Plastic Recycling: DePoly — A Promising Technology, but No Universal Solution

"Over 90% of the world's plastics are not recycled. Innovations are multiplying — but they are far from equal."

The Structural Problem: Why Recycling Plastic Is So Difficult

The global textile industry is under pressure. Polyester — which now accounts for over 54% of global fibre production — is everywhere: in our clothes, sportswear and technical textiles. Yet less than 1% of garments collected at end of life are recycled into new textile fibres. The vast majority end up incinerated or landfilled.

The main reason? Traditional mechanical recycling — shredding, melting, re-extruding — degrades polymer chains with each cycle. After three to five passes, the fibre is no longer of sufficient quality to become a garment again. This is not closed-loop recycling; it is downcycling — a downward spiral towards increasingly low-value applications.

Added to this is a fundamental obstacle that is often overlooked: plastic is not one material, it is a family. Polyethylene, polypropylene, PET, PVC, polystyrene, polyurethane — each has its own distinct chemistry. A technology optimised for one is often unusable for the others. As a result, no universal recycling solution exists today.

DePoly: A Real Technology with a Well-Defined Niche

It is against this backdrop that Swiss startup DePoly (Valais) is attracting attention. Its approach is fundamentally different from mechanical recycling: rather than melting plastic down, it depolymerises it — breaking molecular chains to recover the original building blocks.

The patented process relies on chemical hydrolysis of PET and polyester, producing two purified monomers: Purified Terephthalic Acid (PTA) and Mono-Ethylene Glycol (MEG). These molecules are chemically identical to those derived from crude oil — direct drop-in substitutes, ready to use without modification in existing industrial processes.

What distinguishes DePoly from its competitors (Carbios in France, Eastman in the US) is both technical and decisive: the reaction occurs at room temperature, without additional pressure, using common, non-hazardous chemicals. Most competing processes require 150 to 300°C. Furthermore, DePoly processes coloured, blended and unwashed textile waste — precisely the streams that mechanical recycling cannot handle.

Tangible Results — and the Limitations You Should Know

The verifiable facts to date are solid:

→ 50 t/year pilot operational since 2020; 500 t/year demonstration plant opened in Monthey (Valais) in 2025

→ Complete cycle demonstrated with PTI: polyester waste → recycled PTA → PET pellets → blown bottles, quality identical to virgin resin

→ CO₂ emissions reduction of up to 66% vs. fossil-based virgin PET

→ Partnerships with Odlo, Beiersdorf, BASF Venture Capital; supported by the EU InvestEU Fund

→ World Economic Forum Technology Pioneer 2024; 2nd place Top 100 Swiss Startup Award 2025

But the role of the International Textile Biomass Alliance is to provide honest, grounded analysis. Here therefore are the objective limitations:

⚠️ Limitation #1 — Scope restricted to PET and polyester

DePoly's process relies on ester bond chemistry, specific to PET. It is incompatible with polyolefins (PE, PP), which account for ~55% of global plastic production, as well as PVC, polystyrene and polyurethane.

⚠️ Limitation #2 — Scale still modest

500 t/year for the demonstration plant. The first commercial plant is targeted for 2027, with no publicly announced capacity. By comparison, Carbios is targeting 50,000 t/year for its first industrial plant, currently under construction in France.

⚠️ Limitation #3 — Economic equation yet to be proven

Fossil-based virgin PET trades between €0.80 and €1.50/kg. The competitiveness of DePoly's recycled PTA at commercial scale has not yet been publicly demonstrated — this is the central challenge for the entire chemical recycling sector.

"DePoly is a serious and promising technology for difficult polyester textiles. But presenting it as a global answer to the plastics problem would be inaccurate."

What Comes Next? The Most Promising Pathways to 2030

The question the International Textile Biomass Alliance keeps asking — and that the entire industry is grappling with — is whether a path exists towards universal, residue-free, infinitely circular recycling.

The most significant breakthrough of 2025 comes from South Korea. The Korea Institute of Machinery and Materials (KIMM) has demonstrated that an ultra-brief cold plasma cracking process directly converts unsorted mixed plastics into ethylene and benzene — the fundamental molecules of all petrochemistry — with selectivity exceeding 70% and final purity above 99%. No carbonaceous residues. No prior sorting. An industrial demonstration line is planned for 2026.

The biological route is also progressing: mutant enzymes (PETase) and CRISPR-based approaches can now convert PET directly into bioplastics. Still too slow for industrial scale today, but worth watching closely.

Comparative Overview of Recycling Technologies (2025)

1. Mechanical recycling

• Plastics processed: all types in theory, but in practice limited to clean, homogeneous streams

• No residues: no — non-recoverable residual waste is always produced

• Infinitely recyclable: no — fibre degrades with each cycle (downcycling)

• Industrial viability: yes, mature technology deployed worldwide

• Maturity: fully industrial

2. DePoly — chemical hydrolysis of PET/polyester

• Plastics processed: PET and polyester only (textiles, bottles, packaging)

• No residues: yes — produces purified monomers reusable as-is

• Infinitely recyclable: yes — recovered monomers can be repolymerised indefinitely

• Industrial viability: under validation — first commercial plant targeted for 2027

• Maturity: demonstration plant operational in Monthey (Switzerland) since 2025

3. Enzymatic depolymerisation — Carbios and equivalents

• Plastics processed: PET only

• No residues: yes — mild conditions, high selectivity

• Infinitely recyclable: yes — same monomers recovered

• Industrial viability: in progress — first industrial plant under construction in France (targeting 50,000 t/year)

• Maturity: advanced pilot stage

4. Classic pyrolysis

• Plastics processed: primarily PE, PP, PS — not PET or PVC

• No residues: no — inevitable production of carbonaceous residues (char)

• Infinitely recyclable: partial — pyrolysis oil can substitute petrochemical naphtha

• Industrial viability: yes, industrially deployed technology

• Maturity: industrial, but variable quality depending on feed streams

5. Plasma gasification

• Plastics processed: all types, including highly heterogeneous and contaminated streams

• No residues: yes — produces syngas (CO + H₂) and inert vitrified slag usable in construction

• Infinitely recyclable: yes — syngas can be converted back into new plastic molecules

• Industrial viability: partial — high energy consumption remains a challenge

• Maturity: industrial pilot stage

6. Cold plasma — KIMM breakthrough (South Korea, 2025)

• Plastics processed: all types, no prior sorting required

• No residues: yes — no carbonaceous residues thanks to the ultra-brief pulse

• Infinitely recyclable: yes — directly produces ethylene and benzene, the building blocks of all plastics chemistry

• Industrial viability: yet to be proven — demonstration line planned for 2026

• Maturity: advanced R&D stage — results published 2025, purity >99%, selectivity >70%

The Alliance's Conviction: Design for Recyclability

End-of-life recycling, however effective, cannot be the only answer. The real revolution lies upstream: designing textiles whose chemical composition enables clean, on-demand depolymerisation. This means eliminating substances that inhibit chemical recycling, favouring mono-material structures, and embedding recyclability into design briefs from day one.

This is precisely the purpose of our FiberForever™ certification: a framework that assesses not only companies' current practices, but also their trajectory towards full circularity — including the recyclability of the materials they use.

DePoly deserves the attention and support of the polyester industry. Cold plasma technology opens a more universal perspective for the decade ahead. But the lasting solution to the plastics challenge will be built collectively — through technological innovation as much as through responsible design from the very start.

🌿 Would you like to assess the environmental footprint of your textile products or explore your eligibility for FiberForever™ certification? Visit itba-aibt.org

Sources: DePoly SA (depoly.co), World Economic Forum 2024, Swiss Startup Award 2025, KIMM Cold Plasma Research 2025, Carbios Annual Reports 2024-2025, Ellen MacArthur Foundation, International Textile Biomass Alliance analysis.