JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2021
·Vol. 147
·期 2
·1405-1419
·
IF 4.626
Zhao Xiao-Qiao,Wu Wen-Qian,Li Hua-bo,Chen Wang-Hua,Guo Zi-Chao,Chen Li-Ping
Adiabatic calorimetry is one of the main experimental methods to quantitatively study the thermal hazard in chemical process. There are two problems in adiabatic calorimetry: (1) identification of the reaction model is difficult; (2) the equilibrium of system and the temperature uniformity of sample will be broken under the rapid temperature rise rate, especially at lower thermal inertia. In this work, the heat-quench-heat method in adiabatic calorimetry was proposed to determine the reaction model and slow the reaction rate to evaluate kinetic parameters accurately. A criterion was proposed to identify the reaction model which states that the decomposition is an n-order reaction if T 0,stage1 < T 0,stage2 ; otherwise autocatalytic behavior was observed. Mathematical simulations have been conducted for n-order and autocatalytic decompositions. To further validate the method, it is applied to two representative substances: DTBP and CHP. The validity of this method has been verified by simulation and experiment results.
研究领域:
化学工程
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2019
·Vol. 141
·期 2
·783-796
·
IF 2.471
Ding Jiong,Yu Liming,Wang Xiaona,Xu Qiyue,Yang Suijun,Ye Shuliang,Jiang Juncheng
The accelerating rate calorimetry is a powerful tool for thermal hazard evaluation. However, the existing kinetics approaches ignore the fact that the thermal inertia is varying during the pseudo-adiabatic reaction because of the changing of the sample’s heat capacity and heat loss. To overcome this shortcoming, the expression of the thermal inertia is amended based on the heat balance and transfer in this article. The arithmetic product of the sample’s heat capacity and the amended thermal inertia is obtained by merging the kinetic results of the DSC and ARC data. Then, the data from the ARC are corrected and the more reasonable values of the kinetic parameters are computed based on the varying thermal inertia consideration. With the typical n -order and autocatalytic decomposition experiments under the different sample masses, the validity of the proposed kinetic approach is verified. Meanwhile, the hypotheses of the proposed approach are analyzed and discussed in the end of the article.
研究领域:
化学工程
·
安全科学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2019
·
IF 2.251
Jiong Ding,Liming Yu,Jichen Wang,Qiyue Xu,Suijun Yang,Shuliang Ye
The thermal inertia determination and correction are the significant steps in accelerating rate calorimetric based kinetics calculation and thermal hazard evaluation. However, the existing kinetics approaches based on the constant thermal inertia ignore the fact that the sample’s heat dissipation is varying during the pseudo-adiabatic reaction. To overcome this shortcoming, an amended thermal inertia expression is proposed and a symmetric dual-channel accelerating rate calorimeter is developed in this article. A novel kinetics approach is presented with the varying thermal inertia consideration based on the measured electrical power data. With the different mass percent DTBP/toluene solutions experiments, the validities and advantages of the proposed calorimetry and the corresponding thermal analysis method are verified. Meanwhile, the challenges in the engineering implementation of this proposed method are analyzed and discussed at the end of the article.
研究领域:
化学工程
·
热分析
✓ 已验证
产品关联
DOI
高影响因子
Journal of Chemistry
·
2020
·
IF 1.79
Xiaojuan Wu,Liping Chen,Guoning Rao,Wanghua Chen,Ruili Yin
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.
研究领域:
化学工程
·
安全科学
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
·
2022
·
IF 3.378
Suijun Yang,Jiong Ding,Xingci Zhang,Shuliang Ye,Zichao Guo,Wanghua Chen
Isoconversional method has been preliminarily applied in accelerating rate calorimetry (ARC) and achieved good results. However, it is a new subject and needs to be explored in depth. In this study, the Friedman and the Vyazovkin methods were applied to investigate the influences of thermal inertia on the activation energy estimation of the single-step reaction and autocatalytic reaction. The accuracy and adaptability of the two kinetic methods are compared, and the confidence intervals for activation energy estimated by the Friedman and the Vyazovkin methods are evaluated based on the corrected Student's distribution and F distribution. Finally, the validity of the simulation result is verified by the experiments. The results show that the sets of thermal inertia have different effects on the estimation of activation energy in single-step reaction and multi-step reaction, and the activation energies in multi-step reaction change obviously under different sets of thermal inertia. The thermal inertia increment of 0.03-0.5 and the Vyazovkin method are recommended. This study is helpful to promote the development of isoconversional methods applied for ARC data.
研究领域:
化学工程
·
热力学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）