1、October 2009DEUTSCHE NORM English price group 8No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 75.060!$Z=s“1552680www.
2、din.deDDIN EN ISO 6326-1Natural gas Determination of sulfur compounds Part 1: General introduction (ISO 6326-1:2007)English version of DIN EN ISO 6326-1:2009-10Erdgas Bestimmung von Schwefelverbindungen Teil 1: Allgemeine Einleitung (ISO 6326-1:2007)Englische Fassung DIN EN ISO 6326-1:2009-10www.beu
3、th.deDocument comprises pages13 2 National oreword This standard has been prepared by Technical Committee ISO/TC 193 “Natural gas”, Subcommittee SC 1 “Analysis of natural gas” (Secretariat: NEN, Netherlands). The responsible German body involved in its preparation was the Normenausschuss Materialprf
4、ung (Materials Testing Standards Committee), Technical Committee NA 062-05-73 AA Gasanalyse und Gasbeschaffenheit. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 4260 DIN EN 24260 ISO 6326-3 DIN EN ISO 6326-3 ISO 6326-5 DIN EN ISO 6326
5、-5 ISO 10715 DIN EN ISO 10715 ISO 16664 DIN EN ISO 16664 ISO 19739 DIN EN ISO 19739 DIN EN ISO 6326-1:2009-10 f3 National Annex NA (informative) Bibliography DIN EN 24260, Petroleum products and hydrocarbon Determination of sulfur content Wickbold combustion method DIN EN ISO 6326-3, Natural gas Det
6、ermination of sulfur compounds Part 3: Determination of hydrogen sulfide, mercaptan sulfur and carbonyl sulfide sulfur by potentiometry DIN EN ISO 6326-5, Natural gas Determination of sulfur compounds Part 5: Lingener combustion method DIN EN ISO 10715, Natural gas Sampling guidelines DIN EN ISO 166
7、64, Gas analysis Handling of calibration gases and gas mixtures Guidelines DIN EN ISO 19739, Natural gas Determination of sulfur compounds using gas chromatography DIN EN ISO 6326-1:2009-10 4 This page is intentionally blank DIN EN ISO 6326-1:2009-10 EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN
8、 ISO 6326-1July 2009ICS 75.060English VersionNatural gas - Determination of sulfur compounds - Part 1:General introduction (ISO 6326-1:2007)Gaz naturel - Dtermination des composs soufrs - Partie Introduction gnrale (ISO 6326-1:2007)Erdgas - Bestimmung von Schwefelverbindungen - Teil Allgemeine Einle
9、itung (ISO 6326-1:2007)This European Standard was approved by CEN on 20 June 2009.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and b
10、ibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility
11、 of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Irela
12、nd, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix 17, B-1
13、000 Brussels 2009 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 6326-1:2009: E1:1:2 Contents Page DIN EN ISO 6326-1:2009-10 EN ISO 6326-1:2009 (E) Foreword .3 Introduction.4 1 Scope5 2 Normative references6 3 Sampling 6 3.1 Gen
14、eral .6 3.2 Safety precautions 7 4 Methods for determination of total sulfur content.7 4.1 Wickbold combustion method (ISO 4260) 7 4.2 Lingener combustion method (ISO 6326-5)8 5 Methods for determination of individual sulfur compounds or groups of sulphur9 5.1 Gas chromatography method (ISO 19739) .
15、9 5.2 Potentiometric method (ISO 6326-3) .9 3 Foreword The text of ISO 6326-1:2007 has been prepared by Technical Committee ISO/TC 193 “Natural gas” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 6326-1:2009. This European Standard shall be given the st
16、atus of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2010, and conflicting national standards shall be withdrawn at the latest by January 2010. Attention is drawn to the possibility that some of the elements of this document may be the s
17、ubject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium,
18、 Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The
19、 text of ISO 6326-1:2007 has been approved by CEN as EN ISO 6326-1:2009 without any modification. DIN EN ISO 6326-1:2009-10 EN ISO 6326-1:2009 (E) Introduction Sulfur compounds can occur naturally in natural gas and remain as traces after treatment, or they may have been injected deliberately to all
20、ow subsequent olfactory detection for safety reasons. The standardization of several methods for the determination of sulfur compounds in natural gas is necessary in view of the diversity of these compounds hydrogen sulfide, carbonyl sulfide, tetrahydrothiophene (THT), etc. and the requirements of t
21、he determinations (required uncertainty, measurement at the well head, at clean-up plant or in the transmission pipes, etc.). In order to enable the user to choose the method most appropriate to his needs and to perform the measurements under the best conditions, ISO 6326 has been prepared in severa
22、l parts. This part of ISO 6326 gives a rapid comparison of standardized methods and therefore provides information for the choice of the method. The other parts of ISO 6326 and ISO 19739 describe in detail the various standardized methods. DIN EN ISO 6326-1:2009-10 EN ISO 6326-1:2009 (E) 4WARNING Th
23、e majority of sulfur compounds are extremely toxic and thus present a serious health hazard if handled without precautions. 1 Scope This part of ISO 6326 gives a brief description of standardized methods that can be used for the determination of sulfur compounds in natural gas. The principle of each
24、 method is described generally, the range of concentrations for which the method is suitable is indicated, and the analytical range and precision of each method is given. It should enable the user to select judiciously the proper method for the application being considered. Sulfur analysis is perfor
25、med in order to determine a) total sulfur, b) sulfur contained in specific groups (e.g. thiol sulfur), c) individual sulfur compounds, and d) specific groups of sulfur compounds. The standardized methods available in the field of sulfur analysis are the Wickbold combustion method: for total sulfur d
26、etermination (ISO 4260), the Lingener combustion method: for total sulfur determination (ISO 6326-5), gas chromatography: for determination of individual sulfur compounds (ISO 19739), and potentiometry: for determination of hydrogen sulfide, carbonyl sulfide and thiol compounds (ISO 6326-3). Other m
27、ethods for the determination of sulfur compounds are available but are not considered here. Table 1 gives an overview of the standardized methods which can be used for the determination of total sulfur, hydrogen sulfide, carbonyl sulfide, tetrahydrothiophene, thiol sulfur, individual thiols, individ
28、ual thiophenes, individual organic sulfides and disulfides. DIN EN ISO 6326-1:2009-10 EN ISO 6326-1:2009 (E) 5Table 1 Methods for the determination of sulfur compounds in natural gas Concentration range aDetermination Method mg/m3Reference Total sulfur Wickbold combustion method 1 to 20 000 ISO 4260
29、 Lingener combustion method 0,5 to 1 000 ISO 6326-5 Potentiometry W 1 ISO 6326-3 Hydrogen sulfide (H2S) Gas chromatography 0,1 to 100 (or 0,5 to 600 depending on the detector used) ISO 19739 Gas chromatography 0,1 to 30 ISO 19739 Carbonyl sulfide (COS) Potentiometry W 1 ISO 6326-3 Tetrahydrothiophen
30、e (THT) Gas chromatography 0,1 to 100 ISO 19739 Thiol sulfur Potentiometry W 1 ISO 6326-3 Individual thiols Gas chromatography 0,1 to 100 ISO 19739 Individual thiophenes Gas chromatography 0,1 to 100 ISO 19739 Individual organic sulfides and disulfides Gas chromatography 0,1 to 100 ISO 19739 aFor th
31、e determination of total sulfur, the sulfur content is expressed as milligrams of sulfur per cubic metre of gas. For the determination of sulfur compounds, the mass concentration of sulfur compounds is expressed as milligrams of sulfur compound per cubic metre of gas. 2 Normative references The foll
32、owing referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 4260, Petroleum products and hydrocarbons Determinati
33、on of sulfur content Wickbold combustion method ISO 6326-3, Natural gas Determination of sulfur compounds Part 3: Determination of hydrogen sulfide, mercaptan sulfur and carbonyl sulfide sulfur by potentiometry ISO 6326-5, Natural gas Determination of sulfur compounds Part 5: Lingener combustion met
34、hod ISO 10715, Natural gas Sampling guidelines ISO 16664, Gas analysis Handling of calibration gases and gas mixtures Guidelines ISO 19739:2004, Natural gas Determination of sulfur compounds using gas chromatography 3 Sampling 3.1 General The sampling procedures are very important in the analysis of
35、 sulfur compounds. Sulfur compounds have a strong tendency to adsorb on to, or to chemically react with, different materials of construction. Low contents of sulfur compounds in samples and calibration gas mixtures put demands on the sampling procedure in order to ensure that the sulfur compounds in
36、 correct quantity reach the analytical device. DIN EN ISO 6326-1:2009-10 EN ISO 6326-1:2009 (E) 6Carry out representative sampling in such a way that the sample represents the bulk of the gas at the time of sampling. Sampling and sample transfer shall be in accordance with ISO 10715. Purge time shou
37、ld be long enough to obtain replicate stable analytical results within the acceptable standard deviation of the analyser. The purge time needed depends on the type and concentration of the sulfur compound, materials in contact with the gas, and the gas flow rate through the sample loop. Sampling of
38、the gas can be carried out in two different ways: at atmospheric pressure in a silanized glass vessel, equipped with polytetrafluoroethylene (PTFE) plugs or a sampling bag made of material inert to sulfur compounds, such as polyvinylfluoride (PVF) or PTFE, which has been flushed with dilute hydrochl
39、oric acid, subsequently flushed with distilled water and dried; after the glass vessel is filled with the gas under study, it should be shielded from daylight; under pressure in a stainless steel or aluminium cylinder, if the sulfur content exceeds 50 mg/m3. 3.2 Safety precautions Safety precautions
40、 required in handling gas cylinders with pressurized flammable gas mixtures are described in ISO 10715. If a pressure regulator is to be connected to the cylinder, always use a regulator whose materials of construction are recommended by the producer of the calibration gas. For other precautions and
41、 advice for the use, sampling and handling of gas mixtures containing sulfur compounds, see Clause 3 of ISO 19739:2004 and ISO 16664. 4 Methods for determination of total sulfur content To carry out the analyses, reference should be made to the specific methods which are described in detail in ISO 4
42、260, ISO 19739, ISO 6326-3 and ISO 6326-5. 4.1 Wickbold combustion method (ISO 4260) 4.1.1 Scope This method is applicable to products having sulfur content on the order of 1 mg/m3, and is particularly suitable for gases with total sulfur content in the range 1 mg/m3to 20 000 mg/m3and for distillate
43、s with total sulfur content of less than 300 mg/m3. 4.1.2 Principle The natural gas is supplied to the burner of a hydrogen-oxygen flame, where the sulfur compounds undergo combustion with a considerable excess of oxygen. The resulting sulfur oxides are converted into sulfuric acid by absorption in
44、hydrogen peroxide solution. Depending on the sulfur content of the sample, the sulfate ions in the absorption solution are determined by colorimetric, nephelometric, turbidimetric or conductometric titration (see Table 2). DIN EN ISO 6326-1:2009-10 EN ISO 6326-1:2009 (E) 7Table 2 Concentration range
45、 and precision data for methods of determination of sulfur compounds in natural gas Method Determination Concentration range mg/m3Repeatability % Wickbold combustion method Total sulfur 1 to 10 10 10 to 15 5 to 7 Lingener combustion method Total sulfur 10 to 1 000 6 COS 0,1 to 30 2 to 7 Gas chromato
46、graphy All other S compounds 0,1 to 100 H2S 1 to 10 15 Thiol sulfur 1 to 20 15 Potentiometry COS sulfur 1 to 30 10 4.1.3 Results and precision The total sulfur content of the sample is expressed in milligrams of sulfur per cubic metre of gas. The precision is a function of a) the sulfur concentratio
47、n of the gas, and b) the type of titration used in the determination. The repeatability for samples containing 10 mg/m3ranges from 5 % to 7 % and the reproducibility is 13 %. 4.2 Lingener combustion method (ISO 6326-5) 4.2.1 Scope The method is suitable for the determination of the total sulfur cont
48、ent in natural gas. The method is applicable to gases with sulfur content in the range from 0,5 mg/m3to 1 000 mg/m3. 4.2.2 Principle A given volume of gas undergoes combustion with air at atmospheric pressure in a glass combustion apparatus. The resulting sulfur oxides are converted into sulfuric ac
49、id by absorption in hydrogen peroxide solution. If the total sulfur content is more than 0,1 mg sulfur in the absorption solution, visual titration with an indicator can be chosen, whereas for lower concentrations, turbidimetric titration is preferable. 4.2.3 Results and precision The total sulfur content of the sample is expressed in milligrams of sulfur per cubic metre of gas and rounded off to 0,5 mg/m3in the case of determination by visual titration and to 0,1 mg/m3in the case of determination by turbid
