Oxidative recovery of cobalt oxo catalysts

摘要

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.