Differential Evolution Approach for Reactive Extraction of Propionic Acid Using Tri-n-Butyl Phosphate (TBP) in Kerosene and 1-Decanol

Abstract

Reactive extraction is found to be an efficient, economical, and environmental friendly method for recovery of acids from fermentation broths. In this study, the reactive extraction of propionic acid is carried out using tri-n-butylphosphate (TBP) dissolved in kerosene and 1-decanol (modifier). The results of equilibrium studies indicate that the extraction efficiency increases with an increase in 1-decanol concentration and TBP composition, but decreases with an increase in initial acid concentration. The degree of extraction, distribution coefficient, and loading factors are calculated. The stoichiometry of reactive extraction for the formation acid: TBP complexes and equilibrium constants (K E ) are estimated through chemodel. using conventional method (graphical) and an optimization procedure (differential evolution algorithm). The results of model show 1:1 complexes between acid and TBP in most of the cases. The equilibrium extraction constant (K E1) for 1:1 complex of propionic acid and TBP at 298 K is found to be 2.37. The effect of temperature on recovery of propionic acid with this extraction system is also derived and found to decrease with an increase in temperature (298–334 K). The results of this study are useful to intensify the microbial production of carboxylic acids using renewable sources.