When Ruben Brands walked away from a stable consulting career to start a climate tech company, he didn’t do it for the hype or the funding. He did it because the clock is ticking, and the ocean may just hold the key to reversing climate change.
“I don’t want to tell my kids in 10 years, ‘It’s warmer now, but hey, we made money.’ I want to say, ‘I was part of the solution.’”
That guiding principle turned an academic paper on Direct Ocean Capture (DOC) into SeaO₂, a fast-growing Dutch startup that secured €2 million in seed funding, partnered with major players like Klarna, and built a team of 17 people… all before launching a commercial product.
This is a founder story built on urgency, action, and a deep commitment to solving a global problem. Here’s how they did it.
From Strategy Slides to Seawater Science
Ruben’s background wasn’t technical, but it was strategic. With a business and legal foundation, he spent years as a strategy consultant, including a pivotal role at Rabobank’s Carbon Bank, where he helped farmers unlock new revenue models via carbon credits.
But the consulting life left something to be desired.
“I realized that I was handing over great strategies that might never be implemented. I wanted to be on the other side, building the solution.”
That motivation led him deep into climate research. One paper, in particular, caught his eye: a PhD dissertation by Dr. Rose Sharifian, under the mentorship of Prof. Dr. David Vermaas at Delft University. The paper outlined a method for removing CO₂ directly from seawater, cleaner and more efficient than capturing it from the air.
“I reached out and asked: Are you thinking about bringing this to market? Because this could be huge.”
It turns out, they weren’t yet. But Ruben saw the potential. In late 2021, he joined forces with Dr. Sharifian and Prof. Vermaas, and together, they founded SeaO₂.
Academic Roots, Entrepreneurial Hustle
Spinning out a company from a university isn’t like launching a SaaS product from your garage. The first year of SeaO₂’s existence was less about MVPs and more about negotiating research agreements with Delft University, a process that, while essential, required patience and persistence.
“In the U.S., universities like Stanford know how to commercialize research. In the Netherlands, we’re still catching up.”
Despite the legal complexity, Ruben found an unexpected advantage: access to Dutch innovation grants and subsidies, even before formal incorporation. That allowed him and his co-founder to go full-time early, hire an intern, and slowly assemble a team around the mission.
By early 2023, SeaO₂ was officially incorporated. Within months, they brought on their first employees. Today, the team has grown to 17 members, including oceanographers, engineers, and commercial leads, all aligned around building tech that captures carbon without harming marine ecosystems.
“We’re assembling the pieces of the puzzle. It’s hard, but the stakes are too high to wait.”
Turning Seawater into a Scalable Business
SeaO₂’s tech is built on Henry’s Law, a fundamental scientific principle that ensures when CO₂ is removed from seawater, the ocean naturally absorbs more CO₂ from the atmosphere to restore balance.
But pulling CO₂ out of seawater isn’t enough. You also need a business model that makes it viable. SeaO₂ has two:
- Negative Emissions: Selling carbon credits to companies with small emissions but big budgets (think tech giants, consultancies, and corporations looking to offset voluntarily).
- Carbon Capture & Utilization (CCU): Converting captured CO₂ into green methanol to decarbonize sectors like the shipping and aviation industries, where electrification may never be feasible.
“We’re working with partners to turn CO₂ into green fuels. This way, we tackle climate change from both ends, removal and reuse.”
SeaO₂ is also actively developing Measurement, Reporting, and Verification (MRV) protocols to ensure transparency and credibility in its carbon removal claims.
Unlike many climate startups stuck in the lab, SeaO₂ is already engaging with real customers and collaborators across industries. The opportunity? To be a backbone infrastructure company in the coming carbon economy.
Klarna, Credibility, and €240K in Pre-Sales
Ruben knew that raising money as a deep-tech startup would be hard, especially without a live product. So instead of waiting for perfection, he went to market early. Through the climate platform Milkywire, SeaO₂ caught the attention of Robert Höglund, a leading voice in the carbon removal space.
“We had a few great conversations and then Klarna came on board as our first customer.”
Klarna’s pre-purchase agreement helped validate SeaO₂’s approach, and it wasn’t just a PR win. It led to €240,000 in pre-purchase agreements in 2023, all from forward contracts with companies betting on SeaO₂’s future success.
This traction became a key driver in their €2M seed round, closed in late 2024 with support from investors like DOEN Participaties, CarbonFix, Future Tech Ventures, NV NOM, and Transavia Ventures.
“When you walk into investor meetings and say, ‘We already have revenue,’ even without a finished product, they listen differently. It changes everything.”
Founder Lessons: Start Selling Sooner Than You Think
Ruben isn’t shy about the challenges of building in deep tech. The timelines are longer, the science is harder, and the stakes are existential. But his advice for others is refreshingly simple:
“Don’t wait for everything to be perfect. Especially in deep tech, if you can get commercial traction, even non-binding or early-stage commercial commitments such as letters of intent or pre-purchase agreements…, it puts you on another level with investors and customers.”
He also encourages mission-driven founders to embrace their unique path, even if they don’t come from technical backgrounds.
“I’m not a scientist. But I surround myself with brilliant people and focus on building the ecosystem to let them shine. That’s how progress happens.”
What’s Next for SeaO₂?
SeaO₂ is currently working toward a €20M Series A round planned for 2026. The goal? Scale up pilot projects, deepen MRV protocols, and begin industrial deployment in partnership with fuel providers, logistics companies, and carbon marketplaces.
But Ruben’s vision extends beyond technology and funding.
“I want to build something that matters. Something that gives my kids and their kids a fighting chance.”