Advanced Membrane Design for OxygenAdvanced Membrane Design for Oxygen SeparationR. Kriegel, M. Schulz, K. Ritter, L. Kiesel, U. Pippardt, M. Stahn, I. Voigt

Fraunhofer Institute for Ceramic Technologies and Systems, Hermsdorf

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Outline

1. Manufacturing of ceramic components2. Special material properties3 Modeling3. Modeling4. Testing of state of the art membranes5. Components with complex geometry6. Conclusions

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1. Manufacturing of ceramic components: M b f tiMembranes for oxygen separation

Preparation of precursor powders by mixed oxide route: BSCF5582, L2N, CSFM, LSCF, BCFZ, substituted CeO2, composites …

Ceramic shaping: fl t t t b ill i h b d d b di flat tapes, tubes, capillaries, honeycombs, dense and porous bodies

Coatings: for asymmetric membranes, activation and protection layersextrusion ceramic components asymmetric BSCF membrane

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2. Special material properties: O t i hi t d i b h iOxygen stoichiometry and expansion behavior

2a2a00++

22aa 002a2a 00

2 [BIVO6/2]2– ®® 2 [BIIIO5/2]– + O2–

O-Stoichiometry 3- = f (T, pO2) lattice expansion – chemical expansion chemical induced stress break down chemical induced stress, break down

3%

sion

Ba Sr Co Fe OLa0.8Sr0.2Co0.6Fe0.4O3-

chem.

2%

ical

exp

an

Ba0.5Sr0.5Co0.8Fe0.2O3-Ca0.5Sr0.5Fe0.2Mn0.8O3-MgO

1%

rmal

/che

m

T p =

0%0 500 1000

temperature [°C]

ther ABO3-‘ ABO3-‘‘

T , pO2=

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Left: S.B. Adler: J. Am. Ceram. Soc., 84 (2001), 2117–19; Right: R. Kriegel, I. Voigt, W. Burckhardt, Proc. 10th ECerS Conf., Eds.: J.G.Heinrich and C. Aneziris, Berlin 2007, 2161-2168

2. Special material properties:D t i ti d d li f O t i hi t fDetermination and modeling of O-stoichiometry of BSCF optimized cerimetric titration

2 4

2,5

BO 3

-

optimized cerimetric titration of reference state: 2,51 ± 0,005

high resolved thermogravimetry at defined O2 partial pressures

=3K pO2

n

1 + K p n2,3

2,4

3-

in A

B

1000°C850°C700°C500°C

at defined O2 partial pressures modeling of defect

equilibrium:1 + K pO2

n

2,2-6 -4 -2 0

lg a(O2)

500°Cberechnet

-1,4 0n lg a(O2)

-1,6

-1,5

lg(K

)

-0,02

-0,01

Expo

nent

n

phase instability for T < 700 °C parameters for 700-1000 °C

-1,70,5 1 1,5

1000/T [1/K]

-0,03

E

calculation of O stoichiometry z (in ABOz) = f (T, pO2)

correlation with other properties

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p pR. Kriegel, R. Kircheisen, J. Töpfer, Oxygen stoichiometry and expansion behavior of Ba0.5Sr0.5Co0.8Fe0.2O3-, Sol. St. Ionics 181 (2010) 64-70

2. Special material properties: Ch i l iChemical expansion

mm11 11

0, reflattice expansion on metastable O-deficient samples: Heating up: O2 release Cooling down in Ar

mas

s m

ass

mm22 22

Cooling down in Ar Determination of O-Stoichiometry, lattice constants

0.3

%]

dilatometry

Temperatur Temperatur

=l - l0, ref . =

V - V0, ref .

0.2

nsio

n dl

/l R[% dilatometry

XRD

BSCF5582: = 0,01

= l0, ref . · = 3V0, ref .

h i ffi i t

0.1

emic

al e

xpa

chem. expansion coefficient local chem. = f (z in ABOz) = f (T, pO2) chem. stress distribution

0.02.22.32.42.52.6

oxygen stoichiometry 3-

che

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R. Kriegel, R. Kircheisen, J. Töpfer, Oxygen stoichiometry and expansion behavior of Ba0.5Sr0.5Co0.8Fe0.2O3-, Sol. St. Ionics 181 (2010) 64-70

3. Modeling:M t i l b h i f BSCF5582Material behavior of BSCF5582

air pressure 1/20 bar transport of substance & heat local temperatures, pO2

, O-stoichiometries, loads

laminar N2 flux,

10-5 bar, 600 °C, 0.1 m/s Ø inside: 13 mm

Heat transfer: RH, radiation, convection

air pressure 1/20 bar

30

, local deformations, local stresses,

(neglecting of creeping!)

0.1 m/s Ø inside: 13 mmØ outside: 15 mmlength: 1000 mm

convection, conduction

0

15

[N/m

m]

2 insi

de

thermal inducedchemical

Membrane: BSCF5582Young‘s modulus (T):30-59 GPa, Poisson‘s ratio: 0,22, 0 = 120 N/mm2

laminar air flux, 900 °C

d i ti h i l

45

-30

-15

tial s

tres

s

outside pressure

side

dominating chemical induced stress

minimal tensile stress for pressure-

0,00 0,25 0,5 0,75 1,00position across tube wall [mm]

-60

-45

tang

ent

outs

pdriven processes:high pressure (Feed) outside –low pressure (Sweep) inside!

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[ ] p ( p)M. Schulz, R. Kriegel, W. Burckhardt, Modeling of oxygen flux and stress distribution for Ba0.5Sr0.5Co0.8Fe0.2O3 membranes at application conditions, 10. Intern. Conf. Inorg. Membranes, 18.-22.08.2008, Tokyo, Japan

3. Modeling: M t i l b h i d flMaterial behavior, mass and energy flow

air, flue gas

ed) a

ir

local T, pO2, local local jO2therm.

‘‘‘

O2 permeation

in ABO3-

H of oxygen

(com

pres

se chem. RH of oxygen

exchange

chemical & ther-mal expansion

-DH

mal expansion

joining

elastic deformation

RH = 300 kJ/mol O2absolute pressures

joining

HT creeping

toughness

Combination to reactorsimulation

Flow-conversion model

materialmodel

ABO3-‘‘ + 0,5(‘‘ - ‘) O2ABO3-‘

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4. Testing of state of the art membranes:D t ti it ith lithi BSCF t bDemonstration unit with monolithic BSCF tubes

Modeling: energy consumption, gas throughputs, O2 flux

vacuum operation, 850 °C, 0.2 m2, 190 l O2/h, 0.75 kW for air heatingOne side closedOne side closedmonolithic membrane tubes

Results of test runs:

170 L_STP O2/h >1800 h, 32 cycles (5 K/min) sporadic membrane cracks

probably caused by chemical

Achema, 05/2009Membrane tubes in vacuum carrier plate

p y ystress

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vacuum carrier plateR. Kriegel: Aufbau und Testbetrieb eines Sauerstoff-Erzeugers auf der Basis gemischt leitender keramischer Membranen, DKG-Jahrestagung, Hermsdorf, 22.-24.03.2010

4. Testing of state of the art membranes:M lithi BSCF t b i fl

Constructional approach for usage in flue gas

Monolithic BSCF tubes in flue gas

Constructional approach for usage in flue gas

vacuum operation of 15 BSCF tubes covered by steel sheath tubes

gas burner test stand, oscillating up to 500 °C, max. 1000 °C (outside)g , g p , ( )

outside the sheath: up to 1000°C, 15 K/min without any problems

O2 flux comparable to laboratory results (appr. 1.4 Nml cm-2 min-1)

new technology: high investment costs compared to the benefit: small & cheap components high flux at low driving force

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small & cheap components, high flux at low driving force

5. Components with complex geometry:I t f O th h t d ki d itImprovement of O2 throughput and packing density

l b thi k t i b lower membrane thickness, e.g. asymmetric membranes higher membrane area per volume large O2 flux per reaction volumeg 2 p less raw material needed energy efficient operation conditions

Minimization of invest-ment and operation costsAccelaration of market marketAccelaration of market market launchGeneration of further R&D activities

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R. Kriegel, M. Schulz, K., Ritter, L., Kiesel, U., Pippardt, M., Stahn, I., Voigt, Advanced membrane design for oxygen separation. in: D. Stolten, V. Scherer (Eds.), Process Engineering for CCS Power Plants, Wiley, Weinheim 2011, in press

5. Components with complex geometry: J i i t h i f MIEC i tJoining techniques for MIEC ceramic components

RAB1 - Reactive Air Brazing: joining of MIEC ceramics to each other: Ag/Cu 95/5: stable gastight joinings2

in spite of the sublimation of silver in vacuum!p

BSCF tube der

sid

e

er s

ide

cuum

) sid

e

end

inn

out

inne

r (va

BSCF plate

DDR3 – Doping-supported Diffusive Reaction sinteringBSCF tubes closed

by DDR-joiningreliable joining – prerequisite for complex components

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1 K.M. Erskine, A.M. Meier, S.M. Pilgrim, J. of Mater. Sc. 37 (2002) 1705–1709; 2. Kriegel: Aktuelle Entwicklungstrends von Funktionskeramiken und fügetechnische Anforderungen. DVS-Kolloquium, Berlin, 24.02.2009; 3 R. Kriegel, R. Kircheisen. K., Ritter, DE102009050019.7, 16.10.2009

by DDR joiningj g p q p p

5. Components with complex geometry: I fl f t O tiInfluence of geometry on O2 permeation

Influence of membrane dimensions:Influence of membrane dimensions: monolithic tube, capillary, asymmetric membrane tube (ca. 40 µm) BSCF5582, 850°C,

air (1 bar)/ ac m in)]

monolithic tube monolithic capillary250

]

3

air (1 bar)/vacuum

STP/

(cm

2· m

monolithic tubeasymmetric tube

monolithic capillary

150

200

ml_

STP/

min

2

BSCF (Ba0.5Sr0.5Co0.8Fe0.2O3-) membrane components used for O2 permeation tests 850°C, 1 bar air/ vacuummembrane outer wall length O

2flu

x [m

l_S

100

150

ntal

O2 f

lux

[m

1membranetype

outer diameter

wall thickness

length

monolithictube

14.2 1.5 250

asymmetric1 14 4 1 4 250 norm

aliz

ed O

50ex

perim

en

asymmetrictube

14.4 1.4 250

capillary 3.20 0.25 250

n00 1 2 3

ln(pO2, h/pO2, l)

0

advantages of capillary : simple production, lower leakages

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advantages of capillary : simple production, lower leakages

5. Components with complex geometry:A t f h i l l diAssessment of mechanical loadings

Mechanical stress by pressure for monolithic tube, capillary, flat membrane BSCF5582, 850°C, 25

planar, prop distance 3 mm1, 5, 20 bar air/O2 (50 mbar)

Geometry [mm] of BSCF membranes used for simulation of mechanical stress for 0.05 bar O2 to 1,

20

ss [M

Pa]

planar, prop distance 10 mmp , p p

capillary, 10 % out of roundcapillary, 5 % out of round

2 ,5, 20 bar air at 850 °Cmembranetype

outer dimensions

wall thickness

comments

monolithic 10.0 outer 1.0 5 %, 10 %10

15

tens

ile s

tres

monolithictube

10.0 outer Ø

1.0 5 %, 10 % out of roundCapillary 3.5 outer Ø 0.25

planar cell 100 x 100 0.5 2 mm prop with 10 and

5max

. tube, 10 % out of roundtube, 5 % out of round

with 10 and 3 mm

distance

00 5 10 15 20 25

hydrostatic outside presssure [bar]

tubular membranes: low or no tensile stress

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tubular membranes: low or no tensile stress

5. Components with complex geometry:A t f h i l tAssessment of chemical stress

Chemical induced stress for monolithic tube, capillary, flat membrane BSCF5582, 850°C,

1 5 20 bar air/O (50 mbar)2,48 100

planar, prop distance 3 mm1, 5, 20 bar air/O2 (50 mbar)

Geometry [mm] of BSCF membranes used for simulation of mechanical stress for 0.05 bar O2 to 1,

2,46

- in

AB

O3-

60

80

ress

[MPa

]

tube

planar, prop distance 10 mmcapillary

2 ,5, 20 bar air at 850 °Cmembranetype

outer dimensions

wall thickness

comments

monolithic 10.0 outer 1.0 without out

2,44

chio

met

ry 3

-

40

60

al te

nsile

Str

O-stoichiometry, air side

monolithictube

10.0 outer Ø

1.0 without out of round

Capillary 3.5 outer Ø 0.25planar cell 100 x 100 0.5 2 mm prop

with 10 and 2 40

2,42

O-s

toic

0

20

max

ima

O-stoichiometry, vacuum sidewith 10 and

3 mm distance

2,400 5 10 15 20 25

hydrostatic outside presssure [bar]

0

tubular membranes: dominating but low tensile stress

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tubular membranes: dominating but low tensile stress

5. Components with complex geometry:E i t f 10 000 2Economic assessment for 10.000 m2

Table 3 Material requirement, oxygen flux and production costs of different membrane designs archetype unit tube 19 capillary bunch stack with 100 cells

rial

dimensions [mm] 10 x 8 3.5 x 31 100 x 100 x 1.52 component active length [mm] [mm] 1000 500 600

membrane area [cm2] [cm2] 283 970 16000

material solid volume [cm3] 28 3 25 1280nts

and

mat

er

material solid volume [cm ] 28,3 25 1280component mass [kg] 0.150 0.133 6.784 number of membrane components 353.357 103.093 6.250

com

pone

n

total mass [kg] 53.000 13.660 42.400

x

per component3 [ml_STP/min] 194 2000 20180

O2 f

lux

total oxygen flux [103kg/day] 141 424 259 distance between components [mm] 6 6 20

eact

or

reactor volume [m3] 13 5 6 7 8 0re reactor volume [m ] 13.5 6.7 8.0raw material4 k€ 10.600 2.730 8.480 capital, depreciation5 k€ 1.000 1.360 950 production, personnel k€ 1.300 1.310 4.570

cost

s

total5 sum for 10.000 m2 k€ 12.900 5.400 14.000

c

membrane costs6 per ton O2 [€/103kg O2] 50 € 7 € 30 € 1capillary distance 1.5 mm;2membrane thickness 0.5 mm, cell height 1.5 mm, prop width 2 mm, prop distance 3 mm, vertical cell distance 4 mm, 3at ln(pO2) = 1, 850 °C; 4150 €/kg and 25 % rejection rate; 55 years, 6per year

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5. Components with complex geometry:E i t f 10 000 2Economic assessment for 10.000 m2

Table 3 Material requirement, oxygen flux and production costs of different membrane designs archetype unit tube 19 capillary bunch stack with 100 cells

rial

dimensions [mm] 10 x 8 3.5 x 31 100 x 100 x 1.52 component active length [mm] [mm] 1000 500 600

membrane area [cm2] [cm2] 283 970 16000

material solid volume [cm3] 28 3 25 1280nts

and

mat

er

7 capillary bunch closed at one side with supplying tube for oxygen withdrawal

material solid volume [cm ] 28,3 25 1280component mass [kg] 0.150 0.133 6.784 number of membrane components 353.357 103.093 6.250

com

pone

n

total mass [kg] 53.000 13.660 42.400

x

per component3 [ml_STP/min] 194 2000 20180

O2 f

lux

total oxygen flux [103kg/day] 141 424 259 distance between components [mm] 6 6 20

eact

or

reactor volume [m3] 13 5 6 7 8 0re reactor volume [m ] 13.5 6.7 8.0raw material4 k€ 10.600 2.730 8.480 capital, depreciation5 k€ 1.000 1.360 950 production, personnel k€ 1.300 1.310 4.570

cost

s

total5 sum for 10.000 m2 k€ 12.900 5.400 14.000

c

membrane costs6 per ton O2 [€/103kg O2] 50 € 7 € 30 € 1capillary distance 1.5 mm;2membrane thickness 0.5 mm, cell height 1.5 mm, prop width 2 mm, prop distance 3 mm, vertical cell distance 4 mm, 3at ln(pO2) = 1, 850 °C; 4150 €/kg and 25 % rejection rate; 55 years, 6per year

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6. Summary and Conclusions

available membrane components: monolithic tubular membranes capillaries capillaries asymmetric tubular membranesdevelopment of components with high thro ghp t packing densit stabilitthroughput, packing density, stability: capillary bunches asymmetric single capillaries asymmetric capillary bunches!?

economic assessment: low membrane investment costs

compared to onsite cryogenic O2 production costs: >20 € /103 kg membrane separation - competitive to cryogenic air separation

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