Evaluation of a novel static micro-mixing scrubber for removing ionic liquids from alkylated oils

Alkali wash refining is a critical step in the oil purification process of ionic liquid alkylation. The static mixer currently used in this operation has a weak mixing effect and an insufficient alkali washing capability, which compromises the standard functioning of the plant. In this study, a new variable-diameter cyclonic shear mixer scrubber was constructed and its phase distribution and internal pressure loss were simulated. Unlike the standard SK-type static mixer tube, the majority of droplets formed using the static micro-mixing scrubber were < 25 μm in diameter, resulting in superior dispersion and a 15 % increase in ionic liquid removal efficiency. Furthermore, the robust turbulence within the scrubber effectively inhibits the production of large solid suspended particles, thus avoiding equipment fouling. The novel static micro-mixing scrubber improves the efficiency of the alkali wash for ionic liquid removal and prolongs the operation period of ionic liquid alkylating oil unit by improving the mixing of the two phases. Therefore, it may be utilized in the future to replace commercial static mixers used for alkali wash refining in alkylation processes.