EN 590 Automotive fuels - Diesel - Requirements and test methods
5 Requirements and test methods
5.1 Dyes and markers
The use of dyes or markers is allowed.
In order to improve the performance quality, the use of additives is allowed. Suitable fuel additives without known harmful side-effects are recommended in the appropriate amount, to help to avoid deterioration of driveability and emissions control durability. Other technical means with equivalent effect may also be used.
NOTE Deposit forming tendency test methods suitable for routine control purposes have not yet been identified and developed.
5.2.2 Methylcyclopentadienyl manganese tricarbonyl (MMT)
When methylcyclopentadienyl manganese tricarbonyl (MMT) is used, a specific labelling is required (see also Clause 4). The presence of the MMT is limited via a manganese content limit as in Tables 1 and 2.
5.3 Fatty acid methyl ester (FAME)
Diesel fuel may contain up to 7.0 % (V/V) of FAME complying with EN 14214:2012+A1:2014, in which case the climate dependent requirements set out in 5.4.2 of EN 14214:2012+A1:2014 do not apply.
NOTE 1 A suitable method for the separation and identification of FAME is given in EN 14331.
Climate dependent requirements for FAME as a blending component for use in diesel fuel according to this document are set out in 5.4.3 of EN 14214:2012+A1:2014. The specific grades shall be specified on a national basis according to local climatic conditions and the FAME volume in the diesel fuel.
The finished blend of diesel fuel shall also comply with the climate dependent requirements set out in 5.6. of this document.
Cold flow additives, when used in FAME, should be specifically matched to the base diesel fuel and FAME quality to ensure correct performance consistent with the requirements set out in this European Standard. The choice could result in incompatibility between the cold flow additives used in the FAME and the diesel fuel. The choice of cold flow additive technology should be a contractual matter between the fuel blender and the FAME supplier taking into account the climatic-dependent requirements of the finished diesel fuel.
NOTE 2 Cold flow requirements for FAME as a blend component in diesel fuel are set out in Tables 3a and 3b and the National Annex of EN 14214:2012+A1:2014, in order to control maximum content of saturated monoglycerides in the final EN 590 blend to ensure trouble-free operation. Work is on-going to identify a suitable test method for saturated monoglycerides or a performance test to control this aspect of low temperature performance.
In order to improve the oxidation stability of FAME, it is strongly recommended to add oxidation stability enhancing additives to FAME at the production stage and before storage, providing an oxidation stability similar to that obtained with 1000 mg/kg of 2,6-di-tert-butyl-4-hydroxytoluene (BHT, officially designated by IUPAC as 2,6-bis(1,1-dimethylethyl)-4-methylphenol).
The similar action may be read as providing oxidation stability performance at least equal to that obtained with 1000 mg/kg of BHT.
CAUTION - There is a potential risk of precipitate formation with oxidation stability enhancing additives at low temperatures in low aromatic arctic fuel. Caution should therefore be taken in the choice of oxidation stability enhancing additives to arctic grade FAME.
5.4 Other (bio-) components
Limits for FAME do not apply to other (non-petroleum derived) hydrocarbons, such as Hydrotreated Vegetable Oil (HVO), Gas To Liquid (GTL) or Biomass To Liquid (BTL) derived hydrocarbons, since these paraffinic diesel components are allowed in any proportions provided that the final blend complies with the requirements of this European Standard. The co-processing of renewable feedstock at refineries is also allowed provided that the final fuel meets the requirements of this European Standard.
5.5 Generally applicable requirements and related test methods
5.5.1 When tested by the methods indicated in Table 1, automotive diesel fuel shall be in accordance with the limits specified in Table 1. The test methods listed in Table 1 have been assessed for application to automotive diesel containing FAME. Precision data from inter-laboratory test programmes are given in normative Annex A, where these were found to be different from the precision data given in the test methods for neat petroleum products.
5.5.2 The limiting value for the carbon residue given in Table 1 is based on product prior to addition of ignition improver, if used. If a value exceeding the limit is obtained on finished fuel in the market, EN ISO 13759 shall be used as an indicator of the presence of a nitrate-containing compound. If an ignition improver is thus proved present, the limit value for the carbon residue of the product under test cannot be applied. The use of additives does not exempt the manufacturer from meeting the requirement of maximum 0.30 % (m/m) of carbon residue prior to addition of additives.
5.5.3 Diesel fuel shall be free from any adulterant or contaminant that may render the fuel unacceptable for use in diesel engine vehicles.
NOTE For further information on preventing contamination by water or sediment that may occur in the supply chain, or for cross-contamination, it is advisable to check CEN/TR 15367-1 or CEN/TR 15367-3 respectively.
5.6 Climate dependent requirements and related test methods
5.6.1 For climate-dependent requirements, options are given to allow for seasonal grades to be set nationally. The options are for temperate climates six CFPP (cold filter plugging point) grades and for arctic or severe winter climates five different classes. Climate-dependent requirements are given in Table 2 (temperate climates) and Table 3 (arctic or severe winter climates). When tested by the methods given in Table 2 and Table 3, automotive diesel fuel shall be in accordance with the limits specified in these tables.
NOTE Attention is drawn to CEN/TR 16884 on cold operability testing and fuel performance correlation. In addition, CEN has developed another technical report on cold filterability issues that have been reported in some geographical areas at low temperatures above the cloud point of the fuel. Work to improve understanding of these issues and develop technical solutions is on-going within CEN and some national standardisation bodies.
5.6.2 In a National Annex to this European Standard, each country shall detail requirements for a summer and a winter grade and may include (an) intermediate and/or regional grade(s) which shall be justified by national meteorological data.
5.7 Precision and dispute
5.7.1 All test methods referred to in this European Standard include a precision statement. In cases of dispute, the procedures for resolving the dispute and interpretation of the results based on test method precision, described in EN ISO 4259, shall be used.
5.7.2 In cases of dispute concerning density, EN ISO 12185 shall be used.
5.7.3 In cases of dispute concerning sulfur content, either EN ISO 20846 or EN ISO 20884 shall be used.
5.7.4 In cases of dispute concerning cetane number, EN ISO 5165 shall be used. For the determination of cetane number alternative methods to those indicated in Table 1 and Table 3 may also be used, provided that these methods originate from a recognised method series, and have a valid precision statement, derived in accordance with EN ISO 4259, which demonstrates precision at least equal to that of the referenced method. The test result, when using an alternative method, shall also have a demonstrable relationship to the result obtained when using the referenced method.
5.7.5 In cases of dispute concerning distillation, EN ISO 3405 shall be used.
5.7.6 In cases of dispute concerning CFPP, EN 116 shall be used.