The Halcon Sd Group, Inc.

Walter C Davidson

Richard V Porcelli

Benjamin F Fieselmann

Residues are formed in the carbonylation of esters or ethers, particularly in the production of acetic anhydride or ethylidene diacetate. Such residues contain noble metal, typically rhodium, used as a catalyst, which must be recovered before the residues can be disposed of. The rhodium values are freed from the residues by treatment with amines, preferably primary aliphatic amines and/or hydrazine, thereby enabling the rhodium to be extracted by subsequent contact with an aqueous halogen acid.

Recovery of rhodium from carbonylation residues

Residues are formed in the carbonylation of esters or ethers, particularly in the production of acetic anhydride or ethylidene diacetate. Such residues contain noble metal, typically rhodium used as a catalyst, which must be recovered before the residues can be disposed of. In the process of the invention, the rhodium values are freed from the residues by a series of treatments with amines and other reagents, thereby enabling the rhodium to be extracted by subsequent contact with an aqueous halogen acid.

Residues are formed in the carbonylation of esters or ethers, particularly in the production of acetic anhydride or ethylidene diacetate. When such residues contain noble metal, typically rhodium, used as a catalyst, the noble metals must be recovered before the residues can be disposed of. The metal values are freed from the residues by treatment with amines, thereby enabling the rhodium to be extracted by subsequent contact with an aqueous halogen acid. The residues are pretreated with alkanols and concentrated by evaporation to improve the effect of such amine treatments.

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Mahwah, NJ, United States of America

Walter C Davidson