Hydrogen (H2) got a bad rap in 1937 when the German passenger airship LZ-129 Hindenburg caught fire & was destroyed in New Jersey, US. However, H2 is an important feedstock & so the transportation is not new & since 1938 this gas has been transported in pipelines in Germany with 4,542 km of operational pipelines worldwide.
Decarbonization has meant a shift away from fossil to renewable energy. However, as with several of these energy sources, they are not predictable, & electricity is not cost-effective to store. Also, the source generation of renewable electricity can be a long-distance from demand. Pipelines present an efficient & safe way to transport H2.
Hydrogen can escape through joints the steel of the pipe & damage components exposed including those introduced into the pipeline such as pigs. Even "spiking" gas pipelines can lead to significant impacts on material properties. Using existing carbon steel pipelines to transport either pure or spiked H2 present issues for ensuring integrity.
One of the most commonly accepted means of ensuring integrity is pigging, both utility & in-line inspection. However, the tools are not designed for hydrogen & many of the components are susceptible to degradation in a H2 environment. Conversion or injection needs to be planned to assess what defects that might exist that may be more susceptible. So, what tools can be used?
This paper looks at three aspects of providing integrity assurance. Firstly, what defects you need to find & what tools can be used to be H2 ready, what tools can be used on a day to day basis, & what considerations are required in inspecting H2 as they operate. The paper will use a case study of the inspection of a pure H2 pipeline to demonstrate the solutions required to achieve successful ILI runs.