An intermediate heat-transfer-enabled thermal management strategy for temperature–pressure swing adsorption compressed CO₂ energy storage

Adsorption-based compressed CO₂ energy storage offers high low-pressure-side storage density but remains limited by adsorption-regulation flexibility and thermal coupling. This study proposes a temperature–pressure swing adsorption compressed CO₂ energy storage (TPSA-CCES) system incorporating a pressurized-water intermediate heat-transfer loop. Pressure and temperature swings jointly regulate adsorption and regeneration, while the intermediate loop redistributes compression and adsorption heat between charging and discharging processes. A thermo-economic model integrating energy, exergy, and capital-cost analyses is developed. Under the design conditions, the system achieves an electrical round-trip efficiency of 69.32%, an exergy efficiency of 38.56%, an energy storage density of 4.54 kWh/m 3 , and an investment cost per unit power of 675.75 $/kW. Sensitivity analysis shows that increasing the heat-transfer-medium pressure to approximately 1.5 MPa improves thermal matching, whereas further pressurization provides limited benefit; a smaller pinch-point temperature difference favors thermodynamic performance. Coupled temperature and pressure analyses reveal clear trade-offs among electrical efficiency, storage density, exergy utilization, and capital intensity. Lower adsorption temperature and higher desorption temperature generally improve electrical and volumetric performance, while a larger adsorption–desorption pressure swing enhances adsorption working capacity but may reduce power-conversion efficiency. These results demonstrate the importance of coordinated thermal management and adsorption regulation in TPSA-CCES design.