A breakthrough in enzymatic recycling has emerged, significantly reducing costs and emissions associated with recycling polyethylene terephthalate (PET) plastics.

Researchers from the National Renewable Energy Laboratory (NREL), the University of Massachusetts Lowell, and the University of Portsmouth have developed an economically viable enzymatic process for this purpose.

The findings, published in the journal Nature Chemical Engineering, underscore a collaborative effort to tackle the challenges of implementing enzymatic recycling for complex plastic waste.

Funded by the U.S. Department of Energy, the research aims to transform fundamental science into practical applications, with plans for establishing a U.S. enzymatic plastic recycling plant.

The optimized pre-treatment of plastics enables complete depolymerization within 50 hours, enhancing the recovery of ethylene glycol, another essential component of PET.

This new process design not only improves plastic deconstruction and monomer recovery but also allows for the recycling of contaminated and colored PET waste.

It involves creating diammonium terephthalate, which can be thermally decomposed to regenerate ammonia and produce terephthalic acid, facilitating indefinite reuse of the base.

The new process has achieved a remarkable 74% reduction in annual running costs and a 65% decrease in energy use, addressing previous challenges in enzymatic recycling.

This advancement marks a significant step towards making enzymatic recycling both environmentally sustainable and commercially viable, which is crucial in the ongoing fight against plastic pollution.

The research team, including notable figures like Professor John McGeehan and Dr. Gregg Beckham, emphasized the importance of translating fundamental science into practical applications for real-world use.

In the U.S., a staggering 86% of plastics were landfilled in 2019, highlighting a substantial opportunity to recover energy from waste plastics as global production is projected to rise significantly by 2050.

Professor Pickford noted the innovation of using ammonium hydroxide in the process, which minimizes the need for fresh chemicals and leads to over a 99% reduction in acid and base use.