Deoiling of oil-coated catalyst using high-speed suspending self-rotation in cyclone

Abstract Disposal of waste catalysts has posed considerable threat to the environment and biological health. It has been confirmed that the self-rotation of particles in a hydrocyclone can enhance the efficiency of removing pollutants in catalyst particles. This paper presented the high-speed suspending self-rotation of catalyst particles in cyclone with the help of microfluidic technology and high-speed camera test. The oil-removal efficiency can be improved further by controlling the self-rotation speed and suspending time. Results showed that under the inlet flux of 35 m 3 /h, catalyst particles had a self-rotation speed of more than 14,000 rad/s in cyclone, 80 times as that of the revolution speed under the same operating condition. The self-rotation speed and suspending time of catalyst particles can be enhanced by the increase of inlet flux and cone angle. The coating oil is removed under the periodic resultant centrifugal force when the suspending time is prolonged, and the oil content can be reduced from 36.17% to less than 4% within 100 s in cyclone under 25 °C. This finding is highly significant to non-thermal purification of waste catalyst under gas–solid environment.