In-depth analysis of reactive bubbly flow using two-way coupled spatio-temporal 1D model

Abstract

This work aims to investigate reactive bubbly flow using a comprehensive spatio-temporal 1D model. The work of Darmana et al. (2007) who conducted experimental and numerical study on CO2 chemisorption in NaOH solution is used as the reference case. The gas–liquid hydrodynamics are well captured using a drift-flux loop model. During the transient process, bubble diameter db shrinkage from 5.5 mm at the inlet to 3.7 mm at the outlet is captured by the 1D model. The pH evolution is also well predicted by the 1D model provided that appropriate closures are applied, including the recently proposed enhancement factor and reaction pathway by Krauβ & Rzehak (2017). An asymptotic 0D model is proposed to highlight the key parameters involved during the transient chemisorption process which are enhancement factor E, mass transfer coefficient kL, and interfacial area a. Sensitivity analyses on liquid axial dispersion coefficient, enhancement factor and mass transfer coefficient are then performed to elucidate their impact on reactive mass transfer. As the process is controlled by interfacial mass transfer, the most important parameters are kL and db description.