Process for the recovery and purification of naphthenic acids

Claim 1

PROCESS FOR THE SEGREGATION OF LOW MOLECULAR WEIGHTT NAPHTHENIC ACIDS OF HIGH QUALITY FROM PETROLEUM OILS CONTAINING THE SAME, WHICH COMPRISES WASHING A FEED PETROLEUM OIL CONTAINING RELATIVELY HIGH AND RELATIVELY LOW MOLECULAR WEIGHT NAPHTHENIC ACIDS WITH A CAUSTIC SOLUTION, SEPARATING THE RESPECTIVE OIL AND CAUSTIC PHASES, TREATING SAID SEPARATED CAUSTIC PHASE IN AN INITIAL REGENERATION STAGE WITH A REAGENT ADAPTED TO CONVERT AT LEAST 10% OF THE RELATIVELY HIGH MOLECULAR WEIGHT NAPHTHENATES INTO THEIR CORRESPONDINGLY HIGH MOLECULAR WEIGHT NAPHTHENIC ACIDS, EXTRACTING THE RELATIVELY HIGH MOLECULAR WEIGHT NAPHTHENIC ACIDS WITH A SUITABLE SOLVENT, WHEREBY THE RELATIVELY HIGH MOLECULAR WEIGHT NAPHTHENIC ACIDS AND UNSAPONIFIABLE OIL CONSTITUENTS ARE DISSOLVED IN SAID SOLVENT, SEPARATING THE SOLVENT EXTRACT PHASE FROM THE RELATIVELY LOW MOLECULAR WEIGHT NAPHTHENATE PHASE, AND THEREAFTER IN A SECOND STAGE COMPLETELY REGENERATING THE RELATIVELY LOW MOLECULAR WEIGHT NAPHTHENATES WITH A SUITABLE REAGENT WHEREBY HIGH QUALITY LOW MOLECULAR WEIGHT NAPHTHENIC ACIDS SUBSTANTIALLY COMPLETELY FREE OF UNSAPONIFIABLE OIL CONSTITUENTS ARE SECURED.