Microfluidic solvent extraction of Ce (III) and Pr (III) from a chloride solution using EHEHPA (P507) in a serpentine microreactor

Extractive and separation of Pr/Ce using a Y-junction serpentine microreactor, with 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (EHEHPA, P507), has been investigated. The results clearly indicate separation factor of Pr/Ce (> 3) is to be higher in the microfluidic extraction as compared to separation factor of around 2 to 3 for batch systems. The optimized residence time of 12 s in micro-flow is much less than that in batch system (≅ 300 s). The extraction rates for Pr and Ce are found to match first order kinetics with the rate constants being 0.2649 s^{− 1} and 0.2279 s^{− 1}, respectively, which are > 20 times higher than those for batch extraction. The volumetric mass transfer coefficients (K_La) for various operating conditions vary between 0.007 and 0.57 s^{− 1}, which decrease with increase in channel size (channel width and length). The experimentally mass transfer coefficients are compared with those with conventional extractors such as mixer settler and centrifugal extractors.