Preliminary evaluation of hydrogen blending into high-pressure natural gas pipelines through hydraulic analysis

As a significant measure toward decarbonization, the use of hydrogen as an energy carrier plays a vital role. Based on the supply plan of South Korea, by 2050, 80% of its total hydrogen consumption will be accounted for by imports; therefore, utilization of Natural Gas (NG) infrastructures for hydrogen storage and supply is under consideration. However, since hydrogen blending may violate the operating conditions of the pipeline, it is necessary to evaluate the impact on infrastructures using numerical analysis before implementation. To this end, the feasibility and effect of hydrogen blending into high-pressure NG pipelines in South Korea are evaluated up to the level of pure hydrogen utilization. The numerical method solves the Euler equation, species transport, and GERG-2008. The primary concerns of preliminary evaluation are: (i) hydrogen transport capacity, (ii) pressure drop, and (iii) erosional velocity. The preliminary evaluation reveals that a volumetric fraction of hydrogen below 20% requires no expansion of infrastructures or modification of operation strategy. Nevertheless, an increase in the correlation between pressure drop and the fraction of hydrogen is a matter of concern with a higher fraction of hydrogen. Consequently, this study lays the cornerstone of a plan for repurposing NG infrastructures for hydrogen utilization.