Dynamics and optimization of PEM water electrolyzer process performance

Abstract

Hydrogen is the foremost proficient energy carrier. It can be generated from various resources, among which water electrolysis stands out as an environmentally sustainable method capable of producing high-purity hydrogen. Furthermore, in view of the long viability and environmental effect, proton exchange membrane (PEM) water electrolysis has emerged as a technically feasible approach for hydrogen production using renewable energy sources, with oxygen as the only by-product and no associated carbon emissions. In this study, a dynamic model of a PEM electrolyzer is developed based on mole balance conservation at both the cathode and anode and energy conservation. The model incorporates key physical and electrochemical phenomena. The electrolyzer system is represented through four main sub-models: the anode, cathode, membrane, and voltage modules. Using the identified essential factors, the performances characteristics of the electrolyser are estimated at various operating temperatures. To reduce the required input voltage, the Taguchi optimization technique is employed to determine optimal process conditions. Key parameters considered in the optimization include operating temperature, anode and cathode pressures, membrane water content, membrane thickness and exchange current densities at both electrodes. Furthermore, the relative influence of these parameters on system performance is quantified using analysis of variance (ANOVA) and signal-to-noise ratio (SNR) analysis.