Application Analysis of Electrochemical Model Based on Alkaline Water Electrolyzer

[Objective] With the increase of renewable energy capacity installed each year, hydrogen production by water electrolysis has become an important way to consume renewable energy. [Method] This paper integrated the classical electrochemical model, conservation relationship, and empirical formula of alkaline electrolyzer to investigate the impact of temperature, pressure, current density, and other factors on the performance of water electrolysis system for hydrogen production. By analyzing the impact mechanism in relation to the electrolyzer structure, key materials, and operation conditions the study identifies a direction for optimizing the performance of current water electrolysis system for hydrogen production. [Result] The studied performance parameters include hydrogen yield rate, global efficiency, cell voltage, and hydrogen content in oxygen. The study found that increasing current density and raising the temperature both enhance the hydrogen production rate, while changes in pressure have a relatively minor impact. The paper combines physical mechanisms and practical operating experience to analyze the validity of some empirical parameters in the model. [Conclusion] Optimizing the electrolyzer structure and boosting the performance of catalysts are crucial for improving the current density. Operating the electrolyzer at too high a temperature exceeds the tolerance of the equipment materials, while operating at too low a temperature increases system energy consumption. Therefore, a balanced consideration is necessary. Increasing pressure means higher requirements for the equipment's sealing and the performance of basic materials, but producing high-pressure hydrogen also provides more options for downstream applications, potentially reducing investment in downstream compression and storage systems.