The Halcon Sd Group, Inc.

Halcon Research and Development Corp.

Atlantic Richfield Company

Richard V Porcelli

Sudarshan Lal

Vijay S Bhise

Walter C Davidson

Arnold J Shapiro

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.

Separation of tars from carbonylation reaction mixtures

Carbonylation products such as alkanoic anhydrides, e.g., acetic anhydrides, are produced by carbonylation of esters and/or ethers in the presence of a rhodium or iridium catalyst and an iodine moiety in a reaction zone wherein the reaction mixture is in a continuous boiling state.

Preparation of carbonylation products

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.

Treatment of carbonylation residues

A process is provided for inhibiting the rate of corrosion of titanium metal surfaces from attack by strong acid media in which at least a portion of the titanium metal surface is coated with rhodium metal to provide a treated metal surface which is substantially impervious to corrosion by strong acid media. The article so prepared appears to be uniquely impervious to corrosion by strong acid media and is also claimed herein.

Process for inhibiting titanium corrosion

Acetaldehyde is prepared by reacting methyl acetate and/or dimethyl ether with carbon monoxide and hydrogen in the presence of a palladium catalyst and an iodine moiety in a reaction zone wherein the reaction mixture is in a continuous boiling state.

Preparation of acetaldehyde

In the carbonylation of alkyl esters in the presence of a Group VIII noble metal catalyst to produce a reaction mixture comprising volatile components and the non-volatile Group VIII noble metal catalyst, and the volatile components are separated from the catalyst, catalyst activity is maintained by providing a partial pressure of hydrogen of at least 10 psi during the separation of the volatile products. A partial pressure of at least 15 psi of carbon monoxide is also preferably provided, particularly when a metal promoter for the Group VIII noble metal catalyst is present, during such separation.

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Yonkers, NY, United States of America

Richard V Porcelli