Effects of H/sub 2/S on molten carbonate fuel cells. Progress report, April 1-June 30, 1984

Technical Report · Fri Mar 01 00:00:00 EST 1985

OSTI ID:5868617

Remick, R J

This report summarizes work accomplished to identify the poisoning mechanism(s) responsible for performance losses of molten carbonate fuel cells (MCFC) when operating on sulfur-containing gases. This objective is being addressed by focusing out-of-cell and in-cell experiments on single mechanistic issues, followed by incorporation of the results into a model that correlates cell potential decline to contaminant(s) concentration. When coupled with gas cleanup cost projections, the model can be used to conduct trade-off studies leading to the selection of optimum feed-gas compositions for MCFC power plants. The importance of this program is that the degree to which H/sub 2/S and other contaminants must be removed from typical MCFC fuels can have a profound effect on the cost of cleaning the fuel gas, especially if contaminant levels lower than 0.1 ppM are required. The anticipated product from the overall program is a justifiable specification for gas cleanup requirements for MCFC power plants. The loss in performance experienced by fuel cells operating on contaminated fuels has been traced to the electrochemical formation of a layer of nickel sulfide on the fuel cell electrode. This layer forms as the result of a reaction between the nickel electrode and dissolved sulfide ions in the electrolyte, not as the result of a nickel/hydrogen sulfide interaction as previously supposed. A formula was derived that can be used to calculate the potential at which this layer can form based upon local gas phase concentrations. This formula provides a satisfactory explanation of the results observed in the half-cell experiments and can be applied to various performance models to calculate the conditions at which the onset of performance losses would occur. However, this formula by itself does not provide enough information to allow the performance of a partially contaminated cell to be modeled. Appendix A has been entered separately. 26 refs., 4 figs., 3 tabs.

• Research Organization: Institute of Gas Technology, Chicago, IL (USA)
• DOE Contract Number: AC21-83MC20212
• OSTI ID: 5868617
• Report Number(s): DOE/MC/20212-1739; ON: DE85008310
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
FUELS
SPECIFICATIONS
MOLTEN CARBONATE FUEL CELLS
ELECTRODES
POISONING
SHIFT PROCESSES
CATALYSTS
CHEMICAL REACTIONS
ELECTROCHEMISTRY
HYDROGEN SULFIDES
LEADING ABSTRACT
PERFORMANCE
ABSTRACTS
CHALCOGENIDES
CHEMISTRY
DIRECT ENERGY CONVERTERS
DOCUMENT TYPES
ELECTROCHEMICAL CELLS
FUEL CELLS
HIGH-TEMPERATURE FUEL CELLS
HYDROGEN COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
300502* - Fuel Cells- Performance & Testing