Systems Modeling of Ammonia Borane Bead Reactor for Off-Board Regenerable Hydrogen Storage in PEM Fuel Cell Applications

2010 ◽  
Author(s):  
Kriston Brooks ◽  
Maruthi Devarakonda ◽  
Scot Rassat ◽  
Dale King ◽  
Darrell Herling
Keyword(s):  
Fuel Cell ◽  
Hydrogen Storage ◽  
Pem Fuel Cell ◽  
Ammonia Borane ◽  
Hydrogen Gas ◽  
Reactor System ◽  
Automotive Application ◽  
State Variables ◽  
High Hydrogen ◽  
System Pressure

Research on ammonia borane (AB, NH3BH3) has shown it to be a promising material for chemical hydrogen storage in PEM fuel cell applications. AB was selected by DOE’s Hydrogen Storage Engineering Center of Excellence (HSECoE) as the initial chemical hydride of study because of its high hydrogen storage capacity (up to 19.6% by weight for the release of three molar equivalents of hydrogen gas) and its stability under typical ambient conditions. A model of a bead reactor system was developed to study AB system performance in an automotive application and estimate the energy, mass, and volume requirements for this off-board regenerable hydrogen storage material. The system includes feed and product tanks, hot and cold augers, a ballast tank/reactor, a H2 burner and a radiator. One-dimensional models based on conservation of species and energy were used to predict important state variables such as reactant and product concentrations, temperatures of various components, flow rates, and pressure in the reactor system. The flow rate of AB into the process and the system pressure were governed by a control system which is modeled as an independent subsystem. Each subsystem in the model was coded as a C language S-function and implemented in the Matlab/Simulink environment. Preliminary system simulation results for a start-up case and for a transient drive cycle indicate appropriate trends in the reactor system dynamics.

Systems Modeling of Chemical Hydride Hydrogen Storage Materials for Fuel Cell Applications

2011 ◽  
Vol 8 (6) ◽  
Author(s):  
Kriston Brooks ◽  
Maruthi Devarakonda ◽  
Scot Rassat ◽  
Jamie Holladay
Keyword(s):  
Fuel Cell ◽  
Hydrogen Storage ◽  
Storage System ◽  
Fixed Bed ◽  
Hydrogen Gas ◽  
Fixed Bed Reactor ◽  
Ambient Conditions ◽  
High Hydrogen ◽  
Pressure Drops ◽  
Reactor Models

A fixed bed reactor was designed, modeled and simulated for hydrogen storage on-board the vehicle for PEM fuel cell applications. Ammonia borane was selected by DOE’s Hydrogen Storage Engineering Center of Excellence as the initial chemical hydride of study because of its high hydrogen storage capacity (up to ∼16% by weight for the release of ∼2.5 molar equivalents of hydrogen gas) and its stability under typical ambient conditions. The design evaluated consisted of a tank with eight thermally isolated sections in which H2 flows freely between sections to provide ballast. Heating elements are used to initiate reactions in each section when pressure drops below a specified level in the tank. Reactor models in Excel and COMSOL were developed to demonstrate the proof-of-concept, which was then used to develop systems models in Matlab/Simulink. Experiments and drive cycle simulations showed that the storage system meets thirteen 2010 DOE targets in entirety and the remaining four at greater than 60% of the target.

PEM Fuel Cell Research Direction for Automotive Application

2005 ◽  
Author(s):  
John Fagley ◽  
Jason Conley ◽  
David Masten
Keyword(s):  
Fuel Cell ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Department Of Energy ◽  
Limiting Current ◽  
Automotive Application ◽  
Commercial Application ◽  
Related Research

In recent years, there has been an increasing amount of PEM (proton exchange membrane) fuel cell-related research conducted and subsequently published by universities and public institutions. While a good deal of this research has been useful for understanding the underlying fundamental aspects of fuel cell components and operation, much of it is not as useful for a group working on automotive applications as it could be. The reason for this is that in order to be put to practical use in an automotive application, the system being studied must meet certain constraints; satisfying targets for projected system costs, system efficiency, volumetric and gravimetric power densities (packaging), and operating conditions. For example, numerous recent publications show studies with PEM fuel cells designed and built such that limiting current density is achieved at 0.9 A/cm2 or lower, and voltages of 600 mV can only be achieved at current densities less than 0.6 A/cm2. This type of performance is sufficiently below what is required for commercial application, that any conclusions drawn from these works are difficult to extrapolate to a system of commercial automotive interest. The purpose of this article is to show, through use of engineering calculations and cost projections, what operating conditions and performance are required in a commercial automotive fuel cell application. In addition, best known (public domain) performance and corresponding conditions are given, along with Department of Energy Freedom Car targets, which can be used for state-of-the-art benchmarking. Also, reference is made to a university publication where performance (500 mV at 1.5 A/cm2) close to automotive application targets was achieved, and important aspects of their components and flow field geometry are highlighted. It is our hope that through this publication, further PEM fuel-cell related research can be directed toward the region of greatest interest for commercial, automotive application.

Dynamic Modeling and Simulation Based Analysis of an Ammonia Borane (AB) Reactor System for Hydrogen Storage

2019 ◽  
Vol 33 (1) ◽  
pp. 1959-1972 ◽  
Author(s):  
Maruthi N. Devarakonda ◽  
Jamie Holladay ◽  
Kriston Brooks ◽  
Scott Rassat ◽  
Darrell Herling
Keyword(s):  
Hydrogen Storage ◽  
Modeling And Simulation ◽  
Dynamic Modeling ◽  
Ammonia Borane ◽  
Reactor System ◽  
Simulation Based

Two-Stage Design of Linear Feedback Controllers for a Proton Exchange Membrane Fuel Cell

2015 ◽  
Author(s):  
Verica Radisavljevic-Gajic ◽  
Patrick Rose ◽  
Garrett M. Clayton
Keyword(s):  
Fuel Cell ◽  
Time Scale ◽  
Proton Exchange Membrane ◽  
Cell Model ◽  
Pem Fuel Cell ◽  
Proton Exchange ◽  
Linear Feedback ◽  
Fast Time ◽  
State Variables ◽  
Exchange Membrane

The paper considers the eighth-order proton exchange membrane (PEM) fuel-cell mathematical model and shows that it has a multi-time scale property, indicating that the dynamics of three model state space variables operate in the slow time scale and the dynamics of five state variables operate in the fast time scale. This multi-scale nature allows independent controllers to be designed in slow and fast time scales using only corresponding reduced-order slow (of dimension three) and fast (of dimension five) sub-models. The presented design facilitates the design of hybrid controllers, for example, the linear-quadratic optimal controller for the slow subsystem and the eigenvalue assignment controller for the fast subsystem. The design efficiency and its high accuracy are demonstrated via simulation on the considered PEM fuel cell model.

Materials Safety for Hydrogen Gas Embrittlement of Metals in High-Pressure Hydrogen Storage for Fuel Cell Vehicles

2012 ◽  
Author(s):  
L. Zhang ◽  
M. Wen ◽  
Z. Y. Li ◽  
J. Y. Zheng ◽  
X. X. Liu ◽  
...  
Keyword(s):  
High Pressure ◽  
Fuel Cell ◽  
Hydrogen Storage ◽  
Crack Growth ◽  
Hydrogen Gas ◽  
Materials Testing ◽  
Fuel Cell Vehicles ◽  
Growth Data ◽  
Type Iii ◽  
Pressure Hydrogen

Materials safety and selection for the application of metals in high-pressure hydrogen storage of fuel cell vehicles were introduced based on the hydrogen gas embrittlement (HGE) examinations using the materials testing equipment. Testing steps are as follows; the 1st step is the tensile test in high-pressure hydrogen by slow strain rate technique to evaluate the effect of hydrogen and divide the materials into five categories based on stress-strain curves. The materials of type III, IV and V are picked up and their yield points and ultimate tensile strengths are collected. The 2nd step is the fracture mechanics test to obtain KICs and KIHs of type III, IV and V materials. The materials of type IV and V are considered to be applicable as usual. The 3rd step is the crack growth test to obtain the fatigue crack growth data. A special consideration of HGE is taken for the design of the equipment with limited operation period or cycles for the materials of type III. The issue of the Kth’s reproducibility remains unresolved, which calls another testing method and design concept. Candidate materials are then nominated following the procedure of materials selection.

scholarly journals Solid-State Conversion of Magnesium Waste to Advanced Hydrogen-Storage Nanopowder Particles

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1037
Author(s):  
Mohamed Sherif El-Eskandarany ◽  
Naser Ali ◽  
Sultan Majed Al-Salem
Keyword(s):  
Cold Rolling ◽  
Hydrogen Storage ◽  
Ball Milling ◽  
Nanocrystalline Structure ◽  
Global Scale ◽  
Gas Diffusion ◽  
Hydrogen Gas ◽  
Desorption Kinetics ◽  
Pure Hydrogen ◽  
High Hydrogen

Recycling of metallic solid-waste (SW) components has recently become one of the most attractive topics for scientific research and applications on a global scale. A considerable number of applications are proposed for utilizing metallic SW products in different applications. Utilization of SW magnesium (Mg) metal for tailoring high-hydrogen storage capacity nanoparticles has never been reported as yet. The present study demonstrates the ability to produce pure Mg ingots through a melting and casting approach from Mg-machining chips. The ingots were used as a feedstock material to produce high-quality Mg-ribbons, using a melting/casting and spinning approaches. The ribbons were then subjected to severe plastic deformation through the cold rolling technique. The as-cold roll Mg strips were then snipped into small shots before charging them into reactive ball milling. The milling process was undertaken under high-pressure of pure hydrogen gas (H2), where titanium balls were used as milling media. The final product obtained after 100 h of milling showcased excellent nanocrystalline structure and revealed high hydro/dehydrogenation kinetics at moderate temperature (275 °C). The present study shows that primer cold rolling of Mg-strips before reactive ball milling is a necessary step to prepare ultrafine magnesium hydride (MgH2) nanopowders with advanced absorption/desorption kinetics behavior. These ultrafine powders with their nanocrystalline structure are believed to play an important role in effective gas diffusion process. Moreover, the fine titanium particles came from the ball-powder-ball collisions and introduced to the Mg matrix have not only acted as micro-scaled milling media, but they played a vital catalyzation role for the process.

Performance of a Thermally Coupled Hydrogen Storage and Fuel Cell System Under Different Operation Conditions

2016 ◽  
Vol 13 (2) ◽  
Author(s):  
Gustavo A. Andreasen ◽  
Silvina G. Ramos ◽  
Hernán A. Peretti ◽  
Walter E. Triaca
Keyword(s):  
Fuel Cell ◽  
Hydrogen Storage ◽  
Metal Hydride ◽  
Cell System ◽  
Proton Exchange ◽  
Integrated System ◽  
Equilibrium Pressure ◽  
High Hydrogen ◽  
Hydrogen Flow ◽  
Operation Conditions

The performance of a hydrogen storage prototype loaded with AB5H6 hydride, whose equilibrium pressure makes it suitable for both feeding a H2/air proton exchange membrane (PEM) fuel cell and being charged directly from a low-pressure water electrolyzer, interacting thermally with the fuel cell exhaust air, is reported. The nominal 70 L hydrogen storage capacity of the prototype suffices for hydrogen delivery at 0.5 L min−1, which allows a power supply of 50 W for 140 min from the H2/air fuel cell in the absence of thermal interaction. The storage prototype was characterized by monitoring the internal pressure and the temperatures of the external wall and at the center inside the container at different hydrogen discharge conditions. The responses of the integrated system after either immersing the metal hydride container in air or exposing it to the fuel cell hot exhaust air stream under forced convection were compared. The system shows the best performance when the heat generated at the fuel cell is used to increase the metal hydride container temperature, allowing the operation of the fuel cell at 280 W for 16 min at a high hydrogen flow rate of 4 L min−1.

1-D Computational Model of a PEM Fuel Cell Using Reaction Rate Law Kinetics to Model the Consumption of Hydrogen at the Anode

2008 ◽  
Author(s):  
Sean Goudy ◽  
S. O. Bade Shrestha ◽  
Iskender Sahin
Keyword(s):  
Mass Transfer ◽  
Fuel Cell ◽  
Reaction Rate ◽  
Side Reaction ◽  
Pem Fuel Cell ◽  
Polymer Membrane ◽  
Hydrogen Gas ◽  
Cathode Side ◽  
Anode Side ◽  
Rate Law

Computational models of Polymer Electrolyte Membrane (PEM) fuel cell have historically simulated the anode side reaction assuming the system is mass transfer limited. Specifically, the models assume that the hydrogen gas mass transfer rate is much slower than the reaction rate. Although this assumption makes computational simulations easier, the model does not accurately describe the system. This model introduces a novel method of simulating the anode side reaction. Specifically, the model uses the reaction rate law kinetics of hydrogen gas adsorption onto the platinum electrode and the subsequent ionization of the hydrogen atom to model the anode side reaction dynamics. The benefit is that the model is capable of predicting the actual behavior of the system at the electrode and polymer membrane interface. Because of the computational complexity of this system, the model assumes that a fraction of the hydrogen gas in contact with the polymer membrane dissolves into the polymer membrane and diffuses to the cathode side. The fraction of hydrogen, which is dissolved into the polymer membrane, is proportional to the Damko¨hler number (Da). Specifically, the model assumes that if the reactant is not completely consumed when it comes into contact with the polymer membrane that some fraction of the hydrogen gas will dissolve into the polymer membrane and will be diffused to the cathode side. In addition, because of the slight negative charge of the polymer membrane, the model assumes that no oxygen diffuses into the polymer membrane.

A Millimeter Scale Reactor Integrated PEM Fuel Cell Energy System with an On-Board Hydrogen Production, Storage and Regulation Unit for Autonomous Small Scale Applications

2014 ◽  
Vol 93 ◽  
pp. 131-136
Author(s):  
Arvind Balakrishnan ◽  
Claas Mueller ◽  
H. Reinecke
Keyword(s):  
Fuel Cell ◽  
Hydrogen Production ◽  
Metal Hydride ◽  
Pem Fuel Cell ◽  
Hydrogen Gas ◽  
Pt Catalyst ◽  
Electrical Load ◽  
Cell Energy ◽  
Scale Reactor

We present a millimeter scale reactor integrated PEM fuel cell energy source with an onboard hydrogen production reactor (realized by alkaline chemical hydride), and passive hydrogen buffering unit (realized by metal hydride) of hydrogen. A stacked system of reactor-hydrogen buffer-PEM fuel cell is demonstrated. The system is driven by the hydrolysis of the alkaline chemical hydride (NaOH+NaBH4) in the presence of micro porous catalyst layer (platinum catalyst (Ni-Pt)). The produced hydrogen gas from the reactor is buffered through the hydrogen buffer (Palladium metal hydride) and gets distributed (due to the pressure difference) onto the anode of the PEM fuel cell. The operational behaviour of the complete system is investigated with the hydrogen produced from the alkaline chemical hydride and pure hydrogen gas. Long term voltage measurements under a defined electrical load of the alkaline chemical hydride driven system was measured. The increase in time for the hydrogen production observed in the long term voltage measurement is anticipated to the degradation of the Ni-Pt catalyst. The system is “self-buffering” in nature so any change in electrical load can be handled during system operation.

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