course, and by using this equilibrated approach, we can actually make sure that we are on the safe side here because most of the research showing potentially harmful effects are going back to the use of un-equilibrated alkalinity, so where the reaction is taking place in the ocean water itself. Yeah, that's something that we need to consider, but we are relatively confident that at least in the first phase of scale-up, we wouldn't encounter any roadblocks, because the amount of activity we would discharge would very well dilute in the discharge waters, so that should be critical. There are some physical things that we, of course, need to address. Of course, there's a large part of modeling where we try to actually also, through calculations, find out how stable and how long can we store the alkalinity of the CO2 as alkalinity in the ocean, how well do we mix it and how sure are we that the mixing happens fast enough so that we don't encounter strong alkalinity additions that wouldn't trigger re-precipitation, for instance. But there's also other perspectives, of course, technical issues, the transition from the lab to the garage prototype, and then to the scale-up. There's a whole lot of technical issues that are related to it. Monitoring sensors that we have to develop or to find the sensors that match our needs very well. But also a big thing is... Something that initially we didn't look into too deeply is, of course, the LCA, the lifecycle analysis, like how big is the carbon footprint of what we actually do, and this is especially challenging when talking about a first-of-a-kind solution or reactor unit. You tend not to think about it, but then again if you want to have something, for instance, like this certified on a platform like Isometric, then they will ask for of course the carbon footprint of all the material that you use and all the cars that you used to go to the unit to fix it or to maintain it and all of that is something that is definitely also very challenging and we are able to address this and it looks very good and there is no show stopper but it's really necessary to consider this. This whole approach from all the different angles, from the very science-based carbonate system alkalinity runaway precipitation perspective, as well as the life cycle analysis and all the other components that play a role here as well, of course. 

Frank (26:35): Maybe I was a bit too optimistic four years ago, it just needs to scale up. On the other side, to be fair, a lot of this work was already ongoing and we piggybacked a lot on research that Jens and Thorben have been doing and it's continuing, it's still a research journey, but it's adding more application now, that's good. So I still feel we're on the good path, that it's just scaling. 

27:17 - The Helix Project in Northern Germany

Anna (27:01): So let's get into that. You already mentioned that you're operating a site in the north of Germany, close to Hamburg. Do you want to talk about that project a little bit and where it currently stands, how is it operating, and what are you testing there? 

Thorben (27:17): Yeah, that would be the Helix project, which we are very proud of, of course. It's looking great. You can have a look on our website to get a visual impression as well. And I have to say, whenever I go there, it really amazes me when we drive around the corner, we can see the green container unit. So it's a 20 feet container unit, basically what contains everything. It's always great to see it, I'm always happy to see and to open up the doors and to start a machine. It's a super cool unit and it made a little road trip to different sites across Germany. And now it landed in Heidling and there's a wastewater treatment plant and we can leverage the infrastructure. They have some little biogenic power plants that produce obviously a lot of biogenic CO2 and that's a very nice CO2 source, exactly what we need. They provide us with utility water that is cleaned wastewater so we don't use extra water and we connect all this to our container unit. We run the reactor and then we discharge the water into the process towards the outlet of the wastewater treatment plant. We have the waters mixed and then they are measured through the official monitoring programs, official sensors, to make sure that everything is going to plan, that we don't change the water in a way that would be harmful or even if it wasn't harmful that we hit any kinds of thresholds that are given. We see that it is really unproblematic and yeah, the unit is running. It's validated by isometric. This certifier with which we want to then later have our produced negative CO2 tons also verified. So from that end, we are really proud that we were able to bring this unit from the garage, from this backyard garage that we are building it in, into the field and actually have it validated and to produce actual negative tons of CO2. That is really something that we can be super proud of and it's probably the first project of this kind globally. And as I said previously, it's really tough to use this kind of a prototype unit, this first of kind unit, and meet the very tough requirements from Isometric. 

30:03 - Ocean Storage vs. Underground Storage

Anna (30:03): Yeah. And I think speaking of Isometric, as far as I know you might only be the second project that is doing some version of an ocean-based alkalinity approach that is validated on that registry. Though, interestingly, I remember I came across this in December or so, I think shortly after you were validated for this project, I think they list you under suppliers in the marine pathway or area, but the protocols against which you've been validated are not really protocols in the ocean pathway, right? I think you're using the biogenic carbon capture and storage protocol, which has a module called Enhanced Weathering and Closed Engineering Systems, you mentioned it earlier, that includes the ocean reservoir as a storage pathway. Now, I think we already covered why, of course, Planeteers can be considered a supplier in the marine pathway because of exactly this storage aspect. Why is storing CO2 in the ocean a good idea? I suppose the question is, I think many people probably know or have heard about CO2 storage and underground systems, etc. But paint us the picture about why you're following this approach. 

Frank (31:14): We are deeply convinced that we can set a benchmark to store carbon in the long run and find an alternate way next to what is quite common and commonly used, for instance, in the Americas. Underground storage is something that has been done there for quite a while. Here in Europe, it's also done for a while, but somehow it appears that the challenges linked to this are fundamentally higher. So when we look at conventional processes, and Thorben mentioned this beforehand, talking about capex needs to finance such an equipment, this obviously relates towards open systems where you just spread stone on the field where the capex is going to close to zero. When we compare ourselves to a conventional way to capture and store CO2, then this is classically done. For instance, we are amine scrubbing, so we have a big scrubbing device that sits next to a plant, turning a plant like a cement factory into a chemical factory because you add a huge piece of equipment that then scrubs the CO2. Then you concentrate the CO2, you liquefy it, you store it immediately, you hope that a ship comes or that the pipeline is built, and then you somehow transport the CO2 with very high purity towards the final injection point. And then you inject it in, for instance, an old gas cavern or somewhere in an underground storage field. This is heavy metal. So the whole system is super complex. There are multiple players engaged. It's going across borders. It's really a task that especially in Europe, people are working upon, but also struggling with. There's a lot of focus on the scrubbing part at the moment. There are huge projects out, for instance, in the cement industry, several hundred millions at the EU supports this. Still the question of how to get rid of the CO2 and how to finally store it is a bit unsolved. And when you see the growth of storage capacity in Europe, we are largely behind the initial plans. And it's obvious that there's neither the investment nor the capacity to grow as quickly as initially forecasted. On the other side, our approach, given that we have water access, is a simplified way. We can capture and store in one go. So it's one piece and we mineralize water. We add, obviously, limestone or limestone-like products. And then we have storage at the point where we produce or we emit the carbon, we believe this is superior. It takes out value chain steps, therefore it's cheaper. And it’s a significant lower amount of capex investment linked to our approach, and this is what we are fighting for. 

Anna (33:54): Does it also have a, I guess, less of a limit or upper cap? I mean, one of the issues, maybe not so much today, is that underground CO2 storage is also eventually going to be limited and a discussion at least that was taking place in Germany, I believe in the past year or so was whether such underground storage should actually be available for CO2 from fossil fuel sources or just sustainable or biogenic sources. So would you say from that perspective that the ocean as a storage reservoir also has more. I suppose, capacity. 

Frank (34:26): Every reservoir has a limit, so this is the same in the first place. Obviously, the ocean is one of the larger ones. It's larger than touristic reservoirs. Still, the whole research that's going on there is for a purpose, because it's a pretty new field and we need to carefully explore the way forward. And in the end, we can only win this battle, climate change, and fighting against it, if we bring different approaches on the pathway to support this, and we believe that the ocean can add a significant part and can take more carbon on board in the form of an equilibrated alkalinity. Still we need to do it carefully. We need to follow rigid regimes that we try to do with modeling and also measuring this, and we gradually need to see what happens also when we come to large amounts, like for any other mean in the end. I think that's essential. 

Anna (35:23): I think one thing is very interesting and I'm excited to talk to you about this. You mentioned, and I think under the protocol, you are required to monitor certain things in the marine environments. Essentially what you have to do in the ocean and your current setup is to prove the durability of your carbon storage, which I think it's less of a focus for those OAE pathways that, you know, are doing the dissolution and removal in the open ocean there. It's very much about proving removal in their first place. And so I'm curious what type of monitoring and modeling you're doing in order to prove and show that your carbon is stored. 

Thorben (36:03): Yeah, that's an interesting perspective change that you introduced there. So what we convert is actually super easy to monitor for us because we measure in, we measure out easily. But then of course, downstream, that is a totally different story. And I would actually argue that it's somewhat hard to really measure it as it is usually with things that happen in the ocean, right? 100%. But what we can make sure is initially when we explore the idea is that we employ a near-field model, and we did this, for instance, for the helix discharge point, so that's the wastewater treatment discharge point. We employ a near-field model together with a research institution near Hamburg here. They have a very refined hydrodynamic coupled biogeochemical model. And the first approach was to show that the very little amounts that we introduced are mixed in and diluted so quickly that it doesn't really have an impact that would be even remotely measurable. That of course will change once we aim for more, but still that would always be the first approach because that is very important for us because of the stability issue that we make sure that we dilute very very quickly to get to values that are uncritical from the ecosystem harmfulness perspective, but also from the stability perspective as well. Once this is made sure, we would also of course employ a far-field model to make sure that the overall capacity is maintained, to make that the re-equilibration that we have to expect or that is to be expected when we change the water types, when we run from a river's discharge system into the North Sea, for instance, into the Atlantic. Then we will have certain re-equilibration processes going on that will convert some of the CO2 that we initially captured back to CO2. That is a very natural process and of course we have to account for this. But this is relatively well understood and I think the models that we are able to employ can cover this quite well. This was also something that we got as feedback from Isometric. We even try to build up some capacity in-house to run simpler models ourselves, not to be fully reliant on university capacities, of course. As I said, once we go to higher amounts of air quality discharge, at least in the beginning, we would also need to measure some kind of a baseline beforehand and then measure our actual activity and make sure that models and actual field measurements match just to make sure that everything that we do is in a way that we describe it and is harmful, of course not harmful, harmless to the environment. 

Frank (39:12): And Anna, it's really not funny, but also interesting from that perspective of what you just said for many approaches like conventional OAE or also enhanced rock weathering. The focus is on a different part of measuring, let say, the capturing element. And fun fact, when we were in the EU consultation for the carbon removal, carbon farming regulation last year, there was then a comment from one of the enhanced rock weathering guys stating that yeah, at the end they deduct 15% over. So that 15% is the best case we can go for. So they spent zero focus on this, and it's fair enough to not do so. I think we approach this now with far more modeling, and I think it's also good to do so. 

Anna (39:57): Yeah, I mean, I think what Thorben described as tools, right, is actually quite similar or even, if not the same, as the OAE pathways are using that are doing dissolution and removal in the water, not the open ocean, but in the water. But your focus is on something else, right? Your focus is on assessing potential re-equilibration, whereas their focus is on assessing equilibration in the first place. But I guess I found it interesting because exactly to your point, Frank, the durability aspect of ocean alkalinity enhancement is often considered that, well it's durable right, like once it's stored in the ocean, carbon is very hard to get out again. But I think that assessment is of course a sort of broad assessment of carbon storage in the ocean in general and where you have to prove your storage or model your storage really comes in at this coastal, very near-field dynamic zone. And I think that's interesting. So in that sense, it's not that you're doing something fundamentally different from the others, but with a slightly different end goal. 

Wil (41:03): So we touched a bit on this before, but what are the knocks of these closed system approaches, especially ones with limestone or energy requirements, right? And I was curious what the energy requirements are of your system and why you feel in the long term that won't end up preclusive, both from a standpoint of energy needs and a standpoint of cost. 

Frank (41:27): I think the topic of engineered solutions or technical-based solutions has already been discussed in other episodes that obviously there's a need for regenerative energy with all of these, and it's also true for us. Our, let say, energy requirement is largely driven by water movement as we are mineralizing the water. So we need to push the water through our technology. And that causes, or is caused by using energy there. Our prototypes and also the first equipment we have now out in Hetlingen, I mean, these are early stage units, not yet optimized. What we're targeting is about 500 kilowatt hours per ton of CO2 in the long run. The system we are just building at the moment and it will be the next evolution coming after the Helix one in Hetlingen. Then we go to Kiel also, to a wastewater treatment plan will have 15 to 20 times the capacity of what we have done in the west of Hamburg. There we are targeting 1,400 kilowatt hours per ton on the nominal value. And we further degrade the energy consumption moving forward. It's mainly optimizing the different equipment and focusing more and more of the energy portion on the actual water movement itself. What is, in the end, impacting the energy need is what levels of alkalinity do we have in the water? What kind of feedstocks are we using? And what is the CO2 concentration in the flue gas? This will have the final impact on how much water is to be moved and then results in the energy needs.

Wil (43:11): What's the removal potential of such a point source, sites in Germany and perhaps Europe, if you were to ideally scale this, what could you get? 

Frank (43:22): I think it's a bit of history…and also the tricky element when we started the journey. I mean, I said it was all easy. Germany is a pretty regulated country. So we have regulations for anything. And we are very rich at water regulation. So it was somehow obvious for us that, on the one side, we wanted to prove it's feasible in Germany. On the other side, we needed to find where to do it. And then we tapped into wastewater treatment plans because they manage large water flows. On top, they have biogenic CO2 sources when they incinerate biogas or biomass. So looking a bit on Germany and Europe, we have about 50 million tons of biogenic CO2. Not everything is accessible because partially they are very small appliances. But there's a larger two-digit million ton amount in wastewater treatment plants. Looking broader on other biogenic sources with water access, and that's what's said. So we mapped out the coastlines and larger river estuaries in Europe. We find more than 25,000 megatons of biogenic CO2. And on a global level, this will scale probably with a factor of 2 to 3. And the net, or the CDR potential, so a carbon dioxide removal out of the atmosphere as we're leveraging biogenic CO2, and this can be then linked to more decarbonization approaches on fossil emissions, for instance, in lime or cement, Always incineration, which are so-called hard-to-obey industries that we believe our approach could also work with. So it's a quite significant megaton potential in Europe and then scales up to gigaton potentially on a global level. 

Wil (45:10): And hard to know, I realize, but if you try to pencil this out when you get to an nth of a kind stage of development, what do you think the cost per ton of sequestration could be? 

Frank (45:20): I mean, there's always a bit of a mirror ball inside these projections. We have scaled our technology and have also scaled the learning curves behind and came to values slightly below 100 euro in the long run. The cost drivers that we, let say, need to tackle on the one side energy and the other side material. Capex itself it's not so massive in the overall sum as the equipment in principle is pumps and some vessels and some let's take control units that over the the size of the equipment is marginal so energy and material remain the material side we look into side streams of limestone and lime production. So there's a lot of material that is currently not industrially used because it's partially too fine or the stone doesn't really match the requirements. That's very interesting material for us. It's largely deposited, and we can untap this. So for instance, we are discussing with a Norwegian lime producer. They have half a megaton of unused mineral in a deposited area, which is more or less best feedstock for us, so that will be elements to bring our cost down in reaching this element. And on the energy side, clearly, I mean, in the first place, we look into areas where we have renewable energy on hand to reach this. And then we need to see how we gradually increase capacity. We have intermediate steps and come closer to this 100-year target over time. 

47:04 - The Ikaite Pathway: Open-System OAE

Anna (47:04): Okay, great. So doing a bit more foreshadowing. We sort of alluded to this in our introduction, and you know, folks will find this on your website as well. You are also thinking about a sort of parallel or future pathway where you would be relying on the collaboration through air sea gas removal actually, so the more open system pathway. Do you want to share a bit about where that's at and what that pathway could look like? 

Thorben (47:34): Sure, that's a change of gears from something that we have out in the field to something that we have in our garage. That's the story of ikaite.It's, as you said, more or less this classical oceanic community enhancement approach with solid alkaline minerals. Only here we use a relatively known and old mineral, I would say, but relatively novel for the application in OAE. And that's ikaite. And ikaite is a calcium carbonate mineral that carries along to six molecules of water. And the beauty of it is that it dissolves much faster than a calcite, for instance, maybe not as fast as hydroxides that you would have spread in the ocean to create our community, or alkaline solutions. But at the same time, in deploying this kind of material, it would avoid the pH spikes that we would maybe expect from the deployment of hydroxides. So it's a little less intrusive to the natural system, I would say, and therefore a very interesting mineral to use. Also, it's relatively clean, it doesn't carry any harmful trace elements, heavy metals or whatever. The feedstock used to produce this ikaite that we come to this idea is limestone, so it's a mineral that is actually technically produced. It's nothing that you can easily mine because it's relatively unstable and that's the problem and the beauty of it. It is only stable in the Nordic seas where it's cold. Really, really cold, so almost to the freezing point cold and only there it's really, really stable and the beauty of it is obviously that under other conditions that are predominant in other areas of the world, it dissolves relatively easily. So the idea is that we produce this technically in a reactor unit with limestone as a feedstock with a recycled CO2 as a CO2 source. And with a physical process involving a pressure swing, this ikaite material is produced. It is a patented process. It was described by Jens Hartmann and Phil Renforth, who are also patent holders in a scientific paper. And we tried to bring this based on the pattern. We tried to make this alive in the garage. And once this would be scaled up, the produced material could then be distributed traditionally as discussed, but probably via ships traditionally, right? But probably the better idea due to the instability of the material, would be to use coastal outfalls like other startups are doing it as well to discharge the material into the coastal ocean. And then impacts and the monitoring requirements or the challenges are pretty similar to any other kind of mineral-based social identity enhancement method, I would say. So that's the very simple story of the ikaite.

Anna (51:13): The very simple story of the very complex story. So to summarize, you're trying to merge the fastest solution of a mineral, which is a struggle or a challenge in mineral alkalinity approaches, because you have to ensure that the mineral dissolves in the water actually. So you're trying to merge that benefit with the lower pH spikes compared to the hydroxide approaches. So it sounds like you're still working with limestone. You're still working potentially in the future from a coastal outfall with this approach. How is this future version related to your current operating site? And are you sort of stacking them? Or how are they working together?

Frank (51:53): You could argue, we are a startup with 25 people. How crazy could you be to have two major technology roadblocks ahead of you and address them both? Yes, you could ask this question, right? So that's the strategic decision we have taken. So Thorben already mentioned, it's a pattern that Jens and Phil had. We see a lot of similarities on the technical side. So this dissolution of the calamity before the pressure string and all the supply chain getting access to limestone and the partners and also a lot of the research that has been done was existing. And it was obvious we can build on this. And it's just this little technical step that has to come on top. The little - again, it's not a little one because I mean that's the magic and there's still work required. Still this would give us long-term access to atmospheric CO2 sources so we would have an increased removal potential in the end. So one system we have spoken of before is the the closed system point sources and this one is then capturing atmospheric CO2 directly out of the air. So in the long run, these two systems can go in parallel, and that's also how we will address them. So the ikaite story will always stay behind and follow, and benefit from the evolutions we do on the technical side on producing alkalinity, and then we will push this afterwards, most likely also with partners, because we will need a lot of expertise on the mineral side. That's a strategic decision for the time being. 

Anna (53:42):  Yeah, I mean, I think that that checks out also, right? Like you're sort of building up the operational learning curve as well. Are there any other concrete research questions that you're working on in this regard right now, or is that what you mentioned? That's the core focus of moving towards the ikaite approach. 

Thorben (54:02):  I would say a major challenge right now is the technological upscaling. So everything that was described in the literature so far, described in scientific research projects was the creation of a guide based on chemical process, on chemical additives and now switching over and converting this into a physical production process that does not only work on a bench scale, but also on the prototype that is a little bit larger and then even on upscale versions of that. That is the big challenge. We can see that we were able to decrease the time to produce ikaite from weeks to days. So there was a huge speed improvement on that end, but still there's a lot of questions to be answered on the technical side because it's really nothing that anyone did before. And on the other hand, of course, anything that relates to ecosystem impacts of the distribution of minerals and open systems is, of course, something that is ongoing, that is addressed, of course, by many projects already and will be addressed by future or just started projects like EU Horizon projects in which we are also involved around like MRV system, but also the general effects of our energy additions. And then of course there's a huge perspective on the regulatory issues as well. And in the end, there is social acceptance of ocean activity enhancement approaches in general, I would say. 

55:40 - Regulations and Permitting

Wil (55:40): That's a good segue into our final questions, which are in the regulatory terrain. So let's start with the closed system. What does the regulatory environment look like for this system? You said in Germany, right, everything is regulated and regulated closely. Who's responsible for your permitting, and what have you learned during this process today? 

Frank (56:03): It is very straightforward. We are cooperating with wastewater treatment plants and in the first place operate under their permits. So when it comes to water, we have the regional water authorities and in German they are called Untere Wasserbehörde. So it's the relevant play on site that is translating EU national and regional law into concrete practice. Then it's for air emissions that come from the biogenic incineration. It's also a local authority there on a regional level. And then you have construction permits for foundations and anything. So these three are the ones to talk to. The main one obviously is the water in the first place. There we have the key principle, I think, at least throughout EU and probably also globally to protect a good status of the water body and prevent deterioration. And this is the route we follow, so we don't add anything negative into the water. We add alkalinity, which could be considered an acidity buffer, so potentially also having positive co-benefits. And that's also how the water authorities see this. The first projects are very promising. So our first project in Helix, we followed completely the scheme of the wastewater treatment plant. And as many wastewater treatment plants also limed some of their waters in the past, they know very well what we are talking about and what the outflow is. And we tackle the biogenic CO2 out of the cleaning process. So it's something they're very well familiar with. And the second one in Kiel, which we are just building, we're interacting individually now with the authorities. It's a very open and constructive dialog. They see the element, which is more or less common sense, which is addition of alkalinity. Alkalinity is typically something which is not monitored. It's understood. You cannot monitor. And we have seen, for instance, in Kiel there, they're adding above 100% or 150% of the nominal baseline of the Baltic Sea into the Baltic Sea for the last 30 years. So if you translate this into CO2, you could argue that they convert 1,000 tons of CO2 per year as part of their cleaning process and add this to the Baltic Sea. And this is already ongoing practice for 30 to 40 years. So that's also why we put and trigger the research project on this to really understand what is the impact because this is something we would shoot for in this field. What is working quite well is an open interaction. That's a transparent explanation of what we're doing and we are getting very, very good feedback. And it's also, we're approaching a project in Hamburg, for instance, same story there. So we put the things on the table. There will probably be more critical elements but for the time being, it's easy. We use the water of the wastewater treatment plant. We mineralize it and inject it back and that's also how they see it. 

Wil (58:52): And what does the situation look like for the ikaite-based OAE approach? As some of our listeners may know from a recent episode, up until recently, Germany didn't allow research activities of this sort under the, their operationalization of the London Convention, or the protocol, Parliament's now adopted a bill that would allow for field trials for research purposes. What's that regulatory landscape look like to date if you've had to encounter it yet? 

Frank (59:24): Alexander had outlined this already quite extensively, and he's actually the perfect person to have talked to. So in principle, Germany is the only country in the world that has translated the London Protocol, London Convention into national law, the High Sea Dumping Act, which prohibited putting anything in the ocean. And anything means anything. There was just one exception, one research topic that somehow fell off the table over time. It took years to open this box again, and this was based on strong efforts of many researchers to allow research. And this helps, obviously, to also open this pathway for ikaite. For the time being, it would be illegal for us to operate a plant like this under German law. So even if we would go into a non-German country, we would be prosecuted. So if we want to follow this pathway, then we can just hand over the technology and let an external or non-German subsidiary take over this work. Research, though, and the project itself will help to address this further. And the funny point for me was that, actually, there is a lot of research going on and has been going on in the marine sector. Despite this very rigorous approach, a lot of ground-breaking insights have been brought forward out of projects like CDRmare, so it's actually helpful that this has now opened up a bit and we can continue to do more meso-cosm experiments and stuff like this to get deeper into this field that Thorben has laid out. 

1:01:05 - Looking Ahead

Anna (1:01:05): Great. Thank you so much for that. And to close us off, what are the key milestones that our listeners can expect and that you're hoping to meet, I guess, in the next one to two years? Paint us a bit of the picture and what you're you hoping to work on. 

Frank (1:01:19): I mean, Helix is now operational. We will produce the first tons. It's still more a first technology carrier to demonstrate it's feasible. The next big project will come in Kiel at the end of this year. So we are in the construction process. The assembly on the ground will probably start in the second quarter. We have sold credits linked to this project already. So that's our big milestone moving forward to get this operational in the course of this here. And then to assign one or two additional projects. So we have very positively looking ideas out in Switzerland, in Hamburg and in Norway. And we want to get at least one of them secured to continue up scaling and moving ahead. This includes both carbon dioxide removal and also decarbonization projects. So ideally it would come jointly together. 

Anna (1:02:09): And when you say you've already sold credits, you mean pre-purchased?

Frank (1:02:15): Yeah, not yet delivered. So it's now about delivering what we owe and what we want to do. But we have now at least the first means in hand to do so. And at the end of this year, there will be a second one that can deliver according to these commitments. 

Anna (1:02:32): Out of curiosity, you mentioned Switzerland? Switzerland is not at the ocean, so how would that work? 

Frank (1:02:37): Yes, that's funny. Switzerland is a wonderful country in the mountains and they put a lot of focus on OAE and marine-based carbon dioxide removal. Two of our investors are Swiss-based and we are partnering with one of our investors there, which is a strategic investor out Zurich. They started to build up a negative emission portfolio and they invest in different companies that are capturing in us and also having biochar plants and renewable energy on site. And Switzerland is probably one of the countries that have the highest ambitions when it comes to turning the country into carbon neutrality. Most of the cities have targets by 2035 or 2040 to become neutral and they put a lot of energy and also money into this. What we will do there, we will partner again with wastewater treatment plants. The first one is already contractually very close and do the same process that we have outlined. So we will capture CO2 from biogenic incineration or from let's in the ocean long run using the rivers, for instance, the Rhine is carrier to carry the alkalinity into the ocean or as pipeline. I shouldn't use the word pipeline because it's not a pipeline, but let's put it a carrier. Obviously this has limits, so it won't scale to the max, but we want to demonstrate it's also feasible in Switzerland, which is pretty far away from the ocean. 

Anna (1:04:04): That's interesting and probably worth a full new episode talking about river alkalinity enhancement. All right, thank you both so much Frank and Thorben. It was fantastic to have you on and to hear about the progress that Planeteers has made. Thank you for listening of course as always to our episodes. If you enjoyed it please leave a comment or review and share this episode and if you want to suggest a topic for future ones feel free to reach out to us through LinkedIn or via our email, plansea@ carbontosea.org. And with that, we say thank you and hear you next time.

Frank (1:04:37): Thanks, Wil and Anna. Thank you. 

Thorben: (1:04:40): It was a pleasure. Thank you.