Author: Röhe, Maximilian
Publisher: KIT Scientific Publishing
ISBN: 3731512343
Category :
Languages : en
Pages : 178
Book Description
In this work, the first simulation model of oxygen depolarized cathodes (ODC), which are silver catalyst-based gas diffusion electrodes, is presented that considers the phase equilibrium of the gas-liquid interface and structure-related inhomogeneities in electrolyte distribution. By means of the model it has been identified that mass transport of water and ions in the liquid phase is a crucial factor for electrode performance and how it is influenced by the electrode structure.
Dynamic Model-based Analysis of Oxygen Reduction Reaction in Gas Diffusion Electrodes
Author: Röhe, Maximilian
Publisher: KIT Scientific Publishing
ISBN: 3731512343
Category :
Languages : en
Pages : 178
Book Description
In this work, the first simulation model of oxygen depolarized cathodes (ODC), which are silver catalyst-based gas diffusion electrodes, is presented that considers the phase equilibrium of the gas-liquid interface and structure-related inhomogeneities in electrolyte distribution. By means of the model it has been identified that mass transport of water and ions in the liquid phase is a crucial factor for electrode performance and how it is influenced by the electrode structure.
Publisher: KIT Scientific Publishing
ISBN: 3731512343
Category :
Languages : en
Pages : 178
Book Description
In this work, the first simulation model of oxygen depolarized cathodes (ODC), which are silver catalyst-based gas diffusion electrodes, is presented that considers the phase equilibrium of the gas-liquid interface and structure-related inhomogeneities in electrolyte distribution. By means of the model it has been identified that mass transport of water and ions in the liquid phase is a crucial factor for electrode performance and how it is influenced by the electrode structure.
Experimental and model-based investigation of overpotentials during oxygen reduction reaction in silver-based gas-diffusion electrodes
Author: David Franzen
Publisher: Cuvillier Verlag
ISBN: 3736965141
Category : Science
Languages : en
Pages : 136
Book Description
Chlorine is one of the most important basic chemicals, which is used directly or indirectly in the production of around 60 % of all chemical products. The production is almost exclusively based on energy intensive electrolysis processes, with an average of 2.5 – 3.5 MWh of electrical energy required per ton of chlorine generated. This means that chlorine production alone accounts for around 3 % of the electrical energy used worldwide in industry. By using oxygen depolarized cathodes (ODC), it is possible to reduce the demand for electrical energy on an industrial scale by about 25 %. Instead of hydrogen evolution, oxygen reduction takes place. Due to the low solubility of oxygen, the electrode is designed as a gas-diffusion electrodes (GDE). These are porous silver-based electrodes with hydrophobic regions due to the use of polytetrafluoroethylene (PTFE). During operation, the liquid electrolyte penetrates the pore structure, but the PTFE prevents complete flooding of the electrode. Oxygen is supplied via a gas compartment and enters the internal structure of the electrode. A three-phase interface is formed, consisting of liquid electrolyte, gas and catalytically active solid, at which the electrochemical reaction takes place. Although the technology is already successfully used industrially, many processes, especially the electrolyte distribution, inside the GDE remain unknown. In this dissertation, the influence of PTFE is first systematically investigated. Subsequently the process is described in a pseudo-2D model supported by operando experiments. Finally, the exact penetration depth of the electrolyte is analyzed using specially designed electrodes.
Publisher: Cuvillier Verlag
ISBN: 3736965141
Category : Science
Languages : en
Pages : 136
Book Description
Chlorine is one of the most important basic chemicals, which is used directly or indirectly in the production of around 60 % of all chemical products. The production is almost exclusively based on energy intensive electrolysis processes, with an average of 2.5 – 3.5 MWh of electrical energy required per ton of chlorine generated. This means that chlorine production alone accounts for around 3 % of the electrical energy used worldwide in industry. By using oxygen depolarized cathodes (ODC), it is possible to reduce the demand for electrical energy on an industrial scale by about 25 %. Instead of hydrogen evolution, oxygen reduction takes place. Due to the low solubility of oxygen, the electrode is designed as a gas-diffusion electrodes (GDE). These are porous silver-based electrodes with hydrophobic regions due to the use of polytetrafluoroethylene (PTFE). During operation, the liquid electrolyte penetrates the pore structure, but the PTFE prevents complete flooding of the electrode. Oxygen is supplied via a gas compartment and enters the internal structure of the electrode. A three-phase interface is formed, consisting of liquid electrolyte, gas and catalytically active solid, at which the electrochemical reaction takes place. Although the technology is already successfully used industrially, many processes, especially the electrolyte distribution, inside the GDE remain unknown. In this dissertation, the influence of PTFE is first systematically investigated. Subsequently the process is described in a pseudo-2D model supported by operando experiments. Finally, the exact penetration depth of the electrolyte is analyzed using specially designed electrodes.
5th European Symposium on Electrochemical Engineering
Author: A. A. Wragg
Publisher: IChemE
ISBN: 9780852954171
Category : Technology & Engineering
Languages : en
Pages : 358
Book Description
Materials Aspects of Electrochemical Engineering is the main theme of this symposium. It charts the way ahead for the future development and economic viability of all types of electrochemical processing.
Publisher: IChemE
ISBN: 9780852954171
Category : Technology & Engineering
Languages : en
Pages : 358
Book Description
Materials Aspects of Electrochemical Engineering is the main theme of this symposium. It charts the way ahead for the future development and economic viability of all types of electrochemical processing.
Encyclopedia of Electrochemical Power Sources
Author: Jürgen Garche
Publisher: Newnes
ISBN: 0444527451
Category : Science
Languages : en
Pages : 4532
Book Description
The Encyclopedia of Electrochemical Power Sources is a truly interdisciplinary reference for those working with batteries, fuel cells, electrolyzers, supercapacitors, and photo-electrochemical cells. With a focus on the environmental and economic impact of electrochemical power sources, this five-volume work consolidates coverage of the field and serves as an entry point to the literature for professionals and students alike. Covers the main types of power sources, including their operating principles, systems, materials, and applications Serves as a primary source of information for electrochemists, materials scientists, energy technologists, and engineers Incorporates nearly 350 articles, with timely coverage of such topics as environmental and sustainability considerations
Publisher: Newnes
ISBN: 0444527451
Category : Science
Languages : en
Pages : 4532
Book Description
The Encyclopedia of Electrochemical Power Sources is a truly interdisciplinary reference for those working with batteries, fuel cells, electrolyzers, supercapacitors, and photo-electrochemical cells. With a focus on the environmental and economic impact of electrochemical power sources, this five-volume work consolidates coverage of the field and serves as an entry point to the literature for professionals and students alike. Covers the main types of power sources, including their operating principles, systems, materials, and applications Serves as a primary source of information for electrochemists, materials scientists, energy technologists, and engineers Incorporates nearly 350 articles, with timely coverage of such topics as environmental and sustainability considerations
Multiscale Modeling of Curing and Crack Propagation in Fiber-Reinforced Thermosets
Author: Schöller, Lukas
Publisher: KIT Scientific Publishing
ISBN: 3731513404
Category :
Languages : en
Pages : 230
Book Description
During the production of fiber-reinforced thermosets, the resin material undergoes a reaction that can lead to damage. A two-stage polymerization reaction is modeled using molecular dynamics and evaluations of the system including a fiber surface are performed. In addition, a phase-field model for crack propagation in heterogeneous systems is derived. This model is able to predict crack growth where established models fail. Finally, the model is used to predict crack formation during curing.
Publisher: KIT Scientific Publishing
ISBN: 3731513404
Category :
Languages : en
Pages : 230
Book Description
During the production of fiber-reinforced thermosets, the resin material undergoes a reaction that can lead to damage. A two-stage polymerization reaction is modeled using molecular dynamics and evaluations of the system including a fiber surface are performed. In addition, a phase-field model for crack propagation in heterogeneous systems is derived. This model is able to predict crack growth where established models fail. Finally, the model is used to predict crack formation during curing.
Understanding Degradation Phenomena in Solid-Oxide Fuel-Cell Anodes by Phase-Field Modeling and Analytics
Author: Hoffrogge, Paul Wilhelm
Publisher: KIT Scientific Publishing
ISBN: 3731513633
Category :
Languages : en
Pages : 298
Book Description
The current work analyzes degradation effects in solid-oxide fuel cell anodes with the phase-field method. A model extension for interface diffusion is formulated and calibrated. Large-scale 3D-simulations provide interesting insights into phenomena at the microscale which are responsible for the degradation
Publisher: KIT Scientific Publishing
ISBN: 3731513633
Category :
Languages : en
Pages : 298
Book Description
The current work analyzes degradation effects in solid-oxide fuel cell anodes with the phase-field method. A model extension for interface diffusion is formulated and calibrated. Large-scale 3D-simulations provide interesting insights into phenomena at the microscale which are responsible for the degradation
Electrochemical Oxygen Reduction
Author: Pei Kang Shen
Publisher: Springer Nature
ISBN: 9813360771
Category : Science
Languages : en
Pages : 259
Book Description
This book discusses systematically the theoretical research and the applications of electrochemical oxygen reduction. Oxygen reduction reaction is a common issue in electrochemistry, but is also an important process involved in the field of energy, cryogenic fuel cells, metal–air cells, oxygen sensors and hydrogen peroxide preparation. This book is divided into 6 chapters; it starts with a description of dynamic mechanisms, followed by a detailed introduction on the related experimental methods and related catalyst preparation technology. By providing the basic methods and testing techniques, and by demonstrating their applications, it helps readers gain a better understanding of oxygen reduction reactions, making it a valuable resource for the industrialization of scientific research achievements. Accordingly, the book appeals to a broad readership, particularly graduate students, those working at universities and research organizations, and industrial researchers.
Publisher: Springer Nature
ISBN: 9813360771
Category : Science
Languages : en
Pages : 259
Book Description
This book discusses systematically the theoretical research and the applications of electrochemical oxygen reduction. Oxygen reduction reaction is a common issue in electrochemistry, but is also an important process involved in the field of energy, cryogenic fuel cells, metal–air cells, oxygen sensors and hydrogen peroxide preparation. This book is divided into 6 chapters; it starts with a description of dynamic mechanisms, followed by a detailed introduction on the related experimental methods and related catalyst preparation technology. By providing the basic methods and testing techniques, and by demonstrating their applications, it helps readers gain a better understanding of oxygen reduction reactions, making it a valuable resource for the industrialization of scientific research achievements. Accordingly, the book appeals to a broad readership, particularly graduate students, those working at universities and research organizations, and industrial researchers.
Application of Data Mining and Machine Learning Methods to Industrial Heat Treatment Processes for Hardness Prediction
Author: Lingelbach, Yannick
Publisher: KIT Scientific Publishing
ISBN: 3731513528
Category :
Languages : en
Pages : 278
Book Description
This work presents a data mining framework applied to industrial heattreatment (bainitization and case hardening) aiming to optimize processes and reduce costs. The framework analyses factors such as material, production line, and quality assessment for preprocessing, feature extraction, and drift corrections. Machine learning is employed to devise robust prediction strategies for hardness. Its implementation in an industry pilot demonstrates the economic benefits of the framework. - This work presents a data mining framework applied to industrial heattreatment (bainitization and case hardening) aiming to optimize processes and reduce costs. The framework analyses factors such as material, production line, and quality assessment for preprocessing, feature extraction, and drift corrections. Machine learning is employed to devise robust prediction strategies for hardness. Its implementation in an industry pilot demonstrates the economic benefits of the framework.
Publisher: KIT Scientific Publishing
ISBN: 3731513528
Category :
Languages : en
Pages : 278
Book Description
This work presents a data mining framework applied to industrial heattreatment (bainitization and case hardening) aiming to optimize processes and reduce costs. The framework analyses factors such as material, production line, and quality assessment for preprocessing, feature extraction, and drift corrections. Machine learning is employed to devise robust prediction strategies for hardness. Its implementation in an industry pilot demonstrates the economic benefits of the framework. - This work presents a data mining framework applied to industrial heattreatment (bainitization and case hardening) aiming to optimize processes and reduce costs. The framework analyses factors such as material, production line, and quality assessment for preprocessing, feature extraction, and drift corrections. Machine learning is employed to devise robust prediction strategies for hardness. Its implementation in an industry pilot demonstrates the economic benefits of the framework.
U.S. Government Research Reports
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 236
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 236
Book Description
High temperature polymer electrolyte membrane fuel cells
Author: Christian Siegel
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832539174
Category : Science
Languages : en
Pages : 182
Book Description
A three-dimensional computational fluid dynamics model of a high temperature polymer electrolyte membrane fuel cell, employing a high temperature stable polybenzimidazole membrane electrode assembly doped with phosphoric acid, was developed and implemented using a commercially available finite element software. Three types of flow-fields were modeled and simulated. Selected simulation results at reference operating conditions were compared to the performance curves and to segmented solid-phase temperature and current density measurements. For the segmented measurements, an inhouse developed prototype cell was designed and manufactured. The segmented cell was successfully operated and the solid-phase temperature and the current density distribution were recorded, evaluated, and discussed. Sequentially scanned segmented electrochemical impedance spectroscopy measurements were performed to qualitatively support the observed trends. These measurements were used to identify and determine the causes of the inhomogeneous current density distributions. An equivalent circuit model was developed, the obtained spectra were analyzed, and the model parameters discussed. This work helps to provide a better understanding of the internal behaviour of a running high temperature polymer electrolyte membrane fuel cell and presents valuable data for modeling and simulation. For large fuel cells and complete fuel cell stacks in particular, well designed anode and cathode inlet and outlet sections are expected to aid in achieving flatter quantities distributions and in preventing hot spots over the membrane electrode assembly area, and to develop proper start-up, shut-down, and tempering concepts.
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832539174
Category : Science
Languages : en
Pages : 182
Book Description
A three-dimensional computational fluid dynamics model of a high temperature polymer electrolyte membrane fuel cell, employing a high temperature stable polybenzimidazole membrane electrode assembly doped with phosphoric acid, was developed and implemented using a commercially available finite element software. Three types of flow-fields were modeled and simulated. Selected simulation results at reference operating conditions were compared to the performance curves and to segmented solid-phase temperature and current density measurements. For the segmented measurements, an inhouse developed prototype cell was designed and manufactured. The segmented cell was successfully operated and the solid-phase temperature and the current density distribution were recorded, evaluated, and discussed. Sequentially scanned segmented electrochemical impedance spectroscopy measurements were performed to qualitatively support the observed trends. These measurements were used to identify and determine the causes of the inhomogeneous current density distributions. An equivalent circuit model was developed, the obtained spectra were analyzed, and the model parameters discussed. This work helps to provide a better understanding of the internal behaviour of a running high temperature polymer electrolyte membrane fuel cell and presents valuable data for modeling and simulation. For large fuel cells and complete fuel cell stacks in particular, well designed anode and cathode inlet and outlet sections are expected to aid in achieving flatter quantities distributions and in preventing hot spots over the membrane electrode assembly area, and to develop proper start-up, shut-down, and tempering concepts.