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Journal:Process Safety and Environmental Protection

Key Words:ReaxFF molecular dynamics; Density functional theory; Co-pyrolysis; Polyvinyl chloride; Cellulose

Abstract:Co-pyrolysis of waste plastic and biomass presents great perspectives for sustainable and clean waste recy-cling. Unifying the distribution and generation mechanism of co-pyrolysis products of polyvinyl chloride (PVC) and cellulose (CE) solely through macroscopic experiments is challenging. In this study, the synerget-ic effect mechanism of co-pyrolysis of PVC and CE was comprehensively analyzed through reactive force field molecular dynamics (ReaxFF MD) combined  with density functional theory (DFT) at the molecular level. PVC provides sufficient ·H radicals for the co-pyrolysis system, which promotes biomass degradation and the decarboxylation and dehydroxylation reactions of oxygen-containing groups. Co-pyrolysis limits the release of HCl, and the inhibition diminishes with increasing temperature. The quality of oil and char improves as their oxygen content declines. The dehydroxylation reaction of the CE monomer is most likely to occur under the catalysis of HCl at the C4 site, accompanied by a minimum reaction energy barrier of 23.87 kJ/mol. The alcoholization of furfural compounds is enhanced by ·H radicals. In co-pyrolysis, the bio-mass-derived activated intermediates release CO2 and CO through hydrogenation, oxidation, hydrogen cap-ture, and cracking. The conjunction of ReaxFF MD and DFT effectively exposes the co-pyrolysis mechanism of PVC and CE at the microlevel, which provides a theoretical supplement for resource utilization of solid waste to generate renewable energy.

All the Authors:Kuihua Han,Yongzheng Wang,Hewei Yu

First Author:Zihao Yang

Indexed by:Journal paper

Correspondence Author:Shengli Niu* (* the corresponding author)

Discipline:Engineering

First-Level Discipline:Power Engineering and Engineering Thermophysics

Document Type:J

Volume:194

Page Number:469-485

Translation or Not:no

Date of Publication:2024-12-01

Included Journals:SCI