Density diesel fuel

The density of heavy fuels is greater than 0.920 kg/1 at 15°C. The marine diesel consumers focus close attention on the fuel density because of having to centrifuge water out of the fuel. Beyond 0.991 kg/1, the density difference between the two phases —aqueous and hydrocarbon— becomes too small for correct operation of conventional centrifuges technical improvements are possible but costly. In extreme cases of fuels being too heavy, it is possible to rely on water-fuel emulsions, which can have some advantages of better atomization in the injection nozzle and a reduction of pollutant emissions such as smoke and nitrogen oxides. 

Liquid fuels for ground-based gas turbines are best defined today by ASTM Specification D2880. Table 4 Hsts the detailed requirements for five grades which cover the volatility range from naphtha to residual fuel. The grades differ primarily in basic properties related to volatility eg, distillation, flash point, and density of No. 1 GT and No. 2 GT fuels correspond to similar properties of kerosene and diesel fuel respectively. These properties are not limited for No. 0 GT fuel, which allows naphthas and wide-cut distillates. For heavier fuels. No. 3 GT and No. 4 GT, the properties that must be limited are viscosity and trace metals. 

Fig. 2. Relative volume and mass of different fuel systems normalized to diesel fuel in terms of storage density.

The DMFC is the most attractive type of fuel cell as a powerplant for electric vehicles and as a portable power source, because methanol is a liquid fuel with values for the specific energy and energy density being about equal to half those for liquid hydrocarbon fuels (gasoline and diesel fuel). 

Table 41.3 shows a performance comparison of Pt/Pd TUD-1 with a commercial Pt/Pd catalyst (26). The feedstock is a typical straight run gasoil ( SRGO ), a distillate precursor to diesel fuel. Under identical test conditions, the TUD-1 catalyst achieved 75% aromatics saturation versus 50% for the same volume of commercial catalyst. This superior result is particularly interesting because the TUD-1 catalyst had a much lower density than the commercial material, so that less catalyst by weight was required in the reactor. 

Figure 20. Cell potential and current density as a function of time for /2-decane, toluene, and the diesel fuel. Each of the fuels was fed to the cell with N2 at a concentration of 40 wt % hydrocarbon. (Reprinted with permission from ref 105. Copyright 2001 The Electrochemical Society, Inc.)...

Liquid products contain sulfur and nitrogen and must be hydroprocessed to improve quality. Separate hydroprocessing units for upgrading the naphtha, kerosene, and gas oil fractions can be used to optimize the overall process. Refined gas oil or diesel fuel is aromatic in character and contains more cycloparaffins than conventional crude oil. The resulting fuel is low in cetane number, high in density, and typically has very good low-temperature handling properties. 

Density, g/cm3 15.56°C Typically higher than conventional diesel fuel ... 

The energy density of LNG is about 67% that of gasoline (Table 2-6) and 59% that of diesel fuel. This suggests that it takes 1.5 liters of LNG to equal a liter of gasoline and 1.7 liters of LNG to equal a liter of diesel fuel. Like CNG, LNG tanks have a smaller fuel storage volume compared to total exterior volume than the typical diesel fuel tank because of the insulation required to keep the LNG cold. 

Soybean and rapeseed methyl esters both have densities similar to diesel fuel. Their pour points are not as favorable. Straight soybean methyl ester has a very high pour point (-3°C [-27°F]) which would cause problems for vehicles in most non-tropical climates. The rapeseed methyl ester of Table 2-8 illustrates the improvement in pour point possible just by removing some of the esters that have higher pour points. Additives would no doubt further improve the pour point characteristics of these fuels. 

Table 3 shows that the energy density of LNG per volume (MJ/1) is higher than any alternative gas-based fuels, and offers a range that is roughly 2.5 times the range of CNG. The table also shows that LNG has almost 60% the energy density of diesel fuel. 

Diesel index an approximation of the cetane number (q.v.) of diesel fuel (q.v.) calculated from the density. v.) and aniline point (< .v.). 

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