Scalability of mass transfer in Taylor flow in capillaries

Abstract In the present work, gas–liquid hydrodynamics and mass transfer in horizontal circular capillaries of different diameters are investigated experimentally. The capillary diameters range from 0.5 to 3.2 mm in order to investigate the mass transfer process on both micro and milli scale. The mass transfer is studied using the chemical absorption of CO2 into an alkaline solution. A high speed camera is used to capture images of the flow. Subsequently, the images are analysed thought a specifically developed Matlab code. Such a code is able to extract important hydrodynamic parameters (bubble length, liquid slug length, void fraction, film thickness, bubble velocity etc.) that affect the mass transfer coefficient, kLa. The obtained results both for the hydrodynamics of the flow and for the mass transfer are compared with those present in literature, and the scalability of the mass transfer coefficient is assessed