Numerical modelling and comparative analysis of direct ammonia fuelled protonic and oxygen- ion conducting tubular solid oxide fuel cell

Abstract

The main emphasis of this work is developing a 3D numerical model and investigating the performance characteristic of a direct ammonia fuelled protonic-conducting tubular solid oxide fuel cell (NH3-T–SOFC–H) in comparison with the corresponding hydrogen-fuelled one and direct ammonia feed oxygen -ion conducting tubular solid oxide fuel cell (NH3-T–SOFC–O) under the same operating parameters and geometrical shape. The findings revealed that NH3-T–SOFC–H has outstanding performance over T–SOFC–O counterparts at intermediate temperature (973 K) when operated under similar working conditions and geometrical designs. On the other hand the NH3-T–SOFC–O is promising for higher operating temperatures. The outcomes of the study are also confirmed that the power performance of NH3-AS-T–SOFC–O is better than the other supports of both electrolytes when the anode electrode is constructed at the outside portion of the tubular cell. Yet, the other remarkable result found in this study is that NH3– CS- T–SOFC–O has outstanding performance compared to all supports of both electrolytes when the fuel electrode is built in the inner portion of the tube. In addition, the finding indicates that the power performance of ammonia-fuelled tubular cells is strongly influenced by the anode position, operating temperatures, and pressures in both electrolytes yet the effect of cell temperature is more influential in the protonic-conducting cell. It is also observed that the performance of ES-T-SOFC is lower than AS- and CS-T-SOFC in both electrolytes and anode positions.