CCS and Power Systems
Advanced Energy Systems - Solid Oxide Fuel Cells
Direct Utilization of Coal Syngas in High Temperature Fuel Cells
Performer: West Virginia University
Project No: FG02-06ER46299
This project is based on a multi-scale, multi-disciplinary approach and comprises three integrated tasks: (1) characterization of contaminant effects, (2) multi-scale continuum modeling, and (3) anode material development. The knowledge base gained from experiments (Tasks 1 and 3) will be used in multi-scale computational models (Task 2) to establish the tolerance limits for the impurities and to predict the life of solid oxide fuel cells (SOFCs) operating on coal syngas that contains impurities.
- Conduct long-term anode exposure tests to phosphine (PH3) and measure out-of-plane surface deformations at specified time intervals to quantify the PH3 effects on structural properties. The test results will facilitate the development of long-term anode structural durability and electrochemical degradation models under coal syngas utilization. Kinetics of the PH3/nickel (Ni) reaction will be measured using thermogravimetric analysis. Investigations of the phosphorus penetration rate into the Ni yttria-stabilized zirconia (YSZ) anode.
- Build a model based on the experimental data to determine the influence of the electrical current and water content on the degradation rate and Ni migration. This model will be used to predict the lifetime of the anode operated on coal syngas that contains PH3. The Ni patterned electrode will be used to study the influence of the PH3 on the triple phase boundary (TPB) sites. The data will be integrated with the electrochemical measurements to verify TPB length change during PH3 attack.
- Connect a mass spectrometer to the point at which contaminant gases are mixed with the fuel stream to confirm the composition of gases entering the hot zone of the tube furnace. A sampling tube will be constructed at a point just above the anode surface for sampling and analyses of gasses. These gas analyses will be correlated to determine the fate of contaminants (phosphine, hydrogen sulfide, etc.) inside the furnace as a function of the initial fuel composition, temperature, and current flow through the SOFC.
Design and develop alternative ceramic anode components for operation in sulfur- and phosphor-containing coal syngas using contaminant tolerant materials. The materials of interest are ionically and electronically conductive ceramic oxides with perovskite structure. This type of anode material has been proven to tolerate higher concentrations of sulfur. Previous research indicated that PH3, even at parts per million (ppm) levels, can degrade the perovskite anode. The challenge is to design and synthesize anode materials capable of mitigating both sulfur and phosphorus poisoning. West Virginia University's (WVU's) research experience in SOFC manufacturing and mixed oxides impregnation, together with an atmospheric high-temperature instrument, will be utilized to overcome these technical barriers.