Flooding behavior of the standard liquid–liquid extraction systems in a pilot plant L-type pulse packed extraction column: Experimental study

In this study, the two-phase pressure drop and flooding velocity were investigated in a pilot plant of a new type of extraction column entitled "L-shaped pulsed packed extraction column" using two liquid-liquid systems of butyl acetate-water and toluene-water in the presence of acetone as the mass transfer agent. The effects of operating variables, physical properties, and the presence of mass transfer on the flooding flowrate and pressure drop were considered. It is found that the pressure drop is strongly influenced not only by the flow rates of the continuous and dispersed phases, but also by the pulsation intensity. That is, increasing the values of these parameters increases the shear stresses and the flooding phenomenon to occur sooner. Surprisingly, it is observed that increasing the pulsation intensity and dispersed phase flow rate reduces the maximum throughput of the column but increasing the continuous phase flow rate enhances that. Furthermore, it is achieved that the interfacial tension is a physical property which has significant impact on the flooding and the presence of mass transfer only affect at the low pulsation intensity. Finally, a new correlation is proposed to accurately predict the flooding velocity. Good adaptation between predictions and experiments was found for all investigated operational conditions, chemical systems, and with and without mass transfer.