1、Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:41, Uncontrolled Copy, (c) BSIg49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58T
2、he European Standard EN 15490:2007 has the status of a British StandardICS 71.080.60Ethanol as a blending component for petrol Determination of pHeBRITISH STANDARDBS EN 15490:2007 BS 2000-557:2007BS EN 15490:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:41, Uncontrolled Co
3、py, (c) BSIThis BritiThe PTArequest to its EnBSThis British Standard was published under the authority ofthe Standards Policy and Strategy Committee on 31 October 2007 BSI and Energy Institute 2007ISBN 978 0 580 56678 3Compliance with a British Standard cannot confer immunity from legal obligations.
4、Amendments issued since publicationAmd. No. Date Commentsboth in its annual publication “Standard methods for analysis and testing of petroleum and related products and British Standard 2000 Parts” and individually.Further information is available from: Energy Institute, 61 New Cavendish Street, Lon
5、don W1G 7AR. Tel: 020 7467 7100. Fax: 020 7255 1472.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.National forewordsh Standard is the UK implementation of EN 15490:2007. UK participation in its preparation w
6、as entrusted to Technical Committee I/13, Petroleum testing and terminology.list of organizations represented on this committee can be obtained on secretary.ergy Institute, under the brand of IP, publishes and sells all Parts of 2000, and all BS EN petroleum test methods that would be Part of BS 200
7、0, EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 15490August 2007ICS 71.080.60English VersionEthanol as a blending component for petrol - Determination ofpHeEthanol comme base de mlange lessence -Dtermination du pHeEthanol zur Verwendung als Blendkomponente inOttokraftstoff - Bestimmung des pHe-
8、WertesThis European Standard was approved by CEN on 30 June 2007.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 bibliographical re
9、ferences 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 of a CEN member
10、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, Ireland, Italy, Latvia
11、, 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: rue de Stassart, 36 B-1050 Brussels 20
12、07 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15490:2007: ELicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:41, Uncontrolled Copy, (c) BSIEN 15490:2007 (E) 2 Contents Page Foreword. 3 1 Scope 4 2 Normative re
13、ferences . 4 3 Terms and definitions. 4 4 Principle . 4 5 Reagents and materials 4 6 Apparatus 5 7 Sampling and sample handling . 5 8 Apparatus preparation 5 9 pH meter and electrode system calibration . 5 10 Apparatus verification 6 11 Procedure 6 12 Expression of results 7 13 Precision 7 13.1 Gene
14、ral. 7 13.2 Repeatability, r 7 13.3 Reproducibility, R . 7 14 Test report . 8 Annex A (informative) Background to actual fuel specification needs 9 Bibliography . 10 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:41, Uncontrolled Copy, (c) BSIEN 15490:2007 (E) 3 Foreword This d
15、ocument (EN 15490:2007) has been prepared by Technical Committee CEN/TC 19 “Gaseous and liquid fuels, lubricants and related products of petroleum, synthetic and biological origin”, the secretariat of which is held by NEN. This European Standard shall be given the status of a national standard, eith
16、er by publication of an identical text or by endorsement, at the latest by February 2008, and conflicting national standards shall be withdrawn at the latest by February 2008. This document was prepared by CEN/TC 19s Ethanol Task Force and is based on an extract and translation from a French Wine Re
17、gulation 1. This method has been developed for European fuel ethanol specifications. Interlaboratory studies found that the method is not robust enough. Therefore it is better not to use it to determine the presence of any strong acids or alkalis that may be present in fuel ethanol. This Standard ha
18、s insufficient precision to fulfill actual fuel specification needs (see Annex A). A test for strong acid and for the presence of alkaline substance will be developed by CEN/TC 19 to replace the pHe test method. According to the CEN/CENELEC Internal Regulations, the national standards organizations
19、of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Sl
20、ovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:41, Uncontrolled Copy, (c) BSIEN 15490:2007 (E) 4 1 Scope This European Standard describes a procedure for the determination of acid strength, as a pHe value, of etha
21、nol to be used as a blend component for gasoline. For further background on the applicability of this document, the user is referred to the information in Annex A. NOTE For the purposes of this European Standard, the term “% (V/V)” is used to represent the volume fraction. 2 Normative references The
22、 following 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. EN ISO 3170, Petroleum liquids Manual sampling (ISO
23、3170:2004) EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696:1987) 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply. 3.1 pHe measure of the acid strength 4 Principle The pHe of a test portion of etha
24、nol held at 22 C 2 C is measured using an electrode containing lithium chloride (LiCl) in an ethanol medium connected to a pH meter system. NOTE In non-aqueous media, it is not possible to carry out absolute pH measurements and a pHe value is not directly comparable to pH values of water solutions.
25、5 Reagents and materials Use only reagents of recognized analytical grade. 5.1 Buffer solutions, of pH (4,00 0,02), pH (7,00 0,02) and pH (10,00 0,02), within their valid period for use. CAUTION Buffer solutions can deteriorate with time and it is important that they are used within their valid peri
26、od of use. NOTE Buffer solutions may be prepared from either commercially available tablets dissolved in water or commercially available aqueous solutions. 5.2 Ethanol, 99 % (V/V) containing 1 % (V/V) water. 5.3 Water, conforming to Grade 3 of EN ISO 3696. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA
27、 STANDARDS, 12/12/2007 02:41, Uncontrolled Copy, (c) BSIEN 15490:2007 (E) 5 5.4 Lithium chloride solution, 1mol/l in 99 % (V/V) ethanol (5.2). 5.5 Sodium hydroxide aqueous solution, approximately 1 mol/l 5.6 Hydrochloric acid aqueous solution, approximately 1 mol/l 6 Apparatus 6.1 pH Meter, capable
28、of reading to 0,01 pH with an accuracy of 0,01 pH (or 1 mV), preferably fitted with a temperature compensator. 6.2 Combined pH electrode, filled with a 1 mol/l solution of lithium chloride (LiCl) in 99 % (V/V) ethanol. 6.3 Magnetic stirrer 6.4 PTFE covered magnetic follower. 6.5 Glass beakers, appro
29、ximately 100 ml capacity fitted with a cover to minimise the ingress of carbon dioxide from the air. NOTE The cover should either be a rigid plastic cover with a hole to allow the electrode to pass through or a film of disposable plastic placed over the top of the beaker after the electrode has been
30、 inserted. 6.6 Timer, capable of measuring seconds. 7 Sampling and sample handling 7.1 Samples shall be taken as described in EN ISO 3170. 7.2 Take care to minimise the uptake of atmospheric water during sampling and sample handling. NOTE The use of a glass bottle that can be sealed with a septum ha
31、s been found suitable for sampling and sample handling. A test portion of the sample can be taken through the septum with a syringe fitted with a needle. 8 Apparatus preparation 8.1 Clean/rehydrate new electrodes before use in alcoholic solutions and after measuring the pHe of 10 ethanol samples by
32、alternatively soaking them in 1 mol/l sodium hydroxide solution (5.5) for approximately 30 s then 1 mol/l hydrochloric acid solution (5.6) for approximately 30 s. Repeat this procedure 3 times. 8.2 Wash the electrode free of acid and alkali with water (5.3) and allow draining. If the electrode is no
33、t to be used immediately, place in and store in a solution of lithium chloride in ethanol (5.4). 9 pH meter and electrode system calibration 9.1 Set up the pH meter in accordance with the manufactures instructions and, if fitted, adjust the temperature compensator to 22 C 2C. 9.2 Remove the combined
34、 electrode from the lithium chloride solution (5.4), wash with water (5.3) and allow draining. 9.3 Rinse the combined electrode (6.2) with pH 4,00 buffer solution (5.1). Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:41, Uncontrolled Copy, (c) BSIEN 15490:2007 (E) 6 9.4 In a 10
35、0 ml beaker (6.5), place sufficient volume of pH 4,00 buffer solution (5.1) at 22 C 2C to cover the electrode. Insert the magnetic follower (6.6). 9.5 Place the beaker and its contents on the magnetic stirrer (6.3). NOTE Automatic pH meters may require the user to input the pH value of the buffer so
36、lution. 9.6 Place the combined electrode (6.2) into the pH 4,00 buffer solution (5.1). Cover the beaker (see NOTE under 6.5). 9.7 Switch on the magnetic stirrer (6.3) and allow the pH meter reading to stabilize. 9.8 If necessary adjust the reading to 4,00. 9.9 Remove the combined electrode and rinse
37、 it with water (5.3). 9.10 Repeat 9.3 to 9.9 using the pH 10 buffer solution (5.1) (see NOTE under 9.5). If necessary, adjust the pH meter reading to 10,00 using the slope adjustment. 10 Apparatus verification 10.1 Before testing each day and after cleaning/rehydrating the electrode, see clause 8, v
38、erify the correct functioning of the electrode/pH meter system using a pH 7,00 buffer solution (5.1) in accordance with 10.2 to 10.7. 10.2 Rinse the combined electrode with water (5.3) then with pH 7,00 buffer solution (5.1). 10.3 In a 100 ml beaker (6.5), place sufficient volume of pH 7,00 buffer s
39、olution (5.1) at 22 C 2C to cover the electrode. Insert the magnetic follower (6.4). 10.4 Place the beaker and its contents on the magnetic stirrer (6.3). 10.5 Place the combined electrode (6.2) into the pH 7,00 buffer solution (5.1), cover the beaker (see NOTE under 6.5). 10.6 Switch on the magneti
40、c stirrer (6.3) and allow the pH meter reading to stabilize (see NOTE under 9.5). 10.7 The pH meter shall read pH 7,00 0,04. 10.8 If the reading is not within the tolerance in 10.7, remove the combined electrode, clean in accordance with 8.1 and repeat 10.1 to 10.6. 10.9 If the reading is still not
41、within the tolerance in 10.7, recalibrate the electrode and pH meter in accordance with clause 9. 11 Procedure 11.1 If a temperature compensator is fitted to the pH meter, check and, if necessary, adjust it to 22 C 2 C. 11.2 Bring the ethanol (5.2) to be tested to 22 C 2 C and place sufficient volum
42、e of it to cover the electrode in a 100 ml beaker (6.5). 11.3 Place the beaker and the test portion on a magnetic stirrer (6.3). Insert the magnetic follower (6.4) and the electrode and cover the beaker to minimise the ingress of atmospheric carbon dioxide. Licensed Copy: Wang Bin, ISO/EXCHANGE CHIN
43、A STANDARDS, 12/12/2007 02:41, Uncontrolled Copy, (c) BSIEN 15490:2007 (E) 7 11.4 Stir the test portion, allow the pHe reading to stabilize, see note. Record the pHe to the nearest 0,01. NOTE For some samples this may be in excess of 4 min. In such circumstances extra care should be taken to minimis
44、e the ingress of atmospheric carbon dioxide during the measurement. 12 Expression of results Report the pHe of the sample to the nearest 0,01. 13 Precision 13.1 General The precision given was derived from statistical analysis by EN ISO 4259 2 of the results of interlaboratory testing of a matrix of
45、 ethanol samples produced in Europe from bio materials such as raw wine, molasses, pulp and corn. Typical values are given in Table 1. NOTE The interlaboratory testing and the statistical evaluation are detailed in an UNGDA Report, September 2006 (UNGDA, 174 blvd Camlinat, 92247 MALAKOFF Cedex, Fran
46、ce, www.ungda.org). 13.2 Repeatability, r The difference between two test results, obtained by the same operator with the same apparatus under constant operating conditions on identical test material would in the long run, in the normal and correct operation of the test method, exceed the following
47、value in only one case in twenty. r = 0,033 X (1) where X is the average of results being compared. 13.3 Reproducibility, R The difference between two single and independent results, obtained by different operators working in different laboratories on identical test material, would in the long run,
48、in the normal and correct operation of the test method, exceed the following value only in one case in twenty. R = 0,096 X (2) where X is the average of results being compared. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:41, Uncontrolled Copy, (c) BSIEN 15490:2007 (E) 8 Tabl
49、e 1 Calculated values for repeatability and reproducibility pHe Repeatability r Reproducibility R 5 0,165 0,48 5,5 0,181 5 0,528 6 0,198 0,576 6,5 0,214 5 0,624 7 0,231 0,672 7,5 0,247 5 0,72 8 0,264 0,768 8,5 0,280 5 0,816 9 0,297 0,864 14 Test report The test report shall contain at least the following information: a) reference to this European Standard, i.e. EN 15490; b) type and complete identification of the product tested; c) result of the test (see 12); d) any deviation, by agreement or otherwise, from t
