ASTM D7493-14
(Test Method)Standard Test Method for Online Measurement of Sulfur Compounds in Natural Gas and Gaseous Fuels by Gas Chromatograph and Electrochemical Detection
Standard Test Method for Online Measurement of Sulfur Compounds in Natural Gas and Gaseous Fuels by Gas Chromatograph and Electrochemical Detection
SIGNIFICANCE AND USE
5.1 Gaseous fuels, such as natural gas, petroleum gases and bio-gases, contain sulfur compounds that are naturally occurring or that are added as odorants for safety purposes. These sulfur compounds are odorous, corrosive to equipment, and can inhibit or destroy catalysts employed in gas processing and other end uses. Their accurate continuous measurement is important to gas processing, operation and utilization, and is frequently of regulatory interest.
5.2 Small amounts (typically, total of 4 to 6 ppmv) of sulfur odorants are added to natural gas and other fuel gases for safety purposes. Some sulfur odorants are reactive, and may be oxidized to form more stable sulfur compounds having lower odor thresholds which adversely impact the potential safety of the gas delivery systems and gas users. Gaseous fuels are analyzed for sulfur compounds and odorant levels to assist in pipeline integrity surveillance and to ensure appropriate odorant levels for public safety.
5.3 This method offers an on-line technique to continuously identify and quantify individual target sulfur species in gaseous fuel with automatic calibration and validation.
SCOPE
1.1 This test method is for on-line measurement of volatile sulfur-containing compounds in gaseous fuels by gas chromatography (GC) and electrochemical (EC) detection. This test method is applicable to hydrogen sulfide, C1 to C4 mercaptans, sulfides and tetrahydrothiophene (THT).
1.1.1 Carbonyl sulfide (COS) is not covered in this test method.
1.1.2 The detection range for sulfur compounds is approximately from 0.1 to 100 ppmv (mL/m3) or 0.1 to 100 mg/m3. The detection range may vary depending on the sample injection volume, chromatographic peak separation and the sensitivity to the specific EC detector.
1.2 This test method describes a GC-EC method employing packed GC columns and a specific detector for natural gas and other gaseous fuel composed of mainly light (C4 and smaller) hydrocarbons. Alternative GC columns, detector designs and instrument parameters may be used, provided that chromatographic separation, quality control and measurement objectives needed to comply with user, or regulator needs or both, are achieved.
1.3 This test method does not intend to identify and measure all individual sulfur species, and is mainly employed for monitoring naturally occurring reduced sulfur compounds commonly found in natural gas and fuel gases or employed as an odorant in these gases.
1.4 The test method is typically employed in repetitive or continuous on-line monitoring of sulfur components in natural gas and fuel gases using a single sulfur calibration standard. Need for a multipoint calibration curve or quality control procedures can be satisfied by making use of procedures delineated in Test Methods D5504, D5623, D6228, D6968, ISO 19739, or GPA 2199.
1.5 The test method can be used for measurement of all sulfur compounds listed in Table 1 in air or other gaseous matrices, provided that no compounds that can interfere with the GC separation and electrochemical detection are present.
1.6 This test method is written as a companion to Practices D5287, D7165 and D7166.
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: D7493 − 14
Standard Test Method for
Online Measurement of Sulfur Compounds in Natural Gas
and Gaseous Fuels by Gas Chromatograph and
1
Electrochemical Detection
This standard is issued under the fixed designation D7493; 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 1.5 The test method can be used for measurement of all
sulfur compounds listed in Table 1 in air or other gaseous
1.1 This test method is for on-line measurement of volatile
matrices, provided that no compounds that can interfere with
sulfur-containing compounds in gaseous fuels by gas chroma-
the GC separation and electrochemical detection are present.
tography (GC) and electrochemical (EC) detection. This test
1.6 This test method is written as a companion to Practices
methodisapplicabletohydrogensulfide,C1toC4mercaptans,
D5287, D7165 and D7166.
sulfides and tetrahydrothiophene (THT).
1.1.1 Carbonyl sulfide (COS) is not covered in this test
1.7 The values stated in SI units are to be regarded as
method.
standard. No other units of measurement are included in this
1.1.2 The detection range for sulfur compounds is approxi-
standard.
3 3
mately from 0.1 to 100 ppmv (mL/m ) or 0.1 to 100 mg/m .
1.8 This standard does not purport to address all of the
The detection range may vary depending on the sample
safety concerns, if any, associated with its use. It is the
injection volume, chromatographic peak separation and the
responsibility of the user of this standard to establish appro-
sensitivity to the specific EC detector.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1.2 This test method describes a GC-EC method employing
packed GC columns and a specific detector for natural gas and
2. Referenced Documents
other gaseous fuel composed of mainly light (C4 and smaller)
2
2.1 ASTM Standards:
hydrocarbons. Alternative GC columns, detector designs and
D3609 Practice for Calibration Techniques Using Perme-
instrument parameters may be used, provided that chromato-
ation Tubes
graphicseparation,qualitycontrolandmeasurementobjectives
D4150 Terminology Relating to Gaseous Fuels
needed to comply with user, or regulator needs or both, are
D4626 Practice for Calculation of Gas Chromatographic
achieved.
Response Factors
1.3 Thistestmethoddoesnotintendtoidentifyandmeasure
D5287 Practice for Automatic Sampling of Gaseous Fuels
all individual sulfur species, and is mainly employed for
D5504 TestMethodforDeterminationofSulfurCompounds
monitoring naturally occurring reduced sulfur compounds
in Natural Gas and Gaseous Fuels by Gas Chromatogra-
commonly found in natural gas and fuel gases or employed as
phy and Chemiluminescence
an odorant in these gases.
D5623 Test Method for Sulfur Compounds in Light Petro-
leum Liquids by Gas Chromatography and Sulfur Selec-
1.4 The test method is typically employed in repetitive or
continuous on-line monitoring of sulfur components in natural tive Detection
gas and fuel gases using a single sulfur calibration standard. D6228 TestMethodforDeterminationofSulfurCompounds
Need for a multipoint calibration curve or quality control in Natural Gas and Gaseous Fuels by Gas Chromatogra-
procedures can be satisfied by making use of procedures phy and Flame Photometric Detection
delineated in Test Methods D5504, D5623, D6228, D6968, D6968 Test Method for Simultaneous Measurement of Sul-
ISO 19739, or GPA 2199. fur Compounds and Minor Hydrocarbons in Natural Gas
and Gaseous Fuels by Gas Chromatography and Atomic
Emission Detection
1
ThistestmethodisunderthejurisdictionofASTMCommitteeD03onGaseous
2
Fuels and is the direct responsibility of Subcommittee D03.12 on On-Line/At-Line For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Analysis of Gaseous Fuels. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
CurrenteditionapprovedJune1,2014.PublishedJuly2014.Originallyapproved Standards volume information, refer to the standard’s Document Summary page on
in 2008. Last previous edition approved as D7493-08. DOI: 10.1520/D7493-14. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D7493 − 14
TABLE 1 Typical Retention Times of Sulfur Components of Different GC-ECD Runs
GC-EC instrument GC-EC #1 GC-EC #2 GC-EC #3
1
GC-Column and ⁄8 in. ID× 70 cm L, 1.6 mm ID× 1200 mm L, 4 mm ID× 400 mm L,
parameters N , 12 mL/min, 65 °C N , 100 mL/min, 20 °C N , 100 mL/min, 20 °C
2 2 2
Detector Si
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7493 − 08 D7493 − 14
Standard Test Method for
Online Measurement of Sulfur Compounds in Natural Gas
and Gaseous Fuels by Gas Chromatograph and
1
Electrochemical Detection
This standard is issued under the fixed designation D7493; 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
1.1 This test method is for on-line measurement of volatile sulfur-containing compounds in gaseous fuels by gas
chromatography (GC) and electrochemical (EC) detection. TheThis test method is applicable to hydrogen sulfide, C1-C4 C1 to C4
mercaptans, sulfides and tetrahydrothiophene (THT).
1.1.1 Carbonyl sulfide (COS) is not covered in this test method.
3 3
1.1.2 The detection range for sulfur compounds is approximately from 0.1 to 100 PPMv ppmv (mL/m ) or 0.1 to 100 mg/m .
The detection range may vary depending on the sample injection volume, chromatographic peak separation and the sensitivity of
to the specific EC detector.
1.2 This test method describes a GC-EC method employing packed GC columns and a specific detector as an illustration for
natural gas and other gaseous fuel containing composed of mainly light (C4 and smaller) hydrocarbons. Alternative GC columns,
detector designs and instrument parameters may be used for the same analysis or for different types of gaseous fuel, provided that
appropriate chromatographic separation and optimal detection of these compounds can be used, provided that chromatographic
separation, quality control and measurement objectives needed to comply with user, or regulator needs or both, are achieved.
1.3 This test method does not intend to identify and measure all individual sulfur species, and is mainly employed for
monitoring natural sulfur and sulfur odorant naturally occurring reduced sulfur compounds commonly found in natural gas and fuel
gases or employed as an odorous warning agent in fuelodorant in these gases.
1.4 The test method is normallytypically employed forin repetitive or continuous on-line monitoring of sulfur components in
natural gas and fuel gases withusing a single sulfur standard. The test method may be employed for laboratory-quality
measurement with more extensive calibration. (See calibration standard. Need for a multipoint calibration curve or quality control
procedures can be satisfied by making use of procedures delineated in Test Methods D5504, D5623, D6228, D6968, ISO 19739,
ISO 6326-2, and or GPA 2199.
1.5 The test method can be used for measurement of all listed sulfur compounds listed in Table 1 in air or other gases, gaseous
matrices, provided that no compound, whichcompounds that can interfere with the GC separation and electrochemical detection,
isdetection are present.
1.6 This test method is written in conjunction with as a companion to Practices D5287, D7165 and D7166.
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
D3609 Practice for Calibration Techniques Using Permeation Tubes
1
This test method is under the jurisdiction of ASTM Committee D03 on Gaseous Fuels and is the direct responsibility of Subcommittee D03.12 on On-Line/At-Line
Analysis of Gaseous Fuels.
Current edition approved Dec. 15, 2008June 1, 2014. Published January 2009July 2014. Originally approved in 2008. Last previous edition approved as D7493-08. DOI:
10.1520/D7493-08.10.1520/D7493-14.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D7493 − 14
TABLE 21 Typical Retention Times of Sulfur Components of Different GC-ECD Runs
GC-ED instrument GC-ED #1 GC-ED #2 GC-ED #3
GC-EC instrument GC-EC #1 GC-EC #2 GC-EC #3
1
GC-Column
...
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