Numerical study on effects of CH4–CO2 internal reforming on electrochemical performance and carbon deposition of solid oxide fuel cell.

CH 4 –CO 2 fueled solid oxide fuel cells (SOFCs) are the high-efficiency and low-carbon power generation technology. However, carbon deposition severely hinders its application. Here, the numerical model considering the complex anode CH 4 internal reforming reactions, H 2 electrochemical reaction, gas diffusion and charge transfer of SOFC using CH 4 –CO 2 fuel has been established. The CH 4 –CO 2 internal reforming and electrochemical reactions of SOFC under different CO 2 /CH 4 ratios and temperatures are studied to reveal the optimal operating conditions. The distributions of different reaction rates, gas components and carbon deposition activity at the anode are analyzed. The results show that the increase of CO 2 concentration can decrease the carbon activity but also cause the decrease of electrochemical performance. It is found that the good comprehensive performances including power density, carbon activity and methane conversion rate can be achieved under the CO 2 /CH 4 molar ratio of 1. The thermodynamic calculation of three different methane reforming modes shows that CH 4 –CO 2 reforming leads to the greatest carbon deposition risk compared with CH 4 –H 2 O and CH 4 –O 2 reforming, implying the importance of anti-carbon for CH 4 –CO 2 fueled SOFC. • Methane-fueled SOFCs are the most energy-efficient and low-carbon technology. • A numerical modeling of SOFCs with different CH 4 –CO 2 mixtures is proposed. • Cell performance and carbon deposition with different CH 4 –CO 2 mixtures were examined. • The cell shows the excellent comprehensive performance with CO 2 /CH 4 of 1. • Anodic synergistic catalysis is necessary for the elimination of CH 4 –CO 2 carbon deposition. [ABSTRACT FROM AUTHOR]