Recovery of volatile fatty acids by reactive extraction using tri‐n‐octylamine and tri‐butyl phosphate in different solvents: Equilibrium studies, pH and temperature effect, and optimization using multivariate taguchi approach

Abstract

Recovery of volatile fatty acids from fermentation broth has been investigated by adopting an intensified approach using extractants tri-noctylamine and tri-butyl phosphate dissolved in 1-decanol and methyl isobutyl ketone. The effects on distribution coefficient (K D ) and extraction efficiency (%E) were studied by varying the operating conditions like temperature (293.15-323.15) K, pH (2.5, 3.5, and 4.5), and compositions of extractant (10, 20, and 30 %). Taguchi (L 36 ) orthogonal design with five factors, namely diluents, extractant type, composition, temperature, and pH, was employed for the multivariate optimization of reactive extraction of volatile fatty acids. In the Taguchi approach, a "larger is better" criterion was adopted to maximize K D and %E. The statistical analysis indicated that the degree of influence on K D by experimental variables follows the following trend: extractant type (X 2 ) > pH (X 5 ) > diluent type (X 1 ) > temperature (X 4 ) > extractant concentration (X 1 ). The trend for %E observed is as follows: extractant type (X 2 ) > pH (X 5 ) > temperature (X 4 ) > extractant concentration (X 1 ) > diluent type (X 1 ). The combination of optimum parameters were obtained as X 1 ¼ 1-decanol, X 2 ¼ tri-n-octylamine, X 3 ¼ 20 %, X 4 ¼ 293.15 K, and X 5 ¼ 3.5. A confirmation run was conducted using these parameters and K D and %E values from this run were determined to be 8.65 and of 89.64 %, respectively, which were very close to the predicted values K D ¼ 10.36 and %E ¼ 91.26 %.

Experimental methods in chemical engineering: Preface

“…published in 2016 and 2017. We identified and collated keywords that represent physical and physicochemical properties (pressure, temperature, time), instruments and derived properties (XRD, XPS, viscosity, pH), mathematical methods (CFD, tomography), and statistical tests, and experimental design like response surface methodologies . To illustrate relationships between the network data, we generated bibliometric maps with the VOSViewer software tool .…”

Single Droplet Mass Transfer Experiments for Acetic Acid Extraction with Triisooctylamine‐Based Solvents

“…From the class of high‐boiling solvents, trialkylphosphane oxides and tertiary amines have been investigated. The latter group of reactive extractants needs dilution and modification of the physical properties density, interfacial tension, and viscosity as well as the liquid‐liquid partition characteristic . Third‐phase formation of the laden solvent is a crucial limitation for the maximum amine content of the solvent mixture.…”

Modeling of Single Droplet Mass Transfer of Acetic Acid with Triisooctylamine‐Based Solvent

“…Amine‐based solvents need admixture of modifiers and diluents to correct the physical properties of the laden solvent by adjusting density, interfacial tension and viscosity, and to avoid third phase formation 3–5. To gain data about the interaction of chemistry and mass transfer of acid extraction with tertiary amine‐based solvents, single droplet liquid‐liquid extraction of acetic acid (HOAc) was investigated with solvent mixtures comprising TiOA dissolved in SST and the modifier ISO.…”