C₂CCU IntelligenceCARBON CAPTURE & UTILIZATION
Independent perspective · Evidence first

Technology atlas / Polymer chemistry

CO₂-based polycarbonates and polyols

CO₂ is copolymerised with epoxides to make polycarbonates or polyether-carbonate polyols that partly replace fossil feedstock in polyurethanes.

Technical reference · Updated 2026-10-10 · No current-news claim

n C₃H₆O + n CO₂ → [–CH(CH₃)CH₂O–C(O)O–]ₙ (propylene oxide copolymerisation)

Where the carbon goes

Bound in the polymer for the product's service life; end-of-life incineration releases it, landfill or recycling retains it longer. Not permanent storage.

Conceptual process flow · left to right

  1. 01CO₂ + epoxide feed
  2. 02Copolymerisation reactor
  3. 03By-product removal
  4. 04Polyol finishing
  5. 05Polyurethane production

From chemistry to process

Feedstocks
CO₂, Epoxides (e.g. propylene oxide), Starter molecules
Products
Polyether-carbonate polyols, Aliphatic polycarbonates
Catalysts
Double metal cyanide (DMC) catalysts; zinc and cobalt complexes
Conditions
Moderate temperature and CO₂ pressure in liquid phase; catalyst choice controls CO₂ incorporation and cyclic carbonate by-product.

Performance & demonstrated scale

CO₂-containing polyols have been produced industrially; volumes per site must be checked against producer disclosures.

0.431 t CO₂/t polymer theoretical
Perfectly alternating poly(propylene carbonate). Upper bound; commercial polyols incorporate substantially less CO₂ by mass.

Pathway TRL: not assigned. Project-specific evidence is required.

Economics

Value comes mainly from displacing more expensive epoxide feedstock, not from CO₂ consumption volume.

Climate considerations

Benefits stem mostly from avoided fossil feedstock. Compare full cradle-to-gate polyol results, then account for end-of-life fate.

CCU Reality Check · pathway assessment

What remains to be demonstrated?

This initial assessment separates process knowledge from the evidence needed for a commercial conclusion. Missing information is left unresolved.

DimensionAssessment and evidence gap
CO₂ feedstock availabilityNo site-specific supplier, volume, purity guarantee or delivery contract has been verified.
Capture and delivered costNot quantified. Capture, conditioning, compression and transport need separate boundaries.
Energy and hydrogen demandTheoretical stoichiometric or thermodynamic values are shown above. Actual process energy and feed losses remain scenario assumptions.
Catalyst and reactor performanceDouble metal cyanide (DMC) catalysts; zinc and cobalt complexes. No plant lifetime or sustained performance is verified here.
Product separationThe process flow identifies separation stages where relevant; a quantified separation duty and cost remain unavailable.
CAPEX and OPEXNo plant-specific capital estimate or complete operating-cost dataset is attached.
Minimum selling priceNot calculated. Capital recovery, utilization, financing and a complete operating boundary are required.
Fossil benchmark competitivenessNo verified regional benchmark comparison. Calculator benchmark values, where shown, are illustrative.
Climate performanceBenefits stem mostly from avoided fossil feedstock. Compare full cradle-to-gate polyol results, then account for end-of-life fate.
Scale-up bottlenecksLimited CO₂ mass fraction per tonne of product; Epoxide supply and its own emissions; Product qualification versus incumbent polyols; Small total CO₂ volumes relative to emissions.
Customer and offtake readinessNo qualified-customer or executed-offtake evidence is attached to this pathway profile.
Policy dependenceNot assessed for a specific project or jurisdiction. Do not assume subsidies or certification eligibility.

Source references

Original diagrams and explanatory text. References support process context; no numerical commercial performance has been extrapolated.