This standard does not purport to address all of the safety concerns, if any, associated with its use. The value computed from the equation is termed the calculated cetane index by four variable equation. Astm d4737 pdf d 96a standard test method for calculated cetane index by four variable equation, cetane, cetane index, diesel fuel. P providing e osving document as pop proof of products. Thefigures makeitclearthatwhenitcomesto cetane,lcoisaproblemduetothe highpnacontent. February 2020 learn how and when to remove this template message. Specification of ulsd 10 ppm diesel fuel en590 property.
The physiochemical properties of fuel are important. The cetane index is calculated based on the fuels density and distillation range astm d86. Astm d976 pdf designation d 06 standard test method for calculated cetane index of free astm cetane number of distillate fuels from api gravity and. If the cetane number test cannot be performed, the cetane index may be used astmd4737 10. Pdf predicting cetane index, flash point and content sulfur of.
Throughout the remaining text of this document, the term cetane index implies cetane index by fourvariable equation. Epa should issue a similar document for the preparation and. The importance of cetane number in diesel fuel aong website. Astm d 10 standard test method for calculated cetane index by four variable equation. Dcn measurement using the ignition delay principle, which. It is important to note that cetane index, commonly used to indicate the ignition characteristics of diesel fuels, does not give correct results for biodiesel. The products and processes referred to in this document are trademarks, registered. The index tells you the ignition quality of the basic fuel, before any chemicals are added to it. Astm recently published an updated astm d7170 test method for derived cetane number. Cetane index is a calculated value, which is derived from relatively easily measured fuel properties. An equation of four variables is used to calculate this 1. This document specifies a procedure for the calculation of the cetane index of middledistillate fuels from petroleumderived sources.
Dcn obtained from an additional laboratory as a round robin test results from laboratory methods compared back to research engine method results. Thus, cetane index can provide a measure of fuel ignition quality without the need to run the costly cetane number test. The calculated cetane index is derived from the fuels density and boiling range. The cetane number test is carried out in a monocylindrical engine, where fuel ignition delay is compared with the delay of a mixture of cetane and alphamethylnaphthalene with known cetane number, in accordance with astmd6 7. Test method d is the preferred method as estimator of cetane. Pdf determination of cetane number of biodiesel and its influence. In cases where the cetane number of a fuel has been initially established, the index is useful as a cetane number check on subsequent samples of that fuel, provided its source and mode of manufacture remain unchanged. Kerosenes haveverylowpolynucleararomatics pnacontent,butbecauseofthe lower molecular weight kerosene generallyhascompoundscontain inglessthan16carbonatomsthe cetaneindexisslightlylowerthan forsrdieselmaterial.
It includes all available singlecompound cetane number data found in the scientific literature up until december 2016 as well as a number of previously unpublished values, most measured over. As a supplementary tool, the calculated cetane index by four variable equation must be used with due regard for its limitations. Pdf dependence of cetane index on aromatic content in. Astm d976 062016 standard test method for calculated cetane. Draft document petroleum products calculation of cetane index of middledistillate fuels by the fourvariable equation isodis 4264. It is a supplementary tool for estimating cetane number when a result by test method d is not available and if cetane. Cetane index calculations do not take into account the effects from additives used to enhance the cetane number. D976062016 standard test method for calculated cetane index of distillate fuels cetane index distillate fuels diesel fuels. Hence cetane index is not specified and a cetane number test is necessary. While useful for estimating the cetane number of distillate fuels, this technique can not be applied to fuels. These methods do measure the effect of cetane improver. The calculated cetane index formula is particularly applicable to straightrun fuels, catalytically cracked stocks, and blends of the two. The most significant aspects of this consensus position are its requirements for a minimum fuel.
The index doesnt change when you add a cetane booster to it. The text of this document is unchanged from the 2014 version, except for the numbers. No correlation was found between the specific gravity and the cetane number of various biodiesel. The calculated cetane index is not an optional method for expressing astm cetane number. Pdf biodiesel, an alternative fuel can be used in diesel engine as neat or blended with diesel. The calculated cetane index is one tool available for estimating astm cetane number where a.
The index value, as computed from the formula, is termed the calculated cetane index. Troy cetane index is a value that is calculated based on the density and distillation characteristics of diesel fuel. D6 test method for cetane number of diesel fuel oil. It is a supplementary tool to estimate cetane number when used with due regard for its limitations. Designation d976 06 standard test method for calculated cetane. Cetane number en iso 5161 en 15195 51 min cetane index en iso 4264 calculated 46 min water en iso 12937 mgkg 200 max particulate matter en 12662 mgkg 24 max.
The calculated cetane index by four variable equation provides a means for estimating the astm cetane number test method d6 of distillate fuels from density and distillation recovery temperature measurements. Scribd is the worlds largest social reading and publishing site. Designation d 06 standard test method for calculated cetane index of free astm cetane number of distillate fuels from api gravity and. Cetane is a colorless, liquid hydrocarbon a molecule from the alkane series that ignites easily under compression. Dependence of cetane index on aromatic content in diesel fuels article pdf available in oil gas european magazine 383. Determination of flash point and cetane index in diesel.
Comparing methods to determine cetane ratings of fuel blends. Epa to control diesel fuel aromatics concentrations via a 40 calculated cetane index minimum is based on the correlation between test method d and aromatics concentration. It may be conveniently employed for estimating cetane number when the quantity of sample available is too small for an engine rating. It is a supplementary tool for estimating cetane number when a result by test method d is not available and if cetane improver is not axtm. For this reason, it was given a base rating of 100 and is used as the standard measure of the performance of compression ignition fuels, such as diesel and biodiesel. Specification of ulsd 10 ppm diesel fuel en590 property test method test unit guarantee limit. Astmd976 standard test method for calculated cetane. In the astm standards for diesel fuel the minimum cetane index should be 40. It plays a similar role for diesel as octane rating does for gasoline. Cetane number is a relative ranking of a fuels autoignition characteristics for use in compression. Cetane number is an indicator of the combustion speed of diesel fuel and compression needed for ignition. Pdf artificial neural networks anns were used to predict, not simultaneously flash point, cetane index and sulfur content s1800 of diesel blends.
Referenced documents purchase separately the documents listed below are referenced within the subject standard but are not provided as part of the standard. Astm d976062016 standard test method for calculated. Astm d 96a standard test method for calculated cetane index by four variable equation. Because the astm d6 test is time consuming and expensive, calculated cetane index astm d976 or d4737 is often substituted for cetane number.
That is the reason why cetane index is not effected by addition of cetane improver while cetane number increases. The cetane number see page 4 of the fuel defines its ignition quality. Pure hexadecane would be a soft wax at room temperature. All the hydrocarbon molecules in diesel fuel are indexed against hexadecane. Astm d97606 standard test method for calculated cetane. Adjunct to d976 test methods for calculated cetane index of.
In cases where the astm cetane number of astk fuel has been previously established, the aztm cetane index by four variable equation is useful as a cetane number check on subsequent batches of that fuel, provided the fuels source and mode of manufacture remain unchanged. The calculated value is termed the cetane index by fourvariable equation. The calculations rely on diesel fuels t10, t50, t90 distillation points, and gravitydensity to estimate the cetane number. Cetane s real name is 1hexadecane and scores 100 on the cetane index. Use of cetane indices this is an estimation of measured cetane number based on formulas in astm d976 or astm d4737.
Astm d97606 standard test method for calculated cetane index of distillate fuels. Test fuels subjected to all four methods of cetane evaluation. Astmd4737 standard test method for calculated cetane. Diesel fuel properties free download as powerpoint presentation. The cn is an important factor in determining the quality of diesel fuel, but not the only one. Standard test method for calculated cetane index by four. The older d976, or twovariable equation is outdated and should no longer be used for cetane number estimation. No other units of measurement are included in this standard. Research engine method astm d6 cetane number 2 and 4variable methods astm d976 and d4737 cetane index.
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