Effect of particle size and temperature on woody biomass fast pyrolysis at high temperature (1000–1400°C)

Fast pyrolysis of wood was conducted in a drop tube furnace to study the influence of temperature (1000–1200–1400 °C) and particle size (0.35–0.80 mm) for a particle residence time of some seconds. No effect of particle size has been observed on final pyrolysis products. At 1000 °C, much more gas and tar are produced than char (yield of 96% versus 4%); hydrocarbons, including light species and tar, present a considerable yield of 26%. From 1200 °C, the drastic hydrocarbons decomposition, emphasized with temperature, leads to high yields in soot, H2 and CO. At 1200 °C, no tar are detected; at 1400 °C only low amounts of CH4 and C2H2 still remain. Under the explored conditions, char and soot gasification with H2O and CO2, species produced during pyrolysis, is kinetically blocked. However, even if carbonaceous solids do not seem to be considerably affected by gasification, they suffer some changes when temperature is increased.