ASTM D2421-02

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An American National Standard
Designation: D 2421 – 02
Standard Practice for
Interconversion of Analysis of C and Lighter Hydrocarbons
5
1
to Gas-Volume, Liquid-Volume, or Mass 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.
1. Scope 1 mL gas at 15.6°C (60°F), 101.3 kPa (760 mm Hg),
1.1 This practice describes the procedure for the intercon-
L 5 ~273.16/288.72! 3 ~M/22414! (1)
version of the analysis of C and lighter hydrocarbon mixtures
5
3 @1/@~relative density!3~0.99904!##
to gas-volume (mole), liquid-volume, or mass basis.
–5
4.2251 3 10 3 ~M/relative density!
1.2 The computation procedures described assume that
5 millilitres liquid at 15.6°C 60°F!
gas-volume percentages have already been corrected for non- ~
idealityofthecomponentsasapartoftheanalyticalprocessby
where:
which they have been obtained. These are numerically the
M = molecular mass of the pure compound,
same as mole percentages.
and
1.3 The procedure assumes the absence of nonadditivity
Relative density = relative density, 15.6/15.6°C (60/60°F)
corrections for mixtures of the pure liquid compounds. This is
(vacuum), of the pure compound.
approximately true only for mixtures of hydrocarbons of the
2.3 Where ideal gas volumes have been measured at tem-
same number of carbon atoms, and in the absence of diolefins
peratures and pressures different from 15.6°C (60°F) at 101.3
and acetylenic compounds.
kPa (760 mm Hg), they must be corrected to these conditions.
1.4 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
3. Significance and Use
only.
3.1 For custody transfer and other purposes, it is frequently
1.5 This standard does not purport to address all of the
necessary to convert a component analysis of light hydrocar-
safety concerns, if any, associated with its use. It is the
bon mixture from one basis (either gas-volume, liquid volume,
responsibility of the user of this standard to establish appro-
or mass) to another.
priate safety and health practices and determine the applica-
3.2 The component distribution data of light hydrocarbon
bility of regulatory limitations prior to use.
mixtures can be used to calculate physical properties such as
relative density, vapor-pressure, and calorific value. Consistent
2. Source of Data
and accurate conversion data are extremely important when
2.1 The basic values for the relative density 15.6/15.6°C
calculating vapor, liquid, or mass equivalence.
(60/60°F) of the pure compounds have been obtained from the
Thermodynamics Research Center, Texas A & M University,
4. Procedure
except where otherwise noted. The values for methane, ethyl-
4.1 To convert from the original to the desired basis,
ene, and acetylene are not those of pure materials but are
multiplyordividethepercentofeachcompoundintheoriginal
assumed to apply as a component of a liquid mixture.
basis according to the schedule shown in Table 1. Perform the
2.2 The conversion factors for 1 mL of ideal gas at 15.6°C
calculation, using the corresponding factor indicated in Table
(60°F) and 101.3 kPa (760 mm Hg) to millilitres of liquid at
2. Carry at least one more significant figure in all of the
15.6°C (60°F) have been calculated as follows:
calculations than the number of significant figures in the
original analysis.
1
This practice is under the jurisdiction of ASTM Committee D02 on Petroleum
NOTE 1—The factors or percentages can be multiplied by any constant
Products and Lubricants and is the direct responsibility of Subcommittee D02.H on
number for convenience (such as moving the decimal) without changing
Liquefied Petroleum Gas.
the end result.
Current edition approved April 10, 2002. Published June 2002. Originally
published as D 2421 – 65 T. Last previous edition D 2421 – 01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, 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 mass multiply by 1
Gas-volume liquid-volume multiply by 2
Mass gas-volume divide by 1
Mass liquid-volume divide by 3
Liquid-volume gas-volume divide by 2
Liquid-volume mass multiply by 3
TABLE 2 Mass-Volume Data for Liquefied Petroleum Gases and Low Boiling Hydrocarbons
Column 1 Column 2 Column 3
Liquid Volume in mL of
1 mL of ideal gas at Relative Density 15.6/15.6°C
Compound Molecular Mass Source
15.6°C (60°F) and (60/60°F) (Vacuum)
101.3 kPa (760
...