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Hydrogen Production, Separation and Applications

A special issue of Energies (ISSN 1996-1073).

Deadline for manuscript submissions: closed (15 December 2016) | Viewed by 19397

Special Issue Editor


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Guest Editor
Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan 701, Taiwan
Interests: bioenergy; hydrogen energy; clean energy; thermoelectric generation; environmental engineering; AI & machine leaning for energy
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Hydrogen is a clean fuel for prospective power generation from fuel cells; it can also be employed as a feedstock in some industries to abate greenhouse gas emissions into the atmosphere. Hydrogen production is an essential task to practice hydrogen economy in the future. A variety of routes, including thermochemical, electrochemical, photobiological, and photochemical methods, are being developed to produce hydrogen. In some cases, hydrogen-rich gases rather than pure hydrogen are produced. Therefore, the processes of hydrogen separation and purification, such as membrane separation, pressure swing adsorption and cryogenic distillation, are required. The purified hydrogen can be used in proton exchange membrane fuel cells (PEMFCs), hydrogen internal combustion engines, and chemical and fuel syntheses.
This Special Issue will focus on the state-of-the-art technologies of hydrogen production, separation and applications. Research involving experimental and numerical studies, recent developments, and novel and emerging technologies in this field are highly encouraged.

Dr. Wei-Hsin Chen
Guest Editor

Manuscript Submission Information

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Keywords

  • hydrogen production
  • thermochemical conversion
  • hydrogen separation
  • membrane
  • hydrogen applications
  • fuel cells
  • chemical and fuel syntheses

Published Papers (3 papers)

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Research

2653 KiB  
Article
Numerical Study of the Dynamic Response of Heat and Mass Transfer to Operation Mode Switching of a Unitized Regenerative Fuel Cell
by Hong Xiao, Hang Guo, Fang Ye and Chongfang Ma
Energies 2016, 9(12), 1015; https://doi.org/10.3390/en9121015 - 1 Dec 2016
Cited by 28 | Viewed by 5779
Abstract
Knowledge concerning the complicated changes of mass and heat transfer is desired to improve the performance and durability of unitized regenerative fuel cells (URFCs). In this study, a transient, non-isothermal, single-phase, and multi-physics mathematical model for a URFC based on the proton exchange [...] Read more.
Knowledge concerning the complicated changes of mass and heat transfer is desired to improve the performance and durability of unitized regenerative fuel cells (URFCs). In this study, a transient, non-isothermal, single-phase, and multi-physics mathematical model for a URFC based on the proton exchange membrane is generated to investigate transient responses in the process of operation mode switching from fuel cell (FC) to electrolysis cell (EC). Various heat generation mechanisms, including Joule heat, reaction heat, and the heat attributed to activation polarizations, have been considered in the transient model coupled with electrochemical reaction and mass transfer in porous electrodes. The polarization curves of the steady-state models are validated by experimental data in the literatures. Numerical results reveal that current density, gas mass fractions, and temperature suddenly change with the sudden change of operating voltage in the mode switching process. The response time of temperature is longer than that of current density and gas mass fractions. In both FC and EC modes, the cell temperature and gradient of gas mass fraction in the oxygen side are larger than that in the hydrogen side. The temperature difference of the entire cell is less than 1.5 K. The highest temperature appears at oxygen-side catalyst layer under the FC mode and at membrane under a more stable EC mode. The cell is exothermic all the time. These dynamic responses and phenomena have important implications for heat analysis and provide proven guidelines for the improvement of URFCs mode switching. Full article
(This article belongs to the Special Issue Hydrogen Production, Separation and Applications)
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2840 KiB  
Article
Optimization of Internal Cooling Fins for Metal Hydride Reactors
by Vamsi Krishna Kukkapalli and Sunwoo Kim
Energies 2016, 9(6), 447; https://doi.org/10.3390/en9060447 - 9 Jun 2016
Cited by 9 | Viewed by 5173
Abstract
Metal hydride alloys are considered as a promising alternative to conventional hydrogen storage cylinders and mechanical hydrogen compressors. Compared to storing in a classic gas tank, metal hydride alloys can store hydrogen at nearly room pressure and use less volume to store the [...] Read more.
Metal hydride alloys are considered as a promising alternative to conventional hydrogen storage cylinders and mechanical hydrogen compressors. Compared to storing in a classic gas tank, metal hydride alloys can store hydrogen at nearly room pressure and use less volume to store the same amount of hydrogen. However, this hydrogen storage method necessitates an effective way to reject the heat released from the exothermic hydriding reaction. In this paper, a finned conductive insert is adopted to improve the heat transfer in the cylindrical reactor. The fins collect the heat that is volumetrically generated in LaNi5 metal hydride alloys and deliver it to the channel located in the center, through which a refrigerant flows. A multiple-physics modeling is performed to analyze the transient heat and mass transfer during the hydrogen absorption process. Fin design is made to identify the optimum shape of the finned insert for the best heat rejection. For the shape optimization, use of a predefined transient heat generation function is proposed. Simulations show that there exists an optimal length for the fin geometry. Full article
(This article belongs to the Special Issue Hydrogen Production, Separation and Applications)
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1989 KiB  
Article
Optimal Operation of Combined Photovoltaic Electrolyzer Systems
by Arash Khalilnejad, Aditya Sundararajan, Alireza Abbaspour and Arif Sarwat
Energies 2016, 9(5), 332; https://doi.org/10.3390/en9050332 - 30 Apr 2016
Cited by 14 | Viewed by 7182
Abstract
In this study, the design and simulation of a combination of a photovoltaic (PV) array with an alkaline electrolyzer is performed to maximize the production of hydrogen as a reliable power resource. Detailed electrical model of PV system, as long as thermal and [...] Read more.
In this study, the design and simulation of a combination of a photovoltaic (PV) array with an alkaline electrolyzer is performed to maximize the production of hydrogen as a reliable power resource. Detailed electrical model of PV system, as long as thermal and electrochemical model of electrolyzer is used. Since an electrolyzer is a non-linear load, its coupling with PV systems to get the best power transfer is very important. Solar irradiation calculations were done for the region of Miami (FL, USA), giving an optimal surface slope of 25.7° for the PV array. The size of the PV array is optimized, considering maximum hydrogen production and minimum excess power production in a diurnal operation of a system using the imperialistic competitive algorithm (ICA). The results show that for a 10 kW alkaline electrolyzer, a PV array with a nominal power of 12.3 kW The results show that 12.3 kW photvoltaic system can be utilized for supplying a 10 kW electrolyzer. Hydrogen production and Faraday efficiency of the system are 697.21 mol and 0.3905 mol, respectively. Full article
(This article belongs to the Special Issue Hydrogen Production, Separation and Applications)
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