Keywords: Liquid-Liquid Extraction Interfaces Enrichment Density Gradient Theory Koningsveld-Kleintjens

Interfacial properties such as interfacial mass transfer are essential for the design and optimization of industrial separation processes. In this work we investigate the interfacial behavior of the two quaternary systems water + toluene + ethanol + acetone and water + toluene + ethanol + tetrahydrofuran and the relation between interfacial enrichment and mass transfer. The Concentration Gradient Theory (CGT) is combined with the Koningsveld-Kleintjens (KK) model to calculate interfacial tension and interfacial concentration profiles. By expanding a recent study of ternary systems with ethanol, acetone or tetrahydrofuran as transferring components we demonstrate that interfacial mass transfer in quaternary systems can be modeled with CGT + KK in good accordance to experimental data by adjusting a single additional binary mobility coefficient. Moreover, the present study indicates a hint on a link between interfacial enrichment and interfacial mass transfer.

Automated summary

Interfacial properties, such as interfacial mass transfer, play a crucial role in the design and optimization of industrial separation processes. This study investigates the interfacial behavior of two quaternary systems and the relationship between interfacial enrichment and mass transfer. By combining the Concentration Gradient Theory (CGT) with the Koningsveld-Kleintjens (KK) model, the interfacial tension and interfacial concentration profiles are calculated. The results show that interfacial mass transfer in quaternary systems can be accurately modeled by adjusting a single additional binary mobility coefficient, and indicate a potential link between interfacial enrichment and interfacial mass transfer.