Phase Equilibria in Hydrocarbon Systems VOLUMETRIC AND PHASE BEHAVIOR 'OF n-PENTANE HYDROGEN SULFIDE SYSTEM H . H. R E A M I ~ R B. , H. SAGE, AND
w. N.
LACEY
California Institute of Technology, Pasadena, Calif.
N
*
0 EXPERIMENTAL information appears to be available concerning the volumetric or phase behavior of mixtures of
n-pentane and hydrogen sulfide. However, the components have been studied in detail. Earlier studies of hydrogen sulfide were reviewed by West (16). The volumetric behavior and vapor pressures of hydrogen sulfide were investigated recently (8). The measurements of Giauque and Blue ( 2 ) upon the vapor pressure of hydrogen sulfide are in good agreement with these data, which for present purposes are employed as a basis for establishing the characteristics of hydrogen sulfide. Young (10, 1 7 ) studied the volumetric and phase behavior of n-pentane a t relatively low pressures for temperatures between 104' and 460" F. Brown and coworkers ( 4 , 6 )determined throttling curves for this compound and the volumetric behavior in both the liquid and gas regions was investigated in some detail (11, I S ) . The foregoing data establish the characteristics of n-pentane with an accuracy adequate for present purposes. Studies of mixtures of hydrogen sulfide with the lighter paraffin hydrocarbons appear to be limited t o the m'ethane-hydrogen sulfide (9) and the propane-hydrogen sulfide systems (3). These investigations indicated that hydrogen sulfide in mixtures with the lighter paraffin hydrocarbons followed the general behavior of binary systems where no more than two phases were encountered. I
MATERIALS
The hydrogen sulfide used in this investigation was prepared by the hydration of pure aluminum sulfide. It was dried over anhydrous calcium sulfate and fractionated twice in a column 4 feet in length filled with glass helices. A reflux ratio of 30 to 1 was employed and the f i s t and last 10% portions of the overhead were discarded from each fractionation. The central portion of the overhead from the second fractionation was collected a t a pressure below 0.002 inch of mercury a t the temperature of liquid nitrogen. The purified hydrogen sulfide showed less than 0.2 pound per square inch change in vapor pressure a t 100' F. as a result of a change in fraction vaporized from 0.2 to 0.9. The n-pentane was obtained from the Phillips Petroleum Co. with the specification that the samples contained less than 0.005 mole fraction material other than n-pentane. This relatively pure hydrocarbon was fractionated in contact with anhydrous calcium sulfate in the same column employed for the purification of hydrogen sulfide. The middle 80% ortion of the overhead was collected in a stainless steel weighing Eomb ( I d ) for this study. The vapor pressure of the n-pentane as purified varied by less than 0.1 pound per square inch upon a change in fraction vaporized from 0.003 to 0.30 a t a temperature of 220" F. METHODS
The equipment utilized has been described ( 1 2 ) . In principle, it involved B stainless steel vessel within which the mixture of n-pentane and hydrogen sulfide was confined over mercury. The total effective volume of the vessel was changed by the introduction and withdrawal of mercury. The attain-
.o
0.8
?
2.50
0
z
6 Q
a
z
I-
23
6,
Q
0.6
2.25
a W
a
t
2.00
W b.
0
m 3
0
1.75
w
2
0.2
3
9
1000 PRESSURE
2000
1.50
3000
500
POUNDS P E R S Q U A R E I N C H
Figure 1. Compressibility Factor-Pressure Diagram for Mixture Containing 0.3916 Mole Fraction Hydrogen Sulfide
PRESSURE
1000
1500
POUNDS PER
2000
SQUARE
INCH
Figure 2. Molal Volumes near Bubble Point for Mixture Containing 0.3916 Mole Fraction Hydrogen Sulfide
1805
INDUSTRIAL AND ENGINEERING CHEMISTRY
1806
TABLEI. Pressure, Lb./Sq. Inch -4bs.
D.P.
B.P. 200
400
600 800
1,000 1,250 1,500 1,750
2,000 2,250 2,500 2,750 3,000 3,500 4,000 4,500 5,000 6,000 7,000 8,000 9,000 10,000
h I 0 L A L VOLUMES O F 1 f I X T U R E S O F % - P E N T A X E AND
.-_____.~~___ l I o l e Fraction Hydrogen Sulfide
0.2501
U0)a .53lb,c (6;) 1 .a38 1.5366 1.532 1.528 1.524 1 521
1.516 1.512 1.508 1.504 1,500 1,497 1.493 1.189 1.482 1.476 1.468 1.462 1.450 1.440 1.431 1.424 1.417
0.3916
0 . 7!188
1.133 1.129 1.125 1.121 1.118 1.114 1.110 1.106 1.103 1,100 1.096 1.093 1.091 1,085 1.080 1,075 1.070 1.061 1.052 1,047 1.041 1.035
(148) 0.916 0 915 0.912 0.909 0.906 0.903 0 900 0.897 0.893 0 890 0.887 0.884 0.881 0.879 0.874 0.869 0 865 0.861 0.854 0.848 0.842 0.836 0 832
D.P.
1.382 1.378 1.374 1.371 1.367 1.363 1.359 1.355 1,351 1.347 1,344 1.340 1.336 1.330 1.324 1.318 1.312 1,302 1.293 1.285 1.277 1,270
__ __ D.P. B.P. 200 400 600 800 1,000 1,250 1,500 1,750 2,000 2,250 2,500 2,750 3,000 3,500 4,000 4,500 5,000 6,000 7,000 8,000 9,000 10,000
B.P. 200 400 600 800 1,000 1,250 1,500 1,750 2,000 2,250 2,500 2,750 3,000 3,500 4,000 4,500 5,000 6,000 7,000 8,000 9,000 10,000
- 7
(22)U
261b,c (123) 1.633 1.630b 1.626 1.619 1,613 1.608 1,601 1.595 1.590 1.584 1.579 1.574 1,569 1.564 1,555 1.547 1.539 1.532 1.518 1.505 1.493 1,482 1.473
-
0.6123
Pressure Lb./Sq. I&h Abs.
(82)
65.9 (330) 0.994
1.472 1,467 1.461 1.455 1.450 1.444 1.438 1.432 1.427 1.421 1.416 1.411 1.406 1.398 1.390 1.383 1.375 1.362 1.350 1.338 1.328 1.318
.....
1.216 1.210 1.204 1.198 1.193 1.187 1.182 1,175 1.171 1.166 1.160 1,156 1.147 1,140 1,133 1.126 1.114 1.103 1.093 1,082 1,073
0:993 0.988 0.983 0.979 0.973 0.967 0.962 0. 957 0.952 0.947 0.943
0.939 0.930 0.923 0,917 0.911 0.900 0.891
0.882 0. 873 0.865
ment of equilibrium was hastened by the use of a magnetically driven mechanical agitator. Pressures were measured by means of a balance which was calibrated against the vapor pressure of purified carbon dioxide a t the ice point (1). Pressures were determined within 0.2 pound per square inch or O . l % , whichever was larger. The balance employed in this study has not changed in calibration by more than 0.029'0 in a 10-gear period, during which it has been in nearly constant use. The temperature of the sample was determined by means of a platinum resistance thermometer of the strain-free type. This instrument was compared n i t h a similar device calibrated by the National Bureau of Standards. It is believed that the temperature of the vessel was known within 0.03" F. relative to the international platinum scale. The total volume of the sample was established with a probable error of approximately O . l % , except a t the higher temperatures and pressures, where the uncertainty may have been as muzh a s o.lF~7~.The weight of npentane and hydrogen sulfide employed was determined with a probable error of 0.05%. An evaluation of the effect of the several errors involved in measurements of this kind led t o a n overall estimate of the probable error oi 0.25% in the specific volume a t a given pressure and temperaturr. The purified n-pentane was distilled into the apparatus from a tared weighing bomb ( 1 2 ) . The total volume of the sample of +pentane added was determined and use of available volumetric data (8) permitted check upon the gravimetric measurement. The hydrogen sulfide was introduced by the same R eighing bomb teehniques, but in this instance it was not possible
Vol. 45, No. 8
HYDROGEK SULFIDE Mole Fraction Hydrogen Sulfide 0.2301 0.3916 0.6123 0.7988 (66) 9lbZc (220) 1.756
.....
1,7436 1.732 1.722 1.712 1.701 1.693 1.682 1.673 1.664 1.656 1.649 1.642 1.629 1.618
1.607 1.596 1.578 1.561 1.546 I . 532 1.520
..
..
1 .585
1.574 1.563 1.553 1 543 1.534 1.525 1.516 1.508 1,499 1,492 1.488 1.471 1.459 1.448 1.438 1.421 1.406 1.390 1,378 1.365
...
(263) 22 (623) I . 109 304 I . .
1:330 1 318 1 307 1.296 1.284 1,275 1.265 1.257 1.248 1.241 1.234 1.222 1.210 1.200 1.190 1.173 1,158 1.148 1,132 1.121
1:io5
1.094 1.081 1.068 1.056 1.047 1.038 1.030 I ,022
1.013 1.002 0.991 0.982 0.973 0.956 0.941 0.928 0 917 0.907
7
D.P. B.P. 200 400 600 800 1,000 1,250 1,500 1,750 2,000 2,250 2,500 2,750 3,000 3,500 4,000 4,500 5,000 6,000 7,000 8,000 9,000 10,000
il31)" 46h~C (387) 1.909 1:905b
1.884 1.865 1.848 1.829 1.812 1.796 1,781 1.768 1.756 1.744 1.734 1.715 1.699 1.683 1.670 1,646 1.625 1.606 1.588 1.572
... 1: 742 1.720 1.701 1,679 1.660 1.643 1,628 1.613 1.600 1.589 1.578 1.559 1.542 1,526 1.511 1,487 1.467 1.448 1.431 1.414
...
(553) 10.1 (1021) 1 320 34 15.2
1. 806
...
32d
...
...
1.481
1,452 1:282 1.427 1,242 1.209 1.405 1,385 1. 183 1.368 1.160 1.352 1.141 1.124 1.338 1.327 1.110 1.306 1.088 1,289 1.073 1.273 1.060 1,258 1,049 1.027 1.234 1.213 1,007 1.195 0.988 1.180 0.971 1.167 0.957 (Continued on p a g e 1 8 0 : )
to obtain a check upon the quantity added by auxiliary volumetric measurements. The total volume of the mixture of known weight was determined a t a series of pressures for eight different temperatures between 40" and 460" F. At the end oi these measurements the behavior of each mixture at 100' F. was redetermined in order t o detect any effects resulting from thermal decomposition during the studies a t elevated temperatures. Earlier studies (8, 9) indicated t h a t measurable rates of decomposition of pure hydrogen sulfide are encountered a t temperatures above 340" F. For this reason none of the measurements were extended beyond this temperature, except for a single mixture containing only a small quantity of hydrogen sulfide. In this instance the investigation was carried to a maximum temperature of 460" F. At temperatures above 340" F. additional uncertainty may exist as a reeult of the thermal decomposition of the hydrogen sulfide. The compositions of one of the coexisting phases in heterogeneous equilibrium were determined by the withdrawal of samplcs 01 the gas phase under substantially isobaric, isothermal conditions. The composition of the sample withdrawn was established by measurement of the specific weight of the gas phase a t approuimately atmospheric pressure and a temperature of 100' F. Volumetric studies of the gas phase a t elevated pressures were
INDUSTRIAL AND ENGINEERING CHEMISTRY
August 1953
1
TABLE I. MOLALVOLUMES O F MIXTURES O F n-PENTANX HYDROGEN SULFIDE (Continued) Pressure Lb./Sq. Inch Abfi.
D.P. B.P. 200 400 600 800
..
280' F (570) 9.7 (1103) 1.955 2.024
(255)G 22.8b,C (526) 2.116
34
33 d
...
37 17.2 10.5 7.,l
36 15.9
...
2: 000
2.036 2.001 1.971 1.942
1.936 1.878 1.834 1.797
1 807 1.686 1.617
5.1 3.4 1.94 1,593
2,000 2 250 2 500 2,750
1.917 1.895 1.877 1.859
1.769 1.744 1 722 1.704
1.565 1.528 1.497 1.472
1.462 1.387 1.333 1.293
3,000 3,500 4 000 4 500
1.843 1.815 1.791 1.771
1 687 1 658 1.633 1.611
1.450 1.416 1.386 1.361
1.262 1.214 1,178 1,149
5,000 6,000 7,000
.8,000
1.752 1.718 1.690 1.666
1.592 1.559 1 530 1.505
1.340 1.304 1.275 1.251
1,126 1.087 1.058 1.033
9,000 10,000
1.644 1.626
1.483 1.464
1,231 1 213
1,012 0.994
D.P.
(480)a 10.5bnC (743)
-340' (629) 7.8 (951) 2.650
37d 15.0
38 16.4 8.61
200 400 600 800
2.550
...
21567
...
MEASUREMENTS
.
F.
40 18.1 10.9 7.2
41 19.1 12.0 8.4
1,000 1,250 I ,500 1,750
2.393 2.289 2.206 2.147
2.505 2.271 2.126 2.040
5.1 3.3 2.43 2.07
2,000 2,250 2,500 2,750
2.096 2.056 2.024 1.997
1.976 1,928 1.889 1.855
1.894 1.789 1.712 1.659
2.087 1.803 1.637 1.523
3,000 3,500 4,000 4,500
1.974 1.933 1.898 1.870
1.828 I . 780 1,741 1.708
1.615 1.548 I . 496 1.456
1.444 1.340' 1,270 1.220
5,000 8,000 7,000 8,000
1.843 1.799 1.761 1.731
1.680 1.634 1.597 1.565
1.424 1.373 1.334 1.302
1.182 I. 124 1.081 1.048
9,000 10,000
1.706 1.684
1.539 1.518
1.272 1.246
1.023. 1,001
200 400 600 800
1
VOLUMETRIC
7
1,000 1,250 1,500 1,750
B.P.
0
Mole Fraction Hydrogen Sulfide 0.2501 0,3916 0.6123 0.7988
2: io1 2.068
:
AND
1807
'6.3 4.5 3.4 2.57
0.2501 400" F.
0,2501 460' F.
41 18.1 10.0 5.6
46 20.7 12.4 8.1
1,000 1,250 1,500 1,750
3.52 2.83 2.60 2.45
5,7 3.99 3.27 2.94
2,000 2,250 2,500 2,750
2.348 2.273 2.218 2.174
2.727 2.584 2.479 2.399
3,000 3,500 4,000 4,500
2.137 2.071 2.020 1.979
2.334 2.239 2.164 2.104
5,000 6,000 7,000 8,000
1,$342 1.885 1.836 1.799
2.053 1.977 1.920 1.871
9,000 10,000
1.766 1.742
1.833 1.802
a F i ures in parentheses represent dew point or bubble point pressures expressefin pounds per square inch. b Volumes expressed in cubic feet p&rpound mole. Dew point volumes calculated from volumetric behavior in heterogeneous region. d Volumes in a8 phase interpolated and subject to larger uncertainties than remainder ofthe data.
0.2 MOLE
F i g u r e 3.
0.4 FRACTION
0.0 HYDROGEN
0.8 SULFIDE
Pressure-Composition Diagram for Rubble Point and Dew Point
extrapolated to atmospheric pressure in order to determine the small correction factor for the deviation of the phase at 100" F. and atmospheric pressure from an ideal solution ( 5 )and from the behavior of a perfect gas. I n order t o check the over-all accuracy of the specific weight measurement, the composition of three samples was determined by conventional absorption method& (16). It was not necessary to use the refinements suggested by Shaw (14). Agreement between the_ compositions of individual samples determined from the measurement of the specific weight and from absorption methods was within the uncertainty of measurement of the latter method of analysis. In the majority of cases the composition of the coexisting gas phase was determined in duplicate by withdrawal of two separate samples at substantially the same equilibrium pressure and temperature. The bubble point states were established from the discontinuity in the first derivative of the specific volume-pressure relationship under isothermal conditions with constant composition. EXPERIMENTAL RESULTS
A typical set of experimental data for a mixture containing 0.3916 mole fraction hydrogen sulfide is presented in Figure 1. Experimental points have been included for both the one- and two-phase regions and the data shown have been limited t o a pressure of 4000 pounds per square inch, so that the two-phase region can be shown clearly. The number of measurements shown in Figure 1 is typical of that obtained for the other three mixtures. I n order t o illustrate the accuraoy with which the bubble point may be predicted, Figure 2 shows the molal volume as a function of pressure at constant temperature for one mixture in the vicinity of bubble point. It may be seen that there is a sharp discontinuity in the slope of the isotherm at bubble point. The molal volume of the dew point gas was ascertained from experimental data in the heterogeneous region, together with the
INDUSTRIAL AND ENGINEERING CHEMISTRY
1808 I
Vol. 45, No. 8
.o
TABIc I1 I\
pressure Lb.,'Sq. Idch
Volume Cu. Ft./db.
Mole Frartion
Equilibrium Raqio -~ ___ Hydrogen sulfide n-l'rntane ~~~~
Hydrogen Sulfide Gas
Ab5.
0.8
PROPERTIES OF COEXISTI\(~ LIQLII);IUD G A P~F I A S E ~ TL-PENTANE-HYDROGEN SuLFIijj, SI%ri.Rr
Gas
Iiquix
1212 263a 129 85 62 49 38 31 27.8
1.798 1.738 1.654 1.564 1.458 1.334 1.138 0.891 0,661
Liquid
-7
4 20 40 60 80 100 12: 150
U 0
v 0.6 iL Q
>
4'1
l6OC
k I'
....
12.71 6.28 4.117 2.950 2.215 1.608 1.21 1.000
1,0000 0.2300 0.1219 0.0899 0.0689 0.0560 0.0462 0.041
. .
m
"
100' IC.
vi
15 7" 50 100 150 200 2.50 300 350 394c
0.4
I
s 0.2
Figure 4.
300
200 TEMPERATLJRE
OF
&@+.
Compressibility Factors for Rubble Point and Dew Point States ~
94 9"
The first. term to the right of equality of Equation 1 desrribes the change in molal volume with composition in the two-phase region from the two-pha,se state, a,t80that at bubble point. The .addition of the volume a t a in the second term thus gives thtt molal volume at dew point. A411 the quantit,ies concerned iri Equation 1 apply to a sin.gIe pressure and temperature. Gooil agreement was obtained from values calculated from Equation I and those estimated from information in the single-phase regioii. Dew point was determined a t a iew states at 280" and 340" F. by discontinuities in the first derivative of the compressibilitj. factor with respect to pressure at mnst,aiit temperature 2nd coinposition. In smoothing experimental data a value of the universal gas constant of 10.73185 was employed with the pressure expressed in pounds per square inch, the molal volume in cubic feet per pound mole, and the temperature in degrees Rankine. Thi, tenipersture of the ice point at ntmospheric pressure was taken as iDi.69" R. and the nio1ec:ular weights of n-pentane and hydrogen sulfide as used xvere 72.1 -li arid 34.076. respectively. Suitable residual techniques were employed t o ensure that the c:alculatior~s associated with the smoothing of the experimental daia anil theii, interpolation t o even values of 1)ressure and t,emperature n e w carried out with sufficient precision 1 o avoid signifirant iririraw of the uncertainty of the h 5 i c data. The esperimerital result? establishing the compositioiis of the roexisting phases at thc 'several temperatures invehgated are shown in Figure 3 . Compositions a t dew point were established in most, caseF: by n-ithdr:iwal of samples of the gas phase a r i d determination of its composition, as has been described. The point3 est,ablished Croin discontinuit,ies in the first derivative of volumetric. data a t both den. points and hubhle point F h : i w I,eeii included. Chad a g ~ c w
200 300 400 500 600 700 800 900 1000 1100 1200 1300 1302: 1302 1299f
__
31.6 29.2a 19.2 14.2 11.2 9.1 7.6
300 400 500 600 700 800 900 1000 1100 1200 1245; 1246 12241
1120d
1600 1'. 1 4 2 . 5 2.029 601 1.942 29.2 1.788 18.8 1.631 13.6 1.474 1 0 . 3 1.311 8 . 0 1.147 6 . 4 0.974 5 . 3 1 0 858
220" I 2 183 2 178 2 070 1.968
7
8.48 4 . 26 2.847 2.119
1.670
1 367 I 14
1
ow
__
.....
6.4
2.407 2.392 2.286 2.199 2.131 2.078 2.038 2.005 1.980 1.963 1 955 2 07
3.5 4.6 3 9 3.2 2 . 3 0 I 30 2 37 2.87
0.138: 0.2732 0.3689 0.4420 0.4990 0.5352 0.566
0.576 0.536
0351
0.575
0.0000 0,0402 0.0983
0.15%
0 2217 0.2880 0.3547 0.428 0.513 0 536
.... ,...
3400 1;. 13.41 2.807 1 2 . t i a 2.751
1 0 . 0 2.678 8 . 3 2.607 7 . 0 2.559 6.0
2.557
3 . 2 2 604 4 . 4 2.71 3.7 2.94 3.0 3 0 3.2 3.7
...
...
1
I . 0000
0.5299 0,3399 0,2700 0.2318 0.1993 0.1938 0.186
....
I ,0000 0.9500 0,5900 0.4666 0.4025 0.3601 0.3451 0.3371 0.3440 0.3658 0.4087 0.4759 0.5910 0.912 1.0000
5.ijl 3.85 2.975 2.450
0.9450 0.7193 0.6163 0.5600 0.5299 0.5187 0.5226 0.5442 0.5889 0.663 0.784
.... ~
9.0 4.6 3.2 2.454 2.018 1,727 1,520 1.366 1.251 1.161 1.092 1.040 1.003 1,000
~~
2.093
1.836 1.634 1.472 1.335 1.22 1.10 I ,000
_0 0000
1 . 0000 0.3600 0.2100 0.1504 0.1281 0.1173 0.1113 0 . 108
6.41 3.32 2,283 1.770 1.456 1.243 1.09 1 000
_ _ ~ 280' F..
185 O L
1125e 11041
1.422 1.273
1.865 1.764 1.664 1.569 1.481 5 . 5 1.405 4 . 8 1.339 4 . 0 1.287 3 . 3 1.245 1.68 1.22 1 . 6 4 1.64 I . 65 1.71
200
320 2 1 400 500 600 700 800 900 1000 1100
1.,561
64 5 61') 80 19 6 14.4 11.3 9.2 7.6 6.5
IO0
cornpositlion at dew point. The following basic expression, which does not involve any assumptions as to the behavior of the binan system, was employed for thwe c alculations:
30
1.903
16 8 1 105 1 3 . 8 0.916 1 1 . 6 8 0 731
42 5C' 100 200 300 400 500 600 700 778 ' I c
,
1.818 1.693
26.7 20 8
~
100
366 114b 56
7
...
I .0000
1 . 0000
~, . .
3 . 44 2.779
2.327 1.994 1.733 1,509 1 32 1.12 1,000
1 0000 0.8Y7ii
0.8060 0.7600 0.7169 0.7097 0.120;1 0.759 0. 876 I . 000
Tapox pressure of n-pentane, 5 Dew ,point volumes calculated from voliirnetric hr.liavior i n hrtcrogenr'ous mmon. c Tap'& pressure of kiydrogpn sriifide. d e
Critical state. Xaxcondenbar, which corrr,ponds
111 wsiire.
1. hIaxcondentlierm, t f xtilperatiire.
t o state of maxiiriiim two-phase
whicli corrc-pondi t o jtate of maximum two-phase
INDUSTRIAL AND ENGINEERING CHEMISTRY
August 1953
*
ment was obtained between the volumetric and directly measured compositions of the dew point gas a t states where comparison was possible. The compressibility factors of the bubble point liquid and dew point gas for the n-pentane-hydrogen sulfide system are shown in Figure 4. Detailed experimental volumetric and phase composition data are available ( 7 ) . Smoothed values of the molal volume of the liquid and gas phases at even values of pressure for the experimentally measured temperatures and compositions are recorded in Table I. The molal volumes and compositions of the coexisting liquid and gas phases of this system are presented in Table 11. The equilibrium ratios for n-pentane and hydrogen sulfide are included. The product of the pressure and the equilibrium ratio for npentane and for hydrogen sulfide in this binary system is given in Figure 5. The effect of pressure and temperature upon the values of the equilibrium ratio is comparable to that found for other systems involving hydrogen sulfide and paraffin hydrocarbons. The points shown correspond t o those states for which the composition of the dew point gas was established directly. In most instances the corresponding composition of the bubble point liquid was interyolated from the volumetric measurements. The properties of the binary system a t the critical state, the maxcondentherm, and the maxcondenbar are recorded in Table 111. The values of temperature, pressure, and molal volume reported in this table involve larger uncertainties than those associated with the data recorded in Tables I and 11.
TABLE111.
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
This work constitutes a contribution from Project 37 of the American Petroleum Institute. David Downing contributed to the mpervision of the experimental program. Virginia M. Berry carried out the calculations and Audrey Ambler assisted with the assembly of the manuscript.
5
Critical 489.5C 613 737 861 979 1087 1172 1233 1272 1293 1306b
Mole
4.729 4.4 4.2 3.9 3.6 3.2 2.78 2.40 2.06 1.80 1,566
Maxcondentherm 605 384.8 382.9 720 378.9 833 939 371.3 1038 357.1 1124 332.8 1195 297.9 264.1 1248 236.5 1283 Maxcondenbar 613 737 861 976 1078 1165 1230 1270 1292
Volume,
Cu. Ft./Lb.
385.6 384.2 379.9 370.3 352.9 325.3 291.6 260.0 235.0
4.4 4.3 4.2 4.1 3.9 3.6 3.1 2.59 2.05 4.4 4.2 3.9 3.7 3.4 2.94 2.50 2.13 1.83
Critical state of n-pentane. of hydrogen sulfide.
V: Vb Vd X Y
= = = = =
molal volume in two-phase region a t state a molal volume a t bubble point molal volume a t dew point mole fraction of component in liquid phase mole fraction of component in gas phase LITERATURE CITED
= equilibrium ratio, Y/X
mole fraction of component 1 at state a in two-phase regon = mole fraction of component 1at bubble point = mole fraction of component 1 at dew point = pressure, pounds per square inch absolute
F
p
Temp., F.
NOMENCLATURE
z,+ nl,d
Pressure, Lb./Sq. Inch Abs.
%-PENTANE-
b Critical state
ACKNOWLEDGMENT
nl,b
CRITICAL REGIONI N HYDROGEN SULFIDE SYSTEM
PROPERTIES OF
Mole Fraction Hydrogen Sulfide
a
1809
(1) Bridgeman, 0.C., J . A m . Chem. SOC.,49, 1174 (1927). (2) Giauque, W. I?., and Blue, R. W., Ibid.,5 8 , 831 (1936). (3) Gilliland, E. R., and Scheeline, H. W., IND.ENG.CHEM.,32
48 (1940). (4) Konz, P. R., and Brown, C. G., Ibid.,33, 617 (1941). (5) Lewis, G. N., J. Am. Chem. SOC.,30, 668 (1908). (6) Pattee, E. C., and Brown, G. G., IND.ENG.CHICM., 26, 511 (1934). (7) Reamer, H. H., Sage, €3. H., and Lacey, W. K.,Washington, D. C., AD1 Auxiliary Publications PIoject, Document 3730 (1952). (8) Reamer, H. H., Sage, €3. H., and Lacey, W. N., IND.ENG.CHEM., 42,140 (1950). Ibid.,43,976 (1951). Rose-Innes, J., and Young, S., Phzl. Mag., [5]47, 353 (1899). Sage, B. H., and Lacey, W. N., IND.ENG.CHEM.,34,730 (1942). Sage, R . H., and Lacey, W. N., Trans. A m . Inst. Mining Met. Engrs., 136,136 (1940). Sage, B. H., Lacey, W. N., and Schaafsma, 3. G., IND.ENG CHEM.,27,48 (1935). Shaw, J. A.,Ihid., 32,668 (1940). Tutwiler. C. C.. J . Am. Chem. SOC.,23,173 (1901). West, J. R., Chem. Eny. Progr., 44,287 (1948). Young, S., Sci. Proc. Rog. SOC.(Dublin),12, 374 (1910).
500
U
RECEIVED for review October 6, 1952. ACCEPTED J a n u a r y 12, 1953. Material supplementary t o this article has been deposited &9 Document 3730 with the AD1 Auxiliary Publications Project, Photoduplication Service, Library of Congress, Washington 25, D. C. A copy m a y be secured b y citing the document number a n d by remitting $3.75 for photoprints or $2.00 for 35-mm.microfi1m. Advance payment is required. Make checks or money orders payable to Chief, Photoduplication Service, Library of Congress.
%3
2
0
250 U w vi 3
w
f 250
500
PRESSURE
Figure 5 .
750
1000
POUNDS PER SQUARE
1250 INCH
Equilibrium Ratios for it-Pentane and Hydrogen Sulfide
(Continued on page 1810)
