Decoding the Hydrogen-Transfer Synergy in Camellia oleifera Shell Hydrochar/HDPE Co-Pyrolysis: A Kinetic and Thermodynamic Perspective
9 affiliations
- 1College of Resource & Environment, Shanxi Agricultural University, Taiyuan 030031, China
- 2Institute of Eco-Environment and Industrial Technology, Shanxi Agricultural University, Taiyuan 030031, China
- 3Soil Health Laboratory in Shanxi Province, Taiyuan 030031, China
- 4School of Chemical Engineering of Technology, Tianjin University, Tianjin 300350, China
- 5School of Energy and Power Engineering, Shandong University, Jinan 250061, China
- 6Osmani & Company (Pvt.) Ltd., Karachi 75400, Pakistan
- 7School of Civil Engineering, Guangzhou University, Guangzhou 510006, China
- 8College of Natural Science, Arba Minch University, Arba Minch 21, Ethiopia
- 9Shanxi Agricultural University, Taiyuan 030031, China
Abstract
This study examined the co-pyrolysis of high-density polyethylene (HDPE) and hydrochar from Camellia oleifera shell (HCS), focusing on thermal decomposition behavior, non-isothermal kinetics, thermodynamics, and the interaction mechanism between the two feedstocks. Hydrothermal carbonization raised the heating value of Camellia oleifera shell from 18.07 MJ/kg (raw CS) to 20.80 MJ/kg (HCS), confirming its fuel-upgrading effect, while HDPE alone reached 46.40 MJ/kg. TG-DTG analysis of HDPE, HCS, and their blends at five HCS:HDPE mass ratios (1:9, 3:7, 5:5, 7:3, and 9:1, denoted 1HCS9HDPE through 9HCS1HDPE) at 5–25 °C/min showed a single sharp decomposition stage for HDPE, a broader profile with much higher char yield for HCS, and non-additive DTG behavior in the blends, pointing to a synergistic interaction. Isoconversional kinetics (FWO, KAS, Starink, Friedman) showed activation energy rising steadily with conversion for HDPE (170–240 kJ/mol), a plateau-then-sharp-rise pattern for HCS (180–400 kJ/mol), and marked fluctuations at intermediate conversion for the balanced blends, a signature of composition-dependent synergy. Thermodynamic analysis (ΔH, ΔG, ΔS) confirmed an endothermic, non-spontaneous process throughout, with entropy trends mirroring the kinetic fluctuations. A hydrogen-radical transfer mechanism between HDPE- and hydrochar-derived intermediates is proposed to explain the reduced char yield and non-additive behavior of the blends. Overall, the results support hydrochar–HDPE co-pyrolysis as a viable route for combined agricultural and plastic waste valorization and provide kinetic and mechanistic data to guide co-pyrolysis process design.
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BibTeX
@article{kumar2026decoding,
title = {{Decoding the Hydrogen-Transfer Synergy in Camellia oleifera Shell Hydrochar/HDPE Co-Pyrolysis: A Kinetic and Thermodynamic Perspective}},
author = {Akash Kumar and Lata Kumari and Asma Leghari and Azhar Ali Laghari and Imtiaz Ali Jamro and Moses Akintayo Aborisade and Belay Tafa Oba and Qiuxia Meng and Qiang Zhang},
journal = {Polymers},
year = {2026},
month = oct,
doi = {10.3390/polym18192423},
url = {https://europepmc.org/article/PMC/PMC13666892},
note = {CC BY},
}
RIS
TY - JOUR
TI - Decoding the Hydrogen-Transfer Synergy in Camellia oleifera Shell Hydrochar/HDPE Co-Pyrolysis: A Kinetic and Thermodynamic Perspective
AU - Akash Kumar
AU - Lata Kumari
AU - Asma Leghari
AU - Azhar Ali Laghari
AU - Imtiaz Ali Jamro
AU - Moses Akintayo Aborisade
AU - Belay Tafa Oba
AU - Qiuxia Meng
AU - Qiang Zhang
PY - 2026
DA - 2026/10/01
JO - Polymers
DO - 10.3390/polym18192423
UR - https://europepmc.org/article/PMC/PMC13666892
AB - This study examined the co-pyrolysis of high-density polyethylene (HDPE) and hydrochar from Camellia oleifera shell (HCS), focusing on thermal decomposition behavior, non-isothermal kinetics, thermodynamics, and the interaction mechanism between the two feedstocks. Hydrothermal carbonization raised the heating value of Camellia oleifera shell from 18.07 MJ/kg (raw CS) to 20.80 MJ/kg (HCS), confirming its fuel-upgrading effect, while HDPE alone reached 46.40 MJ/kg. TG-DTG analysis of HDPE, HCS, and their blends at five HCS:HDPE mass ratios (1:9, 3:7, 5:5, 7:3, and 9:1, denoted 1HCS9HDPE through 9HCS1HDPE) at 5–25 °C/min showed a single sharp decomposition stage for HDPE, a broader profile with much higher char yield for HCS, and non-additive DTG behavior in the blends, pointing to a synergistic interaction. Isoconversional kinetics (FWO, KAS, Starink, Friedman) showed activation energy rising steadily with conversion for HDPE (170–240 kJ/mol), a plateau-then-sharp-rise pattern for HCS (180–400 kJ/mol), and marked fluctuations at intermediate conversion for the balanced blends, a signature of composition-dependent synergy. Thermodynamic analysis (ΔH, ΔG, ΔS) confirmed an endothermic, non-spontaneous process throughout, with entropy trends mirroring the kinetic fluctuations. A hydrogen-radical transfer mechanism between HDPE- and hydrochar-derived intermediates is proposed to explain the reduced char yield and non-additive behavior of the blends. Overall, the results support hydrochar–HDPE co-pyrolysis as a viable route for combined agricultural and plastic waste valorization and provide kinetic and mechanistic data to guide co-pyrolysis process design.
SN - 2073-4360
ER -