Mass, energy and economic analysis of supersonic CO₂ separation for carbon capture, utilization and storage (CCUS)

Accelerating global population growth and civilizational progress exacerbate energy demand, and global pressures involving decarbonization, energy poverty and fuel depletion force carbon-intensive countries to highlight carbon-negative carbon capture, utilization and storage (CCUS) technologies. As an emerging CCUS technology, its global applications hold great promise. However, the feasibility and prospects of supersonic CO₂ capture technology remain unclear, particularly regarding energy utilization. To this end, the entropy transport equation was innovatively introduced into the Euler-Euler-Euler real gas numerical model in the present study. The created model was utilized for simulating carbon capture in the CH₄-CO₂ system. To validate the accuracy of the developed model, a CO₂ condensation experiment and a supersonic separator experiment were used. Further, a series of simulations were conducted to investigate and quantify the mass and heat transfer for the CO₂ separation process in a supersonic separator. The results show that an inlet heterogeneous droplet mass concentration between 5 kg/m³ and 7.5 kg/m³ was expected to separate the most CO₂ mass and require the least energy. In addition, this study also investigated the economic parameters of different separation technologies and compared supersonic separation technology with other methods. In the future, major challenges in researching supersonic CO₂ capture technology will be to obtain ample experimental and simulation data, and to calculate the optimal structures and operating conditions.