Extraction with Chemical Reaction through the Plane Liquid-Liquid Interface

Effect of interfacial turbulence on extraction Rate

Abstract

Extraction of an organic acid in an organic solvent by the aqueous solution of caustic soda through the plane interface has been studied. MIBK and isobutanol were used as the organic solvents. The extraction rate, N_A, increased with the initial alkali concentration, C_B0, up to maximum N_A, where C_B0 became nearly equal to the initial concentration of the acid, G_A0. Then N_A decreased with C_B0 and became constant when C_B0 was more than twice G_A0.
These results may be explained as follows. The extraction rate is enhanced by the effect of the reaction in the range of C_B0 below C_A0. When C_B0 is higher than C_B0 the reducing effect by the depression of the interfacial turbulence on the extraction rate overcomes the enhancement effect of the reaction. Then the reaction takes place at the interface and the extraction rate becomes constant.
A simple diffusion-mixing zone model was proposed. The effect of interfacial turbulence on the extraction rate was discussed on the basis of the model. As a result, N_A calculated from the model was in good agreement with the experimental one.