	US 11,858,881 B2
	Method for purifying nitrile solvent
Shota Saito, Takaoka (JP); Ryoji Wada, Takaoka (JP); Keiichiro Matsuda, Takaoka (JP); Ryoyo Nakashima, Takaoka (JP); and Fuminori Komatsu, Takaoka (JP)
Assigned to NIPPON SODA CO., LTD., Tokyo (JP)
Appl. No. 16/975,317
Filed by NIPPON SODA CO., LTD., Tokyo (JP)
PCT Filed Feb. 26, 2019, PCT No. PCT/JP2019/007306 § 371(c)(1), (2) Date Aug. 24, 2020, PCT Pub. No. WO2019/167940, PCT Pub. Date Sep. 6, 2019.
Claims priority of application No. 2018-033238 (JP), filed on Feb. 27, 2018.
Prior Publication US 2020/0399207 A1, Dec. 24, 2020
Int. Cl. C07C 253/34 (2006.01); B01D 3/40 (2006.01); C07C 255/08 (2006.01)

CPC C07C 253/34 (2013.01) [B01D 3/40 (2013.01); C07C 255/08 (2013.01)]

9 Claims

1. A method for purifying a nitrile solvent, comprising:

bringing the nitrile solvent containing at least an imine and a conjugated diene as impurities into contact with an acidic aqueous solution having a pH of 3 or less;

bringing the nitrile solvent having been contacted with the 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; and

bringing the nitrile solvent containing impurities, the nitrile solvent having been contacted with the acidic aqueous solution, the nitrile solvent having been contacted with the aqueous sodium hydrogen sulfite solution, or the nitrile solvent having been contacted with the alkaline aqueous solution, into contact with an oxidizing agent.