Development and optimization of twin-tower system for continuous post-combustion CO2 capture

The urgent need for large-scale carbon emission mitigation has driven the development of energy-efficient and economically viable CO2 capture technologies. This study presents a novel twin-tower fixed-bed system for continuous post-combustion CO2 capture, combining modular design, automation, and operational simplicity. Activated carbon (AC) was selected for its high surface area, regenerability, and cost-effectiveness. The modular chamber allows multi-layer configurations, enabling performance optimization for different gas mixtures. Key operating parameters, including adsorbent mass, layer configuration, inlet flow rate, and adsorption temperature, were systematically evaluated. Under optimal conditions (20% CO2/80% N2 at 1000 cm3/min, 15 bar, 27 °C), the system achieved an adsorption capacity of 18.71 mmol/g, an outlet CO2 concentration below 4%, and 72% desorbed gas purity. Multi-layer arrangements extended breakthrough time and saturation capacity, while single-layer setups produced higher CO2 purity. Energy consumption was measured at 0.6 kWh kg−1 CO2, outperforming many conventional PSA/VSA systems in simplicity and cost potential. A second-order polynomial model was developed to predict desorbed gas purity and adsorption capacity, providing a framework for industrial scale-up and economic evaluation.