This document specifies a procedure for the calculation of the cetane index of middle-distillate fuels from petroleum-derived sources. The calculated value is termed the "cetane index by four-variable equation". Throughout the remaining text of this document, the term "cetane index" implies cetane index by four-variable equation.This document is applicable to fuels containing non-petroleum derivatives from tar sand and oil shale. It is not applicable to pure hydrocarbons, nor to distillate fuels derived from coal. Cetane index calculations do not take into account the effects from additives used to enhance the Cetane number.NOTE 1 This document was originally developed using a matrix of fuels, some of which contain non-petroleum derivatives from tar sands and oil shale.NOTE 2 The cetane index is not an alternative way to express the cetane number; it is a supplementary tool, to be used with due regard for its limitations.NOTE 3 The cetane index is used to estimate the cetane number of diesel fuel when a test engine is not available to determine this property directly, or when insufficient sample is available for an engine rating.The most suitable range of fuel properties for application of this document is as follows:Fuel propertyRangeCetane number32,5 to 56,5Density at 15 °C, kg/m3805,0 to 895,010 % (V/V) distillation recovery temperature, °C171 to 25950 % (V/V) distillation recovery temperature, °C212 to 30890 % (V/V) distillation recovery temperature, °C251 to 363Within the range of cetane number (32,5 to 56,5), the expected error of the prediction via the cetane index equation will be less than ±2 cetane numbers for 65 % of the distillate fuels examined. Errors can be greater for fuels whose properties fall outside this range of application.As a consequence of sample-specific biases observed, the expected error can be greater even when the fuel's properties fall inside the recommended range of application. Therefore, users can assess the required degree of prediction agreement to determine the fitness-for-use of the prediction.NOTE 4 Sample specific biases were observed for distillate fuels containing FAME (fatty acid methyl ester).
This document specifies a procedure for the calculation of the cetane index of middle-distillate fuels from petroleum-derived sources. The calculated value is termed the "cetane index by four-variable equation". Throughout the remaining text of this document, the term "cetane index" implies cetane index by four-variable equation.
This document is applicable to fuels containing non-petroleum derivatives from tar sand and oil shale. It is not applicable to pure hydrocarbons, nor to distillate fuels derived from coal. Cetane index calculations do not take into account the effects from additives used to enhance the Cetane number.
NOTE 1 This document was originally developed using a matrix of fuels, some of which contain non-petroleum derivatives from tar sands and oil shale.
NOTE 2 The cetane index is not an alternative way to express the cetane number; it is a supplementary tool, to be used with due regard for its limitations.
NOTE 3 The cetane index is used to estimate the cetane number of diesel fuel when a test engine is not available to determine this property directly, or when insufficient sample is available for an engine rating.
The most suitable range of fuel properties for application of this document is as follows:
Fuel property
Range
Cetane number
32,5 to 56,5
Density at 15 °C, kg/m3
805,0 to 895,0
10 % (V/V) distillation recovery temperature, °C
171 to 259
50 % (V/V) distillation recovery temperature, °C
212 to 308
90 % (V/V) distillation recovery temperature, °C
251 to 363
Within the range of cetane number (32,5 to 56,5), the expected error of the prediction via the cetane index equation will be less than ±2 cetane numbers for 65 % of the distillate fuels examined. Errors can be greater for fuels whose properties fall outside this range of application.
As a consequence of sample-specific biases observed, the expected error can be greater even when the fuel's properties fall inside the recommended range of application. Therefore, users can assess the required degree of prediction agreement to determine the fitness-for-use of the prediction.
NOTE 4 Sample specific biases were observed for distillate fuels containing FAME (fatty acid methyl ester).
Le présent document décrit une méthode de calcul de l'indice de cétane des distillats moyens de différentes provenances pétrolières. La valeur obtenue est appelée indice de cétane calculé par équation à quatre variables. Le présent document n'est pas applicable aux combustibles contenant des additifs destinés à améliorer l'indice de cétane, ni aux hydrocarbures purs, ni aux distillats issus de la houille. Il est applicable aux combustibles contenant des produits non pétroliers dérivés des schistes bitumeux ou des sables bitumeux. L'indice de cétane calculé n'est pas une notion de remplacement de l'indice de cétane mesuré. Il s'agit d'un outil supplémentaire à utiliser en tenant compte de ses limites. Il est utilisé pour estimer l'indice de cétane mesuré d'un gasoil moteur quand il n'est pas possible d'effectuer un essai moteur et éventuellement pour vérifier l'indice de cétane mesuré.
Le présent document décrit une méthode de calcul de l'indice de cétane des distillats moyens de différentes provenances pétrolières. La valeur obtenue est appelée indice de cétane calculé par équation à quatre variables. Il introduit une note sur les améliorateurs de cétane dans le domaine d'application et supprime les dates des références normatives. Il n'est pas applicable aux combustibles contenant des additifs destinés à améliorer l'indice de cétane, ni aux hydrocarbures purs, ni aux distillats issus de la houille. Il est applicable aux combustibles contenant des produits non pétroliers dérivés des schistes bitumeux ou des sables bitumeux. L'indice de cétane calculé n'est pas une notion de remplacement de l'indice de cétane mesuré. Il s'agit d'un outil supplémentaire à utiliser en tenant compte de ses limites. Il est utilisé pour estimer l'indice de cétane mesuré d'un gasoil moteur quand il n'est pas possible d'effectuer un essai moteur et éventuellement pour vérifier l'indice de cétane mesuré.
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