Combustion of synthetic jet fuels: Naphthenic cut and blend with a gas-to-liquid (GtL) jet fuel

2017 ◽  
Vol 36 (1) ◽  
pp. 433-440 ◽  
Author(s):  
Philippe Dagaut ◽  
Pascal Diévart
Keyword(s):  
Jet Fuel ◽  
Synthetic Jet ◽  
Jet Fuels ◽  
Gas To Liquid

Ignition Characteristics of a Fischer-Tropsch Synthetic Jet Fuel

2008 ◽  
Author(s):  
P. Gokulakrishnan ◽  
M. S. Klassen ◽  
R. J. Roby
Keyword(s):  
Kinetic Model ◽  
Ignition Delay ◽  
Flow Reactor ◽  
Kinetic Mechanism ◽  
Jet Fuel ◽  
Synthetic Jet ◽  
Jet Fuels ◽  
Ignition Delay Times ◽  
Delay Times ◽  
Ignition Characteristics

Ignition delay times of a “real” synthetic jet fuel (S8) were measured using an atmospheric pressure flow reactor facility. Experiments were performed between 900 K and 1200 K at equivalence ratios from 0.5 to 1.5. Ignition delay time measurements were also performed with JP8 fuel for comparison. Liquid fuel was prevaporized to gaseous form in a preheated nitrogen environment before mixing with air in the premixing section, located at the entrance to the test section of the flow reactor. The experimental data show shorter ignition delay times for S8 fuel than for JP8 due to the absence of aromatic components in S8 fuel. However, the ignition delay time measurements indicate higher overall activation energy for S8 fuel than for JP8. A detailed surrogate kinetic model for S8 was developed by validating against the ignition delay times obtained in the present work. The chemical composition of S8 used in the experiments consisted of 99.7 vol% paraffins of which approximately 80 vol% was iso-paraffins and 20% n-paraffins. The detailed kinetic mechanism developed in the current work included n-decane and iso-octane as the surrogate components to model ignition characteristics of synthetic jet fuels. The detailed surrogate kinetic model has approximately 700 species and 2000 reactions. This kinetic mechanism represents a five-component surrogate mixture to model generic kerosene-type jets fuels, namely, n-decane (for n-paraffins), iso-octane (for iso-paraffins), n-propylcyclohexane (for naphthenes), n-propylbenzene (for aromatics) and decene (for olefins). The sensitivity of iso-paraffins on jet fuel ignition delay times was investigated using the detailed kinetic model. The amount of iso-paraffins present in the jet fuel has little effect on the ignition delay times in the high temperature oxidation regime. However, the presence of iso-paraffins in synthetic jet fuels can increase the ignition delay times by two orders of magnitude in the negative temperature (NTC) region between 700 K and 900 K, typical gas turbine conditions. This feature can have a favorable impact on preventing flashback caused by the premature autoignition of liquid fuels in lean premixed prevaporized (LPP) combustion systems.

Experimental and Modeling Study of the Combustion of Synthetic Jet Fuels: Naphtenic Cut and Blend With a GtL Jet Fuel

2016 ◽  
Author(s):  
Philippe Dagaut ◽  
Pascal Diévart
Keyword(s):  
Air Transportation ◽  
Chemical Kinetic ◽  
Jet Fuel ◽  
Synthetic Jet ◽  
Sensitivity Analyses ◽  
Jet Fuels ◽  
Kinetic Reaction ◽  
Experimental Database ◽  
Initial Fuel ◽  
Kinetics Of

Research on the production and combustion of synthetic jet fuels has recently gained importance because of their potential for addressing security of supply and sustainable air transportation challenges. The combustion of a 100% naphtenic cut that fits with typical chemical composition of products coming from biomass or coal liquefaction (C12.64H23.64; M=175.32 g.mol−1; H/C=1.87; DCN=39; density=863.1 g.L−1) and a 50% vol. mixture with Gas to Liquid from Shell (mixture: C11.54H23.35; M=161.83 g.mol−1; H/C=2.02; DCN=46; density=800.3 g.L−1) were studied in a jetstirred reactor under the same conditions (temperature, 550–1150 K; pressure, 10 bar; equivalence ratio, 0.5, 1, and 2; initial fuel concentration, 1000 ppm). Surrogate model-fuels were designed based on fuel composition and properties for simulating the kinetics of oxidation of these fuels. We used new model-fuels consisting of mixtures of n-decane, decalin, tetralin, 2-methylheptane, 3-methylheptane, n-propyl cyclohexane, and n-propylbenzene. The detailed chemical kinetic reaction mechanism proposed was validated using the entire experimental database obtained in the present work and for the oxidation of pure GtL, we used previous results. Kinetic computations involving reaction paths analyses and sensitivity analyses were used to interpret the results.

The Combustion of Synthetic Jet Fuels (Gas to Liquid and Coal to Liquid) and Multi-Component Surrogates: Experimental and Modeling Study

2015 ◽  
Author(s):  
Philippe Dagaut ◽  
Guillaume Dayma ◽  
Florent Karsenty ◽  
Zeynep Serinyel
Keyword(s):  
Chemical Kinetic ◽  
Synthetic Jet ◽  
Sensitivity Analyses ◽  
Jet Fuels ◽  
Chemical Kinetic Model ◽  
Experimental Database ◽  
Stirred Reactor ◽  
Auto Ignition ◽  
Gas To Liquid ◽  
Using Data

Research on synthetic jet fuels production and combustion has recently gained importance because they could help addressing security of supply and sustainable air transportation challenges. The combustion of a 100% Gas to Liquid from Shell (C10.45H23.06; M=148.44 g.mol−1; H/C=2.20; density=737.7 g L−1), a 100% vol. Coal to Liquid from Sasol (C11.06H21.6; M=154.32 g mol−1; H/C=1.95; density= 815.7 g L−1) and surrogates composed of various concentrations of n-decane iso-octane, n-propylcyclohexane, n-propylbenzene, and decalin, were studied in a jet-stirred reactor under the same conditions (temperature, 550–1150 K; pressure, 10 bar; equivalence ratio, 0.5–2). Comparison of these results helped designing optimum surrogate model fuels for the chemical kinetic computations. For simulating the kinetics of oxidation of the synthetic fuels we used new surrogates consisting of mixtures of n-decane, iso-octane, 2-methylheptane, 3-methylheptane, decalin, n-propylcyclohexane, n-propylbenzene, and tetralin. The detailed chemical kinetic reaction mechanism proposed here consisted of 2430 species reacting in 10962 reversible reactions. It was validated using the entire experimental database obtained previously in our laboratory and in the present work. The current chemical kinetic model was also tested for the auto-ignition under shock tubes using data from the literature. Kinetic computations involving reaction paths analyses and sensitivity analyses were used to interpret the results.

scholarly journals Energy System Modelling Challenges for Synthetic Fuels

2020 ◽  
Author(s):  
Seokyoung Kim ◽  
Paul E. Dodds ◽  
Isabela Butnar
Keyword(s):  
Energy System ◽  
High Energy ◽  
Jet Fuel ◽  
Synthetic Jet ◽  
High Energy Density ◽  
Jet Fuels ◽  
System Modelling ◽  
Synthetic Fuels ◽  
Long Distance ◽  
Negative Emissions

Long-distance air travel requires fuel with a high specific energy and a high energy density. There are no viable alternatives to carbon-based fuels. Synthetic jet fuel from the Fischer-Tropsch (FT) process, employing sustainable feedstocks, is a potential low-carbon alternative. A number of synthetic fuel production routes have been developed, using a range of feedstocks including biomass, waste, hydrogen and captured CO2. We review three energy system models and find that many of these production routes are not represented. We examine the market share of synthetic fuels in each model in a scenario in which the Paris Agreement target is achieved. In 2050, it is cheaper to use conventional jet fuel coupled with a negative emissions technology than to produce sustainable synthetic fuels in the TIAM-UCL and UK TIMES models. However, the JRC-EU-TIMES model, which represents the most production routes, finds a substantial role for synthetic jet fuels, partly because underground CO2 storage is assumed limited. These scenarios demonstrate a strong link between synthetic fuels, carbon capture and storage, and negative emissions. Future model improvements include better representing blending limits for synthetic jet fuels to meet international fuel standards, reducing the costs of synthetic fuels, and ensuring production routes are sustainable.

Autoignition Study of “Gas-to-Liquid” Fischer-Tropsch Jet Fuels

2019 ◽  
Author(s):  
Sulaiman A. Alturaifi ◽  
Tatyana Atherley ◽  
Olivier Mathieu ◽  
Bing Guo ◽  
Eric L. Petersen
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Jet Fuel ◽  
Jet Fuels ◽  
Fischer Tropsch ◽  
Reflected Shock ◽  
Ignition Delay Times ◽  
Delay Times ◽  
Gas To Liquid

Abstract In recent years, there has been an interest in finding a jet fuel alternative to the crude oil-based kerosene. Gas-to-liquid (GtL) fuel is being derived via Fischer-Tropsch synthesis processes by converting natural gas to longer-chain hydrocarbons which form the basis for jet fuel. In this study, new experimental ignition delay time measurements of GtL jet fuels have been determined at elevated pressures and temperatures. The measurements were conducted in a heated, high-pressure shock-tube facility capable of initial temperatures up to 200°C. Two GtL jet fuels were investigated, Shell GTL and Syntroleum S-8, which can be used in aviation applications at concentrations up to 50% blended with conventional oil-based kerosene. The ignition delay time measurements were conducted behind reflected shock waves for gaseous-phase fuel in air at a pressure around 10 atm and over a temperature range of 966 to 1266 K for two equivalence ratios, fuel lean (ϕ = 0.5) and stoichiometric (ϕ = 1.0). Ignition delay time was determined by observing the pressure and electronically excited OH chemiluminescence around 307 nm at the endwall location. Similar ignition delay times were observed for the two fuels at the fuel lean condition, while Syntroleum S-8 showed shorter ignition delay times at the stoichiometric condition. Comparisons are made with ignition delay time measurements for Jet-A previously conducted in the same facility and showed reasonable agreement over the tested conditions. The predictions from the available literature for GtL fuel surrogate kinetics models were obtained and compared with the experimental measurements.

Thermal Characteristics of Synthetic Jet Fuels in a Meso-Scale Heat Recirculating Combustor

2013 ◽  
Author(s):  
Teresa A. Wierzbicki ◽  
Ivan C. Lee ◽  
Ashwani K. Gupta
Keyword(s):  
Thermal Characteristics ◽  
Stability Limit ◽  
Jet Fuel ◽  
Synthetic Jet ◽  
Combustion Characteristics ◽  
Pure Oxygen ◽  
Jet Fuels ◽  
Synthetic Fuels ◽  
Lean Combustion ◽  
Meso Scale

A meso-scale heat recirculating combustor was used to examine the combustion characteristics of two specific synthetic fuels. One of the fuels was made via a Fischer-Tropsch (F-T fuel) process, while the other was produced from tallow (bio-jet fuel). The two fuels were burned in the meso-scale combustor using pure oxygen in a non-premixed injection configuration. The extinction behavior at the fuel-rich and fuel-lean combustion conditions has been investigated for each fuel. The results showed that although the two fuels showed some similarities, the F-T fuel exhibited stable, non-sooting combustion behavior at higher equivalence ratios than the bio-jet fuel. The lean stability limit for the bio-jet fuel was found to be lower (lower equivalence ratio) than that of the F-T fuel. The results were compared with conventional JP-8 jet fuel to provide a comparative analysis of combustion characteristics using the same combustor. A fuel characterization analysis was performed for each fuel, and their respective thermal efficiencies calculated. The F-T and bio-jet fuels both reached a maximum thermal efficiency of about 95% near their respective rich extinction limits.

Role of Hydrocarbon Building Blocks on Gas-to-Liquid Derived Synthetic Jet Fuel Characteristics

2013 ◽  
Vol 53 (5) ◽  
pp. 1856-1865 ◽  
Author(s):  
Elfatih E. Elmalik ◽  
Bilal Raza ◽  
Samah Warrag ◽  
Haider Ramadhan ◽  
Ehsan Alborzi ◽  
...  
Keyword(s):  
Building Blocks ◽  
Jet Fuel ◽  
Synthetic Jet ◽  
Fuel Characteristics ◽  
Gas To Liquid

Reaction Model Development for Synthetic Jet Fuels: Surrogate Fuels As a Flexible Tool to Predict Their Performance

2018 ◽  
Author(s):  
Trupti Kathrotia ◽  
Sandra Richter ◽  
Clemens Naumann ◽  
Nadezhda Slavinskaya ◽  
Torsten Methling ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Crude Oil ◽  
Reaction Mechanisms ◽  
Reaction Model ◽  
Jet Fuel ◽  
Synthetic Jet ◽  
Jet Fuels ◽  
Synthetic Fuel ◽  
Soot Precursors ◽  
Combustion Properties

In the last years, the development of synthetic aviation jet fuels has attracted much interest, to provide alternatives to crude-oil based kerosene. Synthetic jet fuels can be produced from a variety of feedstocks and processes. To limit possible harmful effects on the environment when burning a jet fuel, discussions are attributed to the effects of the specific composition of a synthetic fuel on its performance and its emission pattern. A numerical tool, if available, would also be helpful within the specification process any aviation jet fuel must pass. The present work contributes to the studies and efforts how to design a synthetic jet fuel to match predefined properties, e.g. the energy content or a less harmful emission characteristics compared to Jet A-1. The approach of a generic fuel will be followed in order to design a synthetic jet fuel with pre-defined chemical properties: A chemical kinetic reaction mechanism will be elaborated capable predicting the fundamental combustion properties of the generic fuel for each possible mixing ratio of the components included. In this work, a generic mixture serving as an innovative synthetic jet fuel was studied, with n-dodecane, cyclohexane, and iso-octane chosen as single fuel components; no aromatics were added to reduce the concentration of soot precursors. Then, their fundamental combustion properties, i.e. laminar burning velocity and ignition delay time, were measured in a burner test rig and applying the shock tube technique, respectively. These experimental data were used for the validation of the reaction mechanisms developed for each single fuel component, which were then combined to the reaction mechanism for the generic fuel under consideration. To allow a comparison of the combustion behavior of the synthetic jet fuel directly, with the same reaction mechanism, to Jet A-1, toluene was added as a model component for aromatics. A reduced surrogate reaction model was produced, too. All the reaction mechanisms elaborated are shown to reasonably predict the fundamental combustion properties within the parameter range considered. The compact reduced surrogate model can serve as a virtual jet fuel within numerical simulations. Thus, ultimately, an estimation of the suitability of an innovative synthetic jet fuel as a blending component to crude-oil kerosene is enabled. As a result, CFD simulations can be run efficiently tackling the combustion of a synthetic fuel in a jet engine under practical conditions and by taking into account the interaction between turbulence and chemistry.

Evaluation of Combustion Performance of a Coal-Derived Synthetic Jet Fuel

2012 ◽  
Author(s):  
Yang Lin ◽  
Yuzhen Lin ◽  
Chi Zhang ◽  
Quanhong Xu ◽  
Chih-Jen Sung ◽  
...  
Keyword(s):  
Freezing Point ◽  
Jet Fuel ◽  
Synthetic Jet ◽  
Aviation Fuel ◽  
National Standard ◽  
Turbine Engines ◽  
Jet Fuels ◽  
Ability To Act ◽  
Engine Testing ◽  
Chinese Standard

For application to aircraft turbines, the present work experimentally examines the physical and combustion-related properties of an F-T synthetic jet fuel relative to the Chinese standard jet fuel, RP-3. This fuel, derived from coal feedstock, is characterized in terms of its physical properties such as density, flash point, freezing point, surface tension, viscosity, and heating value in accordance with Chinese National Standard Testing Methods. Subsequently, several important characteristics relevant to its use in aircraft turbine engines are investigated using a single cup model combustor rig, including atomization, ignition, blowout, and exhaust emissions experiments are carried out. Preliminary results suggest that the use of coal-derived synthetic jet fuel will not result in adverse effects on the performance of an aircraft turbine combustor relative to conventional aviation kerosene. These initial results support the conclusion that full-scale engine testing is warranted to further investigate the performance of F-T synthetic jet fuels in practical systems, and to determine its ability to act as a “drop-in” replacement for traditional aviation fuel.

A Method for Determining the Laminar Flame Speed of Jet Fuels Using Combustion Bomb Pressure

2012 ◽  
Author(s):  
Andy Yates ◽  
Victor Burger ◽  
Carl Viljoen
Keyword(s):  
Laminar Flame ◽  
Jet Fuel ◽  
Synthetic Jet ◽  
Flame Speed ◽  
Optical Measurements ◽  
Jet Fuels ◽  
Relevant Parameter ◽  
Laminar Flame Speed ◽  
Combustion Pressure ◽  
Pressure Trace

This paper describes the use of a spherical combustion bomb to determine the laminar flame speed and Markstein length of a selection of hydrocarbon fuels. The fuels nominally represented Jet A-1 but some were doped with various component compounds which were chosen so as to vary particular jet fuel specification in relative isolation. Analyses of this kind are typically based on optical measurements and, to simplify the analysis, an approximation of constant pressure is usually achieved by limiting the useable data to the early stages of flame propagation only. The analysis methodology presented in this paper differs inasmuch that calculations were based solely on the recorded pressure data. Moreover, by deducing the response of the flame speed to pressure and temperature, it was possible to utilize the whole combustion pressure record which significantly increased the volume of useful data that could be obtained from each experiment. Other practical difficulties that are often encountered such as flame winkling at large diameters, especially with rich mixtures, were minimized by using a small bomb of only 100mm diameter. The method of analysis via the pressure trace rendered any flame winkling easily discernable wherefrom it could be easily eliminated. For each fuel, at least six repeat combustion pressure records (about 90 data points each) were obtained for each of six different air-fuel ratios spanning the range from lean to rich and the whole sequence was repeated at a higher initial temperature. This provided a database of over 6000 individual calculations of laminar flame speed from which the relevant parameter coefficients were obtained by means of a regression technique. It was found that the effects of changing the blend composition could be discerned in the various laminar flame speed results and that significant variation in laminar flame speed could possibly be “tailored” into a synthetic jet fuel formulation.

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