Separation of esters

Claim 1

IN A CONTINUOUS PROCESS FOR SEPARATING AN ESTER FROM A REACTION MIXTURE PRODUCED IN AN ESTERIFICATION STEP BY REACTION OF A C2 TO C6 MONOOLEFIN WITH A C1 TO C8 ALIPHATIC MONOCARBONBOXYLIC ACID IN THE PRESENCE OF ABOUT 5 TO 10 WEIGHT PERCENT OF RELATIVELY ANHYDROUS SULFURIC ACID BASED ON THE MONOCARBOXYLIC ACID, SAID ESTER BEING ONE CAPABLE OF FORMING A WATER AZEOTROPE WHICH DISTILLS BELOW THE TEMPERATURE OF THE MONOCARBOXYLIC ACID USED. THE IMPROCEMENT WHICH COMPRISES WITHDRAWING THE REACTION MIXTURE FROM THE ESTERIFICATION STEP, DISCHARGING UNCONVERTED OLEFIN FROM THE WITHDRAWN MIXTURE, PROVIDING AN EXCESS OF THE FREE MONOCARBOXYLIC ACID IN THE RESULTING OL EFIN-FREE MIXTURE, ADDING TO SAID OLEFIN-FREE MIXTURE A QUANTITY OF WATER ABOUT SUFFICIENT TO FORM A WATER AZEOTROPE WITH ALL THE ESTER FORMED, HEATING THE RESULTING AQUEOUS MIXTURE IN A DISTILLATION ZONE, WITHDRAWING AN ESTER-WATER AZEOTROPE AS A DISTILLATE FRACTION FROM SAID DISTILLATION ZONE, ALSO WITHDRAWING FROM SAID DISTILLATION ZONE A BOTTOMS FRACTION CONTAINING THE FREE MONOCARBOXYLIC ACID AND RELATIVELY ANHYDROUS SULFURIC ACID, RECYCLING SAID BOTTOMS FRACTION TO THE ESTERIFICATION STEP, AND SEPARATING THE DISTILLATE FRACTION INTO AN AQUEOUS PHASE AND ORGANIC ESTER PHASE.