SECA Coal-Based Systems

Abstract

This report documents the results of Cooperative Agreement DE-FC26-05NT42613 between Siemens Energy and the U.S. Department of Energy for the period October 1, 2008 through September 30, 2010. The Phase I POCD8R0 stack test was successfully completed as it operated for approximately 5,300 hrs and achieved all test objectives. The stack test article contained twenty-four 75 cm active length Delta8 scandia-stabilized zirconia cells. Maximum power was approximately 10 kWe and the SOFC generator demonstrated an availability factor of 85% at 50% power or greater. The Phase II POCD8R1 stack test operated for approximately 410 hrs before being aborted due to a sudden decrease in voltage accompanied by a rapid increase in temperature. The POCD8R1 test article contained forty-eight 100 cm active length Delta8 scandia-stabilized zirconia cells arranged in an array of six bundles, with each bundle containing eight cells. Cell development activities resulted in an approximate 100% improvement in cell power at 900°C. Cell manufacturing process improvements led to manufacturing yields of greater than 40% for the Delta8 cells. Delta8 cells with an active length of 100 cm were successfully manufactured as were cells with a seamless closed end. A pressurized cell test article was assembled, installed into the pressurized test facility and limited pressurized testing conducted. Open circuit voltage tests were performed at one and three atmospheres at 950°C were in agreement wi th the theoretical increase in the Nernst potential. Failed guard heaters precluded further testing. The SOFC analytical basis for the baseline system was validated with experimental data. Two system configurations that utilize a pressurized SOFC design with separated anode and cathode streams were analyzed. System efficiencies greater than 60% were predicted when integrating the separated anode and cathode stream module configuration with a high efficiency catalytic gasifier.