Extraction of Propionic Acid Using Different Extractants (Tri-n-butylphosphate, Tri-n-octylamine, and Aliquat 336)

Abstract

Reactive extraction of propionic acid from aqueous solution containing 0.05 to 0.4 kmol/m3 acid using tri-n-butylphosphate (TBP) (organophosphorous compound), tri-n-octylamine (TOA) (tertiary amine), and Aliquat 336 (quaternary amine) as extractants in 1-octanol was studied. The comparison among the different categories of extractants was made. The order of extraction power was found to be TOA > Aliquat 336 > TBP with K E values of 25.67, 3.58, and 2.36 m3/kmol, respectively. The highest value of equilibrium complexation constant (25.67 m3/kmol) and distribution coefficient (14.09) of TOA suggested it to be the best extractant among the three. The greatest support to highest recovery was also due to the choice of diluent for the system. 1-Octanol was an active diluent which provided good solvation of the acid-extractant complexes. In all the extractions (1:1) acid-extractant complexes were formed with loading ratios less than 0.5, except in Aliquat where values higher than 0.5 were also obtained. This led to the definition of an another equilibrium constant (K E(2:1)) as (2:1) acid−Aliquat complexes were formed, with the value of K E(2:1) = 26.54 (m3/kmol)2.

Recovery of propionic acid by reactive extraction - 1. Equilibrium, effect of pH and temperature, water coextraction

“…Reactive extraction is one of the states of art technology for the recovery of carboxylic acids. In Downloaded by [University of Sussex Library] at 11:06 07 February 2015 reactive extraction, aliphatic amines and organo phosphorous compounds in diluents are used as reactive extractants that can provide higher recovery of acid in comparison to extraction techniques by employing conventional diluents like alcohols, ethers, esters or aliphatic and aromatic hydrocarbons [3][4][5][6][7][8][9][10]. For complete design of reactive extraction, equilibrium, kinetic, thermodynamic, pH and water coextraction data are required.…”

“…Much work on reactive extraction of propionic acid using different diluents like tri-n-octyl amine (TOA), Aliquat 336 and trioctyl phosphine oxide (TOPO) and TBP have been performed and are available in the literature [20][21][22][23]. However, no work could be found on the extraction of propionic acid using TBP in active diluents.…”

Reactive extraction of propionic acid using tri‐n‐octylamine, tri‐n‐butyl phosphate and aliquat 336 in sunflower oil as diluent

“…These results demonstrate that good extraction and recovery of lactic acid can be obtained. Some work on reactive extraction of propionic acid using organophosphorous compounds 19,20 and amines 3 -5,11,21 can be found in the literature but no work on the use of a natural non-toxic diluent (sunflower oil) could be found. In view of this, in the present study, the reactive extraction of propionic acid was carried out using Aliquat 336, TBP, and TOA and their mixed binary solutions in sunflower oil.…”

Intensification of picolinic acid extraction with tri- n -butylphosphate and tri- n -octylamine in three different diluents

“…The mechanism of reactive extraction process may be proposed based on the following assumptions: (i) no acid dimmer formation, (ii) poor solubility of extractant and diluents in water, (iii) solute (picolinic acid) carries fewer amounts of water in the organic phase [2], and, [18,25]. Therefore, with the assumption of 1:1 complex formation in the organic phase, the following model equations are derived.…”