Freezing point aviation fuel

The freezing point of kerosene is not of the same importance as the freezing point of aviation fuel (Chapter 6) but deserves mention because of its influence on kerosene use. 

The pour point (ASTM D-97, IP 15) is the lowest temperature at which the fuel oil will flow under specified conditions. The maximum and minimum pour point temperatures provide a temperature window where a petroleum product, depending on its thermal history, might appear in the liquid as well as the solid state. Pour point data can be used to supplement other measurements of cold flow behavior, and the data are particularly useful for the screening of the effect of wax interaction modifiers on the flow behavior of petroleum. The pour point should not be confused with the freezing point, which is an index of the lowest temperature at which the crude oil will flow under specified conditions. Test methods (ASTM D-2386, ASTM D-5901, ASTM D-5972, IP 434, IP 435) for the freezing point are not usually applicable to fuel oil but are more applicable to diesel fuel and aviation fuel. 

The low-density products manufactured in the SMDS process are predominantly paraffinic and free from impurities such as nitrogen and sulphur. Both the kerosine and gas oil have excellent combustion properties (smoke point and cetane number), and their cold-flow characteristics meet all relevant specifications - even the stringent freezing point requirements of aviation turbine kerosine. They also make excellent blending components for upgrading low-quality stock that would otherwise have to be used in fuel oil. The excellent quality of the products was proved in extensive engine tests. 

Freezing Point of Aviation Fuels," Amer. Soc. for Test, and... 

Jet fuel is kerosene-based aviation fuel. It is medium distillate used for aviation turbine power units and usually has the same distillation characteristics and flash point as kerosene. Jet fuels are manufactured predominately from straight-run kerosene or kerosene-naphtha blends in the case of wide cut fuels that are produced from the atmospheric distillation of crude oil. Jet fuels are similar in gross composition, with many of the differences in them attributable to additives designed to control some fuel parameters such as freeze and pour point characteristics. For example, the chromatogram (Figure 27.4) of a commercial jet fuel (Jet A) is dominated by GC-resolved n-alkanes in a narrow range of n-C-j to n-Cig with maximum being around n-Ci. The UCM is well dehned. 

D2138, Residue in LP gases D2171, Viscosity of asphalts D2386, Freezing point of aviation fuels X X X X... 

B/or—Because there are no liquid hydrocarbon mixtures of known freezing point, which simulate aviation fuels, bias cannot be established. 

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