December 1949
INDUSTRIAL AND ENGINEERING CHEMISTRY
The calculated &shaped x-y curve (Figure 3) is theoretically unpossible and probably results from the breakdown of this purely mathematical method in the region of two liquid phases. However, this curve can be used in the miscible regions for making theoretical plate calculations accurate enough for engineering purposes. ACKNOWLEDGMENT
The authors wish t o thank B. J. Gaffney and L. W. Bass of U. S. Industrial Chemicals, Inc., for their helpful criticism of this paper. Thanks are also due t o J. C. Mannherz for the drafting of the figures. NOMENCLATURE
arbitrary constant in van Laar equations. Equal to log y1 a t x2 = 0 arbitrary constant in van Laar equations. Equal to log 7 2 at z2 = 0 total pressure, mm. of mercury vapor pressures of pure components, mm. of mercury mole fraction in liquid mole fraction in vapor in equilibrium with x activity coefficient,
2831
Subscripts 1 = low-boiling component (water) = high-boiling component (1-butanol) LITERATURE CITED
Arnold, H. R., and Lessig, E. T., in Perry’s “Chemical hrlm neers’ Handbook,” 2nd ed., p. 377, New York, McGraw-Hil) Book Co., 1941. Baker, E. M., Hubbard, R. 0. H., Huguet, J. H., and Miohalowski, s. s., IND.ENG.CHEM.,31, 1260 (1939). Carlson, H. C., and Colburn, A. P., Zbid.,34, 551-9 (1942). Colburn, A. P., Schoenborn, E. M., and Shilling, D., Zbid., 35 1252 (1943). Laar, J. J. van, 2.physik. Chem., 72, 723 (1910); 83, 599 (1913) Lange, “Handbook of Chemistry,” 6th ed., Sandusky. Ohio Handbook Publishers, 1946. Othmer, D. F., Anal. Chem., 20, 764 (1945). Smith, D.M.,Bryant, W. M. D., and Mitchell, J., Jr., J . Am Chem. Soc., 61,2407-12 (1939). Stockhardt, J. S., and Hull, C. M.,
[email protected].,23,1438-40 (1931). Stull, D. R., Ibid., 39,622 (1947). Swietoslawski, “Ebulliometric Measurements,” Chap. I, New York. Reinhold Publishing Corm. 1945. White, R. R., Trans. Am. Init. Chem. Engrs., 41,539-54 (1945) RECEIVED Msrch 21, 1949.
Phase Equilibria in Hydrocarbon J
Systems J
Phase Behavior in the Methane-n-Butane-Decane
System at 160” F.
H. H. REAMER, J. M. FISKIN, AND B. H. SAGE California Institute of Technology, Pasadena, Calg. T h e compositions of the coexisting phases in the methane-n-butane-decane system have been investigated at 160’ F. Experimental measurements were made at pressures of 1000, 2000, 3000, and 4000 pounds per square inch absolute. The data obtained permit the evaluation of the compositions of the phases and the equilibrium constants in relation to pressure. The results are presented in tabular and graphical form.
T
HE phase behavior of many binary paraffin hydrocarbon
Y
-
systems has been investigated and the data indicate marked divergences from simple generalizations. These studies have been supplemented by a limited number of measurements of the composition of coexisting phases in ternary paraffin hydrocarbon systems (1, 3, 4). This work emphasized the importance of the nature and amount of the other components upon the distribution of any one hydrocarbon between the liquid and gas phases. In order to investigate more fully the characteristics of ternary systems a study of the volumetric and phase behavior of the methane-nybutane-decane system was undertaken. This work consisted in part of a relatively detailed study of the pertinent binary systems. T h e compositions of coexisting phases and the volumetric behavior of mixtures of methane and n-butane were investigated (11,15, 16). Similar measurements for the methanedecane system were completed (12, 20) and limited information was reported for the n-butane-decane system in the condensed region (19). The pressure-volume-temperature relations of methane (9) and the volumetric and phase behavior of n-butane (&IO) and of decane (1.3,.31)have been established. I n addition the influence of pressure and temperature upon the volume of
several mixtures of methane, n-butane, and decane is known (14). Using all of this information it is possible t o estimate with reasonable accuracy the phase behavior of the coexisting liquid phase throughout the majority of the heterogeneous region of thie ternary system for temperatures above 100’ F. In order t o establish with certainty the location of the combining lines and of the dew-point curve, measurements were taken of the composition of the coexisting phases. Although this work covered several temperatures, the measurements obtained at 160 O F have been presented first in order t h a t the details of the analpt,ica! procedures and equipment employed might be discussed. METHODS AND PROCEDURES
The equipment utilized in this investigation has been described (17, 18). Essentially i t consists of a stainless steel cham. ber within which the hydrocarbons are confined over mercury This chamber is located within an agitated oil bath, the temperature of which is controlled automatically within 0.01” F of the desired value relative t o the international platinum scale The quantity of mercury introduced into the equilibrium vesseE may be varied, thus changing the effective volume of the apparatus. The pressure is measured by means of a‘balance calibrated against the vapor pressure of carbon dioxide at the ice point. Equilibrium is obtained by use of a spiral agitator rotated about a vertieal axis. A movable probe was employed t o ermit the levels of the mercury-hydrocarbon and the gas-liquid Iydrocarbon interfaces t o be ascertained. Sampling ports were provided to permit withdrawal of samples of the liquid and gas phases at equilibrium. T h e connectin tubing between the equilibrium e uipment and the analyticaf apparatus was heated to avoid con%ensation of the less volatile components. The pressure was maintained at a substantially uniform value during
2872
INDUSTRIAL AND ENGINEERING CHEMISTRY
the sample withdrawal. This was accomplished by the introduction of the amount of mercury needed to compensate for the material withdrawn. The apparatus employed for the determination of the compositions of the coexisting phases is shown schematically in Figure 1. The weighing bombs A and C (19) were tared after evacuation and the requisite weight of sample introduced into -4. The container used in the partial condensation process is shown in Figure 2. I n principle it consists of a spiral channel located within a light-weight stainless steel container. The assembly is provided with dual valves to permit the simultaneous addition and withdrawal of material. The surface within the spiral passages of the container was nearly sufficient to ensure equilibrium partial condensation of the less volatile components. However copper turnings were added to increase the surface available and t o assure a relatively close approach to equilibrium.
M
Figure 1. Schematic Diagram of Analytical Equipment
The partial condenser and weighing bombs were assembled as indicated in Figure 1. Weighing bomb A containing the saniple was cooled to the ice point while the partial condenser, B , and trap D in the exit vacuum line through stopcock S were cooled with liquid air. Weighing bomb C was not used in these first operations. The methane and nearly all of the n-butane were transferred out of weighing bomb A together with a trace of decane The n-butane was condensed in B and the methane was removed through the trap, D , and the stopcock, S,by means of a vacuum pump. That no traces of n-butane escaped from the partial condenser, B , was indicated by the lack of accumulntion of hydrocarbons in the trap of the exit line. The main transfers mere carried out a t pressures below 0.3 inch of mercury and then the pressure was decreased to 10-3 inch of mercury in order t o remove all butane from bomb A . The partial condenser, B, was brought to the ice-point temperature, and gas was withdrawn into weighing bomb C which was immersed in liquid air. This completed the separation of the n-butane and decane. The manometer, Jf, was used to determine the pressure in the system at the various stages of the analysis. The cooled trap, D, in the exit line R as used to be sure t h a t no n-butane or heavier hydrocarbons were lost from the system. The weighing bombs were brought to room temperature, cleaned, and desiccated for approximately 20 minutes. From the changes in weight of the two weighing bombs and the partial condenser, the quantity of ~i~~~~ 2. each of the components could be established ~ ~ of ~ directly. ~ The i quantity l of ~ methane was taken as the loss in weight of weighing bomb A less paI ia1 Condenthe combined gain in weight of partial condenser B and weighing bomb C. The quantity sat i? E g u I pof decane was considered t o be the combined ment gain in weight of weighing bomb A and partial condenser B from their original tares, The gain i n weight of weighing bomb C was taken as the amount of n-butane. A careful check of the operation of this equipment using samples of mixtures of methane, n-butane, and decane of known composition indicated t h a t the proportion of each of the components in a mixture, was ascertained with an uncertainty of approximately 0.001 weight fraction. A period of approximately 1 hour was required to carry out the separation process. A careful investigation was made of the quantities of material remaining in the tubing connecting the equilibrium equipment with the analytical apparatus. Only a negligible amount of methane and butane remained within the tubing after condensation of the sample in weighing bomb A . Evaluation of the
Vol. 41, No. 12
correction t o the measured compositions of the samples for the traces of methane and butane found in the connecting tubing indicated that under the most adverse conditions it amounted to less than 0.001 mole fraction. The decane remaining in the connecting line was removed under vacuum into a liquid-air trap which could be weighed. MATERIALS
The methane utilized in this study was obtained from a well in the San Joaquiii Valley of California. ,4s received, it contained less than 0.002 mole fraction of material other than methane and water. It was passed over potassium hydroxide, activated charcoal, ascarite, and anhydrous calcium sulfate a t pressures in excess of 300 pounds per square inch. Partial condensation analyses indicated that the purified methane Contained less than 0.0005 mole fraction of other hydrocarbons. The amount of nitrogen was estimated from mass spectrometer analysis to be less than 0,001 mole fraction, and carbon dioxide was present in negligible amount. The 7z-butane was purchased from the Phillips Petroleum Company and as received contained less than 0.01 mole fraction of material other than n-butane. The sample was purified further by three successive fractionations in a column packed with glass rings. T h e first and last portions of each fractionation were discarded. T h e purification was carried out a t a reflux ratio of approximately 50. It was found that vaporization from
TABLEI. COEXISTING
EXPERIMEPiTALLY D E T E R U I P E D COMPOSITIONS O F PH.4SES IN THE M E T I x A N E - . ~ ~ - B U T A X E- D E C A N E
SYSTEM Pressure Lb,/Sq.' In. Abs. 1000
2000
3000
4000
(Temperature, 160' F.) Gas Phase, Mole Fraction Liquid Phase, Mole Fraction Methane n-Butane Decane Methane n-Butane Decane 0.970 0.028 0.0025 0.242 0.086 0.672 0.239 0.406 0,355 0,103 0.0024 0.895 0.564 0.192 0.840 0,158 0.0019 0.244 0.803 0.196 o.ooii 0.253 0 . 6 ~ 1 0.086 0.975 0.021 0.0042 0.424 0.086 0.490 0.909 0.085 0.0063 0.437 0.288 0.275 0.851 0.143 0.0059 0,459 0.390 0.151 0.791 0.202 0,0071 0,507 0.422 0.071 0.973 0.016 o 0102 0.5e2 0.054 0.385 0.558 0.062 0.380 0.020 0.0104 0.970 0.204 0,604 0.193 0.895 0.088 0.0171 0.804 0.161 0.0356 0.663 0.229 0.108 0.956 0.018 0.0259 0.688 0.036 0.275 0.876 0.071 0.0529 0.741 0.104 0.155 0.826 0.096 0.0791 0.822 0.098 0,080
METHANE
400
DECANE
3
POUNDS
SQUARE
op MOLE
Figure 3.
PER
INCH
ABSOiU7E
c?
n-BLT4NE
FRACTIONS
Compositions of Coexisting Phases at 160" F.
Vol. 41, No. 12
INDUSTRIAL AND ENGINEERING CHEMISTRY
a74
-\
\,
I
02 I
1000 PRESSURE
Figure 5.
3 POUNDS PER SQUARE INCH
PRESSURE
Figure 4.
Equilibrium Constant for Methane at 160" F.
TABLE 111. COMPARISON OF VALUES OF EQUILIBRKTM CONSTANTS FOR METHANE-PBUTANE-DECANE SYSTEM Pressure, Lb / S q In. Abs.
. . 400
600
LO00
Component Methane
%-Butane
Decane Methane n-Butane Methane n-Butane
Ideal Solutionn 9.5 0.35 0.0012 6.5 0.24 4.4 0.146
__
C =0 8.760 0.2725 0.0023 6.125 0.2450 3.995 0.2260
Experimental C 3 0.6 8.285 0.3170 0.0037 5.705 0.2785 3.640 0.2595
-
C 1.0 7.030 0.4135 0.0050 4.700 0.3420 2.790 0.3330
The behavior of the components in a n ideal solution was taken from the work of Hadden (6).
I 2000
I YaO
I
oow
I
POUNDS PEA W A R E lYCH
Equilibrium Constant for n-Butane at 160' F.
in that the equilibrium constant a t a given pressure and temperature is markedly influenced by the nature and amounts of the other components present. In Figure 4 is shown the product of the pressure and equilibrium constant of methane as a function of pressure for several values of the composition parameter, C. This parameter is defined by the following expression, in which X refers to the mole fraction of a component in the liquid phase and the subscripts 4 and 10 refer t o n-butane and decane, respectively :
Similar information concerning the equilibrium constants of n-butane and of decane is shown in Figures 5 and 6, respectively The information submitted in Figures 4, 5, and 6 serves to emphasize the fact that the equilibrium constant for each of the more volatile paraffin hydrocarbons must be considered as truly a function of the state of each of the phases. Therefore, it is in. fluenced by the composition of the phases as well as by the pressure and temperature which in the case of an ideal solution (7) are considered t o be the only variables involved. A method for estimating the equilibrium constants of thr lighter hydrocarbons which takes into account the propertier of the system has appeared recently (6). Table 111 presents a comparison of the experimentally determined values of the equilibrium constants with those estimated from this correlation but not corrected for convergence pressure. The average deviation of the experimental and predicted equilibrium constants for three states wa8 greater than 5y0. ACKNOWLEDGMENT
This paper is a contribution from American Petroleum Institute Research Project 37. The work of J. B. Opfell was of much assistance in the development of the analytical procedures employed. W. N. Lacey assisted in the preparation of the manuscript. LITERATURE CITED
Figure 6.
Equilibrium Constant for Decane at 160' F.
(1) Billman, Sage, and Lacey, Am. Znat. Mining Met. Engrs., Tech. Pub. 2232, Petroleum Technol. (July 1947). (2) Calingaert and Soroos, J. Am. Chem. Soc., 58, 635 (1936). (3) Carter, Sage, and Lacey, Trans. Am. Inst. Mining Met. Engrs., 142, 170 (1941).
December 1949
bubble point to a quality of approximately 0.5 resulted in less than 0.2 pound per square inch change in vapor pressure at 160" F. The decane was purchased from the Eastman Kodak Company and was fractionated a number of times at relatively high reflux ratios primarily to remove dissolved gases. The purified material was dried over metallic sodium and had an index of refraction of 1.410 for the D line of sodium as measured a t 77" F. The specific volume a t atmospheric pressure and 100" F. was 0.022310 cubic feet per pound. A comparison of these measurements with available data for ndecane (21) and similar information for its several isomers (b, 8 ) indicates that the hydrocarbon used in this study probably was made up of saturated hydrocarbons containing ten carbon atoms per molecule but was not wholly ndecane. EXPERKMENTAL RESULTS
The compositions of the coexisting phases a t pressures up to 4000 pounds per square inch and a t 160" F. are shown in Figure 3. The experimental points representing the composition of the coexisting phases have been indicated by appropriate combining lines. For the sake of clarity, the data concerning the composition of the dew-point gas a t 1000 pounds per square inch have not been included. The smoothed curves drawn through the data were based in part on bubble point compositions established from volu metric data as well as the directly measured comnpositions of the coexisting phases. The values of the experimentally determined compositions of the coexisting phases at 160" F. are recorded Xvithout smoothing in Table I. In Table I1 are presented the smoothed and interpolated compositions of the coexisting phases together r i t h values of the corresponding eqnilibriuni constants. The information in this table conhms results obtained from earlier measurements upon ternary hydrocarbon systems (1, 3, 4 )
INDUSTRIAL AND ENGINEERING CHEMISTRY TABLE 11.
2873
C O M P O S l T I O N S OF COEXIsTING PHASES I N THE M E T l i A N E - n - B U T A N E - D ~ C A N E
Composition
SYSTEM
(Temperature, 160' F.)
fif "*
Pressure, ParamLb,/Bcl, ebr Liquid Phase, Mole Fraction C Methane n-Butane Decane In. Ahs. 400 0.0 0.114 0.000 0.886 0.2 0.109 0.178 0.713 0.4 0.104 0.358 0.538 0.6 0.099 0.541 0.360 0.8 0.095 0.724 0.181 1.0 0.089 0.911 0.000 600 0.0 0.163 0,000 0.837 0.2 0.157 0.169 0.874 0.4 0.153 0.339 0.508 0.6 0.150 0.510 0.340 0.8 0.148 0.682 0.170 1.0 0.10i 0.849 0.000 800 0.0 0.208 0.000 0.792 0.2 0.202 0.160 0.638 0.4 0.198 0.321 0 481 0.6 0.197 0.482 0 321 0.8 0.198 0.642 0.160 1.0 0.212 0.788 0.000 1000 0.0 0.260 0.000 0.760 0.2 0.242 0.152 0.606 0.4 0.238 0.305 0.457 0.6 0.239 0.457 0.304 0.8 0.247 0.602 0.151 1.0 0.271 0.728 0.000 1250 0.0 0.298 0.000 0.702 0.2 0.292 0.142 0.566 0.4 0.291 0.283 0.425 0.6 0.296 0.423 0.282 0.8 0.308 0.553 0.138 1.0 0.348 0.652 0.000 1500 0.0 0.343 0.000 0.657 0.2 0.338 0.132 0.529 0.4 0.339 0.264 0.397 0.6 0.347 0.392 0.261 0.8 0.368 0.506 0.126 1.0 0.433 0.567 0.000 1750 0.0 0.384 0.000 0.616 0.2 0.381 0.124 0.495 0.4 0.384 0.246 0.369 0.6 0.397 0.362 0.241 0.8 0.426 0.459 0.115 1.0 0.542 0.458 0.000 2000 0.0 0.423 0.000 0.577 0.2 0.422 0.116 0.462 0.4 0.428 0.229 0.343 0.6 0.444 0.333 0.222 0.8 0.485 0.412 0.103 2250 0.0 0.459 0.000 0.541 0.2 0.460 0.108 0.432 0.4 0.469 0.212 0.319 0.6 0.49@ 0.306 0.204 0.8 0.542 0.366 0.092 2500 0.0 0.494 0.000 0.506 0.2 0.496 0.101 0.403 0.4 0.509 0.197 0.295 0.6 0.534 0.280 0.186 0.8 0.600 0.320 0.080 2750 0.0 0.527 0.000 0.473 0.2 0.531 0.094 0.375 0.4 0.546 0.182 0.272 0.6 0.577 0.234 0.169 0.8 0.679 0.257 0.064 3000 0.0 0 . 5 6 0 0.000 0.440 0.2 0.564 0.087 0.349 0.4 0.583 0.167 0.250 0.6 0.621 0.227 0.161 3250 0.0 0,591 0.000 0.409 0.2 0.596 0.081 0.323 0.4 0.620 0.152 0.228 0.6 0.666 0.200 0.134 3500 0.0 0.621 0.000 0.379 0.2 0.629 0.074 0.297 0.4 0.656 0.138 0.206 0.6 0.725 0.165 0.110 3750 0.0 0.650 0.000 0.350 0.2 0.659 0.068 0,273 0.4 0.696 0.122 0.183 4000 0.0 0.680 0.000 0.320 0.2 0.691 0.062 0.247 0.4 0.738 0.105 0.157 4250 0.0 0.710 0.000 0.290 0.2 0.727 0.055 0.218 0.4 0.782 0.087 0.131 4500 0.0 0.743 0.000 0,257 0.2 0.761 0.048 0.191 4750 0.0 0.779 0.000 0.221 0.2 0.814 0.037 0.149 5000 0.0 0.825 0.000 0.175
Gas Phase, Mole Fraction Methane n-Butane Decane
0.998 0.948 0.893 0.827 0.737 0.623 0.998 0.956 0.910 0.856 0.791 0.710 0.998 0.960 0.918 0.872 0.816 0.746 0.998
0.963 0.923 0.880
0.829 0.757 0.998
0.964 0.927 0.886
0.834 0.759 0.997 0.966 0.930 0.889 0.834 0.744 0.997 0.967 0.932 0.889
0.831 0.683 0.996 0.967 0.933 0.887 0.826
0.995 0.966 0.931 0.882
0.817 0.994 0.965 0.927 0.874 0,800
0.993 0.963 0.923 0.865
0.749 0.991 0.959
0.917 0.855 0.989 0.955 0.910
0.842
0.000 0.050
0.105 0.171 0.261 0.377 0.000 0.043 0.089 0.142 0.208
0.290 0.000 0.038 0.080
0.127 0.184 0.254 0.000 0.036 0.076 0.119 0.172 0.242 0.000 0.033 0.070 0.111 0.164 0.241 0.000 0.031 0.066
0.108 0.163 0.286
0.000 0.030 0.064 0.106 0.165 0.317 0.000 0.029 0.062 0.107 0.161 0.000 0.028 0.002 0.110
0.174 0.000 0.028
0.064 0.115 0.186 0.000 0.028 0.066
0.120 0.231 0.000 0.029 0.067 0.123 0.000 0.031 0.009 0.126
0.0020
0.0019 0.0017 0.0013 0.0008 0 0000 0.0018 0.0018 0.0017 0,0014 0.0009 o.oooo 0,0018
0.0018 0.0018 0.0017 0.0011 0 0000 0.00'20
0.0021 0.0021 0.0020 0.0016
o.oooo 0.0023
0.0024 0.0026
0.0026 0.0021 0.0000 0,0027 0.0029 0.0031 0.0033 0.0030 0.0000 0,0031 0.0035 0.0039 0.0047 0.0044
o.oooo
0.0037 0.0043 0.0050 0.0058
0.0063 0.0045 0.0055 0 0066 0,0079 0.0094
0.0055
0.0070 0 0086 0.0109 0.0135
O.OOG8 0.0088 0.0114 0.0152 0.0195 0.0089
0.0111 0.0156 0.0248
Equilibrium Constants Methane n-Butane Decane
8.760 8.700 8.570 8.285 7.775 7.030 6.125 6.070 5.955 5.705 5.325 4.700
4.800 4.755 4.830 4.430 4.080 3.520 3.995 3.950 3.830 3.640 3.325 2.790 3.350 3.300 3.185 3.000 2.703 2.180 2.910 2.855 2.750 2.560 2.275 1.720 2.595 2.535 2.425 2.240 1,950 1.260 2.360 2.290 2.180 2.000 1.705
2.170 2.100 1.986 1.800 1.505 2.015 1.945
1.825 1.635
1.320 1.885 1.815 1.690 1.500 1.105 1.770 1.700 1.575 1.375
0,0107 0.0142
1.675
0.0212 0.0328
1.605 1.470 1.265 1.590 1.515 1.370
0,986 0.951 0.900 0,837
0.000 0.030
0.983 0.944 0.891
0.000
0,031 0,071
0,0384
0.978 0.936 0.879 0.972 0.929
0.000 0.032 0.070
0.0221 0,0315 0.0517
1.355 1.180
0,000 0.030 0.069
0,0281
1.370
0.071 0.122
0,0138 0.0188 0.0287 0,0409
1.155
0.0174
1.510 1.430
0.0242
0.965 0.912 0.954 0.896
0,000
0.033 0.000 0.031
0.0406 0,0692 0,0354 0.0546 0,0459 0.0730
0.937
0.000
0,0631
0.862
1.280
1.440
0,2725 0,2810 0.2940 0,3170 0.3810 0.4138 0,2450
0,0022
0.2520 0.2616
0.0027 0.0033
0.2786 0.3065 0.3420
0.0055 0.0072
0,2315 0,2385
0,0029
0,2500
0.2630 0.2875 0.3226 0.2260 0.2348 0 2460 0,2696 0,2865
0.3330 . 0.2240
0.2340 0.2470 0.2635 0.2970 0.3700 0.2260 0.2360 0.2510 0.2745 0,3220 0.4615 0.2300 0,2420 0.2600 0.2920
0,3595
0.0042
0,0023 0 0038 0.0052 0.0074 0.0108 0,0026
0.0034 0,0046 0.0067
0,0104 n.. 1-1172 - .. 0,0033 0.0042 0.0060
0.0092 0.0154 0,0325 0.0040 0,0054
0.0079 0 0127 0.0238 0,0794 0.0050 0.0071 0.0106 0.0195 0,0385
0.6925
n
0.2365 0.2510 0.2725 0.3200 0.4085 0.2440
0 0064 0.0094 0 0145
~~
0.2625
0.2945 0,3590 0.4755 0.2865 0,2790 0.3245 0.4120
2722
0.0263
0.0615 0,0083
0.0128 0.0206
0,0380 0,1022 0,0109 0.0173 0.0290
0.0584
0.5825
0.1687
0.2730
0,0144 0.0234 0,0419
0.3005 0.3600 0.4730 0.8990 0.2950 0.3200 0.4030 0.5435 0.3230 0.3725 0.4540 0,6275 0,3585 0.4085 0.5140
0.7415 0.4030 0.4610 0,5845 0.4550 0,5250 0.6670
1.100 1.300
0.5150 0.5450 0.7850 0.5885
1.200
0.6985
1.225 1.100 1.135
0.6790 0.8320 0.8000
1.276
0,0023 0.0027 0.0031 0,0037 0,0043 0 0050
0,0902 0.3047
0,0193 0,0318 0 0624 0.1642 0.0262 0.0440 0,0929 0.2458
0.0362 0,0624 0.1395 0.3725 0.0498
0,0890 0.2105
0.0690 0.1276 0.3250 0,0966 0.1862 0.5286 0.1380 0,2860 0.2080 0.4900 0.3618
December 1949
INDUSTRIAL AND ENGINEERING CHEMISTRY
(4) Dourson, Sage, and Lacey, Zbid., 151, 206 (1943). (5) Hadden, Chem. Eng. Progress, 44, [ l ] , 37 (1948). (6) Xvalnes and Gaddy, J. Am. Chem. Soc., 5 3 , 3 9 4 (1931). (7) Lewis, Zbid., 3 0 , 6 6 8 (1908). (8) (9)
Marker and Oakwood, Zbid., 60,2598 (1938). Olds, Reamer, Sage, and Lacey, IND.ENG. CHEM.,35, 922 (1943).
Ibid., 3 6 , 2 8 2 (1944). Reamer, Korpi, Sage, and Lacey,Zbid., 39, 206 (1947). Reamer, Olds. Sage, and Lacey, Zbid., 3 4 , 1 5 2 6 (1942). Reamer, Sage, and Lacey, Zbid., 38, 986 (1946). Zbid., 39,77 (1947). (15) Sage, Budenholzer, and Lacey, Zbid., 32,1262 (1940).
(10) (11) (12) (13) (14)
2875
(16) Sage, Hicks, and Lacey, Zbid., 1085. (17) Sage and Lacey, Am. Inst. Mining Met. Engrs., Tech. Pub. 2269, Petroleum Technol. (September 1947). (18) Sage and Lacey, Rev. Sci. Instruments, 18, [9], 650 (1947). (19) Sage and Lacey, Tram. Am. Znst. Mining Met. Engrs., 136, 136 (1940). (20) Sage, Lavender, and Lacey, IND. ENG.CHEM.,3 2 , 7 4 3 (1940). (21) Shepard, Henne, and Midgley, J. Am. Chem. Soc., 53, 1948 (1931). RECEIVED May 19, 1949. Paper 51 in the series "Phase Equilibria in Hydrocarbon Systems." Previous articles have appeared in INDUSTRIAL AND ENQINEBRINQ CABMISTRY during 1934-40 and 1942-46, in January and February 1947, and in March 1949.
Physical Data on Some Organic Compounds -
R. R. DREISBACH AND R. A. MARTIN T h e Dow C h e m i c a l C o m p a n y , M i d l a n d , M i c h .
Four tables are given, listing for 96 organic compounds the freezing point, mole per cent purity, densities at 20" and 25" C., refractive indexes at 20" and 25" C., the C value of the Eylrman equation, the density at 25" C. calculated from the C value and the ny, the A and B values of the Antoine equation, the A* and B* values of the DreisbachSpencer orthobaric vapor density equation, the a and b parameters of the law of rectilinear diameters, boiling point at 760 mm., and the d t l d p values at 760 mm., the rate of change of boiling point with pressure.
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N OBTAINING data for the calculation of the infinite points of Cox chart families, a good many compounds were purified for a determination of their vapor pressure a t several temperatures. The literature data on vapor pressure-temperature relation of these compounds were either lacking or of insufficient accuracy. Inasmuch as these purified compounds were available it was considered advisable to obtain the density and refractive indexes at 20" and 25" C., as well as the boilingpoint, freezing point, and mole per cent purity; these data are recorded here. For the use of pressure-temperature relations in obtaining the infinite points of Cox chart families, a purity of 99.5 mole yowas considered sufficient, since in most cases the impurity consisted of one or more isomers, the value of whose physical properties was not very different from the compound in question. I n each case, however, an attempt was made t o refine the product t o t h e highest degree possible without a t the same time consuming more time and effort than was justified. As can be seen from the tables, some of the compounds were not even 99.5% pure. I n general, distillation was the method used for the purification; the compounds which are the most impure are those which could not be improved by distillation. For the most part the listed compounds were made and purified in the Dow laboratories, but a number, those not of the type made by DOW,were Eastman Kodak products which were further purified. The two cresols were supplied by the Barrett Company with the purity as given in t h e tables. The alkyl halobenzenes were made by halogenation of benzene and the alkyl benzene, using iron as the halo carrier. These compounds were then purified by distillation. Most of the styrenes were made by starting with a bromobenzene or bromoalkylbenzene and making the p-phenylethyl alcohol by means of the Grignard reaction, purifying the alcohol by distillation, dehydrating the alcohol by dropping onto hot caustic soda, and fractionating
the styrene. The m-divinylbenzene was made by dehydrogenating mdiethylbenzene and fractionation. The p-phenylethyl alcohols were made by the Grignard reaction. The a-phenylethyl alcohols were produced by either chlorinating the side chain and hydrolyzing the (Y compound with water or hydrochlorinating the styrene and hydrolyzing the chloro compound. The first property determined was always the freezing point and the purity by means of the freezing point. If the purity was unsatisfactory, the product was further purified before any other properties were determined. The method of determining the freezing point and calculating the degree of purity by an inspection of the time-temperature freezing point curve was as outlined by Mair, Glasgow, and Rossini ( 7 )and later by Stull(9). A platinum resistance thermometer was used, either one calibrated by the Bureau of Standards or another compared t o t h a t standard. The refractive indexes were obtained by means of a five-place Valentine refractometer of the Abbe type and a n accurately controlled temperature bath. This determination and freezing point and purity were carried out by the East General Laboratory of The Dow Chemical Company, Midland, Mich., under the direction of E. N. Luce. The boiling point at various pressures was determined by S. A. Shrader in the apparatus elsewhere described ( I O ) , except that the points for controlling the pressure were placed on the atmospheric side instead of on the pressure side. The results obtained on the boiling points checked the bureau's results to within ==0.Ol0c. The density determinations were carried out by V. A. Stenger and 0. L. Daniels. The pycnometer used was of a shape described elsewhere ( 6 ) , from which it was patterned. However, several modifications were made to permit greater accuracy. Two pairs of pycnometers were used, one pair with a 25-ml. capacity and one of 10 ml. I n each case the sample in one pycnometer was weighed against the other as a tare. The larger size was always used when enough material was available. A second improvement was the use of a smaller capillary in t h e pycnometer. The readings on t h e calibrated capillary were made b y means of a cathetometer while the pycnometer was in the bath. The bath was controlled t o within *0.02" C. T h e mercury thermometer used was calibrated against a thermometer certified by the National Bureau of Standards. As noted in the senior author's paper (S), densities and refractive indexes are abstract values whose accuracies are often indeterminable. In order t o check t h e values of both the density
