High-quality pipes through chemical recycling of plastic waste

PEX pipe production at Uponor. © Uponor

Neste, Borealis, Uponor and Wastewise have successfully produced pipes made of cross-linked polyethylene (PEX) which was based on feedstock gained from chemically recycled post-industrial waste plastic from PEX pipe production, using an ISCC PLUS certified mass-balancing approach. The partner companies believe this project is among the first implementations of chemical recycling of PEX.

PEX pipes are an important contributor to energy efficient heating and safe plumbing due to their robustness, temperature resistance and longevity, yet the interconnected polymer chains make them nearly impossible to recycle with conventional recycling technologies. The project shows that chemical recycling can close the circularity loop for hard-to-recycle waste plastic, turning it into high-quality polymers feedstock and enabling the consecutive manufacturing of products with quality and properties identical to those in their previous life.

The cooperation sees Wastewise use their novel pyrolysis-based chemical recycling technology to liquefy industrial waste from Uponor’s PEX pipe production, breaking the polymers down back into their building blocks, which creates an oil-like recycled intermediate. This liquid is then co-processed in Neste’s oil refinery in Porvoo, Finland and upgraded into recycled Neste RE™, a high-quality drop-in feedstock for the production of new polymers. Borealis is feeding this raw material into their steam cracker and consequently polymerizing it into polyethylene as part of the company’s Borcycle™ C, chemical recycling portfolio. Finally, Uponor is using the polyethylene to create new PEX pipe systems, which can then be used in the construction sector for heating, plumbing and cooling purposes once more – eligible even for sensitive applications with high requirements, for example those used for drinking water systems. The whole value chain is traceable via ISCC PLUS certified mass-balancing.

The partnership holds potential for further cooperation beyond production waste: The PEX pipes made by Uponor have already been optimized from a resource efficiency point of view by reducing their wall thickness and increasing lifetime. At the end of their long life, mechanical recycling is so far the first recycling option, but it also means downcycling the materials, e.g. into other construction materials or items such as hockey sticks. With chemical recycling, though, the PEX waste pipes 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.