Fast pyrolysis is one of the most viable and commonly used thermochemical conversion technologies which can be applied to both fossil-based and bio-based wastes. The conical spouted bed reactor is an alternative to fluidized beds and has been proven to be a versatile reactor for waste biomass fast pyrolysis, which allows obtaining high bio-oil yields because of its high heat and mass transfer rates and very short residence times. Understanding of the stable hydrodynamic operation range of the conical spouted bed is important for operation of fast pyrolysis reactor. This study characterizes the hydrodynamics of conical spouted bed using the analysis of pressure fluctuation signals. Stable hydrodynamic operation rages were identified by evaluation of pressure drop curve and FFT analysis. The stable operation range of a conical spouted bed was maintained while dominant frequency is 10 Hz. This appears to be promising cost-effective tool for precess control especially in fast pyrolysis systems.