Authors : Blanche Dalimier, Charlotte Stalder. 

Making hard-to-recycle PET part of a circular economy 

Plastic recycling is about turning waste into a resource that can replace virgin materials without shifting environmental impacts elsewhere. 

DePoly is scaling a chemical recycling process designed to tackle PET waste that conventional recycling struggles to handle, including certain contaminated, coloured and complex waste streams. Its light-activated depolymerisation breaks PET down into its original building blocks, purified terephthalic acid (PTA) and monoethylene glycol (MEG), which can be used to produce new PET and a variety of performance and specialty materials. 

The potential is significant, but a promising recycling technology raises an important question: does recovering materials translate into an environmental benefit? 

For a company moving from a 500-tonne showcase plant to a planned 50,000-tonne commercial one, that question is also a commercial one. Investors, customers and brands will want the answer in numbers. Answering it takes more than measuring carbon emissions at one stage of the process. It means understanding the full value chain, testing key assumptions, and examining environmental impacts beyond climate change. 

Looking beyond carbon to understand the benefits 

Earth Action, working with Quantis, supported DePoly in developing a life cycle assessment (LCA) to evaluate its technology’s environmental performance. The study examined two value chains: PET packaging waste converted into new bottles, and polyester textile waste converted into new yarn. 

DePoly input: quote on why DePoly chose to run the study 

“LCA is an integral part of our value creation. Our monomers are drop-in in chemical terms, but their environmental footprint is entirely different from virgin products. Being able to prove and quantify that benefit is essential to our customers as well as investors and is part of our credibility.”  

Dr. Samantha Anderson, CEO and co-founder. 

The assessment considered 16 environmental impact categories under the EU Environmental Footprint method (EF 3.1). This multi-criteria approach helps catch burden shifting that a carbon-only assessment could miss, providing a broader view of the technology’s environmental performance. 

A central part of the work was to frame the assessment around two complementary questions: how do DePoly’s recycled materials compare with virgin alternatives, and what are the environmental implications of recycling a tonne of hard-to-recycle PET waste compared with alternative end-of-life routes? Looking at both perspectives helps distinguish the benefits of producing recycled materials from the benefits of diverting waste from other treatments. 

Quantifying the climate benefit and understanding what drives it 

The headline result: DePoly’s recycled PET offers a climate advantage even without end-of-life credits. 

Using the European electricity mix, a bottle produced from DePoly’s recycled monomers achieves a modelled carbon footprint of 3.6 kg CO₂e/kg, compared with 4.2 kg CO₂e/kg for virgin PET, a reduction of approximately 14%, even before accounting for end-of-life benefits. When avoided emissions from alternative waste treatments, namely plastic incineration, are included, the modelled footprint falls further to 2.3 kg CO₂e/kg, approximately 45% below virgin PET.  

The same trend holds for DePoly’s recycled building blocks: recycled PTA has a lower footprint than its virgin equivalent even without credits, and recycled MEG shows a particularly large reduction. The takeaway: DePoly’s recycled materials can reduce emissions without relying on end-of-life credits, and the size of the benefit depends on the material and the waste-management scenario. 

Quantified results make scaling a lower-risk decision 

The climate benefit does not stop at the showcase plant. In a modelled first commercial plant in Europe, the carbon footprint of a bottle made from recycled monomers is 32% lower than that of a virgin PET bottle. This is the information a company planning a plant 100 times the size of its showcase plant needs before it commits capital. It lets DePoly test three elements on numbers rather than assumptions: whether the climate benefit holds without credits, how much the choice of site matters, and which hotspots can be designed out rather than retrofitted. It also gives brands and investors a reviewed basis for their Scope 3 reporting and product claims. 

Hotspots are cheap to fix on paper and expensive to fix in steel. 

Building a robust basis for industrial decisions 

The credibility of an LCA depends on how the questions are framed, how assumptions are supported and how sensitive the conclusions are to methodological choices. 

The system was set up with DePoly, whose input shaped key assumptions, including those for textile recycling and the incineration of plastic fines. Earth Action added its Plasteax data on plastic waste flows to give regional waste-management context, and the independent expert panel’s input helped refine the approach. The assessment also tested allocation choices and reported results both with and without credits, making the influence of these methodological decisions transparent. 

Ensuring transparency and independent review. The study underwent an ISO 14044 critical review involving Roland Hischier (EMPA), Simon Hann (Eunomia) and Guy Castelan (Plastics Europe, acting as an independent expert). 

Together, these elements provide a structured basis for interpreting the results, while recognising that modelled performance depends on the scenarios and assumptions used. 

From environmental assessment to the next stage of scale-up 

In July 2026, DePoly inaugurated its showcase plant in Monthey, Switzerland, with a nominal capacity of around 500 tonnes of feedstock per year. The company is targeting a first commercial plant with a capacity of 50,000 tonnes per year, with the location expected to be announced in 2027. 

The LCA results provide a baseline against which future operational data can be assessed. As the technology develops, actual performance data will help test the projections, refine the understanding of environmental hotspots and identify further opportunities for improvement. 

For Earth Action, the value of this work lies in connecting environmental assessment with industrial decision-making. By combining life cycle thinking, transparent assumptions and multi-criteria analysis, LCA can help innovators understand not only whether a technology offers environmental benefits, but also under which conditions those benefits are strongest. 

Assessing environmental performance before scaling up helps turn promising technologies into better-informed industrial decisions. 

If you are developing a recycling or materials technology and want to understand its environmental performance before scaling, contact Earth Action at contact@e-a.earth or visit e-a.earth.