Hydrogen sulfide anode contamination

Numerical models of the contamination of the anode by CO2 and H2S are not as abundant as their counterparts for CO poisoning. The numerical models found in literature, which take into account the presence of carbon dioxide, are focused on understanding the reverse water-gas shift reaction (WGSR) and its effects on the performance of the cell. The effect of hydrogen sulfide presence on the polarization curve and liquid water distribution in the cell is also studied numerically. It is found that with trace amounts of H2S, the cell performance can be dramatically decreased. The effects of H2S poisoning can be sometimes very severe and cannot be reversed, unlike their counterparts of CO poisoning. 

Hydrogen sulfide is the most important contaminant and even few parts-per-million concentrations the fuel gas at the anode side strongly affect cell performance. H2S has an immediate effect on cell performance, also at 1 ppm [1]. The effect of sulfur poisoning was observed at the initial H2S addition, even though the concentration was very low. 

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