Interaction of coal-derived synthesis gas impurities with solid oxide fuel cell metallic components

Critical Review of Carbon Conversion in “Carbon Fuel Cells”

“…Recent reviews , discuss mechanisms of degradation and developments in sulfur-tolerant anode materials for solid oxide fuel cells that employ gaseous and liquid hydrocarbons, which normally contain varying quantities of sulfur. Outside of sulfur, there are other contaminants including As and P, which are known to rapidly degrade SOFC anodes made of Ni cermet. − There is also evidence for synergistic effects that the presence of sulfur in the form of H 2 S magnifies and accelerates the cooperative deleterious effects of As and P on cell performance through Ni anode degradation. , …”

“…In a steam gasification environment, the formation of gasified contaminants mostly in the form of volatile hydrides such as AsH 3 and PH 3 and their deleterious effect on Ni anodes are well established. − These studies have indicated that AsH 3 and PH 3 even at 1 ppmv level react with Ni irreversibly to form various Ni-phosphide and Ni-arsenide phases that deactivate the Ni anode. In the case of dry gasification, the formation of volatile hydrides is not likely.…”

Overview of SOFC Anode Interactions with Coal Gas Impurities

“…A major mode of degradation was loss of electronic percolation, the result of alteration phase formation, grain growth, and inducement of micro-fractures within the affected portions of the anode support. Arsenic concentrations of 10 ppb or less were estimated to result in acceptable rates of fuel cell degradation [5].…”