Modeling of Packed Bed Methanol Steam Reformer Integrated with Tubular High Temperature Proton Exchange Membrane Fuel Cell

This work proposes a novel tubular structure of high-temperature proton exchange membrane fuel cell(PEMFC) integrated with a built-in packed-bed methanol steam reformer to provide hydrogen for power output. A two-dimensional axisymmetric non-isothermal model was developed in COMSOL Multiphysics 5.4 to simulate the performance of a tubular high temperature proton membrane fuel cell and a packed bed methanol reformer. The model considers the coupling multi-physical processes, including methanol reforming reaction, water gas shift reaction, methanol cracking reaction as well as the heat, mass and momentum transport processes. The sub-model of the tubular packed-bed methanol reformer is validated between 433 K and 493 K with the experimental data reported in the literature. The sub-model of the high temperature proton exchange fuel cell is validated between 393 K and 433 K with the published literature. Our results show that power output and temperature distribution of the integrated unit depend on methanol flow rates and working voltages. It was suggested that stable power generation performance of 0.14 W/cm2and temperature drop in methanol steam reformer of ≤10 K could be achieved by controlling the methanol space-time ratio of ≥250 kg·s/mol with working voltage at 0.6 V, even in the absence of an external heat source.