Mass transfer investigation in liquid-liquid two-phase flow in a corrugated millichannel

• Liquid-liquid mass transfer is studied in millireactors and scaled with channel size. • k L a correlations are proposed for each flow regime observed in the millichannels. • A selective extraction system is proposed to prevent mass transfer during sampling. • Flow velocity seems to drive mass transfer regardless of the zigzag channel's size. The present analysis investigates mass transfer phenomena occurring in liquid-liquid two-phase flow within 2D-meandering millichannels of varying dimensions (2, 3, and 4 mm). Enhanced comprehension is facilitated by previous flow visualizations that led to establishing a flow patterns map for these millichannels. The overall mass transfer coefficient (k L a) is experimentally evaluated by measuring the solute concentration transferred between phases, selectively extracted from the organic phase at the reactor outlet. Additionally, to anticipate mass transfer coefficient variations in zigzag channels of various sizes at varying flowrates, aligning with industrial requirements, experimental k L a results are correlated with observed flow regimes. Consequently, operational conditions and fluid system properties enable flow regime identification from the previously established flow map, facilitating corresponding mass transfer correlation identification. This innovative approach integrates flow study and mass transfer analysis within millireactors.