Fractional Extraction Process Research Articles

Thermodynamic Data of Separating Yttrium from Heavy Rare Earths via a Phenoxypropionate-Based Ionic Liquid

Ion-adsorbed rare-earth minerals often contain high proportions of yttrium; it is a technical challenge to separate yttrium from rare-earth elements (REEs). For the purpose of separating yttrium effectively, a novel ionic liquid [trioctylmethylammonium][(2,6-dimethylheptyl propionate] ([N1888][POPA]) was prepared to separate Y from heavy rare-earth elements (HREEs). The thermodynamic data of the separation process was studied systematically. The extraction mechanism of [N1888][POPA] was demonstrated to be ion association, which conduces to avoid the saponification wastewater. [N1888][POPA] revealed better selectivities for Y and other HREEs (Ho–Lu); also, deionized water could be utilized for stripping the HREE-loaded organic phase. On this basis, the fractional extraction process based on [N1888][POPA] was carried out. This extraction system showed satisfying performance as shown by the fractional extraction, i.e., Y was purified from 85.2 to 99.1 wt % accompanying 85.37% yield by means of nine extraction stages and six scrubbing stages. The developed extraction process has shown application potential in the field of clean production of ion-adsorbed rare-earth minerals.

A Novel Three-Step Extraction Strategy for High-Value Products from Red Algae Porphyridium purpureum.

The microalga Porphyridium accumulates high-value compounds such as phycoerythrin, polyunsaturated fatty acids, and polysaccharides, and thus, the extraction of these compounds could significantly expand the value of Porphyridium biomass. In the present study, a novel fractional extraction strategy based on the characteristics of these compounds was established using cold water, 95% ethanol, and hot water. The yield of phycoerythrin, lipids, and polysaccharides was 63.3, 74.3, and 75.2%, respectively. The phycoerythrin exhibited excellent fluorescence characteristics but had low purity. The crude lipid was dark with poor fluidity. Digalactosyldiacylglycerol and sulphoquinovosyldiacylglycerol containing C20:5 and C20:4 were the most abundant glycerolipids, while glucose, xylose, and galactose constituted the intracellular polysaccharides that had covalently bound to proteins (8.01%), uronic acid (4.13%), and sulfate (8.31%). Compared with polysaccharides and crude lipids, crude phycoerythrin showed the best antioxidant activity. Overall, the three-step fractional extraction process was feasible for Porphyridium; however, further purification is necessary for downstream applications.

Preparative separation of chlorogenic acid from Eucommia ulmoides extract via fractional extraction

AbstractBACKGROUNDChlorogenic acid is an important bioactive substance with wide pharmacological effects mostly related to scavenging free radicals and as an anti‐virus. This article reports on the continuous separation of chlorogenic acid from Eucommia ulmoides crude extract using multistage centrifugal fractional extraction.RESULTSAn efficient extraction system was constructed. A quantitative mathematical model was established to simulate and optimize the fractional extraction process, and the optimum process conditions were obtained. Residual rate was successfully introduced as the purity reference to optimize the separation of chlorogenic acid. Chlorogenic acid was continuously obtained from Eucommia ulmoides extract by fractional extraction in a cascade of ten stages with high purity of 97.2% and yield of 81.4%.CONCLUSIONFractional extraction is an efficient and likely unique technology to continuously and selectively separate target substance from complex natural extract. It has the advantages of large output and low cost, and is more suitable for industrial‐scale production. © 2020 Society of Chemical Industry

Process optimization of reactive extraction of clorprenaline enantiomers by experiment and simulation

This paper studied the process optimization of reactive extraction of clorprenaline enantiomers (CP) by experiment and simulation. An efficient extraction system was obtained through single stage extraction experiments, where boric acid (BA) in aqueous phase and D-isobutyl tartrate (DT) in organic phase were selected as extractant and 1,2-dichlorethane was selected as organic solvent. The best enantioselectivity (α) with 2.012 was obtained. The extraction mechanism was proposed and thermodynamic constants such as physical partition coefficient and reactive equilibrium constants were obtained. Based on single stage extraction, phase and reactive equilibrium as well as the law of mass conservation, a model describing the fractional extraction process was acquired. The process of symmetrical separation of CP was optimized by the model. The optimal conditions including flow rate ratio (O/W) of 1.5, pH of 5.0, CH3COONa/CH3COOH solution of 0.1 mol/L, clorprenaline concentration of 5 mmol/L, BA concentration of 0.10 mol/L and DT concentration of 0.075 mol/L were obtained. Under this case, equal enantiomeric excess (eeeq) could reach up to 67% by 10 stages. The simulated results revealed that the minimum series for eeeq > 97% and eeeq > 99% were 26 and 33, respectively. The results will provide guides for scale up and design.

Process optimization of chiral extraction of 2,3-diphenylpropionic acid by experiment and simulation

Abstract This paper reports the process optimization of chiral extraction of 2,3-diphenylpropionic acid (2,3-2-PPA) enantiomers by experiment and simulation in centrifugal contactor separators. An efficient extraction system was obtained firstly through single-stage extraction experiments and single-stage extraction model, where sulfobutylether-β-cyclodextrin (SBE-β-CD) and 1,2-dichlorethane were selected as the optimal extractant and organic solvent, respectively. The mechanism of the extraction system was proposed and the thermodynamic constants such as physical partition coefficient and reactive equilibrium constants were obtained. Based on phase and reactive equilibrium as well as the law of mass conservation, a model describing the fractional extraction process was acquired. The process of symmetrical separation of 2,3-2-PPA enantiomers was optimized by the fractional extraction model. The optimal conditions composed of flow rate ratio (W/O) of 3.0, pH of 3.00 and SBE-β-CD concentration of 0.10 mol/L were obtained. Under this case, equal enantiomeric excess (eeeq) can reach up to 37% at 10 stages. The simulated results reveal that the minimum series for eeeq > 97% and eeeq > 99% was 78 and 102, respectively.

Experiments and simulation on extraction of esmolol enantiomers from single stage to multistage

Abstract Enantioselective extraction of esmolol (ES) enantiomers was performed with tartaric acid derivatives and boric acid (BA) as chiral extractant. The single–stage extraction experiments were carried out to construct the extraction system for ES enantiomers through investigating type of tartaric acid derivatives, type of the organic solvent and temperature. The optimal conditions for extraction system were achieved, which involves 1,2–dichloroethane as organic solvent, iso–butyl–D–tartrate (DT) as chiral selector and 278 K for extraction temperature. A single–stage extraction model was established based on an interfacial reaction mechanism and proved to be reliable by verified experiments. Based on the single–stage extraction model and the law of mass conservation, a fractional extraction model was explored to simulate and optimize the fractional extraction process. The optimal operation conditions at temperature of 278 K were obtained including ES concentration of 0.01 mol/L, DT and BA concentrations of 0.1 mol/L, F/W of 0.25 and O/W of 1.0347, feeding in the middle stage at pH of 5.50. The eeeq of 0.98 and Yeq of 0.99 can be achieved by symmetric separation with the number of stages of 32 under the optimal conditions. As S–ES is the desired product, 10 stages are enough to obtain 0.98 of eeraffinate for S–ES by asymmetric separation under the conditions containing ES concentration of 0.01 mol/L, DT and BA concentrations of 0.1 mol/L, F/W of 0.25 and O/W of 1.64, feeding in the Stage 2 at pH of 5.50.

Modeling multiple chemical equilibrium in chiral extraction of metoprolol enantiomers from single-stage extraction to fractional extraction

Enantioselective extraction of metoprolol (MT) enantiomers with di-cyclohexyl (D)-tartrate (DT) and boric acid (BA) as chiral extractant was performed. The process involving multiple chemical equilibrium is very complicated and the process optimization is difficult. On the basis of an interfacial reaction mechanism, a single-stage extraction model was established. The operation conditions of pH and DT to BA ratio were obtained through simulation and optimization of the equilibrium of the two phase extraction system. Based on the single-stage extraction model and the law of mass conservation, a fractional extraction model was established to simulate and optimize the fractional extraction process. To pursue a high productivity and reduce the required stages, a high feed to aqueous phase ratio (F/W = 1) and an asymmetric separation mode were applied. By asymmetric separation where the optical purity of the product in extract phase and raffiniate phase is not equal, enantiomeric excess (ee) value for the eutomer of MT can reach up to 98.64% and yield can reach up to 64.68% with 20 extraction stages.

Simulation and analysis of multi-stage centrifugal fractional extraction process of 4-nitrobenzene glycine enantiomers

Based on the interfacial ligand exchange model and the law of conservation of mass, the multi-stage enantioselective liquid–liquid extraction model has been established to analyze and discuss on multi-stage centrifugal fractional extraction process of 4-nitrobenzene glycine (PGL) enantiomers. The influence of phase ratio, extractant concentration, and PF6− concentration on the concentrations of enantiomers in the extract and raffinate was investigated by experiment and simulation. A good agreement between model and experiment was obtained. On this basis, the influence of many parameters such as location of stage, concentration levels, extractant excess, and number of stages on the symmetric separation performance was simulated. The optimal location of feed stage is the middle of fractional extraction equipment. The feed flow must satisfy a restricted relationship on flow ratios and the liquid throughout of centrifugal device. For desired purity specification, the required flow ratios decrease with extractant concentration and increase with PF6− concentration. When the number of stages is 18 stages at extractant excess of 1.0 or 14 stages at extractant excess of 2.0, the eeeq (equal enantiomeric excess) can reach to 99%.

Separating closely resembling steroids with ionic liquids in liquid–liquid extraction systems

Separation of steroids by liquid–liquid extraction with ionic liquids (ILs) as solvent was studied both experimentally and by simulation using a model mixture of progesterone and pregnenolone. The studies involved a solvent screening using COSMO-RS software for estimation of progesterone solubility. An experimental compatibility study of several solvents with reasonable progesterone solubility with several ILs. The results showed tert-butyl methyl ether (TBME)–butyl methyl imidazolium tetrafluoroborate (BMIM BF4) as the most promising solvent combination. Next, equilibrium partitioning of both progesterone and pregnenolone in this solvent combination was determined experimentally. Fixed bed studies using solvent impregnated resin (SIR) obtained by impregnation of BMIM BF4 in silica showed that it is feasible to obtain highly pure progesterone in such a process. However, the yield was far from quantitative and thus a fractional extraction process was studied by simulation of a counter current extraction process. The simulation study showed that with fractional extraction highly pure progesterone (excess >0.99) can be obtained at a yield of >0.95 when a minimum of 24 equilibrium stages are applied.

Synergistic extraction of Ce(IV) and Th(IV) with mixtures of Cyanex 923 and organophosphorus acids in sulfuric acid media

The synergistic effect of mixtures of Cyanex 923 and organophosphorus acids including P204, P507 and Cyanex 272 in extraction of Ce(IV) and Th(IV) from sulfuric acid solutions has been investigated. Under the experimental conditions, the extraction of Ce(IV) presented an significant synergistic effect with the mixed extraction systems of Cyanex 923–P204, Cyanex 923–P507 and Cyanex 923–Cyanex 272. On the contrary, the extraction of Th(IV) showed significant antagonistic effects in the mixed systems. The separation factor for Ce(IV)/Th(IV) reached as 36.8 at a mole fraction of 70% Cyanex 923 in the Cyanex 923–P507 system. It is shown that the mixed extraction systems not only enhance the extraction efficiency of Ce(IV) but also improve the selectivity of Ce(IV) over Th(IV). Furthermore, a fractional extraction process (including 4 stages of extraction, 2 stages of scrubbing and 2 stages of stripping) with the mixed Cyanex 923–P507 to separate Ce(IV) from the bastnasite leach solution has been designed. Cerium solution of Ce2(SO4)3 and CeF3 nanoparticle were obtained with 99.8% and 99.9% purity, respectively.

Separation of Soybean Isoflavone Aglycone Homologues by Ionic Liquid-Based Extraction

The separation of a compound of interest from its structurally similar homologues is an important and challenging problem in producing high-purity natural products, such as the separation of genistein from other soybean isoflavone aglycone (SIA) homologues. The present work provided a novel method for separating genistein from its structurally similar homologues by ionic liquid (IL)-based liquid-liquid extraction using hydrophobic IL-water or hydrophilic IL/water-ethyl acetate biphasic systems. Factors that influence the distribution equilibrium of SIAs, including the structure and concentration of IL, pH value of the aqueous phase, and temperature, were investigated. Adequate distribution coefficients and selectivities over 7.0 were achieved with hydrophilic IL/water-ethyl acetate biphasic system. Through a laboratory-scale simulation of fractional extraction process containing four extraction stages and four scrubbing stages, genistein was separated from the SIA homologues with a purity of 95.3% and a recovery >90%.

A solvent extraction process with mixture of CA12 and Cyanex272 for the preparation of high purity yttrium oxide from rare earth ores

Solvent extraction and separation of yttrium from other rare earths in chloride medium using the mixture of sec-octylphenoxy acetic acid (CA12, HA) and bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex272, HB) has been investigated. Tri- n-butyl phosphate (TBP) was used as the phase modifier to achieve fast phase separation and to improve the stability of the organic phase. The separation coefficients (β) between yttrium and heavy rare earths (HRE) are more significant in the double solvent (HAB) extraction system than the CA12-TBP extraction system. In a laboratory scale test with a fractional extraction process including 15 stages of extraction section and 10 stages of scrubbing section, yttrium was separated from all the other rare earths with a yield of 95% and an yttrium oxide product with 99.94% purity was obtained.

Fractional Extraction Process for Recovery of Pure Tar Acids

Fractional Extraction Process for Recovery of Pure Tar Acids