Pyrolysis Characteristics and Non-Isothermal Kinetics of Integrated Circuits

Ziwei Chen; Linhao Liu; Hao Wang; Lili Liu; Xidong Wang

doi:10.3390/ma15134460

Pyrolysis Characteristics and Non-Isothermal Kinetics of Integrated Circuits

Materials (Basel). 2022 Jun 24;15(13):4460. doi: 10.3390/ma15134460.

Authors

Ziwei Chen^{1

2}, Linhao Liu³, Hao Wang⁴, Lili Liu^{1

2

5}, Xidong Wang^{1

2

5}

Affiliations

¹ Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871, China.
² Beijing Key Laboratory for Solid Waste Utilization and Management, Peking University, Beijing 100871, China.
³ Energy Bureau of Guangdong Province, Guangzhou 510030, China.
⁴ School of Energy and Environmental Engineering, University of Science & Technology Beijing, Beijing 100083, China.
⁵ School of Materials Science and Engineering, Peking University, Beijing 100871, China.

Abstract

Due to the complexity of components and high hazard of emissions, thermochemical conversions of plastics among waste-integrated circuits (ICs) are more favorable compared with the common treatment options of electronic waste (E-waste), such as chemical treatment and burning. In this study, the waste random-access memory, as the representative IC, was used to investigate the thermal degradation behaviors of this type of E-waste, including a quantitative analysis of pyrolysis characteristics and non-isothermal kinetics. The results show that the pyrolysis of the ICs can be divided into three different decomposition stages. The pyrolysis temperature and gas atmosphere play an important role in the pyrolysis reaction, and the heating rate greatly affects the rate of the pyrolysis reaction. The non-isothermal kinetic parameters and reaction mechanisms of ICs are determined using the Friedman method, Coats and Redfern (CR) method, and Kissinger method. The results show that the actual average activation energy of the pyrolysis reaction of ICs should be between 170 and 200 kJ·mol^-1. The optimally fitting model for the ICs pyrolysis is the three-step parallel model consisting of the random nucleation model (A_m) and reaction order model (C_n).

Keywords: electronic waste; non-isothermal kinetics; pyrolysis characteristics; waste integrated circuits.

Grants and funding

This research was funded by the National Key Research and Development Plan of China (2018YFC1901505 and 2018YFC1901503), Shanxi Unveiling Bidding Project (20191101007), Ministry of Land and Resources Public Welfare Industry Research Project (201511062-02), and National Natural Science Foundation of China (51672006).