Abstract

The kinetics of the pyrolysis process of sheep manure were investigated using Thermogravimetric Analysis in this work. It was heated at 30^°C to 900°C with a heating rate of 10^°C/min. There are two stages of mass degradation, namely dehydration and devolatilization. The temperature dehydration stage is 30°C–140°C while the devolatilization stage is 210°C–900°C. However, at temperatures >500°C, mass degradation decreases until it reaches 900°C. This indicates that most of the volatile matter has disappeared at this temperature. The devolatilization stage includes the decomposition of hemicellulose and cellulose (210°C–900°C) and lignin (>590°C). The calculated activation energy from Friedman's non-conversional method is 21.32 kJ/mol and Coast-Redfern is 26,20 kJ/mol, while the frequency factor value is 9.94.10¹⁸ s^-1 for Friedman and 3.42.10¹⁸ for Coast-Redfern Method which indicates that the pyrolysis process of sheep manure is a complicated phenomenon. The estimated activation energy value is then used to calculate thermodynamic properties e.g., Gibbs free energy, enthalpy, and entropy.