Revealing interactions between the operating parameters of protonic ceramic electrolysis cell: A modelling study

Protonic ceramic electrolysis cell (PCEC) is a clean and sustainable technology for hydrogen production. To provide a comprehensive understanding of the effects of various parameters on the performance of PCEC, a framework is proposed to combine the 2D numerical model with One-Factor-At-a-Time (OFAT) and Design of Experiments (DOE) methods. DOE is a simple but effective method to gain deep insight into the effect of different factors on the response variable using a small number of cases. In the OFAT result, a peak optimal Faradaic efficiency (FE) of 82% is found at 600 °C and a current density of 0.4 A cm⁻². The FE increases with the increasing inlet flow rate, while the temperature gradient reduces continuously. It is also found that if the inlet steam mole fraction increases by 5%, the FE can be increased by at least 0.25%. DOE results demonstrate the most important factors are the anodic inlet steam molar fraction and anodic inlet flow rate. Additionally, the interaction effects between them are also found to be significant. Noteworthy, regression models derived from DOE results also demonstrate potential capabilities as surrogate models for 2D numerical model. Therefore, DOE is a powerful tool that can draw rigorous conclusions while saving a lot of computational resources. Overall, this study provides deep insights into the interaction effects of different parameters. The framework proposed in this study can be applied to guide future PCEC design optimization.