ASTM D4651-14(2020)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4651 −14 (Reapproved 2020)
Standard Specification for
Isobutane Thermophysical Property Tables
This standard is issued under the fixed designation D4651; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope base (REFPROP): Version 9.1.” A wide selection of units (SI
units, engineering units, chemical units) and additional prop-
1.1 The thermophysical property tables for isobutane are for
erties are available with this program.
use in the calculation of the pressure-volume-temperature
(PVT), thermodynamic, and transport properties of isobutane
3.2 These thermophysical property tables are:
for process design and operations. Two tables provide proper- 3.2.1 Thermophysical Properties of Isobutane Liquid at
ties at the conditions of liquid-vapor equilibrium (saturation
Vapor-Liquid Equilibrium, in SI units. See Table 1.
properties), one for liquid and one for vapor, at temperatures 3.2.2 Thermophysical Properties of Isobutane Vapor at
between 120 K and the critical point, 407.81 K. A third table
Vapor-Liquid Equilibrium, in SI units. See Table 2.
provides properties at selected T, p points for the equilibrium 3.2.3 Thermophysical Properties of Isobutane Along
phase at temperatures between 120 K and 570 K at pressures to
Isobars, in SI units. See Table 3.
20MPa.ThetablesweredevelopedusingtheNationalInstitute
3.3 The symbols are:
of Standards and Technology Standard Reference Database
T, temperature (K)
product REFPROP, version 9.1. -1
ρ, molar density (mol·L )
-1
1.2 The values stated in SI units are to be regarded as
H, molar enthalpy (J·mol )
-1 -1
standard. No other units of measurement are included in this
S, molar entropy (J·K ·mol )
-1 -1
standard.
C , constant volume molar heat capacity (J·K ·mol )
v
-1 -1
C , constant pressure molar heat capacity (J·K ·mol )
1.3 This standard does not purport to address all of the p
-1
c, speed of sound (m·s )
safety concerns, if any, associated with its use. It is the
η, viscosity (µPa·s)
responsibility of the user of this standard to establish appro-
-1 -1
λ, thermal conductivity (mW·m ·K )
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
3.4 The tabulated thermophysical properties are:
-1
1.4 This international standard was developed in accor-
ρ, molar density (mol·L )
dance with internationally recognized principles on standard- -1
H, molar enthalpy (J·mol )
ization established in the Decision on Principles for the -1 -1
S, molar entropy (J·K ·mol )
Development of International Standards, Guides and Recom- -1 -1
C , constant volume molar heat capacity (J·K ·mol )
v
mendations issued by the World Trade Organization Technical -1 -1
C , constant pressure molar heat capacity (J·K ·mol )
p
Barriers to Trade (TBT) Committee.
-1
c, speed of sound (m·s )
η, viscosity (µPa·s)
2. Applicability
-1 -1
λ, thermal conductivity (mW·m ·K )
2.1 These tables apply directly only to pure isobutane. They
may also be used in mathematical models and tables for the
4. Additional Information
thermophysical properties of mixtures containing isobutane.
4.1 Reference state properties are required to calculate the
3. Tables
thermodynamic properties enthalpy and entropy from an equa-
tion of state formulation. The reference state properties used
3.1 These tables were produced by equations from a com-
are those specified by the International Institute of Refrigera-
puter package, “NIST Standard Reference Database 23; Ref-
tion (IIR): enthalpy,H = 200 J/g, and entropy,S = 1 J/(g·K), for
erence Fluid Thermodynamic and Transport Properties Data-
the saturated liquid at 273.15K (0 °C).
4.2 The molar mass of isobutane is 58.122 g/mol.
This specification is under the jurisdiction of ASTM Committee D03 on
Gaseous Fuels and is the direct responsibility of Subcommittee D03.08 on
Thermophysical Properties.
Current edition approved April 1, 2020. Published May 2020. Originally
approved in 1987. Last previous edition approved in 2014 as D4651 – 14. DOI: Available from Standard Reference Data, National Institute of Standards and
10.1520/D4651-14R20. Technology (NIST), 100 Bureau Drive, Stop 3460, Gaithersburg, MD 20899.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4651 − 14 (2020)
TABLE 1 Thermophysical Properties of Isobutane Liquid at Vapor-Liquid Equilibrium
TP ρ HS C C c ηλ
v p
-1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
K MPa mol·l J·mol J·mol ·K J·mol ·K J·mol ·K m·s µPa·s mW·m ·K
120 1.0633E-07 12.636 -5912.6 -34.216 69.001 99.308 1945.4 6055.8 156.73
122 1.6734E-07 12.603 -5713.6 -32.571 69.251 99.681 1928.5 5441.0 156.30
124 2.5915E-07 12.571 -5513.9 -30.948 69.501 100.06 1911.9 4910.8 155.85
126 3.9524E-07 12.538 -5313.4 -29.344 69.752 100.43 1895.5 4450.9 155.38
128 5.9407E-07 12.506 -5112.1 -27.759 70.004 100.81 1879.3 4049.9 154.89
130 8.8064E-07 12.473 -4910.1 -26.193 70.255 101.18 1863.4 3698.4 154.39
132 1.2883E-06 12.441 -4707.4 -24.646 70.505 101.56 1847.7 3389.0 153.86
134 1.8611E-06 12.408 -4503.9 -23.116 70.754 101.93 1832.2 3115.4 153.32
136 2.6564E-06 12.376 -4299.7 -21.603 71.003 102.30 1816.9 2872.5 152.76
138 3.7483E-06 12.343 -4094.7 -20.107 71.250 102.68 1801.7 2656.0 152.19
140 5.2314E-06 12.311 -3889.0 -18.627 71.497 103.05 1786.8 2462.5 151.60
142 7.2252E-06 12.278 -3682.5 -17.162 71.743 103.42 1772.0 2288.8 150.99
144 9.8793E-06 12.245 -3475.3 -15.713 71.988 103.79 1757.4 2132.5 150.37
146 1.3379E-05 12.213 -3267.4 -14.279 72.233 104.16 1742.9 1991.3 149.74
148 1.7953E-05 12.180 -3058.7 -12.859 72.477 104.53 1728.6 1863.6 149.09
150 2.3880E-05 12.147 -2849.3 -11.454 72.720 104.89 1714.4 1747.6 148.43
152 3.1496E-05 12.115 -2639.1 -10.062 72.964 105.26 1700.3 1642.0 147.75
154 4.1206E-05 12.082 -2428.2 -8.6838 73.207 105.63 1686.4 1545.6 147.07
156 5.3493E-05 12.049 -2216.6 -7.3185 73.451 106.00 1672.6 1457.5 146.37
158 6.8925E-05 12.016 -2004.2 -5.9659 73.695 106.36 1658.9 1376.7 145.67
160 8.8176E-05 11.984 -1791.1 -4.6257 73.940 106.73 1645.3 1302.4 144.95
162 0.00011203 11.951 -1577.3 -3.2975 74.186 107.10 1631.8 1234.1 144.22
164 0.00014139 11.918 -1362.8 -1.9812 74.432 107.47 1618.3 1171.0 143.48
166 0.00017732 11.885 -1147.5 -0.67634 74.679 107.83 1605.0 1112.6 142.74
168 0.00022101 11.852 -931.41 0.61730 74.928 108.20 1591.8 1058.6 141.98
170 0.00027386 11.819 -714.63 1.9000 75.178 108.57 1578.6 1008.4 141.22
172 0.00033740 11.786 -497.11 3.1721 75.430 108.95 1565.6 961.80 140.45
174 0.00041343 11.752 -278.84 4.4337 75.684 109.32 1552.6 918.37 139.67
176 0.00050391 11.719 -59.816 5.6852 75.939 109.69 1539.6 877.85 138.88
178 0.00061107 11.686 159.96 6.9268 76.197 110.07 1526.8 839.98 138.09
180 0.00073738 11.653 380.48 8.1588 76.456 110.45 1514.0 804.54 137.30
182 0.00088560 11.619 601.77 9.3813 76.718 110.83 1501.3 771.33 136.49
184 0.0010588 11.586 823.82 10.595 76.983 111.21 1488.6 740.15 135.68
186 0.0012602 11.552 1046.6 11.799 77.250 111.60 1476.0 710.84 134.87
188 0.0014935 11.519 1270.2 12.995 77.519 111.98 1463.4 683.26 134.05
190 0.0017628 11.485 1494.6 14.182 77.792 112.37 1450.9 657.25 133.23
192 0.0020724 11.451 1719.8 15.360 78.067 112.77 1438.5 632.72 132.40
194 0.0024270 11.418 1945.7 16.531 78.345 113.16 1426.1 609.54 131.57
196 0.0028316 11.384 2172.5 17.694 78.627 113.56 1413.7 587.61 130.73
198 0.0032918 11.350 2400.0 18.849 78.911 113.96 1401.4 566.84 129.90
200 0.0038135 11.316 2628.4 19.996 79.199 114.37 1389.1 547.15 129.06
202 0.0044031 11.282 2857.6 21.136 79.490 114.78 1376.9 528.46 128.21
204 0.0050671 11.248 3087.6 22.269 79.785 115.19 1364.7 510.71 127.37
206 0.0058130 11.213 3318.5 23.394 80.082 115.61 1352.6 493.83 126.52
208 0.0066482 11.179 3550.1 24.513 80.384 116.03 1340.5 477.76 125.67
210 0.0075808 11.145 3782.7 25.626 80.689 116.46 1328.4 462.45 124.82
212 0.0086196 11.110 4016.1 26.731 80.998 116.88 1316.3 447.85 123.97
214 0.0097734 11.075 4250.4 27.831 81.310 117.32 1304.4 433.92 123.12
216 0.011052 11.041 4485.5 28.924 81.626 117.76 1292.4 420.62 122.27
218 0.012465 11.006 4721.5 30.011 81.946 118.20 1280.5 407.90 121.41
220 0.014023 10.971 4958.5 31.092 82.269 118.65 1268.6 395.73 120.56
222 0.015736 10.936 5196.3 32.168 82.596 119.10 1256.7 384.08 119.71
224 0.017618 10.901 5435.1 33.238 82.927 119.55 1244.9 372.92 118.86
226 0.019678 10.865 5674.8 34.302 83.262 120.02 1233.0 362.23 118.02
228 0.021930 10.830 5915.4 35.361 83.601 120.48 1221.3 351.97 117.17
230 0.024387 10.794 6157.0 36.415 83.944 120.96 1209.5 342.12 116.32
232 0.027061 10.759 6399.5 37.464 84.290 121.43 1197.8 332.66 115.47
234 0.029967 10.723 6643.0 38.508 84.640 121.92 1186.1 323.57 114.63
236 0.033118 10.687 6887.5 39.547 84.995 122.41 1174.4 314.83 113.79
238 0.036530 10.651 7133.0 40.582 85.353 122.90 1162.8 306.42 112.94
240 0.040218 10.615 7379.5 41.612 85.714 123.40 1151.2 298.32 112.10
242 0.044196 10.578 7627.1 42.637 86.080 123.91 1139.6 290.53 111.27
244 0.048482 10.542 7875.6 43.658 86.450 124.42 1128.0 283.01 110.43
246 0.053092 10.505 8125.2 44.675 86.823 124.94 1116.4 275.77 109.60
248 0.058042 10.468 8375.9 45.688 87.200 125.46 1104.9 268.78 108.77
250 0.063350 10.431 8627.7 46.697 87.581 126.00 1093.4 262.04 107.94
252 0.069033 10.394 8880.5 47.703 87.966 126.54 1081.9 255.54 107.12
254 0.075109 10.357 9134.4 48.704 88.354 127.08 1070.4 249.25 106.30
256 0.081597 10.319 9389.5 49.702 88.746 127.63 1059.0 243.18 105.48
258 0.088516 10.281 9645.6 50.696 89.142 128.19 1047.5 237.31 104.67
260 0.095885 10.243 9903.0 51.687 89.541 128.76 1036.1 231.63 103.86
262 0.10372 10.205 10161 52.674 89.944 129.33 1024.7 226.14 103.05
264 0.11205 10.167 10421 53.658 90.351 129.91 1013.3 220.83 102.25
266 0.12089 10.128 10682 54.639 90.761 130.50 1002.0 215.68 101.45
D4651 − 14 (2020)
TABLE 1 Continued
TP ρ HS C C c ηλ
v p
-1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
K MPa mol·l J·mol J·mol ·K J·mol ·K J·mol ·K m·s µPa·s mW·m ·K
268 0.13025 10.090 10944 55.617 91.175 131.10 990.63 210.70 100.66
270 0.14017 10.051 11207 56.592 91.592 131.70 979.29 205.87 99.867
272 0.15066 10.012 11472 57.564 92.012 132.32 967.96 201.19 99.082
274 0.16174 9.9721 11738 58.534 92.436 132.94 956.65 196.65 98.301
276 0.17344 9.9324 12005 59.501 92.864 133.57 945.35 192.25 97.524
278 0.18577 9.8925 12273 60.465 93.294 134.21 934.06 187.98 96.753
280 0.19876 9.8523 12543 61.427 93.728 134.86 922.77 183.83 95.986
282 0.21243 9.8118 12813 62.386 94.165 135.52 911.50 179.81 95.224
284 0.22681 9.7710 13086 63.343 94.606 136.19 900.23 175.89 94.467
286 0.24192 9.7300 13359 64.298 95.050 136.87 888.97 172.09 93.715
288 0.25777 9.6887 13635 65.250 95.496 137.56 877.72 168.40 92.969
290 0.27440 9.6470 13911 66.201 95.946 138.26 866.47 164.80 92.227
292 0.29183 9.6051 14189 67.150 96.400 138.97 855.22 161.31 91.491
294 0.31008 9.5628 14468 68.096 96.856 139.70 843.98 157.91 90.761
296 0.32917 9.5202 14749 69.042 97.315 140.43 832.74 154.59 90.036
298 0.34914 9.4773 15031 69.985 97.778 141.18 821.50 151.37 89.316
300 0.37000 9.4339 15315 70.927 98.243 141.94 810.25 148.22 88.602
302 0.39177 9.3902 15600 71.867 98.711 142.72 799.01 145.16 87.894
304 0.41450 9.3462 15887 72.806 99.183 143.51 787.76 142.17 87.191
306 0.43819 9.3017 16176 73.743 99.657 144.32 776.50 139.26 86.494
308 0.46288 9.2568 16466 74.680 100.13 145.14 765.24 136.41 85.803
310 0.48858 9.2114 16758 75.615 100.62 145.98 753.97 133.64 85.118
312 0.51534 9.1657 17051 76.549 101.10 146.84 742.69 130.92 84.439
314 0.54317 9.1194 17346 77.482 101.59 147.71 731.40 128.27 83.765
316 0.57209 9.0727 17643 78.414 102.07 148.61 720.10 125.68 83.098
318 0.60215 9.0255 17942 79.346 102.57 149.52 708.78 123.15 82.437
320 0.63335 8.9777 18242 80.276 103.06 150.46 697.45 120.67 81.781
322 0.66573 8.9295 18544 81.207 103.56 151.42 686.10 118.24 81.132
324 0.69932 8.8806 18848 82.137 104.06 152.40 674.72 115.86 80.489
326 0.73415 8.8312 19154 83.066 104.57 153.41 663.33 113.53 79.851
328 0.77023 8.7811 19462 83.995 105.08 154.45 651.91 111.25 79.220
330 0.80761 8.7304 19772 84.925 105.59 155.52 640.46 109.01 78.595
332 0.84630 8.6790 20084 85.854 106.11 156.62 628.99 106.81 77.976
334 0.88635 8.6270 20398 86.783 106.63 157.75 617.48 104.65 77.363
336 0.92776 8.5741 20715 87.713 107.15 158.92 605.94 102.53 76.757
338 0.97059 8.5206 21033 88.643 107.68 160.13 594.36 100.45 76.156
340 1.0148 8.4662 21354 89.574 108.21 161.39 582.74 98.394 75.561
342 1.0606 8.4109 21677 90.505 108.74 162.69 571.08 96.375 74.973
344 1.1078 8.3548 22002 91.438 109.28 164.04 559.37 94.387 74.390
346 1.1565 8.2977 22330 92.371 109.83 165.44 547.62 92.427 73.814
348 1.2068 8.2396 22661 93.306 110.38 166.91 535.81 90.495 73.243
350 1.2587 8.1805 22994 94.242 110.93 168.44 523.94 88.587 72.679
352 1.3123 8.1202 23330 95.180 111.49 170.04 512.02 86.704 72.120
354 1.3674 8.0588 23668 96.120 112.06 171.73 500.02 84.842 71.567
356 1.4243 7.9961 24010 97.062 112.63 173.50 487.96 83.000 71.020
358 1.4829 7.9321 24354 98.007 113.21 175.38 475.82 81.177 70.479
360 1.5433 7.8666 24702 98.954 113.80 177.37 463.60 79.371 69.944
362 1.6054 7.7996 25053 99.904 114.39 179.48 451.29 77.580 69.415
364 1.6694 7.7310 25408 100.86 114.99 181.74 438.89 75.802 68.891
366 1.7352 7.6606 25766 101.82 115.60 184.15 426.38 74.034 68.374
368 1.8030 7.5883 26128 102.78 116.22 186.76 413.76 72.277 67.862
370 1.8727 7.5139 26494 103.75 116.86 189.58 401.01 70.526 67.356
372 1.9444 7.4372 26864 104.72 117.50 192.66 388.14 68.779 66.856
374 2.0181 7.3580 27239 105.7 118.17 196.03 375.12 67.036 66.363
376 2.0939 7.2762 27619 106.68 118.84 199.74 361.94 65.292 65.877
378 2.1718 7.1913 28005 107.68 119.54 203.88 348.59 63.544 65.398
380 2.2519 7.1031 28396 108.68 120.26 208.53 335.05 61.791 64.926
382 2.3343 7.0111 28794 109.69 121.01 213.80 321.32 60.027 64.465
384 2.4189 6.9149 29198 110.72 121.79 219.85 307.36 58.248 64.014
386 2.5058 6.8138 29611 111.76 122.62 226.90 293.15 56.450 63.577
388 2.5951 6.7072 30032 112.81 123.49 235.25 278.69 54.626 63.158
390 2.6869 6.5941 30464 113.88 124.42 245.34 263.93 52.770 62.764
392 2.7812 6.4732 30907 114.98 125.42 257.82 248.86 50.870 62.403
394 2.8782 6.3430 31365 116.11 126.52 273.75 233.42 48.915 62.093
396 2.9778 6.2012 31840 117.27 127.74 294.88 217.58 46.887 61.861
398 3.0802 6.0444 32336 118.48 129.14 324.44 201.26 44.761 61.762
400 3.1856 5.8674 32862 119.75 130.78 369.01 184.38 42.498 61.898
402 3.2940 5.6611 33429 121.12 132.80 444.47 166.79 40.030 62.501
404 3.4057 5.4067 34065 122.65 135.47 601.19 148.23 37.215 64.151
406 3.5210 5.0501 34847 124.52 139.62 1125.7 128.12 33.651 68.999
407.81 3.6284 4.0403 36583 128.73 152.07 329210 106.84 25.500 348.88
D4651 − 14 (2020)
TABLE 2 Thermophysical Properties of Isobutane Vapor at Vapor-Liquid Equilibrium
TP ρ HS C C c ηλ
v p
-1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
K MPa mol·l J·mol J·mol ·K J·mol ·K J·mol ·K m·s µPa·s mW·m ·K
120 1.0633E-07 1.0657E-07 21733 196.17 44.496 52.811 142.74 3.0131 2.6257
122 1.6734E-07 1.6497E-07 21840 193.27 45.023 53.338 143.79 3.0658 2.7408
124 2.5915E-07 2.5136E-07 21947 190.51 45.546 53.861 144.83 3.1185 2.8569
126 3.9524E-07 3.7727E-07 22055 187.87 46.064 54.379 145.87 3.1711 2.9740
128 5.9407E-07 5.5821E-07 22164 185.34 46.578 54.892 146.90 3.2237 3.0922
130 8.8064E-07 8.1474E-07 22275 182.92 47.087 55.402 147.92 3.2763 3.2114
132 1.2883E-06 1.1738E-06 22386 180.61 47.592 55.907 148.93 3.3288 3.3317
134 1.8611E-06 1.6704E-06 22498 178.39 48.094 56.409 149.94 3.3813 3.4530
136 2.6564E-06 2.3492E-06 22611 176.27 48.591 56.906 150.94 3.4337 3.5753
138 3.7483E-06 3.2669E-06 22726 174.24 49.085 57.400 151.94 3.4860 3.6987
140 5.2314E-06 4.4943E-06 22841 172.30 49.575 57.891 152.92 3.5384 3.8231
142 7.2252E-06 6.1198E-06 22957 170.44 50.062 58.378 153.90 3.5906 3.9485
144 9.8793E-06 8.2517E-06 23074 168.66 50.546 58.862 154.88 3.6429 4.0750
146 1.3379E-05 1.1022E-05 23193 166.95 51.028 59.344 155.84 3.6950 4.2025
148 1.7953E-05 1.4591E-05 23312 165.32 51.506 59.823 156.80 3.7472 4.3310
150 2.3880E-05 1.9149E-05 23432 163.75 51.982 60.300 157.76 3.7992 4.4606
152 3.1496E-05 2.4924E-05 23553 162.25 52.456 60.774 158.71 3.8513 4.5912
154 4.1206E-05 3.2185E-05 23675 160.82 52.928 61.247 159.65 3.9032 4.7228
156 5.3493E-05 4.1247E-05 23798 159.44 53.397 61.717 160.58 3.9551 4.8555
158 6.8925E-05 5.2475E-05 23921 158.12 53.866 62.187 161.51 4.0070 4.9892
160 8.8176E-05 6.6294E-05 24046 156.86 54.332 62.655 162.43 4.0588 5.1239
162 0.00011203 8.3191E-05 24171 155.65 54.798 63.122 163.35 4.1105 5.2596
164 0.00014139 0.00010372 24298 154.49 55.262 63.589 164.26 4.1622 5.3964
166 0.00017732 0.00012852 24425 153.38 55.726 64.054 165.16 4.2138 5.5342
168 0.00022101 0.00015829 24553 152.31 56.188 64.520 166.06 4.2654 5.6729
170 0.00027386 0.00019384 24682 151.29 56.651 64.985 166.95 4.3168 5.8127
172 0.00033740 0.00023606 24812 150.32 57.113 65.451 167.83 4.3682 5.9535
174 0.00041343 0.00028595 24943 149.39 57.575 65.917 168.70 4.4196 6.0953
176 0.00050391 0.00034461 25075 148.49 58.037 66.384 169.57 4.4708 6.2381
178 0.00061107 0.00041325 25207 147.64 58.500 66.852 170.43 4.5220 6.3819
180 0.00073738 0.00049321 25340 146.82 58.963 67.320 171.29 4.5732 6.5267
182 0.00088560 0.00058593 25474 146.04 59.426 67.791 172.13 4.6242 6.6725
184 0.0010588 0.00069300 25609 145.30 59.891 68.262 172.97 4.6751 6.8192
186 0.0012602 0.00081613 25745 144.58 60.356 68.736 173.80 4.7260 6.9669
188 0.0014935 0.00095718 25881 143.90 60.823 69.212 174.63 4.7768 7.1156
190 0.0017628 0.0011181 26018 143.25 61.291 69.690 175.44 4.8275 7.2652
192 0.0020724 0.0013012 26156 142.63 61.760 70.170 176.25 4.8781 7.4158
194 0.0024270 0.0015085 26295 142.04 62.231 70.653 177.05 4.9286 7.5673
196 0.0028316 0.0017426 26434 141.48 62.704 71.140 177.83 4.9790 7.7198
198 0.0032918 0.0020061 26574 140.94 63.179 71.629 178.61 5.0294 7.8732
200 0.0038135 0.0023017 26715 140.43 63.656 72.122 179.38 5.0796 8.0275
202 0.0044031 0.0026324 26857 139.94 64.135 72.618 180.14 5.1297 8.1827
204 0.0050671 0.0030011 26999 139.48 64.617 73.118 180.89 5.1797 8.3389
206 0.0058130 0.0034111 27142 139.04 65.101 73.623 181.63 5.2297 8.4959
208 0.0066482 0.0038658 27285 138.62 65.587 74.131 182.36 5.2795 8.6539
210 0.0075808 0.0043687 27429 138.23 66.077 74.644 183.08 5.3292 8.8127
212 0.0086196 0.0049235 27574 137.85 66.569 75.161 183.78 5.3789 8.9724
214 0.0097734 0.0055342 27720 137.50 67.064 75.684 184.48 5.4284 9.1330
216 0.011052 0.0062046 27866 137.16 67.561 76.211 185.16 5.4778 9.2945
218 0.012465 0.0069390 28012 136.85 68.062 76.743 185.83 5.5271 9.4569
220 0.014023 0.0077418 28159 136.55 68.567 77.281 186.48 5.5763 9.6201
222 0.015736 0.0086174 28307 136.27 69.074 77.824 187.12 5.6254 9.7842
224 0.017618 0.0095704 28455 136.01 69.585 78.373 187.75 5.6744 9.9492
226 0.019678 0.010606 28604 135.76 70.099 78.928 188.37 5.7234 10.115
228 0.021930 0.011728 28753 135.53 70.616 79.488 188.97 5.7722 10.282
230 0.024387 0.012943 28903 135.31 71.137 80.055 189.56 5.8209 10.449
232 0.027061 0.014256 29053 135.11 71.662 80.629 190.13 5.8696 10.618
234 0.029967 0.015671 29204 134.92 72.190 81.208 190.68 5.9182 10.787
236 0.033118 0.017195 29355 134.75 72.722 81.795 191.22 5.9666 10.957
238 0.036530 0.018834 29506 134.59 73.257 82.388 191.75 6.0151 11.128
240 0.040218 0.020593 29658 134.44 73.796 82.988 192.25 6.0634 11.300
242 0.044196 0.022477 29810 134.30 74.339 83.595 192.74 6.1117 11.473
244 0.048482 0.024495 29963 134.18 74.886 84.210 193.22 6.1600 11.647
246 0.053092 0.026651 30116 134.07 75.436 84.832 193.67 6.2082 11.822
248 0.058042 0.028952 30269 133.97 75.990 85.462 194.11 6.2564 11.997
250 0.063350 0.031405 30423 133.88 76.548 86.099 194.52 6.3045 12.174
252 0.069033 0.034017 30577 133.80 77.110 86.744 194.92 6.3527 12.352
254 0.075109 0.036794 30731 133.73 77.676 87.398 195.30 6.4008 12.530
256 0.081597 0.039744 30886 133.67 78.245 88.060 195.66 6.4489 12.710
258 0.088516 0.042874 31041 133.62 78.819 88.730 196.00 6.4971 12.891
260 0.095885 0.046192 31196 133.58 79.396 89.409 196.32 6.5453 13.073
262 0.10372 0.049705 31351 133.55 79.977 90.097 196.62 6.5935 13.256
264 0.11205 0.053421 31506 133.53 80.561 90.793 196.89 6.6419 13.440
266 0.12089 0.057348 31662 133.51 81.150 91.499 197.15 6.6903 13.625
D4651 − 14 (2020)
TABLE 2 Continued
TP ρ HS C C c ηλ
v p
-1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
K MPa mol·l J·mol J·mol ·K J·mol ·K J·mol ·K m·s µPa·s mW·m ·K
268 0.13025 0.061495 31818 133.50 81.742 92.215 197.38 6.7387 13.812
270 0.14017 0.065869 31974 133.50 82.338 92.940 197.59 6.7873 14.000
272 0.15066 0.070480 32130 133.51 82.938 93.675 197.78 6.8361 14.189
274 0.16174 0.075336 32286 133.53 83.542 94.421 197.94 6.8850 14.380
276 0.17344 0.080446 32442 133.55 84.149 95.177 198.08 6.9340 14.572
278 0.18577 0.085821 32598 133.58 84.760 95.944 198.20 6.9833 14.766
280 0.19876 0.091469 32754 133.61 85.375 96.722 198.29 7.0328 14.961
282 0.21243 0.097400 32911 133.65 85.993 97.511 198.35 7.0825 15.159
284 0.22681 0.10362 33067 133.70 86.615 98.312 198.39 7.1325 15.357
286 0.24192 0.11015 33223 133.75 87.241 99.126 198.41 7.1828 15.558
288 0.25777 0.11700 33379 133.81 87.870 99.952 198.39 7.2334 15.761
290 0.27440 0.12417 33535 133.87 88.503 100.79 198.35 7.2844 15.966
292 0.29183 0.13168 33691 133.94 89.140 101.64 198.29 7.3357 16.173
294 0.31008 0.13954 33847 134.01 89.780 102.51 198.19 7.3875 16.382
296 0.32917 0.14776 34003 134.09 90.423 103.39 198.07 7.4397 16.593
298 0.34914 0.15635 34158 134.17 91.070 104.29 197.92 7.4925 16.807
300 0.37000 0.16534 34314 134.26 91.721 105.20 197.74 7.5457 17.024
302 0.39177 0.17472 34469 134.34 92.375 106.13 197.52 7.5996 17.243
304 0.41450 0.18452 34623 134.44 93.033 107.08 197.28 7.6541 17.465
306 0.43819 0.19476 34778 134.53 93.695 108.04 197.01 7.7092 17.691
308 0.46288 0.20544 34932 134.63 94.361 109.02 196.70 7.7650 17.919
310 0.48858 0.21659 35086 134.74 95.030 110.03 196.37 7.8217 18.151
312 0.51534 0.22822 35239 134.84 95.703 111.05 196.00 7.8791 18.387
314 0.54317 0.24034 35392 134.95 96.380 112.10 195.59 7.9375 18.627
316 0.57209 0.25298 35544 135.06 97.061 113.17 195.15 7.9967 18.870
318 0.60215 0.26617 35696 135.18 97.746 114.27 194.68 8.0570 19.118
320 0.63335 0.27991 35847 135.29 98.434 115.39 194.17 8.1184 19.370
322 0.66573 0.29422 35997 135.41 99.125 116.54 193.62 8.1810 19.627
324 0.69932 0.30915 36147 135.53 99.819 117.72 193.04 8.2448 19.889
326 0.73415 0.32470 36296 135.65 100.51 118.93 192.41 8.3100 20.156
328 0.77023 0.34090 36444 135.77 101.21 120.17 191.75 8.3766 20.429
330 0.80761 0.35779 36592 135.89 101.91 121.44 191.05 8.4448 20.708
332 0.84630 0.37539 36738 136.02 102.61 122.75 190.31 8.5146 20.994
334 0.88635 0.39372 36884 136.14 103.31 124.10 189.52 8.5861 21.286
336 0.92776 0.41284 37028 136.26 104.01 125.49 188.69 8.6596 21.585
338 0.97059 0.43277 37171 136.39 104.71 126.93 187.82 8.7352 21.892
340 1.0148 0.45354 37313 136.51 105.41 128.42 186.90 8.8129 22.207
342 1.0606 0.47521 37453 136.64 106.11 129.97 185.94 8.8930 22.531
344 1.1078 0.49781 37592 136.76 106.81 131.58 184.92 8.9757 22.865
346 1.1565 0.52140 37729 136.88 107.52 133.26 183.86 9.0611 23.208
348 1.2068 0.54602 37865 137.00 108.23 135.03 182.75 9.1495 23.562
350 1.2587 0.57173 37998 137.11 108.95 136.89 181.59 9.2411 23.928
352 1.3123 0.59860 38130 137.23 109.67 138.86 180.38 9.3362 24.306
354 1.3674 0.62668 38259 137.34 110.41 140.94 179.11 9.4350 24.698
356 1.4243 0.65606 38386 137.45 111.16 143.17 177.78 9.5379 25.105
358 1.4829 0.68681 38510 137.55 111.93 145.55 176.40 9.6453 25.528
360 1.5433 0.71903 38632 137.65 112.72 148.11 174.96 9.7575 25.968
362 1.6054 0.75280 38751 137.74 113.53 150.87 173.45 9.8750 26.427
364 1.6694 0.78824 38866 137.83 114.37 153.86 171.89 9.9982 26.908
366 1.7352 0.82548 38978 137.92 115.23 157.11 170.25 10.128 27.411
368 1.8030 0.86464 39086 137.99 116.11 160.66 168.55 10.264 27.941
370 1.8727 0.90588 39190 138.06 117.03 164.55 166.77 10.409 28.498
372 1.9444 0.94937 39290 138.12 117.98 168.84 164.92 10.561 29.088
374 2.0181 0.99533 39385 138.17 118.96 173.60 163.00 10.723 29.713
376 2.0939 1.0440 39474 138.21 119.97 178.92 160.99 10.896 30.378
378 2.1718 1.0956 39558 138.24 121.02 184.89 158.90 11.081 31.089
380 2.2519 1.1505 39635 138.25 122.11 191.67 156.73 11.278 31.853
382 2.3343 1.2090 39704 138.25 123.23 199.43 154.46 11.491 32.677
384 2.4189 1.2716 39765 138.24 124.41 208.42 152.10 11.721 33.572
386 2.5058 1.3389 39817 138.20 125.63 218.98 149.63 11.972 34.551
388 2.5951 1.4115 39858 138.13 126.92 231.58 147.06 12.245 35.630
390 2.6869 1.4904 39886 138.04 128.27 246.92 144.37 12.546 36.832
392 2.7812 1.5766 39899 137.92 129.70 266.03 141.57 12.881 38.187
394 2.8782 1.6716 39894 137.75 131.24 290.57 138.63 13.256 39.738
396 2.9778 1.7777 39866 137.54 132.91 323.33 135.56 13.682 41.551
398 3.0802 1.8978 39809 137.25 134.75 369.40 132.32 14.175 43.728
400 3.1856 2.0369 39712 136.88 136.83 439.11 128.90 14.761 46.452
402 3.2940 2.2035 39559 136.37 139.26 557.25 125.27 15.484 50.083
404 3.4057 2.4155 39312 135.63 142.29 801.43 121.33 16.437 55.527
406 3.5210 2.7246 38868 134.43 146.50 1601.4 116.78 17.902 66.347
407.81 3.6284 3.7092 37136 130.09 153.85 409210 107.93 23.329 402.21
D4651 − 14 (2020)
TABLE 3 Thermophysical Properties of Isobutane Along Isobars
T ρ HS C C c ηλ
v p
-1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
K mol·l J·mol J·mol ·K J·mol ·K J·mol ·K m·s µPa·s mW·m ·K
Pressure = 0.1 MPa
120 12.636 -5905.9 -34.226 69.010 99.305 1945.6 6062.7 156.74
130 12.474 -4903.5 -26.204 70.263 101.18 1863.7 3702.4 154.41
140 12.311 -3882.4 -18.637 71.505 103.04 1787.1 2465.0 151.62
150 12.148 -2842.7 -11.465 72.728 104.89 1714.8 1749.3 148.46
160 11.985 -1784.6 -4.6371 73.948 106.72 1645.7 1303.7 144.98
170 11.820 -708.20 1.8882 75.186 108.57 1579.1 1009.4 141.25
180 11.654 386.81 8.1466 76.463 110.44 1514.5 805.33 137.33
190 11.486 1500.8 14.169 77.799 112.37 1451.5 657.90 133.26
200 11.317 2634.3 19.983 79.206 114.36 1389.7 547.68 129.10
210 11.146 3788.3 25.613 80.695 116.44 1329.0 462.89 124.86
220 10.972 4963.6 31.080 82.275 118.63 1269.2 396.09 120.60
230 10.796 6161.3 36.404 83.949 120.94 1210.1 342.40 116.36
240 10.616 7382.9 41.602 85.718 123.39 1151.6 298.53 112.14
250 10.432 8629.6 46.691 87.584 125.99 1093.7 262.16 107.96
260 10.244 9903.2 51.686 89.542 128.76 1036.2 231.65 103.86
261.07 10.223 10040 52.213 89.756 129.06 1030.1 228.69 103.43
...