Article
Chemistry, Physical
Srivathsan P. Sundar, Saddam Al-Hammadi, Zhonghua Ren, Gabriel da Silva
Summary: Quantum chemistry and statistical reaction rate theory calculations were used to investigate the products and kinetics of indenyl radical decomposition, identifying three competitive product sets. The main products of indenyl decomposition were found to be o-benzyne (o-C6H4) + propargyl (C3H3), with some additional byproducts not considered in previous theoretical kinetics investigations.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Thermodynamics
Subhadarsi Nayak, Balla Rajakumar
Summary: Thermal decomposition of Methyl-2-methylbutanoate (M2MB) was investigated in a single pulse shock tube (SPST) using reflected shock waves in the temperature range of 959-1392 K. Gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS) were used to analyze the post shock mixtures quantitatively and qualitatively. The major products observed during the thermal decomposition included Methane, Ethane, Ethylene, Methanol, Propene, and Methyl acrylate. Minor products of oxygenated compounds were also found. The kinetics of the decomposition reactions were calculated using RRKM/ME and a reaction scheme involving 42 species and 61 elementary reactions was proposed.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Pin Liu, Xiongmin Liu, Tei Saburi, Shiro Kubota, Pinxian Huang, Yuji Wada
Summary: This paper investigated the thermal stability and safety of DMF oxidation using an Accelerated Rate Calorimeter (ARC). The results showed that DMF does not react under a nitrogen atmosphere, but undergoes oxidation in an oxygen atmosphere with an onset temperature of 323.49 K and an activation energy of 172.35 kJ/mol. The oxidation products were analyzed by gas chromatography - mass spectrometry, and a simple three-step mechanism of DMF oxidation was proposed.
THERMOCHIMICA ACTA
(2021)
Article
Energy & Fuels
Bo Wang, Ya-Feng Huang, Peng-Fei Wang, Xiao-Jie Liu, Chang Yu, Wei-Guang Li, Xiao-Feng Wang, Xiong-Min Liu
Summary: The thermal oxidation reaction of 2,5-dimethylfuran proceeds through initial oxygen absorption followed by exothermic self-accelerating oxidation, generating high levels of peroxide. The decomposition of peroxides could lead to radical oxidation, resulting in a high level of residue formation with high thermal hazard. Thermal decomposition of the peroxide products could give rise to thermal runaway and possibly detonation.
Article
Chemistry, Physical
Malte Doentgen, Alina Wildenberg, K. Alexander Heufer
Summary: The thermodynamic, transport, bond dissociation, and thermal decomposition properties of methyl-, ethyl-, and dimethyl-substituted dioxolanes have been systematically studied, revealing the effect of substituent position on the barrier heights for H-atom migration.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Thermodynamics
Qifeng Hou, Wang Li, Jiabin Huang, Changyang Wang, Jiuzhong Yang, Zeynep Serinyel, Guillaume Dayma, William J. Pitz, Long Zhao, Feng Zhang
Summary: This study investigates the thermal decomposition mechanism of pyrrolidine and provides rate coefficients for various reaction channels. The results show that the stabilization of cyc-C2H5N is favored over other channels.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Dounia Omar, Thomas Jaravel, Olivier Vermorel
Summary: This paper provides a theoretical basis for the application of alkali metal compounds as fire suppressants. It discusses the manufacturing of efficient powders and the selection of inhibitor candidates for reactive mixtures. Analytical expressions are derived to determine the decomposition position of inhibiting particles and their influence on flame and powder properties. The validity of the analytical derivations is tested through numerical simulations, and a model is proposed to predict the critical particle size for effective inhibition.
COMBUSTION AND FLAME
(2022)
Article
Chemistry, Physical
Fangjian Shang, Ting Wang, Yinhua Ma, Meiheng Lv
Summary: In this study, the initial and subsequent decomposition mechanisms of MTNI were investigated using DFT calculations. It was found that during the nitro isomerization, NO was directly produced instead of a stable loose intermediate -ONO isomer. In the process of H transfer, a synergistic reaction occurs under certain conditions, which is determined by the orientation of the -OH group. Compared to the common decomposition mechanism, less energy is needed in this reaction.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
Malte Doentgen, Alina Wildenberg, K. Alexander Heufer
Summary: This study provides systematic information on the properties of methyl, ethyl, and dimethyl-substituted dioxolanes, which fills the lack of information on their thermodynamic, transport, bond dissociation, and thermal decomposition properties. It is found that while substituents have minimal effect on bond dissociation energies, they clearly affect the barrier heights for H-atom migration.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Thermodynamics
A. Justino, A. C. S. Carvalho, L. G. de Vasconcelos, B. M. Gai, A. L. Stein, A. B. Siqueira
Summary: Tryptophan is a secondary metabolite derived from the shikimate pathway and plays a key role in the synthesis of alkaloids in some animals and plants. It is widely utilized in drug synthesis and exhibits various biological functions in mammalian metabolism. The thermal behavior and decomposition mechanism of the tryptophan methyl ester compound were investigated using thermoanalytical techniques, with intermediate products characterized and optimized through molecular modeling.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Polymer Science
Ning Li, Shicheng Yang, Zhujun Huang, Xiangcheng Pan
Summary: A novel radical strategy has been developed to remove heteroatom chain ends in polymers synthesized from various CRP approaches, improving their thermal and UV stability. This method is scalable and effective in both organic and aqueous conditions, benefitting from the use of stoichiometric N-heterocyclic carbene borane (NHC-BH3) without additional catalysts or hydrogen sources.
Article
Thermodynamics
Jihe Zhao, Jiwen Hu, Yonglu Dong, Daguang He, Xuefeng Gui, Xiaohua Cui, Yuanyuan Tu, Shudong Lin
Summary: The thermal runaway characteristics of AMBN were investigated using DSC, ARC, and GC-MS. The study determined Ton, Q, and Delta T-ad, which are important for the safety of storage and transportation. Thermokinetic analyses were performed to predict SADT, T-NR, and T-C,T-I. The flammable components in the pyrolysis products of AMBN were also studied, especially when mixed with incompatible materials, to predict the risk of thermal runaway.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Chemistry, Physical
Mohanapriya Subramani, Akilan Rajamani, Ramasamy Shankar
Summary: Isoprene, a prominent non-methane hydrocarbon in the lower troposphere, reacts with chlorine radicals at various positions, with the electrophilic addition at the terminal carbon atom playing a dominant role. The subsequent reactions of Cl-isoprene adduct radicals contribute to ozone layer development during daytime. The calculated rate coefficients and branching ratios provide insight into the atmospheric lifetime of isoprene in marine environments.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Fernando Nainggolan
Summary: The molecular structure properties of the cis and trans form of azobenzene molecule from HMNA were investigated using the DFT method. The trans-HMNA has a molecular size of 9.0 t1 and exhibits a p → p* type electronic transition driven by an azo bond. The cis-HMNA has a molecular size of 6.6 t1 and exhibits an n → p* type electronic transition with respect to the non-bonding electrons of oxygen and nitrogen atoms. The study suggests that the mechanism pathway of HMNA from trans to cis form is feasible to undergo at the inversion pathway in the ground state.
JOURNAL OF MOLECULAR MODELING
(2023)
Article
Chemistry, Multidisciplinary
Leila Vatannavaz, Seyyed Javad Sabounchei, Asieh Sedghi, Roya Karamian, Seyed Hamed Moazzami Farida, Nosrat Rahmani
Summary: New complexes of 5-methyl-5-(4-nitrophenyl)-hydantoin with HgX2 were successfully synthesized and characterized, showing a monodentate coordination mode to the metal center and X-bridged dimer structures. The complexes exhibited higher cytotoxicity and antioxidant potency compared to standard ascorbic acid, and theoretical studies revealed the nature of donor-acceptor bonds between the ligand and Hg fragments in the system.
JOURNAL OF THE CHINESE CHEMICAL SOCIETY
(2021)
Article
Thermodynamics
J. Honorien, R. Fournet, P. -A. Glaude, B. Sirjean
Summary: Urea is commonly used in post-combustion processes for NOx reduction, where its decomposition can lead to the formation of NH3 as the reducing agent. However, undesirable pyrolysis by-products can also be produced, especially under suboptimal temperature and pressure conditions. This study proposed a gas phase kinetic model for urea pyrolysis, revealing a new mechanism for the formation of isocyanuric acid through carbamimidic acid and biuret intermediates. The proposed mechanism was validated through experimental conditions and simulations in both gas phase and pseudo condensed phase systems.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Thermodynamics
L. Giarracca, F. Isufaj, J. -C. Lizardo-Huerta, R. Fournet, P. -A. Glaude, B. Sirjean
Summary: This study systematically investigated the ignition delays of cyclohexane, cyclohexene, 1,3-cyclohexadiene, and 1,4cyclohexadiene using experiments and kinetic modeling. The results showed that cyclohexene had the highest reactivity, followed by 14-CHD, cyclohexane, and benzene similar to 13-CHD. Pericyclic reactions were found to play a major role in the initial decomposition of the unsaturated fuels.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Thermodynamics
J. -C. Lizardo-Huerta, B. Sirjean, L. Verdier, R. Fournet, P. -A. Glaude
Summary: Understanding the thermal decomposition chemistry of chemical warfare nerve agents is limited by the scarcity of kinetic data. A comprehensive kinetic model was developed for the decomposition of sarin and simulants, with validation against experimental data. Results show that peri-cyclic eliminations are the primary decomposition pathway for phosphorus compounds studied, with bond-breaking or H-atom abstraction negligible even at high temperatures.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Chemistry, Physical
M. D. Le, V Warth, L. Giarracca, E. Moine, R. Bounaceur, R. Privat, J-N Jaubert, R. Fournet, P-A Glaude, B. Sirjean
Summary: This study presents new methods for generating data for liquid-phase oxidation mechanisms and develops a detailed chemical kinetic model for n-butane autoxidation. The model is validated against experimental data and suggests a 1:1 product ratio in n-butane solvent for certain reactions.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Article
Thermodynamics
Francisco Carlos Paes, Romain Privat, Jean-Noel Jaubert, Baptiste Sirjean
Summary: The computation of solvation energies is widely used in various fields and requires accurate prediction, temperature dependency consideration, and fast and robust thermodynamic models. This study compared different models for solvation energy calculation and found that all models can provide accurate predictions for simple mixtures without hydrogen bonding. For complex mixtures, COSMO-RS and the PSRK model showed the best performance.
FLUID PHASE EQUILIBRIA
(2022)
Article
Chemistry, Applied
Minh Duy, Mickael Matrat, Arij Ben Amara, Fabrice Foucher, Bruno Moreau, Yi Yu, Matieyendou Goussougli, Rene Fournet, Baptiste Sirjean, Pierre-Alexandre Glaude
Summary: The inhibiting effect of the phenolic antioxidant 2,4-xylenol, produced from biomass, on fuel ageing and combustion was studied. The experiments showed that 2,4-xylenol exhibits remarkable antioxidant effect in liquid phase without affecting the main combustion characteristics of the fuel.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Chemistry, Physical
Jonathan Honorien, Rene Fournet, Pierre-Alexandre Glaude, Baptiste Sirjean
Summary: An extensive theoretical study of the thermal decomposition of alkyl- and phenylureas has been conducted using electronic structure calculations and reaction rate theories. The study determined the enthalpies of formation and bond dissociation energies, and computed the potential energy surfaces for the decomposition pathways of these compounds. The study found that these compounds decompose predominantly through four-center pericyclic reactions, producing substituted isocyanates and amines. A new reaction rate rule was proposed based on the characteristics of the transferred H atom and the N-atom acceptor. Applications of the study in the chemical industry were also presented.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Thermodynamics
Fabiola Citrangolo Destro, Rene Fournet, Valerie Warth, Pierre-Alexandre Glaude, Baptiste Sirjean
Summary: The accurate and high-throughput generation of kinetic data for combustion detailed chemical kinetic models remains challenging. This study questions the limits of the rate rule approach for isomerization reaction classes and proposes a new approach using electronic structure calculations and reaction rate theories. The results suggest that a single rate rule is not feasible for reactions with different degrees of branching. A new method of tabulating model transition states and using methyl groups as representatives is proposed as a high-throughput and high-accuracy alternative to on-the-fly calculations of kinetic parameters.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Energy & Fuels
M. D. Le, Z. El Sayah, R. Benrabah, V. Warth, P. -A. Glaude, R. Privat, R. Fournet, B. Sirjean
Summary: The thermal oxidation stability of liquid jet fuels is a major challenge for the aviation industry. This study focuses on the autoxidation of n-decane, a component of jet fuel surrogates, investigating it through both experimental and numerical approaches. The results reveal the quantitative measures of oxidation stability, such as induction periods and hydroperoxides content. A physical model and a kinetic model are developed to simulate the oxidation process and validate the model through experimental data.
Article
Thermodynamics
Jonathan Honorien, Baptiste Sirjean, Pierre-Alexandre Glaude, Rene Fournet
Summary: A detailed mechanism for the combustion of methyl isocyanate is proposed for the first time. The mechanism contains 130 reactions and was merged with the reaction base proposed by Glarborg et al. Experimental data related to the pyrolysis of methyl isocyanate were simulated in a closed reactor and a good agreement was observed. Additionally, the auto-ignition temperature (Ti gn) of methyl isocyanate was calculated based on the standard ASTME659-78 test and was close to the experimental value. Flow rate and sensitivity analysis were performed to highlight the main reaction pathways.
COMBUSTION AND FLAME
(2023)
Article
Chemistry, Physical
M. Goussougli, B. Sirjean, P-A Glaude, R. Fournet
Summary: This study proposes a theoretical investigation on the thermal decomposition of beta-1,4-xylan, elaborating a mechanism based on unimolecular concerted reactions. The study reveals that the main reaction pathways can be modeled by reactions involving specific fragments, and predicts important species observed during the pyrolysis of xylan. Additionally, the study demonstrates the challenges in explaining the significant formation of specific species like furfural through unimolecular homogeneous gas phase reactions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)