1、BSI Standards PublicationBS ISO 17786:2015Dimethyl ether (DME) forfuels Determination ofhigh temperature (105C)evaporation residues Massanalysis methodBS ISO 17786:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 17786:2015. The UK participation in its prep
2、aration was entrusted to TechnicalCommittee PTI/13, Petroleum Testing and Terminology.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for i
3、ts correct application. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 79350 9 ICS 71.080.60; 75.160.20 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standa
4、rds Policy and Strategy Committee on 31 May 2015.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e d ISO 2015Dimethyl ether (DME) for fuels Determination of high temperature (105C) evaporation residues Mass analysis methodDimthylether (DME) pour carburants et combustibles Dter
5、mination de la temprature haute (105C) de rsidus dvaporation Mthode gravimtriqueINTERNATIONAL STANDARDISO 17786First edition 2015-05-01Reference number ISO 17786:2015(E)BS ISO 17786:2015ISO 17786:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015All rights reserved. Unless o
6、therwise specified, no part of this publication may be reproduced or utilized 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 addre
7、ss below or ISOs member body in the country of the requester.ISO copyright officeCase 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 17786:2015ISO 17786:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative
8、 references 13 Principle 14 Reagents and materials . 15 Apparatus . 26 Procedures 47 Calculation 48 Precision . 59 Test report . 5Annex A (informative) The report of the interlaboratory tests 6Bibliography 8 ISO 2015 All rights reserved iiiContents PageBS ISO 17786:2015ISO 17786:2015(E)ForewordISO (
9、the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical commi
10、ttee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotec
11、hnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted
12、 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 elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights
13、. 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 (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute
14、 an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword Supplementary information .The committ
15、ee responsible for this document is ISO/TC 28, Petroleum products and lubricants, Subcommittee SC 4, Classifications and specifications.iv ISO 2015 All rights reservedBS ISO 17786:2015ISO 17786:2015(E)IntroductionIn general, large amount of DME in the international trade and domestic transportation
16、may be executed using sea and/or various land transportations. Throughout the loading and transportation, there may be a risk of increasing evaporation residues.The evaporation residues can over time impact the performance of the equipment when DME is used as fuel. Therefore, evaporation residues in
17、 the DME shall be determined accurately using procedures recognized by the parties concerned. ISO 2015 All rights reserved vBS ISO 17786:2015ISO 17786:2015(E)BS ISO 17786:2015Dimethyl ether (DME) for fuels Determination of high temperature (105C) evaporation residues Mass analysis methodWARNING The
18、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 International Standard to establish appropriate safe
19、ty and health practices and determine the applicability of regulatory limitations prior to use.1 ScopeThis International Standard specifies a procedure of test for high temperature (105 C) evaporation residue in DME used as fuel by the mass analysis method. This procedure is applicable to determine
20、the amount of high temperature (105 C) evaporation residue up to the value specified in ISO 16861.Several tests can be applied to determine amount of evaporation residue in liquefied products. Among them, this International Standard specifies the method that has detection limit sufficient for a DME
21、specification in ISO 16861, using less resource compared to other methods.When more precise quantitative test is required, use of ISO 13757 instead of this International Standard is recommended.Because of the procedure applied, the evaporation residue which has a boiling point lower than 105 C will
22、not be determined.NOTE The precision of this method has been studied for a limited set of samples and content levels by a limited amount 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 me
23、thodology as in ISO 4259.2 Normative referencesThe following 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 docum
24、ent (including any amendments) applies.ISO 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 PrincipleAfter approximately 100 g of liquid
25、sample is evaporated by using an evaporation dish, the residue is weighed, to determine the evaporation residue at 105 C in mass percentage of the total DME.4 Reagents and materials4.1 Ethanol, methanol and/or isopropanol is used for cooling bath.4.2 Dry ice, used for cooling bath.INTERNATIONAL STAN
26、DARD ISO 17786:2015(E) ISO 2015 All rights reserved 1BS ISO 17786:2015ISO 17786:2015(E)5 Apparatus5.1 Sample cylinder.Sample cylinder is made of stainless steel. (size is 1 l, tested pressure not less than 3,0 MPa) that shall be able to be positioned vertically and is weighable. It shall be equipped
27、 so that the sample be drawn as a liquid from the liquid phase of the sample.5.2 Connecting pipe.This is a pipe of approximately 3 mm5 mm in diameter, made of stainless steel. It is provided with a connector to the sample cylinder on one end and with a connector to the cooler on the other end.Key1 s
28、ample cylinder2 connecting pipe3 cooling bathFigure 1 Assembly drawing of evaporation residue testing equipment2 ISO 2015 All rights reservedBS ISO 17786:2015ISO 17786:2015(E)Key1 sample valve2 connecting pipe3 cooling pipe (stainless steel pipe 5 mm)4 dewar vessel5 needle valve6 below 3007 approxim
29、ately 64 mmFigure 2 Cooling bath5.3 Cooling bath.This is of a type shown in Figure 2.5.4 Evaporating dish.The evaporating dish is made of platinum, porcelain, stainless steel, or glass and the volume of the evaporating dish is 100 ml. The diameter of the dish is more than 75 mm and the depth is more
30、 than 30 mm.5.5 Electronic balance.a) Samples weight are determined by means of top loading electronic balance with precision at least 0,1 g.b) Evaporation residue weights are determined by means of top loading electronic balance with accuracy at least 0,1 mg.5.6 Oven.It shall be capable of holding
31、the temperature at 105 C 2 C and shall not be provided with an ignition source.5.7 Desiccator (with silica gel).It shall be able to store the evaporating dish. ISO 2015 All rights reserved 3BS ISO 17786:2015ISO 17786:2015(E)6 Procedures6.1 Samples shall be taken as described in ISO 29945.6.2 The cle
32、an evaporation dish is placed into the oven at 105 C for 60 min, and cooled in the desiccator for another 30 min. The mass is measured to the digit of 0,1 mg. A, mass of the evaporating dish (g).6.3 Dry ice and methanol are put into the cooling bath (to be under 50 C), to cool the spiral tube.6.4 Sa
33、mple cylinder, connecting pipe, cooler are connected as shown in Figure 1. Then, the valves are opened in the order of the sample cylinder valve, sample valve and needle valve, and the connecting pipe, spiral tube are prewashed with the liquid sample.6.5 The sample cylinder valve is opened, and the
34、sample is led into the evaporation dish in liquid state. At this time, the sample is supplied gradually until the evaporation dish cools down. Needle valves should be used to adjust the sample flow.6.6 When approximately 50 g of liquid sample is led into the evaporating dish, the valve is closed and
35、 the mass of sample weighed to the digit of 0,1 g.B, mass of sample DME (g), tare the evaporating dish.6.7 While ensuring that sudden boiling will not occur, the evaporating dish is exposed to atmosphere and the sample will be almost evaporated.6.8 Repeat 6.4 and 6.5. C, mass of sample DME (g), tare
36、 the evaporating dish. B + C is approximately 100 g.6.9 The evaporating dish is placed in the oven at 105 C for 60 min.6.10 The evaporating dish is taken out of the oven. After being left cooling in the desiccator for 30 min, the mass of the evaporating dish is weighed to the digit of 0,1 mg D, mass
37、 of the evaporating dish after the procedure (g).NOTE During these procedures, there is a risk of fire. Extra caution shall be taken, especially procedures including and after 6.3. The procedures including and after 6.3 shall be carried out in a fume food or an equivalent.7 CalculationThe evaporatio
38、n residue is calculated in accordance with Formula (1), and the result is rounded to four decimal.EDABC(%)()mass =+104(1)whereE is the evaporation residue (mass %);A is the mass (g) of the evaporating dish, measured in 6.2;B is the collected amounts of the sample (g), measured in 6.6;C is the collec
39、ted amounts of the sample (g), measured in 6.8;D is the mass (g) of the evaporating dish after evaporation at 105 C, measured in 6.10.4 ISO 2015 All rights reservedBS ISO 17786:2015ISO 17786:2015(E)8 PrecisionThe provisional precision of this method, established during interlaboratory tests relating
40、 to DME sample with residue content of 20,3 mg/kg, and determined on the basis of statistical examination of interlaboratory test results is shown in Table 1. Refer to Annex A for the report of the interlaboratory test.NOTE The emphasis of the interlaboratory study was to confirm that the sample ana
41、lysed fulfils ISO 16861 specification or not, rather than to establish an analytical method applicable for a wide range. The reproducibility determined is only indicative and is not considered as one established according to normal statistical procedures as in ISO 4259. The figures are provisional a
42、nd further work in the future is intended to improve the estimation given.Repeatability, r: The difference between two test results obtained by the same operator with the same apparatus under constant operating conditions on nominally identical test material would, in the long run, in the normal and
43、 correct operation of the test method, exceed the value below in only one case in 20.Reproducibility, R: The difference between two single and independent results obtained by different operators working in different laboratories on nominally identical test material would, in the long run, in the nor
44、mal and correct operation of the test method, exceed the value below in only one case in 20.Table 1 Provisional precisionDimension in mass %Component Content Repeatability, r Reproducibility, REvaporation residue 0 to 0,007 0 0,26X 0,71XNOTE X is the mean value of the measurements.9 Test reportThe t
45、est report shall include at least the following information:a) a reference to this International Standard, i.e. ISO 17786:2015;b) all the necessary information for complete identification of the sample, for example, ISO 29945: date of sampling, and place in the pipeline system at which the sample wa
46、s taken;c) the sampling method used (including the size and type of material of the high-pressure cylinder used);d) the content of the evaporation residue (mass) in mass % to four decimal;e) the details of any deviation from the procedure specified. ISO 2015 All rights reserved 5BS ISO 17786:2015ISO
47、 17786:2015(E)Annex A (informative) The report of the interlaboratory testsA.1 Precisiona) Outline of the testA repeatability standard deviation and a reproducibility standard deviation were calculated from results of a Round-robin test which was carried out with one sample by eight laboratories.b)
48、Round-robin test resultsThe precision was evaluated by Cochrans test and Grubbs test prescribed on ISO 5725-2, then, the repeatability standard deviation and the reproducibility standard deviation were calculated. The test results are shown in Table A.1. These values were determined from a level exp
49、eriment involving 8 laboratories with 0,002 14 mass % of sample, in which one straggler were detected by the Grubbs test and retained.Table A.1 Round-robin test results (Evaporation residues)Dimension in mass %Laboratory 1st 2nd 3rd 4th5th AverageStandard deviationNumber of testsL1 0,000 38 0,001 13 0,001 34 0,000 95 0,000 50 3L2 0,000 89 0,001 07 0,000 87 0,000 94 0,000 11 3L3 0,002 91 0,002 92 0,002 92 0,002 92 0,000 01 3L4 0,005 63 0,006 33 0,004 31 0,005 42 0
