Among the impacts of the pandemic that has wreaked such havoc across the world over the past year and a half has been a huge increase in the use of disposable face masks.

requently simply discarded in the environment. And even when properly disposed of, these end up in landfills or being incinerated, representing a loss of valuable feedstock for new materials.

Now, Fraunhofer UMSICHT, SABIC and Procter & Gamble have partnered on a project designed to demonstrate the feasibility of establishing a closed-loop recycling mechanism for used face masks.

“Recognizing the challenge, we set out to explore how used facemasks could poten-tially be returned into the value chain of new facemask production,” says Dr. Peter Dziezok, Director R&D Open Innovation at P&G. “But creating a true circular solution from both a sustainable and an economically feasible perspective takes partners. Therefore, we teamed up with Fraunhofer CCPE and Fraunhofer UMSICHT’s expert scientists and SABIC’s T&I specialists to investigate potential solutions.”

For the pilot, face masks worn by employees or given to visitors at P&G’s manufacturing and research sites in Germany were collected. Special collection bins were set up, after which the collected used masks were sent to Fraunhofer for further processing in a dedicated research pyrolysis plant.

“A single-use medical product such as a face mask has high hygiene requirements, both in terms of disposal and production. Mechanical recycling would have not done the job” explained Alexander Hofmann, Head of Department Recycling Management at Fraunhofer UMSICHT. “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 the 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,” added Hofmann, who is also Head of the Research Department for Advanced Recycling at Fraunhofer CCPE.

The pyrolysis oil was then sent to SABIC to be used as feedstock for the production of new PP resin. The resins were produced using the widely recognized principle of mass balance to combine the alternative feedstock with fossil-based feedstock in the production process. Mass balance is considered a crucial bridge between today’s linear economy and the more sustainable circular economy of the future.

“The high-quality circular PP polymer obtained in this pilot clearly demonstrates that closed-loop recycling is achievable through active collaboration of players from across the value chain,” said Mark Vester, Global Circular Economy Leader at SABIC. “The circular material is part of our TRUCIRCLE portfolio, aimed at preventing valuable used plastic from becoming waste and at mitigating the depletion of fossil re-sources.”

Finally, to close the loop, the PP polymer was delivered to P&G, where it was processed into non-woven fibre material. “This pilot project has helped us to assess if the close loop approach could work for hygienic and medical grade plastics.” says Hansjörg Reick, P&G Senior Director Open Innovation. “Of course, further work is needed but the results so far have been very encouraging."

The entire closed loop pilot project from facemask collection to production was developed and implemented within only seven months. The transferability of advanced recycling to other feedstocks and chemical products is being further researched at Fraunhofer CCPE.