Diesel index

The diesel index is derived from the API gravity and aniline point (ASTM D-611, IP 2), the lowest temperature at which the fuel is completely miscible with an equal volume of aniline  

The above equation is seldom used because the results can be misleading, especially when applied to blended fuels. 

The hash point of a diesel fuel is the temperature to which the fuel must be heated to produce an ignitable vapor-air mixture above the hquid fuel when exposed to an open hame. The hash point test is a guide to the hre hazard associated with the use of the fuel and can be determined by several test methods, but the results are not always strictly comparable. 

The minimum hash point is usually dehned by the Abel method (IP 170), although the Pensky-Martens method (ASTM D-93, IP 34) may also be specihed. The TAG method (ASTM D-56) is used for both the minimum and maximum limits, whereas certain military specihcations also give minimum limits by the Pensky-Martens method (ASTM D-93, IP 34). The Abel method (IP 170) can give results up to 2-3°C (3-5°F) lower than the TAG method (ASTM D-56). 

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Another characteristic used for some time to measure the propensity of a diesel fuel for auto-ignition, is the Diesel Index (Dl). This is defined by the relation ... 

Some empirical formulas have been devised to link the cetane index to the Diesel Index (D.l.) or even directly to the aniline point. We will cite two such formulas here in order to illustrate their comparative values C ... 

Other methods are also available for the estimation of diesel fuel quaUty. For example, the diesel index (DI) is defined by the relation DI = (A° F X ° API)/100, where A °F is the aniline point in degrees Fahrenheit and °API is the American Petroleum Institute gravity. A high aniline point corresponds to a high proportion of paraffins in the diesel fuel such a fuel has a high diesel index and, therefore, a high cetane number. 

Diesel-kr tstoff, -treibstoff, m, Diesel fuel, Diesel oil, -81, n. Diesel oil. -zahl, /. Diesel (index) number. 

The catalytic Diesel fuel has a lower cetane number than the corresponding component of the virgin charge because of the changes in chemical composition effected in the cracking operation. However, in mild cracking conditions, the drop may amount to only a few numbers in Diesel index. 

Product of 0.5% sulfur content Yield, vol. % Pour point, ° F. Diesel index 97 88 82 91 100... 

Cetane index an approximation of the cetane number (q.v.) calculated from the density (q.v.) and mid-boiling point temperature (q.v.) see also Diesel index. 

The fraction of diesel-oil-like hydrocarbons had also a triple sequence and the main aliphatic componnds may be characterized with carbon numbers 12, 15, 18, 21, 24, 27. In contrast with the experimental results of naphtha diesel oil had considerably lower concentration of aromatics. In the case of each MPW sample its concentration was not more than 1%, because aromatics with lower boiling point stayed in the naphtha-like fraction. Similarly, as mentioned above, the diesel-oil-like fraction also had favourable properties for further fuel-like application. The olefin content was a bit smaller than in case of naphtha-like fractions, because cracking reaction resulting olefins (e.g. P-scission) produced hydrocarbons with a shorter length of carbon chain. Both cetane numbers and diesel indexes of products were high enough, while the CFPP was rather low. 

Catalyst Pour point Relative density Diesel index Aniline point... 

Cetane index, as defined by ASTM D976, is not a measurement, but the result of a calculation based on density and mid-boiling point. It is nearly the same the as cetane number for diesel fuels comprised mostly of straight-run gas oils blended with lesser amounts of cracked stocks. Diesel index is a ... 

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