Thermal Degradation Analysis of Mamoncillo (Melicoccus bijugatus) Waste: Thermal Behaviors, Kinetics, and Thermodynamics

This research studied the thermal conversion characteristics, kinetics, and thermodynamics of mamoncillo peels and seeds using non-isothermal thermogravimetric analysis. Kinetic analysis was performed using the Kissinger-Akahira-Sunose, Flynn-Wall-Ozawa, Starink, and Friedman methods. The reaction kinetic models were obtained by means of the master-plots method for 18 different empirical reaction models, calculating the enthalpy, Gibbs free energy, and entropy as thermodynamics parameters. It was found that the average activation energy for mamoncillo peels and seeds was 238,71 and 197,60 kJ/mol, respectively. The frequency factor was found to be between 109 and 1031 s-1 for mamoncillo peels and between 109 and 1034 s-1 for mamoncillo seeds. The average values of DH and DG were also found to be 233,83 and 192,81 kJ/mol and 164,84 and 162,10 kJ/mol for mamoncillo peels and seeds, respectively. The reaction kinetic models regarding the thermal decomposition of mamoncillo peels were found to be described by the contracting cylinder (R2) and third-order (F3) models, while those for mamoncillo seeds can be described by the second-order (F2) and contracting sphere (R3) models. It was concluded that the pyrolysis process of mamoncillo waste can be described by a complex reaction mechanism, and that these wastes have thermal properties with the potential to produce bioenergy.