Treatment of acetic acid and mixtures thereof

Claim 1

THE PROCESS FOR DEHYDRATING AND RECOVERING IMPURITIES FROM MIXTURES SELECTED FROM THE GROUP CONSISTING OF AQUEOUS ACETIC ACID, AND AQUEOUS MIXTURES OF ACETIC ACID AND ACETIC ANHYDRIDE, SAID MIXTURES CONTAINING LARGE AMOUNTS OF VOLATILE WATER-SOLUBLE IMPURITIES, WHICH COMPRIESE FEEDING THE MIXTURE AND AN ENTRAINER INTO A DISTILLATION ZONE WHERE A PORTION IS VAPORIZED, PASSING VAPORS OF THE WATER-SOLUBLE IMPURITIES, WATER AND THE ENTRAINER ONTO DISTILLING PLATES ABOVE A DECANTATION ZONE WITHIN SAID DISTILLATION ZONE ABOVE THE FEED POINT WHICH IS HEATED BY THE COLUMN AND WHICH DECANTATION ZONE IS TRAVERSED WITHOUT BUBBLING BY SAID ASCENDING VAPORS, SAID ENTRAINER BEING AN ESTER SELECTED FROM THE GROUP CONSISTING OF ETHYL ACETATE, PROPYL ACETATE AND ISOPROPYL ACETATE, REFLUXING THE ENTRAINER ON SAID PLATES ABOVE THE DECANTATION ZONE INTO SAID DECANTATION ZONE, ALLOWING THE LIQUID TO SEPARATE SO THAT A LOWER LAYER CONTAINING A MINOR PROPORTION OF IMPURITIES WITH WATER IS FORMED IN THE DECANTATION ZONE ABOVE WHICH IS A LAYER CONTAINING THE ENTRAINER, CONTINUSOUL WIDHDRAWING FROM THE DISTILLATION ZONE THE AQUEOUS LIQUID WITH A MINOR AMOUNT OF IMPURITIES, DECANTING THE ENTRAINER AND RETURNING IT TO THE COLUMN BELOW THE DECANTATION ZONE, AND REMOVING REMAINING WATER-SOLUBLE IMPURITIES FROM THE SYSTEM AS A DISTILLATE FROM THE TOP OF THE DISTILLATION ZONE SUBSTANTIALLY FREE OF ACETIC MATERIAL.