CEN/TR 17225:2018
(Main)Fuels and biofuels - Assessment on oxidation stability determination methods for distillate fuels and blends thereof with fatty acid methyl esters (FAME)
Fuels and biofuels - Assessment on oxidation stability determination methods for distillate fuels and blends thereof with fatty acid methyl esters (FAME)
This document provides an overview of existing oxidation stability methods, with an emphasis on differences between the Rancimat (EN 14112/EN 15751) and PetroOxy (EN 16091) tests.
Mitteldestillatkraft- und -brennstoffe und Biokraftstoffe - Bewertung der Verfahren zur Oxidationsstabilitätsbestimmung für Mitteldestillatkraft- und -brennstoffe und deren Mischungen mit Fettsäure-Methylestern (FAME)
Carburants et biocarburant - Assessment des méthodes determinations de la stabilité à l'oxydation pour distillats et mélanges avec esters méthyliques d'acides gras (EMAG)
Goriva in biogoriva - Ocenjevanje metod določevanja oksidacijske stabilnosti za destilatna goriva in njihove mešanice z metil estri maščobnih kislin (FAME)
Ta dokument podaja pregled obstoječih metod za določevanje oksidacijske stabilnosti s poudarkom na razlikah med preskusoma Rancimat (EN 14112/EN 15751) in PetroOxy (EN 16091).
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2018
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Fuels and biofuels - Assessment on oxidation stability determination methods for
distillate fuels and blends thereof with fatty acid methyl esters (FAME)
Mitteldestillatkraft- und -brennstoffe und Biokraftstoffe - Bewertung der Verfahren zur
Oxidationsstabilitätsbestimmung für Mittteldestillatkraft- und -brennstoffe und deren
Mischungen mit Fettsäure-Methylestern (FAME)
Carburants et biocarburant - Assessment des méthodes determinations de la stabilité à
l'oxydation pour distillats et mélanges avec esters méthyliques d'acides gras (EMAG)
Ta slovenski standard je istoveten z: CEN/TR 17225:2018
ICS:
75.160.01 Goriva na splošno Fuels in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
CEN/TR 17225
TECHNICAL REPORT
RAPPORT TECHNIQUE
September 2018
TECHNISCHER BERICHT
ICS 75.160.40; 75.160.20
English Version
Fuels and biofuels - Assessment on oxidation stability
determination methods for distillate fuels and blends
thereof with fatty acid methyl esters (FAME)
Carburants et biocarburant - Assessment des méthodes Mitteldestillatkraft- und -brennstoffe und
determinations de la stabilité à l'oxydation pour Biokraftstoffe - Bewertung der Verfahren zur
distillats et mélanges avec esters méthyliques d'acides Oxidationsstabilitätsbestimmung für
gras (EMAG) Mittteldestillatkraft- und -brennstoffe und deren
Mischungen mit Fettsäure-Methylestern (FAME)
This Technical Report was approved by CEN on 4 June 2018. It has been drawn up by the Technical Committee CEN/TC 19.
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, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 17225:2018 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 9
4 Test methods quantifying fuel ageing products . 10
4.1 History . 10
4.2 Generic oxidation stability test . 10
4.3 Turbine and mineral oil test . 11
4.4 Inherent storage stability. 12
4.5 Delta acid method and acid number determination after ageing at 115 °C . 12
4.6 High temperature stability . 13
5 Test methods determing the ageing reserve on the fuel . 13
5.1 General . 13
5.2 Rancimat. 13
5.3 Rancimat at 120 °C . 14
5.4 PetroOxy . 14
6 Differences in Rancimat and PetroOxy tests . 14
6.1 General . 14
6.2 Experimental studies on the share of fuel ageing at the Induction Period . 16
6.3 Discussion of pressure curve characteristics for the PetroOxy-Test (IPPetroOxy) . 17
6.4 Discussion of conductivity curve characteristics for the Rancimat test (IPRancimat). 18
7 Correlation between Rancimat (EN 15751) and PetroOxy (EN 16091) test methods . 21
8 Synopsis . 23
Annex A (informative) Share of fuel ageing on the Induction Period of the Rancimat- and
PetroOxy-tests . 25
Annex B (informative) Correlation exercise between PetroOxyand Rancimat . 29
Bibliography . 31
European foreword
This document (CEN/TR 17225:2018) 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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
During revisions of standards EN 14112, EN 15751, EN 16568 (Rancimat, [17]) and EN 16091
(PetroOxy), CEN/TC 19/JWG 1 “Vegetable fats and oils and their by-products for use in automotive fuels
(Joint working group with CEN/TC 307)” felt the need to create a document that provides extended
background information on oxidation stability test methods complementing the abstracts given in
Annex A of EN 14112, EN 15751 and EN 16568 as well as in Annex C of EN 16091.
This report also gives an overview about the work done by CEN/TC 19/JWG 1 on the correlation
between the Induction Period of the Rancimat and PetroOxy test methods.
Introduction
All fuels, whether of fossil source or biogenic origin, constantly degrade. Although the bulk composition
remains widely unchanged, the presence of oxygen, higher temperature and catalytically active metals
accelerate oxidation of less stable compounds present, thus generating ageing products like acids
oligomers and polymeric compounds. The complex and varying composition of fossil diesel fuels and
the interactions of FAME and its inherent side-products with base diesel fuel components make it
difficult to understand fuel ageing mechanisms at a molecular level. The determination of oxidation
stability of fuels is therefore addressed by phenomenological techniques. Most test methods to
characterize fuel oxidation stability are based on the determination of specific parameters, e.g. polymer
formation, acidity increase, or oxygen consumption.
It has been established that the phenomenon of fuel ageing consists of two consecutive phases, starting
with the depletion of the ageing reserve with few chemical changes to the bulk material, followed by the
fuel ageing process itself during which the fuel is badly decomposed forming ageing polymers and acids
(Figure 1, Table 1). Fuel oxidation takes place via a free radical chain process, initiated by the
abstraction of a hydrogen atom from the fuel molecule and the addition of molecular oxygen to form
hydroperoxides.
Following chemical reactions proceed into two directions: a) Fragmentation of the molecule generates
aldehydes, ketones and short-chain carboxylic acids; b) interlinking of the molecules yielding oxygen
bridged dimers and polymers.
Diesel fuel oxidation is influenced by the chemical constituents of diesel fuel (e.g. specific sulphur- and
nitrogen-containing compounds) and contaminants (e.g. metal impurities). There are many different
chemical reactions, which can occur simultaneously and sequentially, fuel molecules are either
fragmented or increased in their size, e.g. by di-, oligo- and polymerization. These reactions rapidly
increase after a period when little or no chemical oxidation took place. This time interval before fuel
oxidation gets started significantly is called Induction Period.
Stress imposed on the fuel by heat in the presence of oxygen does not necessarily result in immediate
fragmentation or dimer/polymer formation. The reserve capacity of the fuel to resist oxidation is called
ageing reserve, which is related to the Induction Period [1, 2].
Test methods in Figure 1 marked with an asterisk are mentioned in this report for additional
information, but are not the focus of this work.
Rancimat EN ISO 12205 [18], ASTM D2274 [19]
EN 14112 IP 306 mod.* [20]
EN 15751
EN 16568
PetroOxy ∆-acid no. method, JIS draft* [8],
CEN/TR 16885 [10], ASTM D6468* [22]
EN 16091
ASTM D7545 [21]
Key
1 period for the depletion of the ageing reserve (Induction Period)
2 ageing reserve
3 fuel ageing process, strong formation of acids and polymers
t time, h
Y property (such as acid number, conductivity, acidity, polymer formation, etc.)
Figure 1 — Two consecutive phases of fuel ageing and test methods relevant for each phase
Table 1 — Overview about parameters and conditions of oxidation stability test methods
Rancimat PetroOxy IP 306 IP 306 mod. ∆-Acid
EN ISO 12205 ASTM D4625 ASTM D6468
method JIS
EN 14112 EN 16091
ASTM D2274
draft
EN 15751 ASTM D7545
EN 16568
Title
Determination Determination Determination Determination Modifications Standard test Determination Standard test
of oxidation of oxidation of the of oxidation proposed in method for of oxidation method for
stability by stability by oxidation stability of [3] to adapt distillate fuel stability of high
accelerated or rapid small stability of straight IP 306 to storage FAME-blended temperature
rapidly scale oxidation middle mineral oil diesel fuels, stability at diesel fuels stability of
accelerated test (RSSOT) distillate fuels FAME blends 43 °C distillate fuels
oxidation and neat
method FAME
Scope/Determina Oxidation Stability under Inherent Tendency of Inherent Inherent Acid value Relative
tion stability by accelerated stability of straight (i.e. stability under storage increase after stability of
means of oxidation middle plain) mineral accelerated stability of accelerated middle
measuring the conditions by distillate oil to oxidize, oxidation distillate fuels oxidation distillate fuels
Induction measuring the petroleum expressed as conditions under mild conditions under high
Period Induction fuels under total oxidation aging temperature
Period accelerated products conditions aging
oxidation (TOP) with limited conditions
conditions air exposure with limited
air exposure
(venting)
a
FAME content B100 B0 to B100 B0 B0 B0 to B100 [3] B0 B0 to B5 B0
(EN 14112) (EN ISO 12205
ASTM D2274)
B2 to B100 B0 to B7
(EN 15751)
B2 to B50
(EN 16568)
Rancimat
PetroOxy IP 306 IP 306 mod. ∆-Acid
EN ISO 12205 ASTM D4625 ASTM D6468
method JIS
EN 14112 EN 16091
ASTM D2274
draft
EN 15751 ASTM D7545
EN 16568
Oxidation Ageing reserve Ageing reserve Fuel ageing Fuel ageing Fuel ageing Fuel ageing Fuel ageing Fuel ageing
stability + partial fuel behavior by behavior by behavior by behavior by behavior by behavior by
parameter ageing fuel oxidation fuel oxidation fuel oxidation fuel oxidation fuel oxidation fuel oxidation
products products products products products products
Parameter Induction Induction Amount of Amount of Amount of Amount of Acid increase light
Period by Period by total insoluble total insoluble total insoluble total insoluble by soluble reflectance by
conductivity oxygen sludge sludge + sludge + sludge acidity filterable
increase in pressure drop volatile acidity sludge from insoluble
water cell + soluble soluble sludge
acidity polymers +
volatile acidity
+ soluble
acidity
Sample amount 3,0 g 5 ml 350 ml 25 g 25 g 400 ml 350 ml 50 ml
(EN 14112)
7,5 g
(EN 15751)
7,5 g
(EN 16568)
Temperature 110 °C 140 °C 95 °C 120 °C 120 °C 43 °C 115 °C 150 °C
(EN 14112)
110 °C
(EN 15751)
120 °C
(EN 16568)
Time — — 16 h 48 h 16 h up to 24 16 h 1.5 or 3 h
weeks
SIST-TP CEN
...
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