scholarly journals Impacts of Thermal Inertia Factor on Adiabatic Decomposition of 40% Mass Content DCP in Ethyl Benzene

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Xiaojuan Wu ◽  
Liping Chen ◽  
Guoning Rao ◽  
Wanghua Chen ◽  
Ruili Yin
Keyword(s):  
Thermal Decomposition ◽  
Thermal Inertia ◽  
Decomposition Reaction ◽  
Exothermic Peak ◽  
Ethyl Benzene ◽  
Mass Content ◽  
Experimental Conditions ◽  
Initial Decomposition Temperature ◽  
Thermal Hazards ◽  
Exponential Factor

To reduce the fire and explosion accident of dicumyl peroxide (DCP) in experiment and production, the thermal hazards of DCP and 40% mass content DCP in ethyl benzene (40% DCP) have been studied by the differential scanning calorimeter (DSC) and the accelerating rate calorimeter (ARC) in this paper. DSC experiment showed that ethyl benzene has no effect on the characteristic parameters of thermal decomposition of DCP, such as the temperature of the exothermic peak (Tpeak) and the decomposition energy (Ea), and the thermal decomposition reaction of 40% DCP followed the one-step reaction principle. ARC experiment showed that with the increase of inertia factor (Φ), the measured initial decomposition temperature (Ton) would be higher and the caculated Ea and pre-exponential factor (A) would be greater. It was also proved that after modification of Φ, TD24 was relatively consistent near Ton, but different at higher temperatures. Fisher's correction method was used to verify the necessity of consistency between experimental conditions and prediction conditions.

Carbonization Regime Process of Coal Tar Refined Soft Pitch

2013 ◽  
Vol 750-752 ◽  
pp. 1689-1695 ◽  
Author(s):  
Li Juan Gao ◽  
Xue Fei Zhao ◽  
Shi Quan Lai ◽  
Yan Xial Liu
Keyword(s):  
Thermal Decomposition ◽  
Coal Tar ◽  
Decomposition Reaction ◽  
Differential Method ◽  
Polymerization Reaction ◽  
Condensation Polymerization ◽  
Exponential Factor ◽  
Thermogravimetric Analyzer ◽  
Two Temperature ◽  
Differential Thermogravimetry

The thermal behavior of coal tar refined soft pitch (CTRSP) was investigated by using polarizing microscope with heating stage and thermogravimetric analyzer. The phenomena of carbonization regime process of CTRSP were observed directly in the micro-picture taken online. The results showed that the carbonization thermal dynamic process of CTRSP is divided into several typical stages. At 30-250°C,there is small molecular evaporation; at 250-390 °C,there is thermal decomposition and small molecular evaporation; at 390-480°C,there is the condensation of small molecules and radicals into macromolecules and directional arrangement generating small spheres; at 480-520°C,there is the coking stage; at 520-560°C, there is the semicokes dehydrogenation and shrinkage. The spherules are formed at about 390°C. The growth process of the spherules is divided into several stages: absorption optical isotropic matrix asphalt to grow, two spherule collision fusion and growth, finally (at 480-520°C) due to gravity is greater than surface tension small spheroid disintegration deformation and became fibrillar semicoke (at 520-560 °C). Thermogravimetric (TG) - differential thermogravimetry (DTG) curve are treated by Freeman-Carrolls non isothermal differential method, coal tar soft pitchs first-order reaction is from 253°C to 325°C, from 370 °C to 413°C two temperature stages, activation energy is 28.575 kJ/mol and 60.210 kJ/mol, pre-exponential factor is 2.328×106and 1.4833×107, respectively. The microscopic picture recording was consistent with thermal heavy kinetic equation and the results confirmed that the chief of thermal decomposition reaction is operated from 253 °C to 325 °C, the most of condensation polymerization reaction is operated from 370 °C to 413 °C.

scholarly journals DETERMINATION OF THERMAL DECOMPOSITION REACTION CHARACTERISTICS (A, E) OF WOOD SAMPLES FOR FIRE DYNAMICS SIMULATION

2013 ◽  
Vol 1 (2) ◽  
pp. 13-24 ◽  
Author(s):  
László Beda ◽  
Attila Szabó
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Decomposition Reaction ◽  
Dynamics Simulation ◽  
Fire Dynamics ◽  
Exponential Factor ◽  
Decomposition Reactions ◽  
Reaction Characteristics ◽  
Reaction Activation Energy

Abstract The purpose of this work is to determine the pre-exponential factor (A) and the reaction activation energy (E) of decomposition reactions that are needed for Fire Dynamics Simulation (FDS) using Derivatograph Q 1500D. The materials we investigated: Pine Wood Board (PWB), Multilayered Parquet Board (MPB), Particleboard Core (PBC) and Oriented Standard Board (OSB).

Kinetic Investigation of Thermal Decomposition Reactions of Podophyllic Acid and Picropodophyllic Acid

2011 ◽  
Vol 391-392 ◽  
pp. 1230-1234
Author(s):  
Pu Hong Wen
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Model ◽  
Kinetic Parameters ◽  
Decomposition Reaction ◽  
Exponential Factor ◽  
Decomposition Reactions ◽  
Integral Forms ◽  
Free Energy Of Activation ◽  
Entropy Of Activation ◽  
Temperature Programmed

The thermal behavior and thermal decomposition kinetic parameters of podophyllic acid and picropodophyllic acid in a temperature-programmed mode have been investigated by means of DSC and TG-DTG. The kinetic model functions in differential and integral forms of the thermal decomposition reactions mentioned above for leading stage were established. The kinetic parameters of the apparent activation energy Ea and per-exponential factor A were obtained from analysis of the TG-DTG curves by integral and differential methods. The most probable kinetic model function of the decomposition reaction in differential form was 2/3•α-1/2 for podophyllic acid and 1/2• (1-α)-1 for picropodophyllic acid. The values of Ea indicated that the reactivity of picropodophyllic acid was highter than that of podophyllic acid in the thermal decomposition reaction. The values of the entropy of activation ΔS≠, enthalpy of activation ΔH≠ and free energy of activation ΔG≠ of the reactions were estimated.

Thermal hazards evaluation of insensitive JEOL-1 polymer bonded explosive

2019 ◽  
Vol 9 (6) ◽  
pp. 596-603
Author(s):  
Rui Yu ◽  
Shusen Chen ◽  
Guanchao Lan ◽  
Jing Li ◽  
Chenglong Wei ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Thermal Decomposition ◽  
Ignition Time ◽  
Decomposition Temperature ◽  
Liquid Pool ◽  
Transient Temperature ◽  
Response Level ◽  
Thermal Hazards ◽  
Exponential Factor ◽  
Thermal Stimuli

Thermal stimuli is one of the major external stiumuli resulting from an overheated explosion of a munition. In order to evaluate the influence of external thermal stiumuli on the thermal hazards of JEOL-1 (32 wt% octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), 32 wt% 3-nitro-1,2,4-triazole-5-one (NTO), 28 wt% Al and 8 wt% binder system) explosive, accelerating rate calorimeter (ARC) is used to study the adiabatic thermal decomposition properties of JEOL-1 molding powders, and the slow cook-off properties of JEOL-1 are studied by experimental test and numerical simulation. The activation energy Ea, pre-exponential factor A, mechanism function f(α) and self-accelerating decomposition temperature (SADT) of adiabatic thermal decomposition of JEOL-1 molding powders are obtained according to ARC results. The response level of JEOL-1 polymer bonded explosive (PBX) columns exposed to an engulfing liquid pool fire is examined by the slow cook-off test. The ignition location, ignition temperature, ignition time and the transient temperature distributions of JEOL-1 PBX columns during the slow cook-off are obtained by numerical simulation. It can be concluded from this study that JEOL-1 is a low vulnerable explosive with high thermal safety.

scholarly journals Study on Thermal Decomposition Behavior, Gaseous Products, and Kinetic Analysis of Bis-(Dimethylglyoximato) Nickel(II) Complex Using TG-DSC-FTIR-MS Technique

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 331
Author(s):  
Ergang Yao ◽  
Siyu Xu ◽  
Fengqi Zhao ◽  
Taizhong Huang ◽  
Haijian Li ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Analysis ◽  
Evolved Gas Analysis ◽  
Decomposition Reaction ◽  
Exothermic Peak ◽  
Gas Analysis ◽  
Gaseous Products ◽  
Random Nucleation ◽  
Thermal Decomposition Behavior ◽  
Decomposition Behavior

The fiber-like bis-(dimethylglyoximato) nickel(II) complex, Ni(DMG)2 was successfully synthesized. The obtained samples were characterized by SEM-EDS, FT-IR, XRD, and XPS. The TG-DSC-FTIR-MS coupling technique was used to characterize the thermal decomposition behavior and evolved gas analysis of Ni(DMG)2. The non-isothermal decomposition reaction kinetic parameters were obtained by both combined kinetic analysis and isoconversional Vyazovkin methods. It was found that Ni(DMG)2 begins to decompose at around 280 °C, and a sharp exothermic peak is observed in the DSC curve at about 308.2 °C at a heating rate of 10 °C·min−1. The main gaseous products are H2O, NH3, N2O, CO, and HCN, and the content of H2O is significantly higher than that of the others. The activation energy obtained by the combined kinetic analysis method is 170.61 ± 0.65 kJ·mol−1. The decomposition process can be described by the random nucleation and growth of the nuclei model. However, it was challenging to attempt to evaluate the reaction mechanism precisely by one ideal kinetic model.

Kinetic Investigation of Thermal Decomposition Reactions of 4'-Demethypodophyllotoxin and Podophyllotoxin

2013 ◽  
Vol 800 ◽  
pp. 517-521
Author(s):  
Pu Hong Wen
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Model ◽  
Kinetic Parameters ◽  
Decomposition Reaction ◽  
Exponential Factor ◽  
Decomposition Reactions ◽  
Integral Forms ◽  
Free Energy Of Activation ◽  
Entropy Of Activation ◽  
Temperature Programmed

The thermal behavior and thermal decomposition kinetic parameters of podophyllotoxin (PPT) and 4-demethypodophyllotoxin (DMPPT) in a temperature-programmed mode have been investigated by means of DSC and TG-DTG. The kinetic model functions in differential and integral forms of the thermal decomposition reactions mentioned above for leading stage were established. The kinetic parameters of the apparent activation energy Ea and per-exponential factor A were obtained from analysis of the TG-DTG curves by integral and differential methods. The most probable kinetic model function of both decomposition reactions in differential form was (1-α) 2. The values of Ea indicated that the reactivity of PPT was higher than that of DMPPT in the thermal decomposition reaction. The values of the entropy of activation ΔS≠, enthalpy of activation ΔH≠ and free energy of activation ΔG≠ of the reactions were estimated.

Kinetic Investigation of Thermal Decomposition Reaction of Ethane-1,2-Diamine Copper(II) Chloride, C2H8N2CuCl2

2014 ◽  
Vol 665 ◽  
pp. 255-259
Author(s):  
Pu Hong Wen
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Decomposition Reaction ◽  
Kinetic Investigation ◽  
Thermal Decomposition Process ◽  
Exponential Factor ◽  
Free Energy Of Activation ◽  
Enthalpy Of Activation ◽  
Entropy Of Activation ◽  
Temperature Programmed

:The thermal behavior and thermal decomposition kinetic parameters of ethane-1,2-diamine copper (II) chloride (EDCC) in a temperature-programmed mode have been investigated by mean of TG-DTG. There are four stages in the thermal decomposition process. The kinetic parameters of the apparent activation energyEa(130.2, 143.6 and 158.9 KJ·mol–1) and per-exponential factorA(1011.80, 1012.18and 1011.83s–1) in II, III and IV stages were obtained from analysis of the TG-DTG curves by Kissinger method. The values ofEaindicated that the difficulty coefficient of pyrolysis in II, III and IV stages was increased in the order: II < III < IV. The values of the entropy of activation ΔS≠, enthalpy of activation ΔH≠and free energy of activation ΔG≠of the reaction were estimated.

The Investigation of Thermal Degradation and Combustion of Ultra-High Molecular Weight with the Addition of Triphenylphosphate

2011 ◽  
Vol 6 (4) ◽  
pp. 125-134
Author(s):  
Munko Gonchikzhapov ◽  
Aleksandr Paletsky ◽  
Oleg Korobeinichev
Keyword(s):  
Molecular Weight ◽  
Thermal Decomposition ◽  
High Molecular Weight ◽  
Decomposition Reaction ◽  
Mass Spectrometric ◽  
Exponential Factor ◽  
Gaseous Products ◽  
Dynamic Mass ◽  
Kinetics Of ◽  
Ultra High Molecular Weight

The influence of triphenylphosphate (TPP) on ultra-high molecular weight polyethylene (UHMWPE) gasification under thermal decomposition was studied. The temperature at which formation of gaseous products begins was measured for pure and TPP-doped UHMWPE. The kinetics of thermal decomposition of pure UHMWPE and mixed with TPP at high rates of heating (~ 100–200 K/s) was studied. The activation energy and the pre-exponential factor of the rate constant of the decomposition reaction were determined for pure and TPP-doped UHMWPE. The time ignition of the samples in air at their heating from the top surface to a temperature of 350 and 400 С was determined. The studies were conducted using dynamic mass-spectrometric thermal analysis (DMSTA) microthermocouples and visualization of process

Thermodynamic and Kinetic Study on Lithium Bis(Oxalato)Borate Thermal Decomposition Reaction

2012 ◽  
Vol 455-456 ◽  
pp. 947-953 ◽  
Author(s):  
Ping Ping ◽  
Qing Song Wang ◽  
Jin Hua Sun ◽  
Chun Hua Chen
Keyword(s):  
Thermal Decomposition ◽  
Lithium Ion Batteries ◽  
Lithium Salt ◽  
Lithium Ion ◽  
Decomposition Reaction ◽  
Reaction Heat ◽  
Exponential Factor ◽  
Battery Materials ◽  
Fire And Explosion ◽  
C80 Calorimeter

.Reported accidents such as fire and explosion on account of lithium-ion batteries remind us it is important to understand the thermal stability of battery materials. Lithium salt plays an important role in the safety of lithium ion batteries. Thermal decomposition reaction of a lithium salt-lithium bis (oxalato) borate (LiBOB) was studied using C80 calorimeter under argon atmosphere. The samples were heated at a 0.2 K min-1 heating rate from ambient temperature to 573 K in single scanning rate experiments, or at different constant temperatures (528 K, 533 K, 538 K, 543 K) in isothermal experiments. The results show that LiBOB decomposes near 433 K, and its decomposition reaction order was calculated to be n=1.43. In addition, thermodynamic parameters and kinetic parameters were obtained. The reaction heat associated with LiBOB decomposition process is 197.33 J g-1, the activation energy and pre-exponential factor were calculated to be E=177.23 kJ mol-1 and A=6.51×106 s-1, respectively. Nomenclature

scholarly journals Isothermal Kinetic Analysis of the Thermal Decomposition of Wood Chips from an Apple Tree

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 195
Author(s):  
Ivan Vitázek ◽  
Martin Šotnar ◽  
Stella Hrehová ◽  
Kristína Darnadyová ◽  
Jan Mareček
Keyword(s):  
Thermal Decomposition ◽  
Apple Tree ◽  
Combustion Process ◽  
Reaction Model ◽  
Wood Chips ◽  
Small Scale ◽  
Exponential Factor ◽  
Air Atmosphere ◽  
First Order Chemical Reaction ◽  
Isothermal Kinetic

The thermal decomposition of wood chips from an apple tree is studied in a static air atmosphere under isothermal conditions. Based on the thermogravimetric analysis, the values of the apparent activation energy and pre-exponential factor are 34 ± 3 kJ mol−1 and 391 ± 2 min−1, respectively. These results have also shown that this process can be described by the rate of the first-order chemical reaction. This reaction model is valid only for a temperature range of 250–290 °C, mainly due to the lignin decomposition. The obtained results are used for kinetic prediction, which is compared with the measurement. The results show that the reaction is slower at higher values of degree of conversion, which is caused by the influence of the experimental condition. Nevertheless, the obtained kinetic parameters could be used for the optimization of the combustion process of wood chips in small-scale biomass boilers.

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