The MCFC as Small Scale CHP System and Large Central Power Plant

8.2.3.1 FuelCell Energy

FuelCell Energy is based in Danbury, CT, and has a second facility in Torrington. The company was formed out of Energy Research Corporation (founded in 1969), which is probably best known for setting up the largest fuel cell power plant ever operated in the North America — the Santa Clara Demonstration Project, with a nominal electric power output of 2.5 MW. Like other demonstration plants, it was based on 300-kW MCFC stack technology called Model 9000. Current plant sizes are 300 kW, 1.5 MW, and 3 MW. FuelCell Energy refers to its technology as direct fuel cell, as it is based on internal reforming technology capable of using a multitude of fuels, including natural gas, methanol, ethanol, biogas, and any other fuel that contains methane.

FuelCell Energy and Caterpillar, Inc., signed a distribution and joint development agreement in November 2001 under which Caterpillar will distribute FuelCell Energy products through selected Caterpillar dealers in the United States.

In Asia, FuelCell Energy is working with Marubeni Corporation to generate at least 45 MW in power plant orders over the forthcoming two years, while providing the necessary infrastructure for successfully delivering products in Japan and elsewhere in Asia. The first Asian 250-kW power plant will be sited at the Kirin brewery plant outside of Tokyo. It will be operated in co-generation mode as part of a contracting relationship under which Marubeni supplies electricity and steam to the brewery, and it will run on digester gas from the plant's effluent. In the future, a joint venture with component assembly in Asia is planned.

FuelCell Energy's European partner, MTU, a subsidiary of DaimlerChrysler, has actively contributed to the technology base by developing the so-called Hot Module (see below). In 2001, MTU began a field trial at the Rhön-Klinikum Hospital in Germany. In North America, the company shipped 250-kW power plants to Mercedes-Benz in Alabama and to the Los Angeles Department of Water and Power.

Orders at the end of 2001 stood at an additional 12 MW of co-generation and multiple-fuel applications for delivery in the U.S., Europe, and Asia. FuelCell Energy expects to deliver commercial submegawatt-class power plants by the second half of calendar 2002 and megawatt power plants in 2003. For 2004, the projected milestone is 400 MW. Initial operation of the proof-of-concept DFC/T, a power plant combining its fuel cell technology and a Capstone micro turbine for more efficient electricity generation, began in July 2001.

MTU's best-known contribution to MCFC development is the Hot Module design, which includes all heated parts of the system in a common heat-insulated compartment, as shown in Fig. 8.11(a). This design helps to reduce heat insulation efforts and reduces sealing problems.

The stacks are supplied by FuelCell Energy and are of the externally manifolded type. Uniquely among all fuel cells, the stack is placed inside the Hot Module in a horizontal position. Fig. 8.11(b) shows the gas flow and the various components inside the Hot Module.

The longest operation time stands at 5700 hours in a pilot plant trial at Bielefeld, Germany, where the plant ran 4300 hours in excess of 200 kW with peak power at 263 kW. A second German plant has recently taken up operation at the Rhön-Klinikum, Bad Neustadt. The installation of this plant is illustrated in Fig. 8.12. The pilot plant operates in co-generation mode and supplies electric and thermal power (as steam at 200°C) of approximately 270 and 160 kW, respectively, to the hospital, covering roughly 25% of the annual power demand. Plant lifetime is expected at 20,000 h (HyWeb, 2001a). The current price for a 250-kW plant stands at ca. 6 million DM (just over 3 million Euros). Electric efficiencies of 56% for the stack and 47% for the plant are achieved.

At the 2001 Grove Fuel Cell Symposium, MTU presented a list of seven future MCFC projects. The locations are:

RWE: Heat and power at an energy park (Meteorit) in Essen, Germany

IZAR: Energy for this shipbuilding company

Mtu Chp Plants
FIGURE 8.11 (a) Opened hot module. (Please check Color Figure 8.11(a) following page 9-10.) (b) Cross-flow of reactant gases inside the Hot Module. (Photograph and drawing courtesy of MTU.)

Deutsche Telecom: DC backup power for a telecommunication center

EnBW/Michelin: Electricity and process steam for a tire manufacturing plant

E.ON/Degussa: Generation of power, heat, and CO2 gas for industrial use

IPF KG: Backup power and co-generation for the Otto-v-Guericke University Medical Institute

VSE AG: Co-generation for industrial laundry and CO2 use for greenhouse fertilization

For quite a number of years, M-C Power has been known as another leading developer of molten carbonate fuel cell (MCFC) technology. This company uses a patented design concept invented by the

FIGURE 8.12 Installation of an MTU MCFC power plant at Rhön-Klinikum, Neustadt (Germany).

Institute of Gas Technology (IGT). Along with IGT, M-C Power has partnered with the Bechtel Group of San Francisco and Stewart & Stevenson Services, Inc. of Houston.

In contrast with FuelCell Energy and MTU, M-C Power employs an external reforming concept based on its plate steam reformer. M-C Power has supplied a range of pilot power plants to the Naval Air Station at Miramar, CA (EG&G, 2000) and plans to supply a new 250-kW plant. The plant also co-generates steam for the district heating system. The current status of the M-C Power program is unclear.

8.2.4 The SOFC as Small-Scale CHP System and Large Central Power Plant

The SOFC has good potential to operate as a large central power plant once highly efficient combined cycle plants (with the fuel cell replacing the combustion chamber of a gas turbine) have been established. Currently, SOFCs are mainly rated between 100 and 1000 kW electric power, with optional use of high-temperature steam.

8.2.4.1 Siemens-Westinghouse Power Corporation

For this type of power plant, Siemens-Westinghouse Power Corporation (SWPC) is currently the most advanced developer. Therefore, tubular technology in Section 8.1.3 was essentially introduced using the Siemens-Westinghouse design concept. SWPC's record of demonstration plants is impressive. Table 8.3 shows that from 1995 the new AES technology (compare Section 8.1.3) was used, leading to significantly improved power densities. One plant using the current 150-cm tubes (active length) is the 100-kW atmospheric EDB/ELSAM power station previously operating in the Netherlands (Fig. 8.13).

It is also interesting to see that in addition to natural gas a variety of fuels have been employed, including syngas and logistic fuels (fuels defined by the military: JP-8 jet fuel and DF-2 diesel fuel).

In 2001 and after almost 13,000 h of operation, the EDB/ELSAM plant (Fig. 8.13) was moved from Westvoort, the Netherlands, to its new site at RWE's energy park in Essen, Germany, where another two fuel cell installations are planned, a pressurized SWPC SOFC (see Table 8.3) and an MCFC supplied by MTU (compare Section8.2.3.2).

In parallel, SWPC is evaluating pressurized hybrid(microgasturbine) technologyina220-kWsystem for Southern California Edison Figure 8.14 shows thisplant. 8.15 isasimplified versionof the process diagram for the hybrid process.

TABLE 8.3 Westinghouse and Siemens-Westinghouse Field Units

Year

Customer

Stack Rating (kWe)

Cell Type

Cell Length (mm)

Cell Number

Oper. (hrs)

Fuel

MWh

1986

TVA

0.4

TK-PST

300

24

1760

h2+co

0.5

1987

Osaka Gas

3

TK-PST

360

144

3012

h2+co

6

1987

Osaka Gas

3

TK-PST

360

144

3683

h2+co

7

1987

Tokyo Gas

3

TK-PST

360

144

4882

h2+co

10

1992

JGU-1

20

TN-PST

500

576

817

PNG

11

1992

UTILITIES-A

20

TN-PST

500

576

2601

PNG

36

1992

UTILITIES-B1

20

TN-PST

500

576

1579

PNG

108

1993

UTILITIES-B2

20

TN-PST

500

576

7064

PNG

108

1994

SCE-1

20

TN-PST

500

576

6015

PNG

99

1995

SCE-2

27

AES

500

576

5582

PNG/

118

DF-2/JP-8

1995

JGU-2

25

AES

500

576

13,194

PNG

282

1998

SCE-2/NFCRC

27

AES

500

576

3394+

PNG

73+

1997

EDB/ELSAM

100

AES

1500

1152

4035+

PNG

471+

1999

EDB/ELSAM

100

AES

1500

1152

12,653

PNG

1474

2001

RWE

1340+

147+

2000

SCE

220

AES

1500

1152

778

PNG

131

Note: These data are correct as of August 2001. AES: air electrodesupported technology. PST: (older)poroussupport tube technology. The EDB/ELSAM plant (Fig. 8.13) has recentlybeenmovedfromitsDutchsite toanewsiteat Meteorit energy park (Essen, Germany), operated byutility RWE.

Source: Courtesy of Siemens-Westinghouse Power Corporation.

100 Chp Sofc
FIGURE 8.13 EDB/ELSAM 100-kW SOFC plant at Westvoort (the Netherlands). After more than 13,000 h of operation, the plant was moved to its new site at Meteorit energy park, Essen (Germany).

SWPC has agreed with four key European utilities to provide the first 1-MW pressurized hybrid system to be demonstrated as a pre-commercial plant for the European market (Table 8.3). The project will be funded under the Framework Five Program of the European Commission and, at the same time, by the U.S. Department of Energy (DOE). EnBW, headquartered in Stuttgart, Germany, will be the host utility at a site in Marbach and the program manager for the strategic demonstration project. Also, the French national utilities Electricite de France and Gaz de France, both located in Paris, will participate in providing and coordinating the micro turbine and the balance of plant along with Tiroler Wasserkraftwerke AG (TIWAG), a major power utility of Innsbruck, Austria.

Micro Gas Turbine Chp
FIGURE 8.14 Pressurized hybrid (micro gas turbine) technology in a 220-kW system for Southern California Edison. (Photograph courtesy of Siemens-Westinghouse.) (Please check Color Figure 8.14 following page 9-10.)
Siemens Sofc Ph300
FIGURE 8.15 Simplified diagram of pressurized, combined cycle SOFC plant. (Drawing courtesy of Siemens-Westinghouse.)

The 1-MW pressurized (3 bara) hybrid system will feature a scale-up of a tubular SOFC generator module. The generator module will be integrated with a microturbine generator that will provide 20% of the electricity produced. The 1-MW system (total cost approximately 25 million Euros), which will have electrical efficiencies approaching 60%, will be connected to the EnBW utility grid. The system is to be in operation by October 2003 and will operate for a period of at least 12 months. Key objectives of the project are to gain experience with operating characteristics and to qualify SOFC system designs to European codes and standards (EnBW, 2000).

In 2002, Siemens-Westinghouse will ship another pre-commercial 300-kW SOFC power system for RWE Power AG to be located at Meteorit energy park (replacing the older, 100-kW plant, Fig. 8.13) and

TABLE 8.4 Future and Ongoing Siemens-Westinghouse SOFC Field Trials

Year

Customer

Type of Plant

Stack Rating (kWel)

Number of Cells

2001

OPT

CHP 250

250

2304

2002

RWE

PH 300

230

1728

2002

Edison

PH 300

230

1728

2003

EnBW

PH 1000

800

5760

2003

SW Hannover

CHP 250

250

2304

2003

Shell

CHP 250 ZE

250

2304

Note: PH: pressurized hybrid; CHP: combined heat and power/co-generation; ZE: "zero emission" plant employing CO2 sequestration.

Source: Courtesy of Siemens-Westinghouse Power Corporation (Fall, 2001).

Note: PH: pressurized hybrid; CHP: combined heat and power/co-generation; ZE: "zero emission" plant employing CO2 sequestration.

Source: Courtesy of Siemens-Westinghouse Power Corporation (Fall, 2001).

a second system for Edison spa of Milan, Italy, the lead company of the energy sector within the Montedison Group — see Table 8.4.

Partly funded by the DOE, SWPC and Norske Shell are going to employ a re-configured 250-kW SOFC power plant in Norway to concentrate and capture CO2 generated for subsequent sequestration or industrial use (Williams, 2001; Lequeux, 2001).

SWPC plans to commercialize SOFC systems by 2004 with first commercial deliveries in the 250- to 1000-kW range. Included in the systems will be simple co-generation systems of 250 kW and hybrid systems of 300 and 1000 kW using the SOFC with a microturbine. The SOFC 300-kW class hybrid systems will offer electrical efficiencies approaching 60% (50 kW from the micro turbine) and will be used for all electric applications supplying electricity to the utility grid. Table 8.4 gives an overview of future technology demonstrations.

Guide to Alternative Fuels

Guide to Alternative Fuels

Your Alternative Fuel Solution for Saving Money, Reducing Oil Dependency, and Helping the Planet. Ethanol is an alternative to gasoline. The use of ethanol has been demonstrated to reduce greenhouse emissions slightly as compared to gasoline. Through this ebook, you are going to learn what you will need to know why choosing an alternative fuel may benefit you and your future.

Get My Free Ebook


Post a comment