Coextraction Of Water Research Articles

Recovery of excess sulfuric acid in the lithium-ion batteries recycling process

Excess sulfuric acid which is needed for the leaching process of spent lithium-ion batteries is commonly neutralized generating significant waste streams. This research aims to extract and recover sulfuric acid using tri-n-octylamine as an extraction agent. 1-octanol, 2-ethylhexanol, and tributyl phosphate are investigated as synergetic extractants and phase modifiers. An equilibrium study is carried out on both, sulfuric acid and leachate. The equilibrium constant and the stoichiometric coefficient for the overall equilibrium reaction are determined by slope analysis. The enthalpy and Gibb’s enthalpy are studied by investigation of the effect of temperature. Regarding the experiments using leachate, the co-extraction of aluminum, cobalt, copper, iron, lithium, manganese, and nickel is studied, too. Moreover, the co-extraction of water is investigated as a significant increase in metal concentration in the raffinate is observed.

The Aptness of Organic Diluents with Tri‐n‐Butyl Phosphate for Liquid‐Liquid Equilibria of Acrylic Acid

AbstractSeparation of carboxylic acids from downstream is a bottleneck in the chemical industry since it takes nearly 30–50 % of the overall production cost. In view of this, an attempt was made for the extraction of acrylic acid from aqueous solution with tri‐n‐butyl phosphate dissolved in organic diluents like benzene, toluene, xylene, hexane, and petroleum ether. The results are explained in terms of distribution coefficient (σ), extraction efficacy (η%), equilibrium complexation constant (Kε), loading ratio (ϕ), and coextraction of water. At lower concentration of acrylic acid and higher concentration of tri‐n‐butyl phosphate for the acrylic acid‐tri‐n‐butyl phosphate system, maximum extraction efficacy and distribution coefficient for benzene was found as 88.60 % and 7.772, respectively. Coextraction of water in the extract phase and law of mass action were discussed, too. Diffusivity of acrylic acid to the interface of extract (organic) and raffinate (aqueous) phases was calculated using the Wilke‐Chang equation and Reddy‐Doraiswamy equation. In view of designing a continuous extraction column, the number of theoretical stages and minimum solvent‐to‐feed ratio were also determined.

The complexation of lanthanides by glycolamide extractants: Evidences from electronic spectroscopy and DFT calculations

The extraction of trivalent metal ions (Nd and Eu) in N,N,N’,N’-tetraoctyldiglycolamide (TODGA) was compared with N,N-di-octyl-2-hydroxyacetamide (DOHyA), a monoglycolamide derivative of TODGA. The studies based on UV–visible spectroscopy showed the differences in Nd(III) ion complexation for the extractants in both polar and non-polar diluents. n-Dodecane modified with 5 vol% 1-octanol was employed as diluent for extraction studies with TODGA, while DOHyA was studied with no modifiers in n-Dodecane. Time resolved luminescence spectroscopy studies of the Eu(III) extracted organic phases showed strong complexation of metal ion with both the extractants. The co-extraction of water in DOHyA solvent phase during Eu(III) extraction from nitric acid medium was found to be more as compared to TODGA. The better solubilization of water in DOHyA solvent was substantiated by DFT analysis of the optimized electronic structures of Eu-DMHyA (dimethyl hydroxyacetamide) and Eu-TMDGA (tetramethyldiglycolamide) complexes.

Extraction of Selected Metal Ions with Mixtures of N,N,N’,N’-tetra-n-octyldiglycolamide and 4,4′(5′)-di-t-butylcyclohexano 18-crown-6

ABSTRACT Previous work has shown that solvent extraction (SX) and extraction chromatography (EXC) systems containing mixtures of extractants can be utilized to impart selectivity and improved physical characteristics that were not achievable with a single extractant. In an effort to discover EXC materials with unique selectivity and improved physical properties, we studied the extraction of selected metal ions from nitric acid and hydrochloric acid by EXC resins prepared from mixtures of N,N,N’,N’-tetra-n-octyldiglycolamide (TODGA) and 4,4′(5′)-di-t-butylcyclohexano 18-crown-6 (dtBCH18C6). Except for enhanced extraction of Ra and Ba from dilute HNO3, the EXC resins essentially exhibited the metal ion extraction properties expected from materials prepared with the individual extractants. The origin of the Ra/Ba enhancement was studied by solvent extraction variation studies in 1-octanol and n-dodecane and on extraction chromatography resins, indicating that the enhancement may not be a true synergistic interaction between the extractants, but a phase modification by the TODGA related to the co-extraction of HNO3 and water. Additionally, the influence of alkyl substituents on the DGA extractant and potential applications of the mixed extractant system in analytical chemistry and nuclear medicine were explored with extraction chromatography resins prepared from the extractant mixtures.

Electrochemical monitoring of the co-extraction of water with hydrated ions into an organic solvent

An electrochemical cell based on the interface between two immiscible electrolyte solutions (ITIES) was designed and used to study the co-extraction of water with hydrated chloride ions from the aqueous to the organic solvent phase. The interfacial potential was controlled by the distribution of a common tetralkylammonium (TAA+) ion. Transfer of hydrated chloride ions is accompanied by the transfer of TAA+, decreasing its concentration on the aqueous side of the interface. Changes in the TAA+ concentration at the interface were monitored by measuring the open circuit potential (OCP). The proposed mechanism of TAACl transport involves a follow-up reaction with the co-extracted water molecules, leading to the formation of clusters of water containing TAACl in the organic phase.

Specific phenomena in carboxylic acids extraction by selected types of hydrophobic ionic liquids

An overview on specific phenomena in extraction of carboxylic acids with hydrophobic ionic liquids (ILs) based on results of new measurements with selected phosphonium, ammonium and imidazolium ILs and published data is presented. Formation of IL – acid hydrated complexes with multiple molecules of organic acid per one IL ion pair was observed. The distribution coefficient of carboxylic acids and water content in ILs strongly decreases with the increasing acid concentration. Dependence of water content in the solvent passes through a minimum at loading of IL with butyric acid of about 3. Two extraction mechanisms are involved: competitive extraction of acid and water with the release of water from the solvent and co-extraction of water with acid depending on the IL concentration. A strong synergistic effect was observed between the cation and anion of ILs enhancing their extractive properties compared to IL precursors. A new extraction model suggests the formation of water bridges and polar nano-channels which is in agreement with the molecular modelling results. ILs are nano-segregated liquids with a structure sensitive to the content of molecular compounds. Water and carboxylic acids accumulate in polar domains and dodecane in non-polar domains modifying the IL structure and decreasing the solvent phase viscosity. The hypothesis of hopping mechanism in polar channels for acid molecules transport between acid chains at IL binding sites is suggested.

New Mechanism and Model of Butyric Acid Extraction by Phosphonium Ionic Liquid

A new model of the liquid/liquid equilibrium of butyric acid (BA) and water extraction from aqueous solutions to an organic solvent containing phosphonium ionic liquid and dodecane has been derived. It has seven fitting parameters and describes experimental data well. Reactive extraction with formation of the (p, 1) acid-IL complexes with p ≤ 11 acids on one hand and their aggregation by water bridges on the other hand refer to the dualistic character of the extraction process and the developed model. The values of two equilibrium constants characterizing the stability of hydrogen bonds between acid and IL anion are 3 and 2 orders of magnitude larger as compared with constants characterizing stability of acid–acid H-bonds. Water is extracted via two reactive mechanisms. The first is a competitive extraction of acid and water which results in the release of water from the solvent as the BA extraction proceeds. The second mechanism is coextraction of water with BA. At the acid loading of IL above 3, this me...

Insights into coextraction of water and ammonia with nickel(II) through structural investigation

The coordination structures of the nickel(II) complexes of 4-ethyl-a-pheneyl-1,3-octadione (denotes A) formed upon solvent extraction from ammoniacal media have been investigated. The combination analysis of their X-ray absorption spectroscopy with IR, UV–Vis and NMR spectroscopies provides a molecular-level understanding on the coextraction behavior of both water and ammonia molecules during nickel extraction. XANES spectra not only verify that the nickel extracts with octahedral configuration are independent on aqueous pH of ammoniacal solutions; and also demonstrates the structures are independent of the nickel complexes being solid or in solution. The structural investigation and elemental analysis of solid nickel extract indicate that both water and ammonia molecules can simultaneously coordinate with nickel extract to form a hexa-coordination complex of NiA2·H2O·NH3. The structural parameters of nickel extracts were extracted by EXAFS fitting. The mean Ni–Oeq bond length of nickel chelate rings is 2.00Å, and the mean Ni–O/Nax bond length of axially coordinated water and ammonia is 2.09Å.

Reactive extraction of sodium hydroxide from alkali solutions for the separation of sodium and aluminum—Part II. Effect of diluent

Enhancing the precipitation of Al(OH)3 from supersaturated sodium aluminate solution has been a challenge for the alumina industry for decades in its effort to increase the productivity. However, limited by the thermodynamic equilibrium of alumina solubility in caustic solutions, the processes that are available to date for promoting the precipitation of Al(OH)3 are unsatisfactory. An acid–base reactive solvent extraction method is proposed to enhance the separation of sodium hydroxide from sodium aluminate mother liquor by creating a condition for re-precipitation. The extraction process has been reported in Part I of this study by the present authors. In this paper the effects of diluents on sodium extraction when using 2-tert-butyl-4-methylphenol as the main organic extractant were systematically investigated. According to the classification of diluents, the capabilities for extracting sodium in different types of diluents were compared, and the protonic polar diluents were identified as being the most effective diluent. In the absence of alkyl phenol organic extractant, the sodium extraction equilibrium in 1-octanol and 2-ethyl hexanol, and the co-extraction of water in each of them were compared. In the presence of alkyl phenol, the extraction capabilities for sodium in different C8 alcohols, including 1-octanol, 2-ethyl hexanol and 2-octanol, were compared and analyzed. The results showed that 1-octanol is the most effective diluent among the three that are studied in this project. Furthermore, inert diluents including kerosene, octane and heptane, were used to dilute the pure 1-octanol solvent in different proportions in order to decrease the viscosity of the organic phase. The effects of the inert diluent on sodium extraction and water co-extraction were studied. Finally, the particle size distributions in the equilibrated organic phases and the Margules ternary 2-suffix equations were introduced to discuss the mechanisms of sodium extraction by 1-octanol and 2-ethyl hexanol. The results of this systematic research are expected to provide valuable guidance for the selection of diluents.

Coextraction of water into nitrobenzene with organic ions.

Various organic anions (sulfonates (RSO3(-)), carboxylates (RCO2(-)), and phenolates (RO(-))) and ammonium cations (RNH3(+), R2NH2(+), and R3NH(+)) were distributed in the nitrobenzene (NB)-water system by using Crystal Violet and dipicrylaminate, respectively. The number of water molecules (n) being coextracted into NB with an ion was then determined by the Karl Fischer method. The n values determined and those reported previously showed the variation from 0.51 to 3.4, depending on not only the charged groups but also the noncharged R-groups. In this study, we focused our attention to the strong electric field on the charged group and its facilitation effect for binding water molecules in NB. The local electric field (Ei) on the surface of an organic ion was evaluated by using Gaussian09 program with a subprogram developed in our recent study. It was found that the n values showed a clear dependence on the average value of Ei on oxygen or hydrogen atoms, respectively, of an anionic or cationic group.

Solvent and Emulsion Extractions of Gallic Acid by Tributylphosphate: Mechanisms and Parametric Study

The aim of this paper was to study solvent extraction or liquid-liquid extraction (LLE) and extraction by emulsion (ELM) of gallic acid, a biomolecule present in many plants. A mechanism involving three tributylphosphate molecules for one molecule of undissociated gallic acid with co-extraction of water was found in LLE. ELM process is as fast as LLE and more efficient; in addition, it is more environmentally-friendly because lower extractant concentrations and smaller organic phase volumes were needed.

COSMO-RS assisted solvent screening for liquid–liquid extraction of mono ethylene glycol from aqueous streams

Separation of polar mixtures from water is one of the most energy consuming operations in industry, because of the high heat of vaporization of water. Avoiding evaporation of water by applying liquid–liquid extraction instead of (multi-effect) evaporation can yield large energy-savings. The distribution of mono ethylene glycol and the co-extraction of water are key parameters that depend on the characteristics of the solvent. We here report on the solvent screening for mono ethylene glycol (MEG) extraction from water to maximize the distribution coefficient (DMEG) and selectivity (S) of MEG over water. To speed-up the screening process and avoid unnecessary experiments, COSMO-RS was used to predict the LLE performance of both real and hypothetical solvents for the extraction of MEG from aqueous streams. Based on the σ-electron density-profile analysis, hypothetic tetraoctyl ammonium carboxylate, phosphinate and boronate ILs were considered as potentially interesting. These ILs were tailor made and evaluated in LLE experiments. They outperformed other solvents tested thus far with DMEG up to 0.45, and S up to 3.2 vs DMEG=0.08 and S=1.5 for α-terpineol.

Pervaporation membranes highly selective for solvents present in fermentation broths

Pervaporation is an energy-efficient alternative to distillation for removing volatile organic compounds (VOCs) from water especially solvents from their dilute solutions in a fermentation broth. Polymeric, ceramic and liquid membranes have been used in the pervaporation process for removing such solvents; however, polymeric and ceramic membranes have rather poor solvent selectivity compared to liquid membranes even though they achieve reasonable solvent mass fluxes. Liquid membranes have stability problems due to various losses. The loss of liquid membrane (LM) to the feed solution leads to toxicity for the organisms in a fermentation broth. A new liquid membrane-based pervaporation technique has been developed to achieve high selectivity, ensure stability and prevent contamination of the fermentation broth. Trioctylamine (TOA) as a liquid membrane was immobilized in the pores of a hydrophobic hollow fiber substrate having a nanoporous coating on the broth side and studied for pervaporation-based removal of solvents (acetone, ethanol, and butanol) from their dilute aqueous solutions. The LM of TOA in the coated hollow fibers demonstrated high selectivity and reasonable mass fluxes of solvents in pervaporation. The selectivities of butanol, acetone, and ethanol achieved were 275, 220, and 80, respectively with 11.0, 5.0, and 1.2 g/m 2 h for the mass fluxes of butanol, acetone and ethanol, respectively at a temperature of 54 °C for a feed solution containing 1.5 wt% butanol, 0.8 wt% acetone, and 0.5 wt% ethanol. The mass fluxes were increased by as much as five times with similar selectivity of solvents when an ultrathin liquid membrane was used. However, acetic acid in the feed solution reduced the selectivities of the solvents without reducing the solvent fluxes due to coextraction of water which increases the rate of water permeation to the vacuum side. The TOA-based LM present throughout the pores of the coated substrate demonstrated excellent stability over many hours of experiment and essentially prevented the loss of liquid membrane to the feed solution and the latter's contamination by the liquid membrane.

Reactive extraction of d, l-α-phenylglycine with a quaternary ammonium salt: Effect of hydroxide anions and water coextraction

The extraction equilibria of α-phenylglycine in alkaline solutions with tri- n-octylmethylammonium chloride (TOMAC) (10%, v/v) in 1-decanol as diluent have been studied. Hydroxide anion and water co-extraction were also investigated. Equilibrium constants for the extraction of phenylglycine and OH - ions have been determined experimentally at 20 °C, being K ePhg = 1.09 and K eOH = 0.30. A mathematical model has been developed to predict the equilibrium concentrations from initial conditions, the equilibrium constants and mass balances to the system. The model takes into account the coextraction of water (3.5 ± 0.4%, v/v) that was determined to be independent of feed concentration.

Supercritical fluid extraction of fat from ground beef: effects of water on gravimetric and GC-FAME fat determinations.

This study investigated the supercritical carbon dioxide (SC-CO(2)) extraction of fat from ground beef and the effects of several factors on the gravimetric determination of fat. The use of ethanol modifier with the SC-CO(2) was not necessary for efficient fat extraction; however, the ethanol did increase the coextraction of water. This coextraction of water caused a significant overestimation of gravimetric fat. Oven-drying ground beef samples prior to extraction inhibited the subsequent extraction of fat, whereas oven-drying the extract after collection decreased the subsequent gas chromatographic fatty acid methyl ester (GC-FAME) fat determination. None of the drying agents tested were able to completely prevent the coextraction of water, and silica gel and molecular sieves inhibited the complete extraction of fat. Measurements of collection vial mass indicated that CO(2) extraction/collection causes an initial increase in mass due to the density of CO(2) (relative to displaced air) followed by a decrease in vial mass due to the removal of adsorbed water from the collection vial. Microwave-drying of the empty collection vials removes approximately 3 mg of adsorbed water, approximately 15-20 min is required for readsorption of the displaced water. For collection vials containing collected fat, microwave-drying effectively removed coextracted water, and the vials reached equilibration after approximately 10-15 min. Silanizing collection vials did not significantly affect weight loss during microwave-drying. SC-CO(2) can be used to accurately determine fat gravimetrically for ground beef, and the presented method can also be followed by GC-FAME analysis to provide specific fatty acid information as well.

Hydration to benzo-15-crown-5, benzo-18-crown-6 and the benzo-18-crown-6-potassium ion complex in the low-polar organic solvents.

The coextraction of water with benzo-15-crown-5 (B1SC5), benzo-18-crown-6 (B18C6) and the B18C6-K+ complex into seven low-polar solvents, i.e., carbon tetrachloride (CTC), chloroform (CF), dichloromethane (DCM), 1,2-dichloroethane (1,2-DCE), benzene (BZ), chlorobenzene (CB) and o-dichlorobenzene (o-DCB), has been investigated. The mean hydration number, nH2O, of these solutes in the water-saturated organic solvents was determined. There is a trend that the nH2O values for any solutes increase with increasing the water concentration in the solvents. Those of B18C6 and B15C5 converge at almost 0.8 for B18C6 and 0.4 - 0.5 for B15C5 in the solvents with the relatively high water concentration, i.e., CF, 1,2-DCE, DCM, and nitorobenzene (NB). The nH2O value of B15C5 is about one-half of that of B18C6 for a given organic solvent. The dominant species of the B18C6-K+ complex in these solvents is non-hydrated. From these results, the hydration equilibrium constants, KH2O, in the organic solvents were estimated.

HYDRATION OF SEVERAL METAL PERCHLORATES EXTRACTED WITH TRIOCTYLPHOSPHINE OXIDE IN HEXANE

ABSTRACT Extraction of M(ClO4)m, (Mm+ = Li+, Na+, Mg2+, and Ca2+) from their aqueous solutions into hexane with trioctytphosphine oxide (TOPO) and the co-extraction of water have been measured at 298 K. The solvation number of TOPO is concluded to be 3 for Li(l) and Na(I), 4 and 7 for Mg(II), and 4 and 6 for Ca(II) from the curve-fining calculations.. The hydration number of the extracted metal salts is 2 - 3 for Li(l), Na(I), and Ca(I) but 6 - 8 for Mg(II). The hydration number seems to increase on increasing in the TOPO concentration. It is deduced that TOPO solvates both the metal ion and waters of hydration of the metal ion.

Amine extraction of citric acid: effect of diluent

Distribution of citric acid between water and trialkylamine C 7-C 9 dissolved in 7 various diluents ( p-xylene, toluene, benzene, MIBK, 1-octanol, methylene chloride, chloroform) was studied. Using a “chemical modeling” approach two acid: amine complexes, ACID. AMINE and ACID. (AMINE) 2, have been assumed to exist in the organic phase in the case of proton-donating diluents (octanol, chloroform, methylene chloride), while the complexes ACID. AMINE and (ACID) 2(AMINE) 3 have been suggested in the case of aromatics and MIBK. The estimated values of overall extraction constants, K 11, K 12 and K 23, were correlated with solvatochromic parameters of the diluents according to the linear solvation energy relationship (LSER). Using this correlation the extractability of citric acid can be predicted for a wide range of diluents or their mixtures. The coextraction of water with acid was explained in terms of the corrected physical solubility of water, m w *, and hydration coefficients, h 11, h 12 and h 23. The values of hydration coefficients were also correlated with the solvatochromic parameters of the diluents.

Amine extraction of hydroxycarboxylic acids. 1. Extraction of citric acid with 1-octanol/n-heptane solutions of trialkylamine

Extraction of citric acid from aqueous solutions with TAA, a mixture of tertiary aliphatic amines, dissolved in 1-octanol/n-heptane mixtures, and coextraction of water have been studied as a function of acid, amine, and octanol concentrations at different temperatures. Using a chemical modeling approach, two complexes [acid-amine-h 11 H 2 O and acid-(amine) 2 .h 12 H 2 O] have been assumed to exist in the organic phase, and the corresponding equilibrium constants, apparent enthalpies, and entropies of complex formation have been evaluated

Extraction of carboxylic acids with amine extractants. 3. Effect of temperature, water coextraction, and process considerations

Coextraction of water during extraction of succinic acid by Alamine 336 in different dulents has been measured. The amounts of coextracted water lie in the same order as the solubilities of water in the diluents without amine present. Water coextraction with different acids follows the order fumaric>malonic>maleic=succinic>lactic>acetic. The effects of temperature on extraction of succinic and lactic acids by Alamine 336 with chloroform and methyl isobutyl ketone (MIBK) diluents have been measured. Enthalpies and entropies of complex formation have been derived from the results and are interpreted in terms of the differences in interactions among the species involved. Two approaches for regeneration through back-extraction into an aqueous phase are considered