METHOD FOR THE FORMATION OF COBALT CARBONYL COMPOUNDS AND THE USE OF THE METHOD IN THE OXO SYNTHESIS PROCESS

摘要

1281727 Cobalt carbonyls ESSO RESEARCH & ENG CO 19 Sept 1969 [8 Nov 1968 10 March 1969] 46331/69 Heading C1A Complex cobalt carbonyl compounds containing a cobalt tetracarbonyl anion are prepared by reacting in an aqueous medium a cobalt material with carbon monoxide in the presence of hydrogen, a reaction promoter and a noble metal catalyst at elevated temperature and pressure, the said promoter being incapable of forming simple carbonyl compounds but capable of reacting with a cobalt tetracarbonyl anion to form a complex cobalt carbonyl with the proviso that if the promoter is a salt, the anion of the salt is an anion of an acid having a dissociation constant less than 1 x 10-2. The promoter may be an alkali metal salt or hydroxide, an alkaline earth metal salt or hydroxide, an ammonium salt or hydroxide, a mercury salt, a quaternary ammonium salt or hydroxide, a lower aliphatic amine or mixture thereof. The promoter is preferably a salt as above. The reaction is preferably carried out at a temperature of from 120‹ to 350‹ F. and at a pressure of from 200 p.s.i.g. to 4500 p.s.i.g., the catalyst is preferably palladium contained on a carbon support. The cobalt material may be metallic cobalt, cobalt oxide, organic and inorganic cobalt salts, cobalt hydroxide and mixtures thereof. The molar ratio of promoter to cobalt material is preferably 1:1 if the said cobalt material is a salt of an acid having a dissociation constant less than about 1 Î 10-2 and 3:1 in the case of an acid having a dissociaconstant greater than 1 Î 10-2. The cobalt material may be obtained from the decobalting step of a hydroformylation process and, after the treatment described above, may be treated with a strong mineral acid to give a cobalt carbonyl catalyst which may be recycled as a catalyst to the hydroformylation step.