DEVOLATILIZATION AND COMBUSTION OF WOOD CHARS

Thermogravimetric curves in air of wood chars, obtained from different species and conventional or fast pyrolysis, show a low-temperature shoulder (devolatilization) followed by a high-temperature peak (combustion). A n-order global reaction provides a very poor description of the differential curves and requires relatively low activation energies. The combination with an additional first-order reaction for the devolatilization stage produces accurate predictions of both integral and differential curves. It also gives rise to much higher activation energies.