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Detailed kinetic mechanism for the hydrogen production via the oxidative reforming of ethanol. Chem Eng Sci 2021. [DOI: 10.1016/j.ces.2021.116591] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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2
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Marques CST, da Silva JR. Reduced Reaction Mechanisms for Ethanol under Ultra-lean Conditions in Internal Combustion Engines. ACS OMEGA 2021; 6:206-216. [PMID: 33458473 PMCID: PMC7807477 DOI: 10.1021/acsomega.0c04170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
Chemical kinetics models for ethanol under ultra-lean engine conditions were evaluated to couple with CFD multidimensional simulations of a spark-assisted homogeneous charge compression ignition (HCCI) rotary engine. Five reduced reaction sets proper for CFD simulations and two detailed reaction mechanisms for comparison were tested by simulating ignition delay times, laminar flame speeds, and a single-cycle HCCI engine with virtual piston dimensions. The simulated results of the new mechanism with 188 reactions were well-fitted to both experimental ignition delay times for ultra-lean ethanol/air conditions and laminar flame speeds at high pressures. This reaction set resulted in better-simulated ignition delay times at 30 and 40 bar for ultra-lean ethanol/air conditions than other chemical kinetics models. Maximum temperatures and pressures of 2500-2580 K and 280-289 bar, respectively, were observed for hydrous ethanol/air under ultra-lean conditions in HCCI engine. In addition, the simulation results of the HCCI ethanol engine presented high pressure rise rates of 8-26 bar/CAD at 3600 rpm. These results indicated that the engine test should be carried out at 2500 rpm with 2 bar of boost pressure for CFD model calibration with the new optimized reaction mechanism.
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Affiliation(s)
- Carla S. T. Marques
- Perto
Gestão de Tecnologia S.A., Rua Natingui, 1282—Vila Madalena, São
Paulo, São Paulo 05443-002, Brazil
- Department
of Mechanical Engineering, Polytechnic School, University of São Paulo, Av Prof. Mello de Moraes, 2231—Cidade Universitária, São Paulo, São Paulo 05508-030, Brazil
| | - José R.
M. da Silva
- Perto
Gestão de Tecnologia S.A., Rua Natingui, 1282—Vila Madalena, São
Paulo, São Paulo 05443-002, Brazil
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3
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Liu Y, Ding J. Combustion chemistry of n-heptane/ethanol blends: a ReaxFF study. MOLECULAR SIMULATION 2021. [DOI: 10.1080/08927022.2020.1862416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Yalan Liu
- Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemistry and environmental engineering, Wuhan Institute of Technology, Wuhan, People’s Republic of China
| | - Junxia Ding
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, People’s Republic of China
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Fuller ME, Morsch P, Preußker M, Goldsmith CF, Heufer KA. The impact of NO x addition on the ignition behaviour of n-pentane. REACT CHEM ENG 2021. [DOI: 10.1039/d1re00055a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Modern engine concepts present several opportunities for nitrogen combustion chemistry, particularly the interaction of NOx (NO + NO2) with fuel fragments and products of partial combustion.
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Affiliation(s)
- Mark E. Fuller
- Physico-Chemical Fundamentals of Combustion, RWTH Aachen University, 52062 Aachen, Germany
| | - Philipp Morsch
- Physico-Chemical Fundamentals of Combustion, RWTH Aachen University, 52062 Aachen, Germany
| | - Matthias Preußker
- Physico-Chemical Fundamentals of Combustion, RWTH Aachen University, 52062 Aachen, Germany
| | | | - K. Alexander Heufer
- Physico-Chemical Fundamentals of Combustion, RWTH Aachen University, 52062 Aachen, Germany
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Elucidating the differences in oxidation of high-performance α- and β- diisobutylene biofuels via Synchrotron photoionization mass spectrometry. Sci Rep 2020; 10:21776. [PMID: 33311537 PMCID: PMC7733457 DOI: 10.1038/s41598-020-76462-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 10/21/2020] [Indexed: 11/09/2022] Open
Abstract
Biofuels are a promising ecologically viable and renewable alternative to petroleum fuels, with the potential to reduce net greenhouse gas emissions. However, biomass sourced fuels are often produced as blends of hydrocarbons and their oxygenates. Such blending complicates the implementation of these fuels in combustion applications. Variations in a biofuel's composition will dictate combustion properties such as auto ignition temperature, reaction delay time, and reaction pathways. A handful of novel drop-in replacement biofuels for conventional transportation fuels have recently been down selected from a list of over 10,000 potential candidates as part of the U.S. Department of Energy's (DOE) Co-Optimization of Fuels and Engines (Co-Optima) initiative. Diisobutylene (DIB) is one such high-performing hydrocarbon which can readily be produced from the dehydration and dimerization of isobutanol, produced from the fermentation of biomass-derived sugars. The two most common isomers realized, from this process, are 2,4,4-trimethyl-1-pentene (α-DIB) and 2,4,4-trimethyl-2-pentene (β-DIB). Due to a difference in olefinic bond location, the α- and β- isomer exhibit dramatically different ignition temperatures at constant pressure and equivalence ratio. This may be attributed to different fragmentation pathways enabled by allylic versus vinylic carbons. For optimal implementation of these biofuel candidates, explicit identification of the intermediates formed during the combustion of each of the isomers is needed. To investigate the combustion pathways of these molecules, tunable vacuum ultraviolet (VUV) light (in the range 8.1-11.0 eV) available at the Lawrence Berkeley National Laboratory's Advanced Light Source (ALS) has been used in conjunction with a jet stirred reactor (JSR) and time-of-flight mass spectrometry to probe intermediates formed. Relative intensity curves for intermediate mass fragments produced during this process were obtained. Several important unique intermediates were identified at the lowest observable combustion temperature with static pressure of 93,325 Pa and for 1.5 s residence time. As this relatively short residence time is just after ignition, this study is targeted at the fuels' ignition events. Ignition characteristics for both isomers were found to be strongly dependent on the kinetics of C4 and C7 fragment production and decomposition, with the tert-butyl radical as a key intermediate species. However, the ignition of α-DIB exhibited larger concentrations of C4 compounds over C7, while the reverse was true for β-DIB. These identified species will allow for enhanced engineering modeling of fuel blending and engine design.
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Experimental Investigation and Benchmark Study of Oxidation of Methane–Propane–n-Heptane Mixtures at Pressures up to 100 bar. ENERGIES 2019. [DOI: 10.3390/en12183410] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Dual fuel combustion exhibits a high degree of complexity due to the presence of different fuels like diesel and natural gas in initially different physical states and a spatially strongly varying mixing ratio. Optimizing this combustion process on an engine test bench is costly and time consuming. Cost reduction can be achieved by utilizing simulation tools. Although these tools cannot replace the application of test benches completely, the total development costs can be reduced by an educated combination of simulations and experiments. A suitable model for describing the reactions taking place in the combustion chamber is required to correctly reproduce the dual fuel combustion process. This is why in the presented study, four different reaction mechanisms are benchmarked to shock tube (ST) and rapid compression machine (RCM) measurements of ignition delay times (IDTs) at pressures between 60 and 100 bar and temperatures between 671 and 1284 K. To accommodate dual fuel relevant diesel-natural gas mixtures, methane–propane–n-heptane mixtures are considered as the surrogate. Additionally, the mechanisms AramcoMech 1.3, 2.0 and 3.0 are tested for methane–propane mixtures. The influence of pressure and propane/n-heptane content on the IDT based on the measurements is presented and the extent to which the mechanisms can reflect the IDT-changes discussed.
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Abstract
There has been considerable progress in the area of fuel surrogate development to emulate gasoline fuels’ oxidation properties. The current paper aims to review the relevant hydrocarbon group components used for the formulation of gasoline surrogates, review specific gasoline surrogates reported in the literature, outlining their utility and deficiencies, and identify the future research needs in the area of gasoline surrogates and kinetics model.
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Niegemann P, Fikri M, Wlokas I, Röder M, Schulz C. Methodology for the investigation of ignition near hot surfaces in a high-pressure shock tube. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:055111. [PMID: 29864877 DOI: 10.1063/1.5017275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Autoignition of fuel/air mixtures is a determining process in internal combustion engines. Ignition can start either homogeneously in the gas phase after compression or in the vicinity of hot surfaces. While ignition properties of commercial fuels are conventionally described by a single quantity (octane number), it is known that some fuels have a varying propensity to the two processes. We present a new experimental concept that generates well-controlled temperature inhomogeneities in the shock-heated gases of a high-pressure shock tube. A shock-heated reactive mixture is brought into contact with a heated silicon nitride ceramic glow plug. The glow-plug temperature can be set up to 1200 K, higher than the post-reflected-shock gas temperatures (650-1050 K). High-repetition-rate chemiluminescence imaging is used to localize the onset of ignition in the vicinity of the hot surface. In experiments with ethanol, the results show that in most cases under shock-heated conditions, the ignition begins inhomogeneously in the vicinity of the glow plug and is favored because of the high wall temperature. Additionally, the interaction of geometry, external heating, and gas-dynamic effects was investigated by numerical simulations of the shock wave in a non-reactive flow.
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Affiliation(s)
- P Niegemann
- Institute for Combustion and Gas Dynamics-Reactive Fluids, University of Duisburg-Essen, 47048 Duisburg, Germany
| | - M Fikri
- Institute for Combustion and Gas Dynamics-Reactive Fluids, University of Duisburg-Essen, 47048 Duisburg, Germany
| | - I Wlokas
- Institute for Combustion and Gas Dynamics-Fluid Dynamics, University of Duisburg-Essen, 47048 Duisburg, Germany
| | - M Röder
- Institute for Combustion and Gas Dynamics-Reactive Fluids, University of Duisburg-Essen, 47048 Duisburg, Germany
| | - C Schulz
- Institute for Combustion and Gas Dynamics-Reactive Fluids, University of Duisburg-Essen, 47048 Duisburg, Germany
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Barraza-Botet CL, Wagnon SW, Wooldridge MS. Combustion Chemistry of Ethanol: Ignition and Speciation Studies in a Rapid Compression Facility. J Phys Chem A 2016; 120:7408-18. [DOI: 10.1021/acs.jpca.6b06725] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Cesar L. Barraza-Botet
- Department of Mechanical Engineering and ‡Department of Aerospace
Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Scott W. Wagnon
- Department of Mechanical Engineering and ‡Department of Aerospace
Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Margaret S. Wooldridge
- Department of Mechanical Engineering and ‡Department of Aerospace
Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
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Auzmendi-Murua I, Bozzelli JW. Thermochemical Properties and Bond Dissociation Enthalpies of 3- to 5-Member Ring Cyclic Ether Hydroperoxides, Alcohols, and Peroxy Radicals: Cyclic Ether Radical + 3O2 Reaction Thermochemistry. J Phys Chem A 2014; 118:3147-67. [DOI: 10.1021/jp412590g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Itsaso Auzmendi-Murua
- Department of Chemistry and
Chemical Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Joseph W. Bozzelli
- Department of Chemistry and
Chemical Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
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Somers KP, Simmie JM, Gillespie F, Conroy C, Black G, Metcalfe WK, Battin-Leclerc F, Dirrenberger P, Herbinet O, Glaude PA, Dagaut P, Togbé C, Yasunaga K, Fernandes RX, Lee C, Tripathi R, Curran HJ. A comprehensive experimental and detailed chemical kinetic modelling study of 2,5-dimethylfuran pyrolysis and oxidation. COMBUSTION AND FLAME 2013; 160:http://dx.doi.org/10.1016/j.combustflame.2013.06.007. [PMID: 24273333 PMCID: PMC3837218 DOI: 10.1016/j.combustflame.2013.06.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The pyrolytic and oxidative behaviour of the biofuel 2,5-dimethylfuran (25DMF) has been studied in a range of experimental facilities in order to investigate the relatively unexplored combustion chemistry of the title species and to provide combustor relevant experimental data. The pyrolysis of 25DMF has been re-investigated in a shock tube using the single-pulse method for mixtures of 3% 25DMF in argon, at temperatures from 1200-1350 K, pressures from 2-2.5 atm and residence times of approximately 2 ms. Ignition delay times for mixtures of 0.75% 25DMF in argon have been measured at atmospheric pressure, temperatures of 1350-1800 K at equivalence ratios (ϕ) of 0.5, 1.0 and 2.0 along with auto-ignition measurements for stoichiometric fuel in air mixtures of 25DMF at 20 and 80 bar, from 820-1210 K. This is supplemented with an oxidative speciation study of 25DMF in a jet-stirred reactor (JSR) from 770-1220 K, at 10.0 atm, residence times of 0.7 s and at ϕ = 0.5, 1.0 and 2.0. Laminar burning velocities for 25DMF-air mixtures have been measured using the heat-flux method at unburnt gas temperatures of 298 and 358 K, at atmospheric pressure from ϕ = 0.6-1.6. These laminar burning velocity measurements highlight inconsistencies in the current literature data and provide a validation target for kinetic mechanisms. A detailed chemical kinetic mechanism containing 2768 reactions and 545 species has been simultaneously developed to describe the combustion of 25DMF under the experimental conditions described above. Numerical modelling results based on the mechanism can accurately reproduce the majority of experimental data. At high temperatures, a hydrogen atom transfer reaction is found to be the dominant unimolecular decomposition pathway of 25DMF. The reactions of hydrogen atom with the fuel are also found to be important in predicting pyrolysis and ignition delay time experiments. Numerous proposals are made on the mechanism and kinetics of the previously unexplored intermediate temperature combustion pathways of 25DMF. Hydroxyl radical addition to the furan ring is highlighted as an important fuel consuming reaction, leading to the formation of methyl vinyl ketone and acetyl radical. The chemically activated recombination of HȮ2 or CH3Ȯ2 with the 5-methyl-2-furanylmethyl radical, forming a 5-methyl-2-furylmethanoxy radical and ȮH or CH3Ȯ radical is also found to exhibit significant control over ignition delay times, as well as being important reactions in the prediction of species profiles in a JSR. Kinetics for the abstraction of a hydrogen atom from the alkyl side-chain of the fuel by molecular oxygen and HȮ2 radical are found to be sensitive in the estimation of ignition delay times for fuel-air mixtures from temperatures of 820-1200 K. At intermediate temperatures, the resonantly stabilised 5-methyl-2-furanylmethyl radical is found to predominantly undergo bimolecular reactions, and as a result sub-mechanisms for 5-methyl-2-formylfuran and 5-methyl-2-ethylfuran, and their derivatives, have also been developed with consumption pathways proposed. This study is the first to attempt to simulate the combustion of these species in any detail, although future refinements are likely necessary. The current study illustrates both quantitatively and qualitatively the complex chemical behavior of what is a high potential biofuel. Whilst the current work is the most comprehensive study on the oxidation of 25DMF in the literature to date, the mechanism cannot accurately reproduce laminar burning velocity measurements over a suitable range of unburnt gas temperatures, pressures and equivalence ratios, although discrepancies in the experimental literature data are highlighted. Resolving this issue should remain a focus of future work.
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Affiliation(s)
- Kieran P. Somers
- Combustion Chemistry Centre, National University of Ireland, Galway, University Road, Galway, Ireland
| | - John M. Simmie
- Combustion Chemistry Centre, National University of Ireland, Galway, University Road, Galway, Ireland
| | - Fiona Gillespie
- Combustion Chemistry Centre, National University of Ireland, Galway, University Road, Galway, Ireland
| | - Christine Conroy
- Combustion Chemistry Centre, National University of Ireland, Galway, University Road, Galway, Ireland
| | - Gráinne Black
- Combustion Chemistry Centre, National University of Ireland, Galway, University Road, Galway, Ireland
| | - Wayne K. Metcalfe
- Combustion Chemistry Centre, National University of Ireland, Galway, University Road, Galway, Ireland
| | - Frédérique Battin-Leclerc
- Laboratoire Réactions et Génie des Procédés, CNRS, Université de Lorraine, BP 20451, 1 rue Grandville, 51001 Nancy, France
| | - Patricia Dirrenberger
- Laboratoire Réactions et Génie des Procédés, CNRS, Université de Lorraine, BP 20451, 1 rue Grandville, 51001 Nancy, France
| | - Olivier Herbinet
- Laboratoire Réactions et Génie des Procédés, CNRS, Université de Lorraine, BP 20451, 1 rue Grandville, 51001 Nancy, France
| | - Pierre-Alexandre Glaude
- Laboratoire Réactions et Génie des Procédés, CNRS, Université de Lorraine, BP 20451, 1 rue Grandville, 51001 Nancy, France
| | - Philippe Dagaut
- CNRS-INSIS, ICARE, 1C, Avenue de la recherche scientifique, 45071 Orléans Cedex 2, France
| | - Casimir Togbé
- CNRS-INSIS, ICARE, 1C, Avenue de la recherche scientifique, 45071 Orléans Cedex 2, France
| | - Kenji Yasunaga
- Department of Applied Chemistry, National Defense Academy, Hashirimizu 1-10-20, Yokosuka, Kanagawa, Japan, 239-8686
| | - Ravi X. Fernandes
- Physico-Chemical Fundamentals of Combustion, RWTH Aachen University, Templergraben 55, D-52056, Aachen, Germany
| | - Changyoul Lee
- Physico-Chemical Fundamentals of Combustion, RWTH Aachen University, Templergraben 55, D-52056, Aachen, Germany
| | - Rupali Tripathi
- Physico-Chemical Fundamentals of Combustion, RWTH Aachen University, Templergraben 55, D-52056, Aachen, Germany
| | - Henry J. Curran
- Combustion Chemistry Centre, National University of Ireland, Galway, University Road, Galway, Ireland
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Gong K, Park J, Su D, Adzic RR. Metalizing carbon nanotubes with Pd–Pt core–shell nanowires enhances electrocatalytic activity and stability in the oxygen reduction reaction. J Solid State Electrochem 2013. [DOI: 10.1007/s10008-013-2214-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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13
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Tran LS, Glaude PA, Fournet R, Battin-Leclerc F. EXPERIMENTAL AND MODELING STUDY OF PREMIXED LAMINAR FLAMES OF ETHANOL AND METHANE. ENERGY & FUELS : AN AMERICAN CHEMICAL SOCIETY JOURNAL 2013; 27:2226-2245. [PMID: 23712124 PMCID: PMC3663996 DOI: 10.1021/ef301628x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
To better understand the chemistry of the combustion of ethanol, the structure of five low pressure laminar premixed flames has been investigated: a pure methane flame (φ=1), three pure ethanol flames (φ=0.7, 1.0, and 1.3), and an ethanol/methane mixture flames (φ=1). The flames have been stabilized on a burner at a pressure of 6.7 kPa using argon as dilutant, with a gas velocity at the burner of 64.3 cm/s at 333 K. The results consist of mole fraction profiles of 20 species measured as a function of the height above the burner by probe sampling followed by online gas chromatography analyses. A mechanism for the oxidation of ethanol was proposed. The reactions of ethanol and acetaldehyde were updated and include recent theoretical calculations while that of ethenol, dimethyl ether, acetone, and propanal were added in the mechanism. This mechanism was also tested against experimental results available in the literature for laminar burning velocities and laminar premixed flame where ethenol was detected. The main reaction pathways of consumption of ethanol are analyzed. The effect of the branching ratios of reaction C2H5OH+OH→Products+H2O is also discussed.
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Affiliation(s)
- Luc-Sy Tran
- Laboratoire Réactions et Génie des Procédé, Université de Lorraine, CNRS, BP 20451, 1 rue Grandville, 54001 Nancy, France
| | - Pierre-Alexandre Glaude
- Laboratoire Réactions et Génie des Procédé, Université de Lorraine, CNRS, BP 20451, 1 rue Grandville, 54001 Nancy, France
| | - René Fournet
- Laboratoire Réactions et Génie des Procédé, Université de Lorraine, CNRS, BP 20451, 1 rue Grandville, 54001 Nancy, France
| | - Frédérique Battin-Leclerc
- Laboratoire Réactions et Génie des Procédé, Université de Lorraine, CNRS, BP 20451, 1 rue Grandville, 54001 Nancy, France
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