Oxygen Transport Membranes

Transcription

1 Oxygen Transport Membranes BIGCO2 Achievements Paul Inge Dahl, Marie-Laure Fontaine, Florian Ahouanto, Christelle Denonville, Thijs Peters, Yngve Larring, Ove Paulsen, Partow P. Henriksen, Rune Bredesen SINTEF Materials and Chemistry Trondheim CCS Conference, June 15, 2011

2 Outline Introduction o Air separation with OTM o Applications and integration concepts BIGCO2 Task A achievements o Membrane fabrication o Sealing technology o Membrane testing o Material development Summary

3 Air separation Oxygen transport membranes (OTM) Dense layer (perovskite related) Pressurized air Macroporous mechanically strong support (same composition) Driving force Feed side: High p(o 2 ) Pressure vessel / housing 2O 2 4e N 2 Permeate side: Low p(o2) 2 O 2

4 Applications and integration concepts Oxygen production, i.e. for oxy-fuel processes O 2 (g), 1 atm O 2 (g) Air (30 atm) O 2- O 2 (g), 1 atm N 2 (g) Syn-gas production Catalytic membrane reactor CH 4 +H 2 O=CO(g)+H 2 (g) O 2 (g) Air O 2- CO 2 (g)+h 2 O(g) N 2 (g)

5 BIGCO2 Task A High temperature t membranes Overall objectives ( ) o Establish and develop fabrication and sealing technology for ceramic high temperature membranes o Use the technology for fabrication of membrane modules for oxygen and/or hydrogen separation Main activities o Membrane fabrication o Sealing technology o Testing and characterization Including material development

6 Fabrication of asymmetric tubular membranes Air N 2 +O 2 O 2 L J O II ln p O 2 RT el ion ln 2 16F L p 2 O I ln p el ion O 2 2 Tubular membranes o Extrusion of porous support o Coating of thin dense membrane layer Extruded tubular support Dense membrane layer coated onto porous support

7 Paste formulation and ceramic extrusion (La 2 NiO 4 ) Mixer As extruded tubular supports Piston extruder 90 cm 100 cm Tubular supports with close ends

8 Slurry preparation and coating of dense membrane layers (La 2 NiO 4 ) Stability of various dispersions investigated Coated supports Uncoated areas SEM micrographs (cross-section) of selected asymmetric membranes

9 Sealing development air braze o o HT alloy Thermo-chemicall y compatible with membrane material Matching thermal expansion behaviour of braze, membrane/ housing material (HT alloy) Alloy 2,5 Support Haynes 242 cap Seal Ag-Cu braze Cool Coa ating Braze Membra ane embrane e M (%) Thermal exp. 2,0 1,5 1,0 0,5 0,0 Membrane La2NiO4 Sandvik Sanergy Temperature ( C)

10 Sealing development air braze o o Thermo-chemicall y compatible with membrane material Matching thermal expansion behaviour of braze, membrane/ housing material (HT alloy) Alloy cap Braze HT alloy o Coa ating Braze Membra ane embrane e M Alloy Cr 2 O Cu 2Cr 2O 5 Detected challenges after 4 weeks at highh temperature ( C): 960 C) Undesired interaction between braze and protective coating Thermal expansion mismatch between formed chromium oxide and cupper-chromium oxide (formed from reacton with Cu in braze)

11 Thermal expa ansion (%) BIGCO2 Task A Achievements Sealing development glass ceramics 1,60 1,40 1,20 1,00 0,80 0,60 0,40 0,20 0,00 BaO-La 2 O 3 -SiO 2 glass (BLS) La2NiO4 BLS cryst. Ba2La8Si6O Temperature ( C) Ba 3 Si 5 O 13 BaSi 2 O 5 Seal Ba 2 La 2 Si 4 O 13 Ba 2 La 8 Si 6 O 26 La 2 NiO 4 Reaction zone Membrane

12 Thermal expa ansion (%) BIGCO2 Task A Achievements Sealing development glass ceramics 1,60 1,40 1,20 1,00 0,80 0,60 0,40 0,20 0,00 BaO-La 2 O 3 -SiO 2 glass (BLS) La2NiO4 BLS cryst. Ba2La8Si6O Temperature ( C) Ba 3 Si 5 O 13 BaSi 2 O 5 Ba 2 La 2 Si 4 O 13 Seal Na 2 O-CaO-Al 2 O 3 -SiO 2 glass (NCAS1) Thermal exp p. (%) Haynes 242 NCAS1 (cryst) Cool La2NiO4 Sandvik Sanergy Temperature ( C) Compatible with membrane material Cracks on interface seal alloy housing Compatible with alternative housing omachinable glass ceramic Seal Seal Ba 2 La 8 Si 6 O 26 La 2 NiO 4 Reaction zone Membrane Alloy Machinable glass ceramic

13 Thermal expa ansion (%) BIGCO2 Task A Achievements Sealing development glass ceramics 1,60 1,40 1,20 1,00 0,80 0,60 0,40 0,20 0,00 BaO-La 2 O 3 -SiO 2 glass (BLS) La2NiO4 BLS cryst. Ba2La8Si6O Temperature ( C) Ba 3 Si 5 O 13 BaSi 2 O 5 Ba 2 La 2 Si 4 O 13 Seal Complex material systems Many possible reaction products to consider Na 2 O-CaO-Al 2 O 3 -SiO 2 glass (NCAS1) Thermal exp p. (%) Haynes 242 NCAS1 (cryst) Cool La2NiO4 Sandvik Sanergy Temperature ( C) Compatible with membrane material Cracks on interface seal alloy housing Compatible with alternative housing omachinable glass ceramic Seal Seal Ba 2 La 8 Si 6 O 26 La 2 NiO 4 Reaction zone Membrane Alloy Machinable glass ceramic

14 Membrane testing Gold seals Various single tube modules investigated Tubular membranes tested in Probostat cells up to 8 bars and 80% O 2 (32 bar air equivalent) Dense alumina base Glass ceramic seal Machined alloy caps Brazed alloy caps Air flow Sweep gas Membrane e Oxygen + Sweep gas pressure e vessel Steel Air out Air in

15 Membrane testing Dense tubular membrane (reference material La 2NiO 4 4) tested over 2500 hours at various conditions o o Pressurized up to 8 bars and 80% O 2 in feed (32 bars air equivalent) Varying gas flows and temperature ranging from 800 to 1000 C

16 Membrane testing 0,025 Dense tubular membrane (reference material La 2NiO 4 4) tested over 2500 hours at various conditions o o 8 bars/900c Pressurized up to 8 bars and 80% O 2 in feed (32 bars air equivalent) Varying gas flows and temperature ranging from 800 to 1000 C Measurements at 2-8 bars, constant sweep flow Relative O 2 flux 0,02 0,015 0,01 0,005 4 bars/900c 2 bars/900c 1 bars/900c o Data currently being processed for modelling purposes Ambipolar conductivity Flux model as function of T, po 2 and membrane thickness Preliminary model indicates flux goal of 10 ml/(cm 2 min) is achievable Oxygen % in Feed side

17 Material development Improved stabilit y in reducin g atmosphere b y B-site substitution with iron (La 2 Ni 1-x Fe x O 4, x < 0.3) and no CO 2 absorption (from HPTGA) Improved transport properties by A-site deficiency (La 2-x NiO 4, x<0.5)

18 Material development Improved stabilit y in reducin g atmosphere b y B-site substitution with iron (La 2 Ni 1-x Fe x O 4, x < 0.3) and no CO 2 absorption (from HPTGA) Improved transport properties by A-site deficiency (La 2-x NiO 4, x<0.5) P / ml cm -1 min -1 0,030 0,025 0,020 0,015 0,010 0, C 900 C Air/Ar gradient 800 C La-deficient Fe-substituted La2NiO4 reference o Improved O 2 flux of La 2-x NiO 4 compared to reference material (La 2NiO 4 4) Doubled at 900 C o Decreased activation energy: From measurements in Air/Ar gradient La 2 NiO 4 : 86 kj/mol La 2-x Ni 2 O 4 : 45 kj/mol 2-x 2 4 0,000 0,75 0,80 0,85 0,90 0, T -1 / K -1

19 Material development Improved stabilit y in reducin g atmosphere b y B-site substitution with iron (La 2 Ni 1-x Fe x O 4, x < 0.3) and no CO 2 absorption (from HPTGA) Improved transport properties by A-site deficiency (La 2-x NiO 4, x<0.5) P / ml cm -1 min -1 0,050 0,045 0,040 0,035 0,030 0,025 0,020 0,015 0,010 0, C 900 C 800 C O 2 /Ar gradient La-deficient Fe-subsituted La2NiO4 reference o Improved O 2 flux of La 2-x NiO 4 compared to reference material (La 2NiO 4 4) Doubled at 900 C o Decreased activation energy: From measurements in Air/Ar gradient La 2 NiO 4 : 86 kj/mol La 2-xNi 2O 4: 45 kj/mol o La 2 Ni 1-x Fe x O 4 : Flux comparable to reference material at high po T -1 / K -1 0,000 0,75 0,80 0,85 0,90 0,95

20 Summary BIG!!! BIGCO2 achievements on OTM o Membrane fabrication Long porous tubular supports (up to 1 m) Asymmetric membranes with thin dense layers (10-20 µm) o Material development Increased stability with Fe-substitution Increased transport properties by La-deficiency o Membrane testing Long term tests (2500+ hours) of tubular membranes Pressurized tests u p to 8 bars ( 32 bars air pressure eq uivalent) Modeling using experimental results in progress o Sealing with brazing or glass ceramics in progress OTM: high potential for various applications when integrated in high temperature systems (oxy-fuel, Pox, )

21 Acknowledgement Funding through the BIGCO2 project, performed under the strategic Norwegian research program Climit. Thanks to the Research Council of Norway (178004/I30 and /I30) and Gassnova (182070) for their support. And supporting industrial partners: Thank you for your kind attention!