Enhanced CO2/N2 separation via optimized temperature/vacuum swing adsorption (TVSA) Processes: Experimental and simulation studies

Abstract

The idling of equipment caused by prolonged cooling times is a significant challenge impeding the upscaling application of temperature vacuum swing adsorption (TVSA) for carbon dioxide (CO₂) capture from industrial flue gas. Increasing the adsorption temperature is a promising approach to reducing cooling times, mitigating equipment idling, and improving operational efficiency. However, maintaining CO₂ purity and recovery rates at elevated adsorption temperatures remains unexplored. Through experimental and simulation studies, this work systematically optimized the operation parameters of a pilot-scale two-bed eight-step TVSA system to ensure its feasibility at a high adsorption temperature 343 K, a temperature that is 40 K higher than the optimal operation temperature of 13X-APG adsorbent and can warrant the continuous operation of the TVSA process. After optimization, CO₂ purity of 95.08 % and recovery of 91.84 % were achieved under the conditions of an adsorption time of 380 s, an adsorption temperature of 343 K, a regeneration temperature of 393 K, a regeneration pressure of 11 kPa, and a purge gas flow rate of 0.083 m/s, which is comparable to the performance of low-temperature TVSA process. The effects of key operating parameters such as feed time (260–360 s), adsorption temperature (343–363 K), desorption temperature (383–403 K), vacuum (7–12 kPa) and purge gas flow rate (0–0.166 m/s) on the process performance were systematically examined. By resolving the issue of equipment idling, this study extends the practical applicability of the TVSA process in industrial scenarios.