Abstract:In order to achieve the goals of carbon neutrality and emission peak and to solve the problem of large-scale storage of hydrogen, combined with the trends of hydrogen development in China, a “production-storage-use” integrated hydrogen chain was proposed. Scenario one is the current phase of hydrogen development, during which the salt cavern hydrogen storage is mainly for transportation and industry fields. In scenario two, salt cavern hydrogen storage and CO₂–O₂ mixed gas respectively, while the hydrogen is used for ground synthesis of methane as well as methane-enriched combustion for power generation. In scenario three, salt cavern stores synthetic methane for other purposes besides power generation. From the perspective of the full life cycle of salt cavern hydrogen storage, the role of salt cavern hydrogen storage under three scenarios was analyzed, and a new concept of multifunctional hydrogen storage was proposed. The multifunction of salt cavern is waste electricity utilization, power balance, safe storage of hydrogen and CO₂ emission reduction. Taking Anning salt mine and Yunnan Province as examples, the potential of multifunctional salt cavern hydrogen storage was analyzed. In scenario one, for steelmaking, which needs 1.3×10⁸ m³ of total gas volume storing 6.0×10⁵ t of green hydrogen and reducing CO₂ emission of 722 t. In scenario two, in view of the seasonal power shortage in the future of Yunnan, installing a capacity of 200 MW methane-enriched power plant providing a half-year power generation plant just needs 4.78×10⁶ m³ of multifunctional salt caverns, which can absorb 5.34×10⁸ kW·h of hydropower and provide 2.88 ×10⁸ kW·h of power generation in dry season.