Removal of trace olefins from aromatics by using ionic liquid

Room-temperature ionic liquids were used as catalysts for removal of trace olefins from the aromatics. The influences of various reaction parameters such as reaction time, dosage and type of catalyst were investigated. The experimental results demonstrated that the [bmim]Br-AlCl₃ ionic liquid exhibited excellent activity under mild reaction conditions, with above 99% conversion of olefins and the bromine index of the aromatics varied from 773.5 to below 10. Furthermore, the ionic liquids could be reused easily. A possible reaction mechanism was proposed.