Concepts and systems for power production and storage using solid oxide cells Pierluigi LEONE Andrea LANZINI Dipartimento Energia Perugia 23 novembre 2012 Workshop italiano sulle celle a combustibile 1
SOFC Cell development - Investigation of innovative structures for electrodes and electrolyte - Utilization of low processing manufacturing processes to enable structure and material diversification o Cooperation with CNR-ISTEC and Department of Applied Science and Technology (POLITO) o Cooperation with Edison Research Center, Trofarello o Cooperation with institutions in Latin America. 2
Electrolyte by RF-Sputtering YSZ film Ni YSZ Homogeneous coverage, granes are fairly densified and cohesive each other Columnar growth must be reduced F.Smeacetto, M.Salvo, S.Perero, M.Ferraris, POLITO 3
Electrolyte by RF-Sputtering F.Smeacetto, S.Perero, P.Leone, POLITO and S.Boldrini, CNR-IENI 4
Electrolyte and cathode by EB-PVD - Single step electrolyte and electrode production - Nanostructured eletrolyte and electrode - No firing step GDC YSZ M. Bindi, D.Beretta, Edison S.p.a. A.Lanzini, P.Leone, F. Smeacetto, POLITO 5
Electrolyte and cathode by EB-PVD Acceptable OCV values Durability proved up to 1000hr Cathode polarization is still an issue 6
Cell components characterizations - Full cells investigated under gas and liquid fuels up to 1000 hr o Effect of contaminants o Effect of reforming capability o Degradation issues - Cell Components investigated o Charge transport o Catalytic activity o Mass transport 7
Catalytic activity A.Lanzini, C.Guerra, P.Leone, POLITO and A.Sanson, E.Mercadelli, A.Gondolini, CNR-ISTEC and N.Brandon, Imperial College 8
Catalytic activity 72 mg Ni-YSZ 1500 2h (65.8 mg after experiments) C removed, 1.51 mg 72.5 mg Ni-GDC (72.5 mg after experiments) C removed, 5.67 mg 71.3 mg Ni-YSZ commercial C removed, 11.67 mg 9
Mass Transport VENT PURGE FUEL CHAMBER 1 D P CHAMBER 2 AIR PURGE 10
Mass Transport 11
SOFC Stack development Design Sealant tape processing Self healing sealants New sealants compositions Surface coating processes 12
SOFC Stack development - Investigation of functional components (sealants, coatings) in research configuration stack - Investigation of innovative stack design o o o o Fluid distribution In-operation homogeneity Efficient cooling Integration capability with BoP components - Cooperation with Department of Applied Science and Technology (POLITO) and Edison Research Center, Trofarello - Two stacks (200 W) will be delivered to Latin America institutions in early 2013. - 3 Stack patents pending - 1 Coating patent pending - 1 Stack Patent under development 13
Voltage (mv) Power (mw) Politecnico di Torino Dipartimento Energia SOFC Stack development Voltage 1000 800 600 500 400 300 250 Power 1000 800 600 500 400 300 250 1200 8 1000 7 6 800 5 600 4 3 400 2 200 1 0 0 0,2 0,4 0,6 0,8 Current density A/cm2 0 0 0,2 0,4 0,6 0,8 Current density A/cm2 14
SOFC Stack development Uncoated Cathode surface, MnCrO4 faceted crystals Coated Cathode surface 15
SOFC Stack development 16
Solid Oxide Electrolysis Cells Steam Electrolysis Asymmetry of SOEC and SOFC performance for a Ni/YSZ-supported single cell with LSCF electrode due to depletion of oxygen vacancies at the interface between mixed ionic/electronic conductive (MIEC) oxygen electrode and the electrolyte. Asymmetry of SOEC and SOFC performances is also due to an asymmetric behavior for steam reduction and H2 oxidation. 17
- Img(Z) [mω] -Img(Z) [mω] Politecnico di Torino Dipartimento Energia Solid Oxide Electrolysis Cells Steam Electrolysis EIS SOEC (N1-N3) EIS SOFC (N1-N3) 3 3 35%H 2 O - 65%H 2 2.5 2.5 50%H 2 O - 50%H 2 50%H 2 O - 50%H 2 65%H 2 O - 35%H 2 2 2 1.5 65%H 2 O - 35%H 2 N1 1.5 35%H 2 O - 65%H 2 N1 1 R ohm = 0.15 Ω cm 2 N2 N3 1 R ohm = 0.15 Ω cm 2 N2 N3 0.5 0.5 0 0 2 4 6 8 10 12 Re(Z) [mω] 0 0 2 4 6 8 10 12 Re(Z) [mω] The Nyquist plots show that the ohmic part of the cell resistance is the same for all the tests and modalities (about 0.15 Ω cm2), whereas the polarization resistance at a specified reactant-toproduct ratio is higher for the SOEC spectra. The spectra also show a higher medium frequency semi-circle arc related to higher resistance in oxy-reduction processes. 18
Solid Oxide Electrolysis Cells CO2 Electrolysis and co-electrolysis of H2O and CO2 Polarization curves of M13 test in comparison with M1 (50%H2-50%H2O) and M7 (50%CO -50%CO2) curves Polarization curves of M14 test in comparison with M6 (30%H2-70%H2O) and M8 (30%CO -70%CO2) curves. D.Ferrero, P.Leone, A.Lanzini, M.Santarelli, submitted for publication, International Journal of Hydrogen Energy 19
People: Activities on biogas + SOFC - Davide Papurello, PhD student (Politecnico di Torino & Istituto Agrario di San Michele a/a; - Andrea Lanzini, post-doc; - Pierluigi Leone, assistant professor. 20
Activities on SOFC and biogas - Study of fuel reforming directly in the fuel cell; - effect of biogas contaminants (H 2 S, HCl, Siloxanes, etc.); - biogas filtration; - biogas reforming (collaboration with CNR- ITAE); - Issues for fuel cell systems running on biogas; 21
Carbon deposition issues 100% 100% 100% 22
Voltage (mv) Politecnico di Torino Dipartimento Energia Direct reforming of biogas 1.100 1.000 900 POx direct reforming %CH 4 Voltage - POx100%CH4 Voltage - POx70%CH4 Voltage - POx50%CH4 Voltage - POx30%CH4 800 700 600 500 400 300 200 100 0 0 20 40 60 80 Test time (h) The anode-supported cell is operated at ~800 C. H 2 S can be tolerated at low amount (~1 ppm) and for at least 1 day. 23
Voltage (mv) Politecnico di Torino Dipartimento Energia Effect of contaminants 1.100 POx Reforming 50%CH 4 +C 2 H 2 H 2 S Effects 1.000 900 800 700 Voltage - POx50%CH4 Voltage - POx50%CH4+C2H2 Voltage - POx50%CH4+H2S Voltage - POx50%CH4+C2H2+H2S 600 500 400 300 200 100 0 0 20 40 60 80 Test time (h) Acetylene (C 2 H 2 ), a well-known carbon precursor, is well tolerated at 1% vol. in the biogas feed 24
Direct POx reforming 25
Monitoring of contaminants in biogas from a wastewater treatment plant 26
Activities on energy systems analysis People: - Marta Gandiglio, research associate; - Domenico Ferrero, PhD student; - Andrea Lanzini, post-doc; 27
Activities on energy systems analysis Techno-economic analysis of a PEM micro- CHP unit (in collaboration with Giacomini S.p.a. and Hysytech S.r.l.). Energy and economic performances of large SOFC power plants (collaboration with Princeton University since 2010). Energy and economic performances of electrolysis plants for storage of electricity from RES. 28
Thermo-economic analysis of SOFC plants SOFC hybrid plant: main energy flows 29
Thermo-economic analysis of SOFC plants SOFC hybrid plant: layout 30
SOEC-based renewable cycles A) Hydrogen closed-loop sustainable cycle B) Synthetic liquid fuels closed-loop sustainable cycle C) Power-to-gas heat electricity H 2 O Sabatier H 2 SOEC H 2 O electrolysis CO 2 Synthetic methane H 2 Biogas Purification Bio-methane Nuclear and/or renewable sources Power Cogeneration Power & heat Final users Gas 31
Thank you for the attention 32