Aceto

Claim 1

A PROCESS FOR PURIFYING ACETONE IN A CRUDE FEED CONTAINING PREDOMINANTLY ACETONE AND A MINOR BUT SIGNIFICANT PROPORTION OF CARBONYL IMPURITIES INCLUDING MESITYL OXIDE AND ALDEHYDES, SAID FEED BEING DIFFICULT TO PURIFY BY CONVENTIONAL DISTILLATION, WHICH COMPRISES THE STEPS OF TREATING THE CRUDE FEED WITH AN AQUEOUS CAUSTIC SOLUTION CONTAINING ABOUT 30-45 WEIGHT PER CENT CAUSTIC FOR A TIME OF FIFTEEN MINUTES TO THREE HOURS WITH AN AQUEOUS CAUSTIC TO FEED RATIO OF 2/1 TO 1/10 FEEDING THE CAUSTIC TREATED MIXTURE TO A FRACTIONAL DISTILLATION ZONE AT AN INTERMEDIATE POINT THEREOF; CONTINUOUSLY ADDING WATER TO THE FRACTIONAL DISTILLATION ZONE SUBSTANTIALLY ABOVE THE FEED POINT OF THE MIXTURE TO MAINTAIN A VOLUMETRIC SOLVENT TO FEED RATIO IN THE RANGE OF 2-8/1; DISTILLING FROM SAID DISTILLATION ZONE A VAPOROUS MIXTURE ASCENDING COUNTERCURRENT TO THE LIQUID WATER INTERNAL REFLUX; REMOVING FROM THE DISTILLATION ZONE A DISTILLATE COMPRISING A PREDOMINANT PROPORTION OF WATER CONTAINING SUBSTANTIALLY ALL THE CARBONYL IMPURITIES AND SOME ACETONE, AND WITHDRAWING AS A BOTTOMS FRACTION FROM THE FRACTIONAL DISTILLATION ZONE ACETONE AND WATER, FREE OF CARBONYL IMPURITIES.