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.

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

2014 ◽  
Vol 137 (1) ◽  
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.

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

2014 ◽  
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 ◽  
Initial Fuel ◽  
Using Data ◽  
Kinetics Of

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.

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.

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

2013 ◽  
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.

scholarly journals A Study on the Emissions of Alternative Aviation Fuels

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Sebastian Riebl ◽  
Marina Braun-Unkhoff ◽  
Uwe Riedel
Keyword(s):  
Crude Oil ◽  
Plug Flow ◽  
Synthetic Jet ◽  
Jet Fuels ◽  
Detailed Knowledge ◽  
Low Carbon ◽  
Emission Data ◽  
Chemical Kinetic Model ◽  
Soot Precursors ◽  
Synthetic Aviation

Currently, the aviation sector is seeking for alternatives to kerosene from crude oil, as part of the efforts combating climate change by reducing greenhouse gas (GHG) emissions, in particular carbon dioxide (CO2), and ensuring security of supply at affordable prices. Several synthetic jet fuels have been developed including sustainable biokerosene, a low-carbon fuel. Over the last years, the technical feasibility as well as the compatibility of alternative jet fuels with today's planes has been proven However, when burning a jet fuel, the exhaust gases are a mixture of many species, going beyond CO2 and water (H2O) emissions, with nitrogen oxides (NOx), carbon monoxide (CO), unburned hydrocarbons (UHC) including aromatic species and further precursors of particles and soot among them. These emissions have an impact on the local air quality as well as on the climate (particles, soot, contrails). Therefore, a detailed knowledge and understanding of the emission patterns when burning synthetic aviation fuels are inevitable. In the present paper, these issues are addressed by studying numerically the combustion of four synthetic jet fuels (Fischer–Tropsch fuels). For reference, two types of crude-oil-based kerosene (Jet A-1 and Jet A) are considered, too. Plug flow calculations were performed by using a detailed chemical-kinetic model validated previously. The composition of the multicomponent jet fuels was imaged by using the surrogate approach. Calculations were done for relevant temperatures, pressures, residence times, and fuel equivalence ratios φ. Results are discussed for NOx, CO as well as for benzene and acetylene as major soot precursors. According to the predictions, the NOx and CO emissions are within about ±10% for all fuels considered, within the parameter range studied: T = 1800 K, T = 2200 K; 0.25 ≤ φ ≤ 1.8; p = 40 bar; t = 3 ms. The aromatics free GtL (gas to liquid) fuel displayed higher NOx values compared to Jet A-1/A. In addition, synthetic fuels show slightly lower (better) CO emission data than Jet A-1/A. The antagonist role of CO and NOx is apparent. Major differences were predicted for benzene emissions, depending strongly on the aromatics content in the specific fuel, with lower levels predicted for the synthetic aviation fuels. Acetylene levels show a similar, but less pronounced, effect.

The Measurement and Prediction of Gaseous Hydrocarbon Fuel Auto-Ignition Delay Time at Realistic Gas Turbine Operating Conditions

2005 ◽  
Author(s):  
G.-J. M. Sims ◽  
A. R. Clague ◽  
R. W. Copplestone ◽  
K. R. Menzies ◽  
M. A. MacQuisten
Keyword(s):  
Kinetic Model ◽  
Gas Turbine ◽  
Ignition Delay ◽  
Test Section ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Chemical Kinetic ◽  
Operating Conditions ◽  
Chemical Kinetic Model ◽  
Auto Ignition

Auto-ignition delay time measurements have been attempted for a variety of gaseous fuels on a flow rig at gas turbine relevant operating conditions. The residence time of the flow rig test section was approximately 175 ms. A chemical kinetic model has been used in Senkin, one of the applications within the Chemkin package, to predict the auto-ignition delay time measured in the experiment. The model assumes that chemistry is the limiting factor in the prediction and makes no account of the fluid dynamic properties of the experiment. Auto-ignition delay time events were successfully recorded for ethylene at approximately 16 bar, 850K and at equivalence ratios between 2.6 and 3.3. Methane, natural gas and ethylene (0.5 < φ < 2.5) failed to auto-ignite within the test section. Model predictions were found to agree with the ethylene measurements, although improved qualification of the experimental boundary conditions is required in order to better understand the dependence of auto-ignition delay on the physical characteristics of the flow rig. The chemical kinetic model used in this study was compared with existing ‘low temperature’ measurements and correlations for methane and natural gas and was found to be in good agreement.

scholarly journals A Study on the Emissions of Alternative Aviation Fuels

2016 ◽  
Author(s):  
Sebastian Riebl ◽  
Marina Braun-Unkhoff ◽  
Uwe Riedel
Keyword(s):  
Crude Oil ◽  
Plug Flow ◽  
Synthetic Jet ◽  
Jet Fuels ◽  
Detailed Knowledge ◽  
Low Carbon ◽  
Emission Data ◽  
Chemical Kinetic Model ◽  
Soot Precursors ◽  
Synthetic Aviation

Currently, the aviation sector is seeking for alternatives to kerosene from crude oil, as part of the efforts combating climate change by reducing greenhouse gas (GHG) emissions, in particular carbon dioxide (CO2), and ensuring security of supply at affordable prices. Several synthetic jet fuels have been developed including sustainable bio-kerosene, a low-carbon fuel. Over the last years, the technical feasibility as well as the compatibility of alternative jet fuels with today’s planes has been proven However, when burning a jet fuel, the exhaust gases are a mixture of many species, going beyond CO2 and water (H2O) emissions, with nitrogen oxides (NOx), carbon monoxide (CO), unburned hydrocarbons (UHC) including aromatic species and further precursors of particles and soot among them. These emissions have an impact on the local air quality as well as on the climate (particles, soot, contrails). Therefore, a detailed knowledge and understanding of the emission patterns when burning synthetic aviation fuels is inevitable. In the present paper, these issues are addressed by studying numerically the combustion of four synthetic jet fuels (Fischer-Tropsch fuels). For reference, two types of crude-oil based kerosenes (Jet A-1 and Jet A) are considered, too. Plug flow calculations were performed by using a detailed chemical-kinetic model validated previously. The composition of the multi-component jet fuels were imaged by using the surrogate approach. Calculations were done for relevant temperatures, pressures, residence times, and fuel equivalence ratios φ. Results are discussed for NOx, CO as well as benzene and acetylene as major soot precursors. According to the predictions, the NOx and CO emissions are within about ± 10% for all fuels considered, within the parameter range studied: T = 1800 K, T = 2200 K; 0.25 ≤ φ ≤ 1.8; p = 40 bar; t = 3 ms. The aromatics free GtL (Gas to Liquid) fuel displayed higher NOx values compared to Jet A-1/A. In addition, synthetic fuels show slightly lower (better) CO emission data than Jet A-1/A. The antagonist role of CO and NOx is apparent. Major differences were predicted for benzene emissions, depending strongly on the aromatics content in the specific fuel, with lower levels predicted for the synthetic aviation fuels. Acetylene levels show a similar, but less pronounced, effect.

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