The motion and separation mechanism of droplets in the cyclone reactor for ionic liquid alkylation

The light‐phase separation efficiency is capped at 90% in the liquid–liquid cyclone reactor (LLCR), and the migration and separation of droplets are essential for elucidating the separation mechanism and addressing the limitations. The computational fluid dynamics–population balance model coupled model was applied to investigate the droplet motion in the cyclone reactor. The motion pattern of the droplets based on the radial forces was summarized, and the effect of the operating parameters on the droplet separation was investigated. The results show that a stable envelope of zero radial acceleration exists in the cone section of the LLCR. The LLCR can be divided into decelerated separation zone (Zone DS) and accelerated separation zone (Zone AS) based on the envelope. Light‐phase separation failure occurs through two mechanisms: strong coercive effects from the heavy phase in zone DS and prolonged settling times in zone AS. The settling time is effectively inhibited with the increase of feed ratio, overflow ratio and inlet flow rate. Nevertheless, the entrapment of the heavy phase is enhanced with the increase of feed ratio and inlet flow rate. Thus, the best separation of the light phase occurs at F = 0.55, E = 1.00, Q = 3.5 m 3 /h, with a separation efficiency of 92.58%.