Kavun çekirdeği pirolizine ait kinetik parametrelerin ve termodinamik özelliklerin belirlenmesi

Abstract

The aim of this study is to examine the behaviour of melon seed pyrolysis and to calculate its kinetic parameters along with thermodynamic properties. The thermogravimetric analysis experiments were conducted from ambient temperature to 800°C under nitrogen atmosphere at the heating rates of 5, 10, 20 and 40°C/min. It was determined that the pyrolysis process underwent through four stages where the second and third stages were the active pyrolysis stages. Kinetic calculations were carried out using model-free Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, Starink and model-based Coats-Redfern methods. The apparent activation energy values of the second and third stages were calculated to be in the ranges of 123.9–215.5 and 141.9– 234.2 kJ/mol, respectively. The Coats-Redfern method demonstrated that the second and third stages fit the reaction mechanisms of F1.65 and D5, respectively. Moreover, the enthalpy, entropy and Gibbs energy changes of the active pyrolysis stages performed at 10°C/min heating rate were determined using the results calculated from the model-free kinetic methods. The results obtained in the present study will be useful to provide necessary information needed for the design of melon seed pyrolysis processes.