Gas-solid pyrolysis of tire wastes — Kinetics and material balances of batch pyrolysis of used tires

Pyrolysis processes have been proposed for converting tire wastes into valuable products, particularly through gas-solid contact in various reactor designs. In this paper, the pyrolysis reaction is analyzed in terms of physical and chemical kinetics. A specific method is described for experimentally studying the kinetics of pyrolysis of tire chips. Pyrolysis time is examined as a function of temperature and sample size for determining limitations of the process: heat transfer and chemical kinetics. Conversion curves are modelled and discussed. As a technical basis for evaluating the realistic potential of any industrial batch process, pyrolysis of used tires is studied in a pilotscale unit (100-L retort reactor). Results of material balances as well as quality of products are presented.