Kinetic and Thermogravimetric Analysis of Rice Husk and its Derived Biochar

Abstract

This study aims to investigate the thermal properties of rice husk and rice husk biochar. It accelerates heating rates at 5, 10, 20, and 30 °C/min in an inert atmosphere with a conversion ratio of 0.1 to 1. To determine the thermodynamic and kinetic parameters, three model-free methods were used: Flynn-Wall-Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), and Starink. Between 168 and 390°C, 40–55% of the mass loss was attributed to the active pyrolysis zone. As a result, rice husk biomass has an average activation energy of 179.88, 179.59, and 176.81 kJ/mol. In addition, rice husk biochar has an average activation energy of 77.05, 75.72, and 74.14 kJ/mol, respectively, in the FWO KAS and Starink models. The average enthalpy values of rice husk were 174.44 kJ/mol for the FWO, 174.14 kJ/mol for the KAS, and 171.36 kJ/mol for the Starink methods.