Assessment of Research Needs for Advanced Fuel Cells

236 Pages·1986·6.081 MB·English

by  S. S. Penner (Eds.)

ASSESSMENT OF RESEARCH NEEDS FOR
ADVANCED FUEL CELLS
by the
DOE ADVANCED FUEL CELL WORKING GROUP
(AFCWG), 1984-85
Editor
S. S. Penner
Chairman of DOE/AFCWG Energy Center and Department of Applied Mechanics and Engineering Sciences,
University of California, San Diego, La Jolla, CA 92093, U.S.A.
PERGAMON PRESS
NEW YORK . OXFORD · TORONTO · SYDNEY · FRANKFURT
U.S.A. Pergamon Press Inc., Maxwell House, Fairview Park,
Elmsford, New York 10523, U.S.A.
U.K. Pergamon Press Ltd., Headington Hill Hall,
Oxford 0X3 OBW, England
CANADA Pergamon Press Canada Ltd., Suite 104, 150 Consumers Road,
Willowdale, Ontario M2J 1P9, Canada
AUSTRALIA Pergamon Press (Aust.) Pty. Ltd., P.O. Box 544,
Potts Point, N.S.W. 2011, Australia
FEDERAL REPUBLIC Pergamon Press GmbH, Hammerweg 6,
OF GERMANY D-6242 Kronberg, Federal Republic of Germany
BRAZIL Pergamon Editora Ltda., Rúa Ega de Queiros, 346,
CEP 04011, Sao Paulo, Brazil
JAPAN Pergamon Press Ltd., 8th Floor, Matsuoka Central Building,
1-7-1 Nishishinjuku, Shinjuku, Tokyo 160, Japan
PEOPLE'S REPUBLIC Pergamon Press, Qianmen Hotel, Beijing,
OF CHINA People's Republic of China
Copyright © 1986 Pergamon Press Ltd.
All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system or
transmitted in any form or by any means: electronic, electrostatic, magnetic tape, mechanical, pho­
tocopying, recording or otherwise, without permission in writing from the publishers.
ISBN 0-08-033990-5
This work was supported by the U.S. Department of Energy, Office of Energy Research, Office of
Program Analysis, under Contract DE-AC01-84ER30060.
Disclaimer
This report was prepared as an account of work sponsored by the United States Government. Neither
the United States nor the United States Department of Energy, nor any of their employees, makes
any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy,
completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents
that its use would not infringe privately owned rights. Reference herein to any specific commercial
product, process, or service by trade name, mark, manufacturer, or otherwise, does not necessarily
constitute or imply its endorsement, recommendation, or favoring by the United States Government
or any agency thereof. The views and opinions of authors expressed herein do not necessarily state
or reflect those of the United States Government or any agency thereof.
In order to make this volume available as economically and as rapidly as possible, the author's
typescripts have been reproduced in their original forms. This method unfortunately has its typographical
limitations but it is hoped that they in no way distract the reader.
Published as a special issue of the journal Energy, Volume 11, Number 1/2 and
supplied to subscribers as part of their normal subscription. Also available to non-
subscribers.
Printed in Great Britain by A. Wheaton & Co. Ltd., Exeter
PREFACE
The DoE Advanced Fuel Cell Working Group (AFCWG) was formed
and asked to perform a scientific evaluation of the current status of fuel
cells, with emphasis on identification of long-range research that may have
a significant impact on the practical utilization of fuel cells in a variety of
applications. The AFCWG held six meetings at locations throughout the
country where fuel cell research and development are in progress, for pre­
sentations by experts on the status of fuel cell research and development
efforts, as well as for inputs on research needs. Subsequent discussions
by the AFCWG have resulted in the identification of priority research areas
that should be explored over the long term in order to advance the design
and performance of fuel cells of all types.
Surveys describing the salient features of individual fuel cell types
are presented in Chapters 2 to 6 and include elaborations of long-term
research needs relating to the expeditious introduction of improved fuel
cells.
The Introduction and the Summary (Chapter 1) were prepared by
AFCWG. They were repeatedly revised in response to comments and
criticism. The present version represents the closest approach to a con­
census that we were able to reach, which should not be interpreted to mean
that each member of AFCWG endorses every statement and every unex­
pressed deletion. The Introduction and Summary always represent a
majority view and, occasionally, a unanimous judgment.
Chapters 2 to 6 provide background information and carry the
names of identified authors. The identified authors of Chapters 2 to 6,
rather than AFCWG as a whole, bear full responsibility for the scientific
and technical contents of these chapters.
MEMBERS AND EX OFFICIO MEMBERS OF THE DOE ADVANCED FUEL CELL WORKING GROUP (AFCWG)
University Members
Professor J.O'M. Bockris Professor J. Robert Selman
Department of Chemistry Department of Chemical Engineering
Texas A & Μ University Armour College of Engineering
College Station, Texas 77840 Illinois Institute of Technology, I IT Center
409-845-4947 or 409-845-5335 Chicago, 111inois 60616
312-567-3037
Professor S.S. Penner, AFCWG Chairman Professor David Shores
Director, Energy Center, B-OlO Department of Metallurgical Engineering
University of California, San Diego 151 Amundson Hall, Univ. of Minnesota
La Jolla, California 92093 421 Washington Ave., SE
619-452-4Z84 Minneapolis, Minnesota 55455
Office: 612-373-4183, Home: 612-721-7530
Professor Ernest B. Yeager
Case Center for Electrochemical Sciences
Case Western Reserve University
10,900 Euclid Ave.
Cleveland, Ohio 44106
216-368-3626
Industry and Research Organization Members
Dr. John Appleby, Project Manager Mr. William E. Houghtby
(Mr. E.A. Gil lis, Alternate Member) Power Systems Division
Advanced Fuel Cell Technology United Technologies Corporation
Electric Power Research Institute P.O. Box 109
P.O. Box 10412 South Windsor, Connecticut 06074
Palo Alto, California 94303 203-727-2200
415-855-2543
Dr. Bernard S. Baker, President Dr. A. Kaufman, Res. Mgr. for Fuel Cells
(Dr. Hans Maru, Alternate Member) (Dr. L. Michael Quick, Alternate Member)
Energy Research Corporation Engelhard Corporation
3 Great Pasture Road Menlo Park
Danbury, Connecticut 06810 Edison, New Jersey 08818
203-792-1460 201-321-5286
Dr. Jack T. Brown Dr. L.G. Marianowski, Associate Director
Manager, Materials and Conversion Energy Conversion and Storage Research
Systems Department Institute of Gas Technology
Westinghouse Electric Corporation 3424 South State Street
R&D Center Chicago, Illinois 60616
1310 Beulah Road 312-567-3650
Pittsburgh, Pennsylvania 15235
412-256-1950
Dr. Diane T. Hooie Dr. Halina Wroblowa, Principal Res. Scientist
(Dr, John J. Cuttica, Alternate Member) Ford Motor Company
Residential/Commercial Energy Advanced Components and Energy Systems Dept.
Systems Research P.O. Box 2053
Gas Research Institute Dearborn, Michigan 48121-2053
8600 West Bryn Mawr Ave. 313-337-5052
Chicago, Illinois 60631
312-399-8100
vii
viii Members and Ex Officio Members
Ex Officio Members
Dr. John Ackerman Dr. Ken Rogers
Manager, Electric Chemical Research Program Director of the Kinetics, Catalysis
CMT/205 and Reaction Engineering Program
Argonne National Laboratory Chemical and Process Division
9700 South Cass Avenue Room 1126
Argonne, IL 60439 National Science Foundation
1800 G Street, NW
Washington, D.C. 20550
Commander Dr. Albert Landgrebe
U.S. Army Belvoir R&D Center (Alternate: Dr. Stanley Ruby)
ATTN: STRBE-EC (Dr. J.A. Joebstl] Office of Energy Storage
Fort Belvoir, VA 22060 CE-141, FORSTL
U.S. Department of Energy
Washington, D.C. 20585
Alternates
Mr. F. Don Freeburn,
DoE Project Manager Mr. Robert Rader
General Engineer Director, Research and
ER-33, GTN Technical Assessment Division
U.S. Department of Energy ER-33, GTN
Washington, D.C. 20545 U.S. Department of Energy
Washington, D.C. 20545
Dr. C. Lowell Miller Mr. Graham Hagey
Acting Director of Advanced Energy (Alternate: Mr. Charles Pax, 301-353-2832)
Conversion Systems Office nf Advanced Energy
FE-22, GTN Conversion Systems
U.S. Department of Energy FE-22, GTN
Washington, D.C. 20545 U.S. Department of Energy
Washington, D.C. 20545
Mr. John E. Sholes Dr. John Wilson
Chief, Fuel Cells Project Branch Director, Coal Projects
Coal Projects Management Division Management Division
Morgantown Energy Technology Center Morgantown Energy Technology Center
P.O. Box 880 P.O. Box 880
Morgantown, WV 26505 Morgantown, WV 26505
Dr. Marvin Warshay Dr. Henry Slone
Manager, Fuel Cells Project Office Director, Space Technology
M.S. 500-203 M.S. 3-5
NASA/Lewis Research Center NASA/Lewis Research Center
Cleveland, OH 44135 Cleveland, OH 44135
INTRODUCTION
This is the final report covering work performed under Contract No.
DE-AC01-84ER30060 with the U.S. Department of Energy. It was prepared for
the Office of Program Analysis (CPA) within the Department's Office of Energy
Research. OPA provides independent, objective analyses of the Department's
technical needs and opportunities. A function of this activity includes
assessing the adequacy of the long-range (technology base) research that sup­
ports the Department's research and development (R&D) programs. This report
deals with an assessment of the long-range research needs for advanced fuel
cells.
The Principal Investigator of this study was S. S. Penner, Director,
Energy Center, and Professor of Engineering Physics, University of California/
San Diego. He was assisted by the DOE Advanced Fuel Cell Working Group (AFCWG).
AFCWG members are experts on fuel cell R&D and were selected from academic
institutions, industry, and not-for-profit organizations. Experts from the
government. National Laboratories, and DOE Energy Technology Centers served as
observers and resource personnel at AFCWG meetings.
The original AFCWG work statement is reproduced in Appendix A. It served
as a basis for the development of the ideas presented in this report and was
refined and explicated as the result of progressive discussions involving both
AFCWG members and the ex officio members who represented the Department of
Energy and other federal agencies.
The Summary (Chapter 1) contains our principal findings and recom­
mendations. It is followed by surveys describing the salient features of fuel
cells, including elaborations concerning the identification of long-range
research needs (Chapters 2 to 6).
Cost evaluations and potential market penetration of new fuel-cell tech­
nologies have formed integral components of our deliberations and references
to these problem areas wll be found in connection with the discussions of
individual fuel cells.
Our research recommendations over a wide spectrum of activities and empha­
size fundamental science and understanding rather than cell design and develop­
ment. They have not been constructed to satisfy the primary goal of optimizing
a particular cell design or configuration. Adequate long-range, stable support
for research on materials science, fundamental electrochemistry, etc. may aid
commercial implementation of the right technologies over the long term and may
also be of value in the definition and identification of new or different fuel-
cell designs that merit investigation and development.
The members of AFCWG acknowledge with thanks the advice and assistance pro­
vided by many individuals in government, industry and the universities. The
following individuals, among others, have contributed to our discussions,
evaluations and final recommendations: C. Antoine (NASA Lewis Research Center),
R. Barta (GE), J. E. Bauerle (Westinghouse), M. J. Brand (Engelhard), E. J.
Cairns (LBL), W. Feduska (Westinghouse), D. Fee (ANL), F. Gmeindl (DOE/METC),
D. Q. Hoover (Westinghouse), J. Huber (DOE/METC), C. D. lacovangelo (GE),
H. Isaacs (BNL), A. 0. Isenberg (Westinghouse), B. King (NASA Lewis Research
Center), K. Kordesch (U. of Graz, Austria), A. K. Kush (ERC), R. M. Latanision
(MIT), S. K. Lau (Westinghouse), A. Leonida (ERC), G. Liu (Dow Chemical Co.),
0. Lindstrom (Volvo, Inc., Stockholm, Sweden), R. Meredith (DOE/CE/ESR),
L. Paetsch (ERC), D. Pierce (ANL), E. Pigeand (ERC), C. A. Reiser (UTC),
R. Rosey (Westinghouse), P. Ross (LBL), R. J. Ruka (Westinghouse), D. W.
Sheibley (NASA Lewis Research Center), M. Simnad (USCD), P. Singh (ERC),
S. C. Singhal (Westinghouse), S. Srinivasan (Inst, of Hydrogen Systems,
Ontario, Canada), J. Taylor (Physical Sciences, Inc.), J. Werth (Engelhard),
G. W. Wiener (Westinghouse), E. R. Williams (UCSD), and C. M. Zeh (DOE/METC).
Introduction
The Importance of Fuel-Cell Development to the U.S.
The productive use of energy with emphasis on electrical energy during
the past one hundred years has been a major factor in the improvement of the
quality of life for people living in the industrialized world. For a long
time, until the early nineteen seventies, energy use was facilitated by its
very low cost. In the past decade, however, there has been worldwide a
rapid rise in the real price of energy. This increase has manifested itself
in the industrialized world in lower growth rates and a small but perceptible
decrease in the quality of life as people are forced to use a larger portion
of their income to finance basic primary and secondary energy requirements.
In some countries of the Third World, huge and politically hazardous debt
accounts are a consequence of energy costs.
To return to the pre-70s era with respect to energy, in terms of how much
time a person must work to buy a kWh or BTU, may not be possible. Clearly,
however, we can and should seek to obtain greater output from existing energy
inputs. Reasonable measures to aid conservation have been taken in order to
reduce input requirements to the energy system. It is now necessary to
improve the basic energy structure itself. This goal can be achieved by
the development of entirely new technologies, which are intrinsically more
efficient and of lower cost than currently used energy-utilization methods.
Implementation of this goal is especially important in the generation of
electri city.
A very attractive technique for reducing the amount of energy required
to produce a specific amount of electricity involves the use of fuel cells
(FCs). Furthermore, the use of FCs offers the potential of lowering the
cost of electricity. Reducing required energy inputs and lowering the cost
of electricity are related but separate issues. Both are important. Reducing
the required energy inputs decreases the need for energy imports and also
the amount of domestic GNP required for new energy production or utilization.
These advantages, in turn, improve the balance of payments and free resources
for other uses. Reducing the cost of electricity will benefit consumers and
their utility suppliers. Japan, a country which imports virtually all of
its energy and is very cost-conscious in its manufactured exports, has
realized the impact of both of these factors and has launched a major
national FC program.
The potential benefits of FC development and use are the result of
unique FC properties. The FC is an electrochemical device which produces
electricity directly from the galvanic oxidation (combustion) of a fuel.
The usual steps involving primary conversions to heat and mechanical
energy are omitted. The theoretical FC efficiencies are not limited by
the Carnot cycle and may be very high. Actually achieved efficiencies
in electricity production with FCs exceed those of conventional methods
for power generation. For example, FCs using natural gas today produce
electrical energy at a conversion efficiency of 40% and will in the future
have efficienees up to 65%. Coal-fueled FC systems with comparable FC
technology are expected to reach the 35 to 60% efficiency range. The
U.S. average for electric power generation is currently about 33%. For
a new system, a doubling of fuel efficiency will reduce the required
primary energy inputs correspondingly, whether imported or domestic fuel
supplies are used.
A second important characteristic of the FC is the relative independence
of power-plant efficiecy on power-plant size. Thus, a 500-kWe power plant
may have the same efficiency as a 500-MWe power pTant. This fact has a very
large impact on utility purchase of FCs. In the sixties and seventies,
electric utilities in the U.S. and elsewhere began to purchase power-plant
units of very large size. One thousand MWg coal and nuclear plants were
designed and built or almost built. Unfortunately, nuclear power plants
in the U.S. have required 10 to 15 years for construction and their costs
have often escalated substantially. Moreover, because of the long required
lead times, planning to meet future needs has been very difficult. With
the FC, smaller units of a standardized modular construction can be added
to the grid in a short period of time without sacrificing efficiency. This
fact greatly reduces utility financing problems and thus directly improves
the financial well-being of the rate payer, who now will only pay for the
amount of generation equipment actually needed by his utility. As already
noted,, because of the high FC efficiency, the cost of electricity is expected
to be less than for competing systems, regardless of FC system size.
Introduction
Because FCs can be made in a variety of sizes, they may be placed at
different locations on the grid system, thus allowing the utilities, in some
instances, to reduce transmission costs. This advantage is particularly
important in congested urban centers, where needed transmission and distribu­
tion facilities are expensive to install. Since FC systems operate efficiently
at part load, their use may be tailored to actual requirements. Furthermore,
FC systems are environmentally highly acceptable. Acid emissions and the
resulting air pollution are reduced by several orders of magnitude compared
with conventional fossil-fuel-fi red generators. Because of this desirable
property, FCs may be located anywhere.
The siting advantages provide the opportunity to locate FCs near points
of use and, therefore, allow utilization of the waste heat produced by the
FCs for such desirable purposes as space heating, water heating or
absorption cooling. This last feature has led to interest by U.S. gas
utilities and consideration of the use of FCs in conjunction with their
extensive gas-distribution systems. The combined use of electricity and
heat may result in fuel-utilization systems with overall energy efficiencies
of 90%. Point-of-use FC systems are also attractive for industrial
cogeneration.
Estimates made of the cost of electricity suggest that natural-gas-
fueled FC systems could produce electricity for about 6(i/kWgh, which
equals about half of the interest costs alone for many new nuclear plants.
The desirable flexibility in constructing cost-effective, dispersed
power plants will also increase the nation's security in the event of war.
In the succeeding Chapters 1 to 5, we present overviews on FCs in
general and on each of five distinct FC systems that are currently avail­
able or under development. There are a number of competing technical
approaches and some of the FCs that are at relatively early stages of
development offer the best future prospects for higher efficiency and
lower system costs. This is the normal sequence of development as
technology evolves and is improved. To bring the new FCs to successful
commercialization will require coordinated efforts of government, industry,
utilities, and universities. Achieving this goal will provide the U.S.
with a valuable product for internal use and for export. The potential,
long-term capital value of FC equipment sales is very large (^^^ $10 billion
per year) and therefore merits U.S. attention.
1. SUMMARY OF RESEARCH RECOMMENDATIONS
S-I. Advantages of Fuel Cells
Compared with other electricity-generating systems that are in current use, fuel cells
(FCs) offer the following potential advantages: substantially higher conversion efficiency of fuel
energy to electricity, modular construction, high efficiency at part load, minimal siting restric­
tions, potential for cogeneration, and much lower production of pollutants (including acid-rain
precursors). The anticipated results of effective fuel-cell commercialization will be reduced
fuel and capital costs, cleaner environments, and hence lower costs to users of electricity.
S-II. Commercialization Schedules
The current (early 1985) approach to commercial development and relative funding re­
quirements for fuel cells are summarized in Fig. S-1. Phosphoric acid fuel cells (PAFCs) are
seen to be within a few years of commercialization for both utility and on-site applications,
whereas the molten carbonate fuel cells (MCFCs) and solid oxide fuel cells (SOFCs) could be­
come available 7 to 9 years later. Commercial applications of alkaline fuel cells (AFCs) and
solid-polymer-electrolyte fuel cells (SPEFCs) could follow PAFCs by 10-14 years if a decision
is made for development.
We estimate the desirable level of basic supporting research for FCs to be 10% of total
R&D effort after development work begins, which is in accord with industry norms for high-
technology, high-risk programs. Prior to initiation of development for commercialization, a
critical level of effort must be supported that will depend on FC-type and on the perceived
urgency for introducing an alternative or complementary technology into the market.
S-III. Research Priorities for Selected FCs
Research priorities are summarized for five selected FCs. Supporting documentation
for these recommendations will be found in Chapters 2 to 6, respectively.
1. Acid Fuel Cells
The phosphoric acid fuel cell (PAFC) is the most mature FC (see Fig. S-1) in terms of
technological advancement and readiness for commercialization in near- and medium-term
applications. PAFCs have been under development for about 20 y, and it is estimated that the
total investment to date from all sources is 400-500 million dollars. The PAFC was selected
for development as the most viable acid FC type because of its superior and unique stability
characteristics and despite its inherently poor ionic properties. The major driving force for its
dominant position has been the widespread view in the U.S. that it alone among the lower tem­
perature FCs shows relative tolerance for reformed hydrocarbon (HC) fuels (steam raised in the
FC is used for reforming, CO is removed by a shift reaction, and rejection of CO2 occurs natu­
rally by acid).
Significant improvements in the performance, cost, and durability of PAFCs have been
realized during their development. The promise of continued improvement with important com­
mercial implications exists to this day. Improvements have involved all aspects of PAFC devel­
opment, from basic electrochemistry to overall system optimization. Crucial accomplishments
in the emergence of PAFCs as a commercially acceptable power system have involved the quali­
fication and exploitation of carbon materials as the backbone of the fuel-cell stack, reduction of
electrocatalyst platinum (Pt) loadings by more than an order of magnitude with the substitution of
highly-dispersed, carbon-supported catalysts for the Pt-black types used previously, and eleva­
tion of the operating temperature by óO-SO'O to about 200*0, which has resulted in significant
augmentation of cell and overall system efficiencies. For larger PAFCs of the type directed
toward electric utility applications, the development of pressurized systems has further im­
proved efficiency and, hence, economic attractiveness.
Despite the specified significant advances in PAFC technology, the incentive for ongoing
and further improvements is great. PAFCs are now projected to establish a significant niche in
the electric- and gas-utility markets and other application areas by providing benefits in terms
of fuel savings, environmental impacts, and packaging and siting logistics. However, the total
market penetration for PAFCs will be dictated by hard economic decisions, and further tech­
nological advances are likely to have a major effect on the economic attractiveness of the PAFC
relative to available competing systems. For electric utility application, it has been estimated
at EPRI that an FC efficiency improvement of \0% will increase market penetration from about
6-7% to about 16%. Efficiency improvements of this magnitude have actually been achieved
Energy, The International Journal
Critical support level for program initiation
\
0.5 1.0
^= *ApiOtotype
Fig. S-1. Percentages of cumulative costs are plotted vs» fractional time τ required for
FC development (solid curve); for PAFCs, tpj.ototype development"' Y- ^Iso
shown are our estimates at 10% of total R&D costs lor needed basic research
(dotted curve); in order to facilitate visual display, the scale for basic research
has been augmented by a factor of five relative to the total R&D scale. Prior to
development for commercialization, research programs of critical size (dot-
dash curve) are needed to support alternative or complementary FC develop­
ments; PAFCs = phosphoric acid FCs; MCFCs = molten carbonate FCs;
SOFCs = solid-oxide FCs; AFCs = alkaline FCs; SPEFCs = solid-polymer-
electrolyte FCs. Horizontal arrows indicate uncertainties in time.