Kinetic study on reactive extraction for chiral separation of phenylsuccinic acid enantiomers

Abstract

The kinetics of the extraction of phenylsuccinic acid (PSA) enantiomers by hydroxypropyl--cyclodextrin (HP--CD) in a modified Lewis cell was studied, in which HP--CD dissolved in 0.1 mol L 1 NaH 2 PO 4 /H 3 PO 4 buffer solution (pH = 2.5) was selected as the chiral extractant. PSA enantiomers were extracted from organic phase to aqueous phase in the extraction module. The theory of extraction accompanied by a chemical reaction has been used to obtain the intrinsic kinetics of this extraction module. The different parameters affecting the extraction rate such as agitation speed, interfacial area, initial concentration of PSA enantiomers in organic phase as well as HP--CD concentration in aqueous phase were separately studied. The experimental results demonstrate that the extraction reactions are fast. The reactions were found to be first order with respect to PSA and second order with respect to HP--CD with forward rate constants of 3.4 × 10 2 m 6 mol 2 s 1 for R-PSA and 9.96 × 10 3 m 6 mol 2 s 1 for S-PSA. These data will be useful in the design of extraction processes.

Modeling of kinetics of a microfluidic reaction–extraction process for the preparation of KH 2 PO 4

“…Four regimes have been identified depending on the value of a dimensionless parameter, Hatta number [30,31], which is represented by for a reaction of mth-order in the solute A, and nth-order in the extractant B. There is no effect of mass transfer on the extraction rate when Ha number is less than 0.3 in Regime 1 (for a very slow reaction in the bulk phase) or larger than 3 in Regime 3 (for a fast reaction at the liquid-liquid interface).…”