COMBUSTION CHARACTERISTICS OF BIOMASS CHARCOAL PRODUCED AT DIFFERENT CARBONIZATION CONDITIONS

The combustion properties of spruce chars and spruce forest residue chars were studied in the kinetic regime by a series of TGA experiments. The work aimed at establishing how the pressure of the char preparation affects the reactivity with oxygen. In the present phase of the work the pressure during char preparation was employed on a thin layer of biomass with ample ventilation. In this way only negligible pressure effects were observed during char combustion. The kinetics of the char burn-off was described by assuming a main reaction and a side reaction. 12 experiments at three different temperature programs were evaluated by the method of least squares to obtain a dependable kinetic model. A common activation energy of 137kJ/mol gave a reasonable description of both reactions in all the 12 experiments.