Mass transport in PEM water electrolysis
M.Sc. Gergely Schmidt, Prof. Dr. Insa Neuweiler
Proton exchange membrane water electrolysis (PEMWE) produces hydrogen from water and electricity which preferably comes from renweable sources. Hydrogen can serve for energy storage or as base material for various common chemicals. For improving PEMWE's efficiency through voltage loss reduction, models are needed that quantify component (species) transport across PEMWE cell parts, in particular through porous transport layers (PTL), catalyst layers (CL) and flow field channels. Such model can help to design materials for efficient operation as state-of-the-art cell parts still require optimization regarding mass transport. We adopt component transport and multiphase flow models on the Darcy scale (DuMux) as well as on the pore scale (OpenFOAM) to quantify transport of oxygen and water inside the anode half cell. The models are used to predict the spatial distribution of fluids and components for different PTL properties and at different operating conditions, i.e. current density, pressure and temperature. Model results are compared to our cooperation partners' mesurements and to evidence in scientific literature. For instance, we examine by model-experiment comparison in which cases Darcian models are applicable for describing multiphase flow through flow field channels and for predicting voltage losses, i.e. overpotentials, which are related to mass transport through PTLS.
Letzte Änderung: 06.11.19
