Countercurrent Droplet‐flow‐based mini extraction with pulsed feeding and without moving parts

Abstract

A countercurrent arrangement of immiscible liquid‐liquid mini contactors based on droplets is described in this article. Mini mixers without any moving parts were used as the contactors. The single stage mini mixer consists of a top and bottom mixing chamber. Both of the mixing chambers have two recirculating channels on either side. In these mini mixers, a liquid was broken up into droplets that dispersed into other continuously flowing liquid, consequently achieving a mass transfer between the two liquids. To realize the countercurrent arrangement, the two liquids were alternately fed into the system from opposite ends by compressed air according to a periodic program. One period consists of the following stages: organic phase feeding stage, droplet aggregation stage I, aqueous phase feeding stage, and droplet aggregation stage II. This continuous countercurrent arrangement is without the defects of continuous countercurrent arrangements based on laminar flows and multiple‐stage countercurrent arrangements based on droplets. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3685–3698, 2016