Valorization of Disposable COVID-19 Mask through the Thermo-Chemical Process

Graphical abstract

Highlights

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  A sustainable platform for COVID-19 PPE and CO ₂ to syngas was studied.

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  Chemical composition and thermal stability of face mask waste were identified.

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  Ni catalyst promoted syngas production from pyrolysis of disposable face mask.

Abstract

It becomes common to wear a disposable face mask to protect from coronavirus disease 19 (COVID-19) amid this pandemic. However, massive generations of contaminated face mask cause environmental concerns because current disposal processes ( i.e., incineration and reclamation) for them release toxic chemicals. The disposable mask is made of different compounds, making it hard to be recycled. In this regard, this work suggests an environmentally benign disposal process, simultaneously achieving the production of valuable fuels from the face mask. To this end, CO ₂-assisted thermo-chemical process was conducted. The first part of this work determined the major chemical constituents of a disposable mask: polypropylene, polyethylene, nylon, and Fe. In the second part, pyrolysis study was employed to produce syngas and C _1-2 hydrocarbons (HCs) from the disposable mask. To enhance syngas and C _1-2 HCs formations, multi-stage pyrolysis was used for more C-C and C-H bonds scissions of the disposable mask. Catalytic pyrolysis over Ni/SiO ₂ further expedited H ₂ and CH ₄ formations due to its capability for dehydrogenation. In the presence of CO ₂, catalytic pyrolysis additionally produced CO, while pyrolysis in N ₂ did not produce it. Therefore, the thermo-chemical conversion of disposable face mask and CO ₂ could be an environmentally benign way to remove COVID-19 plastic waste, generating value-added products.