ASTM D1946-90(2015)e1
(Practice)Standard Practice for Analysis of Reformed Gas by Gas Chromatography
Standard Practice for Analysis of Reformed Gas by Gas Chromatography
SIGNIFICANCE AND USE
4.1 The information about the chemical composition can be used to calculate physical properties of the gas, such as heating (calorific) value and relative density. Combustion characteristics, products of combustion, toxicity, and interchangeability with other fuel gases may also be inferred from the chemical composition.
SCOPE
1.1 This practice covers the determination of the chemical composition of reformed gases and similar gaseous mixtures containing the following components: hydrogen, oxygen, nitrogen, carbon monoxide, carbon dioxide, methane, ethane, and ethylene.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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.
General Information
Relations
Buy Standard
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
´1
Designation: D1946 − 90 (Reapproved 2015)
Standard Practice for
Analysis of Reformed Gas by Gas Chromatography
This standard is issued under the fixed designation D1946; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—Section 5 updated editorially in December 2015.
1. Scope (calorific) value and relative density. Combustion
characteristics, products of combustion, toxicity, and inter-
1.1 This practice covers the determination of the chemical
changeability with other fuel gases may also be inferred from
composition of reformed gases and similar gaseous mixtures
the chemical composition.
containing the following components: hydrogen, oxygen,
nitrogen, carbon monoxide, carbon dioxide, methane, ethane,
5. Apparatus
and ethylene.
5.1 Detector—The detector shall be a thermal conductivity
1.2 The values stated in SI units are to be regarded as
type or its equivalent in stability and sensitivity. The thermal
standard. No other units of measurement are included in this
conductivity detector must be sufficiently sensitive to produce
standard.
a signal of at least 0.5 mV for 1 mol% methane in a 0.5-mL
1.3 This standard does not purport to address all of the
sample.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5.2 Recording Instruments—Either strip chart recorders or
priate safety and health practices and determine the applica- electronicintegrators,orboth,areusedtodisplaytheseparated
bility of regulatory limitations prior to use.
components. It is highly desirable to evaluate the performance
of strip chart recorders or electronic integrators.
2. Referenced Documents
5.2.1 Therecorder,whenused,shallbeastripchartrecorder
2.1 ASTM Standards:
with a full-range scale of 5 mV or less (1 mV preferred). The
E260Practice for Packed Column Gas Chromatography
width of the chart shall be not less than 150 mm.Amaximum
pen response time of2s(1s preferred) and a minimum chart
3. Summary of Practice
speed of 10 mm/min shall be required. Faster speeds up to 100
3.1 Components in a sample of reformed gas are physically
mm/min are desirable if the chromatogram is to be interpreted
separatedbygaschromatographyandcomparedtocorrespond-
using manual methods to obtain areas.
ing components of a reference standard separated under
5.2.2 Electronic or Computing Integrators—Proof of sepa-
identical operating conditions, using a reference standard
ration and response equivalent to that for the recorder is
mixture of known composition. The composition of the re-
required for displays other than by chart recorder.
formed gas is calculated by comparison of either the peak
5.3 Attenuator—If manual methods are used to interpret the
height or area response of each component with the corre-
chromatogram, an attenuator must be used with the detector
sponding value of that component in the reference standard.
output signal to keep the peak maxima within the range of the
4. Significance and Use recorderchart.Theattenuatormustbeaccuratetowithin0.5%
between the attenuator range steps.
4.1 The information about the chemical composition can be
usedtocalculatephysicalpropertiesofthegas,suchasheating
5.4 Sample Inlet System:
5.4.1 The sample inlet system must be constructed of
materials that are inert and nonadsorptive with respect to the
This practice is under the jurisdiction of ASTM Committee D03 on Gaseous
Fuels and is the direct responsibility of Subcommittee D03.07 on Analysis of
components in the sample. The preferred material of construc-
Chemical Composition of Gaseous Fuels.
tion is stainless steel. Copper and copper-bearing alloys are
Current edition approved Nov. 1, 2015. Published December 2015. Originally
unacceptable.
approved in 1962. Last previous edition approved in 2011 as D1946–90 (2011).
DOI: 10.1520/D1946-90R15.
5.4.2 Provision must be made to introduce into the carrier
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
gasaheadoftheanalyzingcolumnagas-phasesamplethathas
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
beenentrappedineitherafixedvolumelooportubularsection.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Theinjectedvolumemustbereproduciblesuchthatsuccessive
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
D1946 − 90 (2015)
runsofthesamesampleagreewithinthelimitsofrepeatability 5.8 Columns:
for the concentration range as specified in 11.1.1.
5.8.1 The columns shall be constructed of materials that are
5.4.3 If the instrument is calibrated with pure components,
inert and nonadsorptive with respect to the components in the
theinletsystemshallbeequippedtointroduceasampleatless
sample. The preferred material of construction is stainless
than atmospheric pressure. The pressure-sensing device must
steel. Copper and copper-bearing alloys are unacceptable.
be accurate to 0.1 kPa (1 mm Hg).
5.8.2 Either an adsorption-type column or a partition-type
column, or both, may be used to make the analysis.
5.5 Column Temperature Control:
5.5.1 Isothermal—When isothermal operation is used, the
NOTE 1—See Practice E260 for general gas chromatography proce-
analytical columns shall be maintained at a temperature con-
dures.
stant to 0.3°C during the course of the sample run and the
5.8.2.1 Adsorption Column—This column must completely
corresponding reference run.
separate hydrogen, oxygen, nitrogen, methane, and carbon
5.5.2 Temperature Programming—Temperature program-
monoxide.Ifarecorderisused,therecorderpenmustreturnto
ming may be used, as feasible.The oven temperature shall not
thebaselinebetweeneachsuccessivepeak.Equivalentproofof
exceedtherecommendedtemperaturelimitforthematerialsin
separationisrequiredfordisplaysotherthanbychartrecorder.
the column.
Fig. 1 is an example chromatogram obtained with an adsorp-
5.6 Detector Temperature Control—The detector tempera-
tion column.
ture shall be maintained at a temperature constant to 0.3°C
(1)Because of similarities in thermal conductivities, he-
during the course of the sample run and the corresponding
lium should not be used as the carrier gas for hydrogen when
reference run. The detector temperature shall be equal to, or
hydrogen is less than 1% of the sample. Either argon or
greater than, the maximum column temperature.
nitrogen carrier gas is suitable for both percent and parts per
5.7 Carrier Gas—The instrument shall be equipped with million quantities of hydrogen.
suitable facilities to provide flow of carrier gas through the (2)The use of a carrier gas mixture of 8.5% hydrogen and
analyzer and detector at a flow rate that is constant to 1% 91.5%heliumwillavoidtheproblemofreversingpolaritiesof
throughout the analysis of the sample and the reference hydrogen responses as the concentration of hydrogen in the
standard. The purity of the carrier gas may be improved by sample is increased.
flowing the carrier gas through selective filters before its entry (3)The precision of measurement of hydrogen can be
into the chromatograph. Refer to 5.8.2.1(1) through (4) for the increased by using a separate injection for hydrogen, using
appropriate selection of carrier gases. either argon or nitrogen for the carrier gas.
Column: 2-m by 6-mm inside diameter Type 13× Flow rate: 60-mL helium/min
molecular sieves, 14 to 30 mesh Sample size: 0.5 mL
Temperature: 35°C
FIG. 1 Chromatogram of Reformed Gas on Molecular Sieve Column
´1
D1946 − 90 (2015)
(4)Another technique for isolating the hydrogen in a 6. Reference Standards
sample is to use a palladium transfer tube at the end of the
6.1 Moisture-free mixtures of known composition are re-
adsorption column; this will permit only hydrogen to be
quired for comparison with the test sample.They must contain
transferred to a stream of argon or nitrogen carrier gas for
known percentages of the components, except oxygen (Note
analysis in a second thermal conductivity detector.
2), that are to be determined in the unknown sample. All
5.8.2.2 Partition Column—This column must separate
componentsinthereferencestandardmustbehomogeneousin
ethane, carbon dioxide, and ethylene. If a recorder is used, the
the vapor state at the time of use.The fraction of a component
recorder pen must return to the baseline between each succes- in the reference standard should not be less than one half of,
sive peak. Equivalent proof of separation is required for nor differ by more than 10 mol% from, the fraction of the
correspondingcomponentintheunknown.Thecompositionof
displays other than by chart recorder. Fig. 2 is an example
thereferencestandardmustbeknowntowithin0.01mol%for
chromatogram obtained with a partition column.
any component.
5.8.3 General—Those column materials, operated either
isothermally or with temperature programming, or both, may
NOTE 2—Unless the reference standard is stored in a container that has
be used if they provide satisfactory separation of components. beentestedandprovedforinertnesstooxygen,itispreferabletocalibrate
Column: 1.2 m by 6.35 mm Temperature: 40°C
Porapak Q, 50 to 80 mesh Flow rate: 50-mL helium/min
Current setting: 225 mA Sample size: 0.5 mL
FIG. 2 Chromatogram of Reformed Gas on Porapak Q Column
´1
D1946 − 90 (2015)
for oxygen by an alternative method.
oxygen is approxim
...
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.
´1
Designation: D1946 − 90 (Reapproved 2011) D1946 − 90 (Reapproved 2015)
Standard Practice for
Analysis of Reformed Gas by Gas Chromatography
This standard is issued under the fixed designation D1946; 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.
ε NOTE—Section 5 updated editorially in December 2015.
1. Scope
1.1 This practice covers the determination of the chemical composition of reformed gases and similar gaseous mixtures
containing the following components: hydrogen, oxygen, nitrogen, carbon monoxide, carbon dioxide, methane, ethane, and
ethylene.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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
2.1 ASTM Standards:
E260 Practice for Packed Column Gas Chromatography
3. Summary of Practice
3.1 Components in a sample of reformed gas are physically separated by gas chromatography and compared to corresponding
components of a reference standard separated under identical operating conditions, using a reference standard mixture of known
composition. The composition of the reformed gas is calculated by comparison of either the peak height or area response of each
component with the corresponding value of that component in the reference standard.
4. Significance and Use
4.1 The information about the chemical composition can be used to calculate physical properties of the gas, such as heating
(calorific) value and relative density. Combustion characteristics, products of combustion, toxicity, and interchangeability with
other fuel gases may also be inferred from the chemical composition.
5. Apparatus
5.1 Detector—The detector shall be a thermal conductivity type or its equivalent in stability and sensitivity. The thermal
conductivity detector must be sufficiently sensitive to produce a signal of at least 0.5 mV for 1 mol % methane in a 0.5-mL sample.
5.2 Recording Instruments—Either strip chart recorders or electronic integrators, or both, are used to display the separated
components. Although a strip chart recorder is not required when using electronic integration, it is highly desirable for evaluation
of instrument performance.It is highly desirable to evaluate the performance of strip chart recorders or electronic integrators.
5.2.1 The recorder, when used, shall be a strip chart recorder with a full-range scale of 5 mV or less (1 mV preferred). The width
of the chart shall be not less than 150 mm. A maximum pen response time of 2 s (1 s preferred) and a minimum chart speed of
10 mm/min shall be required. Faster speeds up to 100 mm/min are desirable if the chromatogram is to be interpreted using manual
methods to obtain areas.
5.2.2 Electronic or Computing Integrators—Proof of separation and response equivalent to that for the recorder is required for
displays other than by chart recorder.
This practice is under the jurisdiction of ASTM Committee D03 on Gaseous Fuels and is the direct responsibility of Subcommittee D03.07 on Analysis of Chemical
Composition of Gaseous Fuels.
Current edition approved Nov. 1, 2011Nov. 1, 2015. Published December 2011December 2015. Originally approved in 1962. Last previous edition approved in 20062011
as D1946 – 90 (2006).(2011). DOI: 10.1520/D1946-90R11.10.1520/D1946-90R15.
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
D1946 − 90 (2015)
5.3 Attenuator—If manual methods are used to interpret the chromatogram, an attenuator must be used with the detector output
signal to keep the peak maxima within the range of the recorder chart. The attenuator must be accurate to within 0.5 % between
the attenuator range steps.
5.4 Sample Inlet System:
5.4.1 The sample inlet system must be constructed of materials that are inert and nonadsorptive with respect to the components
in the sample. The preferred material of construction is stainless steel. Copper and copper-bearing alloys are unacceptable.
5.4.2 Provision must be made to introduce into the carrier gas ahead of the analyzing column a gas-phase sample that has been
entrapped in either a fixed volume loop or tubular section. The injected volume must be reproducible such that successive runs
of the same sample agree within the limits of repeatability for the concentration range as specified in 11.1.1.
5.4.3 If the instrument is calibrated with pure components, the inlet system shall be equipped to introduce a sample at less than
atmospheric pressure. The pressure-sensing device must be accurate to 0.1 kPa (1 mm Hg).
5.5 Column Temperature Control:
5.5.1 Isothermal—When isothermal operation is used, the analytical columns shall be maintained at a temperature constant to
0.3°C during the course of the sample run and the corresponding reference run.
5.5.2 Temperature Programming—Temperature programming may be used, as feasible. The oven temperature shall not exceed
the recommended temperature limit for the materials in the column.
5.6 Detector Temperature Control—The detector temperature shall be maintained at a temperature constant to 0.3°C during the
course of the sample run and the corresponding reference run. The detector temperature shall be equal to, or greater than, the
maximum column temperature.
5.7 Carrier Gas—The instrument shall be equipped with suitable facilities to provide flow of carrier gas through the analyzer
and detector at a flow rate that is constant to 1 % throughout the analysis of the sample and the reference standard. The purity of
the carrier gas may be improved by flowing the carrier gas through selective filters before its entry into the chromatograph. Refer
to 5.8.2.1(1) through (4) for the appropriate selection of carrier gases.
5.8 Columns:
5.8.1 The columns shall be constructed of materials that are inert and nonadsorptive with respect to the components in the
sample. The preferred material of construction is stainless steel. Copper and copper-bearing alloys are unacceptable.
5.8.2 Either an adsorption-type column or a partition-type column, or both, may be used to make the analysis.
NOTE 1—See Practice E260 for general gas chromatography procedures.
5.8.2.1 Adsorption Column—This column must completely separate hydrogen, oxygen, nitrogen, methane, and carbon
monoxide. If a recorder is used, the recorder pen must return to the baseline between each successive peak. Equivalent proof of
separation is required for displays other than by chart recorder. Fig. 1 is an example chromatogram obtained with an adsorption
column.
(1) Because of similarities in thermal conductivities, helium should not be used as the carrier gas for hydrogen when hydrogen
is less than 1 % of the sample. Either argon or nitrogen carrier gas is suitable for both percent and parts per million quantities of
hydrogen.
(2) The use of a carrier gas mixture of 8.5 % hydrogen and 91.5 % helium will avoid the problem of reversing polarities of
hydrogen responses as the concentration of hydrogen in the sample is increased.
(3) The precision of measurement of hydrogen can be increased by using a separate injection for hydrogen, using either argon
or nitrogen for the carrier gas.
(4) Another technique for isolating the hydrogen in a sample is to use a palladium transfer tube at the end of the adsorption
column; this will permit only hydrogen to be transferred to a stream of argon or nitrogen carrier gas for analysis in a second thermal
conductivity detector.
5.8.2.2 Partition Column—This column must separate ethane, carbon dioxide, and ethylene. If a recorder is used, the recorder
pen must return to the baseline between each successive peak. Equivalent proof of separation is required for displays other than
by chart recorder. Fig. 2 is an example chromatogram obtained with a partition column.
5.8.3 General—Those column materials, operated either isothermally or with temperature programming, or both, may be used
if they provide satisfactory separation of components.
6. Reference Standards
6.1 Moisture-free mixtures of known composition are required for comparison with the test sample. They must contain known
percentages of the components, except oxygen (Note 2), that are to be determined in the unknown sample. All components in the
reference standard must be homogeneous in the vapor state at the time of use. The fraction of a component in the reference standard
should not be less than one half of, nor differ by more than 10 mol % from, the fraction of the corresponding component in the
unknown. The composition of the reference standard must be known to within 0.01 mol % for any component.
NOTE 2—Unless the reference standard is stored in a container that has been tested and proved for inertness to oxygen, it is preferable to calibrate for
oxygen by an alternative method.
´1
D1946 − 90 (2015)
Column: 2-m by 6-mm inside diameter Type 13× Flow rate: 60-mL helium/min
molecular sieves, 14 to 30 mesh Sample size: 0.5 mL
Temperature: 35°C
FIG. 1 Chromatogram of Reformed Gas on Molecular Sieve Column
6.2 Preparation—A reference standard may be prepared by blending pure compon
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.