Among the most efficient and valuable methods for treating organic solid waste is pyrolysis technology. In this study, waste tires (WTs) and waste polypropylene (WPp) were selected as experimental materials, and their pyrolysis characteristics, kinetic parameters, synergistic effects and the pattern of pyrolysis product distribution were thoroughly investigated. In contrast to single-component WTs and WPp pyrolysis procedures, the mixed pyrolysis of WTs and WPp notably extended the overall temperature range for pyrolysis. This extension significantly facilitated the separation and recovery of the resulting pyrolysis products. Moreover, the elevation in the pyrolysis temperature range resulted in the mean value of activation energy for the mixed pyrolysis of WTs/WPp being greater than that associated with the individual pyrolysis of WTs and WPp .The synergistic effect analysis showed that the WTs/WPp co-pyrolysis process mainly showed positive synergistic effect. It showed that the improved distribution of pyrolysis products was a result of the combined pyrolysis of WTs and WPp. In contrast to single-component WT and WPp pyrolysis, the actual oil yield (66.7%) from the combined WTs/WPp pyrolysis exceeded the predicted oil yield (55.3%) by 11.4%. This arose from the positive synergistic effect of the mixed pyrolysis that promoted more pyrolysis gases to be converted into pyrolysis oil. The experimental and estimate findings mentioned above can serve as a theoretical guide and source of information for the industrial pyrolysis of WTs, WPp, and WTs/WPp.

Keywords: waste plastics, waste tires, pyrolysis properties, kinetics, synergies, pyrolysis products