Pyrolysis of Pine and Beech Wood Samples under Isothermal Experimental Conditions. the Determination of Kinetic Triplets

The pyrolysis process of pine and beech wood samples was investigated by the isothermal thermogravimetric technique, at five different operating temperatures, in nitrogen flowing stream. It was found that the isothermal pyrolysis process of wood samples can be described by the three-dimensional diffusion mechanisms, with different reaction geometry (Janders type for pine, and Ginstling-Brounsteins type for beech). The evaluated models for both processes represent the global one-step reaction mechanisms. Some differences in the values of the kinetic parameters and diffusion geometry of the volatile products were established, probably resulting from sensitive alterations of the structure and the chemical composition of the investigated wood samples, occurring during the pyrolysis process