Hydroprocessed Renewable Jet Fuel Evaluation, Performance, and Emissions in a T63 Turbine Engine

Abstract

Hydroprocessed Renewable Jet Fuel Evaluation, Performance, and Emissions in a T63 Turbine EngineDue to potential beneficial environmental impacts and increased supply availability, alternative fuels derived from renewable resources are evolving on the forefront as unconventional substitutes for fossil fuel. Focus is being given to the evaluation and certification of Hydroprocessed Renewable Jet (HRJ), a fuel produced from animal fat and/or plant oils (triglycerides) by hydroprocessing, as the next potential synthetic aviation fuel. Extensive efforts have recently been performed at the Air Force Research Laboratory (AFRL) at Wright Patterson Air Force Base (WPAFB) to evaluate the potential of two HRJ fuels produced from camelina and tallow feedstocks. These have included characterization of the fuel chemical, physical fuel characteristics and Fit-for-Purpose properties (FFP). The present effort describes general combustion performance and the emission propensity of a T63-A-700 Allison turbine engine operated on the HRJs and 50/50 (by volume) HRJ/JP-8 fuel blends relative to a specification JP-8. In addition, engine and emission testing with a blend of the tallow-derived HRJ and 16% bio-derived aromatic components was completed. Fundamental engine performance characterization allows for determination of the suitability of potential synthetic fuels while quantitation of gaseous and particulate matter emissions provides an assessment of the potential environmental impact compared to current petroleum-derived fuels. In addition, an extended 150 h endurance test was performed using a 50/50 blend of tallow-derived HRJ with JP-8 to evaluate the long-term operation of the engine with the synthetic fuel blend. This paper discusses the laboratory testing performed to characterize HRJs and results from the basic engine operability and emissions studies of the alternative fuel blends.

Synthetic Jet Fuels and Their Impact in Aircraft Performance and Elastomer Materials

“…Figure 4 shows the variation of thrust specific fuel consumption for the tested fuels. Calculated values do not differ much between fuels, as reported previously by Klingshirn et al 6 who tested the same HEFA fuels in a T63 engine test bench at the AFRLA. However this is not true for the Shell FT, and its blends with Jet-A and UOP Tallow, particularly at idle power.…”

“…For the Syntroleum fuel, syngas is liquefied with cobalt-based catalysts, obtaining c5-c200 paraffins and oleofins, which are further processed by hydrocracking and hydro-isomerization in order to obtain a close to Jet-A/JP-8 fuel 5,17 . On the other hand, the tested HEFA fuels were manufactured by UOP taking camelina and beef tallow as feedstock, which is pressurized and mixed with hydrogen in order to remove oxygen and produce n-paraffins, which are later hydrocracked and isomerized to obtain a freezing point and boiling distribution similar to Jet-A/JP-8 fuel 6 . Synthetic and Hydrotreated, renewable jet fuel samples, were supplied by the Air Force Research Laboratory, and relevant properties for this study, such as density, heating value and aromatics content are listed in table 2.…”

Alternative Microturbine Fuels Feasibility Study Through Thermal Stability, Material Compatibility, and Engine Testing

“…Figure 9 shows the variation of thrust specific fuel consumption for the tested fuels. The calculated values do not differ much between fuels, as reported previously by Klingshim et al [19], who tested the same HEFA fuels in a T63 engine test bench at the Air Force Research Lab.…”

“…On the contrary, the tested hydrotreated esters and fatty acids (HEFA) fuels were manufactured by UOP taking Camelina and beef tallow as feedstock. This is then pressurized and mixed with hydrogen in order to remove oxygen and produce «-paraffins, which are later hydrocracked and isomerized to obtain a freezing point and boiling distribution similar to Jet-A/JP-8 fuel [19]. Two biodiesel fuel samples, obtained by transesterifying soybean and cooking oil, were also used.…”

The Impact of Fatty Acid Composition on Transportation Fuel Yields via the Non‐Catalytic Cracking of Triacylglyceride Oils

“…The term "second-generation" when describing biofuel processes is used to describe a variety of technologies, which may be classified based on the type of feedstock being used for fuel production, such as cellulose-derived fuels, lignin-derived fuels [3,4], direct photosynthetic derivatives [5,6], lipid-derived fuels [7][8][9], and feedstockflexible bioconversion processes using multiple feedstocks. Within each of these classes typically only a small subset has demonstrated capability to produce drop-in-compatible biofuels (DCBs) [7,8], whereas others produce ethanol or other homogeneous chemical substances (furfural, butanol, etc.) or combustible chemicals, which are uniquely different from petroleum fuels.…”