Semi-empirical model and experimental validation for the performance evaluation of a 15 kW alkaline water electrolyzer

Sánchez, Mónica; Amores, Ernesto; Rodríguez, Lourdes; Clemente-Jul, Carmen

doi:10.1016/j.ijhydene.2018.09.029

Cited by 160 publications

(61 citation statements)

References 46 publications

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“…This correlation can be extended with the effects of the operation pressure p in (8) by adding the empirical parameters d i , which specify the additional losses owing to pressurized operation [39]. In general, the reversible cell voltage increases with the pressure; however, the ohmic resistance caused by the gas bubbles decreases as the bubble diameter becomes smaller.…”

Section: Cell Design and Cell Voltagementioning

confidence: 99%

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Alkaline Water Electrolysis Powered by Renewable Energy: A Review

2020

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Alkaline water electrolysis is a key technology for large-scale hydrogen production powered by renewable energy. As conventional electrolyzers are designed for operation at fixed process conditions, the implementation of fluctuating and highly intermittent renewable energy is challenging. This contribution shows the recent state of system descriptions for alkaline water electrolysis and renewable energies, such as solar and wind power. Each component of a hydrogen energy system needs to be optimized to increase the operation time and system efficiency. Only in this way can hydrogen produced by electrolysis processes be competitive with the conventional path based on fossil energy sources. Conventional alkaline water electrolyzers show a limited part-load range due to an increased gas impurity at low power availability. As explosive mixtures of hydrogen and oxygen must be prevented, a safety shutdown is performed when reaching specific gas contamination. Furthermore, the cell voltage should be optimized to maintain a high efficiency. While photovoltaic panels can be directly coupled to alkaline water electrolyzers, wind turbines require suitable converters with additional losses. By combining alkaline water electrolysis with hydrogen storage tanks and fuel cells, power grid stabilization can be performed. As a consequence, the conventional spinning reserve can be reduced, which additionally lowers the carbon dioxide emissions.

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Section: Cell Design and Cell Voltagementioning

confidence: 99%

“…The calculated cell voltage of an atmospheric alkaline water electrolyzer at a temperature of 60 • C according to Equation(8). The overall cell voltage consists of the reversible cell voltage U rev , ohmic losses I • R ohm , and activation overvoltages η act[39,40].…”

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confidence: 99%

Alkaline Water Electrolysis Powered by Renewable Energy: A Review

2020

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“…Next to the H 2 production rate, cell voltage and gas impurity are significant parameters of interest for AELs. Hence, both variables are calculated by empirical correlations depending on current density, temperature, pressure, and electrolyte concentration 9, 10. The efficiency of AELs is mainly influenced by the required cell voltage and gas impurity.…”

Section: Methodsmentioning

confidence: 99%

Modeling the Dynamic Power‐to‐Gas Process: Coupling Electrolysis with CO₂ Methanation

Kreitz

Brauns

Turek

2020

Chemie Ingenieur Technik

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The dynamic operation of a power-togas plant powered by wind energy is theoretically studied by coupling an empirical model of an alkaline water electrolyzer with a 1D heterogeneous model of a methanation reactor. H 2 produced by the electrolyzer follows the wind power profile, but operation in the part-load range can raise safety concerns. The dynamically generated methane quality comes close to the required value for injection into the gas grid, if the stoichiometric ratio is controlled. To satisfy the gas quality at all times, it is necessary to design a more tolerant reactor.

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“…The energy transition to a zero-carbon model requires an ambitious growth plan for renewable energies [1]. However, renewable energy sources (mainly wind and solar power) involve a critical issue that needs to be addressed [2]; their dependence on weather conditions makes them very intermittent, causing a mismatch between supply and demand. Furthermore, in the medium-long term, it is expected that these discrepancies can produce failures in the electricity grid.…”

Section: Introductionmentioning

confidence: 99%

CFD Modeling and Experimental Validation of an Alkaline Water Electrolysis Cell for Hydrogen Production

Rodríguez

Amores

2020

Processes

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Although alkaline water electrolysis (AWE) is the most widespread technology for hydrogen production by electrolysis, its electrochemical and fluid dynamic optimization has rarely been addressed simultaneously using Computational Fluid Dynamics (CFD) simulation. In this regard, a two-dimensional (2D) CFD model of an AWE cell has been developed using COMSOL® software and then experimentally validated. The model involves transport equations for both liquid and gas phases as well as equations for the electric current conservation. This multiphysics approach allows the model to simultaneously analyze the fluid dynamic and electrochemical phenomena involved in an electrolysis cell. The electrical response was evaluated in terms of polarization curve (voltage vs. current density) at different operating conditions: temperature, electrolyte conductivity, and electrode-diaphragm distance. For all cases, the model fits very well with the experimental data with an error of less than 1% for the polarization curves. Moreover, the model successfully simulates the changes on gas profiles along the cell, according to current density, electrolyte flow rate, and electrode-diaphragm distance. The combination of electrochemical and fluid dynamics studies provides comprehensive information and makes the model a promising tool for electrolysis cell design.

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Semi-empirical model and experimental validation for the performance evaluation of a 15 kW alkaline water electrolyzer

Cited by 160 publications

References 46 publications

Alkaline Water Electrolysis Powered by Renewable Energy: A Review

Alkaline Water Electrolysis Powered by Renewable Energy: A Review

Modeling the Dynamic Power‐to‐Gas Process: Coupling Electrolysis with CO₂ Methanation

CFD Modeling and Experimental Validation of an Alkaline Water Electrolysis Cell for Hydrogen Production

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Semi-empirical model and experimental validation for the performance evaluation of a 15 kW alkaline water electrolyzer

Cited by 160 publications

References 46 publications

Alkaline Water Electrolysis Powered by Renewable Energy: A Review

Alkaline Water Electrolysis Powered by Renewable Energy: A Review

Modeling the Dynamic Power‐to‐Gas Process: Coupling Electrolysis with CO2 Methanation

CFD Modeling and Experimental Validation of an Alkaline Water Electrolysis Cell for Hydrogen Production

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Product

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Modeling the Dynamic Power‐to‐Gas Process: Coupling Electrolysis with CO₂ Methanation