Thermogravimetric analysis of face mask waste: Kinetic analysis via iso-conversional methods

¹ Department of Chemical and Energy Engineering, Faculty of Engineering and Science, Curtin University Malaysia, CDT 250, 98009, Miri, Sarawak, Malaysia
² Department of Chemical and Energy Engineering, Faculty of Engineering and Science, Curtin University Malaysia, CDT 250, 98009, Miri, Sarawak, Malaysia
³ Energy and Environment Research Cluster, Faculty of Engineering and Science, Curtin University Malaysia, CDT 250, 98009, Miri, Sarawak, Malaysia
⁴ Department of Chemical and Energy Engineering, Faculty of Engineering and Science, Curtin University Malaysia, CDT 250, 98009, Miri, Sarawak, Malaysia
⁵ Curtin Malaysia Research Institute (CMRI), Curtin University Malaysia, CDT 250, 98009, Miri, Sarawak, Malaysia
⁶ Research Centre for Sustainable Technologies, Faculty of Engineering, Computing and Science, Swinburne University of Technology, Jalan Simpang Tiga, 93350 Kuching, Sarawak, Malaysia
⁷ Research Centre for Sustainable Technologies, Faculty of Engineering, Computing and Science, Swinburne University of Technology, Jalan Simpang Tiga, 93350 Kuching, Sarawak, Malaysia
⁸ Generation Unit (Fuel Combustion Section), Tenaga Nasional Berhad Research (TNBR) Sdn Bhd, No. 1, Kawasan Institusi Penyelidikan, Jln Ayer Hitam, 43000 Kajang, Selangor, Malaysia

^* Corresponding author: melvinweexj@postgrad.curtin.edu.my

Abstract

The surge of face mask waste in response to the global pandemic has proven to be a liability to the environment. Microfibers from plastic constituents of the face mask would cause microplastic pollution in the water bodies. Fortunately, these waste could be converted into renewable source of energy via thermochemical method, i.e. pyrolysis. However, the studies on the thermal decomposition of face masks and their kinetic mechanisms are not well-established. The aim of this paper focuses on the prospects of pyrolysis at low to high heating rates ranging from 10 °C min^-1 to 100 °C min^-1, to cater for the slow pyrolysis and fast pyrolysis modes. Following this, the thermal degradation behaviour of the face mask waste was studied via thermogravimetric analysis which determined the single peak temperature degradation range at 218 to 424 °C at 10 °C min^-1, and maximum degradation rate was determined at 172.51 wt.% min^-1 at 520 °C, with heating rate of 100 °C min^-1. Flynn-Wall-Ozawa (FWO) and Starink method was employed to determine the average activation energy and average pre-exponential factor of the pyrolysis process of face mask waste. i.e., 41.31 kJ mol^-1 and 0.9965, 10.43 kJ mol^-1 and 0.9901 for FWO and Starink method, respectively.