A review on kinetic study approach for pyrolysis of plastic wastes using thermogravimetric analysis

The necessity of balancing in consumption and recycling process is evident to manage the life cycle of plastics wastes. Obtaining approaches for plastics degradation with the aim of energy recovery and produce value-added materials to close the waste loop gained attention in recent years and among, pyrolysis is the promising way to thermal degradation of plastics. Pyrolysis of plastics still lacks the proper design and kinetic background to target certain value added chemicals. Perspective knowledge of plastics degradation mechanism helps to select suitable kinetic models to fit the thermogravimetric data in which not only meet statistics parameters but can justify mechanistic chemistry of feedstock pyrolysis. Since thousands of reaction may occur during pyrolysis of polymers, reduction the number of reactions in moment model is essential, thus mechanistic chemistry models of typical polymers can be obtained by analyze of abundance of pyrolysis products. Thermogravimetric analysis is an effective way to quantify rates of devolatilization and several TGA curves at different heating rates and thermal schedule required to determine kinetic parameters. Different kinetic methods including isoconversional methods, model fitting and random scission are investigated in details for typical plastics. In this paper, comprehensive study on kinetic methods and models were carried out and deduct that using random scission model in combined kinetic method describe nearly real interpretation of waste plastics degradation. This route can shorten the path to design processes for pyrolysis of plastics wastes by performing different thermal schedules in TGA experiments including isothermal, constant heating rate sample controlled thermal analysis (SCTA).

Automated summary

The importance of balancing consumption and recycling to manage the life cycle of plastics wastes is evident. Pyrolysis is a promising way to thermal degradation of plastics for energy recovery and production of value-added materials. Comprehensive studies on kinetic methods and models are necessary to accurately describe waste plastics degradation.