Study on pyrolysis characteristics and kinetics of mixed plastic waste

Different types of plastic wastes have caused serious environmental problems. Co-pyrolysis and separation techniques are being widely used because of the complex components of plastic wastes. In this study, Thermogravimetric Analysis for mixed plastics with different compositions (Polypropylene/Polyvinyl chloride and Polypropylene/Polyvinyl chloride/Polystyrene mixtures) was carried out under three heating rates. Aiming at the complex pyrolysis reaction process of mixed plastics, a model-free method and a model-fitting method were combined to obtain the complete kinetics, which makes the results more reliable. The activation energy of the mixture pyrolysis process was carried out by the model-free method, and two stages of pyrolysis mechanism functions were summarized in the model-fitting method. Verification test proves that the mechanism function of this research can be reliable to express the pyrolysis reaction process. This research can provide support for the optimization of pyrolysis process parameters and the design of pyrolysis reactors for chlorine-containing mixed plastics.