Molecular sieving for industrial gas streams

UniSieve builds membranes from metal-organic frameworks and zeolites in Zurich, then delivers them as containerised systems that recover product, add capacity and capture CO₂. No separation chemicals, no heating or cooling cycles.

Read the operating principle

A single pore, schematic. Small molecules pass, larger ones are held back.

$25M raised, incl. a $9M Series A in October 2026

  • Orano Venture Fund
  • Supernova Invest
  • Amadeus APEX
  • Founderful
  • Zürcher Kantonalbank
  • Guenat Holding

1Summary

Separating molecules uses an estimated 10 to 15% of the world's energy, mostly as heat for distillation and solvent regeneration. UniSieve replaces that heat with pressure and a crystal pore sized to the job.

Founded
2018, Zurich
Origin
ETH Zurich
Founders
Samuel Hess, Elia Schneider
Materials
MOFs and zeolites
Delivery
Containerised, turnkey
Units in the field
5+ demonstration units

2Operating principle

Feed gas enters a membrane cartridge. A pressure difference drives molecules toward a layer of crystals whose pores are fixed by their structure. Molecules small enough to fit pass through and leave as permeate. The rest stay on the feed side and leave as retentate. Both streams run continuously.

Cross-section of a UniSieve membrane Feed gas at high pressure flows over a selective layer of MOF or zeolite crystals. Molecules smaller than the pore aperture pass through the crystals and the porous support into the permeate side. Larger molecules are retained and continue as the retentate stream. ΔP Feed gasmixed stream, higher pressure Retained moleculescontinue as retentate Selective layerMOF or zeolite crystals,pore aperture tuned per stream Porous supportmechanical strength, low resistance Permeatemolecules smaller than the pore FEED SIDEPERMEATE SIDE
Fig. 2.1 Membrane cross-section, schematic, not to scaleFull technology section

3Figures and baselines

The three numbers on the current website, with the baseline column an engineer will ask for first. Cells marked amber are the ones this concept would ask UniSieve to fill in before launch.

FigureValueCompared withWhere measured
Energy for the separation step−90%Thermal separation of the same streamReference process to be namedSite, year, stream to confirm
Production capacity of an existing asset+8%Same plant before debottleneckingPlant type and unit to confirm
CO₂ captured per year25,000 tPer installed system sizeSystem size to confirm
Fig. 3.1 Energy index for the separation step, derived from the −90% figureSource: unisieve.com

4Delivery

Equipment, licence and service are sold as one system. The customer buys an outcome, not a component to de-risk alone.

1

Line drawing of a plant with the process area chosen for membrane integration highlighted in green

Identify the opportunity

Source, concentration, annual volume and destination of the stream. Viability before hardware.

2

Line drawing of a containerised UniSieve pilot unit

Validate with a pilot

A unit installed on the plant, running on the customer's own gas, producing operating data.

3

Isometric line drawing of a full-scale separation system with piping and process units

Deploy and operate

The full system configured for the site, integrated, commissioned and operated on site.

5Applications

One separation platform, tuned by changing the crystal. Three applications are in commercial focus.

ApplicationTypical useValue to the plantStatus
Hydrocarbon separationOlefin off-gas, flare gas recoveryProduct recovered, capacity addedNearing commercial readiness
Carbon capturePoint-source CO₂ from flue gasCO₂ for use or storageLive test at Qemetica
Specialty gasesRefrigerants, PFAS, semiconductor gasesEmissions controlled, gas reusedApplication development

6Field record

Industrial plant with chimneys beside a river at sunset

Illustrative photo from the UniSieve website, not the Qemetica site

Qemetica, Poland

Qemetica, formerly CIECH, has started live testing a UniSieve CO₂ capture unit. The captured CO₂ is used on site to make carbonates such as soda ash.

  • ApplicationPoint-source carbon capture
  • CO₂ routeOn-site use, carbonates
  • StageLive test, 2026

Source: Tech Funding News, Oct 2026

Technical data sheet

Membrane principle, system envelope, utilities and the questions we need answered about your stream. Sent by an engineer, not a mailing list.

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