1、Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:48, Uncontrolled Copy, (c) BSIg49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58a
2、cidity Colour indicator titration methodThe European Standard EN 15491:2007 has the status of a British StandardICS 71.080.60Ethanol as a blending component for petrol Determination of total BRITISH STANDARDBS EN 15491:2007BS 2000-538:2007BS EN 15491:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA S
3、TANDARDS, 12/12/2007 02:48, Uncontrolled Copy, (c) BSIThis BritiThe PTArequest to its EnBSNational forewordThis British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2007 BSI and Energy Institute 2007ISBN 978 0 580 56679 0Compliance with a Br
4、itish Standard cannot confer immunity from legal obligations.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 a
5、vailable from: Energy Institute, 61 New Cavendish Street, London 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.sh Standard is the UK implementation of EN 15491
6、:2007. UK participation in its preparation was 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 petrole
7、um test methods that would be Part of BS 2000, EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 15491August 2007ICS 71.080.60English VersionEthanol as a blending component for petrol - Determination oftotal acidity - Colour indicator titration methodEthanol comme base de mlange lessence -Dterminati
8、on de lacidit totale - Mthode de titrage parindicateur colorEthanol zur Verwendung als Blendkomponente inOttokraftstoff - Bestimmung der Gesamtsurezahl -Farbindikator-TitrationThis European Standard was approved by CEN on 30 June 2007.CEN members are bound to comply with the CEN/CENELEC Internal Reg
9、ulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This E
10、uropean Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility 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 na
11、tional standards bodies of 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, Slovakia, Slovenia, Spain, Sweden, Switzerland and
12、United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15491:2007:
13、ELicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:48, Uncontrolled Copy, (c) BSIEN 15491:2007 (E) 2 Contents Page Foreword. 3 1 Scope 4 2 Normative references . 4 3 Terms and definitions. 4 4 Principle . 4 5 Reagents and materials 4 6 Apparatus 5 7 Sampling and sample handling .
14、6 8 Procedure 6 9 Calculation. 6 10 Expression of results 6 11 Precision 7 11.1 General. 7 11.2 Repeatability, r 7 11.3 Reproducibility, R . 7 12 Test report . 7 Bibliography . 8 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:48, Uncontrolled Copy, (c) BSIEN 15491:2007 (E) 3 Fo
15、reword This document (EN 15491:2007) 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 s
16、tandard, either 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 the Energy Institute standard IP 53
17、8 1. According to the CEN/CENELEC Internal Regulations, the national standards organizations 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, It
18、aly, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:48, Uncontrolled Copy, (c) BSIEN 15491:2007 (E) 4 1 Scope This European S
19、tandard specifies a method for determining the total acidity, calculated as acetic acid, of ethanol to be used in petrol blends. It is applicable to ethanol having total acid contents of between 0,003 % (m/m) to 0,015 % (m/m). NOTE For the purposes of this European Standard, the term “% (m/m)” and “
20、% (V/V)” are used to represent the mass fraction and the volume fraction respectively. WARNING Use of this standard may involve hazardous materials, operations and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the
21、 user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition
22、 cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 3170, Petroleum liquids Manual sampling (ISO 3170:2004) EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696:1987) 3 Terms and definit
23、ions For the purposes of this European Standard, the following terms and definitions apply. 3.1 total acidity acidity, calculated as acetic acid, determined by titration and colour indicator as given in this standard 4 Principle A test portion of the ethanol is mixed with an equal volume of neutrali
24、zed, carbon dioxide free water. The acid content is titrated with potassium hydroxide solution, to the neutral endpoint of phenolphthalein. The total acidity is then calculated as acetic acid. 5 Reagents and materials Use only reagents of recognized analytical grade and water complying with the requ
25、irements of grade 3 of EN ISO 3696. 5.1 Potassium hydrogen phthalate 5.2 Potassium hydroxide solution 0,01 mol/l, a solution prepared in accordance with 5.2.1 or a commercially available standardized potassium hydroxide solution of equivalent concentration and purity. The reagent shall be protected
26、against carbon dioxide absorption and restandardized frequently enough to detect concentration changes of 0,000 5 mol/l. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:48, Uncontrolled Copy, (c) BSIEN 15491:2007 (E) 5 5.2.1 Dissolve approximately 0,6 g potassium hydroxide in 1
27、l of water and standardize using potassium hydrogen phthalate in accordance with 5.2.2. 5.2.2 Dry a quantity of potassium hydrogen phthalate (5.1) in an oven at approximately 120 C for approximately 2 h. Place in a desiccator and allow to cool. Weigh approximately 0,1 g to the nearest 0,1 mg into a
28、250 ml flask and record this mass. Add approximately 50 ml of carbon dioxide free water (5.5) and swirl to dissolve. Add 2 drops of phenolphthalein indicator solution (5.3) and using a 50 ml burette (6.5), titrate to neutral endpoint with the potassium hydroxide solution. Carry out a blank determina
29、tion using the same volume of carbon dioxide free water (5.5). Calculate the concentration C, in moles per litre, of the potassium hydroxide solution from the equation: ()0123,2041000VVmC= (1) where m is the mass, in grams, of potassium hydrogen phthalate; V1is the volume, in millilitres, of potassi
30、um hydroxide solution for the titration; V0 is the volume, in millilitres, of potassium hydroxide used for the blank. 5.3 Phenolphthalein indicator solution, approximately 10g/l Weigh approximately 1 g of phenolphthalein into the 100 ml volumetric flask (6.1). Add approximately 20 ml of ethanol (5.4
31、) and swirl until dissolved. Make up to 100 ml with ethanol. 5.4 Ethanol, approximately 95 % (V/V). 5.5 Carbon dioxide free water NOTE A suitable way of preparing carbon dioxide free water is to place approximately 100 ml of water in a 250 ml conical flask (6.3), fitted with a standard ground glass
32、joint, heat to boiling on either a hot plate or gas burner and boil for 2 min to 3 min. Remove the flask and its contents from the heat and insert a soda-lime filled guard tube (6.7) and cool to ambient temperature before use. 5.6 Soda lime, for the guard tube (optional). 5.7 Nitrogen, carbon dioxid
33、e free (optional). 6 Apparatus 6.1 Volumetric flask, Class A, 100 ml capacity. 6.2 Measuring cylinder, 100 ml capacity. 6.3 Conical flask, glass, with standard ground glass joint, approximately 250 ml capacity. 6.4 Burette, Class A 50 ml capacity. 6.5 Burette, Class A 10 ml capacity and graduated in
34、 0,05 ml, or less, subdivisions. 6.6 Pipette, Class A 50 ml capacity. 6.7 Glass guard tube, with ground glass joint to fit the conical flask (6.3) (optional). Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:48, Uncontrolled Copy, (c) BSIEN 15491:2007 (E) 6 7 Sampling and sample
35、handling 7.1 Unless otherwise specified, laboratory samples shall be obtained by the procedures described in EN ISO 3170. 7.2 Take care to minimise the uptake of atmospheric carbon dioxide during sampling and sample handling. 8 Procedure 8.1 Fill the 10 ml burette (6.5) with the potassium hydroxide
36、solution (5.2). 8.2 Using the measuring cylinder (6.2) measure approximately 50 ml of carbon dioxide free water (5.5) into the conical flask (6.3). Add two drops of phenolphthalein solution (5.3). Titrate with the standardized potassium hydroxide solution (5.2) to a faint pink endpoint. 8.3 Using th
37、e pipette (6.6) add 50 ml of the test portion to the neutralised water. Stopper the flask and swirl to mix the test portion and the water. 8.4 Remove the stopper and immediately titrate the mixture using the standardized potassium hydroxide to a faint pink end point. Take care not to prolong the tit
38、ration as the up-take of atmospheric carbon dioxide by the ethanol water mix will appreciably affect the result. NOTE Atmospheric carbon dioxide can be prevented from entering the titration flask by bubbling nitrogen (5.7) through the solution during the titration. 8.5 If the density of the ethanol
39、to be tested is not known, determine it, in g/ml, at 15 C to two decimal places. 9 Calculation Calculate the total acidity, As, as acetic acid, of the sample in % (m/m), using the following equation: 0,12s=VCA (2) where C is the concentration, in moles per litre, of potassium hydroxide solution, see
40、 equation (1); V is the volume, in millilitres, of potassium hydroxide solution required to neutralize 50 ml of test portion; is the density, in grams per millilitre, of the test portion at 15 C. 10 Expression of results Report the total acidity content of the sample to the nearest 0,001 % (m/m). Li
41、censed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:48, Uncontrolled Copy, (c) BSIEN 15491:2007 (E) 7 11 Precision 11.1 General The precision given was derived from statistical analysis by EN ISO 4259 2 of the results of interlaboratory testing of a matrix of ethanol samples produced
42、in Europe from biomaterials such as raw wine, molasses, pulp and corn. NOTE The interlaboratory testing and the statistical evaluation are detailed in Research Report IP 538 3. 11.2 Repeatability, r The difference between two test results, obtained by the same operator with the same apparatus under
43、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 value in only one case in twenty. r = 0,000 960 4 11.3 Reproducibility, R The difference between two single and independent results, obtained b
44、y different operators working in different laboratories on identical test material, would in the long run, in the normal and correct operation of the test method, exceed the following value only in one case in twenty. R = 0,001 370 12 Test report The test report shall contain at least the following
45、information: a) reference to this European Standard, i.e. EN 15491; b) type and complete identification of the product tested; c) result of the test (see 10); d) any deviation, by agreement or otherwise, from the procedure specified; e) date of the test. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA S
46、TANDARDS, 12/12/2007 02:48, Uncontrolled Copy, (c) BSIEN 15491:2007 (E) 8 Bibliography 1 IP 538/06, Determination of the total acidity of ethanol Colour indicator titration method. Available from the Energy Institute, 61 New Cavendish Street, London, W1G 7AR, UK. 2 EN ISO 4259, Petroleum products De
47、termination and application of precision data in relation to methods of test (ISO 4259:2006). 3 Research Report: IP 538/06, Precision evaluation on IP 538, Determination of the total acidity of ethanol Colour indicator titration method. Available from the Energy Institute, 61 New Cavendish Street, L
48、ondon, W1G 7AR, UK. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:48, Uncontrolled Copy, (c) BSIblankLicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:48, Uncontrolled Copy, (c) BSILicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/12/2007 02:48, Unco
49、ntrolled Copy, (c) BSIBS 2000 Series Energy InstituteBuying Parts of BS 2000Orders for BS 2000 publications should be addressed to either:Energy Institute Library and Information Service61 New Cavendish StreetLondonW1G 7ARTel: +44 (0)20 7467 7100Fax: +44 (0)20 7255 1472www.energyinst.org.ukOrder standards securely via:www.energyinstpubs.org.ukor:British Standards Institution Customer Services389 Chiswick High RoadLondonW4 4ALTel: +44 (0)20 8996 9001Fax: +44 (0)20 8996 7001www.bsi-Order hard copy standards securely via:www.bs
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