A unified mechanism of the combustion reactions of lignocellulosic fuels

tThermogravimetric curves in air, measured for beech and fir wood and three agro-industrial residues(hazelnut shells, olive husks and wheat straw) at different heating rates (5-40 K/min), are subjected tokinetic evaluation. It is shown that a five step mechanism (three reaction for the devolatilization stage andtwo reactions for the combustion stage) provides good predictions in all cases. Moreover, for the combus-tion stage (amounts of volatile released between 25 and 40%) the activation energies are the same (113and 183 kJ/mol). On one side, the devolatilization stage is also very similar for the residues which requireactivation energies of 125, 170 and 164 kJ/mol for the pseudo-components hemicellulose, cellulose andlignin. On the other, the behavior of the last two pseudo-components is also similar for the beech and firwood (activation energies of 200 and 176 kJ/mol) whereas the different nature of hemicellulose requiressignificant changes (activation energies of 147 and 110 kJ/mol, respectively).