Production of aldehydes, carboxylic acids and/or carboxylic acid anhydrides by means of catalysts containing vanadium oxide, titanium dioxide, and antimony oxide

US7371893B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Sebastian Storck · Mannheim, DE
• Jürgen Zühlke · Speyer, DE
• Samuel Neto · Brussels, BE
• Frank Rosowski · Mannheim, DE

Key dates

• Filing date: May 21, 2004
• Grant date: May 13, 2008
• Expiry date: May 21, 2024

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C51/313
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A description is given of a process for preparing aldehydes, carboxylic acids and/or carboxylic anhydrides, in particular phthalic anhydride, in which a gaseous stream comprising an aromatic hydrocarbon and molecular oxygen is passed at elevated temperature over a bed of a first catalyst and a bed which is made up of a second catalyst having a higher activity than the first catalyst and is located downstream of the first catalyst in the flow direction of the gaseous stream, wherein the catalytically active composition of the first catalyst comprises at least vanadium oxide, titanium dioxide and antimony oxide and the ratio of vanadium, calculated as V2O5, to antimony, calculated as Sb2O3, in the first catalyst is from 3.5:1 to 5:1. The source of antimony oxide used for the first catalyst is preferably particulate antimony trioxide having a mean particle size of from 0.5 to 5 μm. The process allows the desired oxidation products to be obtained in high yield over longer periods of time.