A separation vessel for separating an effluent stream that comprises a mixture of hydrocarbons and ionic liquid. The separation vessels may be vertically orientated. Ionic liquid is utilized to remove entrained ionic liquid droplets form rising hydrocarbons within the separation zone. The ionic liquid may be provided with a stream of the ionic liquid from the separation vessel. The ionic liquid may be provided as a layer or travel counter-current to the hydrocarbons rising in the separation vessel.