Recovery and reactivation of rhodium hydroformylation catalysts

Claim 1

IN A METHOD FOR RECOVERING AND REACTIVATING RHODIUM CATALYSTS IN A PROCESS WHEREIN UNSATURATED HYDROCARBONS, OR UNSATURATED FATTY COMPOUNDS ARE HYDROFORMYLATED AT TEMPERATURES OF ABOUT 100* TO 300*C, WITH HYDROGEN AND CARBON MONOXIDE UNDER PRESSURES OF FROM ATMOSPHERIC PRESSURE TO 3000 P.S.I.G. IN THE PRESENCE OF A CATALYST CONSISTING OF RHODIUM METAL ON A RELATIVELY INERT SUPPORT ADMIXEDD WITH A TRISUBSTITUTED PHOSPHINE, AND WHEREIN THE HYDROFORMYLATED REACTION PRODUCTS ARE FILTERED AND DISTILLED LEAVING A RESIDUE WHICH CONTAINS ESSENTIALLY ALL OF THE SOLUBLE RHODIUM, THE IMPROVEMENT COMPRISING THE FOLLOWING STEPS: A. MIXING SAID RESIDUE WITH A REFRACTORY CATALYST SUPPORT, B. VOLATILIZING AND CARBONIZING ESSENTIALLY ALL ORGANIC MATERIALS PRESENT IN THE MIXTURE RESULTING FROM STEP (B) BY HEATING SAID MIXTURE TO FROM 150* TO 450*C, IN AN ATMOSPHERE SUCH THAT VOLATILE MATERIALS GIVEN OFF WILL BE PREVENTED FROM IGNITING, C. REACTING IN A SUITABLE VESSEL ESSENTIALLY ALL OF THE CARBON-IZED MATERIAL REMAINING FROM STEP (B) WITH OXYGEN CONTAINED IN AIR AT A TEMPERATURE OF FROM 350* TO 1000*C, FOR A LENGTH OF TIME SUFFICIENT TO FORM CARBON DIOXIDE AND WATER, AND D. COOLING SAID VESSEL AND REMOVING THE RESULTING RESUPPORTED CATALYST.