Recovery of rhodium from carbonylation residues
AssigneeThe Halcon SD Group, Inc.
InventorsWalter C. Davidson, Benjamin F. Fieselmann
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Abstract
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.
Claims11
A process for recovering Group VIII noble metals bound to residues of noble metal catalyzed carbonylation reactions wherein said residues are separated from the carbonylation reaction mixture and thereafter residues containing unextracted bound noble metals are treated with a reagent comprising an amine, in an amount sufficient to free said noble metals from said residues and enable said bound noble metals to be extracted by a subsequent contact with an aqueous halogen acid.
Dependencies are inferred from the claim text.