Paper Title
Recovery of Propanoic Acid by Extractive Fermentation using Tri-N-Butyl Phosphate in Nheptane

Abstract
Propanoic acid is used mainly for the food preservation and also in pharmaceutical, cosmetics and plastic industries. Extractive fermentation enable reactor productivity and easy recovery of the fermentation product in single step and also reduces further processing load and recovery cost. Results of investigations into reactive extraction of propanoic acid from an aqueous solution using tri-n-butyl phosphate (TBP) as an extractant in n-heptane as diluents have been reported. The effect of initial propanoic acid (0.03–0.20 kmol.m−3), and TBP (1.099–2.564 kmol.m−3) concentrations on reactive extraction efficiency was investigated in batch mode. This study confirmed that the reactive extraction using TBP and n-heptane is an efficient method of propanoic acid recovery. Reactive extraction efficiency increases with an increase in initial propanoic acid and TBP concentration. (1:1) acid-extractant complexe was reported for the studied concentration range of initial acid and extractant. Reactive extraction of propanoic acid conducted in batch mode results in 85 % extraction efficiency. Keywords - Propanoic acid, Reactive extraction, Equilibrium, Extractive Fermentation.