Catalytic pyrolysis characteristics of scrap printed circuit boards by TG-FTIR

•Application of ZSM-5, CaO, and MgO for the catalytic pyrolysis of WPCBs is proposed.•Catalysts enhanced the mass loss and promoted the degradation of compounds.•DAEM was used to analyze the kinetic parameters of the WPCBs pyrolysis.•The whole pyrolysis process was optimized when the catalyst ZSM-5 was added.•The generated compounds under different conditions had no marked difference. In the present work, pyrolysis and catalytic pyrolysis of waste printed circuit boards (WPCBs) was carried out in the coupling of Thermo Gravimetric Analysis and Fourier Transform Infrared Spectroscopy (TG-FTIR) under nitrogen atmosphere. The reaction temperature was increased from 30 to 700°C, while the heating rates were varied from 10 to 40°C/min. Experimental results show that the effect of catalyst on the WPCBs particles pyrolysis was significance. Compared with another two combustion-supporting agents (MgO, CaO), the whole pyrolysis process was optimized when the catalyst ZSM-5 was added into the WPCBs particles. The distributed activation energy model (DAEM) was used to analyze the kinetic parameters of the WPCBs pyrolysis. It was found that values of frequency factor (k0) changed with different activation energy (E) values during pyrolysis process. The activation energy values range from 129.15 to 280.53kJ/mol, and the frequency factor values range from 9.02×1010 to 4.21×1022s−1. The generated major products for the catalytic pyrolysis of WPCBs were H2, CO2, CO, H2O, phenols and aromatics.