MTU CoCell

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MTU CoCell
CoCell Combination of MCFC and PEFC Optimisation
of the heat balance of a MCFC to produce
hydrogen for a PEFC
Lars Adamek MTU CFC Solutions GmbH Ottobrunn
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MTU CoCellQuestions to be answered
What do we do today ? What is the CoCell ? What
benefits do we expect ? Does it work ? Is it
sensible for any application ?
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MTU CoCellMCFC today
HotModule
Production of non-storable energies on demand

• Electrical energy (250 kW)

• Heat (180 kW)

Utilisation of fuel 75
Electrical efficiency 45
Thermal efficiency 32
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MTU CoCellDisadvantages HotModule

• bad dynamic behaviour
• energy is not storable
• Hydrogen utilisation can not exceed 75
• ? excess Hydrogen is burned

Idea Why not using this Hydrogen electrically ?
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MTU CoCellMCFC as reformer
System border
Gasflow ? ? utilisation ? ? el. efficiency ?
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MTU CoCellChanges in MCFC
Anode
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MTU CoCellChanges in MCFC
Cathode
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MTU CoCellChanges in MCFC
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MTU CoCellAdvantages of configuration
Better suitable for load variations, due to lower
utilisation ? heat gradient in cell is smoothed
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MTU CoCelllimiting factors
Energy balance
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MTU CoCellAutothermal utilisation
QFC f (ut, ?, iMC)
QRef f (nCH4)
QSys f(ut)
QSys 0 f(ATU)
To determine ATU thermodynamic model of plant is
needed !
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MTU CoCellProducing or using H2?
H2 is fed to PEFC directly to increase el.
utilisation
H2 is stored and supplied to cars
CoCell
H2Fill

• Changes in mode of operation
• System has to be heated sufficiently

Cleaning of H2 is necessary
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MTU CoCellWhy use in PEFC ?

• high electrical efficiency
• increased electrical utilisation of hydrogen
• power density of PEFC is high

? increased overall efficiency by CoCell ?
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MTU CoCellThermodynamic Modell CoCell
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MTU CoCellThermodynamic Modell H2Fill
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MTU CoCellIncreasing heat supply
4 Methods to increase heat supply to increase
hydrogen production
S1 Nitrogen in Feed as heat carrier
S2 Prereforming of fuel
S3 Increase of current density im MCFC
S4 Increase of preheated air supply
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MTU CoCellStudy results
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MTU CoCellExperimental results
Maximum current density limited by
TCX lt 680C
UA lt 137 mV
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MTU CoCellExperimental results
H2-Filling Station
ut 40
The HotModule fuel cell enables a clean,
reliable and efficient conversion
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MTU CoCellPossible applications
Ships
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MTU CoCellAim of CoCell in ships
(neglecting parasitic losses)
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MTU CoCellPerformance of CoCell system
iMC,max 280 mA/cm² iPE,max 520 mA/cm²
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MTU CoCellenergy density
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MTU CoCellConclusion
Increase Energy density by factor 3
1/3 of Volume or Weight
Increasing efficiency
Increasing capital cost
Opening new market segment for big propulsion
systems
Making Fuel cells available for ship propulsion