# US 4,400,299 A · Oxidative recovery of cobalt oxo catalysts > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,400,299 A - Document ID: US4400299A - Status: Granted - Kind: A - Application number: 06/333,693 - Filed: 1981-12-23 - Granted: 1983-08-23 - Earliest claimed: 1981-12-23 - Assignees: Exxon Research & Engineering Co. - Inventors: Linda S. Lagace; Richard C. Miller; David A. Young - Web page: https://patentgrep.com/patent/US4400299A ## CPC - B01J 31/20: Carbonyls - B01J 31/04: containing carboxylic acids or their salts {(B01J31/0277 - B01J31/0298 take precedence; multi-metal carboxylate complexes like Pd (II) acetate, i.e. Pd3 (OAc) 6 or Cr(II)acetate, i.e. Cr2(OAc)4 B01J31/2226)} - B01J 31/403: {containing iron group metals or copper} - C01G 51/01: Preparation or separation involving a liquid-liquid extraction, an adsorption or an ion-exchange - C01G 51/02: Carbonyls - C07C 45/50: by oxo-reactions - C22B 3/26: by liquid-liquid extraction using organic compounds - B01J 2231/321: Hydroformylation, metalformylation, carbonylation or hydroaminomethylation - B01J 2531/0208: Bimetallic complexes, i.e. comprising one or more units of two metals, with metal-metal bonds but no all-metal (M)n rings, e.g. Cr2(OAc)4 - B01J 2531/845: Cobalt - C09K 2323/061: Inorganic, e.g. ceramic, metallic or glass - Y02P 10/20: Recycling - Y02P 20/584: Recycling of catalysts - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20) - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## 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. ## Claims ### Claim 1 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) contacting said first aqueous phase in an oxidation zone with molecular oxygen-containing gas at a temperature of from about 0.degree. to 90.degree. C. to form Co.sub.2 (CO).sub.8 ; (d) contacting the oxidized aqueous mixture of step (c) with an organic solvent at elevated pressure to extract said Co.sub.2 (CO).sub.8 and to thereby form an organic extract containing said Co.sub.2 (CO).sub.8 and an aqueous raffinate substantially free of Co.sub.2 (CO).sub.8 and containing dissolved Co.sup.++ acid salt values; (e) passing said organic extract to an oxo reaction zone as catalyst; and (f) contacting at least a portion of said aqueous raffinate with a higher molecular weight fatty acid, an organic solvent therefor and an alkaline reacting agent to form an organic phase containing the corresponding Co.sup.++ higher fatty acid salt suitable for recycle to an oxo reaction zone as catalyst. ### Claim 2 (depends on 1) The process according to claim 1 wherein the pressure in the oxidation zone is in the range of from about 15 to 1500 psig. ### Claim 3 (depends on 1) The process of claim 1 wherein steps (c) and (d) are combined and wherein said oxidation is effected in the presence of said organic solvent. ### Claim 4 (depends on 1) The process according to claim 1 in which at least a portion of the aqueous raffinate from the extraction with the organic solvent in step (d) is passed to the first demetalling zone. ### Claim 5 (depends on 1) The process according to claim 1 in which said Co.sup.30 + salt is cobalt acetate, cobalt formate or mixtures thereof. ### Claim 6 (depends on 1) The process according to claim 1 in which the organic solvent is selected from the group consisting of the feed olefins, hydroformylation product, the heavy oxygenated bottoms fraction from the distillation of oxo alcohols and mixtures thereof. ### Claim 7 (depends on 6) The process according to claim 6 in which the organic solvent is a portion of the feed olefins. ### Claim 8 (depends on 1) The process according to claim 1 in which the extraction with the organic solvent is carried out in the presence of CO gas at a pressure in the range of about 10 to about 2500 psig at a temperature of 0.degree. to about 180.degree. C., and with from about 0.1 to 10 volumes of the organic solvent per volume of said oxidized aqueous mixture so contacted. ### Claim 9 (depends on 1) The process according to claim 1 in which at least a portion of the organic phase containing said corresponding Co.sup.++ higher fatty acid salt produced in step (f) is passed as recycle to step (d) in order to provide at least a portion of said organic solvent required in step (d), to thereby form an organic extract containing said Co.sup.++ higher fatty acid salt and said Co.sub.2 (CO).sub.8 suitable for recycle to an oxo reaction zone as catalyst. ### Claim 10 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) contacting said first aqueous phase in an oxidation zone with molecular oxygen-containing gas at a temperature of from about 0.degree. to 90.degree. C. to form Co.sub.2 (CO).sub.8 in the presence of an organic solvent to extract said Co.sub.2 (CO).sub.8 and to thereby form an organic extract containing said Co.sub.2 (CO).sub.8 and an aqueous raffinate substantially free of Co.sub.2 (CO).sub.8 and containing dissolved Co.sup.++ acid salt values; (d) passing said organic extract to an oxo reaction zone as catalyst; and (e) contacting at least a portion of said aqueous raffinate with a higher molecular weight fatty acid, an organic solvent therefor and an alkaline reacting agent to form an organic phase containing the corresponding Co.sup.++ higher fatty acid salt suitable for recycle to an oxo reaction zone as catalyst. ### Claim 11 (depends on 10) The process according to claim 10 wherein the pressure in the oxidation zone is in the range of from bout 15 to 1500 psig. ### Claim 12 (depends on 10) The process according to claim 10 in which at least a portion of the aqueous raffinate obtained in step (c) is passed to the first demetalling zone. ### Claim 13 (depends on 10) The process according to claim 10 in which the oxidation and extraction of step (c) is effected in the presence of gaseous carbon monoxide at a total pressure of from about 10 to 2500 psig. ### Claim 14 (depends on 10) The process according to claim 10 wherein at least a portion of said organic phase containing the said Co.sup.++ higher fatty acid salt produced in step (e) is passed to step (c) to provide at least a portion of the organic solvent required therein, to thereby form an organic extract containing said Co.sub.2 (CO).sub.8 and said Co.sup.++ higher fatty acid salt suitable for recycle to an oxo reaction zone as catalyst. ### Claim 15 The 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) contacting said first aqueous phase in an oxidation zone with molecular oxygen-containing gas at a temperature of from about 0.degree. to 90.degree. C. to form Co.sub.2 (CO).sub.8 ; and (d) contacting the oxidized aqueous mixture of step (c) in a combined extraction/contacting zone with an organic solvent at elevated pressure in the presence of a higher molecular weight fatty acid and an alkaline reacting agent to extract said Co.sub.2 (CO).sub.8 into the organic phase and to form the corresponding Co.sup.++ higher fatty acid salt, thereby forming an organic extract phase containing said extracted Co.sub.2 (CO).sub.8 and said Co.sup.++ higher fatty acid salt suitable for recycle to an oxo reaction zone as catalyst. ### Claim 16 The 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; and (c) contacting said first aqueous phase in a combined oxidation/contacting zone with molecular oxygen-containing gas at a temperature of from about 0.degree. to 90.degree. C. and in the presence of a higher molecular weight fatty acid, an organic solvent therefor, and an alkaline reacting agent to form an organic phase containing Co.sub.2 (CO).sub.8 and Co.sup.++ higher fatty acid salt corresponding to said higher fatty acid, said organic phase being suitable for recycle to an oxo reaction zone as catalyst.