Separation of Picric Acid with Trioctyl Amine (TOA) Extractant in Diluents

Separation of 2,4,6-trinitrophenol (Picric acid) from aqueous solution by trioctyl amine (TOA), which is a long-chain aliphatic amine, has been studied at 298 K. Diluents (alcohols) (isoamyl alcohol, octan-1-ol, decan-1-ol) have been used to dissolve TOA. Experimental results of batch extraction are calculated and reported as distribution coefficients (K_D), loading factors (Z), and extraction efficiency (E). The most effective diluent has been found to be isoamyl alcohol with a distribution coefficient value of 19.333. In this article, the linear solvation energy relationship (LSER) modeling (included Hidebrand-Hansen solubility parameters) has been done on the reactive extraction of picric acid to obtain the model parameters. Modeling using an LSER model predict a close resemblance of experimental data.     

Reactive Extraction of Formic Acid by using Tri Octyl Amine (TOA)

Abstract

Distribution of formic acid (methanoic acid) between water and tri octyl amine (TOA) dissolved in various alcohols (isoamyl alcohol, hexan-1-ol, octan-1-ol, nonan-1-ol, decan-1-ol) as diluents, as well as the extraction capacity of pure diluent alone have been studied at isothermal conditions. All measurements were carried out at 298.15 K. The difference between the physical extraction and reactive extraction was studied. The loading factor, T _T, extraction efficiency, D _E, modified separation factor, S _F, and, distribution coefficients, K _D were calculated. The isoamylalcohol was found most effective solvent with maximum distribution value of 14.521. Possible equilibrium complexation constants for (acid:amine) (5:1), (6:1), and (7:1) have been determined as values of about 21.8 × 10³, 15.6 × 10⁴, and 11.1 × 10⁵ for K₅₁, K₆₁, and K₇₁, respectively with isoamylalcohol. Furthermore, Linear Solvation Energy Relationship (LSER) model equation has been obtained to calculate distribution coefficients for alcohols with regression coefficient of 0.981.     

Extraction of Gibberellic Acid from Aqueous Solution by Trioctyl Amine (TOA)

Gibberellic acid (GA) extraction from fermentation broth by trioctyl amine (TOA), which is a long chain aliphatic amine was studied. Initial concentration of GA was 0.65 g · L^?1. This was performed using the fungi Gibberella fujikuroi in fermentation. Alcohols (isoamyl alcohol, n-octanol, n-decanol) have been used to dissolve TOA for preparing organic phases. All experiments were studied as batch extraction. Distribution coefficients (K_D), loading factors (Z), and extraction efficiency (E) were calculated. The highest extraction efficiency, distribution coefficient, and loading factor were achived with isoamyl alcohol diluent as value of 80.6, 98.7, and 4.58, respectively. Furthermore, the linear solvation energy relationship (LSER) model including Hansen solubility parameters regressed to experimental results. The LSER model predicts a close resemblance of experimental data.     

Investigations on the Reactive Extraction of Glyoxylic Acid by Amberlite-LA2 Dissolved in Alcoholic Diluents

In this study, reactive extraction of glyoxylic acid (0.93 kmol·m^?3) using Amberlite-LA2 (0.24 to 1.67 kmol·m^?3) in five different alcoholic diluents is performed at 298 K. The extraction ability of Amberlite-LA2 is found to be in the order of isoamylalcohol (IAA) > nonan-1-ol > octan-1-ol > decan-1-ol > dodecanol. Maximum extraction efficiency, 98.92% is obtained at 1.67 kmol·m^?3 of Amberlite-LA2 in IAA. The values of stoichiometric coefficient (m), overall equilibrium constant (K_E) and individual constants (K₁₁, K₂₁, and K₁₂) are estimated. The effect of diluent on K_D is also quantified by applying LSER model using solvatochromic parameters of diluents.     

Reactive extraction and LSER model consideration of lactic acid with tripropylamine+organic solvent systems from aqueous solution at room temperature

The extraction of lactic acid was done by tripropylamine (TPA) dissolved in seven single solvents (isoamyl alcohol, heptan-1-ol, hexan-1-ol, octan-1-ol, nonan-1-ol, decan-1-ol, and dodecanol). All measurements were carried out at 298.15 K. The extent to which the organic phase may be loaded with lactic acid is expressed as loading ratio, Z, its value extraction efficiencies, E, and overall particular distribution coefficients, D, were calculated. Equilibrium complexation constants for (acid:amine) (1:1), (1:2) have been determined according to Bizek's approach. The maximum removal of lactic acid accomplished was about 81% with isoamyl alcohol having 1.935 mol dm^− 3 initial concentration of TPA. All of the obtained data have been correlated by linear solvation energy relationship (LSER) model. LSER model results were compared with the experimental results and well agreement between them was observed. Regression coefficient (R²) of LSER model is 0.972.     

A Study on Glutaric Acid Extraction by Tridodecylamine: Equilibria and Models

The extraction of glutaric acid was studied using tridodecyl amine (TDA) with respect to the functional groups of the diluent. The diluents studied were 1‐octanol (alcohol), methyl isobuthyl ketone, MIBK (ketone), and toluene (aromatic hydrocarbon) and these were used to dilute the TDA. The experimental results of batch extraction experiments are reported as distribution coefficients, D_C, loading factors, Z, and extraction efficiency, E. All measurements were carried out at 298.15 K. The results of the liquid‐liquid equilibrium measurements are correlated by a linear solvation energy relationship (LSER) model that takes into account physical interactions and modified Freundlich and Langmuir equations. The experimental results are compared with model results.     

Comparative Study on Reactive Extraction of Picolinic Acid with Six Different Extractants (Phosphoric and Aminic) in Two Different Diluents (Benzene and Decan-1-ol)

The equilibrium study on reactive extraction of picolinic acid by six different extractants (phosphoric and aminic) dissolved in two different diluents (benzene and decane-1-ol) is carried out to evaluate the performance of extractants and diluents. The extraction ability in terms of the distribution coefficient (K _D) is found to be in the order of tri-n-octylamine (TOA) ≥ tri-n-dodecylamine (TDDA) > di-2-ehylhexyl phosphoric acid (D2EHPA) > tri-n-butyl phosphate (TBP) > tri-octyl methyl ammonium chloride (Aliquat 336) > tri-n-octyl phosphine oxide (TOPO) with both diluents. Decan-1-ol is found to be the better solvating medium for the acid-extractant complexes. A mathematical model based on mass action law is employed to estimate the values of partition coefficient (P) and dimerization constant (D) in physical extraction, and equilibrium extraction constants (K _E) in chemical extraction. The values of loading ratios (Z) less than 0.5 imply the formation of (1:1) acid:extractant solvates in the organic phase. Decan-1-ol with TOA is the most effective solvation medium with K _{D, max} = 9 at 0.01 kmol · m^?3 of picolinic acid and K _E = 19.448 m³ · kmol^?1.     

Reactive Extraction of Pyridine Carboxylic Acids with N,N-Dioctyloctan-1-Amine: Experimental and Theoretical Studies

The paper represents the equilibrium study on reactive extraction of pyridine-3-carboxylic acid (NA) and pyridine-4-carboxylic (iNA) acid from aqueous solution by N, N-dioctyloctan-1-amine (TOA) dissolved in five different diluents [dodecane, methyl benzene, decan-1-ol, 4-methylpentan-2-one (MIBK), and chloroform] at constant temperature of 298 ± 1 K. According to an experimental study, the extraction ability of diluents with TOA is found to be in the order of chloroform > decan-1-ol > MIBK > methyl benzene > dodecane for both acids. The highest extraction efficiency in terms of the distribution coefficient (K _D) is found to be 45.15 and 25.79 for NA (0.12 mol · dm^?3) and iNA (0.03 mol · dm^?3), respectively. The values of loading ratio, Z (between 0.194 and 0.512) for both acids indicate the formation of 1:1 acid-TOA complexes in the organic phase. The values of the equilibrium constants (K ₁₁) are determined from the experimental data using mass action law. These estimated values of K ₁₁ are compared with the predicted values of K ₁₁ from relative basicity and linear solvation energy relationship (LSER) models. The LSER model predicts the K ₁₁ with an error limit of ±3% for NA and ±2% for iNA.     

Solvent modification effect on the physical and chemical extraction of acetic acid

Combined use of inert diluents with polar modifiers enables former to be utilized for the recovery of polar value-added chemicals. The results show that polarities of both solvent and modifier are critical for efficient separations. Thus, K_D values with 1-octanol were higher than those with 1-decanol; however, those with xylene were superior to those with hexane and toluene. Increasing the amine concentrations increased the K_D values, in contrast to the trends with pH and temperature. About 33%, 79% and 67% of acetic acid was recovered using 25% (v/v) Alamine 336 in xylene, 1-octanol and 30% 1-octanol-modified xylene, respectively. Therefore, solvent modification positively affects the extraction power of inert diluents for acetic acid recovery.     

Extraction Equilibria of Butyric Acid with Organic Solvents

Abstract

Fourteen solvents (five with a tertiary amine and different diluents, four C8-C18 alcohols, dibutylether, two hydrocarbons, and two vegetable oils) have been tested for the extraction of butyric acid. The highest distribution coefficient for butyric acid is shown by solvents with tertiary amines. A ternary solvent with amine extractant, n-alkanes as diluent, and higher alcohol as modifier can be advantageous in this procedure. Amines enable the extraction of acid at a pH above the pK _a value up to about pH 5.6. With an increase of the molecular weight of alcohol, the value of the distribution coefficient decreases. Its value for pure alcohols is independent of the concentration of acid in the aqueous phase. Equilibrium data suggest that the stoichiometry of the acid-alcohol complex is 2:1, and only undissociated acid is extracted.     

Characteristics of Lactic Acid Transport in Supported Liquid Membranes

Abstract

Transport of lactic acid in supported liquid membranes containing tertiary amines (Alamine 336, Henkel Corp.) as the carrier was investigated. Both equilibrium extraction constants (K _t) and effective diffusion coefficients (D) of the acid-amine complex were measured for systems with various diluents. Larger K _t values and, thus, more efficient extraction were found when diluents were used, especially with oleyl alcohol which improved the polarity of the oil membrane and led to an approximately sixtyfold increase in the K _t value. Experimental results of D for different supported liquid membranes were found in the range of 2 to 7 × 10^?7 cm²/s. Although much lower than those predicted by the Wilke-Chang equation, the values are consistent in the orders of magnitude with the literature results for other permeates in similar supported liquid membranes.     

INFLUENCE OF SOLVENT POLARITY ON INTERFACIAL MECHANISM AND EFFICIENCY OF SUCCINIC ACID REACTIVE EXTRACTION WITH TRI-n-OCTYLAMINE

This article presents the results of a comparative study of reactive extraction of succinic acid with tri-n-octylamine (TOA) dissolved in solvents with different dielectric constants (dichloromethane, n-butyl acetate, and n-heptane), with and without octan-1-ol addition as phase modifier. The positive effect of octan-1-ol on extraction efficiency was quantified by means of amplification factors. For all studied systems, the addition of octan-1-ol into the solvent phase led to an increase of extraction efficiency, the most important effect being recorded for the solvent with the lowest polarity, namely n-heptane. The maximum value of amplification factor was reached for pH = 6 and indicated an increase of reactive extraction yield of about 1.26 times for dichloromethane, 1.55 times for n-butyl acetate, and 2.88 times for n-heptane.     

Extraction Equilibria of 4-Hydroxypyridine using Di (2-ethylhexyl) Phosphoric Acid

Extractions of 4-Hydroxpyridine (4HP) from aqueous solutions using Di(2-ethylhexyl)phosphoric acid (D2EHPA) as extractant in 1-octanol and kerosene were studied. The factors that affected the distribution coefficient (D), such as equilibrium pH, the concentration of D2EHPA, and the type of diluents were discussed. The interaction mechanism between 4HP and D2EHPA was validated by infrared spectroscopic analysis. D increased with the increase of the concentration of D2EHPA and peak values appeared at equilibrium pH = 3.6–5.0. D in the polar diluent (1-octanol) was much higher than those in the non-polar diluent (kerosene). The extraction reaction was found to be a proton-transfer process and D2EHPA mainly reacted through its –OH with –N– of 4HP. The apparent reactive extraction equilibrium constants K ₁₁ and K ₁₂ were obtained by fitting the experimental data of extraction equilibrium. By comparing calculated D values from the proposed model with the experimental ones, the accuracy of the proposed model was examined.     

Intensification of Nicotinic Acid Separation using Organophosphorous Solvating Extractants by Reactive Extraction

Nicotinic acid (3‐pyridine carboxylic acid) is widely used in food, pharmaceutical, and biochemical industries. Compared to chemical methods, enzymatic conversion of 3‐cyanopyridine is an advantageous alternative for the production of nicotinic acid. This study is aimed to intensify the recovery of nicotinic acid using reactive extraction with organophosphorus solvating extractants such as tri‐n‐octyl phosphine oxide (TOPO) and tri‐n‐butyl phosphate (TBP). The distribution of nicotinic acid between water and phosphorus‐based solvents dissolved in various diluents and the comparison of extraction efficiency with pure diluents are studied at isothermal conditions. Pure diluents are not found to be good extracting agents and the maximum distribution coefficient (K_D) obtained with 1‐octanol is 0.31. Experimental studies are carried out to investigate the effect of diluent, initial acid concentration, extractant type, and extractant composition on the degree of extraction. The maximum recovery of nicotinic acid is obtained by dissolving TOPO in MIBK at an initial nicotinic acid concentration of 0.10 kmol/m³. Solvation numbers and extraction equilibrium are also estimated with both TBP and TOPO.     

Parametric optimization of green synergistic reactive extraction of lactic acid using trioctylamine,Aliquat336, and butan-2-ol in sunflower oil by response surface methodology

A novel green synergistic reactive extraction technique for the removal of lactic acid (LA) from aqueous solution was explored. Response surface methodology (RSM) was applied to optimize the process variables for LA synergistic reactive extraction using a mixture of trioctylamine and Aliquat336 as extractants. During this present investigation, 2-butanol and sunflower oil were used as organic and green diluent. Systematic investigation has been carried out to obtain the optimum process conditions viz. initial LA concentration, pH of aqueous solution, extractant ratio, extractant concentration, solvent ratio, phase ratio, temperature, stirring speed, and contact time for maximizing the LA distribution coefficient (K_D) and extraction efficiency (%, η). The highest experimentally achievable LA distribution coefficient (K_D) and extraction efficiency (%) at optimized process conditions were found to be in close agreement with those predicted by numerical optimization using RSM. Thus, the results of present finding have been shown a great ability of sunflower oil as an economic and environmentally friendly green solvent for LA extraction.     

Aggregation of unsaturated long-chain fatty alcohols in nonaqueous systems

Aggregation and related phenomena in nonaqueous binary and ternary solutions containing unsaturated long-chain fatty alcohol amphiphiles have been studied. Six C₁₈ fatty alcohols were studied—oleyl alcohol (9Z-octadecen-1-ol), elaidyl alcohol (9E-octadecen-1-ol), linoleyl alcohol (9Z, 12Z-octadecadien-1-ol), elaidolinoleyl alcohol (9E, 12E-octadecadien-1-ol), linolenyl alcohol (9Z, 12Z, 15Z-octadecatrien-1-ol) and elaidolinolenyl alcohol (9E, 12E, 15E-octadecatrien-1-ol). Equivalent conductivity and photon correlation spectroscopy confirmed that unsaturated long-chain fatty alcohols form large and polydisperse aggregates in methanol. Critical micelle concentration (CMC) results showed that the degree of unsaturation and configuration of the double bonds in the fatty alcohol significantly influences aggregation. Aggregation of oleyl alcohol in a series of straight and branched medium-chainlength (C₃-C₈) alkanol solvents was studied. For shorter-chained alkanols (C₁-C₄), decreasing solvent dielectric constant decreases the CMC; however, for longer-chained alkanols (C₄-C₈), no significant effects occurred on the CMC. The effect of solubilized soybean oil on the viscosity of long-chain fatty alcohol/methanol solutions was also analyzed. Relative viscosity results were consistent with those expected for microemulsions. Although preliminary in nature, these results generally support the notion that soybean oil is solubilized by incorporation into large soybean oil-in-fatty alcohol aggregates in methanol solvent, resembling a nonaqueous detergentless microemulsion. Presented at the 67th Colloid and Surface Science Symposium, Toronto, Canada, June 20–23, 1993.     

Solvent-free Oxidation of Primary Alcohols to Aldehydes using Supported Gold Catalysts

Supported Au catalysts are investigated for the oxidation of primary alcohols under solvent-free conditions in the absence of base. Three representative primary alcohols have been investigated: benzyl alcohol, octan-1-ol and geraniol using a range of supports for gold nanocrystals prepared using coprecipitation, deposition precipitation and impregnation. For benzyl alcohol and octan-1-ol selective oxidation to the corresponding aldehydes is observed, particularly with Au/CeO₂, whereas for more acidic supports, e.g. Fe₂O₃, subsequent oxidation of the aldehydes to the corresponding acids, forming an ester (benzyl benzoate, octyl octanoate, respectively) by reaction with the alcohol, by a standard acid-catalysed mechanism. Alternatively, the mechanism of ester generation could involve hemiacetal formation between the aldehyde and residual alcohol, followed by direct oxidation to the observed ester. The reaction of geraniol is much more complex and the reaction is carried out in the presence and absence of acids to gain a full understanding of the interplay between oxidation and isomerisation reactions. Comparison with other active catalysts reveals that using Au catalysts in solvent free conditions gives very high turnover frequencies for the synthesis of the aldehydes with 100% selectivity (150 h⁻¹ and 26 h⁻¹ for benzyl alcohol and octan-1-ol, respectively), which are comparable to the best reported to date for these reactions.     

Liquid–Liquid Extraction of Isovaleric Acid Using Alamine 308/Diluent and Conventional Solvent Systems: Effect of Diluent and Acid Structure

Abstract

Distribution of isovaleric (3‐methyl butanoic) acid between water and Alamine 308 (triisooctylamine) dissolved in C₅ and C₆‐ring included diluents of proton‐donating and ‐accepting (cyclopentanol, cyclohexanone), polar (chlorobenzene) and inert (toluene) types, as well as a comparison with the extraction equilibria of pure diluent alone (chloroform) have been studied at 298 K. Among the tested C₆ ring‐containing and aliphatic diluents, cyclic alcohol/amine system yields the highest synergistic extraction efficiency. The strength of the complex solvation was found to be reasonably large for halogenated aromatics favoring mainly the formation of acid₁‐amine₂ structure. The influence of the acid structure over distribution has been interpreted through comparing the extractabilities of seven acids containing different functional groups, i.e., isovaleric, formic, levulinic, acetic, propanoic, pyruvic and nicotinic acids. The results were correlated using a modified linear solvation energy relation (METLER) and versions of the mass action law, i.e., a chemodel approach and a modified Langmuir equilibrium model comprising the formation of one or two acid‐multiple amines complex formation.     

Treatment of settled piggery waste by a down‐flow anaerobic fixed bed reactor

A study of the effect of organic volumetric loading rate (B_V) on the performance of a down‐flow anaerobic fixed bed reactor (DFAFBR) treating settled piggery waste was carried out at a range of between 1.1 and 6.8 g COD dm^?3 d^?1. The reactor operated at good removal efficiencies and stability under the operational conditions studied. Logarithmic empirical equations described adequately the removal efficiency for different parameters studied (COD, SCOD, BOD, TS, VS, TSS, VSS and phosphorous). Although process stability was affected by the increase of B_V, process failure was not observed. A logarithmic relationship was found to describe the influence of B_V on the TVFA/alkalinity ratio (p). A linear correlation was found between the effluent substrate concentration and the values of p and between p and the CO₂/CH₄ ratio in the biogas. The effect of the hydraulic volumetric loading rate (H_V) on the flow pattern of the reactor was evaluated. Dispersion number (D_n) was in the range of 0.17–0.37 for the maximum and minimum values of H_V studied, respectively. The ratio between the real and theoretical HRT increased as the H_V decreased. These results demonstrate that axial dispersion increased as the H_V and the Reynolds number decreased. Due to the hydraulic behaviour of the reactor, the kinetic model developed by Lawrence and McCarty was used for describing the experimental results obtained. Maximum specific substrate removal rate (K), specific organic loading rate constant (K_L), microbial decay coefficient (K_d), microbial yield coefficient (Y), maximum microbial growth rate (U_M) and saturation constant (K_S) were found to be: 3.1 (g COD g VSS^?1 d^?1), 3.0 (g COD g VSS^?1 d^?1), 0.062 (d^?1), 0.15 (g VSS g COD removed^?1), 0.39 (d^?1) and 2.6 (g SCOD dm^?3), respectively. Copyright © 2004 Society of Chemical Industry     

Comparison of Overall Gas‐Phase Mass Transfer Coefficient for CO2 Absorption between Tertiary Amines in a Randomly Packed Column

The mass transfer performance of CO₂ absorption into an innovative tertiary amine solvent, 1‐dimethylamino‐2‐propanol (1DMA2P), was investigated and compared with that of methyldiethanolamine (MDEA) in a packed column with random Dixon‐ring packing. All experiments were conducted under atmospheric pressure. The effects of inert gas flow rate, amine concentration, liquid flow rate, CO₂ loading, and liquid temperature on mass transfer performance were analyzed and the results presented in terms of the volumetric overall mass transfer coefficient (K_Ga_v). The experimental findings clearly indicate that 1DMA2P provided better mass transfer performance than MDEA. For both 1DMA2P and MDEA solutions, the K_Ga_v increased with rising amine concentration and liquid flow rate, but decreased with higher CO₂ loading. The inert gas flow rate only slightly affected the K_Ga_v. A satisfactory correlation of K_Ga_v was developed for the 1DMA2P‐CO₂ system.