Preparation of phthalic anhydride from o-xylene

US5225574A · kind A · utility

Assignee

• BASF SE

Inventors

• Heinrich Aichinger · Mannheim, DE
• Wilhelm Ruppel · Mannheim, DE
• Rolf Seubert · Bischofswerda, DE
• Karl-Heinz Boehning · Darmstadt, DE
• Walter Scheidmeir · Schifferstadt, DE
• Johannes E. Schmidt · Ludwigshafen, DE
• Matthias Schwarzmann · Schifferstadt, DE

Key dates

• Filing date: Apr 9, 1991
• Grant date: Jul 6, 1993
• Expiry date: Apr 9, 2011

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01J2523/00
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Phthalic anhydride is prepared in a multiple tube reactor provided with separate salt baths, the temperature of the salt bath used for cooling the first layer of catalyst, as regarded in the direction of flow of the reaction mixture, being from 2.degree. to 20.degree. C. higher than that of the salt bath(s) associated with the following layer(s).