Kinetic and Thermodynamic Analyses of Co-Pyrolysis of Nylon-Polyethylene Pouch Wastes

In this study, thermogravimetric measurements of nylon-6/polyethylene double-layer pouch wastes were conducted in N-2 under a constant heating-rate mode, and the multiple heating-rate results were analyzed in terms of degradation features and specific temperatures. Experimental results show that the waste pyrolysis involves one reaction stage, and all specific parameters appear to increase with the heating rate. Kinetic analysis of non-isothermal data was thoroughly performed using various isoconversional model-free methods for the calculations of the activation energy, resulting in 143 similar to 215 kJ/mol over the whole pyrolysis process. By means of the model-fitting method, the reaction mechanism model g(alpha) and pre-exponential factor lnk(0) are concurrently determined with the aid of the linear compensation effect. With such methodology proposed, the Avrami-Erofeev kinetic model A(3/2) of g(alpha) = [-ln(1 - alpha)](2/3) is found to be the most appropriate mechanism function for describing the pyrolysis of the nylon-6/polyethylene waste along with lnk(0) of 23.14 to 34.26 min(-1). With the Arrhenius parameters thus obtained, the predictions were made and performed very satisfactorily to correlate experimental results. Additionally, the service life and thermodynamic parameters over the entire pyrolysis process were also estimated.

Automated summary

This study conducted experimental measurements and kinetic analysis of the pyrolysis process of nylon-6/polyethylene double-layer pouch wastes. By utilizing various isoconversional model-free methods, the most appropriate mechanism function and kinetic parameters were identified, and the experimental results were accurately predicted. The study also estimated the service life and thermodynamic parameters of the pyrolysis process.