Process for removing metallic corrosion products from carbonylation reactions carried out under anhydrous conditions

US5124290A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Heinz Erpenbach · Cologne, DE
• Reinhard Gradl · Hürth, DE
• Erhard Jagers · Bornheim, DE
• Andreas Seidel · Dormagen, DE
• Peter Prinz · Ethel, US

Key dates

• Filing date: Oct 16, 1991
• Grant date: Jun 23, 1992
• Expiry date: Oct 16, 2011

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C51/47
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for removing metallic corrosion products from carbonylation reactions which are carried out under anhydrous conditions and in which methyl acetate and/or methanol and/or dimethyl ether are reacted over a noble metal catalyst system which comprises a noble metal of group VIII of the periodic table of the elements, a co-catalyst, such as iodide or bromide, in particular methyl iodide, and a promoter, such as an organophosphonium or organoammonium salt, and if appropriate a lithium salt, to give acetic acid and/or acetic anhydride is described, the process comprising PA0 a) bringing the reaction solution which is contaminated with metallic corrosion products and contains the catalyst system into contact with an ion exchanger; PA0 b) separating this reaction solution which has been brought into contact in this way from the ion exchanger; PA0 c) desorbing the promoter adsorbed on the ion exchanger before regeneration with acetic acid and/or acetic anhydride; PA0 d) combining the eluate obtained in step c) with the reaction solution separated off in step b) and recycling the components together into the carbonylation reaction; PA0 e) regenerating the ion exchanger obtained from…