EFFECTS OF H_2S AND HCl IN COAL GAS ON MCFC PERFORMANCE

摘要

The MCFC power generating system is one of the most promising systems for future power generation, especially when fueled from a coal gasifier. However, the MCFC is anticipated to be sensitive to coal-derived contaminants such as H_2S and HCl. Then, single and mixed effects of H_2S and HCl on the MCFC performance were investigated using 100cm~2 fuel cells under atmospheric pressure and with simulated coal-gasified gas, in order to design a cleanup unit. The experiments revealed the following. H_2S of O.lppm did not affect the cell performance. However, H_2S of over 0.3ppm had an adverse effect. This degradation was due to suppression of the water-gas shift reaction at the anode surface, which was poisoned by H_2S. For HCl of 10ppm. it did not appear to undergo the degradation process since the performance did not change immediately. However, it was found that NaCl was formed in the cell. The formation of NaCl indicated Li/Na electrolyte loss occurred because of the HCl. No mixed effects of H_2S (0.1 ppm) and HCl (5ppm and 10ppm) were observed from the degradation of cell voltages.