Research on the coupling principle of revolution and self-rotation of catalysts in a bio-oil hydrodeoxidation ebullated bed reactor

[Display omitted] •An axial-flow hydrocyclone achieve in-situ desorption of catalyst attachment.•Catalyst self-rotation and coupled centrifugal force models were analyzed.•Self-rotation and revolution speeds are affected by flow rate and insertion depth.•Increasing flow rate and insertion depth enhance the oil phase centrifugal force.•The oil phase is subjected to a periodically varying coupled centrifugal force. As a renewable and environmentally friendly resource, biomass energy has been widely used and is considered to be a promising alternative to petroleum-based liquid fuels. At present, the ebullated bed reactor is generally used to upgrade the biomass pyrolysis liquid, but the catalyst is prone to deactivation due to the polycondensation and coking of bio-oil. This paper proposes an ebullated bed with a built-in axial hydrocyclone to achieve in-situ activation of the catalyst. The influences of the vortex finder insertion depth and the inlet flow rate on the particles' revolution and self-rotation were investigated by numerical simulation, high-speed imaging technology and particle image velocimetry (PIV), and the coupling principle of revolution and self-rotation of catalysts was also analyzed. The results show that increasing flow rate and decreasing vortex finder insertion depth will increase the particles' revolution speed, which varies in the range of 18–78 rad/min. The particles' self-rotation speed varies in the range of 240–1200 rad/min. With the increase of flow rate and vortex finder insertion depth, the particles' self-rotation speed increases, the attached oil phase on particle pores and surfaces receives greater centrifugal force, the coupled centrifugal separation factor increases, and the oscillation period of the coupled centrifugal force decreases, which is beneficial to the desorption of the oil phase. The self-rotation, revolution and their coupling principle are beneficial to the removal of pore pollutants in the catalyst.