Multiphysics modeling and optimization of a methanol-fueled SOFC for distributed power applications

A comprehensive multiphysics model of a solid oxide fuel cell (SOFC) system externally fueled by a methanol reforming unit (MRU) is developed and validated using experimental measurements. The model enables a combined analysis of the three main operating concerns: electrical efficiency, energy efficiency, and carbon deposition. A 2D axisymmetric finite element model of the SOFC is coupled with a thermodynamic equilibrium model of the MRU to examine the effects of five operating parameters: temperature, methanol feed rate, steam-to-carbon ratio (S/C), air-to-carbon ratio (A/C), and current density. Both models are validated against experimental data, including GC-MS reformate analysis and polarization curves. A full parametric study is then carried out to assess electrical efficiency and overall energy balance. Results show that temperature is the dominant factor, with nearly a 60 % efficiency drop when decreasing from 850 °C to 750 °C. Increasing S/C slightly improves electrical efficiency but adds a significant thermal penalty, while higher A/C consistently reduces efficiency despite potential heat-balance advantages. The optimal operating window is identified at high temperature (800–850 °C), low methanol feed rate, and low S/C or A/C ratios (0.15–0.3). These conditions maximize electrical efficiency, avoid external energy input, and prevent coke formation at the anode. • An integrated solid oxide fuel cell and methanol reforming unit was modeled. • The modelling framework was systematically validated against experimental data. • An optimal setpoint for electrical and energy efficiency was identified. • A low steam-to-carbon ratio (0.15–0.3) was sufficient to prevent anode coking.