March, 1942
INDUSTRIAL AND ENGINEERING CHEMISTRY
= constant for one kind of oil in Equation 2 = pressure, Ib./sq. inso T = press temperature C. W , = oil content of seed, dry basis ’
K P
W z g a
e Y
= = = = = =
oil yield, weight per cent on dry basis exponent for pressure exponent for ressing time exponent for finematic viscosity r i n g time, hours inematic viscosity of oil at press temperature, stokes
Subscripts d = dry basis w = wet basis
Acknowledgment The author wishes to thank W. H. McAdams of the Massafor his suggestions and adchusetts InstituteOf vice.
345
Literature Cited Beisler, W. H., Chem. & Met. Eng., 37, 614 (1930). Better, E. I., and Munk, F., Allegem. Oel- u. Fett-Ztg., 29, 79 (1932). Fischer Scientific Co.oatalog, p. 864. GoldovskiL A. M., Fettohem. Umsohau, 43,21, 57, 84 (1936). Goldovskii, A. M., Trudy NZRMMZ, 1, 64 (1933). Goldovskii, A. M.,and Lynbaskaya, M., Masloboho Zhirovoe DeZo, 11, 586 (1935). Heublyum, R., and Japhe, H., Allegem. 0 e l . - u. Fett-Ztg., 32, 9 , 254 (1936). 401,447,497 (1935); 33, 13,49,96, 141,19’ Jamieson, G. S., “Vegetable Fats and Oils”, A. C. S. Monograph 58,p. 20, New York. Chemical Catalog Co., 1932. Kolpakov, I., and Pasmanik, M., Chimie & industrie, 31, 639 (1935). (10) Kio, E.‘C., J. Chem. Eng. China, 4 , 15,207 (1937); 5, 47, 69 (1938); 7, l(1940); 8 (1941). (11) Taylor, R. B., Chem. & Met. Eng., 44,478 (1937). (12) Woolrich, W.R., and Carpenter, E. L., Food Industries, 5 , 260 (1933). PnBLisxmn by permission of the Director, National Bureau of Industrial Research. China,.
Vapor-Liquid Equilibria of the System Acetone-Acetic Acid-W ater ROBERT YORK, JR., AND ROBERT C. HOLMES’ Carnegie Institute of Technology, Pittsburgh, Penna.
One method is described for measuring the one described is to obtain vapor EVEFUL industrial procvapor-liquid equilibria of miscible ternary samples in equilibrium with a esses, particularly those for boiling liquid by distilling a manufacturing cellulose systems under constant total pressure. relatively small amount (o.5 per acetate and related products, revalues are Presented for these cent) of vapor from a flask conquire separating an aqueous aceequilibria of the ternary system acetonetaining a large amount of liquid, tic acid solution from an organic solvent. This separation is acetic acid-water, and of the corresponding This method has the advantage usually accomplished by distillabinary systems acetone-water, acetoneof simplicity, but the disadvantages of requiring a large tion with rectification in fracacetic acid, and acetic tionating columns. Both the deliquid sample, of collecting a sign and operation of these small vapor sample for analysis, and of obtaining vapor condensation on the cold sides of columns are facilitated by having values of the vapor-liquid the flask during the initial part of a run. This condensaequilibrium compositions. Because most commercial columns operate under an approximately constant total pressure, tion results in reflux, which causes rectification and a partial scrubbing action and which yields a vapor that is richer in generally atmospheric, it is desirable to have the equilibria the more volatile component than is a vapor in equilibrium corresponding to this total pressure. Relatively few ternary systems have been investigated with the liquid. The second method, proposed by Rosanoff, Lamb, and under constant total pressure. Most values for the vaporBreithut (.%?),consists of passing a vapor of constant comliquid equilibria of ternary systems have been determined a t position through a liquid until equilibrium is reached. Thereconstant temperature, primarily for thermodynamic study of nonideal solutions. With acetone as the third comfore the composition of the vapor does not change on bubponent, the vapor-liquid equilibria were studied for the sysbling through the liquid. Although this method is capable of tem acetone-acetic acid-water under a total pressure of 760 producing accurate results, it requires skillful manipulation in supplying a stream of vapor of constant composition. The mm. of mercury. experimental technique is even more difficult with a ternary Experimental Methods Available system than with a binary mixture. The third method, suggested and successfully used by For measuring vapor-liquid equilibria, there are four accepted methods from which to choose. The first and earliest Rosanoff, Bacon, and White (IO),consists of collecting several successive portions Of the condensed vapor from a batch 1 Present address, Engineering Department, E. I. du P o n t de Nemours & tillation. By extrapolating the composition of these samples Company, Inc., Wilmington, Del.
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INDUSTRIAL AND ENGINEERING CHEMISTRY
to the point where zero distillate would be collected, 0 5 IO values for the vapor-liquid u equilibria are obtained. By extending this mathenptical procedure, many results may be calculated from few experimental data. However, the calculations involved are somewhat tedious. By this method an equilibrium vapor is not produced a t the start of the run because of initial condensation and the resulting reflux. This difficulty is obviated, however, by recycling the condensed vapors a t the start of a run until the flask reaches boiling temperature, after which no condensation occurs (1). The fourth, and perhaps most widely accepted method, is that proposed and developed by Othmer K (13-16). It consists of distilling a liquid from a flask, FIGURE 1. EQUILIBRIUM condensing the resulting STILL vapor, collecting the condensate in a holdup trap, and returning this condensate to the flask without contacting the vapors from the distillation. After sufficient time the compositions of the liquid in the flask and of the liquid in the holdup trap become and remain constant. These compositions are those of a liquid and its equilibrium vapor, respectively. The apparatus developed for this method is usually referred to as the Othmer equilibrium still. Of these several methods, that of Othmer was chosen for this investigation, first, because of the relatively simple experimental technique, and secondly, because of the accuracy bf the measurements.
Apparatus
Vol. 34, No. 3
the holdup trap; and a tube K , for returning the liquid t o the still. Both the still and holdup trap are provided with groundglass stoppers, L and M , for withdrawing samples for analysis. The small capillary hook on the bottom of tube E was drawn in order to eliminate liquid drops from splashing onto the thermometer bulb. The still was fabricated entirely from Pyrex glass and thus avoids contamination from rubber, cork, or other materials commonly used in making joints. To determine boiling temperatures, a thermometer is suspended from a glass hook inside the large ground-glass stopper at the top of the still head in the central vapor tube E. The type used is the short-stem Anschutz thermometer, completely immersed and therefore requiring no stem correction. The still is equipped with both internal and external heating coils; the former gives a hot spot for producing smooth boiling and the latter provides heat for vaporization. The internal coil is Chrome1 resistance wire covered with glass to prevent both corrosion and electrolysis, and is silver-soldered to tungsten leads sealed in the ground-glass stopper L. The external coil is resistance wire wrapped around asbestos paper and covered with additional asbestos paper and cord. BAROSTAT.Since the still was t o be operated under a constant absolute pressure, it was desirable to utilize a pressure control. The barostat used was constructed and assembled as described by Gould and Evans ( 5 ) and equipped with a vacuum tube control circuit. &SEMBLY. The schematic arrangement of the assembled apparatus is illustrated by Figure 2. The equilibrium still, G, is connected through the reflux condenser to a 5-gallon carboy, E,which serves as a constant-pressure reservoir. This carboy is provided with a safety trap, F , containing mercury in the Utube portion. Air is supplied t o reservoir E through solenoid valve D, which is activated by the electrical circuit of the barostat. The electrical circuit of the barostat is closed by the change in mercury level of the closed manometer, C, sealed at the top of the central tube and provided with tungsten leads B. Rise (or fall) of mercury in the central tube of the manometer closes (or opens) the contact in the grid circuit of the vacuum tube through the leads B. The operating pressure of the barostat is adjusted by adding or removing mercury through the stopcocks in the ri ht hand column of the manometer. The barostat is finally afjuited to the desired pressure by noting the reading of the open manometer, A , above the barometer. Once adjusted, the barostat need not be reset, because the sealed control manometer is not subject to variations in atmospheric pressure.
Experimental Procedure Operation of the still and barostat is simple, once they are properly adjusted. Samples of approximately the expected compositions are added to the still and t o the holdup trap. The electrical heating coils are switched on, and the current
The Othmer equilibrium still was modified by Scatchard, Raymond, and Gilmann (21). They provided an outside vapor jacket to avoid reflux and a Cottrell liquid pump to avoid superheating and to ensure the determination of precise boiling temperatures. They also employed a reflux condenser to shorten the still and thereby reduce condensation. W7hile the Scatchard still appears to be the preferred apparatus for obtaining isothermal values suitable for thermodynamic study, its construction is complicated; a simpler equilibrium still would seem to be satisfactory for obtaining most engineering data. Our still is basically the same as Othmer’s but was modified b y using the reflux condenser arrangement of Scatchard and co-workers. STILL, The equilibrium still used is shown in Figure 1. It consists of the followin5 essential parts: a large (1-liter) still body A , contaming the liquid, B , and provided with b o d internal, C, and external, D, electric heating coils; a tube, E, for removing the vapors, in which a thermometer is suspended; an inclined tube, F, for conducting the vapors to reflux condenser U and any condensate to holdup trap H; a capillary tube, I, for equalizing pressure; a tube, J, for conducting the condensate to
B
u
ARRANGEMENT OF APPARATUS FIGURE 2. SCHEMATIC
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347
ACEJONE
GRAVITY OF ACETONE-ACETIC ACID-WATERSOLUTIONS AT 25O C. FIGURE3. SPECIFIC RELATIVE TO WATERAT 25" C.
is later adjusted by rheostats to give the desired rate of boiling. The still is then vented to the atmosphere to allow the escape of any trapped air, which otherwise would alter the true vapor composition. The barostat is then brought into operation t o raise the total pressure to 760 mm. of mercury. With each sample the still was allowed to run for approximately 20 hours. This cycle of operation is undoubtedly much longer than necessary for reaching equilibrium, since the liquid in the holdup trap is displaced about every 20 minutes. However, this interval of 20 hours ensured the attainment of equilibrium and was chosen because samples could not conveniently be withdrawn more than once a day. I n stopping the still to obtain liquid samples, the heating coils are first shut off. After cooling, the contents of the stiil are allowed to reach existing atmospheric pressure by switching off the barostat. Samples are then withdrawn through drawoff tubes equipped with rubber stoppers inserted into the ground-glass joints of both the still and holdup trap. The pressure of the barostat is utilized to force the samples from the still. This avoids any flashing that might occur with the reduced pressure necessary to remove the samples with pipets. These samples are collected in ice-cooled glassstoppered bottles to avoid evaporation loss and then analyzed.
Analysis For analyzing binary liquid mixtures, either a chemical or a physical method may be used. The chemical method must be one in which side reactions are negligible. The physical method consists of measuring a 'physical property that varies with composition. Such properties as density (or specific gravity), refractive index, boiling point, and freezing point are commonly used. For analyzing ternary liquid mixtures,
values of two independent properties are needed to determine a composition. As a practical working principle, it is well to bear in mind that a wide divergence in properties increases the accuracy of analysis. It is usually necessary to calibrate physical properties as a function of composition. For ternary systems, constant values of these properties are plotted for convenience as lines on a triangular diagram. It is desirable that such lines for different properties intersect a t approximately right angles. Such an intersection will improve the accuracy of determining a composition from two separate properties. Of the several properties available for the analysis of the acetic acid-acetone-water system, specific gravity and acidity were chosen for simplicity and accuracy. Acidity was measured by titrating the samples with 0.1 N barium hydroxide solution. Specific gravity was determined by weighing on an analytical balance a 25-ml. pycnometer filled with the solution. Specific gravity calibrations were obtained for each of the three binary systems involved by weighing in the gravity bottles solutions of known compositions made from the pure components. Further gravities were obtained for the ternary system by adding weighed amounts of acetone to fixed mixtures of acetic acid and water. From these data, curves of specific gravity were plotted for a mixture coneisting of acetone and a fixed ratio of acetic acid to water. Since all compositions of this nature are represented by straight lines on triangular coordinate paper, it was relatively simple to cross plot for compositions of a fixed specific gravity. From these compositions curves for fixed specific gravity were then drawn on the triangular diagram. The final plot of specific gravity a t 25" C. relative to water a t 25" C. is shown as Figure 3.
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Vol. 34, No. 3
TABLE I. VAPOR-LIQUID EQUILIBRIA OF ACETONE-WATER TABLE11. VAPOR-LIQUIDEQUILIBRIA OF ACETONE-ACETIC SYSTEM UNDER 760 MM. ABSOLUTE PRESSURE ACIDSYSTEM UNDER 760 MM.ABSOLUTE PRESSURE u, Acetone in Vapor ~ ~ i l 2i, Acetone ~ ~ in Liquid ~ ~ i l D,i Acetone ~ ~ in Liquid y, Acetone in Vapor Temp., e C. 100.0 103.2 100.0 84.7 75.0 75.1 68.3 64.6 64.0 63.8 62.4 63.3 60.4 60.0
Weight %
1 .o
3.3 3.8 7.7 15.6 22.3 27.2 37.3 43.7 61.4 72.1 84.2 92.6 98.1
Mole % 0.3 1.1 1.1 2.5 5.4 8.2 10.4 15.6 19.4 33.0 44.5 62.2 79.5 94.1
Weight % 13.1 35.8 45.3 70.2 85.1 87.1 89.8 92.4 92.6 93.8 94.1 95.1 96.6
98.7
Mole % 4.4 14.7 20.4 42.2 61.5 67.8 73.0 79.1 i 79.5 82.5
83.2 85.5 89.6 95.9
Temp., C. 112.1
l0?:4 106.3 106.1 105.4 104.6 101.4 98.7 94.3 92.5 90.4
87.0
86.3 78.6 74.2
70.8
65.6 63.6
Weight % 4.1 8.0 10.0 11.7 12.4 11.5 15.4 18.9 18.0 22.0 23.1 26.4 28.7 30.0 42.5 53.1 54.3 66.0 75.4 93.3
Mole %
Weight %
Ilole %
4.2 8.2 10.3 12.0 12.7 11.8 15.8 19.4 18.6 22.6 23.6
27.1 29.4 30.7 43.3 53.8 55.0 66.8 76.1 93.5
60.7 The acetone and acetic acid used in obtaining specific gravity data were c. P. grade and were carefully dried. Distilled water was used throughout. TABLE111. VAPOR-LIQUID EQUILIBRIA OF ACETIC ACID-WATER SYSTEM UNDER 760 Mix ABSOLUTEPRESSURE Results on the specific gravities for the acetic acid-acetone-water system are presented graphioally on the triY, Water in Vapor ~ ~ i 1 i % ~ D, Water in Liquid Temp., C. Weight % Mole 7c Weight 70 Mole 70’ angular diagram of Figure 3. The specific gravity of only 2.7 8.5 113.7 5.2 15.5 the acetone-water system could be checked with values in 9.8 26.7 16.5 108.7 39.8 the literature. Our values agree well with those determined 18.0 42.3 26.4 54.5 105.7 27.5 55.9 37.6 66.8 104.2 by McElroy ( l a ) and fairly well with those of Squibb (9.9). 36.8 66.0 49.2 102.5 76.4 101.8 48.5 75.8 60.0 83.3 Other values available in the literature were inconsistent with 82.5 68.5 102.2 58.6 87.9 the above data. 66.7 87.0 75.9 91.3 100.8 Results for the three pairs of systems are presented in Tables I, 11, and I11 and graphically as Figure 4. The ordinate, y, is the mole per cent of the more volatile component Acetone-Water System (M. V. C.) in the vapor phase; the abscissa, x, is the mole per cent of the more volatile component in the liquid phase. Experimental values for the vapor-liquid equilibria of the The experimental results on each of the three binary systems acetone-water system under a constant total pressure of 760 are compared with values in the literature as follows. mm. of mercurv absolute are Dresented in Table I. These values are &ranged in order of increasing acetone concentration, expressed both as weight per cent and as mole per cent, Boiling temperatures are also listed, although it should be emphasized that they are in error by as much as 0.5’ C. This error is probably due to radiation from the inner heating coil to the thermometer bulb. The only sound method for making this measurement is to allow vaporization t o take place on the thermometer bulbfor example, by using a Cottrell pump. The x-yvalues are also shown graphically as the upper curve of Figure 4 labeled “Acetone (M. V. C.)-Water”. The corresponding values determined by Bergstrom (2, 6) are shown as the dashed curve. Only the smoothed curve was available from Bergstrom’s data. Our points lie consistently below h i curve. If this difference had been due to reflux in one or the other of the stills, it must necessarily have been in Bergstrom’s still since reflux would yield a vapor richer in the more volatile component. The deviations might conceivably be due to entrainment, but vapor velocities are so low that this can hardly be expected. The upper solid curve of Figure 4 shows that points around 2 = 15 per cent do not lie on a smooth line. This might be expected from experimental observation of erratic boiling, regardless of how the heat input was varied. This same “critical-boiling” region was found to extend FIQURE 4. EQUILIBRIUM DIAGRAMS FOR BINARYSYSTEMS UNDER A TOTAL slightly into the ternary system. It does PRESSURE OF 760 MM.OF MERCURY
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INDUSTRIAL A N D ENGINEERING CHEMISTRY
349.
ACETONE
FIGURE5. VAPOR-LIQUID EQUILIBRIA FOR ACETONXPACETIC ACID-WATER SYSTEMUNDER 760 MM. TOTALPRESSURE
not, therefore, seem unreasonable to predict that this same phenomenon will occur in commercial~distillingunits a t compositions around 15 mole per cent acetone. By using boiling temperatures estimated from the boiling pointrcomposition data of Carveth (3) and Haywood (Y), and vapor pressures for acetone (9) and for water (8),these zy values were fitted t o the van Laar equation for activity (10):
The best fit of experimental values to the van Laar equation was obtained with A = 0.89 and B = 0.65. In fitting data to an equation of this type, the assumption has been made that under 760 mm. total pressure the vapors of acetone and water obey the perfect gas laws. Strictly speaking, the van Laar equation holds only a t constant temperature, but since activity coefficients change only slightly with temperature for this system, the equation may be applied to constant pressure values.
Acetone-Acetic Acid System
A * a constant = 0.89 (for acetone-water) B = a constant = 0.65 (for acetone-water) p = partial pressure of a component P = vapor pressure of pure component 2 = mole fraction in liquid phase 2/ = mole fraction in vapor phase ?r = total pressure on system (760 mm. Hg) y = activity coefficien6 Subscript 1 = acetone (M. V. C.) Subscript 2 = water
Experimental values for the vapor-liquid equilibria of the acetone-acetic acid system under 760 mm. absolute total pressure are presented in Table I1 and are shown graphically as the middle curve, “Acetone (M. V. C.)-Acetic Acid”, of Figure 4. No values on this system were found in the literature for comparison. In all calculations for converting weight fractions involving acetic acid mixtures into mole fractions, a molecular weight of 60.03 for the single molecule of acetic acid was used throughout. On the one hand, MacDougall (11) recently showed that at room temperature the molecular weight of acetic acid vapor is slightly less than 120, which corresponds t o the double molecule. He showed further that a t higher temperatures dissociation into the single molecule increases. For example, a t 100” C. and under atmospheric pressure the molecular weight of acetic acid vapor is around 107, this approximate value being dependent upon other vapors present. On the other hand, to obtain the same value of Trouton’s constant, a molecular weight of approximately 85 is necessary. Equal values of Trouton’s constant are desirable for rectification calculations, because the molal vaporization and con-
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OF ACETONE-ACETICACID-WATER TABLEIV. VAPOR-LIQUIDEQUILIBRIA SYSTEM UNDER 760 MM. ABSOLUTE PRESSURE
.
Boiling Temp.,
c.
.
2.3 3.0 5.1 5.4 7.7
1.2 2.0 3.9 2.1 5.3
41.5 24.1 14.2 70.4 21.3
70.2 51.4 3’5 5 88 7 47.3
16.4 15.9 21.6 49.6 31.0
8.1 9.8 15.0 25.7 20.5
47.2 28.9 18.8 42.2 23.8
92.0 95.0 93.9 93.4 83.8 84.6
9.1 9.3 14.0 14.6 18.0 18.8
5.0 4.9 11.4 10.3 10.0 11.0
37.1 41.4 19.7 3G.G 32.8
66.1 70.1 30.3 44.8 65.6 61.7
45.6 46.0 47.2 49.6 70.1 71.1
26.7 26.7 37.0 35.3 47.6 49.7
32.1 32.9 13.1 18.7 21.4 19.6
90.0 81.4 87.2 82.9 75.2
19.4 24.7 25.2 30.1 30.9
16.0 17.7 24.9 18.6
10.6 18.8 lG.9 9.1 30.2
28.1 43.3 40.1 25.4 58.7
59.1 75.0 67.6 75.5 83.5
48.3
18.6
52.9 65.5 65.1
10.5 13.3 12.9 7.1 12.7
80.8
33.6 36.1 37.4 43.5 45.0
28.9 28.4 29.0 28.7 39.8
8.2 12.9 13.8 23.8 6.6
22.8 32.7 34.4 50.5 18.8
79.8 83.2 83.7 89.4 88.5
71.3 71.0 71.0 76.0 81.0
5.6 7.8 8.2 8.6 4.2
45.1 48.9 50.2 52.2 55.9
24.9 40.8 40.7 37.0 51.1
36.8 9.6 11.0 18.9 4.8
65.4 26.8 28.8 43.2 14.1
90.6 89.5 90.1 91.4 92.9
75.9 79.9 80.0 79.0 87.3
2.9
62.3 62.9 64.1 75.3
54.3 53.2 41.8
3.7 7.8 24.2 4.9
87.6
74.8 87.9
12.2 22.0 50.8 14.3 21.4 5.0
94.4 94.8 93.9 97.0 96.6 98.8
89.5 87.9 83.1 92.5 90.2 96.6
2.5 3.6 5.8 2.2 3.2 0.9
.I.
70.8
70.9 70.7 68.0 69.8 66.5 65.0 61.9 60.7 61.0 58.6
90.8
68.3
ll.G
7.8 1.6
08.0
;:; 5.7 8.1
densation are fixed by an enthalpy balance. Sometimes variations in Trouton’s constant, and hence in the molal enthalpy of vaporization, are allowed for by assigning a fictitious molecular weight to one component and thus giving the so-called latent heat units. Such units could be computed and used for these vapor-liquid equilibria in distillation calculations.
Water-Acetic Acid System Experimental z-y values for the water-acetic acid system under 760 mm. pressure are presented in Table I11 and shown graphically as the lower curve, “Water (M. V. C.)-Acetic Acid”, of Figure 4. Data of Cornell and Montonna (4), of Povarnin and Markov ( I @ , and of Pascal, Dupuy, and Garnier (27’) are also included. Inspection of the lower curve and its neighboring points shows good agreement between our values and those of Cornell and Montonna, but decided inconsistencies with those of the other two groups of investigators. These inconsistencies are apparently due to reflux which gives a vapor richer in the more volatile component.
TABLE V. COMPARISON OF VAPORCOMPOSITIONS FROM EXPERIMENT, FROM FIGURE 5, AND FROM CALCULATIONS AS IDEAL SOLUTIONS (IN MOLEPERCENT) Liquid Acetone 0.0
10.0 11.4 17.7 23.6 33.0 37.0 39.8 68.3
Acetone-Acetic Acid-Water System
Experimental values for the vapor-liquid equilibria of the ternary system acetone-acetic acid-water, under 760 mm. total pressure are presented in Table IV. The values are arI‘i.0 57.3 ranged in order of increasing acetone con43.5 70.2 centration. By suitable cross plotting, these 50.6 values were interpolated for fixed compositions 60.8 of acetone in the vapor phase and likewise 61.5 for water. It is customary t o represent prop33.0 42.9 erties of a ternary system by an equilateral 46.8 triangular diagram. Figure 5 is a plot of the 44.0 27.7 liquid compositions, with curves of constant 33.2 vapor composition shown solid for acetone 32.4 and dashed for water. As an example of the 19.8 32 0 use of this diagram, a liquid of 20 mole per 16.1 cent acetone, 60 per cent acetic acid, and 20 21.5 per cent water yields a vapor of 57 per cent 22.4 23.3 acetone, 18 per cent water, and the difference 12.5 from 100 (25 per cent) for acetic acid. 23.5 As a check on the accuracy expected in read16.8 16.4 ing values from this triangular diagram, values 19.8 8.8 were chosen a t random from Table IV and 7.6 compared with corresponding values from 10.7 Figure 5 . They are listed in Table V and are 16.6 6.8 in agreement within 0.5 per cent. I n addition,- the vapor compositions have been calcu2.9 9.7 lated by assuming that Raoult’s lam; holds for the liauid Dhase and that Dalton’s law is valid ‘for ihe vapor phase. These calculated values are listed in Table V and differ from experimental compositions by an average (arithmetic) of 17 per cent. The assumption that this ternary system obeys the ideal solution laws would lead t o considerable error in designing or operating fractionating columns.
Liquid 7 Vapor --Acetone--Water---Acetone-WaterW t . % hIole W t . % 3Iole % W t . % Mole % W t . % Mole 5% 7
99.4 101.4 101.8 92.3 98.8
70.0
VOl. 34, No. 5
Water
55.9 65.6 30.3 43.3 0.0 67.0 43.2 18.8 14.3
Experiment Acetone Water
0.0 47.6 37.0 58.0 58.0 82.5 79.0 81.0
92.5
66.8 46.8 33.0 33.2 0.0 17.5 19.8
12.5 6.8
Vapor Figure 5 Acetone Water
0.0 47.3 37.0 57.0 58.0 82.5 79.0 81.0 92.7
60.8 47.0 33.0 35.0 0.0
17.5 19.9 12.5 6.5
Calculations Acetone Water
0.0 35.1 40.9 54.3 67.8 73.0 77.8 78.3 94.0
c,
c
Literature Cited Baker, E. M., Chaddock, R. E., Lindsay, R. A., and Werner, R. c . , IND.ENQ.CHEM.,31, 1263 (1939). Bergstrom, H., Bzh. Jernkont. Ann., 13, 37 (1912). . , Carveth, H. R., J . Phgs. Chem., 3, 193 (1899). (4) Cornell, L. W., and Montonna, R. E., IND.ENG. CmM., 25,
1331 (1933). ( 5 ) Gould. F. A.. and Evana. J. C., J . Sci. Instruments, 10, 215 (1933). (6) Hausbrand. E., ”Principles and Practice of Industrial Distillation”, p. 215, New York, John Wiley & Sons, 1926. (7) Haywood, J. K., J . Phgs. Chem., 3, 317 (1899). (8) Hodgman, C. D., Handbook of Chemistry and Physics, 20th ed., p. 1263, Cleveland, Chemical Rubber Pub. Co., 1935. (9) International Critical Tables, Vol. 111, p. 218, New York, McGraw-Hill Book Co., 1928. (10) Lam, J. J. van, 2. physik. Chem., 72, 723 (1910), 83,599 (1913);
(11) (12) (13) (14) (15) (16) (17) (18)
Hildebrand, J. H., “Solubility of Non-Electrolytes”, A. C. S. Monograph 17, 2nd ed. pp. 41-2, New York, Iteinhold Pub. Corp., 1936. MacDougall, F. H., J . Am. Chem. SOC.,58, 2585 (1936). McElroy, K. T . P., Ibid., 16,618 (1894). Othmer, D. F., IND. ENQ.CHEM.,20, 743 (1928). Ibid., 22, 232 (1930). Othmer, D. F., IND.EXG.CHEX.,ANAL.ED., 1, 97 (1929). Ibid., 4, 232 (1932). Pascal, P., Dupuy, D., andGarnier, Bull. SOC. chim., 29, 9 (1921); International Critical Tables. Vol. 111,1). 310 (1928). Povamin, G., and Markov, V.,J . Russ. P h y s . Chem. Soc., 55, 381 (1924): International Crltical Tables, Vol. 111, p. 310
69.4 53.5 28.4 30.1
(1928). (19) Rosanoff, M. A,, Bacon, C. W., and White, R. H., J . Am. Chem. SOC.,36, 1803 (1914).
0.0
(20) Rosanoff, M. A., Lamb, A. B., and Breithut, F. E., I b i d , 31,
27.0 17.5 7.7 3.5
448 (1909’). (21) Soatchard, G., Raymond, C. L., and Gilmann, H H., Ibid., 60, 1275 (1938). (22) Squibb, E. R., Ibid., 17, 187 (1895).
