Wet torrefaction of forest residues - Combustion kinetics

摘要

Fresh branches of Norway spruce and birch were torrefied in hot compressed water at varied temperatures (175, 200, or 225 °C) and for 30 minutes. The combustion of untreated and torrefied branches in synthetic air (21% O2 and 79% N2) was experimentally studied by means of a thermogravimetric analyzer, followed by a kinetic analysis adopting the distributed activation energy model. It appears that, wet torrefaction has significant effects on the combustion reactivity of forest residues. Compared with the raw materials, wet-torrefied branches are less reactive during devolatilization, but more reactive in the char combustion stage.