Development of an Experimentally Validated Computational Fluid Dynamics Model for a PBI Membrane-Based Anhydrous HCl Electrolyzer

Abstract

We report the development of an experimentally-validated computational fluid dynamics (CFD) model for simulation of an anhydrous HCl electrolyzer. The experimental data from 3 membrane variants was used to provide kinetic and membrane parameters for the model. The model not only accurately simulates overall electrolyzer performance, but it also provides key insights into the transport phenomena within the electrolyzer. The model allows simulation of experimental parameters like high HCl flowrates and increased cell pressure that pose a high safety risk to researchers. The model shows hotspots in the temperature distribution that will need to be addressed by flow field modification when scaling up the electrolysis process. The increasing of cell pressure reduces the gradient of current distribution throughout the electrolyzer and lowers the cell voltage required for a given current density. Increasing electrolyzer temperature reduces cell voltage by decreasing losses due to kinetic overpotential and ohmic overpotential. The implications of the simulated results are discussed, including potential limitations in our experiments and how the model can be used effectively when considering important steps like industry scale-up.