The Fraunhofer Institute, SABIC and Procter & Gamble (P&G) have worked together to trial the chemical recycling of single-use face masks.
With huge volumes of single-use face masks created during the Covid pandemic, landfill or incineration has been the only treatment solution so far.
P&G director R&D Open Innovation Peter Dziezok said: “Recognising the challenge, we set out to explore how used face masks could potentially be returned to the value chain of new face mask production.
“But creating a true circular solution from both a sustainable and economically feasible perspective takes partners. Therefore, we teamed up with Fraunhofer Cluster of Excellence for the Circular Economy and Fraunhofer UMSICHT’s scientists and SABIC’s technology and innovation specialists to investigate potential solutions.
As part of the pilot, P&G collected used face masks from employees and visitors at its manufacturing and research sites in Germany. These were then sent to Fraunhofer for further processing in a dedicated research pyrolysis plant. The resultant pyrolysis oil was then sent to SABIC as a feedstock for the production of new PP resin. The PP polymer was then used by P&G in its non-woven fibres.
Fraunhofer UMSICHT head of department recycling management Alexander Hofmann added: “A single-use medical product such as a face mask has high hygiene requirements, both in terms of disposal and production. Mechanical recycling would not have done the job.
“In our solution, therefore, the masks were first automatically shredded and then thermochemically converted to pyrolysis oil. Pyrolysis breaks the plastic down into molecular fragments under pressure and heat, which will also destroy any residual pollutants or pathogens, such as coronavirus. In this way, it is possible to produce feedstock for new plastics in virgin quality that can also meet the requirements for medical products.”