1、BRITISH STANDARD BS EN ISO 6974-4:2001 Incorporating Amendment No. 1 to BS ISO 6974-4:2000 (renumbers the BS ISO as BS EN ISO 6974-4:2001) Natural gas Determination of composition with defined uncertainty by gas chromatography Part 4: Determination of nitrogen, carbon dioxide and C1 to C5 and C6+ hy
2、drocarbons for a laboratory and on-line measuring system using two columns The European Standard EN ISO 6974-4:2001 has the status of a British Standard ICS 75.060 BS EN ISO 6974-4:2001 This British Standard, having been prepared under the direction of the Sector Committee for Materials and Chemical
3、s, was published under the authority of the Standards Committee and comes into effect on 15 August 2000 BSI 15 July 2002 ISBN 0 580 36320 1 National foreword This British Standard is the official English language version of EN ISO 6974-4:2001. It is identical with ISO 6974-4:2000. The UK participati
4、on in its preparation was entrusted to Technical Committee PTI/15, Natural gas and gas analysis, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or
5、 European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the
6、 necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committ
7、ee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN ISO title page, the EN ISO
8、 foreword page, pages ii to v, a blank page, pages 1 to 12, the Annex ZA page and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments 13838 15 July 2002 Implementation of the European
9、StandardEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM ENISO69744 August2001 ICS75.060 Englishversion NaturalgasDeterminationofcompositionwithdefined uncertaintybygaschromatographyPart4:Determinationof nitrogen,carbondioxideandC1toC5andC6+hydrocarbons foralaboratoryandonlinemeasuringsystemusingtwo c
10、olumns(ISO69744:2000) GaznaturelDterminationdelacompositionavecune incertitudedfinieparchromatographieenphasegazeuse Partie4:Dterminationdelazote,dudioxydedecarbone etdeshydrocarbures(C1C5etC6+)pourunlaboratoire etunsystmedemesureencontinuemployantdeux colonnes(ISO69744:2000) ErdgasBestimmungderZusa
11、mmensetzungmit definierterUnsicherheitdurchGaschromatographieTeil4: BestimmungvonStickstoff,KohlenstoffdioxidundC1bis C5undC6+KohlenwasserstoffenfreinLaborundOn lineMesssystemmitzweiSulen(ISO69744:2000) ThisEuropeanStandardwasapprovedbyCENon22June2001. CENmembersareboundtocomplywiththeCEN/CENELECInt
12、ernalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeoffic
13、ialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,G
14、ermany,Greece, Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2001CEN Allrightsofexploitationinanyformand
15、byanymeansreserved worldwideforCENnationalMembers. Ref.No.ENISO69744:2001EINESO9647:42(100E) 2 CORRECTED20020313 Foreword ThetextoftheInternationalStandardfromTechnicalCommitteeISO/TC193“Naturalgas“of theInternationalOrganizationforStandardization(ISO)hasbeentakenoverasaEuropean StandardbyCMC. ThisE
16、uropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationof anidenticaltextorbyendorsement,atthelatestbyFebruary2002,andconflictingnational standardsshallbewithdrawnatthelatestbyFebruary2002. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsof thefollow
17、ingcountriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,Czech Republic,Denmark,Finland,France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg, Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandtheUnitedKingdom. Endorsementnotice ThetextoftheInternationalStandardISO69744:2000hasbeena
18、pprovedbyCENasa EuropeanStandardwithoutanymodifications. NOTENormativereferencestoInternationalStandardsarelistedinannexZA(normative). ENISO69744:2001Referencenumber ISO6974-4:2000(E) INTERNATIONAL STANDARD ISO 6974-4 Firstedition 2000-04-01 NaturalgasDeterminationof compositionwithdefineduncertaint
19、yby gaschromatography Part4: Determinationofnitrogen,carbondioxide andC1toC5andC6+hydrocarbonsfora laboratoryandon-linemeasuringsystem usingtwocolumns Gaz naturel Dtermination de la composition avec une incertitude dfinie par chromatographie en phase gazeuse Partie 4: Dtermination de lazote, du diox
20、yde de carbone et des hydrocarbures (C1 C5 et C6+) pour un laboratoire et un systme de mesure en continu employant deux colonnes ENISO69744:2001ii ISO-47964:(0002)Eiii Contents Page Foreword.iv Introduction.v 1 Scope1 2 Normativereferences2 3 Principle2 4 Materials.2 5 Apparatus.2 6 Procedure.4 6.1
21、Gaschromatographicoperatingconditions.4 6.2 PerformancerequirementsPeakresolution7 6.3 DeterminationOutlineoftheanalysis8 7 Expressionofresults8 7.1 Calculation8 7.2 Precisionandaccuracy.8 8 Testreport8 AnnexA(informative)Procedureforsettingvalvetimingsandrestrictionsetting.9 AnnexB(informative)Fina
22、ltime.10 AnnexC(informative)Typicalprecisionvalues11 Bibliography12 ENISO69744:2001ISO-47964:(0002)E iv Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(ISO memberbodies).TheworkofpreparingInternationalStandardsisnormallycarriedoutthroughISO
23、technical committees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas therighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnon-governmental,in liaisonwithISO,alsotakepartinthework.ISOcollaboratescloselywiththeInternationalElectrotechnical
24、 Commission(IEC)onallmattersofelectrotechnicalstandardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part3. DraftInternationalStandardsadoptedbythetechnicalcommitteesarecirculatedtothememberbodiesforvoting. PublicationasanInternationalStandardrequiresapp
25、rovalbyatleast75%ofthememberbodiescastingavote. AttentionisdrawntothepossibilitythatsomeoftheelementsofthispartofISO6974maybethesubjectofpatent rights.ISOshallnotbeheldresponsibleforidentifyinganyorallsuchpatentrights. InternationalStandardISO6974-4waspreparedbyTechnicalCommitteeISO/TC193, Natural g
26、as, Subcommittee SC1, Analysis of natural gas. ThispartaswellastheotherfivepartsofISO6974cancelandreplaceISO6974:1984whichspecifiedonlyone method. ISO6974consistsofthefollowingparts,underthegeneraltitle Natural gas Determination of composition with defined uncertainty by gas chromatography : Part 1:
27、 Guidelines for tailored analysis Part 2: Measuring-system characteristics and statistics for data treatment Part 3: Determination of hydrogen, helium, oxygen, nitrogen, carbon dioxide and hydrocarbons up to C 8 using two packed columns Part 4: Determination of nitrogen, carbon dioxide and C 1 to C
28、5 and C 6+ hydrocarbons for a laboratory and on- line measuring system using two columns Part 5: Determination of nitrogen, carbon dioxide and C 1 to C 5 and C 6+ hydrocarbons for a laboratory and on- line process application using three columns Part 6: Determination of hydrogen, helium, oxygen, nit
29、rogen, carbon dioxide and hydrocarbons up to C 8 using three capillary columns AnnexesAtoCofthispartofISO6974areforinformationonly. ENISO69744:2001ISO-47964:(0002)Ev Introduction ThispartofISO6974specifiesapreciseandaccuratemethodforthedeterminationofthecompositionofnatural gas.Thecompositionaldatao
30、btainedareusedforthecalculationofthecalorificvalue,therelativedensityandthe Wobbeindex.Thismethodrequirestheuseoftwocolumnsplacedinseriesinasingle-ovengaschromatograph. Thecombinationoftwocolumnsmakesbackflushingpossible.Alltheconstituentsincludingthebackflushpeakare detectedbyathermalconductivityde
31、tector(TCD). ThismethodisderivedfromISO6568, Natural gas Simple analysis by gas chromatography. ThispartofISO6974providesoneofthemethodsthatmaybeusedfordeterminingthecompositionofnaturalgas inaccordancewithparts1and2ofISO6974. ENISO69744:2001blank 1002:44796OSINEINTERNATIONALSTANDADR ISO-47964:(0002
32、)E1 NaturalgasDeterminationofcompositionwithdefined uncertaintybygaschromatography Part4: Determinationofnitrogen,carbondioxideandC1toC5andC6+ hydrocarbonsforalaboratoryandon-linemeasuringsystem usingtwocolumns 1 Scope ThispartofISO6974describesagaschromatographicmethodforthequantitativedeterminatio
33、nofnaturalgas constituentsusingatwo-columnsystem.Thismethodisapplicabletodeterminationsmadeinon-lineprocessesor inthelaboratory.Itisapplicabletotheanalysisofgasescontainingconstituentswithinthemolefractionranges giveninTable1.Theserangesdonotrepresentthelimitsofdetection,butthelimitswithinwhichthest
34、ated precisionofthemethodapplies.Althoughoneormorecomponentsinasamplemaynotbedetectedpresent,the methodcanstillbeapplicable. ThispartofISO6974isonlyapplicableifusedinconjunctionwithparts1and2ofISO6974. Table1Applicationranges Component Molefractionrange % Nitrogen 0,001to15,0 Carbondioxide 0,001to10
35、 Methane 75to100 Ethane 0,001to10,0 Propane 0,001to3,0 iso-Butane (2-methylpropane) 0,001 to 1,0 n-Butane 0,001to1,0 neo-Pentane(2,2-dimethylpropane) 0,001to0,5 iso-Pentane (2-methylbutane) 0,001 to 0,5 n-Pentane 0,001to0,5 Hexanes sumofallC 6 andhigherhydrocarbons 0,001to0,2 NOTE1 Oxygenisnotanorma
36、lconstituentofnaturalgasandwouldnotbeexpectedtobepresentingassampledforan on-lineinstrument.Ifanyoxygenispresentasaresultofaircontamination,itwillbemeasuredwiththenitrogen.Theresulting (nitrogen oxygen)valuewillbeinerrortoasmallextentbecauseoftheslightdifferencebetweendetectorresponsesfor oxygenandn
37、itrogen.Nonetheless,theresultforthenaturalgas/airmixturewillbereasonablyaccuratesinceneithercomponent contributestothecalorificvalue. ENISO69744:2001ISO-47964:(0002)E 2 NOTE2 Thecontentofheliumandargonareassumedtobenegligibleandunvaryingsuchthatheliumandargonneednot bedetermined. 2 Normativereferenc
38、es Thefollowingnormativedocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsof thispartofISO6974.Fordatedreferences,subsequentamendmentsto,orrevisionsof,anyofthesepublications donotapply.However,partiestoagreementsbasedonthispartofISO6974areencouragedtoinvestigatethe possi
39、bilityofapplyingthemostrecenteditionsofthenormativedocumentsindicatedbelow.Forundated references,thelatesteditionofthenormativedocumentreferredtoapplies.MembersofISOandIECmaintain registersofcurrentlyvalidInternationalStandards. ISO6142, Gas analysis Preparation of calibration gas mixtures Gravimetr
40、ic method. ISO6143, Gas analysis Determination of the composition of calibration gas mixtures Comparison methods. ISO6974-1:2000, Natural gas Determination of composition with defined uncertainty by gas chromatography Part 1: Guidelines for tailored analysis. ISO6974-2: 1) , Natural gas Determinatio
41、n of composition with defined uncertainty by gas chromatography Part 2: Measuring-system characteristics and statistics for data treatment. ISO7504:1984, Gas analysis Vocabulary. 3Principle Determinationofnitrogen,carbondioxide,methane,ethane,propane,butanesandpentanesbygas chromatographyusingtwocol
42、umns(ashortoneandalongone)ofDC-200onChromosorbPAWinabackflush arrangement.Theshortcolumnretainshydrocarbonsheavierthannormalpentanewhichareelutedafter backflushingasaC 6 compositepeak.Thelongcolumnisusedforthedeterminationofnitrogen,carbondioxide, methaneuptonormalpentane.Detectioniscarriedoutbyathe
43、rmalconductivitydetector(TCD).Oxygen,argon, hydrogenandheliumarenotmeasuredbythismethod. 4 Materials 4.1 Heliumcarriergas,99,99%pure. 4.2 Working-referencegasmixtures(WRM),thecompositionofwhichshallbechosentobesimilartothatof theanticipatedsample. Prepareacylinderofaworking-referencegasmixture,byagr
44、avimetricmethod,inaccordancewithISO6142, and/orcertifiedandvalidatedinaccordancewithISO6143.Theworking-referencegasmixtureshallcontainat leastnitrogen,carbondioxide,methane,ethane,propane, n-butane, iso-butane and possibly neo-pentane, iso- pentaneand n-pentane. 5 Apparatus 5.1 Laboratorygaschromato
45、graphic(GC)system,consistingofthefollowingcomponents. 5.1.1 Gaschromatograph(GC),capableofisothermaloperationandequippedasfollows: 1)Tobepublished. ENISO69744:2001ISO6-4794:(0002)E3 a) columnoven,capableofmaintainingthetemperatureofthecolumntemperaturetowithin 0,1Coverthe temperaturerangefrom70Cto15
46、0C; b) valveoven:capableofbeingmaintainedoverthetemperaturerangefrom70Cto150Coralternatively havingthecapacitytofitthevalvesinthecolumnoven; c) flowregulators:capableofregulatingthecarriergasflowrates. 5.1.2 Injectiondevice,consistingofaten-portsample-injectionvalveV1andalsousedforbackflushingC 6 co
47、mponents(twosix-portvalvesmaybeusedfortheseduties). 5.1.3 Metalcolumnspackedwith28%DC-200onChromosorbPAW,satisfyingtheperformance requirementsgiveninclause6.2andconsistingofthefollowingpackingmaterialsandcolumndimensions,given asexamples,forusewithconventionalandreadilyavailableinjectionvalvesandTCD. Columnsshallsatisfythefollowingrequirements: a) metaltubing: column1:0,45mlong,4,75mminternaldiameter(i.d.)(1/4ino.d.), column2:9mlong,4,75mmi.d.(1/4ino.d.) b) packing: stationaryphase:28%DC-200(viscosity:35010 6 m 2 /s), support:Ch
