A bench-scale, continuous reactor for reductive polyolefin depolymerization
5 affiliations
- 1Department of Chemical Engineering
- 2Massachusetts Institute of Technology
- 3Renewable Resources and Enabling Sciences Center
- 4National Laboratory of the Rockies
- 5BOTTLE Consortium
Abstract
Catalytic deconstruction of polyolefins is central to chemical recycling, but most laboratory studies use batch reactors that obscure kinetics and limit reproducibility. Flow operation enables rigorous measurement of rates and selectivities, yet processing viscous polymer melts at small scales remains challenging. Here we present a laboratory-scale flow reactor that couples a hydraulic melt pump to a stirred-tank vessel, enabling continuous and semi-continuous operation at high pressure. The system achieves pseudo-steady state, where volatile production rates reflect C–C scission kinetics, validated by a first-principles model. Using this reactor with H-ZSM-5, we demonstrate three features of polyethylene hydrocracking difficult to probe in batch systems, namely that alkene selectivities exceed batch reactions by nearly tenfold, hydrogen availability within the melt governs the balance between alkene and alkane products, and catalyst acidity and crystallite size jointly tune this product balance through intermediate diffusion from the zeolite. This reactor provides a platform for kinetic and mechanistic studies of catalytic polymer deconstruction.
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BibTeX
@misc{drake2026benchscale,
title = {{A bench-scale, continuous reactor for reductive polyolefin depolymerization}},
author = {Griffin Drake and Juliana Lu-Yang and Anna E. Brenner and Joel Miscall and Gregg T. Beckham and Yuriy Román-Leshkov},
howpublished = {ChemRxiv},
year = {2026},
month = sep,
doi = {10.26434/chemrxiv.15009124/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009124/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - A bench-scale, continuous reactor for reductive polyolefin depolymerization
AU - Griffin Drake
AU - Juliana Lu-Yang
AU - Anna E. Brenner
AU - Joel Miscall
AU - Gregg T. Beckham
AU - Yuriy Román-Leshkov
PY - 2026
DA - 2026/09/21
PB - ChemRxiv
DO - 10.26434/chemrxiv.15009124/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009124/v1
AB - Catalytic deconstruction of polyolefins is central to chemical recycling, but most laboratory studies use batch reactors that obscure kinetics and limit reproducibility. Flow operation enables rigorous measurement of rates and selectivities, yet processing viscous polymer melts at small scales remains challenging. Here we present a laboratory-scale flow reactor that couples a hydraulic melt pump to a stirred-tank vessel, enabling continuous and semi-continuous operation at high pressure. The system achieves pseudo-steady state, where volatile production rates reflect C–C scission kinetics, validated by a first-principles model. Using this reactor with H-ZSM-5, we demonstrate three features of polyethylene hydrocracking difficult to probe in batch systems, namely that alkene selectivities exceed batch reactions by nearly tenfold, hydrogen availability within the melt governs the balance between alkene and alkane products, and catalyst acidity and crystallite size jointly tune this product balance through intermediate diffusion from the zeolite. This reactor provides a platform for kinetic and mechanistic studies of catalytic polymer deconstruction.
ER -