Kinetic and Thermodynamic Analysis of Thermal Decomposition of Deodar (Cedrus Deodara) Saw Dust and Rice Husk as Potential Feedstock for Pyrolysis

Abstract

Abstract A comparative study on thermal analysis of two waste biomass materials of Kashmir namely deodar (Cedrus deodara) saw dust (DSD) and rice husk (RH), was carried out at different heating rates of 10, 25, 50 and 100 °C min−1 in air and nitrogen atmospheres. The onset, peak and burnout temperatures and rates of decomposition of components were determined and compared to understand the combustion and pyrolysis kinetics of selected biomass materials using iso-conversional Kissinger-Akahira-Sunose (KAS) and Ozawa-Flynn-Wall (OFW) models. The kinetic parameters calculated were in turn used to calculate the changes in thermodynamic parameters, the enthalpy (ΔH), the Gibbs free energy (ΔG) and the entropy (ΔS). The physicochemical characterisation was carried out by elemental analyser and FTIR spectroscopy. The average activation energy values for RH were found to be 107.6 and 101.2 kJ mol−1 in air atmosphere and 85.5 and 92.1 kJ mol−1 in nitrogen atmosphere based on KAS and OFW models, respectively. The activation energy for DSD on the other hand was found to be 89.9 and 95.3 kJ mol−1 in air, 179.2 and 180.6 kJ mol−1 under nitrogen atmosphere based on KAS and OFW models, respectively. The heating values of the two biomasses (~ 10 to16 MJ kg−1) and Gibbs free energy values (between 165 to 176 kJ mol−1) indicate that the selected biomass can not only prove to be potential feedstock for pyrolysis but also can become a useful source of energy and chemicals.