1. Status of the INL High-Temperature Electrolysis Research Program
System Modeling and Experimental
J. E. O’Brien
J. S. Herring, C. M. Stoots, M. G. McKellar, E. A. Harvego, K. G. Condie, G. K. Housley, J. J. Hartvigsen
Fourth Information Exchange Meeting on the Nuclear Production of Hydrogen
Nuclear Energy Agency
Chicago, IL
April 14 – 16, 2009

2. High-Temperature Electrolysis
INL has been designated as the lead laboratory for High-Temperature Electrolysis (HTE) research and development, under the DOE Nuclear Hydrogen Initiative (NHI)

3. INL HTE Research Scope Experimental CFD Simulation
Demonstration and Scale-Up
System Modeling

4. System Modeling
Process flow diagram for the helium-cooled reactor / direct Brayton / HTE system with air sweep (reference case).

5. System Analysis Results
Overall Hydrogen Production Efficiencies, HTE Reference Case, as a function of Cell Voltage
The red line follows from the definition of the overall thermal-to-hydrogen efficiency and direct application of the first law

6. System Analysis Results
Overall Hydrogen Production Efficiencies
HTE Reference Case (air sweep)
vs Hydrogen Production Rate
vs Steam Utilization
(imax corresponds to Vtn)

7. System Analysis Results
Overall Hydrogen Production Efficiencies
Dependence on Reactor Type and Outlet Temperature

8. HTE Experimental Program
INL High-temperature electrolysis laboratory
Integrated Laboratory Scale Facility (15 kW)
Small-scale experiments

9. HTE Experimental Program
Schematic of single-cell electrolysis test apparatus

10. HTE Experimental Program
Exploded view of Ceramatec electrolysis stack components

11. HTE Experimental Program
Cell Performance Characterization: Polarization curves
Button cell
stack
Outlet gas composition as a function of current density for co-electrolysis experiments, 10-cell stack

12. HTE Experimental Program
Cell and Stack Performance Degradation
Area-specific resistance vs time over ~ 1000 hrs
Single button cell
Stack

13. HTE Experimental Program
Demonstration and Scale-Up: Integrated Laboratory Scale Facility
Exploded view of heat exchanger, base manifold unit, and four-stack electrolysis unit
ILS modules, mounted in hot zone

14. HTE Experimental Program
Integrated Laboratory Scale Facility
ILS hydrogen production rate time history
Initial production rate in excess of 5 m3/hr

15. HTE Experimental Program
Performance Improvement: Single-cell test stand (electrode-supported cells)
Exploded view
Assembly view
Installed

16. Conclusions and Research Plans
System analysis results indicate excellent potential for large-scale hydrogen production based on HTE
Good initial and long-term cell performance is critical to achieve competitive hydrogen production costs
INL HTE experimental program is now focused on cell and stack performance issues:
Development of improved cell compositions (with Ceramatec)
Evaluation of advanced electrode-supported cells
Demonstration of stable long-term performance

17. More Information is available in numerous publications from our group!
Thank You!