ASTM D4468-85(2006)
(Test Method)Standard Test Method for Total Sulfur in Gaseous Fuels by Hydrogenolysis and Rateometric Colorimetry
Standard Test Method for Total Sulfur in Gaseous Fuels by Hydrogenolysis and Rateometric Colorimetry
SIGNIFICANCE AND USE
This test method can be used to determine specification, or regulatory compliance to requirements, for total sulfur in gaseous fuels. In gas processing plants, sulfur can be a contaminant and must be removed before gas is introduced into gas pipelines. In petrochemical plants, sulfur is a poison for many catalysts and must be reduced to acceptable levels, usually in the range from 0.01 to 1 ppm/v. This test method may also be used as a quality-control tool for sulfur determination in finished products, such as propane, butane, ethane, and ethylene.
SCOPE
1.1 This test method covers the determination of sulfur gaseous fuels in the range from 0.001 to 20 parts per million by volume (ppm/v).
1.2 This test method may be extended to higher concentration by dilution.
This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns 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. Specific precautionary statements are given in 6.7, 6.8, and 7.3.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
Designation:D4468–85(Reapproved2006)
Standard Test Method for
Total Sulfur in Gaseous Fuels by Hydrogenolysis and
Rateometric Colorimetry
This standard is issued under the fixed designation D4468; 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 4. Significance and Use
1.1 This test method covers the determination of sulfur 4.1 This test method can be used to determine specification,
gaseousfuelsintherangefrom0.001to20partspermillionby or regulatory compliance to requirements, for total sulfur in
volume (ppm/v). gaseous fuels. In gas processing plants, sulfur can be a
1.2 This test method may be extended to higher concentra- contaminantandmustberemovedbeforegasisintroducedinto
tion by dilution. gas pipelines. In petrochemical plants, sulfur is a poison for
1.3 This standard may involve hazardous materials, opera- many catalysts and must be reduced to acceptable levels,
tions, and equipment. This standard does not purport to usually in the range from 0.01 to 1 ppm/v. This test method
address all of the safety concerns associated with its use. It is may also be used as a quality-control tool for sulfur determi-
the responsibility of the user of this standard to establish nation in finished products, such as propane, butane, ethane,
appropriate safety and health practices and determine the and ethylene.
applicability of regulatory limitations prior to use. Specific
5. Apparatus
precautionary statements are given in 6.7, 6.8, and 7.3.
5.1 Pyrolysis Furnace—A furnace that can provide an
2. Referenced Documents
adjustable temperature of 900 to 1300°C in a quartz or ceramic
2.1 ASTM Standards: tube of 5 mm or larger tube (ID) is required for pyrolysis of the
D1193 Specification for Reagent Water sample. (See Fig. 1.) The flow system is to be a fluorocarbon
D1914 Practice for Conversion Units and Factors Relating orothermaterialinerttoH Sandothersulfurcompounds.(See
to Sampling and Analysis of Atmospheres Fig. 1.)
D4045 Test Method for Sulfur in Petroleum Products by 5.2 Rateometric H S Readout—Hydrogenolysis products
Hydrogenolysis and Rateometric Colorimetry contain H S in proportion to sulfur in the sample. The H S
2 2
concentration is determined by measuring rate of change of
3. Summary of Test Method
reflectance of a tape impregnated with lead acetate caused by
3.1 The sample is introduced at a constant rate into a darkening when lead sulfide is formed. Rateometric electron-
flowing hydrogen stream in a hydrogenolysis apparatus. The
ics, adapted to provide first derivative output, allows sufficient
sampleandhydrogenarepyrolyzedatatemperatureof1000°C sensitivity to measure to 0.001 ppm/v. (See Fig. 2.)
or above, to convert sulfur compounds to hydrogen sulfide
5.3 Recorder—A suitable chart recorder may be used for a
(H S). Readout is by the rateometric detection of the colori- permanent record of analysis.
metric reaction of H S with lead acetate. Units used are ppm/v,
6. Reagents and Materials
which is equivalent to micromoles/mole.
6.1 Purity of Chemicals—Reagent grade unless specified
otherwise.
ThistestmethodisunderthejurisdictionofASTMCommitteeD03onGaseous 6.2 Purity of Water—Unless otherwise indicated, reference
Fuels and is the direct responsibility of Subcommittee D03.05 on Determination of
to water shall be understood to mean Type II, reagent grade
Special Constituents of Gaseous Fuels.
water, conforming to Specification D1193.
Current edition approved June 1, 2006. Published August 2006. Originally
6.3 Sensing Tape—Lead acetate impregnated analytical
approved in 1985. Last previous edition approved in 2000 as D4468–85 (2000).
DOI: 10.1520/D4468-85R06.
quality filter paper shall be used.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.4 Acetic Acid (5 %)—Mix 1 part by volume reagent grade
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
glacial acetic acid with 19 parts water to prepare 5 % acetic
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. acid solution.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D4468–85 (2006)
FIG. 1 Hydrogenolysis Flow Diagram
FIG. 2 Photorateometry H S Readout
D4468–85 (2006)
6.5 Gastight Syringe—A gastight 0.1- and 0.5-mL syringe 7.6 If the change in the recorder zero is less than 4 %, then
for preparing calibration standard. Volumetric measurement reset the recorder zero to the desired position while the
hydrogen is flowing.This should be performed with the span at
accuracy of the syringe shall be 1 % or better.
maximum.
6.6 PistonCylinder—Usea10-Lacryliccylinderwithafree
moving piston and silicone rubber “O” ring lubricated with a
8. Standardization
free-flowing silicone lubricant. This cylinder is used to prepare
8.1 With hydrogen flow at 200 mL/min, advance tape to an
ppm/v calibration samples volumetrically.
unexposed area and note baseline.
6.7 Carbonyl Sulfide (COS)—Alecture bottle of COS, 99 %
8.2 Prepare a reference standard as described in Section 9.
purity, with a needle valve connected to the lecture bottle
Connect the reference sample to the pump and the pump to the
outlet. Connect 2 ft of tygon tubing to allow insertion of a
analyzer. When a stable reading is obtained, record this value
hypodermic syringe to withdraw pure COS while tubing is
(C in 11.1). Advance the tape and introduce reference sample
purged from the lecture bottle. Other sulfur compounds can be
gas flow with a sulfur concentration near that expected in the
used with adequate odor control. If the sulfur compound has
unknown(see9.2).Adjustthesampleflowto65mL/min.After
two sulfur atoms per molecule, reduce the volume by one half.
about 4 min, adjust the recorder span such that the recording
(Warning—Work with COS should be done in a well-
indicates to desired response. The response is linear.Acalibra-
ventilated area, or under a fume hood.)
tion standard, such as 0.8 ppm/v, can be prepared and the
6.8 Hydrogen Gas—Use sulfur-free hydrogen of laboratory
recorder span adjusted to 80 % of full scale so that full scale is
grade. (Warning—Hydrogen has wide explosive limits when
1 ppm/v and any lower value can be read directly on a scale
mixed with air. See 1.3 regarding precautions.)
divided into 100 parts.
6.9 Carrier Gas for Calibration Standards—Use sulfur-free
9. Calibration and Standardization
laboratory grade bottled gas of the same type or similar density
9.1 Reference Standard—Reference standards are prepared
as the gas to be analyzed or calibrate the flowmeter to establish
by volumetric measurement at the time the reference material
correct flow setting for an available carrier gas. Test, as in 7.5,
is to be used. (See Fig. 3.) This minimizes deterioration of the
adding the carrier gas flow to the hydrogen flow.
sample. Normally this reference standard will deteriorate less
6.10 Purge Gas—Sulfur-free purge gas, nitrogen, CO,or
than 1 % in 15 min. Small volumes of pure sulfur compound
other inert gas. Commercial grade cylinder gas is satisfactory.
aremeasuredusingagastightsyringe.Dilutio
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.