Thermochimica Acta最新文献

Investigation on the effect of carbon powder structural characteristics derived from ethylene decomposition on powder explosion 乙烯分解产生的碳粉结构特征对粉末爆炸影响的研究

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2024-11-02 DOI: 10.1016/j.tca.2024.179895

{"title":"Investigation on the effect of carbon powder structural characteristics derived from ethylene decomposition on powder explosion","authors":"","doi":"10.1016/j.tca.2024.179895","DOIUrl":"10.1016/j.tca.2024.179895","url":null,"abstract":"<div><div>In LDPE production, ethylene underwent polymerization under high temperature and pressure. However, the heat generated during polymerization could cause ethylene pyrolysis, leading to safety risks. More critically, the carbon powder produced could further decompose, posing additional hazards. This study examined the pyrolysis characteristics of high-pressure, high-temperature ethylene and the explosive behavior of the resulting carbon powder. The decomposition of ethylene was carried out under 80–200 °C and 80–200 MPa with the oxygen concentration of 1000–5000 ppm using ethylene explosive device, and the explosive testing of derived carbon powder was carried out in a 20 L sphere chamber under the powder concentration of 200 g/m<sup>3</sup>. It was found that higher initial ignition pressure, temperature, and oxygen concentration intensified ethylene pyrolysis. The size of resulting carbon powder ranged from 0.5 to 500 μm and fewer structural defects, leading to stronger explosive intensity due to a larger specific surface area and longer suspension time in the air. Conversely, carbon powder with larger particle sizes and more defects tended to agglomerate, reducing suspension time and explosion intensity. This research provided a theoretical foundation for understanding powder explosions caused by ethylene decomposition.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Characterization of thermal behavior of two types of kaolin in China by ultrafast Joule heating combined with XRD, FT-IR, TG-DSC and SEM 利用超快焦耳加热结合 XRD、FT-IR、TG-DSC 和 SEM 对中国两种高岭土的热行为进行表征

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2024-11-02 DOI: 10.1016/j.tca.2024.179894

引用次数: 0

Extending the Transient Plane Source Scanning method for determining the specific heat capacity of low thermal conductivity materials through a numerical study 通过数值研究扩展用于确定低导热材料比热容的瞬态平面源扫描方法

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2024-10-28 DOI: 10.1016/j.tca.2024.179883

{"title":"Extending the Transient Plane Source Scanning method for determining the specific heat capacity of low thermal conductivity materials through a numerical study","authors":"","doi":"10.1016/j.tca.2024.179883","DOIUrl":"10.1016/j.tca.2024.179883","url":null,"abstract":"<div><div>In contrast to the conventional Transient Plane Source (TPS) method, the Transient Plane Source Scanning (TPSS) technique allows for the direct determination of the specific heat capacity and requires the use of a specially designed sample holder for accurate measurements. While this method correctly determines the specific heat capacity of samples with moderate and high thermal conductivity, it tends to underestimate the values for those with low thermal conductivity. This paper demonstrates that the underestimated specific heat capacity results from heat loss during the measurement process. To precisely quantify the heat loss, a numerical model based on the finite element method was developed, with key material properties tuned based on measurement data. This model can closely describe the curve of measured thermal response, thereby enabling the precise determination of the specific heat capacity. Consequently, this study introduces a novel approach that incorporates numerical simulation to enhance TPSS measurements of poorly conducting samples, providing a reliable alternative for determining the specific heat capacity.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Determination of the apparent activation energy surface from isothermal data of char combustion and gasification 根据炭燃烧和气化的等温数据确定表观活化能面

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2024-10-26 DOI: 10.1016/j.tca.2024.179892

引用次数: 0

Heat capacities and thermodynamic functions of three 1-benzyl-4-aryl-1H-1,2,3-triazoles in the temperature range of (0 – Tm) K 三种 1-苄基-4-芳基-1H-1,2,3-三唑在 (0 - Tm) K 温度范围内的热容量和热力学函数

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2024-10-23 DOI: 10.1016/j.tca.2024.179881

引用次数: 0

Study of Heavy Oil In-situ Combustion with Copper Biocatalysts: Kinetics and Thermodynamic Aspects of High-Temperature Oxidation Reactions 利用铜生物催化剂研究重油原位燃烧：高温氧化反应的动力学和热力学问题

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2024-10-22 DOI: 10.1016/j.tca.2024.179882

{"title":"Study of Heavy Oil In-situ Combustion with Copper Biocatalysts: Kinetics and Thermodynamic Aspects of High-Temperature Oxidation Reactions","authors":"","doi":"10.1016/j.tca.2024.179882","DOIUrl":"10.1016/j.tca.2024.179882","url":null,"abstract":"<div><div>In-situ combustion is considered an efficient thermally enhanced oil recovery method. However, the combustion front stabilization remains a challenge for the scientific community. The present study examines the efficacy of copper tall oil (Cu-TO) and copper sunflower oil (Cu-SFO) on heavy oil high-temperature oxidation reactions, which are believed to solve this challenge. We applied non-isothermal differential scanning calorimetry (DSC) analyses combined with an isoconversional kinetic approach in order to calculate kinetic parameters, thermodynamic functions, and the effective rate constant of these reactions. The obtained results demonstrated that both catalysts are able to reduce the activation energies and shift oxidation regions to lower temperatures, with Cu-SFO showing superior performance. Kinetic predictions further supported these findings and revealed that the selected catalysts contributed significantly to decreasing oxidation times across all conversion ranges. Additionally, thermodynamic analyses indicated that Cu-SFO facilitated a more ordered and energetically favorable oxidation process, as demonstrated by increasingly negative entropy values and consistently lower Gibbs free energy. The research highlights the Cu-SFO catalyst exceptional ability to accelerate the transition from low-temperature to high-temperature oxidation while maintaining high catalytic activity. Taken together all these results, this research work contributes to provide comprehensive insights from the kinetic and thermodynamic analysis that reveal unique catalytic effects and reaction mechanisms, presenting an approach to stabilize combustion front and improve heavy oil recovery efficiency, addressing a critical challenge in the field of in-situ combustion.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design and implementation of an accelerating rate calorimeter based on Modelica modeling 基于 Modelica 建模的加速热量计的设计与实施

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2024-10-18 DOI: 10.1016/j.tca.2024.179877

引用次数: 0

Insights into the thermal stabilization mechanism of zeolitic imidazolate framework-8 for poly(vinyl chloride) 沸石咪唑酸盐框架-8 对聚氯乙烯热稳定机制的启示

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2024-10-16 DOI: 10.1016/j.tca.2024.179880

引用次数: 0

Thermoluminescence characteristics of UV-irradiated natural hackmanite 紫外线辐照天然黑云母的热致发光特性

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2024-10-11 DOI: 10.1016/j.tca.2024.179879

引用次数: 0

Thermal properties and decomposition of perovskite energetic materials (C6H14N2) NH4 (ClO4)3 过氧化物高能材料 (C6H14N2) NH4 (ClO4)3 的热性能和分解过程

IF 3.1 2区化学

Thermochimica Acta Pub Date : 2024-10-11 DOI: 10.1016/j.tca.2024.179878

{"title":"Thermal properties and decomposition of perovskite energetic materials (C6H14N2) NH4 (ClO4)3","authors":"","doi":"10.1016/j.tca.2024.179878","DOIUrl":"10.1016/j.tca.2024.179878","url":null,"abstract":"<div><div>(C<sub>6</sub>N<sub>2</sub>H<sub>14</sub>) NH<sub>4</sub> (ClO<sub>4</sub>)<sub>3</sub> (DAP-4) have attracted an increasing focus recently as an ammoniumperchlorate-based molecular perovskite energetic material with outstanding features. Microscopy, variable temperature X-ray diffraction, in situ infrared spectroscopy, differential scanning calorimetry-thermogravimetry simultaneous thermal analysis coupled with infrared spectroscopy and mass spectrometry (DSC-TG/FTIR/MS) techniques were used to systematically investigate DAP-4 thermal properties from -40 °C to 550 °C. The results revealed that DAP-4 have two solid-solid crystallization phase transitions with a non-characteristic melting process. The generated activation energies of HCN, CO, CH<sub>2</sub>NH<sub>2</sub>, CO<sub>2</sub> and NO<sub>2</sub> gas products are all lower than the macroscopic decomposition's of DAP-4. This finding strongly proves that DAP-4 is easy to form these gas products during thermal stimulus. The two stages decomposition mechanism accompanying a large of CH<sub>2</sub>NH<sub>2</sub> and NH<sub>2</sub>C<sub>2</sub>H<sub>4</sub> gases and kinetic model of DAP-4 were proposed under the condition of high-purity argon gas. This study provides new insight into the in-depth and accurate description thermal decomposition mechanism of DAP-4 as a potential energetic material.</div></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0