Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
ISOCONVERSIONAL MODELING FOR DETERMINING PYROLYSIS KINETIC AND THERMODYNAMIC PARAMETERS OF BIOMASS RESIDUES
Submission Author:
Mayara Gabi Moreira , DF
Co-Authors:
Mayara Gabi Moreira, Giulia Lamas, EDGAR AMARAL SILVEIRA, Pedro Oliveira
Presenter: Mayara Gabi Moreira
doi://10.26678/ABCM.COBEM2023.COB2023-0904
Abstract
Biomass is promising as a green energy vector, as it is renewable, with high availability, and a safe source not subject to changes in price and supply in the foreign market and reducing dependence on oil. For biomass conversion processes to operate under conditions of maximum efficiency, a thorough understanding of biomass’s kinetic and thermodynamic parameters is required. One of the techniques for obtaining this data is the use of isoconversional methods, which allow obtaining these parameters without the need to assume a reaction model through experimental results of thermal degradation with at least three different heating rates. Therefore, this work aims to perform and validate the numerical resolution of four methods: Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa method (FWO), Starink and Friedman. For this, a Python routine was developed. The data used were taken from the literature and referred to the pyrolysis of corn stalks. The activation energy values varied significantly with the conversion in the same way as the reference, with an average error of less than 0.5% for the results of the KAS’s, FWO’s and Starink’s methods and an error of about 3% for Friedman’s method. As for the pre-exponential factor, the results showed the same variation between 10^11 and 10^19 s–1. The errors of the KAS, FWO and Starink methods were less than 0.2%, 0.1% and 10% concerning enthalpy, Gibbs free energy and entropy, respectively. However, these errors were significantly higher for Friedman’s method, reaching an average error of 117% for entropy. Thus, it is evident that the results of the first three methods were satisfactory and that the numerical routine was performed adequately. However, Friedman’s method presents considerably discrepant values. In the literature, the results for this method are often divergent from the others. Therefore, numerical resolution of the KAS’s, FWO’s and Starink’s methods is recommended to obtain the kinetic and thermodynamic parameters.
Keywords
isoconversional methods, Biomass, numerical resolution
