Standard Test Method for Noncondensable Gases in C<sub>2</sub> and Lighter Hydrocarbon Products by Gas Chromatography

SIGNIFICANCE AND USE
The presence of trace amounts of hydrogen, oxygen, and carbon monoxide can have deleterious effects in certain processes using hydrocarbon products as feed stock. This test method is suitable for setting specifications, for use as an internal quality control tool and for use in development or research work.
SCOPE
1.1 This test method covers the determination of hydrogen, nitrogen, oxygen, and carbon monoxide in the parts per million volume (ppmv) range in C2 and lighter hydrocarbon products. This test method should be applicable to light hydrocarbons other than ethylene, but the test program did not include them.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety problems, 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. For some specific hazard statements, see the Annex A1.

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Publication Date
31-Oct-2004
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ASTM D2504-88(2004)e1 - Standard Test Method for Noncondensable Gases in C<sub>2</sub> and Lighter Hydrocarbon Products by Gas Chromatography
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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.
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Designation:D2504–88 (Reapproved 2004)
Standard Test Method for
Noncondensable Gases in C and Lighter Hydrocarbon
Products by Gas Chromatography
This standard is issued under the fixed designation D2504; 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.
´ NOTE—Warning notes moved into text editorially in November 2004.
1. Scope Compressed Gas Association Booklets G-4 and G-4.1 on
the use of oxygen.
1.1 This test method covers the determination of hydrogen,
nitrogen, oxygen, and carbon monoxide in the parts per million
3. Summary of Test Method
volume (ppmv) range in C and lighter hydrocarbon products.
3.1 The sample is separated in a gas-solid chromatographic
This test method should be applicable to light hydrocarbons
system using molecular sieves as the solid adsorbent. The
other than ethylene, but the test program did not include them.
concentration of the gases to be determined is calculated from
1.2 The values stated in SI units are to be regarded as the
the recorded peak heights or peak areas.Argon can be used as
standard. The values given in parentheses are for information
a carrier gas for the determination of hydrogen in concentra-
only.
tions below 100 ppmv. Argon, if present in the sample,
1.3 This standard does not purport to address all of the
interferes with oxygen determination.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Significance and Use
priate safety and health practices and determine the applica-
4.1 Thepresenceoftraceamountsofhydrogen,oxygen,and
bility of regulatory limitations prior to use. For some specific
carbon monoxide can have deleterious effects in certain pro-
hazard statements, see the Annex A1.
cesses using hydrocarbon products as feed stock. This test
2. Referenced Documents method is suitable for setting specifications, for use as an
2 internal quality control tool and for use in development or
2.1 ASTM Standards:
research work.
D2505 Test Method for Ethylene, Other Hydrocarbons, and
Carbon Dioxide in High-Purity Ethylene by Gas Chroma-
5. Apparatus
tography
5.1 Chromatograph—Any chromatographic instrument
E260 Practice for Packed Column Gas Chromatography
havingeitherathermalconductivityorionizationdetectorwith
F307 Practice for Sampling Pressurized Gas for GasAnaly-
an overall sensitivity sufficient to detect 2 ppmv or less of the
sis
3 compounds listed in the scope, with a peak height of at least 2
2.2 Other Standard:
mm without loss of resolution.
5.2 Detectors—Thermal Conductivity—If a methanation re-
actor is used, a flame ionization detector is also required. To
This test method is under the jurisdiction of ASTM Committee D02 on
determine carbon monoxide with a flame ionization detector, a
PetroleumProductsandLubricants andisthedirectresponsibilityofSubcommittee
D02.D0 on Hydrocarbons for Chemical and Special Uses. methanation reactor must be inserted between the column and
Current edition approved Nov. 1, 2004. Published November 2004. Original-
the detector and hydrogen added as a reduction gas. Details on
lyapproved in 1966. Last previous edition approved in 1998 as D2504 – 88 (1998).
the preparation and use of the reactor are given in Appendix
DOI: 10.1520/D2504-88R04E01.
X1.
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
5.3 Constant-Volume Gas Sampling Valve.
Standards volume information, refer to the standard’s Document Summary page on
5.4 Column—Any column or set of columns that is capable
the ASTM website.
3 of resolving the components listed in the scope can be used.
Available from Compressed Gas Association, 1253 Jefferson Davis Highway,
Arlington, VA, 22202. Copper, stainless steel, or aluminum tubing may be used. The
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959, United States.
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D2504–88 (2004)
columns chosen must afford a resolution such that the depth of is not critical and can be measured by any convenient means
the valleys ahead of the trace peak is no less than 50 % of the such as an orifice meter, rotameter, manometer, etc. Do not use
trace peak height. a wet test meter.
8.2 ChromatographicColumn—Purgethemetaltubingwith
5.5 Recorder—A recorder with a full-scale response of 2 s
dry nitrogen. Insert a small amount of glass wool in the end.
or less and a maximum rate of noise of 60.3 % of full scale.
Fill rapidly with the screened and activated molecular sieves,
5.6 Oven—The oven used for activating molecular sieves
adding the latter in 1-g increments. Vibrate the column, adding
must be maintained at 260 to 288°C (500 to 550°F) and should
additional sieves during this period, if necessary, to fill. Insert
bedesignedsothatthegasesmaybedisplacedcontinuouslyby
asmallamountofglasswoolinthetop.Bendthecolumninthe
a stream of inert gas. The oven may be a thermostated piece of
shape required to fit the chromatographic instrument. Regen-
1-in. pipe about 0.3 m (1 ft) in length. Electrical heating tapes
erate the column in the oven in the same manner as described
or other means may be used for heating provided the heat is
in 8.1 whenever the oxygen is not completely separated from
distributed uniformly.
the nitrogen peak.
NOTE 1—The use of copper tubing is not recommended with samples
containing acetylene as this could lead to the formation of potentially 9. Calibration
explosive copper acetylide.
9.1 Bring the equipment and column to equilibrium and
maintain a constant carrier gas rate and temperature.
6. Reagents and Materials
NOTE 4—Carrier gas rates of 36 to 60 mL/min and temperatures of 50
6.1 Molecular Sieves, 5A, 13A, or 13X—Any mesh sizes
to 60°C have been used successfully.
canbeusedsolongassensitivityandresolutionaremaintained
9.2 Prepare at least three synthetic standard samples con-
(see Note 2). If a 40 to 60-mesh sieve size is desired, but is not
taining the compounds to be determined over the range of
available, it may be prepared as described in 8.1.
concentration desired in the products to be analyzed, using the
6.2 Coconut Charcoal, 30 to 60-mesh sieve size (optional).
pure gases or the certified blend. For the preparation of the
NOTE 2—Columns that have been found to give the desired separation second, third, and following calibration samples it is always
include a 1-m by 3.175-mm outside diameter column of 100 to 120 mesh
preferable not to dilute the first sample.
5Amolecular sieve, a 3-m by 6.35-mm outside diameter column of 40 to
NOTE 5—Synthetic standard samples should be prepared as described
60-mesh 5Asieve, and a 7.7-m by 6.35-mm outside diameter column with
in Test Method D2505.
13A or 13X sieve in the first 7.4 m and charcoal in the 0.3 m.
9.3 Inject a known volume of one of the standard samples,
6.3 Gases for Calibration—Pure or research grade hydro-
using a minimum of 1 mL for detecting 2 ppmv.
gen, oxygen, nitrogen, and carbon monoxide will be needed to
preparesyntheticstandardsamplesasdescribedinTestMethod
NOTE 6—Use of a reverse-flow arrangement will facilitate removal of
D2505.(Warning—Flammable gases. Hazardous pressure. heavier gases and decrease the elapsed time of analysis.
See Annexes A1.1-A1.5.) (Warning—Flammable. Poison.
9.4 Record all of the desired peaks on each of the synthetic
Harmful if inhaled. Dangerous when exposed to flame. See
blends prepared.
Annex A1.5.) (Warning—Hazardous pressure. See Annex
9.5 Prepare a chart for each compound, plotting the peak
A1.2.) Certified calibration blends are commercially available
height of the compound or peak area of the compound against
from numerous sources and can be used as the synthetic
the concentration of the compounds in ppmv. The peak area
standard samples.
can be determined by any method that meets the precision
6.4 Carrier Gases—Argon or helium.
requirements of Section 12. Methods found to be acceptable
include planimetering, integration (electronic or mechanical or
NOTE 3—Practice E260 contains information that will be helpful to
computer processing), and triangulation.
those using this test method.
10. Procedure
7. Sampling
10.1 Connect the sample cylinder containing a gaseous
7.1 Samples shall be supplied to the laboratory in high-
sample to the gas sample valve with a metal tube and allow the
pressure sample cylinders, obtained using the procedures
sample to flow from the sample tube for about ⁄2 min. at a rate
described in Practice F307 or similar methods.
of 70 to 100 mL/min.
10.2 Inject into the instrument the same volume of sample
8. Preparation of Apparatus
as used for calibration, (pressure of sample and calibration gas
8.1 Chromatographic Column Packing—Crush in a porce- must be the same in the sample loop) and record the peak areas
lain mortar and sieve to 40 to 60-mesh size about 200 g of or peak heights desired.
molecular sieves 5A in order to have enough for several
11. Calculation
columns. All work of preparing molecular sieves and packing
columns with this material shall be done rapidly, preferably 11.1 From the peak height or area of the compound in the
under a blanket of dry nitrogen in order to minimize moisture sample, determine the moles per million of the compound
absorption. Heat the screened molecular sieves in an oven at using the charts prepared in calibration.Atypical characteriza-
274 6 14°C (525 6 25°F) for 24 h purging with dry nitrogen tion showing hydrogen, oxygen, and nitrogen in ethylene is
at a rate of about 5 mL/min during this time. The nitrogen rate presented in Fig. 1.
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