US startup Protein Evolution lands US$20M to scale-up enzymatic plastic recycling

PEI scientist working at New Haven facility, US (All image credits: Protein Evolution).

02 Nov 2022 --- US-based startup Protein Evolution (PEI) has established what it says is the world’s first enzymatic plastic recycling business, landing initial funding of US$20 million. The group couples artificial intelligence (AI) with synthetic biology and maps tens of millions of enzymes capable of transforming plastic waste into reusable chemicals. This process can be infinitely repeated, it claims. 

PEI’s developments follow recent scientific breakthroughs in AI and natural science, for which numerous studies have shown enzymes can degrade plastics both in laboratories and in the natural environment. 

Scott Stankey, co-founder and chief technology officer of PEI, tells PackagingInsights that the business is the first to take these discoveries to scale and make them readily applicable for packaging and textile waste. 

After engineering an enzyme that can, for example, break down a PET bottle, “we take our enzyme and grow it in fermentation tanks so that we have enough enzyme to break down large quantities of plastic,” he explains. 

Lab scale bioreactors breaking down plastic at the PEI facility.“We then use the grown enzyme to recycle the plastic water bottle, breaking it down into its building blocks. If plastic waste is like a chocolate chip cookie, we are breaking it down into the ingredients for a new cookie - the milk, the eggs, the flour and so on.” 

“Our technology condenses a million-year evolutionary process into a single day – helping us create an affordable, scalable and effective solution to revolutionize the plastic waste industry.” 

A new advanced recycling? 
Stankey emphasizes that PEI’s process should be distinguished from the “advanced” or “chemical” recycling methods currently taking industry by storm. 

We prefer to refer to our process as “biological recycling,” he says. 

“Chemical recycling is often energy-intensive, given it uses an immense amount of heat or high-pressure chemical reactions to break down used plastic. Many actually consider it to be worse for the environment than the production of new plastic.” 

“We also view chemical recycling as relatively imprecise, and this can be seen in the comparatively low yields of chemical recycling processes, like pyrolysis.” 

A recent report by Zero Waste Europe found that emissions from plastic pyrolysis are, on average, nine times higher than those of mechanical recycling methods. Many campaigners have dismissed the many emerging advanced recycling projects as ruses by which the plastics industry can justify continued mass production. 

Co-founders Scott Stankey and Connor Lynn.Protein Evolution’s initial US$20 million funding was raised from entrepreneurs and industry leaders and led by Collaborative Fund’s recently announced climate fund, Collab SOS, which is in partnership with fashion designer Stella McCartney.

Scaling up biological recycling 
PEI says biological recycling is now industry’s low-energy, zero-emission process. “It relies on enzymes to break down plastic into its original building blocks, called monomers; those monomers can be reused and made into good-as-new materials,” continues Stankey.  

“We can engineer extremely specific enzymes, such that our enzymes only act on the waste stream that their DNA codes for. This has allowed our process to deal with higher contamination levels than other chemical recycling methods.”

Bringing this technology to an affordable scale is the next challenge. Connor Lynn, co-founder and chief business officer of PEI, says the economics make sense. 

“First of all, we are incredibly optimistic about the future of the bioeconomy and believe that we have a tremendous opportunity to partner with the petrochemical industry, consumer goods companies and textile manufacturers to reduce their reliance on fossil fuels,” he says. 

“However, a big challenge for the broader plastics industry is the recycling of ‘very hard to recycle’ materials, such as tires, industrial rugs, nylons, and multi-layer plastics. These materials are often lumped into the basket of ‘mixed plastic waste,’ which can be hard to process using current recycling technology.” 

“Protein Evolution’s [biological recycling] process is poised to tackle mixed-plastic waste, and we expect to make headway on this important industry priority in the near term,” Lynn concludes. 

By Louis Gore-Langton

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