Investigation of Water Interactions with Petroleum-Derived and Synthetic Aviation Turbine Fuels

Abstract

While undesirable in aviation fuel systems, water is both ubiquitous and tenacious; thus, interactions between water and aviation turbine fuel occur regularly. From a fuel user perspective, it is important to know, understand, and be able to predict such fuel–water interactions, e.g., water solubility, water settling rate, and interfacial tension, for proper mitigation. We explore these interactions as well as surface tension of both petroleum-derived and alternative jet fuels to compare potential differences between product compositions on these physical interactions. Observations indicate a positive, nonlinear correlation between water solubility and both aromatic content and temperature (from 0 to 50 °C). Water settling rates appear to follow a Stokes’ law model; therefore, bulk chemical composition indirectly influences settling rates via density and viscosity. Finally, surface tension appears positively correlated to sample density, while interfacial tension is correlated to both surface tension and fuel aromatic content.

Complexities associated with nucleation of water and ice from jet fuel in aircraft fuel systems: A critical review

“…Figure 4 From figure 4, the water solubility curve has been established as an exponential function by CRC; hence the decrease in solubility at high temperature in figure 4a deviates from the physical expectation. Water solubilities in alternative fuels in work reported by West et al all fit an exponential trend as reported by CRC in figure 4a), and no form of limit was noticed above 30 ºC as reported by Charro et al [42] [61]. Even though both authors the experimental technique adopted by the authors.…”

“…However, water is always present and cannot be eliminated. Therefore, the water content should be kept to a minimal level [61]. Typically, a water-saturated fuel contains between 40 and 80 ppm dissolved water at ambient temperature (about 21 °C) [8].…”

“…When an aircraft is cruising at a high altitude, the fuel in the wing tank becomes cold, causing water to separate into a second phase. This has the appearance of a cloud or fog in the fuel [61][69] [70]. As seen in figure 2, previous studies on this topic found that the solubility of water in hydrocarbons increases with an increase in temperature It was concluded that anti-icing agent has no effect on the water content of jet fuel; however, temperature and aromaticity play a key role in the fuel water solubility.…”

“…Replicating the experiments for each temperature explored will provide a more precise judgment by either refuting or corroborating the trends from the experiment. A major comparative study by West et al further analysed the water solubility trends with respect to temperature for thirty-six dropin aviation fuel and model solvents samples (conventionally refined and synthetic aviation fuels) [61]. This work indicated that two out of thirty-six samples analysed had high water solubility because of their high aromatic content.…”

Comprehensive Modeling in Predicting Biodiesel Density Using Gaussian Process Regression Approach

“…Some other disadvantages of this fuel are lower oxidation stability, higher cloud point, and lower energy content in comparison with petroleum-based diesel [14]. The observational and modeling studies for the establishment of these properties become important because the concentration on usages of the biofuels and their properties have been grown [15,16]. For example, the density of biodiesel is the important property that has a significant matter in the thermophysical process.…”