Bojan Janković , Marija Janković , Ivana Smičiklas , Mihajlo Jović , Ivana Vukanac , Ana Mraković , Nebojša Manić
{"title":"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","authors":"Bojan Janković , Marija Janković , Ivana Smičiklas , Mihajlo Jović , Ivana Vukanac , Ana Mraković , Nebojša Manić","doi":"10.1016/j.tca.2024.179763","DOIUrl":null,"url":null,"abstract":"<div><p>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 <em>P</em>1̅ → <em>I</em>1̅ phase transition, and then production of incongruent melting product (ternary system: CaO·Al<sub>2</sub>O<sub>3</sub>·2SiO<sub>2</sub> (CAS<sub>2</sub>), 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 (<em>T<sub>iso</sub></em>), which corresponds to active vibrational frequency of surroundings of SiO<sub>2</sub> reaction site, manifested through Si‒O bond weakening by catalytic reaction of freed hydroxide ion (OH<sup>−</sup>). It was concluded that at temperature <em>T</em> = <em>T<sub>iso</sub></em>, the course of process loses its dependence on temperature and pressure, regulating changes between thermodynamic parameters, through enthalpy-entropy compensation (EEC) effect.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":null,"pages":null},"PeriodicalIF":3.1000,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"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\":null,\"url\":null,\"abstract\":\"<div><p>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 <em>P</em>1̅ → <em>I</em>1̅ phase transition, and then production of incongruent melting product (ternary system: CaO·Al<sub>2</sub>O<sub>3</sub>·2SiO<sub>2</sub> (CAS<sub>2</sub>), 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 (<em>T<sub>iso</sub></em>), which corresponds to active vibrational frequency of surroundings of SiO<sub>2</sub> reaction site, manifested through Si‒O bond weakening by catalytic reaction of freed hydroxide ion (OH<sup>−</sup>). It was concluded that at temperature <em>T</em> = <em>T<sub>iso</sub></em>, the course of process loses its dependence on temperature and pressure, regulating changes between thermodynamic parameters, through enthalpy-entropy compensation (EEC) effect.</p></div>\",\"PeriodicalId\":23058,\"journal\":{\"name\":\"Thermochimica Acta\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.1000,\"publicationDate\":\"2024-05-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Thermochimica Acta\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0040603124001023\",\"RegionNum\":2,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, ANALYTICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Thermochimica Acta","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0040603124001023","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, ANALYTICAL","Score":null,"Total":0}
Novel insights into the problem of enthalpy and entropy convergence in thermal decomposition of coal slag using the data from non-isothermal kinetic measurements
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.
期刊介绍:
Thermochimica Acta publishes original research contributions covering all aspects of thermoanalytical and calorimetric methods and their application to experimental chemistry, physics, biology and engineering. The journal aims to span the whole range from fundamental research to practical application.
The journal focuses on the research that advances physical and analytical science of thermal phenomena. Therefore, the manuscripts are expected to provide important insights into the thermal phenomena studied or to propose significant improvements of analytical or computational techniques employed in thermal studies. Manuscripts that report the results of routine thermal measurements are not suitable for publication in Thermochimica Acta.
The journal particularly welcomes papers from newly emerging areas as well as from the traditional strength areas:
- New and improved instrumentation and methods
- Thermal properties and behavior of materials
- Kinetics of thermally stimulated processes