Hybrid Renewable Energy Systems: Integration of Urban Mobility Through Metal Hydrides Solution as an Enabling Technology for Increasing Self-Sufficiency

Numerical simulation of a metal hydride tank with LaNi4.25Al0.75 using a novel kinetic model at constant flows

Metal hydrides are very much reported as a potential safe option for high-density hydrogen storage materials. A combined system of proton-exchange membrane hydrogen fuel cell (PEMFC) and metal hydride (MH) tanks is designed to investigate their characteristics and performances as hydrogen storage and stable power supply system. An AB5-type (LaCe)Ni5 material containing three MH tanks is selected for investigation. Endothermic dehydrogenation of metal hydride controls the hydrogen evolution rates during a discharging period, which reduces the risk of accidents. The MH tank charged at a 20°C water bath sustains and supplies hydrogen for a longer time of 240 min. The performances of the MH tank at a water bath of 20°C and 10-bar conditions correspond to the optimum condition of hydrogen storage at the MH tank of Pragma Industries. The performances of the combined system were investigated in different working conditions. The system sustains and supplies hydrogen to PEMFC for 240, 160, 130, and 110 min for the working loads of 250, 500, 1,000, and 2,000 W, accordingly. It is concluded that hydrogen consumption frequency increases for higher load demand.

A novel electrical energy storage system based on a reversible solid oxide fuel cell coupled with metal hydrides and waste steam

Impact of using a heat transfer fluid pipe in a metal hydride-phase change material tank

Impacts of external heat transfer enhancements on metal hydride storage tanks

A study on ideal distance between staggered metal hydride tanks in forced convection

Use of cold start-up operations in the absence of external heat sources for fast fuel cell power and heat generation in a hydrogen energy system utilizing metal hydride tanks

This work demonstrates the study of the numerical modelling and a design of a compact energy generator based on green hydrogen. This generator aims allowing the energy storage, electricity, cold and heat productions as well as a supply the energy for the production of the sanitary hot water. The generator is considered to be powered by 30 solar cells panels and will mainly consist of a Proton Exchange Membrane (PEM) electrolyzer compiled with a Metal Hydride (MH) tank, a PEM fuel cell, and a system of heat exchangers sized to recover the heat from the electrolyzer, PEM fuel cell and MH tank. Furthermore, the generator will contain an adsorber to manage air conditioning (cooling and heating) and a production of the sanitary hot water. A converter block is included in the generator, in particular, a Buck-booster to raise the voltage of the solar panels and the DC-AC converter for the electricity consumption in the household. The desorption of the hydrogen contained in the tank MH will take place using the heating resistance. In overall, the designed generator is foreseen to have a dimension of 1800 × 1000 × 500 mm and its role is to allow integration of the hydrogen energy for the tertiary and residential sectors. As such it is a suitable choice of components for the cost reduction and high yield hydrogen production, storage, and consumption.

Design of a AB2-metal hydride cylindrical tank for renewable energy storage

Thermal coupling potential of Solid Oxide Fuel Cells with metal hydride tanks: Thermodynamic and design considerations towards integrated systems

High-pressure metal hydride (MH) tank is a possible hydrogen storage system for fuel cell vehicles. The merit of the high-pressure MH tank system is improved by the use of a metal hydride with high dissociation pressure. In this study, TiCrV and TiCrVMo alloys with BCC structure have been developed for the system. The developed TiCrVMo alloy shows 2.5mass% of effective hydrogen capacity in the pressure range between 0.1MPa and 33MPa at 298K. In TiCrV, the dissociation pressure of the alloy increases with the decrease of the lattice size. This trend is consistent with a general trend often observed for other metal hydrides. However, for TiCrVMo alloy, the dissociation pressure is sensitive not only to the lattice size but also to the content of Mo. As a result, it turned out that Mo has a special effect to increase the dissociation pressure of the hydride. Combined with the developed TiCrVMo alloy, hydrogen charging/discharging properties as a high pressure MH tank was also investigated. The whole tank system has a potential to store 5kg of hydrogen within 95L and 225kg, which means 0.053kgH2/L and 0.022kgH2/kg as a total system, respectively.

An air-breathing single cell small proton exchange membrane fuel cell system with AB5-type metal hydride and an ultra-low voltage input boost converter

By using a newly constructed bench-scale hydrogen energy system with renewable energy, ‘Pure Hydrogen Energy System’, the present study demonstrates the operations of a metal hydride (MH) tank for hydrogen compression as implemented through the use solar thermal energy. Solar thermal energy is used to generate hot water as a heat source of the MH tank. Thus, 70 kg of LaNi5, one of the most typical alloys used for hydrogen storage, was placed in the MH tank. We present low and high hydrogen flow rate operations. Then, the operations under winter conditions are discussed along with numerical simulations conducted from the thermal point of view. Results show that a large amount of heat (>100 MJ) is generated and the MH hydrogen compression is available.

Numerical investigations on the absorption of a metal hydride hydrogen storage tank based on various thermal management strategies

A three-dimensional mathematical model has been developed to study the performance of a coupled hydrogen-storage and thermal-energy-storage system. The heat transfer between the metal hydride tank and the sensible heat-storage system has been simulated. Embedded cooling tubes with water as the heat-transfer fluid were used to transfer heat between the metal hydride and thermal-energy-storage system during absorption and desorption cycles. The concrete-based thermal-energy-storage system stores the heat produced during absorption of hydrogen in the hydride tank and transfers it to the heat-transfer fluid. The stored heat is then reversibly utilised by the hydride tank during desorption of hydrogen. Simulations have shown that, on integration of the sensible heat storage system with the metal hydride tank, only 37% of the heat generated in the metal hydride tank is stored in the storage system. Thus, in order to store a higher amount of available thermal energy, an alternate material with higher thermal conductivity and specific heat will be required.