DIN EN ISO 16960-2015 Natural gas - Determination of sulfur compounds - Determination of total sulfur by oxidative microcoulometry method (ISO 16960 2014) German version EN ISO 169.pdf

1、February 2015 Translation by DIN-Sprachendienst.English price group 9No part of this translation 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).IC

2、S 75.060!%B(“2293105www.din.deDDIN EN ISO 16960Natural gas Determination of sulfur compounds Determination of total sulfur by oxidative microcoulometry method(ISO 16960:2014);English version EN ISO 16960:2014,English translation of DIN EN ISO 16960:2015-02Erdgas Bestimmung von Schwefelverbindungen B

3、estimmung des Schwefelgehalts mittels oxidativem mikrocoulometrischen Verfahren(ISO 16960:2014);Englische Fassung EN ISO 16960:2014,Englische bersetzung von DIN EN ISO 16960:2015-02Gaz naturel Dtermination des composs soufrs Dtermination de la teneur totale en soufre par microcoulomtrie oxydante(ISO

4、 16960:2014);Version anglaise EN ISO 16960:2014,Traduction anglaise de DIN EN ISO 16960:2015-02www.beuth.deDocument comprises 13 pagesIn case of doubt, the German-language original shall be considered authoritative.01.15 DIN EN ISO 16960:2015-02 2 A comma is used as the decimal marker. National fore

5、word This document (EN ISO 16960:2014) has been prepared by Technical Committee CEN/TC 193 “Natural gas” (Secretariat: NEN, Netherlands) in collaboration with Technical Committee CEN/CS. The responsible German body involved in its preparation was the DIN-Normenausschuss Materialprfung (DIN Standards

6、 Committee Materials Testing), Working 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 3696 DIN ISO 3696 ISO 6142 DIN EN ISO 6142 ISO 6144 DIN EN ISO 6144 ISO 10715 DIN EN ISO

7、10715 ISO 13443 DIN EN ISO 13443 National Annex NA (informative) Bibliography DIN ISO 3696, Water for analytical laboratory use Specification and test methods DIN EN ISO 6142, Gas analysis Preparation of calibration gas mixtures Gravimetric method DIN EN ISO 6144, Gas analysis Preparation of calibra

8、tion gas mixtures Static volumetric method DIN EN ISO 10715, Natural gas Sampling guidelines DIN EN ISO 13443, Natural gas Standard reference conditions EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 16960 October 2014 ICS 75.060 English Version Natural gas - Determination of sulfur compou

9、nds - Determination of total sulfur by oxidative microcoulometry method(ISO 16960:2014) Gaz naturel - Dtermination des composs soufrs - Dtermination de la teneur totale en soufre par microcoulomtrie oxydante (ISO 16960:2014) Erdgas - Bestimmung von Schwefelverbindungen - Bestimmung des Schwefelgehal

10、ts mittels oxidativem mikrocoulometrischen Verfahren (ISO 16960:2014) This European Standard was approved by CEN on 24 August 2014. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national stan

11、dard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in a

12、ny other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Rep

13、ublic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEA

14、N COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 16960:2014 ECon

15、tents PageForeword .:.3Introduction 41 Scope . 52 Normative references 53 Test principle . 54 Reagents 55 Apparatus . 65.1 Converter . 65.2 Titration cell 65.3 Microcoulometer . 65.4 Flow controller 65.5 Electromagnetic agitator 65.6 Medical syringe . 65.7 Volumetric flask . 66 Test preparation . 66

16、.1 Preparation of electrolyte 66.2 Reference sample 66.3 Apparatus installation 76.4 Preparation of instrument 76.5 Check and adjustment of the instrument . 76.6 Determination of recovery factor of sulfur . 77 Test procedure 87.1 Sampling . 87.2 Sample injection and measurement . 88 Calculation 88.1

17、 Volume conversion 88.2 Calculation of total sulfur mass concentration in the gas sample 99 Precision 109.1 General 109.2 Repeatability 10Bibliography . 11DIN EN ISO 16960:2015-02 EN ISO 16960:2014 (E) 2 Foreword This document (EN ISO 16960:2014) has been prepared by Technical Committee ISO/TC 193 “

18、Natural gas“. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 2015, and conflicting national standards shall be withdrawn at the latest by April 2015. Attention is drawn to the possibility t

19、hat some of the elements of this document may be the subject 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

20、to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,

21、Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 16960:2014 has been approved by CEN as EN ISO 16960:2014 without any modification. DIN EN ISO 16960:2015-02 EN ISO 16960:2014 (E) 3 IntroductionThree methods for determination o

22、f sulfur compounds in natural gas already exist as International Standards: 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 Pa

23、rt 5: Lingener combustion method; ISO 19739, Natural gas Determination of sulfur compounds using gas chromatography.DIN EN ISO 16960:2015-02 EN ISO 16960:2014 (E) 4 WARNING The use of this International Standard can involve hazardous material, operations, and equipment. This International Standard d

24、oes not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this International Standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.1 ScopeThis International

25、Standard specifies a method for the determination of total sulfur in the range from 1 mg/m3to 200 mg/m3in pipeline natural gas by oxidative microcoulometry. Natural gas with sulfur contents above 200 mg/m3can be analysed after dilution with a suitable sulfur-free solvent.2 Normative referencesThe fo

26、llowing documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 3696, Wate

27、r for analytical laboratory use Specification and test methodsISO 6142, Gas analysis Preparation of calibration gas mixtures Gravimetric methodISO 6144, Gas analysis Preparation of calibration gas mixtures Static volumetric methodISO 6146, Gas analysis Preparation of calibration gas mixtures Manomet

28、ric methodISO 10715, Natural gas Sampling guidelines3 Test principleA gas sample containing sulfur is mixed with oxygen in a quartz furnace tube in order to convert the sulfur compounds to sulfur dioxide by oxidative pyrolysis. The obtained sulfur dioxide enters the titration cell along with carrier

29、 gas and reacts with iodine contained therein. The consumed iodine is complemented by the electrolysis of potassium iodide. In accordance with Faradays law of electrolysis, the sulfur concentration in the gas sample can be calculated from the consumed electric quantity by electrolysis and corrected

30、by comparison to a reference standard sample.4 Reagents4.1 Test water, conforming to the requirements of Grade 3 of ISO 3696,4.2 Glacial acetic acid, analytical purity.4.3 Potassium iodide, analytical purity.4.4 Oxygen, minimum purity 99,99 % (by volume fraction), maximum volume fraction of sulfur c

31、ontaining gases 0,01 % (by volume fraction).DIN EN ISO 16960:2015-02 EN ISO 16960:2014 (E) 5 4.5 Carrier gas, argon, helium, or nitrogen with a minimum purity 99,99 % (by volume fraction), maximum volume fraction of sulfur containing gases 0,01 % (by volume fraction).5 Apparatus5.1 ConverterThere ar

32、e three independent heating sections in a converter: preheating section (800 C 20 C), combustion section (900 C 20 C), and exit section (800 C 20 C).5.2 Titration cellInstall a pair of electrolysis electrodes and a pair of indicator-reference electrodes in the cell.5.3 MicrocoulometerElectrolysis co

33、mmences automatically when there is a reduction in the concentration of iodine caused by the presence of sulfur dioxide in the titration cell, to maintain the concentration of iodine at its original level. The microcoulometer can automatically record the electrolysis time and current and directly di

34、splay the sulfur content.5.4 Flow controllerProvides the specified flow rates at the outlet.5.5 Electromagnetic agitatorProvides the specified rotational rates in the titration cell.5.6 Medical syringeAir tight syringes of volumes 0,25 ml, 1 ml, 2 ml, and 5 ml. Syringe-delivered volumes should be ca

35、librated by weighing pure water prior to initial use. Periodic calibration might be required thereafter.5.7 Volumetric flaskOne standard laboratory volumetric flask of nominal 25 ml volume.6 Test preparation6.1 Preparation of electrolyteWeigh 0,5 g potassium iodide, dissolve it in 100 ml water, add

36、in 5 ml glacial acetic acid, and then dilute the solvent to 1 L with water. The electrolyte should be stored in a brown reagent bottle. The electrolyte shelf life after preparation is three months.6.2 Reference sampleUse calibration gas mixtures of sulfur compounds prepared according to ISO 6142, IS

37、O 6144, or ISO 6146. Sulfur concentration in the calibration gas mixtures shall be close to that in the tested sample.It is recommended that sulfur compounds in the calibration gas mixture were hydrogen sulfide (H2S) in a methane matrix.DIN EN ISO 16960:2015-02 EN ISO 16960:2014 (E) 6 6.3 Apparatus

38、installationInstall the apparatus following the instruction. Connect the carried gas tube and oxygen tube. An example of a typical microcoulometer set-up is given in Figure 1.Key1 microcoulometer2 titration cell3 electromagnetic stirrer4 reforming furnace5 quartz furnace tube6 injection port7 flow m

39、eter8 needle valveFigure 1 Typical microcoulometric set-up6.4 Preparation of instrumentReplace the silicone rubber plug in the injection port. Regulate the flow rate of carrier gas and oxygen to the values specified by the apparatus. Then switch on the electromagnetic stirrer, adjust stirring speed

40、to produce a slight vortex in the electrolyte6.5 Check and adjustment of the instrumentCheck and adjust all the operating parameters according to the instruction manual of the instrument.6.6 Determination of recovery factor of sulfurInstall software of microcoulometer and display the sulfur recovery

41、 factor using computer software, typically installed on a person computer (PC), suited for the microcoulometer being used.6.6.1 Sampling and injectionTake samples after flushing the syringe with the gas standard sample four to five times. The syringe plunger should be pushed to the required scale by

42、 the gas pressure in the bottle when sampling. Insert the syringe into the injection port, the injection rate is about 0,15 ml/s to 0,2 ml/s and the injection volume is typically 0,25 ml to 5 ml.DIN EN ISO 16960:2015-02 EN ISO 16960:2014 (E) 7 6.6.2 MeasurementSwitch the instrument to correction fac

43、tor mode. Enter the concentration of the standard sample and the injection volume. Carry out the determination of the microcoulometer recovery factor by injecting a standard sample according to the method described in 6.6.1. The sulfur recovery factor displayed on the instrument can be used when the

44、 relative standard deviation of five consecutive recovery factors is equal or less than 2 %, take the average of these five consecutive values as the recovery factor of the instrument used for measurements.In case the recovery factor is less than 75 % (F in Formula (3), 2 decimal places), it is nece

45、ssary to identify the reason23.7 Test procedure7.1 Sampling7.1.1 Sampling from natural gas pipelineSampling shall be performed in accordance with ISO 10715.7.1.2 Sampling from gas cylindersAnalysis should be performed as soon as possible after receiving the samples. Sampling shall be performed in ac

46、cordance with 6.6.1.7.2 Sample injection and measurementSwitch the instrument to sample measurement mode. Input volume parameters into the microcoulometer software (corrected to reference conditions). Carry out the determination of the sample recovery factor by injecting the sample according to the

47、method described in 6.6.1. The sulfur recovery factor displayed on the instrument can be used. The sulfur recovery factor and the sulfur mass of the sample can be displayed on the instrument. Carry out the measurement twice, taking the average of the two measurement results.8 Calculation8.1 Volume convers