Critical Evaluation and Thermodynamic Optimization of Calcium-magnesium-manganese-oxygen System PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Critical Evaluation and Thermodynamic Optimization of Calcium-magnesium-manganese-oxygen System PDF full book. Access full book title Critical Evaluation and Thermodynamic Optimization of Calcium-magnesium-manganese-oxygen System by Sourav Panda. Download full books in PDF and EPUB format.
Author: Sourav Panda
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
"The prediction of thermodynamic properties and phase equilibria of an oxide system can plays an important role in the development and understanding of metal1urgical, ceramic and geological processes. The thermodynamic databases, developed by a critical evaluation and optimization of all existing thermodynamic properties and phase diagram, can help in understanding the reaction mechanism in various industrial processes more clearly and in developing new technology for various industries. As part of a large thermodynamic database development for steelmaking applications, all solid and liquid phases of Ca-Mg-Mn-O system were critically evaluated and optimized in the present study. The optimization of all systems in this study is self-consistent with thermodynamic principles. All the binary and ternary system have been critically evaluated and optimized based upon available phase-equilibrium and thermodynamic data. All thermodynamic models for each solutions used in this study were developed on the basis of their structure. In this way, the configurational entropy of solution can be taken into account properly in the Gibbs energy of solution. The molten oxide was modeled by the Modified Quasichemical Model, which takes into account short-range ordering of second-nearest-neighbor cations in the ionic melt. Extensive solid solutions such as spinel were modeled within the framework of the Compound Energy Formalism with consideration of their complex sublattice crystal structures. Other solid solutions such as monoxide were modeled using random mixing of ions on cation sites using a polynomial expansion of the excess Gibbs energy. All the thermodynamic calculations in the present study were carried out using FactSageTM thermodynamic software." --
Author: Sourav Panda
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
"The prediction of thermodynamic properties and phase equilibria of an oxide system can plays an important role in the development and understanding of metal1urgical, ceramic and geological processes. The thermodynamic databases, developed by a critical evaluation and optimization of all existing thermodynamic properties and phase diagram, can help in understanding the reaction mechanism in various industrial processes more clearly and in developing new technology for various industries. As part of a large thermodynamic database development for steelmaking applications, all solid and liquid phases of Ca-Mg-Mn-O system were critically evaluated and optimized in the present study. The optimization of all systems in this study is self-consistent with thermodynamic principles. All the binary and ternary system have been critically evaluated and optimized based upon available phase-equilibrium and thermodynamic data. All thermodynamic models for each solutions used in this study were developed on the basis of their structure. In this way, the configurational entropy of solution can be taken into account properly in the Gibbs energy of solution. The molten oxide was modeled by the Modified Quasichemical Model, which takes into account short-range ordering of second-nearest-neighbor cations in the ionic melt. Extensive solid solutions such as spinel were modeled within the framework of the Compound Energy Formalism with consideration of their complex sublattice crystal structures. Other solid solutions such as monoxide were modeled using random mixing of ions on cation sites using a polynomial expansion of the excess Gibbs energy. All the thermodynamic calculations in the present study were carried out using FactSageTM thermodynamic software." --
Author: Alessandro Bo
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 0
Get Book Here
Book Description
This PhD thesis presents an in-depth characterization of the magnesium manganese oxide redox system for energy storage applications. The study is divided into three main parts. Each one of them explores the features of the energy storage material at increasing length scales: starting from the pellet-scale (on the order of millimeters), then moving to the packed-bed scale (on the order of centimeters), and finally reaching the reactor-scale (on the order of meters), in which the energy storage concept is demonstrated in an experimental reactor.℗ The first part of the study deals with the experimental characterization and modeling of the magnesium manganese oxide redox system thermodynamics. The test sample is an individual cylindrical pellet in the 1:1 magnesium-to-manganese molar ratio composition. Its extent of oxidation is measured via a series of thermogravimetric experiments conducted at temperatures between 1000 and 1500 ℗ʻC and oxygen partial pressures between 0.01 and 0.9 bar(a). The experimental results are used to develop two thermodynamic models that accurately predict the behavior of the redox system within these temperature and oxygen partial pressure ranges. Furthermore, these models allow to improve the material characterization by providing estimates on the average enthalpy and entropy of reaction. This study provides the minimum theoretical knowledge needed to develop computational models to predict and optimize the operation of such energy storage material when integrated in a large-scale reactor.The second part of the study deals with the measurement of the effective electrical conductivity of a packed bed of magnesium manganese oxide pellets. During this experimental campaign, different pellet form factors (cylindrical and spherical) and compositions (1:1 and 3:2 magnesium-to-manganese molar ratios) have been examined. These measurements are performed using a four-wire technique at temperatures ranging between 1000 and 1500 ℗ʻC under atmospheric pressure. This study demonstrates that, under such conditions, the energy storage material is electrically conductive. This result plays a crucial role in the development of fast charging strategies for energy storage systems based on the magnesium manganese oxide redox system. In fact, given its electrical properties, the packed bed can be thermally charged by directly passing an electrical current through it (Joule heating) instead of relying on external heating elements. This study provides valuable insights into the design and operation of such energy storage systems, and the findings have important implications for the development of more efficient and cost-effective energy storage products.The third part of the study deals with the modeling and experimental validation of a thermochemical energy storage reactor based on the magnesium manganese oxide redox system. The model combines transient lumped (0D) species and energy governing equations for both the solid and gas phases within the packed bed, with 1D axial and radial transient heat conduction equations within the reactor insulating layers. The model is validated using the experimental data collected during a redox cycling campaign of a nominally 1 kW/5 kWhth reactor based on the magnesium manganese oxide redox system. The redox material chemical kinetics is modeled using an equilibrium kinetics approach. Experimental correlations are also used to validate the pressure drop measured across the packed bed upon system discharge. This model provides a starting point for the design and optimization of commercial-scale energy storage systems based on the magnesium manganese oxide redox system.Overall, this PhD thesis provides a foundational understanding of the magnesium manganese oxide redox system behavior at different length scales, starting from the pellet-scale, moving to the packed bed scale, and finally reaching the reactor-scale. The results of this study have significant implications for the development of efficient and scalable thermochemical energy storage systems.
Author: Rui Gao
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
"The main purpose of the present study is to obtain accurate thermodynamic database to describe the phase equilibria and thermodynamic properties of the entire Mg-Ca-Nd system, which can be utilized for Mg alloy design containing Ca and RE. The Ca-RE (RE = Nd, Y, Ce) binary systems were optimized based on assessed phase diagram data. All available data in the literature were critically evaluated and used to optimize the model parameters to reproduce all available phase diagram data. Liquid solution was described using the Modified Quasichemical Model (MQM), and the solid solutions were described with the Compound Energy Formalism (CEF). It should be noted that all Ca-RE systems show liquid miscibility gap. In order to facilitate the thermodynamic optimization of the Mg-Ca-Nd ternary system, key phase diagram experiments were performed to supplement the few existing phase diagram experimental data. Differential scanning calorimetry (DSC) was successfully conducted up to 750oC on samples of 5 different compositions in the Mg-rich side and up to about 30 mole percent Nd and 50 mole percent Ca. To prevent the volatilization and oxidation of samples, sealed Fe capsule was employed. Based on the new phase diagram data and all available information in literature, thermodynamic optimization of the ternary Mg-Ca-Nd system was carried out. In particular, the solubility of Ca in Mg41Nd5 and Nd in Mg2Ca were well reproduced by CEF. In general, the available phase diagram data were well reproduced and the phase diagram of the entire Mg-Ca-Nd system was predicted"--
Author:
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 1042
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 1390
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Weights and measures
Languages : en
Pages : 650
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 912
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Chemical abstracts
Languages : en
Pages : 2210
Get Book Here
Book Description
Author: Karl U. Kainer
Publisher: John Wiley & Sons
ISBN: 3527605967
Category : Technology & Engineering
Languages : en
Pages : 293
Get Book Here
Book Description
The need for light-weight materials, especially in the automobile industry, created renewed interest in innovative applications of magnesium materials. This demand has resulted in increased research and development activity in companies and research institutes in order to achieve an improved property profile and better choice of alloy systems. Here, development trends and application potential in different fields like the automotive industry and communication technology are discussed in an interdisciplinary framework.
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1126
Get Book Here
Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
