INDUSTRIAL AND ENGINEERING CHEMISTRY
2908
Although depth measurements may be slightly more reproducible, weight measurements are more sensitive in detecting differences in rate of tread wear. This apparently paradoxical situation is due to the lack of proportionality of depth loss to mileage, which results in the ratings of tires to be dependent on the length of the test and in the underestimation of differences in rate of wear between different tires. Front wheel positions can and should be used together with rear positions for the greatest efficiency in testing truck tires and economy in gathering information on their relative rates of tread wear. Because of the large difference in rate of wear on front and rear positions, however, it is necessary to average the data geometrically or by a mathematically equivalent method.
Vol. 43, No. 12
this opportunity to express their appreciation to the members of the Office of Rubber Reserve, Government Tire Test Fleet, Lake Shore Tire and Rubber Go., and the carbon black industry who contributed to make this study a success. They also wish to acknowledge the financial support of the Reconstruction Finance Corp., under whose auspices the entire program was conducted. LITERATURE CITED
ACKYOWLEDGRIENT
(1) Brownlee, K. A,, “Industrial Experimentation,” Brooklyn, N. Y., Chemical Publishing Co., 1949. (2) Cochran, mi. G., and Cox, G. M., “Experimental Designs,” New York, John Wiley & Sons, 1950. (3) Fisher, R. A,, “The Design of Experiments,” Edinburgh, Scotland, Oliver & Boyd, 1949. (4) Roth, F,L., and Holt, W. L., J . Research Natl. Bur. Standards, 32, 61 (1944).
An investigation of this magnitude naturally requires the cooperation of a large number of people. Since it is not possible to mention each contributor individually, the authors are taking
RECEIVED March 2, 1951. Presented before the 58th Meeting of the Division of Rubber Chemistry of the AUERICANCHEMICAL SOCIETY, February 28 t o March 2 , 1951, Washington. D. C.
Vapor-Liquid Equilibria at Subatmospheric Pressures DQDECANE-OCTADECENE SYSTEM B. T. JORDAN, JR., AND MATTHEW VAN WINKLE L’niuersity of Texas, Austin, Tex. T h e purpose of this investigation was to evaluate vaporliquid equilibria at subatmospheric pressures for a high boiling paraffin-olefin binary. This is one of a series of investigations to determine the effect of subatmospheric pressures on vaporization characteristics of higher boiling hydrocarbons. Vapor-liquid equiIibriuln data were determined for the n-dodecane-1-octadecene system at 10, 20, 50, 100, 200, 400, and 760 mm. of mercury pressure. The activity coefficients for both compounds decreased with increasing pressure and were less than unity at all pressures studied. The deviations of the activity coefficients from unity indicate this binary to behave in a nonideal manner even at moderately low pressures. However, the variation from ideal behavior is not great.
THE
study of vapor-liquid equilibria of various systems has occupied a place of considerable importance in the field of chemical engineering, for it is with the data from these studies that a large portion of the equipment used to manufacture and process chemicals is designed. There have been no investigations of the vapor-liquid relations of higher molecular weight substances of the type found in large quantities in petroleum prior to that of Rasmussen (6) for the tetradecane-hexadecene system and that of Keistler ( 4 ) for the dodecane-hexadecene system. This work on the n-dodecane-1-octadecene system is one of a series of investigations to study the vapor-liquid relationships of the paraffin-olefin systems. PURITY OF COMPOUNDS
The dodecane and octadecene used were obtained in relatively purified form. Comparison of experimental and literature values of properties is shown in Table I.
The octadecene showed some thernial instabilit~particularly at the higher temperatures. It was found that the refractive index of the octadecene increased from 1.44287 to 1.44570 and the density increased from 0.7862 to 0.7890 gram per ml. with refluxing for 30 minutes at 760 mm. of mercury pressure. An iodine test indicated the presence of peroxides vhich possibly n ere catalyzing dimerization of the octadecene. Similar difficulties were reported by Meistler ( 4 ) . The peroxides were removed by refluxing and distilling in the presence of solid ferrous sulfate. This reduced to some evtent the change of refractive index, but vapor-liquid equilibrium data determined using this material mere inconsistent. After three fractionating distillations the increase in refractive index of the octadecene mas reduced to 0.00134 when refluxed a t 760 mm. for 30 minutes. The materials from the triple distillations were used in obtaining the results reported in this work. The index of refraction of the product of the treatment for peroxides and subsequent distillations was the same as that of the octadecene originally received. The temperature remained constant during refluxing,indicating that the amount of dimeror other eubstance formed was not sufficient t o change the boiling temperature or t o alter the volatility of the octadecene appreciably.
OF PURE COMPOUNDS TABLE I. PROPERTIES
Dodecane Experimental Literature Refraotive index, n g 1.42016 1.11967 ( g ) Density, dzc 0,7462 0,7164 ( 2 ) Purity by bromine numher, ’?& by weight (8) . ... Purity hy freezmg point, mole 70 (6)
.. ...
...
Octadecene Experimental Literature 1.44287 0.7862
1.4421) ( 9 ) 0.7857 (9)
97.1
...
97.4
...
December 1951
2909
INDUSTRIAL AND ENGINEERING CHEMISTRY
TABLE 11. EXPERIMENTAL CALIBRATION FOR ANALYTICAL ANALYSIS OF VAPORAND LIQUIDSAMPLES
760-mm. isobar
400-mm. isobar
200-mm. isobar
100-mm. isobar 50-mm. isobar 20-mm. isobar All pressures
Figure 1. Vapor Pressure Chart. for Dodecane and Octadecene
VAPOR PRESSURE DATA
The vapor pressures of the dodecane octadecene were determined at the experimental pressures and are plotted in Figure 1. These data produced straight-line functions when plotted with the log P as the ordinate and 1/T OR.as the abscieaa. The experimental data for dodecane checked those determined by Krafft and reported by Stull ( 7 ) within the experiI450 mental error of 0.5" F. EXPERIMENTAL METHODS
Liquid Sample Dodecane, mole % 0.0 12.1 24.3 38.3 51.0 64.1 0.0
12.1 24.3 38.3 51.0 0.0 12.1 24 3 38.3 51.0 0.0 12 1 24.3 39.3 0.0 12.1 0.0 Vapor Sample 0.0 1.44287 5.1 25.1 30.5 39.4 47.7 55.0 68.9 85.7 93.6 97.2 100.0
1.44204 1.43857 1.43779 1.43583 1.43242 1.42912 1.42461 1.42240 1.42108 1.42016
case of boiling. It was found, however, that the vapor condensate index of refraction was not affected. Therefore. a calibration curve for the vapor sample and unheated mixtures WBB determined by preparing mixtures of definite compositions and measuring their indexes of refraction at 25" C. The resulte obtained are shown in Table 11.
1445
The determinations of vapor-liquid equilibria were 0 made using a Colburn-type (3) equilibrium still. The $ still was heated by three No. 26 Nichrome resistance CN I 4 4 0 wire windings placed one each on the flash boiler, the 2 residue chamber, and the vapor tube. The vacuum outlet for the system was connected directly to a 1435 3-liter bottle to eliminate pressure fluctuations. The Z pressure in the system was controlled by a needle-valve air bleed into the surge chamber and by a Cartesian>" 1 4 3 0 type manostat connected directly in the vacuum line between the surge chamber and the still. The pressure was indicated by a mercury manometer. The tem$ 1425 perature was determined by means of a copper-constantan thermocouple connected to a Brown portable potentiome€er capable of measuring 0.01 millivolt 0 10 20 30 40 50 60 70 80 90 100 (0.5"F.). The thermocouple was standardized in the still by the boiling points of benzene, aniline, chloroMOLE % DODECANE benzene, and nitrobenzene. Figure 2. Kefractive Index Calibration for the DodecaneA total charge of 15 ml. of materials was used for Octadecene System each run. Heat input to the still and the vaporization rate were carefully adjusted until only a drop of liquid remained in the lower part of the flash boiler and until the temperature remained constant. Each run was concluded I n order to determine the composition of the liquid sample 30 minutes after the time when heat was first applied to the still. from the refractive index. a correction had to be aoDlied to compensate for the increase caused by boiling. Figure 2 shows ANALYSIS OF VAPOR AND LIQUID SAMPLES the relation of composition and refractive index for the vapor The equilibrium samples were analyzed by index of refraction sample by the curve labeled ideal and the liquid sample by the methods, utilizing a Bausch and Lomb precision refractometer series of curves labeled for each experimental pressure. The using a sodium d line light source. As indicated above, the reindex of refraction was not appreciably increased by boiling a t fractive index of the octadecene and its mixtures increased 10 mm., and, therefore, the same curve, marked ideal, applied to on boiling, the amount of increase dependent upon the composithe analysis of both the vapor and liquid samples. The corrected tion, time of refluxing, and the temperature or pressure, as in the curves for the liquid samples were constructed from data obtained
6
2
INDUSTRIAL AND ENGINEERING CHEMISTRY
2910
Vol. 43, No. 12
EQUILIBRIUM DATAAND ACTIVITYCOEFFICIENTS FOR DODECASE-OCTADECENE SYSTEM TABLE 111. EXPERIVEXTAL VAPOR-LIQUID Temperature, F.
xa
-
P 3 7 8.2 10 4 15.0 21.8 28.3 33.5 42.7 44.8 54.4 69.2
Terngerature, va
YO
F.
Yb
va
XU
P
760 mm. of mercury 0,968 0.738 0.698 0,672 0.705 0.775 0,797 0.866 0.839 0,860 0.906
0.938 0.983 0.962 1.029 1.003 0.986 0.960 0.915 0,975 0.956 0,720
5.6 11.3 19.7 25.0 34.0 40.5 42.6 64.0 74 1
400 mm. 20.9 34.3 48.6 69.6 77.4 84 7 88.8 91.0 96.4 98.2
0.761 0.831 0.695 0.785 0.856 0.837 0.958 0.928 0.930 0.869
0.970 0.960 0.990 0.979 0.964 0,988 0,933 0,884 0.795 0.947
5.5 9.3 11.2 20.3 22.3 23.6 33.0 39.4 46.0 58.5 71.5
P = 200 mm. 34.0 51.8 52.3 72.1 76.8 82.0 86.0 90.1 93.5 96.2 98.2
0.735 0.802 0.702 0.796 0.825 0.910 0.811 0.867 0.842 0.913 0.973
0,991 0.956 1.013 1.050 1.010 0.894 1,010 1.041 0.866 0,962 0.900
0,623 0,785 0 764 0.705 0,842 0.849 0.933 0.926 0.994
0,993 1.010 1.031 1.020 1.038 1.054 0.779 1.209 1.000
96.1
38.0 43.3 52.1 66.3 76.4 81.8 89.1 89.0 92.9 97.3
P
=
2 .. 4.
399.6 391.7 382.7 368.8 353.3 347.0 335.4 327.0 313.5 303.0 281.8 271 0
20.5 39.3 56.9 69.4 83.6 86.6 95.3 97.1 98.9
2.7 3.6 5.0 5.9 8.2 14.2 19.7 27.1 37.2 61.2 75.7
P ' P 20 mm. 34.0 44.8 48.8 51.1 62.7 80.5 85.6 90 4 94.6 96.9 99.2
P
P = 100 rnm. 3.1 5.8 10.6 14.7 25.2 29.5 46.5 65.5 78.4
4.0 3.8 6.0 10.7 15.3 17.8 21 . 9 28.0 33.1 41.6 64.7 82.0
1.o
a25.3 809.3 299.5 293.2 284.7 279.0 272.0 252.5 240.7 225.6 215.2
by preparing several mixtures of known composition, refluxing a t each experimental pressure for a 30-minute period, and then noting the change of refractive index. The experimental data for these curves are presented in Table 11.
4.8
J 8
6.1 10.0 13.3 13.6 20 8 29.7 43.5 52 6
=
Yh
YO
50 mm. 26.6 38.2 47 2 63.9 72.1 78.2 83.2 88.0 91.5 93.9 97.5 99.2
=
10mm. 26.7 46.3 60.7 62.2 73.7 77.8 76.7 90.1 90.7 96.8 97.3
0 . ,552
0.928 0.820 0.775 0.780 0.820 0.875 0.835 0.945 a.940 0.950 0,976
1.008 0.985 1.022 0.969 1,088 1.010 1.062 0.984 1.025 1.070 1.200 1.025
0.859 0.965 0 . i96 0,734 0.851 0.920 0.874 0.8780.965 0.933 0 918
0.970 0,957 0.964 1.047 1.096 0.965 0.995 0.964 1.070 1.616 1.087
1,467 0.715 0,936 1.037 0.896 0.795 0.892 1.012 0.933 0.963 1.029
0,905 1,019 0.957 1.080 0.968 0.969 1.120 0.942 1,388 0 884 1 181
These relations were used to smooth the experimental data. The experimental data were plotted on a temperature-composition diagram and a smooth visual curve was drawn to approximate thedata. The activity coefficients,yo and Yb, werecalculated a t 10" F. intervals over the temperature range of the isobar and plotted against the liquid composition. A set of Van Laar
VAPOR-LIQUID EQUILIBRIUM DATA
The experimental data are presented in Table I11 and graphically in Figures 3 and 4. The reported smoothed curves of Figures 3 and 4 are the values of composition and temperature calculated from the Van Laar solutions of the Gibbs-Duhem equation which beat approximated the experimental data. ACTIVITYCOEFFICIENTS.The Gibbs-Duhem equation, in one of its familiar forms d log y. =
-
I -
Nn
~
xa
d log
~6
(1)
was derived assuming constant temperature and constant pressure. It may be extended to apply to nonisothermal data a t constant pressure without serious error if the ratio of partial pressure and vapor pressures does not change rapidly over the temperature range covered by the data a t constant preesure. The Van Laar solutions of this equation have been found to represent the data of many binaries very successfully. The Van Laar solutions are log
A
yo
(2)
Ax.,
0
20
40
60
80
100
MOLE % DODECANE
log
7'6
=
rl + L
B B(1 - 2,) "..
fiiza
1' J
(3)
Figure 3. Equilibrium Boiling Point Diagram for the Dodecane-Octadecenc System
INDUSTRIAL AND ENGINEERING CHEMISTRY
December 1951
2911
TABLE IV. SMOOTHED VAPOR-LIQUID EQUILIBRIUM DATAAND ACTIVITYCOEFFICIENTS FOR DODECANE-OCTADECENE SYSTEM Temperature, F.
Temgerature, ua
xu
P 596.0 590 580 570 580 560 540 530 520 510 500 490 480 470 460 450 440 430 418.1
=
0.0 8.0 21.6 33.5 43.2 52.3 60.3 67.0 73.0 78.4 82.9 86 8 89.9 92.5 94.7 96.6 98.1 99.1 100.0
P 0.0 1.4 3.9 6.8 9.8 13'1 16.5 20.3 24.6 29.7 35.2 41.2 47.5 53.8 60.6 67.9 76.9 87.9 100.0
497.0 490 480 470 460 450 440 430 420 410 400 390 380 370 350 340 330.4
0.0 1.6 4.1 6.6 9.6 13.1 16.9 21.0 25.2 30.0 34.8 40.3 46.5 53.6 62.4 73.1 86.0 100.0
454.2 450 440 430 420 410 400 390 380 370 360 350 340 330 320 310 300 293 9
0.0 0.8 3.1 5 5 8.1 10.8 13.6 17.1 21.0 25.6 30.8 37.1 44.6 53.2 63.0 74.6 89.7 100.0
414.6 410 400 390 380 370 360 350 340 330 320 310 300 290 280 270 261.0
0.0 0.8 2.7 4.7 7.0 9.7 12.6 16.1 20.5 25.5 31.3 38.5 47.1 56.3 68.3 83.7 100.0
360 ...
=
0.600 0.611 0.628 0.650 0.670 0.688 0.708 0.727 0.753 0.776 0.798 0.822 0.845 0.870 0.899 0.930 0.964 0.985 1.000
lo00 0.999 0.999 0.998 0.997 0.995 0.991 0.984 0.977 0.967 0.954 0.940 0.918 0.895 0.862 0.814 0.748 0.672 0.551
400 mm.
0.0 8.8 22.0 34.5 45.3 54.6 62.9 69.9 75.9 81.0 85.5 89.2 92.2 94.4 96.3 97.5 98.5 99.4 100.0
P
"
?b
F.
0.683 0.689 9.698 0,710 0.722 0.737 0.751 0.767 0.783 0.802 0.825 0.851 0,874 0.898 0.921 0.944 0 969 0.991 1,000
1.000 1.000 0.999 0.998 0.997 0.994 0.990 0.986 0.980 0.972 0.958 0.941 0.920 0.895 0.864 0.826 0,773 0.703 0,603
0.730 0.736 0.743 0.752 0.762 0.772 0.784 0.790 0.811 0.837 0.842 0 860 0.882 0.903 0.932 0.960 0.987 1.000
1.000 0.999 0.999 0.998 0.996 0.994 0.990 0.888 0.583 0.978 0.968 0.966 0.941 0.922 0.881 0.832 0.750 0.625
= 200 mm.
0.0 10.0 25.0 38.4 50.0 59.6 67.7 73.8 79.3 83.7 87.6 90.7 93.3 95.6 97.4 98.8 99.7 100.0
I
366.6 360 350 340 a30 320 310 300 290 280 270 260 250 240 230 210 t
.
Ya
X.l
760 mm. of meroury
0.0 1.7 4.7 7.8 1b.O 14.3 17.9 21.7 25.7 30.0 34.7 39.8 45.1 51.2 58.3 67.0 76.8 86.8 100.0
546 0 540 630 520 510 500 490 480 470 460 450 440 430 420 410 400 390 380 371.1
yo
0.0 1.1 2 7 4.7 6.8 9.4 12.5 16.3 21 0 26.7 33.5 41.7 51.8
63.9 79.1
100.0
P = 20mm 0.0 13.3 31 5 46.4 57.7 67.6 75.6 81.5 86.5 90.3 93.3 95.4 97.1 98.4 99.3 100.0
P 335.7 330 320 310 300 290 280 270 260 250 240 230 220 210 198.8
0.0
0.7 2.1 3.7 6.7 8.1 11.0 14.6 19.0 24.3 31.0 39.0 50.2 65.6
100.0
-
10mm. 0.0 11.0 30.0 46.2 58.4 68.1 75.9 82.4 87 1 90.7 93.7 95.9 97.3 98.7
100.0
YU
0 861 0.862 0.364 0.868 0.872 0.877 0.882 0.888 0.896 0.905 0.917 0.931 0.947 0.967 0,986 1.000
0.908 0.908 0.909 0.911 0.913 0.916 0.920 0.924 0.930 0.936 0.944 0.952 0.964 0.979 1,000
Yb
1.ooo
1.000 1.000 1.000 0.999 0.999 0 99s 0.997 0.996 0.992 0.986 0.977 0.962 0.937 0.892 0.785 1 ,000 1.000 1.000 1.000 1,000 0.999 0.999 0.998 0.997 0.996
0.993 0.988 0.977 0.957 0.858
constants, A and B, was selected which best represented this relation, and the Van Laar equations, using these constants, were plotted in the same manner by solving for Y,, and Y b a t selected compositions. The vapor and liquid compositions corresponding to the set of Van Laar coefficients were calculated by trial and error using the relations (4)
(5)
The values of ya and Yb to be substituted were found by assuming the liquid compositions of the visual curve to be correct and taking their values from the plot of the Van Lam equations. If xa calculated from these values of coefficients did
P = 100mm.
I
P
-
0.0 6.2 23.6 37.6 49.6 59.0 67.2 74.0 79.5 84.1 88.2 91.7 94.2 96.2 97.7 98.8 99.7 100.0
0.769 0.772 0.776 0.783 0,789 0.796 0.803 0.814 0 824 0.838 0.850 0.870 0.891 0.913 0.940 0,967 0.994 1,000
1 000 1.000
1,000 0 999 0.999 0.999 0.997 0.994 0.992 0.988 0.980 0.971 0.957 0.933 0.898 0.833 0.728 0.656
50 mm. 0.0 7.7 25.0 39.6 52.0 61.8 70.1 76.7 82.2 86.6 90.0 92.8 95.1 97.0 98.4 99.3 100.0
0.798 0.802 0.805 0.810 0.815 0.821 0.828 0.837 0.849 0.862 0.878 0.896 0.905 0.938 0.963 0.988 1.000
1,000
1.000 1.000 0.999 0.999 0.998 0.997 0.995 0.993 0.989 0.983 0.972 0.964 0.931 0.888 0.822 0.715
MOLE % DODECANE IN LIQUID, x
Figure 4.
Vapor-Liquid Equilibrium Diagram for the Dodecane-Octadecene System
INDUSTRIAL A N D ENGINEERING CHEMISTRY
2912
Vol. 43, No. 12
possible and still complied with the Gibbs-Duhem and Van Laar relations. The calculated data for the smoothed curves are presented in Table I V and graphically in Figures 3 and 4. The activity coefficients of the experimental and calculated data are plotted against liquid composition in Figures 5 and 6. The Van Laar coefficients corresponding to the calculated isobars are presented in Table V. CONCLUSIONS
Figure 3 indicates the agreement of the calculated curves and experimental 60 80 100 data to be good with but a few random MOLE % DODECANE IN LIQUID, x variations. When plotted in the x - y diagram of Figure 4, it is noted that Figure 5 . Activity Coefficients of the Dodecane-Octadecene Sys tern there is a small amount of dissimilarity in the curvature of the various isobars. Considering the fact that the presentaof equilibrium data in the form of activity coefficients greatly tion not agree with the original assumed value, the new value of zo was used to repeat the calculation until agreement was attained. magnifies the experimental errors, there is fair agreement of the experimental and calculated activity coefficients in Figure 5 except The vapor composition^ Y ~ was I then calculated from the for isobars of lomrer pressures. The terminal points of the activity value of xa. coefficient curves increase with decreasing pressure and approach a value of unity. However, the coefficknts were found n o t to 1.1 increase beyond unity at the pressures investigated. The Van Laar constants show a definite and relatively uniform trend to I .o increase from more to less negative values as the pressure is decreased. 0.9 Carlson and Colburn ( I ) have observed that a large number of nonideal systems show positive deviations and that negative 0.8 deviations appear to occur in electrolytes and other liquids where association or compound formation of some type reduces the 0.7 volatility. Whether the paraffin-olefin systems are an exception + 1.1 requires further study. I-’ The trend of activity coefficients in this study does not agree z 1.0 with that reported by Rasmussen (6) for the tetradecane-hexaw decene system, for which the coefficients were greater than uniky 0.9 a t 760 mni. and decreased to values less than unity as the pressure w decreased. 0.8 061 0
I
I
20
I
I
44
I
I
60
I
I
BO
I \
100
20
0
40
9
c
0.7
NOMENCLATURE
a = subscript indicating a property of the more volatile com-
MOLE % DODECANE, x
Figure 6. Activity Coefficients of the Dodecane-Octadecene System
These vapor and liquid compositions, corresponding t o the selected set of Van Laar constants, were plotted on the same diagram with the visual curves and the average of the two curves was used to repeat the entire procedure of calculation until the compositions resulting from successive calculations agreed. Thus the calculated curve w a s as close to the original visual curves as OF SMOOTHED EQUILIBRIUM TABLE V. VANLAARCONSTANTS DATAFOR DODECANE-OCTADECENE SYSTEX
P,Ma.
Mercury 760 400 200 100 50 20 10
A -0.187
-0,166
-0.137 -0.114 -0.097 -0.065
-0,042
B -0.268 -0.220 -0,204
-0.183 -0.146 -0.105
ponent, dodecane b = subscript indicating a property of the less volatile component, octadecene A = constant of the Van Laar solutions of the Gibbs-Duhem equation B = constant of the Van Laar solutions of the Gibbs-Duhem equation D = density a t 25’ F., grams per ml. n = index of refraction T = temperature, F. x = mole % component in liquid y = mole % component in vapor y = activity coefficient P = vapor pressure LITERATURE CITED (1)
Carlson, H. C., and Colburn, A. P., IXD.EXG.CHEM.,34, 581 (1942).
Egloff, G., “Physical Constants of Hydrocarbons,” Vol. 1, pp. 80, 289, New York, Reinhold Publishing Corp., 1839. (3) Jones, C. A., Schoenborn, E M., and Colburn, A. P., IND. ENQ. CHEM.,35, 666 (1943). (4) Keistler, J. R., “Vapor-Liquid Equilibria of the DodecaneHexadecene System at Subatmospheric Pressures,” thesis in chemical engineering, University of Texas, 1950. (5) Mair, A. R., Streiff, A. J., and Rossini, F. D., J . Research Natl. (2)
BUT.Standards, 35, 355 (1945). (6) Rasmussen, R. R., and Van Winkle, M., IND. ENG.CHEM.,42, 2121 (1950). (7) Stull, D. R., I b X , 39, 517 (1947).
(8) Universal Oil Products Co., Chicago, “Laboratory Test Method8 (9)
for Petroleum and Its Products,” H-25, 1947. Wibaut, J. P., and Geldof, H., Rec. trav. chim., 65, 125 (1946).
-0.066
RPCEIVEDDecember 4. 1950.
