Process for the purification of crude acetic anhydride

US4107002A · kind A · utility

Assignee

• Wacker Chemie AG · DE

Inventors

• Herbert Eck · Burghausen, DE
• Elmar Bethe · Burghausen, DE
• Hans Schwarzbauer · Burghausen, DE
• Hellmuth Spes · Burghausen, DE
• Klaus Kaiser · Neustadt, DE

Key dates

• Filing date: Feb 2, 1976
• Grant date: Aug 15, 1978
• Expiry date: Feb 2, 1996

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S203/20
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the purification of crude acetic anhydride by continuous fractional distillation, which comprises first introducing the anhydride into an evaporator, thereafter removing from the evaporator the non-distillable components contained in the crude anhydride, then introducing the distillable components of the anhydride in vapor form into about the central section of a fractionating column, withdrawing from the top of the column the low boiling components together with acetic acid, withdrawing near the bottom of the column a high-percentage of pure acetic anhydride, and separating from the sump of the column up to about 8% by weight based on the initial amount of crude acetic anhydride and returning the same to the evaporator.