Effect of H2S and HCl on solid oxide fuel cells fed with simulated biosyngas containing primary tar

Abstract

Abstract Integrated biomass gasifier solid oxide fuel cell systems are an alternative to fossil‐fuel‐based combined heat and power generators. However, biosyngas contaminants represent a bottleneck for small‐scale systems. In this work, we present the results of experiments on the effects of H2S, HCl, and acetic acid as model primary tar on Ni‐GDC SOFC. First, the effects of 17‐128 g/Nm3 dry basis acetic acid were studied. On a second cell, 0.8 and 1.3 ppm(v) H2S were added to the simulated biosyngas anode flow. After a full recovery, the cell was exposed to 42 g/Nm3 acetic acid and 0.8 ppm(v) H2S. On a third cell, 3.4, 20, and 50 ppm(v) HCl were tested and, after a recovery period, 42 g/Nm3 acetic acid and HCl were added. Even 0.8 ppm(v) H2S caused an immediate voltage drop. H2S affected CH4 reforming and water‐gas shift reaction. Differently, even 50 ppm(v) HCl appeared not to significantly affect these reactions. Acetic acid increased the cell voltage but caused carbon deposition at the cell inlet. The voltage increase seemed not to be affected by H2S or HCl, and no acetic acid was measured at the cell outlet, indicating that these contaminants do not affect the primary tar conversion.

Keywords

• biomass gasifier
• contaminants cross‐influence
• direct internal tar reforming
• H2S
• HCl
• SOFC