The general features of biomass pyrolysis are analysed both on the basis of a specifically conceived set of experiments and on the basis of a detailed kinetic analysis including successive gas phase reactions of released species. Experiments are performed in a lab-scale Entrained Flow Reactor (EFR) to investigate biomass pyrolysis under high temperatures (1073-1273 K) and fast heating rate conditions (>500 K/s). The influence of the particle dimensions, of the temperature and of the residence time of gas and particles has been tested. The particle size appeared as the most crucial parameter. Volatile components released by the solid particles are then involved in a detailed kinetic scheme of gas phase pyrolysis and combustion, in order to better understand their successive fate. In this way it is possible not only to explain the formation of CH4and C2species, but also to predict the successive formation of benzene and aromatic components.