Process of recovery of exhausted ionic liquids used in the extractive desulfurization of naphthas

摘要

A process for recovering ionic liquids comprising the steps of: providing a first ionic liquid mixture, the first ionic liquid having a halogen metallate anion, the mixture containing an organic solvent; adjusting the pH of the mixture to pH 7-10 by the addition of a base to form a first precipitate; separating the first precipitate from the mixture; removing the organic solvent from the first mixture to form a second precipitate and separating the second precipitate from the first mixture; acidifying the resulting mixture to pH 2-7 by the addition of an acid; and drying the mixture to obtain a second ionic liquid having a halogen anion.