Reactive extraction of 6-aminopenicillanic acid with aliquat-336: Equilibrium and kinetics

The reactive extraction of 6-aminopenicillanic acid (6-APA) from aqueous buffer solution has been studied using a liquid anion exchanger, tricaprylylmethyl ammonium chloride (Aliquat-336) in n-butyl acetate as the solvent. The extraction equilibrium constant and partition coefficient increase with increase in pH up to a limiting value of pH, beyond which extraction decreases due to coextraction of OH^? and buffer anions and hydrolytic decomposition of 6-APA. The experimental data could be predicted from an equilibrium model which takes into account the ideal behaviour of the two liquid phases. The coextraction of the buffer anion under low pH conditions was found to be negligible. The extraction rate measured in a stirred cell of constant interfacial area appears to be dependent on the interfacial mass transfer of the reactive species as well as on the interfacial reaction through its dependence on the concentration of 6-APA in the aqueous and organic phases, respectively.     

NON-DISPERSIVE LIQUID EXTRACTION OF Cr(VI) BY TBP/ALIQUAT 336 USING CHITOSAN-MADE HOLLOW FIBER

ABSTRACT

TBP and alkylammonium extractants were investigated for chromate removal from dilute solutions using chitosan-made hollow fibers. Chromate is adsorbed by the chitosan fiber and simultaneously desorbed by the extractant. The influence of chromate concentration, extractant concentration, extractant volume on relative concentration deccrease were investigated as a function of time. These experimental parameters barely influenced the decrease in the relative concentration. Fiber length is more significant in the control of the extraction kinetics. In recirculation flow mode, the relative concentration can be well described as an exponential function of time. The kinetic constant varies as a linear function of fiber length. Amine extractants (Aliquat 336, Alamine 336, Amberlite LA-2) are better extractants than TBP both from the kinetics and equilibrium standpoints. With Aliquat 336 the final Cr(VI) concentration tends to zero, while with TBP, the equilibrium is controlled by the volume of the extractant.     

Synergic Extraction of Folic Acid with Di(2-ethylhexyl) Phosphoric Acid and Amberlite LA-2

The influences of extractants concentrations and solvent polarity on the efficiency of folic acid separation by synergic extraction with Amberlite LA-2 and di(2-ethylhexyl) phosphoric acid (D2EHPA) mixture have been analyzed. The results indicated the formation of an interfacial compound which includes one molecule of folic acid and one of D2EHPA, the hydrophobicity of this compound being increased by solvation with Amberlite LA-2 molecules. The number of aminic molecules participating in the interfacial complex formation is controlled by solvent polarity and D2EHPA concentration, decreasing from 3 to 1 with the increase of these two parameters. The results indicated that the most important synergic effect corresponds to the extractants mixture dissolved n-heptane, at low D2EHPA concentration in the organic phase (5 g/l).     

Extraction of penicillin G from aqueous solutions: Analysis of reaction equilibrium and mass transfer

Analysis of the reaction equilibrium and mass transfer in the extraction of penicillin G (Pen G) into an organic phase is an important research area to develop a cost-effective process for its separation from an aqueous fermentation media. In order to evaluate this, equilibrium experiments were first carried out to select the organic phase (composed of the carrier and solvent) that gives good values for the distribution of penicillin G between the aqueous and organic phases. An organic phase of Amberlite LA-2 in any of the solvents (Shellsol TK/butyl acetate/tributyl phosphate) gave high distribution coefficient and the stoichiometry of the reaction has been shown to follow a simple ratio of 2:2. The performance of the organic phases was evaluated in a membrane contactor and very high percentage extraction was achieved. The extraction was performed by contacting a “feed” solution containing penicillin G (flowing in the fiber side) with an “organic phase” of Amberlite LA-2 in one of the solvents (flowing on the shell side) of the contactor. The antibiotic solutes formed complex with the Amberlite LA-2 molecules which were transported across the fiber wall to the shell side and extracted in the organic phase. The extraction in once-through mode was low and the feed/organic solutions need to be recycled to increase the percentage extraction. In the recycle mode operated at flow rates of 3.6–4.4 mL/s, an extraction of 90–98% was achieved. A simple mathematical model and its semi-analytical solution presented here can be used to determine the overall mass transfer coefficient using the experimental values of the distribution coefficient, operating parameters and the dimensions of the membrane module.     

POLYNITROGEN REAGENTS,IN METAL SEPARATION. PART 5 THE EXTRACTION OF URANIUM(VI) FROM SULPHURIC,NITRIC AND HYDROCHLORIC ACID MEDIA WITH ALKYLDIAMHONIUM EXTRACTANTS.

ABSTRACT

A variety of a1kyldiammonium extractants (tertiary and quaternary) were used to extract uranium(VI) from sulphuric, nitric and hydrochloric acid media. The performance of these extractants was compared with that of Aliquat-336 and Alamine-336. Extractions from dilute uranium(VI) solutions were carried out in order to simulate conditions employed in the local mining industry     

POLYNITROGEN REAGENTS IN METAL SEPARATION. PART 1. DITERTIARY AND DIQUATERNARY AMMONIUM EXTRACTANTS FOR COBALT(II) AND COPPER(II) IN HCl MEDIUM.

Abstract

A variety of alkyldiammonium extractants (tertiary and quaternary)were prepared, characterised and used to extract cobalt(II) and copper(II) from HCl medium. These extractants were compared with Aliquat-336 and Alamine-336. The diammonium derivatives of ethylene diamine proved to be superior to their mono analogues.     

Equilibria and kinetics for reactive extraction of lactic acid using Alamine 336 in decanol

Lactic acid is an important commercial product and extracting this from aqueous solution is a growing requirement in fermentation‐based industries. The design of an amine extraction process requires (i) equilibrium and (ii) kinetic data for the acid–amine (solvent) system used. The equilibrium complexation constants for ratios of (1:1) and (2:1) have been estimated. The kinetics of extraction of lactic acid by Alamine 336 in decanol has also been determined. The reaction between lactic acid and Alamine 336 in decanol in a stirred cell falls in Regime 3, ie extraction accompanied by a fast chemical reaction occurring in the diffusion film. The reaction has been found to be zero order in Alamine 336 and first order in lactic acid with a rate constant of 0.21 s^?1. These data will be useful in the design of extraction processes. © 2002 Society of Chemical Industry     

STUDIES ON THE EXTRACTION OF PLUTONIUM(IV) FROM AQUEOUS NITRIC ACID - OXALIC ACID BY ALIQUAT-336

ABSTRACT

The extraction of Pu(IV) by Aliquat-336 from aqueous nitric acid containing oxalic acid was studied with a view to exploring the feasibility of recovery of Pu(IV) from Pu(IV) oxalate precipitation effluents. Distribution ratio data were obtained as a function of concentration of nitric acid, oxalic acid and Aliquat-336. The data obtained revealed that Pu(IV) can be extracted almost quantitatively by 20% Aliquate-336 in xylene from aqueous medium containing oxalic acid up to 0.25 M provided the nitric acid concentration is ≥ 4 M. These data suggest that Pu(IV) can be recovered directly from nitric acid - oxalic acid waste generated in Pu-oxalate precipitation by Aliquat-336 extraction.     

Study on rosmarinic acid separation by synergic extraction

Separation of rosmarinic acid by synergic reactive extraction using a mixture of two extractants (one of aminic and one of basic type) dissolved in solvents with different polarities has been studied. By analysing the influences of the main factors (organic phase polarity, extractant concentration in the mixture) on the synergic effect, the most important synergic effect (C_S = 10.89) was found to correspond to the extractants mixture containing 5 g/l D2EHPA and 5 g/l Amberlite LA-2 dissolved in n-heptane. In this system the extraction constant reached the maximum value of 6.78 l²/mol².     

Extraction behavior of Am(III) and Eu(III) by tri-n-octylmethylammonium diglycolamate ionic liquid impregnated XAD-7

Aliquat-336-based strongly hydrophobic ionic liquid, tri-n-octylmethylammonium diglycolamate ([A336]⁺[DGA]^?), was prepared and impregnated in Amberlite XAD-7 (abbreviated as [A336]⁺[DGA]^?/XAD-7) for studying the extraction behavior of Am(III) and Eu(III) from nitric acid medium. The distribution ratio of Am(III) and Eu(III) in [A336]⁺[DGA]^?/XAD-7 decreased with an increase in the concentration of nitric acid and the mechanism of trivalent metal ion extraction in the resin phase was elucidated. The uptake of Am(III) and Eu(III) in [A336]⁺[DGA]^?/XAD-7 followed a second order and from the Langmuir adsorption model the apparent europium extraction capacity was determined. The conditions needed for efficient separation of Am(III) from Eu(III) was optimized.     

EXTRACTION BEHAVIOUR OF TECHNETIUM AND ACTINIDES IN THE ALIQUAT-336/NITRIC ACID SYSTEM

ABSTRACT

The extraction behaviour of technetium, thorium, uranium, neptunium, plutonium, americium and curium in the Aliquat-336 (diluted with 1,3-diisopropyl benzene) - nitric acid system have been studied. Aliquat-336 (tricapryl-methyl ammonium nitrate) is a quaternary ammonium salt extracting different species with an anion exchange mechanism. Distribution data obtained are modeled by anion exchange (technetium) and ion-pair formation mechanisms (actinides) with the extraction of nitric acid included to account for the lowering of the free extractant concentration. Reasonably high distribution ratios were obtained for technetium and the tetravalent elements (Th, Np and Pu) and Aliquat-336 can therefore be useful for partitioning of these elements.     

Penicillin G extraction from model media using an emulsion liquid membrane: Determination of optimum extraction conditions

Penicillin G extraction by an emulsion liquid membrane (ELM) was investigated. The effects of surfactants, diluents, and carrier mixtures, together with their combined effects on the initial extraction rate and the emulsion stability were examined. Surfactants, diluents, and carriers used were Span80 (sorbitan monooleate)/ECA4360J (nonionic polyamine), n-butyl acetate/kerosene, and DOA (dioctylamine)/Amberlite LA-2 (secondary amine), respectively. The optimum extraction conditions were found to be 20% (v/v) of Span80 in ECA4360J as a surfactant, kerosene as a diluent and Amberlite LA-2 as a carrier.     

EXTRACTION OF Se,Y, AND LANTHANIDES BY QUATERNARY AMMONIUM SALTS

The separation of Sc and Y from the lanthanides by extraction with various quaternary ammonium salts was investigated. Aliquat-336,methyltrioctylammonium nitrate (MTOA), methyldibutylhexadecylammonium nitrate (MDBHDA) and tributylhexadecylammonium nitrate (TBHDA) were used as extractants. The synthesis of MDBHDA and TBHDA from industrial products is described. From the results obtained in the extraction studies of REE as a function of the parameters of aqueous and organic phases, we have determined the optimal separation conditions. The salting-out action in these systems of a great number of cations such as Al³⁺, Fe³⁺, Mg³⁺, Cu³⁺, Ni³⁺, Li³⁺, Cs³⁺, was investigated. To determine the functional dependences of the separation factors for the REE, the viscosity of the water layer around the ion was used.     

Recovery of rare earth elements from simulated fluorescent powder using bifunctional ionic liquid extractants (Bif‐ILEs)

BACKGROUND: Numerous high purity ammonium‐type ionic liquid extractants have been prepared for engineering purposes. Bifunctional ionic liquid extractants (Bif‐ILEs) have been widely applied to separate and extract rare earths and metal ions with high extraction efficiencies and selectivities. In the present study, new Bif‐ILEs [A336][P204] and [A336][P507] have been used to extract rare earths from a simulated solution of a fluorescent powder in a high concentration of Al(NO₃)₃. RESULTS: Bif‐ILEs were prepared from Aliquat336 (A336) and the commercial organophosphorus acid extractants, P204 and P507. These extractants [A336][P204] and [A336][P507] have similar characteristics to neutral organophosphorus extractants. When these Bif‐ILEs were used to extract RE(III) from a simulated waste fluorescent powder system a third phase appeared which could be eliminated by the addition of 10% isopropanol modifier. The coexisting Al₂O₃ in the fluorescent powder was changed to a salting‐out agent (Al(NO₃)₃) in the extraction process and promoted the extraction efficiency of RE(III). Using a countercurrent extraction process at a phase ratio V_o:V_w = 4:1 and pH = 0.56, the RE(III) recovery reached 95.2% in 5–7 stages. Finally, the extractabilities of these bifunctional extractants were compared with the neutral organophosphorus extractants P350, TBP and Cyanex923 at different concentrations, initial pHs and temperatures. CONCLUSIONS: By comparison with other neutral organophosphorus extractants, Bif‐ILEs [A336][P204] and [A336][P507] can be considered efficient potential extractants for separating and recycling REEs and Al₂O₃ from waste fluorescent powder. Copyright © 2011 Society of Chemical Industry     

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

BACKGROUND : Propionic acid is widely used in chemical and allied industries and can be produced by biocultivation in a clean and environmentally friendly route. Recovery of the acid from the dilute stream from the bioreactor is an economic problem. Reactive extraction is a promising method of recovering the acid but suffers from toxicity problems of the solvent employed. There is thus a need for a non‐toxic solvent or a combination of less toxic extractants in a non‐toxic diluent that can recover acid efficiently. RESULTS: The effect of different extractants (tri‐n‐butylphosphate (TBP), tri‐n‐octylamine (TOA) and Aliquat 336) and their mixed binary solutions in sunflower oil diluent was studied to find the best extractant‐sunflower oil combination. Equilibrium complexation constant, K_E, values of 4.02, 3.13 and 1.87 m³ kmol^?1 were obtained for propionic acid extraction using Aliquat 336, TOA and TBP, respectively, in sunflower oil. The effect of different modifiers (1‐decanol, methylisobutyl ketone, butyl acetate and dodecanol) on the extraction was also studied and it was found that modifiers enhance extraction, with 1‐decanol found to be the best. CONCLUSION: The problem of toxicity in reactive extraction can be reduced by using a non‐toxic diluent (sunflower oil) or a modifier in a non‐toxic solvent, with the extractant. The addition of modifiers was found to improve the extraction. Copyright © 2008 Society of Chemical Industry     

Reactive extraction of itaconic acid using tri‐n‐butyl phosphate and aliquat 336 in sunflower oil as a non‐toxic diluent

Itaconic acid finds a place in various industrial applications. It can be produced by biocultivation in a clean and environment friendly route but recovery of the acid from the dilute stream of the bioreactor is an economic problem. Reactive extraction is a promising method to recover carboxylic acid but suffers from toxicity problems of the diluent and extractant employed. So there is need for a non‐toxic extractant and diluent or a combination of less toxic extractants in a non‐toxic diluent that can recover acid efficiently. Effect of different extractants: tri‐n‐butylphosphate (TBP) (an organophosporous compound) and Aliquat 336 (a quaternary amine) in sunflower oil was studied to find the best extractant–sunflower oil combination. Equilibrium complexation constant, K_E, values of 1.789 and 2.385 m³ kmol^?1, respectively, were obtained for itaconic acid extraction using TBP and Aliquat 336 in sunflower oil. The problem of toxicity in reactive extraction can be reduced by using a natural non‐toxic diluent (sunflower oil) with the extractant. Copyright © 2010 Society of Chemical Industry     

Equilibria,Kinetics, and Modeling of Extraction of Citric Acid from Aqueous Solutions with Alamine 336 in 1-Octanol

Experimental equilibrium and kinetic data on the extraction of citric acid from aqueous solutions using Alamine 336 in 1-octanol have been determined. The distribution coefficient has increased from 0.029 to 71.727 with increase of Alamine 336 concentration from 0 to 30% (v/v). The chemical equilibria was interpreted as a result of consecutive formation of acid-amine species with 1:1 stoichiometry and the equilibrium complexation constant, K _E1 , has been estimated as 20.186 m³ kmol^?1. The mass-transfer coefficients of citric acid, Alamine 336, and 1:1 acid-alamine complex in 1-octanol were calculated from acetic acid mass-transfer coefficient, which was determined by measuring its fluxes of simple diffusion from kerosene to water. Based on the Hatta number and the criterion given by Doraiswamy and Sharma, the reaction regime has been found to be instantaneous reaction regime occurring at the interface on the organic phase side. An extraction model comprising 1:1 equilibrium complextion constant, K _E1 , and complex mass-transfer coefficient, k _BA (3.79 × 10^?6 m s^?1), has been developed, and it explained the present system satisfactorily.     

Study on extraction kinetics of α-cyclopentylmandelic acid enantiomers with hydroxyethyl-β-cyclodextrin as chiral selector

In this work,the kinetic study on reactive extraction ofα-cyclopentylmandelic acid(α-CPMA)enantiomers was performed in a Lewis cell using hydroxyethyl-β-cyclodextrin(HE-β-CD)as chiral selector.The enantioselective complexation equilibrium between HE-β-CD andα-CPMA enantiomers was studied by phase solubility method.The important process parameters affecting the initial extraction rate were separately studied and the reaction rate equations were deduced.The optimal conditions for kinetic study were as follows:stirring speed of 75 r·min~(-1),interfacial area of 12.56 cm~2,pH of 2.5,initial HE-β-CD concentration of 0.05 mol·L~(-1),initialα-CPMA concentration of 5 mmol·L~(-1),and temperature of 278 K.The reaction has been found to be first order inα-CPMA and second order in HE-β-CD with the forward rate constants of 2.056×10~(-3)m~6·mol~(-2)·s~(-1)and 1.459×10~(-3)m~6·mol~(-2)·s~(-1)for(S)-α-CPMA and(R)-α-CPMA,respectively.The complexation equilibrium constants were evaluated as 61 L·mol~(-1) and 117 L·mol~(-1)for(S)-α-CPMA and(R)-α-CPMA,and the intrinsic enantioselectivity is estimated as 1.92.     

Analysis of the Interaction between Organophosphorus Acid and Tertiary Amine Extractants in the Binary Mixtures by Fourier Transform Infrared Spectroscopy (FT-IR)

In the synergistic solvent extraction of rare earth elements by binary mixtures of organophosphorus acid and tertiary amine extractants, the extraction reaction depends on the nature and strength of the interaction between the two extractants in the mixtures. In order to correlate qualitatively the interaction in different mixtures, the FT-IR spectra for organophosphorus acid (D2EHPA, PC88A, and Cyanex 272) and tertiary amine (Alamine 336 and TEHA) extractants and their mixtures have been analyzed. The primary focus was on investigating the changes in the characteristic functional groups of acidic and amine extractants in the binary mixtures as the strength and concentration of these extractants varied. IR spectroscopy of the organics confirmed the interaction in the binary mixtures, and strength of the interaction increased with the increase in the acidity of acidic extractant and the basicity of the amine extractant.     

Recovery of zinc from pickling baths with amberlite LA-2. Influence of modifier on the extraction equilibrium

The extraction of zinc chloride by Amberlite LA-2, a long chain secondary alkylamine, dissolved in Shellsol K, a naphthenic solvent, has been studied at room temperature. Isodecanol was used as modifier. The aqueous phases were chloride solutions of Zn(II) and Fe(II) in the concentration range commonly encountered in pickling baths, viz. about 1 and 1.5 mol/l, respectively. The ionic strength was kept constant at 4 mol/l in all experiments. Measurement of the distribution equilibrium of zinc chloride was carried out over wide concentration ranges of amine, zinc chloride, free chloride and isodecanol. It was assumed that the zinc chloride was extracted according to the following reaction On the basis of this reaction, an easy to use model was developed to describe the extraction behaviour of Zn in typical pickling baths. Prediction and optimization of a solvent extraction plant performance under changing industrial feed conditions is then possible. This model takes account of the influence of isodecanol used as modifier.