Globally, around 70 million tons of polyethylene terephthalate (PET) plastic are manufactured every year. This equates to around 20% of all plastic produced.
However, plastic used in packaging degrades over time through repeated conventional thermomechanical processes, meaning that new virgin plastic is required to retain its quality.
Now, French biotech company Carbios has developed the ‘world’s first’ food-grade PET plastic bottles produced entirely from enzymatically recycled plastic, which it said makes the promise of endlessly recycled plastic ‘one step closer’.
Consumer brands back innovation
The sample bottles are the result of a consortium established by Carbios and L’Oréal in 2017. Two years later, in 2019, the founders were joined by Nestlé Waters, PepsiCo, and Suntory Beverage & Food Europe.
The consortium’s objective is to industrialise recycling technology designed and developed by Carbios and, in doing so, promote the circular economy of plastics.
Having successfully manufactured sample bottles of consortium brands Biotherm, Perrier, Pepsi Max, and Orangina, the companies are now working to scale this innovation to help meet the global demand for sustainable packaging solutions.
“The consortium objective is to provide this eco-friendly solution at commercial scale to consumers and inform them that this product can be fully and endlessly recycled once deposed of,” a Carbios spokesperson told this publication.
Indeed, Carbios revealed that this coming September, it will break ground on a demonstration plant. By 2025, the green biotech firm will have launched a 40,000-ton capacity industrial facility.
What is enzymatically recycled plastic?
The innovation is the culmination of close to 10 years’ R&D to ‘supercharge’ a biological tool, called an enzyme, and create a recycling process that uses it, explained the spokesperson.
“This enzyme – cutinase – occurs naturally in compost heaps, helping to break down leaf membranes of dead plants. By optimising this enzyme, Carbios scientists in collaboration with the Toulouse Biotechnology Institute, have fine-tuned the technology to break down any kind of PET plastic into its original building blocks, which can then be turned back into like-new, virgin-quality plastic (without the need to add actual virgin plastic).”
An enzyme is a natural protein that significantly speeds up the rate of chemical reactions. Essentially, it is a catalyst made by stringing together amino acids in a very specific and unique order. The chain of amino acids then folds into a highly specific shape.
“A good image of the role of an enzyme is to [envisage] an enzyme as having a lock, with the PET polymer being the key,” the spokesperson explained. “The shape of lock is perfectly adapted to the key, and once that connection has been made, the reaction can occur.”
Carbios claims the new enzymatic process is 10,000 times more efficient than any other biological plastic recycling trials to date, breaking down 97% of PET plastic in just 16 hours. “It produces feedstock, made entirely of enzymatically recycled post-consumer PET plastic waste that companies can use to manufacture new plastic bottles with, that are endlessly recyclable,” we were told.
Unsurprisingly, the key technical challenge facing Carbios was working with the enzyme itself. Enzymes are already used in numerous applications, from detergents to biofuels, textiles and food processing, but using them for the recycling of polymers hadn’t been considered.
“Carbios was the first company in the world to apply the use of enzymes in the plastics industry. This innovative approach represented a real technological challenge,” explained the spokesperson.
After the identification of a natural occurring enzyme, the sequence and the thermostability of the enzyme had to be drastically improved to achieve the level of performance reached today, we were told.
“The ambition of Carbios has always been to bridge the gap between biology and the plastic industry to ensure that plastic could enter a virtuous cycle and never become waste.
“This was once thought to be impossible, but after years of research and engagement, this consortium of some of the world’s biggest brands has proved the potential of this singular approach based on the use of enzymes.”
The consumer brands backing the development say the new enzymatically recycled bottles align with their sustainability strategies.
Nestlé Waters, for example, said it was exciting to see that the quality of the prototype bottles made from coloured recycled PET materials is ‘virtually identical’ to clear virgin PET. “When we reach industrial scale, this enzymatic recycling technology will enable us to produce high-quality rPET bottles and help Nestlé Waters in our journey to boost the circular economy and reduce the use of virgin plastics,” noted Head of Packaging Material Science and Environmental Sustainability Jean-Francois Briois.
Suntory Beverage & Food Europe, too, associated the development to its sustainable plastic target. “The global issue of plastic waste requires transformational thinking, creative partnerships and innovative brands coming together to seek out new solutions,” said Chief R&D Officer Roberto Vanin.
“Continued investment in new ways of tackling waste and creating true circularity such as this ground-breaking technology from Carbios will be key to Suntory Beverage and Food Europe achieving its 100% sustainable plastic ambition.”
PepsiCo said it was committed to building a circular economy to achieve its vision that ‘packaging never becomes waste’. “We are dedicated to reducing the virgin plastic we use and with the breakthrough Carbios enzymatic recycling technology, we can help keep valuable material in the circular economy, reduce waste and take another step towards a truly closed loop system,” noted Ron Khan, Global VP of Packaging, Beverages.