Abstract: Tarry residues often are formed in carbonylation reactions, such as those in which esters or ethers are carbonylated to produce ethylidene diacetate or carboxylic acid anhydrides, such as acetic anhydride. Such residues contain Group VIII noble metal catalysts, typically rhodium, which must be separated before the residues can be disposed of. In the process of the invention, a portion of the carbonylation reaction mixture is flashed to a lower pressure and the resulting residues-containing liquid is extracted with solvents which preferentially remove the tars. The tars are separated from the solvents and disposed of while the solvents are recycled for further use. The catalyst-containing liquid is processed to remove residual solvent and returned to the carbonylation reaction.

Abstract: Catalysts containing niobium or tantalum halides which have been deactivated by contact with oxygen are regenerated by being contacted with a halogenated hydrocarbon.

Abstract: The disclosure relates to a process for purifying and recovering a contaminated catalyst solution which is obtained in the carbonylation of methyl acetate and/or dimethylether, the catalyst solution containing carbonyl complexes of noble metals of group VIII of the Periodic System of the elements, quaternary heterocyclic aromatic nitrogen compounds or quaternary organophosphorus compounds as organic promoters, undistillable organic contaminants as well as acetic acid, acetic anhydride and ethylidene diacetate.