Parameter optimization of the direct air capture (DAC) process to achieve net zero emission targets

Abstract

Direct Air Capture (DAC) technology has gained recognition as an effective method for reducing atmospheric carbon dioxide (CO₂) levels. This study emphasizes the optimization of critical process parameters to improve the efficiency of DAC systems while lowering operational costs. Aspen Plus simulations were employed to model the process flow, pinpoint key reaction mechanisms, and evaluate how different operating conditions influence CO₂ capture efficiency. A sensitivity analysis explored the impact of variables such as air contactor parameters, solvent concentration, temperature, pressure, and moisture content on system performance. The results demonstrated that adjusting the Ca (OH)₂ flow rate to 760 t/h achieves a 75% CO₂ capture rate at the air contactor, while maintaining an inlet air pressure of 1.1 atm enhances absorption. Furthermore, structured packing materials like BX packing outperformed Mellapak 250Y and Mellapak 350Y in efficiency. These insights support the development of economical DAC strategies, advancing technologies for carbon removal to achieve net zero emissions.