Vapor-Liquid Equilibrium Diagrams of Alcohol-Ketone Azeotropes as a Function of Pressure 1
E. C. BRITTON, H. S. NUTTING, and L. H. HORSLEY
Downloaded by SUNY STONY BROOK on November 3, 2014 | http://pubs.acs.org Publication Date: June 1, 1973 | doi: 10.1021/ba-1973-0116.ch003
The Dow Chemical Co., Midland, Mich.
Pressure has a marked effect on the azeotropic composition and vapor -liquid equilibrium diagrams of alcohol-ketone systems (1). This is due to the fact that the slopes of the vapor pressure curves of alcohols are appreciably greater than for ketones; it results in an unusually large change in the relative boiling points of the components of an alcohol -ketone system with change in pressure. As a result of the study of these systems, it has been found that the methanol-acetone azeotrope exhibits the unusual phenomenon of becom ing nonazeotropic at both low and high pressures—that is, below 200-mm. pressure the system is nonazeotropic with methanol as the more volatile product, while above 15,000 mm. the system is nonazeotropic with ace tone the more volatile component. Some of the equilibrium data for this system and two other alcohol -ketoneazeotropes are shown in Figures 1 and 2 on the following pages. The similarity of the diagrams for the different systems at suitable pres sures is of interest. For example, the diagram for methanol-acetone at 10,000 mm. corresponds approximately to the diagram for methanol -methyl ethyl ketone at 1000 mm. and for ethanol-methyl propyl ketone at 100 mm. Literature Cited (1) Britton, E. C., Nutting, H. S., Horsley, L. H. U.S. Patent 2,324,255 (July 13, 1943).
1
Deceased. 623
In Azeotropic Data—III; Horsley, L.; Advances in Chemistry; American Chemical Society: Washington, DC, 1973.
Downloaded by SUNY STONY BROOK on November 3, 2014 | http://pubs.acs.org Publication Date: June 1, 1973 | doi: 10.1021/ba-1973-0116.ch003
624
200,
AZEOTROPIC DATA
METHANOLETHANOLMETHYL ETHYL METHYL PROPYL KETONE KETONE
METHANOL ACETONE >r
180
160
r
IV
11
11,09 Omm II 090 mm.
5,4 00 mm.
\
—
140 4,€>30rrim. 120
\
I
2,0 40 m m.
Ι00| α. δ
80 75 7mn
ο m 60
747mm.
)——
Ν
f
V , •
27 5mm
10 0
•
10Omm • —
2 00 mm. 10Omm
20
Î7mnn. —
)
)
40
I\
•71
\
r
20 40
60
kl 80 KX) 0 20 40 Θ0 80100 \\0 WEIGHT PER CENT ALCOHOL
20 40
60
80 100
Figure 1. Vapor-liquid equilibrium diagrams of alcohol-ketone systems at various pressures
In Azeotropic Data—III; Horsley, L.; Advances in Chemistry; American Chemical Society: Washington, DC, 1973.
625
Alcohol-Ketone Azeotropes
Downloaded by SUNY STONY BROOK on November 3, 2014 | http://pubs.acs.org Publication Date: June 1, 1973 | doi: 10.1021/ba-1973-0116.ch003
METHANOL ACETONE
METHANOLETHANOLMETHYL ETHYL METHYL PROPYL KETONE KETONE
Ο
20 40 60 80 100 0 20 40 60 80100 .0 20 40 60 80100 AVERAGE WEIGHT %ALC0H0L IN LIQUID AND VAPOR IN EQUILIBRIUM
Figure 2.
Difference in composition of vapor and liquid in equilibrium
Shown as a function of corresponding average composition of vapor and liquid for alcohol-ketone systems
In Azeotropic Data—III; Horsley, L.; Advances in Chemistry; American Chemical Society: Washington, DC, 1973.
