The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
V. Burklé-vitzthum - One of the best experts on this subject based on the ideXlab platform.
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INFLUENCE OF H 2 S ON THE THERMAL CRACKING OF ALKYLBENZENES AT HIGH PRESSURE (70 MPA) AND MODERATE TEMPERATURE (583-623 K)
Journal of Analytical and Applied Pyrolysis, 2019Co-Authors: V. Burklé-vitzthum, N.c. Leguizamon Guerra, C. Lorgeoux, D. Faure-catteloin, R. Bounaceur, R. MichelsAbstract:Highlights Pyrolysis of n-Butylbenzene/H 2 S mixture (80 % : 20% mol) at 70 MPa and from 583 K to 623 K was performed in sealed gold tubes. The main products are toluene, ethylbenzene, iso-Butylbenzene and hydrocarbon gases (C 1 , C 2 and C 3). Several organosulfur compounds are produced: mainly short thiols, phenylbutanethiols, and phenylthiophenes. H 2 S accelerates the pyrolysis of n-Butylbenzene by a factor up to almost 4 depending on the experimental conditions. The molecular composition of the products is highly modified in the presence of H 2 S. Abstract The thermal cracking of n-Butylbenzene was experimentally studied in the presence of H 2 S (80% : 20% mol) at high pressure (70 MPa), moderate temperature (583, 603 and 623 K) and for durations of 3, 7 and 15 days. The pyrolysis was performed in sealed gold tubes under isobaric conditions. Under these conditions, the conversion of n-Butylbenzene varied between 2.5% and 73.2%. The pyrolysis of n-Butylbenzene is accelerated by H 2 S by a factor of up to 3.6 depending on the operating conditions. This acceleration factor seems to decrease with increasing time and temperature. The apparent activation energy of the pyrolysis of n-Butylbenzene decreases from 66.6 kcal/mol (pure n-Butylbenzene) to 55.9 kcal/mol (n-Butylbenzene in mixture with H 2 S). The main hydrocarbons produced are alkylbenzenes (mostly toluene and ethylbenzene), branched alkylbenzenes (mostly isomers of iso-Butylbenzene and iso-heptylbenzene to a lesser extent) and short alkanes (from CH 4 to C 3). Several sulfur compounds are also produced and their relative abundances are in the range 4-16% depending on the operating conditions. These sulfur compounds are mostly short thiols (methanethiol, ethanethiol and propanethiols), phenylbutanethiols and phenylthiophenes. Additional experiments were also conducted with alkylbenzenes bearing shorter substituents than n-Butylbenzene (toluene, ethylbenzene and n-propylbenzene) in order to hightlight the influence of the length of the side chain. Finally, the kinetic effect of H 2 S on the pyrolysis of n-Butylbenzene was compared to its effect on n-octane pyrolysis: the effect seems antagonistic under the studied experimental conditions but some similarities can be highlighted.
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Influence of H2S on the thermal cracking of alkylbenzenes at high pressure (70 MPa) and moderate temperature (583–623 K)
Journal of Analytical and Applied Pyrolysis, 2019Co-Authors: V. Burklé-vitzthum, Roda Bounaceur, C. Lorgeoux, D. Faure-catteloin, N.c. Leguizamon Guerra, R. MichelsAbstract:Abstract The thermal cracking of n-Butylbenzene was experimentally studied in the presence of H2S (80% : 20% mol) at high pressure (70 MPa), moderate temperature (583, 603 and 623 K) and for durations of 3, 7 and 15 days. The pyrolysis was performed in sealed gold tubes under isobaric conditions. Under these conditions, the conversion of n-Butylbenzene varied between 2.5% and 73.2%. The pyrolysis of n-Butylbenzene is accelerated by H2S by a factor of up to 3.6 depending on the operating conditions. This acceleration factor seems to decrease with increasing time and temperature. The apparent activation energy of the pyrolysis of n-Butylbenzene decreases from 66.6 kcal/mol (pure n-Butylbenzene) to 55.9 kcal/mol (n-Butylbenzene in mixture with H2S). The main hydrocarbons produced are alkylbenzenes (mostly toluene and ethylbenzene), branched alkylbenzenes (mostly isomers of iso-Butylbenzene and iso-heptylbenzene to a smaller extent) and short alkanes (from CH4 to C3). Several sulfur compounds are also produced and their relative abundances are in the range 4–16% depending on the operating conditions. These sulfur compounds are mostly short thiols (methanethiol, ethanethiol and propanethiols), phenylbutanethiols and phenylthiophenes. Additional experiments were also conducted with alkylbenzenes bearing shorter substituents than n-Butylbenzene (toluene, ethylbenzene and n-propylbenzene) in order to hightlight the influence of the length of the side chain. Finally, the kinetic effect of H2S on the pyrolysis of n-Butylbenzene was compared to its effect on n-octane pyrolysis: the effect seems antagonistic under the studied experimental conditions but some similarities can be highlighted.
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Thermal cracking of n -Butylbenzene at high pressure: Experimental study and kinetic modelling
Journal of Analytical and Applied Pyrolysis, 2018Co-Authors: N.c. Leguizamon Guerra, R. Bounaceur, René Fournet, Baptiste Sirjean, Aurélien Randi, J.c. Lizardo Huerta, C. Lorgeoux, R. Michels, V. Burklé-vitzthumAbstract:Highlights Pyrolysis of n-Butylbenzene at 70 MPa and from 583 K to 623 K was performed in sealed gold tubes. The main products are toluene, ethylbenzene, iso-heptyl-and iso-Butylbenzene, CH4 and C2H6. A detailed kinetic model was constructed and validated over the entire experimental range of conversion (0.7-62%). Thermochemical and kinetic parameters of key decomposition routes were computed using theoretical calculations.
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Thermal cracking of n-Butylbenzene at high pressure: Experimental study and kinetic modelling
Journal of Analytical and Applied Pyrolysis, 2018Co-Authors: N.c. Leguizamon Guerra, Roda Bounaceur, C. Lorgeoux, R. Michels, J.c. Lizardo Huerta, René Fournet, Baptiste Sirjean, Aurélien Randi, V. Burklé-vitzthumAbstract:Abstract The thermal cracking of n-Butylbenzene was experimentally studied at high pressure (70 MPa), and moderate temperatures (583, 603, 623 K), for conversions of n-Butylbenzene ranging between 0.7% and 62%. The pyrolysis was performed in sealed isobaric gold tubes (confined pyrolysis). Three main chemical families were observed: short alkylbenzenes (mostly toluene and ethylbenzene), branched alkylbenzenes (isomers of iso-Butylbenzene and iso-heptylbenzene) and short alkanes (from CH4 to C4H10). As minor products, alkenylbenzenes (styrene and butenylbenzene), methylindane and biaromatic structures were also quantified. A detailed kinetic model composed of 3542 free-radical reactions and 383 species (molecules and free-radicals) was written in a systematic manner by taking into account all relevant elementary free-radical reactions. A large number of thermochemical and kinetic parameters were computed by theoretical calculations. A very good agreement between experimental and simulation results is observed for every operating condition and for most major and minor compounds. The apparent kinetic parameters were computed at 623 K, 70 MPa and 30% conversion under the assumption of a first-order global rate law: the apparent activation energy was found equal to 66.6 kcal mol−1 and the frequency factor to 6.3 × 1016 s−1. The extrapolation to low temperature (473 K), which is characteristic of deeply buried oil reservoirs, shows that the stability of n-Butylbenzene is about the same as the stability of alkanes, but n-Butylbenzene is more stable than n-decylbenzene and less stable than toluene.
R. Michels - One of the best experts on this subject based on the ideXlab platform.
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INFLUENCE OF H 2 S ON THE THERMAL CRACKING OF ALKYLBENZENES AT HIGH PRESSURE (70 MPA) AND MODERATE TEMPERATURE (583-623 K)
Journal of Analytical and Applied Pyrolysis, 2019Co-Authors: V. Burklé-vitzthum, N.c. Leguizamon Guerra, C. Lorgeoux, D. Faure-catteloin, R. Bounaceur, R. MichelsAbstract:Highlights Pyrolysis of n-Butylbenzene/H 2 S mixture (80 % : 20% mol) at 70 MPa and from 583 K to 623 K was performed in sealed gold tubes. The main products are toluene, ethylbenzene, iso-Butylbenzene and hydrocarbon gases (C 1 , C 2 and C 3). Several organosulfur compounds are produced: mainly short thiols, phenylbutanethiols, and phenylthiophenes. H 2 S accelerates the pyrolysis of n-Butylbenzene by a factor up to almost 4 depending on the experimental conditions. The molecular composition of the products is highly modified in the presence of H 2 S. Abstract The thermal cracking of n-Butylbenzene was experimentally studied in the presence of H 2 S (80% : 20% mol) at high pressure (70 MPa), moderate temperature (583, 603 and 623 K) and for durations of 3, 7 and 15 days. The pyrolysis was performed in sealed gold tubes under isobaric conditions. Under these conditions, the conversion of n-Butylbenzene varied between 2.5% and 73.2%. The pyrolysis of n-Butylbenzene is accelerated by H 2 S by a factor of up to 3.6 depending on the operating conditions. This acceleration factor seems to decrease with increasing time and temperature. The apparent activation energy of the pyrolysis of n-Butylbenzene decreases from 66.6 kcal/mol (pure n-Butylbenzene) to 55.9 kcal/mol (n-Butylbenzene in mixture with H 2 S). The main hydrocarbons produced are alkylbenzenes (mostly toluene and ethylbenzene), branched alkylbenzenes (mostly isomers of iso-Butylbenzene and iso-heptylbenzene to a lesser extent) and short alkanes (from CH 4 to C 3). Several sulfur compounds are also produced and their relative abundances are in the range 4-16% depending on the operating conditions. These sulfur compounds are mostly short thiols (methanethiol, ethanethiol and propanethiols), phenylbutanethiols and phenylthiophenes. Additional experiments were also conducted with alkylbenzenes bearing shorter substituents than n-Butylbenzene (toluene, ethylbenzene and n-propylbenzene) in order to hightlight the influence of the length of the side chain. Finally, the kinetic effect of H 2 S on the pyrolysis of n-Butylbenzene was compared to its effect on n-octane pyrolysis: the effect seems antagonistic under the studied experimental conditions but some similarities can be highlighted.
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Influence of H2S on the thermal cracking of alkylbenzenes at high pressure (70 MPa) and moderate temperature (583–623 K)
Journal of Analytical and Applied Pyrolysis, 2019Co-Authors: V. Burklé-vitzthum, Roda Bounaceur, C. Lorgeoux, D. Faure-catteloin, N.c. Leguizamon Guerra, R. MichelsAbstract:Abstract The thermal cracking of n-Butylbenzene was experimentally studied in the presence of H2S (80% : 20% mol) at high pressure (70 MPa), moderate temperature (583, 603 and 623 K) and for durations of 3, 7 and 15 days. The pyrolysis was performed in sealed gold tubes under isobaric conditions. Under these conditions, the conversion of n-Butylbenzene varied between 2.5% and 73.2%. The pyrolysis of n-Butylbenzene is accelerated by H2S by a factor of up to 3.6 depending on the operating conditions. This acceleration factor seems to decrease with increasing time and temperature. The apparent activation energy of the pyrolysis of n-Butylbenzene decreases from 66.6 kcal/mol (pure n-Butylbenzene) to 55.9 kcal/mol (n-Butylbenzene in mixture with H2S). The main hydrocarbons produced are alkylbenzenes (mostly toluene and ethylbenzene), branched alkylbenzenes (mostly isomers of iso-Butylbenzene and iso-heptylbenzene to a smaller extent) and short alkanes (from CH4 to C3). Several sulfur compounds are also produced and their relative abundances are in the range 4–16% depending on the operating conditions. These sulfur compounds are mostly short thiols (methanethiol, ethanethiol and propanethiols), phenylbutanethiols and phenylthiophenes. Additional experiments were also conducted with alkylbenzenes bearing shorter substituents than n-Butylbenzene (toluene, ethylbenzene and n-propylbenzene) in order to hightlight the influence of the length of the side chain. Finally, the kinetic effect of H2S on the pyrolysis of n-Butylbenzene was compared to its effect on n-octane pyrolysis: the effect seems antagonistic under the studied experimental conditions but some similarities can be highlighted.
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Thermal cracking of n-Butylbenzene at high pressure: Experimental study and kinetic modelling
Journal of Analytical and Applied Pyrolysis, 2018Co-Authors: N.c. Leguizamon Guerra, Roda Bounaceur, C. Lorgeoux, R. Michels, J.c. Lizardo Huerta, René Fournet, Baptiste Sirjean, Aurélien Randi, V. Burklé-vitzthumAbstract:Abstract The thermal cracking of n-Butylbenzene was experimentally studied at high pressure (70 MPa), and moderate temperatures (583, 603, 623 K), for conversions of n-Butylbenzene ranging between 0.7% and 62%. The pyrolysis was performed in sealed isobaric gold tubes (confined pyrolysis). Three main chemical families were observed: short alkylbenzenes (mostly toluene and ethylbenzene), branched alkylbenzenes (isomers of iso-Butylbenzene and iso-heptylbenzene) and short alkanes (from CH4 to C4H10). As minor products, alkenylbenzenes (styrene and butenylbenzene), methylindane and biaromatic structures were also quantified. A detailed kinetic model composed of 3542 free-radical reactions and 383 species (molecules and free-radicals) was written in a systematic manner by taking into account all relevant elementary free-radical reactions. A large number of thermochemical and kinetic parameters were computed by theoretical calculations. A very good agreement between experimental and simulation results is observed for every operating condition and for most major and minor compounds. The apparent kinetic parameters were computed at 623 K, 70 MPa and 30% conversion under the assumption of a first-order global rate law: the apparent activation energy was found equal to 66.6 kcal mol−1 and the frequency factor to 6.3 × 1016 s−1. The extrapolation to low temperature (473 K), which is characteristic of deeply buried oil reservoirs, shows that the stability of n-Butylbenzene is about the same as the stability of alkanes, but n-Butylbenzene is more stable than n-decylbenzene and less stable than toluene.
Stephen E. Stein - One of the best experts on this subject based on the ideXlab platform.
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Monte Carlo/RRKM/classical trajectories modeling of collisional excitation and dissociation of n-Butylbenzene ion in multipole collision cells of tandem mass spectrometers.
The journal of physical chemistry. A, 2010Co-Authors: Vadim D. Knyazev, Stephen E. SteinAbstract:The two-channel reaction of collision-induced dissociation (CID) of the n-Butylbenzene cation under the conditions of multipole collision cells of tandem mass spectrometers was studied computationally. The results were compared with the experimental data from earlier CID studies. The Monte Carlo method used includes simulation of the trajectories of flight of the parent (n-C4H9C6H5+) and the product (C7H7+ and C7H8+) ions in the electromagnetic field of multipole ion guides and collision cells, classical trajectory modeling of collisional activation and scattering of ions, and RRKM modeling of the parent ion decomposition. Experimental information on the energy dependences of the rates of the n-Butylbenzene cation dissociation via two channels was used to create an RRKM model of the reaction. Effects of uncertainties in the critical parameters of the model of the reaction and the collision cells on the results of calculations were evaluated and shown to be minor. The results of modeling demonstrate a good...
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monte carlo rrkm classical trajectories modeling of collisional excitation and dissociation of n Butylbenzene ion in multipole collision cells of tandem mass spectrometers
Journal of Physical Chemistry A, 2010Co-Authors: Vadim D. Knyazev, Stephen E. SteinAbstract:The two-channel reaction of collision-induced dissociation (CID) of the n-Butylbenzene cation under the conditions of multipole collision cells of tandem mass spectrometers was studied computationally. The results were compared with the experimental data from earlier CID studies. The Monte Carlo method used includes simulation of the trajectories of flight of the parent (n-C4H9C6H5+) and the product (C7H7+ and C7H8+) ions in the electromagnetic field of multipole ion guides and collision cells, classical trajectory modeling of collisional activation and scattering of ions, and RRKM modeling of the parent ion decomposition. Experimental information on the energy dependences of the rates of the n-Butylbenzene cation dissociation via two channels was used to create an RRKM model of the reaction. Effects of uncertainties in the critical parameters of the model of the reaction and the collision cells on the results of calculations were evaluated and shown to be minor. The results of modeling demonstrate a good...
Yan Zhang - One of the best experts on this subject based on the ideXlab platform.
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Exploring fuel isomeric effects on laminar flame propagation of Butylbenzenes at various pressures
Proceedings of the Combustion Institute, 2020Co-Authors: Yan Zhang, Bowen Mei, Xiaoyuan ZhangAbstract:Abstract This work reports an experimental and kinetic modeling investigation on the laminar flame propagation of three Butylbenzene isomers (n-Butylbenzene, iso-Butylbenzene and tert-Butylbenzene)/air mixtures. The experiments were performed in a high-pressure constant-volume cylindrical combustion vessel at the initial temperature of 423 K, initial pressures of 1–10 atm, and equivalence ratios (ϕ) of 0.7–1.5. The laminar burning velocities of Butylbenzene/O2/He mixtures were also measured at 423 K, 10 atm and ϕ = 1.5 to provide additional experimental data under conditions that the Butylbenzene/air experiments are susceptible of cellular instability. Comparison among the laminar burning velocities of Butylbenzenes including both the three isomers investigated in this work and sec-Butylbenzene investigated in our recent work [Combust. Flame 211 (2020) 18–31] shows remarkable fuel isomeric effects, that is, iso-Butylbenzene has the slowest laminar burning velocities, followed by n-Butylbenzene and tert-Butylbenzene, while sec-Butylbenzene has the fastest laminar burning velocities. A kinetic model for Butylbenzene combustion was developed to simulate the laminar flame propagation of Butylbenzenes. Sensitivity analysis was performed to reveal important reactions in laminar flame propagation of Butylbenzenes, including both small species reactions and fuel-specific reactions. Kinetic effects are concluded to result in the different laminar burning velocities of four Butylbenzene isomers. Small species reactions control the laminar flame propagation under lean conditions, which results in small differences of laminar burning velocities. Chain termination reactions, especially fuel-specific reactions, have important contributions to inhibit the laminar flame propagation under rich conditions. The structural features of Butylbenzene isomers can significantly affect the formation of some crucial radicals such as methyl, cyclopentadienyl and benzyl radicals under rich conditions, which leads to remarkable fuel isomeric effects on their laminar burning velocities, especially at high pressures.
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Flow reactor pyrolysis of iso-Butylbenzene and tert-Butylbenzene at various pressures: Insight into fuel isomeric effects on pyrolysis chemistry of Butylbenzenes
Proceedings of the Combustion Institute, 2020Co-Authors: Yan Zhang, Xiaoyuan Zhang, Chuangchuang Cao, Jiabiao Zou, Jiuzhong YangAbstract:Abstract This work reports an experimental and kinetic modeling investigation on the flow reactor pyrolysis of iso-Butylbenzene and tert-Butylbenzene at 0.04 and 1 atm. Pyrolysis products were detected and identified using synchrotron vacuum ultraviolet photoionization mass spectrometry, and their mole fractions versus heating temperature were measured. High-pressure-limit and pressure-dependent rate constants of unimolecular decomposition reactions of iso-Butylbenzene were calculated in this work using the same method as the theoretical calculation investigation on similar reactions of n-Butylbenzene, sec-Butylbenzene and tert-Butylbenzene reported by Belisario-Lara et al. [J. Phys. Chem. A, 122 (2018) 3980–4001]. Furthermore, a pyrolysis model of four Butylbenzene isomers was developed from our previous models of n-Butylbenzene and sec-Butylbenzene and validated by the present experimental data. Modeling analysis was performed to reveal key pathways in fuel decomposition and polycyclic aromatic hydrocarbon (PAH) formation of iso-Butylbenzene and tert-Butylbenzene. The dominant decomposition reactions of iso-Butylbenzene and tert-Butylbenzene under pyrolysis conditions are benzylic C C bond dissociation reactions, while the major products in pyrolysis process are produced by β-scission reactions of primary radical products. Fuel-specific pathways are found to strongly affect the formation of PAHs, especially for indene, naphthalene and phenanthrene. Fuel isomeric effects on the pyrolysis of four Butylbenzene isomers were also analyzed with special concerns on the fuel decomposition and PAH formation processes. Different sidechain structures result in different distributions of major products, while different formation pathways and concentrations of precursors lead to different formation tendency of typical PAHs.
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Experimental and kinetic modeling investigation on sec-Butylbenzene combustion: Flow reactor pyrolysis and laminar flame propagation at various pressures
Combustion and Flame, 2020Co-Authors: Yan Zhang, Bowen Mei, Xiaoyuan Zhang, Chuangchuang Cao, Wenhao Yuan, Jiuzhong YangAbstract:Abstract This work reports the investigation on pyrolysis and laminar flame propagation of sec-Butylbenzene. The pyrolysis experiments were performed in a flow reactor using synchrotron vacuum ultraviolet photoionization mass spectrometry from 780 to 1166 K at 0.04 and 1 atm. The pyrolysis products were identified and their mole fraction profiles versus the heating temperature were evaluated. The laminar burning velocities of sec-Butylbenzene/air mixtures were measured at the initial temperature of 423 K and initial pressures of 1–10 atm in a high-pressure constant-volume cylindrical combustion vessel with the equivalence ratio from 0.7 to 1.5. Furthermore, a kinetic model was developed to predict the pyrolysis and laminar flame propagation of sec‑Butylbenzene. Validation of the present model was performed against the new experimental data in this work. Rate of production analysis and sensitivity analysis were performed to provide insight into the chemistry in fuel decomposition and polycyclic aromatic hydrocarbons (PAHs) formation. In the flow reactor pyrolysis, the consumption of sec‑Butylbenzene is mainly controlled by the unimolecular decomposition reactions and H-atom abstraction reactions at both low and atmospheric pressures. Fuel specific pathways through propenylbenzene and α-methylstyrene become the dominant formation pathways of indene and naphthalene. In the laminar flame propagation, the laminar burning velocity of sec‑Butylbenzene is sensitive to the reactions of both small species and fuel-relevant intermediates under all investigated conditions. In particular, the pyrolysis reactions in the fuel sub-mechanism play inhibition effects on the laminar flame propagation of sec‑Butylbenzene under rich conditions. The laminar burning velocity of sec‑Butylbenzene is also compared with benzene, toluene and ethylbenzene under same initial conditions. Both the thermodynamic and kinetic effects are responsible for the difference in laminar burning velocities of these aromatic fuels.
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pyrolysis of n Butylbenzene at various pressures influence of long side chain structure on alkylbenzene pyrolysis
Energy & Fuels, 2017Co-Authors: Yan Zhang, Chuangchuang Cao, Jiuzhong Yang, Wenhao Yuan, Xiaoyuan Yang, Tzuping Huang, Yinyu LeeAbstract:This work investigates the pyrolysis of n-Butylbenzene, which widely exists in transportation fuels and their surrogate mixtures. Both reactive and stable pyrolysis products were comprehensively detected with synchrotron vacuum ultraviolet photoionization mass spectrometry. Their mole fractions versus temperature were also evaluated at 30, 150, and 760 Torr. A kinetic model of n-Butylbenzene pyrolysis was developed, and new data were used to validate the model. On the basis of the modeling analysis, the benzylic C–C bond dissociation that forms the benzyl radical and the propyl radical was found to be a key decomposition reaction of n-Butylbenzene at all investigated pressures, whereas H abstraction provided increasing contributions with increasing pressure. Compared with small alkylbenzenes, such as toluene and ethylbenzene, n-Butylbenzene demonstrates different pyrolysis characteristics and chemistry because of the existence of its long alkyl side chain. n-Butylbenzene has a higher pyrolysis reactivity ...
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experimental and kinetic modeling study of premixed n Butylbenzene flames
Proceedings of the Combustion Institute, 2017Co-Authors: Wenhao Yuan, Yan Zhang, Zhandong Wang, Yizun Wang, Long Zhao, Zhongyue ZhouAbstract:Abstract Laminar premixed n -Butylbenzene/O 2 /Ar flames are studied at low pressure (4.0 kPa) and three equivalence ratios ( ϕ = 0.75, 1.0, and 1.79) using synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). A detailed n -Butylbenzene mechanism is developed to describe the decomposition of n -Butylbenzene in flames as well as the growth of polycyclic aromatic hydrocarbon (PAH) species. The analysis results show that n -Butylbenzene is mainly consumed by H-atom abstraction reactions under the investigated conditions. As the equivalence ratio increases, the contribution of benzylic C C bond dissociation reaction increases. Unsaturated phenylalkenes and phenyldialkenes formed from the decomposition of fuel radicals are demonstrated to be the main source of formation of indene and naphthalene in n -Butylbenzene flames, especially in the lean flame. As the length of the alkyl-chain increases, the combustion of the alkylbenzene produces more unsaturated phenylalkenes and phenyldialkenes, which in turn enhances the production of indene and naphthalene, as well as the total concentration of PAHs. The model was further validated on the premixed and diffusion flame data of n -Butylbenzene reported in the literature.
Ralf I. Kaiser - One of the best experts on this subject based on the ideXlab platform.
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Computational Study on the Unimolecular Decomposition of JP-8 Jet Fuel Surrogates III: Butylbenzene Isomers (n-, s-, and t-C14H10)
The journal of physical chemistry. A, 2018Co-Authors: Daniel Belisario-lara, Alexander M. Mebel, Ralf I. KaiserAbstract:Ab initio G3(CCSD,MP2)//B3LYP/6-311G(d,p) calculations of potential energy surfaces have been carried out to unravel the mechanism of the initial stages of pyrolysis of three C10H14 isomers: n-, s-, and t-Butylbenzenes. The computed energy and molecular parameters have been utilized in RRKM-master equation calculations to predict temperature- and pressure-dependent rate constants and product branching ratios for the primary unimolecular decomposition of these molecules and for the secondary decomposition of their radical fragments. The results showed that the primary dissociation of n-Butylbenzene produces mostly benzyl (C7H7) + propyl (C3H7) and 1-phenyl-2-ethyl (C6H5C2H4) + ethyl (C2H5), with their relative yields strongly dependent on temperature and pressure, together with a minor amount of 1-phenyl-prop-3-yl (C9H11) + methyl (CH3). Secondary decomposition reactions that are anticipated to occur on a nanosecond scale under typical combustion conditions split propyl (C3H7) into ethylene (C2H4) + methyl (CH3), ethyl (C2H5) into ethylene (C2H4) + hydrogen (H), 1-phenyl-2-ethyl (C6H5C2H4) into mostly styrene (C8H8) + hydrogen (H) and to a lesser extent phenyl (C6H5) + ethylene (C2H4), and 1-phenyl-prop-3-yl (C9H11) into predominantly benzyl (C7H7) + ethylene (C2H4). The primary decomposition of s-Butylbenzene is predicted to produce 1-phenyl-1-ethyl (C6H5CHCH3) + ethyl (C2H5) and a minor amount of 1-phenyl-prop-1-yl (C9H11) + methyl (CH3), and then 1-phenyl-1-ethyl (C6H5CHCH3) and 1-phenyl-prop-1-yl (C9H11) rapidly dissociate to styrene (C8H8) + hydrogen (H) and styrene (C8H8) + methyl (CH3), respectively. t-Butylbenzene decomposes nearly exclusively to 2-phenyl-prop-2-yl (C9H11) + methyl (CH3), and further, 2-phenyl-prop-2-yl (C9H11) rapidly eliminates a hydrogen atom to form 2-phenylpropene (C9H10). If hydrogen atoms or other reactive radicals are available to make a direct hydrogen-atom abstraction from Butylbenzenes possible, the C10H13 radicals (1-phenyl-but-1-yl, 2-phenyl-but-2-yl, and t-phenyl-isobutyl) can be formed as the primary products from n-, s-, and t-Butylbenzene, respectively. The secondary decomposition of 1-phenyl-but-1-yl leads to styrene (C8H8) + ethyl (C2H5), whereas 2-phenyl-but-2-yl and t-phenyl-isobutyl dissociate to 2-phenylpropene (C9H10) + methyl (CH3). Thus, the three Butylbenzene isomers produce distinct but overlapping nascent pyrolysis fragments, which likely affect the successive oxidation mechanism and combustion kinetics of these JP-8 fuel components. Temperature- and pressure-dependent rate constants generated for the initial stages of pyrolysis of Butylbenzenes are recommended for kinetic modeling.
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computational study on the unimolecular decomposition of jp 8 jet fuel surrogates iii Butylbenzene isomers n s and t c14h10
Journal of Physical Chemistry A, 2018Co-Authors: Daniel Belisariolara, Alexander M. Mebel, Ralf I. KaiserAbstract:Ab initio G3(CCSD,MP2)//B3LYP/6-311G(d,p) calculations of potential energy surfaces have been carried out to unravel the mechanism of the initial stages of pyrolysis of three C10H14 isomers: n-, s-, and t-Butylbenzenes. The computed energy and molecular parameters have been utilized in RRKM-master equation calculations to predict temperature- and pressure-dependent rate constants and product branching ratios for the primary unimolecular decomposition of these molecules and for the secondary decomposition of their radical fragments. The results showed that the primary dissociation of n-Butylbenzene produces mostly benzyl (C7H7) + propyl (C3H7) and 1-phenyl-2-ethyl (C6H5C2H4) + ethyl (C2H5), with their relative yields strongly dependent on temperature and pressure, together with a minor amount of 1-phenyl-prop-3-yl (C9H11) + methyl (CH3). Secondary decomposition reactions that are anticipated to occur on a nanosecond scale under typical combustion conditions split propyl (C3H7) into ethylene (C2H4) + methyl...
