Process for the purification and recovery of the contaminated solution of the catalyst produced on carbonylation of methanol and/or methyl acetate and/or dimethyl ether

US5047377A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Heinz Erpenbach · Cologne, DE
• Eitel Goedicke · Wipperfürth, DE
• Winfried Lork · Lechenich, DE
• Heribert Tetzlaff · Frankfurt am Main, DE

Key dates

• Filing date: Aug 6, 1990
• Grant date: Sep 10, 1991
• Expiry date: Aug 6, 2010

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/584
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

In a process for the purification and recovery of a contaminated catalyst solution produced during carbonylation of methanol and/or methyl acetate and/or dimethyl ether and containing carbonyl complexes of rhodium, organic and/or inorganic promoters, undistillable organic impurities and acetic acid, acetic anhydride and ethylidene diacetate, the organic impurities and acetic acid, acetic anhydride and ethylidene diacetate are removed from the contaminatd catalyst solution by extraction at pressures from 35 to 450 bar and temperatures from 0.degree. to 120.degree. C. with a liquefied or supercritical gas, and the phase of the liquefied or supercritical gas is separated from the purified, promoter-containing catalyst solution, the phase of the liquefied or supercritical gas is separated by flash vaporization, the recovered gas is re-employed for extraction, acetic acid, acetic anhydride and ethylidene diacetate are separated off from the component which remains liquid, and are combined with the purified catalyst complex to prepare fresh catalyst solution and, finally, the organic impurities remaining as the residue on separation of the phase of the liquefied or supercritical gas is p…