Halcon Research and Development Corp.

The Halcon Sd Group, Inc.

Joseph Pugach

Heavy residues produced by noble metal catalyzed carbonylation reactions and containing Group VIII noble metals, particularly rhodium, are treated with reagents to precipitate solids containing substantially all of the noble metal contained in the residues. The solids may be further treated to concentrate the noble metals or they may be returned directly for reuse in the carbonylation reaction. Suitable reagents include aliphatic alcohols, carboxylic acids, and carboxylic acid esters. Preferred are branched-chain alcohols, especially tertiary alcohols; of the acids, acetic acid is particularly preferred; and of the esters, n-butyl acetate and ethylidene diacetate are preferred. Subsequent treatments with other solvents, e.g., alkanes, cycloalkanes, ethers, and aromatic compounds, may be used to further concentrate the rhodium content of the precipitated solids.

Recovery of noble metal values from carbonylation residues

Heavy residues produced by noble metal catalyzed carbonylation reactions and containing Group VIII noble metals, particularly rhodium, are treated with a mixture of immiscible liquids to precipitate solids containing substantially all of the noble metal contained in the residues. The solids may be returned directly for reuse in the carbonylation reaction. One group of liquids consists of water with immiscible alcohols or hydrocarbons, or mixtures thereof. A second group consists of acetic anhydride with immiscible hydrocarbons.

Recovery of noble metal values from carbonylation residues using

Heavy residues produced by noble metal catalyzed carbonylation reactions and containing Group VIII noble metals, particularly rhodium, are treated with reagents to precipitate solids containing substantially all of the noble metal contained in the residues. The solids may be further treated to recover the noble metals or they may be returned directly for reuse in the carbonylation reaction. Suitable reagents include alkali metal hydroxides, alkali metal peroxides, alkali metal borohydrides, and other reducing agents, such as formaldehyde and acidified sodium bisulfite.

Acetic anhydride is prepared from methyl acetate and/or dimethyl ether in carbonylation processes comprising the use of a halide, carbon monoxide and a Group VIII noble metal in the presence of promoters comprising metallic zirconium and an organo-phosphorus compound or an organo-nitrogen compound wherein the phosphorus and nitrogen are trivalent, or an arsine of the formula: ##STR1## wherein R and R.sup.1 are monocyclic aryl groups or alkyl groups and R.sup.2 is the radical ##STR2## a monocyclic aryl group or an alkyl group, and wherein R.sup.3 and R.sup.4 are each a monocyclic aryl group or an alkyl group, n being zero or a digit from 1-20.

Process for the preparation of acetic anhydride

Acetic anhydride is prepared from methyl acetate and/or dimethyl ether in carbonylation processes comprising the use of a halide, carbon monoxide and a Group VIII noble metal in the presence of promoters comprising metallic hafnium and an organo-phosphorus compound or an organo-nitrogen compound wherein the phosphorus and nitrogen are trivalent, or an arsine of the formula: ##STR1## wherein R and R.sup.1 are monocyclic aryl groups or alkyl groups and R.sup.2 is the radical ##STR2## a monocyclic aryl group or an alkyl group, and wherein R.sup.3 and R.sup.4 are each a monocyclic aryl group or an alkyl group, n being zero or a digit from 1-20.

A carboxylic acid anhydride, such as acetic anhydride, is prepared from a carboxylate ester or a hydrocarbyl ether in carbonylation processes comprising the use of a halide, carbon monoxide and a Group VIII noble metal in the presence of promoters comprising at least one metal of Group VIB of the Periodic Table, or their compounds, and an arsine of the formula ##STR1## wherein R and R.sup.1 are monocyclic aryl groups or alkyl groups and R.sup.2 is the radical ##STR2## a monocyclic aryl group or an alkyl group, and wherein R.sup.3 and R.sup.4 are each a monocyclic aryl group or an alkyl group, with the proviso that at least one of R, R.sup.1 and R.sup.2 is a monocyclic aryl group, n being zero or a digit from 1-20.

Process for preparing carboxylic acid anhydrides

A process is provided for extracting monovalent thallium and alkali metal values from a liquid medium containing a carboxylic acid having limited solubility in water and containing dissolved trivalent thallium values, monovalent thallium values and, optionally, alkali metal compound, which comprises contacting the carboxylic acid medium with an extractant comprising an acidic aqueous medium having a pH of not greater than about 6 to preferentially extract monovalent thallium and alkali metal values into the aqueous medium, and recovering a raffinate comprising a treated carboxylic acid medium containing trivalent thallium carboxylate and depleted of monovalent thallium and alkali metal values.

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Ho-Ho-Kus, NJ, United States of America

Joseph Pugach