Spray Characteristics of Fischer-Tropsch Alternate Jet Fuels

2013 ◽  
Author(s):  
Kumaran Kannaiyan ◽  
Reza Sadr
Keyword(s):  
Physical Properties ◽  
Energy Demand ◽  
Alternative Energy ◽  
Measurement Techniques ◽  
Jet Fuel ◽  
Synthetic Jet ◽  
Jet Fuels ◽  
Fischer Tropsch ◽  
Spray Characteristics ◽  
Pressure Swirl

Increase in energy demand and stringent emission norms drive the need for clean, alternative energy source. Recently, gas-to-liquid (GTL), a synthetic jet fuel produced from natural gas using Fischer-Tropsch synthesis has grabbed global attention due to its cleaner combustion aspects when compared to the conventional jet fuel. The chemical and physical properties of GTL fuels are different from the conventional fuels which could potentially affect the atomization and in turn the combustion characteristics and pollutant formation. In this work the spray characteristics of two GTL blends and conventional Jet A-1 fuels are investigated downstream of a pressure swirl nozzle exit at two injection pressures and the results are then compared. Microscopic spray characteristics, droplet size and velocity distributions are obtained at global as well as local levels of the spray using global sizing velocimetry and phase Doppler anemometry measurement techniques, respectively. Results clearly show that although the GTL fuels have different physical properties, such as viscosity, density, and surface tension the spray characteristics of the GTL fuels are found to be similar to those of Jet A-1 fuel.

Experimental Study of the Effect of Fuel Properties on Spray Performance of Alternative Jet Fuel

2014 ◽  
Author(s):  
Kumaran Kannaiyan ◽  
Reza Sadr
Keyword(s):  
Physical Properties ◽  
Energy Demand ◽  
Alternative Fuels ◽  
Comprehensive Evaluation ◽  
Atmospheric Condition ◽  
Diagnostic Technique ◽  
Jet Fuel ◽  
Fuel Properties ◽  
Aviation Fuel ◽  
Spray Characteristics

Increase in energy demand and stringent emission norms lay emphasis on the need for cleaner, alternative fuels. Application of Gas-to-Liquid (GTL) fuel, a synthetic fuel obtained from Fischer-Tropsch synthesis, as an alternate aviation fuel has been the subject of attention in recent years. This is mainly due to its cleaner combustion characteristics when compared to conventional jet fuel and the reduction of dependence on the crude oil supply. However, chemical and physical properties of the GTL are different from conventional jet fuels owing to the difference in their production methodology. The change in GTL fuel physical properties could potentially alter the atomization characteristics, which, in turn affects the evaporation, mixing, combustion, and finally the pollutant formation processes. Therefore, it is important to have a thorough understanding of the combustion precursors of GTL fuel to better understand the combustion and emission processes. A comprehensive evaluation of the microscopic spray characteristics of GTL and Jet A-1 fuels are carried out using a point-wise laser diagnostic technique, Phase Doppler Anemometry at atmospheric condition. The spray characteristics are investigated at several axial and radial locations of the spray. Results obtained clearly show that the influence of fuel properties on the spray characteristics at atmospheric condition is mostly observed near the nozzle exit, rather than in regions further downstream.

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.

Chemical Analysis of Combustion Products From a High-Pressure Gas Turbine Combustor Rig Fueled by Jet A1 Fuel and a Fischer-Tropsch-Based Fuel

2006 ◽  
Author(s):  
Fredrik Hermann ◽  
Jens Klingmann ◽  
Rolf Gabrielsson ◽  
Jo¨rgen R. Pedersen ◽  
Jim O. Olsson ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Gas Turbine ◽  
Combustion Products ◽  
Jet Fuel ◽  
Synthetic Jet ◽  
Operating Conditions ◽  
Gas Chromatography Mass Spectrometry ◽  
Gas Turbine Combustor ◽  
Fischer Tropsch ◽  
Synthetic Fuel

A comparative experimental investigation has been performed, comparing the emissions from a synthetic jet fuel and from Jet A1. In the investigation, the unburned hydrocarbons were analyzed chemically and the regulated emissions of NOx, CO and HC were measured. All combustion tests were performed under elevated pressures in a gas turbine combustor rig. A Swedish company, Oroboros AB, has developed a novel clean synthetic jet fuel, LeanJet®. The fuel is produced synthetically from synthesis gas by a Fischer-Tropsch process. Except for the density, the fuel conforms to the Standard Specification for Aviation Turbine Fuels. The low density is due to the lack of aromatics and polyaromatics. Organic emissions from the gas turbine combustor rig were collected by adsorption sampling and analyzed chemically. Both the fuels and the organic emissions were analyzed by gas chromatography/flame ionization (GC/FID) complemented with gas chromatography/mass spectrometry (GC/MS). Under the operating conditions investigated, no significant differences were found for the regulated emissions, except for emission of CO from the synthetic fuel, which, at leaner conditions, was one-quarter of that measured for Jet A1. Detailed analysis of the organic compounds showed that the emissions from both fuels were dominated by fuel alkanes and a significant amount of naphthalene. It was also found that Jet A1 produced a much higher amount of benzene than the synthetic fuel.

Effect of Aromatics in Jet Fuels on Spray Characteristics Downstream of an Aeronautical Pressure Swirl Atomizer

2016 ◽  
Author(s):  
Julien Leparoux ◽  
Renaud Lecourt ◽  
Olivier Penanhoat
Keyword(s):  
Alternative Fuels ◽  
Jet Fuel ◽  
Injection System ◽  
Jet Fuels ◽  
Particle Emissions ◽  
Aromatic Content ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
The Impact ◽  
Pressure Swirl Atomizer

Standard aeronautic fuels have a lower limit of aromatics of 8% (by volume) with about 18% for regular Jet A1. It has been shown that aromatics contained in Jet fuel have an impact on the fine particle emissions. In order to reduce these emissions, alternative fuels with lower aromatic content have been identified as a promising solution. Change Jet fuel composition can have several effects on spray and combustion behaviors, among others: atomization process, droplet evaporation, flame structure, pollutant and particle emissions. Then, it is necessary to evaluate the impact of this change on gas turbine performance and operability. The present study is focused on the spray behavior investigation with different aromatic content. Four Jet fuels are investigated including conventional Jet A1 kerosene, drop-in fuel with a mixture of half conventional Jet fuel and synthetic paraffinic kerosene (SPK), SPK with 8% of aromatics and pure SPK. The tests are performed at atmospheric conditions on the MERCATO testbed located at ONERA (FR). Phase Doppler Anemometry (PDA) measurements are carried out for the four fuels on an injection system composed of a pressure swirl atomizer and an air swirler. In this paper, a spray analysis of liquid velocity and droplet diameter measurements is described and linked to the variations of fuel properties. In the range of parameters covered by the four different fuels, it is shown that the spray behavior of each fuel is similar to the conventional Jet A1.

scholarly journals Altitude Performance of a Turbojet With Alternate Fuels

2011 ◽  
Author(s):  
Craig R. Davison ◽  
Wajid A. Chishty
Keyword(s):  
Performance Testing ◽  
Jet Fuel ◽  
Jet Fuels ◽  
Fischer Tropsch ◽  
Alternative Aviation Fuels ◽  
Test Engine ◽  
Speed Up ◽  
The Government ◽  
Government Of Canada ◽  
Alternate Fuels

To enhance energy security and reduce the environmental impact of aviation, alternate fuels derived from various non-petroleum based sources are being developed. Currently alternate fuels are produced to match the properties of existing jet fuels allowing the new fuels to be used in current fleets concurrently with traditional jet fuel. The alternate fuels must, therefore, perform as well as the traditional fuels through the entire operating envelope. This paper provides the results of performance testing in an altitude chamber up to 11,300 m (35,000 feet) with a simulated forward speed up to Mach 0.75. The test engine was an instrumented 1.15 kN thrust turbojet burning conventional Jet A-1 as a baseline; a semi-synthetic blend of camelina based hydro processed renewable jet and JP8; a blend of 50% Fischer-Tropsch synthetic paraffinic kerosene and 50% JP8; and a 100% Fischer-Tropsch synthetic paraffinic kerosene. Both steady state and transient performance are presented. The theoretical effect of the alternate fuels for a simple idealized Brayton cycle is also presented. The work was conducted as part of on-going efforts by departments within the Government of Canada to systematically assess alternative aviation fuels.

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.

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