Steam distilling and crystallization to separate succinic acid, glutaric acid and adipic acid from mixture thereof

Claim 1

A PROCESS FOR THE SEPARATION OF SUCCINIC ACID, GLUTARIC ACID AND ADIPIC ACID FROM MIXTURES CONTAINING SUCH DICARBOXYLIC ACIDS WHICH COMPRISES INTRODUCING A MIXTURE CONTAINING SAID DICARBOXYLIC ACIDS AT A PRESSURE OF 40 TO 200 MM. HG INTO AN EVAPORATING ZONE INCLUDING A STEAM DISTILLATION ZONE, THE INNER WALL OF WHICH IS HEATED TO AT LEAST 180*C. AND WHEREIN SAID ZONE''S BOTTOM TEMPERATURE IS KEPT AT 195* TO 220*C., EVAPORATING ESSENTIALLY THE SUCCINIC ACID PORTION OF SAID MIXTURE BY MEANS OF STEAM STRIPPING DISTILLATION, COOLING THE EFFLUENT VAPORS TO ROOM TEMPERATURE IN AN AQUEOUS MEDIUM, SEPARATING THE SUCCINIC ACID BY CRYSTALLIZATION OF THE SUCCINIC ACID IN THE RESULTANT AQUEOUS LAYER, WITHDRAWING A PORTION OF THE BOTTOMS FROM THE EVAPORATING ZONE AND SEPARATING IT BY STEAM STRIPPING DISTILLATION UNDER SUBATMOSPHERIC PRESSURE OF 30 TO 100 MM. HG AT THE TOP OF THE EVAPORATING ZONE AND BOTTOMS TEMPERATURE OF 180*C. TO 200*C. INTO AN OVERHEAD FRACTION CONSISTING SUBSTANTIALLY OF GLUTARIC ACID AND A BOTTOMS FRACTION CONSISTING SUBSTANTIALLY OF ADIPIC ACID.