1、BSI Standards PublicationBS ISO 17196:2014Dimethyl ether (DME) for fuels Determination of impurities Gas chromatographicmethodBS ISO 17196:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 17196:2014.The UK participation in its preparation was entrusted to T
2、echnicalCommittee PTI/13, Petroleum Testing and Terminology.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The B
3、ritish Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 79347 9ICS 71.080.60; 75.160.20Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee
4、 on 31 December 2014.Amendments issued since publicationDate Text affectedBS ISO 17196:2014 ISO 2014Dimethyl ether (DME) for fuels Determination of impurities Gas chromatographic methodDimthylether (DME) pour carburants et combustibles Dtermination des impurets Mthode par chromatographie en phase ga
5、zeuseINTERNATIONAL STANDARDISO17196First edition2014-11-15Reference numberISO 17196:2014(E)BS ISO 17196:2014ISO 17196:2014(E)ii ISO 2014 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2014All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized
6、otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright off
7、iceCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 17196:2014ISO 17196:2014(E)Contents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 25 Analysis a
8、nd analytical requirements 25.1 Apparatus and materials 25.2 Resolution . 36 Procedures 36.1 Setting up the analytical system 36.2 Sample preparation 36.3 Injection 37 Calibration, calculation, and control charts . 47.1 Calibration 47.2 Calculation 47.3 Control charts 48 Precision . 59 Test report .
9、 5Annex A (informative) Examples of chromatographic systems and conditions (1) 7Annex B (informative) Examples of chromatographic systems and conditions (2) .12Annex C (informative) Example of working reference gas mixture 15Annex D (informative) Report of the interlaboratory tests .17Annex E (infor
10、mative) Solubility of CO and CO2in DME 22Bibliography .25 ISO 2014 All rights reserved iiiBS ISO 17196:2014ISO 17196:2014(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International
11、 Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, a
12、lso take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1.
13、 In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the eleme
14、nts of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received
15、 (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adheren
16、ce to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword Supplementary information .The committee responsible for this document is ISO/TC 28, Petroleum products and lubricants, Subcommittee SC 4, Classifications and specifications.iv ISO 2014 All rights rese
17、rvedBS ISO 17196:2014ISO 17196:2014(E)IntroductionThroughout the manufacturing process, impurities can generate in the dimethyl ether (DME). In addition, there is a possibility that DME becomes contaminated during loading and transportation by sea and/or various land transportations. Examples of suc
18、h impurities include methanol, water, carbon dioxide, ethyl methyl ether, sulfur, residues, and so on.Gas chromatography is recommended to analyse many kinds of vaporizable impurities. ISO 2014 All rights reserved vBS ISO 17196:2014BS ISO 17196:2014Dimethyl ether (DME) for fuels Determination of imp
19、urities Gas chromatographic methodWARNING The use of this International Standard can involve hazardous materials, operations, and equipment. This International Standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this Intern
20、ational Standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.1 ScopeThis International Standard specifies a procedure of test for methanol, CO, CO2, methyl formate, ethyl methyl ether, and hydrocarbons up to C4, in DME u
21、sed as fuel by the gas chromatography method. This procedure is applicable to determine the amount of methanol, CO, CO2, methyl formate, ethyl methyl ether, and hydrocarbons up to C4, up to the value specified in ISO 16861.NOTE The precision of this method has been studied for a limited set of sampl
22、es and content levels by a limited number of labs. It allows establishment of a quality specification of DME but cannot be considered as a full precision determination in line with the usual statistical methodology as in ISO 4259.2 Normative referencesThe following documents, in whole or in part, ar
23、e 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 6975, Natural gas Extended analysis Gas-chromatograp
24、hic methodISO 16861, Petroleum products Fuels (class F) Specifications of Dimethylether (DME)ISO 29945, Refrigerated non-petroleum-based liquefied gaseous fuels Dimethylether (DME) Method of manual sampling onshore terminals3 Terms and definitionsFor the purposes of this document, the following term
25、s and definitions given in ISO 6975 and the following apply.3.1componentsDME, methanol, ethyl methyl ether, methyl formate, carbon dioxide, carbon monoxide, hydrocarbons up to C43.2hydrocarbons (up to C4)components such as ethane (C2H6), ethylene (C2H4), propane(C3H8), propylene(C3H6), i-butane(i-C4
26、H10), n-butane(n-C4H10), i-butene (i-C4H8), 1-butene (1-C4H8), trans-2-butene (trans-2- C4H8), cis-2-butene (cis-2- C4H8), and 1,3-butadiene (1,3-butadiene)INTERNATIONAL STANDARD ISO 17196:2014(E) ISO 2014 All rights reserved 1BS ISO 17196:2014ISO 17196:2014(E)3.3working reference gas mixtureWRMmixt
27、ures which are used as working standards for regular calibration of the measuring systemNote 1 to entry: WRM can be prepared by gravimetric method in accordance with ISO 6142 or certified and validated by comparison with gas mixtures in accordance with ISO 6143.4 PrincipleThe components to be determ
28、ined in a gaseous sample are separated by gas chromatography and compared with calibration data obtained under the same set of conditions.The components are separated using packed or open tubular columns in a gas chromatograph and detected by TCD or FID or FID with methanizer.5 Analysis and analytic
29、al requirements5.1 Apparatus and materials5.1.1 Analytical systemThe analytical system shall consist of a gas chromatograph and an appropriate data handling system.NOTE Examples of analytical systems and conditions are informatively proposed in this International Standard. See Annex A and Annex B.Th
30、e gas-chromatographic unit can consist of one or more gas chromatographs capable of isothermal and/or temperature-programmed operation and equipped with a TCD and an FID and a sample heated transfer and introduction system. A methanizer is optional.The sample is preferably transferred as a gas phase
31、 to the injection system through a constant volume system according to the annexes.If the sample is transferred as a gas phase, a specific procedure to allow full vaporization of liquid sample is required (see 6.3.1).A liquid sampling valve can also be used to inject the sample in a liquid phase.5.1
32、.2 Reference gas mixtures5.1.2.1 Working reference gas mixtureThe concentration of each component in the WRM shall be within the tolerances given in Table 1 relative to the maximum value allowed in the specification in ISO 16861.WRM for the following components should be prepared: CO, CO2, methanol,
33、 methyl formate, propane, butane, and ethyl methyl ether.WRM for other hydrocarbons up to C4can be prepared.Standard reagents or standard gas for ethyl methyl ether might not be widely available in the market. However, it is necessary to obtain such a mixture to perform test methods described in thi
34、s International Standard.Example of a WRM is shown in Annex C.2 ISO 2014 All rights reservedBS ISO 17196:2014ISO 17196:2014(E)Table 1 Tolerance between concentrations of components in the WRM and the sampleComponent concentration allowed in specification ISO 16861 mass %Deviation of component concen
35、tration in WRM (% relative to value specified in ISO 16861)Up to 0,1 500,1 to 1 255.1.2.2 Control gasA control gas is a high-pressure gas mixture containing all the components present in the working-reference gas mixture. A sample gas mixture having a composition closely related to the WRM can be us
36、ed.A control gas is used for the determination of the mean (p) and standard deviation (a) of the concentrations of the components detected.5.2 ResolutionThe resolution between two adjacent peaks for each component shall not be less than 2.In the event that a valve switching is performed in multicolu
37、mn analysis, the resolution between the peak of the component eluted before switching the valve and the peak of the component that would be eluted without the valve switching shall not be less than 4.If the resolution is unsatisfactory, the selection of chromatograph columns and/or the analytical co
38、nditions should be optimized until the expected resolution is obtained.6 Procedures6.1 Setting up the analytical systemSet up all the analytical system in accordance with the manufacturers instructions and the analytical methods chosen.Condensation and sorption in the sampling system shall be avoide
39、d. The sample cylinder and the transfer line and all the lab equipment shall be in a well air-conditioned room or the sample cylinder and transfer line shall be heated to at least 10 C above the greater of the sampling temperature or ambient temperature. If necessary, use a heated vaporizer to ensur
40、e complete vaporization. In case of gas phase transfer and injection, special precautions shall be taken at any spot in the system where pressure reduction occurs.6.2 Sample preparationSamples shall be taken as described in ISO 29945.NOTE Since DME is a liquefied gas, depending on the filling level
41、and pressure, CO and CO2might be more concentrated in the vapour phase of the sample container. The CO and CO2concentration in the vapour phase can be calculated if the distribution coefficient of CO and CO2in liquid phase and vapour phase is known at given pressure. See Annex E for values of the di
42、stribution coefficient.6.3 InjectionEither of the two following procedures can be used. ISO 2014 All rights reserved 3BS ISO 17196:2014ISO 17196:2014(E)6.3.1 Gas phase injectionConnect a sample cylinder to the sample injector. Replace by letting the sample gas flow into the sample measuring pipe. Pu
43、rge the transfer line and the sampling loop for a sufficient period. Then inject the sample gas into the column by switching the passage of the sample injector and measure the peak area.Note that the sample should be taken from the liquid phase of the sample cylinder. It is necessary to take measure
44、s to ensure complete evaporation of the sample. Measures should also be taken to avoid condensation of the sample.For an example of the gas phase sample injection, refer to the practices in Annex A.6.3.2 Liquid injection with liquid injection valveIf liquid injection valve is used, the sample should
45、 be kept under pressure to avoid evaporation, and hence ensure repeatable injection. Ensure liquid DME is flowing at the vent of the liquid sampling valve before injection into the column.7 Calibration, calculation, and control charts7.1 CalibrationAnalysis of the WRM according to the present proced
46、ure is carried out periodically or if required by control chart inspection (see 7.3).7.2 CalculationObtain the concentration, in volume %, of each component in sample gas according to Formula (1). Next, calculate the content, in mass %, of each composition to four decimal places according to Formula
47、 (2) in order to convert volume % to mass % and round off to three decimal places.CviAi PiAsi=(1)whereCvi is the calculated concentration, in volume %, of compound i in the sample;Ai is the peak area of compounds i in the sample;Asi is the peak area of compounds i in the last analysis of the WRM;Pi
48、is the concentration, in volume %, of compounds i in the last analysis of the WRM.CwiCviMiCviMiin=()1(2)whereCwi is the calculated concentration, in mass %, of compound i in the sample;Mi is the molecular mass, in grams, of compounds i in the sample;n is the total number of compounds.7.3 Control cha
49、rtsRefer to ISO 6975 for the detailed description of control charts.4 ISO 2014 All rights reservedBS ISO 17196:2014ISO 17196:2014(E)Carry out a control gas (5.1.2.2) analysis with each batch of sample. Its composition is unvarying and so the results of this analysis can be used as an indication as to whether the method is no longer working satisfactorily or recalibration is necessary, or both.8 PrecisionThe provisional precision of this method, established during interlaboratory tests relating to DME sample with c
