Underground hydrogen storage:An overview of material damage under the synergistic effect of sulfate reducing bacteria and hydrogen gas

Under the background of "dual-carbon" strategy, with the transformation of energy structure to cleaner and lower carbon, hydrogen energy, as a green and efficient secondary energy carrier, has attracted much attention for its large-scale storage technology. However, the coexistence of high-pressure hydrogen and sulfate-reducing bacteria (SRB) in underground hydrogen storage (UHS) environments leads to synergistic damage from microbial corrosion and hydrogen embrittlement (HE), seriously threatening the structural integrity and safe operation of hydrogen storage facilities. This study first introduces the types of UHS reservoirs and the complex environment where SRB coexist with H₂, and then elaborates on the microbial corrosion mechanism of SRB in depth, focusing on the regulatory role of H₂ in the growth and metabolism of SRB. Then, the failure mechanisms of metallic materials in a high-pressure, pure hydrogen environment are summarized, including HE, hydrogen-induced cracking (HIC) and hydrogen blister (HB). The interaction mechanism between SRB biofilms/corrosion product films and hydrogen permeation behavior is analyzed, especially in an UHS environment. Based on the existing research, three research perspectives on the mechanism of multi-physical field coupled hydrogen damage, SRB-H₂ synergistic mechanism, and HE protection measures are proposed to ensure the safe operation of UHS facilities.