STORAGE AND RECOVERY OF HYDROGEN IN NON-SALT BEARING STRATA FOR FLEXIBLE-FUEL POWER GENERATION

Salt caverns have been used for hydrogen storage by the chemical and refining sectors in the United States since the 1980s. Salt deposits suitable for hydrogen storage are not widely distributed across the North America continent. The Illinois State Geological Survey (ISGS) along with the Gas Technology Institute (GTI) are developing a concept design for hydrogen storage in a saline reservoir to augment deliverability to a flexible-fuel gas turbine providing power to a local electrical grid. Assessment of the saline aquifer involves both static exocellular models as well as dynamic simulations of reservoir performance. This includes identification of potential strata for storage (reservoir properties, fluid composition, reservoir pressures); identification of strata to be used as barriers/baffles (caprock analysis including leakage potential/rate); preliminary estimates of hydrogen losses via diffusion, dissolution, potential chemical/microbial interactions and storage volume estimates.

In the preliminary concept/design phase, a regional sandstone brine aquifer present across the central and northern Illinois basin was characterized for storage. Specific attention was given to working gas performance under short-duration cycles, cushion gas influence on water production, and hydrogen mobility in both lateral and vertical directions. In addition, the impact of subsurface well design on gas saturations for extended injection/withdrawal cycles was investigated. Vertical heterogeneous reservoir and containment intervals using relative permeability data allowed examination of sealing capacity. Results were integrated into this demonstration project to test viability of commercial-scale implementation.