Optimization of semi‐pulsatile liquid‐liquid extraction operations in milli‐channels

Abstract

The work in this manuscript presents liquid‐liquid extraction augmentation and optimization due to flow pulsations on a continuous flow. The mass transfer is achieved via a transfer species (acetic acid) that diffuses in the aqueous phase (water), which is in a continuous flow, from the organic phase (toluene), exhibiting pulsed flow pattern. It is observed through experiments that the incorporation of pulsation leads to enhanced extraction/mass transfer compared to continuous flows. Also, an increase of the pulsation parameters, such as amplitude and frequency, increases the mass transfer, but when the process is evaluated in terms of economy, it is found that the rate of extraction per unit power is maximum for moderate frequencies and amplitudes. Based on the experiments, a Linton and Sherwood‐like correlation for determining extracted concentration at the exit of the test section in semi‐pulsatile flow conditions is proposed. During the course of experiments, it is found that the flow pattern changes from dispersed‐type flow pattern of the organic phase to slug and then slug dispersed with an increase of superficial velocity of toluene, at a particular superficial velocity of the water. Also, the total power consumed during the extraction process increases with an increase in the product of amplitude and frequency. With the experimental approach presented in this paper, one will be able to optimize semi‐pulsatile liquid‐liquid mass transfer operations.

Process intensification in Desalination operation in mesoscale systems

“…figures 2,3. From the plot it can be interpreted that increasing flow amplitude, a, and frequency, results in higher flow rate which in turn results in rise in shear rate leading to increased concentration of salt extracted in the solvent [37], [40].…”