Impact of HEFA Feedstocks on Fuel Composition and Properties in Blends with Jet A

摘要

Alternative aviation fuels and their approval process contribute to one of the biggest challenges in deployment of an enhanced volume of aviation fuels. One of the approved fuel blending components is hydroprocessed esters and fatty acids (HEFAs) for mixing with petroleum-derived fuel (Jet A/A-1) up to 50 vol %. As the ASTM fuel specification (D7566) is merely based on the performance expected, the final blend concentration of HEFA in Jet A/A-1 can vary depending on the resultant fuel properties. Currently, there is a lack of information on how these properties are affected by the constituent chemical composition. The aim of this study was to compare three HEFAs sourced from different feedstocks (camelina, tallow, and mixed fat) and their blends with Jet A (10-60 vol %) based on the detailed chemical composition. The chemical composition was obtained using two-dimensional gas chromatography with mass spectrometry and flame ionization detector. The properties of interest were the distillation profile, density, viscosity, flash point, freezing point, and net heat of combustion. The key observation was that the distillation profile had the main impact on the final fuel properties. Additionally, the selection of the feedstock or the process conditions yielding an end HEFA composition can adversely affect properties, such as viscosity and/or freezing point.