Particle high-speed self-rotation in cyclones with different diameters and application in catalyst deoiling

Abstract

One of the keys of cleaner production in the petrochemical industry is the reduction and recycling of spent catalysts. The centrifugal force generated by the high-speed self-rotation of particles in cyclone provides a possibility for the recovery of oil in the porous catalyst. In this study, five cyclones with nominal diameters of 75, 150, 200, 300 and 500 mm were designed from the perspective of industrial scaled-up applications. The effects of structural and operational parameters such as cyclone diameter, particle diameter, and inlet flow rates on the particle self-rotation, revolution, temperature variation and residence time were investigated through CFD-DEM simulation and high-speed motion analyzer (HSMA). The results show that with the increase of the cyclone diameter, the particle self-rotation velocity gradually increases and the residence time becomes longer. For a 200 mm diameter cyclone, the smaller the particle diameter and the greater the inlet flow rates, the higher the particle self-rotation velocity, and the self-rotation velocity of 1 mm particles reached a maximum of 8000 rad/s. Particle high-speed self-rotation in cyclones was applied to spent catalyst deoiling at room temperature and pressure, and the deoiling efficiency with different operating parameters was investigated. This study can provide guidance for the self-rotation separation of pore contaminants in porous media.