Searched for: author%3A%22Haverkort%2C+J.W.%22
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Valle Marchante, N. (author), Haverkort, J.W. (author)
The high mass transfer to or from gas-evolving electrodes is an attractive feature of electrochemical reactors, which can be partly attributed to the large convective flows that arise due to the buoyancy of bubbles. We derive exact analytical expressions for mass transfer coefficients for the case of constant gas flux boundary conditions. For...
journal article 2024
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Haverkort, J.W. (author), Sanderse, B. (author), Padding, J.T. (author), Blake, J.W. (author)
In flow-by capacitive deionization (CDI) brackish water flows between two electrodes that capacitively remove salt. We assume low inlet concentrations so “salt shocks” appear in the electrodes and the process becomes diffusion-limited. For unit charge efficiency, a simplified model is derived consisting of two coupled partial differential...
journal article 2024
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Haverkort, J.W. (author)
Electrochemical engineering deals with electrochemical devices like electrolysers, fuel cells, and batteries. While several excellent books exist in this long-standing and still growing field, their focus is usually on chemistry or phenomenology. In this textbook, we focus on mathematical modelling of the physical phenomena involved. Instead of...
book 2024
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Phadke, S.A. (author), de Jong, W. (author), Haverkort, J.W. (author)
The anodic co-production of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) during alkaline water electrolysis has gained interest as a sustainable alternative for anthraquinone oxidation. However, electrochemical H<sub>2</sub>O<sub>2</sub> production is often studied with idealized laboratory setups to determine the H<sub>2</sub>O<sub>2</sub>...
journal article 2024
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Rajora, A. (author), Haverkort, J.W. (author)
Understanding multiphase flow close to the electrode surface is crucial to the design of electrolyzers, such as alkaline water electrolyzers for the production of green hydrogen. Vertical electrodes develop a narrow gas plume near their surface. We apply the integral method to the mixture model. Considering both exponentially varying and step...
journal article 2023
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Martinez Lopez, V.A. (author), Ziar, H. (author), Haverkort, J.W. (author), Zeman, M. (author), Isabella, O. (author)
This review provides a comprehensive overview of the dynamics of low-temperature water electrolyzers and their influence on coupling the three major technologies, alkaline, Proton Exchange Membrane (PEM) and, Anion Exchange Membrane (AEM) with photovoltaic (PV) systems. Hydrogen technology is experiencing considerable interest as a way to...
review 2023
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Bhadra, A. (author), Haverkort, J.W. (author)
Microfluidic fuel cells, electrolyzers, and redox flow batteries utilize laminar flow channels to provide reactants, remove products and avoid their crossover. These devices often also employ porous flow-through electrodes as they offer a high surface area for the reaction and excellent mass transfer. The geometrical features of these...
journal article 2023
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Blake, J.W. (author), Konderla, V. (author), Baumgartner, L.M. (author), Vermaas, D.A. (author), Padding, J.T. (author), Haverkort, J.W. (author)
The use of gas diffusion electrodes that supply gaseous CO<sub>2</sub> directly to the catalyst layer has greatly improved the performance of electrochemical CO<sub>2</sub> conversion. However, reports of high current densities and Faradaic efficiencies primarily come from small lab scale electrolysers. Such electrolysers typically have a...
journal article 2023
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Rajora, A. (author), Haverkort, J.W. (author)
Membraneless parallel-plate electrolyzers use electrolyte flow to avoid product crossover. Using a mixture model neglecting inertia, and assuming an exponential gas fraction profile, we derive approximate analytical expressions for the velocity profile and pressure drop for thin plumes. We verify these expressions using numerical solutions...
journal article 2022
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Rajora, A. (author), Haverkort, J.W. (author)
The diffusion layer is a crucial part of most fuel cells and electrolyzers. We analytically solve a simplified set of visco-capillary equations for the gas and liquid saturation profiles inside such layers. Contrary to existing numerical simulations, this approach allows us to obtain general scaling relations. We derive simple explicit equations...
journal article 2021
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Haverkort, J.W. (author), Rajaei, H. (author)
Reducing the gap between the electrodes and diaphragm to zero is an often adopted strategy to reduce the ohmic drop in alkaline water electrolyzers for hydrogen production. We provide a thorough account of the current–voltage relationship in such a zero-gap configuration over a wide range of electrolyte concentrations and current densities....
journal article 2021
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Hoelzl, M. (author), Huijsmans, G. T.A. (author), Pamela, S. J.P. (author), Bécoulet, M. (author), Nardon, E. (author), Haverkort, J.W. (author), Hu, D. (author), Morales, J. A. (author), Verbeek, M. (author)
JOREK is a massively parallel fully implicit non-linear extended magneto-hydrodynamic (MHD) code for realistic tokamak X-point plasmas. It has become a widely used versatile simulation code for studying large-scale plasma instabilities and their control and is continuously developed in an international community with strong involvements in...
journal article 2021
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Mangel Raventos, A. (author), Kluivers, Gerard J. (author), Haverkort, J.W. (author), de Jong, W. (author), Mulder, F.M. (author), Kortlever, R. (author)
Both daily and seasonal fluctuations of renewable power sources will require large-scale energy storage technologies. A recently developed integrated battery and electrolyzer system, called battolyser, fulfills both time-scale requirements. Here, we develop a macroscopic COMSOL Multiphysics model to quantify the energetic efficiency of the...
journal article 2021
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Blake, J.W. (author), Padding, J.T. (author), Haverkort, J.W. (author)
The electrochemical reduction of CO<sub>2</sub> on planar electrodes is limited by its prohibitively low diffusivity and solubility in water. Gas-diffusion electrodes (GDEs) can be used to reduce these limitations, and facilitate current densities orders of magnitude higher than the limiting current densities of planar electrodes. These...
journal article 2021
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Rajaei, H. (author), Rajora, A. (author), Haverkort, J.W. (author)
Flow-through electrolyzers, with flow parallel to the current, are used in a wide range of industrial applications. The presence of flow avoids concentration gradients but can also be used to separate evolved gases, allowing membrane-less operation. In this work, we propose a simple multiphase flow-through electrode model. We derive and...
journal article 2021
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Haverkort, J.W. (author), Rajaei, H. (author)
Under alkaline conditions, hydroxide ions can deplete at the anode of a water electrolyser for hydrogen production, resulting in a limiting current density. We found experimentally that in a micro-porous separator, an electro-osmotic flow from anode to cathode lowers this limiting current density. Using the Nernst-Planck equation, a useful...
journal article 2020
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Rajaei, H. (author), Haverkort, J.W. (author)
A new compact electrode architecture with hollow pillar-shaped anodes and cathodes arranged in a ‘checkerboard’ pattern is analysed and shown to be equivalent to a particular arrangement of corrugated plate electrodes. Because all four sides of the flow channels are electrodes, this design takes up at least 1.5 to two times less volume...
journal article 2020
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Haverkort, J.W. (author)
Combined diffusion, migration, and advection of ions in a binary electrolyte plays a role in various applications, including water electrolysis, electrodeposition, deionization, and electrophoresis. Here we analyze a dilute binary electrolyte with arbitrary ion valencies in a porous or nonporous medium using the one-dimensional Nernst-Planck...
journal article 2020
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Haverkort, J.W. (author)
Using electrodes or catalytic layers that are porous increases the reactive surface area but also the distance that ions and electrons have to travel. Thicker electrodes, through their larger surface area, reduce the activation overpotential but increase the ohmic losses. There will therefore be an electrode thickness for which the voltage...
journal article 2019
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Haverkort, J.W. (author), Peeters, T.W.J. (author)
journal article 2010
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