Doris discusses how Electrochaea's technology produces sustainable methane, helps with decarbonizing the gas grid, and supports the transition to renewable energy. She also explores the science, implementation challenges, and future potential of this innovative technology.

Supertrends: Welcome, everyone, to Supertrends interviews. My guest this time is Doris Hafenbradl. Doris has a Ph.D. in microbiology and extensive experience as a scientist and a corporate executive. She's now Managing Director and CTO at Electrochaea. Hello, Doris.

Doris Hafenbradl: Hello.

Supertrends: Let's start with you explaining to us what Electrochaea does.

D.H.: Yes, I'll start with an overview. We have an archaea strain, a biocatalyst, that uses CO2 and hydrogen and turns it into methane. If the input is renewable hydrogen and biologically originated CO2, then our biocatalyst generates renewable methane or e-methane. We have a licensing business model, meaning that we provide the technology to our clients, support them with technology implementation, and also bring the biocatalyst to them.

Supertrends: So, in the end, what you're producing is methane, right?

D.H.: That's correct.

Supertrends: You mentioned that you use a biocatalyst, which is archaea. Could you explain a bit more about what archaea actually are?

D.H.: Archaea, generally speaking, are the third domain of life. There are bacteria and multicellular organisms like humans, plants, and animals, and archaea were only discovered about 40 years ago. They look like bacteria, but they are not. Mostly, you find them in really extreme environments, like hot springs or places with super high pH or salinity. These are environments where people didn't think life was possible. In particular, in hot springs, even at 100°C or more, you can find archaea. They can survive—or actually need—this kind of environment. We use a very specialized strain of archaea as a biocatalyst, a so-called methanogenic archaea. This group of organisms is specialized in utilizing hydrogen and CO2 to make methane. Our strain is very special: it has been trained to operate in industrial environments. It's not genetically modified but has evolved in a laboratory environment. It's very productive, robust, and easy to handle in industrial settings.

Supertrends: If I understood correctly, the fact that it's very productive and efficient is the reason you're using this specific strain right now.

D.H.: Yes.

Supertrends: You also mentioned that they can resist extreme conditions. Is this also useful in your process?

D.H.: Yes, we work at 65°C and 10 bar pressure. That's the operating environment we generate, and this is something that the biocatalyst likes very much because it originally comes from a hot spring in Iceland. Its ancestor was identified when scientists took a sample in Iceland from a hot spring. 65°C is its favorite temperature, which helps us in the industrial use of methanation technology. There aren't many organisms that can survive in this environment, and it can be very advantageous because you don't have to be very sterile or take other precautions to prevent contamination with other organisms.

Supertrends: It's very interesting because you often hear that people use microorganisms for different processes, but these are either bacteria or yeast. It's not so often you hear about archaea.

D.H.: Yes, maybe one point to add is why these methanogenic archaea are a bit of a special case. It's their natural energy-generating metabolism that we are utilizing here. That's why the methanation is so efficient and they produce so much methane. It's actually what they do to survive, so we're not trying to convince them to do something unnatural. They can only survive if they perform the methanation reaction.

Supertrends: So you are exploiting their natural capabilities to achieve your goal.

D.H.: Exactly.

Supertrends: How does the methane produced by this biocatalyst differ from conventional gas in terms of sustainability or efficiency?

D.H.: The gas molecules are the same. Fossil methane and our renewable methane are chemically the same. However, with the utilization of our methane, fossil sources of gas can be avoided. When making renewable methane, we use waste CO2 that would otherwise be emitted into the atmosphere and green hydrogen from renewable low-cost electricity or electricity that wouldn’t be generated if there was no demand. This can happen, for example, if a wind turbine needs to be curtailed because the electricity grid cannot handle the surplus power. The difference lies in the carbon intensity. Our renewable methane molecule has a significantly smaller carbon footprint, especially when using green hydrogen from renewable electricity and CO2 from biological sources. The CO2 molecule originating from biological material differs from CO2 produced by industries such as cement, steel, or other flue gas emissions in terms of its carbon footprint.

If you start with a biological origin for your CO2 molecule, your carbon footprint is extremely low. That's the difference: you can decarbonize the gas grid by using renewable methane. It's in decarbonization where the value is generated.

Supertrends: Not only is your process green but you also help other processes become greener. Can we say that?

D.H.: Exactly, yes.

Supertrends: You mentioned that you can use CO2 produced by other industries. Do you have any data on how much CO2 you can sequester or capture and then transform into methane?

D.H.: I would say it's unlimited in a certain way because our biocatalyst is very hungry. To give you a sense of scale, in our pilot plants, which had an electrolyzer capacity of 1 MWe, we utilized 55 Nm3 /h of CO2 and generated 50 Nm3 /h of renewable methane. We've now scaled up to 75 MWe, meaning you have 75 times these amounts of CO2 utilization and production. We aim to use this technology at the 10 MWe scale and eventually scale up to 100 MWe, making a difference in greening the gas grid. You can do that with biogas, gas from pyrolysis, renewable hydrogen, or our gas. We want to contribute to becoming more energy independent by using renewable resources.

Supertrends: Mentioning renewable resources, I can imagine that different countries or regions are better or worse for producing green energy. Do you target markets considering this?

D.H.: Yes. One straightforward market at the moment is Quebec in Canada. The government there has generated demand for renewable gases, including e-methane, with aggressive goals for decarbonizing their gas grid. They want the gas grid to remain but want it green, with only renewable gases allowed at a certain time point. They have assertive targets for 2030 and 2050. This market is well-defined regarding demand, pricing, and regulatory aspects. You can count on that and get projects financed. This is not what you normally find in Europe. In Europe, there's a clear regulatory demand and expectation for the maritime sector, requiring renewable fuel for fleets. But it's harder to identify the certification process for these gases, and there's no clarity on electricity prices or exact offtake prices. More clarity is needed to count on such a market.

Supertrends: We started talking about the challenges you face when commercializing your system. Could you elaborate more on this? One challenge is unclear regulations, but maybe there are more.

D.H.: Yes, but that's the main hurdle. If there's an interesting incentive that could be utilized—but it needs further clarification or special certification—demand needs to be specified, which drags out decision-making on getting a project financed. That's been the biggest hurdle overall.

Supertrends: Let's move on to another topic. What are the benefits for a customer using your system? Sustainability is one, but what about costs compared to standard solutions?

D.H.: There is a price difference between the renewable methane product and fossil methane, but there's also a value difference. The price for gas based on the thermal value is more or less the same worldwide. However, the extra that people are willing to pay is based on the carbon footprint reduction. You need to look for where the value is recognized for reduced carbon intensity. The price is mostly driven by electricity, the main input into the system. CO2 is often free or inexpensive, but hydrogen can be expensive. If your output price isn't much higher than your input costs, it's impossible to make a business case. You have to find cheap electricity as input, and then the price of your gas is attractive in certain markets. There will be interesting market dynamics in the future.

Supertrends: Renewable energy technologies are continually advancing, so it's reasonable to expect that the cost of electricity from these sources will decrease in the future, right?

D.H.: Exactly. By 2030, it's expected that Europe, for example, will have a high percentage of renewable electricity. The more we implement, the more overcapacity we'll have, meaning we can use it to produce renewable methane. When there's a gap with no wind or sunlight, this green gas could be utilized for making renewable electricity. It's a round trip, so we lose efficiency overall, but it's a solution to replace fossil gas for electricity generation. You can store it in the existing gas grid.

Supertrends: Another aspect of your technology is that you can store what you produce. Renewable sources like solar or wind aren't stable, so it's a nice solution to save energy in the form of methane.

D.H.: Exactly. The infrastructure for storage is already there. No further investment is needed for storage; it's long-term and large-scale. It makes energy production and use independent in terms of time and location. You can produce electricity in one place, turn it into gas molecules, and then use it in a completely different place.

Supertrends: Coming back to your biocatalyst for a moment, you mentioned training your strain, and that it underwent a lab-environment evolution. Are you still improving it? Are there limitations to this strain you'd like to improve?

D.H.: The biocatalyst is actually outperforming in many ways. It's more about what we can offer to help it outperform. The limitation of such technologies is always hydrogen mass transfer. CO2 goes into solution easily, but hydrogen does not. We have an agitator and work at 10 bar pressure to get more hydrogen into the solution. The biocatalyst isn't limited. It's more about how much hydrogen you can get into solution. We are improving feeding strategies to get higher performance, but it's not limited by the biocatalyst. It's more limited by the overall design and the challenge of overcoming technical limitations. We're already very good, but improvements would have to come from our development and engineering team to overcome hydrogen mass transfer limitations.

Supertrends: The biocatalyst is doing its job, and now it's your turn to help it be even better.

D.H.: Exactly.

Supertrends: Looking into the future, how do you see the global transition towards renewable energy sources evolving in the next 10 to 20 years?

D.H.: According to the International Energy Agency, we'll see a dramatic increase in renewable electricity generation over the next 5 to 10 years. This will generate opportunities for renewable methane. It's often forgotten that gas is about 50% of the energy supply, depending on the country. We focus on wind and solar energy in the electricity sector, but it is also necessary to green gas. As we install more wind, solar, and hydroelectric power, the demand for solutions to manage the overproduction of electricity will increase. In California, a lot of wind parks have to be curtailed daily. We can utilize all that electricity, taking advantage of the flexibility of our biocatalyst. It doesn't always need to be fed at 100%—it can go on a little diet when electricity is limited. If there is no electricity available, we can even shut it down and resume operation when power is restored. This makes it perfectly compatible with the intermittent availability of electricity.

Supertrends: Is there any technology or scientific achievement you're looking forward to seeing in the energy sector?

D.H.: I don't have to look far. I can share our second-generation technology in development, where we're overcoming hydrogen mass transfer problems. We're developing a microbial electrochemical cell system, using an electrolyzer, and pushing our biocatalyst through it. We are bringing the biocatalyst directly to where hydrogen is being made. We don't have to use energy for mixing or pressure to bring the hydrogen into solution. Hydrogen is made directly at its source, improving efficiency and reducing costs. That's in development. It will also bring down overall costs because you don't have to buy an electrolyzer and a biomethanation system separately.

Supertrends: That sounds really awesome. I am eager to see how everything will unfold. Doris, do you have anything you'd like to add that we might have missed and you find important?

D.H.: We didn't touch on another highlight of the biocatalyst: it can use mixed gas sources. We've talked about CO2 as the carbon requirement, but it can also use raw biogas, which consists of CO2, methane, hydrogen sulfide, and other contaminants. It needs a sulfur source, so hydrogen sulfide is good food for our biocatalyst. It doesn't mind if there's already methane going into the reactor. You can combine a biogas plant and use the output directly in our reactor, resulting in 100% methane. We've tested the biocatalyst with CO2 from breweries, bioethanol generation, wineries, and geothermal gas in Iceland. It's robust and doesn't mind a little ethanol or other things. The only objection is high concentrations of oxygen, as it's an anaerobic process.

Supertrends: In general, it looks super flexible, and you can adjust it to many different processes.

D.H.: Yes, and you can cut out super purification steps needed for thermochemical catalysts. Hydrogen sulfide can destroy thermochemical catalysts, but we can use it as a food source for the biocatalyst.

The text is a transcript of an interview conducted on 14 October 2024. The interview was conducted as part of Supertrends' 'Interviews with Experts' series. Please note that the transcript may have been lightly edited for editorial reasons.