Kinetic and thermodynamic analyses of date palm surface fibers pyrolysis using Coats-Redfern method

This study presents the thermo-kinetics and thermodynamic analyses of date palm surface fibers (DPSFs) using thermogravimetric analysis. DPSFs were heated non-isothermally from 20 to 800 ^OC at a ramp rate of 10 ^OC/min in nitrogen atmosphere. Thermogravimetric analysis indicated that there have been two stages for pyrolysis of DPSFs. Kinetic and thermodynamic parameters have been calculated for the second stage which is further subdivided into two mass-loss regions. The low-temperature stable components were decomposed in a temperature range of 270–390 ^OC and high-temperature stable components were degraded in a temperature range of 390–600 ^OC. The Coats–Redfern integral method was employed with 21 different kinetic models from four major solid-state reaction mechanisms. Among all models, the two diffusion models: Ginstling–Brounshtein and Ginstling diffusion were the best fitted models with highest regression coefficient values (R² > 0.99) in both mass-loss regions. For mass-loss regions: I (270–390 ^OC) and II (390–600 ^OC), the activation energy values were found to be 96–98 and 113–114 kJ/mol, respectively. Thermodynamic parameters (ΔH, ΔG, ΔS) were calculated using kinetic data. The findings reported herein are helpful in characterizing date palm fibers as a source of energy, designing reactors, producing chemicals, and understanding the properties of surface fibers for making composites.