Basic Research Needs for the Hydrogen Economy
Total Page：16
File Type：pdf, Size：1020Kb
Cover Image: The cover shows the crystal structure of the alanate NaAlH4, a new class of hydrogen storage material. Al atoms are red, Na atoms are green, and H atoms are blue. In this class of materials, hydrogen “encapsulates” Al to form a hydrogen-rich - anion, AlH4 , whose structure resembles that of methane, CH4. The alanate structure differs from that of the metal hydrides like MgH2, where hydrogen is encapsulated by metal ions, and the hydrogen density is correspondingly lower. In the cover image, the diameter of the hydrogen atoms is enlarged to reflect the very high scattering cross section of neutrons for hydrogen and deuterium. This high sensitivity makes neutron scattering a natural tool for probing the interaction of hydrogen with materials. (In the report, see the sidebar, Using Neutrons to “See” Hydrogen, on page 38). Report prepared by Argonne National Laboratory. Argonne is a U.S. Department of Energy Office of Science Laboratory operated by The University of Chicago under contract W-31-109-Eng-38. Basic Research Needs for the Hydrogen Economy Report on the Basic Energy Sciences Workshop on Hydrogen Production, Storage, and Use Chair: Mildred Dresselhaus, Massachusetts Institute of Technology Associate Chairs: George Crabtree, Argonne National Laboratory Michelle Buchanan, Oak Ridge National Laboratory Panel Chairs: Production Tom Mallouk, Pennsylvania State University Laurie Mets, The University of Chicago Storage Kathy Taylor, General Motors (retired) Puru Jena, Virginia Commonwealth University Fuel Cells Frank DiSalvo, Cornell University Tom Zawodzinski, Case Western Reserve University Office of Basic Energy Sciences Contact: Harriet Kung, Basic Energy Sciences, U.S. Department of Energy Special Assistance Technical: Ian S. Anderson, Oak Ridge National Laboratory Phil Britt, Oak Ridge National Laboratory Larry Curtiss, Argonne National Laboratory Jay Keller, Sandia National Laboratory Romesh Kumar, Argonne National Laboratory Wai Kwok, Argonne National Laboratory John Taylor, Argonne National Laboratory Administrative: Janice Allgood, Oak Ridge National Laboratory Brenda Campbell, Oak Ridge National Laboratory Karen Talamini, Basic Energy Sciences, U.S. Department of Energy This report is available on the web at http://www.sc.doe.gov/bes/hydrogen.pdf. i Second Printing, February 2004 Revisions p 9, footnote 1: In terms of energy use, 1 gigawatt (GW) of power — the output of most light- water nuclear reactors — corresponds to approximately 0.29 million tons/year (Mtons) of hydrogen. One terawatt-year (TW-yr) of energy is equivalent to 0.29 gigatons (Gtons) of hydrogen or 5.13 billion barrels (BB) of oil. The 3.3 TW use of fossil fuels in 2000 would thus correspond to approximately 0.95 Gtons of hydrogen. p 11, paragraph 2: Natural gas resources will be sufficient for several decades to expand this capacity to support the FreedomCAR and Fuel Initiative. By 2040, it is anticipated that the use of hydrogen in fuel cell powered cars and light trucks could replace consumption of 18.3 MB per day of petroleum. Assuming that hydrogen powered vehicles have 2.5 times the energy efficiency of improved gasoline vehicles, this reduction in petroleum use would require the annual production of approximately 150 Mtons of hydrogen by 2040. If all of this hydrogen were produced by petroleum reforming, the net savings in petroleum use would be 11 MB per day (U.S. Department of Energy [DOE] 2003). The total energy used for transportation in the U.S., however, includes a substantial component of other kinds of vehicles (Figure 1a), and meeting that need poses a greater challenge to hydrogen production. p 12 (bottom) - p13 (top): The estimated power output from 10% efficient solar cells covering 1.7% of the land area of the U.S. (an area comparable to the land devoted to the nation's highways) is 3.3 TW, equivalent to the total U.S. fossil fuel use in 2000. The CD attached to the inside back cover contains low- and high-resolution PDFs of the report and high-resolution files of the report graphics. ii PREFACE Global energy consumption is expected to increase dramatically in the next decades, driven by rising standards of living and a growing population worldwide. The increased need for more energy will require enormous growth in energy generation capacity, more secure and diversified energy sources, and a successful strategy to tame greenhouse gas emissions. Among the various alternative energy strategies, building an energy infrastructure that uses hydrogen — the third most abundant element on the earth’s surface — as the primary carrier that connects a host of energy sources to diverse end uses may enable a secure and clean energy future for the Nation. The Basic Energy Sciences (BES) Workshop on Hydrogen Production, Storage, and Use, held May 13–15, 2003, was stimulated in part by an earlier study commissioned by the Basic Energy Sciences Advisory Committee (BESAC) to assess the basic research needs to assure a secure energy future. The charge to that study was to identify the fundamental scientific challenges of the 21st century that “… Basic Energy Sciences must consider in addressing the [DOE] missions in energy efficiency, renewable energy sources, improved use of fossil fuels, safe and publicly acceptable nuclear energy, future energy sources, science-based stockpile stewardship, and reduced environmental impact of energy production and use.” The study identified 10 basic research directions in response to this charge, one of which was “Basic Research toward the Hydrogen Economy.”1 In his State of the Union address in January 2003, President Bush unveiled the Administration’s Hydrogen Fuel Initiative. The goals of this Initiative are to lessen America’s dependence on imported oil and reduce greenhouse gas emissions. The President stated: With a new national commitment our scientists and engineers will overcome obstacles to taking these cars from laboratory to showroom, so that the first car driven by a child born today could be powered by hydrogen and [be] pollution free. Inspired, in part, by the President’s announcement, and as a follow-on to the BESAC-sponsored energy security study published in February 2003,1 BES established the present study on Basic Research Needs for the Hydrogen Economy. The study was planned and executed in the period from March to July 2003. Prof. Mildred Dresselhaus of the Massachusetts Institute of Technology chaired the workshop, and Drs. George Crabtree (Argonne National Laboratory) and Michelle Buchanan (Oak Ridge National Laboratory) served as the Associate Chairs. The Associate Director of DOE’s Office of Science, Basic Energy Sciences, Dr. Patricia M. Dehmer, challenged the workshop chair and associate chairs to: Identify fundamental research needs and opportunities in hydrogen production, storage, and use, with a focus on new, emerging and scientifically challenging 1 “Basic Research Needs to Assure a Secure Energy Future,” A Report from the Basic Energy Sciences Advisory Committee (Feb. 2003); available at http://www.sc.doe.gov/bes/besac/Basic_Research_Needs_To_Assure_A_ Secure_Energy_Future_FEB2003.pdf. iii areas that have the potential to have significant impact in science and technologies. Highlighted areas will include improved and new materials and processes for hydrogen generation and storage, and for future generations of fuel cells for effective energy conversion. Three panels were assembled to examine the charge in depth. Their topics and chairs were: Basic Research Challenges for Hydrogen Production Co-Chairs: Tom Mallouk (Pennsylvania State University) Laurie Mets (The University of Chicago) Basic Research Challenges for Hydrogen Storage Co-Chairs: Kathy Taylor (General Motors, retired) Puru Jena (Virginia Commonwealth University) Basic Research Challenges for Fuel Cells and Novel Fuel Cell Materials Co-Chairs: Frank DiSalvo (Cornell University) Tom Zawodzinski (Case Western Reserve University) Each panel was composed of about 15 panelists and 5 speakers with a broad spectrum of expertise from universities, DOE national laboratories, and industry. The panelists and speakers also included foreign experts, primarily from Japan and Europe. The names of the panel members and speakers, as well as the agenda for the workshop, are provided in the appendix. Four questions were posed to the panels: • Where are we now? • What do we already know? • Where do we want to be? • What do we need to do to get there? To initiate answers to these four questions, program officers in the DOE Office of Energy Efficiency and Renewable Energy (EERE) briefed each of the panels before the Workshop and provided a multitude of reading materials. Mark Paster briefed participants on hydrogen production and delivery, JoAnn Milliken on hydrogen storage, and Nancy Garland on fuel cell activities under the FreedomCAR and Fuel Initiative. Harriet Kung served as the BES contact throughout the study. To set the stage for the Workshop, overview presentations were given. The panels carried out their in-depth work from the evening of the first day through the morning of the third day. The afternoon of the third day was devoted to oral reports of the findings of each panel, followed by closing remarks. iv Millie Dresselhaus launched the Workshop with an overview presentation on its goals, approaches, and framework. Pat Dehmer then gave a brief overview of BES, the background for the Workshop, and her expectations. To broaden the perspective, a plenary session of five speakers reviewed the present status of