Pyrolysis and combustion of community masks: Thermogravimetric analyses, characterizations, gaseous emissions, and kinetic modeling

Used community masks are often thrown away or scattered in the environment. In addition to the unsightly aspect of such waste, these masks are a diffuse source of pollution because of some of their synthetic components: polypropylene, polyethylene terephthalate (PET), polyamide 6, polyamide 66, and elastane. These diffuse sources of pollution must be processed in an appropriate way, once they are collected. Among such processes, pyrolysis or combustion are to be explored. In the present study, five different masks were characterized before being submitted to pyrolysis and combustion experiments performed in a thermobalance under temperature ramps of 5, 10, 15, or 20 degrees C/min. Kinetic modeling of these pyrolysis or combustion processes was performed using the EIPR model because each mask contains different layers or components. The optimal values of the kinetic parameters were compared for the five masks and compared with that of their components. In complement to the thermogravimetric experiments, the main gaseous emissions (CO, CO2, THC, NO and NO2) were continuously measured during combustion tests in a horizontal oven. The gaseous emissions and mass rates curves were compared for each mask.