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

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)

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

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

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

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

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

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

HTE Experimental Program Schematic of single-cell electrolysis test apparatus

HTE Experimental Program Exploded view of Ceramatec electrolysis stack components

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

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

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

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

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

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

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