Thermochimica Acta最新文献_第10页

Novel insights into the problem of enthalpy and entropy convergence in thermal decomposition of coal slag using the data from non-isothermal kinetic measurements 利用非等温动力学测量数据对煤渣热分解焓熵收敛问题的新见解

IF 3.5 2区化学

Thermochimica Acta Pub Date : 2024-05-01 DOI: 10.1016/j.tca.2024.179763

Bojan Janković , Marija Janković , Ivana Smičiklas , Mihajlo Jović , Ivana Vukanac , Ana Mraković , Nebojša Manić

{"title":"Novel insights into the problem of enthalpy and entropy convergence in thermal decomposition of coal slag using the data from non-isothermal kinetic measurements","authors":"Bojan Janković , Marija Janković , Ivana Smičiklas , Mihajlo Jović , Ivana Vukanac , Ana Mraković , Nebojša Manić","doi":"10.1016/j.tca.2024.179763","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179763","url":null,"abstract":"<div>This study provides insight into benefits of thermo-chemical conversion of coal slag as recovery process into value-added products. This research involves kinetic analysis of process conducted through non-isothermal thermal analysis measurements, with additional raw material characterization. Kinetic results showed that decomposition proceeds through two consecutive reactions steps (first one, including anorthite P1̅ → I1̅ phase transition, and then production of incongruent melting product (ternary system: CaO·Al2O3·2SiO2 (CAS2), where viscosity of slag changes), and second one including dehydration and formation of meta-muscovite, and subsequently, thermal disruption of muscovite de-hydroxylated phase, which proceeds with breaking of octahedral Al–O bonds), and one single-step reaction (attributed to CO-reduction of hematite to magnetite). Thermodynamic results showed an existence of physically meaningful isokinetic temperature (Tiso), which corresponds to active vibrational frequency of surroundings of SiO2 reaction site, manifested through Si‒O bond weakening by catalytic reaction of freed hydroxide ion (OH−). It was concluded that at temperature T = Tiso, the course of process loses its dependence on temperature and pressure, regulating changes between thermodynamic parameters, through enthalpy-entropy compensation (EEC) effect.</div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"736 ","pages":"Article 179763"},"PeriodicalIF":3.5,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140823140","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

Ignition and combustion characteristics of aluminum-based fluorine-containing composite powder 铝基含氟复合粉末的点火和燃烧特性

IF 3.5 2区化学

Thermochimica Acta Pub Date : 2024-04-28 DOI: 10.1016/j.tca.2024.179757

Peini Xie, Xueqin Liao, Jianzhong Liu

引用次数: 0

The experimental study of the kinetics and modes of polymethyl methacrylate thermal degradation in argon flows 聚甲基丙烯酸甲酯在氩气流中的热降解动力学和模式的实验研究

IF 3.5 2区化学

Thermochimica Acta Pub Date : 2024-04-28 DOI: 10.1016/j.tca.2024.179756

Eugene A. Salgansky , Marina V. Salganskaya , Dmitrii O. Glushkov , Andrey O. Pleshko

引用次数: 0

Convolutional denoising for large-volume Seebeck calorimeter 用于大容积塞贝克量热计的卷积去噪技术

IF 3.5 2区化学

Thermochimica Acta Pub Date : 2024-04-27 DOI: 10.1016/j.tca.2024.179760

Wu-Shou Zhang

引用次数: 0

Synthesis and pyrolysis of polyacrylate-supported flavor precursors 聚丙烯酸酯支撑的香料前体的合成与热解

IF 3.5 2区化学

Thermochimica Acta Pub Date : 2024-04-25 DOI: 10.1016/j.tca.2024.179759

Chen Zhu , Wei-Po Jiang , Chun-Hua Liu , Liangyuan Jia , Zeng-Yang He , Jin Zhang , Peng Zou , Yuan-Yuan Zhu

{"title":"Synthesis and pyrolysis of polyacrylate-supported flavor precursors","authors":"Chen Zhu , Wei-Po Jiang , Chun-Hua Liu , Liangyuan Jia , Zeng-Yang He , Jin Zhang , Peng Zou , Yuan-Yuan Zhu","doi":"10.1016/j.tca.2024.179759","DOIUrl":"10.1016/j.tca.2024.179759","url":null,"abstract":"<div>Herein we present a novel ‘polymerization strategy’ aimed at synthesizing flavor precursors, with a focus on enhancing their thermal stability and release properties. Three volatile flavors, menthol, methyl cyclopentenolone, and ethyl maltol, are reacted with acryloyl chloride to produce corresponding vinyl monomers. These monomers undergo radical polymerization to form homopolymers (P1−P3). To improve solubility in alcohol solvents, a hydrophilic oligoethylene glycol monomer is introduced, copolymerized with the flavor containing monomers, resulting in copolymers (P4−P6). An important advantage of these polymers lies in their significantly enhanced thermal stability, exhibiting an increase of approximately 100 to 200 °°C compared to small molecular flavors. Furthermore, our methodology enables efficient release of the target flavors upon heating, as evidenced by online analyses of volatiles from pyrolysis using fixed-bed reactor combined with single photoionization mass spectrometry (FBR-SPIMS) and pyrolysis-gas chromatography-mass spectrometry (Py-GC–MS). This work represents a practical and innovative approach to improving the thermal stability of volatile flavors and elevating their release temperature, offering promising applications in high-temperature food processing and tobacco industries.</div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"736 ","pages":"Article 179759"},"PeriodicalIF":3.5,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140791927","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

Oxidation kinetics of typical high FeO ferrous spinels 典型高氧化铁尖晶石的氧化动力学

IF 3.5 2区化学

Thermochimica Acta Pub Date : 2024-04-21 DOI: 10.1016/j.tca.2024.179758

Chenmei Tang , Congcong Yang , Jian Pan , Deqing Zhu , Zhengqi Guo

{"title":"Oxidation kinetics of typical high FeO ferrous spinels","authors":"Chenmei Tang , Congcong Yang , Jian Pan , Deqing Zhu , Zhengqi Guo","doi":"10.1016/j.tca.2024.179758","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179758","url":null,"abstract":"<div>In this study, the isothermal oxidation kinetics of magnetite (OM), high-Mg magnetite (MM), titanomagnetite (TM), and chromite (CM) were investigated by applying thermogravimetry (TG) analysis at temperatures ranging from 1073 K to 1223 K. The results show that different high-FeO spinels possess distinct oxidizability. The oxidation process of OM in the temperature range from 1073 K to 1223 K is faster than others, followed by MM and TM. While CM exhibits the poorest oxidizability, and generally undergoes complex phase transitions. In the initial stage of oxidation, high FeO spinels have a higher oxidation rate due to the surface oxidation of spinel particles. However, the oxidation rate gradually declines in the later stages of oxidation due to increased internal diffusion resistance. The results of oxidation kinetics indicate that the initial oxidation stage of four spinels can be described as random nucleation and subsequent growth mechanism. The average apparent activation energies of the initial oxidation stage of OM, MM, TM, and CM are 25.09 kJ/mol, 32.39 kJ/mol, 58.10 kJ/mol, and 82.42 kJ/mol, respectively.</div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"736 ","pages":"Article 179758"},"PeriodicalIF":3.5,"publicationDate":"2024-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140647067","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

In-situ study on CO/CO2/H2/CH4 emissions during high temperature oxidative pyrolysis of coal via tetrahydrofuran extraction 四氢呋喃萃取法高温氧化热解煤炭过程中 CO/CO2/H2/CH4 排放的现场研究

IF 3.5 2区化学

Thermochimica Acta Pub Date : 2024-04-20 DOI: 10.1016/j.tca.2024.179742

Guolan Dou , Liying Zhang , Deming Wang , Xiaoxing Zhong , Botao Qin

{"title":"In-situ study on CO/CO2/H2/CH4 emissions during high temperature oxidative pyrolysis of coal via tetrahydrofuran extraction","authors":"Guolan Dou , Liying Zhang , Deming Wang , Xiaoxing Zhong , Botao Qin","doi":"10.1016/j.tca.2024.179742","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179742","url":null,"abstract":"<div>The study examined the oxidative pyrolysis of raw and residual coals extracted with tetrahydrofuran, as well as the CO/CO2/H2/CH4 emissions at high temperatures (200∼900 °C). Tetrahydrofuran was found to extract aromatic and aliphatic hydrocarbons from lower metamorphic coal, as well as hydroxyl, increasing the specific surface area of char formed by oxidative pyrolysis of residual coal. The CO2/CO ratio was temperature dependent, and the increase period was fit by a polynomial and a linear function, with critical temperature of around 570 °C. The greater CO2/CO ratio of raw coal suggested that oxidative pyrolysis produced more CO2. The kinetic analysis showed that the change in activation energy is inconsistent with the gas production, and the gases were found to be proportionate to the specific surface area of the coal chars, implying that the char structure has a significant influence on gaseous product emissions and the coal oxidative pyrolysis at high temperatures is a diffusion-controlled heterogeneous reaction. The findings of this study could be useful for determining the status of coal fire.</div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"736 ","pages":"Article 179742"},"PeriodicalIF":3.5,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140638840","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

A modification to the Friedman and Ortega isoconversional methods for evaluation of the activation energy as a function of conversion and temperature 对弗里德曼和奥尔特加等转换法进行修改，以评估活化能与转换率和温度的关系

IF 3.5 2区化学

Thermochimica Acta Pub Date : 2024-04-15 DOI: 10.1016/j.tca.2024.179748

Alireza Aghili , Amir Hossein Shabani

引用次数: 0

Effect of metals and brominated flame retardants on thermal degradation kinetics of waste printed circuit board 金属和溴化阻燃剂对废印刷电路板热降解动力学的影响

IF 3.5 2区化学

Thermochimica Acta Pub Date : 2024-04-14 DOI: 10.1016/j.tca.2024.179747

Bibari Boro, Pankaj Tiwari

引用次数: 0

In-situ copper-loaded hollow porous carbon nanospheres derived from phenolic resin for thermal energy storage 用于热能储存的酚醛树脂原位铜负载空心多孔碳纳米球

IF 3.5 2区化学

Thermochimica Acta Pub Date : 2024-04-12 DOI: 10.1016/j.tca.2024.179746

Jiahui Wu , Lei Shi , Jie Liu , Yali Luo , Yunfei Liu , Yinong Lyu

{"title":"In-situ copper-loaded hollow porous carbon nanospheres derived from phenolic resin for thermal energy storage","authors":"Jiahui Wu , Lei Shi , Jie Liu , Yali Luo , Yunfei Liu , Yinong Lyu","doi":"10.1016/j.tca.2024.179746","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179746","url":null,"abstract":"<div>Hollow porous carbon nanospheres (HPCS) are ideal scaffolds for phase change materials in thermal energy storage. However, their synthesis traditionally relies on template-based routes, involving tedious procedures and high costs. This study presents a facile method for preparing HPCS through one-step carbonization of phenolic resin using CuCl2 as the activation agent. This mild activation agent not only helps create a rich porous structure, but also maintains the hollow spherical architecture of the polymer precursor. More importantly, copper ions are reduced to copper nanoparticles during the carbonization process and are in-situ loaded into porous carbon, enhancing the thermal conductivity of the scaffold. After incorporating paraffin, the resulting composite exhibits a high phase change enthalpy of 104.4 J g−1, improved thermal conductivity of 0.95 W m−1 K−1, and excellent thermal cycling stability (100.5 J g−1 after 50 heating-cooling cycles), indicating significant potential for thermal energy storage and management.</div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"736 ","pages":"Article 179746"},"PeriodicalIF":3.5,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140552460","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