Tri-n-octylamine Research Articles

Reactive Extraction of Levulinic Acid using Tri-n-octylamine in 1-Octanol: Equilibria and Effect of pH

Reactive extraction is a sophisticated separation technique used for the recovery of carboxylic acids from fermentation broth. Levulinic acid is a versatile chemical. A right combination of extractant and diluent will provide a high yield. The reactive extraction of levulinic acid from aqueous solution with tri-n-octylamine (TOA) dissolved in 1-octanol was investigated at room temperature. The effect of pH was studied. From the physical and chemical equilibrium experimental results, the distribution coefficient (KD), extraction efficiency (E%), loading ratio (Z), stoichiometric loading factor (ZS) and modified separation factor (Sf) are calculated. It was found that physical extraction provided less yield compared to chemical extraction. A maximum KD was obtained as 5.248 using 40% TOA (0.9059 mol/L) while 83.99 % of the levulinic acid was extracted. By increasing the initial concentration of levulinic acid increased the concentration of levulinic acid in both the organic phase and aqueous phase. As the concentration of TOA increases from 10 to 40 % (0.2264 mol/L to 0.9059 mol/L), the distribution coefficient and extraction efficiency also increase. By increasing the pH from 3 to 7, the distribution coefficient and extraction efficiency were drastically affected.

Tri-n-octylamine impregnated Seplite LX-16 resin for extraction of U(VI) from sulfate medium

Impregnation of tri-n-octylamine (TOA) into Siplite LX-16 resin, by two commonly used methods namely; wet and dry impregnation method, was studied and applied for uranium extraction from sulfate medium. The resin beads were characterized using FT-IR and FE-SEM analysis. The influence of different parameters such as effect of TOA concentration, pH, aqueous sample and eluant flow rates were investigated. Maximum sorption of U(VI) was obtained using 30% TOA/Siplite LX-16 prepared by the dry method at a pH range of 1.4–1.6. Flow rate of 1.0 mL/min for the pregnant sample was favorable for quantitative sorption of uranium during the extraction step while the flow rate of 0.5 mL/min for eluant solution was effective for the elution step. TOA-impregnated Siplite LX-16 resin has been properly prepared and applied for U(VI) extraction from sulfuric acid medium.

Liquid-liquid extraction of mineral acids using Tri-n-octylamine

The present work reports the extraction behaviors of mineral acids: HClO4, HNO3, HCl and H2SO4 (commonly found in acidic bleed solutions from the hydrometallurgical route of metal extraction processes) by tri-n-octylamine (TOA) dissolved in distilled colorless kerosene. The systems have been investigated as functions of various experimental parameters, such as time, [acid], [TOA], temperature, extraction stage and the organic to aqueous phase volume ratio (O/A). Strippings was also examined. Equilibration time is less than 60 min. The acid concentration in the organic phase at equilibrium is increased with increasing initial acid concentration in the aqueous phase for all systems. However, the is after %extraction decreased with increasing initial acid concentration in the aqueous phase. The % extraction increased remarkably with increasing [TOA] for all cases. Being the ratio of the [acid] in the organic to aqueous phase at equilibrium equal to extraction ratio, D; the log D vs. log [TOA] plot is almost a curve with slope 1 at lower concentration region and with slope ~2 at higher concentration region. The extraction efficiency of TOA varies in the order: HClO4> HNO3> HCl > H2SO4. The acid-base-neutralization (extraction) reactions are exothermic with ΔH value much higher than -57 kJ/mol obtainable for of a strong acid - strong base neutralization. The loading capacity of extractant (g per 100 g TOA) for acids varied in the order: HClO4 (30.69) > HNO3 (20.49) > H2SO4 (17.87) > HCl (10.31). On using lower organic to aqueous phase volume ratio (O/A), the organic phase saturated with acid can be obtained on stage-wise extraction. The extracted organic phase, for all systems (excepting H2SO4-system) under investigation, can be stripped effectively in a single stage by 0.10 g eq/L NaOH solution to the extents of more than 96%. However, for H2SO4-system, two-stage stripping will be found effective.
 Bangladesh J. Sci. Ind. Res.54(4), 339-346, 2019

Reactive extraction of levulinic acid using tri-n-octylamine in 1-hexanol

Reactive extraction of levulinic acid using trin- octylamine (TOA) in 1-hexanol was investigated by physical and chemical extractions from aqueous solution at room temperature. Using the equilibrium data, the distribution coefficient (KD), extraction efficiency (E%), loading ratio (Z), stoichiometric loading factor (ZS) and modified separation factor (Sf) are evaluated. It was observed that chemical extraction provided a better yield than physical extraction. A maximum KD was obtained as 10.715 using 40% TOA (0.9059 mol/L) while 91.46% of the levulinic acid was extracted. By increasing the initial concentration of levulinic acid resulted in a decrease of KD and E%. The KD and E% increased by increasing the TOA concentration from 10 to 40% (0.2264 mol/L to 0.9059 mol/L).

Study on the Biocompatible Solvent Systems for the Reactive Extraction of Itaconic Acid

The separation of itaconic acid (0.2 mmol·kg–1) from its aqueous solution is performed by dissolving tri-n-octylamine (TOA) in the biocompatible mixtures of 1-decanol + n-dodecane, dodecanol + n-dodecane, and oleyl alcohol + n-dodecane at different compositions. Also, the physical extraction data are presented with dodecane, oleyl alcohol, dodecanol, and 1-decanol. Here, fixing the TOA composition at 20 vol %, the vol % of modifiers (oleyl alcohol, dodecanol, and 1-decanol) is changed from 20 to 60 vol % in dodecane (diluent) to find the best combination for the extraction of the acid. The extraction system comprised of 20 vol % TOA + 40 vol % dodecanol + 20 vol % n-dodecane gives the best separation efficiency (95.06%). Then, with this solvent system, equilibrium studies are carried out at different acid concentrations (0.05 and 0.251 mmol·kg–1). Based on the theoretical study, the insights of the extraction mechanism are determined in terms of equilibrium constants (overall and individual, KE, K11, and ...

Reactive extraction of gallic acid from aqueous solution with Tri-n-octylamine in oleyl alcohol: Equilibrium, Thermodynamics and optimization using RSM-rCCD

Concern of the recovery of important constituents found in nature, industrial waste streams and fermentation broth, the present study is aimed to recover gallic acid (HGA) from aqueous solution using tri-n-octylamine (TOA) in a non-toxic diluent, oleyl alcohol (OA). The optimal conditions for maximum extraction of HGA (90.1%) are determined as (i) initial concentration of HGA (CHGA,o) = 0.0588 mol/L, (ii) initial TOA concentration (C¯TOA,o) = 0.2762 mol/L, (iii) pH = 2.0 and (iv) temperature (T) = 25.0 °C, at atmospheric pressure (101.325 kPa), using response surface methodology (RSM) with rotatable central composite design (rCCD). The statistical analysis with ANOVA is used to model fitness and shows a high coefficient of determination (R2 = 97%). At optimum conditions, the insights of reactive extraction are determined using differential evolution (DE) approach, a bio-inspired algorithm. The apparent stoichiometric coefficient (number moles of acid per mole of extractant, m = 1.28) of reactive extraction, overall equilibrium constant (KE = 85.77) and individual equilibrium constants (K11 = 110.32 and K21 = 1106.77) are calculated. Thermodynamic study at four different temperatures (20, 30, 40 and 50 °C) is also carried out to determine enthalpy (ΔH = −12.97 J/mol), entropy (ΔS = −3.77 J/mol·K) and Gibb’s energy change (ΔG = −12370.44 to −5399.96 J/mol·K) of reactive extraction.

Swing processes for solvent regeneration in liquid-liquid extraction of succinic acid

Solvent regeneration processes for liquid-liquid extraction of succinic acid (HSuc) from aqueous streams were investigated. Tri-n-octyl amine (TOA) and tri-n-octyl phosphine oxide (TOPO) in methyl isobutyl ketone (MIBK) showed good extraction. For 20 wt% TOA in MIBK, addition of pentane at anti-solvent-to-solvent ratio of 1 (vol/vol) decreased KD from 10.2 to 0.46, applying ethane at 30 bar decreased KD to 0.45 and increasing the temperature to 60 °C decreased KD to 1.6. Evaporation of MIBK from a solvent of 40 wt% TOA in MIBK decreased KD from 10.2 to 4.0. For these processes, capital investments and energy requirements were calculated for 10 kiloton per year at a concentration factor of 5. Costs of all processes to obtain the product at maximum solubility are less than evaporation (2600 kJ/kg product at maximum solubility). A combination of a swing in diluent and temperature results in higher product concentrations after back-extraction, and reduced the energy input to obtain the pure HSuc to 19 MJ/kg. The ethane-based process is most effective with 13 MJ/kg to obtain the pure HSuc product. Although additional capital investments for compressors and pumps are required, only 110 days of production are required for return on investments.

The potential of polystyrene-block-polybutadiene-block-polystyrene triblock co-polymer as a base-polymer of polymer inclusion membranes (PIMs)

The use of polystyrene-block-polybutadiene-block-polystyrene triblock co-polymer (SBS) as the base-polymer of polymer inclusion membranes (PIMs) is studied for the first time. SBS is an inexpensive and accessible thermoplastic elastomer which possesses the required properties to be used as a base-polymer in PIMs, namely mechanical strength and high resistance to acids/bases. Its compatibility with commonly used extractants in PIMs was assessed and it was observed that successful PIMs could be obtained when di(2-ethylhexyl)phosphoric acid (D2EHPA), LIX84I or tri-n-octylamine (TOA) were used as the extractants. The performance of these PIMs was investigated for the extraction of Zn(II), Cu(II) and Cr(VI), respectively, although only the TOA-based PIMs did not perform well. Both D2EHPA- and LIX84I-based PIMs were characterized by water contact angle measurements, atomic force microscopy, differential scanning calorimetry, and Fourier transform infrared spectroscopy. In comparison with PIMs containing other base-polymers, the SBS-based PIMs were found to extract faster and more Zn(II) or Cu(II), and moreover, the LIX84I-based PIM did not require the inclusion of an expensive plasticizer unlike its counterparts containing other commonly used base-polymers. The stability of these PIMs was also assessed over three transport cycles (i.e., simultaneous extraction and back-extraction), and it was observed that the transport rate decreased significantly when using D2EHPA-based PIMs, and in the case of LIX84I-based membranes it stabilized after the first cycle.

Separation of Protocatechuic Acid Using Tri-n-Octylamine: Experimental and Mathematical Investigation

Protocatechuic acid has wide pharmacological significance. The separation of protocatechuic acid (0.001–0.01 mol·kg–1) from tri-n-octylamine (TOA) (0.3140–2.827 mol·kg–1), in petroleum ether, toluene, and isobutyl acetate was investigated at 298 ± 1 K as well as atmospheric pressure. The equilibrium complexation constant (KE), extraction efficiency (E), distribution coefficients (KD) as well as loading ratio (Z) are used to explain the magnitude of protocatechuic acid loading in the organic phase. The best diluent was isobutyl acetate having a maximum distribution value as 4.57 and efficiency of 82.06% for 0.01 mol·kg–1 protocatechuic acid and 2.827 mol·kg–1 TOA concentration. For the various diluents in TOA, considering KD and %E the extraction capability was observed in the order isobutyl acetate (82.06%) > toluene (61.21%) > petroleum ether (58.88%). The design parameters for the extraction process, minimum ratio of solvent to feed (S/Fmin), and theoretical stages required were calculated. The Langmuir...

Extractive Separation of Acetic Acid from Aqueous Solution using Tertiary Amine + Biodiesels at 298±K

The present paper deals with the removal of acetic acid from aqueous solution using Tri-n-octyl amine (TOA) as extractant in biodiesels synthesized from sunflower, sesame and rice bran. Batch extraction of acetic acid from aqueous solution was carried out and extraction efficiency and loading factors were calculated by varying initial acid concentration and the percentage of Tri-n-octyl amine (TOA) in biodiesels on volume/volume basis. For sunflower oil biodiesel system- the extraction efficiency lies between 57.74 (10% TOA)-77.14 (30% TOA), for sesame oil biodiesel system- the extraction efficiency lies between 53.31 (10% TOA)-79.79 (30% TOA) and for ricebran oil biodiesel system- the extraction efficiency lies between 58.10 (10% TOA)-76.50 (30% TOA). The results revealed that the combination of TOA and biodiesel is efficient for removing acetic acid from aqueous solution.

Efficacy of tri-n-octylamine, tri-n-butyl phosphate and di-(2-ethylhexyl) phosphoric acid for reactive separation of protocatechuic acid

ABSTRACTOwing to its chemical and pharmacological significances, the efficacy of reactive separation of protocatechuic acid (0.001–0.01 kmol m−3) from aqueous stream by means of tri-n-octylamine (TOA), di-2-ethylhexyl phosphoric acid (D2EHPA) as well as tri-n-butyl phosphate (TBP) in octanol has been investigated, in terms of extraction efficiency, loading ratio, equilibrium complexation constants, and distribution coefficients. Extraction ability was obtained in the order TOA (91.2%) > TBP (88.64%) > D2EHPA (86.43%). In all cases, 1:1 protocatechuic acid:extractant complex is obtained. Further, diffusion coefficients, number of stages for extraction systems, and relative basicity model were used for relating the efficacy.

Towards an in situ product recovery of bio‐based 3‐hydroxypropionic acid: influence of bioconversion broth components on membrane‐assisted reactive extraction

AbstractBACKGROUNDBioconversion broths are complex media with microorganisms that convert substrates into products in the presence of salts and nitrogen sources and that may release biomolecules. This paper deals with the impact of bioconversion broth components on the membrane‐based reactive extraction of 3‐hydroxypropionic acid (3‐HP) by tri‐n‐octylamine (TOA) in n‐decanol in preparation for an in situ product recovery. The focus here is on the influence of 3‐HP concentration (0.5–10 g L−1), initial pH of the solution (3–5) and presence of proteins and salts on the extraction yield and kinetics.RESULTSIt was found that reducing the initial acid concentration caused an acceleration of the extraction kinetics because of a higher extent of complexation with TOA. pH effects were dramatic, as enhancing the pH from 3 to 5 decreased the extraction yield from 74% to only 5% due to acid dissociation. Proteins were shown to have negligible impact on the extraction yield and kinetics, probably because of their negligible mass transfer resistance at the liquid–liquid interface compared with the membrane. Conversely, the presence of salts (potassium chloride and potassium biphosphate) was highly detrimental. The decrease in extraction yield was shown to be due to an anion exchange between the carboxylate anion of 3‐HP in the organic phase and the anion of the salt in the aqueous phase. Chloride ions had more impact than biphosphate ions.CONCLUSIONThese results give valuable information for the implementation of a membrane‐based reactive extraction as an in situ product recovery process, suggesting recommendations for bioconversion tuning. © 2018 Society of Chemical Industry

Liquid-liquid extraction of Zr(IV) from sulphuric acid medium using tri-n-octyl amine in kerosene

The extraction behavior of Zr(IV) with tri-n-octyl amine (TOA) in kerosene was studied through a new method of solvent extraction. The mechanism of extraction and the species extracted were identified. Quantitative extraction of Zr(IV) with TOA in kerosene was studied by changing different parameters such as acid variation, diluent effect, metal concentration variation, extractant variation, effect of salting out reagent concentration and effect of temperature. It was observed that the percentage of extraction of Zr(IV) increased when the concentration of TOA and the percentage of extraction also increased when the metal ion concentration increased. The percentage of Zr(IV) became 97.4% with 0.1 M TOA from 3.0 M sulphuric acid. Kerosene was found to be effective diluent for the extraction of Zr(IV) with TOA.

Solvent Extraction of Rhodium from Chloride Solutions added Tin(II) with Amine Extractants

Chloride is one of the effective medium in which platinum group metals (PGMs) can be brought into a solution, thus chlorocomplexes are particularly important in the process chemistry of PGMs separations. Rh (III) chlorocomplexes are poorly extracted into organic solvents, which is due to the charge of the complex as well as those inert character in a solution, that is, formation of RhCl6-n(H2O)n(3-n) - (n=1-6) . The problem of solvent extraction of Rh from chloride solutions has not yet been solved and there is no effective industrial extractant for Rh. PGMs are traditionally separated from one another and the other metals by a complex series of selective precipitation techniques. These are generally inefficient in terms of the degree of separation achieved. Solvent extraction applied to refining process for PGMs offers several advantages over the traditional precipitation methods. Adding Sn (II) to a Rh (III) feed is a good procedure which can be used to make Rh react more easily to extraction, however, stripping of Rh from the loaded organic pahse is very difficult. In the present study, the extraction of Rh from hydrochloric acid solutions with tri-n-octylamine (TOA) and tri-octyl methyl ammonium chloride (TOMAC) were tested to clarify the effect of addition of Sn (II) on the extraction of Rh and stripping of Rh.

Modeling and Optimization of Reactive Extraction of Isonicotinic Acid Using Tri-n-octylamine in Biocompatible Diluents Mixture: Response Surface Methodology and Regeneration of Solvents

The present study is aimed to recover the pharmaceutically and biochemically important compound, isonicotinic acid (iNA) from aqueous/fermentation broth in a biocompatible extraction system using an intensified approach, reactive extraction. Tri-n-octylamine (TOA) is used as extractant in nontoxic diluent mixtures of dodecane and n-decanol (modifier) in 1:1 v/v. However, modeling and optimization of reactive extraction using three process parameters, that is, initial iNA concentration in aqueous solution (0.0032–0.0368 kmol·m–3), TOA concentration in organic phase (0.110–1.259 kmol·m–3) and initial pH values of aqueous phase (1.32–4.68) is performed using response surface methodology (RSM), and the rotatable central composite design (rCCD) matrix is used in the experimental design. The RSM model suggests that initial acid concentration is the most influential factor, whereas pH value change shows antagonistic impact on %E. At equilibrium, under constraint condition (lowest TOA concentration selected) that...

Thermal Activity in Affinity Separation Techniques Such as Liquid-Liquid Extraction Analyzed by Isothermal Titration Calorimetry and Accuracy Analysis of the Technique in the Molar Concentration Domain.

The applicability and accuracy of isothermal titration calorimetry (ITC) to investigate intermolecular interactions in a high concentration domain applicable to liquid–liquid extraction (LLX) was studied for acid–base interactions. More accurate fits can be obtained using a sequential binding mechanism compared to a single reaction model, at the risk of finding a local minimum. Experiments with 0.24 M tri-n-octylamine (TOA) resulted in a residue of fit of 4.3% for the single reaction model, with a standard deviation σ of 1.6% in the stoichiometry parameter n, 12% in the complexation constant Kn,1, and 2.5% in the enthalpy ΔHn,1. For the sequential model, σ was higher: 11% in K1,1, 26% in Kn+1,1, and 12% in ΔHn+1,1. This study clearly showed that, at higher concentrations (order of moles per liter), accurate parameter estimation is possible and parameter values are concentration dependent. It is thus important to do ITC at the application concentration.

Reactive separation of protocatechuic acid using Tri-n-octyl amine and Di-(2-ethylhexyl) phosphoric acid in Methyl isobutyl ketone

Abstract Protocatechuic acid is used extensively in pharmacological and related industries which can also be obtained by fermentation. Reactive separation by means of reactive extractant is a favourable alternative to recover carboxylic acids from the aqueous dilute streams and the fermentation broth. In this paper, the reactive separation of protocatechuic acid were performed by D2EHPA (Di-(2-ethylhexyl) phosphoric acid) and TOA (tri-n-octyl amine) dissolved in MIBK (Methyl isobutyl ketone) at 298 K. Distribution coefficients, degree of extraction, complexation constants and loading ratio were estimated. The equilibrium for protocatechuic acid-extractant-diluent system was represented using Langmuir model, mass action law and relative basicity model. Results obtained from model were found to be close to experimental data. TOA was found more effective than D2EHPA for the recovery of protocatechuic acid having 5.39 as maximum distribution coefficient and 84.36% efficiency at 0.01 mol L−1 and 1.1437 mol L−1 concentration of protocatechuic acid and TOA respectively.

Thermodynamics and kinetics analysis of thermal dissociation of tri-n-octylamine hydrochloride in open system: A DFT and TGA study

The thermal dissociation of tri-n-octylamine hydrochloride (TOAHCl) in open system was investigated by TGA and DFT methods. The dissociation starts at the temperature of about 120 °C which was predicted with DFT calculations and verified by isothermal TGA. Then a thermodynamic cycle depicting the dissociation process was built. The thermal dissociation which couples with the evaporation of products tri-n-octylamine (TOA) and HCl undergoes two continuous steps due to the evaporation speed difference between the two compounds. Based on the assumption, kinetics analysis was performed by employing isoconversional methods of Friedman, Kissinger-Akahira-Sunose (KAS) and Starink. The activation energies of the two steps fall in the range of 81.1 ± 2.6 kJ mol−1 and 96.8 ± 13.4 kJ mol−1, which are comparable with the enthalpy values from 94.7 ± 5.6 kJ mol−1 to 100.1 ± 5.4 kJ mol−1.The comparability indicates that the dissociation of TOAHCl is a process with no transition state which is in accordance with the DFT prediction. Model-fitting methods were performed by simultaneous treatment of kinetic curves under different temperature programs via reaction-order kinetics mechanism. And the results reveal that the reaction orders are 0.21 and 0.07 respectively for the two steps.

Reactive Extraction of Gallic Acid Using Aminic and Phosphoric Extractants Dissolved in Different Diluents: Effect of Solvent’s Polarity and Column Design

The current study is focused on the reactive extraction of gallic acid from aqueous solution using tri-n-octylamine (TOA) and tri-n-butyl phosphate (TBP) as extractants dissolved in four different diluents (4-methylpentan-2-one, kerosene, octane-1-ol, and decane) at 298 ± 1 K and 101.325 ± 1 kPa. A mathematical model for mass action law is used for estimation of equilibrium parameters and stoichiometric coefficients. The extraction results were interpreted as distribution coefficient (KD) and degree of extraction (E). The solvent’s ability to extract acid is observed as MIBK > octane-1-ol > n-decane > kerosene and MIBK > n-decane ≥ kerosene > octane-1-ol with TOA and TBP, respectively. On basis of extraction capabilities, TOA with active diluents and TBP with inactive diluents are found suitable for recovery of gallic acid from aqueous solution/fermentation broth. The feasibility of the extraction process for a counter current reactive liquid extraction column is assessed by calculating design parameters ...

Recovery of levulinic acid by reactive extraction using tri-n-octylamine in methyl isobutyl ketone: Equilibrium and thermodynamic studies and optimization using Taguchi multivariate approach

Abstract Recovery of levulinic acid from an aqueous solution using a tertiary amine, tri-n-octylamine (TOA), as an extractant in methyl isobutyl ketone (MIBK) was studied at different temperatures (293–333 K). The physical equilibrium studies were performed using MIBK as a diluent. Partition ( P ) and dimerization ( D ) coefficients were found to decrease noticeably with increasing temperature. The coefficient of distribution was found to be very low in physical equilibrium. Chemical equilibrium studies were conducted using various concentrations of the extractant. The highest coefficient of distribution ( K D ) and efficiency of extraction ( % E ) were found to be 58.0 and 98.0% respectively for 0.1 kmol m−3 of levulinic acid and 0.678 kmol m−3 of TOA at 293 K. Chemical equilibrium studies showed the formation of 2:1 complex as the main mechanism in the reactive extraction. Taguchi mixed design multivariate approach ( L 18 ) was used to optimize the process variables. S/N ratio (larger-is-better) criterion was adopted to maximize the performance parameters. The optimum combination of variables was found to include acid concentration ( X 1 ) = 0.3 kmol m−3, TOA concentration ( X 2 ) = 0.678 kmol m−3 and temperature ( X 3 ) = 293 K. A confirmation run was conducted using these parameters and K D and % E values from this run were determined to be 11.83 and of 92.2%, respectively, which were very close to the predicted values of K D = 12.78 and % E = 94%.