Geometric factors affecting CO₂ separation in a supersonic separator

The current work evaluates a potential carbon separation approach with swirl flows and spontaneous condensation. Euler-Euler model is established to depict the spontaneous condensation. By combining Euler-Lagrange model and Euler-Euler model, the droplet motion behavior is predicted, and the influence of separator structure including swirl generator and gap length on the separation efficiency of CO₂ is quantified. The flue gas expands under pressure to create a non-equilibrium system, which leads to the emergence of CO₂ condensation nuclei. On the surface of nuclei, metastable molecules aggregate and promote the growth of CO₂ droplets. Based on the force on droplets, the droplet behavior can be separated into three categories: impacting the straight tube wall, entering the collector and entering the diffuser. When the angle of swirl generator and gap length rises by 315° and 3.75 mm respectively, the separation efficiency rises by 60.3 % and 48.6 %, respectively.