Browsing by Author "Ghernaout, Djamel"

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    Forecasting the thermal degradation depending on the kinetics of dracaena Draco lignocellulosic fibers using an artificial neural network
    (Journal of Natural Fibers;Taylor &Francis, 2025-07-17) Hadou, Abdelwaheb; Belaadi, Ahmed; Ghernaout, Djamel; Mukalazi, Herbert
    In order to forecast the thermal degradation of Dracaena draco plant fibers (DDFs) using thermogravimetric analysis (TGA) at heating rates ranging from 5 to 30°C/min, this study employed artificial neural networks (ANNs). Hemicellulose, cellulose, and lignin break-down were represented by the three different degradation stages that were seen. The enhanced ANN27 model successfully captured pyrolysis behavior and degradation patterns, achieving a high prediction accuracy (R2 = 0.99966). The model performed well at lower heating rates (5 and 10°C/min), but because of bias and heteroscedasticity, adjustments are required at higher rates (15–30°C/min). In contrast to the experimental averages of 131.244 kJ/mol, 109.269 kJ/mol, and 131.694 kJ/mol, respectively, kinetic analysis showed that the ANN27-predicted activation energies (Ea) were 133.420 kJ/mol (KAS), 53.692 kJ/mol (FWO), and 133.784 kJ/mol (STR). Without requiring a lot of testing, our ANN method provides insights into DDF thermal behavior and optimizes processing settings by properly forecasting degradation curves
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    Unraveling the Pyrolysis mechanisms of Syagrus palm waste fibers through Gaussian deconvolution and kinetic modeling
    (Journal of Natural Fibers, 2025-09-22) Ferfari, Oussama; Belaadi, Ahmed; Alshahranib, Hassan; Ghernaout, Djamel; Mukalazi, Herbert
    The thermal decomposition kinetics and thermodynamics of Syagrus romanzoffiana waste rachis fibers (SrWRFs) were investigated through thermogravimetric analysis in a nitrogen atmosphere at heating rates (β) of 30, 40, and 50°C/min. The Coats–Redfern method was employed to determine kinetic parameters, including activation energy (Ea), pre-exponential factor (A), and reaction mechanisms. In contrast, thermodynamic properties such as enthalpy change (ΔH), Gibbs free energy (ΔG), and entropy change (ΔS) have been derived to evaluate the energy requirements and spontaneity of the pyrolysis process. A three-parallel Gaussian reaction model was employed to deconvolute the degradation profiles of hemicellulose, cellulose, and lignin, revealing distinct temperature intervals for each component: hemicellulose (200–345°C), cellulose (305–398°C), and lignin (220–650°C), with high fitting accuracy (R2 ≥ 0.99537). The kinetic analysis identified sigmoidal rate (SR) models (SR6, SR7, and SR8) as the most suitable, yielding Ea values ranging from 97.31 to 262.11 kJ/mol, which increased with higher heating rates. Thermodynamic results indicate that SrWRF pyrolysis is endothermic (ΔH > 0) and nonspontaneous (ΔG > 0), with negative entropy changes (ΔS) suggesting an increase in molecular order among the degradation products. The kinetic compensation effect was confirmed, demonstrating a linear relationship between lnA and Eₐ.