Millions of single-use face masks are discarded every day in the wake of the pandemic. A consortium of scientists from China, South Korea and Singapore investigated the feasibility and potential environmental benefits of converting discarded surgical masks into high-quality fuel via pyrolysis.
By June 2020, China alone was producing about 200 million surgical masks every day. A new study suggests an innovative waste-to-energy approach could put this material to good use while helping to meet some of the UN’s sustainability goals.
While subjecting polypropylene to pyrolysis has already been studied in detail, surgical masks contain other fillers that could affect the process. This means the R&D team, led by Professor Yong Sik Ok and Dr. Xiangzhou Yuan of Korea University, had to carefully analyse how the series of lab experiments affected the different materials, which came in gaseous, liquid, and solid forms.
The scientists report how one set of pyrolysis conditions yielded a carbon-rich and oxygen-deficient liquid oil as the main product. Further analyses revealed that this oil had a high heating value of 43.5 MJ/kg, which is ‘only slightly lower’ than that of diesel fuel and gasoline.
Moreover, the researchers conducted a ‘promising’ life-cycle assessment of their proposed methodology. It suggests that transforming face masks into electricity through pyrolysis offered better performance compared to most conventional waste management approaches, including less CO2 emissions, less terrestrial ecotoxicity, and less phosphorous emissions.
‘We verified that upcycling post-consumer surgical masks into value-added energy products represents a sustainable and promising route with notable environmental benefits,’ says Dr. Yuan.
‘Understanding new ways to turn surgical masks into value-added energy products will help us mitigate plastic pollution and achieve sustainable waste-to-energy conversion in the future,’ Prof. Ok points out. ‘The novel upcycling route proposed in our study could help us protect Earth’s ecosystems and reach several of the United Nation’s sustainable development goals.’
The full work was recently published in the journal Bioresource Technology.
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