scholarly journals Multiphysical Models for Hydrogen Production Using NaOH and Stainless Steel Electrodes in Alkaline Electrolysis Cell

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ivan Newen Aquigeh ◽  
Merlin Zacharie Ayissi ◽  
Dieudonné Bitondo
Keyword(s):  
Stainless Steel ◽  
Hydrogen Production ◽  
Supporting Electrolyte ◽  
Cell Voltage ◽  
Water Electrolysis ◽  
Maximum Error ◽  
Electrolysis Cell ◽  
Alkaline Water Electrolysis ◽  
Interelectrode Gap ◽  
Alkaline Electrolysis

The cell voltage in alkaline water electrolysis cells remains high despite the fact that water electrolysis is a cleaner and simpler method of hydrogen production. A multiphysical model for the cell voltage of a single cell electrolyzer was realized based on a combination of current-voltage models, simulation of electrolyzers in intermittent operation (SIMELINT), existing experimental data, and data from the experiment conducted in the course of this work. The equipment used NaOH as supporting electrolyte and stainless steel as electrodes. Different electrolyte concentrations, interelectrode gaps, and electrolyte types were applied and the cell voltages recorded. Concentrations of 60 wt% NaOH produced lowest range of cell voltage (1.15–2.67 V); an interelectrode gap of 0.5 cm also presented the lowest cell voltage (1.14–2.71 V). The distilled water from air conditioning led to a minimum cell voltage (1.18–2.78 V). The water from a factory presented the highest flow rate (12.48 × 10−1cm3/min). It was found that the cell voltage of the alkaline electrolyzer was reduced considerably by reducing the interelectrode gap to 0.5 cm and using electrolytes that produce less bubbles. A maximum error of 1.5% was found between the mathematical model and experimental model, indicating that the model is reliable.

scholarly journals Development of an operation strategy for hydrogen production using solar PV energy based on fluid dynamic aspects

2017 ◽  
Vol 7 (1) ◽  
pp. 141-152 ◽  
Author(s):  
Ernesto Amores ◽  
Jesús Rodríguez ◽  
José Oviedo ◽  
Antonio de Lucas-Consuegra
Keyword(s):  
Hydrogen Production ◽  
Fluid Dynamic ◽  
Renewable Energy Sources ◽  
Water Electrolysis ◽  
Weather Conditions ◽  
Energy Sources ◽  
Electrolysis Cell ◽  
Operation Strategy ◽  
Solar Pv ◽  
Alkaline Water Electrolysis

AbstractAlkaline water electrolysis powered by renewable energy sources is one of the most promising strategies for environmentally friendly hydrogen production. However, wind and solar energy sources are highly dependent on weather conditions. As a result, power fluctuations affect the electrolyzer and cause several negative effects. Considering these limiting effects which reduce the water electrolysis efficiency, a novel operation strategy is proposed in this study. It is based on pumping the electrolyte according to the current density supplied by a solar PV module, in order to achieve the suitable fluid dynamics conditions in an electrolysis cell. To this aim, a mathematical model including the influence of electrode-membrane distance, temperature and electrolyte flow rate has been developed and used as optimization tool. The obtained results confirm the convenience of the selected strategy, especially when the electrolyzer is powered by renewable energies.

scholarly journals Evolutionary Design Optimization of an Alkaline Water Electrolysis Cell for Hydrogen Production

2020 ◽  
Vol 10 (23) ◽  
pp. 8425
Author(s):  
Damien Le Bideau ◽  
Olivier Chocron ◽  
Philippe Mandin ◽  
Patrice Kiener ◽  
Mohamed Benbouzid ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Current Density ◽  
Operating Cost ◽  
Cell Voltage ◽  
Electrolysis Cell ◽  
Alkaline Water Electrolysis ◽  
Financial Investment ◽  
Operation Conditions ◽  
Optimal Current ◽  
The Cost

Hydrogen is an excellent energy source for long-term storage and free of greenhouse gases. However, its high production cost remains an obstacle to its advancement. The two main parameters contributing to the high cost include the cost of electricity and the cost of initial financial investment. It is possible to reduce the latter by the optimization of system design and operation conditions, allowing the reduction of the cell voltage. Because the CAPEX (initial cost divided by total hydrogen production of the electrolyzer) decreases according to current density but the OPEX (operating cost depending on the cell voltage) increases depending on the current density, there exists an optimal current density. In this paper, a genetic algorithm has been developed to find the optimal evolution parameters and to determine an optimum electrolyzer design. The optimal current density has been increased by 10% and the hydrogen cost has been decreased by 1%.

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

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1634
Author(s):  
Jesús Rodríguez ◽  
Ernesto Amores
Keyword(s):  
Fluid Dynamics ◽  
Hydrogen Production ◽  
Current Density ◽  
Fluid Dynamic ◽  
Water Electrolysis ◽  
Operating Conditions ◽  
Cfd Modeling ◽  
Electrolysis Cell ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water

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.

scholarly journals Lignin-Assisted Water Electrolysis for Energy-Saving Hydrogen Production With Ti/PbO2 as the Anode

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiayi Li ◽  
Wei Zhou ◽  
Yuming Huang ◽  
Jihui Gao
Keyword(s):  
Energy Consumption ◽  
Hydrogen Production ◽  
Electricity Consumption ◽  
Cell Voltage ◽  
Linear Sweep Voltammetry ◽  
Water Electrolysis ◽  
High Energy ◽  
Alkaline Water Electrolysis ◽  
Lignin Concentration ◽  
Slow Kinetics

Replacing the oxygen evolution reaction (OER), which is of high energy consumption and slow kinetics, with the more thermodynamically favorable reaction at the anode can reduce the electricity consumption for hydrogen production. Here we developed a lignin-assisted water electrolysis (LAWE) process by using Ti/PbO2 with high OER overpotential as the anode aimed at decreasing the energy consumption for hydrogen production. The influence of key operating parameters such as temperature and lignin concentration on hydrogen production was analyzed. Compared with alkaline water electrolysis (AWE), the anode potential can be decreased from 0.773 to 0.303 (V vs. Hg/HgO) at 10 mA/cm2 in LAWE, and the corresponding cell voltage can be reduced by 546 mV. With increasing the temperature and lignin concentration, current density and H2 production rate were efficiently promoted. Furthermore, the anode deactivation was investigated by analyzing the linear sweep voltammetry (LSV) and cyclic voltammetry (CV) tests. Results showed that the anode deactivation was affected by the temperature.

Alkaline Electrolysis at Sea for Green Hydrogen Production: A Solution to Electrolyte Deterioration

2018 ◽  
Author(s):  
Rafael d’Amore-Domenech ◽  
Emilio Navarro ◽  
Eleuterio Mora ◽  
Teresa J. Leo
Keyword(s):  
Hydrogen Production ◽  
High Efficiency ◽  
Water Electrolysis ◽  
Alkaline Electrolyte ◽  
Alkaline Water Electrolysis ◽  
Logistic Problem ◽  
Combined Solution ◽  
Electrolysis Method ◽  
Novel Method ◽  
Alkaline Electrolysis

This article illustrates a novel method to produce hydrogen at sea with no carbon footprint, based on alkaline electrolysis, which is the cheapest electrolysis method for in-land hydrogen production, coupled to offshore renewable farms. The novelty of the method presented in this work is the solution to cope with the logistic problem of periodical renewal of the alkaline electrolyte, considered problematic in an offshore context. Such solution consists in the integration of a small chlor-alkali plant to produce new electrolyte in situ. This article describes a proposal to combine alkaline water electrolysis and chlor-alkali processes, first considering both in a separate manner, and then describing and discussing the combined solution, which seeks high efficiency and sustainability.

Modeling and Optimization of an Alkaline Water Electrolysis for Hydrogen Production

2021 ◽  
Author(s):  
Katherine Stewart ◽  
Laurianne Lair ◽  
Brenda De La Torre ◽  
Nguyen L. Phan ◽  
Rupak Das ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Water Electrolysis ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water ◽  
Modeling And Optimization

scholarly journals Aging of Polyphenylene Sulfide-Glass Composite and Polysulfone in Highly Oxidative and Strong Alkaline Environments

2020 ◽  
Vol 7 ◽  
Author(s):  
X. X. Zheng ◽  
A. J. Böttger ◽  
K. M. B. Jansen ◽  
J. van Turnhout ◽  
J. van Kranendonk
Keyword(s):  
Glass Fibers ◽  
Water Electrolysis ◽  
Polyphenylene Sulfide ◽  
Raw Material ◽  
Chemical Degradation ◽  
Pure Oxygen ◽  
Creep Recovery ◽  
Alkaline Water Electrolysis ◽  
Alkaline Environments ◽  
Alkaline Electrolysis

Alkaline water electrolysis becomes increasingly important for the supply of renewable energy, and of raw material for the chemical industry. An attractive choice for the encapsulation of the electrolyte cell is an (advanced) engineering polymer. The objective of this paper is to find a suitable one that can withstand for many years: 30 wt% KOH solution and pure oxygen at a high pressure of 50 bar and at an elevated temperature of 90°C. Using CES EduPack, 12 possible thermoplastic polymers were selected, of which polyphenylene sulfide (PPS) and polysulfone (PSU) were further investigated using accelerated testing. The polymers have been exposed to three KOH concentrations (15, 30 and 45 wt%), two oxygen pressures (pure O2 at 5 bar and air with pO2 = 20%), and three temperatures (90°C, 120°C, and 170°C). Extensive characterization of the exposed samples has been carried out using various techniques, including weight, tensile, DMA, and creep-recovery measurements, as well as DSC, FTIR, XRD and SEM. After 12 weeks of aging, glass fiber reinforced PPS failed in a strong alkaline solution at high temperatures, due to the dissolution of the glass fibers. The PPS matrix itself and PSU turned out to be resistant to thermo-oxidative and chemical degradation under the conditions tested. Only marginal changes in mechanical, visco-elastic and thermal behavior were observed, which can be ascribed to physical rather than chemical aging. In view of the brittle nature of PPS, it could be concluded that PSU is the most promising candidate for the long-term application in alkaline electrolysis. Extrapolating the data using time-temperature superposition, it is predicted that PSU will retain its integrity and mechanical properties for a period of 20 years of operation.

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