Metal Hydride Reactor Design Optimization for Hydrogen Energy Storage

2016 ◽  
Vol 708 ◽  
pp. 85-93 ◽  
Author(s):  
Vamsi Krishna Kukkapalli ◽  
Sun Woo Kim
Keyword(s):  
Heat Transfer ◽  
Metal Hydride ◽  
Hydrogen Absorption ◽  
High Pressures ◽  
Hydrogen Generation ◽  
Renewable Energy Sources ◽  
Hydrogen Gas ◽  
Attractive Alternative ◽  
Hydrogen Energy ◽  
Metal Hydride Alloys

As hydrogen generation technologies using renewable energy sources are being developed, considerable attention is paid to storage and transportation of hydrogen gas. Metal hydride alloys are considered as promising materials because they are viewed as an attractive alternative to conventional hydrogen storage cylinders and mechanical hydrogen compressors. Compared to storing in a classic gas cylinder, which requires compression of hydrogen at high pressures, metal hydride alloys can store the same amount of hydrogen at nearly room pressure. However, this hydrogen absorption necessitates an effective way to reject the heat released from the exothermic hydriding reaction. In this paper, fin structures are employed to enhance the heat transfer of metal hydride alloys in a cylindrical reactor. Numerical simulations are performed based on a multiple-physics modeling to analyze the transient heat transfer during the hydrogen absorption process. The objective is to minimize the time elapsed for the process and to reduce the hotspot temperature by determining the number and shape of rectangular fins while the total volume of fins used are fixed. The simulation results show that the more fins are applied the better heat transfer is achieved and that there exists an optimal length of the fins.

scholarly journals Design and calculation of heat transfer of the passive cooling modules for low-pressure hydrogen vessels

2021 ◽  
Vol 9 (11) ◽  
pp. 212-217
Author(s):  
Marián Lázár ◽  
Filip Duda ◽  
Ľubomíra Kmeťová ◽  
Natália Jasminská ◽  
Šimon Hudák
Keyword(s):  
Heat Transfer ◽  
Metal Hydride ◽  
Hydrogen Absorption ◽  
Energy Intensity ◽  
Hydrogen Gas ◽  
Current Level ◽  
Temperature Management ◽  
Passive Cooling ◽  
Science And Research ◽  
Pressure Hydrogen

This paper deals with the issue of improving the temperature management of a metal hydride tank to reduce the energy intensity of cooling. The problem of absorption and adsorption of hydrogen gas in metals, cooling of metal hydride tanks in the process of hydrogen absorption while protecting the current level of development of science and research for this area is analysed. The work also deals with numerical and experimental verification of a prototype metal hydride tank with passive cooling.

Hydrogen Storage with Annular LaNi5 Metal Hydride Pellets

2014 ◽  
Vol 875-877 ◽  
pp. 1671-1675
Author(s):  
Sun Woo Kim ◽  
Kwang J. Kim
Keyword(s):  
Heat Transfer ◽  
Metal Hydride ◽  
Thermal Conduction ◽  
Heat Transfer Performance ◽  
Hydrogen Gas ◽  
Reactor Temperature ◽  
Physics Modeling ◽  
Powder Type ◽  
Gas Supply ◽  
Hydride Powder

Thermal conduction capability of metal hydrides can be enhanced by 400 ~ 500% through pelletizing the metal hydride powder after a well-controlled copper-coating treatment. In this paper, pelletized LaNi5 metal hydride is studied to evaluate its heat transfer performance and hydrogen absorption rate. In order to analyze the transient heat transfer and hydriding reaction, numerical simulations are carried out based on a multiple-physics modeling. The reactor temperature variation and the dimensionless mass of absorbed hydrogen are plotted for different hydrogen gas supply pressures. The results are compared with the conventional powder-type metal hydride reactor.

Small-Scale, Green-Powered Hydrogen Generation System

2008 ◽  
Author(s):  
David Arruda ◽  
David Browne ◽  
Chris Thongkham ◽  
Mansour Zenouzi
Keyword(s):  
Fossil Fuels ◽  
Hydrogen Generation ◽  
Low Cost ◽  
Hydrogen Gas ◽  
Thermal Design ◽  
Small Scale ◽  
Attractive Alternative ◽  
Hydrogen Fuel ◽  
Generation System ◽  
Average Consumer

One of the major road blocks in the transition from the current oil economy to the future hydrogen fuel economy is the availability of low cost hydrogen fuel for the average consumer. Currently, the price per kilogram of hydrogen fuel is higher than the cost of an equivalent measure of gasoline and its availability is limited to large metropolitan areas. Both of these factors prevent hydrogen from being an attractive alternative to gasoline for most consumers. The goal of this project, in a senior thermal design course, is to design and construct a low-cost hydrogen generation system for residential hydrogen fuel production and storage. The system will be powered by renewable sources of energy; namely a micro-scale wind turbine and a solar panel. The power generated will be used to power a small-scale PEM electrolyzer to produce hydrogen gas that will then be stored at low pressure in a safe, metal hydride storage tank. This relatively low cost system will provide the average consumer with the ability to safely produce hydrogen fuel for use in residential fuel cells or fuel cell-powered vehicles, making hydrogen fuel an attractive alternative to fossil fuels.

Numerical investigation of heat and mass transfer during hydrogen sorption in a mixture of AB2 – AB5 metal hydride for hydrogen storage

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mapula Lucey Moropeng ◽  
Andrei Kolesnikov ◽  
Mykhaylo Lototskyy ◽  
Avhafunani Mavhungu
Keyword(s):  
Heat Transfer ◽  
Activation Energy ◽  
Mass Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat And Mass Transfer ◽  
Metal Hydride ◽  
Sorption Process ◽  
Hydrogen Gas ◽  
Hydrogen Sorption

AbstractThis paper presents the investigation of a two dimensional coupled model of heat and mass transfer in a mixture of AB2 – AB5 metal hydride (MH) systems of a cylindrical configuration during hydrogen sorption using COMSOL 5.3a commercial software. The parametric study on the sorption process has been studied with variation of heat transfer coefficient (HTC), and activation energy (AE) to understand the effects they have on the reaction kinetics of the sorption process. The simulation results demonstrate the importance of mutual dependence between the temperature propagation in the body of metal hydride, the absorbed concentration of the hydrogen gas, and the gas pressure for the absorption of hydrogen gas in metal hydrides. The decrease in the activation energy is found to have significant effect on the dynamic performances of hydrogen absorption in the MH reactors with an increased amount of hydrogen conversion, whilst the variation of heat transfer coefficient displayed insignificant change in hydrogen conversion. The simulated results show good agreement with the experimental results obtained from HYSA Systems and were implemented for use in the STILL RX60-30L electric forklift fuel cell applications designed by HYSA Systems in the University of the Western Cape.

CHARACTERIZING THE HYDROGEN TRANSPORT PROPERTIES OF RUBBERY POLYMERS BY GRAVIMETRIC ANALYSIS

2021 ◽  
Author(s):  
Jae Kap Jung ◽  
In Gyoo Kim ◽  
Sang Koo Jeon ◽  
Ki Soo Chung
Keyword(s):  
Transport Properties ◽  
High Pressures ◽  
Hydrogen Gas ◽  
Ex Situ ◽  
Total Charge ◽  
Hydrogen Energy ◽  
Gravimetric Analysis ◽  
Butadiene Rubber ◽  
Sample Shape ◽  
Rubbery Polymers

ABSTRACT We develop an ex situ technique to quantitatively analyze the transport properties of hydrogen gas dissolved under high pressure in rubbery polymers, such as cylindrical and spherical samples of nitrile butadiene rubber (NBR), ethylene propylene diene monomer (EPDM), and fluoroelastomer (FKM), which are potential sealing materials for hydrogen energy infrastructures. The technique consists of real-time gravimetric measurements during the desorption of hydrogen gas from samples using an electronic balance and a self-developed analysis program to determine the total charge (CH0), diffusivity (D), solubility (S) and permeability (P) of hydrogen. Dual absorption behavior is found for all three rubbers as the charging pressure increases. CH0 follows Henry's law at low pressures of up to ∼25 MPa, whereas the Langmuir model applies at high pressures. No significant pressure, size, or shape dependences are observed for D and P. The measured P values are consistent with those from the literature within the combined uncertainty evaluated. The effect of a carbon black filler mixed into rubber is discussed with respect to S and D. This method can be applicable as a standard test for the transport properties versus the pressure of various polymers irrespective of sample shape.

A Cell Based Approach to Determine the Minimum Weight of Metal Hydride Hydrogen Storage Devices

2009 ◽  
Author(s):  
G. Mohan ◽  
M. P. Maiya ◽  
S. Srinivasa Murthy
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Hydrogen Storage ◽  
Metal Hydride ◽  
Hydrogen Gas ◽  
Operating Conditions ◽  
Total Weight ◽  
Storage Device ◽  
Total System ◽  
Storage Devices

Determination of the minimum total weight is the main criterion in the design of a solid state hydrogen storage device for mobile or portable applications. The design should address additional requirements such as storage capacity, charge/discharge rates, space constraints, coolant temperature and hydrogen supply pressure. The typical metal hydride based storage device studied here consists of several filters to distribute hydrogen gas, and heat exchanger tubes to cool or heat the hydride bed based on whether hydrogen is absorbed or desorbed. The total weight of the system includes hydrogen storage material, heat exchanger tubes and associated heat transfer media, porous sintered filters and the cylindrical outer container. Systematic simulation of the heat and mass transfer during hydrogen sorption has been carried out for different feasible configurations. LaNi5 is used as the representative hydriding alloy in the device as its sorption performance is limited by heat transfer in the bed. The effect of geometric parameters on total system weight and charging time are plotted at specified operating conditions. These plots are used for the design of hydrogen storage devices with minimum system weight satisfying the imposed constraints.

scholarly journals Analysis of the Heat Balance of a Metal Hydride Separator Used for the Separation of Hydrogen from Syngas

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 251
Author(s):  
Tomáš Brestovič ◽  
Marián Lázár ◽  
Natália Jasminská ◽  
Jozef Živčák ◽  
Lukáš Tóth ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Metal Hydride ◽  
Heat Balance ◽  
Alloy Powder ◽  
Hydrogen Absorption ◽  
Heat Removal ◽  
Hydrogen Separation ◽  
Thermal Recovery ◽  
Field Homogeneity

The present article discusses the potential for hydrogen separation using a metal hydride separator, which facilitates the generation of hydrogen contained in syngas following the thermal recovery of wastes. The article provides a detailed description of the separator heat balance using analytical calculations and optimised calculations, and by applying numerical methods. The proposed concept of a separator intended for hydrogen separation from syngas offers a solution to a problem associated with the use of metal hydride alloy powders; in particular, their low thermal conductivity. In order to eliminate big temperature differences in the alloy, a heat transfer intensifier was implemented in the metal hydride alloy volume; the intensifier was made of metal and exhibited high thermal conductivity. For the purpose of comparing the thermal fields, the first stage comprised the creation of a numerical simulation of hydrogen absorption without the use of an intensifier. Subsequently, three different geometries were created for an intensifier intended to remove heat from the metal hydride alloy powder towards the separator cover, and the effects of these three geometries were analysed. The implementation of heat transfer intensifiers into the metal hydride alloy powder improved the heat removal by as much as 43.9% and increased the thermal field homogeneity by 77%. A result of the heat removal optimisation was an increase in the hydrogen absorption kinetics and the efficiency of the separator operation.

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