Patent ID: 8597517
Filing Date: 2013-12-03
Classification: B01D

Abstract:
1. A process for regeneration of ionic liquids having an organic cation and a halogenmetallate anion, after being used as an extracting agent for sulfur compounds, said process comprising: a) Dissolving said used ionic liquid in acetone in a ratio (w/w) of 1:1 to 1:10, b) Adjusting the pH of the solution obtained in a) by addition of an aqueous solution of sodium hydroxide to obtain a pH of 7-10, and and form a precipitate, c) Filtering the solution obtained in b) to remove the precipitate from the solution, d) Removing the solvent from the filtrate obtained in c) by evaporation under reduced pressure, e) dissolving the residue obtained in step d) in acetone at a ratio (w/w) of 1:10 to 1:50, f) Filtering the solution to remove the precipitate obtained in step e), g) Adjusting the pH of the solution obtain in f) by adding an aqueous solution of hydrochloric acid to a pH range of 2-7, h) Removing the solvent from by evaporation of the filtrate obtained in step f) under reduced pressure to obtain regenerated ionic liquid, i) heating the regenerated ionic liquid obtained in step h) to 70-80° C., under reduced pressure until dry.