Kinetics of Oxidation of a 100% Gas-to-Liquid Synthetic Jet Fuel and a Mixture GTL/1-Hexanol in a Jet-Stirred Reactor: Experimental and Modeling Study

Research activities on the combustion of synthetic jet fuels and bio-derived jet fuels have increased notably over the last 10 years in order to solve the challenging reduction of dependence of air transportation on petroleum. Within the European Community’s Seventh Framework Programme, the combustion of a 100% GtL from Shell and a 80/20% vol. GtL/1-hexanol blend were studied in a jet-stirred reactor (JSR). This synthetic GtL fuel mainly contains n-alkanes, iso-alkanes, and cyclo-alkanes. We studied the oxidation of these alternatives jet fuels under the same conditions (temperature, 550–1150 K; pressure, 10 bar; equivalence ratio, 0.5–2; initial fuel concentration, 1000 ppm). For simulating the oxidation kinetics of these fuels we used a new surrogate mixture consisting of n-dodecane, 3-methylheptane, n-propylcyclohexane, and 1-hexanol. A detailed chemical kinetic reaction mechanism was developed and validated by comparison with the experimental results obtained in a jet-stirred reactor. The current model was also tested for the autoignition of the GtL fuel under shock tubes conditions (φ = 1 and P = 20 atm) using data from the literature. Kinetic computations involving reaction paths analyses and sensitivity analyses were used to interpret the results. The general findings are that the GTL and GTL/hexanol blend have very similar reactivity to Jet A-1, which is important since GTL is a drop-in fuel that should have similar performance to the Jet A-1 baseline and 1-hexanol should not significantly affect the reactivity if it is to be used as an additive.

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Kinetics of Oxidation of a 100% Gas-to-Liquid Synthetic Jet Fuel and a Mixture GtL/1-Hexanol in a Jet-Stirred Reactor: Experimental and Modeling Study

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4028259 ◽

2014 ◽

Vol 137 (1) ◽

Cited By ~ 5

Author(s):

Amir Mzé-Ahmed ◽

Philippe Dagaut ◽

Guillaume Dayma ◽

Pascal Diévart

Keyword(s):

Current Model ◽

Chemical Kinetic ◽

Synthetic Jet ◽

Sensitivity Analyses ◽

Jet Fuels ◽

Research Activities ◽

Stirred Reactor ◽

Auto Ignition ◽

Using Data ◽

Kinetics Of

Research activities on the combustion of synthetic jet fuels and bioderived jet fuels have increased notably over the last 10 yr in order to solve the challenging reduction of dependence of air transportation on petroleum. Within the European Community's Seventh Framework Programme, the combustion of a 100% GtL from Shell and a 80/20% vol. GtL/1-hexanol blend were studied in a jet-stirred reactor (JSR). This synthetic GtL fuel mainly contains n-alkanes, iso-alkanes, and cyclo-alkanes. We studied the oxidation of these alternative jet fuels under the same conditions (temperature, 550–1150 K; pressure, 10 bar; equivalence ratio, 0.5–2; initial fuel concentration, 1000 ppm). For simulating the oxidation kinetics of these fuels we used a new surrogate mixture consisting of n-dodecane, 3-methylheptane, n-propylcyclohexane, and 1-hexanol. A detailed chemical kinetic reaction mechanism was developed and validated by comparison with the experimental results obtained in a JSR. The current model was also tested for the auto-ignition of the GtL fuel under shock tubes conditions (φ = 1 and P = 20 atm) using data from the literature. Kinetic computations involving reaction paths analyses and sensitivity analyses were used to interpret the results. The general findings are that the GtL and GtL/hexanol blend have very similar reactivity to Jet A-1, which is important since GtL is a drop-in fuel that should have similar performance to the Jet A-1 baseline and 1-hexanol should not significantly affect the reactivity if it is to be used as an additive.

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

Volume 3: Coal, Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration; Organic Rankine Cycle Power Systems ◽

10.1115/gt2016-56086 ◽

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.

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

Volume 3: Coal, Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration ◽

10.1115/gt2015-42004 ◽

2015 ◽

Cited By ~ 2

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.

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Characterizing Combustion of Synthetic and Conventional Fuels in a Toroidal Well Stirred Reactor

Volume 1B: Combustion, Fuels and Emissions ◽

10.1115/gt2013-94944 ◽

2013 ◽

Cited By ~ 2

Author(s):

Shazib Z. Vijlee ◽

John C. Kramlich ◽

Ann M. Mescher ◽

Scott D. Stouffer ◽

Alanna R. O’Neil-Abels

Keyword(s):

Aromatic Compounds ◽

Chemical Reactor ◽

Synthetic Jet ◽

Premixed Combustion ◽

Liquid Fuels ◽

Jet Fuels ◽

Synthetic Fuels ◽

Lean Premixed Combustion ◽

Stirred Reactor ◽

Lean Premixed

The use of alternative/synthetic fuels in jet engines requires improved understanding and prediction of the performance envelopes and emissions characteristics relative to the behavior of conventional fuels. In this study, experiments in a toroidal well-stirred reactor (TWSR) are used to study lean premixed combustion temperature and extinction behavior for several fuels including simple alkanes, synthetic jet fuels, and conventional JP8. A perfectly stirred reactor (PSR) model is used to interpret the observed behavior. The first portion of the study deals with jet fuels and synthetic jet fuels with varying concentrations of added aromatic compounds. Synthetic fuels contain little or no natural aromatic species, so aromatic compounds are added to the fuel because fuel system seals require these species to function properly. The liquid fuels are prevaporized and premixed before being burned in the TWSR. Air flow is held constant to keep the reactor loading roughly constant. Temperature is monitored inside the reactor as the fuel flow rate is slowly lowered until extinction occurs. The extinction point is defined by both its equivalence ratio and temperature. The measured blowout point is very similar for all four synthetic fuels and the baseline JP8 at aromatic concentrations of up to 20% by volume. Since blowout is essentially the same for all the base fuels at low aromatic concentrations, a single fuel was used to test the effect of aromatic concentrations from 0 to 100%. PSR models of these complex fuels show the expected result that behavior diverges from an ideal, perfectly premixed model as the combustion approaches extinction. The second portion of this study deals with lean premixed combustion of simple gaseous alkanes (methane, ethane, and propane) in the same TWSR. These simpler fuels were tested for extinction in a similar manner to the complex fuels, and behavior was characterized similarly. Once again, PSR models show that the TWSR behaves similar to a PSR during stable combustion far from blowout, but as it approaches blowout and becomes less stable a single PSR no longer accurately describes the TWSR. This work is a step towards developing chemical reactor networks (CRNs) based on computational fluid dynamics (CFD) of the simple gaseous fuels in the TWSR. Ultimately, CRNs are the only realistic way to accurately perform detailed chemical modeling of the combustion of complex liquid fuels.

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Synthetic Jet Fuel Combustion: Experimental and Kinetic Modeling Study

Volume 2: Combustion, Fuels and Emissions, Parts A and B ◽

10.1115/gt2011-45234 ◽

2011 ◽

Cited By ~ 1

Author(s):

P. Dagaut ◽

A. Mze´-Ahmed ◽

K. Hadj-Ali ◽

P. Die´vart

Keyword(s):

Kinetic Modeling ◽

Jet Fuel ◽

Synthetic Jet ◽

Liquid Fuels ◽

Sensitivity Analyses ◽

Gas Chromatography Mass Spectrometry ◽

Infrared Spectrometry ◽

Temperature Oxidation ◽

Kinetics Of Oxidation ◽

Kinetics Of

Fischer-Tropsch liquid fuels synthesized from syngas, also called synthetic paraffinic jet fuel (SPK), can be used to replace conventional petroleum-derived fuels in jet engines. Whereas currently syngas is mostly produced from coal of natural gas, its production from biomass has been reported. These synthetic liquid fuels contain a very high fraction of iso-alkanes, while conventional jet fuels contain large fractions of n-alkanes, cycloalkanes (naphtenes), and aromatics. In that contest, a jet-stirred reactor (JSR) was used to study the kinetics of oxidation of a 100% SPK and a 50/50 SPK/Jet A-1mixture over a broad range of experimental conditions (10 atm, 560 to 1030K, equivalence ratios of 0.5 to 2, 1000 ppm of fuel). The temperature was varied step-wise, keeping the mean residence time in the JSR constant and equal to 1s. Three combustion regimes were observed over this temperature range: the cool-flame oxidation regime (560–740K), the negative temperature coefficient (NTC) regime (660–740K), and the high-temperature oxidation regime (>740K). More than 15 species were identified and measured by Fourier transform infrared spectrometry (FTIR), gas chromatography/mass spectrometry (CG/MS), flame ionization detection (FID), and thermal conductivity detection (TCD). The results consisting of concentration profiles of reactants, stable intermediates and products as a function of temperature showed similar kinetics of oxidation for the fuels considered, although the 100% SPK was more reactive. A surrogate detailed chemical kinetic reaction mechanism was used to model these experiments and ignition experiments taken from the literature. The kinetic modeling showed reasonable agreement between the data and the computations whereas model improvements could be achieved using more appropriate surrogate model fuels. Kinetic computations involving reaction paths analyses and sensitivity analyses were used to interpret the results.

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