1、Designation: D7652 11Standard Test Method forDetermination of Trace Hydrogen Sulfide, Carbonyl Sulfide,Methyl Mercaptan, Carbon Disulfide and Total Sulfur inHydrogen Fuel by Gas Chromatography and SulfurChemiluminescence Detection1This standard is issued under the fixed designation D7652; the number
2、 immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1
3、 This test method describes a procedure primarily for thedetermination of hydrogen sulfide, carbonyl sulfide, methylmercaptan, and carbon disulfide (Table 1) in hydrogen fuels forfuel cell vehicles (FCV) by gas chromatograph with sulfurchemiluminescence detection. The reporting limit is 0.02 ppbv(na
4、nomole per mole as volume), based upon the analysis of a500 mL hydrogen sample. The procedures described in thismethod were designed to satisfy sulfur contaminant determi-nation requirements contained in SAE TIR J2719 and theCalifornia Code of Regulations, CFR , Title 4, Division 9,Chapter 6, Articl
5、e 8, Sections 4180 4181.1.2 This test method can be extended to other sulfur speciesin hydrogen fuel that are eluted through a chromatographiccolumn.1.3 This test method can be modified to analyze all sulfurcompounds present without chromatographic separation; thus,providing a total sulfur estimatio
6、n without speciation (Appen-dix X1).1.4 If any new sulfur compounds need to be analyzed inhydrogen fuel, the calibration or spiking sulfur standards mustinclude these new compounds after their method detectionlimit study. In addition, no co-elution is allowed in thechromatographic analysis of the ca
7、libration standard contain-ing both the newly added and the existing sulfur targetcompounds. If necessary, the chromatographic conditions maybe modified to achieve this goal.1.5 Although, primarily intended for determining sulfur inhydrogen used as a fuel for fuel cell or internal combustionengine p
8、owered vehicles, this test method can also be used tomeasure sulfur compounds in other gaseous fuels and gaseousmatrices provided data quality objectives are satisfied.1.6 The values stated in SI units are standard. The valuesstated in inch-pound units are for information only.1.7 Mention of trade n
9、ames in this standard does notconstitute endorsement or recommendation for use. Othermanufacturers of equipment or equipment models can be used.1.8 Alternative DetectorsThis test method is written pri-marily for the use of sulfur chemiluminescent detectors butother detectors can be used provided the
10、y can detect hydrogensulfide, carbonyl sulfide, methyl mercaptan, and carbon disul-fide at 0.02 ppbv in hydrogen and meet data quality objectivesfor the intended use.1.9 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of t
11、he user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For safety issuesrelated to liquid nitrogen, refer to material safety data sheet(MSDS) from liquid nitrogen supplier.2. Referenced Documents2.1 ASTM
12、 Standards:2D5504 Test Method for Determination of Sulfur Com-pounds in Natural Gas and Gaseous Fuels by Gas Chro-matography and ChemiluminescenceD7606 Practice for Sampling of High Pressure Hydrogenand Related Fuel Cell Feed Gases2.2 SAE Standards:3SAE TIR J2719 Information Report of the Developmen
13、t ofa Hydrogen Quality Guideline for Fuel Cell Vehicles2.3 California Code of Regulations:41This test method is under the jurisdiction ofASTM Committee D03 on GaseousFuels and is the direct responsibility of Subcommittee D03.14 on Hydrogen andFuel Cells.Current edition approved March 1, 2011. Publis
14、hed March 2011. DOI 10.1520/D765211.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from SAE Inter
15、national (SAE), 400 Commonwealth Dr., Warrendale,PA 15096-0001, http:/www.sae.org.4Available from the Office ofAdministrative Law, 300 Capitol Mall, Suite 1250,Sacramento, CA 958144339.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
16、California Code of Regulations Title 4, Division 89, Chap-ter 6, Article 8, Sections 41804181.2.4 US Code of Federal Regulations:5CFR Title 40, Appendix B, PART 136 (Guideline Establish-ing Test Procedures for the Analysis of Pollutants)3. Terminology3.1 Definitions:3.1.1 absolute pressurepressure m
17、easured with referenceto absolute zero pressure, usually expressed as kPa, mm Hg,bar or psia.3.1.2 constituentcomponent (or compound) found withina hydrogen fuel mixture.3.1.3 contaminantimpurity that adversely affects the com-ponents within the fuel cell system or the hydrogen storagesystem.3.1.4 c
18、ryogena refrigerant used to obtain very low tem-peratures. The cryogen used in this method is liquid nitrogen(bp -195C).3.1.5 dynamic calibrationcalibration of an analytical sys-tem using calibration gas standard generated by diluting aknown concentration of compressed gas standard with a diluentgas
19、.3.1.6 fuel cell grade hydrogenhydrogen satisfying thespecifications in SAE TIR J2719.3.1.7 gaseous fuelmaterial to be tested, as sampled, with-out change of composition by drying or otherwise.3.1.8 poisoningprocess by which catalysts are made in-operative due to the activity of substances such as h
20、ydrogensulfide or other sulfur substances that can bind to the catalystused in the fuel cell.3.1.9 qualitative accuracythe ability of an analytical sys-tem to correctly identify compounds without necessarily pro-viding a precise concentration.3.1.10 quantitative accuracythe ability of an analyticals
21、ystem to measure the concentration of an identified compoundto a specified degree of accuracy.3.1.11 static calibrationcalibration of an analytical sys-tem using standards in a matrix, state or manner different thanthe samples to be analyzed.3.1.12 reporting limitThe limit is reported for eachsample
22、 analysis. The spike analysis at the reporting limit (10.7)must be performed to demonstrate the reporting limit can bereached. The reporting limit is 0.02 ppbv for each sulfur targetcompound analyzed by this method.3.1.13 method detection limitThe method detection limitis described in US Code of Fed
23、eral Regulations, CFR Title 40,Appendix B, PART 136 (Guidelines Establishing Test Proce-dures for the Analysis of Pollutants). For this method, sevenreplicates of each sulfur target compound at the reporting limit,0.02 ppbv, in hydrogen are analyzed to establish the methoddetection limits (10.5).3.2
24、 Acronyms:3.2.1 FCVFuel Cell Vehicle.3.2.2 PEMFCproton exchange membrane fuel cell.4. Summary of Test Method4.1 The analysis of sulfur compounds at trace level inhydrogen is challenging due to the reactivity of these sub-stances, especially hydrogen sulfide. These substances can beabsorbed by or out
25、 gas from metal surfaces such as stainlesssteel. Absorption and reaction with metals impacts both sam-pling and analysis of sulfur compounds in gaseous streams. An1800 psi rated sampling cylinder is used for the samplecollection as described in Practice D7606. The cylinder isinternally coated with a
26、n inert material, such as silicon oxide,to reduce the surface adsorption and reactivity of sulfurcompounds on the metal surface. Analytic systems must alsobe passivated against sulfur loss and reactivity. Passivation canbe provided by using TFE-fluorocarbon, silica or glass, orsurface treated metal
27、in the analytic system as well as anytransfer lines from the sample to the analysis system.4.1.1 The diagram for analysis of H2S, COS, CH3SH, CS2and total sulfur in Hydrogen is shown in Fig. 1, in which thesulfur analysis is performed by concentrating and analyzing a500 mL of sample taken from sampl
28、e container by a 500 mLgas tight syringe with plunger tip covered with TFE-fluorocarbon. Due to high hydrogen pressure, it is difficult totake hydrogen sample directly into a syringe. One method is touse a short clean thick wall TFE-fluorocarbon tube (minimum0.185 cm wall thickness) as a medium for
29、sample transfer, asshown in Fig. 2 and described in the following passage.Ashortthick wall TFE-fluorocarbon tube is connected to one valve(Valve 1, Fig. 2) on a hydrogen fuel sample bottle. The otherend of the short TFE-fluorocarbon tube is connected to anothervalve (Valve 2, Fig. 2) with a septum o
30、n the other end to accepta needle of a 500 mL gas tight syringe. With Valve 2 closed,open Valve 1 to pressurize the TFE-fluorocarbon tube. CloseValve 1 first and then open Valve 2 slowly to release thepressurized hydrogen sample into a 500mLsyringe.WarningPlease allow syringe plunger to expandfreely
31、 to avoid pressure inside the syringe over 30 psi when thesyringe plunger stops. For the first time only, remove thehydrogen sample from syringe. Repeat the procedure severaltimes to achieve a 500 mL sample in the syringe. If the samplepressure is less than 200 psi, a 500 mL sample can be directlyta
32、ken from the sample bottle through a septum. Alternativemethods can be used other than a gas tight syringe for5Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.TABLE 1 Trace Sulfur ContaminatesCom
33、pound Formula MW BCC MPC CAS No.Hydrogen sulfide H2S 34.08 -61 -86 7783064Carbonyl sulfide COS 60.07 -50 -139 463581Methyl maercaptan CH2SH 48.11 6 -123 74931Carbon disulfide CS276 46.5 -111.6 75150D7652 112sampling. These methods could include automated gas valves.Other sampling devices are accepta
34、ble as long as they areconstructed of appropriate passivated materials and can intro-duce a sample of at least 500 mL.4.1.2 A 500 mL sample of hydrogen is introduced into aTFE-fluorocarbon tube that is suspended over a bath of liquidnitrogen using syringe injection of the sample through Injec-tion P
35、ort 1 of Fig. 1. All sulfur compounds are trapped whilehydrogen is expelled through the vent valve of T-Union 1shown in Fig. 1. The trap is warmed to room temperature byimmersing it into a water bath at room temperature. Trappedsulfur compounds are desorbed onto a capillary column forseparation. The
36、 sulfur compounds eluting from the capillarycolumn are detected by sulfur chemiluminescence detection.Alternative trapping methods and devices may be used pro-vided sensitivity requirements as defined in SAE J2719 and theCalifornia Code of Regulations, Title 4, Division 9, Chapter 6,Article 8, Secti
37、ons 4180 4181. These Alternative methodsmay or may not require the use of a cryogen.5. Significance and Use5.1 Low operating temperature fuel cells such as protonexchange membrane fuel cells (PEMFCs) require high purityhydrogen for maximum material performance and lifetime.Sulfur compounds are prese
38、nt in many of the materials used inhydrogen production and small quantities typically remainafter processing and purification. Part-per-billion concentra-tions of sulfur gases such as hydrogen sulfide (H2S), carbonylsulfide (COS) and mercaptans diminish single fuel cell capac-ity.6. ApparatusNOTE 1A
39、dditional details on general sulfur gas determination can befound in Test Method D5504.6.1 Gas chromatography (GC) A gas chromatograph ofstandard manufacture, with hardware necessary for interfacingto a sulfur chemiluminescence detector, possessing an inletsystem as described in 6.2, and containing
40、all other featuresnecessary for measuring sulfur compounds in hydrogen can beused.6.2 Sample Inlet SystemA sample inlet system capable ofcryogenic or ambient concentration of sulfur compounds in aTFE-fluorocarbon tube or appropriate trapping device withoutloss of analytes is required. The inlet syst
41、em must be evaluatedfrequently for possible sulfur contamination. The injection andconcentration systems must transfer all compounds of interestto the GC column without loss or absorption. Since stainlesssteel can absorb or off gas sulfur compounds, it must be limitedin its use within the sample con
42、centration system or it must betreated specifically for use with sulfurs. The injection systeminsert can either be made of glass, TFE-fluorocarbon, or otherappropriate material which does not adsorb or off gas sulfurFIG. 1 Diagram for Analysis of H2S, COS, CH3SH, CS2and Total Sulfur in HydrogenFIG.
43、2 Hydrogen Sample from a High Pressure Sample ContainerD7652 113compounds. Fig. 1 shows a configuration that has beensuccessfully used in this application. As shown in Fig. 1,Injector Port 1 is connected to a T-Union 1 using a one meterTFE-fluorocarbon tube with an approximate 1 mm ID. Theremaining
44、two openings of T-Union 1 are connected to a 75 m0.53 mm ID 3 micron DB-624 capillary column and a ventvalve. The TFE-fluorocarbon tube is used as a cryogenic trapfor the sulfur compounds in hydrogen. The vent valve is usedto rapidly release hydrogen after cryogenically trapping theanalytes in the T
45、FE-fluorocarbon tube during introduction of a500 mL hydrogen sample. After sample introduction, the valveis closed, the TFE-fluorocarbon trap is removed from liquidnitrogen to ambient air and the GC/SCD run starts.6.3 Sulfur Chemiluminescence Detector (SCD)The speci-fication of SCD is the same as th
46、ose in 5.1.3.2 of Test MethodD5504.6.4 Data AcquisitionA computer or other data recorderloaded with appropriate software for data acquisition, datareduction, and data reporting and possessing the followingcapabilities is required.6.4.1 Graphic presentation of the chromatogram.6.4.2 Digital display o
47、f chromatographic peak areas.6.4.3 Identification of peaks by retention time or relativeretention time, or both.6.4.4 Calculation and use of response factors.6.4.5 External standard calculation and data presentation.6.5 Hydrogen fuel collection vesselsAny collection vesselwith working pressures up t
48、o 1800 psi can be used provided thevessel internal surface is inert towards sulfur compounds. A1-liter 1800 psi pressure proof stainless steel container withtwo valves on opposite ends and silicon coating on the insidesurface has been successfully used in this application. Thevessel must have a DOT
49、3A1800 label (United Stated Depart-ment of Transportation mandated label) affixed to the outsidesurface for transportation of hydrogen samples.6.6 Carrier Gas ControlConstant flow control of carrierand detector gases is critical for optimum and consistentanalytical performance. Control is achieved by use of pressureregulators and fixed flow restrictors. Mass flow controllers orelectronic pressure controllers can be used for optimal instru-ment performance.6.7 Chromatographic ColumnA variety of columns havebeen used successfully for the de
