MANUFACTURING OF MICROPOROUS CERAMIC MEMBRANES FOR ENVIRONMENTAL APPLICATIONS I. CO 2 -free power plants II. Fuel cells

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1 Mitglied der Helmholtz-Gemeinschaft Innovation for Sustainable Production i-sup 2008 Congrescentrum Oud Sint-Jan, Brugge April 2008 MANUFACTURING OF MICROPOROUS CERAMIC MEMBRANES FOR ENVIRONMENTAL APPLICATIONS I. CO 2 -free power plants II. Fuel cells Tim Van Gestel, Wilhelm A. Meulenberg, Hans Peter Buchkremer Forschungszentrum Jülich GmbH Institute of Energy Research Materials Synthesis and Processing (IEF-1) D Jülich

2 Membrane research topics in IEF-1 Focus on energy-related applications : 1 Development of porous and dense membranes for application in CO 2 -free power plants dense membranes for O 2 /N 2 separation microporous membranes for CO 2 /H 2 separation 2 Development of porous and dense membranes for application in advanced Solid Oxide Fuel Cells (SOFC s) porous anode and cathode layers dense electrolyte membrane Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

3 Microporous membranes for CO 2 separation Example: Metal-supported Membranes for H 2 /CO 2 -Separation Separation membrane Detail: H 2 CO 2 Pore size ~ 0.5 nm 3. Interlayer 2. Interlayer 1. Interlayer (metallic) Pore size 3-10 nm metallic substrate * bar = 200 nm Gas Molecule H 2 CO 2 N 2 d kin in nm 0,29 0,33 0,36 * bar = 10 µm Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

4 Microporous membranes for CO 2 separation Example: Multilayer-Membrane on ceramic ZrO 2 substrate 3% Y 2 microporous toplayer (Pore size < 1 nm) Sol-Gel Method: γ-al 2 mesoporous layer (Pore size ~ 5 nm) Nano-Particle sol Particle size ~ 6 nm Sol-Gel Method: Colloidal Particle Sol Particle size ~ 30 nm 8Y 2 macroporous layer (Pore size ~ 100 nm) 8Y 2 substrate (Pore size ~ 1 µm) * bar = 10 µm Suspension Method: Particle size ~ 350 nm - Vacuum slip-casting - Dip-coating - Screen-printing Powder Method: Warm-pressing Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

5 Microporous membranes for CO 2 separation Substrate preparation - Warmpressing Warmpressing 8Y 2 Substrate + Sintering (1200 ºC) Large-scale Support: Preparation with Standard IEF-1 Technology for Solid Oxide Fuel Cells SOFC s (25 x 25 cm) Lab-scale Support for R & D: Polishing with diamant particles for improving Surface roughness (4 x 4 cm) Particle size: 3-5 µm Average Pore size: ~ 1 µm pore volume (mm³/g) Pore size distribution Substrate (Firing 1200 C, Hg-porosimetry) 0,0 0,5 1,0 1,5 2,0 2,5 3,0 pore size (mm) Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

6 Macroporous Interlayer Suspension coating 8Y 2 macroporous layer 8Y 2 substrate 8Y 2 macroporous layer * bar = 100 µm * bar = 1 µm abundance Particle size distribution Coating liquid (8Y 2 Suspension, Tosoh corp.) pore volume (mm³/g) Pore size distribution Membrane material (Firing 1100 C, Hg-porosimetry) particle size (nm) pore size (nm) Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

7 Mesoporous interlayer Sol-gel coating 8Y 2 mesoporous layer 8Y 2 mesoporous layer 8Y 2 macroporous layer 8Y 2 substrate 8Y 2 macroporous layer * bar = 10 µm * bar = 1 µm abundance Particle size distribution Coating liquid (Colloidal 8Y 2 Sol) pore volume (cm³/g) 0,30 0,25 0,20 0,15 0,10 0,05 Pore size distribution Membrane material (Firing 500 C, N 2 -ads./desorption) particle size (nm) 0, pore size (nm) Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

8 Microporous toplayer Sol-Gel Coating 8Y 2 microporous layer 8Y 2 microporous layer 8Y 2 mesoporous layer 8Y 2 double mesoporous layer 8Y 2 mesoporous layer 8Y 2 macroporous layer * bar = 1 µm * bar = 200 nm Particle size distribution Coating liquid (8Y 2 Nano-Particle Sol) 0,030 0,025 Pore size distribution Membrane material (Firing 450 C, N 2 -ads./desorption) pore volume (cm³/g) 0,020 0,015 0,010 0,005 0, pore size (nm) Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

9 Microporous toplayer Sol-Gel Coating 8Y 2 microporous double-layer 8Y 2 mesoporous double-layer * bar = 1 µm * bar = 200 nm Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

10 Microporous toplayer Sol-Gel Coating 8Y 2 microporous double-layer 8Y 2 mesoporous double-layer 8Y 2 macroporous layer * bar = 1 µm Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

11 Overview subsequent membrane coating steps Particle size 8Y 2 Suspension Particle size Colloidal 8Y 2 Sol Particle size Polymeric 8Y 2 Nano-Sol average particle size 350 nm average particle size 40 nm average particle size 6 nm abundance abundance particle size (nm) particle size (nm) macroporous layer mesoporous layer microporous layer * bar = 1 µm Pore size ~ 90 nm (1200ºC) Phase structure: Cubic * bar = 200 nm Pore size ~ 6-7 nm (500ºC) Phase structure: Cubic * bar = 200 nm Pore size ~ 1 nm (450ºC) Phase structure: Cubic Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

12 Membrane research topics in IEF-1 Focus on energy-related applications : 1 Development of porous and dense membranes for application in CO 2 -free power plants dense membranes for O 2 /N 2 separation microporous membranes for CO 2 /H 2 separation 2 Development of porous and dense membranes for application in advanced Solid Oxide Fuel Cells (SOFC s) porous anode and cathode layers dense electrolyte membrane Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

13 Standard FZ-Jülich SOFC (La,Sr)Mn cathode (La,Sr)Mn /8Y 2 cathode layer 8Y 2 electrolyte layer NiO/8Y 2 anode layer * bar = 10 µm NiO/8Y 2 substrate Planar configuration ( 20 cm x 20 cm) Anode supported concept with thin-film electrolyte I = ~ 1.5 A/cm 2 at 800ºC and 0.7 V (single cell); ~ 1.1 A/cm 2 (stack) Demonstrated 60-cell stack with 13 kw; in progress 20 kw system Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

14 Novel membranes for advanced SOFC s dense 8Y 2 electrolyte membrane on porous NiO/8Y 2 substrate * bar = 10 µm Conventional preparation method: (1) Deposition of macroporous membrane starting from ZrO 2 powder suspension (2) Sintering of macroporous membrane at high temperature (1400 C, 5h) Proposed alternative preparation method: (1) Deposition of membrane starting from ZrO 2 nano-particles (e.g. Coating with ultra-fine suspension or sol) (2) Sintering at lower temperature (objective < 1100 C) (3) Possibility to apply steel substrate, reduction of production cost Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

15 Novel membranes for advanced SOFC s Coating with ultra-fine suspension 8Y 2 mesoporous electrolyte membrane made from ultra-fine suspension (particle size = 80 nm) Surface 8Y 2 layer 8Y 2 /NiO anode layer 8Y 2 /NiO substrate * bar = 10 µm Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

16 Novel membranes for advanced SOFC s Coating with ultra-fine suspension 8Y 2 mesoporous membrane made from ultrafine suspension (particle size = 80 nm) Surface 8Y 2 layer 8Y 2 membrane layer made from colloidal and polymer sol 8Y 2 /NiO anode layer * bar = 2 µm Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

17 Novel membranes for advanced SOFC s Coating with ultra-fine suspension 8Y 2 mesoporous membrane made from ultrafine suspension (particle size = 80 nm) 8Y 2 membrane layer made fromsurface colloidal 8Yand 2 -ZrO polymer 2 layer sol anode layer substrate Application of developed mesoporous and microporous membrane coating technology for making thin and continuous electrolyte layers on standard SOFC substrate with a coarse structure * bar = 10 µm Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

18 Novel membranes for advanced SOFC s Coating with ultra-fine suspension Surface 8Y 2 layer after firing at 600 C 8Y 2 layer anode layer * bar = 1 µm Coating with ultra-fine suspension and sol * bar = 200 nm Surface 8Y 2 layer after firing at 600 C * bar = 1 µm * bar = 200 nm Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

19 Novel membranes for advanced SOFC s Coating with ultra-fine suspension (+ firing 1300 C) Surface 8Y 2 layer after firing at 1300 C Standard 1400 C * bar = 10 µm Coating with ultra-fine suspension and sol (+ firing 1300 C) * bar = 2 µm Surface 8Y 2 layer after firing at 1300 C Standard 1400 C * bar = 10 µm * bar = 2 µm Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

20 Novel membranes for advanced SOFC s 8Y 2 dense electrolyte membrane layer (1300 C) 8Y 2 /NiO anode layer * bar = 1 µm Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

21 Novel membranes for advanced SOFC s 8Y 2 dense electrolyte membrane layer (1300 C) anode layer substrate Application of developed mesoporous and microporous membrane coating technology for making thin and continuous electrolyte layers on standard SOFC substrate with a coarse structure * bar = 10 µm Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

22 Novel membranes for advanced SOFC s 8Y 2 dense electrolyte membrane layer (1200 C) anode layer substrate Standard firing 1400 C previous example 1300 C * bar = 10 µm this example 1200 C Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

23 Novel membranes for advanced SOFC s 8Y 2 dense electrolyte membrane layer (1200 C) anode layer substrate Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

24 Novel membranes for advanced SOFC s Surface Coating with 8Y 2 Oultra-fine 3 /NiO suspension anode layer (on standard SOFC substrate) Coating with ultra-fine suspension and sol Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

25 Novel membranes for advanced SOFC s Surface 8Y 2 porous membrane after firing at 600 C Coating with ultra-fine suspension Coating with ultra-fine suspension and sol Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

26 Novel membranes for advanced SOFC s Coating with ultra-fine suspension Surface 8Y 2 membrane after firing at 1200 C Coating with ultra-fine suspension and sol Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

27 Novel membranes for advanced SOFC s Detail 8Y 2 membrane after firing at 1200 C Coating with ultra-fine suspension Coating with ultra-fine suspension and sol Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

28 State of the art - Conclusion Current gas separation membranes aremadeof SiO 2 materials, having an insufficient (hydro)thermal stability for application in power plant streams Current solid oxide fuel cells are made by unwanted high-temperature sinter treatments In this work : Manufacturing of novel nano-structured ZrO 2 membranes Widely accepted material for long-term operation in gas separation Densification material at a lower temperature for SOFC manufacturing In progress : Optimization of the membrane pore size (target: high H 2 /CO 2 selectivity) Manufacturing SOFC s for current density characterization Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge

29 Acknowledgement : Funding by Helmholtz Association of German Research Centers Helmholtz Alliance MEM-BRAIN SEM images made by Dr. Doris Sebold IEF-1 Institute of Energy Research IEF-1 Van Gestel, Meulenberg, Buchkremer, Brugge