Intercomparison of numerical simulation models for hydrogen storage in porous media using different codes

•Five codes compared for hydrogen behavior on four scenarios.•Transport processes examined, but not reaction or geomechanics.•Substantial agreement found between results predicted from different simulators.•Differences due to the treatment of fluid properties and discretization approaches.•Code intercomparison builds confidence in use of simulation models for H2 storage. Large-scale subsurface hydrogen storage in porous formations may play a crucial role in the future energy system. While numerical simulation has been used to assess hydrogen storage, simulators have not been proven to be reliable and accurate by a systematic and detailed code comparison. The hypothesis of this work is that codes will perform similarly with results within 5%. In this study, five numerical simulators were used to simulate a suite of test problems of increasing complexity applicable to subsurface hydrogen storage in porous formations. Intercomparison of results showed a good quantitative agreement of predicted molar fractions, saturations or phase pressures, with only subtle differences arising due to the details of fluid properties and numerical discretization approaches. This intercomparison analysis thereby builds confidence in numerical simulation for subsurface hydrogen storage and provides a basis for more complex scenarios including geomechanical or geochemical effects.