The most expensive part of cleaning up a cement plant or a chemical refinery is often the heat. Traditional separation processes, like those used to capture carbon dioxide from flue gas or purify hydrocarbons, run furnaces hot enough to melt steel, turning kilowatt-hours into a primary cost driver. A Swiss startup called UniSieve is betting it can cut that bill by swapping the furnace for a sieve.
Founded in 2018 by ETH Zürich classmates Samuel Hess and Elia Schneider, the company makes membranes that combine zeolitic porous crystals with polymers. The idea is to separate molecules by size and shape at near-ambient temperatures, a process that the company claims uses a fraction of the energy of conventional thermal methods [Perplexity Sonar Pro Brief]. They sell these as add-on systems to industrial customers, starting with CO₂ capture in cement and moving into hydrocarbon purification for chemicals.
A cooler path to separation
The technical wedge is straightforward physics. Separating CO₂ from nitrogen, or propylene from propane, typically requires boiling mixtures to exploit slight differences in volatility. That demands immense, continuous heat. UniSieve’s membranes aim to do the job mechanically, like a screen filtering sand from gravel. The proprietary crystal-polymer matrix is engineered with pores just the right size to let one gas molecule slip through while blocking another [Perplexity Sonar Pro Brief]. For a plant manager, the promise is a bolt-on unit that fits into cramped, dusty industrial sites,like a cement plant’s flue stack,and slashes the energy line item on the operating ledger [Slawomir Wojcik Ph.D. - InnoCore Consulting | LinkedIn, retrieved 2026].
Traction in heavy industry
Commercializing hardware for heavy industry is famously slow, but UniSieve has been methodical. The company reported more than 24 clients and was already generating revenue by April 2023 [TechCrunch, April 2023]. Its playbook involves on-site pilots, like one initiated with Qemetica Soda Polska for CO₂ capture, followed by contracts for full-scale units [Startupticker, April 2023]. It was also selected for the Fundación Repsol accelerator, positioning it for trials at a major energy player’s facilities [Silicon Canals, March 2024]. This pilot-to-deployment rhythm has attracted a patient syndicate of European climate tech investors.
The company’s funding history shows a steady climb from grant-backed research to venture-scale industrial testing.
2020 Financing | 4.6 | M USD
2023 Seed | 5.5 | M USD
2026 Series A | 9 | M USD
Led by CEO Samuel Hess and CTO Elia Schneider, the team has navigated the company through three major rounds, bringing total disclosed funding to $25 million by October 2026 [Tech Funding News, October 2026]. The Series A was led by the Orano Venture Fund, managed by Supernova Invest, with continued support from earlier backers like Amadeus APEX and Zürcher Kantonalbank [Tech Funding News, October 2026]. The capital is earmarked for scaling production and moving from pilots into broader commercial deployment.
The incumbent on the other side of the bet
The obvious counter-bet is that thermodynamics are stubborn. While membranes are established in some niche separations, displacing century-old thermal processes in capital-intensive, risk-averse industries is a brutal slog. The risks for UniSieve are less about the crystal science and more about industrial reality.
- Performance durability. A membrane in a cement plant’s flue gas faces particulates, humidity, and trace contaminants that can foul or degrade materials over time. Proven long-term stability in harsh, real-world conditions is the ultimate test.
- Scale economics. The cost per square meter of membrane and the system’s footprint must compete not just with the energy bill of a thermal unit, but with its total installed cost. A modest energy saving can be erased by higher capital expense or more frequent replacement.
- Customer inertia. Plant engineers have decades of institutional knowledge operating distillation columns and absorbers. Convincing them to bet production reliability on a new, untested box requires more than a pilot; it requires a paradigm shift in maintenance and operations training.
The company’s reported roster of two dozen clients suggests it is clearing the first technical hurdles. But the real milestone is a multi-year, full-scale deployment that becomes a repeatable reference sale.
A back-of-the-envelope calculation frames the opportunity. If a traditional amine-based CO₂ capture system for a mid-sized cement plant consumes roughly 4 gigajoules of thermal energy per ton of CO₂ captured, and UniSieve’s membrane can cut that by, say, 70%, the energy savings alone could approach $20 per ton at European industrial power prices. For a plant emitting 500,000 tons annually, that’s a $10 million yearly operating cost avoidance. The unit economics, not the carbon, are what get the plant manager’s signature. To win, UniSieve must consistently beat the incumbent on that ledger: the thermal separation tower.
Sources
- [Perplexity Sonar Pro Brief] UniSieve company and product overview
- [TechCrunch, April 2023] UniSieve’s filters use special crystals to reduce industrial … | https://techcrunch.com/2023/04/25/unisieve/
- [Slawomir Wojcik Ph.D. - InnoCore Consulting | LinkedIn, retrieved 2026] Post on UniSieve's cement plant applications
- [Startupticker, April 2023] USD 5.5m to unlock decarbonizing opportunities for heavy industry | https://www.startupticker.ch/en/news/usd-5-5m-to-unlock-decarbonizing-opportunities-for-heavy-industry
- [Silicon Canals, March 2024] EIT Climate-KIC backs Swiss cleantech startup that allows chemical and energy industry to be more sustainable | https://siliconcanals.com/eit-climate-kic-backs-swiss-cleantech-startup-unisieve/
- [Tech Funding News, October 2026] ETH Zurich classmates land $9M to replace thermal … | https://techfundingnews.com/unisieve-secures-9m-series-a-mof-membranes-orano-carbon-capture/
- [Startupticker, November 2020] UniSieve banks USD 4.6 million | https://www.startupticker.ch/en/news/unisieve-banks-usd-4-6-million