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Excellent catalysis of TiO2 nanosheets with high-surface-energy {001} facets on hydrogen storage properties of MgH2
摘要： Transition metal compound is one of the highly efficient catalysts in improving the reaction kinetics of hydrogen storage materials. Among all the transition metal, titanium and its compounds show great catalytic effect on magnesium hydride. In this paper, TiO2 nanosheets with exposed {001} facets were synthesized and doped into MgH2 for the first time. The TiO2 nanosheets (NS) doped MgH2 shows superior kinetic performance and lowest desorption temperature. The onset temperature of MgH2 + 5 wt% TiO2 NS to release hydrogen is 180.5 °C and the corresponding peak temperature is 220.4 °C, which are greatly lower than those of pure MgH2 and also distinctly lower than those of MgH2 + 5 wt% TiO2 nanoparticles (NP). For isothermal dehydrogenation analysis, the MgH2 + 5 wt% TiO2 NS can release 6.0 wt% hydrogen within 3.2 min at 260 °C and desorb 5.8 wt % hydrogen within 6 min at 240 °C. It is worth noting that the MgH2 + 5 wt% TiO2 NS can even release 1.2 wt% hydrogen at a temperature as low as 180 °C within 300 min. The hydrogenation kinetics of MgH2 + 5 wt% TiO2 NS is also greatly improved, which could absorb hydrogen within only a few seconds at the mild temperature. It can uptake 3.3 wt% hydrogen at 50 °C and 5.4 wt% at 100 °C within 10 s. It is demonstrated that the tremendous enhancement in reaction kinetics of MgH2 can be ascribed to the nanometer size and highly active {001} facets of anatase TiO2. The higher average surface energy can significantly reduce the hydrogen desorption activation energy of MgH2 to 67.6 kJ/mol, thus easily improves the hydrogen desorption properties.
关键词： Magnesium hydride,Hydrogen storage,Catalytic effects,crystal facets,TiO2
更新于2025-11-14 17:03:37
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Design and analysis of a multigeneration system with concentrating photovoltaic thermal (CPV/T) and hydrogen storage
摘要： Concentrated photovoltaics (CPV) is an auspicious technology to overcome the high cost problem of highly efficient multi-junction solar cells. However, due to huge concentration of light energy, high heat flux dissipation from a confined space is a challenge. The proposed system here is first of its type to apply and thermodynamically analyze the Nucleate Pool Boiling Heat Transfer (NBHT) for thermal management of CPV. In order to increase overall efficiency of CPV system, a multigeneration system using concentrated photovoltaic thermal (CPV/T) and hydrogen storage is designed and thermodynamically analyzed to fulfill electricity, hot and cold water, heating ventilation and cooling (HVAC) requirement of a residential community with continuous operation. A part of the generated electricity from CPV is used to power the electrolyzer to produce hydrogen and oxygen. The produced gases are stored, and reused by proton exchange membrane fuel cell (PEMFC) to fulfill the system's electrical energy requirement during night time and unfavourable energy conditions in day time. The resultant thermal energy from CPV/T is used for the heating, hot water and cooling requirement of the buildings by employing lithium bromide absorption chiller (AbC). A humidity harvesting system is connected, at the outlet of the absorption chiller, to convert humid air into water and ventilation air requirement of the building. The designed system performs at 67.52% overall energy efficiency, 34.89% of overall exergy efficiency and up to 1862 times concentration ratio at designed steady-state conditions. The results show that with an increase in boiling temperature of NBHT from 353 K to 373 K, the maximum concentration ratio ability increases significantly from 1392 to 2400 times due to increase in critical heat flux, while the electrical efficiency of the CPV system decreases from 28.65% to 27.09% because of increase in cell temperature. To verify the performance of the designed system for different locations, operating conditions and capacities, the effects of Direct Normal Irradiance (IDNI), ambient temperature, relative humidity ratio and the installed capacity are also analyzed by the parametric studies.
关键词： Concentrated photovoltaics,Multigeneration system,Hydrogen storage,Exergy,Solar photovoltaics/thermal system,Electrolyzer and fuel cell
更新于2025-09-23 15:23:52
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[ASME ASME 2014 8th International Conference on Energy Sustainability collocated with the ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology - Boston, Massachusetts, USA (Monday 30 June 2014)] Volume 1: Combined Energy Cycles, CHP, CCHP, and Smart Grids; Concentrating Solar Power, Solar Thermochemistry and Thermal Energy Storage; Geothermal, Ocean, and Emerging Energy Technologies; Hydrogen Energy Technologies; Low/Zero Emission Power Plants and Carbon Sequestration; Photovoltaics; Wind Energy Systems and Technologies - Magnesium Hydride Slurry — A Better Answer to Hydrogen Storage
摘要： Hydrogen has many properties that make it an attractive energy storage medium for a sustainable future. But hydrogen is also difficult to store safely and cheaply. By storing hydrogen in an oil-based slurry with powdered magnesium hydride, cheap and safe hydrogen storage can be realized. This paper describes the characteristics and benefits of cycling hydrogen in and out of magnesium hydride slurry. Based on our experience with magnesium hydride slurry, we have performed a study to evaluate the cost effectiveness of applying bulk hydrogen storage, using magnesium hydride slurry, in a baseload wind power system that we will also discuss. This study concludes that a 150 MW baseload wind power system would produce an Internal Rate of Return (IRR) of 10% with an electric price of $0.088/kWh. The costs and performance characteristics of this power plant are described.
关键词： electricity storage,energy storage,hydrogen storage,magnesium hydride slurry,baseload wind farm
更新于2025-09-19 17:15:36
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Lightning-Rod Effect of Plasmonic Field Enhancement on Hydrogen-Absorbing Transition Metals
摘要： The plasmonic enhancement of electromagnetic ?eld energy density at the sharp tips of nanoparticles or nanoscale surface roughnesses of hydrogen-absorbing transition metals, Pd, Ti, and Ni, is quantitatively investigated. A large degree of energy focusing is observed for these transition metals in the microwave region, even surpassing the enhancement for noble metals according to the conditions. Pd, for instance, exhibits peak ?eld enhancement factors of 6000 and 2 × 108 in air for morphological aspect ratios of 10 and 100, respectively. Metal surfaces possibly contain such degrees of nano- or micro-scale native random roughnesses, and, therefore, the ?eld enhancement e?ect may have been unknowingly produced in existing electrical and optical systems. In addition, for future devices under development, particularly in hydrogen-related applications, it is desirable to design and optimize the systems, including the choice of materials, structures, and operating conditions, by accounting for the plasmonic local energy enhancement e?ect around the metal surfaces.
关键词： nuclear fusion,sensing,transition metal,surface plasmon,nanophotonics,energy device,hydrogen storage,nanoparticle
更新于2025-09-12 10:27:22
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[IEEE 2019 Electric Vehicles International Conference (EV) - Bucharest, Romania (2019.10.3-2019.10.4)] 2019 Electric Vehicles International Conference (EV) - Modelisation of Hydrogen Production using Photovoltaic Electrolysis
摘要： The Electric Vehicle (EV) technology addresses the issue of the reduction of greenhouse gas emissions (GHG). Normally, EVs are recharged with electricity generated from conventional energy sources. For full clean mobility and to have zero emissions and favorable environmental impact, it is better to charge the vehicles from Renewable Energies Systems (RESs). Using RESs for producing hydrogen is a main method to store RESs. This option is required to integrate energy storage system based on hydrogen storage. Hydrogen can be produced by using solar photovoltaic energy for the electrolysis of water. This paper focuses on the Proton Exchange Membrane Electrolyzer (PEME) and covers a board array of subjects linked to this electrolyzer. Gives a control oriented modeling of the PEME, as well as the auxiliary system for the hydrogen production process. In fact, PEME is the most suitable for transforming electricity from RESs. In this context, the present paper describes the essential steps of hydrogen production from the photovoltaic solar energy through PEME, in order to describe the various phenomena related to this technology.
关键词： Modeling and optimization,Hydrogen storage,PEM electrolyzer,Electric vehicle
更新于2025-09-12 10:27:22
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[IEEE 2018 2nd International Conference on Energy Conservation and Efficiency (ICECE) - Lahore, Pakistan (2018.10.16-2018.10.17)] 2018 2nd International Conference on Energy Conservation and Efficiency (ICECE) - Cost Optimization of Hybrid Microgrid using Solar PV, Fuel Cell and Diesel Generator in HOMER
摘要： DC microgrids comprising of hybrid distributed generation is a welcoming trend in renewable systems based power generation. It is also considered as a viable solution to provide electricity to the rural areas in underdeveloped countries. Distributed generation is beneficial because it reduces the transmission losses, has less environmental hazards, and is comparatively cheaper when renewables are employed. In this paper, a hybrid microgrid is proposed for the irrigation system in Gujranwala. The system is designed in Hybrid Optimization of Multiple Energy Resources (HOMER). The solar resource data is obtained from National Solar Radiation Database. The different sources considered in this case include solar photovoltaic (PV), hydrogen gas based fuel cell, and diesel generator. An optimization analysis is performed and a comparative study is completed in HOMER based on the sensitivity variables chosen. The various design configurations are evaluated and the optimal design is chosen based on load demand, available resources, and the cost of energy.
关键词： fuel cells,hydrogen storage,DC pump,HOMER,Solar photovoltaics
更新于2025-09-09 09:28:46