Oxidative Pyrolysis of a Large Wood Particle: Effects of Oxygen Concentration and of Particle Size

International audienceIn this study, the oxidative pyrolysis of large pine wood particles was analysed using a Macro-ThermoGravimetric apparatus (Macro-TGA). The effects of the concentration of oxygen in the surrounding gas and of particle size were investigated. Three different oxygen concentrations (0 %, 10 % and 20 %) and three sizes of cylindrical pine wood samples (4 mm, 8 mm and 12 mm in diameter) were tested at a heating rate of 20 degrees C/min. The results showed that oxygen had a strong influence on pyrolysis behaviour. We observed that the peak of wood pyrolysis was higher and appeared at a lower temperature with an increase in the oxygen concentration. When the size of the particle was increased, there was a short delay in DTG curve. But generally speaking, particle size had no significant influence on oxidative pyrolysis at this low heating rate. With the 4 mm diameter particles and at a heating rate of 20 degrees C/min, degradation behaviours (TG and DTG curves) were similar and resembled intrinsic degradation behaviours: heat and mass transfer phenomena did not limit the process