GB742496A - Improvements in or relating to purification of acetone by distillation - Google Patents

Abstract

<PICT:0742496/III/1> Crude acetone containing a minor proportion of mesityl oxide and aldehydes is purified by intimately mixing it with 1/2 to 10 times its volume of an aqueous caustic alkali solution containing 20-50 per cent by weight of caustic alkali for 15 minutes to 3 hours at about 15 DEG -33 DEG C., feeding the treated acetone to a distillation column fed at a higher point with water in an amount of 2 to 8 times the volume of acetone, removing an overhead fraction containing water and substantially all the carbonyl impurities, and removing a bottoms fraction comprising water and acetone substantially free from carbonyl impurities. In an example the crude acetone contained 86.8 per cent acetone, 2.3 per cent water, 0.5 per cent mesityl oxide and aldehyde impurities and 10.3 per cent isopropanol. The crude acetone is intimately mixed in a tank 3 with aqueous caustic soda solution. After 15 minutes-3 hours the mixture is allowed to settle and the lower aqueous caustic phase is recycled via line 4 while the upper organic phase, preheated if desired, is fed to a fractional distillation column 6. Water is fed to a higher point of the column via line 12, external reflux being provided via condenser 15. The bottoms from column 6 comprising acetone, isopropanol and water is fed to a second fractionating column 13 provided with external reflux via condenser 18. Isopropanol and water are recovered from the bottom of column 13 and chemically pure acetone is recovered from the top.