350

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Figure 2: Equilibrium temperature exit IIR-chambers with catalyzed hardware in 7 kW MCFC pilot plant. The constant equilibrium temperature indicates no deactivation. The MCFC stack was delivered by ERC.

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Figure 2: Equilibrium temperature exit IIR-chambers with catalyzed hardware in 7 kW MCFC pilot plant. The constant equilibrium temperature indicates no deactivation. The MCFC stack was delivered by ERC.

Figure 3: Methane leakage exit anode chamber in 8 kW pilot plant illustrating good performance of the anode chamber catalyst. The plant was at constant load from 2000-6000 hours of operation. The anode exit gas is in chemical equilibrium at the last data point (6200 hours) taken at low fuel utilization. The MCFC stack was delivered by ERC.

Figure 3: Methane leakage exit anode chamber in 8 kW pilot plant illustrating good performance of the anode chamber catalyst. The plant was at constant load from 2000-6000 hours of operation. The anode exit gas is in chemical equilibrium at the last data point (6200 hours) taken at low fuel utilization. The MCFC stack was delivered by ERC.

Cathode outlet Cathode outlet

Cathode outlet Cathode outlet

Figure 4: Calculated temperature pro- Figure5: Calculated temperature profile (°C) at start of run conditions. file (°C) close to end-of-life conditions.

STATUS OF THE M-C POWER EVÏHEX® MCFC COMMERCIALIZATION PROGRAM

René M Laurens*, Joseph A Seroppo, Randy J Petri and Thomas G Benjamin M-C Power Corporation 8040 South Madison Street

Burr Ridge, IL 60521 U.S.A.

Phone 708.986.8040 Fax 708.986.8153

COMMERCIALIZATION and MARKETING STATUS

Six years ago, M-C Power (MCP) developed a comprehensive business plan to commercialize molten carbonate fuel cell (MCFC) power plants. On an annual basis the plan has been reviewed and modified to adapt to identified end user needs and technological advancements. As a result, product definition kept abreast with maiketing requirements. Over the last five years, there was order and reason for subtle shifts in supply, demand, competition and pricing policies. Today, however, traditional market assessment assumptions must be challenged. There is a revolution taking place. The revolution can be summed up in one word... deregulation Deregulation of the airline industry led to consideration of the natural gas industry. Now that natural gas deregulation is behind us, it is electric power and telecommunications that are receiving attention Increased emphasis is being placed on achieving market-priced power. The net result will be thinner margins for the seller and the end user. What does this mean for the commercialization of molten carbonate fuel cells ?

The imminent electric market restructuring will create new forces that will move the MCFC market in new directions. First, the energy customer will enjoy a wide range of choices for electric power and services. Efficiency improvement, power quality and on-site generation will be at the top of the purchase menu. Then, creative electric pricing programs will emerge and price indexing will become common. Under mature deregulation, energy options for large industrial and commercial customers will be optimized based on specific customer requirements. Restructuring is likely to cause transmission congestions as participants move away from regulated transmission activities. Transmission congestion within sensitive air basins will provide the opportunity for strategic placement of MCFC power plants. The extremely competitive nature of wholesale power generation suggests that MCFC applications are best suited for placement at or near customer sites. Thus, MCFC power plants can compete in a retail market while exploiting their environmentally benign characteristics.

After the Year 2005, power generation capacity shortages are likely because of retired, stranded generating assets. Mature market electric power pricing in the deregulated environment will only result after restructuring is completely implemented nationwide. This means that full electric price reductions will hot occur until around the Year 2005. Considering electric restructuring, the U.S. Department of Energy is predicting stable natural gas prices through the year 2015, increasing by only 1.5 % per year.1 Although a high fuel gas price enhances the benefits from the high efficiency characteristics of the MCFC power plant, our analyses reveal that four opportunity segments will remain in the deregulated environment. These four market segments are:

Market Segment Representative Business

1. Commercial facilities Hospitals, hotels, offices and retails establishments.

2. Industrial manufacturing Textile mills, paper and allied products, chemicals, glass and primary metals.

3. Off-site power generation Distributed generation; supports electric distribution system.

4. Opportunity fuels Landfill gas, sewage treatment digester gas, refineries, petrochemical plants, chemical and allied products.

Hospitals have the most favorable energy use characteristics of any commercial building for on-site (»generation systems. They are electrical-energy intensive, require significant thermal energy and their energy use pattern is fairly constant- that is, it does not diminish appreciably at night or on weekends and holidays. Additional candidates include: other kinds of health care facilities such as nursing homes and convalescent center, prisons and hotels.

Distributed generation, as presented here, is power capacity that is owned by the electric utility and is classified as distribution assets rather than as a generation asset The initial distributed generation applications of MCFC's will be in areas where electrical transmission and distribution costs are the highest. Other high priority uses will be areas where a utility can defer or cancel new substation construction or upgrades. During the Years 2000 to 2005, fuel cells could capture as much as 500 MW of capacity.

The primary uses for MCFC's in industrial manufacturing is for (»generation and manufacturing plant emission reduction. Opportunity fuels in the petroleum refinery, petrochemical and chemical industries include hydrogen and carbon monoxide. Methane from landfills and waste water treatment plants are also considered opportunity fuels.

TESTING and TECHNOLOGY DEVELOPMENT

Full-area, short height stack testing. Short height full-area stack testing is conducted to verify stack design changes or qualify components used in full height prototypes. MCP conducted one full-area, short height test (MCP-7) to qualify the components for the Naval Air Station (NAS) Miramar demonstation. The principal objectives of the test were to verify: 1) performance of the components, 2) the effect of increased negative fit up, 3) the effect of integrated feed rails towards reducing the cell pressure drop, and, 4) unattended stack test operation. A brief summaiy of the results obtained is given below.

Performance- Figure 1 contains typical MCP-7 polarization data. The polarization was conducted at 1 atm and 75% fiiel utilization at 160 mA/cm2, using system gases (simulated cathode recycle power plant gases). The test duration was 2,369 h with 1,050 h of steady state operation on simulated power plant gases. The average power produced on system gases at 1 atm equates to 19.6 kW (-1 kW/cell) at 160 mA/cm1.

Fit up- Negative fit up is used to ensure good seal pressure in the gas manifold area while maintaining the ability of the rail to follow cathode creepage. A potentail drawback was that internal resistances may increase; however, data collected showed this was not the case. In fact we noted a slight improvement or reduction of resistance by 3.4%, over previous data.

Integrated feed rail- Previous plate designs used pressed/machined pieces to distribute reactant gases. A total of ten (10) feed rails were used; manufacturing was costly and time consuming. Integration of the feed rails into the main plate not only reduced plate cost but provided the added benefit of reduced cell face pressure drop. Data collected during MCP-7 revealed a 5% reduction in pressure drop when compared with other short height stacks for a wide range of cathode flows.

Figure 1. MCP-7 Polarization

Figure 1. MCP-7 Polarization

Unattended operation- To meet low operating cost and remote siting capabilities an MCFC-based power plant must operate unattended. The MCP test facility control system was improved to enable this type of operation. During MCP-7, the facility operated 1,300 h in this mode and responded well to both scheduled and unscheduled power outages and other simulated tests.

Prototype testing. We completed the construction of our second prototype 250 kW full height stack-The first stack- installed at Unocal's Fred Hartley Research Center — was not successful. Consequently, MCP stopped manufacturing of the Miramar stack and conducted an extensive review of its component manufacturing, assembly, conditioning, transportation, field installation and startup procedures. While the stack produced 80 kW in the acceptance test facility (ATF), the review team identified that the most probable causes for the lack of stack performance were the in-field oxidation of the anodes and loss of clamping pressure. In addition, the team identified 48 issues where improvement was needed. The great majority of these were implemented. A summary of the significant changes made to ensure the success of the NAS Miramar stack is presented below:

Manufacturing- Modified procedures yielded much improved component tolerances. In general, the manufacturing teams achieved tolerances of + 2 mils on components with areas in excess of 10,000 cm1.

Assembly- A comprehensive three-dimensional, finite element, thermo-mechanical stack asembly model was completed. The model enables stack engineers to evaluate the effect of stacking tolerances on gas sealing requirements and active area contact forces. The model was validated via a series of live stack assembly tests of from 50 to 250 cells that were instrumented with a real-time strain gauge system as well as pressure sensitive film. The computer simulations and live Figure 2. NAS Miramar 250 kW Stack assembly tests confirmed that force distribution plates are needed to realize good gas seals and electrical contact. The verified model was then used to specify the number, spacing and thickness of these force distribution plates. Figure 2 shows the assembled Miramar stack; a total of 9 such "intermediate", or force distribution plates were used.

Conditioning- Several bench scale tests were made to validate the procedures to be used for conditioning the Miramar stack. Redundant equipment and instrumentation were added to the acceptance test facility to enhance its reliability. The actual conditioning process for the NAS Miramar stack was uneventful. We met the 200 hours goal set for on-load operation in the ATF, with over 150 hours of operation at 25% load; using simulated power plant gases set at 60% fuel utilization. The maximum power output was 104 kW for a six hour period. The maximum load could not be sustained due to facility cooling limitations. To prevent loss of clamping pressure after stack conditioning — a key' recommendation made by the review team— a redundant spring clamping system was installed.

Transportation and Field Assembly- Figure 3 shows the power module leaving the MCP manufacturing facility. The procedures used for transportation of the NAS Miramar stack were identical to those used for the Unocal stack. Confirmation testing after stack arrival at Miramar revealed no adverse effects due to transportation The field stack assembly was completed on schedule and the power module is ready

for integration after the startup test(s) are completed on the balance of plant (BOP) equipment. Redundant stack height measurement systems, another key recommendation made by the review team, were installed and verified by MCP engineers. Figure 3. NAS Miramar power module

Market Entry Component Development To achieve market entry performance, life and cost requirements, MCP has modified the existing cell package components using a continuous improvement approach. Particular emphasis was placed on the development and scale up of a sodium-based electrolyte and a Ni dissolution resistant cathode.

For example, the IMHEX team completed a very successful series of bench scale tests using first and second generation stabilized cathodes. Detailed results for the solid solution cathodes are given elsewhere.2- Here, a brief description of the results obtained from a new, second generation stabilized cathode are given. The test completed 10,000 h of operation, including more than a year on load with simulated power plant system gases. The cell operated at 3 atm pressure at a

Figure 4. New, Lower Cost Stabilzed

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