Investigations on heat transfer and hydrodynamics under pyrolysis conditions of a pilot-plant draft tube conical spouted bed reactor

This paper describes the hydrodynamic and heat transfer performance of a pilot-plant scale conical spouted bed reactor designed for the pyrolysis of biomass wastes. The spouted bed reactor is the core of a fast pyrolysis pilot plant with continuous biomass feed of up to 25 kg/h, located at the Ikerlan-IK4 facilities.The aim of this paper is to obtain a deeper understanding of the spouted bed reactor performance at pyrolysis temperatures, in order to operate under stable conditions, improve the heat transfer rate in the reactor and minimize energy requirements. The influence of temperature on conical spouted bed hydrodynamics has been studied and wall-to-bed and bed-to-surface heat transfer coefficients have been determined.

► The hydrodynamic performance of a pilot plant (25 kg/h) for biomass pyrolysis has been studied. ► The validity of a previous hydrodynamic correlation obtained at laboratory scale has been analysed. ► Wall-to-bed and bed-to-surface heat transfer rates have been determined. ► Temperature distribution in the bed has been determined for different inlet temperatures.