UNESCO Desire – Net project Molten Carbonate Fuel Cells State of the Art & Perspectives State of...
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UNESCO UNESCO Desire – Net project Desire – Net project Molten Carbonate Fuel Cells Molten Carbonate Fuel Cells State of the Art & Perspectives State of the Art & Perspectives Angelo Moreno, Stephen McPhail Angelo Moreno, Stephen McPhail ENEA – Hydrogen and Fuel Cell Project ENEA – Hydrogen and Fuel Cell Project [email protected] [email protected] [email protected] [email protected] UNESCO UNESCO Rome , 13 Rome , 13 th th March 2007 March 2007
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Transcript of UNESCO Desire – Net project Molten Carbonate Fuel Cells State of the Art & Perspectives State of...
UNESCO UNESCO Desire – Net projectDesire – Net project
Molten Carbonate Fuel CellsMolten Carbonate Fuel Cells State of the Art & PerspectivesState of the Art & Perspectives
Angelo Moreno, Stephen McPhail Angelo Moreno, Stephen McPhail ENEA – Hydrogen and Fuel Cell ProjectENEA – Hydrogen and Fuel Cell Project
[email protected]@[email protected]@casaccia.enea.it
UNESCOUNESCORome , 13Rome , 13thth March 2007 March 2007
Summary
• Fuel cell lessons programmeFuel cell lessons programme
• Hydrogen and fuel cellsHydrogen and fuel cells
• MCFC: cell, stack, system, plantMCFC: cell, stack, system, plant
• Difficulties, solutions, perspectivesDifficulties, solutions, perspectives
FC lessons programme
13 March MCFC ENEAMoreno, McPhail
14 March MCFC Ansaldo Parodi
29 March MCFC Ansaldo Capobianco
12 AprilMCFC System configurations
ENEAMoreno, Cigolotti
PEM/SOFC lessons in planning
H2 production plant
Fuel cell plant
HH22
Natural gas
Filling station
Depleted gas well Deep saline aquifer
Power generation plant
COCO22
HH22
Thermal solar Wind turbines
Biomass
PV plant
Hydropower
Turbine avanzate
Efficiency, %
Plant size, MW
SOFC-GT
Steam turbinesDiesel
Gas engines
Combined cycle turbines
Internal combustion engines
PAFCPEFC
MCFC, SOFC
0,1 1 10 100 1000
80
60
70
50
40
30
20
10
0
Microturbines
Advanced turbines
Fuel cells & competing technologies
Hydrogen and Fuel Cells
Hydrogen and Fuel Cells – Roadmap
Why Fuel Cells?
Chemical Energy Thermal
conversion
Work
qloss
CO2 CO NOx SOx PM
qlossqloss
H2O (CO2)
FUEL CELL
CONVENTIONAL SYSTEM
Fuel Cells – principle
Electric power
Hydrogen(Fuel)
Oxygen(air - oxidant)+
heat
water
No thermal cycles
Fuel Cells – principle
No thermodynamic limitations (Carnot)
Electric power
Hydrogen(Fuel)
Oxygen(air - oxidant)+
heat
water
Thermal efficiency
Fuel Cells – principle
H
G
available
usefulT
for H2/O2 reaction: H = 285.8 kJ/mole G = 237.1 kJ/mole
With pure H2/O2: η = 0.83
Temperature: 60-120 °C Efficiency: 60% State of the art technology: 5-150 kW Market: Special applications
(military, space) transportation
Alkaline, AFCAlkaline, AFC
Temperature: 160-220 °C Efficiency: 40-50% State of the art technology: 50 kW -1 MW
plants up to 11 MW Applications: CHP, distributed generation
Temperature: 70-100 °C Efficiency: 40% State of the art technology: 1-250 kW Applications: Transport
ResidentialPremium powerRemote generation
Polymer elctrolyte, PEFCPolymer elctrolyte, PEFC
Temperature: 600-650 °C Efficiency: 45-55% State of the art technology: 100 kW - 3 MW Applications: CHP, distributed generation
(plants up to 20 MW)
Molten carbonate, MCFCMolten carbonate, MCFC
Temperature: 800-1000°C Efficiency: 45 - 60% State of the art technology: 50 kW- 1 MW Applications: CHP, distributed
generation (plants up to 20 MW, transport (APU)
Solid oxide, SOFCSolid oxide, SOFC
Temperature: 50-100 °C Efficiency: 30-40% State of the art technology: : < 1kW Applications: portable, electronics
Direct methanol, DMFCDirect methanol, DMFCPhosphoric acid , PAFCPhosphoric acid , PAFC
Fuel Cells – types
Anode H2 + CO3
= → H2O + CO2 + 2 e-
Cathode 1/2 O2 + CO2 + 2 e- → CO3
=
Water is produced at the anode side
CO2 is needed at the cathode side
Temperature 650 °C ELECTROCHEMICAL REACTIONSELECTROCHEMICAL REACTIONSELECTROCHEMICAL REACTIONSELECTROCHEMICAL REACTIONS
MCFC – characteristics
Electrolyte: combination of alkali carbonates – Li, K, Na
Anode H2 + CO3
= → H2O + CO2 + 2 e-
Cathode 1/2 O2 + CO2 + 2 e- → CO3
=
CO2 is needed at the cathode side:
Temperature 650 °C ELECTROCHEMICAL REACTIONSELECTROCHEMICAL REACTIONSELECTROCHEMICAL REACTIONSELECTROCHEMICAL REACTIONS
MCFC – characteristics
• Supply CO2 from alternate source
• Produce CO2 by combustion anode off-gas
• Transfer CO2 fm anode exit to cathode inlet
Anode H2 + CO3
= → H2O + CO2 + 2 e-
Cathode 1/2 O2 + CO2 + 2 e- → CO3
=
Temperature 650 °C ELECTROCHEMICAL REACTIONSELECTROCHEMICAL REACTIONSELECTROCHEMICAL REACTIONSELECTROCHEMICAL REACTIONS
MCFC – characteristics
CO is a fuel:
through combination with water to H2: CO + H2O → H2 + CO2 (water-gas-shift)
through direct electrochemical oxidation: CO + CO3
= → 2 CO2 + 2 e-
MCFC – stack
MCFC – stack
With sealing & manifolds
MCFC – stack
Manifolds:
Sealing:
Ensure leak-tight closing in highly corrosive atmosphere
• Between cells • Between stack & manifolds
Gas flow distribution
• Homogeneous reactant distribution to the cell • Lower pressure drops• Uniform fuel utilisation
MCFC – stackFuel and oxidant feed
MCFC – Fuelling
Fuel:
• H2
• CO
Oxidant:
• O2
• CO2
Possible sources:
• Natural gas• Syngas (coal gasification)• HC-rich fuel (butane, methanol…)• Biomass (gasification, digestion…)• Chemical production (electrolysis…)
Possible sources:
• Air• Reaction products (recirculation)
MCFC – Fuelling
Fuel:
• H2
• CO
Possible sources:
• Natural gas• Light hydrocarbons (butane, methanol, …)
CxHy + x H2O (g) → x CO + (½y+x) H2
(Endothermic reaction → heat required)
Yield: • H2 75%• CO 10%• CO2 15%
Traces of NH3, CH4, SOx…
MCFC – Fuelling
ReformingExternal
Heat provided by burn-up of anode exit gas + HX
Internal
Heat provided by cell reaction
+
Simplicity inside cell
Separation of functions
-
Complexity in system
Large coolant flow required
+
Cell cooling provided
System simplicity & lightness (=
cost)
-
Reforming catalyst required in cell
Not ideal for high P
MCFC – Fuelling
Fuel:
• H2
• CO
Possible sources:
• Biomass, coal (gasification)• Heavy hydrocarbons (distillate, oil)
CxHy + ½x O2 → x CO + ½y H2
(Exothermic reaction → heat released)
Yield: • H2 20%• CO 25%• CO2 10%• N2 40%
CH4, NH3, SOx, H2S, HCl, …
MCFC – Fuelling
Partial oxidation (gasification)
+High-T heat produced
Quick start & reaction
Works on many fuels
-Low H2 yield
High emission of pollutants (upgrading,
clean-up required)
Complex external components
MCFC – stack
300 W, 10-cell stack (MTU)
With fuel & oxidant inlets & CO2 recirculation
125 kW, 150-cell (Ansaldo, Italy)
MCFC – Heat Recovery
Thermal management of cell:
Optimum temperature for cell & system ≈ 650°C
Fuel cell reactions generate heat
Tcell ↓
• Open circuit potential ↑• Available heat quantity ↑• Electrolyte loss ↓• Corrosion effects ↓
Tcell ↑
• Polarization ↓• Reaction kinetics ↑• Reforming conditions ↑• Available heat quality ↑
MCFC – stack
With heat recovery
250 kW, HotModule (MTU, Germany)
100 kW (KEPCO, Korea)
MCFC – Power conditioning
• Power consolidation• Current control• Invert DC to AC• Voltage increase
Efficiency of power conditioning between 94-97%
MCFC – system
Fuel
Treatment
Heat
Recovery
MCFC
Stack
System
Control
Fuel
Heat
Heat
Heat
H2O
H2, CO
DC
AC
Air
Power
Cond.
MCFC – Balance of Plant (BoP)
Balance of Plant components:
• Pumps and fans • Heat exchangers• Spray nozzles• Piping• Filters• Seals• Gaskets• Valves• Regulators
MCFC – Balance of Plant (BoP)
500 kW Joint effort (Ansaldo, Iberinco, Balke, ENEA, AMG – Madrid)
AFCO: 500 kW system ConfigurationConfigurationConfigurationConfiguration
Cell SizeCell Size
Operating Pressure
Operating Pressure
Operating TemperatureOperating
Temperature
Modular Integrated Reformer
Modular Integrated Reformer
TWINSTACK®TWINSTACK®
0.81 m²Rectangular
shape
0.81 m²Rectangular
shape
3.5 bar3.5 bar
650°C650°C
MCFC – Plant
MCFC – Plant
Modular build-up to MMW units!
