ETH-spin-off neustark has developed a process that stores CO2 permanently and efficiently in demolition concrete. Concrete recyclers can seamlessly integrate the so-called mineralization technology within their existing operations. The resulting carbonated concrete aggregate is reused to produce fresh, recycled concrete or as a base layer for road construction.

CO2 from biogas plants is transported to concrete recycling plants and stored in tanks. It passes through an evaporator unit and is introduced into containers with the crushed concrete aggregate, where a chemical process called mineralization is triggered. The CO2 is bound into the pores and onto the surface of the concrete granules as calcium carbonate. The storage is permanent and precisely measurable.

Concrete recyclers pay for the capital expenditure but get a share of neustark’s revenue from selling carbon offset credits. neustark counts large corporations such as Microsoft and UBS among its credit clients, as well as a plethora of local concrete recyclers and global construction giant Holcim as its storage partners.

Verve Ventures first invested in neustark in 2023. In June 2024, neustark raised USD 69 million in a growth equity round led by Decarbonization Partners, a partnership between BlackRock and Temasek.

Neustark has just raised one of the largest growth financing rounds in carbon removal. What is your ambition?

We want to provide a reliable solution to capture and remove carbon dioxide permanently. Carbon removal is one of the main pillars of climate strategy. Next to massive emission reductions, we also need negative emission technologies to remove the remaining hard-to-abate emissions from more than 50 billion tons to 0. This is why we have set the ambitious milestone of 1 million tons of CO2 removed in 2030. We want neustark to become climate-relevant by 2050 and remove several hundred million tons by then. Technologies that are not mature enough by 2030 will not be relevant by 2050. By then, we will need to develop negative emissions with a removal capacity of around 10 billion tons per year. As a comparison, the global concrete industry today produces around 2.5 billion tons of CO2 annually.

How does it feel to have raised so much money from some of the world’s largest investors?

The capital we raised is necessary to bring us closer to our goal. A key element is building a team that can deliver on that goal. neustark was founded in 2019. In 2023, we tripled the number of employees to around 60. By early 2025, we want to double the team size again. We need people who can sell new installations, run operations smoothly, certify our negative emissions, and sell the CO2 certificates we create. We need a lot of talented people.

Who should consider joining neustark?

We want to attract talented people who are enthusiastic about our mission of fighting climate change for the benefit of future generations. Another common denominator is that they need to be technology savvy. We need sales talent that reaches out to concrete recycling plant owners and explains the benefits of our installations, namely the additional revenue stream it unlocks for them. The second big category we are currently hiring is plant engineers, who design the plants, and the field personnel, such as technicians and electricians, who run them. This is a very important part for us, not just to ensure our technology runs as it should, but also to learn how to improve them further.

How was it for you to transition from the role of doctoral student to entrepreneur?

There are obvious differences between these roles. As a Ph.D., you are in a safe position, but as an entrepreneur, you need to manage and take risks. But there are also similarities. You can shape your opportunities. As a scientist and as an entrepreneur, you need to embrace uncertainty. What I find fascinating about my role today is that there is no job description to follow, and we need to establish a lot of hypotheses, test them, learn, and change direction if needed.

neustark launched its first commercial site at the end of 2022. Now, 19 are in operation, and more than 40 are currently (status: July 2024) under construction. Where does neustark want to expand geographically?

We have established a new carbon value chain in Switzerland, from biogas plants to concrete recyclers. The financing round will allow us to roll out this blueprint rapidly across new markets. We have first sites already deployed in Germany, Austria, and Liechtenstein and more under construction across Europe. As for our key expansion markets, we are particularly eyeing Germany, France, the UK, Italy, the US, and Canada, where we will widely deploy our model in the next two years.

You inked a partnership with the concrete multinational Holcim and secured an investment from the firm. Why?

Holcim is one of the world’s largest construction material companies and a strategic investor active in more than 70 countries. They are investing heavily in making construction more circular by refocusing their strategy and working closely with start-ups to deploy new solutions. They have tested our technology in Switzerland and want to roll it out fast across their sites in different countries. This partnership is very important for us as it accelerates our scaling up significantly.

neustark is not alone; the competition is heating up. Startups in the US are developing carbon-reduced concrete, while others are developing new building materials in the EU. Some even want to replace concrete with a bacteria-based material.

We don’t see building materials producers as competitors but as potential partners. The concrete recycling industry is huge. More than 500 million tons of construction waste is generated annually in Europe – it’s actually the world’s largest waste stream! Which gives us a great existing material stream in which to store CO2. In our market segment, permanent storage of CO2 in mineral waste streams, there isn’t much competition. We are optimizing our solution for scalability and speed of implementation. This is how we want to become climate-relevant fast.

neustark sells CO2 certificates to companies that want to reduce their carbon footprint. This is a voluntary market. What if such customers lose their appetite?

The voluntary carbon market grew by 600% in 2023, and we’re confident it will continue growing fast. One thing that sets our company apart is that our certificates have the Gold Standard label. CO2 is mineralized and turned into calcium carbonate forever. This permanence is important; it is not given to many nature-based storage projects. Though reforestation has many other benefits, when it comes to carbon storage, a forest can burn down and is not considered a permanent solution. Furthermore, our technology-based method can be measured very accurately. Our customers highly value the combination of strictly certified and permanent carbon removal.

Returning to your question about the voluntary market, it is a political question of how serious we are about fighting climate change. If we want to push the compliance markets further as a society, permanent carbon removal indeed has a role to play. This gives us optionality. Emitting carbon into the atmosphere can no longer be as cheap as it was in the past.

Prof. Schmidt from ETH said the same in a recent interview. Higher carbon prices will foster innovation.

We must realize that climate change is not just a threat but also an incredible chance. Countries with high emissions have huge value-creation potential in reducing and removing these emissions. But people must stop thinking they can just do their business as usual. We must act now to stop climate change and aggressively pursue long-term goals. Eventually, negative emission technologies will become massive, boring, vital industries like recycling or wastewater treatment.