Sebastian Andreassen

Sebastian Andreassen has spent essentially his whole career inside one material, and that is unusual enough to be the whole story. He is an engineer from a family of engineers, and as he puts it, silicon carbide was "all I knew." Before Cembrane he spent five years at LiqTech International, the Danish silicon carbide pioneer, working on the ceramic products and the early immersed membranes through its 2012 listing on the New York Stock Exchange. So when he co-founded Cembrane in 2014 with his father and his brother, all three of them already knew this strange, brittle, expensive ceramic better than almost anyone, and they had one idea about what to do with it.

Sebastian Andreassen built Cembrane on a paradox, and he is the first to admit it. Silicon carbide is "very, very costly," far more expensive than the plastic the membrane market runs on, and his pitch was that this costly material is exactly what makes membrane treatment cheaper. The logic holds up once you stop comparing the price of the membrane and start comparing the price of running a plant for a decade. A membrane is a sheet full of microscopic holes that lets water through and holds dirt back, and the plastic ones the industry is built on are, in his words, "a pain in the behind to operate", sensitive, prone to clogging, and quietly destroyed a little more every time you clean them with chemicals. The silicon carbide version shrugs off the chemicals, the heat and the dirty water, lasts far longer, and lets a plant drop some of the expensive equipment that usually props a membrane up. It is one of the clearer examples of a materials bet in water technology, where a tougher input quietly rewrites the running cost of everything downstream.

Sebastian Andreassen did not get there through years of quiet lab work. He calls his approach "innovation through implementation", which means Cembrane took a calculated risk together with its own customers, put an unfinished product into real plants, and learned in the field. That sounds reckless, and the best illustration is the one he tells from the early days: a water-scarce region in the Middle East where conventional technologies had failed, people were genuinely desperate, and the situation was serious enough that secret police stood watch during the commissioning. Cembrane delivered, the plant worked, and that became one of the references that let a tiny Danish company start selling a ceramic membrane to a deeply conservative industry.

Sebastian Andreassen never planned to sell. His stated dream was a durable family company in the mould of Grundfos, the Danish pump giant, something that lasts for hundreds of years rather than flips to an exit. What changed his mind was a hard physical fact: a silicon carbide factory is brutally capital-intensive, and even a profitable company cannot self-fund one at the speed the demand needed. Ovivo had been a customer since the beginning and took a minority stake in 2018, so when Cembrane needed real capital it went, in his words, "organically" into the Ovivo group, which it formally joined in 2021. Ovivo, owned by Susanne Klatten's SKion Water, then put more than $25 million into a 110,000-square-foot "twin" of the Danish plant in Hutto, Texas, and since 2024 Sebastian Andreassen has run the Cembrane business from there, as its CEO and as a senior vice president of Ovivo Water.

Sebastian Andreassen's sharpest opinion is not about his own technology, which is what makes it worth quoting. Asked what really holds the water sector back, he does not say the science. He says risk: "you prefer the devil you know over the devil that you don't know", and taking risk, he notes drily, "is not a virtue that is very pronounced in the water treatment industry." His fix, the thing he would change with a magic wand, is to make himself redundant and push technology choices away from a handful of large municipalities toward more decentralized decision-making, because he is convinced that is where better, cheaper, higher-quality treatment actually comes from. It is a notably un-vendor-like thing for a vendor to say, and it runs right through how Cembrane sells: stay a material maker, sell the silicon carbide through a long list of OEMs, and let the market do the rest.

“We don't really know what it can do. We don't know much of what it can do, but let's try and bring it into the market. And see what happens.”

That was Cembrane's whole strategy in two sentences, and the fact that it worked, all the way to the world's largest silicon carbide membrane factory rising in Texas, is most of why Sebastian Andreassen is worth listening to.