The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Pascal Diévart - One of the best experts on this subject based on the ideXlab platform.
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Combustion of a gas-to-liquid-based alternative jet fuel: Experimental and detailed kinetic modeling
Combustion Science and Technology, 2014Co-Authors: Philippe Dagaut, Kamal Hadj-ali, Guillaume Dayma, Pascal Diévart, Amir Mzé-ahmedAbstract:The kinetics of oxidation of blends of gas-to-liquid (GtL) jet fuel with 20% vol. of 1-hexanol was studied. New experimental results were obtained using a jet-stirred reactor (p = 10 bar, constant mean residence time of 1 s, over the temperature range 550-1150 K, and for equivalence ratios of 0.5, 1, and 2). Concentration profiles of reactants, stable intermediates, and final products were obtained by probe sampling followed by on-line and off-line gas chromatography analyses and on-line Fourier transformed infra-red spectrometry. A comparison with corresponding results for Jet A-1 and pure GtL showed these fuels have similar combustion properties. The oxidation of the GtL-hexanol fuel under these conditions was modeled using a detailed kinetic reaction mechanism consisting of 8217 reactions and 2185 species and a 4-component surrogate fuel mixture (n-decane, iso-octane, n-propyl cyclohexane, and 1-hexanol). The proposed kinetic model showed good agreement with the presently reported jet-stirred reactor concentration profiles. ©
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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, 2014Co-Authors: Amir Mzé-ahmed, Guillaume Dayma, Philippe Dagaut, Pascal DiévartAbstract: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 (uφ1 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. Copyright © 2015 by ASME.
Raymond L Huhnke - One of the best experts on this subject based on the ideXlab platform.
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Butanol and hexanol production in Clostridium carboxidivorans syngas fermentation: Medium development and culture techniques
Bioresource Technology, 2015Co-Authors: J. R. Phillips, Juan R. Torres, Jyotisna Saxena, RALPH S TANNER, Hasan K. Atiyeh, Mark R. Wilkins, Raymond L HuhnkeAbstract:Clostridium carboxidivorans was grown on model syngas (CO:H2:CO2 [70:20:10]) in a defined nutrient medium with concentrations of nitrogen, phosphate and trace metals formulated to enhance production of higher alcohols. C. carboxidivorans was successfully grown in a limited defined medium (no yeast extract, no MES buffer and minimal complex chemical inputs) using an improved fermentation protocol. Low partial pressure of CO in the headspace, coupled with restricted mass transfer for CO and H2, was required for successful fermentation. In the absence of substrate inhibition (particularly from CO), growth limitation increased production of alcohols, especially butanol and hexanol. Concentrations of butanol (over 1.0g/L), hexanol (up to 1.0g/L) and ethanol (over 3.0g/L) were achieved in bottle fermentations. Minimal medium and controlled supply of CO and H2 should be used in characterizing candidate butanol and hexanol producing strains to select for commercial potential.
Amir Mzé-ahmed - One of the best experts on this subject based on the ideXlab platform.
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Combustion of a gas-to-liquid-based alternative jet fuel: Experimental and detailed kinetic modeling
Combustion Science and Technology, 2014Co-Authors: Philippe Dagaut, Kamal Hadj-ali, Guillaume Dayma, Pascal Diévart, Amir Mzé-ahmedAbstract:The kinetics of oxidation of blends of gas-to-liquid (GtL) jet fuel with 20% vol. of 1-hexanol was studied. New experimental results were obtained using a jet-stirred reactor (p = 10 bar, constant mean residence time of 1 s, over the temperature range 550-1150 K, and for equivalence ratios of 0.5, 1, and 2). Concentration profiles of reactants, stable intermediates, and final products were obtained by probe sampling followed by on-line and off-line gas chromatography analyses and on-line Fourier transformed infra-red spectrometry. A comparison with corresponding results for Jet A-1 and pure GtL showed these fuels have similar combustion properties. The oxidation of the GtL-hexanol fuel under these conditions was modeled using a detailed kinetic reaction mechanism consisting of 8217 reactions and 2185 species and a 4-component surrogate fuel mixture (n-decane, iso-octane, n-propyl cyclohexane, and 1-hexanol). The proposed kinetic model showed good agreement with the presently reported jet-stirred reactor concentration profiles. ©
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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, 2014Co-Authors: Amir Mzé-ahmed, Guillaume Dayma, Philippe Dagaut, Pascal DiévartAbstract: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 (uφ1 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. Copyright © 2015 by ASME.
Y Viisanen - One of the best experts on this subject based on the ideXlab platform.
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measurement of the molecular content of binary nuclei use of the nucleation rate surface for ethanol hexanol
Journal of Chemical Physics, 1993Co-Authors: R Strey, Y ViisanenAbstract:We measured the homogeneous nucleation rates J of mixed droplets in supersaturated ethanol–hexanol vapor mixtures in argon as functions of the vapor phase activities a1 and a2 of ethanol and hexanol, respectively. Measurements ranged from pure ethanol to pure hexanol at T=260 K. The experimental nucleation rate curves shape a nucleation rate surface in the three‐dimensional J−a1−a2 space. We develop a theory for obtaining the average size and composition of a nucleus from this surface determined experimentally. Following this procedure experimental nucleus compositions are determined. This theory is then combined with our measurements in order to determine the makeup of the binary ethanol–hexanol nuclei. Results are compared with the predictions of classical binary nucleation theory. Qualitatively similar trends are observed for the nearly ideal ethanol–hexanol system studied.
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Measurement of the molecular content of binary nuclei. Use of the nucleation rate surface for ethanol–hexanol
Journal of Chemical Physics, 1993Co-Authors: R Strey, Y ViisanenAbstract:We measured the homogeneous nucleation rates J of mixed droplets in supersaturated ethanol–hexanol vapor mixtures in argon as functions of the vapor phase activities a1 and a2 of ethanol and hexanol, respectively. Measurements ranged from pure ethanol to pure hexanol at T=260 K. The experimental nucleation rate curves shape a nucleation rate surface in the three‐dimensional J−a1−a2 space. We develop a theory for obtaining the average size and composition of a nucleus from this surface determined experimentally. Following this procedure experimental nucleus compositions are determined. This theory is then combined with our measurements in order to determine the makeup of the binary ethanol–hexanol nuclei. Results are compared with the predictions of classical binary nucleation theory. Qualitatively similar trends are observed for the nearly ideal ethanol–hexanol system studied.
Keiichi Tomishige - One of the best experts on this subject based on the ideXlab platform.
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production of renewable Hexanols from mechanocatalytically depolymerized cellulose by using ir reox sio2 catalyst
Chemsuschem, 2015Co-Authors: Yasuyo Okuyama, Masazumi Tamura, Yoshinao Nakagawa, Akio Imai, Keiichi TomishigeAbstract:: Hexanols were produced in high yield by conversion of cellulose over Ir-ReOx /SiO2 (molar ratio Re/Ir=2) catalyst in biphasic reaction system (n-decane+H2 O). The cellulose was depolymerized by mechanocatalysis with the aid of H2 SO4 . The influence of solvent amount, reaction temperature and hydrogen pressure was systematically investigated and the highest yield of Hexanols reached 60 % under the conditions of n-decane/water ∼2 (v/v), 413 K, 10 MPa H2 for 24 h. Mechanocatalytic depolymerization of cellulose with the aid of H2 SO4 or HCl and the use of sufficient n-decane were very crucial for the production of Hexanols. H2 SO4 not only catalyzed cellulose to water-soluble oligosaccharides but also promoted the hydrogenolysis activity of Ir-ReOx /SiO2 catalyst. The role of n-decane was to extract Hexanols and to suppress over-hydrogenolysis of Hexanols to n-hexane.