Underground hydrogen storage (UHS) in depleted gas reservoirs is an effective strategy for balancing renewable energy supply and demand, with cushion gases being used to maintain storage pressure. Here CO 2 is investigated as a cushion gas via measurements of the dispersion between hydrogen and CO 2 in a (Bentheimer sandstone) rock core, performed at reservoir-relevant conditions using a novel core flooding apparatus. Such dat...

The atmospheric partial pressure of CO 2 ( p CO 2 ) has been increasing dramatically since the beginning of the industrial revolution and about 30% of the CO 2 produced by anthropogenic activities was absorbed by the ocean. This led to a perturbation of the seawater carbonate chemistry resulting in a decrease of the average surface ocean pH by 0.1 and termed ocean acidification (OA). Projections suggest that p CO 2 may reach 9...