SECA Solid Oxide Fuel Cell Program Nguyen Minh 3 rd Annual SECA Workshop Washington, DC March 21-22, 2002
SECASolid Oxide Fuel Cell Program
Nguyen Minh
3rd Annual SECA WorkshopWashington, DCMarch 21-22, 2002
3rd SECA WorkshopMarch, 2002
Program ObjectiveProgram Objective
• Approach– System approach– Development focus
�High performance� Low cost�Reliability�Modularity�Fuel flexibility
• Overall objective– Demonstrate a fuel-flexible, modular 3-to-10-kW solid oxide
fuel cell (SOFC) system that can be configured to create highlyefficient, cost-competitive, and reliable power plants tailored tospecific markets
3rd SECA WorkshopMarch, 2002
SOFC System ConceptSOFC System Concept
36 IN.
15 IN.
20 IN.
3rd SECA WorkshopMarch, 2002
Key System FeaturesKey System Features
• SOFC– High-performance reduced-temperature cells– Operation on light hydrocarbons– Tape calendering manufacturing process
• Fuel processor– Low-cost, fuel-flexible fuel processor design– Catalytic process– Pre-reforming function
• Other subsystems– Integrated thermal management– Flexible control subsystem
3rd SECA WorkshopMarch, 2002
Program FeaturesProgram FeaturesDEM O NSTRATIO NO F FUEL FLEXIBLE
PROTO TYPESYSTEM
PROTO TYPEDEM O NSTRATIO N
TECH NO LO G Y IM PRO VEM ENTAND CO ST REDUCTION
PACK AG ED SYSTEMDEM O NSTRATIO N
TECH NO LO G Y ADVANCEM ENTAND CO ST REDUCTION
FIELD TEST O FPACK AG ED SYSTEM
SELECTEDAPPLICATIONFOR PHASES
II, III
DEM O NSTRATIO NO F PACK AG ED SYSTEM
FO R SELECTEDAPPLICATIO N
FIELD TEST O FPACK AG ED SYSTEMFO R SELECTEDAPPLICATIO N
• IMPROVED PERFORMANCE, YIELDS,EFFICIENCY
• ENABLE INCREASED MANUF.AUTOMATION
• DESIGN PACKAGING
PH ASE I PH ASE II PH ASE III
DESIGN, STACK DEVELOPMENT,FUEL PROCESSING, THERMAL MANAGEMENT,CONTROLS/SENSORS, POWER ELECTRONICS
K EY TECH NO LO GY DEVELO PM ENT
• ADVANCED MATERIALS/ PROCESSES• ENABLE FULL MANUF. AUTOMATION• OPTIMIZE PACKAGING
MARKETANALYSISAND COSTESTIMATES
MARKETANALYSISAND COSTESTIMATES
COSTESTIMATES
3rd SECA WorkshopMarch, 2002
Phase I Work ElementsPhase I Work Elements
• System analysis
• Cost estimate
• Stack technology development
• Fuel processing
• Thermal management
• Control and sensor development
• Power electronics
• System prototype demonstration
3rd SECA WorkshopMarch, 2002
Schematic of Method for Cost EstimationSchematic of Method for Cost Estimation
Define SystemIdentify Components
Establish Performance Specifications
Size Components
Identify BOP Suppliers/Manufacturers
Calculate Costs
Solicit Cost Information
Perform System Cost Estimation
Map Manufacturing Process
Design Stack, Fuel processor
Stack and Fuel ProcessorBOP Components
Determine Production Rates
Raw Materials CostEquipment CostLabor CostFacilities/Utilities Cost
VendorsHoneywell Businesses
Engineering Judgement
Assembly Costs
3rd SECA WorkshopMarch, 2002
Key AssumptionsKey Assumptions
• Main system design assumptions– 5 kW stationary system operating on natural gas– Fuel processor as pre-reformer
• Key manufacturing assumptions– Production rate of 250 MW/year– Single plant located in Southwest
3rd SECA WorkshopMarch, 2002
Cost EstimatesCost Estimates
• Projected system cost when fully developed:$388/kW
• Stack Costs
Equipment (18.7%)
Labor (12.1%)
Materials (50.5%)
Land & Building (0.9%)
Utilities (17.8%)
3rd SECA WorkshopMarch, 2002
System ConceptSystem Concept
Air Feed
PWater Feed
Natural Gas Feed
System Exhaust
Water Filtration
Hot Exhaust Gas
P
C
Fuel Mix Preheater/VaporizerLiquid Fuel
Inverter
C
Fuel Cell Air
Prereformer Air
Fuel Feed
FuelProcessing
NOTES:1. Optional liquid fuel feed for non-stationary applications
Note 1
SOFCCore
Anode Fuel Gas
Stack with Air Preheating
DCPower
ACPower
3rd SECA WorkshopMarch, 2002
System Design and Analysis ApproachSystem Design and Analysis Approach
• Propose Conceptual Design• Steady-state Model• Assume Components &Performances• Detailed Thermal/TransientSystem Model
• DesignComponents• System Analysis• Trade Studies
• Compare to Requirements• Identify Gaps
ConceptualSystem Definition
TechnologyGaps
System Definition
TechnologyDevelopment
System RequirementsTechnology Base
3rd SECA WorkshopMarch, 2002
Performance EstimatesPerformance Estimates
Stationary Mobile Military
Fuel Natural Gas Gasoline Diesel
StackVoltage, VUtilization
0.750.80
0.750.80
0.750.80
PowerFuel cell, kWNet, kW
5.75.0
5.95.0
6.15.0
EfficiencyNet, % 40 33 30
3rd SECA WorkshopMarch, 2002
Low Cost Manufacturing ProcessLow Cost Manufacturing Process
• Fabricationprocess withtape calendering
• Multilayer electronicsfabrication process
3rd SECA WorkshopMarch, 2002
Fracture SurfaceLaMnO3Cathode
ZrO2Electrolyte
NiO/ZrO2Anode
Thin Electrolyte CellThin Electrolyte Cell
3rd SECA WorkshopMarch, 2002
Stack ConfigurationsStack Configurations
• Thin film electrolytes• Thin foil metallic interconnects• Gas manifold options• Gas flow configuration flexibility
• Thin film electrolytes• Thin foil metallic interconnects• Gas manifold options• Gas flow configuration flexibility
Crossflow Design Radial Flow Design Unitized Cell Design
3rd SECA WorkshopMarch, 2002
SOFC PerformanceSOFC Performance
0
0.2
0.4
0.6
0.8
1
1.2
1.4
0 0.5 1 1.5 2 2.5
Current Density (A/cm²)
Vo
ltag
e (V
)
0
0.2
0.4
0.6
0.8
1
1.2
1.4
Po
wer
Den
sity
(W
/cm
²)
Voltage in Syngas
Power Density in Syngas19% H2, 24% CO, 1% CO2, Bal N2
Power Density in H2
Voltage in H2
• 800°C operation• Open circuit voltages
in agreement withtheoretical values
• Peak power density:– 1.3 W/cm² in hydrogen– 0.85 W/cm² in JP-8
syngas
• 800°C operation• Open circuit voltages
in agreement withtheoretical values
• Peak power density:– 1.3 W/cm² in hydrogen– 0.85 W/cm² in JP-8
syngas
3rd SECA WorkshopMarch, 2002
SOFC Cell Performance at Reduced TemperaturesSOFC Cell Performance at Reduced Temperatures
0
0 .2
0 .4
0 .6
0 .8
1
1 .2
1 .4
0 0 .5 1 1 .5 2 2 .5 3
C ur rent D ens ity , A/c m 2
Cel
l Vol
tage
, V
0
0 .2
0 .4
0 .6
0 .8
1
1 .2
1 .4
Pow
er D
ensi
ty, W
/cm
2
800C
750C
700C
650C
600C
Hydrogen fuel
Air oxidant
High power densities (e.g., 0.9 W/cm² at 650°C) achieved at reducedtemperatures (<800°C) with anode-supported thin-electrolyte cells
High power densities (e.g., 0.9 W/cm² at 650°C) achieved at reducedtemperatures (<800°C) with anode-supported thin-electrolyte cells
3rd SECA WorkshopMarch, 2002
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
0 20 40 60 80 100 120
Time, H
Cel
l Vo
ltag
e, V
780
785
790
795
800
805
810
815
820
Cel
l Te
mp,
C
V C
75% Fuel Utilization, J=1.72A/cm2
Power Density = 1.1 W/cm2 80%
85%Fuel: Hydrogen
Oxidant: Air
Cell Fuel UtilizationCell Fuel Utilization
3rd SECA WorkshopMarch, 2002
Other Cell/Stack AccomplishmentsOther Cell/Stack Accomplishments
• Demonstration of high cell performance (1.8 W/cm2
at 800°C) with high utilization (50%)• Operation of a stack module for more than 3000
hours– Identification and modeling of degradation rate
• Fabrication scaleup and improvement
3rd SECA WorkshopMarch, 2002
Reforming OptionsReforming Options
STEAMREFORMING
PARTIAL OXIDATION
AUTOTHERMALREFORMING
Fuel ReformerFuelSteam
H2, CO2
AirFuel Fuel Reformer H2, CO, CO2, H2O, N2
Fuel ReformerFuelSteamAir
H2, CO, CO2, H2O, N2
3rd SECA WorkshopMarch, 2002
Fuel Processing ApproachFuel Processing Approach
• Fuel processor as a pre-reformer for hydrocarbonfuels
• Approach: Catalytic partial oxidation (CPOX) asbaseline and process modifications as required fordifferent types of fuels
3rd SECA WorkshopMarch, 2002
CPOX for Processing Hydrocarbon FuelsCPOX for Processing Hydrocarbon Fuels
• Fuels: propane, butane,octane, JP-8, and diesel
• Duration: 700 hours to date
• Thermal cycles: 10
• Sulfur tolerance: 1000 ppmdibenzothiophene in JP-8
• Yield: 70-80% of LHV in JP-8
• Fuels: propane, butane,octane, JP-8, and diesel
• Duration: 700 hours to date
• Thermal cycles: 10
• Sulfur tolerance: 1000 ppmdibenzothiophene in JP-8
• Yield: 70-80% of LHV in JP-8
0%
20%
40%
60%
80%
100%
0 40 80 120 160 200 240 280 320
Time (Hours)
Per
cen
t Y
ield
%
H2
COThermal Cycle
3rd SECA WorkshopMarch, 2002
Control System FunctionsControl System Functions
– Control system functionality drives integration– Coordinate subsystems for shared resources
and efficient operation– Efficiently regulate over a wide operating range
� Flow / Composition� Temperature� Pressure� Power
– Provide safe system operation through built-intest
– Perform process and component healthmonitoring for improved life cycle
– Provides user interface and automated systemoperation� Startup/ Shutdown� Scheduled operation� Status indicators/alarms� Emergency Shutdown
Operational ModeInputs
Com
man
d fl
ow
System-level control
Subsystem
Subsystem
Subsystem
3rd SECA WorkshopMarch, 2002
Control & Sensing ApproachControl & Sensing Approach
– Honeywell’s proprietary Fuel Cell DynamicComponent Library allows for rapiddevelopment of dynamic system models andprototyping of control systems throughsimulation.
– Rapid prototyping capabilities allow fordirect transfer of controls designed insimulation to control of fuel cell system.
– Advanced control and sensing techniquescan investigated through simulation tradestudies and then the most promisingapproaches easily implemented in hardwaresystem.
PlantSensors
Feedback
Feedforward
Estimation
Controls
Rapid Prototyping
3rd SECA WorkshopMarch, 2002
Controls Analysis and Design ProcessControls Analysis and Design Process
Control Requirements Definition•Model Development•Subsystem Analysis•Control Loop Analysis•Cell Monitoring
Preliminary Control Design•Simulation Based Design•Assume Component Performance•Controllability of System Addressed
Control Evaluation and Development•Control Design Trade Studies•Focus Control Design for Application•Built-In Test and Health Monitoring•Final Control Design for Phase I•Develop Sensor Requirements•Develop Actuator Requirements
Sensor and Actuator Evaluation•Sensor Trade Studies•Sensor Testing•Actuator Trade Studies•Actuator Testing
Sensor and Actuator Development•Sensor Development•Actuator Development
Control System Integration•Rapid Prototyping System Implementation of Control Strategy•Hardware Selection and Procurement•Software Development•Hardware/Software Implementation
SystemDesign
-FMEA -Event Ledger . . .
“Design for Control”
Current Effort
3rd SECA WorkshopMarch, 2002
Concluding RemarksConcluding Remarks
• SECA SOFC system concept• System features
– High performance– Low cost– Flexibility
• Various activities to support system development