Hydrogen Generation from a Small-Scale Solar Photovoltaic Thermal (PV/T) Electrolyzer System: Numerical Model and Experimental Verification

In this study, the electrical, electrochemical and thermodynamic performance of a PV/T electrolyzer system was investigated, and the experimental results were verified with a numerical model. The annual amounts of electrical and thermal energy from the PV/T electrolyzer system were calculated as 556.8 kWh and 1912 kWh, respectively. In addition, the hydrogen production performance for the PV/T electrolyzer was compared with that of a PV electrolyzer system. The amount of hydrogen was calculated as 3.96 kg annually for the PV system, while this value was calculated as 4.49 kg for the PV/T system. Furthermore, the amount of hydrogen production was calculated as 4.59 kg for a 65 °C operation temperature. The electrical, thermal and total energy efficiencies of the PV/T system, which were obtained hourly on a daily basis, were calculated and varied between 12–13.8%, 36.1–45.2% and 49.1–58.4%, respectively. The hourly exergy analyses were also carried out on a daily basis and the results showed that the exergy efficiencies changed between 13.8–14.32%. The change in the electrolysis voltage was investigated by changing the current and temperature in the ranges of 200–1600 mA/cm2 A and 30–65 °C, respectively. While the current and the water temperature varied in the ranges of 400–2350 mA/cm2 and 28.1–45.8 °C respectively, energy efficiency and exergy efficiency were in the ranges of 57.85–69.45% and 71.1–79.7%, respectively.

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The Activation of Mg Powder Promoted by Chloride and Activation Mechanism

Metals ◽

10.3390/met11091435 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1435

Author(s):

Xiaoxuan Wang ◽

Xiaoyan Guo ◽

Lixiang Zhu ◽

Shuo Wang ◽

Meishuai Zou ◽

...

Keyword(s):

Hydrogen Production ◽

Ball Milling ◽

Photoelectron Spectroscopy ◽

Hydrogen Generation ◽

Synergistic Effects ◽

Milling Process ◽

Production Performance ◽

Activation Mechanism ◽

X Ray ◽

Highly Active

Magnesium has bright market prospects such as generating thrust for under water engines and hydrogen production. However, the passive oxide film on the surface of magnesium powder prevents the further reaction of magnesium with water at room temperature. In this paper, highly active magnesium-based materials were prepared via ball milling pure Mg with different chlorides (NiCl2, CoCl2, CuCl2, FeCl3). The activity of the as obtained powder was analyzed through Scanning Electron Microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), synchrotron X-ray tomography, Extended X-ray Absorption Fine Structure (EXAFS), etc. Among the various compositions, the Mg-6%CoCl2 composite exhibited the best hydrogen production performance with a hydrogen generation volume of 423 mL/(0.5 g) and a conversion yield of 96.6%. The related activation mechanism was thoroughly studied, showing that the addition of chloride during ball milling can effectively break the continuity of oxide films on Mg surfaces and introduces a large number of micro defects. In addition, the EXAFS and tomography data verified that metallic cobalt was generated during the ball milling process, subsequently forming a Mg-Co micro glance cell, and the Cl− in the system accelerates the corrosion of Mg. The active mechanism can be verified as synergistic effects of micro glance cell and as-generated surface microcracks.

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Hydrolysis-Based Hydrogen Generation Investigation of Aluminum System Adding Low-Melting Metals

Energies ◽

10.3390/en14051433 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1433

Author(s):

Zeng Gao ◽

Fei Ji ◽

Dongfeng Cheng ◽

Congxin Yin ◽

Jitai Niu ◽

...

Keyword(s):

Aluminum Alloy ◽

Hydrogen Production ◽

Hydrogen Generation ◽

Production Capacity ◽

Graphite Crucible ◽

Production Performance ◽

Second Phase ◽

Hydrogen Energy ◽

Reaction Products ◽

Scanning Calorimetry

In this age of human civilization, there is a need for more efficient, cleaner, and renewable energy as opposed to that provided by nonrenewable sources such as coal and oil. In this sense, hydrogen energy has been proven to be a better choice. In this paper, a portable graphite crucible metal smelting furnace was used to prepare ten multi-element aluminum alloy ingots with different components. The microstructure and phase composition of the ingots and reaction products were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). The reaction was carried out in a constant temperature water bath furnace at 60 °C, and the hydrogen production performance of the multi-element aluminum alloys in different proportions was compared by the drainage gas collection method. The experimental results show that the as-cast microstructure of Al–Ga–In–Sn aluminum alloy is composed of a solid solution of Al and part of Ga, and a second phase of In3Sn. After the hydrolysis reaction, the products were dried at 150 °C and then analyzed by XRD. The products were mainly composed of AlOOH and In3Sn. Alloys with different compositions react at the same hydrolysis temperature, and the hydrogen production performance is related to the ratio of low-melting-point metal elements. By comparing two different ratios of Ga–In–Sn (GIS), the hydrogen production capacity and production rate when the ratio is 6:3:1 are generally higher than those when the ratio is 7:2:1. The second phase content affects the hydrogen production performance.

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Study on Al-Li3AlH6-CaO Composite for Hydrogen Production Performance

Materials Science Forum ◽

10.4028/www.scientific.net/msf.852.841 ◽

2016 ◽

Vol 852 ◽

pp. 841-847

Author(s):

Xiang Fei Zhang ◽

Fen Xu ◽

Li Xian Sun ◽

Fang Yu ◽

Chong Zhao

Keyword(s):

Hydrogen Production ◽

Ball Milling ◽

Hydrogen Generation ◽

Production Performance ◽

Hydrogen Yield ◽

Practical Application ◽

Corrosion Resistant ◽

The Poor ◽

Stability Limits ◽

Poor Stability

The Al-Li3AlH6 composite as a promising hydrogen production material has attracted increasing attention. However, the poor stability limits practical application. In this paper, the Al-Li3AlH6-CaO composite has been synthesized by ball milling. The results show that the increase of the amount of added CaO can enhance the rate of the hydrogen generation. The rate of the hydrogen generation reaches 40.1 % when the amount of added CaO is 30 wt%, which is due to the fact that the added CaO can destroys the Al2O3 films. The influence of amount of added CaO on the corrosion resistant of the Al-Li3AlH6-CaO is also investigated. The Al-Li3AlH6-CaO with 35 wt% CaO exhibits well corrosion resistant performance, and the hydrogen yield decreases by 22.65 % in 30 days, while the hydrogen yield of the Al-Li3AlH6-CaO without CaO drops by 45.4% in 5 days.

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Energy and exergy analyses of a novel sulfur–iodine cycle assembled with HI–I2–H2O electrolysis for hydrogen production

International Journal of Hydrogen Energy ◽

10.1016/j.ijhydene.2021.04.129 ◽

2021 ◽

Author(s):

Zhi Ying ◽

Jingyang Yang ◽

Xiaoyuan Zheng ◽

Yabin Wang ◽

Binlin Dou

Keyword(s):

Hydrogen Production ◽

Energy And Exergy ◽

Exergy Analyses

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Photocatalytic hydrogen generation using mesoporous silicon nanoparticles: influence of magnesiothermic reduction conditions and nanoparticle aging on the catalytic activity

Nanoscale ◽

10.1039/d0nr07463b ◽

2021 ◽

Vol 13 (4) ◽

pp. 2685-2692

Author(s):

Isabel S. Curtis ◽

Ryan J. Wills ◽

Mita Dasog

Keyword(s):

Catalytic Activity ◽

Hydrogen Production ◽

Silicon Nanoparticles ◽

Hydrogen Generation ◽

Oxide Content ◽

Magnesiothermic Reduction ◽

Mesoporous Silicon ◽

High Crystallinity ◽

Photocatalytic Hydrogen Generation

High crystallinity, low oxide content, and low sintering lead to optimally performing mesoporous Si photocatalysts for solar-driven hydrogen production.

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