January 1952
INDUSTRIAL AND ENGINEERING CHEMISTRY
culations along with a comparison of the experimental and calculated slopes. This test, like the former, was applied only to the data for the 450-mm. isobar. Sample calculations showed that the activity coefficient data were virtually temperature independent over the range of this investigation. The satisfactory fit of the data with the van Laar equation and the agreement between the calculated and observed boiling point curve slopes indicate that the data of this investigation are thermodynamicallyconsistent. ACKNOWLEDGMENT
The authors gratefully acknowledge the support given t o this investigation by the Research Council of Rutgers University. LITERATURE CITED
(1) Atkins, W.R.G., J . Chem. SOC.,1920,218. ( 2 ) Bachman, K.C., thesis, Rutgers University, 1950. (3) Beilstein, “Handbuch der Organischen Chemie,” 2nd supplement, Vol. 1, p. 22,Ann Arbor, Mich., Edwards Bros., 1941. (4) Bramley, A.,J. Chenz. SOC.,1916,lO.
20s
(5) Carlson, H. C., and Colburn, A. P., IND.ENG.CHEM.,34, 581 (1942). (6) Davis, W., Jr., Chem. Revs., 40,201 (1947). ENG.CHEM.,41,2875 (7) Dreisbach, R. R., and Martin, R. A,, IND. (1949). (8) Dreisbach, R. R.,and Shrader, S. A., Zbid., 41,2879 (1949). (9) Gilmont, R.,Anal. Chem., 23, 157 (1951). (10)Gilmont, R.,IND. ENG.CHEM.,ANAL.ED., 18,633 (1946). (11) Haywood, J. K.,J . P h y 8 . Chem., 3,317 (1899). (12) Horsley, L.H.;AnaZ. C h a . , 19,603 (1947). (13) Lecat, M., “Tables Azeotropiques,” Tome Premier, 2nd ed., p. 194,Ucole-Bruxelles, published by the author, 1949. (14) Nutting, H.8.,and Horsley, L. H., A n d . Chem., 19, 602 (1947). ENG.CHEM.,35,614 (1943). (15)Othmer, D. F.,IND. (16) Othmer, D.F.,and Ten Eyck, E. H., Jr., Ibid., 41, 2897 (1949). (17) Redlich, O.,and Kister, A. T., Ibid., 40,341 (1948). (18) Robinson, 5. R.,‘and Gilliland. E. R., “The Elements of Fractional Distillation,” 3rd ed., p. 221,New York, McGraw-Hill Book Co., Inc., 1939. (19) Skolnik, H., IND. ENG.CHEM.,43, 172 (1951). (20) Young, S.,“Distillation Principles and Processes,” p. 61, London, Macmillan and Co., Ltd., 1922. RECEIVED April 12, 1961. Presented before the Division of Industrial and CHEMICAL Engineering Chemistry at the 119th Meeting of the AMERICAN SOCIETY, Boston. Mass.
Vapor-Liquid Equilibria in Methanol Binary Systems N
METHANOL-PROPANOL, METHANOL-BUTANOL, AND METHANOL-PENTANOL WILLACE D. HILL’ AND M. VAN WINKLE University of Texas, Austin, Tex.
V
APOR-liquid equilibrium studies of the low molecular weight, oxidized hydrocarbons have been restricted largely to the first and second members of homologous series. This investigation is the first of a series of projects to develop data for the possible evaluation of some correlating factors for vapor-liquid equilibrium data based on the type of oxidized hydrocarbon. With the growing commercial importance of the direct oxidation process, accurate data for the design of separator units has become necessary. T o the authors’ knowledge, no complete data have been reported on any of the systems investigated. All vapor pressures used in calculating the activity coefficients were obtained from the literature. MATERIALS
The source and the physical constants of the purified materials are presented in Table I. The pentanol was fractionated for purification in a glass column, which had a &foot height and a */,-inch diameter, and was packed with glass helices. Approximately 200 ml. of a constant boiling center cut were obtained for use in the investigation. The other compounds were considered to be sufficiently pure when received. Because of the tendency of anhydrous methanol to absorb moisture from the atmosphere, the material was exposed to the atmosphere only momentarily while chargisg the equilibrium still. Periodic refractive index checks were made on all materials to detect any change in purity. Present addreaa, Monsanto Chemioal Co., Texas City, Tex.
APPARATUS
A Bausch and Lomb recision refractometer was used to determine the cornposition ofliquid and vapor Sam les taken from the equilibrium still and the purity of the chemicaE used in the investigation. Prism temperature was maintained a t 20’ C. (68’ F.) i 0.05” C. (0.09’ F.) with a Precision Scientific Co. constant temperature circulator. Monochromatic light for the optical system was obtained from a sodium vapor lamp. A Cottrell boiling point apparatus was used to check urity and to calibrate the equilibrium still thermocouple (4). &e boiling temperatures were obtained with a thermometer graduated in 0.2” C. (0.36’F.)divisions, and the temperaturedata were re orted to f0.1’ C. (0.18’ F.). Either pressure or vacuum o o u l d t e applied to the system and it could be controlled manually or with a Cartesian manostat. The boiling temperatures were transposed from the temperature at the pressure in the still to the temperature a t 760 mm. pressure, usrng the vapor pressure data for t h e pure materials as reported in the literature (8,9). The va or-liquid equilibria were determined in a Colburn still (6) modifed with respect to size and the addition of an extra
TABLE I. REFRACTIVE INDEX AND BOILINGPOINTS FOR Amonom
Compound Methanol
Propanol Butanol Pentanol
Source J. T.Baker Chem. Co. Eastman KOdak Co. J. T. Baker Chem. Co. J. T.Baker Chem. Co.
Normal Refractive B.P., O C. Index Temp., Exptl. Lit. Exptl. Lit. C. 64.7 64.7 1,32870 1.32875 20.5 97.0
97.8 1.38581 1.38543
20
117.0
117.5 1.39911 1.39931
20
137.0
137.8 1.41146 1.40994
20
INDUSTRIAL AND ENGINEERING CHEMISTRY
206 3
Vol. 44, No. 1
1 METHANOL-PROPANOL
' I W
LL 3
I4 D:
P W
I
W
c 4
3
I 0
METHANOL-PENTANOL
I
I
20 40 60 80 MOLE PER CENT METHANOL
100
Figure 1. Activity Coefficient-Composition Diagram for MethanolAlcohol Systems I . Methanol 760 mm. of mercury
heater winding (6). The still consisted of a residue chamber, a condenser, a condensate chamber, and a flash chamber. An ice water condenser, with sufficient heat transfer area t o ensure comlete condensation of the vapors rising from the condensate chamger, was used to isolate the system from the pressure source. The still was encased in a large box t o reduce the effect of convection currents on the temperature reading. The door was fitted with a glass port for observations. Residue, Bash, and condensate chambers were wound with 2 6 gage Nichrome wire covered with glass insulation. Each winding was connected t o a n independent voltage control system, and the power supply was obtained from a Solo constant voltage transformer. A 150-watt light globe was placed in series with each heater winding t o act as a voltage divider and to reduce the sensitivity of the voltage controls. Pressure control was obtained either manually or automatically by varying the static pressure of air applied a t the isolation condenser. A manometer containing n-dodecane as a n indicating fluid was used to measure the equilibrium still pressure. The manometer was isolated from the still with a n ice trap to prevent the materials in the still from contaminating the manometer fluid.
WEIGHT PER
CENT
METHANOL
Figure 2. Equilibrium Boiling Point Diagram for Methanol-Alcohol Systems
quantity of condensing vapors, After sufficient hydrostatic head was built up in the condensate chamber to start circulation, the flash and condensate heaters were turned on and the necessary voltage adjustments were made t o maintain steady circulation. Correct power settings were established as follows: the power input t o the reflux heater was adjusted to prevent refluxing; the flash boiler heater was then adjusted to allow only one drop of liquid t o remain in the boiler; finally, the flash boiler adjustment was coordinated with the residue heater input to achieve the pro er liquid holdup and t o maintain circulation. &e equilibrium still was allowed to operate until a constant liquid temperature was reached, usually for about 20 minutes.
PROCEDURE
The feed samples were prepared volumetrically to total volumes of 25 ml. A closed measuring system was used to prevent evaporation losses and moisture contamination. The sample was gravity fed from the closed system through the condensate stopcock. Condenser water was then turned on and the still pressure raised t o 760 mm. of mercury by appl ing a static air pressure at the t o p of the isolation condenser. d e air supply was obtained at 15 pounds per square inch gage and expanded through a needle valve into a jar containing calcium chloride. The jar acted as a surge tank and dryer. Two outlets were provided from the dryer; one was connected through a small needle valve to the atmosphere, and the other through a glass tee to the still and to the manometer. Pressure was adjusted by controlling the supply valve and the bleed valve. A Cartesian manostat was provided for automatic pressure control; however, manual adjustment proved more satisfactory. The barometric readings were corrected for temperature, altitude, and latitude. After the pressure had been adjusted, the residue and reflux heaters were turned on and the temperature of the liquid was raised to the boiling point. If the liquid sample was heated too rapidly, there was a tendency to superheat and to blow most of the liquid out of the still. In each run, just before the boiling began, the power input to the reflux heater was increased and the liquid level in the condensate chamber increased by the larger
WEIGHT
Figure 3.
P E R CENT
METHANOL IN LIQUID-X
Vapor-Liquid Equilibria for MethanolAlcohol Systems 760 mm. of mercury
INDUSTRIAL AND ENGINEERING CHEMISTRY
January 1952
207
TABLE 11. VAPOR-LIQUID EQUILIBRIUM DATA FOR METHANOL-PROPANOL SYSTEM AT 760 MM, OF MERCURY Tg'?!'i
1
192.2
2
181.7
3
175.5
4
172.9
5
170.0
6
165.0
7
160.3
8
157.0
9
152.0
Phase Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid
Methanol, Weight % 24.0 7.8 46.5 17.2 59.4 25.1 62.7 27.9 67.7 32.6 74.9 41.6 82.2 52.1 87.9 62.5 94.8 81.1
Methanol, Mole % 26.0 9.0 45.5 17.2 66.8 31.9 77.7 44.5 84.2 55.5 88.9 65.2 92.1 73.8 95.1 81.4 97.1 88.3
Yl ,
71,
y, Methanol
Methanol 1.12
Propanol 1.06
Corrected 25 3
1.15
1.02
44 1
1.16
0.98
65.9
1.11
0.91
77.5
1.09
0.93
84.0
1.05
0.93
88.8
1.05
0.91
92.2
1.04
0.98
94 8
1.02
1.03
96.9
EQUILIBRIUM DATAFOR METHANOL-BUTANOL SYSTEM AT TABLE 111. VAPOR-LIQUID 760 MM. OF MERCURY l/TEMPERATURE-%."
IO'
Figure 4. Vapor Pressures for
Alcohols
The run was continued for at least 30 minutes longer to ensure thermal equilibrium conditions. The main power switch was then opened, and the three-way stopcock was closed. After the still had cooled about half the liquid in the condensate and residue chambers was drained and discarded t o prevent sample contamination by any liquid that might have remained in a dead zone during circulation. The liquid and condensed vapor were then collected in a clean, dry, cold sampling oontainer and immediately sealed and chilled. Liquid and va or samples were analyzed with a gausch and Lomb precision refractometer. A rrtlibration chart prepared by plotting refractive index versus composition for each binary mixture was used to obtain the composition of the Sam les. The calibrations were obtainex by weighing one of the pure components with a chainomatic balance, adding the second component, weighing, mixing, and measuring the refractive index of the mixtureat 20" C. (68'F.).
Run No. 1
Tyn
3.'
216.5
2
203.6
3
192.2
4
183.6
5
178.1
6
177.8
7
175.0
8
166.7
9
160.5
Phase Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Liquid Vapor Liquid Vapor Liquid Vapor Liquid Liquid Vapor
Methanol, Weight % 41.1 5.5 57.7 11.0 66.9 16.0 73.6 21.0 76.2 23.9 76.9 24.4 81.5 30.6 86.9 40.0 91.4 53.1
Methanol, Mole % 59.6 10.8 75.0 20.5 ' 86.0 36.6 90.9 49.8 93.8 60.7 95.7 69.8 97.0 77.6 97.9 84.4 98.7 90.2
MethAnol 1.47
Butanol 1 .oo
72,
y, Methanol
1.29
0.83
73.3
1.10
0.87
85.0
1.07
0.91
90.6
1.06
0.94
93.8
1.04
0.98
95.7
1.02
1.05
96.9
1.01
1.14
97.9
1.00
1.18
98.7
71
Corrected 59.6
TABLE IV. VAPOR-LIQUID EQUILIBRIUM DATAFOR METHANOLPENTANOL SYSTEM AT 760 MM. OF MERCURY Run No, 1
Tyn
8''
252.5
2
235.6
3
210.9
4
190.3
5
174.5
6
172.7
7
163.9
8
153.5
SMOOTHING DATA
Phase Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid VFpp9r Liquid Vapor Liquid Vapor Liquid Vapor Liquid
There are several mathematical 9 150.9 methods for smoothing vapor-liquid equilibrium data and determining the thermodynamic consistency of the experimental results (9, 7, 10). However, none of these methods combine both simplicity of application and accuracy. Redlich (7) discusses the problems involved in developing any generalized procedure that will apply to all systems and concludes that any procedure is subject to severe limitations. Beatty and Calingaert ( 1 ) checked isobaric and isothermal data and found that a modified Duhem equation adequately expressed the experimental data over a moderate temperature range.
Methanol, Weight % ' 17.5 0.8 45.6 4.3 65.4 9.0 78 4 15.2 89.1 27.7 89.8 29.0 93.5 37.4 96.8 59.2 98 2 74.2
Methanol, Mole % 72.6 12.6 85.6 23.4 93.3 40.8 96.5 54.1 97.6 65.0 98.4 73.4 98.8 80.5 99.2 86.5 99.5 91.7
The equation (3) dlnm
dx
71
72
9, Methanol
Methino1 1.24
Penta'nol 1.00
Corrected 72.6
1.17
0.92
84.7
1.13
0.96
93.0
1.12
0.96
96.0
1.14
1.02
97.6
1.13
1.12
98.4
1.09
1.20
98.8
1.06
1.26
99.2
1.05
1.32
99.5
1 - z dln -x dx 72
where y is the activity coefficient and x the mole fraction, is applicable when the vapor is an ideal gas and the standard state is that of the pure liquid. This equation is strictly applicable only to constant temperature and constant pressure conditions. The activity coefficient is defined as:
INDUSTRIAL AND ENGINEERING CHEMISTRY
208
= "
Px
where
r
= total pressure
y
= mole fraction component in vapor = mole fraction component in liquid
P = vapor pressure of component
x
The activity coefficients for each component in each binary were calculated using even increments of mole fraction obtained from the visually smoothed weight per cent x-y curves and vapor pressure data reported in the literature (8, 9). The modified Duhem equation was applied by determining the ratio of the slopes of the logarithm of the activity coefficient versus mole fraction curves, presented in Figure 1, for each binary system. This slope ratio should equal the value of (1 - z)/z, where z represents the mole fraction. At any value of z where the ratios were not equal, the vapor compositions were adjusted within the estimated limits of experimental error ( 1 mole yo)to produce data more nearly thermodynamically consistent, as indicated by compliance with the modified Duhem equation. The greatest difficulty involved in utilizing this method was the mechanical problem of accurately measuring the slope.
Vol. 44, No. 1
contamination with small quantities of nonequilibrium material trapped in the still than would the composition of the larger same ple. Theoretically, the activity coefficients for both compoundmust be greater than one, or less than one. For this reason ths curves for propanol, butanol, and pentanol in Figure 1 were smoothed in with activity coefficient values greater than one. Thipl apparent discrepancy in activity coefficients could be caused by a slight difference in the actual vapor pressures of the compounds used in this study and the vapor pressures of the pure components as reported in the literaturc. All vapor pressure data used in the calculation of activity coefficients are presented graphically in Figure 4. NOMENCLATURE
mole fraction in liquid y = mole fraction in vapor y = activity coefficient ?r = total pressure P = vapor pressure subscript 1 = methanol subscript 2 = other binary component 5
=
LITERATURE CITED RESULTS AND CONCLUSIONS
The vapor-liquid equilibrium data were determined for the methanol-alcohol binaries a t 760 mm. of mercury pressure, tabulated in Tables I1 through IV, and presented graphically in Figures 2 and 3. The data were checked for thermodynamic consistency using the method described above, which is strictly applicable only to isobaric and isothermal data. The activity coefficients for propanol, butanol, and pentanol were all slightly less than unity a t low methanol concentrations, even after the vapor concentrations were adjusted within the estimated limit of experimental error (1%). Arbitrarily, all corrective changes in composition were made on the vapor because of the relative volumes of the vapor and liquid samples. This was done because the composition of the smaller sample would be more affected by
(1) Beatty, H.A.,and Calingaert, G., IND. ENG.CHEM.,26, 904 (1934). (2) Carlson, H.C.,and Colburn, A. P., Ibid., 34,581-9 (1942). (3) Dodge, B. F., "Chemical Engineering Thermodynamlcs,"p. 133, New York, McGraw-Hill Book Co., 1944. (4) Griswold, J., Sndres, D., and Klein, V. A., Trans. Am. Inst. Chem. Engrs., 39, 2 (1943). (5) Griswold, J., and Buford, C. B., IND.ENG.CHFM.,41, 2347, Fig. 1 (1949). ENG. (6) Jones, C. A.,Schoenborn, E. M., and Colburn, A. P., IND. CHEM.,35, 666-72 (1943). (7) Redlich, O.,and Kister, A. T., Zbid., 40,341-5 (1948). (8) Stull, D. R., Ibid., 39, 51740 (1947). (9) Thomson, Butler, and Ramchandani, J. Chem. Soc., 1935,28C-5. (10) Wohl, K., Trans. Am. Inst. Chem. Engrs., 42, 21549 (1946). RECEIVED October 7, 1960. From a thesis in partial fulfillment of the requirements for the degree of Master of Science in Chemical Engineering.
(Vapor-Liquid Equilibria in Methanol Binary Systems)
METHANOL-METHYL ETHYL KETONE, METHANOLMETHYL PROPYL KETONE, METHANOL-METHYL ISOBUTYL KETONE WALLACE D. HILL AND M. VAN WINKLE
T
HE data reported here result from one of a series of studies of
vapor-liquid equilibria of binary and ternary oxidized hydracarbon systems. Data were obtained on three of the methanolketone systems whose vapor-liquid equilibria have not been reported in the literature.
literature values for the refractive indexes and boiling points are also presented in the table. Because of the tendency of anhydrous methanol toabsorb moisture from the air, the refractive index was determined periodically to check on water contamination. APPARATUS AND PROCEDURE
MATERlALS
The chemicals used in this investigation with the exception of methyl ethyl ketone were all purchased as pure compounds. The methyl ethyl ketone was available as commercial grade containing about 96% of the desired material. A column packed with glass helices was used to purify the methyl ethyl ketone. About 500 ml. of a constant boiling center cut were obtained for use in this investigation. The source, boiling points, and refractive index of the compounds used in evaluating the vapor-liquid data for the binary systems studied are presented in Table I. The
The procedures used in purifying the materials, calibrating the equipment, and analyzing the samples were the same as those reported by Hill and Van Winkle ( 1 ) . The vapor-liquid equilibria were determined in a modified Colburn equilibrium still ( 3 )with additional modifications described in ( 1 ). DISCUSSION
Experimental activity coefficients were calculated using vapor pressure data from the literature (4). The vapor pressure-
January 1952
INDUSTRIAL AND ENGINEERING CHEMISTRY
209
METHANOL- METHYLPROWL KETONE
MOLE PER GENT METHANOL
Figure 2. Activity CoefficientComposition Diagram for Methanol-Ketone Systems 1. Methanol 760 mm. of mercurs
WEIOHT PER CENT
METHANOL
Figure 3. Equilibrium Boiling Point Diagram for Methanol-Ketone Systems WEIGHT
PER CENT METHANOL IN LIQUID-X
temperature plots are shown in Figure 1. The modified Duhem Figure 4. Vapor-Liquid Equilibria for MethanolKetone Systems equation, discussed in (I), was used to examine the experimental data and to compute “thermodynamically consistent” activity 760 mm. of mercury coefficientcomposition curves appearing in Figure 2. Vapor compositions arbitrarily corrected by this means apTABLE I. REFRACTIVE INDEX AND BOILINGPOINTS FOR KETONES pear in Tables 11, 111, and IV. B.P., C. Refractive Index The activity coefficientcomposition Compounds Source Exptl. Lit. Exptl. Lit. Temp., C . curves for each of the systems reported Methanol J. T. Baker Chem. Co. 64.7 64.7 1,32870 1.32875 20.5 Methyl ethyl ketone Commercial grade 78.6 79.6 1.38074 1.38071 16.9 here exhibit inflections. As the equation Methyl propyl ketone Mathieson Co. 102.2 103.3 1.39156 1.38946 20 used to examine the data and to correct Methyl isobutyl ketone EastmanKodakCo. 116.2 119.0 1.39611 1.3969 20 the compositions represents matheO
210
INDUSTRIAL A N D ENGINEERING CHEMISTRY
TABLE 11. VAPOR-LIQUID EQUILIBRIUM DATA FOR METHANOL-METHYL ETHYL KETONESYSTEMAT 760 MM. OF MERCURY 7%
Run No. 1
Temp., ' F. 152.9
2
151.2
3
150.0
4
148.8
6
143.5
6
146.5
7
145.9
8
146.6
9
145.0
10
146.7
Phase Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid
Methanol, Weight % 20.3 8.5 28.1 14.7 31.0 17.7 42.9 31.1 45.2 34.6 53.9 47.7 63.2 61.4 71.2 71.7 73.1 73.9 81.3 83.2
Methanol, Mole % 28.4 10.6 39.2 20.0 53.0 36.0 61.6 49.1 68.2 60.0 73.6 69.2 98.6 77.1 84.0 84.0 89.1 90.0 94.4 95.3
Methanol 2.13
Methyl Ethyl Ketone 1.04
Methanol Corrected 28.4
1.77
1.13
39.2
71,
1.43
1.14
53.0
1.27
1.23
61.6
1.16
1.31
68.2
1.11
1.44
73.6
1.06
1.57
78.6
1.05
1.69
84.0
1.03
1.94
89.1
1.03
1.98
94.4
EQUILIBRIUM DATA FOR METHANOL-METHYL PROPYL TABLE 111. VAPOR-LIQUID KETONESYSTEMAT 760 MM. OF MERCURY YZ
1
Temp., O F. 172.3
2
164.8
3
162.1
Run No.
4
156.7
6
153.1
6
161.0
7
l48.2
8
147.0
9
147.1
Phase Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid
Methanol, Weight % 27.4 7.1 41.3 14.8 49.8 22.4 56.4 30.1 63.3 40.7 72.5 55.4 79.9 67.7 88.9 83.2 94.3 91.9
Methanol, Mole % 42.1 12.4 57.6 23.0 70.5 40.2 77.0 53.5 81.9 64.2 85.9 72.9 89.1 80.2 92.0 85.6 94.7 91.5
71, Methanol 1.86
Methyl Propyl Ketone 1.54
iMethanol Corrected 42.1
1.63
1.58
57.6
1.33
1.74
70.5
No.
8''
1
188.6
2
170.9
a
180.5
4
158.1
6
157.0
6
154.1
7
153.8
8
150.5
9
148.5
10
146.0
Phaae Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor Liquid
Methanol, Mole Yo 64.7 14.1 75.1 25.8 83.4 43.9 87.2 57.3 89.6 67.6 81.5 75.8 93.3 82.4 95.0 88.0 96.6 92.6 98.3 96.6
The vapor-liquid equilibrium data were determined for three methanolketone binary systems a t 760 mm. of mercury pressure. The data are tabulated in Tables 11., '111., and IV and are presented graphically in Figures 3 and 4. The data were checked for thermodynamic consistency based on the modified Duhem equation. The data are not strictly thermodynamically consistent by this test. However, the authors feel that because of the limitations of the equations discussed above, there is no reason to believe the smoothed data are more accurate than the experimental data. The binary system methanol-methyl ethyl ketone a t 760 mm. of mercury pressure exhibits an azeotrope a t 70 weight % methanol a t a temperature of 164.5"F. This agrees with the azeotrope data reported by Horsley ( 9 ) . The other binary systems do not form azeotropes at 760 mm. of mercury pressure. LITERATURE CITED
1.88
77.0
1.11
2.10
81.9
1.09
2.37
85.9
1.07
2.62
89.1
1.05
2.69
92.0
RECEIVED October 7, 1950. From a thesis in
1.02
3.04
94.7
71
Methanol Weight %' 35.7 4.8 61.6 11.6 62.5 21.0 65.3 25.8 72.1 37.0 73.6 41.1 74.3 41.6 79.9 55.4 65.8 69.7 90.8 81.0
RESULTS AND CONCLUSIONS
1.18
KETONE SYSTEM AT 760 Mhi. OF MERCURY
TEm
matically a hyperbola, no slope ratios were used in the region of the inflections. For the same reason neither the van Laar nor Margules equations could be used to represent the data in this region.
(1)Hill, W. D., and Van Winkle, hl., XND. ENG.CHEM.,44, 205 (1952). (2) Horsley, L.H., A n d . Chem.,19,508-85 (1947). (3) Jones, C. A., Schoenborn, E. M., and Colburn, A. P., IND. ENG.CHEM., 35,666-72(1943). (4)Stull, D.R., Ibid., 39,51740 (1947).
EQUILIBRIUM DATAFOR METHANOL-METHYL ISOBUTYL TABLE IV. VAPOR-LIQUID
Run
Vol. 44, No, 1
Metha'nol 2.10
Met'hyl Isobutyl Ketone 1.49
Methanol Corrected 64.7
1.81
1.82
75.1
1.41
2.16
83.4
1.28
2.44
87.2
1.17
2.80
89.6
1.10
2.22
91.5
1.07
3.57
93.3
1.05
4.06
95.0
1.03
4.56
96.6
1.01
5.00
98.3
Y1
partial fulfillment of the requirements for the degree of Master of Science in Chemical Engineering.
