Dynamic modeling of hydrogen desorption from a metal hydride tank using the electrical fluidic analogy

WHEC 2016, World Hydrogen Energy Conference, Saragosse, ESPAGNE, 13-/06/2016 - 16/06/2016International audienceThe current work presents a modeling study of the thermal behavior during discharge of a hydride hydrogen tank. In a thermal coupling between a fuel cell and its associated hydride hydrogen tank, the hydrogen desorption kinetics depends on temperature, nature of the hydride, the tank design, but also on the hydrogen demand from the fuel cell in terms of mass flow and pressure. The objective of the study is to demonstrate the dynamic response of hydrogen discharge from a metal hydride tank by using the fluidic electrica

Advanced study of hydrogen storage by substitutional doping of Mn and Ti in Mg

The substitutional doping of Mn and Ti in Mg2Ni phase has been investigated by first principles density functional theory calculations. The calculation of enthalpy of formation shows that among the four different lattice sites of Mg(6f), Mg(6i), Ni(3b) and Ni(3d) in Mg2Ni unit cell, the most preferable site of substitution of Mn in Mg2Ni lattice has been confirmed to be Mg(6i) lattice site. The most preferable site of Ti substitution in Mg2Ni lattice is Mg(6i) position and the stability of Ti-doped Mg2Ni decreases with the increase of substitution quantity of Ti for Mg

Advanced study of hydrogen storage by substitutional doping of Mn and Ti in Mg2Ni phase

The substitutional doping of Mn and Ti in Mg2Ni phase has been investigated by first principles density functional theory calculations. The calculation of enthalpy of formation shows that among the four different lattice sites of Mg(6f), Mg(6i), Ni(3b) and Ni(3d) in Mg2Ni unit cell, the most preferable site of substitution of Mn in Mg2Ni lattice has been confirmed to be Mg(6i) lattice site. The most preferable site of Ti substitution in Mg2Ni lattice is Mg(6i) position and the stability of Ti-doped Mg2Ni decreases with the increase of substitution quantity of Ti for Mg

Analysis of structure and magnetic properties of nanocrystalline milled alloys

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Electrochemical properties of the CaNi 4 . 8 M 0.2 (M=Mg, Zn, and Mn) mechanical milling alloys used as anode materials in nickel‐metal hydride batteries

International audienceAbstract The present research work examines the electrochemical properties of CaNi 4.8 M 0.2 (M=Mg, Zn) type alloy applied as an anode in nickel metal hybrid batteries. Based on an extensive study of the CaNi 4.8 Mn 0.2 compound prepared by mecano‐synthesis; under an argon atmosphere, with a variation of milling time and weigh ratio, using a Retsch PM400 type ball mill. The experimental results show that the excellent electrochemical properties were obtained for a milling time of 40 h and a ball‐to‐powder weight ratio equal to 8:1. Based on this study, we examined electrochemically the CaNi 4.8 M 0.2 (M=Mg, Zn, and Mn) compound according to the optimized parameters. Several methods, such as galvanostatic polarization and potentiodynamic polarization, were applied to characterize these electrodes. CaNi 4.8 M 0.2 (M=Mg, Zn, and Mn) electrodes were activated, respectively, during the first, second, and third cycles. The maximum discharge capacity was about 87, 60, and 96 mAhg −1 at ambient temperature. These electrochemical findings correlate with the kinetic results provided during a long cycle

OenVHy, to study hydride storage and Fuel cell system coupling

FDFC 2015 - 6th International Conference on Fundamentals and Development Fuel Cell, TOULOUSE, FRANCE, 03-/02/2015 - 05/02/2015The choice of the hydride material is necessary not only for the hydrogen tank sizing but also for the optimal thermal and electrical energy balance in the overall system including a hydride hydrogen tank coupled to a fuel cell generator. A comprehensive state of the art concerning the coupling between hydride storage and different types of fuel cells (low and high temperature) is proposed. According to the different syntheses, different hydride types can be used for hydrogen storage in order to optimize thermal coupling between hydrogen tanks with various fuel cell system technologies

Energetic modeling, simulation and experimental of hydrogen desorption in a hydride tank

International audienceThis paper presents a zero-dimensional (0D) model of hydride tank. The model aims to study the dynamic heat and mass transfers during desorption process in order to investigate the thermal-fluidic behaviors of this hydride tank. This proposed model has been validated experimentally thanks to a tailor-made developed test bench. This test bench allows the hydride characterization at tank scale and also the energetic characterization. The simulation results of the heat exchanges and mass transfer in and between the coupled reaction bed, show good agreement with the experimental ones. It is shown that the heat produced by a Proton Exchange Membrane Fuel Cell (PEMFC) (estimated starting from an electrical model) is enough to heat the metal alloy (FeTi) and therefore release the hydrogen with a sufficient mass flow rate to supply the PEMFC. Furthermore, the obtained results highlight the importance of the developed model for energy management of the coupling of fuel cell and hydride tank system

A new method for the characterization of hydrides hydrogen tanks dedicated to automotive applications

In recent years, hydrogen has emerged as one of the best candidates in the field of renewable energy. Hydrogen storage in solid form has created new areas of application. Knowing the thermodynamic parameters of intermetallic compounds featuring stable hydrides is of great importance when using these hydrides in energy sources such as fuel cell generators for embedded or stationary applications. In this work, a new experimental method is described for measuring the hydrogen absorption/desorption characteristics of hydrogen storage material. This method is able to determine the Pressure-Composition-Temperature isotherm of a scale 1 hydride tank used in a fuel cell vehicle. This kind of characterization is useful for optimizing energy management between two vehicle powertrain components: the fuel cell stack and the hydride storage unit

Energy management of a thermally coupled fuel cell system and metal hydride tank

Being produced from renewable energy, hydrogen is one of the most efficient energy carriers of the future. Using metal alloys, hydrogen can be stored and transported at a low cost, in a safe and effective manner. However, most metals react with hydrogen to form a compound called metal hydride (MH). This reaction is an exothermic process, and as a result releases heat. With sufficient heat supply, hydrogen can be released from the asformed metal hydride. In this work, we propose an integrated power system of a proton exchange membrane fuel cell (PEMFC) together with a hydride tank designed for vehicle use. We investigate different aspects for developing metal hydride tanks and their integration in the PEMFC, using water as the thermal fluid and a FeTi intermetallic compound as the hydrogen storage material. Ground truth simulations show that the annular metal hydride tank meets the hydrogen requirements of the fuel cell, but to the detriment of the operating temperature of the fuel cell (FC)

Hydride Material for optimal hydrogen storage system of fuel cell electrical vehicles

14 th International Symposium on Metal-Hydrogen Systems, MANCHESTER, ROYAUME-UNI, 20-/07/2014 - 25/07/2014This study proposes the thermal management of the hydrogen 'metal-hydride' storage system. The thermal topic is the main problem of the interaction between this kind of tanks and the fuel cell. A state of the art concerning the coupling between hydride storage and various types of fuel cells (low and high temperature) is given with the perspectives of our study