Succinic acid and anhydride separation process

Claim 1

A PROCESS FOR SEPARATING SUCCINIC ACID FROM A MIXTURE THEREOF WITH AT LEAST ONE DIBASIC ACID OF THE FORMULA HOOC(CH2)NCOOH WHERE N IS AN INTEGER GREATER THAN 2 WHICH COMPRISES FORMING A DISTILLAND OF SAID MIXTURE AND AN INERT HYDROPHOBIC ORGANIC SOLVENT, SAID SOLVENT HAVING AN ATMOSPHERIC BOILING POINT OF BETWEEN 175 AND 220*C. AND BEING CAPABLE OF DISSOLVING AT LEAST ABOUT 5 GRAMS OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF SUCCINIC ACID, SUCCINIC ANHYDRIDE AND MIXTURES THEREOF PER 100 GRAMS OF SAID SOLVENT AT A TEMPERATURE OF 175-220*C., DISTILLING A PORTION OF SAID DISTILLAND AT A TEMPERATURE BETWEEN 175 AND 220*C. THEREBY FORMING A VAPOR COMPRISING SUCCINIC ANHYDRIDE, SUCCINIC ACID, SAID SOLVENT AND WATER, CONDENSING AT LEAST THE MAJOR PORTION OF SAID SOLVENT, SAID SUCCINIC ANHYDRIDE, AND SAID SUCCINIC ACID COMPRISING SAID VAPOR, COOLING THE RESULTING CONDENSATE TO A TEMPERATURE BETWEEN ABOUT 60 AND 150*F., SEPARATING THE RESULTING SOLID PHASE SUCCINIC ANHYDRIDE AND SUCCINIC ACID FROM THE CONDENSED LIQUID SOLVENT, RETURNING SAID CONDENSED SOLVENT TO SAID DISTILLAND AND CONTINUING THE FOREGOING OPERATIONS UNTIL SAID DISTILLAND IS SUBSTANTIALLY DEPLETED OF SUCCINIC ACID.