From chain-length stochastic simulations to carbon-number product distributions in polypropylene pyrolysis: A kernel-based Monte Carlo modeling framework
Year: 2026
Type: article
Abstract: Polypropylene pyrolysis involves complex free-radical degradation mechanisms that govern the evolution of product distributions. In this work, a stochastic kinetic Monte Carlo framework is developed to investigate polypropylene pyrolysis while enabling consistent comparison between intrinsic chain-length simulations and experimentally accessible carbon-number distributions. Direct comparison between chain-length-resolved stochastic simulations and experimentally reported carbon-number product distributions remains a major challenge in polymer pyrolysis modeling. The model incorporates a reduced free-radical degradation mechanism within a chain-resolved stochastic formulation, allowing molecular transformations and molecular-weight distribution evolution to be tracked during pyrolysis. Reactor-level reflux effects are represented through a probabilistic formulation based on a probability function (PF), capturing the influence of evaporation and reflux-dependent fragment removal on product selectivity. A mass-conserving chain-length to carbon-number (CL–C) kernel mapping procedure, supported by Centered Log-Ratio (CLR)-based comparison of compositional distributions, is introduced to connect intrinsic simulation outputs with experimentally reported product windows. The proposed framework is assessed against experimental polypropylene pyrolysis data obtained in a semi-batch reflux reactor heated at 480°C, using the PF values selected for each reflux condition and the corresponding optimized kernel widths. Good agreement is obtained for both overall product yields (C1–C4, C5–C7, and C8+) and detailed carbon-number distributions within the GC-resolved window across multiple reflux conditions. The results demonstrate that variations in product selectivity across reflux regimes can be consistently captured through monotonic adjustment of the PF parameter, providing mechanistic insight into the coupling between intrinsic degradation kinetics and reactor-level effects in polypropylene pyrolysis.
Language: English
Topic: Thermal and Kinetic Analysis
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,050
OpenAlex ID: W7225331603