Study on mass transfer in reactive liquid-liquid systems

Abstract

This work examines the mass transfer in reactive liquid-liquid systems applying the dynamic concentration gradient theory (CGT). The CGT is based on a square gradient approach delivering an expression for the Gibbs energy of an inhomogeneous system as basis for the mass transfer in a two-phase system. For this work, the CGT was combined for the first time with a reaction kinetics model to model the reactive mass transfer. The model was validated by experiments. As model reaction the reversible diacetone alcohol formation in a water-toluene system was chosen. To parameterize the Gibbs excess energy model, phase equilibria were measured and furthermore, the predictive power of the model to calculate interfacial tension in equilibrium was also checked by own experiments. To analyze the mass transfer in liquid-liquid systems the model prediction was compared to experimental data from Nitsch-cell experiments. It was found that the model predictions are in excellent agreement to the forward reaction predictions as well as to the backward reaction.