Multi-stage Monitoring of Hydrogen Systems for Improved Maintenance Approaches: An Extensive Review

Hydrogen is considered a promising solution for global decarbonisation as an alternative to fossil fuels. However, it can interact with and brittle most metallic materials and is highly flammable. These properties call for a systematic investigation of physical and chemical hazards and for the definition of a comprehensive risk management and monitoring framework, including proper maintenance planning. This study aims at establishing a hydrogen monitoring scheme and it provides a descriptive, bibliometric, and interpretative review of the current state-of-the-art of suitable techniques to ensure the safe handling of hydrogen systems. The descriptive analysis outlines the technologies available to supervise the hydrogen-material interactions and detect hydrogen leaks and flames. The bibliometric analysis shows quantitative data to identify the most relevant research groups. The interpretative study discusses the findings and examines the possibility of combining the identified techniques with maintenance programs to prevent catastrophic events.