Hydrogen Blending in Natural Gas: Technologies and Challenges

Abstract

Abstract In this paper, a comprehensive review of the technologies and challenges associated with hydrogen-blended natural gas (HBNG) systems is provided. The background, hydrogen production pathways, blending technologies, and implementation strategies of HBNG were systematically reviewed, while the effects of hydrogen addition on gas properties, pipeline transportation systems, and end-use applications were critically examined. The results indicate that HBNG technologies are gradually evolving from low-concentration feasibility studies toward high-hydrogen-ratio applications. At elevated hydrogen blending levels, major technical challenges include hydrogen embrittlement of pipeline materials, leakage and explosion risks, combustion stability control, and determination of hydrogen blending ratios. Besides, high hydrogen production costs, infrastructure retrofitting requirements, and the lack of harmonized international standards continue to hinder large-scale deployment. Therefore, future implementation of HBNG technologies will require breakthroughs in material durability, technical standardization, accurate hydrogen concentration control, and end-use system adaptability, thereby providing important support for the transition toward low-carbon and sustainable energy systems.