Stack performances in High temperature steam electrolysis and co- · PDF file ·...
Transcript of Stack performances in High temperature steam electrolysis and co- · PDF file ·...
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Stack performances in High temperature steam
electrolysis and co-electrolysis
J. Mougin, M. Reytier, S. Di Iorio, A. Chatroux, M. Petitjean, J. Cren, J. Aicart, M. De Saint Jean
Hydrogen Components and Systems ServiceCEA-LITEN, Grenoble, France
Whec2014, Gwangju, Korea, 18 June 2014
OUTLINE
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Introduction
Presentation of the technology
Development strategy
Some specificities
ResultsHigh temperature steam electrolysisCo-electrolysis
Cost analysis:System manufacturing cost and selling priceLevelized cost of hydrogen
Conclusions
Whec2014, Gwangju, Korea, 18 June 2014
INTRODUCTION
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Why Water Electrolysis to produce H 2?To produce H2 with low carbon footprintPrinciple:
H2 production = proportional to the intensity of electric currentIncrease of current density (A/cm²) � compacity � decrease of investment costEfficiency (kWh/Nm3) = inversely proportional to the voltage
0.6
0.8
1
1.2
1.4
1.6
1.8
-3 -2.5 -2 -1.5 -1 -0.5 0
i (A/cm²)
E (
V)
1.34 0.450.90 0.230.681.12
H2 production (L/h/cm²)
To date: Most mature technology: technology using alkaline electrolyte Technologies using polymer electrolyte upon advanced development For both technologies 80 % of the price of kg H2 produced due to the price of electrical energy
Whec2014, Gwangju, Korea, 18 June 2014
<800°C
�H = �G + T�SH2O → H2 + ½ O2
Energy gain with gas phases
∆H almost constant~ 250 kJ/mol
∆G decreasesT∆S increases
T∆S : waste heat � low cost
Increasing temperature:- Decrease of electricity demand thanks to thermodynamics - Improved electrochemical kinetics But limitations due to materials
Source: Chase NIST-JANAF Thermochemical Tables (1998) Monograph 9, 1325
�H : total energy
�G : electrical energy
Q=T�S : Heat
0 200 400 600 800 10000
1
2
3
Energ
y (
kW
h /
Nm
3of
H2)
Temperature (°C)
Gas
Liq
uid
INTRODUCTION
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Why High temperature Steam Electrolysis (HTSE)?
Whec2014, Gwangju, Korea, 18 June 2014
INTRODUCTION
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Electrolysis efficiency:Comparison of operating points of alkaline, PEM and High Temperature Steam electrolysis
U (
V)
-0,5-2 -1-1,5
HTSE
i (A/cm²)
0
0,5
1
1,5
2PEMWE ALKALINE
H2 production (Nm3/h)
A better efficiency :- low T electrolysis : 4 to 6 kWh/Nm3
- high temperature electrolysis< 3,5 kWh/Nm3
Less sensitive to the price of electricity (but higher cost for initial investment)
A better efficiency :- low T electrolysis : 4 to 6 kWh/Nm3
- high temperature electrolysis< 3,5 kWh/Nm3
Less sensitive to the price of electricity (but higher cost for initial investment)
Whec2014, Gwangju, Korea, 18 June 2014
PRESENTATION OF THE HTSE TECHNOLOGY
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Stack = assembly of several cells:Complex assembly of:
- brittle ceramics (cells=anode/electrolyte/cathode)- And rigid mechanical components (interconnects)
gastightness to be achieved and maintained with timehigh temperature: 700-800°C
Whec2014, Gwangju, Korea, 18 June 2014
Maximum Hydrogen production and efficiency (kWh/Nm3)Cells quality + No losses due to stacking and systemRobustness (start-up and shut-
down), reliability and reproducibility
Compactness (cells quality)“low weight” and simple stack Solutions able to be scaled up in industrial way
Cells qualityNo losses due to stacking (protective coatings, …)Optimization of operating parameters
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PRESENTATION OF THE HTSE TECHNOLOGY
Key parameters for the technology
Whec2014, Gwangju, Korea, 18 June 2014
Low-weightstack design
Co-electrolysisCO2/H2O
Power to gas, Power to liquid
Hydrogenproduction
(Industry, énergy)
Refuellingstation,…
ElectricityProduction
StationaryCHP
SOEC/SOFCreversible
Renewableenergiesstorage
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�
�
Coretechnology
Stack
PRESENTATION OF THE HTSE TECHNOLOGY:SOME SPECIFICITIES
800°C, 90%H2O/10%H2 on the hydrogen
side, air or O2 on the oxygen side,
SC=45% for i = -1.6 A/cm²
Good performance - 1.6 A/cm² at 1.2-1.3 VFor the 3 stack scales⇒ stack upscalingvalidated1.7 Nm3/h of H 2 producedfor the 25-cell stack
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HTSE:PERFORMANCE RESULTS
3-cell, 10-cell and 25-cell stacks
Whec2014, Gwangju, Korea, 18 June 2014
800°C, 90%H2O/10%H2 on the hydrogen
side, air or O2 on the oxygen side,
SC=45% for i = -1.6 A/cm²
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HTSE:PERFORMANCE RESULTS
Very low scattering between different cells100% gas tightness⇒ Design of low-weight stack validated
3-cell, 10-cell and 25-cell stacks
Whec2014, Gwangju, Korea, 18 June 2014
800°C, 90%H2O/10%H2 on the hydrogen
side, air or O2 on the oxygen side,
SC=37% for i = -1.8 A/cm²
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HTSE:PERFORMANCE RESULTS
Focus on 25-cell stack
Whec2014, Gwangju, Korea, 18 June 2014
Good performance - 1.8 A/cm² at 1.2-1.3 VWhen flow rate increasedPower consumed by the stack = 5.6 kWTo produce 1.88 Nm 3/h H2
Efficiency = 3 kWh/Nm 3
800°C, different compositions on the
hydrogen side, O2 on the oxygen side,
SC=52% for i = -0.8 A/cm²
Good performance Performances close to those measured in steam electrolysis (even for inlet gas composition 45 vol.% H 2O + 45 vol.% CO 2 + 10 vol.%H 2)-0.8 A/cm² at 1.15 V
with a conversion rate of 52% (0.92 kW)
100% of gas recovery at the outletH2+CO production: 0.34 Nm 3/h
at 80 AO2 production: 0.17 Nm 3/h at
80 A
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CO-ELECTROLYSIS:PERFORMANCE RESULTS
10-cell and 25-cell stacks
Whec2014, Gwangju, Korea, 18 June 2014
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current (A)
sta
ck p
ote
nti
al
(V)
-64 -54 -44 -34 -24 -14 -4
conversion (%)
Ustack-90vol.%H2O-10%H2
Ustack-65vol.%H20-25%CO2-10% H2
Ustack-45vol.%H20-45%CO2-10%H2
10-cell stack in electrolysis and
co-electrolysis mode - 800°C
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-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0
current (A)
sta
ck p
ote
nti
al
(V)
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conversion (%)
Ustack-90vol.%H2O-10%H2
Ustack-65vol.%H20-25%CO2-10% H2
Ustack-45vol.%H20-45%CO2-10%H2
10-cell stack in electrolysis and
co-electrolysis mode - 800°C
Good performance Same conclusions for 25-cell stack
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CO-ELECTROLYSIS:PERFORMANCE RESULTS
10-cell and 25-cell stacks
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-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0
current (A)
sta
ck p
ote
nti
al
(V)
-64 -54 -44 -34 -24 -14 -4
conversion (%)
Ustack-90vol.%H2O-10%H2
Ustack-65vol.%H20-25%CO2-10% H2
Ustack-45vol.%H20-45%CO2-10%H2
10-cell stack in electrolysis and
co-electrolysis mode - 800°C
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-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0
current (A)
sta
ck p
ote
nti
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(V)
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conversion (%)
Ustack-90vol.%H2O-10%H2
Ustack-65vol.%H20-25%CO2-10% H2
Ustack-45vol.%H20-45%CO2-10%H2
10-cell stack in electrolysis and
co-electrolysis mode - 800°C-64 -54 -44 -34 -24 -14 -4
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conversion (%)
sta
ck p
ote
nti
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current (A)
Ustack-90vol.%H2O-10%H2
Ustack-65vol.%H20-25%CO2-10% H2
Ustack-50vol.%H20-40%CO2-10%H2
25-cell stack in electrolysis and
co-electrolysis mode - 800°C
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conversion (%)
sta
ck p
ote
nti
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(V)
current (A)
Ustack-90vol.%H2O-10%H2
Ustack-65vol.%H20-25%CO2-10% H2
Ustack-50vol.%H20-40%CO2-10%H2
25-cell stack in electrolysis and
co-electrolysis mode - 800°C
Good agreement between experiment and simulation⇒ Predictive in-house model at stack level
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CO-ELECTROLYSIS:OUTLET GAS COMPOSITION
Measurements of the outlet gas composition and comparison to in-house modelling results
Example for the 10-cell stack
Whec2014, Gwangju, Korea, 18 June 2014
800°C, Cathodic inlet: 65 vol.% H2O + 25 vol.% CO2 +
10 vol.% H2 - Conversion rate of oxidized species =
64% at -1 A/cm², i.e. -100 A.
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current (A)
pa
rtia
l p
ress
ure
at
the
ou
tle
t (µ
GC
) (-
)
P_H2simulation
P_CO2sim.
P_COsim.
PH2_experimental
PCO2_exp.
PCO_exp.
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current (A)
pa
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at
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t (µ
GC
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P_H2simulation
P_CO2sim.
P_COsim.
PH2_experimental
PCO2_exp.
PCO_exp.
Selling price = 11.2 k€/Nm 3/hClose to PEMHigher than alkaline technology in terms of CAPEX, but…
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COST ANALYSISMANUFACTURING COST / PRICE OF THE SYSTEM
Hypothesis for the studySOEC system coupled with heat source for steam gene rationH2 Production capacity = 100 kgH 2/dayOperating point: 13 bars
Manufacturing cost of the system determined with:Analytical assessment of the stack costing for 100 systems/year, 30% margin and 20% contingencyActivity based costing methodology
Whec2014, Gwangju, Korea, 18 June 2014
LCOH with HTSE always cheaper than PEMWEBecomes similar to alkaline for electricity price > 100 €/MWh(European average = 123 €/MWh)
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COST ANALYSISLEVELIZED COST OF HYDROGEN
Levelized cost of hydrogen (LCOH)Expected to be lower thanks to high electrical effi ciency, which is 20-30% higher than for low T electrolysis: 3.6 kWh/Nm 3 at system level
Hypothesis of the studyCalculated with discount rate of 10% and operating time of 20 years (with replacement frequency of 3 years for SOEC sys tem), and additional surfaces to compensate performance losses over timeComparison to PEMWE and alkaline:
- No additional surface taken into account- Replacement frequency: 10 years for alkaline, 6 yea rs for PEMWE
Whec2014, Gwangju, Korea, 18 June 2014Evolution of LCOH versus electricity price
Compairons of HTSE, PEMWE and alkaline
CONCLUSIONS
Performing low-weight and low-cost stack design develop edValidated at several scales, including upscaling
High performances obtained in HTSE mode- 1.6 to – 1.8 A/cm² at 1.2-1.3V100% of hydrogen recovery at the outlet
Stack also able to be operated in co-electrolysis modeGood performance obtained for different H2O/CO2 inlet compositionsClose to pure steam electrolysis one Outlet gas composition measured, found as expected and as calculatedwith our in-house model
Cost analysis:HTSE manufacturing cost and selling price: ~ PEMWE, and abovealkalineBut high efficiency prevails over high investment costLeading to a levelized cost of hydrogen: < PEMWE whatever the electricity price, < alkaline for reasonable electricity price (100 €/MWh)
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Thank you for your attention
Whec2014, Gwangju, Korea, 18 June 2014
Acknowledgments to:T. Donnier-Maréchal P. Szynal, M. Planque, B. Oresic at CEA
and Hygrogen Joint Undertaking (FCH-JU-2013-1)/ 621 173
for support for the HTSE developmentsKIC InnoEnergy (MINERVE project) for support of the co-electrolysis works