In what the four partners - Neste, Borealis, Uponor and Wastewise - believe to be a one of the first projects to do so, an initiative aimed at the chemical recycling of PEX waste from pipe production operations into feedstock for new PEX pipe production has yielded successful results.
Robust PEX pipes, mainly used in cooling, heating and plumbing applications, offer temperature resistance and longevity. However, the interconnected polymer chains make them nearly impossible to recycle with conventional recycling technologies. The present initiative demonstrates that industrial PEX waste can be chemically recycled and, using an ISCC plus certified mass-balancing approach, reprocessed into a feedstock suitable for the production of new PEX pipes.
“We are very excited about this collaboration as it gives us a head start on our transition to circular materials,” says Thomas Fuhr, Chief Technology Officer at Uponor. “At Uponor we have just celebrated the first 50 years of our PEX piping, and now our new long-term goal is to use 100% of our PEX waste as raw material through closed loop recycling.”
Neste, Borealis, Uponor and Wastewise each contributed their specific expertise to the project. Wastewise has used its pyrolysis-based chemical recycling technology to liquefy industrial waste from Uponor’s PEX pipe production, breaking the polymers down back into their building blocks. The resultant oil-like liquid is then co-processed in Neste’s oil refinery in Porvoo, Finland and upgraded into recycled Neste RE, a drop-in feedstock for the production of new polymers. Borealis subsequently fed this raw material into its steam cracker, polymerising it into polyethylene as part of the company’s Borcycle C, chemical recycling portfolio which could be used by Uponor to create new PEX pipe systems. These pipes can find application in the construction sector, and are suitable even for sensitive applications with stringent requirements, such as in drinking water systems. The whole value chain is traceable via ISCC plus certified mass-balancing.
“Hard-to-recycle waste plastic as input and high-quality polymers as output are not in contradiction anymore,” said John Webster, Global Commercial Director Infrastructure at Borealis. He noted that no additional tests, approvals or validation were required, as it is a drop-in solution ready.
The project also showed that not only can PEX be recycled via chemical recycling, high yields can be achieved. “Some 80% of the PEX production waste can be added back to the circle,” explained Kaisa Suvilampi, Managing Director and Partner at Wastewise. “Through our processes, we were able to turn PEX into pyrolysis oil of sufficient quality to use it as input for a refinery, which in turn can process it into a high quality cracker feed.”
Mercedes Alonso, Executive Vice President Renewable Polymers and Chemicals at Neste, cautioned that it will still take time to reach large-scale operations, but observed that the project could serve as a blueprint for circular value chains for polymers via chemically recycling. “It’s pushing the technology from the promise to the delivery phase. Further, it shows the importance of bringing the right partners together to cooperate,” she said.
The project took just six months to get from start to the production of the first PEX pipes. It is also already looking at a further step that would take it beyond using only industrial waste. Currently, end-of-life pipes produced by Uponor are mechanically recycled - or downcycled - into other construction materials or items such as hockey sticks. With chemical recycling, though, these can be turned into fully functional PEX pipes again. Moving forward, the partners will evaluate further opportunities for cooperation. Aside from broadening the waste material pool, this may also include higher recycled volumes.