Study on coupled combustion behaviors and kinetics of plastic pyrolysis by-product for oil

Abstract

The pyrolysis of waste plastics alleviates the ecological pollution of plastics. In addition to the high-quality oil component of the target product, there are solid residues from incomplete pyrolysis. These residues have a great potential as fuels due to their high carbon content and partial oil content. Currently, few studies have focused on the rational utilisation of waste plastics pyrolysis by-products, especially the simultaneous combustion of carbon and oil and their coupled combustion mechanisms. In this paper, the combustion performance of plastic pyrolysis residues with different particle sizes was firstly evaluated and the TG-DTG curves were kinetically analysed. The melting characteristics of the ashes were observed by XRD and SEM. It was found that the samples showed better combustion performance as the particle size increased. However, the particle size had less effect on the combustion of the residue after plastic pyrolysis, with multiple peaks of weight loss during the combustion process. Oil-carbon coupling characteristic promotes combustion reaction. In addition, the activation energy of combustion of the residue after plastic pyrolysis is low according to the kinetic parameters. Therefore, plastic pyrolysis residue has the advantage of low combustion point compared to coal and is an ideal fuel.