ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Kinetics of thermal degradation of wood biomass

Ivan Hrablay and Ľudovít Jelemenský

Department of Chemical and Biochemical Engineering, Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37, Bratislava, Slovakia

E-mail: ludovit.jelemensky@stuba.sk

Abstract: 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 ¹³C 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 ¹³C NMR.

Keywords: beech pyrolysis – kinetics – mechanism – NMR

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-014-0622-y

Chemical Papers 68 (12) 1725–1738 (2014)