Reactive Extraction of Nicotinic Acid using Tri-n-Octylphosphine Oxide (TOPO) Dissolved in a Binary Diluent Mixture

摘要

The aim of present work is to intensify the recovery of nicotinic acid from fermentationbroths using reactive extraction. Tri-n-octylphosphine oxide (TOPO) in a diluent mixture ofan active (also called modifier, MIBK) and an inactive (inert, kerosene) diluent (1:1 v/v) isemployed. The effect of acid concentration and TOPO concentration on degree of extractionis determined. TOPO/diluent system favors the formation of 'not overloaded' complexes ofpolar acid-TOPO structures with the Z factors restricted mainly between 0.032 and 0.684.The maximum value of K_D is found to be 4.168 with TOPO (0.365 mol/L) at an acidconcentration of 0.02 mol/L. The mathematical model, based on mass action law, is proposedto estimate the values of partition coefficient (P) and dimerization constant (D) in physicalextraction and equilibrium constants (K_E) and number of reacting extractant molecules peracid molecule in chemical extraction. The model predicted values of KE are showing goodcorrelation with R~2 ＞ 0.98 and maximum value of SD = 0.092.