Hydrogen Related Issues at Hydrogen Transport via Existing Gas Pipelines

The chapter investigates the critical challenges and innovative solutions for transporting hydrogen through existing gas pipelines, a cost-effective and infrastructure-leveraging approach to accelerate hydrogen adoption. It examines the primary technical hurdle of material compatibility, focusing on the embrittlement of pipeline steel caused by hydrogen, particularly under high pressure. The text explores the mechanisms of hydrogen uptake and charging, which can induce residual tensile stresses, leading to blistering, cracking, and delamination, even without mechanical loading. The chapter presents a novel experimental technique to assess hydrogen-induced stress in pipeline steel, revealing the impact of hydrogen charging and desorption on the material's stress state. It also delves into the role of hydrogen-induced stresses in strain ageing and the development of hydrogen-induced defects and delamination in pipeline steels. The chapter concludes with a discussion on the implications of these findings for the safe and efficient transport of hydrogen via existing gas pipelines, providing valuable insights for stakeholders in the energy sector.