Purification of ethanol

Claim 1

IN A METHOD FOR PURIFYING AND REFINING CRUDE AQUEOUS ETHANOL PRODUCED BY THE HYDRATION OF AN ETHYLENE-CONTAINING STREAM, SAID CRUDE ETHANOL CONTAINING BOTH LOWER AND HIGHER BOILING IMPURITIES, INCLUDING DIETHYL ETHER AND INCLUDING MALODOROUS ORGANIC IMPURITIES BOILING ABOVE ETHANOL, WHICH COMPRISES THE STEPS OF CONTINUOUSLY PASSING SAID CRUDE AQUEOUS ETHANOL INTO A FRACTIONAL EXTRACTIVE DISTILLATION ZONE, CONTINUOUSLY FEEDING WATER INTO SAID FRACTIONAL EXTRACTIVE DISTILLATION ZONE AT A POINT ABOVE THE AQUEOUS ETHANOL FEED STREAM, MAINTAINING AN INTERNAL LIQUID REFLUX HAVING AN ETHANOL CONTENT OF 5 TO 40 WEIGHT PERCENT WITHIN THE ZONE BELOW THE WATER FEED POINT, CONTINUOUSLY REMOVING FROM THE UPPER PORTION OF SAID EXTRACTIVE DISTILLATION ZONE A STREAM CONTAINING ORGANIC IMPURITIES INCLUDING BOTH LOWER AND HIGHER BOILING MATERIALS, CONTINUOUSLY REMOVING FROM THE LOWER PORTION OF SAID EXTRACTIVE DISTILLATION ZONE A DILUTE AQUEOUS ETHANOL STREAM, PASSING SAID AQUEOUS ETHANOL STREAM TO A CONCENTRATING, FRACTIONAL DISTILLATION ZONE, AND REMOVING FROM AN UPPER PORTION OF SAID CONCENTRATING DISTILLATION ZONE A STREAM OF PURIFIED ETHANOL, THE IMPROVEMENT WHICH COMPRISES THE STEPS OF INITIALLY PASSING SAID CRUDE AQUEOUS ETHANOL INTO A FRACTIONAL DISTILLATION ZONE, REMOVING FROM THE UPPER PORTION OF SAID ZONE A STREAM CONTAINING LOWER BOILING IMPURITIES INCLUDING SUBSTANTIALLY ALL OF THE DIETHYL ETHER, REMOVING FROM THE LOWER PORTION OF SAID ZONE AN AQUEOUS ETHANOL STREAM, AND CONTINUOUSLY PASSING SAID ETHER-FREE AQUEOUS ETHANOL STREAM INTO THE ABOVE-DESCRIBED FRACTIONAL EXTRACTIVE DISTILLATION ZONE.