Three-dimensional computational fluid dynamics modelling and experimental validation of the Jülich Mark-F solid oxide fuel cell stack

This work is among the first where the results of an extensive experimental research programme are compared to performance calculations of a comprehensive computational fluid dynamics model for a solid oxide fuel cell stack. The model, which combines electrochemical reactions with momentum, heat, and mass transport, is used to obtain results for an established industrial-scale fuel cell stack design with complex manifolds. To validate the model, comparisons with experimentally gathered voltage and temperature data are made for the Jülich Mark-F, 18-cell stack operating in a test furnace. Good agreement is obtained between the model and experiment results for cell voltages and temperature distributions, confirming the validity of the computational methodology for stack design. The transient effects during ramp up of current in the experiment may explain a lower average voltage than model predictions for the power curve

Combined modelling and experimental analysis of a solid oxide fuel cell stack

The proper distribution of reactant species and removal of excess heat and reaction products are fundamental to the success of solid oxide fuel cell (SOFC) stack technology. Experimental advances are limited due to the time and expense of varying the parameters over a range of designs and operating conditions. Modelling of SOFCs at the stack scale, as opposed to at the cell scale, has generally been confined to studies of the fluid distribution, neglecting any coupled effects associated with electrochemistry and/or species transport. The present work considers results from an original computational fluid dynamics (CFD) model and compares them with experimentally gathered data obtained for the Jülich Mark F stack design. The model couples the equations of momentum, heat and species transport with electrochemical reactions for large SOFC stacks with internal and external manifolds, with calculations being performed in reasonably short computation times. To validate the model, comparisons with voltage and temperature data from an 18-cell stack operating in a test furnace are made. Good agreement is obtained between the model and experiment results, confirming the validity of the methodology for stack design

Rutile TiO2–Pd Photocatalysts for Hydrogen Gas Production from Methanol Reforming

Palladium/rutile TiO2 has been explored as a photocatalyst for hydrogen gas production from methanol photoreforming in the liquid and gas phase reactions, and it is compared with similar catalysts prepared on P25 titania. Rutile makes an excellent photoactive support when used for the gas phase reaction, but is not effective in the liquid phase. By exploring the effect of Pd loading on the rate of hydrogen production, an induction time is observed at high Pd content. Reduction of the catalysts prior to the reaction reduces Pd nanoparticles size and improves the catalyst activity. Investigation of the activity in the liquid phase and in the gas phase reveals that the amount of adsorbed methanol on the catalyst surface is crucial to enhance the interface charge carrier transfer that leads to high activity in the gas phase