Reactive Extraction as an Intensifying Approach for the Recovery of Organic Acids from Aqueous Solution: A Comprehensive Review on Experimental and Theoretical Studies

Abstract: Kinetic studies for the extraction of succinic acid from aqueous solution with 1‐octanol solutions of tri‐n‐octylamine (TOA) were carried out using a stirred cell with a microporous hydrophobic membrane. The interfacial concentrations of species were correlated and thus the intrinsic kinetics was obtained. The overall extraction process was controlled by the chemical reaction at or near the interface between the aqueous and organic phases. The formation reaction of succinic acid‐TOA complex was found to be first order with respect to the concentration of succinic acid in the aqueous phase and the order of 0.5 with respect to that of TOA in the organic phase with a rate constant of (3.14 ± 0.6) × 10−8 m2.5·mol−0.5·s−1. The dissociation reaction of succinic acid‐TOA complex was found to be the second‐order with respect to that of succinic acid‐TOA complex in the organic phase and the order of –2 with respect to that of TOA in the organic phase with a rate constant of (1.44 ± 1.4) × 10−4 mol·m−2·s−1.

Abstract: The fact that fossil fuels will be depleted in near future and the increase of environmental awareness in humans causes biotechnology to seek new and develop existing processes constantly. That is why researchers have turned to work in this field in recent years. In this study, the separation of lactic acid, an industrially important organic acid, from aqueous solutions by reactive extraction method where tripropylamine (TPA) has been used as an extractant and hydrophobic ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) as a diluent was investigated. Six different traditional organic solvents (n-pentane, toluene, 2-octanone 1-octanol, methyl isobutyl ketone (MIBK), dimethyl phthalate (DMP)) have been chosen to compare the efficiency of the selected ionic liquid. The batch physical and reactive extraction experiment results were presented as distribution coefficient (D), loading factor (Z), and extraction efficiency (E). All experiments were performed at 298.15 K with an initial lactic acid concentration of 1.28 mol·L-1 (10.275% w/w). In reactive extraction experiments, the effect of different TPA concentrations (0.35–1.4 mol·L-1) on extraction efficiency was investigated. While the extraction efficiency in physical extraction varied between 5.55 and 14.06%, ionic liquid has the highest extraction efficiency. In the reactive extraction results, it was seen that the ionic liquid has 99.61% extraction efficiency at 1.40 mol·L-1 TPA concentration. According to this result, the use of (TPA + 1-butyl-3-methylimidazolium hexafluorophosphate) organic mixtures is a suitable alternative to separate lactic acid from aqueous solutions.

Abstract: 4-hydroxybenzoic acid (4-HBA) 1 is potential antidiabetic, anticancer, antioxidant, antifungal, cardioprotective etc. 4-HBA is worth to be recovered as it has bright applications in pharmaceutical, cosmetics and plastic industries. The experiments were performed for the separation of 4-HBA from its aqueous solution using nontoxic solvents; sesame oil, canola oil and conventional solvents; benzene, toluene and petroleum ether. The equilibrium for this physical extraction experiment was evaluated and the parameters like distribution coefficient KD 2 , % extraction efficiency E% 3 , partition coefficient P 4 and dimerization constant D 5 were found and correlated with different physicochemical properties of solvents. The results for KD and E% were found as: sesame oil (0.49,33.24%) > canola oil (0.23,18.85%) > petroleum ether (0.092,8.32%) > toluene (0.09,8.25%) > benzene (0.08,7.49%).

Abstract: This paper rigorously establishes that standard multilayer feedforward networks with as few as one hidden layer using arbitrary squashing functions are capable of approximating any Borel measurable function from one finite dimensional space to another to any desired degree of accuracy, provided sufficiently many hidden units are available. In this sense, multilayer feedforward networks are a class of universal approximators.

Abstract: Table de donnees (pour de nombreux solvants) des valeurs des parametres M*, α et β donnant respectivement la polarisabilite du solvant, son pouvoir de donneur de proton, et d'accepteur de protons dans les liaisons hydrogene solute-solvant

Abstract: The purpose of this article is to provide a survey of the various stages in the development of response surface methodology RSM. The coverage of these stages is organized in three parts that describe the evolution of RSM since its introduction in the early 1950s. Part I covers the period, 1951-1975, during which the so-called classical RSM was developed. This includes a review of basic experimental designs for fitting linear response surface models, in addition to a description of methods for the determination of optimum operating conditions. Part II, which covers the period, 1976-1999, discusses more recent modeling techniques in RSM, in addition to a coverage of Taguchi's robust parameter design and its response surface alternative approach. Part III provides a coverage of further extensions and research directions in modern RSM. This includes discussions concerning response surface models with random effects, generalized linear models, and graphical techniques for comparing response surface designs. Copyright © 2010 John Wiley & Sons, Inc.

Abstract: The purpose of this article is to provide a survey of the various stages in the development of response surface methodology RSM. The coverage of these stages is organized in three parts that describe the evolution of RSM since its introduction in the early 1950s. Part I covers the period, 1951-1975, during which the so-called classical RSM was developed. This includes a review of basic experimental designs for fitting linear response surface models, in addition to a description of methods for the determination of optimum operating conditions. Part II, which covers the period, 1976-1999, discusses more recent modeling techniques in RSM, in addition to a coverage of Taguchi's robust parameter design and its response surface alternative approach. Part III provides a coverage of further extensions and research directions in modern RSM. This includes discussions concerning response surface models with random effects, generalized linear models, and graphical techniques for comparing response surface designs. Copyright © 2010 John Wiley & Sons, Inc.

Abstract: Microbial production of organic acids is a promising approach for obtaining building-block chemicals from renewable carbon sources. Although some acids have been produced for some time and in-depth knowledge of these microbial production processes has been gained, further microbial production processes seem to be feasible, but large-scale production has not yet been possible. Citric, lactic and succinic acid production exemplify three processes in different stages of industrial development. Although the questions being addressed by current research on these processes are diverging, a comparison is helpful for understanding microbial organic acid production in general. In this article, through analysis of the current advances in production of these acids, we present guidelines for future developments in this fast-moving field.