Developed by French green chemistry firm Carbios, the method involves applying a liquid mixture of enzymes to used PET plastics and polyester fibres. Through a reaction similar to digestion, the enzymes break the polymers down into monomers – single-element particles which are then sent through a filtration and purification system.
The resulting materials are of “equivalent quality” to virgin PET, according to Carbios, making them ready for reuse in new plastic packaging such as drinks bottles. Carbios claims that the approach can be used for all forms of PET – regardless of colour, opacity or the number of plastic layers in the product – and that it requires “limited” heat and no pressure or solvents to complete.
Carbios and its new academic partner, the Toulouse Biotechnology Institute (TBI) have published a new article in the peer-reviewed paper in Nature, outlining how the organisations have been able to increase the degradation of plastics waste to 90% over a 10-hour period. Previously, the technology was only able to deliver an initial degradation yield of 1% after several weeks.
Carbios had previously partnered with health and beauty firm L’Oreal to launch a business consortium aimed at bringing the recycling process to market on an industrial scale. Last year, PepsiCo, Nestle Waters and Suntory Beverage & Food Europe all joined the consortium for a four-year term, committing them to support the market for enzymatically recycled PET.
Business implications
The businesses hope that the technology will overcome today’s conundrum when recycling plastics bottles. Conventional, thermo-mechanical recycling works well for clear bottles and packaging, but is commonly unable to treat coloured, opaque or multi-layered plastics. This method also degrades the material after several cycles, leading to the material to be incinerated or to leak into the natural environment. Carbios claims its technology will help prevent plastic pollution through a biological breakdown.
As such, this could be a big breakthrough for businesses aiming to eliminate what they deem to be unnecessary single-use plastics. Beverage giant Suntory, for example, has pledged to eliminate virgin fossil-fuel-based plastics from its packaging portfolio across Europe by 2030.
Elsewhere, PepsiCo has announced plans to reduce the use of virgin plastic across its portfolio by 35% by 2025, which will eliminate around 2.5 million metric tonnes of the material from circulation.
The need to improve the recycling of plastics is apparent. Between eight and 12 million tonnes of plastics are believed to be seeping into oceans and waterways every year – and that’s not to mention the plastic waste which is littered or otherwise mismanaged, leading to pollution on land.
It has recently been claimed that four of the world’s largest users of plastic packaging – Coca-Cola, PepsiCo, Unilever and Nestlé – are responsible for half a million tonnes of plastic pollution that are burnt or dumped each year in six developing countries, creating emissions equivalent to adding two million cars onto roads.
Matt Mace