Method for the recovery of hydrogen peroxide

Claim 1

A PROCESS FOR RECOVERING AN AQUEOUS SOLUTION OF HYDROGEN PEROXIDE FROM A CRUDE PRODUCT OF PARTIAL OXIDATION OF A LOWER SECONDARY ALIPHATIC ALCOHOL, SAID PRODUCT CONTAINING HYDROGEN PEROXIDE, UNCONSUMED LOWER SECONDARY ALIPHATIC ALCOHOL, CORRESPONDING KETONE, AND SMALL BUT APPRECIABLE AMOUNTS OF OTHER OXYGENATED ORGANIC MATERIALS, SAID OTHER OXYGENATED ORGANIC MATERIALS INCLUDING COMBINED PER-OXYGEN IN AMOUNTS RANGING FROM ABOUT 5% TO ABOUT 50% OF THE TOTAL AMOUNT OF ACTIVE OXYGEN CONTAINED IN SAID PRODUCT AND THE TOTAL CONTENT OF ACTIVE OXYGEN BEING AT LEAST ABOUT 5% BY WEIGHT OF THE PRODUCT, WHICH PROCESS COMPRISES INTRODUCING AN AQUEOUS STREAM OF SAID PRODUCT INTO AN UPPER PORTION OF A FRACTIONATING COLUMN COMPRISING A STRIPPING ZONE WHEREIN THERE IS MAINTAINED AN ABSOLUTE PRESSURE WITHIN THE RANGE OF FROM ABOUT 400 TO ABOUT 700 MILLIMETERS OF MERCURY SO THAT A LIQUID PORTION OF THE AQUEOUS STREAM FLOWS DOWNWARDLY THROUGH THE STRIPPING ZONE IN SUBSTANTIAL VAPOR-LIQUID EQUILIBRIA WITH ASCENDING VAPORS EVOLVED THEREFROM UNDER CONSTANT CONDITIONS OF REFLUXING AND REBOILING, CONTINUOUSLY WITHDRAWING A VAPOROUS MIXTURE OF THE LOWER SECONDARY ALIPHATIC ALCOHOL, THE CORRESPONDING KETONE, AND WATER OVERHEAD FROM SAID ZONE, CONTINUOUSLY WITHDRAWING AQUEOUS SOLUTION OF HYDROGEN PEROXIDE FROM A BOTTOM PART OF SAID ZONE, AND ADJUSTING THE RATES OF INTRODUCTION OF FEED TO SAID ZONE AND THE RATES OF WITHDRAWAL OF SAID VAPOROUS MIXTURE AND SAID AQUEOUS SOLUTION FROM SAID ZONE SO AS TO PROVIDE A SUBSTANTIALLY CONSTANT RESIDENCE TIME WITHIN THE STRIPPING ZONE OF THE DESCENDING LIQUID PORTION OF THE FEED OF FROM ABOUT 10 TO NOT OVER 80 MINUTES.