Process for purifying and recovering catalyst solution contaminated during the carbonylation of methyl acetate and/or dimethylether

US4746640A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Heinz Erpenbach · Cologne, DE
• Klaus Gehrmann · Lechenich, DE
• Winfried Lork · Lechenich, DE

Key dates

• Filing date: Mar 16, 1987
• Grant date: May 24, 1988
• Expiry date: Mar 16, 2007

Classification

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

Abstract

Catalyst solution contaminated during the carbonylation of methyl acetate and/or dimethylether. To this end, the contaminated catalyst solution is subjected in a first processing stage to extraction with a dialkylether and alkanol, each of which has from 1-4 carbon atoms per alkyl group, and thereby freed from its organic contaminants, from acetic acid, acetic anhydride and ethylidene diacetate, and the ether phase is separated from the purified promoter-containing catalyst solution; next, the ether phase is treated in a second processing stage with iodine and/or methyl iodide; the precipitated promoter containing catalyst complex is separated and dissolved in the purified catalyst solution coming from the first processing stage; the ether phase is separated into its constituents by distilling it; recovered dialkylether and alkanol are used again in the extraction stage; fresh catalyst solution is prepared from the recovered mixture of acetic acid, acetic anhydride and ethylidene diacetate and from the united purified catalyst solution while residual dialkylether and alkanol are distilled off, and the organic contaminants retained in the residue of the ether phase distillation are …