The global shift towards cleaner energy has accelerated the application of hydrogen as a clean fuel. Retrofitting and reusing existing natural gas (NG) pipeline infrastructure is a cost-effective way to enable bulk deployment of hydrogen. This study investigates the technical feasibility of retrofitting and rehabilitating NG pipelines for hydrogen transport. Material compatibility, especially hydrogen embrittlement, fatigue resistance, and permeability in steel pipes and weld joints, is examined in the analysis. Retrofitting approaches such as internal coatings, flow regulation, and pipeline pressure adjustments are reviewed in the context of current engineering standards. Structural integrity assessments, using established codes, are conducted to evaluate post-retrofit performance and safety. This is a literature-based technical assessment using existing codes and standards, such as CSA Z662 and ASME B31.12, combined with industry case studies and experimental insights to evaluate the readiness of legacy pipelines for hydrogen service. This paper provides a foundational framework for assessing the safe reuse of legacy pipeline systems for pure or blended hydrogen transport. It sets the stage for further techno-economic analysis in future research.
Khaing et al. (Tue,) studied this question.