Fatty and Resinic Acids Extraction from Crude Tall Oil

Abstract

The separation of fatty and resinic acidic fractions from crude tall-oil soap solutions with n-heptane by the technique of dissociation extraction is discussed. The theory of the overall process is supported by a systematic study developed to cover the high selectivity demonstrated in the differential solubility and the aptness between fatty and diterpenic acids to both liquids phases. To study the main factors affecting those liquid-liquid extraction systems and the amphiphilic behavior of such molecules involved, sodium salts aqueous solutions of crude tall oil and synthetic mixtures as molecular acidic models were used.     

Refining and Separation of Crude Tall-Oil Components

Abstract

Methods for crude tall-oil refining and fractionation involving research studies of long-chain fatty and resinic acids separation are reviewed. Although several techniques have been applied since the 1940s with industrial aims, only distillation under high vacuum is economically practicable for crude tall-oil fractionation. Techniques such as adsorption and dissociation extraction seem to be the most industrially promising for implementation in the future for the separation of long-chain fatty and resinic acids fractions with a high purity level at low cost.     

Trivalent Lanthanide/Actinide Separation Using Aqueous-Modified TALSPEAK Chemistry

TALSPEAK is a liquid/liquid extraction process designed to separate trivalent lanthanides (Ln³⁺) from the minor actinides (MAs) Am³⁺ and Cm³⁺. Traditional TALSPEAK organic phase is comprised of the monoacidic dialkyl bis(2-ethylhexyl)phosphoric acid extractant (HDEHP) in diisopropyl benzene (DIPB). The aqueous phase contains a soluble aminopolycarboxylate diethylenetriamine-N,N,N’,N”,N”-pentaacetic acid (DTPA) in a concentrated (1.0–2.0 M) lactic acid (HL) buffer with the aqueous acidity typically adjusted to pH 3.0. This process balances the selective complexation of the actinides by DTPA against the electrostatic attraction of the lanthanides by the HDEHP extractant to achieve the desired trivalent lanthanide/actinide group separation. In this study, the aqueous phase has been modified by replacing the lactic acid buffer with a variety of simple and longer-chain amino acid buffers. The results show successful trivalent lanthanide/actinide group separation with the aqueous-modified TALSPEAK process at pH 2. The amino acid buffer concentrations were reduced to 0.5 M (at pH 2), and separations were performed without any effect on phase-transfer kinetics. Successful modeling of the aqueous-modified TALSPEAK process (p[H⁺] 1.6–3.1) using a simplified thermodynamic model and an internally consistent set of thermodynamic data is presented.     

Third Phase Formation in the Extraction of Inorganic Acids by TBP in n‐Octane

Abstract

The extraction of HNO₃, HClO₄, H₂SO₄ and H₃PO₄ by 20% (v/v) TBP (0.73 M) in n‐octane was measured under identical conditions up to and beyond the critical point of third phase formation (Limiting Organic Concentration, or LOC condition). The data, together with those obtained previously for HCl, allowed us to establish the following lyotropic series of effectiveness with respect to third phase formation in the extraction of acids by TBP: HClO₄>H₂SO₄>HCl>H₃PO₄>HNO₃. This series correlates with the amount of water present into the organic phase at the point of phase splitting. This result reinforces the validity of the reverse micellar model developed previously for the extraction of metal salts by TBP. The measurements of LOC values as a function of temperature revealed major differences among the acid‐TBP systems investigated. For HClO₄, the strong increase of the LOC value with increasing temperatures is accompanied by a large favorable entropy change. The opposite is true for HCl, while H₂SO₄ and H₃PO₄ represent intermediate cases. Measurements of the LOC values for the extraction of HClO₄ by TBP dissolved in a series of diluents confirmed that topological parameters, such as the Connectivity Index, CI, are useful for predicting the critical condition for phase splitting in different diluents. Based on the linear correlation between LOC values for HClO₄ and CI values of diluents, the effective Connectivity Index of the French nuclear reprocessing diluent, HTP, a complex mixture of highly branched alkanes, was determined.     

Aggregation in Solvent Extraction Systems Containing a Malonamide,a Dialkylphosphoric Acid and their Mixtures

Abstract

Aggregation phenomena in n-alkane solutions of di-n-hexylphosphoric acid (HDHP), N,N′-dimethyl-N,N′-dioctylhexylethoxymalonamide (DMDOHEMA), and their mixtures, were investigated by electrospray ionization–mass spectrometry (ESI-MS), vapor pressure osmometry (VPO), and small-angle X-ray and neutron scattering (SAXS and SANS). The objective of the study was to probe the formation of mixed HDHP-DMDOHEMA species before and after extraction of trivalent lanthanide and actinide (M³⁺) nitrates. The most important species formed by HDHP upon metal extraction has the composition M(DHP)₃(HDHP)₃(H₂O). These species exist as spherical aggregates of the reverse micelle type with a polar core diameter of ～ 7 Å and total diameter of ～ 11 to ～ 15 Å. The aggregation of DMDOHEMA is a progressive phenomenon, with an average aggregation number of ～ 2 in the 0.2 to 0.6 M range and larger aggregates forming at higher concentrations. The metal loaded DMDOHEMA aggregates can be considered as interacting spheres with a polar core diameter between ～ 11 and ～ 16 Å, depending on composition, a total diameter of up to ～ 25 Å, and a weight-average aggregation number of ～ 9. The results obtained in this work provide strong evidence for the formation of mixed aggregates when mixtures of HDHP and DMDOHEMA are used for the extraction of trivalent Ln and An cations. These mixed reverse micelles have a diameter between 19 and 24 Å with a polar core diameter of 10 and to 14 Å. The most recurrent micellar composition is 2 HDHP and either 4 or 5 DMDOHEMA molecules.     

EFFECT OF CHAIN LENGTH OF ALKANE-1-HYDROXY-1, 1′-METHYLDIPHOSPHONIC ACIDS ON THE IRON (III) LIQUID–LIQUID EXTRACTION

ABSTRACT

(1-Hydroxy-1-phosphonohexadecyl) phosphonic acid (HPHPA) and (1-hydroxy-1-phosphonododecyl) phosphonic acid (HPDPA) were prepared by reaction of phosphorus trichloride with palmitic and lauric acids, respectively. After purification, these products were characterized by elemental microanalysis and by IR, ¹H, ³¹P?NMR spectroscopies. In this paper, we propose a tentative assignment for the shifts of those two ligands and their specific complexes with iron (III). A spectroscopic analysis has showed that coordination of iron (III) takes place via oxygen atoms. We also measured the extraction of Fe⁺³ by HPHPA and HPDPA from [CCl₄-Octanol (v/v: 90%/10%)] solutions. The complexes formed in the organic phase may be Fe[C₁₁ H₂₃C(OH)(PO₃H)₂]Cl, 3H₂O with HPDPA and Fe[C₁₅H₃₁C(OH) (PO₃H)₂]Cl, 3H₂O with HPHPA, respectively. HPHPA as ligand exhibits a stronger extracting power for Fe³⁺ and has a more hydrophobic character than HPDPA.     

Metal Extraction by Sulfur‐Containing Symmetrically‐Substituted Bisphosphonic Acids. Part I. P,P′‐di(2‐ethylhexyl) Methylenebisthio‐Phosphonic Acid

Abstract

P,P′‐dialkyl methylenebisphosphonic acids are powerful metal extraction reagents exhibiting strong affinity for a variety of metal ions, especially lanthanides and actinides. While the affinity of gem‐bisphosphonic acids is generally high for most metal ions because of their relative high acidity and ability to form six‐member chelate rings, the selectivity often is low. Thus, a strategy of incorporating soft‐donor atoms such as sulfur into gem‐bisphosphonic acids has been adopted to obtain enhanced metal selectivity while retaining high extraction efficiency. To this end a new class of sulfur‐containing gem‐bisphosphonic acid solvent extraction reagents was designed, synthesized, and evaluated for heavy element separations. Specifically, the novel sulfur‐containing P,P′‐di(2‐ethylhexyl) methylenebisthiophosphonic acid, H₂DEH[MBTP], was synthesized, characterized and its aggregation, metal extraction and acid‐base behavior assessed. Vapor phase osmometry measurements indicate that H₂DEH[MBTP] is less aggregated than its P,P′‐di(2‐ethylhexyl) methylenebisphosphonic acid analogue, H₂DEH[MBP], existing in toluene primarily as an equilibrium mixture of monomer and dimer in the concentration range studied. The acid dependency data for the extraction of Am³⁺ and Eu³⁺ from aqueous perchlorate solutions by H₂DEH[MBTP] in o‐xylene exhibit slopes close to ?3 at low acidity, consistent with extraction of a trivalent metal ion. The extractant dependency data exhibit pH dependent slopes, suggesting different stoichiometry of metal extraction under different acidities.     

Preliminary Studies on Furfural Production from Lignocellulosics

This study focused on the production of furfural from agricultural and industrial biomass residues by a hydrodistillation process. Corncobs, sugarcane bagasse, and eucalypt wood were treated with sulfuric, hydrochloric, and phosphoric acids as catalysts, with different acid concentrations (1.5 to 5.2 mol.L ^?1). In addition, the eucalypt liquor from the auto-hydrolysis, kraft-dissolving pulp production process was also investigated as a source of furfural, using sulfuric and hydrochloric acids as a catalyst (0.9 and 3.9 mol.L ^?1) . Furfural yields of 30.2, 25.8, and 13.9% were achieved for corncob, sugarcane bagasse, and eucalypt wood, respectively, on the basis of biomass dry weight. The efficiency of conversion from pentose to furfural using eucalypt liquor from the auto-hydrolysis kraft process was 71.5% using HCl 3.9 mol.L ^?1 . Due to the presence of a high amount of pentose, corncob produced the highest amount of furfural, followed by sugarcane bagasse and then eucalypt wood.     

WATER ACTIVITY IN SOLUTIONS CONTAINING ORGANIC ACIDS

ABSTRACT

A thermodynamic model for the activity coefficient was used to predict au in some food-related solutions. Water activity values for organic acids solutions (malic, tartaric and citric) were measured experimentally and used to adjust interaction parameters for the UNIFAC model. The partial dissociation phenomenon for weak electrolytes in aqueous systems was considered and concentrations of species were calculated. Predictions of au with mean deviations of 0.26% were obtained.     

Behavior of Micellar Solutions in Gel Permeation Chromatography. A Theory Based on a Simple Model

Abstract

Gel permeation chromatograms are interpreted in terms of V, the peak elution volume, which is characteristic for the size of the solute species. If solute association takes place, V may become extensively concentration dependent. To further the understanding of this effect a simple theory, which ignores axial diffusion, has been developed, the model for molecular association being a micellar surfactant in equilibrium with its monomer.     

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.     

Polyprenylated benzophenone-enriched extracts obtained using SC–CO2 from the dry ethanolic extract of Brazilian red propolis

Red propolis is a well-known potent antimicrobial source because of its various bioactive compounds. This work aims to submit a sample of Brazilian red propolis to supercritical CO₂ extraction, with subsequent chemical characterisation by HPLC and UHPLC–MS, and to evaluate the antifungal activity against three strains of Candida glabrata. The method proved to be selective for the extraction of benzophenones. The results demonstrated a correlation between the presence of benzophenones and antifungal activity. The supercritical extract that seems to be the richest in benzophenones was the one obtained with a pressure of 300 bar and was the most active against the C. glabrata strains.

Abbreviations: SFE, Supercritical Fluid Extraction; MIC, Minimal Inhibitory Concentration; SC, Supercritical; BZP, benzophenones     

Strong and Selective Ni(II) Extractants Based on Synergistic Mixtures of Sulfonic Acids and Bidentate N-Heterocycles

ABSTRACT

Bidentate 5,5?-alkyl-3,3?-bi-1H-pyrazole and 2-(5-alkyl-1H-pyrazol-3-yl)pyridine ligands, L⁵ and L⁶, have been shown to be stronger synergists for the solvent extraction of Ni(II) from sulfate solutions by dinonylnaphthalene sulfonic acid (DNNSAH) than the structurally related tridentate ligand 2,6-bis-[5-n-nonylpyrazol-3-yl]pyridine, L¹, previously reported by Zhou and Pesic. The bidentate ligands are highly selective, providing the option of sequential recovery of Ni(II) and Co(II) and rejection of other metals commonly found in the liquors resulting from the acidic sulfate leaching of laterite ores. They were the strongest synergists identified in a screening carried out on 18 types of bidentate and tridentate N-heterocyclic ligands, including the recently reported 2-(2?-pyridyl)imidazoles, L^9?11. X-ray crystal structures of Ni(II) complexes of model ligands for L⁵ and L⁶, having t-butyl rather than long-chain alkyl groups and with 2-naphthalene sulfonate rather than DNNSA^? as counteranions, show that the [Ni(L)₃]²⁺ complexes form strong H-bonds from the pyrazolyl NH groups to the oxygen atoms of the sulfonate groups, an arrangement that will stabilize [Ni(L)₃·(DNNSA)₂] assemblies and shield their polar functionalities from diluent molecules of the water-immiscible phase. UV–visible spectra and mass spectrometry provide evidence for the strong synergists displacing all water molecules from the inner coordination sphere of the Ni(II) ions.     

Upper Rim Thioether Derivatives of Calix[4,6]Arenes: Extraction of Fission Pd(II) and Ag(I)

Abstract

We report studies on the Pd(II) and Ag(I) complexation and extraction by tetraalkyl(tolyl)thiomethylcalix[4]arenes (1a–c) stabilized in the cone conformation, and by the stereochemically mobile tetraalkyl(tolyl)thiomethylcalix[6]arenes (2a, b). These are found to be 100–1000 times more efficient as extractants of nitric and nitrous forms of Pd(II) and Ag(I) than their ungrafted monodentate analogues. Extraction experiments performed on real HLW show that tetrabutylthiomethylcalix[4]arene 1b is able to concentrate and separate Pd from main fission products. The extraction constants for mono‐ and binuclear Ag complexes have been determined. The stoichiometry and structural features of the complexes of Pd and Ag have been studied experimentally by extraction, IR‐ and mass‐spectroscopy methods as well as in quantum‐mechanical calculations.     

SANS Study of Third Phase Formation in the Extraction of HCl by TBP Isomers in n‐Octane

Abstract

Third phase formation in the extraction of HCl by triisobutyl phosphate (T‐iso‐BP) and tri‐sec‐butyl phosphate (T‐sec‐BP) has been investigated and compared with the tri‐n‐butyl phosphate (T‐n‐BP) system. The three TBP isomers exhibit comparable affinities for HCl, but the branched isomers extract much more water than the linear one. For T‐sec‐BP, the LOC (limiting HCl organic concentration) is characterized by much lower HCl concentrations both in the organic and aqueous phase than for the other isomers. SANS data for T‐iso‐BP and T‐sec‐BP organic phases loaded with progressive amounts of HCl have been interpreted using the Baxter model for hard spheres with surface adhesion. The critical values of the stickiness parameter, τ^?1, and the interaction potential energy, U(r), are slightly different and characteristic for each of the extractants. Their values are consistent with the expectation derived from the micellar interaction model.     

Liquid-Liquid Extraction of Copper from Ammoniacal Solution with β-Diketones

Abstract

Some β-diketones such as LIX 51 (Henkel KGaA), Hostarex DK 16 (Hoechst AG), LIX 54 (Henkel KGaA), and MX 80A (Sigma Innovation, Sweden) were developed for technical applications (1) but only LIX 54 is commercially available. The use of LIX 54 to separate copper from ammoniacal etch solutions is described by patent applications (2–4) and an information paper of Henkel KGaA. The extraction of transition metals with LIX 54 was studied by Ramesh et al. (5). LIX 54 in a mixture with neutral donor ligands also proved suitable for the extraction of lanthanide elements (6). The active component of LIX 54 and MX 80A was recently identified as a mixture of isomeric l-phenyl-3-iso-heptyl-1,3-propanediones (7, 8). Analogous P-diketones are easily available.     

Feasibility Studies on Palladium Extraction from Leach Liquors of Automotive Catalysts Using p-Diethylphosphonomethylthiacalix[6]arene

Feasibility studies for the recovery of Pd(II) from leach liquors of automotive catalysts using p-diethylphosphonomethylthiacalix[6]arene (1) and p-tert-butylthiacalix[6]arene (2) were conducted. Compound 1 was found to be a more efficient extractant than 2 for Pd(II) ions, indicating selective extraction of Pd(II) ions [E% = 98.4%] from the leach liquors. The majority of other metal ions present in the leached solution were not extracted except Zr(IV) ions [E% = 22%]. Stripping of the Pd(II) ions from the extractants was performed using acidic thiourea, thereby enabling the recycling of the extractants.     

Effect of drying methods on bioactive compounds,nutritional, antioxidant,and antidiabetic potential of brown alga Durvillaea antarctica

Abstract

The effects of vacuum, solar, convective, infrared, and freeze drying (VD, SD, CD, IRD, FD) on Durvillaea antarctica were evaluated in terms of nutritional composition, color, bioactive components, and antioxidant and antidiabetic activities. Nutritional composition of the dried seaweeds scarcely varied, while a tendency to lose the reddish tone occurred. CD-seaweed had highest phytochemical and vitamin contents, while FD-samples showed best retention of pigments. Both samples also exhibited the strongest antioxidant and antidiabetic activities. The highest essential amino acids and polyunsaturated fatty acids contents were found in IRD- and SD-samples, respectively. In general, FD and CD were proved to be viable drying options for D. antarctica.     

Liquid–liquid extraction of hydroxytyrosol,tyrosol, and oleuropein using ionic liquids

ABSTRACT

Hydroxytyrosol (HT), tyrosol (TY), and oleuropein (OL) are valuable compounds that can be obtained from olive oil production waste. This study implemented liquid–liquid extraction to obtain HT, TY, and OL from model solutions using two organic solvents, namely, ethyl acetate and n-butyl acetate, and three ionic liquids (ILs), namely, [P_6,6,6,14][Tf₂N], [P_6,6,6,14][DCA], and [omim][Tf₂N]. [P_6,6,6,14][DCA] showed the best performance, with extraction efficiencies of 92%, 96%, and 83% for HT, TY, and OL, respectively. [omim][Tf₂N] showed the highest selectivity in the extraction of TY. Comparisons of the results of a proposed mathematical model with experimental data yielded errors lower than 0.5%.