Performance Analysis of an Adsorption-Based CO2 Reservoir for Compressed CO2 Energy Storage: Experiments and Dynamic Modeling

Temporary CO2 storage is gaining interest for applications requiring compact storage at moderate pressures, where the low volumetric density of gaseous CO2 limits storage capacity without high-pressure compression. Adsorption in porous materials offers a potential means of increasing storage density, although tank-scale studies remain scarce. This work experimentally and numerically investigated adsorption-based CO2 storage using a 17 L tank containing 6 kg of coconut shell activated carbon over a 1–10 bar charge–dormancy–discharge sequence. Experimental measurements of the CO2 mass flow rate, pressure, and temperature were used to calibrate a lumped-parameter dynamic model that can be integrated into system-level simulations. The activated carbon increased the volumetric storage capacity compared with an empty tank, with deliverable storage enhancement factors between 4 and 8 depending on the discharge conditions. Heat exchange with the atmosphere during charging and discharging had only a minor influence, while cooling during dormancy reduced the recoverable working capacity. Compared with isothermal operation, the working capacity decreased by approximately 35% under adiabatic conditions, with an additional 37% reduction when heat exchange with the surroundings was included, highlighting the importance of limiting heat losses during storage. These findings highlight the potential of adsorption as a strategy for temporary CO2 storage.