Extraction Equilibria of Pyruvic Acid Using Tri-n-butyl Phosphate: Influence of Diluents

Abstract

Pyruvic acid is extensively utilized in the chemical, pharmaceutical, and agrochemical industries. Novel biotechnological routes to pyruvic acid production receiving great attention and recent focus of research are toward its separation from fermentation broth or recovery from waste streams. Based on reversible complexation, extraction equilibria of the system (water + pyruvic acid + extractant/diluents) were measured at T = 308.2 K using various concentrations of pyruvic acid (0.1 kmol·m–3 to 0.5 kmol·m–3) and extractant (tri-n-butyl phosphate, TBP) (0.36 kmol·m–3 to 2.56 kmol·m–3) in different diluents (n-heptane, toluene, and methyl-iso-butyl ketone, MIBK). Different physiochemical properties such as dipole moment and E T parameter have been used for comparison. Results are given in terms of various parameters such as distribution coefficient, equilibrium complexation constant, loading ratio and extraction efficiency. Using expressions derived for extraction equilibria, equilibrium complexation constants (K E) were evaluated to be 0.369 m3·kmol–1, 0.482 m3·kmol–1, and 0.578 m3·kmol–1 for n-heptane, toluene, and MIBK, respectively, whereas solvation number of TBP (m) was estimated to be one for all the three diluents. Only (1:1) complex was proposed for all the three diluents with no overloading (Z < 0.5) in any case. Higher chemical extraction was observed in inactive diluents: n-heptane and toluene.

Recent Progress in the Microbial Production of Pyruvic Acid

“…Recent studies have also considered mixing phosphate extractants with amine extractants in decanol, resulting in >98% pyruvate recovery [96]. Extraction equilibria for TBP with several diluents suggest that n-heptane and toluene provide the greatest extraction [97]. Most systems show that the pyruvate and extractant react with a 1:1 molar ratio.…”

Reactive Extraction of Citric Acid Using Different Extractants: Equilibrium, Kinetics and Modeling

“…Recently, reactive extraction has emerged as more economic and convenient over other recovery techniques. [5][6][7] It is especially suited when the product to be recovered is inhibitory and concentration is less than 10 wt %. 5,6 It matches the conditions in a fermentation broth and thus this promising technology has been widely adopted for carboxylic acid recovery.…”

“…Secondly, there are phosphorus-bonded oxygen donor extractants, such as tri-n-butyl phosphate (TBP), trioctyl phosphine oxide (TOPO), etc., and third category com-prises of high molecular weight aliphatic amine extractants, such as tri-n-octyl amine (TOA), Aliquat 336 (A336), etc. [5][6][7][8][9] As these extractants are costly as well as viscous, they are often employed after dilution in some conventional solvent (diluent). The diluent provides the desired solvation media to the extractant by tuning its desired physicochemical properties.…”

“…Doubtlessly, active diluents provide a better solvation media to the carboxylic acid, and hence show greater efficiency. 5 Although studies on reactive extraction of various carboxylic acid are abundant in literature, the same for complete extraction study (equilibrium, kinetics and modeling) for citric acid are limited, a handful of research work can be found in the literature including equilibrium [5][6][7][8][9][10][11][12] and kinetic studies [12][13] of citric acid extraction. Bizek et al 9 were the first to study the physical and reactive extraction equilibria of citric acid in different diluent and trialkyamine as an extractant.…”

Liquid-liquid extraction equilibrium for pyruvic acid recovery: experimental data and modeling

“…However, reported extraction studies on pyruvic acid are limited (Ma et al, 2005;Senol, 2006;Marti et al, 2011;Pal and Keshav, 2014;. Marti et al (2011) have reported an equilibrium study of physical extraction of pyruvic acid with alcohols as solvents and found a higher distribution coefficient (K D =0.30) with 1-octanol over oleyl alcohol.…”