Oxidative carbonylation and catalyst recovery

Claim 1

IN THE OXIDATIVE CARBONYLATION OF A HYDROCARBON OLEFIN HAVING FROM 2 TO ABOUT 5 CARBONS TO AN OXYGENATED PRODUCT THEREOF WHEREIN THE OLEFIN AND CARBON MONOXIDE ARE INTRODUCED INTO A REACTION ZONE TO CONTACT, UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS, AN ORGANIC REACTION MEDIUM COMPRISING A LOW MOLECULAR WEIGHT, ALKANOIC ACID WHICH CONTAINS A CATALYST CONSISTING OF FROM 0.001 TO 5 WEIGHT PERCENT OF A PLATINUM GROUP METAL BROMIDE OR CHLORIDE AND FROM 0.U TO 10 WEIGHT PERCENT OF A REDOX AGENT SELECTED FROM THE CLASS CONSISTING OF THE SOLUBLE SALTS OF NITROGEN OXIDES AND OF MULTIVALENT METALS HAVING OXIDATION POTENTIALS MORE POSITIVE THAN SAID PLATINUM GROUP METAL IS SAID REACTION MEDIUM TO FORM SAID OXIDIZED PRODUCTS AND TO REDUCE THE CATALYST TO A LOWER OXIDATION STATE AND WHEREIN THE REACTION MEDIUM IS CONTACTED WITH PXYGEN TO RESTORE SAID CATALYST TO ITS HIGHER OXIDATION STATE, THE IMPROVED METHOD FOR PREVENTING PERMANENT DEACTIVATION OF THE CATALYST CONTAINING MEDIUM FOR THE REACTION WHICH COMPRISES REMOVING FROM 1 TO ABOUT 20 WEIGHT PERCENT OF THE REACTION MEDIUM FROM THE REMAINDER OF SAID MEDIUM, SISTILLING SAID REMOVED PORTION TO RECOVER REACTION PRODUCTS AND SOLVENT, REACTING THE TARRY RESIDUE FROM SAID DISTILLATION WITH FROM 0.5 TO 10 VOLUMES OF A STRONG MINERAL ACID SELECTED FROM THE CLASS CONSISTING OF NITRIC, SULFURIC AND HYDROHALIC ACIDS FORMING MIXTURES THEREOF AT A TEMPERATURE FROM ABOUT 20* TO ABOUT 150* AND ADDING FROM 1 TO ABOUT 50 VOLUMES OF AN ORGANIC DILUENT HAVING FROM 4 TO ABOUT 7 CARBONS AND SELECTED FROM THE CLASS CONSISTING OF MONOHYDROXY ACYCLIC AND ALICYCLIC ALCOHOLS AND KETONES AND ESTERS OF ACYCLIC MONOCARBOXYLIC ACIDS AND ACYCLIC AND ALICYCLIC ALCOHOLS AND GLYCOLS AND ESTERS OF DICARBOXYLIC ACIDS AND ACYCLIC ALCOHOLS, SEPARATING THE RESULTING ADMIXTURE INTO AN ORGANIC AND AN AQUEOUS PHASE AND SEPARATING THE AQUEOUS PHASE THEREFROM AND RECOVERING THE CATALYST VALUES FROM SAID SEPARATED AQUEOUS PHASE.