Solid Oxide Fuel Cells (SOFCs) are of great interest due to their high
energy efficiency, low emission level, and multiple fuel utilization. SOFC
can operate with various kinds of fuels such as natural gas, carbon
monoxide, methanol, ethanol, and hydrocarbon compounds, and they are
becoming one of the main competitors among environmentally friendly energy
sources for the future. In this study, a mathematical model of a co-flow
planar anode-supported solid oxide fuel cell with internal reforming of
natural gas has been developed. The model simultaneously solves mass, energy
transport equations, and chemical as well as electrochemical reactions. The
model can effectively predict the compound species distributions as well as
the cell performance under specific operating conditions. The main result is
a rather small temperature gradient obtained at 800 °C with S/C = 1 in
classical operating conditions. The cell performance is reported for several
operating temperatures and pressures. The cell performance is specified in
terms of cell voltage and power density at any specific current density. The
influence of electrode microstructure on cell performance was investigated.
The simulation results show that the steady state performance is almost
insensitive to microstructure of cells such as porosity and tortuosity
unlike the operating pressure and temperature. However, for SOFC power
output enhancement, the power output could be maximized by adjusting the
pore size to an optimal value, similarly to porosity and tortuosity. At
standard operating pressure (1 atm) and 800 °C with 48% fuel
utilization, when an output cell voltage was 0.73 V, a current density of
0.38 A cm-2 with a power density of 0.28 W cm-2 was predicted. The
accuracy of the model was validated by comparing with existing experimental
results from the available literature.