Pyrolysis kinetics and mechanism of typical industrial non-tyre rubber wastes by peak-differentiating analysis and multi kinetics methods

Abstract

Pyrolysis is increasingly employed to dispose rubber wastes by thermal cracking into chemicals. Previous studies focus on pyrolysis recycling of tyre rubber wastes. The pyrolysis of non-tyre rubber wastes, which may be different from that of tyre rubber wastes, receives scarce attention. For the purpose of providing guidance for thermo-chemical process management for the pyrolysis recycling of non-tyre rubber wastes, the pyrolysis kinetics and mechanism of representative industrial non-tyre rubber wastes namely the mixture of waste hoses, floor coverings and sealing strips are investigated using thermogravimetry in nitrogen and peak-differentiating analysis with Guassian function. Multi kinetics methods are adopted. Results indicate that three peaks and three shoulders occur in the reaction rate curves. Guassian function is capable to well separate the pyrolysis of non-tyre rubber wastes mixture into six independent one-step sub reactions. The six sub reactions may be characterized by traditional power law model and nucleation mechanism. However, the pyrolysis of non-tyre rubber wastes mixture may be well characterized employing a modified power law model f(α)=1.89×10-5α-1.19 and nucleation mechanism. The average value of activation energy and pre-exponential factor for the whole pyrolysis process of non-tyre rubber wastes mixture is 97.77 kJ/mol and 1.37 × 1010 min−1, respectively.