SECTION 23
Physical Properties This section contains a number of charts, correlations, and calculation calculatio n procedures to be used for predicting physical properties of hydrocarbons and components found with them. Fig. 23-1 shows 23-1 shows the nomenclature used in this section.
ponents. Immediately following is a detailed list of references and footnoted explanation for the values in Fig. 23-2. 23-2. Physical properties for eighteen selected compounds can be found in GPA Standard 2145, "Table of Physical Constants of Paraffin Hydrocarbons and Other Components of Natural Gas."
Fig. 23-2 is 23-2 is a table containing frequently used physica l properties for a number of hydrocarbons and other selected com-
FIG. 23-1 Nomenclature B = second second viria viriall coeffi coefficie cient nt for for a gas mixt mixtur ure, e, -1 [kPa (abs)] B′ = mole mole frac fracti tion on H2S in sour gas stream, Eq 23-6 Bii = second second virial virial coefficien coefficientt for componen componentt i Bij = second cross virial virial coefficient coefficient for components components i and j bi1/2 = summat summation ion factor factor for compo component nent i CABP CABP = cubi cubicc aver average age boilin boiling g poin point, t, °C d = dens ensity ity, g/cc G = rela relati tive ve den densi sity ty (ga (gass dens density ity)) Gi = relative density (gas gravity) gravity) of ideal ideal gas, MW/MWa id Gi = molecular molecular mass ratio of component component i in mixture Hv = gross heating heating value value per unit volume volume of ideal gas, gas, MJ/m3 K w = Watson atson characteriz characterization ation factor factor,, Fig. 23-12 k = ther therma mall condu conduct ctiv ivit ity y, W/(m W/(m • °C) ka = thermal conductivity conductivity at one atmosphere atmosphere,, W/(m W/(m • °C) M = mass frac fracttion ion m = mass, kg MW = mole molecu cular lar mass mass,, g mole mole MABP MABP = molal molal averag average e boi boilin ling g poin point, t, °C or K MeAB MeABP P = Mean Mean aver average age boi boilin ling g point point,, °C or or K n = numb number er of of moles moles (mass (mass/mo /mole le weig weight ht)) P = press ressur ure, e, kPa kPa (ab (abs) s) Pc′ = pseudo pseudocrit critical ical pressur pressure e adjusted adjusted for acid gas composition, kPa (abs) Pvp = vapor pressure at a reduced temperature temperature of 0.7 o Pw = vapor pressure of water, water, 7.3811 7.3811 kPa (abs) at 40°C R = gas gas cons consta tant nt,, 8.314 8.3145 5 [kPa [kPa (ab (abs) s) • m3]/(K • kg mole) for all gases (see Section 1 for R in other units) S = rela relati tive ve den densi sity ty at 15° 15°/1 /15° 5°C C T = abso absolu lute te temp temper erat atur ure, e, K t = ASTM ASTM D-86 D-86 distilla distillation tion tempera temperature ture,, °C or K, K, Eq 23-11 Tc′ = pseudocritical pseudocritical temperature temperature adjusted adjusted for acid acid gas composition, K V = volume, m 3 VABP VABP = volumetric volumetric average average boiling point, °C
23-1
W = mass, kg WABP ABP = weigh weightt avera average ge boil boiling ing point point,, °C yi = mole fraction of of component component i from analysis analysis on dry basis, Eq 23-37 x = mole mole frac fracti tion on in in liqu liquid id pha phase se w yi = mole mole fraction fraction of componen componentt i adjuste adjusted d for water content y = mole mole frac fracti tion on in gas gas phas phase e Z = comp compre ress ssib ibil ility ity fact factor or Greek ε = pseudocritical pseudocritical temperature temperature adjustment adjustment factor, factor, Eq 23-6 θ = MeABP/T P/T pc ρ = dens density ity,, kg/ kg/m m3 µ = viscosity viscosity at operating operating temperatur temperature e and pressure, pressure, centipoise µ A = viscosit viscosity y at 101.325 101.325 kPa (abs) (1 atm) atm) and operating operating temperature, centipoise ξ = factor factor defined defined by Eq Eq 23-20 23-20 σ = surfac surface e tensio tension, n, dynes/cm dynes/cm acentri tricc facto factorr ω = acen η = kinemati kinematicc viscosit viscosity y, centistokes centistokes Subscripts a = air b = boiling c = critical i = component i L = liquid m = mixture pc = pseud eudocr ocritic itica al r = reduced sta statte V = vapor v = volume w = water Superscripts id = ideal gas w = water o = refer referen ence ce state state
FIG. 23-2 Physical Constants NOTE: Numbers in this table do not have accuracies greater than 1 part in 1000; in some cases extra digits have been added to calculated values to achieve internal consistency or to permit recalculation of experimental values.
PHYSICAL CONSTANTS
A.
See Note No.
B.
C.
*See the Table of Notes and References
D. Critical constants
r e b m u N
Compound
a l u m r o F
) t h g i e s w s r a a l u m r c e a l l o o M M (
) s C b å a , ( t a n P i k o P 0 5 g 2 n i 3 . l i 1 o 0 B 1
1 2 3 4 5
Methane Ethane Propane lsobutane n-Butane
C H4 C2 H 6 C3 H 8 C4 H 10 C4 H 10
16.043 30.070 44.097 58.123 58.123
-161.51 -88.59 -42.07 -11.79 -0.51
6 7 8
Isopentane n-Pentane Neopentane
C5 H 12 C5 H 12 C5 H 12
72.150 72.150 72.150
27.83 36.05 9.50
9 10 11 12 13
n-Hexane 2-Methylpentane 3-Methylpentane Neohexane 2,3-Dimethylbutane
C6 C6 C6 C6 C6
H 14 H 14 H 14 H 14 H 14
86.177 86.177 86.177 86.177 86.177
68.72 60.24 63.26 49.72 57.96
14 15 16 17 18 19 20 21
n-Heptane 2-Methylhexane 3-Methylhexane 3-Ethylpentane 2,2-Dimethylpentane 2,4-Dimethylpentane 3,3-Dimethylpentane Triptane
C 7 H16 C 7 H16 C 7 H16 C 7 H16 C 7 H16 C 7 H16 C 7 H16 C 7 H16
100.204 100.204 100.204 100.204 100.204 100.204 100.204 100.204
98.37 90.03 91.85 93.47 79.17 80.47 86.04 80.86
22 23 24 25 26 27 28 29 30
n-Octane Diisobutyl Isooctane n-Nonane n-Decane Cyclopentane Methylcyclopentane Cyclohexane Methylcyclohexane
C8 H 18 C8 H 18 C8 H 18 C9 H 20 C10 H 22 C5 H 10 C6 H 12 C6 H 12 C7 H 14
114.231 114.231 114.231 128.258 142.285 70.134 84.161 84.161 98.188
125.65 109.08 99.21 150.78 174.11 49.22 71.83 80.78 100.94
31 32 33 34 35 36 37 38 39 40
Ethene(Ethylene) Propene(Propylene) 1-Butene(Butylene) cis-2-Butene trans-2-Butene Isobutene 1-Pentene 1,2-Butadiene 1,3-Butadiene Isoprene
C2 C3 C4 C4 C4 C4 C5 C4 C4 C5
H4 H6 H8 H8 H8 H8 H 10 H6 H6 H8
28.054 42.081 56.108 56.108 56.108 56.108 70.134 54.092 54.092 68.119
41 42 43 44 45 46 47 48 49
Acetylene Benzene Toluene Ethylbenzene o-Xylene m-Xylene p-Xlyene Styrene Isopropylbenzene
C2 C6 C7 C8 C8 C8 C8 C8 C9
H2 H6 H8 H10 H10 H10 H10 H8 H12
26.038 78.114 92.141 106.167 106.167 106.167 106.167 104.152 120.194
50 51 52 53 54 55
Methyl alcohol Ethyl alcohol Carbon monoxide Carbon dioxide Hydrogen sulfide Sulfur dioxide
CH4 O C2 H6 O CO CO2 H2 S SO2
32.042 46.069 28.010 44.010 34.082 64.065
56 57 58 59 60 61 62 63 64
Ammonia Air Hydrogen Oxygen Nitrogen Chlorine Water Helium Hydrogen chloride
NH3 N 2 + O2 H2 O2 N2 Cl2 H2O He HCl
17.0305 28.9625 2.0159 31.9986 28.0134 70.9054 18.0153 4.0026 36.461
) s C ˚ b , a t ( n a i o P k p 0 g 5 n i 2 z 3 e . 1 e r 0 F 1
, e r C ˚ u s 0 s 4 , e r ) s p r b a o ( p a a P V k
, x e d n i e v i t c C ˚ a r 5 f 1 e D R n
, e ) r s u b s ( a s a e r P P k
K , e r u t a r e p m e T
g k / m , e m u l o V
3
r e b m u N
(35000)* (6000)* 1369.8 530.89 379.61
-182.45* -182.79* -187.62" -159.59 -138.35
1.00040* 1.21403* 1.29558* 1.3251* 1.33631*
4599. 4880. 4240. 3640. 3784.
190.56 305.41 369.77 407.82 425.10
0.00617 0.00489 0.00454 0.00446 0.00439
1 2 3 4 5
151.31 114.70 270.0
-159.89 -129.71 -16.58
1.35658 1.36024 1.345*
3381. 3365. 3199.
460.35 469.65 433.71
0.00427 0.00434 0.00420
6 7 8
-95.31 -153.67 -162.89 -99.825 -128.53
1.37746 1.37417 1.37918 1.37157 1.37759
3030. 3010. 3120. 3080. 3130.
506.4 497.46 504.4 488.66 499.86
0.00429 0.00426 0.00426 0.00417 0.00415
9 10 11 12 13
12.342 17.226 16.155 15.265 26.32 24.85 20.94 25.41
-90.55 -118.26 — -118.58 -123.78 -119.21 -134.44 -24.56
1.39017 1.38743 1.39119 1.39594 1.38475 1.38408 1.39342 1.39196
2740. 2730. 2810. 2890. 2770. 2740. 2950. 2950.
539.2 530.06 535.16 540.46 520.36 519.66 536.26 531.06
0.00426 0.00420 0.00403 0.00415 0.00415 0.00417 0.00413 0.00397
14 15 16 17 18 19 20 21
4.146 8.417 12.966 1.358 0.4814 73.99 33.75 24.64 12.211
-56.76 -91.160 -107.35 -53.48 -29.63 -93.827 -142.43 6.550 -126.59
1.39981 1.39488 1.39392 1.40773 1.41411 1.40927 1.41240 1.42892 1.42566
2490. 2490. 2570. 2280. 2100. 4508. 3784. 4073. 3471.
568.4 549.96 543.86 594.7 617.7 511.6 532.75 553.5 572.15
0.00420 0.00422 0.00410 0.00433 0.00439 0.00371 0.00379 0.00366 0.00375
22 23 24 25 26 27 28 29 30
-169.15* -185.25* -185.35* -138.90 -105.54 -140.34 -165.21 -136.19 -108.89 -145.95
(1.241)* 1.313* 1.351* 1.368* 1.359* 1.358* 1.3746 — — 1.4253
5040. 4665. 4043. 4243. 3964. 4000. 3513. (4502) 4277. (3856)
282.34 365.55 419.92 435.54 428.59 417.86 464.74 (444)* 425. (484)
0.00466 0.00448 0.00426 0.00417 0.00424 0.00425 0.00421 (0.0043)* 0.00407 (0.0041)*
31 32 33 34 35 36 37 38 39 40
— 24.38 7.895 2.873 2.051 2.528 2.648 2.00 1.47
-80.8" 5.532 -94.98 -94.963 -25.18 -47.86 13.26 30.63 -96.021
— 1.5043 1.49960 1.49856 1.50795 1.49980 1.49839 1.5496 1.49400
6139. 48 98. 4106. 3606. 37 34. 35 36. 35 11. 4050. 3209.
308.31 5 62 .12 591.76 617.16 6 30 .29 6 17 .01 6 16 .19 (646)* 631.1
0.00432 0 .0 033 2 0.00343 0.00352 0 .0 03 48 0 .0 03 54 0 .0 03 57 0.00333 0.00355
41 42 43 44 45 46 47 48 49
64.67 78.26 -191.45 -78.464* -60.266 -9.94
35.44 17.903 — — 2859.7 630.2
-97.65 -114.1 -204.99* -56.56* -85.48* -75.47*
1.33028 1.36345 1.00036* 1.00049* 1.00061* 1.00062*
8097. 6148. 3494. 7374. 8963. 7884.
512.60 513.88 132.86 304.11 373.37 430.8
0.00368 0.00362 0.00329 0.00214 0.00288 0.00190
50 51 52 53 54 55
-33.32 -194.34 -252.850* -182.954* -195.798 -33.95 99.974* -268.95 -85.14
1555. — — — — 1146. 7.3849 — 6547.
-77.69* — -259.347* -218.792* -209.997* -100.95 0.000 — -114.17*
1.00036* 1.00028* 1.00013* 1.00027* 1.00028* 1.3878* 1.33347 1.00003* 1.00042
11350. 3771. 1293. 5043. 3398. 7977. 22064. 227.5 8310.
405.5 132.43 33.0 154.59 126.21 416.86 647.10 5.20 324.68
0.00425 0.00323 0.03185* 0.00229 0.00318 0.00175 0.003102 0.01436 0.00222
56 57 58 59 60 61 62 63 64
-103.73 -47.68 -6.23 3.72 0.88 -6.91 29.95 10.84 -4.41 34.05 -84.01* 80.07 110.60 136.17 144.39 139.09 138.32 145.23 152.38
37.297 50.68 45.73 73.41 55.34
(9700) 1691. 459.0 338.3 366.5 477.4 141.65 269. 436.1 123.8
5/99
23-2
Revised (5-99)
FIG. 23-2 (Cont’d) Physical Constants
23-3
FIG. 23-2 (Cont’d) Physical Constants
23-4
FIG. 23-2 (Cont’d) Notes and References for the Table of Physical Constants
23-5
FIG. 23-2 (Cont’d) Notes and References for the Table of Physical Constants
23-6
FIG. 23-2 (Cont’d) Notes and References for the Table of Physical Constants
23-7
FIG. 23-2 (Cont’d) Notes for the Table of Physical Constants a.
Values in parentheses are estimated values.
p.
An extrapolated value.
b.
The temperature is above the critical point.
q.
Gas at 15°C and the liquid at the normal boiling point.
c.
At saturation pressure (triple point).
r.
d.
Sublimation point.
Fixed points on the 1968 International Practical Temperature Scale (IPTS-68).
e.
The + sign and number following specify the number of cm of TEL added per gallon to achieve the ASTM octane number of 100, which corresponds to that of Isooctane (2,2,4Trimethylpentane).
s.
Fixed points on the 1990 International Temperature Scale (ITS-90).
t.
Densities at the normal boiling point are: Ethane, 554.0 [29]; Propane, 581.0 [28]; Propene, 609.1 [5]; Hydrogen Chloride, 1192 [43]; Hydrogen Sulfide, 949.0 [25]; Am monia, 681.6 [43]; Sulfur Dioxide, 1462 [43].
u.
Technically, water has a heating value in two cases: net ((2.466 MJ/kg) when water is liquid in the reactants, and gross (+1.879 MJ/m3) when water is gas in the reactants. The value is the ideal heat of vaporization (enthalpy of the ideal gas less the enthalpy of the saturated liquid at the vapor pressure). This is a matter of definition; water does not burn.
3
f.
These compounds form a glass.
g.
Average value from octane numbers of more than one sample.
h.
Saturation pressure and 15°C.
i.
Index of refraction of the gas.
j.
Densities of the liquid at the normal boiling point.
k.
Heat of sublimation.
m.
Equation 2 of the reference was refitted to give: a = 0.7872957; b = 0.1294083; c = 0.0 3439519.
n.
Normal hydrogen (25% para, 75% ortho).
v.
Extreme values of those reported by reference 19.
A.
Molar mass (molecular mass) is based upon the following atomic weights: C = 12.011; H = 1.00794; O = 15.9994; N = 14.0067; S = 32.066; Cl = 35.4527. The values were rounded off after calculating the molar mass using all significant figures in the atomic weights.
J.
The liquid value is not rigorously CP, but rather it is the heat capacity along the saturation line C S defined by: CS = C P – T (∂ V/ ∂T)P(∂P/ ∂T)S. For liquids far from the critical point, CS ≈ CP.
B.
Boiling point: the temperature at equilibrium between the liquid and vapor phases at 101.3250 kPa.
K.
C.
Freezing point: the temperature at equilibrium between the crystalline phase and the air saturated liquid at 101.3250 kPa.
D.
The refractive index reported refers to the liquid or gas and is measured for light of wavelength corresponding to the sodium D-line (589.26 nm).
E.
The relative density: ρ(liquid, 15°C)/ ρ (water, 15°C). The density of water at 15°C is 999.10 kg/m 3.
F.
The temperature coefficient of density is related to the expansion coefficient by: ( ∂ρ / ∂T)P / ρ = –(∂ρ V/ ∂T)P /V, in units of 1/T.
G.
Pitzer acentric factor: ω = –log 10(P/Pc) –1, P at T = 0.7 Tc
H.
Compressibility factor of the real gas, Z = PV/RT, is calculated using the second virial c oefficient.
The heating value is the negative of the enthalpy of combustion at 15°C and 101.3250 kPa (abs.) in an ideal reaction (one where all gasses are ideal gasses). For an arbitrary organic compound, the combustion reaction is: CnHmOhS jNk (s,l,or,g) + (n + m/4 – h/2 + j) O2(g) → n CO2(g) + m/2 H 2O (g or l) + k/2 N 2(g) + j SO2(g), where s, l and g denote respectively solid, liquid and ideal gas. For gross heating values, the water formed is liquid; for net heating values, the water formed is ideal gas. Values reported are on a dry basis. To account for water in the heating value, see GPA 2172. The MJ/kg liquid column assumes a reaction 3 with the fuel in the liquid state, while the MJ/m ideal gas column assumes the gas in the ideal gas state. Therefore, the values are not consistent if used in the same calculation, e.g. a gas plant balance.
I.
The density of an ideal gas relative to air is calculated by dividing the molar mass of the of the gas by 28.9625, the calculated average molar mass of air. See ref. 34 for the average composition of dry air. The specific volume of an ideal gas is calculated from the ideal gas equation. The volume ratio is: V(ideal gas)/V(liquid in vacuum).
L.
The heat of vaporization is the enthalpy of the saturated vapor at the boiling point at 101.3250 k Pa minus the enthalpy of the saturated liquid at the same conditions.
M. Air required for the combustion of ideal gas for compounds of formula CnHmOhS jNk is: V(air)/V(gas) = (n + m/4 - h/2 + j)/0.20946.
COMMENTS Units: reported values are in SI units based on the following: mass: kilogram, kg length: meter, m temperature: International Temperature of 1990 (ITS-90), where 0°C = 273.15 K. Other derived units are: volume: cubic meter, m3 pressure: Pascal, Pa (1 Pa = N/m2) energy: Joule, J Gas constant, R: 8.314510 J/(K • mol) 3 0.008314510 m (kPa/(K •mol)
1.987216 calth /(K • mol) 1.985887 Btu(I.T.)/(R(lb •mol) Conversion factors: 3 3 1 m = 35.31467 ft = 264.1721 gal.(U.S.) 1 kg = 2.204623 lbm 3 3 3 1 kg/m = 0.06242795 lbm/ft =0.001 g/cm 1 kPa = 0.01 bar = 0.009869233 atm = 0.1450377 psia 1 atm = 101.3250 kPa = 14.69595 psia = 760 Torr 1 kJ = 0.2390057 kcal th = 0.2388459 kcal (I.T.) = 0.9478172 Btu (I.T.)
23-8
Revised (5-99)
