1、BS EN 14112:2016Fat and oil derivatives FattyAcid Methyl Esters (FAME) Determination of oxidationstability (accelerated oxidationtest)BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS EN 14112:2016 BRITISH STANDARDNational forewordThis British Standard is the UK imp
2、lementation of EN 14112:2016.It supersedes BS EN 14112:2003 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee AW/307, Oilseeds, animal and vegetable fats and oils andtheir by-products.A list of organizations represented on this committee can beobtained on
3、 request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 86291 5ICS 67.200.10Compliance with a Briti
4、sh Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 September 2016.Amendments/corrigenda issued since publicationDate Text affectedBS EN 14112:2016EUROPEAN STANDARD NORME EUROPENNE EUROPI
5、SCHE NORM EN 14112 September 2016 ICS 67.200.10 Supersedes EN 14112:2003English Version Fat and oil derivatives - Fatty Acid Methyl Esters (FAME) -Determination of oxidation stability (accelerated oxidation test) Produits drivs des corps gras - Esters mthyliques dacides gras (EMAG) - Dtermination de
6、 la stabilit loxydation (Essai doxydation acclre) Erzeugnisse aus pflanzlichen und tierischen Fetten und len - Fettsure-Methylester (FAME) - Bestimmung der Oxidationsbestndigkeit (Beschleunigte Oxydationsprfung) This European Standard was approved by CEN on 8 July 2016. CEN members are bound to comp
7、ly with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
8、 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 translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the sa
9、me status as the official versions. CEN members are the national standards bodies of 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
10、, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 20
11、16 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14112:2016 EBS EN 14112:2016EN 14112:2016 (E) 2 Contents Page European foreword . 3 Introduction 4 1 Scope 5 2 Normative references 5 3 Terms and definitions . 5 4 Principle . 5 5
12、Reagents and materials . 6 6 Apparatus . 6 7 Sampling . 8 8 Preparation of measurement . 9 8.1 Preparation of test sample 9 8.2 Preparation of apparatus . 9 8.2.1 Cleaning procedure 9 8.2.2 Temperature correction . 9 9 Measurement . 10 10 Calculation and Evaluation . 13 10.1 Automatic evaluation 13
13、10.2 Manual evaluation . 15 11 Expression of results . 16 12 Precision 16 12.1 General . 16 12.2 Repeatability, r 16 12.3 Reproducibility, R 16 13 Test report 16 Annex A (informative) Background of the method . 18 Annex B (informative) Results of an Interlaboratory Study 19 Bibliography . 20 BS EN 1
14、4112:2016EN 14112:2016 (E) 3 European foreword This document (EN 14112:2016) has been prepared by Technical Committee CEN/TC 307 “Oilseeds, vegetable and animal fats and oils and their by-products - Methods of sampling and analysis”, the secretariat of which is held by AFNOR. This European Standard
15、shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2017, and conflicting national standards shall be withdrawn at the latest by March 2017. Attention is drawn to the possibility that some of the elements of this docu
16、ment may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights This document supersedes EN 14112:2003. Significant changes between this document and EN 14112:2003 are: a) the limitation of the scope of the method to a maximum induction perio
17、d of 48 h, reflecting the precision range of the method; b) indication of a potential alteration of the induction period in the presence of cetane enhancers; c) editorial changes in order to clarify the test procedure; d) addition of Clause 2 Normative references; e) addition of Clause 11 Expression
18、 of results; f) background information on the method added as Annex A. According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmar
19、k, 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 the United Kingdom. BS EN 14112:2016
20、EN 14112:2016 (E) 4 Introduction This document is based on EN 14112:2003, which was specifically adapted for the determination of oxidation stability of fatty acid methyl esters (FAME). This method had been developed under CEN/TC 307 (Fats and oils). The modifications as given in this document addre
21、ss the field experience with this method made since its introduction as a standard test method. Editorial changes are made in order to specify some aspects of the test. Additionally, the cleaning procedure is modified based on field experience. BS EN 14112:2016EN 14112:2016 (E) 5 1 Scope This Europe
22、an Standard specifies a method for the determination of the oxidation stability of fatty acid methyl esters (FAME) at 110 C, by means of measuring the induction period up to 48 h. NOTE 1 EN 15751 1 describes a similar test method for oxidation stability determination of pure fatty acid methyl esters
23、 and of blends of FAME with petroleum-based diesel containing 2 % (V/V) of FAME at minimum. NOTE 2 The precision statement of this test method was determined in a Round Robin exercise with induction periods up to 8,5 h, thus covering the limit value in EN 14214. Results from precision studies on EN
24、15751 indicate that the precision statement is valid for induction periods up to 48 h but not for higher values. NOTE 3 Limited studies on EN 15751 with EHN (2-ethyl hexyl nitrate) on FAME blends indicated that the stability is reduced to an extent which is within the reproducibility of the test met
25、hod. It is likely that the oxidation stability of pure FAMEs is also reduced in the presence of EHN when EN 14112 is used for testing. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated
26、 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 3170) EN ISO 3171, Petroleum liquids - Automatic pipeline sampling (ISO 3171) 3 Terms and defin
27、itions For the purposes of this document, the following terms and definitions apply. 3.1 induction period time which passes between the moment when the measurement is started and the moment when the formation of oxidation products begins to increase rapidly 3.2 oxidation stability induction period d
28、etermined according to the procedure specified in this European Standard, expressed in hours 4 Principle A stream of purified (dried) air is passed through the sample which has been heated to the target temperature which is 110 C in the usual application of the method. Volatile compounds are formed
29、during the oxidation process. They are, passed together with the air into a flask containing demineralized or distilled water, equipped with a conductivity electrode. The electrode is connected to a measuring and recording device. It indicates the end of the induction period by rapid increase of the
30、 conductivity due to the dissociation of volatile carboxylic acids produced during the oxidation process and absorbed in the water. For more details on the background of the method see Annex A. BS EN 14112:2016EN 14112:2016 (E) 6 5 Reagents and materials Use only reagents of analytical grade and dis
31、tilled or demineralized water. 5.1 Ternary solvent mixture, consisting of methanol/toluene/acetone 1:1:1 (by volume). 5.2 Alkaline laboratory glass cleaning solution. 5.3 2-Propanol. 6 Apparatus Usual laboratory equipment and glassware, together with the following: 6.1 Device for the determination o
32、f oxidation stability, comprising the following parts (see Figures 1 and 2)1). 6.1.1 Air filter, comprising a tube fitted with filter paper at the ends and filled with a molecular sieve (6.6), connected to the suction end of a pump. 6.1.2 Gas membrane pump, with an adjustable flow rate of (10 1,0) l
33、/h. 6.1.3 Reaction vessels of borosilicate glass, provided with a sealing cap. The sealing cap shall be fitted with a gas inlet and outlet tube. 6.1.4 Closed measurement cells, of approximately 150 ml capacity, with an air inlet tube extending to the bottom inside of the vessel. The cell shall have
34、ventilation holes at the top. 6.1.5 Electrodes, for measuring conductivity within a range of 0 S/cm to 300 S/cm aligned with the dimensions of the measurement cell (6.1.4). 6.1.6 Measuring and recording apparatus, comprising: a) an amplifier; and b) a recorder registering the signal of each of the e
35、lectrodes (6.1.5). 6.1.7 Thyristor and contact thermometer graduated in 0,1 C or Pt 100 element to measure the block temperature, with attachments for relay connection and an adjustable heating element; temperature scale 0 C to 150 C. 1) Rancimat is the trade name of a product supplied by Metrohm AG
36、, Herisau, Switzerland; OSI is the trade name of a product supplied by Omnion Inc., Rockland, Massachusetts, USA. This information is given for the convenience of users of this European Standard and does not constitute an endorsement by CEN or CENELEC of the products named. Equivalent products may b
37、e used if they can be shown to lead to the same results. BS EN 14112:2016EN 14112:2016 (E) 7 6.1.8 Heating block, made of cast aluminium, adjustable to a temperature up to (150 0,1) C. The block shall be provided with holes for the reaction vessels (6.1.3) and an aperture for the contact thermometer
38、 (6.1.7). Alternatively a heating bath may be used, filled with oil suitable for temperatures up to 150 C, and adjustable to the nearest 0,1 C. 6.2 Certified and calibrated thermometer or Pt100 element, with a temperature range up to 150 C, graduated in 0,1 C. Key 1 air filter (6.1.1) 5 electrode (6
39、.1.5) 2 gas membrane pump with flow rate control (6.1.2) 6 measuring and recording apparatus (6.1.6) 3 reaction vessel (6.1.3) 7 thyristor and contact thermometer (6.1.7) 4 measurement cell (6.1.4) 8 heating block (6.1.8) Figure 1 Apparatus BS EN 14112:2016EN 14112:2016 (E) 8 Dimensions in mm Key 1
40、measuring vessel 5 sample 2 electrode 6 heating block 3 distilled/demineralized water 7 air inlet 4 reaction vessel Figure 2 Diagrammatic representation of heating block, reaction vessel and measurement cell 6.3 Measuring pipettes and/or measuring cylinders. 6.4 Oven, adjustable to a temperature up
41、to (150 3) C. 6.5 Connecting hoses, flexible and made of inert material polytetrafluoroethylene (PTFE) or silicone. 6.6 Molecular sieve, with moisture indicator, pore size 0,3 nm, dried in an oven set at 150 C and cooled down to room temperature in a desiccator before use. 6.7 Balance, capable of we
42、ighing with an accuracy of 0,1 g or less. 7 Sampling Unless otherwise specified, sampling shall be conducted according to EN ISO 3170 or EN ISO 3171 and/or in accordance with the requirements of national standards or regulations for the sampling. It is important that the laboratory receives a sample
43、 which is truly representative and has not been damaged or changed during transport and storage. Store the sample in the dark at about 4 C and measure it as soon as possible after receipt. BS EN 14112:2016EN 14112:2016 (E) 9 8 Preparation of measurement 8.1 Preparation of test sample In order to ens
44、ure a consistent test condition, all samples shall be treated in the way described below: take the required quantity from the centre of the carefully homogenized sample using a pipette; analyse the samples immediately after sample preparation. 8.2 Preparation of apparatus 8.2.1 Cleaning procedure Th
45、e use of new disposable reaction vessels, air inlet tubes and connecting hoses is recommended in order to save the cleaning procedure. Sealing caps, measuring cells and electrodes shall be cleaned with 2-Propanol in order to remove organic residues. The connecting hoses should also be washed in the
46、same manner if not replaced. Rinse with tap water and finally with demineralized or distilled water. Dry the cleaned parts in an oven at 80 C for at least 2 h. The temperature may not exceed 80 C due to elastomer stability. Residual fuel and aging products from the previous experiment and the solven
47、t from the cleaning may remain adsorbed in the elastomers and shall be removed. A drying time of 2 h ensures that all volatile compounds are removed. In case of reuse, purge the empty reaction vessels and the air inlet tubes at least three times with ternary solvent mixture (5.1) in order to remove
48、residual fuel and adherent organic ageing residues. The last solvent portion should remain colourless. Rinse with 2-Propanol and tap water. Put the inlet tube into the reaction vessel and fill completely with an aqueous alkaline laboratory cleaning solution. Store the vessels at room temperature ove
49、rnight. Rinse the purified vessels and their inlet tubes thoroughly with tap water and finally with demineralized or distilled water. Dry them in an oven for at least 2 h at 80 C. In case of doubt, the cleanliness of the sealing caps and connecting hoses can be checked by running a blank sample under standard test conditions. In this case the conductivity increase shall not exceed 10 S/cm within 5 h. 8.2.2 Temperature correction 8.2.2.1 General Any deviation between the temperature of the fuel sample in the test vessel
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