New Method Uses Enzymes from Laundry Detergent to Recycle Single-use Bioplastics

Scientists at King’s College London have developed an innovative solution for recycling single-use bioplastics. Single-use plastics are commonly used in disposable items such as coffee cups and food containers.

This chemical recycling method uses enzymes found in biological laundry detergents to depolymerize landfill-bound bioplastics.

84x Faster Breakdown than Conventional Approach

Within 24 hours, the process achieves full degradation of the bioplastic polylactic acid (PLA). The approach is 84 times faster than the 12-week-long industrial composting process.

The team of chemists at King’s found that in a further 24 hours at a temperature of 90°C, the bioplastics break down into their chemical building blocks.This offers a widespread recycling solution for single-use PLA. Once converted into monomers the materials can be turned into high-quality plastic for multiple reuse.

Current rates of plastic production outstrip our ability to dispose of it sustainably. According to Environmental Action, it is estimated that in 2023 alone more than 68 million tons of plastic ended up in natural environments. This is due to the imbalance between the huge volumes of plastics produced and the recycling capacity. A recent OECD report predicted that the amount of plastic waste produced worldwide is on track to almost triple by 2060, with around half ending up in landfill and less than a fifth recycled.

"Being able to harness biology to deliver sustainable solutions through chemistry, allows us to start thinking of waste as a resource so that we can move away from oil and other non-renewable sources to create the materials we need for modern life," Dr Alex Brogan, lecturer in Chemistry.

Sustainable Blueprint for Recycling Single-use Bioplastic

While bioplastics are a more sustainable choice, production costs are high. Mechanical recycling methods are inefficient, generate CO2 and do not produce high-quality materials. These ‘green’ plastics primarily end up in landfill after just one use, causing many retailers to revert back to using oil and fossil-based materials.

The speed at which the bioplastics breakdown using this new method could revolutionize plastic production. It offers an efficient, scalable and sustainable blueprint for recycling single-use bioplastics. The research opens up the opportunity for a sustainable, circular economy that stamps out the production of fossil-based plastics. It also tackles the huge volume of plastic waste that ends up in landfill and natural environments.

Dr Alex Brogan, lecturer in Chemistry at King’s College London said, “The inspiration for this project came from a problem with bioplastics used in medical and surgical products degrading in the body. We’ve turned this problem around and applied it to the issue of recycling the single-use bioplastics we use in our everyday lives using a common enzyme found in biological laundry detergent.”

"Being able to harness biology to deliver sustainable solutions through chemistry, allows us to start thinking of waste as a resource so that we can move away from oil and other non-renewable sources to create the materials we need for modern life.”

The aim is now to improve the recycling of other common plastics, like in single-use water bottles, film and sheet plastic packaging, and clothing.

"Our research marks the first step in developing new technologies in waste management for recycling bioplastics that are of equal quality to the virgin product," Susana Meza Huaman, PhD researcher on the project.

Susana Meza Huaman, PhD researcher on the project at King’s College London, said, “Our research marks the first step in developing new technologies in waste management for recycling bioplastics that are of equal quality to the virgin product. Until now this has been a major challenge in plastics recycling, as while bioplastics are made of biological materials, they are not all compostable and most current recycling methods are inefficient.”

"Our chemical approach significantly speeds up the degradation of bioplastics, enabling them to be recycled and reused.”

Source: King's College London/omnexus.specialchem