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General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Downloaded from orbit.dtu.dk on: May 17, 2021 SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and subsequent decline Publication date: 2009 Link back to DTU Orbit Citation (APA): Hagen, A., Hendriksen, P. V., & Søgaard, M. (2009). SOFC and Gas Separation Membranes. In Energy solutions for CO2 emission peak and subsequent decline: Proceedings (pp. 153-161). Danmarks Tekniske Universitet, Risø Nationallaboratoriet for Bæredygtig Energi. Denmark. Forskningscenter Risoe. Risoe-R No. 1712(EN)
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Page 1: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.

Users may download and print one copy of any publication from the public portal for the purpose of private study or research.

You may not further distribute the material or use it for any profit-making activity or commercial gain

You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

Downloaded from orbit.dtu.dk on: May 17, 2021

SOFC and Gas Separation Membranes

Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin

Published in:Energy solutions for CO2 emission peak and subsequent decline

Publication date:2009

Link back to DTU Orbit

Citation (APA):Hagen, A., Hendriksen, P. V., & Søgaard, M. (2009). SOFC and Gas Separation Membranes. In Energysolutions for CO2 emission peak and subsequent decline: Proceedings (pp. 153-161). Danmarks TekniskeUniversitet, Risø Nationallaboratoriet for Bæredygtig Energi. Denmark. Forskningscenter Risoe. Risoe-R No.1712(EN)

Page 2: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

Solid Oxide Fuel Cells Solid Oxide Fuel Cells and

Gas Separation MembranesGas Separation Membranes

A H gen P V Hend ik en M Søg dA.Hagen, P.V. Hendriksen, M. SøgaardFuel Cells and Solid State Chemistry Division

Risø DTU Risø DTU

Page 3: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

Outline

Background Motivation

Combination of Energy Conversion Technologiesgy g

Solid Oxide Fuel Cells

G S ti M bGas Separation Membranes

Summary and Outlook

16 September 20092 Risø DTU

Page 4: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

Wind

Water Sun

BiomassWind Biomass

Energy supply

How can we satisfy our needs for energy – in the right forms and at the right times –in the right forms and at the right times

with what nature offers?

Energy need

ElectricityHeat Fuel

16 September 20093 Risø DTU

Page 5: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

Backgroundg

Biomass

Gasification

Fuel Cells Membranes

Heat Electricity

16 September 20094 Risø DTU

Page 6: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

Biomass: Gasification

Gasification of biomass to CO and H2

•High temperature process•High temperature process•Use of waste (wood chips, organic waste)Effi i f d f •Efficiency of wood for

electricity exceeds 25% •Potential for increase of l t i l ffi i b f

SOFCOTM

electrical efficiency by use of fuel cells and oxygen enriched gasification

! Carbon capture !

16 September 20095 Risø DTU

Viking gasifier at Risoe DTU

Page 7: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

Combination: Gasification – SOFC-Membrane

• Increase of total efficiency:• Increase of total efficiency:– SOFC convert fuel to electricity with higher efficiency than

conventional technologies– Oxygen rich gasification gives a gas with lower nitrogen content (less – Oxygen rich gasification gives a gas with lower nitrogen content (less

diluted fuel)

• New option: Carbon capture• New option: Carbon capture

• Challenges:– Changing composition according to used biomassChanging composition according to used biomass– Load fluctuations– Impurities, minor components in gasification gas:

• Sulphur containing ammonia higher hydrocarbons etc• Sulphur containing, ammonia, higher hydrocarbons, etc.

16 September 20096 Risø DTU

Page 8: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

Solid Oxide Fuel Cells: SOFCs

Electrical power and high value Fuel derived from conventional and sustainable sources p g

heat(e.g., methane, natural gas, hydrogen)

Solid oxide fuel cells (SOFCs)Higher efficiency than conventional power generation systems

16 September 20097 Risø DTU

Reduction of emissions and pollution (NOx, CO2, noise) Modular concept (from kW to MW)

Page 9: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

SOFC Working Principle and Main SOFC Working Principle and Main Components

CATHODE• Catalytic activity for oxygen reduction

Gas transport (porosity)• Electron- (ion-) conducting

CATHODE• Catalytic activity for oxygen reduction

Gas transport (porosity)• Electron- (ion-) conducting

O2

O2 + 4e- → 2O2-

Electron (ion ) conducting

O2

ELECTROLYTE• Gas tight

• (Oxygen) ion

O2

O2 + 4e- → 2O2-

Electron (ion ) conducting

O2

ELECTROLYTE• Gas tight

• (Oxygen) ion

ANODE

2H2 + 2O2- → 2H2O + 4e-

H2

O2-• (Oxygen) ion conducting

• Electronic isolator e-

ANODE

2H2 + 2O2- → 2H2O + 4e-

H2

O2-• (Oxygen) ion conducting

• Electronic isolator e-

ANODE• Catalytic activity for fuel oxidation

• Gas transport (porosity)• Electron- (ion-) conductingGENERAL

ANODE• Catalytic activity for fuel oxidation

• Gas transport (porosity)• Electron- (ion-) conductingGENERAL

• Chemical inertness• Thermal compatibility

• Mechanical strength and flexibility

• Chemical inertness• Thermal compatibility

• Mechanical strength and flexibilityGasification gas

16 September 20098 Risø DTU

Page 10: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

SOFCs at Risoe DTU: Generation G2

•Risoe DTU has developed several SOFC generations based on ceramic materials, which are tailored for different operating conditionswhich are tailored for different operating conditions•A pre-pilot manufacture line was established using scale-able and economically competitive processes

16 September 20099 Risø DTU

Page 11: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

Durability of SOFCs – Generation G2y

• Good initial performance• Good initial performance• Good durability over thousands of hours in different fuels:

– Hydrogen, synthesis gas (CO + H2), methane + steam

0.8

1m

2

Durability tests on 2G, synthesis gas, 75% fuel utilization

0.6

ity in

W/c

m

850 oC750 oC0.4

ower

den

si 850 oC750 oC

0

0.2Po

16 September 200910 Risø DTU

0 500 1000 1500 2000Time under current in h

Page 12: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

Durability of SOFCs – Generation G2:H2S ImpuritiesH2S Impurities

800cell B CH4/H2O/H2O

700

V

H2/H2O

600tage

in m

V

1 A/cm2H2SH2S

CH4/H2O/H2O

500

Cel

l vol

cell A

850 oC 1 A/cm22G cell

400H2S

850 C, 1 A/cm

• Tolerance of 2G SOFCs towards H S impurities in a fuel mainly containing

4000 500 1000 1500 2000

Time under current in h

16 September 200911 Risø DTU

• Tolerance of 2G SOFCs towards H2S impurities in a fuel mainly containing hydrogen and also hydrocarbons (methane) and steam not sufficient

Page 13: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

SOFC: Improvement of Anode of 2G Cellp

Impedance analysis, 750 oC, 20% H2O

0.15

0.20

2 ]

FitCat IAno I

Cell AElectro-

Convs.Diff.

Impedance analysis, 750 oC, 20% H2O

0.15

0.20

2 ]

FitCat IAno I

Cell AElectro-

Convs.Diff. Electro-

Convs.Diff. Electro-

Convs.Diff.

(2G)

56,000 Hz10,000 Hz

790 Hz

110 Hz19 Hz

0 00

0.05

0.10

-Z''

[ Ω c

m

Ano ICat IIDiffusionConversionCell #A

Cathode

Anode lyte 56,000 Hz

10,000 Hz790 Hz

110 Hz19 Hz

0 00

0.05

0.10

-Z''

[ Ω c

m

Ano ICat IIDiffusionConversionCell #A

Cathode

Anode lyte

Cathode

Anode lyte

Cathode

Anode lyte

0.000.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80

Z' [Ω cm2]

0.15

0.20

FitCat I

Cell B

Cathode

Electro-l t

Convs.Diff

0.000.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80

Z' [Ω cm2]

0.15

0.20

FitCat I

Cell B

CathodeCathodeCathode

Electro-l t

Convs.Diff

Electro-l t

Convs.Diff

Electro-l t

Convs.Diff

43,000 Hz5,500 Hz 680 Hz

56 Hz18 Hz0.05

0.10

-Z''

[ Ω c

m2 ]

Cat IAno ICat IIDiffusionConversionCell #B Cathode

AnodelyteDiff.

43,000 Hz5,500 Hz 680 Hz

56 Hz18 Hz0.05

0.10

-Z''

[ Ω c

m2 ]

Cat IAno ICat IIDiffusionConversionCell #B Cathode

AnodelyteDiff.

CathodeAnode

lyteDiff.

CathodeAnode

lyteDiff.

0.000.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80

Z' [Ω cm2]

0.000.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80

Z' [Ω cm2]

Smaller resistance from anode and smaller electrolyte resistance

16 September 200912 Risø DTU

Smaller resistance from anode and smaller electrolyte resistance= Better performing cell

Page 14: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

Durability of SOFCs – Generation G2.X with Improved Anode: H2S Impurities

800cell B CH4/H2O/H2O

Improved Anode: H2S Impurities

800cell B CH4/H2O/H2O

700

V

H2/H2O700

V

H2/H2O

600tage

in m

V

1 A/cm2H2SH2S

CH4/H2O/H2O600tage

in m

V

1 A/cm2H2SH2S

CH4/H2O/H2O

500

Cel

l vol

cell A

850 oC 1 A/cm22G cell

500

Cel

l vol

cell A2G cell850 oC 1 A/cm2

400H2S

850 C, 1 A/cm

400H2S

850 C, 1 A/cm

4000 500 1000 1500 2000

Time under current in h• Tolerance of 2G SOFCs towards H S impurities in a fuel mainly containing

4000 500 1000 1500 2000

Time under current in h• Significantly improved tolerance of improved 2G SOFCs towards H S

16 September 200913 Risø DTU

• Tolerance of 2G SOFCs towards H2S impurities in a fuel mainly containing hydrogen and also hydrocarbons (methane) and steam not sufficient

• Significantly improved tolerance of improved 2G SOFCs towards H2S impurities in the fuel

Page 15: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

From Solid Oxide Fuel Cells – Oxygen From Solid Oxide Fuel Cells Oxygen Transfer Membranes

CATHODE• Catalytic activity for oxygen reduction

Gas transport (porosity)• Electron- (ion-) conducting

CATHODE• Catalytic activity for oxygen reduction

Gas transport (porosity)• Electron- (ion-) conducting

O2

O2 + 4e- → 2O2-

Electron (ion ) conducting

O2

ELECTROLYTE• Gas tight

• (Oxygen) ion

O2

O2 + 4e- → 2O2-

Electron (ion ) conducting

O2

ELECTROLYTE• Gas tight

• (Oxygen) ionO2 + 4e- → 2O2-

O2O2 + 4e- → 2O2-

O2

ANODE

2H2 + 2O2- → 2H2O + 4e-

H2

O2-• (Oxygen) ion conducting

• Electronic isolator e-

ANODE

2H2 + 2O2- → 2H2O + 4e-

H2

O2-• (Oxygen) ion conducting

• Electronic isolator e-2H 2O2 2H O 4O2-

2H 2O2 2H O 4O2-

ANODE• Catalytic activity for fuel oxidation

• Gas transport (porosity)• Electron- (ion-) conductingGENERAL

ANODE• Catalytic activity for fuel oxidation

• Gas transport (porosity)• Electron- (ion-) conductingGENERAL

• Chemical inertness• Thermal compatibility

• Mechanical strength and flexibility

• Chemical inertness• Thermal compatibility

• Mechanical strength and flexibility

16 September 200914 Risø DTU

Page 16: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

Oxygen Transfer Membranes (OTMs)yg ( )

Oxygen is separated from air, transported through a membrane and transported through a membrane and supplied to partial oxidation of methane

Cross section SEM picture of a ceria Cross section SEM picture of a ceria based membrane

16 September 200915 Risø DTU

Page 17: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

OTMs: Performance (Flux)( )

MeasurementsEconomical feasibility

CalculationsEconomical feasibility

101

102

cm-2

]

100

[ ml O

2 min

-1 c

T = 600CT = 700C

100 101 102 10310-2

10-1

Vf /

[

T = 800C T = 900C T = 1000C

Flux

Flux

Hydrogen

10 10 10 10 lEly / [ μm ]

0.02 atm O2

Membrane thickness

Air

y g30 µm thick CGO

10 atm air

2

CGO

16 September 200916 Risø DTU

Page 18: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

Summary Outlooky

Combination of biomass gasification and SOFC:

• Potential electric efficiency of +50% through use of a SOFC • Potential electric efficiency of +50% through use of a SOFC

• By using intelligent heat management, high total efficiencies ~ 90% possible

• Well performing and durable SOFCs developed and demonstrated for several fuels, even in presence of H2S impurities

– Challenge: Tolerance towards other impurities

Combination of biomass gasification and OTM:

Increase of overall efficiency due to gasification gas with higher • Increase of overall efficiency due to gasification gas with higher energy density (less diluted)

• Know-how developed for SOFCs can be utilized

• Promising results regarding performance (flux) and economic feasibility

– Challenge: Increase of flux and durability

16 September 200917 Risø DTU

g y

Page 19: SOFC and Gas Separation Membranes · SOFC and Gas Separation Membranes Hagen, Anke; Hendriksen, Peter Vang; Søgaard, Martin Published in: Energy solutions for CO2 emission peak and

Acknowledgementsg

W t f ll k l d t f •We gratefully acknowledge support from our sponsors:

•Topsoe Fuel Cell A/S•Topsoe Fuel Cell A/S•Danish Energy Authority•Energinet.dkg•EU Framework Programmes•Danish National Advanced Technology Foundation •Danish Research Councils•DONG Energy•Areva

16 September 200918 Risø DTU


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