Numerical modeling for characterization of CO2 bubble formation through submerged orifice in ionic liquids

Abstract

Industrial applications of Ionic liquids (ILs) in CO2 capture are still limited due to lack of research on CO2-ILs bubble dynamics. A CFD model was developed to understand CO2 bubble formation in the pool of ILs by coupling improved VOF (Volume of Fluid) method with FW–H (Ffowcs Williams and Hawkings) acoustic formulation. Conventional VOF method was improved by adding suitable drag force for CO2-ILs interaction and ILs viscosity was considered as a variable with dissolved CO2. The predicted results are in good agreement with experimental measurements. Based on current CFD model, distinct acoustics pressure signals were examined to characterize CO2 bubble formation stages (growth, necking, detachment). It was investigated that bubble diameter and detachment time were increased with increasing of orifice diameter. Moreover, effects of gas and ILs inlet velocities were explained by fluctuations in Reynolds number and acoustic pressure signals respectively. Higher dissolved CO2 quantity and earlier bubble detachment time were obtained in aqueous ILs than pure ILs. The results have potential to give some useful guidelines to design industrial gas distributor (multiple-holes) for CO2-ILs system.