US 4,404,119 A · Process for recovery of cobalt oxo catalysts

Abstract

According to one embodiment of the improved process of this invention, dicobalt octacarbonyl is produced in an olefinic medium by contacting an aqueous solution of a tetracarbonylcobaltate metal salt with an oxygen-containing gas in the presence of an olefinic extractant for dicobalt octacarbonyl to oxidize the tetracarbonylcobaltate anion to dicobalt octacarbonyl which is efficiently extracted into the olefinic phase, thereby producing an organic phase which can then be recovered and passed to a cobalt-catalyzed olefin hydroformylation reaction zone as source of at least a portion of the catalyst and olefin required in the olefin hydroformylation reaction to form the corresponding aldehydes. According to another aspect of this invention, an aqueous solution of tetracarbonylcobaltate metal salt is contacted with an oxygen-containing gas in the presence of gaseous carbon monoxide, and optionally also in the presence of an organic solvent for the dicobalt octacarbonyl, to efficiently oxidize the tetracarbonylcobaltate anion to dicobalt octacarbonyl.

Claims23

Dependent claims

A process for forming an olefinic liquid containing dissolved dicobalt octacarbonyl suitable for use as feed to an olefin hydroformylation reaction, which comprises contacting an aqueous solution containing a water-soluble tetracarbonylcobaltate salt in an oxidation zone with a molecular oxygen-containing gas in the presence of a liquid olefinic extractant for dicobalt octacarbonyl to oxidize at least a portion of said tetracarbonylcobaltate to dicobalt octacarbonyl;

and recovering said olefinic liquid containing dissolved dicobalt octacarbonyl from said oxidation zone, said recovered liquid being substantially free of oxidation by-products formed in said oxidation zone from any portion of said olefinic extractant.

A process for demetalling an oxo product contaminated with cobalt-containing catalyst residues and recovering cobalt carbonyls therefrom which comprises:

(a) treating the oxo product in a first demetalling zone with a first aqueous solution of a Co.sup.++ salt of an organic or inorganic acid to extract at least a portion of the cobalt-containing catalyst residues from the oxo product into a first aqueous phase and to form products including said Co.sup.++ salt and Co[Co(CO).sub.4 ].sub.2 therein;
(b) substantially completing the demetalling of the thus treated oxo product by treatment in a second demetalling zone with an aqueous organic or inorganic acid in the presence of oxygen to form a Co.sup.++ salt of said acid;
(c) treating said first aqueous phase with synthesis gas in a high pressure reactor at a pressure in the range of from about 15 psig to about 1500 psig and at a temperature in the range of from about 0.degree. to about 200.degree. C., to form a second aqueous solution containing additional quantities of Co[Co(CO).sub.4 ].sub.2 ;
(d) contacting said second aqueous solution in an oxidation zone with molecular oxygen at a temperature of from about 0.degree. to 90.degree. C. to form Co.sub.2 (CO).sub.8 ;
(e) contacting the aqueous effluent of step (d) with an organic solvent to extract said Co.sub.2 (CO).sub.8 ;
and
(f) passing said organic solvent extract to an oxo reaction zone as catalyst.

4 more elements

Dependencies are inferred from the claim text.

Process for recovery of cobalt oxo catalysts

Life of this patent

Process for recovery of cobalt oxo catalysts

Life of this patent

Abstract

Claims23