Closed-Loop Recycling of Mixed Polyesters via Catalytic Methanolysis and Monomer Separations

Journal Article · Mon Sep 08 00:00:00 EDT 2025 · Nature Chemical Engineering

DOI:https://doi.org/10.1038/s44286-025-00275-x· OSTI ID:3011824

Curley, Julia ^[1]; Liang, Yuanzhe ^[1]; DesVeaux, Jason ^[1]; Choi, Hoon ^[1]; Clarke, Ryan ^[1]; Maurya, Anjani ^[2]; Michener, William ^[1]; Stanley, Lisa ^[1]; Wu, Yue ^[2]; Hesse, Sarah ^[2]; Baer, Andrea ^[1]; Neyer, Hudson ^[1]; Tassone, Christopher ^[2]; Jacobsen, Alan ^[3]; Mante, Ofei ^[3]; Beckham, Gregg ^[1]; Knauer, Katrina ^[1]

---

1. National Renewable Energy Lab., Golden, CO (United States)
2. BOTTLE Consortium; SLAC National Accelerator Laboratory
3. Amazon

A sustainable plastics future will require high recycling rates and the use of biogenic feedstocks, which together are catalyzing interest in replacing fossil fuel-derived, noncircular polyolefin packaging materials with bio-based, chemically recyclable polyesters. Here we present a catalytic methanolysis process capable of depolymerizing both fossil fuel- and bio-based polyesters, including polyethylene terephthalate (PET), polylactic acid, polybutylene adipate terephthalate and polybutylene succinate in one reactor under mild conditions with high monomer yields. We scaled this process to 1 kg and integrated separations engineering using activated carbon, crystallization, extraction and distillation to remove contaminants and recover individual monomers from depolymerized mixed polyesters with high yield and purity. PET synthesized from monomers isolated from postconsumer materials showed comparable mechanical and thermal properties to PET from commercial monomers. Techno-economic analysis and life cycle assessment show that this process is economically viable and exhibits lower environmental impacts than primary production of respective polymers.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Advanced Manufacturing and Materials Technologies Office (AMMTO); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Bioenergy Technologies Office
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 3011824
• Report Number(s): NREL/JA-2800-96757
• Journal Information: Nature Chemical Engineering, Journal Name: Nature Chemical Engineering Vol. 2
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
36 MATERIALS SCIENCE
catalytic methanolysis
polybutylene adipate terephthalate (PBAT)
polybutylene succinate (PBS)
polyethylene terephthalate (PET)
polylactic acid (PLA)
recycling mixed polyesters