IS THERE A CONTINUING ROLE FOR THE
FEDERAL GOVERNMENT IN FUEL CELL
R&D FOR TRANSPORTATION?

Steven G. Chalk
Office of Transportation Technologies
U.S. Department of Energy
Washington, D.C.

S. R. Venkateswaran
Energetics, Incorporated
Columbia, Maryland

1998 Fuel Cell Seminar           November 16 - 19, 1998           Palm Springs, California

WHERE ARE WE TODAY?
     The U.S. Department of Energy (DOE) initiated a significant program in proton-exchange-membrane (PEM) fuel cells for transportation in the early 1990s, in the face of considerable skepticism and uncertainty about the potential benefits and feasibility of fuel cell technology, especially for demanding vehicular applications. Less than ten years later, DOE's investments in fuel cell technology are bearing fruit. Building on a series of technology breakthroughs, the DOE program has developed a large enabling technology base in PEM fuel cells. A unique and versatile National "team" has been assembled to take advantage of the best available technical talent and financial resources in industry, government, and academia. This team is now working cooperatively under the umbrella of the Partnership for a New Generation of Vehicles (PNGV) toward the goal of a fuel cell automobile with up to 80-mpg fuel economy.
     On the technology front, solid performance gains in fuel cell stacks, fuel processing, and systems have been achieved through DOE-supported R&D and allied efforts as described below:
     Under the DOE/Ford program, which started in July 1994, International Fuel Cells (IFC) has developed a 50-kWe net fuel cell system that operates on hydrogen and air (at near ambient pressure of 1-2 psig). The low parasitic power requirements associated with this design contribute to very high efficiency. Performance-wise, the hydrogen-air PEM stack meets the key requirements for automobiles. However, two major technical chaflenges have come to the forefront with the hydrogen systems, namely, reducing manufacturing costs and achieving adequate reliability. These barriers would inhibit the commercial viability of hydrogen fuel cell cars even if a hydrogen fuel infrastructure was in place today.
     DOE has been working with General Motors (GM) to develop a 30-kWe net PEM fuel cell system with steam reforming of methanol. A brassboard system has been successfully tested, but it does not yet include air management compressor and expander. This program has uncovered serious system integration challenges associated with thermal and air management as well as start-up time, transient response, and fuel processor efficiency.
     In October 1997, a PEM fuel cell/reformer system fueled by gasoline generated electricity for the first time in the laboratory (Figure 1). This landmark achievement has validated the technical feasibility of DOE's fuel flexible fuel strategy. The system includes a 50-kW fuelflexible fuel processor developed by A.D. Little (now Epyx) - the result of DOE projects initiated in the early 1990s. Recognizing that fuel flexibility and compatibility with existing infrastructure are key requirements, this project has placed considerable emphasis on fuel processing, especially gas cleanup, and successfully utilized partial oxidation (POX) technology. While the basic technology approach has been demonstrated, several problems have been uncovered that are related to fuel composition and impurities, gas cleanup, and catalyst performance as well as greater system complexity and lower operating efficiency when compared to a methanol-based system.
     DOE's experience with these and other R&D projects indicates that, as we move toward the use of more realistic and near-term fuels (such as gasoline), new problems arise and the barriers become more challenging to overcome. In effect, the lack of infrastructure for fuels such as hydrogen and methanol is putting a greater burden on the vehicle fuel cell propulsion system to be fuel flexible and accommodate available conventional fuels.

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Figure 1: PEM Fuel Cell System Producing Electricity from Gasoline, Ethanol, Methanol, or Natural Gas (First Demonstrated October 1997)

WHERE DO WE GO FROM HERE?
     Given the potential for PEM fuel cells to deliver large economic and environmental benefits to the Nation and the challenging barriers that still remain to be overcome, the DOE will continue to take a leadership role in further developing and validating PEM fuel cell technology. Areas presenting significant high-risk technical challenges include:
  • System Integration - Beyond the laboratory scale, there are no integrated systems running on hydrocarbon fuels such as gasoline. Achieving extensive thermal integration within the processor and with the fuel cell system presents difficult challenges.
  • Manufacturing cost reductions - from $500/kW (at high volume) for the fuel cell engine to the levels of competitive internal combustion engine technology (<$50/kW). While there are no fundamental barriers to achieving PEM stack goals, stringent cost targets need to be met for every material, component, and manufacturing step.
  • Fuel processing - Processors are in the proof-of-principle stage and none meet 0 of the criteria for automotive applications including rapid cold-start.
     DOE's primary R&D objective is to develop an automotive-sized (i.e., 50-kWe) power system that operates on conventional and alternative fuels. The Fuel Cells for Transportation Program will not develop fuel cell cars but, instead, focus on the critical fuel cell system and enabling component technology necessary to power an 80-mpg automobile. The network chart of Figure 2 presents the overall approach to addressing the key technical barriers. The Ford/IFC hydrogen fuel cell system and the General Motors 30-kWe methanol system discussed earlier are considered to be "first generation" because they are first-of-a-kind laboratory devices. At least two mor6 generations of hardware development are required to address all the major technical barriers.
     In October 1997, development of a second generation, 50-kW, reformate capable stack system was initiated with AlliedSignal, Energy Partners, Plug Power, and EFC. The technical challenges associated with fuel cell performance on hydrocarbon reformate are significantly greater than with methanol reformate or hydrogen. Epyx and Hydrogen Burner Technology are developing a 50-kW fuel-flexible fuel processor. Plug Power and IFC will combine the fuel cell and fuel processor subsystems to provide a complete automotive-sized fuel cell power system meeting DOEIPNGV technical targets established for the year 2000. If development of the integrated power system is successful, it will be made available to Chrysler, Ford, and General Motors for testing and possible subsequent integration into concept or test vehicles.
     The national laboratories support the fuel processor and fuel cell stack system development by working on catalysts, gas cleanup, and other advanced components. In parallel, industry suppliers are working on compressor/expander and other low-cost component designs as well as high-volume manufacturing techniques. For example, 3M is developing high-volume manufacturing processes for the membrane electrode assembly and the Institute of Gas Technology has developed a high-volume process for bipolar plates. Looking at the year 2000 and beyond, a third generation of hardware development, similar to the second generation approach, will be needed to achieve the year 2004 technical targets established by the PNGV. This is indicated by the bars labeled as "future R&D" in Figure 2.

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Figure 2: DOE Program Approach to Address Key Technology Barriers for Post-2000 Fuel Cell Concept Vehicles with 80-mpg Fuel Economy
     Focusing on the fuels arena, DOE's fuel-flexible fuel processing approach accepts the reality of today's fuel infrastructure while creating future pathways for alternative fuels. Fuel processors developed under the DOE program must convert gasoline, ethanol, methanol, and natural gas into hydrogen-rich streams. However, gasoline is the primary fuel of focus because of its availability today and for the next 50 years. Several key issues related to fuel quality and availability remain to be addressed. For example, specific fuel requirements for on-board processing in fuel cell vehicles must be determined with respect to sulfur content, additive requirements, oxygenated components, the impact of metal impurities and other contaminants and so forth. Very recently, several major oil companies have agreed to begin working with the PNGV and DOE to take a closer look at petroleum based fuels for fuel cells. This could lead to a more "fuel-processing friendly" fuel than gasoline as we know it today.

HOW CAN WE GET THERE?
     To improve chances of success, an effective overall strategy to push forward fuel cell vehicles must emphasize the following:
     A systems approach involving the fuel, fuel processor and gas cleanup, the fuel cell stack, and balance of plant components
     A team approach to develop technical solutions involving the auto, supplier, and energy industries
     Application of government resources and expertise to support high-risk, pre-competitive R&D in a manner that is consistent with agency missions and industry needs and priorities
     In this overall context, the focus of DOE's strategy is to ensure that the Fuel Cells for Transportation Program is working with the right partners on the most promising and critical enabling technology areas while leveraging available DOE resources to the maximum degree. Figure 3 lays out the Fuel Cells for Transportation Program "Team". The DOE role is to provide overall leadership for the technology through technical direction, prioritized allocation of resources, and financial management.
     Recognizing the key government role in building a domestic fuel cell supplier base, the majority of DOE-supported R&D is carried out by suppliers through cost-shared cooperative agreements and contracts with DOE. The contractors include the traditional automotive suppliers as well as new developers of fuel cell technology. National laboratories also play a key role in conducting R&D by applying their extensive technical expertise in electrochemistry, catalysis, fuel processing, and materials processing to high-risk technical issues such as carbon monoxide cleanup, catalyst development, and direct methanol fuel cells. The results of laboratory research are made available to all domestic suppliers.

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Figure 3: The Fuel Cells for Transportation Program "Team"
     As auto manufacturers have steadily increased their investments in fuel cells, they have taken on the primary responsibility for the design and engineering effort needed to integrate the fuel cell power system into a vehicle whose safety, performance, cost, and reliability will meet the expectations of the driving public. Within the PNGV, Chrysler, Ford, and General Motors are working with the DOE (under the auspices of the U.S. Council for Automotive Research or USCAR) to help define system requirements, technology goals, and R&D priorities for fuel cell power systems and components. The auto companies also participate in technical reviews of supplier and laboratory R&D. This collaborative approach ensures that the DOE fuel cell program remains focused on the needs of the automakers as they proceed with the development of 80-mpg (PNGV) concept vehicles in the post-2000 timeframe.

CONCLUSIONS
  • A critical need exists for the Federal Government to sustain a continued, intensive governmentindustry R&D effort in PEM fuel cells for transportation, with overall objectives as follows:
  • Building upon the dramatic progress achieved since the early 1990s to overcome remaining technical barriers to market introduction through a strong program of enabling research
  • Leveraging the technical expertise and financial resources of the unique OEM -- supplier -- national laboratory -- academia team that has been assembled
  • Resolving market constraining issues related to fuel infrastructure, such as fuel quality and availability
  • Building a strong domestic supplier base that can provide fuel cell power systems to domestic and foreign OEMs
  • Taking advantage of technology development and market synergies with other fuel cell markets such as on-site residential, commercial, and industrial power and portable power and generation Accelerating the commercialization of fuel cell vehicles in the next decade
  • This strong government role increases the chances of delivering to consumers the advanced fuel Cell technology that will meet the Nation's future transportation and other energy needs in an environmentally clean, efficient, and sustainable manner.