The thermal decomposition of wood wastes obtained from jack pine has been studied in both oxidising and inert atmospheres using thermogravimetric techniques supported by gaseous and residue product analysis. The effects of selected sequences of chemical additives on the reaction rate parameters of both native and extracted bark samples have also been examined. The maximum rate of wood waste pyrolysis is believed to be related to the rapid decomposition of the cellulose constituent, which occurs at around 350 ~ in nitrogen. In air, this value is shifted to around 300 ~ and may be explained by the intervention of exothermic reactions involving other wood constituents present in the complex wood matrix. The trend shown in the analytical results for the various wood waste residues was similar to that established by previous workers for the pyrolysis of coalification products on the basis of H/C and O/C ratios which proceed towards the carbonisation and oxidation poles, respectively, for residues obtained from heating in inert and oxidising atmospheres. Isothermal weight-change data were found to fit model kinetic expressions which indicate that the pyrolysis process may be transportcontrolled.
* We are pleased to acknowledge the award of support funds (C.F.) from the Ontario Ministry of the Environment.