An EIC Accelerator Detour: UniSieve's Propylene Sieve Meets CO2

Distillation, the boiling and condensing that splits chemical mixtures into pure products, is heat-hungry: separation processes account for over 10% of global energy consumption, UniSieve's EU project report says. UniSieve, a Zurich company spun out of ETH Zurich, makes membranes that separate gases by molecule size instead, like a sieve with pores smaller than a nanometre. In the European Innovation Council's Green Deal round of May 2020 it won a grant for GREENMEM, a project to take that membrane from the lab to a chemical plant, starting with propylene, the raw material of polypropylene plastic.

The EU paid €2,395,618.75 of the €3,422,312.50 project. UniSieve told the EIC it expected 56 separation units to be installed by 2026, according to the project's CORDIS report. It is now October 2026. No installed propylene unit has been announced. What UniSieve has announced is two pilots that capture carbon dioxide, a market the GREENMEM objective did not mention, and a USD 9 million Series A on 8 October 2026.

Where UniSieve Stands in October 2026

UniSieve is active and freshly funded. Its Series A was led by the Orano Venture Fund, a vehicle of the French group Orano managed by the venture firm Supernova Invest, with Amadeus APEX Technology Fund, Founderful, Zürcher Kantonalbank and Guenat Holding, according to the company's press release and Trending Topics. The round brings total funding to USD 25 million, the company says. The Zurich commercial register shows the round earlier than the announcement: on 22 May 2026 shareholders raised the share capital from CHF 176,164 to CHF 230,821 and created 54,657 new "Series A" preference shares, and Supernova's investment director Jonathan Grosskopf joined the board along with a second new director, according to Zefix and North Data.

The company now describes itself as a supplier of gas separation systems, not of membranes alone. Its website offers three lines: hydrocarbon separation, carbon capture, and specialty gases such as refrigerant recovery and PFAS emission control, for industries from polymer plants to cement, waste incineration and refining. The Series A release says the membranes have reached "pre-commercial maturity" in two applications, olefins and point-source carbon capture. That wording is the company's own, and it matters for the EIC record: pre-commercial is not 56 installed units.

The Technology: A Sieve for Molecules

UniSieve's membranes mix crystalline "molecular sieve" particles into a polymer film. The particles, metal-organic frameworks (MOFs) and zeolites, have regular channels of a fixed size; small molecules pass through, larger ones are held back, according to Tech Funding News and the company's own technical note. The research behind the membrane began in 2013 at ETH Zurich's Institute of Chemical and Bioengineering, CORDIS says.

UniSieve's claim is that it has solved the step in between: turning these crystals into durable membranes that can be made on standard roll-coating lines and packed into ordinary spiral-wound cartridges. "Until now, turning these advanced materials into durable gas-separation membranes that can be manufactured reliably at industrial scale has remained a major challenge," the Series A release says; it adds that UniSieve has overcome it. No independent test data for the membranes could be found.

The headline benefit, saving "up to 90%" of separation energy, has been the company's figure since 2018, when it won CHF 130,000 from Venture Kick, and it reappears in the CORDIS report. It is a ceiling claimed by the company, not a measured plant result. The patent record is concrete: UniSieve filed a European application on 15 December 2020 for a polypropylene process in which a membrane recovers unreacted propylene behind the reactor, naming Schneider and Hess as inventors, according to the European Patent Office. North Data lists two further patent publications, in March 2024 and January 2025.

What GREENMEM Promised, and What the Record Shows

GREENMEM ran from 1 December 2020 to 30 November 2022 under the EIC Accelerator pilot's Green Deal topic. The Commission's list of the May 2020 winners names UniSieve alone for the project, as a grant-only award; no partner company is listed. The objective said UniSieve was "ready to deliver demonstrators" at customer sites, aimed for a 16% share of the chemical and energy industries within ten years, and expected the project to "yield a total >€86.3M in additional revenue by 2026" and create more than 290 jobs.

The two CORDIS documents on the outcome do not say the same thing. The final periodic report, for the period ending November 2022, describes the pilot only in the future tense: the test "is expected to confirm" the savings. A CORDIS editorial results summary from April 2023 says fabrication was scaled up "to the point needed to serve the first pilot clients" and that "test results confirmed" savings in energy and cost. Neither names the site, the gas or any figure. In April 2023 Hess said UniSieve had "run pilot testing with industry leaders", without naming them, according to AIN.UA and Packaging Europe.

1. Scale membrane fabrication to pilot scaleDeliveredReported in the CORDIS results summary; the 2026 release cites "repeatable manufacturing".
2. Pilot test at a chemical sitePartlyCORDIS sources disagree; no site or data published. A CO2 test at Qemetica's soda plant began in 2024, after the project.
3. Propylene, hydrogen and biogas productsPartlyOlefin membranes "pre-commercial" in 2026; no hydrogen or biogas product announced.
4. 56 separation units installed by 2026Not achievedNo installation announced by October 2026.
5. €86.3M extra revenue and 290 jobs by 2026Not achievedNo revenue or staff figures announced; nothing suggests either target was met.

The project delivered what a grant can most directly buy: a membrane that can be made in volume and taken to customer sites. The commercial forecasts attached to it were not met on the timetable UniSieve gave, and the company has never published a result from a propylene pilot.

From Propylene to Flue Gas

The first field work UniSieve named after the grant was in carbon capture. In March 2024 it reported that its pilot plant "Trift", named after a Swiss glacier, had run at a Swiss waste incineration plant "throughout 2023" and extracted CO2 from its exhaust, according to the company's post, now only in the web archive; the plant is not named and no other source for the pilot could be found. In September 2024 UniSieve said Qemetica Soda Polska, part of the Polish chemicals group formerly called CIECH, had begun live testing of its CO2 capture unit and would use the gas on site to make soda ash, according to another archived company post and Tech Funding News. Qemetica's venture arm is also a shareholder, the company post says, so the test is with an investor.

Propylene has not disappeared. In 2020 UniSieve was picked from 1,275 applicants for the Fundación Repsol accelerator to run an on-site pilot at a Repsol plant, according to its archived post and Silicon Canals; no result of that pilot has been published. In October 2026 the company's website was still pitching propylene recovery from polypropylene plant off-gas, the application of its 2020 patent. UniSieve also partners the Spanish wastewater firm Ingeobras in BIOEnergHII, a Eurostars project on biohydrogen and biomethane in which UniSieve handles the gas purification, according to an archived company post and Ingeobras. CORDIS lists no EU project for UniSieve other than GREENMEM.

The Money

UniSieve's private funding has grown round by round. The EIC grant came alongside a round of about €3.9 million led by Wingman Ventures with EIT Climate-KIC, as the company put it in an archived post; Silicon Canals gave the same round as USD 4.6 million and, in the same article, the company's total funding as about USD 5.2 million, both converted to "approx €3.9M", so the split between grant and equity is not clear. Wingman's Lukas Weder joined the board in September 2020, the register shows. In April 2023 UniSieve raised a USD 5.5 million seed round from Amadeus APEX Technology Fund, Wingman Ventures, Ciech Ventures and Zürcher Kantonalbank, according to AIN.UA and Packaging Europe, which called it oversubscribed.

What the money has bought in sales is not public. UniSieve is a private Swiss company; the commercial register entry carries no accounts, and North Data shows key figures only behind a paywall. APEX's Wolfgang Neubert said in the Series A release that UniSieve had moved "from pilot deployments to larger systems with paying customers". No customer contract, revenue figure or staff number has been published. UniSieve is not among the 319 organisations listed in the EIC Fund portfolio, which fits a grant-only award.

Why Europe Should Care

The pivot towards CO2 has put UniSieve inside current EU industrial policy. The Commission's Industrial Carbon Management Strategy of 6 February 2024 aims to "scale up carbon management" in the EU, and the Net-Zero Industry Act sets a binding target of 50 million tonnes of annual CO2 injection capacity by 2030, the same page says. The Act counts carbon capture and storage among the net-zero technologies it supports. Storage capacity is useless without capture at cement kilns, incinerators and chemical plants and UniSieve pitches a capture process without liquid solvents or a chemical treatment loop. Its own design puts a 12-metre container at up to 50,000 tonnes of CO2 a year, a design figure, not a demonstrated one.

The ownership tells a European story too: a Swiss ETH spin-out, funded by the EU, a Polish chemicals group, a Zurich cantonal bank and now the venture fund of the French group Orano.

The Verdict

UniSieve has not been asked for comment for this article. It is based entirely on public records, company statements and EU project data, linked throughout.