J. Chem. Eng. Data 1884, 29, 417-419 RIOldry No. COP 124-38-9; n-dotrlacontane, 544-85-4; n-docosane, 629-97-0.
417
(11) Sebastlan, H. M.; Sknnlck, J. J.; Un, H.-M.; Chao, K.C. J. Chem. Eng. Date 1980, 25, 138. (12) Hule, N. C.; Luks, K. D.; Kohn, J. P. J . Chem. Eng. /Ma 1973, 18,
-31. 1..
Llterature Clted (1) Reamer, H. H.; Sage, 6 . H. J . Chem. €178.Date 1963, 8,,500. (2) Kulkami, A. A.; Zarah, B. Y.; Luks, K. D.; Kohn, J. P. J . Chem. Eng. Date 1974, 19, 92. (3) Stewart, W. C.; Nlelsen, R. F. Rod. Mon. Jan 1954, 18, 27. (4) Meldrum. A. H.; Nlelsen, R. F. Rod. Mon. Aug 1955, 19, 22. (5) Schnelder, 0.;Alwanl, 2.; Helm, W.; Horvath, E.; Franck, E. Chem.Ing.-Tech. 1967, 39, 649. (6) Schneider, G. Chem. Eng. Frog., Symp. Ser. 1968, 64. 9. (7) Schnelder, G. A&. Chem. phvs. 1970, 17, 1. (6) Francis, A. W. J . W y s . Chem. 1954. 58, 1099. (9) Hayduk, W.; Walter, E. 8.; Simpson, P. J . Chem. Eng. Data 1972, 17, 59. (10) King, M. 6.; AI-Najjar, H. Chem. Eng. Scl. 1977, 32, 1246.
(13) Hottovy, J. D.; Luks, K. D.; Kohn, J. P. J . Chem. Eng. Date 1961, 26, 256. (14) Angus, S.; Armstrong, 6.; de Reuck, K. M. "International Thermodynamlc Tables of the Fluld State Carbon Dioxide"; Pergamon Press: Oxford, 1976. (15) Vargaftlk, N. 6. "Tables on the Thermophyslcal Properties of Liquids and Gases", 2nd ed.;Wlley: New York, 1975; pp 167-8. (16) Robinson, R. L. Oklahoma State University, Stillwater, OK, personal communlcation, 1983. Recehred for revlew October 17, 1983. Accepted April 10, 1984. Support for this research was proQlded by the National Sclence Foundation (Grant No. CPE-8100430). The apparatus used Is part of the PvTx Laboratory at the Unhrerslty of Tulsa and was purchased with funds provided by several Industries, the University of Tulsa, and a National Sclence Foundation speclallzed equipment grant (No. CPE-8014650).
Vapor-Liquid Equilibria in Mixtures of Cyclohexane and Methyl Methacrylate Dlane M. Hull and Benjamln C.-Y. LU" Department of Chemical Engineering, Universi?y of Ottawa, Ottawa, Canada K I N 984 -
Isothermal vapor-llquld equlllbrlum values were measured for mlxtures of cyclohexane and methyl methacrylate at 318.12, 333.13, and 348.14 K by uslng a modffled Dvorak and Boubllk reclrculatlng dlll. The experlmental results were correlated wlth the Wllson equatlon by Ilttlrig the total pressure and vapor composltlon values. A binary azeotrope was found to exld at all three temperatures. Introductlon
An ester interchange reaction between methyl methacrylate (MMA) and higher alcohols can be carried out In the presence of a catalyst to produce higher esters. This transesterificatlon of alcohols is usually conducted in an inert solvent, such as hexane, benzene, or cyclohexane, which can form a low-boiling azeotrope with the liberated alcohols. The data available in the literature on the vapor-liquid equilibrium (VLE) values for mixtures of cyclohexane and MMA are limited to those reported by Frolova et ai. ( 7 ) at 760 mmHg (101.325 kPa). I t appears that these values are of uncertain quality. The purpose of this work is to establish isothermal VLE values for the mixture at three temperatures by means of a recirculating stili.
temperature of the equilibrium mixture was measured by using a Hewiett-Packard (Model 2801 A) quartz thermometer, which was checked at the triple point of water. The accuracy of the temperature measurement is estimated to be fO.O1 K. For pressure measurements, a Texas Instruments pressure gauge (type 144-01) together with a Bourdon Capsule (0-174 kPa) was used. This instrument was calibrated by measuring the vapor pressure of distilled and demineralized water in a Swietoslawski type ebulllometer, and checked by a mercury manometer in conjunction with a cathometer. The system pressure was controlled by a two-liquid manostat. The accuracy of the pressure measurements is estimated to be f0.05 torr. Analyses of the condensed vapor and liquid samples were made withban Anton-Paar K.G. (Model DMA 02A) digital den0.01 K. simeter with its temperature maintained at 288.15 The accuracy of the determined composition is estimated to be f0.002 mole fraction.
*
Results and Discuselon The experimentally determined equilibrium pressure, P , and liquid and vapor compositions, x and y, together with the calculated activity coefficients, y/, are listed in Table 11. The values of In y1 were obtained from
+ ( B l 1 - vl0KP-
In y1 = In Experlmental Sectlon
pl0)/RT+
(1 - Y1I2612P/RT (1)
Chemk8lS. Phillips 66 Researchgrade cyclohexane, supplied by the Phillips Petroleum Co., and Aldrich Analyzed-grade MMA, containing 65 ppm hydroquinone monomethyl ether, supplied by the Aklrich Chemical Co., were used without fwther purification. The purlty of both liquids was estimated to be 99 mol % minimum. Physical constants of these materials are given in Table I. The vapor pressure data avallable in the literature for pure MMA are generally not in good agreement, and for this reason those that were obtained in this work were preferred. Apparatus. Vapor-liquid equilibria were established by means of a modified Dvorak and Boubiik recirculating still, whose operation has been previously described (2, 3). The
and similarly for In y2. I n these equations 612
= 2812 - 8 1 1 - 8 2 2
(2)
and x and y are the equilibrium mole fractions of cyclohexane in the liquid and vapor phases at pressure P. The quantities p,', B,,, and v,' are the vapor pressure, second viriai coefficient, and liquid molar volume of component i and 8 12 is the cross second virial coefficient. The experimentally obtained p,' values as listed in Table Iwere used in the calculation. The values of v,O for cyclohexane and MMA were taken from T i m mermans (4) and Matheson et ai. (5). Since values of 8, and B 1 2 are not available at the three temperatures investigated, they were estimated by using the
002l-9568/84/1729-0417$01.50/00 1984 American Chemical Society
410 Journal of Chemical and Engineering Data, Vol. 29, No. 4, 1984
Table I. Physical Properties of Pure Components Used p(288.i5 K), g/cm3 cyclohexane methyl methacrylate
exptl 0.7832 0.9491
318.12 K 111.57 ( 4 ) 109.49 (5) vapor press., torr
lit. 0.783 15 ( 4 ) 0.9488 (5)
318.12 K
333.13 K
exptl 224.24 94.74
lit. 224.62 (6) cyclohexane 90.9 (7) methyl methacryalte 95.29 (8) second virial coeff, cm3/a-mol .cyclohexane methyl methacrylate
318.12 K -1529.0 -2260.0
333.13 K -1333.3 -1915.8
molar vol, cmS/g-mol 333.13 K 113.78 (4) 111.67 (5)
348.14 K -1178.2 -1650.0
exptl 388.86 180.59
T,,K 553.4 (9) 554.75 (IO)
empirical correlation of Tsonopoulos (72). The calculated 6, values together with all the pure-component propertles used in their calculation are also listed in Table I. I t should be noted that the acentric factor that was used for MMA was that of its homomorph, 2-methylhexane (9). The 612 values obtained are -1757.7, -1520.3, and -1333.6 cm3/g-mol for the temperatures 318.12, 333.13, and 348.14 K, respectively. An attempt was made to detect the possible occurrence of polymerization of MMA throughout the work. The results indicate that the volatility of the shipping lnhlbltor is adequate for preventing the poiymerizatkm of MMA in the condensed vapor. The thermodynamic consistency of the data was tested by the area test of Redlich-Kister (73).The net areas obtained were 1.2%, 0.8%, and 0.2% of the total area for the temperatures 318.12, 333.13, and 348.14 K, respectively. The data were correlated by using the Wilson equation (74) where
348.14 K 116.08 ( 4 ) 114.00 (5)
348.14 K
lit. 388.91 (6) 178.6 (7) 181.37 (8)
F',, atm 40.2 (9) 35.8 (IO)
explt 637.32 322.89
lit. 637.32 (6) 316.3 (7) 323.13 (8)
V,, cm3/g-mol
w
P, D
308.0 (9) 332.9 (IO)
0.213 (9) 0.330
0.3 (9) 1.675 (11)
60C
500
In y1 = 7
400
b I-
Y
n
ca
In y2 =
- In ( x ,
In In
+ A H x l )- x 1
t
n
-o
A12 = (vz0/vlo) exp(-AAl,/RT) Azl = (vlo/vZo) exp(-AXzl/RT)
300
(5)
The quantities vlo and v Z o are the liquid molar volumes of cyclohexane and MMA, respectively. The parameters AX1, (=Al2 - All) and AA21(=Al2 - A,,) were obtained by fitting the total pressure and vapor composition with the maximum Ilks lihood principle and are reported in Table 111. The calculated y and P at given T and x are compared with the experimental values in Figure 1. The average absolute deviations obtained in the calculated y and P values are also reported in Table III. Using the parameter values reported in Table 111, we calculated values of y, and compared them with the experimental values. The average absolute deviatkns between experhnental and calculated y1values, IAyllw, are 0.01, 0.01, and 0.01 and the corresponding lAy,l, values are 0.02, 0.01, and 0.01 for the temperatures 318.12, 333.13, and 348.14 K, respectively. An azeotrope exists In the binary mixture at the three temperatures studied. The calculated azeotropic composltbn and pressure at these temperatures agree well with those obtained graphically as shown in Table I V .
200
100, I
1
I
I
0.2 0.4 0.6 0.8 Mde Fraction of Cyclohexane, xI ,yI Figure 1. Comparison of caicutated total presswes and vapor mole fractions with experimental results for cyclohexane (1) and methyl methacrylate (2) mixtures at three Isothermal conditions.
Glossary
4
B 12
second virial coefficient of pure component i cross virial coefficient
GE N
molar excess Gibbs free energy of mixing number of observations
Journal of Chemical and Englneering Data, Vol. 29, No. 4, 1984 419 T a b l e 11. I s o t h e r m a l V a p o r - L i q u i d Equilibrium R e s u l t s f o r Cyclohexane (1) and M e t h y l M e t h a c r y l a t e (2) XI
P P, R T
Y1
P,torr
Yl
Y9
0.047 0.066 0.103 0.145 0.197 0.273 0.357 0.443 0.529 0.605 0.671 0.731 0.771 0.807 0.867 0.907 0.935 0.956 0.964
0.198 0.258 0.346 0.421 0.494 0.569 0.630 0.680 0.722 0.753 0.782 0.810 0.831 0.849 0.882 0.912 0.933 0.953 0.961
318.12 K 112.93 119.60 131.33 142.91 156.21 171.66 185.60 196.53 205.63 211.73 216.63 220.13 222.15 223.78 225.76 226.34 225.98 225.71 225.53
0.039 0.061 0.094 0.137 0.183 0.247 0.335 0.421 0.506 0.581 0.656 0.702 0.756 0.798 0.833 0.893 0.937 0.963
0.152 0.215 0.291 0.372 0.441 0.510 0.587 0.644 0.688 0.726 0.762 0.785 0.815 0.836 0.860 0.900 0.933 0.958
333.13 K 204.63 216.56 232.93 253.03 271.90 294.15 319.52 339.28 354.70 365.94 375.61 380.39 385.93 388.24 390.31 391.87 391.50 390.75
2.08 1.99 1.88 1.79 1.70 1.57 1.45 1.34 1.24 1.18 1.12 1.09 1.07 1.05 1.04 1.02 1.00 1.00
1.oo 1.00 1.00 1.01 1.02 1.05 1.09 1.14 1.22 1.30 1.41 1.49 1.59 1.72 1.78 1.99 2.27 2.41
0.058 0.084 0.132 0.168 0.227 0.311 0.399 0.483 0.562 0.631 0.689 0.746 0.786 0.824 0.882 0.927 0.967
0.183 0.245 0.333 0.393 0.460 0.537 0.604 0.658 0.700 0.735 0.768 0.801 0.824 0.849 0.888 0.924 0.963
348.14 K 372.68 393.26 426.37 451.79 482.33 521.63 554.20 581.20 599.83 613.38 623.62 631.84 636.53 639.92 643.16 642.38 640.00
1.88 1.83 1.71 1.68 1.55 1.42 1.32 1.25 1.18 1.12 1.09 1.07 1.05 1.03 1.02 1.00 1.00
1.00 1.00 1.01 1.01 1.03 1.07 1.11 1.17 1.25 1.34 1.41 1.50 1.59 1.66 1.85 2.03 2.18
2.14 2.11 1.98 1.86 1.76 1.60 1.47 1.35 1.25 1.18 1.13 1.09 1.07 1.05 1.02 1.01 1.01 1.00 1.00
1.00 1.00 1.01 1.02 1.03 1.07 1.12 1.18 1.27 1.38 1.50 1.62 1.71 1.82 2.09 2.23 2.43 2.51 2.55
total pressure vapor pressure of pure component i gas constant absolute temperature
T a b l e 111. W i l s o n Parameters and Average Absolute D e v i a t i o n s in t h e C a l c u l a t e d y land P Values
AXlz, cal/g-mol AXz1, cal/g-mol lAY llav’ torr
laqav,.
318.12 K 138.67 557.01 0.0023 0.1476
‘Average deviation (PXI, =
333.13 K 120.25 529.03 0.0023 0.3190
348.14 K 112.68 490.85 0.0019 0.4996
( ~ l X s l p-t lXddl)/N.
T a b l e IV. Azeotropic M o l e F r a c t i o n and P r e s s u r e f o r Cyclohexane and M e t h y l M e t h a c r y l a t e M i x t u r e s azeotropic compn, mole fraction of cyclohexane temp,
K
318.12 333.13 348.14
v/O x/ Y/ Y/ 4 2 9
azeotropic press., torr
exptl
calcd
exptl
calcd
0.921 0.915 0.906
0.923 0.916 0.909
226.4 392.5 643.8
226.2 392.3 643.2
molar volume of pure liquid i mole fraction of component iin liquid mole fraction of component iin vapor liquid activity coefficient of component i parameters in Wilson equation
A219
Ah2, AX21
CL P w
dipole moment density acentric factor Registry No. Cyclohexane, 110-82-7; methyl methacrylate, 80-62-6.
LHeralure Cited (1) Frolova, E. A,; Ustavahchlkov, B. F.; Ershova, T. P.; Khallstova, I. D. Osnov. Org. Slnt. Neffekhim. 1976, 6 , 109. (2) Boubllkova, L.; Lu, 6.C.-Y. J. App. Chem. 1969, 19, 89. (3) Polak, J.; Lu, 8 . C.-Y. J . Chem. 7Ywmadyn. 1972, 4 , 469. (4) Tlmmermans, J. “Physlco-Chemlcal Constants for Pure Organic Compounds”; Elsevler: Amsterdam, 1950. (5) Matheson, M. S.; Aver, E. E.; Bevllacqua, E. B.; Mart, E. J. J . Am. Chem. Soc. 1949, 7 1 , 497. (6) Boubllk, T.; Fried, V.: Hala, E. “The Vapour Pressures of Pure Substances”; Elsevler: Amsterdam, 1973. (7) Stull, D. R. Ind. Eng. Chem. 1947, 39, 517. (8) Boubllk, T. Instkute of Chemical Process Fundamentals, Prague, Czechoslovakia, personal communication, 1979. (9) Reid, R. C.; Prausnitz, J. M.; Sherwocd, T. K. “The Properties of Gases and Liquids”, 3rd ed.; Mc(3raw-HIII: New York, 1977. (10) Foerst, W.; “Fritz Ullmanns EncykoNdle der Technlschen Chemle“, 3rd ed.; Urban and Schwarzenberg: Munich, 1980: Vol. 12. (11) Le Fevre, R. J. W.; Sundaram, K. M. S. J . Chem. Soc. 1963, 1880. (12) Tsonopoubs, T. A I M J . 1978, 24, 1112. (13) Redllch, 0.; Klster. A. T. Ind. €ng. Chem. 1948, 40. 345. (14) Wilson. 0. M. J . Am. Chem. Soc. 1964, 86, 127.
Received for review September 23, 1983. Accepted M a y 30. 1984. We are Indebtedto the Natural Sciences and Engineering Research Council of Canada for financial support.
