Electrolytic hydrogen application

In alkaline electrolyzers, hydrogen is obtained at the cathode with a purity of approximately 98 vol%, with oxygen and water vapor as the only impurities. Hydrogen may be further purified to almost 100% by the removal of oxygen in a catalytic deoxidizer and the subsequent removal of water vapor in a dryer. In the purification step, 5-10% of the produced hydrogen may be lost therefore, the use of electrolytic hydrogen without purification should always be considered in priority for each application. 

The hurdles to be passed for a major evolution of fuels and transport, by use of nuclear energy and electrolytic hydrogen are quite important. Among those, are the new interfaces between the petroleum industry and the power industry, which have very different time lines and mental sets. As the positive potential of this solution is proven, it is now of major importance to exchange with the oil industry and progressively identifying economic opportunities for first applications or demonstrations of clean synfuel production. 

Production and Application of Electrolytic Hydrogen Present and Future... 

Development of other non-fossil fuel energy sources, such as geothermal, solar, wind and ocean thermal systems will undoubtedly broaden the scope of application for electrolytic hydrogen — perhaps not because they represent a source of low cost electrical power, but because it represents the most attractive means for providing a transportable fuel from these renewable resources. 

All the commercial or potentially commercial energy-related applications for electrolytic hydrogen fall into one or more of these three categories. For example, vehicle fueling makes sense because of crossover arbitrage. 

Other Feedstocks - Metiwiol or ethanol can be used as feedstock in steam-reforming processes, but no commercial use has bron reported. Other feedstocks such as electrolytic hydrogen, coal, and fuel oil be discussed separately under applicable process headings. 

Electrolytic hydrogen is quite pure and is acceptable for most applications. The only major distinguishing features of the three processes are the presence or absence of mercury and the wide variation in water content of the gas. 

It is difficult to be at all quantitative as to when and to what degree these various possible applications will come to pass. Among the many factors which will determine the future energy scene are technical factors (advances in fuel cells, electric vehicles, electrolyzers, LH2 fuelled aircraft, etc.), environment factors (SO2 emissions, mining of fossil fuels, etc.) and, of course, the ubiquitous economics and politics which control all major human activities. What does seem clear is that, in the early years, synthetic fluid fuels will be manufactured by steam reforming, both for economic reasons and for institutional reasons associated with the expertise of the petroleum and gas industries. Electrolytic hydrogen will enter upon the scene more slowly, as it will be dependent upon the availability of cheap or surplus electricity and will tend to be produced by the chemical industry or electricity utilities rather than by the fuel industries. Moreover, its first use is likely to be for chemical synthesis, rather than as a fuel. 

The basic structure of all fuel cells is similar The cell consists of two electrodes that are separated by the electrolyte and that are connected with an external circuit. The electrodes are exposed to gas or liquid flows to supply the electrodes with fuel or oxidant (e.g., hydrogen or oxygen). The electrodes have to be gas or liquid permeable and, therefore, possess a porous stracture. The structure and content of the gas diffusion electrodes (GDEs) are quite complex and require considerable optimization for practical application. The electrolyte should possess gas permeability as low as possible. For fuel cells with a proton-conducting electrolyte, hydrogen is oxidized at the anode (according to Eq. (1.4)) and protons enter the electrolyte and are transported to the cathode ... 

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