Designation: D 2421 – 95
An American National Standard
Standard Practice for
Interconversion of Analysis of C 5 and Lighter Hydrocarbons to Gas-Volume, Liquid-Volume, or Weight Basis 1 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 superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
5 millilitres liquid at 15.6°C ~ ~ 60°F !
1. Scope Scope 1.1 This practice practice describes describes the procedure procedure for the interconinterconversion of the analysis of C 5 and lighter hydrocarbon mixtures to gas-volum gas-volumee (mole), (mole), liquid-vol liquid-volume, ume, or weight weight in vacuum vacuum basis. 1.2 The comput computati ation on proced procedure uress descri described bed assume assume that that gas-volume percentages have already been corrected for nonideality of the components as a part of the analytical process by which which they they have have been been obtain obtained. ed. These These are numeri numerical cally ly the same as mole percentages. 1.3 The procedure procedure assumes the absence absence of nonadditi nonadditivity vity corrections for mixtures of the pure liquid compounds. This is approximately true only for mixtures of hydrocarbons of the same number of carbon atoms, and in the absence of diolefins and acetylenic compounds. 1.4 The values values stated in SI units are to be regarded regarded as the standard. The values given in parentheses are for information only. standard rd does not purport purport to addre address ss all of the 1.5 This standa safe safety ty conc concer erns ns,, if any any, asso associ ciat ated ed with with its its use. use. It is the the responsibility of the user of this standard to establish appro priate safety and health practices and determine the applicability of regulatory limitations prior to use.
where: M
5 molecular weight of the pure compound, and Relative density 5 relative density, density, 15.6/15.6°C (60/60°F) (vacuum), of the pure compound. 2.3 Where Where ideal gas volumes have been measured measured at temperatures and pressures different from 15.6°C (60°F) at 760 mm Hg, they must be corrected to these conditions. 3. Significanc Significancee and Use 3.1 For custody custody transfer and other purposes, purposes, it is frequently frequently necessary to convert a component analysis of light hydrocarbon mixture from one basis (either gas-volume, liquid volume, or weight) to another. 3.2 The component component distribut distribution ion data of light light hydrocarb hydrocarbon on mixtures can be used to calculate physical properties such as relative density, vapor-pressure, and calorific value. Consistent and accurate accurate conversio conversion n data are extremel extremely y important important when calculating vapor, liquid, or mass equivalence. 4. Procedur Proceduree 4.1 4.1 To conv conver ertt from from the the orig origin inal al to the the desi desire red d basi basis, s, multiply or divide the percent of each compound in the original basis according to the schedule shown in Table 1. Perform the calculation, using the corresponding factor indicated in Table 2. Carr Carry y at leas leastt one one more more sign signifi ifica cant nt figur figuree in all all of the the calcul calculati ations ons than than the number number of signifi significan cantt figures figures in the original analysis.
2. Source Source of Data Data 2.1 The basic values for the relative relative density density 15.6/15.6°C 15.6/15.6°C (60/60°F) of the pure compounds have been obtained from the Thermodynamics Research Center, Texas A & M University, except where otherwise noted. The values for methane, ethylene, ene, and acetylen acetylenee are not those those of pure pure materi materials als but are assumed to apply as a component of a liquid mixture. 2.2 The conversion conversion factors factors for 1 mL of ideal gas at 15.6°C (60°F) and 760 mm Hg to millilitres of liquid at 15.6°C (60°F) have been calculated as follows: 1 mL gas at 15.6°C (60°F), 760 mm Hg L 5 ~ 273.16/288.72! 3 ~ M /22414!
NOTE 1—The factors factors or percentages percentages can be multiplied by any constant number for convenience (such as moving the decimal) without changing the end result.
4.2 Add the products products or quotients quotients obtained obtained in accordanc accordancee with 4.1. 4.3 Multiply Multiply the products products or quotients quotients obtained obtained in accordance with 4.1 by 100 divided by the sum of the products or quotients. Round off the results so that the same number of significant figures is obtained in the final answer as was used in the original analysis. 4.4 Add the percentages percentages of the desired basis from 4.3 and distribute the round-off error (difference between the sum and 100 %) proportio proportionatel nately y. Usually Usually only the largest largest percentag percentagee will be changed in the final digit.
(1)
3 @ 1/ ~relative density!~0.99904!# 4.2251 3 10 –5 3 ~ M /relative dens ity! 1
This practice is under the jurisdiction of ASTM Committee D-2 on Petroleum Products Products and Lubricantsan Lubricantsand d is the direct responsibility responsibility of Subcommittee Subcommittee D02.Hon D02.Hon Liquefied Petroleum Gas. Current Current edition edition approved approved Feb. 15, 1995. Published Published April 1995. Originally Originally published as D 2421 – 65 T. Last previous edition D 2421 – 89.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
1
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D 2421 TABLE TAB LE 1 Conversion Factors Scheduled Scheduled
5. Keyw Keywords ords
Or ig iginal Basis
Desired Basis
Operation
Factor Column in Table 2
Gas-volume Gas-volume Weight Weight Liquid-volume Liquid-volume
weight liquid-volume gas-volume liquid-volume gas-volume weight
multiply by multiply by divide by divide by di divide by multiply by
1 2 1 3 2 3
5.1 analysis; liquefied petroleum petroleum gases; natural gas liquids
TABLE TAB LE 2 Weight-V Weight-Volume olume Data for Liquefied Petroleum Gases and Low Boiling Hydrocarbons
Compound MethaneA EthaneB AcetyleneA EthyleneA PropaneB PropyleneB Propadiene (Allene) B MethylacetyleneB n -Butane -ButaneB IsobutaneB 1-ButeneB trans -2-Butene -2-ButeneB cis -2-Butene -2-ButeneB IsobutyleneB 1,2-ButadieneB 1,3-ButadieneB EthylacetyleneB n -Pentane Isopentane NeopentaneB 1-Pentene trans -2-Pentene cis -2-Pentene 2-Methyl-1-butene 3-Methyl-1-butene 2-Methyl-2-butene Cyclopentane Isoprene 1-trans 1trans -3-Pentadiene 1-cis 1cis -Pentadiene 1,2-Pentadiene A
Column 1
Column 2
Column 3
Molecular Weight
Liquid Volume in millilitre of 1 mL of ideal gas at 15.6°C (60°F) and 760 mm Hg
Relative Density 15.6/15.6°C (60/60°F) (Vacuum)
Source
16.04 30.07 26.04 28.05 44.10 42.08 40.06 40.06 58.12 58.12 56.11 56.11 56.11 56.11 54.09 54.09 54.09 72.15 72.15 72.15 70.13 70.13 70.13 70.13 70.13 70.13 70.13 68.12 68.12 68.12 68.12
0.00226 0.003548 0.00263 0.0032 0.003675 0.003413 0.00282 0.00273 0.004205 0.004362 0.003944 0.003887 0.003780 0.003949 0.00347 0.003643 0.00328 0.004830 0.004882 0.005108 0.004589 0.004537 0.004482 0.004519 0.004684 0.00447 0.003948 0.004195 0.004224 0.004133 0.004125
0 .3 0 0.3581 0.418 0.37 0.5070 0.5210 0.600 0.621 0.5840 0.5629 0.6011 0.6100 0.6272 0.6004 0.658 0.6272 0.696 0.6311 0.6244 0.5967 0.6457 0.6530 0.6611 0.6557 0.6325 0.663 0.7505 0.6861 0.6815 0.6964 0.6976
2145-94 2145-94 GPSA est. 2145-94 GPSA API-88 API-88 2145-94 2145-94 GPSA GPSA GPSA GPSA GPSA GPSA API-88 2145-94 21 2 145-94 21 GPSA GPSA GP TRC TRC TRC TRC TRC GPSA GPSA API API API
Apparent values for dissolved gas at 15.6°C (60°F). (60°F). Property of liquid phase measured at its saturation pressure at 15.6°C (60°F). (60°F). Sources: GPA 2145-94: “Physical Constants of Paraffin Hydrocarbons and Other Components of Natural Gas,” Gas Processors Association, GPSA:“ Engineering Data Book, 10th Edition,” Gas Processors Suppliers Association, API: Technical Data Book, American Petroleum Institute, and TRC: Thermodynamic Research Center, Texas A&M University.
B
NOTE 2—For sample calculations, see the Appendix.
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D 2421 APPENDIX (Nonmandatory Information) X1.. X1
EXAM EX AMPL PLES ES
X1.1 Example 1: Original basis: Gas-volume or mole, % Desired basis: Weight Original Basis Mole, %
Compound
Methane Ethane Propane Total
Factor Column 1 (Table 2)
Operation (Table 1) 3 3 3
3 3 .3 3 3 .3 3 3 .4 100.0
Product
5 534.1 5 1001.3 5 1472.9 3008.3
16.04 30.07 44.10
Product
Methane Ethane Propane Total
Quotient
Ethane Propane Isobutane Total
14.133 0.4976 183.253 0.4976 3.60 3 0.4976
534.1 3 0.03324 5 1001.3 3 0.03324 5 1472.6 3 0.03324 5
Ethane Propane Isobutane Total
5 .0 6 92.91 2 .0 3 100.0
17.8 33.3 48.9 100.0
Compound
Original Basis Liquid Volume, %
Propane n -butane Isopentane Total
1 0 .0 84.3 5 .7 100.0
Factor Column 2 (Table 2)
Operation (Table 1) 4 4 4
Quotient
0..003675 0 0.004205 0.004882 0.
2721 20048 1168 23937
100.0/23937 5 0.004176 Factor Column 3 (Table 2)
Operation (Table 1) 4 4 4
7.03 91.19 1.74 100.0
Original basis: Liquid-volume
Original basis: Weight Desired basis: Liquid-volume Compound
X1.3 Example 3:
Weight, %
X1.2 Example 2:
Original Basis Weight, %
5 5 5
Desired basis: Gas-volume
100.0/3008.3 5 0.03324 Compound
% by Liquid Volume, 15.6°C (60°F)
Compound
0.3581 0. 0 .5 .5070 0.5639
Quotient
14.13 183.25 3.60 200.98
Compound
Propane n -Butane Isopentane Total
% by Gas Volume (Ideal, 98.1 kPa, 15.6°C 15.6° C 1atm , 60°F)
Quotient
2726 3 0.004176 20062 3 0.004176 1168 3 0.004176
5 5 5
100.00/200.98 5 0.4976 The American Society for Testing Testing and Materials takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, 100 Barr Harbor Drive, West Conshohocken, PA 19428. This standard is copyrighted by ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585 (phone), 610-832-9555 (fax), or
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11.37 83.75 4.88 100.0
