Process optimization of reactive extraction of clorprenaline enantiomers by experiment and simulation

Abstract

This paper studied the process optimization of reactive extraction of clorprenaline enantiomers (CP) by experiment and simulation. An efficient extraction system was obtained through single stage extraction experiments, where boric acid (BA) in aqueous phase and D-isobutyl tartrate (DT) in organic phase were selected as extractant and 1,2-dichlorethane was selected as organic solvent. The best enantioselectivity (α) with 2.012 was obtained. The extraction mechanism was proposed and thermodynamic constants such as physical partition coefficient and reactive equilibrium constants were obtained. Based on single stage extraction, phase and reactive equilibrium as well as the law of mass conservation, a model describing the fractional extraction process was acquired. The process of symmetrical separation of CP was optimized by the model. The optimal conditions including flow rate ratio (O/W) of 1.5, pH of 5.0, CH3COONa/CH3COOH solution of 0.1 mol/L, clorprenaline concentration of 5 mmol/L, BA concentration of 0.10 mol/L and DT concentration of 0.075 mol/L were obtained. Under this case, equal enantiomeric excess (eeeq) could reach up to 67% by 10 stages. The simulated results revealed that the minimum series for eeeq > 97% and eeeq > 99% were 26 and 33, respectively. The results will provide guides for scale up and design.