Acetone is produced on the manufacturing scale by several completely different processes. The chief of these are: (1) Fermentation processes.

(2) The decomposition of acetate of lime, derived from various sources.

(3) Conversion of acetic acid to acetone in presence of a catalyst. (4) From crude wood spirit. But hitherto it has not been found possible to produce pure acetone from this source by distillation.

As the acetone in each case is mixed with considerable quantities of water, some general information on the separation of mixtures of acetone and water by distillation will first be given. The removal of the various volatile impurities will be considered separately in the more detailed description of the distillation of crude acetone from different sources, as the impurities to be removed differ in each case.

1. Separation of Acetone from Water when Mixtures of these Substances are distilled. - The vapour always contains a higher percentage of acetone than the liquid distilled. There is no general rule giving the composition of vapour and liquid in every case. But Table 88 gives the results of experiments made on a large number of mixtures.

Table 89, which is taken from E. Hausbrand, Rektifizier- und Des-tillier-Apparate, 1916, p. 164, shows the minimum heat abstraction required in the condenser of a column to produce a kilo of acetone from various mixtures of acetone and water. As in the case of ethyl alcohol and water a minimum is reached, in this case when the mixture contains 50 to 55 per cent of acetone.

Table 90 shows the composition of vapour and liquid on each plate of a rectifying column. A comparison of the corresponding tables for the distillation of ethyl alcohol and water shows that in the case of acetone and water, fewer plates are required in the column and that the necessary heat abstraction in the condenser is smaller.

Table 88

Acetone per cent by weight in liquid and vapour, H. Bergstrom. Boiling points [ ] H. R. Carveth, ( ) J. H. Pettit.1

Boiling point of liquid. °C.

Acetone in liquid.

Weight per cent.

Acetone in vapour.

Weight per cent.

Boiling point of liquid. °C.

Acetone in liquid.

Weight per cent.

Acetone in vapour.

Weight per cent.

(56.9)

100

100

[73.3]

17.5

86

99

99.5

15

84.2

[57.2]

95

97.5

[77.16]

12.5

81.93

90

96.3

(81.1)

11

79.95

[58.3]

89

96.18

10

78.4

[58.9]

85.5

95.76

[80.7]

9.5

77.6

80

95.3

8

74.4

[60.7]

76.5

95.02

7

71.2

[60.45]

72

94.72

6

67.4

70

94.6

5

62.6

(61.6)

65.5

94.33

[88.7]

4.5

59.3

(62.4)

60.5

94.03

3

47.0

[62]

55

93.6

[94.63]

2

36.0

50

93.3

1

20.4

(64.4)

45.5

9303

0.5

11.0

(65.3)

40.5

92.55

0.4

8.93

[65.9]

36

91.94

0.3

6.85

(67)

33.5

91.56

0.2

4.78

(70.7)

24.5 20

89.59 87.6

99.8

0.1

2.7

Table 89

Acetone and Water

Minimum amount of heat in great calories to be abstracted in the condenser to produce 1 kilo of acetone 99.75 per cent by weight from mixtures of water and acetone containing 95.5 to 1 per cent by weight of acetone.

Acetone content. Weight per cent.

Calories.

Acetone content. Weight per cent.

Calories.

Liquid.

Vapour.

Liquid.

Vapour.

95.5

97.75

35

91.8

55.9

95

97.5

132.9

30

91.0

59.5

90

96.3

87.7

25

89.0

66.8

85

95.7

70.2

20

87.6

81.7

80

95.3

60.5

15

84.2

108.0

7.

94.9

55.4

10

78.4

1540

70

94.6

52.3

9

76.8

168.9

65

94.3

50.3

8

74.4

192.4

60

94

49.8

7

71.2

225.1

55

93.6

49.6

6

67.4

269.3

50

93.3

49.6

5

62.6

332.6

45

93.0

49.7

2

36.0

994.3

40

92.5

51.7

1

20.0

2188.8

1 H. Bergstrom, Stockholm Aftryk ur Bitrang til Jem-KontoreVs Annaler, 1912; H. R. Carveth, J. Phys. Chem., 1899, 3, 193; J. H. Pettit, J. Phys. Chem., 1899, 3, 349.