Pirólise não-isotérmica de resíduo da colheita do milho por termogravimetria: caracterização e estudo cinético utilizando modelos isoconversionais integrais

Abstract

The Biomass can be a great alternative to substitution of fossil fuels because it is known as sustainable and renewable fuel, besides having low emission of pollutants, contributing to low emissions of greenhouse gases. The prodution of biofuels can be obtained through biomass pyrolysis, and for that it is necessary to know the kinetic parameters. In this work, the kinetic study of pyrolysis of corn crop residue was carried out in experiments in thermogravimetric analyzer (TGA) for four heating rates (10, 15, 25 and 40°C/min) until the final temperature of 900°C. The pyrolysis results was demonstrated through TG and DTG curves, where was possible to verify mass losses during the process of pyrolysis, as well as the temperature of each peak of mass loss. From the thermogravimetric data, it was possible to calculate the activation energy (𝐸𝑎) for each conversion (in the pyrolysis range of 150-600° C) using the integral isoconversional methods of FlynnWallOzawa (FWO), KissingerAkahiraSunose (KAS) and Starink (STK). The values found for 𝐸𝑎 are between 124.73–328.46 kJ/mol for the RCM, considering the three models evaluated. Upon immediate analysis, it was possible to verify that the RCM has a high content of volatile material, 78.93%. The biomass has a theoretical PCS and PCI of 19.39 MJ / kg and 17.40 MJ / kg, respectively. In addition, the biomass sample has H / C values of 1.47 and O / C of 0.68, being considered energy efficient.