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.

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.

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.

Modelling and control of an alkaline water electrolysis process

2018 ◽  
Vol 1 (2) ◽  
pp. 9-14
Author(s):  
Marisol Cervantes-Bobadilla ◽  
Ricardo Fabricio Escobar Jiménez ◽  
José Francisco Gómez Aguilar ◽  
Tomas Emmanuel Higareda Pliego ◽  
Alberto Armando Alvares Gallegos
Keyword(s):  
Process Model ◽  
Water Electrolysis ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water ◽  
Electrolysis Process ◽  
Linear Dynamic ◽  
Energy Current ◽  
Identification Technique ◽  
Nonlinear Static ◽  
And Control

In this research, an alkaline water electrolysis process is modelled. The electrochemical electrolysis is carried out in an electrolyzer composed of 12 series-connected steel cells with a solution 30% wt of potassium hydroxide. The electrolysis process model was developed using a nonlinear identification technique based on the Hammerstein structure. This structure consists of a nonlinear static block and a linear dynamic block. In this work, the nonlinear static function is modelled by a polynomial approximation equation, and the linear dynamic is modelled using the ARX structure. To control the current feed to the electrolyzer an unconstraint predictive controller was implemented, once the unconstrained MPC was simulated, some restrictions are proposed to design a constrained MPC (CMPC). The CMPC aim is to reduce the electrolyzer's energy consumption (power supply current). Simulation results showed the advantages of using the CMPC since the energy (current) overshoots are avoided.

scholarly journals Boosting alkaline water electrolysis by asymmetric temperature modulation

2021 ◽  
Vol 119 (1) ◽  
pp. 013901
Author(s):  
Qinpeng Zhu ◽  
Peihua Yang ◽  
Tao Zhang ◽  
Zehua Yu ◽  
Kang Liu ◽  
...  
Keyword(s):  
Water Electrolysis ◽  
Temperature Modulation ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water

scholarly journals Towards the Hydrogen Economy—A Review of the Parameters That Influence the Efficiency of Alkaline Water Electrolyzers

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3193
Author(s):  
Ana L. Santos ◽  
Maria-João Cebola ◽  
Diogo M. F. Santos
Keyword(s):  
Energy Content ◽  
Water Electrolysis ◽  
High Energy ◽  
Operating Conditions ◽  
Energy Sources ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water ◽  
New Energy ◽  
Recent Developments ◽  
Cell Components

Environmental issues make the quest for better and cleaner energy sources a priority. Worldwide, researchers and companies are continuously working on this matter, taking one of two approaches: either finding new energy sources or improving the efficiency of existing ones. Hydrogen is a well-known energy carrier due to its high energy content, but a somewhat elusive one for being a gas with low molecular weight. This review examines the current electrolysis processes for obtaining hydrogen, with an emphasis on alkaline water electrolysis. This process is far from being new, but research shows that there is still plenty of room for improvement. The efficiency of an electrolyzer mainly relates to the overpotential and resistances in the cell. This work shows that the path to better electrolyzer efficiency is through the optimization of the cell components and operating conditions. Following a brief introduction to the thermodynamics and kinetics of water electrolysis, the most recent developments on several parameters (e.g., electrocatalysts, electrolyte composition, separator, interelectrode distance) are highlighted.

scholarly journals Electrode-diaphragm assembly for alkaline water electrolysis

2020 ◽  
Vol 1683 ◽  
pp. 052011
Author(s):  
V N Kuleshov ◽  
S V Kurochkin ◽  
N V Kuleshov ◽  
D V Blinov ◽  
O Y Grigorieva
Keyword(s):  
Water Electrolysis ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water

scholarly journals The Effect of Iron Impurities on Transition Metal Catalysts for the Oxygen Evolution Reaction in Alkaline Environment: Activity Mediators or Active Sites?

2020 ◽  
Author(s):  
Ioannis Spanos ◽  
Justus Masa ◽  
Aleksandar Zeradjanin ◽  
Robert Schlögl
Keyword(s):  
Transition Metal ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Active Sites ◽  
Water Electrolysis ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Alkaline Water Electrolysis ◽  
Co Catalysts ◽  
Model Transition

AbstractThere is an ongoing debate on elucidating the actual role of Fe impurities in alkaline water electrolysis, acting either as reactivity mediators or as co-catalysts through synergistic interaction with the main catalyst material. This perspective summarizes the most prominent oxygen evolution reaction (OER) mechanisms mostly for Ni-based oxides as model transition metal catalysts and highlights the effect of Fe incorporation on the catalyst surface in the form of impurities originating from the electrolyte or co-precipitated in the catalyst lattice, in modulating the OER reaction kinetics, mechanism and stability. Graphic Abstract

Sign in / Sign up

Export Citation Format

Share Document