Computational Fluid Dynamics Analysis of Gas Crossover in an Alkaline Electrolyzer Using a Multifluid Model

A comprehensive three-dimensional, two-phase isothermal model is developed for an alkaline water electrolyzer, aimed to accurately simulate complex interactions at gas-liquid interfaces, ion transport mechanisms, and electrochemical reactions. The present model accounts for the local volume fraction of gas, the species spatial distributions and both electrical and electrolyte potentials. The crossover of the product gases is a result of diffusion of the dissolved species in the liquid phase. This work explores the role of parameters such as mass transfer coefficients and supersaturation within the cell. Despite the model demonstrating trends that are consistent with anticipated physical behaviors, it currently tends to underestimate the crossover effect.