1.1This practice covers, by compositional analysis, the approximate determination of the following physical characteristics of commercial propane, special-duty propane, commercial propane/butane mixtures, and commercial butane (covered by Specification D1835): vapor pressure, relative density, and motor octane number (MON).
1.1.1This practice is not applicable to any product exceeding specifications for nonvolatile residues. (See Test Method D2158.)
1.1.2For calculating motor octane number, this practice is applicable only to mixtures containing 20 % or less of propene.
1.1.3For calculated motor octane number, this practice is based on mixtures containing only components shown in Table 1.
|
Component |
Vapor Pressure Blend Factor, kPa-gage (PSIG) at 37.8°C (100°F) |
Relative Density at 15.6°C (60°F) |
MON Blend Value |
|
Methane |
17547 (2545) |
0.3 |
. . . |
|
Ethane |
4213 (611) |
0.3563 |
100.7 |
|
Ethene (Ethylene) |
8720 (1265) |
0.37 |
75.6 |
|
Propane |
1200 (174) |
0.5072 |
97.1 |
|
Propene (Propylene) |
1466 (213) |
0.5226 |
84.9 |
|
Methylpropane (Isobutane) |
400 (58) |
0.5629 |
97.6 |
|
n-Butane |
255 (37) |
0.5842 |
89.6 |
|
t-2-Butene |
242 (35) |
0.6099 |
… |
|
1-Butene |
328 (48) |
0.6004 |
80.8 |
|
2-Methylpropene (Isobutylene) |
340 (49) |
0.6004 |
… |
|
c-2-Butene |
216 (31) |
0.6275 |
83.5 |
|
2,2-Dimethylpropane (Neopentane) |
152 (22) |
0.5961 |
80.2 |
|
Cyclopentane |
-33 (-4.7) |
0.7503 |
84.9 |
|
2-Methylbutane (Isopentane) |
40 (5.8) |
0.6251 |
90.3 |
|
n-Pentane |
6.4 (0.9) |
0.6307 |
62.6 |
|
n-Hexane |
-67 (-9.7) |
0.6641 |
26.0 |
1.2The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
1.2.1Exception-Motor octane number and relative density are given in MON numbers and dimensionless units, respectively.
