HAZOP Study of a Water Electrolysis Plant Used in Green Hydrogen Production

To advance the green hydrogen economy, ensuring high reliability and safety of the water electrolysis plant is crucial. This study presents a HAZard and OPerability (HAZOP) analysis to identify the probable deviations in a water electrolysis plant with proton exchange membrane (PEM) electrolyzer from its intended operation, along with their causes and consequences. HAZOP is a risk and reliability analysis technique that identifies operational failures by analyzing logical sequences of cause-deviation-consequence for various process parameters. To conduct HAZOP, the water electrolysis plant is divided into sub-subsystems and deviations for each sub-systems is identified using guideword and process parameters. A literature review is performed to identify the causes and consequences of each deviation and recorded in a dedicated HAZOP table. The HAZOP analysis shows that deviations in a PEM electrolyzer are interconnected, with one deviation potentially triggering another. The performance of the entire plant is heavily influenced by its sub-systems, as faults in auxiliary components can impact the electrolyzer's efficiency, degradation, and safety. Key consequences of these deviations include reduced efficiency, degradation of the PEM electrolyzer, and the formation of a flammable mixture. This work provides great input for forecasting component failures and performing maintenance actions to prevent failures/ accidents, or to restore desired hydrogen production rate.

Keywords: Green hydrogen, HAZOP, Water electrolysis, PEM electrolyzer, Reliability.