april 22-23, 2009 - purdue university · 05:00 pm–05:30 pm transfer to the neil armstrong hall of...
TRANSCRIPT
April 22-23, 2009 Stewart Center, Room 214ABCD
Purdue UniversityWest Lafayette, Indiana
http://www.purdue.edu/dp/energy/research/hydrogenenergysystems.php
EA/EOU
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Dear Guests and Participants,
It is our pleasure to welcome you in West Lafayette, Indiana for the 4th Hydrogen Symposium at Purdue University.
The 2009 symposium will be divided into three primary areas with more than 15 presentations from industrial, national lab, and academic leaders providing a unique opportunity to expand understanding and exchange state-of-the art knowledge in hydrogen science and engineering.
The first session will explore fundamental physics-based questions related to the generation and use of hydrogen gas in practi-cal devices. Of particular interest in this session are large-scale production methods such as the fusion torch process, electroly-sis, and biological methods.
The second session will examine existing and new hydrogen production and storage technologies necessary for a realistic and safe implementation of hydrogen-powered systems. Recent developments in solid-state storage systems including metal hydrides & cryo-sorbents will be presented by experts in the field and compared with practical needs of many power systems.
In addition, this year’s symposium expands our series into the topic areas of hydrogen utilization for automotive and aero-space applications. The third session will feature presentations on state-of-the-art and future plans for hydrogen-fueled transportation systems and power demanding electronic devices to be further developed and implemented in our society. Lessons learned from several decades of space exploration using hydrogen fueled rockets and current development programs of advanced rocket technologies will be presented. Hydrogen usage for ground transportation will also be discussed in light of the great benefits and challenges surrounding its wide-spread implementation.
We have also organized several opportunities for all participants to interact during the breaks and the reception in the atrium of the Neil Armstrong Hall of Engineering on Wednesday evening.
We will conclude the symposium with tours of several laboratories across the Purdue University campus directly involved in the production, storage, and practical use of hydrogen.
We look forward to a productive symposium that will result in forging future collaborations and advancing the frontiers of sci-ence and engineering in hydrogen research.
Most Sincerely,
Timothée Pourpoint–ChairResearch Assistant Professor, Ph.D.School of Aeronautics and Astronautics
David Koltick–Co-ChairProfessor of PhysicsDirector, Applied Physics LaboratoryCoordinator, Center for Sensing Science and TechnologyDepartment of Physics
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2009 HYDROGEN SYMPOSIUM ORGANIZING COMMITTEE
SESSION CHAIRS
Timothée Pourpoint
Research Assistant Professor, Ph.D. Purdue University School of Aeronautics and Astronautics 500 Allison Road West Lafayette, IN 47907 High Pressure Lab Phone: 765.494.1543 Hydrogen Lab Phone: 765.494.1541
E-mail: [email protected]
David Koltick
Professor of PhysicsDirector, Applied Physics LaboratoryCoordinator, Center for Sensing Science and Technology Department of Physics, Room 335 525 Northwestern Avenue West Lafayette, IN 47907-2036 Telephone: 765.494.5557
E-mail: [email protected]
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CONFERENCE ADMINISTRATION
ENERGY CENTER IN DISCOvERY PARK
Potter Engineering Center, Room 322 500 Central Drive West Lafayette, IN 47907-2022
Dr. Jay P. Gore
Reilly University Chair Professor of EngineeringDirector, Energy Center in Discovery Park Phone: 765.494.1610 E-mail: [email protected]
Ronald J. Steuterman
Managing Director, Energy Center in Discovery Park Phone: 765.494.4437 E-mail: [email protected]
Wendy Madore
Event Manager, Energy Center in Discovery Park Phone: 765.494.6792 E-mail: [email protected]
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HERBERT C. BROWN AWARD FOR INNOvATIONS IN HYDROGEN RESEARCH
The Herbert C. Brown Award for Innovations in Hydrogen Research award is a $5,000 cash award made to an individual in rec-ognition of outstanding contributions in hydrogen research and for advancing energy issues around the globe.
The Herbert C. Brown award is named after the late Purdue Chemistry professor and 1979 Nobel Prize recipient. Dr. Brown shared with Georg Wittig (Germany) the Nobel Prize “for their development of the use of boron- and phosphorus-containing compounds, respectively, into important reagents in organic synthesis.”
2008 RECIPIENT
Dr. Etsuo Akiba, National Institute of Advanced Industrial Science and Technology (AIST)
Dr. Etsuo Akiba is Deputy Director of Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan and adjunct professor of Utsunomiya University, Hiroshima University and Kyushu University, Japan. He received B. Sc from Saitama University in 1974, M. Sc and Ph. D from The University of Tokyo in 1976 and 1979, respectively in physical chemistry. He joined AIST in 1979 and started the research on metal hydrides. He was a research associate of National Research Council Canada from 1983 to 1984 and a visiting scientist at Lab. de Cristallographie, CNRS, France in 1991. During his carrier, he developed various types of hydrogen storage materials including Ti based BCC struc-tured alloys named as “Laves phase related BCC solid solution alloys”, Mg based BCC alloys prepared by ball milling and new types of alanates such as SrAl2H2, Sr2AlH7 and BaAlH5. He and his co-workers analyzed crystal structures of these novel hydrides and other hydrides using the powder X-ray and neutron diffraction method. He received several awards on the research and development of hydrogen absorbing alloys including The Ichikawa Prize of Technology from New Technology Development Foundation Japan in 1998 and the Herbert C. Brown Award for Innovations in Hydrogen Research from Purdue University in 2008. He is the project leader of “Advanced Fundamental Research on Hydrogen Storage Materials” conducted by New Energy and Industrial Technology Development Organization (NEDO) since 2007.
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AGENDA STEWART CENTER 214ABCD
Wednesday, April 22, 2009
08:00 AM–08:15 AM Registration & Networking Coffee
08:15 AM–08:30 AM Welcome
08:30 AM–09:30 AM PURDUE HYDROGEN RESEARCH PROGRAM: A PANEL DISCUSSION
SESSION I: BASIC ENERGY SCIENCE 09:30 AM–10:00 AM Neutron Scattering Studies of Hydrogen Storage Materials Paul E. Sokol, Professor and Director, Indiana University Cyclotron Facility
10:00 AM–10:30 AM Using Neutron Imaging to Study Hydrogen Fuel Cells and Hydrogen Storage Devices David L. Jacobson, National Institute of Standards and Technology
10:30 AM–11:00 AM Break
11:00 AM–11:30 AM A Computational Tool for Complex Ionic Hydrides: Global Optimization Using Prototype Electrostatic Ground States Eric H. Majzoub, University of Missouri–St. Louis, Department of Physics and Astronomy and Center for Nanoscience
11:30 AM–12:00 PM Stabilization of Aluminum Hydride: Implementation of Ionic Liquids Martin Sulic, GM/Purdue Post-doc, General Motors
12:00 PM–01:30 PM Hydrogen Symposium Luncheon, STEW 214
01:30 PM–02:30 PM SESSION II: HYDROGEN PRODUCTION AND STORAGE The US Department of Energy’s Hydrogen Production and Storage Program Jim Miller Argonne National Lab
02:30 PM–03:00 PM Distributed and Large Scale Hydrogen Production Methods George H. Miley, Professor, University of Illinois
03:00 PM–03:30 PM Automotive Storage of Hydrogen in Alane: Performance of On-board System and Off-board Regeneration Rajesh Ahluwalia, Argonne National Lab
03:30 PM–04:00 PM Break
04:00 PM–04:30 PM Engineered Systems for Solid-State Hydrogen Storage Chris Moen, Transportation Energy Center, Sandia National Laboratory
04:30 PM–05:00 PM High Density Hydrogen Storage in Cryogenic Capable Pressure Vessels Salvador M. Aceves, Lawrence Livermore National Laboratory
05:00 PM–05:30 PM Transfer to the Neil Armstrong Hall of Engineering Atrium 701 West Stadium Ave.
05:30 PM–07:00 PM Poster Session & Reception, Neil Armstrong Hall of Engineering Atrium
07:00 PM - 09:00 PM Dinner Presentation by Dr. Etsuo Akiba, 2008 H.C. Brown Award Recipient Neil Armstrong Hall of Engineering Atrium
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AGENDA STEWART CENTER 214ABCD
Thursday, April 23, 2009
08:00 AM–08:30 AM Coffee & Networking
08:30 AM–09:30 AM SESSION III: UTILIZATON AND vEHICLE DEMONSTRATION National Aeronautics and Space Administration (NASA) Hydrogen Fueled Propulsion Systems William Gerstenmaier, Assoc. Administrator for Space Operations, NASA
09:30 AM–10:00 AM Challenges with using of Hydrogen in Rocket Propulsion Jeffrey Muss, Sierra Engineering
10:00 AM–10:30 AM Hydrogen Distribution and Safety Dr. R. Paul Williamson, Alternative Energy Technologies H2 & AE R&D, University of Montana
10:30 AM–10:45 AM Break
10:45 AM–11:15 AM The Status of Hydrogen/Fuel Cell Technology–A Review of Next Generation Transportation Options Mei Cai, General Motors
11:15 AM–11:45 AM Use of ammonia borane as a hydrogen source for portable power systems Paul Clark, PE, PhD, Manager, Advanced Power Systems, General Atomics
11:45 AM–12:15 PM Low-cost Coal to Hydrogen for Electricity with CO2 Sequestration Dr. Robert E. Buxbaum, REB Research & Consulting Co.
12:30 PM Symposium Adjourns
LAB TOURS, Boxed luncheon for registered tour participants
1:30 PM–3:00 PM Scheduled Lab Tours & Meetings Meet tour bus across from the Purdue Memorial Union near the Grant Street Parking Garage entrance
SYMPOSIUM 2009
Session I Basic Energy Science
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NEUTRON SCATTERING STUDIES OF HYDROGEN STORAGE MATERIALS
Paul Sokol, Department of Physics, Indiana University, Bloomington
ABSTRACT
Utilizing hydrogen as an energy transfer medium is a key element in current plans to reduce our dependence on oil with all of its political and environmental costs. One of the key enabling technologies necessary to make such a hydrogen based economy a reality is suitable hydrogen storage systems that are safe, compact and reliable. The development of appropriate hydrogen storage media poses one of the biggest challenges to current materials and technologies and new materials, such as hydrides, alanates, borane complex’s, MOF’s and carbon based structures are all being explored as potential storage materials. However, successful efforts to develop these materials for hydrogen storage will require detailed information on the micro-scopic dynamics of hydrogen. A detailed understanding of the bonding and motion of hydrogen in these materials will be essential to optimizing their properties for hydrogen storage. Neutrons provide a unique probe for the study of the structure and dynamics of potential hydrogen storage materials; the large neutron cross section for hydrogen makes neutrons particu-larly appropriate for studies of hydrogen storage materials. In addition, neutron energies at modern sources allow the study of phenomena ranging from chemical bonding to diffusion. In this talk I will focus on inelastic neutron scattering studies and the information that it can provide on both the local binding and the diffusion of hydrogen in potential storage materials.
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USING NEUTRON IMAGING TO STUDY HYDROGEN FUEL CELLS AND HYDROGEN STORAGE DEvICES
David L. Jacobson, National Institute of Standards and Technology
ABSTRACT
The National Institute of Standards and Technology (NIST) Neutron Imaging Facility is a national user facility located at the NIST Center for Neutron Research dedicated to the use of neutrons for radiography and tomography. Neutrons penetrate metal components of fuel cells and are extremely sensitive to hydrogen bound up primarily in water molecules inside the fuel cell. This sensitivity to water in the presence of metal makes the neutron radiography method ideal for studying, in situ, the water transport properties of an operating fuel cell and the constituent components. Due to the penetrating properties of the neutron to pass through metal, standard fuel cell hardware can be used for in situ studies. Here we will provide an overview of the imaging facility at NIST and the method of neutron radiography applied to the study hydrogen fuel cells. The advances in spatial resolution with neutron imaging systems will be discussed as well as the impact these advances has made on fuel cell research. We will also discuss planned future directions for research at the facility such as imaging of hydrogen storage devices.
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A COMPUTATIONAL TOOL FOR COMPLEx IONIC HYDRIDES: GLOBAL OPTIMIZATION USING PROTOTYPE ELECTROSTATIC GROUND STATES
Eric H. Majzoub, University of Missouri - St. Louis, Department of Physics and Astronomy and Center for Nanoscience
ABSTRACT
Reaching the hydrogen storage targets of weight capacity and volumetric density set by the U.S. Department of Energy requires materials outside the traditional metallic interstitial hydrides such as LaNi5, which stores about 1.2 wt.% H2 in the fully hydrided LaNi5H6. Examples of state-of-the-art hydrogen storage materials are insulating molecular ionic compounds such as lithium borohydride,LiBH4, and sodium alanate, NaAlH4, which store about 18 and 8 wt.% H2, respectively. Polar-covalent bonds between hydrogen and boron or aluminum form anionic tetrahedral BH4 -, and AlH4–anions which are charge balanced by Li+, or Na+. These materials present two difficulties. First, these compounds do not retain the metal lattice substructure upon dehydrogenation. For example Na, and Al are completely immiscible, even in the melt. NaAlH4 decomposes in a two-step process, first into Na3AlH6, which further decomposes at higher temperature into NaH. We therefore have a two-step pla-teau with different equilibrium pressures belonging to each of the decomposition reactions. Secondly, alloying these materials to “tune” the hydrogen equilibrium pressure, a common practice with interstitial hydrides, is much more difficult due to the ionic bonding. However, the class of complex anionic hydrides is rich and consists of large numbers of combinations of several types of cations, including all of the alkali and alkaline earth metals, with anions such as AlH4, BH4, AlH6, and also nitrogen containing anions such as NH, and NH2. Identifying new compounds, with perhaps only one step is possible. We will present a novel computational approach to search for new molecular ionic hydride crystal structures based on a prototype electrostatic ground state model (PEGS), and will present computational and experimental results for the bialkali borohydride NaK(BH4)2. We also show that the PEGS Hamiltonian, combined with first-principles density functional theory, Metropolis Monte Carlo, and potential energy smoothing, provides a robust global optimization procedure that is able to address subtleties such as dis-tinguishing polymorphs in Ca(BH4)2 as a function of temperature. We will also show how the procedure has identified poten-tial ground state structures for Mg(BH4)2, and LiSc(BH4)4, among others. Finally, we will show how the PEGS method has been used to identify the impact of closo-borane B12H12 salts on the decomposition pathways of LiBH4, Mg(BH4)2, and Ca(BH4)2.
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STABILIZATION OF ALUMINUM HYDRIDE: IMPLEMENTATION OF IONIC LIqUIDS
Martin Sulic, College of Engineering, Purdue University stationed at General Motors R&D Center, Warren, MI
ABSTRACT
Aluminum hydride, AlH3, is of interest for on-board vehicular hydrogen storage applications due to its potential to store hydro-gen up to 10 weight percent and 148 g/L, twice the density of liquid H2. Originally prepared in an ethereal state, AlH3(C2H5)O2, [1] and later in the non-solvated form, AlH3, by use of pentane or ligroin and vacuum treatment to promote precipitation [2], a reliable method was not established until 1976 by Brower et al. at the Dow Chemical Company. It was discovered that a small excess of LiAlH4 and/or LiBH4 along with a heat treatment promoted the reduction of the ethereal product to AlH3 [3]. This work also included the identification of seven polymorphs. However, AlH3 exists in a metastable state that is thermodynamically unstable and readily decomposes under ambient conditions over time; therefore for any long term on-board applications this condition must be addressed.
Ionic liquids may provide the route required to stabilizing AlH3. They exhibit very low vapor pressures, are stable at high temperatures and can act as solvents. In addition, their weakly coordinated cations and anions are ideal for synthesis. Recently, it was reported that 1-butyl-3-methylimidazolium chloride (bmimCl) enhanced the rate and extent of hydrogen evolved from ammonia borane (NH3BH3) [4]. For the current study the ionic liquid 1-ethyl-3-methylimidazolium chloride (emimCl) was chosen. EmimCl is well documented in the literature and therefore allowed us to establish a basis for which future ionic liquids could be considered. Furthermore, the anion component of emimCl is a fundamental reactant in the traditional synthesis of AlH3. Emim-AlH3 exhibits faster rate of decomposition as well as prolonged hydrogen release over a wider temperature range. These results indicate immediate hydrogen availability with the advantage of long term delivery.
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SYMPOSIUM 2009
Session IIHydrogen Production and Storage
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THE US DEPARTMENT OF ENERGY’S HYDROGEN PRODUCTION AND STORAGE PROGRAM
James F. Miller1, Richard Farmer2, Sara Dillich2, Sunita Satyapal2, and JoAnn Milliken2, 1Argonne National Laboratory, 9700 S. Cass Ave, Argonne, IL, 2US Department of Energy, Hydrogen, Fuel Cells and Infrastructure Program, Washington, DC
ABSTRACT
The U.S. Department of Energy (DOE) carries out a portfolio of activities to enable a cleaner, more reliable, and secure energy future. As a strategic element in achieving these goals, the DOE Hydrogen Program continues to make significant advance-ments in research, development and demonstration efforts on hydrogen and fuel cell technologies, providing the nation with the opportunity to significantly decrease greenhouse gas emissions through the utilization of a clean, domestic fuel.
The DOE Hydrogen Program features a diverse research portfolio. Significant progress has been made in overcoming the tech-nology barriers, which include hydrogen fuel cost and onboard hydrogen storage. The “critical-path” barrier for hydrogen cost ($2-3 per gallon of gasoline equivalent) has been met by reducing the cost of hydrogen production via natural gas reforming to $3/kg for high volumes. Hydrogen storage research and development continues to identify new materials for low-pressure onboard storage that will enable a vehicle range of 300 miles.
This presentation will provide an overview of the US Department of Energy hydrogen production and storage program. De-velopment challenges and technical targets, recently revised, will be presented. The size and scope of current DOE-sponsored R&D activities will be described. Current status of hydrogen production and storage technology will be reported. Recent ac-complishments will be highlighted. Remaining challenges, future research needs, and potential funding opportunities will also be discussed.
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DISTRIBUTED AND LARGE SCALE HYDROGEN PRODUCTION AND STORAGE METHODS.
George H. Miley, Fusion Studies Laboratory, NPRE Department, University of Illinois, U-C Campus, Urbana, Illinois 61801E-mail: [email protected]
ABSTRACT
The future hydrogen economy requires development of improved hydrogen production, transport and storage methods. Here we consider production and storage in some detail, including several speculative new methods under study at the U of Illinois. The presentation will first briefly review the traditional concepts for the economy based on large centralized production plants in combination with distributed storage. Then alternatives to this approach will be discussed.
Production methods typically considered range from reforming natural gas to water electrolysis using nuclear fission reactor. A new concept that uses plasma dissociation of water by a high temperature plasma produced with a fusion reactor will also be discussed. This basic processing unit, termed a “fusion torch”, is also under study for other applications, including waste disposal and materials recycle. A near-term version would use electrical input rather than fusion power to create the plasma.
Storage methods depend strongly on the application, e.g. stationary or mobile. Methods commonly discussed range from high pressure tanks to metal hydrides and carbon nano-tubes. A new concept based on high density condensed state “cluster” formation in certain hydrides is under study at the U of Illinois and will be described in some detail.
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AUTOMOTIvE STORAGE OF HYDROGEN IN ALANE: PERFORMANCE OF ON-BOARD SYSTEM AND OFF-BOARD REGENERATION
R. K. Ahluwalia, T. q. Hua and J-K Peng, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439E-mail: [email protected]
ABSTRACT
The prospects of using alane (AlH3) slurry for vehicular hydrogen storage and regenerating it off-board by liquid organometal-lic routes are evaluated. A model for the on-board storage system is developed to analyze the AlH3 decomposition kinetics, heat transfer requirements, stability, startup energy and time, H2 buffer requirements, storage efficiency, and gravimetric and volumetric capacity. The results from the model indicate that reactor temperatures higher than 200oC are needed to decom-pose alane at reasonable space velocities, >60 h-1. A system gravimetric capacity of 4.2 wt% usable hydrogen and a system volumetric capacity of 50 g-H2/L may be achievable with a 70% solids slurry. Under optimum conditions, ~80% of the H2 stored in the slurry may be available for the fuel cell engine. The model indicates that H2 loss is limited by the decomposition kinet-ics rather than by the rate of heat transfer from the ambient to the slurry tank. A three-step regeneration process is evaluated in which AlH3 is first formed as an adduct to trimethylamine by reacting aluminum with hydrogen in a solvent and is then displaced into triethylamine which is subsequently decomposed in the presence of a catalyst to release AlH3. Our analysis of a pathway in which hydrogen is produced from steam reforming of methane shows that the well-to-tank efficiency may be 40±10% depending on the availability of low-grade waste heat and vacuum distillation requirements.
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ENGINEERED SYSTEMS FOR SOLID-STATE HYDROGEN STORAGE
C.D. Moen, D.E. Dedrick, and T.A. Johnson, Transportation Energy Center, Sandia National Laboratories, Livermore, CA 99450
ABSTRACT
Complex metal hydrides offer a path towards achieving target hydrogen storage energy densities for hydrogen-fueled ve-hicles. The complex metal hydrides are desirable because they can provide reversible, on-board storage. Sandia National Labo-ratories and General Motors have worked together over the past five years to develop solid-state hydrogen storage technology and demonstrate key elements of a large-scale, metal hydride storage system.
Current high-capacity complex metal hydrides are trending toward significant enthalpies of formation. Storage system design with these materials is challenging from the thermal management and control perspectives. The sodium alanates were select-ed as a model material system that would motivate innovation in heat transfer design. Conceptual designs and computational design tools were developed that can be readily adapted for use with future high-capacity storage materials.
We will present the basic design philosophy we used for the demonstration system as well as some comparisons between large-system storage performance and small-sample performance.
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HIGH DENSITY HYDROGEN STORAGE IN CRYOGENIC CAPABLE PRESSURE vESSELS
Salvador M. Aceves, Ph.D., Lawrence Livermore National Laboratory
ABSTRACT
We are developing cryogenic pressure vessels with thermal endurance at least five times longer than conventional liquid hydrogen (LH2) tanks that eliminate evaporative losses in routine use. Cryogenic pressure vessels can be fueled with ambient temperature H2 and/or LH2. When filled with LH2, these vessels contain 2-3 times more fuel than compressed H2 tanks at room temperature. LLNL demonstrated the concept onboard a hydrogen fueled Toyota Prius hybrid vehicle, achieving a 650-mile driving range on a single hydrogen tank. Ongoing work will develop better cryogenic pressure vessels that achieve practical requirements for thermal endurance while further improving weight and volume storage density.
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SYMPOSIUM 2009
Session IIIUtilization and vehicle Demonstration
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NATIONAL AERONAUTICS AND SPACE ADMINISTRATION (NASA) HYDROGEN FUELED PROPULSION SYSTEMS
Mr. William H. Gerstenmaier, Associate Administrator for Space Operations, Space Operations Mission Directorate300 E Street, SW, Washington DC 20546
ABSTRACT
NASA has been a preeminent user of hydrogen since the Apollo era, when President John F. Kennedy’s directive to land a man on the Moon by the end of the 1960’s became a reality. As Apollo designs were maturing, NASA was turning its attention to designing safe and efficient hydrogen fuel cells to provide astronauts with electricity and water. After Apollo, NASA’s research and development of hydrogen powered engines enabled the design and “lift capability to orbit” of the world’s first safe, reus-able man-rated launch platform, the Space Shuttle. The Space Shuttle’s use of hydrogen fuel for its main engines will be the primary focus of this presentation. By the end of this decade NASA will begin a transition from the Space Shuttle operating in Low Earth Orbit to next generation Constellation launch vehicles destined to enable exploration of the Moon and beyond. During this transition period, NASA’s dependence on hydrogen and investment in its safe handling will only continue to grow. Finally, NASA’s development and extensive Space Shuttle program flight history with the use of hydrogen fuel cell technology may well be the key to helping the United States make the “giant leap” forward to a clean energy, hydrogen economy.
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CHALLENGES WITH USING OF HYDROGEN IN ROCKET PROPULSION
Jeffrey Muss, Sierra Engineering Inc.
ABSTRACT
Hydrogen is an extremely desirable rocket fuel. The high temperature and low molecular weight of hydrogen combustion products result in a specific impulse unequaled by all but the most exotic propellants. It burns robustly and cleanly, simplify-ing a number of combustion problems common to other propellants. But the low-density, cryogenic characteristics of liquid hydrogen also make the overall vehicle large and introduce a number of handling and design challenges. This paper describes the benefits, disadvantages and overall-all design challenges associated with using hydrogen in rocket propulsion applications.
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HYDROGEN DISTRIBUTION AND SAFETY
Dr. R. Paul Williamson, Alternative Energy Technologies, H2 & AE R&D, University of Montana
ABSTRACT
At the onset of envisioning a hydrogen economy, one of the first topics that comes to the forefront is hydrogen safety. Whether it be “Joe the Plumber”, homemaker, student, industrial business person, mechanic, emergency responder or consumer, all want to know if the incorporation of hydrogen into their lives will be safe. In many instances, hydrogen can be more safe than traditional fuels, however there is a requisite learning curve that everyone must participate in before comfort levels are met. The Department of Transportation has taken a great interest in hydrogen safety and assisted in creating the Hydrogen Ex-ecutive Leadership Panel (HELP) through the National Association of State Fire Marshals. From the impetus of this group, the University of Montana’s Alternative Energy Technologies group used its hydrogen safety training funding from the Depart-ment of Energy and the Department of Transportation to collaborate with West Virginia University ‘s Alternative Fuels Training Consortium in creating an awareness level, 8-hour training program for first responders, building on the foundation of DOE’s introductory first responder program.
Extensive research, curriculum development, national professional first responder input, beta testing at local, regional and industrial levels, and input from DOE and DOT leaders has produced a training program that is being offered at the Hydrogen Safety Training Site in Missoula, Montana, the National Alternative Fuels Training Consortium in Morgantown, WV or at identi-fied emergency responder , community or industrial sites.
The Hydrogen Safety Training Site at the University of Montana is one of the only hydrogen refueling stations in the country that provides hands-on safety training and interface with renewable wind and solar equipment; hydrogen electrolyzer produc-tion; 5000 psi hydrogen compression and refueling; hydrogen storage and distribution; hydrogen fuel cell operation; hydrogen sensing and detection; mobile hydrogen flammability demonstration unit; and vehicle usage.
The program was developed in a way that allows for dividing it topics, learning activities, modules, hands-on, and/or incident/problem solving actions to meet organizational needs. Module One focuses on ‘Hydrogen Basics and Fuel Properties’ taking participants through the basic knowledge that anyone interested in or in contact with hydrogen will want to know. Module Two addresses ‘Safety Issues and First Responder Training Scenarios’ including protective gear, risks and hazards, procedures, H2 vehicles procedural steps, and incident identification.
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THE STATUS OF HYDROGEN/FUEL CELL TECHNOLOGY–A REvIEW OF NExT GENERATION TRANSPORTATION OPTIONS
Mei Cai, James A. Spearot, Chemical and Environmental Sciences Laboratory, General Motors Research and Development Center, Warren, MI 48090
ABSTRACT
Energy supply and utilization is a critical issue that will become a major rate limiting step in the growth of the world economy. Existing sources of energy will be severely challenged in meeting the energy and environmental needs of countries striving to grow and compete in the world marketplace. Transportation fuel requirements represent a major percentage of future energy needs. The need for increasing amounts of transportation fuels is also critical in developing economies if they are to have the same opportunities for personal mobility that the developed countries of the world have had during the past century. For personal transportation vehicles based on conventional petroleum as an energy source, the expanding global economies and greater use of petroleum-based fuels are expected to exacerbate emissions of criteria pollutants (CO, hydrocarbons, and oxides of nitrogen) in urban environments, and contribute to growing concentrations of carbon emissions in the atmosphere. These economic and environmental issues represent a significant challenge to the future of the world automotive industry. GM’s intent is to continue developing technical solutions with combinations of propulsion technologies and future fuels that will provide more sustainable options for personal mobility options during the next century.
One very plausible option for creating a sustainable transportation system is the development of technically robust and com-mercially viable hydrogen/fuel cell propulsion technologies. Such technologies would include hydrogen production from renewable energy sources, fuel cell propulsion using cost effective, durable materials and designs, and practical, high energy density methods for storage of hydrogen both on-board vehicles and at fuel station facilities. This presentation describes the results of recent research and development programs focused on each of these technologies conducted at General Motors. The current status of each technology area is described as is the expected future capability and performance of each of these critical elements of a hydrogen/fuel cell transportation system.
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AMMONIA BORANE AS A HYDROGEN SOURCE FOR PORTABLE POWER SYSTEMS
Paul N. Clark, Thomas Tamoria, General Atomics E-mail: [email protected]
Mack W. Knobbe, Jadoo Power Systems
ABSTRACT
Dismounted soldiers are routinely burdened with many pounds of batteries that are required to power a wide variety of battle-field electronics. Consequently, there is an urgent need for lightweight power systems to reduce this load. General Atomics (GA) has been developing a lightweight soldier power system that will potentially reduce the soldier’s mass burden substan-tially. The 50 watt power system uses a proton exchange membrane (PEM) fuel cell to generate electrical power. A critical aspect of PEM fuel cells is the supply of high-purity hydrogen gas for fuel. GA has been developing a hydrogen delivery system that uses ammonia borane as the source of hydrogen. Pellets of ammonia borane are contained inside a fuel cartridge that couples to the fuel cell. As the fuel cell operates, pellets are activated individually to supply hydrogen. The cartridge is replace-able so that multiple cartridges can be used for longer run times. Ammonia borane fuel cartridges offer a solid state hydrogen source, containing no liquids or moving parts.
GA has been working closely with Purdue University to developed low costs methods for the synthesis of ammonia borane. These new techniques will significantly lower the cost of ammonia borane making this power technology appealing from both a cost and performance standpoint. This paper provides an overview of the technology and presents the performance merits of the system.
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SYMPOSIUM 2009
H2 to fuel cell or gas turbine
H2Scleanup
Coal gas
Coal$1.00/MMBtu
CO2 to heat recovery and sequestration
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LOW-COST COAL TO HYDROGEN FOR ELECTRICITY WITH CO2 SEqUESTRATION
Dr. Robert E. Buxbaum, REB Research & Consulting co., 12851 Capital St., Oak Park, MI 48237Phone: 248-545-0155; Fax: 248-545-5430, E-mail: [email protected]; web: www.rebresearch.com
ABSTRACT
The goal of our process is to produce hydrogen at low cost from clean coal for electric generation: generation that does not “strengthen our adversaries and threaten our planet.” Addressing economics first, the average customer cost of electricity in Oakland county, MI, is 10.64¢/kwhr, or $31.17/ MMBtu. Much of this electricity is made from coal, a commodity that currently costs about $1 to $2 /MMBtu, or less than 1/10 the sale-price of the electricity. Part of the difference between the cost of coal and the electricity is due to the inefficiency of the generator system; the rest supports the capital cost of production, various maintenance costs, and a small profit distributed to the stock-holders. Even at this price differential, utilities are not particularly profitable endeavors. While it is desirable to switch to a cleaner-burning alternative, like natural gas or pure hydrogen, these re-sources are much more expensive than coal. Natural gas prices trades currently at $5/MMBtu, and rose to $12/MMBtu this sum-mer. Divide this price is by the 30 to 40% efficiency of current gas to electric generators, and we see that electric production from natural gas is almost unprofitable even at 0% financing. Hydrogen-based electric generation is even less cost competitive because hydrogen is more expensive than natural gas on an energy-basis. I would like to suggest, therefore, coal gasification that uses membrane –reactors to perform the water-gas reaction and extract semi-pure hydrogen from the coal gas. The hydrogen produced this way can be used to feed high temperature fuel cells or gas-turbine electric generators. Because of the characteristics of membrane reactors, the waste carbon-dioxide (CO2) remains at high pressure, and thus is more-easily se-questered than CO2 produced at lower pressures. We thus suggest a version of the cancelled FutureGen project with the same low-cost energy source, but with cheaper sequestration, fewer parts and lower capital-cost.
The general scheme I propose is shown in the figure below. The first steps are coal gasification and H2S removal. This is done by one of the several, attractive coal gasifier designs that are commercially available. A particularly attractive one of these, the GE design, can produce clean coal gas at about 800 psi., with a hydrogen content approaching 40%.There is also a significant CO (carbon monoxide) content, and the rest is largely CO2. For FutureGen, the CO was converted to H2 and CO2 through a series of water-gas-shift (WGS) reactors. Hydrogen was then extracted by a pressure-swing scrubber that produced low-pressure CO2. For sequestration, the CO2 had to be repressurized. By contrast, the approach I propose could use a single water gas shift (WGS) membrane reactor with no heat-interchange because the membrane reactor helps drive the reaction. The hydrogen would be delivered at lower pressure, but the CO2 would remain at high pressure for easy sequestration. REB Research & Con-sulting has been developing membrane reactors like this for the last 15 years, and I hope to have good, relevant data from one we shipped for use on the 5 ton/day gassifier at Western Research Institute, Laramie WY.
Because there are fewer components in this design, it should be possible to make hydrogen at a much lower capital cost with the membrane reactor. Further since the CO2 is delivered at higher pressure, about 800 psi, sequestration should be much easier, requiring far fewer compressors, and far less compression energy. The science of membrane reactors and sequestration will be discussed briefly.
http://www.purdue.edu/dp/energy 27
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SYMPOSIUM 2009
Lab ToursBirck Nanotechnology Center
Zucrow Laboratories
http://www.purdue.edu/dp/energy 29
BIRCK NANOTECHNOLOGY CENTER
The Birck Nanotechnology Center opened in July of 2005. This $58 million facility com-prises 187,000 square feet, providing office space for 45 faculty, 21 clerical and techni-cal staff, and up to 180 graduate students. The heart of the building is a 25,000 sq. ft. Class 1-10-100 nanofabrication cleanroom (Scifres Nanofabrication Laboratory), part of which is configured as a biomolecular cleanroom with separate entry and gowning areas and isolated air flow. The building also includes over 22,000 sq. ft. of laboratory space external to the cleanroom, including special low vibration rooms for nanostruc-tures research, with temperature control to less than 0.1 °C. Other laboratories are spe-cialized for nanophotonics, crystal growth, bio-nanotechnology, molecular electronics, MEMS and NEMS, surface analysis, SEM/TEM, electrical characterization, RF systems, instruction and training, and precision micro-machining and the Hall Nanometrology Laboratory. In addition, a unique nanotechnology incubator facility is provided for interaction with industry.
The building is organized into three wings on two floors. A third level houses air filtra-tion equipment (not shown). An enclosed walkway on the second floor provides easy access to an additional 50,000 sq. ft. of research space in the adjacent Bindley Biosci-ences Center.
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ZUCROW LABORATORIES
Zucrow Labs is a research facility affiliated with the School of Mechani-cal Engineering at Purdue University. The lab complex consists of six buildings located for safety reasons in a remote area west of the main campus.
Zucrow Labs consists of six buildings housing twenty-two individual laboratories, a computer lab with two server clusters on site, a profes-sional machine shop, and air compressors and air tanks capable of delivering 3300 cubic feet of air at 2200 psi. Associated with eight of the twenty-two individual labs are a total of eighteen “hazard” test cells and four “high hazard” test cells.
http://www.purdue.edu/dp/energy 31
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Poster SessionCash prizes will be awarded for best posters in both undergraduate and graduate student categories.
We would like to thank 2K Corporation and the Departments of Aeronautics and Astronautics and Mechanical Engineering for providing the prize funds.
http://www.purdue.edu/dp/energy 33
NOvEL NONCATALYTIC METHODS TO RELEASE HYDROGEN FROM BORON COMPOUNDS FOR FUEL CELL APPLICATIONS
Moiz Diwan, Ahmad Al-Kukhun, Hyun Tae Hwang, and Arvind varma E-mail: [email protected]
ABSTRACT
A widespread use of hydrogen fuel cells is limited by the lack of availability of a practical, high density fuel source. Among vari-ous alternatives, chemical methods of hydrogen storage provide high specific energy at relatively easy storage conditions. So-dium borohydride (SBH) and ammonia borane (AB) are considered to be promising hydrogen storage materials as they contain 10.8 and 19.6 wt% hydrogen, respectively. Thermolysis, catalytic hydrolysis and heat generated by additional reactive mixtures are usually employed, but these methods have disadvantages that decrease the efficiency of hydrogen storage systems. We have proposed new approaches to release H2 which do not require any catalyst and produce high H2 yield and environmentally benign byproducts. One such approach involves the use of SBH or AB with gelled water and magnesium or nanoaluminum. Due to the highly exothermic metal-water reaction, such mixtures, upon ignition, exhibit self-sustained propagation of com-bustion wave with simultaneous release of H2 from the boron compounds and water. For AB, we have also studied combustion in a separated AB - metal/water system. The other approach involves external heating of aqueous AB solutions under modest inert gas pressure. The research program involves various experimental methods (e.g., digital video recording, mass spectrom-etry, XRD, NMR and isotopic labeling)
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PLANAR INvERSE DECONvOLUTION ESTIMATION OF SCALAR vALUES IN AN UNSTEADY LAMINAR HYDROGEN FLAME
Brent Rankin, David Blunck, Yuan Zheng, and Jay Gore E-mail: [email protected]
ABSTRACT
The estimation of temperature and species concentrations in hydrogen flames is important to understanding fundamental combustion phenomena, studying flame structure, and validating models. Safely producing and transporting hydrogen is critical to developing and maintaining a hydrogen economy. The present work utilizes an infrared (IR) camera to obtain two-dimensional instantaneous radiation measurements of a laboratory-scale unsteady laminar hydrogen flame (Re = 860). The flame intensity was measured for two spectral bands. Using this, planar distributions of the temperature and water vapor mole fraction were generated by implementing inverse deconvolution calculations. The scalar values agree with CFD and thin filament pyrometry results previously reported for a similar flame. The present thermal imaging and inverse deconvolution technique could be applied to large-scale axisymmetric hydrogen flames.
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http://www.purdue.edu/dp/energy 35
COMPUTATIONAL DESIGN AND ExPERIMENTAL vERIFICATION OF HEAT ExCHANGER DESIGN FOR ON-BOARD STORAGE OF HYDROGEN IN AUTOMOBILES
Milan visaria, School of Mechanical Engineering, Purdue UniversityE-mail: [email protected]
Dr. Issam Mudawar, School of Mechanical Engineering, Purdue University
Dr. Timothée Pourpoint, School of Aeronautics and Astronautics Engineering, Purdue University
ABSTRACT
Recent advancements in development of high-pressure metal hydrides have made them a promising mode of hydrogen stor-age for automobiles. However, most current HPMH have low thermal conductivity and low gravimetric/volumetric densities. These factors assume additional significance in on-board storage where space is limited. The process of hydriding (charging) is a kinetics driven, temperature limited process releasing large amounts of heat. Therefore fast removal of heat is necessary for shorter refueling times. Thus, thermal management becomes one of the major challenges in the development of an efficient on-board hydrogen storage system.
Heat exchanger design for hydrogen storage has many variable parameters. Each kinetic and heat transfer parameter not only influences the heat transfer performance but also the hydrogen carrying capacity. Ti-Cr-Mn based HPMH used has thermal conductivity in the order of 1W/m-K and hydrogen storage capacity of ~2 wt %. The design objective was to achieve a fill time of 300 sec while maximizing the storage capacity. A 2-D transient model was developed in FLUENT to evaluate the performance of each of these designs. The model was then used to optimize the design in order to reduce its size. The design was then used to build a prototype for experimental testing and verification. The results obtained from the experiments are presented and are compared with the results obtained previously from the model.
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HYDROGEN TRIPLE FLAME RESPONSE TO vARIATION IN MIxTURE STRATIFICATION AND EGR RE-PLACEMENT
Rebecca Owston, Department of Mechanical Engineering, Purdue UniversityE-mail: [email protected]
ABSTRACT
A promising way of introducing hydrogen in hydrogen-fuelled internal combustion engines is through direct injection, which leads to stratification along the fuel jet boundary. Triple flame structures can arise as a result of combustion occurring in such stratified mixtures. Variation in the thickness of the fuel/air mixing layer can cause changes in behavior of the propagating flame front. Thus, 2D mixing layer studies using a detailed hydrogen chemical mechanism have been carried out; where the mixing layer thickness is varied from 5 to 100 times that of the stoichiometric premixed laminar flame thickness at comparable unburned temperature and pressures. The stabilization speed of the propagating flame front is shown to increase with increas-ing mixing layer thickness as a result of streamline divergence ahead of the triple flame structure.
The volume of high-temperature products increases with increasing mixing-layer thickness. This leads to increased formation of nitrogen oxides. Therefore, the influence of exhaust gas recirculation (EGR) on emissions is considered in studies where air layer species concentrations are replaced with up to 50% EGR by mole. Resulting changes in flame structure, heat release rates, flame speed, and emission concentrations–estimated through use of the standard Zeldovich NO mechanism, are detailed.
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http://www.purdue.edu/dp/energy 37
PHOTOELECTROCHEMICAL CHARACTERISTICS OF CARBON-DOPED WO3 FILMS PREPARED vIA A SPRAY PYROLYSIS METHOD
Yanping Sun, Carl J. Murphy, Karla R. Reyes-Gil, Enrique A. Reyes-Garcia, Jason Thornton, Nathan Morris, Rina M Rajpura, Daniel Raftery
ABSTRACT
A simple route for the synthesis of the carbon-doped tungsten trioxide (WO3) films has been developed. Glucose was used as the carbon dopant source. The films were characterized by XRD, UV-vis, SEM, and SSNMR. The photoelectrochemical activ-ity was evaluated under UV-visible light and visible light only irradiation. The C-doped WO3 electrodes exhibited photocur-rent densities up to 1.6 mA/cm2 for water splitting in 1 M HCl electrolyte and 2.6 mA/cm2 in addition of methanol, with a high contribution (~50%) from visible light irradiation. Under the same irradiation conditions, C-doped WO3 produced enhanced photocurrent densities compared with undoped electrode synthesized with the same procedures. The photoelectrochemi-cal performance was evaluated with synthetic parameters, including dopant concentration, calcination temperature and film thickness. These results indicate the potential for further development of WO3 photocatalysts, and provide useful information towards understanding the structure and enhanced photoelectrochemical properties of these new materials.
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NOvEL SOLUBLE “H-ONLY” TRANSITION METAL COMPLExES AND THEIR USE IN THE SYNTHESIS OF METAL PARTICLES
Donald Linn; Jerod Kieser, Department of Chemistry, 2101 Coliseum Blvd. E., Indiana University Purdue UniversityFort Wayne, Fort Wayne, IN 46805-1499 E-mail: [email protected]
ABSTRACT
Soluble species like those containing hexahydridoferrate(4-) are produced by reactions between a transition metal halide com-pound and phenylmagnesium halide under hydrogen. Two new cobalt complex hydride species, one of which is diamagnetic, are characterized by elemental analyses and infrared spectroscopy. 1H NMR of the diamagnetic species suggests it to be a clas-sical Co(I) hydride, analogous to the solid state species, Mg2CoH5. Preliminary elemental analyses for these species have been obtained by UV-visible spectroscopy, atomic absorption spectroscopy, halide titration, and hydrogen gas evolution analysis. The soluble iron hydride readily comproportionates under mild solution conditions to form “bare” iron particles, as confirmed by X-ray powder diffraction (XRD). These iron particles can be functionalized, for example, by reacting with a gold reagent to greatly modify their chemical behavior. Here the XRD reports a FCC gold structure superimposed upon an intact metallic BCC iron core according to 57Fe Mössbaurer. Also, SEM images of the surface of α-iron particles after gold treatment show a
“coral-like” appearance. Experiments are underway to modify the size and composition of these particles and to examine their reactivity under various conditions.
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http://www.purdue.edu/dp/energy 39
HYDROGEN PRODUCTION FROM OxIDATIvE REFORMING OF METHANOL OvER CATALYSTS PREPARED BY NOvEL COMBUSTION SYNTHESIS METHODS
Anand Kumar, A. S. Mukasyan, E. E. Wolf E-mail: [email protected], E-mail: [email protected]
ABSTRACT
A novel method for catalysts synthesis, known as impregnated layer combustion synthesis (ILCS), is used to prepare catalysts for oxidative reforming of methanol. A qualitative description of the ILCS method and evolution of catalysts is introduced. These complex catalysts containing copper, zinc, zirconium and palladium were characterized by their activity and selectiv-ity for hydrogen production. It was shown that preparation procedures, including dispersion of Pd and the presence of ZrO2 support have significant effects on the catalytic behavior. Catalyst with 3%Pd loaded in, so-called, second wave impregnation (SWI) had no significant effect on the catalyst structure but showed exceptionally high activity for methanol conversion at low temperatures. Zirconia supported catalysts have high surface area, but their catalytic performance is significantly affected by the presence of palladium. The catalysts promoted with both zirconia and palladium, have high surface area and displayed superior selectivity toward hydrogen production over the whole range of investigated temperatures.
Acknowledgements: We gratefully acknowledge the funding from the NSF grant 0730190 to support this work.
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INvESTIGATION OF HYDROGEN STORAGE KINETICS IN METAL HYDRIDES
Tyler voskuilen, Yuan Zheng, Timothee Pourpoint, Purdue UniversityE-mail: [email protected]
ABSTRACT
Metal hydrides offer a potential form of solid state storage of hydrogen for use in power generation in mobile applications. The kinetic properties of hydrogen absorption in TiCrMn, a metal hydride of interest, are largely unknown. For this analysis, the absorption reaction rates and capacities of TiCrMn were measured under quasi-isothermal conditions at temperatures ranging from 258 K to 294 K. These measurements were taken using a customized high pressure Sievert apparatus which can maintain close to isothermal conditions during reaction. The analysis of the measured reaction progress was used to identify major rate limiting processes. This experimental work was compared to coupled diffusion/reaction models of a single spherical particle with a diameter of 2 microns (the approximate size of activated TiCrMn). This model showed that if the diffusion through the hydride layer is sufficiently slow, the hydride formation rate is only apparent during the formation of surface hydride, beyond which only the diffusive rate can be measured.
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http://www.purdue.edu/dp/energy 41
MODELING SYSTEM SCALE AMMONIA BORANE HYDROLYSIS
Sumit Basu, Yuan Zheng, Jay P. Gore, School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907E-mail: [email protected]
ABSTRACT
Ammonia borane (AB) hydrolysis is a source of hydrogen for use in mobile applications involving hydrogen-powered fuel cells. The catalyst, used in the hydrolysis, is one of the factors that dictate reaction rates and thereby, the reactor volume and weight. The present work reports a preliminary investigation of the influence of ruthenium (Ru) on the volume of a subscale 1 kWe cylindrical packed-bed reactor in an AB hydrolysis-based H2 generation system. AB hydrolysis inside the reactor, packed with ruthenium supported on carbon pellets, was modeled for varying flow rates (10-100 g min-1) and inlet concentrations (5-25 wt%) of the AB solution. The intrinsic kinetic parameters of the hydrolysis, needed for the reactor simulations, were obtained through isothermal measurements of Ru-catalyzed AB (1 wt%) hydrolysis at a temperature range of 26-56 ºC. The effects of internal diffusion, across the catalyst pellets, could not be eliminated at temperatures above 26 ºC. This problem was solved by estimating the reaction efficiency (h) which in turn, depends on the effective mass diffusion coefficient (Deff ) inside the catalyst pores. Deff was estimated to be 1.41 x10-11 m2 s-1 through appropriate kinetic measurements at batch sizes of 10 ml. The remaining kinetic parameters were determined using a Langmuir-Hinshelwood (LH) kinetic model and a non-linear fitting approach. The hydrolysis was found to have an activation energy of 60.4 kJ mol-1 and an adsorption energy of -31.7 kJ mol-1.
It is difficult to maintain isothermal conditions and therefore, determine kinetic parameters while hydrolyzing high concentra-tions of AB. Hence, the kinetic parameters of AB hydrolysis obtained at dilute (1 wt%) conditions have been used to simulate high-concentration (5-20 wt%) hydrolysis. The model predictions match experimental data reasonably well.
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THERMAL PROPERTY MEASUREMENTS OF HIGH PRESSURE METAL HYDRIDES
Scott Flueckiger, Purdue University, School of Mechanical EngineeringE-mail: [email protected]
ABSTRACT
Metal hydrides are potential materials for onboard hydrogen storage. Thermal property measurements are needed to opti-mize the thermal management design of metal hydride storage systems with considerations of the thermodynamics of the hydriding process and the pyrophoric nature of the material. In the present work, a transient plane source (TPS) apparatus was integrated with a pressure vessel to measure effective thermal conductivity (Keff) and thermal diffusivity () of metal hydrides in a high pressure hydrogen environment (up to 275 bar). In addition, thermal contact resistance (Rtc) between the metal hy-dride and a solid surface was estimated by two-dimensional simulation of the heat conduction process in TPS measurements. Thermal properties of Ti1.1CrMn were measured in oxidized and activated powder. The Keff of the oxidized powder varied from 0.80 ~ 1.6 W/mK as a function of hydrogen pressure. In contrast, Keff of activated powder decreased to 0.31 ~ 0.70 W/mK with hydrogen pressure due to the smaller particle size of activated metal hydrides.
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http://www.purdue.edu/dp/energy 43
PHYSICS BASED MODELS FOR EFFECTIvE THERMAL CONDUCTIvITY OF METAL HYDRIDES AND HIGHLY CONDUCTING COMPOSITES
Presenter, Kyle C. Smith
Advisor, Timothy S. Fisher
ABSTRACT
Metal hydrides possess high volumetric H2 storage density but have low effective thermal conductivity due to their particulate nature. Higher conductivity of these materials can be achieved by making metal hydride composites with conducting matri-ces. These matrices have continuous connectivity throughout the composite, which also helps them maintain mechanical sta-bility. Thermal models have previously been used to fit effective thermal conductivity of plain and composited metal hydrides, but few have been able to make predictive models which could be utilized to guide experimental research and development efforts. The evolution of packing structure due to applied strain via particle rearrangement and plastic deformation influences thermal transport tremendously. The cyclic decrepitation of metal hydride particles with hydrogenation requires a matrix or robust inter-particle connecting network to be mechanically stable and highly conductive. Reduced conduction through the gas phase due to ballistic transport of heat depends on the local confining geometry as well. Also metal hydride particles inherently exhibit faceted morphology and small contact areas in the semi-loose state in which electrons and phonons are confined. The degree of ballistic and diffusive conduction in the solid phase depends on the change in chemical composition of the metal hydride system due to hydrogenation and dehydrogenation. The authors present here part of a comprehensive approach to model each of the important physical aspects which govern the effective thermal properties of metal hydrides and composites. An isotropic fracture model is used to simulate size and shape distributions for metal hydride particles. The discrete element method is used to simulate evolution of packing structure during compaction of non-spherical, polydis-perse metal hydride powders, which also provides a framework for modeling the cyclic stability of compacts. Enhancement of conductivity by addition of metal matrix particles is also studied, and exhibits a percolation threshold which depends highly on the particle ratio of the matrix particles to metal hydride particles. Confinement of carriers in gas and solid phases is mod-eled with thermal boundary resistances at interfaces. Finally, first-principles density functional theory and plane-wave lattice dynamics are utilized to determine density of states of electrons and phonons, respectively, in the solid phases.
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HEAT TRANSFER CHARACTERIZATION OF METAL ORGANIC FRAMEWORKS AND ACTIvATED CARBONS FOR CRYO-ADSORPTION OF HYDROGEN GAS
Casey Porta, Dr. Timothy S. Fisher, Dr. Timotheé Pourpoint E-mail: [email protected]
ABSTRACT
New materials are being considered to facilitate the storage of energy carried by hydrogen. Some hydrogen storage materi-als include activated carbons and Metal Organic Frameworks (MOFs). The present work focuses primarily on the hydrogen adsorption characteristics from theoretical and experimental perspectives. This discussion also includes a brief comparison of and contrast between the chemisorption and physisorption processes, both of which could be present in hydrogen storage although one process is more dominant than the other depending on the material being considered. General material charac-teristics including structure, density, and heat of adsorption are presented. A theoretical model for the adsorption equilibrium is necessary for determining the amount and rate of hydrogen adsorbed.
The progression from a simplified, lumped parameter model to a 1-dimensional, transient model is explained based on the relaxation of assumptions such as uniform temperature and heat generation. Assumptions regarding the boundary and initial conditions from the models are related to the physical system. For example, the system design must include precise tempera-ture control from ambient to cryogenic states for both the jacket surrounding the test article as well as hydrogen inlet gas.
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http://www.purdue.edu/dp/energy 45
STATE-OF-THE-ART TECHNIqUES AND CHALLENGES IN CHARACTERIZATION OF NEW HYDROGEN STORAGE MATERIALS
Andre A. Levchenko, Setaram Inc., Newark, California; Karl J. Gross, H2 Technology Consulting, LLC, Newark, CA, Newark, California
ABSTRACT
The new hydrogen storage materials discovered in the last few years present a number of challenges to the research commu-nity from a viewpoint of materials characterization. These include both evaluation of the performance in real-world applica-tions of hydrogen storage materials and understanding the underlying fundamental mechanisms controlling their properties. This presentation gives an overview of state-of-the-art characterization techniques for hydrogen storage materials. It covers simultaneous TPD-gas sorption/mass-spectrometry measurements, volumetric PCT isotherm measurements on thin-film and extremely small metal-hydride samples, as well as direct van’t Hoff and in-situ calorimetric measurements of enthalpy of for-mation of hydrides. Challenges in performing measurements on particular types of materials or under demanding conditions are discussed.
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http://www.purdue.edu/dp/energy 47
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ENERGY CENTER IN DISCOvERY PARKPotter Engineering Center, Room 322 | 500 Central Drive | West Lafayette, IN 47907-2022Office: 765.494.1610 | [email protected] | http://www.purdue.edu/dp/energy