Thermodynamic, pyrolytic, and kinetic investigation on the thermal decomposition of polyvinyl chloride in the presence of franklinite

Altarawneh, Sanad; Al-Harahsheh, Mohammad; Dodds, Chris; Buttress, Adam; Kingman, Sam

Abstract

Thermal co-treatment of Electric Arc Furnace Dust (EAFD) and polyvinyl chloride (PVC) may provide a viable route for reprocessing these hazardous materials within the circular economy. To develop and optimise a commercial treatment process, the complex mechanistic pathway resulting from the reaction of these two wastes must be understood. Franklinite (ZnFe2O4) is a major zinc containing phase in EAFD and to date, little work has been undertaken on the decomposition of PVC in its presence. Herein, we present a thermodynamic, pyrolytic, and kinetic study of PVC degradation in the presence of ZnFe2O4. It was found that ZnFe2O4 decomposed to its associated halides. Additionally, the kinetics data confirmed the catalytic activity of ZnFe2O4, dropping the de-hydrochlorination onset temperature of PVC from 272 to 235 °C. The distribution of the activation energy with conversion suggests the presence of several competitive reactions each with a different energy barrier. In such a case, reaction channelling can take place leading to selective zinc chlorination. Moreover, since the reduction of Fe2O3 is slow at low temperatures, it is recommended to operate at a temperature as low as 235 °C which can promote the chlorination selectivity towards zinc leaving iron bearing compounds in their stable form (Fe2O3).

Citation

Altarawneh, S., Al-Harahsheh, M., Dodds, C., Buttress, A., & Kingman, S. (2022). Thermodynamic, pyrolytic, and kinetic investigation on the thermal decomposition of polyvinyl chloride in the presence of franklinite. Process Safety and Environmental Protection, 168, 558-569. https://doi.org/10.1016/j.psep.2022.10.028

• Journal Article Type: Article
• Acceptance Date: Oct 12, 2022
• Online Publication Date: Oct 20, 2022
• Publication Date: Dec 1, 2022
• Deposit Date: Oct 19, 2022
• Publicly Available Date: Oct 21, 2023
• Journal: Process Safety and Environmental Protection
• Print ISSN: 0957-5820
• Publisher: Elsevier BV
• Peer Reviewed: Peer Reviewed
• Volume: 168
• Pages: 558-569
• DOI: https://doi.org/10.1016/j.psep.2022.10.028
• Keywords: Safety, Risk, Reliability and Quality; General Chemical Engineering; Environmental Chemistry; Environmental Engineering
• Public URL: https://nottingham-repository.worktribe.com/output/12617062
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S095758202200893X