EFFECT OF THE WOOD BIOMASS TYPE ON THE BEHAVIOUR OF PYROLYSIS CHAR IN AIR AND IN CO2 AT HIGH TEMPERATURES

Samples of three different wood biomass types, viz. eucalyptus, olive tree, and a sawdust mix, were pyrolyzed applying two temperature modes: heating to 800 degrees C at a rate of 10 degrees C/min, and heating to 1000 degrees C at a rate of 20 degrees C/min. The wood mass degradation patterns were examined with respect to the proportions of the major components, i.e. cellulose, hemicellulose and lignin, and in dependence on the heating rate, where the result was different for the different samples. In the next part of the thermogravimetric investigation, the resulting pyrolysis char was heated from the starting 1000 degrees C to the final 1300 degrees C with a constant air or carbon dioxide feed. The observed data were used to calculate parameters such as the degree of conversion and reactivity of the samples. The properties of the pyrolysis char were found to be affected appreciably by the composition of the starting wood material. The selection of the starting material has a basic effect on the material's thermochemical processes such as combustion, gasification and pyrolysis, on their development and the results of the process.