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Hydrogen and Fuel Cells
Published in Muhammad Asif, Handbook of Energy Transitions, 2023
Saeed-ur-Rehman, Hafiz Ahmad Ishfaq, Zubair Masaud, Muhammad Haseeb Hassan, Hafiz Ali Muhammad, Muhammad Zubair Khan
Alkaline water electrolysis is a well-established technology for hydrogen production that is operating worldwide up to megawatt scale commercial plants. AEC consists of two compartments containing alkaline solution consisting of KOH and NaOH that are separated by an asbestos diaphragm. Ni-based electrodes are dipped into the solution, which produced hydrogen and hydroxyl (OH−) ions at the cathode when a DC electric current is applied. Hydroxyl ions then move toward the anode through the diaphragm under the influence of DC electric current and produce oxygen and water molecules at the anode. The diaphragm separates the two chambers and also the produced hydrogen and oxygen gases. Alkaline water electrolysis operates are low temperatures from 30°C to 80°C (Figure 9.2).
Alkaline Liquid Electrolyte for Water Electrolysis
Published in Lei Zhang, Hongbin Zhao, David P. Wilkinson, Xueliang Sun, Jiujun Zhang, Electrochemical Water Electrolysis, 2020
Xuefeng Guo, Shanyong Chen, Yu Zhang, Mingjiang Xie, Jian Chen
Besides the anode/cathode catalysts, electrolytes and separators are also critical components for water splitting. Ionic conductivity between the electrodes and within the porous structures of catalysts is provided by the electrolytes. Hence, the criteria of a suitable electrolyte are high ionic conductivity and non-corrosive to electrodes. In this regard, alkali (potassium or sodium hydroxide) solutions are the common commercial electrolytes for alkaline water electrolysis systems because they are more conductive than the other alkali metal bases (with respect to equal molarities) and unreactive to electrodes, hence, avoiding large corrosion loss.114,115
Grey, blue, and green hydrogen: A comprehensive review of production methods and prospects for zero-emission energy
Published in International Journal of Green Energy, 2023
Priyanka Saha, Faysal Ahamed Akash, Shaik Muntasir Shovon, Minhaj Uddin Monir, Mohammad Tofayal Ahmed, Mohammad Forrukh Hossain Khan, Shaheen M. Sarkar, Md. Kamrul Islam, Md. Mehedi Hasan, Dai-Viet N. Vo, Azrina Abd Aziz, Md. Jafar Hossain, Rafica Akter
The working concept of alkaline water electrolysis is electrochemical water splitting in the presence of electricity. The process incorporates two independent half-cell processes, hydrogen evolution reaction (HER) at the cathode and oxygen evolution reaction (OER) at the anode. During the process, two moles of alkaline solution are first reduced at the cathode to create one mole of hydrogen (H2) and two moles of hydroxyl ions (OH−). The H2 is removed from the cathodic surface, and the residual hydroxyl ions are transmitted through the porous separator to the anode side under the effect of an electric circuit. At the anode, the hydroxyl ions are released to form one molecule of oxygen (O2) and one molecule of water (H2O).
CFD analysis for optimizing superheater components for high temperature steam production for use in an SOEC
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Yunji Kim, Hyunseung Byun, SeongRyong Park, Chongpyo Cho, Youngsoon Baek
Water electrolysis can be conducted in two mediums: basic and acidic. Low-temperature alkaline water electrolysis in basic mediums has been proven to be stable and price competitive through various empirical projects; however, although this approach has high technological maturity, it has a low current density. Polymer membrane electrolysis in acidic mediums is characterized by a safe and compact design with high current density; however, its lifetime is short and the membrane cost is high(Cho, Cho, and Kim 2018; Colli, Girault, and Battistel 2019).