Method for purifying nitrile solvent

Abstract

A method for manufacturing a higher purity nitrile solvent by purifying a nitrile solvent containing an impurity, e.g an imine. The nitrile solvent may contain an imine and a conjugated diene, a carbonyl compound, or a high-boiling material as impurities. A method for purifying a nitrile solvent, such as isobutyronitrile, including bringing nitrile solvent containing an imine, e.g., as an impurity, into contact with an acidic aqueous solution having a pH of 3 or less, such as hydrochloric acid; bringing the nitrile solvent having been contacted with acidic aqueous solution into contact with an aqueous sodium hydrogen sulfite solution; bringing the nitrile solvent having been contacted with the aqueous sodium hydrogen sulfite solution into contact with an alkaline aqueous solution, such as an aqueous sodium hydroxide solution; and distilling the nitrile solvent having been contacted with the alkaline aqueous solution.

Dependencies are inferred from the claim text.