Method for purifying adipodinitrile (ADN)

US9822067B2 · kind B2 · utility

Assignee

• BASF SE (Ellwanger & Baier Patentanwälte) · DE

Inventors

• Hermann Luyken · Ludwigshafen, DE
• Peter Pfab · Schwarzheide, DE
• Tim Jungkamp · Sandhausen, DE

Key dates

• Filing date: Feb 3, 2015
• Grant date: Nov 21, 2017
• Expiry date: Feb 3, 2035

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C253/10
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for purifying adiponitrile (ADN), wherein crude ADN is introduced into a rectification apparatus (R1). The rectification apparatus (R1) comprises a first side draw and preferably also a second side draw, the first side draw being disposed below the crude ADN introduction point and the optional second side draw being disposed above the crude ADN introduction point. The first side draw is used to draw off a gaseous stream comprising ADN while the optional second side draw is used to draw off undesired by-products such as 1-amino-2-cyanocyclopentene (ACCP) which are often generated in ADN production and consequently may be present in the crude ADN. The gaseous stream from the first side draw of (R1) is introduced into a second rectification apparatus (R2). (R2) is used to separate off ADN from remaining high boilers and any other by-products present, pure ADN being drawn off from (D2) as overhead product. It is preferable when the process according to the invention employs crude ADN from a reaction of butadiene with hydrocyanic acid (HCN).