Agro-industrial wastes pyrolysis:comparison of the kinetic parameters obtained applying different models

Abstract

Pyrolysis of regional agro-industrial wastes was studied using thermogravimetric analysis. Experimental data were analyzed using different kinetic methods: Kissinger, FWO, linear multiple regression and DAEM methods. The results showed that kinetic parameters values are in acceptable agreement applying different methods and can be used to understand the degradation mechanism during active pyrolysis. The E values calculated by the DAEM, FWO and Kissinger methods were higher than those obtained by the linear multiple regression method. The values of activation energy obtained from the Kissinger method are consistent with the range of values obtained by the FWO and DAEM methods and are very near to their average values (between 130.29 and 261.10 kJ/mol for all studied agro-industrial wastes). DAEM and FWO methods provides E and A distributions but linear multiple regression method provide the knowledge of kinetic triplets for each studied heating rate, presenting a slower good fit than the other methods. However, Kissinger method provides only one E and A values for all heating rates. Considering the application of FWO and DAEM methods, different kinds of reaction mechanisms are produced about a conversion values greater than 0.6-0.7 indicating the beginning of passive pyrolysis. A fluctuation of E was observed, also. All obtained results applying different methods reveal the process complexity and physical transformation the temperaturedependent or contributions of parallel reaction steps can affect this process. Experimental results showed that values of kinetic parameters are in acceptable agreement applying different methods and it could be an auspicious and justifiable feedstock for alternative methods.