Beech wood particles (cylinders) with varying particle sizes (1.5 ­15 mm) were pyrolyzed in a fed­batch­wise operated fluidized bed reactor. The effects of the particle size on the pyrolysis (conversion) time, char yield and oil (total liquid) yield and composition was studied at pyrolysis reactor temperatures of 400, 500 and 600 oC. It has been observed that with increasing particle size the amount of produced char increases and the oil yield decreases slightly. The oil composition, however, changes significantly while varying the particle size. More “lights” in the oil and a significant increase in the amount of produced water and water content of the oil have been observed with increasing particle size. The amount of water insoluble (high molecular mass) compounds decreases slightly as the particle size is increased. It has been proposed that the increasing char yield and varying oil composition as a result of increasing the particle size can be (partly) ascribed to the relative decrease of the evaporation rate over the reaction rates (polymerization and cracking) of the organic liquid present in the particle’s pores during pryolysis.

Proceedings of the 18th European Biomass Conference and Exhibition, 3-7 May 2010, Lyon, France, pp. 1052-1054