Grenpol: enzymatic recycling platform for bio-based polyesters

Overview

GREnPOL offers an enzymatic depolymerization platform for bio-based and biodegradable polyesters, including PLA, PHBV, PBAT, PBAT-starch blends, and PEF. The technology addresses a critical sustainability challenge by enabling the green recycling and upcycling of bio-based packaging materials that are increasingly adopted as alternatives to petro-based plastics. By using specific ester hydrolase enzymes, the platform can break down these polymers into their starting monomers and oligomers under mild reaction conditions, enabling closed-loop recycling or bio-upcycling into commercially valuable compounds such as polyhydroxyalkanoates (PHAs).

Technical specifications

Key features:

• Broad substrate compatibility — validated on PLA, PHBV, PBAT, PBAT-starch, PLA-PLC, and PEF, including polymer blends such as PLA-PBAT
• High-efficiency enzymatic hydrolysis — complete depolymerization of 10–15 g/L substrate loading achieved in under 24 hours
• Mild reaction conditions — operates at ambient temperature and pressure, reducing energy demand compared to conventional chemical recycling
• Specific, controllable product release — enzymatic selectivity enables targeted monomer and oligomer recovery with straightforward purification
• Scalable process design — reactions demonstrated at laboratory scale with clear scale-up potential, suitable for consolidated bioprocessing
• Bio-upcycling pathway — recovered monomers can be fed to microbial strains for production of bioplastics or other industrially relevant compounds
• Analytical validation — results confirmed via weight loss analysis, HPLC, and NMR characterization

Technology readiness level

The technology is currently at TRL 3–4 (experimental proof of concept to laboratory validation). Preliminary laboratory tests have demonstrated successful enzymatic depolymerization of multiple bio-based polyesters, co-polyesters, and blends, with complete hydrolysis confirmed within 24 hours. Optimization of critical process variables using statistical design (Design Expert) and screening of microbial strains for bio-upcycling are planned over the next 8–12 months. The platform requires further development to establish a consolidated bioprocess for industrial-scale application, including process optimization, strain selection for monomer uptake, and demonstration of product recovery at scale.