ABSTRACT
The co-pyrolysis of waste tires (WT) with waste lubricating oil (WLO) can significantly improve the quality of products. The co-pyrolysis behavior of WT and WLO was investigated by using thermogravimetric analyzer. Three isoconversional methods, Flynn–Wall–Ozawa, Friedman and Kissinger–Akahira–Sunose, were used to calculate the activation energy of the mixture at the heating rates of 5, 10, 15, and 20K/min. The obtained data were used to determine the kinetic model and thermodynamic parameters. The results showed that WLO promoted the pyrolysis of WT. The synergistic effect was shown in the reduction of the activation energy of the mixture by 10%. The mean activation energy of the main decomposition stage is 90.8 kJ/mol. Moreover, the thermodynamic stability of reaction was determined by the calculation of change in entropy, Gibbs free energy, and enthalpy. The value of pre-exponential factor is 2.48 × 107/min, which means that the co-pyrolysis reaction is not a complex interface reaction. Among all the models, the 3D diffusion model best fits the co-pyrolysis mechanism judging by Malek master plot method. The reaction function was also determined. This study will provide basic knowledge into the co-processing of WT and WLO for predicting the performance of reactor and simulating the process.
Nomenclature and Abbrevation
α | = | Conversion rate |
t | = | Reaction time |
k(T) | = | Reaction rate constant depending on the temperature |
ΔH,ΔS,ΔG | = | Changes in enthalpy, entropy, Gibbs free energy |
∆W | = | Mass loss between the theoretical and experimental |
A | = | Pre-exponential factor |
DTG | = | Differential thermogravimetric analysis |
Eα | = | Activation energy |
FWO | = | Flynn–Wall–Ozawa |
HHV | = | High-heating value |
KAS | = | Kissinger-Akahira-Sunose |
NR | = | Natural rubber |
R | = | Ideal gas constant |
R2 | = | Correlation coefficient |
SBR | = | Styrene butadiene rubber |
TG | = | Thermogravimetric analysis |
T | = | Absolute temperature |
WLO | = | Waste lubricating oil |
WT | = | Waste tires |
Acknowledgements
The authors wish to acknowledge the financial support from the Natural Science Foundation of Shandong Province (ZR2019MEE015) and 2020 Science and Technology Project of QingdaoWest Coast New Area (2020-99).
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Notes on contributors
Junzhi Wang
Junzhi Wang is currently studying for a doctorate at Qingdao University of Technology, China. He received a bachelor's degree in energy and power engineering from Qingdao University of Technology and a master's degree in architecture and civil engineering. His current research interests include waste heat utilization, Thermochemistry conversion of biomass and solid waste treatment.
Xiaowen Qi
Xiaowen Qi is currently studying for a doctorate at Qingdao University of Technology, China. His research interest is Thermochemistry conversion of biomass.
Xinjiang Dong
Xinjiang Dong is currently studying for a master's degree at Qingdao University of Technology, China. His research interests are waste heat utilization and solid waste treatment.
Kai Zhang
Kai Zhang currently works in the Technical Research and Development Department of Baowu Group Environmental Resources Technology Co., Ltd. in Shanghai, China. She received her bachelor's degree in environmental science from Qingdao University of Technology. He obtained a master's degree in environmental science from Tongji University. Her research interest is soil remediation.
Siyi Luo
Siyi Luo is currently an associate professor and doctoral supervisor of Qingdao University of Technology. Doctor and Master graduated from Huazhong University of Science and Technology. Obtained a Bachelor's degree from Wuhan University of Science and Technology. Director of the Key Laboratory of Energy and Environment of Shandong Province, Director of the Department of Energy and Power Engineering of Qingdao University of Technology. His main research directions are the utilization of metallurgical slag waste heat, the utilization of solid waste resources for energy, and the development and utilization of biomass energy.