1、Designation: D7653 10Standard Test Method forDetermination of Trace Gaseous Contaminants in HydrogenFuel by Fourier Transform Infrared (FTIR) Spectroscopy1This standard is issued under the fixed designation D7653; the number immediately following the designation indicates the year oforiginal adoptio
2、n 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 This test method employs an FTIR gas analysis systemfor the determination o
3、f trace impurities in gaseous hydrogenfuels relative to the hydrogen fuel quality limits described inSAE TIR J2719 (April 2008) or in hydrogen fuel qualitystandards from other governing bodies. This FTIR method isused to quantify gas phase concentrations of multiple targetcontaminants in hydrogen fu
4、el either directly at the fuelingstation or on an extracted sample that is sent to be analyzedelsewhere. Multiple contaminants can be measured simulta-neously as long as they are in the gaseous phase and absorb inthe infrared wavelength region. The detection limits as well asspecific target contamin
5、ants for this standard were selectedbased upon those set forth in SAE TIR J2719.1.2 This test method allows the tester to determine whichspecific contaminants for hydrogen fuel impurities that are inthe gaseous phase and are active infrared absorbers which meetor exceed the detection limits set by S
6、AE TIR J2719 for theirparticular FTIR instrument. Specific target contaminants in-clude, but are not limited to, ammonia, carbon monoxide,carbon dioxide, formaldehyde, formic acid, methane, ethane,ethylene, propane and water. This test method may be extendedto other impurities provided that they are
7、 in the gaseous phaseor can be vaporized and are active infrared absorbers.1.3 This test method is intended for analysis of hydrogenfuels used for fuel cell feed gases or for internal combustionengine fuels. This method may also be extended to the analysisof high purity hydrogen gas used for other a
8、pplicationsincluding industrial applications, provided that target impuri-ties and required limits are also identified.1.4 This test method can be used to analyze hydrogen fuelsampled directly at the point-of-use from fueling stationnozzles or other feed gas sources. The sampling apparatusincludes a
9、 pressure regulator and metering valve to provide anappropriate gas stream for direct analysis by the FTIR spec-trometer.1.5 This test method can also be used to analyze samplescaptured in storage vessels from point-of-use or other sources.Analysis of the stored samples can be performed either in am
10、obile laboratory near the sample source or in a standardanalytical laboratory.1.6 A test plan should be prepared that includes (1) thespecific impurity species to be measured, (2) the concentrationlimits for each impurity species, (3) the determination of theminimum detectable concentration for each
11、 impurity species asmeasured on the apparatus before testing.1.7 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.7.1 ExceptionAll values are based upon common termsused in the industry of those particular values and when notco
12、nsistent with SI units, the appropriate SI unit will beincluded in parenthesis after the common value usage. (4.4,7.8, 7.9, 10.5, and 11.6)1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to
13、 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D5287 Practice for Automatic Sampling of Gaseous FuelsD6348 Test Method for Determination of Gaseous Com-pounds by Extractive Direct
14、Interface Fourier TransformInfrared (FTIR) SpectroscopyD7606 DESIGATTRIBUTE D7606 HAD NO TITLE INSAD_TABLES2.2 SAE Document:3SAE TIR J2719 Informational Report on the Developmentof a Hydrogen Quality Guideline for Fuel Cell Vehicles2.3 EPA Documents41This test method is under the jurisdiction ofASTM
15、 Committee D03 on GaseousFuels and is the direct responsibility of Subcommittee D03.14 on Hydrogen andFuel Cells.Current edition approved Sept. 1, 2010. Published March 2011. DOI: 10.1520/D765310.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
16、 serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale,PA 15096-0001, http:/www.sae.org.4Available from United States Environmental Protection Age
17、ncy (EPA), ArielRios Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460, http:/www.epa.gov.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.EPA 40 CFR Protection of the Environment, Appendix B toPart 136 Definition and Procedure
18、for the Determinationof the Method Detection Limit.EPA 40 CFR Protection of the Environment, Appendix B topart 60: Performance Specification 15 PerformanceSpecification for Extractive FTIR Continuous EmissionsMonitoring Systems in Stationary Sources2.4 Other Document:“Fourier Transform Infrared Spec
19、trometry” (Second Edi-tion) Peter R. Griffiths and James A. de Haseth, JohnWiley and Son, 2007.3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 analytical interference, nthe physical effects ofsuperimposing two or more light waves. Analytical interfer-ences occur when two or mo
20、re compounds have overlappingabsorbance bands in their infrared spectra.3.1.2 analytical algorithm, nthe method used to quantifythe concentration of the target contaminants and interferencesin each FTIR Spectrum. The analytical algorithm shouldaccount for the analytical interferences by conducting t
21、heanalysis in a portion of the infrared spectrum that is the mostunique for that particular compound.3.1.3 apodizationa mathematical transformation carriedout on data received from an interferometer to reduce the sidelobes of the measured peaks. This procedure alters the instru-ments response functi
22、on. There are various types of transfor-mation; the most common forms are boxcar, triangular, Happ-Genzel, and Norton-Beer functions.3.1.4 background spectrumthe spectrum taken in theabsence of absorbing species or sample gas, typically con-ducted using dry nitrogen or zero air in the gas cell.3.1.5
23、 classical least squares (CLS)common method ofanalyzing multicomponent infrared spectra by scaled absor-bance subtraction, also referred to as K-Matrix.3.1.6 constituentcomponent (or compound) found withina hydrogen fuel mixture.3.1.7 contaminantimpurity that adversely affects the com-ponents within
24、 the fuel cell system or the hydrogen storagesystem.3.1.8 dry nitrogen (or dry N2)nitrogen gas with a dewpoint at or below -60 C.3.1.9 dynamic calibrationcalibration of an analytical sys-tem using certified calibration gas standards that are diluted toknown concentration.3.1.10 FCVHydrogen fuel cell
25、 vehicle.3.1.11 FTIRabbreviation for Fourier Transform Infrared.Typically refers to a type of infrared spectrometer whichincorporates a Michelson interferometer to modulate the infra-red radiation before probing the sample. The resultant radiationis then measured with an infrared detector and the re
26、sultingsignal is decoded using a Fourier transform algorithm tocompute the infrared spectrum.3.1.12 Fuel Cell Grade Hydrogenhydrogen satisfying thespecifications in SAE TIR J2719.3.1.13 gaseous fuelhydrogen gas intended for use as afuel cell feed gas or as a fuel for internal combustion engines.3.1.
27、14 gauge pressurepressure measured above ambientatmospheric pressure. Zero gauge pressure is equal to theambient atmospheric (barometric) pressure (psig).3.1.15 path lengththe distance that the sample gas inter-acts with the infrared radiation.3.1.16 poisoningprocess by which catalysts are madeinope
28、rative due to the activity of substances such as hydrogensulfide or other sulfur substances that can bind to a componentin the catalyst (such as a noble metal like platinum) used in thefuel cell.3.1.17 Proton Exchange Membrane Fuel Cells(PEMFCs)PEMFC is an electrochemical apparatus that usesan anode
29、 and cathode to convert H2and O2into electricity.3.1.18 purified nitrogen (or purified N2)nitrogen gas thatis purified to Ultra-High Purity Grade (99.9995 %) or equiva-lent, containing total impurities 35 C) to avoidfluctuations or temperature mismatch due to changes in theambient temperature. Be su
30、re to use the same FTIR spectralresolution and apodization function for calibrations and mea-surements. The gas cell path length is chosen to provideadequate sensitivity while maintaining maximum absorbanceunit (AU) values for the quantification region to be at or under1.0 AU. If necessary, the maxi
31、mum absorbance requirementcan be met by choosing analytical regions that exclude strongabsorption features. The number of FTIR scans (or measure-ment time) can be increased to improve detection limits.Record all settings and actual gas cell absolute pressure andtemperature for each calibration spect
32、rum.9.1.3 Determine the Number of Gas Cell Volumes Requiredto Flush the FTIR Gas CellThe Environmental ProtectionAgency (EPA) recommends 5 cell volumes are adequate tofully flush the gas cell of the sample (See EnvironmentalProtection Agency 40 CFR: Protection of the Environment,Appendix B to part 6
33、0). For a flow rate of 1 litre per minute(LPM) and a gas cell volume of 200 ml the number of cellvolumes would be 1.0 LPM/0.2 L = 5 volumes flushed per 1min. For a larger cell volume of 500 ml for the same flow rateyou would only achieve 1.0LPM/0.5 L = 2 volumes flushed per1 min. Therefore the amoun
34、t of time required to completelyflush the gas sample from the gas cell is dependant upon thegas cell internal volume and the gas sample flow rate. Forfaster data acquisition a smaller gas sample volume is desiredor a faster flow rate can be used but that must be balanced bythe amount of sample that
35、is resident in the gas samplechamber/cylinder that was collected.9.1.4 Prior to collecting the calibration spectra verify theFTIR performance is within acceptable limits following theinstructions inAnnexA1 as well as those specified by the FTIRmanufacturer.9.2 Collect Calibration Spectra for Species
36、 in CalibrationGas Cylinders:9.2.1 Purge the gas blending apparatus and FTIR gas cellwith purified H2. Monitor for one or more surrogate contami-nant species (generally H2O is selected) using the FTIR toverify that the reported concentrations have reached a mini-mum and stable value. As needed a new
37、 background spectrumis acquired.9.2.2 Program the gas blending apparatus to prepare therequired concentration mixtures while maintaining a relativelyconstant flow rate to prevent an increase in pressure in theFIG. 3 Apparatus for Measuring Samples from High Pressure Storage Containers. Line Switchin
38、g Valve (V), Needle Valve (NV)D7653 106FTIR gas cell. For each blend, allow the mixture to flowthrough the FTIR gas cell purging at the required number ofcell volumes as determined in 9.1.3.9.2.3 Collect at least three calibration spectra for eachconcentration blend level. The three spectra can late
39、r be used toverify that the calibration gas concentration was within 6 2%of the calibration gas value. Record the FTIR settings, gas celltemperature, gas cell absolute pressure and gas cell path length.Repeat this process for each desired concentration for eachspecies in the calibration gas cylinder
40、.9.2.4 As desired, a single set of calibration gas blends canbe prepared that spans the desired range for all species in thecalibration gas bottle providing that there is no spectral overlapbetween the target contaminants in the blend. In general it isnot possible or reasonable to combine all of the
41、 componentsinto a single standard but a sub set of contaminants that do nothave spectral overlaps can be combined. For example, hydro-carbons, can be blended with NO, N2O, CO or CO2(forexample, methane and CO or methane and CO2) and have nooverlap within the usable infrared region. Care should be ta
42、kento ensure that contaminants in the blends do not react with eachother.9.3 Collect Calibration Spectra for Species from Perme-ation Tubes:9.3.1 Purge the gas blending apparatus and FTIR gas cellwith purified H2. Monitor for one or more surrogate contami-nant species (for example, H2O which tends t
43、o be more sticky)using the FTIR to verify that the reported concentrations havereached a minimum and stable value such as applying an f-testto determine the values are no longer significant. As needed anew background spectrum is acquired.9.3.2 Set the temperature of the permeation tube oven asdirect
44、ed by the permeation tube manufacturer and set the massflow controllers as required to prepare the desired concentra-tion. The use of permeation tubes at ambient temperature is notacceptable as this will result in excessive variability in perme-ation rates due to a lack of fine temperature control.
45、Asnecessary, the output flow from the permeation oven can besplit using the output mass flow controller and a backpressureregulator in order to prepare lower concentration standards. Foreach blend, allow the mixture to flow through the FTIR gas cellpurging at the required number of cell volumes as d
46、efined in9.1.3.9.3.3 Collect at least three calibration spectra for eachcontaminant (impurity) concentration. The three spectra can beused to verify that the calibration gas concentration was notchanging within 6 2 %. Record the FTIR settings, gas celltemperature, gas cell absolute pressure and gas
47、cell path length.Also record the permeation tube serial number, concentrationcalculation, oven temperature, and flow conditions. Repeat thisprocess for each desired concentration for each contaminantspecies that requires a permeation tube to be used.9.3.4 Follow Annex A3 for more details on the crea
48、tion ofthe FTIR Reference Spectra.9.4 Prepare Analytical Methods for Each Impurity Species:9.4.1 For gas impurity analysis the main analytical methodused is based upon Classical Least Squares (CLS) algorithms.This method requires that each component that might bepresent in the final gas sample be in
49、cluded in the full analysismethod. A calibration method is created for each componentusing the 10 or more concentrations that were created with thegas blending system described above. The analysis region ischosen to minimize interferences from other componentsknown to be present in the gas sample. Linear, quadratic, cubic,quartic or spline data interpolation functions may be used to fitthe concentration range and reduce the prediction error of themethod. For more details on Classical Least Squares see“Fourier Transform Infrared Spectrometry” (Second Edition),
