Experimental investigation on dispersed phase holdup in an L-shape pulsed packed extraction column

Abstract

In this study, the dispersed phase hold-up has been investigated in a pilot plant of a new type of extraction column entitled “L-shaped pulsed packed extraction column” by using two liquid systems of toluene/acetone/water and n-butyl/acetone/water in the presence of mass transfer in two directions. The effects of operational variables, physical properties and mass transfer direction have been considered on the dispersed phase hold-up. It is found that the dispersed phase hold-up is significantly affected by the pulsation intensity, dispersed phase flow rate and interfacial tension of liquid system. However, the continuous phase flow rate and mass transfer direction have a weaker impact. Furthermore, it is observed that the behavior of hold-up in the horizontal and vertical sections of the used column is distinctive in some case. Such that any factor which reduces the dispersed drop size, leads to an increase in hold-up in the vertical section of the column and a decrease in hold-up in the horizontal section of the column. Finally, new correlation is proposed to accurately predict the dispersed phase hold-up. Good agreement between predictions and experiments was found for all operating conditions, chemical systems and mass transfer direction that were investigated.