Thermal treatment of solid waste plastic has been widely recognized as an environmentally friendly method of converting the inherent polymer units into fuel or chemicals. In the proposed study, the co-pyrolysis of printed circuit boards (PCB) and used tires (WT) was carried out using thermogravimetry (TG) and pyrolysis gas chromatography / mass spectrometry. PCB and WT were mixed in different ratios to investigate synergistic effects on product properties and heteroatom migration. The TG results show that the PCB / WT blends shifted the PCB decomposition peak from 325 to 357 ° C, but accelerated the WT decomposition in the later stages. The pyrolysis products of PCB consisted of phenolic and brominated compounds, while in WT pyrolysis olefins were the predominant products. The addition of WT significantly improved the formation of small phenols at the expense of bisphenol A, which led to a 40–51% and 24–92% increase in phenol and p-isopropylphenol production, respectively. Meanwhile, the production of key compounds from WT pyrolysis, including isoprene and D-limonene, has been significantly reduced, suggesting that the H donor sources in WT may be beneficial for further degradation of the PCB, while phenol production may be improved. In addition, the co-pyrolysis of PCB and WT led to a 26–47% and 50–59% decrease in tetrabromobisphenol A and benzothiazole production, which indicates the excellent removal of toxic compounds. The characterization of the pyrolytic coal showed that co-pyrolysis was beneficial for the conversion of sulfur compounds to sulfates, while the addition of 75% by weight was able to capture 12 times the amount of bromine in the coal. The results suggest that co-pyrolysis of PCB and WT may be a potential treatment to restore high phenol production in low bromine oils.

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