ASTM D2421-01

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Designation: D 2421 – 01 An American National Standard
Standard Practice for
Interconversion of Analysis of C and Lighter Hydrocarbons
5
1
to Gas-Volume, Liquid-Volume, or Weight Basis
This standard is issued under the fixed designation D 2421; 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 (e) indicates an editorial change since the last revision or reapproval.
L 5 ~273.16/288.72! 3 ~M/22414! (1)
1. Scope
3 1/ relative density!3 0.99904!
1.1 This practice describes the procedure for the intercon- @ @~ ~ ##
–5
version of the analysis of C and lighter hydrocarbon mixtures
5
4.2251 3 10 3 ~M/relative density!
to gas-volume (mole), liquid-volume, or weight in vacuum
5 millilitres liquid at 15.6°C ~60°F!
basis.
1.2 The computation procedures described assume that
where:
gas-volume percentages have already been corrected for non-
M = molecular weight of the pure compound,
ideality of the components as a part of the analytical process by
and
which they have been obtained. These are numerically the
Relative density = relative density, 15.6/15.6°C (60/60°F)
same as mole percentages.
(vacuum), of the pure compound.
1.3 The procedure assumes the absence of nonadditivity
2.3 Where ideal gas volumes have been measured at tem-
corrections for mixtures of the pure liquid compounds. This is
peratures and pressures different from 15.6°C (60°F) at 760
approximately true only for mixtures of hydrocarbons of the
mm Hg, they must be corrected to these conditions.
same number of carbon atoms, and in the absence of diolefins
3. Significance and Use
and acetylenic compounds.
1.4 The values stated in SI units are to be regarded as the
3.1 For custody transfer and other purposes, it is frequently
standard. The values given in parentheses are for information
necessary to convert a component analysis of light hydrocar-
only.
bon mixture from one basis (either gas-volume, liquid volume,
1.5 This standard does not purport to address all of the
or weight) to another.
safety concerns, if any, associated with its use. It is the 3.2 The component distribution data of light hydrocarbon
responsibility of the user of this standard to establish appro-
mixtures can be used to calculate physical properties such as
priate safety and health practices and determine the applica- relative density, vapor-pressure, and calorific value. Consistent
bility of regulatory limitations prior to use.
and accurate conversion data are extremely important when
calculating vapor, liquid, or mass equivalence.
2. Source of Data
4. Procedure
2.1 The basic values for the relative density 15.6/15.6°C
(60/60°F) of the pure compounds have been obtained from the
4.1 To convert from the original to the desired basis,
Thermodynamics Research Center, Texas A & M University,
multiply or divide the percent of each compound in the original
except where otherwise noted. The values for methane, ethyl-
basis according to the schedule shown in Table 1. Perform the
ene, and acetylene are not those of pure materials but are
calculation, using the corresponding factor indicated in Table
assumed to apply as a component of a liquid mixture.
2. Carry at least one more significant figure in all of the
2.2 The conversion factors for 1 mL of ideal gas at 15.6°C
calculations than the number of significant figures in the
(60°F) and 760 mm Hg to millilitres of liquid at 15.6°C (60°F)
original analysis.
have been calculated as follows: 1 mL gas at 15.6°C (60°F),
NOTE 1—The factors or percentages can be multiplied by any constant
760 mm Hg,
number for convenience (such as moving the decimal) without changing
the end result.
4.2 Add the products or quotients obtained in accordance
1
with 4.1.
This practice is under the jurisdiction of ASTM Committee D02 on Petroleum
Products and Lubricants and is the direct responsibility of Subcommittee D02.H on 4.3 Multiply the products or quotients obtained in accor-
Liquefied Petroleum Gas.
dance with 4.1 by 100 divided by the sum of the products or
Current edition approved Aug. 10, 2001. Published October 2001. Originally
quotients. Round off the results so that the same number of
published as D 2421 – 65 T. Last previous edition D 2421 – 95.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
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D 2421
TABLE 1 Conversion Factors Scheduled
Factor Column in
Original Basis Desired Basis Operation
Table 2
Gas-volume weight multiply by 1
Gas-volume liquid-volume multiply by 2
Weight gas-volume divide by 1
Weight liquid-volume divide by 3
Liquid-volume gas-volume divide by 2
Liquid-volume weight multiply by 3
TABLE 2 Weight-Volume Data
...