Effect of H2S and COS in the fuel gas on the performance of ambient pressure phosphoric acid fuel cells
Abstract
The objective of this project was to determine in laboratory cells the tolerance of phosphoric acid fuel cells (PAFC) to hydrogen sulfide and carbonyl sulphide impurities in the anode feed gas. The study was conducted in three phases: the first was testing in a small (1 sq cm) free electrolyte cell to examine the effect of electrode structure on cell tolerance and to determine the order of magnitude of sulfur causing failure in cells at zero utilization; the second was testing in standard 2' x 2' PAFC laboratory hardware at ambient pressure to examine the effect of hydrogen utilization on tolerance and the possible effect of fuel impurities on cathode performance; the final phase was testing with a 2' x 2' cell in a pressure vessel to determine the effect of pressurized operation on cell tolerance. The poisoning effect of hydrogen sulfide was characteristically different from the effects of carbon monoxide, in that it was not manifested by a marginal (e.g., 0 to 50 mV) increase in anode potential but either had no effect or caused catastrophic polarization. Critical levels were derived for hydrogen sulfide as related to cell operating conditions.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- April 1985
- Bibcode:
- 1985STIN...8610446R
- Keywords:
-
- Carbon Monoxide;
- Gas Pressure;
- Phosphoric Acid Fuel Cells;
- Poisoning (Reaction Inhibition);
- Hydrogen Sulfide;
- Mass Spectrometers;
- Reaction Kinetics;
- Electronics and Electrical Engineering