RESEARCH REPORT TO NATURAL GAS PROCESSORS ASSOCIATION TULSA, OKLAHOMA INTERPRETATION OF CALORIMETRIC DATA FOR TWO BINARY MIXTURES OF METHANE AND ETHANE RAVI KANT, A.W. FURTADO AND J.E. POWERS THERMAL PROPERTIES OF FLUIDS LABORATORY THE UNIVERSITY OF MICHIGAN ANN ARBOR, MICHIGAN MARCH, 1973

INTRODUCTION The need for accurate thermodynamic data for natural gas mixtures and the components of natural gas has been accentuated by recent developments in the area of natural gas processing at cryogenic conditions including liquofication. Accurate values of thermodynamic properties are required not only for direct use in design of heat exchangers, compressors, and expanders but also to be used as a basis for testing and comparing various methods of prediction. In recognition of these needs, a calormetric facility for accurate determinations at cryogenic conditions was developed as the Thermal Properties of Fluids Laboratory at the University of Michigan with financial support from the National Science Foundation, the Petroleum Research Fund of ACS and the Natural Gas Processors Association. Recently, calorimetric data on two binary mixtures of methane and ethane were obtained under sponsorship of NSF but funding to interpret these data was lacking. Such support was authorized by the Enthalpy Steering Committee of NGPA and made available after preliminary analyses gave strong indication that results useful to the natural gas processing industry would be obtained. Therefore, the objective of this report is to summarize the procedures used in interpreting the data and present the results in the form of skeleton tables of enthalpy values.

-2EXPERIMENTS Composition As mentioned in the Introduction, experimental data were obtained on two binary mixtures of methane and ethane. Samples taken from the recycle system were analyzed by chromatograph at frequent intervals during the entire course of the investigation. The methane and ethane content was determined by comparison with results of chromatographic analyses obtained at the same time using samples from a tank containing a standard mixture. The composition of the standard tank was analyzed for trace components in addition to methane and ethane. The results are given in Appendix I Analyses for individual runs are presented in Tables A2 and A3 in Appendix IV. The analyses of the samples from the recycle system were averaged to give the nominal binary compositions listed in Table I. TABLE I Nominal Binary Compositions of the Methane - Ethane Mixtures Investigated Methane 77.7 47.7 Ethane 22.3 52.3 100.0 100.0 In obtaining these average values, added weight was given to the compostion of runs made across the two-phase region and near the critical point. Experimental Data The range of experimental determinations is indicated on PT diagrams as Figures 1 and 2. Each group of experiments is

-3identified by a number within a circle. Isobaric measurements over most of the single phase region were made in groups of three to nine runs with the same inlet temperature. Power input was adjusted to yield outlet temperatures increasing in increments of about 20~F. In regions where C varied significantly (such P as near the critical point) smaller temperature rises were used (as small as 5~F). Isobaric determinations were made across the two phase region to establish bubble and dew points and heats of vaporization as well as enthalpy values within the two phase region. Isothermal determinations were made mainly in the single phase region. Pressure drops were usually between 100 and 500 psia. A limited number of isenthalpic determinations were made at low temperatures in the liquid phase. The basic experimental results obtained under sponsorship of the National Science Foundation are reported in Appendix IV. Experimental Difficulties During the course of time required to make extensive calorimetric determinations on two binary systems a number of operational difficulties are usually encountered. Nothing unusual occurred during this investigation but in the process of checking out equipment after completion of the runs, several small leaks were noted in the all-important section between the calorimeter and flowmeter. In addition, consideration of the possibility of bypassing of fluid which might occur when both the isobaric and throttling calorimeters are connected to the system resulted in a change of operating procedure so that only one calorimeter is connected into the system at a time. Even later it was found that a short in the battery used to power the

-4potentiometer yielded erroneous results. It is impossible to determine whether any of these operational problems which were detected after completion of the investigation of two binary systems influenced the results substantially but at a minimum the possibility of systematic error must be taken into account. It should be noted that leaks between the calorimeter and flowmeter will tend to yield property values that are too high.

-5SELECTION OF BASES AND USE OF OTHER PUBLISHED DATA Bases for Enthalpy Values Analysis of the basic calormetric determinations presented in Appendix IV yields values of the derivative properties C — (H/TT)p, C (H/3P)T and p = (aT/aP)H in addition to the enthalpy function itself, H. The bases that H = 0 for pure methane and pure ethane as saturated liquids at -280"F were selected to yield results that are consistent with prior analyses of other systems (5-8). Published Data for Pure Methane and Pure Propane At zero pressure all gases form ideal mixtures and therefore it is possible to calculate the enthalpy of mixture at zero pressure from a knowledge of the enthalpy of pure components. The procedure not only permits values at low pressure to be included to the final tables, but also provides a basis for comparison with the calorimetric determinations for the mixtures which were made only at elevated pressures. In brief, for each pure component, one utilizes accurate published data on the heat capacity of saturated liquid, Cp and the enthalpy change on vaporization, AH ap together with an estimate of the enthalpy change from the pressure at which AH is known to zero pressure to estimate the enthalpy of the -vap pure compound as an ideal gas at the temperature of vaporization relative to the reference state of saturated liquid at -280~F.

-6Further, by using the properties of the ideal gas as calculated from theoretically based analyses of spectroscopic and calormetric data, one can calculate the enthalpy of all pure components at any temperature of interest and thereby the enthalpy of the mixture HO =Zy.H - M i-H i (1) where the subscripts M and i refer to the mixture and the individual components of the mixture respectively and yi refers to the mole fractions of the individual pure components. Details of the calculations are presented in Appendix II. The applicable results are summarized in Table II. TABLE II Zero Pressure Enthalpies of Methane - Ethane as Calculated from Published Data of Acceptable Accuracy Nominal Ethane Content 22.3% 52.3% Temperature Enthalpy* Temperature Enthalpy T(~F) H(Btu/lb) T(~F) H(Btu/lb) -58.45 332.4 1.75 351.4 79.0 397.1 101.5 395.8 255.0 490.8 252.5 472.3 *Bases H = 0 for pure methane and pure ethane as saturated liquids at -280~F. Estimates of Excess Enthaly of Mixing Used in Conjunction with Calormetric Data for Pure Methane and Pure Propane In general, excess enthalpy of mixing, H of liquid hydrocarbons is small and fairly insensitive to pressure. Therefore, approximate values of H for methane-ethane mixtures can be used together with accurate enthalpy values for the two pure compounds to establish check points in the liquid region

-7for the mixture data. The results of calculations described in detail in Appendix III are presented in Table III. TABLE III Estimated Values of Enthalpies of Liquid Methane-Ethane Mixtures to be Used as Checks on Calorimetric Determinations Nominal T P C HE Ethane T 4 C26 M Composition (~F) (psia) (Btu/lb) (Btu/lb) (Btu/lb) (Btu/lb) 22.38 -240 1000 34.7 25.0 1.0 32.8 52.3% -220 1500 54.0 37.7 0.6 43.5 These estimated values together with the calculated enthalpy values for the ideal gas state serve as severe checks on values obtained from interpretation of the calorimetric data and resulted in systematic correction of the interpreted data as will be discussed in a later section. CALCULATIONAL PROCEDURES A number of steps were taken in processing the calorimetric data to obtain the best possible property values that are thermos dynamically self-consistent and also in agreement with the other published data presented in a previous section. Initial Interpretation of Basic Data The basic data presented in Appendix IV are in terms of differences in enthalpy for a particular experimental mixture, x, corresponding to values of temperature and pressure measured at the inlet, i, and outlet, o, of the calorimeter: AH_= -^o [lii HP- p. (2)

-8As mentioned previously, periodic checks were made of the composition of the experimental mixture and variation of as much as 1.2% ethane from the nominal values was noted. Similarly the system pressure during any series of isobaric runs ranged as much as + 3 psi and the inlet temperature varied as much as + 1.5~F in extreme cases. Final interpretation of the data is both simplified and made more meaningful by adjusting the basic calorimetric data to the binary compositions listed in Table I, normalizing all isobaric determinations obtained at one pressure level to a convenient value (such as 1000 psia) and adjusting to an average value all inlet temperatures for one set of isobaric determinations. The sum total of all such corrections was usually less than 0,1% with a maximum adjustment of 3%. Details of this normalization procedure are presented elsewhere C5). In addition to the minor corrections to normalized values mentioned above, additional small corrections are made to account for the small measured pressure drop in the isobaric calorimeter and the fact that small differences in temperature existed between the inlet and outlet of the calormeter during isothermal runs. These corrections were made in a rigorous manner as described elsewhere (5) and in extreme cases amounted to 0.3% of the experimentally determined enthalpy difference. Smoothin of Adjusted Calormetric Data The isobaric, isothermal and isenthalpic data obtained in the single phase region were analyzed to yield values of the derivative *'flme large corrections occurred only for the run made through the critical point for the nominal 52.3% mixture (Run 10). For all other runs the corrections did not exceed 1.5%,

-9functions Cp, ( - (8H/9P)T and p E (aT/aP)H, respectively. In this process it is possible to identify individual points with considerably greater than average experimental error and therefore the smoothed values are probably of improved accuracy compared to the individual data points. Integration of the smoothed derivative functions yield provisional values of enthalpy differences which must be checked for thermodynamic consistency. Data taken within and near the two-phase region are generally not interpreted in terms of derivative functions but are merely smoothed graphically to yield enthalpy values in this important region. Details of the analysis have been presented elsewhere (5). Brief summaries are given below in an attempt to make this report self-contained. Isobaric Data Single-Phase. The calorimetric data adjusted as described in the preceeding section were used to calculate mean values of C from the adjusted values of isobaric increases p in enthalpy and temperature. [ET2 -T1]P P T (3 T 2 1 Values thus calculated apply over the temperature interval T1+T2 and are plotted as solid horizontal lines as illustrated on Figure 3. All values for a set of isobaric runs are adjusted to an average inlet temperature and therefore additional isobaric enthalpy differences can be inferred from the data and used to calculate additional values of C. Typical values are plotted as dashed horizontal lines on Figure 3.

-10Point values of the derivative function, Cp, are determined to satisfy the constraint I. [-T. -TJ p P- (4) [HTj - -L~ r m Ti i.e. equal area constraints were applied. Computer aided graphical procedures were used as described in detail elsewhere (5). After each trial curve for Cp = f (T) was established, integration of Equation (4) was carried out by computer using the Gauss-Legendre technique for each individual data point and difference point. Values of percentage error are listed on Figure 3 for each of the original data points used to generate the curve. One point has an indicated error of 1.56 percent. Also note that several values of C obtained by differences involving this point (indicated by asterisks) deviate markedly from the curve. It was thus concluded that this point was in error and it was given little weight in determining the final curve. All isobaric data obtained in the single phase were interpreted in this way. The values of C so obtained are reported as C (S) P P in the skeleton tables. In general, the difference between the experimental data and values calculated by numerical integration of smoothed values of C showed random variation in sign and agreement was of the order of + 0.2% or better. The same integration procedure was applied to yield isobaric differences in enthalpy between the temperatures of isothermal runs. These differences are used in checking the thermodynamic donsistency of the data as described in the next scetion. Two-Phase (Enthalpy Traverse). The calorimetric data

-11in and through the two phase region were obtained with a constant inlet temperature. Plots of temperature vs enthalpy difference were made as illustrated in Figure 4. Interpretation of such plots yielded not only smoothed values of enthalpy in and near the two-phase region, but also the isobaric heat of vaporization and values of the bubble- and dew-points. Isothermal Data Interpretation of the isothermal data to yield smooth values of ( was very similar to the interpretation of the isobaric data. Figure 5 is a plot of HP -H!pl [ P2 -P1]T ~ =2 P1 (5) as represented by horizontal lines extending over the experimentally measured pressure interval. The solid line results from use of the iterative, computer-aided, graphical-numerical procedure described elsewhere (5). Percentage deviations between the experimental data and values calculated by Gauss-Legendre integration of P [2 [iP2 P1]T = dPT (6) P are expressed as percentages for the individual data points on the figure. The lower limit of pressure which could be attained experimentally was about 100 psia. At lower pressures % values were estimated so as to be in agreement with experimental values and follow the pressure dependence indicated by several prediction methods (5). Thus, the curve drawn on Figure 5 between 0 and 350 psia is in good agreement

-12with the experimental data between 100 and 350 psia and is of a shape in agreement with predictions made at low pressures. All isothermal data were interpreted in this manner (Several runs were made completely in the liquid region i.e. above the two phase curve). The values of ( so obtained are reported as in the skeleton tables as p(S) The numerical integration procedure was applied to yield isothermal enthalpy differences between the pressures of isobaric determinations for use together with similar isobaric calculations to check the thermodynamic consistency of the data. Isenthalpic Data At low temperatures and elevated pressures the fluid temperature increases with a decrease in pressure. Under these conditions no energy was added to the calorimeter and an isenthalpic expansion occured. The data were first interpreted to yield values of the Joule-Thomson coefficient v = (T/aP)H (7) which were used to establish values of ( along an isotherm. The procedure has been described in detail elsewhere (5). Smoothed values of V thus obtained are reported in the skeleton tables. Adjustment of Values to Insure Thermodynamic Consistency and Agreement with other Published Data Checks of Internal Thermodynamic Consistency The individual enthalpy differences calculated by numerical integration of C and ( obtained as described in the preceeding section are summarized on P-T diagrams as Figures 6 and 7. These values are not in parentheses. Enthalpy is a point function of state and therefore these independently determined values of differences in

-13enthalpy can be tested against the rigorous thermodynamic requirement that the sum of all differences around a closed loop must equal zero. Values of the actual sums (taken in the clockwise direction with proper attention to sign) and the percentage deviations, ZAH. percentage deviation - x 100 Z|AHiJ (6) are included within each closed loop and provide an excellent measure of the internal thermodynamic consistency of the smoothed data. Consideration of the values presented in Figures 6 and 7 reveal that the data are indeed self-consistent to about 0.4% in most cases. Unfortunately, if the flow determination for all runs is in error by a constant factor, all values will have an equal percentage error and the results will be thermodynamically consistent but in error. As mentioned previously, leaks were found in the system after completion of the investigation and therefore it was decided to insure not only internal thermodynamic consistency but also agreement with other published data of acceptable accuracy. Comparison with Other Data As discussed under the section entitled SELECTION OF BASES AND USE OF OTHER PUBLISHED DATA, accurate data for pure methane and pure ethane were used to establish enthalpy values for the mixture at zero pressure as listed in Table II. Similarly estimates of the excess enthalpy of mixing of liquid methane and ethane established values of enthalpy for one liquid mixture for each binary as listed in'Table III. These "check points" were used to calculate differences in enthalpy for comparison with the experimentally reported values as summarized in Table IV.

-14TABLE IV Comparison of Differences Between Check Values of Enthalpy Estimated from Published Data and Direct Calorimetric Determinations Enthalpy Values Obtained by Nominal Check Values Integration of D Ethane Composition T P H H Composition (~F) psia Btu7lb Btu7lb 22.3 255.0 0 490.8a 490.8C 255.0 1000 - 469.7d -240. 1000 32.8b 28.8e 458.0 462.0 Difference between'4.0 Btu/lb check values 52.3 252.5 0 472.3a 472.3c 252.5 1500 - 431.0d -220 1500 43.5b 36.4e 428.8 435.9 Difference between 7.1 Btu/lb check values a. Zero pressure check point from Table II. b. Estimated value from Table III. c. Basis of comparison. d. Obtained from zero pressure value using calculated isothermal difference from zero pressure to pressure of low temperature check point. For example, 469.7 = 490.8 - 21.08. e. Obtained from high temperature value by. integration of isobaric data. For example, 28.8 = 469.7 - (113.00 + 166.10 + 93.99 + 67.8]

-15The discrepancies [4.0 Btu/lb (1%) in one case and 7.1 Btu/lb (1.6%) in the other are much larger than had been expected as similar comparisons made on other data (1,9,12) had been exceedingly consistent. Therefore, it was decided that systematic errors were involved in the data and all values were adjusted in accordance with several goals: 1) Obtain agreement with the "check points" for enthalpy based on other published data. 2) Utilize values of isothermal enthalpy differences estimated by several consistent methods at high temperatures where such estimations have proven to be accurate (5). 3) Make adjustments in the derivative functions, C and 9, such that integration yields thermodynamic consistency. Further, these adjustments should not be excessive i.e. in keeping with corrections made for similar determinations on the same equipment. With the exception that it was necessary to make corrections to both the isobaric and isothermal data in excess of those applied in the analysis of similar systems, it was possible to satisfy all other conditions by a laborious trial and error procedure. The resulting, thermodynamically-consistent values of enthalpy differences are listed in parentheses on Figures 6 and 7. In some cases, it was necessary to make adjustmetts to isothermal determinations by as much as 7.1% as indicated by the dashed line in Figure 5. Similarly corrections as large as 1.3% were made on the isobaric values (center line on Figure 3). Thus, these data, though thermodynamically self-consistent to better than 0.5% were judged to be in error by much larger amounts in comparison to other data. Taking into account the possibility of systematic errors during the experiment, unusually large adjustments

-16were made in preparing the skeleton tables. The values so adjusted are listed as C (A) and ~(A) in the skeleton tables together with P values of H which are consistent with the values of the derivative functions. SKELETON TABLES OF THERMODYNAMIC DATA The tables which follow contain values of thermodynamic properties for the two methane-ethane mixtures obtained as described in preceeding sections. Tables IXa and IXb include enthalpy values at the intersections of isobaric and isothermal determinations. These values are probably the better known of all reported enthalpy values. Values of C, $, and H reported in Tables Va, Vb, VIa, and VIb, comprise the major contribution of this report. Both smooth and adjusted values of C and f are listed as discussed previously. p Th'e enthalpy values are consistent with the adjusted values of the derivative functions, C (A) and ~(A). P Tables Va, and Vb report C and H at the pressures of measurement over a temperature range from -260 to +320~F at temperature intervals of 10~F. At pressures below the critical, values of C are not reported within and near the two phase region except for the 250 psia isobar in Table Va. Similarly Tables VIa and VIb contain ( and H values at the temperatures of isothermal determinations and p, $, and H at temperatures of isenthalpic determinations. Results of isothermal determinations are reported at intervals of 50 psi and those corresponding to isenthalpic determinations at intervals of 100 psi.

-17Data obtained from enthalpy traverses across the two phase region are reported in Tables VIIa and VIIb. Near the critical region C attains a maxima. In this region C p P is a strong function of temperature i.e. (UC /T)p is large and consequently thermodynamic properties change very rapidly. Therefore, it was felt necessary to report C and H at closer intervals of p temperature in this region. Tables VIIIa and VIIIb report these values. The format of these tables is same as Va and Vb. ACKNOWLEDGEMENTS The data presented in this report were obtained by Joseph C. Golba and he is to be commended for his patience and attention to detail so necessary to obtain precise calormetric data. The experimental investigation was funded by the National Science Foundation. This interpretation of data was made under a grant from the Enthalpy Steering Committee of the NGPA.

TABLE Va Table of Thermodynamic Properties at the Pressures o' Isobaric Determinations Mixture of Methane and Ethane Containing Approximately 22.3 Mole Percent Ethane P - 250 psia P 500 pas P - 1000 psiaP p 1500 psia P - 2000 psis 2 Cp H Op H Cp(SI Cp(A) H pS) Cp(A) H Cp(S) Cp(A) H Btu/16'F Btu7lb Btu/lbF Btu7lb Btu/lb0F Btu/lb~F Btu7lb Btu/lb~F Btu/lb~F Btu7lb Btu/lhbF Btu/lb'F Btu/ Temp. Temp.emp. *F C- ~F -260.0 -260.0 0.7247 0.7207 18.26 -260.0 -250.0 0.7209 22.54 -250.0 0.7304 C.7264 25.49-250.0 -240,0 0.7305 29.80 -240.0 0.7343 6.7303 32.78 -240. C -230.0 0.7400 37.15 -230.0 0.7377 0.7336 40.09 -230.0 -220.0 0.7495 44.60 -220.0 0.7412 0.7371 47.44 -220.0,-210.0 0.7590 52.14 -210.0 0.7465 0.7424 54.84 -210.0 -200.0 0.7685 59.7R -200.0 0.7526 0.7485 62.29 -200.0 -190.0 0.7780 67.51 190.C 0.7588 0.7546 69.80 -190.0 -180.0 0.7R7? 75.34 -180.C 0.7605 0.7623 77.38 -180.0 -170.0 0.7067 A3.26 -170. C 0. 7767 0,7724 85.03 -170.0 -160.0 0.8058 91Q.27 -160.0 0.7903 0.71860 92.91 -160.0 -150.0 131.37 99.87 -150.0 0.8070 0.8031 100,65 -150.0 -140.0 170.67 108.87 -140.0 0.8248 0. 8208 109.08 -14C. 0 -130.0 q196.37 117.37 -130.0 0.8471 0.8430 117.37 -130.0 -120 0 215.87 126.67 -120.0 0,6798 0,8756 125,96 -120.0 -110.0 233.87 145.87 -110.0 0.9240 Q.9196 134.86 -110.0 -100.0 252.77 185.37 -100.0 0.9865 0.9818 144, 36' -100.0 -90.0 274.27 209.37 -90.0 1.0582 1.0531 154.56 -90.0 -80.0 296.57 231.27 -80.0 1.1458 1.1403 165.46 -80. C -70.0 308.87 252.87 -70.0 1.2836 1.2774 177.46 -70.0 -60.0 0.5730 315.10 273.87 -60.C 1.5582 1.5507 191.36 -60.0 0.9154 0.9110 178l.1 -50.0 0.5410 320.66 294.57 -50.0 2.1819 2.1695 209,97 1.1234 1,1220 192.07 -50.0 0.9526 0.9480 186.9. -40.0 0.5532 326.12 306.37 -40.0 2.3519 2.3365 233.08 1.1902 1.1887 203.60 -40.0 0.9885 0.9837 196.6; -30.0 0.5445 331.61 312.37 -30.0 1.9485 1.9374 254.79 1.2769 1.2753 215.88 -30. C 1.0246 1.0197 206.6. -20.0 0.5317 337.02 -20.0 1.4988 1.4903 271,79 1.3945 1.3927 229.29 -20.0 1.0596 1.0545 217.0 10.0 0.5?72 342.34 -10.0 1.1940 i.1872 285.10 1.4115 1.4097 243.37 -10.0 I.0R97 1.0844 227,7J 0.0 0.5224 347.59 0.0 1.0170 1.0112 296.00 1.3487 1.3470 257.20 0.0 1.1008 1.U955 238.6J 10.0 0.5199 352.80 10.0 0.9188 0.9136 305.61 1.2510 1.2494 270.20 10.0 1.1028 1.0975 249.55 20.0 0.5186 357.99 20.0 0.8639 0.8590 314.51 1.1423 1.1408 282.18 20.0 1.0917 1.0864 260.51 30.0 0.5174 363.17 30.0 0C.8203 0.8156 322,81 1.0496 1.0483 293,13 30.0 1.0677 1.0626 271.27 40.0 0.5169 36A.34 40.0 0.783S 0.7794 330.82 0.9755 0.9743 303,19 40.0 1.0376 1.0326 281.7( 50.0 0.5169 373.51 50,0 0.7522 0.7479 338.42 0.9252 0.9240 312.65 50.0 1.0055 1.0007 291.88 60.0 0.5169 378.68 60.0 0,7225 0,7184 345.72 0.8865 C. 8854 321,71 60.0 0.9700 0.9653 301.75 70.C 0.5169 383.85 70.0 0.695C 0.6910 352.83 0.8480 0.8469 330.38 70.0 0.9330 0.9285 311.23 80.0 0.5169 389.02 80.0 0.6785 0.6741 359.60 0.8160 0.8150 338.64 8. 0 0.9000 0,9009 320.32 90.0 90.0 0.6680 0.6637 3(6.40 90.0 0.8729 0,8738 329.17 100.0 100.0 0,6597 0.6554 373.00100.0 0.8464 0.8472 337.82 110.0 110.0 0.6531 0.6489 379.59 110.0 0,8205 0.8213 346.17 120.0 120.0 0.6477 0,6435 386.09 120.0 0,8005 C.8013 354.32 130,0 130.0 0.6427 0.6385 392.54 130.0 0.7826 0.7834 362.17!40.0 140.0 0.6385 0.6343 398.97 140.0 0.7678 0,7086 370.01 150.0 150.0 0.6356 0.6315 405.25 150.0 0.7518 0.7526 377.56 160.0 160.0 0.6335 0.6294 411.53 160.0 0.7403 0.7410 385.10 170.0 170.0 0.6319 0.6278 417.79 170.0 0.7333 0,7340 392.45 180.0 180.0 0.6310 0.6269 424.04 180.0 0,7274 0,7281 399.79 190.0 190.0 0.6305 0.6264 430.29 19C. 0 0.7227 0.7234 407.03 200.0 200.0 U.63G7 0.6266 436.53200.0 Ap7186 0.7193 414.28 210.0 210.0 0.6220 0.6279 442.78210.0 0.7147 ).7154 421.42 220.0 220.0 0.6345 0.6304 449.05220.0 0.7112 0.7119 428.56 230.0 230.0 0.6373 0.6332 455.34230.0 0.7080 0.70H7 240.0 240.0 0.6400 0.6358 461.67'40.0 0.7048 0. o10t5., J5 250.0 250.0 0.6426 0.6384 468.02 _50.0 0.7033 0,7040 449.79 260.0 260.0 0.6450 0,6408 474.39 260.0 0.7018 0.7025 456.83 270.0 270.0 0.6476 0.6434 480.79 270.0 0.7003 0.7010 463.87 280.0 280.0 0.6510 0.6468 487.22 280.0 0.6988 0.6995 470.91 290.0 290.0 0.6t542 0.64q9 493.6o 290.0 0.6972 0.6979 477.85 300.0 300.0 0.,6575 0.6532 500.17 3;C. 0..6960 0.6967 484.90 310.0 310.u 0,6598 0,6555 506.70 310.0 3. 0 0320.0 0,661C 0.6567 513.24 320.0 1. Cp values at 500 paia are not reported as most of the data lies in two phase region. 2. Cp values at 250 psia are not reported in the two phase region.

TABLI Vb Table 6f Thermodynamic Properties at the Pressures of Isobaric Determinations Mixture of Methane and Ethane Containing Approximately 52.3 Mole Percent Ethane P 250 psia P - 500 psia P - 750 psia P -978 peia P 1250 psia P - 1500 psiaP-2000psia Cp H Cp H Cp H Cp(S) Cp(A) H Cp(S) Cp(A) H Cp(S) Cp(A) H Cp(S) Cp(A) H Btu/1b`7 Btu7lb Btu/lbOF Btu7lb Btu/lb~F Btu7lb Btu/lb~F Btu/lb~F Btu7lb Btu/lb'F 3tu/lb`F Btu7lb Btu/lb~F Btu/lb0l Btu7lb Btu/lb'F Btuflb~F Btu/lb TW. Temp. Temp. -250.0 -250.0 -250.0 0.6419 0.6352 24.39 -240.0 -240.0 -240.0 0.6427 0.6360 30.75 -230.0 -230.0 -230.0 0.6440 0.6372 37.11 -220.0 -220.0 -220.0 0,6457 0.6389 43.50 -210.0 -210.0 -210.0 0.6475 0.6407 49.90 -200,0 -200.0 -200.0 0.649C 0.6422 56.31 -190.0 -190.0 -190.0 0.6500 0.6432 62.74 -180.0 -130.0 -180.0 0.6527 0.6458 69.19 -170.0 -170.0 -170.0 0.6560 0.6491 75.66 -160.0 -160.0 -160.0 0,6596 0.6527 82.17 -150.0 -150.0 -15u.0 0.6640 0.6570 88.72 -140.0 -140.0 -140.0 0.6b88 0. 6618 95.32 -130.099.45 -130.3 -13G.U 0.6755 0.6684 101.97 -120.0 120.35 -120.0 -i20.u 0.6850 0.6778 1C8.70 -11O.O 137.65 -110.0 0.7252 0.7245 114.43 -110.0 0.6960 0.6887 115.54 -100.0 153.45 121.05 121.56 -100.0 0.7352 0.7345 121.72 -100.0 0.7080 0.7006 122.48 -90.0 170.85 127.85 129.26 -90.0 0.7451 0.7444 129.11 -90.0 0.7220 0.7143 129.59 -80.0 190.55 134.95 136.66 -80.0 0.7601 0.7594 136.62 -80.0 0.7363 0.7284 136.79 -70.0 211.85 149.55 144.26 -70.0 07789 0,7782 144.30 -70.0 0.755C 0.746< 144.19 -60.0 2,35.55 167.55 162.76 -6 30. 0.8047 0.8039 152.20 -60.0 0.7725 0.7642 151.69 -50.0 263.35 185.55 161.76 -50.0 0.8333 0.8325 160.37 -50.3 0.7910 0.7825 159.49 -40,0 299.05 204.55 170.96 -40.0 086773 0.8765 168.90 -40.0 0.8110 0 8023 167,39 -30.0 320.35 224.05 182.76 -30.0 0,9451 0,9442 177.97 -30.0 0.8345 0.8256 175.49 -20.0 325.05 245.55 201.76 -20.0 1.0385 1.0375 187.80 -20.0 C.86CC C.8508 18.3.89 -10.0 330.35 272.05 220.26 -30.0 1.1947 1,1936 198,90 -10.0 0.8969 0.8873 192.59 0.0 335.35 302.65 239.01 0.0 G14500 1.4486 212.01 0.0 0.9420 0.9319 201.69 0.8730 0.8730 198.42 10.0 318.55 264.26 10.0 1,8773 1.8591 228.52 1.1873 1.1715 215.75 10.-0 1.0044 0.9929 211.29. 0.8846 0.8846 207.20 20.0 324.o5 289.76 20.0 2.1461 2.1253 249.01 1.3258 1,3082 228.16 20.0 1.07C9 1.0587 221.59 0.8980 0.8980 216.12 3090 332.55 304.06 30.0 1,8349 1,8171 268099 1.4572 1.4378 241.93 30.0 1.1497 1.1366 232.59 0.9128 0.9128 225.17 40.0 339.05 316.96 40.0 1.5338 1.5189 285.58 1.5340 1.5136 256.77 40.0 1.2295 1.2155 244.0 0.9301 0.9301 234.38 50.0 344.05 50.0 1.3246 1.3117 299.57 1.4774 1.4577 271.74 50.0 1.2821 1.2675 256.69 0.9487 0.9487 243.78 60.0 60.0 1.1509 1.1397 311.86 1.3511 1.3331 285.74 60.0 1.2760 1.2615 269.29 0.9786 0.9786 253.40 70.0 70.0 0.9945 0.9849 322.45 1.2288 1.2125 298.46 70.0 1.2164 1,2025 281.69 1.0270 1.0270 263,40 80*0 80,0 0.8658 0,8574 331,64 1.1166 1.1017 310,05 80.0 1.1548 1.1416 293.39 1.0990 1.0990 274.01 90.0 90.0 0.7782 0.7707 339.73 1.0080 0.9946 320.53 90.0 1.0830 1.0707 304.49 100.0 100.0 0.7028 0.6960 347,03 0.8979 0.8860 329.91 100.0 1.0204 1.0088 314.89 11,0.0 110.0 0.6407 0,6345 353.62 0.7881 0.7776 338.29 110.0 0.9625 0.9527 324,69 120.0 120.0 0.5755 0,5699 359.72 120.0 0,9152 0,9059 333. 99 130,0 130.0 130.0 0,8736 0.8647 J42.79 140.0 140.0 140.0 0.8345 Ce8260 351.29 150.0 150,0 150.0 0,8046 0,7964 359.39 160.0 160.0 L60.0 J07817 0.7737 367.19 170.0 170.0 170.1 0.7636 0,7558 374.89 1 800 180.0 180.0 0.7498 0.7422 382,39 190.0 190.0 190.0 Q.7397 0.7322 389.69 200.0 200.0 200.0 0.7301 0.7227 396.99 2100 0210.0?10.0 0,7217 0,7143 404,19 220.0 220.0 220.0 0.7133 0.7060 411.29 230.0 230.0 230.0 0.7059 0.6987 418.29 24050 240.0 240.0 0.7005 0.6934 425.29 250.0 250.0 250.0 0.6957 0.6886 432.19 270.0 260.0. 260.0 0,6913 06842 439.09 280.0 270.0 270.0 0.6883 0.6813 445,89 2900 0280.0 280.0 0.6862 0.6792 452.69 290.0 290.0 0.6850 0.6780 459.49 300.0 300,0 300.0 0.6855 0.6785 466.29 310.0 310.0 310.0 0.6860 0.6790 472.99 1. Cp values at 250 psia, 500 psia and 750 psia are not reported as moat of the data lies in two phase region.

TABLE Via Thermodynamic Properties at the Temperatures of Isothermal and Isenthalpic Determinations. Mixture of Methane and Ethane Containing Approximately 22.3 Mole Percent Ethane T = -253.2~F T = -150.55~F T =-58.45~F T 79.0~FT - 255.0~F 4 4 4 4 U x 104 4 x 104 H x 4 x 104 H H (S) 4 (A) H (S) $ (A) H 4(S) 4(A) H ~F/Psi Btu/lb Psi Btu/lb ~F/Psi Btu/lb Psi Btu/lb Btu/lb Psi Btu/lb Psi Btu/lb Btu/lb Psi Btu/lb Psi Btu7lb Btu/lb Psi Btu/lb Psi Btu7lb Pressure Pressure Pressure psia psia psia?..o %'~''"^^~~~~~~~~~~~~~~ *"~ -n -03 4 -f.3 2, 39B7.1 0.0 -r>.02?? -0.014.7 "97., 50.0 50.0 -0. 0350 -0. 0336 395.43 50.0 -0.0212 -0.0197 489.81 1C000 100.0 -0.0356 -0.0342 393. 74 100.0 -0.0212 -0.0197 488.3 15C0 "150,0 -0.0361 -0.0347 392,01 150.0 -0.0212 -0.0197 487.84 2CC.0 200.0 -0.0367 -0.0353 390.27 200. -0.0212 -0.0198 486.85 250,J 250,0 -0.0373 -0.0358 388.49 250,0 -0.0212 -0.0198 485.86 300*0 300.0 -0.0379 -0.0364 386.68 300.0 -0.0212 -0.0198 484,88 350.0 350.0 -0,0385 -0.0370 384.85 350.0 -0.0212 -0.0197 48389 4000 -23.50 1R.74 9q.387 400.0 -0.0391 -0.0375 382.98 400.0 -00212 -0.0197 482.90 45C0. 0 450.0 -0. 0396 -0.0381 381.10 450.0 -0.0212 -0.0197 481.92 -21.40 17.10 qq.565 500.0 500.0 -0.0401 -0.0386 379.18 5CC.0 -0. C212 -0.0197 480.93 550.0 550.0 -0.0406 -0,0391 377.24 550.0 -0.0211 -0.0197 479 95 60G. 0 -98.4O 71.80 20.547 -19.40 15.44 99.727 600.0 -0.0411 -0.0395 375.28 600.0 -00211 -O00196 478.96 65O0.0 650.0 -0.0415 -0,0399 373,29 650.0 -0.0211 -00196 477 99 7CO.0 -94.30 68.40 21.246 -17.35 13.85 99.R73 700.0 -0.0418 -0.0402 371,29 700.0 -0.0210 -0O1l5 477.00 750. 0 50.0 -0.0422 -0.0406 369.27 75.0 -0. G210 -0.0195 47603 600.0 -q90.00 50n 21.917 -15.40 12.30 100.003 800.0 -0.0426 -0.0409 367.23 800.0 -0.0209 -00194 47506 85G.80 850.0 -0.0429 -0.0412 365.18 850.0 -0,0208 -0U0194 474.08 900.0 -85.80 62.60 22.558 -13.57 10.82 100.11 900.0 -0.0432 -0.0415 363.11 900.0 -0027 -0.0193 473.12 c50.0 c50.0 -0.0435 -0.0418 361.02 50.0 -0.0206 -00192 47216 1CCC.0 -R2.20 59.80 23.170 -1.I 9.43 100.220 1CC000 -0.0437 -0.0420 358.93 1000.0 -C.0205 -0.0191 471.20 1050.j 1050.0 -0.0345 -0.0345 191.95 -0.0440 -0.0423 356.82 150.0 -0.0204 -0.0190 470.25 110.O0 -7R.70 57.30 23.755 -10.??2.1 100.30H 11C00.0 -0.0312 -0.0312 190.31 -0.0441 -0.0424 354.70 1100.0 -00203 -0.0189 469.30 115C.0 1150.0 -0.0236 -0.027b 188,84 -0.0443 -0.0426 352.58 115.0 -C.0202 -0.0188 46836 1200.0 -75.950 55.n0 24.31I -R.70..q 10no.383 1200.0 -0.0241 -U.0241 187.55 -0.0443 -0.0426 35044 1200 -022 -0 87 46742 1250C0 1250.0 -C.0207 -0.0207 186.43 -0.0443 -0.0426 348.32 1250.0 -0.0200 -00 1O 406.49 1300.0 -72.0 53.00 2?4.57 -7.20 5.75 100.447 1300.0 -0.0177 -0.0177 185.47 -0.0441 -0.0424 346.20 1300.0 -0.199 -0.0185 46556 1350.0 1350. 0 -0.0152 -0.0152 184.65 -0.0438 -0.0421 344.08 1350.O -0.Gi8 -0014 46.4 1400.0 -.80? 51.00N 25.37R -5.70 4.54 100.498 1400.0 -0.0132 -0.0132 183.94 -0.0435 -0.0418 341.99 1400.0 -00196 -0.0182 46372 i4C. 0 1450.0 -0.0116 -0.0116 183.32 -0.0430 -0.0414 339.90 145 5 0.0 -00195 -0 46281 1500.0 -67.30 49.2N 25.878 -4.20 3.35 100.538 1500.0 -0.0105 -0.0105 182.77 -0.0425 -0.0408 337, 34 15CC. -.194 -0.0180 461.91 1550.0 1550.0 -0. CCS7 -0.0097 182.27 -0.0419 -0.0403 335.82 1550 J -0. - 17 4 01 1800.0 -44.90 47.30 2.36n -2.40 2.24 100.544 1600.0 -0.0092 -u.0092 181.79 -0.0412 -0.03 333,82 1600.0 -0011 -0.0178 46012 1650C., I50.0 -0.0085 -0.0085 181.35 -0.0405 -0.0389 331.86 1650.0 -0.019 -00176 459.24 17CO. 0 -2.8n 45.70 26. 25 -1.45 1.14 100.5.3 1700.0 -0.0079 -0.0079 180.94 -0. C396 -0.0381 329. 93 17000 - 188 -007 4536 1750.0 1750, 0 -0.0073 -0.0073 180.56 -0.037 -0.0372 328.05 5. 016 -0 17 457i 5490 1ECC. 0 -0. 70 44.2 27.2?74 -0.19 0.12? 100.5RQ 1800.0 -0.0067 -0.0067 180.21 -0. 0370 -0.0362 326.22 180.O - -017 4564 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~1850.0 G!8 007]46 I1 E 6~50 C a ~0'1850.0 -0.0062 -0.0062 179.89 -0.0365 -0.0351 324.43 185C -001 -.1.557 1900.0 -58.70 4?27.70 27.708 1.10 -0.92 100.5R5 10CC0.0 -0.0057 -0.0057 179.59 -0.0353 -0.0340 322.7 1 79 0.0 -0.0180 -0.0167 454.94 lIsc.0 1950.0 -0.0052 -0.0052 179.32 -0, C342 -0. 0329 321.04 1950.0 -0 17 -016..54.12 2000.0 -s4.75 41.30, ^ 8.1I28?2.35 -1.8 1r00.571 2COO.0 J -0,0049 -0.0049 179.07 -0.0331 -003 319,41 2CC0. -00172 -0.0160 453.31

TABLE VIb Thermodynamic Properties at the Temperatures of Isothermal and Isenthalpic Determinations. Mixture of Methane and Ethane Containing Approximately 52.3 Mole Percent Ethane. T - -228.45~F T - -99.05'F T - 1.75 T 101.5 252.5 u 4 X 104 x 104 H (S) *(A) H 104(S) (A) ) (S) (A) T - ~ 10145~ H - Pieeasr BBtu/lb ns! BtuPlb Bl ~~0.~~~~~~0, p~~Bsia /b p 5p.0 j -0. 042.- -0.Bu l400 s5.R Bt./ -OP.Q?6iB t /b -.Bu/49b Psi B3u/lb Psi loc-0~~~~~~~ 8~~~~~~ 100.~'~-0.0425 -0.0405 395379 50.0 -0.0268 -0.0249 474 06 100O 100.. -0.0433 -0.0412 391.75 100.0 -0.0269 -0.0250 46981 0.0 15200.0 -0.0440 -0.0419 389.68 150.0 -0.0270 -0.0251 46856 250.0 200.0 - 0.0/449 -0.0427 387.56 200.0 -0.0270 -0.0251 467.30 30050 2500 -0.0457 -0.0435 385.41 250.0 -0.0271 -0.0252 46604 35C00 30.0 -0.0467 -0. 0444 383.21 300.0 -0.0272 -0.0253 46478 30C0 350.0 -0. 04 77 -0.0453 380.97 35Co0 -0.0273 -0.0254 4635 450.0 1.99 122.12 09 -0.0487 -0.0464 378.67 400.0 -0.0274 -0.0255 462.24 450.1)450.0~ -0.0499 -0 *0475 376.32 45C.O -0.0275 -0.0255 460.97 5CC0.0 -24.10 L5.50 37.186 -4.00 3.02 122.150 500.0 -052 -004 37393 5000 -0 0276 -00256 45968 550 0 550.0 -U00523 -0*0498 371946 550.0 -o.0277 -0.0257 458.60 600 -21.80 14.nO0 37.341 -5.50 4.05 22.184 6CC.0 -0. 0535 -0.05090 368.94 600. 0 -0.0277 -0.0258 4572 65C* 0 E50.0 -0. 0548 -0.0521 366.337 650.0 -0.0278 -0.0258 455.83 70C00 -19.70 12..0 37.474 -7.00 5.08 12.229 700.0 -0.0560 -0.0533 36374 700.0 -0.02 -00259 554 5C. 0 750.0 -0.0573 -0.0545 361.03 752e0. -0.0280 -0.0260 453.24 8CC:0 -17.40 11.30 37. 94 -8.70.44 22.287 8000 -00585 -0.0556 358.28. -0.080 -0.020 451 850.0850. 0 -0. 0596 -0.0567 355.48 850.0 -0. 0281 -0.02b1 450.63 90.0 -15.40 10.0O 37.701 -10.80 8.5o 122.359 900.0 - 060 -0.0578 352.61 950.0 -090281 -0.0261 4932 9 5 0. 0 95 0. 0 - 0.0 6 2 0 - 0. 0 590 3 4 9.6 9 9 5 0.0 - 0.0 2 8 1 - 0.0 2 6 1 4 4 8.0 2 100:0. -13.4n 8.80 37.795 -13.40 9.87 1?2.440 1C00. 0 -0,0632 -00601 346.72 1000.0 -0.021 -0.0261 446.71 1~~~~~105~~~0.0 -11.80~~~~~~ 7.6 775 54 1 50.0 -0.0272 -0.0272 210.87 -0~0643 -0.0612 343.68 1050.0 -0.0281 -0.0261 445.41 1100.0 -11.80 7.45 37.77 -15.75 11.54 122.547 11CC.O -0.0243 -0.0243 209.58 -0.0653 -0.0621 340.60 1100.0 -C.0280 -0.02b0 444.11 1150.0 -1"-20 - 37*q~s --- 1150.0 -0 0213 -00213 208.44 -O.0659 -0.0627 337.47 115 0.0 -0.0279 00259 4428 1200.0 -10.20 6.40 37.948 -18.20 13.32 122.473 1200.0 -0.0187 -0.0187 207.44 -0.0659 -0.0627 334.34 1200.0 -0.0278 -0.0258 441.52 1250. 0 -0. 0169 -0.0169 206.55 -0.0655 -0.0623 331.21 1250s0 -0.0277 -0,0257 440.23 13000S -8.60 5.55 38.n09 -?0.50 15.09 122.8 15 13000 -0.0154 -00154 2075 -00646 -0 4 3281 13, -275 -00256 43895 13 50. 0 -0.0137 - 0.0137 205. 02 -0. 0633 -0.0602 325, 07 135C, - 0. 02 74 -0.0255 437.67 1400.0 -7.10 4.55 38.059 -22.80 14.79 122.975 1400.0 -0.0121 -00121 204. 38 -0.0617 -00587 322 09 14C, -027 -0.253 4364 ~~~~~1450. Oa ~~~0 ~1450.0 -0.0108 -'0.0108 203.80 -0.0599 -0.0570 319.20 14.C,0 -.0 C270 -0.0251 435.15 1500.0 -5.70 3.45 38.100 -25.25 18.59 123.154 1500.0 -0.0097 -0.0097 203.29 -0.0579 -0.0551 316.3s 1500.0 -0.0 268 -0.0249 433,89 1550.0 1 155 0.0 -0.0089 -0,0089 202.83 -0.0555 -0.o28' 313.69 1550.0 -0. 0266 -0.0247 43i,65 1600.0 -4.40 2.90 38.132 -27.70 20.35 123.349 1600.0 -0.0082 -0.0082 20240 -0. 0527 -00501J 31112 160. 0 -00264 -0.0245 4312 1850. 0 165C.0 -0.0075 -0.0075 202.01 -0.0495 -0.0471 308.69 1650.0 -0.0261 -0.0242 430,21 1700.0 -3.50 2.15 38.157 -30.10 22.54 123.560 1700.0 -0. OC69 -0.0069 201.65 -0.0462 -0,0440 306.41 170C0 -0.0258 -0.0240 429.00 1750.0 -0o0063 -0,0063 201.32 -0.0429 -0.0408 304.29 1750,0 -0Oa0255 -0.0237 427.81 1 00.0 -2.10 1.35 38.174 -32.50 23.93 123.790 18CO..0.0058 -0.0058 o.02 -0.0402 -0.383 3232 8000 0025 -00234 426.6 1850. 0i 1850.0 -0.0052 -0.0052 200.75 -0.0379 -0.0360 300-47 1 850.0 -070248 -0.00 230 025.48 1900.0 -1.00 0.45 38.184 -35.00 25.77 24.038 100.0 -0.0047 -0.0047 2C0.50 -0.0360 -0.0342 28.66 1000 -00243 -00226 23 0150.00 -00043 -0.0043 2_0027 70.0344 -0.03207 297a 04 1950.0 -0.0239 -0222 42321 2000,0 0.20 -0.15 38.187 -37.60 27.48 124.305 2CG10.0 -00039 -00039 07.0403 -0.0315 295.42 2 00.0 -0.0234 -00218 422.1

TABLE VIla Empirical Data Obtained from Interpretation of Enthalpy Traverses. Mixture of Methane and Ethane Containing Approximately 22.3 Mole Percent Ethane. Pressure Bubble Point Dew Point H psia OF OF Btu Btu/lb 250 -154.2 -77.2 204.2 500 -112.5 -46.8 166.5 TABLE VIIb Empirical Data Obtained from Interpretation of Enthalpy Traverses. Mixture of Methane and Ethane Containing Approximately 52.3 Mole Percent Ethane. Pressure Bubble Point Dew Point H vap psia ~ F ~FBt Btu/lb 250 -129.0 -35.7 213.80 500 -76.5 2.7 173.40 750 -33.25 14.2 102.30

TABLE Villa Table of Thermodynamic Properties, at the Pressures of Isobaric Determinations, in the Regions of Rapid Change. (High (XCp/aT)p) Mixture of Methane and Ethane Containing Approximately 22.3 Mole Percent Ethane. P 1000 psia P - 1500 psia2000 pia Cp(S) Cp(A) H Cp(S) Cp(A) H Cp(S) Cp(A) H Btu/lb~F Btu/lb~F BtuTlb Btu/lb~F Btu/lb~F Btul7b Btu/lb~F Btu/lb~F BtuTlb Temp. Temp. Temp. oF oF oF -60.00 1.5582 1.5507 191.3o -30,a00 1.2769 1.2753 215.88 -30.,J 1,io4c 1.0197 2C6.63 -59.00 1.6185 1. o107 192.9 -27.50 i. 3108 13091 219.12 -25.00 1,042. 1.0376 211.78 -58.45 1.b528 1.6449 193.76 -25.00 1.3437 1.3420 222.44 -20.00 1.0596 1,0545:17.01 -58.00 i 1. 68C9 1.6713 194.56 -22. 5u 1*3736 1.3718 225.83 -15.00 1.0767 1.0715 222*33 -57,00 i.7443 1.7344 19. 26 -20.00 l1.3945 1.3927 229*29 -10 00 1.o897 1.0844 227.71 -5),. O 1.8(J0o7 1.79t4 198a.06 -18.75 1.4015 1.3997 231.03 -5.00 1.0957 1.0904 233.15 -55.C0O 1.A680 1.857' 190.b6 -17.50 1.4055 1.4037 232.78 0.0 1.1008 1.0955 236862 - 4.00 1.9304 i.9194 201,76 - 16.25 1,4C95 1.4077 234.55 5.00 1.1028 1.0975 244.10 -53.00 1.9938 1.9824 203.66 -15.00 1.4125 1.4107 236.31 10.00 1.1028 1.0975 249.5 -52.00 2.a0551 2.0464 205.oo -13,75 14135 1.4117 238.07 15.00 1.0987 1,0934 255.07 -51.00 2.120. 2.1084 2C7.77 -12.50 1.4145 1.4127 239.83 20.00 1.0917 1.0864 260.51 -50.00 2.1819 2.1695 209.97 -11.25 1.4135 1.4117 241.61 25.00 1.0807 1.0755 265.92 -49.00 2.2422 2.22S4 212.17 -10,00 1.4115 1.4097 243.37 30.00 1.0677 1.0626 271.27 -48.00 2.2855 2.2725 214.37 -7.50 i.4015 1.3997 246.88 -47.00 2.3116 2.29o4 216.67 -5,00 1.3b876 1.3858 250.36 -46.00 2.3376 2.3245 218.97 -2.50 1.3706 1.3o88 253.81 -4).0 351 3385 22127 370 2351 33857.20 -44.50 2. 3589 2.3455 222.47 2.50 1.3228 1.3211 260,54 -44.00 2.365C 2.3515 223,67 5.00 1 3 1 3 1.3G11 263.82 -43. 50 2.3690 2.3555 224.87 7.,0 1.276 ) 1.2753 267.04 -43.00 2.3710 2.3575 225,97 10.00 1.2510 1.2494 270.20 -42.50 2.3720 2.3585 227.17 -42.00 2. 3710 2.3575 228.37 -41.50 2.3660 2.3555 229.57 -41.00 2. 3o50 2.3515 230.68 -40 50 2.3585 2.3455 231.88 -40.00 2.3519 2.33E5 233,08 -39,00 2.337d 2.3245:35.38 -38.00 2.3116 2.2984 237.68 -37.00 2.2855 2.2725 239,9E -36.00 2. 253 2.2375 242.28 -35.00 2.2080 2.195'4 44.48 -34.00 2.1607 2.1484 246.68 -33.00 2.1105 2.0985 248.78 -32.00 2.0561 2.0444 250.88 -21.00 2.001 e 1.9904 252.88 -30.a00 1.9435 1.9374 254,79 -27,50.,bl157 1.8053 259,49 -25.00 i.69 20 1.68294 263,89 -22.50 1.a89 1.d803 267.89 -20.00 i.4983 1,4903 271,79

TABLE VIlib Table of Thermodynamic Properties, at the Pressures of Ioobaric Determinations, in the Regions of Rapid Change. (High (3Cp/aT)p) Mixture of Methane and Ethane Containing Approximately 52.3 Mole Percent Ethane P - 978 psia P - 1250 psia P - 1500 psia Cp(S) Cp(A) H Cp(S) Cp(A) H Cp(S) Cp(A) H Btu/lb~F Btu/lb~F Btu71b Btu/lb~F Btu/lb~F Btu7lb Btu/lb~F Btu/lb~F Btu7lb empTemp. Temp. OF oF OF 5.00 1.6682 1.6520 219 73 15 00 1 2581 1.2414 221.79 30.00 1.1497 1 1366 232 59 10.00 1.8773 1,8591 228.52 17.50 1.2914 1,2742 224.93 40.00 1.2295 1.2155 244.09 15.00 2,0835 2.0633 238.41 20,00 1.3258 1.3082 228.16 41.00 1.2407 1.2266 245.29 15 50 2.0996 2.0792 239.51 22.50 1. 3622 1*3441 231.48 42.00 1.2497 1.2355 246.59 16.00 2.1178 2.0973 240.51 25.00 1.3965 1.3779 234.89 43.00 1.2588 1.2444 247.79 16.50 2.1340 2.1133 241.61 27.50 1*4268 1.4078 238.37 44.00 1.2659 1.2515 249.09 17,00 2.1451 2.1243 242.61 30.00 i.4572 1.4378 241.93 45.00 1.2720 1.2575 250.29 17.50 2.1501 2.1292 243.71 30,62 1.4642 1.4447 242.83 46.O 1.2760 1.2615 251.59 18.00 2.1532 2.1323 244.81 31.25 1.4703 1.4507 243.74 47.00 1.2790 1.2644 252*89 18.50 2.1552 2.1343 245.81 31,88 1.4774 1.4517 244.66 48.00 1.2801 1.2655 254.09 19,00 2.1542 2.1333 246.91 32o50 1.4844 1.4647 245,56'9q.O 1.2811 1.2665 255.39 19.50 2.1522 2.1313 248.01 33.13 1.4905 1.4707 246.48 50.00 1.2821 1.2675 256.69 20.00 2.1461 2.1253 249.01 33,75 1.4956 1,4757 247.40 51,00 1.2831 1.2685 257*89 20.50 2.1380 2.1173 250,11 34,38 1.5006 1.4806 248.33 52.00 1.2841 1.2695 259.19 21.00 2.1279 2.1073 251.1C 35.00 1.5067 1.4867 249.26 53,00 1.2841 1.2695 260.4S 21.50 2.1148 2.0943 252.20 35,62 1.5117 1.4916 250.17 54.00 1.2841 1.2695 261.69 22.00 2.0996 2.0792 253.2C 30,25 1.5168 1,4966 251.12 55.00 1.2831 1.2685 262.99 22.50 2.0824 2*0622 254.30 36,87 1.5218 1.5016 252.05 56.00 1.2821 1.2675 264*29 23.00 2.0663 2,0463 255.30 37.50 195259 1.5056 253.CC 57.00 1 2811 1.2665 265.49 23e50 2,C491 2.0292 256.3C 38.13 3.5279 1,5076 253.95 58.00 1.2801 1.2655 266.79 24,00 2.0329 2.0132 257.30 38.75 1.5299 1.5096 254.88 59.00 1.2790 1.2644 268*09 24.50 2.0188 1.9992 258.3C 39.38 1.5319 1*5115 255.83 60.00 1.2760 1.2615 269.29 25.00 2.0077 1,9882 259.30.40,00 1.5340 1.5136 256.77 61.00 1.2720 1.2575 27C.59 30o00 1.8349 1.8171 268.99 40,63 1.5340 1.5136 257.73 62.00 1.2659 1.2515 271.89 35.00 1.6763 1.6600 277.58 41.25 1.5340 1.5136 258.67 63.00 1.2598 1.2454 273.09 40 00 1.5338 1.5189 285.58 41 87 1 5340 1.5136 259.6C 64.00 1.2528 1.2385 274.39 45.00 1.4166 1.4029 292.87 42.50 1.5329 1.5125 260.56 t5.00 1.2467 1.2325 275*59 43 13 1.529) 1.5096 261.51 66.00 1.2407 1.2266 276,79 43,75 1.5279 1.5076 262.45 67.00 1.2.:46 1.2205 277.99 44,38 1.5249 1.5046 263.39 60d00 1.2285 l.2145 279.29 45,00 1.5208 1.500o 264.33 69. 0 1.2225 1.2086 280.49 45.63 1.5158 1.4956 265.27 70.00 1.2164 1.2C25 281.69 46,25 1.5117 1.4916 266.20 80.00O 1,1548 1.411t 293.39 40. 88 1. 5067 1.48o7 267.14 47,50 1.5016 1,4816 268.0b 48.12 1,4956 1.4757 268.98 48.75 1.4895 1.4697 269.91 49,38 1.4834 1.4o37 270 83 50,00 1.4774 1.4577 271.74 50,63 1,4703 1.4507 272.65 51.25 1,.432 1.4437 273,55 51.38 1,4561 1.4367 274.4o 52.50 1,4501 1.4308 275,35 53.13 1.4440 1.4248 276.25 5,3.75 143ct 1.4 178 277.13 54.38 i.4289 1.4099 278.02 55,00 1.4198 1.,009 278,90 57.50 1.3844 1*3660 282.35 60.00 1.3511 1.3331 285.74 62.50 1.3187 1.3 0i2 289.03 65 00 1.2874 1.2703 292.24

TABLE IXa Enthalpy Values at the Points of Thermodynamic Consistency Mixture of Methane and Ethane Containing Approximately 22.3 Mole Percent Ethane emperature \ ~F -253.2 -150.55 -58.45 79.0 255.0 pressure psia 0 291.7 332.4 397.1 4S0.8 250 129.86 388.49 500 99.565 1000 23.17 100.22 193.76 358.93 471.2 1500 182.77 337.84 2000 179.07 319.41 453.31 Base Points: Basis: H = 0 Pure Saturated liquids at -280~F a) Calculated zero pressure value: H = 397.1 Btu/lb for mixture at 79.0~F. b) Liquid Consistency point: H = 32.8 Btu/lb for mixture at -240~F and 1000 psia.

TABLE IXb Enthalpy Values at the Points of Thermodynamic Consistency. Mixture of Methane and Ethane Containing Approximately 52.3 Mole Percent Ethane.,-Temperature O~F -228.45 -99.05 1.75 101.5 252.5 pressure psia | 0 j 301.35 351.4 395.8 472.3 250 155.19 336.35 500 122.15 307.87 750 122.258 242.23 978 122.421 1 214.63 348.03 1250 206.55 331.21 1500 38.1 123.154 203.29 316.39 433.89 2000 200.07 295.42 Base Points: Basis: H = 0 Pure Saturated liquids at -280~F a) Calculated zero pressure value: H 395.8 Btu/lb for mixture at 101.5~F b) Liquid consistency point: H = 43.50 Btu/lb for mixture at -220~F and 1500 psia.

APPENDIX I Composition of Standard Mixture As mentioned in the section on EXPERIMENTS under the subheading Composition, the chromatograph was calibrated in conjunction with the analysis of samples withdrawn from the system by use of a mixturesof constant compositions stored in a standard tank. The composition of the standard mixture as determined by chromatograph and mass spectrometer are reported in Table Al. TABLE Al Composition of Standard Mixture Used to Calibrate the Chromatograph Nominal Ethane Content 22 3% 52.3% Composition mol% mol% Nitrogen N2 0.08 0.05 Carbon Dioxide CO2 0.03 0.03 Methane CH4 77.71 47.90 Ethane C2H6 22.10 51.70 Propane C3H8 0.03 0.03 Propylene C3H6 0.05 0.29 100.00 100.00

APPENDIX II Calculation of Enthalpy Values for the Methane-Ethane Mixtures at Zero Pressure As a first step in this process, the enthalpy of pure methane and ethane were calculated at 192~F and zero pressure using the bases H = 0 for saturated liquids at -280~F. The results are summarized individually below: Methane Btu/lb 1. Enthalpy of saturated liquid at -280~F and 5 psia 0.00 2. Enthalpy of vaporization at -280~F and 5 psia. 227.72 [Experimental data of Frank & Clusius (4)] 3. Isothermal enthalpy difference between saturated vapor 1.15 at 5 psia and ideal gas at -280~F [Estimated using a correlation of published data on the second virial coefficient for methane developed by Furtado (5)] 4. Enthalpy change as an ideal gas between -280~F and 243.32 +192~F [Calculated by interpolation of tabulated values of (H~ - Ho )/T published by Rossini et al (10)] 5. Enthalpy of pure methane as an ideal gas at 192~F 472.19 Ethane 1. Enthalpy of saturated liquid at -280~F. 0.00 2. Enthalpy change from saturated liquid at -280~F to 84.50 saturated liquid at -128.1~F and 14.696 psia [Integration of heat capacity data of Witt and Kemp (11)] 3. Enthalpy of vaporization at -128~F and 14.696 psia 210.9 [Experimental data of Witt and Kemp (11)] 4. Isothermal enthalpy change from saturated vapor at 2.40 14.696 psia to the ideal gas state at -128~P. [Estimated using a correlation of published data on the second virial coefficient for propane developed by Furtado (5)].

5. Enthalpy change as an ideal gas between -128.1~F and 127.70 +192~F [Calculated by interpolation of tabulated values of (H~ - H~ )/T published by Rossini et al (10)] 6. Enthalpy of pure ethane as an ideal gas at 192~F 394.63 Molecular weights of 16.04 and 30.06 were used for methane and ethane respectively to yield the following values of H~ -M at 192~F: Nominal Ethane H~ at 192~F -- M Composition (Btu/lb) 22.3 445.04 52.3 419.98 The tabulated values of (H~ - H~ )/T for methane and ethane as published by Rossini et al were used to calculate values of H~ at other temperatures as listed in Table II.

APPENDIX III Estimation of Enthalpy Values for Met'nane-Ethane in the Liquid State at Elevated Pressures to Serve as Checks on the Calorimetric Data As indicated on Figures 1 and 2, isobaric determinations were made over the entire temperature range (-240~F to +300~F) at only one pressure each; 1000 psia for the 22.3% mixture and 1500 psia for the 52.3% mixture. Therefore, enthalpy values were estimated at -240~F, 1000 psia and -220~F, 1500 psia respectively for these mixtures. Enthalpy values for pure methane were taken from the thesis of Jones (7) and corrected at elevated pressures as suggested by Yesavage (12' For ethane, values were obtained directly from a tabulation by Furtado(5). These values are reported in Table III. Note that if ideal mixing is assumed, it is predicted that H = 31.4 Btu/lb for the 22.3% mixture at -240~F and 1000 psia and 42.9 Btu/lb for the 52.3% mixture at -2209F and 1500 psia. H is positive in sign for mixtures of light hydrocarbons in the liquid state and therefore these values represent a lower limit on the enthalpies of the mixtures. Estimation of Excess Enthalpy of Methane-Ethane Mixtures. Unfortunately no published data on the excess enthalpy of liquid methane-ethane mixtures have come to our attention. However, Cutler and Morrison (3) have published data on the excess enthalpy data of methane-propane mixtures and these serve to establish an upper bound to such values for methane-ethane mixtures. These authors report values of HE for liquid methane-propane mixtures at 100~K (-280~F). A broad maximum occurs between 30-50% propane with H of about 1.6 Btu/l1

These data are for low pressure. Yesavage (12, 13) has reported enthalpy data for a mixture containing about 50% propane in methane. Using these data in conjunction with the corrected methane values of Jones (7,8) and the corrected propane values of Yesavage (12,2) at 1500 psia and -220~F the calculated value of HE is 1 Btu/lb. Assuming the H will be roughly constant for methane-ethane mixtures in the composition range from 22 to 50%(based on the results of Cutler and Morrison for methane-propane), that the heat of mixing of liquid hydrocarbons decreases with pressure and that HE should be less for methane-ethane mixtures than for methanepropane mixtures at similar conditions yields the estimates for H presented in Table III. Values of H are calculated according to H 4 i-iH+ H (AIII-1) where xi refers to the mole fraction in the liquid. 1.

APPENDIX IV The basic calorimetric determinations made on the two binary mixtures of methane and ethane are reported in this appendix. As indicated by the headings following each run number are listed the mole fractions of methane (XC1), ethane (XC2) and propane (XC3) which are normalized to 1.000 because the other trace impurities were not determined by chromatographic analysis. In sequential columns are listed the experimentally determined values of temperature at the inlet and outlet of the calorimeter, pressure at the inlet and pressure drop and the energy added during the experiment. Table A2 lists results for the normal 22.3% ethane mixture and Table A3 presents values for the normal 52.3% ethane mixture. In each case isobaric data are presented in Table (a), isothermal data in Table (b) and isenthalpic data in Table (c). In each case the mean value of the corresponding derivative function (C, j and p) as calculated from the raw data are listed in the last column. As mentioned in the text these values were corrected for minor variations in composition, pressure level, inlet temperature, etc. before being processed to fit and smooth the data.

02-16-73 02-16-73 02-16-73 02 -16TARLE A2(a) ISORARIC DATA FIR NOMINAL 0.777 CH4, 0.223 C2H6RUtN Nnl. XC] XC2 XC3 INLET OUTLET INL FT PRES. HEAT MEANl HEA T TEMP. TEMP. PRES.o )RKP NPUIPIT CAPACITY (MFLE FRACTIfN) ( F)( F) (PSIA) (PSD) (BTIJ/LB)(BTIJ/LB F) 15.010 0.778 0.221 0.001 -240.72 -214.98 249./ 0, t 0 18.990 0.73771 15.020 0.778 0.221 0.001 -240,71 -185.18 250. 1 ( 10 41.758 0.75199 15.025 0.778 0.221 0.001 -240,71 -185.18 250.1] 0.10 41.853 0.75370 15.030 0.778 0.221 0.001 -240.70 -158.85 251.3 0.10 62.592 0.76470 16.010 0.771 0.228 0.001. -165.84 -161.30 250.1 0.(1) 3.756 0.82878 16.()020.771 0.228 c.0) 1 -165.81 -155.50 248.4 0.1 8.551 (0.8965 16.030 0.771 0.228 0.()(001 -l(5,80 -153,97 250.4 0.34 14.197 1.19996 16.040 0.771 0.2278 0.0o01 -165.81 -153.47 248.c) 0.34 21.154 1.71408 1.6.045 0.771 0.228 0.001. -165.81 -153.47 248.9 0.34?1.214 1o71864 16.050 0.771 0.228.00)1. -165.81 -150.23 248.5 0.34 43.735 2.806()0 16.06O 0.771 0.22F8 0.00. -165.78 -137.35 249.7 0.34 92.025 3.23785 16.070 0.769 0.230 0.001 -165.78 -116.63 249,5 0.34 134.749 2.74196 16.080 0.769 0.230 0.00] -165.77 -92.31 249.3 0.34 182.357 2.48231 16.090 0.769 0.230 0.001 -165.77 -90q25 249.1 0.34 186.023 2.46306 16.100 0.769 0.230 0.001 -165.77 -86.45 249.7 0.34 194.764 2.45534 16.110 0.769 0.230 0.001 -165.76 -78.89 248.9 0.34 212.651 2.44794 16.120 0.769 0.230 0.001 -165,69 -75,14 249,5 0,34 218,055 2.40806 16.130 0.769 0.230 0.001 -165.75 -59.92 249.1 0.34 227.104 2.14592 11.010 0.777 0.222 0.001 -59.55 -36.41 251.5 0.38 12.736 0.55042 11.020 0.777 0.222 0.001 -59.56 -18,86 251.2 0.39 22.246 0.54650 11.0'30 n0.777 0.222 0.001 -59.57 1.40 250.3 0.39 32.737 0.53693 11.040 0.778 n.221 0.00l -59.58 25,85 249.7 0.39 45.377 0,53118 11.050 0.778 0.221 0.001. -59.55 50.47 250.0 0.39 58.203 0.52900 11.060 0.778 0.221 0.001 -59.56 75,29 252.1 0.39 71.295 0.52868 17.010 0.777..22 0.R )01 -152.30 -130O.83 498.8 0.07 18.797 0.87550 17.020 0.771 0.228 0.001 -152.29 -126.03 500.1 0,07 22.954 0.87423 17.030 0.771 0.228 O.001 -1 52.31 -116.34 499.4 0.07 32.267 0.89716 17.040 0.771 0.228 0.001 -152.30 -113.10 499,5 0.07 35.137 0.89647 17.050 0.771 0.228 0,00 1 -152.29 -102.79 501.9 0.17 78.641 ].58857 17.060 0.780 0.219 0.001 -152.28 -90.48 498.9 0.1 7 111.371 1.80200 17.070 0.7r0 0.219 0.n01 -152.22 -66.00 501.8 0.17 163.664 1.89804 17.080 0.780 0.219 0.001 -152.16 -56,78 500.3 0,17 183.233 1.92109 17.090 0.769 0.230 0.001 -152.17 -51.26 499.5 0.17 193.828 1.92089 17,100 0,769 0.230 0,001 -152.20 -42.23 499.0 0.17 206.370 1.87650 14.010 0.777 0.,22 0.001 -240,69 -221.28 999.1 0.05 14.179 0.73050 14.020 0.777 0.222 0.001 -240.76 -189,32 1000.4 0.05 37.998 0.73865 14.0(30 0.777 0.222 0.001 -240.73 -169.16 1002.2 0.05 53.421 0.74632 14.040 0.777 0.222 0.001 -240.76 -148.43 1002.8 0.05 69.734 0.75530 18,010 0.770 0.229 0.001 -152.14 -127.12 1001.1 0,06 20.524 0,82026 18.015 0.770 0.229 0.00) -152.14 -127.1? 10(1.1 0.06 20.581 0.82252 18.020 0.770 0.229 00()0] -152.14 -102.44 999.7 0.06 42.507 0.85522 18.030 0.771 0.228 0.001 -152.13 -82.18 999.1 0.06 63.265 0.90444 18.040 0.771 0,228 0.001 -152.10 -60,85 1002,1. 0,06 90.203 0,98850 10.010 0.778 0.221 0,001 -59.47 -54.92 998.7 0,06 R,126h 1.78589 10.015 0.778 0.221 0,.)01 -59.47 -54.92 998.7 0.06 8.100) 1.78009

10.016 0.778 0.221 0.001 -59.47 -54,92 998.7 0.0h 8,152 1.791 8 10.020 0.778 0.221 0.001 -59.45 -49.65 1001.4 0.06 19.048 1.94450 10.030 0.778 0.221 0.001 -59.47 -40.21 1000.1 0.(6 41.634 2.16154 10.040 0.778 0.221 0.001 -59.47 -29.23 1001.8 0.06 64,717 2.14012 10.050 0.777 0.222 0.001 -59.43 -19.64 1003.1 0.06 8().418 2.02102 1O.060 0.777 0.222 0.001 -59.42 0.24 999.1 0 006 104,674 1.75440 10,070 0.777 0.222 0.001 -59.46 26,53 1000,0 0.06 128,013 1.48882 10.080 0.778 0.221 0.001 -59.42 51.65 1000.5 0,06 147.537 1.32833 10.090 0.778 0.221 0.001 -59.49 75.58 1000.9 0.06 164,543 1.21824 3.010 0.779 0.220 0.001 78.23 87,84 1001.9 0,14 6.460 0.67258 3.020 0.779 0.220 0.001 78.00 108.37 999.3 0.16 20.144 ()66325 3.030 0.779 0.220 0,001 78,00 138,47 999.8 0.19 39.768.65765 3.035 0.779 0.220 0.001 78.00 138.47 999.8 0. 19 39.701 0.65654 3.040 0.778 0.221 0.001 78,01 167.57 1001.7 0.19 57.916 0.64667 3.050 0.778 0.221 0.001 77.92 202.95 1000.0 0.19 80.211 0.641.52 5.010 0.778 0.221 0.01)1 202.28 212.81 998.4 0.18 5.862 0.55682 5.015 0.778 0,221 0.001 202,28 212,81 998.4 0.18 5,957 0.56581 5.020 0.778 0.221 0.0021 202.21 227.11 1002.6 0.18 15.756 0.63258 5.030 0,778 0.221 0.001 202.25 251.74 1000.5 0.18 31.443 0.63535 5.040 0,778 0.221 0.001 202.20 276.66 1001.9 0.18 47.491 0.63777 5.050 0.778 0.221 0.001 202.17 300.70 1001.4 0.18 63.208 0.64150 9.010 0.776 0,.223 0.001 -59.44 -40.36 1502.2 0.05 21.460 1.12491 9.020 0.776 0.223 0.001 -59.47 -19.66 1501.0 0.05 48.349 1.21457 9e.030 0.,776 0.223 0.001 -59.46 -29.25 1503.4 0.05 35.028 1.15965 9.0(40 0.776 0.223 0.001 -59.46 -24.67 1502.4 0.05 41.763 1.20055 9.050 0.777 0.222 0.001 -59.44 1.41. 1500.7 0.05 77.449 1.27277 9.060 0.777 0.222 0,001 -59.37 25.36 1499,3 0.05 106,816 1,26073 9,070 0.777 0.222 0.001 -59.28 52.35 1497.9 0.05 132.760 1.18924 9.,080 0.777 0.222 0.001 -59.37 77.28 1499.4 0.05 155.126 1.13517 8.010 0.778 0 221 0.001 -59.23 -38.57 2000.1 0.07 19.686 0.95249 8. 020 0.778 0.221 0.001 -59.20 -19.20 1999.8 0.07 39 543 0.98870 8,030 0.778 0.221 0.001 -59.13 1.02 2001.9 0.07 61.709 1.02598 8,040 0.778 0.221 0.(.)01 -59.21 26.01 2002.2 0.07 88.872 1.04284 8.050 0.778 0.221 0.001 -59.27 37.80 199.8 0.07 101.557 1.04624 0. 06 0,0778 0,221 0,001 -59.28 42.93 2001.8 0,07 106,836 1.04530 8.070 0.778 0.221 0.001 -59.25 52.04 2000.6 0.0.7 114.794 1.03149 8.080 0.778 0.221 0.001 -59.23 75.73 2000.8 0.07 138.655 1.02 736 2.010 0.777 0.222 0.001 78.06 88.37 2001.8 0.05 9.140 0.88683 2.02( 0,777 0,222 0.0 1 78.12 108.64 2002.5 0.05 26,190 0.85831 2.030 0.777 0.222 0.001 78.02 137.38 2001.1 0.06 49.082 0.82684 2.040 0.775 0.224 0.001 78.0? 168.68 2002.2 0.09 72.452 0.79915 2.050 0.775 0.224 0.001 78.02 202.04 199.6 0.0(9 96.592 0. 7 7 88 5 4.010 0.778 0.221 0.00.1 202.09 212.68 1999.7 0.11 7.559 0.71395 4.020 0.778 0.221 0.001 202.14 226.74 2003.4 0.11 17.320 0.70433 4.030 (0.777 0.222 0.001 202.16 252.35 2003.3 0.12 35.479 0.70691 4.040n 0.777 0.222 0.0) 1 202.31 277.43 2002.6 0. 14 52.846 0.70349 4,050 0.777 0.222 0,001 202.24 301,15 2001,2 0,14 69,459 0.70220

TARLF A2(b) ISOTHERt'AL iATA FOR NOMINAL 0.777 CH4, 0.223 C2H6 RUN NO. COMPOSIT IN INLET OUTLET INLET PKES. HEAT ISOTHERMAL XC1 XC2 XC3 TEMP. TEMP. PRES. I)OR'P INPUT J.-T.COEFF. (MOL E FRACTION) ( F) ( F) (PSIA)T (P ( BTU/LB) ( TI)/L H P S I A) 7.010 0.778 0.221 o.n0. -58.37 -58.31 1999.4 178.-5 1.033 -0.00578 7.020 0.778 0.221 0,001 -58.46 -58.39 1799.6 70.62 1.595 -0.02258 7.030 0.778 0.221.0n01 -58.45 -58.37 1603.??63.46 3.138 -0.01191 7.040 0.778 0.221 0. 01 -58,44 -58.40 1600.8 4 52,04 6.312 -0.01461 7.050 0.778 0.221 o0.001 -58,49 -58.45 1390.5 394.20 0 0 10.13 -()0.02566 7.060 0.778 0.221 0.001 -58.60 -58.71 1405.1 517.47 14.667 -0.02834 7.065 0.778 0.221 0.001 -58.60 -58.71 1405.1 504.50 14667 -0.()02907 7.070 0.778 0.271 0.001 -58.47 -58.60 12(02,1 243.42 90285 -0.03814 7.080 0.778 0.221 0.001 -58.32 -58.17 998.8 155.75 20.113 -0.12913 7.090 0.778 0.221 0.001 -58.37 -.58.30 984.7 288.02 45.239 -0.15707 7.095 0.778 0.221 0.011 -58.37 -58.30 984.7 275.99 45.232 -0.16389 ]..010 0.777 0.222 0.001 79.28 79.31 1096.3 203.70 7.269 -0.03568 1.020 0.777 0.222 0.001 79.14 79.13 2000.0 415.98 15.711 -0.03777 1.025 0.777 0.222 o 0.01 79,1.4 79.13 2000.0 415.98 1 5772 -0.03792 1.026 0.777 0.222 0.001 79.14 79.13 2000.0 415.98 15.656 -0.03764 1.030 0.777 0.222 0.001 79,16 79.12 1602.6 105.93 4.433 -0.04185 1.040 0.778 0.221 0.001 79.07 79.09 1601.2 339.09 14.464 -0.04266 1.050 0.778 0.221 0.001 79.12 79.06 1600.9 541.47 23.433 -0.04328 1.060 0.778 0221 0.001 79.06 79.04 1045.8 220.67 9.421 -0.04269 1.070 0.777 0.222 0.001 78.97 78.90 1045.8 439.20 18.576 -0.04230 1.075 0.777 0.222 0.001 78.97 78.90 1045.8 439.20 18.643 -0.04245 1.076 0.777 0.222 0.001 78.97 78.90 1045.8 439.20 18.510 -0.04215 1.080 0.777 0.222 0.001 79.08 79.02 1048.4 636.18 26.555 -0.04174 1.090 0.777 0.222 0.001. 79.07 79.09 1045.6 842.79 34.322 -0.04072 1.095 0.777 0.222 0.001 79.07 79.09 1045.6 842.79 34.415 -0.04083 1.096 0.777 0.222 0.001 79.07 79.09 1045.6 842 79 34.231 -0.04062 1.100 0.777 0.222 0.001 79.07 79.09 1045.2 918.97 37.292 -0.04058 6.010 0.778 0.221 0.001 254.86 254.88 1999.9 08.48 3.769 -0.01808 6.020 0.778 0.221 0.001 254.92 254,87 2001.5 424.86 7.876 -0.01854 6.030 0.778 0.221 0.001 254.93 254.93 2000.5 6h4,95 12.189 -0.01884 6.040 0.778 0.221 0.0')1 255.00 254.94 2004.1 857.1 16.394 -0.01913 6.050 0.778 0.221 0.001 255.04 255.04 1153.0 228.69 4,647 -0.02032 6.060 0.778 0.221 0.001 256.22 256.24 1148.2 455.62 9.398 -0.02063 6.070 0.778 0.221 0.001 255.81 255.81 1148.9 635.89 13.144 -0.02067 6.080 0.778 0.221 0.001 256.08 256.05 1148.5 846.91 17.570 -0.02075 6.090 0.778 0.221 0.001 256.13 256.11 1145.1. 1038.00 21.489 -0.02073

TARLE A2(c) ISENTHALPIC DATA FOR NOMINAL 0.777 CH4, 0.223 C2H6 RUN NO(). CoMP[]SI TIO N INLET OUTLET INLE T PRE.S HEAT J. IHOMS/ON XC1 XC? XC3 TEMP. TEMP PRES. )ROP( INPUT C.OEFF. (MOLE FRACTION) ( F) ( F) (PSIA) (PSIl)) (6T3T/Lt) ( F/PSIA) 13.010 0.777 0.22? 0.001 -253.21 -252.39 2008.2 142.38 0.000 -0.00580( 13.020 0.777 0.222 0.001 -?53.22 -252.29 1703.3 135.72 0.000 -0.00686 13.030 0.777 0.222 0.001 -253.23 -252.22 1393.9 132.89 0.000 -0).00 757 13.040 0.777 0.222 0.001 -253.1R -252.09 1035.1 119.97 0.000 -0.()0906 13.050 0.777 0.222 0.001 -253.23 -252.17 804.0 129.04 0.000 -0.0()083 13.055 0.777 0.222 0.001 -253.23 -252.17 804.0 124.02 0.000 -0.00(856 12.010 0.778 0.221 0.001 -150.55 -150.57 2000.6 161.29 0.000 0.00014 12.020 0.778 0.221 0.001 -150.64 -150.56 1701.1 154.23 0.00( -()00051 12.03(0 0.778 0.221 0.00 1 -1.50.58 -150.47 1401.7 161.12 0.000 -0.00070 12.040 0.778 0.221 0.001 -150.57 -150.38 1099.8 161.50 0.000 -0.00114 12.050 ()o778 0.221 0.00 -15 -15015027 804.0 171.13 0.000 -0.00151 12.060 0.778 0.221 0.001 -150.51 -150.22 603.9 180.39 0.000 -0.00156 12.070 0.778 0.221 0.001 -150.51 -150.14 499.5 160.69 0.000 -().00230

TABLE A3(a) ISORARIC DATA FOR NOMINAL 0.477 CH4, 0.523 C2H6 RUNl Nn. XC1 XC2 XC3 INLEE T OUT ET INLET PKS. HEAT MEAN HEAT TEMP. TEMP. PRES. O)K)P I NP[UT CAPACITY (MOLE FRACTinN) ( F) F) (PSIA) (PSIn) (KTIJ/LH) (HTTU/LF F) 4.010 0.485 0.512 0.003 -13677 -132.08 250.7 f.07 3.405 0.72732 4.020 0.485 0,512 0.003 -136.71 -128.23 250. ). 07 7.054 0.83244 4.030 0.485 0.512 0.003 -136.75 -123,R8 249.8 0.07 17.310 1.34503 4.040 0.485 0.512 0.003 -136.77 -125.33 248.8 0,07 14.661 1.28094 4.050 0.485 0.532 0.00 F3 -136.75 -120.92 249.6 0.07 23.426 1.47929 4.060 0.485 0.512 0.()03 -136.75 -115.20 249.2 O.U, 34.406 1.59674 4.070 0.485 0.51? 0.00B3 -136.81 -81.699 249.6 0.( 92.359 1.67540 4.080 0.485 0.512 0.(003 -136.71 -4655 250. 7.(0 176,913 1.962 235 4.090 n.480 0.517 orn4 -136.71 -41.94 250.? 0.07 194.255 2.04988 4.100 0.480 0.517 ) 0.003 -136.70 -37.41 251.3 0.07 213.092 2.14621 4.110 0.480 0.517 0.003 -136.75 -18.40 251.6 0.07 228.971 1.93467 4.120 0.480 0.517 0.003 -136.71 6.27 250.6 0.07 240.602 1.68270 5.010 0.477 0.520 0.003 -99.42 -78.40 499.7 0.14 16.353 0.77818 5.020 0.477 0.520 0.003 -99.35 -75.05 499.h 0.14 19.104 0.78612 5.030 0.477 0.520 0.003 -99.33 -69.80 500.7 0.14 28.842 0.97678 5.040 0.477 0.520 0.003 -99.33 -64,05 501.5 0.14 39,286 1.11329 5.050 0.483 0.514 n0.03 -9935 -5964 501.6 0.14 47.317 1.19149 5.060 0.483 0.514 0.003 -99.26 -10.74 500.6 0.14 148.787 1.68077 5.070 0.483 0.514 0.0)3 -99.30 -3.95 499.7 0,14 169.551 1.77817 5.080 0.483 0.514 0.003 -99.33 1.13 500.0 0.14 186.991 1.86118 5.090 0.480 0.517 0.003 -99.33 9.43 500,7 0.14 195.934 1.80148 5.100 0.480 0.517 0.003 -99.20 19.70 500.4 0.14 202.654 1.70444 5.110 0.480 0.517 0.01)3 -99.35 50.14 501.2 0.14 222.354 1.48749 6.010 0.475 0.522 0.003 -101.11 -70.33 749.9 0.35 23.257 0.75561 6.020 0.475 0.522 0.003 -100.86 -35.97 751.4 0.22 53,394 0.82290 6.030 0.476 0.521 0.003 -101.49 -31.64 749.5 0.22 58.893 0.84311 6,040 0.476 0.521 0.0q3 -101,48 -26o18 749.1 0.22 69.119 0.91796 6.050 0.476 0.521 0.003 -101.45 -6.30 749.1 0.22 106.737 1,12178 6.060 0.474 0.523 0.003 -101.43 5.83 748.7 0.22 133.614 1.24579 6.070 0.474 0.523 0.003 -101.43 19.99 750.,0 0.22 169.160 1.39322 6.080 0.474 0.523 0.0n3 -101.41 39,13 749,7 0.22 194.937 1.38704 7.010 0.479 0.518 0.003 -100.04 -65.41 975.3 0.08 25.935 0.74883 7.020 0.479 0.518 0.003 -100.04 -32.48 975.4 0.08 53.901 0.79787 7.030 0.479 0.518 0.003 -99,96 0.42 975.2 0,08 91.054 0.90714 7.040 0.479 0.518.00t3 -100.04 4.68 974.5 0.08 98.225 0.93796 7.050 0.479 0.518 0.003 -100.03 8,85 976.3 0.08 105.569 0.96956 10.010 0.480 0.517 0.003 0.90 5.87 979.3 0.07 8.041 1.62060 1().02( 0.480 0.517 0.003 1.08 8.66 979.6 0.07 13.121 1.73031 10.030 0.480 0.517 0.003 0.95 11.17 978.8 0.07 18.381 1.79725 10.040 0.480 0.517 0.003 0.88 12.65 979.0 0.07 21.658 1.84047 10.050 0.480 0.517 0.003 1.12 15.83 980.7 0.07 27.496 1.86920 10.060 0.479 0.518 0.003 0.98 20.76 979.8 0.07 38.661 1.95505 10.070 0.479 0.518 0.003 1.16 25.69 982.1 0.07 48.736 1.98622 10().080 0.479 0.518 0.003 0.94 32.55 982.7 0.07 62.617 1.98050 10.090 0.479 0.518 0.003 0.69 70.80 980.8 0.07 110.389 1.57443 10.100 0.479 0.518 0.003 1.38 103.07 980.1 0.07 135.513 1.33259

15.010 0.479 0.518 0,003 0.31 15,62 1253,6 0.10 17.901 ],16H71 15.020 0.479 0.518 0.003 0,23 20.10 1253.7 0.10 23.715 1.19314 15,030 0.479 0,518 0,003 0.31 25,69 1253.9 0.10 31.432 1,23812 15.040 0.477 0.520 0.003 0,23 30.38 1251.0 0.10 38.224 1.26791 15.050 0.477 0.520 0.003 0.20 35.91 1249.6 0.1) 46.906 1.31361 15.060 0.477 0.520 0.003 0.31 44.70 1248.6 ( 10 60.039 1.35234 15.070 0,478 00519 0,003 0,25 58.62 1251.9 0,10 80.495 1.37893 15.080 0,478 0.519 0.003 -0,44 108.37 1249.6 0,10 133.888 1.23051 3.010 0.479 0.518 0,003 -230.03 -204.41 1490,6 0.05 16.624 0).64877 3.020 0.479 0,518 0.003 -230.01 -176.32 1490.5 0.05 34.522 ().643(00 3.030 0.480 0.517 0.003 -22.9.9 -151,58 1489,3 0.05 50.507 0.64412 3.040 0,480 0.517 0.003 -229.99 -127.44 1490.3 0.05 66.492 0.64839 3,050 0.480 0.517 0.003 -229.94 -99,68 1490,4 0,05 85,413 ().65570 8.010 0,479 0.518 0,003 -100.17 -69.83 14995 0.()6 21.834 0.71972 8,020 0.479 0.518 0,003 -100.13 -30.16 1499.6 0.06 53.577 0.76564 8.030 0,479 0,518 0,003 -100.13 0.53 1501.3 0,06 80,001 0,79470 16,010 0.475 0.522 0.003 0,32 30.04 1499,8 0.10 31.314 1,05369 16.020 0475 0.522 0.003 0.36 45.82 1502.0 0,10 49.846 1.09664 16,030 0,475 0.522 0.003 0.29 49,53 1503.1 0,10) 54,226 1 10130 16.040 0,475 0.522 0.003 0.14 53.57 1501.0 0.10 59.847 1.12010 16.050 0.475 0.522 0,003 0.16 57,76 1499.7 0.10 65,432 1,13588 16.060 0.475 0.522 0.003 0.21 80.47 1499.1 0.10 93.322 1.16263 16,070 0,475 0.522 0003 0,25 102.86 1500,0 0.10 117.013 1.14035 14.010 0,477 0,520 0.003 99.95 133.98 1499,0 0.15 31,293 0,91957 14.020 0,477 0.520 0.003 99.72 161.32 1499.8 0.15 53.159 0.86290 14,0300 (0,477 0.520 0,003 99.41 194.38 1499.3 0.15 77.120 0.81204 14.035 0.477 0.520 0.003 99.41 194.38 1499.3 0.15 75.099 0.79076 14,036 0.477 0.520 0.003 99.41 194,38 1499.3 0.15 76.726 0.80790 14,040 0.478 0.519 0.003 99.81 220.49 1502.1 0.15 96.753 0.80172 14.0500 0,478 0,519 0.003 100,20 251.34 1499.9 0.15 117.742 0.77904 11.010 0.482 0.514 0.003 249.88 271.97 1500.2 0.10 15,013 0,67971 11.020 0.482 0.514 0.003 249.90 291 23 1500.8 0.10 28.198 0.68227 11.030 0482 0.514 0.003 249.96 302,80 1500,9 0.10 36.337 0.68772 17.010 0.480 0.517 0.003 0.40 28.69 1999.4 0.13 25.032 0.88469 170020 0,480 0.517 0.003 0.25 51.97 1999.8 0,13 46.758 0.90408 17,030 0.480 0.517 0.003 0.28 75.92 199.4 0.13 71.930 0.95090 17,040 0.477 0.520 0,003 0.32 81,41 2002,8 0,13 76,394 0.94198 17.045 0.477 0.520 0.003 0.32 81.41 2002.8 0.13 75.991 0.93701 17.046 0.477 0,520 0,003 0,32 81.41 2002.8 0.13 76.696 0.94570 17,050 0,477 0.520 0.003 0.28 87.18 2001.4 0.13 83.036 0.95562

TA LF A3(b) ISOTHERMAL )ATA FOR NOMINAL 0.477 CH4, O 523 C2H6 RUN NO. COMP)S I TION INLET OUTLETL ET INLT P ES. HEA T ISOTHERMAL XC1 XC? XC,3 TEMP. TEMP. PRES.O DR P INPUT J.T.COEFF. (MOLE FRACTIN) ( F) (F) (PSIA) (PSI)) (BTUJ/LK) (RTU/LR PS IA) 18.010 0.479 0.518 0.OO)3 1.71 1.65 2020.7 149.34 0.623 -0.00417 18.020 0.479 0.518 0.003 1.64 1.56 1803.8 152o24 0.940 -0.00618 18.030 0.479 0.518 0.003 1.53 1.47 1602.7 154.55 1.561 -0.0101.0 18.035 0.479 0.518 0.003 1.53 1.47 1602.7 154.55 1.399 -0.00905 18.040 0.479 0.518 0.nr3 1.77 1.65 1397.0 157.35 2.191 -0.01392 18.050 0.479 0.518 0.003 1.95 1.90 1202.1 163.50 4.060 -0.02483 18.n55 0.479 0.518 n0.00n 1.95 1.90 1202.1 163.50 4.050 -0.02477 18.056 0.479 0.518 0.003 1.95 1.90 1202.1 163.50 4.068 -0.n2488 18.060 0.479 0.518 0.00N3 1.66 1.86 977.3 134.63 15.876 -0.11792 18.070 0.479 0.518 0.003 2.00 2.04 978.3 270.76 38,601 -0.14257 18.080 0.479 0.518 0.03B 1.37 1.34 691.5 293.53 71.912 -0.24499 18.090 0.479 0.518 0.003 0.69 0.55 447.9 341.39 27.609 -0.08087 13.010 0.480 0.517 0.003 101.43 101,31 1959.0 223.91 8.719 -0.03894 13.020 0.480 0.517 0.003 101.45 101.41 1604.8 258.55 15.119 -0.05848 13.030 0.480 0.517 0.003 101.32 101.33 1224.2 301.46 19.197 -0.06368 13.040 0.480 0.517 o.00B 101.62 101.63 989.1 358.64 20.807 -0.05802 13.050 0.480 0.517 0.003 101.52 101.50 793.6 344,16 18.330 -0.05326 13.060 0.480 0.517 0.003 101.59 101.67 598.1 281.95 13.995 -0.04964 13.070 0.480 0.517 0.003 101.64 101.55 397.2 294.81 13.333 -0.04522 12.010 0.479 0.518 0.003 252.57 252.55 1996.8 189.09 4.5.92 -0.02428 12.020 0.479 0.518 O.n003 252.23 252.23 1679.5 234.31 6.500 -0.02774 12.030 0.479 0.518 0.003 252.22 252.23 1511.7 282.75 7.721 -0.02731 12.035 0.479 0.518 0.003 252.22 252.23 1511.7 281.08 7.721 -0.02747 12.040 0.478 0.519 0.0(03 252.38 252.47 1133.9 377.75 10.521 -0.02785 12.050 0.478 0.519 0.003 252.36 252.27 829.7 300.20 8.287 -0.02761 12.055 0.478 0.519 0.003 252.36 252.27 829.7 300.20 8.327 -0.02774 12.056 0.478 0.519 0.003 252.36 252.27 827.7 300.20 8.248 -0.02747 12.060 0.478 0.519 0.003 252.67 252.77 535.9 296.55 8.131 -0.02742 12.070 0.478 0.519 0.003 252.78 252.76 335.4 242 22 3.200 -0.01321

TABLE A3(c) ISENTHALPIC DATA FOR NOMINAL 0.477 CH4, 0.523 C2H6 RtJN NO. COMPOSITION INLET (OJT_ ET INLFT PRES. HFAT tJ.THOMS(ON XC1 XC2 XC3 TEMP. TEMP. PRES. k )ROP INPUT C FFF. (MOLE FRACTION) ( F)( F) (PSIA) (PSI )) (BTIJ/L ) ( F/PSIA) 1.010 0.481 0.516 0.003 -228.45 -228.40 1961.0 191.09 0.000 -0.00024 1.020 0.481 0.516 0.003 -228.41 -228.32 1648.6 204.90 0.000 -0.00044 1.030 0.481 0.516 0.003 -228.46 — 228.40 1331.1 197.28 0.000 -0.()()(3] 1,040 0.481 0o516 0.003 -228.47 -227.91 1005.h 212.41 0.000 -0.00266 1.060 0.468 0.529 0.003 -228.42 -228.18 588.5 204.37 0.000 -(). 001 1 1.050 0.468 0.529 0.003 -228.45 -228.18 795.0 205.15 0.000 -0.00135 1.040 0.481 0.516 0.003 -228.47 -227.91 1005.6 212.41 0.000 -0.00266 2.010 0.479 0.518 0.003 -99.14 -98.69 1980.7 208.76 0.000 -0.00211 2.020 0,477 0.520 0.003 -99.09 -98.17 1668.5 140.48 0.000 -0.00658 2.030 0.476 0.521 0.003 -99.12 -98.50 1354.5 353.17 0.000 -0.00176 9.010 0.479 0.518 0.003 -99.04 -98.63 1272.5 231.76 0.000 -0.00177 9.020 0.479 0.518 0.003 -99.09 -98.93 883.0 184.57 0.000 -0.00086 9.030 0.486 0.511 0.003 -99.01 -98,92 602.6 218.44 0.000 — 0.00041 9.045 0.486 0.511 0.003 -99.00 -98.91 395.5 272.23 83.494 -0.30671 359 LINES PR INTED

NOTATION C Isobaric heat capacity (3H/DT)p (Btu/lb~F) C (A) Smoothed C after thermodynamic consistency checks. P P C (S) Smoothed C before thermodynamic consistency checks. P P H Specific enthalpy (Btu/lb). H. Specific enthalpy of ith component (Btu/lb) HM Specific enthalpy of mixture (Btu/lb) H Excess enthalpy (Btu/lb) P Pressure (psia) T Temperature (OF) x. Mole fraction of component i in the liquid phase yi Mole fraction of component i in the vapor phase Greek Notation AH. Change in the specific enthalpy between two states (Btu/lb) AH Change in specific enthalpy between two temperatures at constant _P pressure (Btu/lb) AHT Change in specific enthalpy between two pressures at constant temperature (Btu/lb) AH Specific enthalpy of vaporization (Btu/lb) -yap Joule-Thomson coefficient. (~F/psia) Isothermal throttling coefficient (Btu/lb-psia) f(A) Smoothed 4 after thermodynamic consistency checks ~(S) Smoothed 4 before thermodynamic consistency checks. Subscripts i Component in a mixture or a running variable M Mixture ~ Liquid p Property at pressure P psia T Property at temperature T~F

Subscripts cont. 1,2 Reference states or component number in a mixture o Ideal gas property at absolute zero Superscripts E Excess property 0 Designates ideal gas property Mean property REFERENCES 1. Bhirud, V.L. and J.E. Powers, "Thermodynamic Properties of a 5 mole Percent Propane in Methane Mixture", Report to NGPA, Tulsa, Oklahoma (August 1969). 2. Bhirud, V.L. and J.E. Powers, "Thermodynamic Properties of Propane" Report to NGPA, Tulsa, Oklahoma (In Progress). 3. Cutler, A.J., and J.A. Morrison, Trans. Farad. Soc. 61, 429 (1965). 4. Frank, A., and K. Clusius, Z. Physik. Chem., B36, 291 (1937). 5. Furtado, A.W. In preparation. 6. Furtado, A.W., D.L. Katz and J.E. Powers, Presented at the Symposium on the Enthalpy of Mixtures, Annual Meeting of the ACS, Houston, Texas, February 1970. 7. Jones, M.L. Jr., Ph.D. Thesis, University of Michigan (1961). 8. Jones, M.L, Jr., D.T. Mage, R.C. Faulkner, Jr. and D.L. Katz, Chem. Eng. Prog. Symp. Ser. 59 (44), 52 (1963). 9. Mather, A.E., Ph.D. Thesis, University of Michigan (1967). 10. Rossini, F.D., et al., Selected Values of Physical and Thermodynamic 11. Witt, R.K. and J.D. Kemp, J. Am. Chem. Soc. 59, 273 (1937). 12. Yesavage, V.F., Ph.D. Thesis, University of Michigan (1968). 13. Yesavage, V.F., D.L. Katz and J.E. Powers, AIChE J. 16, 867 (1970).

2000~ r ---- j 1500 -------- — (8 —— @@ —J -i o \ — (5 — 47.7 % CI CL. ~ - I I 52.3 % C2 L ~ \ Univ. of Mich. -- O0(/Fg,_(.__r 4/70 (Ia O -250 -200 -150 -100 -50 0 50 I00 150 200 250 300 TEMPERATURE, OF Figure 1. Pressures and Temperatures of Measurements for a 52.3 Mole Percent Ethane in Methane Mixture.

2000 F -~ - — t- - - - 1500- 77.~ b —-- @ -— 77% CI 22.3% C2 Univ. of Mich. o0 - NSF C - 2/70 _ 0a. 3 ilD 1000 -O- dog — ^- ^ ^ —-@ ---- — ^ —-(5 - - bJ OL:1 / 1 j - a. 500 - - -- -4 -250 -200 -150 -100 -50 0 50 100 150 200 250 300 TEMPERATURE OF Figure 2. Pressures and Temperatures of Measurements for a 22.3 Mole Percent Ethane in Methane Mixture.

ISOBARIC MEAN HEAT CRPRCITY CH4-C2H6 (.777 CH4) 1500PSI,UI,~o'iL|~~~~ — _ Cp (Smooth) CS=P~~~~~~~~~~~f~... ---— Cp (Adjusted) & -.0743 ----— \-........... -.::....2..579 1. 56* _- ---------- -s —---- 3o -.20 1 -— I —------ --- ---- ---- -- - --- -- --: -.074 3 0. 17 3 - ------ ------ -------- - - --- ------- _ - | 3->....-'''0....-' —;. -....- ~o:::.;::.; ~;::~^........................... 10/0'-70. -^5. A40. -25. -10. 5. 20. 35. 50.. 80. 95. TEMPERATURE ( F) Figure 3. Isobaric Heat Capacity Curve for 22.3 Percent Ethane Mixture at 1500 psia.

2)0 -52.3% Ethane in Methane 250 psia 0- Run 4 u. -20 / 0 u -40a: D.^^ Dew Point 5 -60,- / -35.7~F Li. a. -80 - -100-120 Bubble Point -140t1 -129.0~F AH 213.8 l vap - -160 1 __ -__' — - - 0 20 40 60 80 100 120 140 160 180200220 40 ENTHALPY DIFFERENCE BTU/LB Figure 4. Isobaric Enthalpy Traverse Through Two Phase Region at 250 psia for 52.3 Percent Ethane Mixture.

ISOTHERMAL JOULE-THOMSON COEFFICIENT CH4-C2H6(.4I77CHI4) 101.5 — 4 ~ (Smooth)..-..4 (Adjusted) 8 10/0 C, CD -0.00873 0 -0.12320 00/ r40 S, 0.0436 \o ~ 0.037 10' ISO. \\750. 900. 1050. 1 156.9.

95.35 2000......2000t —- ---- _- — ____ ___(95.35) ot0 -oIn on oL cJ -0.23 o< D - olo H=43.5Btu/lb _ _ -0.098% 1~d,00r -0.098% e T' ~d / r1 I 5.457 / 80.49 81.0 114.4 1 18.7 (5.4) (79.654) 80.136 (113.1) (117.5) Cl c (D.D +0.285 0- C\ rucu CC,~- cR. 6do r.. +0.11% L0/0U -< 1250'-_ro ro +0.773 126.327 1250167 T, — nC: 00 +0.417% 124.66 o00 o oo +1 231 o00 o Oaj N 0 - e) Cr 0G6 G6 +0.429%.,i 7o i:' " " 92.30 "' 134.70 oo 9784 —-- c,, 97... (92.209) 1 33.40 IAH +0.08 b ^ a_ Cod ~) () rZA!da d o -i <. | o0 16H x100=+0025% X ~00 ~~~750F_ ^ aoloo^ 119.972 750 -- -. —---—. I o^ 000o 1 19.972 - ro ". -~10 r' " 0 d0 00 185.72 - (185.72) 15 0 I l _ _ 181.16 ~~~~~25030;1:(181.16) __ i1____05___ ____0__ _______ 0l... 1 50.05 i 44.40. 76.50 (50.05) (44.40) (76.50) -250.0 -228.45 -220.0 -99.05 1.75 101.5 252.5 300 TEMPERATURE OF Figure 6. Summary of Consistency Checks. 52.3 Percent Ethane Mixture.

~20001 - ________- ___ _ _ 141.02 133.70 2000 t-~ T (140.34) (133.90) tol~r If)0 ro 0c) C\O or 00 + 0.123 -- r CMO~J j l 0r- 1-71c\icj o ~ r00 +0.385% o' o 2AHi =-I. 17 155.27 C\ 00. I 500 ---- 1 (155.07) xl00o-0,381% T ~~ ooco 0S 0,Q ^ r r —o o ^ +0.12 o0) < C MN H=328Btu/lb o:tb 0d 0.034% 00 000 9.666 67.81 93.99 166.10 I 113.00 40 |1(9.61 (67.44) (93.54) (165.17) (112.27). to inL 0o dI d I I0 +0.66 (177.80) "' I c* *N.l l | l II I 1 ~) o) d d 0 100.06 186.09 ___ 72.54 250, 1 (100.06) (186.09) (72.54) (D - _____/. __ 40.70 1 64.70 1 93.70 (40.70) (64.70) (93.70) -260 -253.2 -240.0 -150.55 -58.45 79.0 255.0 300.0 TEMPERATURE OF Figure 7. Summary of Consistency Checks. 22.3 Percent Ethane Mixture.

I

I