A review on hydrogen blending in gas network: Insight into safety, corrosion, embrittlement, coatings and liners, and bibliometric analysis

Climate change is the most pressing challenge faced today. Carbon emissions from industry, transport and other forms of energy continue to threaten the future. Industrialised countries are desperately considering running carbon-neutral goals by 2050. Among the strategies under consideration, integrating hydrogen into natural gas streams, known as hydrogen blending with natural gas, has achieved substantial attention from academia, industry, and governmental bodies. This article thoroughly explores the potential of decarbonisation by integrating hydrogen into natural gas networks. It aims to provide valuable insights by addressing challenges, opportunities, and crucial factors influencing hydrogen-natural gas (H₂-NG) blends in gas distribution systems. The article covers safety considerations across hydrogen's entire lifecycle, including production, transportation, storage, and utilisation. It also delves into the complex issue of pipeline corrosion, highlighting its significance for structural integrity when dealing with H₂-NG blends. Furthermore, the article significantly focuses on hydrogen embrittlement (HE), discussing classifications, mechanisms, consequences, and mitigation strategies within blended gas networks. It also explores developments in pipeline coatings, evaluating their compatibility and efficacy in mitigating HE and corrosion within H₂-NG blends. Finally, the study employs bibliometric analysis to guide researchers by drawing insights from existing literature and identifying potential avenues for future progress in H₂-NG blending. By addressing the multifaceted aspects of decarbonisation through H₂-NG blending, this article aims to contribute to the ongoing dialogue on sustainable energy strategies.