Kinetic, thermodynamic and chemical reaction analyses of typical surgical face mask waste pyrolysis

The epidemic of Corona Virus Disease 2019 (COVID-19) has led to the generation of a large number of waste surgical masks. In recent years, pyrolysis is considered to be an environmental-friendly and efficient method to dispose such solid waste. In this work, the thermal degradation behaviors, kinetic parameters, thermodynamic parameters, pyrolytic products and chemical reactions of typical surgical face mask waste were studied using thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR)-mass spectrometry (MS) analysis in inert atmosphere. It is concluded that the surgical face mask waste pyrolysis in nitrogen can be considered to be a one-step reaction. In addition, the mean E (activation energy) value and the mean A (pre-exponential factor) value are 237.19 kJ/mol and 1.36 x 1014 min-1, respectively. g(alpha) = (- ln(1-alpha))2/3 (reaction model) may be utilized to characterize the surgical face mask waste pyrolysis in nitrogen. The above kinetic parameters are capable to estimate the surgical face mask waste pyrolysis behaviors in nitrogen. Thermodynamic parameters suggest that the surgical face mask waste pyrolysis can be considered to be an endothermic and non-spontaneous reaction. Inorganic substances, alkanes, alkenes, naphthenic hydrocarbons, aldehydes and ketones are the major volatile products. The amount of the aliphatic compounds is the highest. Specific chemical reactions generating these volatile products are proposed.

Automated summary

This study investigated the thermal degradation behaviors and products of typical surgical face mask waste using thermogravimetric and Fourier transform infrared analysis. The findings suggest that the pyrolysis process in nitrogen is a one-step reaction and the thermodynamic parameters indicate it is an endothermic non-spontaneous reaction. The major volatile products include inorganic substances, alkanes, alkenes, with specific chemical reactions proposed for their generation.