Convert used PET bottles into circular polyester polyol
Kimpur
SKD TürkiyeSummary
Post-consumer PET bottles are depolymerised into polyester polyol, replacing part of the fossil raw material in rigid polyurethane systems without a performance concession.
Context
Submitted through the COP31 Sustainable Transformation Awards - SKD Türkiye (WBCSD Global Network Partner)
The company manufactures polyester polyols and polyurethane systems in the chemicals sector from two production sites in Türkiye and supplies raw material systems to industrial customers, among them producers of sandwich panels for construction (1).
Rigid polyurethane systems are built on polyols, and those polyols are conventionally derived from fossil feedstock. The raw material stage therefore carries a large part of the embodied emissions of the finished insulation product, and it is the part the panel producer cannot change on its own.
At the same time, post-consumer PET bottles are a large and consistent waste stream. Mechanical recycling returns some of that stream to packaging and fibre, but a substantial share still reaches landfill, and mechanical recycling does not produce a chemical building block that can enter polyol synthesis.
The company's response was to close that gap chemically. Depolymerisation breaks the PET polymer back into constituents that can be used in the production of polyester polyol, so that a waste plastic replaces part of the fossil raw material rather than being downcycled into a lower-value application.
The application began on 1 July 2025 and is run as an institutionalised process rather than as a project. The year 2025, in which the product formulation was designed in the company's research and development centre, is taken as the baseline year (4). In 2026 the PET processing steps were moved into the company's own facilities.
Both production sites hold ISCC PLUS certification, and the recycled content is accounted for using the mass balance approach, which makes the claim traceable from feedstock to delivered product (2). The recycled content percentages of the relevant products are additionally verified by a third-party organisation under the ReMade certification (3).
Location of the initiative: Gebze and Düzce, Türkiye
Solution
The technology converts post-consumer PET bottle waste into a polyester polyol that substitutes for part of the conventional fossil-based raw material in polyurethane systems.
Depolymerisation breaks the polymer chain back into building blocks, which is what allows the recycled material to enter polyol synthesis instead of being limited to remelting and reforming.
The recycled content is set per product rather than as a single company-level figure. The polyester polyol grade carries between 28 and 40 per cent recycled PET content, and the rigid sandwich panel system built on it carries 10 per cent. Stating the content per product is what allows a customer to carry the figure into its own calculations.
The systems are designed to run in existing customer processes without a performance concession, so that the panel producer does not have to requalify its line in order to take a lower-impact raw material.
The chain of custody is certified. Both production sites are covered by ISCC PLUS and ReMade certification, and the mass balance approach tracks the share of recycled content through the production system in a way that independent auditors recognised by the scheme can verify.
Figure 1: From PET waste to high-performance solutions
The route from PET waste to finished product in four steps: collection of used PET bottles, chemical depolymerisation by glycolysis, the oligomeric polyester polyol obtained from it, and the rigid polyurethane foam the polyol forms with isocyanate, with its thermal insulation, mechanical and fire performance.
Figure 2: Post-consumer PET flake before depolymerisation
Figure 3: Polyester polyol obtained from recycled PET in the laboratory
Impact
Sustainability impact
Climate
The effect is on emissions embodied in raw material production, which fall in Scope 3 and pass on to customers as a reduction in the embodied carbon of the systems they buy. Under the GHG Protocol the substitution sits in Category 1, purchased goods and services, for the company itself. Substituting recycled material for fossil-based raw material lowers those upstream emissions for the substituted share; the company reports the mechanism but does not publish a tonnage.
The company also reports a transport effect: replacing part of the imported fossil petrochemical feedstock with domestically sourced PET waste removes the cross-border logistics that the imported material would have required.
The measurement basis is the mass balance approach, an internationally recognised method that allows the share of bio-circular and recycled content in products to be tracked verifiably when sustainable and conventional raw materials are processed in the same production system.
The baseline year is 2025 and impact data has been monitored continuously since July 2025. Verification is carried out through audits by independent bodies recognised by the ISCC PLUS and ReMade certification schemes, together with periodic reporting.
Nature
The initiative diverts post-consumer PET bottles from disposal and returns them to industrial production. Chemical recycling by depolymerisation breaks the material down at molecular level into building blocks that match the quality of fossil-based raw material, which avoids the degradation associated with mechanical recycling and keeps the plastic in the production cycle.
Substituting recycled material for conventional fossil-based raw material reduces primary resource consumption for the share substituted, which is where the resource efficiency of the application is created.
The application also supports the waste collection and recycling ecosystem in the value chain, since a stable industrial demand for post-consumer flake is what makes collection economically viable upstream.
The polyol also has a use-phase effect through the product it goes into: the rigid polyurethane sandwich panels built on it have low thermal conductivity, so they reduce the operational energy a building needs for heating and cooling over its life.
Social
Because the systems integrate into standard production processes without a performance concession, customers can adopt them without requalifying their lines, which removes the main practical barrier to switching raw material and moves the sustainability transition of the company's customers forward.
The formulation work is carried out with university collaborations, through which the research and development engineers and the academic partners exchange knowledge, and the resulting expertise is returned to the sector rather than held internally.
Full traceability from supply chain to finished product gives customers and other stakeholders a verifiable basis for their own carbon reduction and sustainability claims, which reduces the risk of unsupported environmental statements moving downstream.
Business impact
Benefits
Bringing the PET processing steps in-house through the recovery line investment is the operational result the company emphasises: higher process control, an increase in operational efficiency and continuity of quality in production, together with reduced dependence on external processors.
Substituting recycled material for fossil-based raw material reduces exposure to primary petrochemical feedstock and to its price behaviour for the share substituted.
ISCC PLUS certification of both sites, combined with mass balance accounting, allows the products to be marketed transparently and verifiably worldwide, which is a market access benefit in export markets where customers must evidence their own supply chain claims.
The systems are designed to meet the post-consumer recycled content requirements applied in European markets, particularly in public procurement, under the European Green Deal, the Ecodesign for Sustainable Products Regulation and the Italian minimum environmental criteria.
The company aims for 25 per cent of total product sales to come from sustainable systems - bio-based, recycled and low-carbon-footprint products - by 2030, and for sales of PET-based polyester polyol and polyurethane systems to reach 5,000 tonnes by that year. On that projection it estimates that approximately 1,160 tonnes of PET waste would be recycled rather than released to the environment (1).
Costs
The largest single cost was avoided rather than incurred. Instead of importing a new depolymerisation reactor, the company refurbished reactor infrastructure that was no longer in active use, completed its technical rehabilitation and added automation to convert it into a modern PET depolymerisation reactor. That kept the capital requirement down and brought an existing asset back into the production system.
Development cost sits in the laboratory and pilot stages: optimising the depolymerisation reaction conditions, formulation development, product stability testing, mechanical and chemical testing, and the research and development staff time behind them.
The PET recycling line established at the facility required investment in industrial crushing and shredding machinery that brings incoming PET waste to the size the reaction needs, which is what secures process control, consistent input quality and operational efficiency.
Certification is a recurring cost. ISCC PLUS and ReMade audits verify the validity, transparency and regulatory compliance of the recycled-content polyol and polyurethane systems in international markets, and mass balance accounting requires bookkeeping that follows the certified material through the production system into each delivery.
The raw material supply is a dependency. The process starts with post-consumer PET flake, and both the availability and the consistency of that flake determine what recycled content can be maintained.
The company does not publish the capital cost of the recovery line, the cost differential against fossil polyol or a payback period.
Impact beyond sustainability and business
Co-benefits
Industrial demand for post-consumer PET flake strengthens the collection and recycling ecosystem upstream and adds economic value to the circular economy in the value chain, which benefits actors who are not party to the initiative.
The chemistry is not confined to construction. The application was designed first for sandwich panel systems, and the company is continuing development to adapt it to other polyurethane applications - footwear, flexible foam, and coatings, adhesives, sealants and elastomers - which widens the volume of fossil raw material that could eventually be substituted.
Verified traceability is itself a shared asset: it gives customers a defensible basis for their own targets and gives the sector a working example of a certified chain of custody for recycled chemical content.
Potential side-effects
Demand for post-consumer PET from chemical recycling competes with bottle-to-bottle recycling and with textile fibre for the same feedstock, which exposes the application to price and availability pressure as more industrial users enter the market.
The recycled content ratios are product-specific and modest at the panel system level, so the substitution reduces rather than removes fossil dependence, and scaling it depends on both feedstock supply and customer demand.
Mass balance accounting allocates certified content across production rather than guaranteeing that every unit physically contains the stated share. It is a recognised and audited method, but end users often read it as a physical content claim, so the basis is worth stating whenever the figure is passed on.
Implementation
Typical business profile
The approach suits polyurethane systems houses and chemical formulators supplying industrial customers, that hold their own research and development centre and operate more than one production site, so that formulation development and certified chain of custody can be managed together.
It is most relevant where customers are themselves under pressure to reduce the embodied impact of their products, as construction sandwich panel producers are, because the raw material supplier is the only party that can change the upstream footprint.
Delivery engages research and development, production, quality, procurement, and a commercial function that can carry certified sustainability claims into customer conversations.
In European markets the use of recycled content is a requirement in many public tenders and in the supply chains of international corporations, so meeting those standards is what allows a supplier to stay in those channels.
Approach
Choose the waste stream and the recycling chemistry together: Select post-consumer PET as the feedstock and depolymerisation as the route, because chemical recycling returns the polymer to building blocks that can enter polyol synthesis, which mechanical recycling cannot do.
Develop the formulation in the research and development centre and fix a baseline: Design the polyester polyol so that recycled content substitutes fossil raw material without changing the properties downstream systems depend on, and take the year of formulation development as the baseline year for measuring impact.
Set the recycled content per product rather than per company: Define the content for each system - 28 to 40 per cent for the polyester polyol and 10 per cent for the rigid panel system - so that a customer can carry a specific figure into its own reporting instead of a corporate average.
Bring the processing steps in-house: Invest in a PET recovery line so that incoming waste is crushed and processed on the company's own sites, which raises process control, increases operational efficiency and holds quality steady across batches.
Certify the chain of custody across every site: Obtain ISCC PLUS and ReMade certification covering all production sites and apply the mass balance method, so that recycled content can be tracked and claimed from feedstock through to the finished product rather than asserted.
Submit the flows to independent audit: Have the material flows verified through audits by bodies recognised by the certification scheme and report periodically, so that customer-facing claims rest on third-party verification rather than on internal records.
Prove the systems in the customer's own process: Validate that the products run in standard production without requalification, because a sustainable raw material that changes line behaviour will be rejected on operational grounds regardless of its environmental merit.
Set a portfolio target and extend the platform: Commit to a share of total sales from lower-impact systems by a stated year, and adapt the technology to further polyurethane applications such as footwear, flexible foam and coatings, adhesives, sealants and elastomers.
Stakeholders involved
Project leads: The recycling objective is owned at board and senior management level. Senior management kept the work aligned with the sustainable product portfolio and the growth targets, and carried the cross-departmental coordination, the resource allocation and the scale-up decisions. Operational management sits with the deputy general manager responsible for sales, marketing and sustainability, which keeps the commercial and the sustainability sides of the application in one line of accountability.
Company functions: Delivery was company-wide rather than confined to one department. Research and development handled synthesis, formulation, laboratory validation and technical improvement; procurement researched suitable raw materials and suppliers; the sustainability function ran the environmental performance calculations and the compliance work for the certification audits; marketing and product management covered regulation, customer selection and product positioning; sales managed customer communication, samples and field trials; and production and quality controlled process conditions and product consistency through the scale-up.
Main providers: Suppliers of post-consumer PET flake start the material flow by bringing waste into the system; the company then processes that material on its own sites to secure quality continuity and operational efficiency. The supplier relationship is therefore a feedstock supply arrangement rather than a technology partnership, and the processing know-how is held internally. Audit and verification are performed by independent bodies recognised by the ISCC PLUS and ReMade certification schemes, which is what makes the recycled content claim verifiable for customers.
Other: Universities collaborate with the company's research and development engineers during the formulation process, and the company describes the knowledge exchange as mutually reinforcing between the academic partners and the sector. Customers are the other active party: industrial users, particularly sandwich panel producers, adopt the systems into existing processes and use the certified traceability in their own sustainability reporting.
Key parameters to consider
The application started on 1 July 2025 and impact data has been monitored continuously since that month. The baseline year is 2025, when the formulation was developed; PET processing moved in-house during 2026, and the administrative work for the environmental permits and licences is still under way.
Four indicators are tracked: recycled PET content in the polyester polyol at 28 to 40 per cent; recycled PET content in the rigid sandwich panel system at 10 per cent; the 2030 sales objective of 5,000 tonnes of polyester polyol and polyurethane systems made with recycled PET; and certification coverage, with both plants under ISCC PLUS and the products verified under ReMade at 100 per cent.
The accounting method is mass balance, verified through audits by bodies recognised by the certification scheme.
The technical constraint is that recycled content must be introduced without changing the properties the downstream systems depend on, which is what sets the achievable content per product.
Implementation and operations tips
Match the recycling technology to the destination of the material. Mechanical recycling is cheaper, but only a chemical route produces a building block that can enter polyol synthesis, so the choice is determined by what the material has to become.
Bring the processing in-house if quality continuity matters. Buying processed flake leaves batch-to-batch variation outside the company's control, which is the variable that most often stops a recycled raw material from being used in a specification-driven product.
Certify the chain of custody before making claims to customers. Mass balance accounting under an established scheme, audited by recognised independent bodies, is what turns a recycled content figure into something a customer can put in its own report.
Protect performance parity above all else. The adoption barrier for a recycled raw material is operational, not environmental: if the systems run unchanged in the customer's process, the decision moves from engineering approval to procurement.