Influences of Hydrogen-Natural Gas Mixtures on the Performance of an Internal Reforming Solid Oxide Fuel Cell Unit: A Simulation Study

Blending hydrogen into natural gas grid can effectively reduce carbon emissions and promote the development of the hydrogen economy. Utilizing hydrogen-natural gas mixtures through internal reforming solid oxide fuel cells (SOFCs) can convert the chemical energy of the fuels direct into electricity, which is a promising technology for combined heat and power systems. In this study, a three-dimensional model for an internal reforming solid oxide fuel cell unit is developed coupling chemical and electrochemical reactions, mass, momentum and heat transfer processes. The model is validated by both the patterned anode experiments and the button cell experiments with porous electrodes. The distributions of temperature, gas compositions, and current density between pure methane and 30% hydrogen addition are simulated and compared. The influences of the hydrogen addition on the performance of the SOFC unit are further studied by changing the hydrogen blending ratio. The simulation results show that the addition of hydrogen affects the coupling of the endothermic reforming reactions and exothermic electrochemical reactions, which leads to improved temperature uniformity and higher current density of the SOFC unit compared with pure methane feeding.