PNNL

Abstract

Carbon dioxide capture via solvent based absorption in a packed column is being recognized as an efficient technology for the decarbonization process of point source. Significant efforts are being made to improve the design of packings with the novel 3D printing technique for efficient carbon capture. Multiphase flow studies for countercurrent flows in novel 3D printed columns with different designs of triply periodic minimal surface (TPMS) are a challenging problem. The volume of fluid (VOF) method is used to extensively investigate the effects of solvent properties, liquid load, and gas load on the hydrodynamics of TPMS columns, such as interfacial area, liquid holdup, pressure drop, flooding, etc. The solvents include potential water-lean solvents (EEMPA) as well as the commercially used aqueous monoethanolamine (MEA) solvent for carbon capture. The interfacial area and liquid holdup increase with increasing liquid loads (q_L) for all TPMS columns included. Schwarz column consistently shows the highest liquid holdup value. The EEMPA exhibits higher values for the interfacial area and liquid holdup in comparison to the MEA. At all gas loads, TPMS columns exhibit the intermediate pressure drop between the random and the structure packed columns. Moreover, out of all the TPMS columns, gyroid packing exhibits the lowest pressure decrease. The gas load has little impact on the interfacial area at lower value while a higher gas load leads to column flooding. Before the flooding regime, the interfacial area for Schwarz packing is insensitive to gas load, while it rises for the other TPMS packings with gas loads. However, liquid holdup and wet pressure drop rise as gas load increases in all included columns. Moreover, Fisher Koch packing is more susceptible to flood as compared to other TPMS packings. With rigorous simulations, loading and flooding regimes are delineated and further compared in these packings.