The effect of hydrogen odorisation with mercaptans on hydrogen uptake in L360NB pipeline steel: An experimental study

• L360 pipeline and welded material do not fail by HE at 120 bar H 2 under 120% YS. • The addition of 1 bar H 2 S, 5% NaCl brine and odorant also causes no failure. • The welded material shows a higher hydrogen uptake than the base pipeline material. • The mercaptan odorants do not contribute remarkably to the hydrogen uptake. As a result of the expansion of hydrogen usage, hydrogen odorising draws great interest. In this research, the influence of odorising hydrogen gas with mercaptans based on t-butyl mercaptan (TBM) on the hydrogen uptake in pipelines is studied for the first time. A section of L360 natural gas pipeline with a circumferential weld is sampled from an existing natural gas grid to assess the applicability for pure hydrogen transport. At 120 bar dry hydrogen and 120 bar hydrogen + 5% NaCl brine with and without 1 bar H 2 S, Constant Load Tests (CLTs) were conducted on both the weld and base materials under stresses of 0 and 1.2 × yield strength. No macroscopic or microscopic failures were observed in the tested specimens under the applied stress conditions. In addition, the presence of the odorant did not significantly affect hydrogen uptake.