Safety aspects for large-scale hydrogen plants

To meet the CO₂ emission reduction goals from the Climate Agreement, we need large-scale production of green hydrogen through water electrolysis. Hydrogen plays a key role in the future energy system as an energy carrier and storage of green energy. Furthermore, it will serve as feedstock for climate-neutral industrial processes. In the process industry safety aspects of fossil-based hydrogen production is well-known, but there is limited experience with large-scale water electrolysis.

The Institute for Sustainable Process Technology (ISPT) and the consortium partners HyCC, Ørsted, Shell, Yara, DNV, RHDHV and TNO initiated a new project: Green Hydrogen Inherent Safety Practices on large industrial scale. This project will increase awareness of safety for large industrial scale water electrolysis plants. After all, industry, authorities, and society want zero incidents. 

The knowledge-gap 

Today electrolyser suppliers, operators, and owners have limited operating experience with large-scale water electrolysis installations.  Only small-scale installations exist whereas these large-scale installations are becoming reality soon. Therefore, all partners wish to further advance all related safety aspects and develop a uniform safety approach for large-scale water electrolysis plants.

One question is, for example, how to objectively assess scenarios with exceptionally low probability and high potential consequences (black swans) and how to determine cost-effective safety measures to address these. Therefore, there is a need to further develop joint safety practices and guidelines based on credible scenarios for large-scale plants. It is also important to communicate about safety risks transparently.  

The project aim 

In this project, we want to deepen the understanding of the potential risks due to mixtures of hydrogen and oxygen in electrolysis equipment. The tools, methods, and data for assessments of these risks, which typically have a low chance of occurrence but may have severe consequences, will be investigated.  The project provides credible scenarios and facts on the fundamentals of explosions and the validity of detonation.  

The focus is on an objective risk assessment methodology regarding fire and explosion risks with oxygen and hydrogen mixtures in equipment. The development of consistent assessment methods covers failure frequencies and consequences, including data on delayed ignition and detonation, leading to corresponding safeguarding and appropriate safety distances. 

Developing safe water electrolysis

Based on these insights, the project team compiles best practices for inherent safe design and guidance for hazard assessment and risk mitigation. The project will also deliver a roadmap to validate the findings with experimental data.  

ISPT is the overall coordinator and will execute the project with DNV, RHDHV and TNO. All topics will be explored together with the experts from industrial partners HyCC, Ørsted, Shell and Yara. This project is co-funded by TKI-Energy & Industry of the Dutch Ministry of Economic Affairs and Climate Policy. Safety Delta Nederland supports this project and is a very important party for connecting to other H2-safety projects and knowledge.