SOEC: Key enabling Technology for sustainable Fuels and Feedstocks. John Bøgild Hansen, Haldor Topsøe Presentation to NSF February 2, 2018

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1 SOEC: Key enabling Technology for sustainable Fuels and Feedstocks John Bøgild Hansen, Haldor Topsøe Presentation to NSF February 2, 2018

2 Fuel Cell and Electrolyser SOFC SOEC H 2 H 2 O H 2 O H 2 H 2 + O 2- H 2 O + 2e - O 2- ½O 2 + 2e - O 2- H 2 O + 2e - H 2 + O 2- O 2- O 2-2e - +½O 2 ½O 2 ½O 2 H 2 + CO + O 2 SOFC SOEC H 2 O + CO 2 + electric energy ( G) + heat (T S)

3 SOEC more efficient than present Electrolysers Internal waste heat used to split water Energy needed to evaporate water kwh per Nm3 H Waste heat which can be utilised to split water Minimum Electricity Input Deg C.

4 SOEC Electrolysis Power Steam CO 2 CO CO 2 H 2 Syngas Hydrogen SNG Methanol DME Gasoline Diesel CO

5 Cell Development from 1989 ESC LSM YSZ Ni/YSZ ASC LSM YSZ Ni/YSZ Cell generations with ceramic support 3G metallic support LSCF CGO YSZ or SSZ Ni/YSZ 1G 2.XG 2.5G MSC LSCF CGO YSZ or SSZ FeCr 1000 o C 850 o C 750 o C 600 o C Performance Robustness Cost reduction

6 Development of stacks Base case design: 75 cells 12x12 cm 2 Design for robustness Design for manufacturability TOFC Incremental development Platform towards and industrial product Stack

7 CO from CO 2 by SOEC electrolytic process Commercially available Biggest plant so far 250 kw Electrochemical reaction at the fuel electrode side +2 + Production of oxygen-rich gas +2

8 Biogas upgrade by means of SOEC CH 4 + CO 2 + 3H 2 O + El 2CH 4 +H 2 O + 2O 2

9 SNG Technology Methanation generates a lot of heat CO 2 + 4H 2 CH 4 + 2H 2 O (- H = 165 kj/mol) Syngas = SNG + heat Energy: 100% = 80% + 20% Heat 20% 100% SNG 80%

10 Biogas to SNG via SOEC and methanation of the CO 2 in the biogas:

11 Exergy Flows in CO 2 case

12 Synergy between SOEC and fuel synthesis Product CO 2 SOEC Syn Gas Synthesis H 2 O Steam

13 Methanation and SOEC at Foulum

14 Production (100 % = 10 Nm 3 /h CH 4 ) vs hours on stream. 3.1 kwh/nm 3 H % Hours on Electrolysis 120% 100% 80% 60% 40% 20% Percent of Design production

15 Methanator catalyst very active and stable

16 Transient operation of methanator

17 Average gas compositions June 2, 2016 Position CH 4 CO 2 N 2 H 2 Inlet Exit 1 st stage Product gas

18 Key numbers Denmark (2008) Final energy consumption: 673 PJ Biogas potential: 40 PJ If upgraded by SOEC: 67 PJ ~ 10 % NG used for power plants: 73 PJ NG used in household, industry and service: 76 PJ Saved CO 2 ~ 1 MT/capita

19 Methanol synthesis CO + 2H 2 = CH 3 OH + 91 kj/mol CO 2 + 3H 2 = CH 3 OH+H 2 O + 41 kj/mol

20 The Active Site of Syngas Catalyst H 2 H 2 /H 2 O Cu(200), d=0.18nm Cu(111), d=0.21nm Cu(111) Cu(111) Cu is metallic when catalyzing: - WGS - MeOH synthesis - MeOH reforming 1.5mbar, 220 o C ZnO(011), d=0.25nm ZnO(012), d=0.19nm 1.5mbar, H 2 /H 2 O=3/1, 220 o C Catalyst dynamic: - Number of active sites depends on conditions

21 Conversion of methanol as function of CO 2 content in stoichiometric gas 100 Carbon conversion % J.B. Hansen Data Condensing methanol K.Klier Data Lab data 225 C Percent CO2 in

22 Methanol from CO 2 and Steam SOEC Oxygen Water CO 2 Recycle Purge Methan ol synthesis Separator Methanol

23 Space velocity and byproducts as function of CO 2 converted in SOEC Space velocity Relative % Space Velocity Byproducts Relative % Byproducts Percent CO2 through SOEC 100

24 Results of to pressurize SOEC stacks or not SOEC Pressure Syngas Comp, % CO 2 Comp LHV Efficiency, % Atmospheric bar Max. theoretical 83-88

25 Heat of Reactions per mole H 280 C Product From CO From CO 2 kj/mol kj/mol Gasoline CH DME MeOH Evaporation of 1 mol of water requires ~ bar g NB: Steam conversion is only % in SOEC plants

26 From SOEC Science to Commercial Product Lifetime Reliability & Performance Materials Design Cost Processing

27 Energinet.dk s vision for fossil fuel free Denmark in 2050 The Wind Scenario El- Transmission Low priced SOEC Electrolysis DH Peak Shave: Gas Turbine SOFC High priced District Heating O2 Heat Biomass Gasifier/ Digester Cleaning DH Gas System Storage Catalysis: MeOH, DME Gasoline, SNG Green Synfuels District Heating Air Capture Compress Upgrade To Methane District Heating Gas Transmission

28 CEESA plan requires 4-8 GW electrolysis capacity needed for Denmark

29 SOEC Challenges Degradation Better defined testing protocols? Understanding of fundamental mechanisms Robustness Pressurisation Upscaling geometric area Upscaling manufacturing And of course cost