KINETIC STUDY OF MALT BAGASSE PYROLYSIS BY ISOCONVERCIONAL METHODS

Abstract

Biomass is considered a viable alternative for diversifying the energy matrix, and its use as fuel is due to numerous advantages, especially the neutrality related to CO₂ emissions. The production of biofuels can be made by the pyrolysis of biomass, in which the analysis of reaction kinetics is essential to elucidate the involved mechanisms for large range of operating conditions. This work presents the characterization of an agroindustrial residue, the malt bagasse (BM), and its kinetic study of pyrolysis by thermogravimetry (TG). First, the solid was grounded, sieved to particles smaller than 300 μm and characterized by proximate analysis, heating value and SEM. The waste of BM presented a fibrous, homogeneous and porous morphological structure, in addition to a low ash content (3.0%), a high volatile matter content (80.5%) and an HHV of 19.22 MJ kg^-1. The pyrolysis testes were carried out different heating rates (10, 15, 25 and 40°C min^-1), up to the final temperature of 700°C. From the TG data, it was possible to identify two main events of mass loss, dehydration and pyrolysis. The isoconversional integral models of Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose were fitted with good linearity to the experimental data of pyrolysis. The activation energies calculated by the models are in the range of 172-277 kJ mol^-1.