Study of the kinetic parameters of thermal and oxidative degradation of various residual materials

Abstract

The thermal decomposition of three biomass residues was studied in this work: cork powder, paper sludge and sewage sludge. Firstly, characterization of the materials was carried out by elemental and proximate analysis and FT-IR spectroscopy. Experiments were carried out in a thermobalance to obtain thermogravimetric curves (TG) and differential thermogravimetric curves (DTG). Two different types of atmosphere were investigated: pyrolysis (100% N2) and combustion (80% N2 20% O2). The effect of the heating rate (5 K min−1, 10 K min−1 and 20 K min−1) was also investigated. Moreover, important combustion parameters were calculated, namely ignition and burnout temperatures and calorific value. A model was proposed for each of the materials and atmospheres in order to calculate the kinetic parameters. The proposed model fitted adequately to the obtained experimental data in all cases, giving and R2 higher than 0.995 and 0.9858 in TG and DTG curves respectively.