Kinetics of Pyrolysis of Durian (Durio zibethinus L.) Shell Using Thermogravimetric Analysis

The characteristics and kinetics of durian shell (DS) pyrolysis were investigated using non-isothermal thermogravimetric analysis (TGA). DS is a cellulose-rich biomass with high volatile matters content, which is suitable for bio-oil production. Thermal decomposition experiments were performed under nitrogen flow at various heating rates (i.e., 5 degrees C min(-1), 10 degrees C min(-1) and 20 degrees C min(-1)). The model-fitting method represented by Coats-Redfern was applied on the experimental TGA data of DS pyrolysis. The decomposition of DS was divided into three stages: first stage (59 degrees C-200 degrees C) involved removal of moisture and light volatiles; second stage (200 degrees C-400 degrees C) showed decomposition of cellulose and hemicellulose; and third stage (above 400 degrees C) presented lignin decomposition. There was 56% weight loss observed in second stage, revealing that decomposition of cellulose and hemicellulose contributed the most on volatile production. The model shows that the activation energy was between 42.08 kJ mol(-1) and 84.40 kJ mol(-1) for the second stage of the pyrolytic process from 200 degrees C to 400 degrees C using different decomposition mechanisms. The Coats-Redfern method is applied successfully for the correlation of experimental TGA data with an average correlation coefficient (R-2) of 0.991 while one-way diffusion model D1 gave the highest correlation coefficient of 0.998. DS biomass is a suitable raw material for energy or chemicals production.