Growing interest in ammonia as a carbon-free hydrogen carrier has heightened the need for safe, economical, and efficient long-distance transport solutions. Leveraging its high volumetric hydrogen density and mature industrial infrastructure, liquid ammonia (LNH3) pipelines offer a promising alternative to gaseous or liquid hydrogen networks. This review synthesizes opportunities and challenges in deploying large-scale LNH3 pipeline systems. Safety aspects are examined through mechanistic analysis of flash boiling, aerosol generation, and dense-gas dispersion, with emphasis on complex terrain effects and limitations of conventional and CFD-based consequence models. Long-term integrity considerations focus on ammonia-induced stress corrosion cracking in carbon steels and impurity-dependent threshold behavior. Global operational experiences and regulatory frameworks are assessed, alongside prospects for repurposing existing hydrocarbon pipelines for ammonia service. Findings highlight the need for ammonia-specific standards, advanced multiphysics risk prediction, and impurity–SCC interaction studies to enable safe, cost-effective integration of ammonia pipelines into future hydrogen energy networks.
Source: https://www.sciencedirect.com/science/article/abs/pii/S0360319926031319
