Kinetics of thermal degradation of wood biomass

• Published in: Chemical papers 2014, Vol.68 (12), p.1725-1738
• Main Authors: Hrablay, Ivan, Jelemenský, Ľudovít
• Format: Article
• Language: English
• Subjects: beech pyrolysis; Biochemistry; Biotechnology; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Industrial Chemistry/Chemical Engineering; kinetics; Materials Science; mechanism; Medicinal Chemistry; NMR; Original Paper
• ISSN: 0366-6352; 1336-9075
• DOI: 10.2478/s11696-014-0622-y

Pyrolysis kinetics of a hardwood representative, beech ( Fagus sylvatica ), was investigated by two different kinetic approaches: model-free isoconversional method and model-fitting method. The model-free isoconversional method was used for the determination of apparent kinetic parameters, i.e. the activation energy and pre-exponential factor. The model fitting method was used for the optimization of kinetic parameters of the reaction pathways of three selected reaction mechanisms: one-step, two-step, and three-step one. In both approaches, thermo-gravimetric data were used at five heating rates: 2°C min −1 , 5°C min −1 , 10°C min −1 , 15°C min −1 and 20°C min −1 . As the most suitable mechanism, the three-step mechanism containing the intermediate degradation step was chosen. This selection was supported by experimental results from the 13 C NMR analysis of solid residues prepared at the key temperatures within the range of 230–500°C. The progress of mass fraction values of each component in this mechanism was simulated. Conclusions from the simulation were confronted with experimental results from the 13 C NMR.