Multistage Countercurrent Extraction Research Articles

Improving Jatropha curcas seed protein recovery by using counter current multistage extraction

Jatropha curcas seed press cake contains 23 wt% proteins (dry basis). Due to the toxic compounds in Jatropha, we will use the proteins for non-food applications. Related to non-food applications, an efficient protein extraction to obtain a high protein recovery and high protein concentration with good protein functional properties is required. To achieve this, we conducted protein extractions at room temperature by using different solvents at various solvent to solid ratios and performed multistage counter current extraction to improve protein recovery and protein concentration. We obtained the highest protein recovery of 82% by using 0.055 M NaOH at solvent to solid ratio of 10 g/g after four-stage counter current extraction. By using 0.055 M NaOH extraction at lower solvent to solid ratio of 4 g/g, protein recovery was 35% after one-stage extraction and improved up to 71% with a high protein concentration of 63 mg/mL after four-stage counter current extraction. The highest amount of protein was precipitated from crude extracts at pH 4–5.5 and resulted on precipitate with protein content of 70%. The multistage counter current extraction did not influence Jatropha seed protein molecular weight distributions, which were within the range of 3–98 kDa.

Pilot-Scale Multi-Stage Countercurrent Extraction of Scutellarein from Erigeron breviscapus (Vant.) Hand-Mazz

A low-temperature, timesaving, lower solvent consumption, and energy cost and multi-stage countercurrent extraction (MCCE) technique was developed for pilot-scale production of scutellarein from Erigeron breviscapus (Vant.) Hand-Mazz. The optimum conditions of MCCE process were obtained using the orthogonal array design method, i.e., 70% (v/v) of ethanol water solution, 16 L/kg of solvent to herbal sample ratio, 45°C of extraction temperature and 30 min of extraction time. A comparison between the MCCE technique and single pot extraction (SPE) under respective optimized operation conditions was made and time courses of scutellarein of MCCE and SPE processes were plotted, indicating that the MCCE technique can lower the extraction temperature and decrease five-sixth of the extraction time and two-thirds of the solvent consumption at the equivalent extraction yield of scutellarein.

Deacidification of olive oil by countercurrent supercritical carbon dioxide extraction: Experimental and thermodynamic modeling

Supercritical carbon dioxide was used as an extractive solvent to remove free fatty acids from cold-pressed olive oil. Crude oil of different acidity content (from 0.5 to 4.0 wt%) was extracted in a packed column at 313 K and pressures of 180, 234 and 250 bar. The group contribution equation of state was employed to simulate the separation process, representing the oil as a simple pseudo-binary oleic acid + triolein mixture. Despite the simple representation of oil composition to simulate the deacidification process, a satisfactory agreement between the experimental and calculated yields and acidity of raffinates was obtained. The thermodynamic model was employed to study a continuous countercurrent multistage extraction process which yielded a raffinate having acidity lower than 0.7 wt%, when crude olive oil with different FFA content was processed.

SEPARATION OF TAXANE COMPOUNDS BY LIQUID-LIQUID EXTRACTION

Experimental and numerical studies on liquid-liquid extraction of taxane compounds that are extracted from yew needles by solid-liquid extraction are carried out. In the treatment, the materials are classified to three components, and separation of component C from components A and B is discussed. In experiments, distribution coefficients and selectivities of those components are measured with various solvents. Based on the experimental results, numerical simulation of the countercurrent multistage liquid-liquid extraction process for separating the components is carried out with various operating conditions. Then, the fractional countercurrent multistage liquid-liquid extraction process is examined, and the effect of reflux operation on separation performance of the fractional liquid-liquid extraction process is studied. Based on the numerical results, it is found that the fractional countercurrent multistage liquid-liquid extraction with reflux is superior to the other extraction processes for separating taxane compounds.

An Assessment of Multistage Counter Current Extraction of TRU from Spent Molten Salt into Liquid Metal II. Effect of Stage Efficiency, Scrub Stage, and TRU Concentration

Calculation procedures have been developed to evaluate the performance of the multistage counter current extraction of transuranics (TRU) from spent molten salt into liquid metal, taking into account stage efficiency and also the scrub stage. The following results, which supplement previous papers, were derived using these procedures. When Cd is used as the liquid metal and the stage efficiency is assumed to be 100%, at least four stages are necessary to recover 99% of TRU from the salt with a decontamination factor (DF) higher than five. A stage efficiency of the extraction better than 80% is desirable for a practical application. The scrub stage is not very effective in improving the DF when the total number of extractions is less than five. The DF slightly increases with higher TRU concentration in the salt since the accompanying lanthanide FP extracted into the Cd in the later stages works as a mild reducing agent in the earlier stages. Although the extraction process has high separation capability, it is very difficult to separate Np, Am, or Cm from Pu due to their similar separation factors. Therefore, the extraction process has inherent proliferation resistance.

An Assessment of Multistage Counter Current Extraction of TRU from Spent Molten Salt into Liquid Metal II. Effect of Stage Efficiency, Scrub Stage, and TRU Concentration

An Assessment of Multistage Counter Current Extraction of TRU from Spent Molten Salt into Liquid Metal II. Effect of Stage Efficiency, Scrub Stage, and TRU Concentration

Single-Stage Extraction Test with Continuous Flow of Molten LiCl-KCl Salt and Liquid Cd for Pyro-Reprocessing of Metal FBR Fuel

A single-stage extraction test with the continuous flow of both molten salt and liquid Cd was carried out as a preliminary step of the development of a multistage countercurrent extraction process for the pyrometallurgical reprocessing of metal FBR fuel. Ce, Gd, and Y were selected as the substitutes for U, other actinides, and rare-earth elements, respectively. More than 97% of Ce could be recovered in one of the experiments, in which 97% of Gd and 63% of Y were also recovered. This meant that high recovery yield could be obtained in the system, but mutual separation was not sufficient when the high recovery yield was required in a single-stage extraction. In another experiment in which the recovery yields of Ce, Gd, and Y were about 87, 70, and 8%, respectively, the separation factors of Gd and Y against Ce were 0.27 and 0.0092, respectively, which were about the same as their equilibrium values. The result showed that higher separation efficiency was achieved under the condition of relatively lower recovery yield. The mass transfer coefficient of rare-earth elements in the salt was estimated to be 0.14 cm/s, which was much larger than that in the previous experiments without a baffle plate in the extractor.

PREDICTION OF A MUTUAL SEPARATION OF ACTINIDE AND RARE EARTH GROUPS IN A MULTISTAGE REDUCTIVE EXTRACTION SYSTEM

The mutual separation behavior of actinides and rare earths in a countercurrent multistage reductive extraction system was predicted by computer calculation. The distribution information for actinides and rare earths in the reductive extraction systems of LiCl-KCl/Cd and LiCl-KCl/Bi was collected from literature and then it was used for the calculation of a multistage extraction. The results of the concentration profiles throughout the extraction cascade, recovery yields of various metal solutes, and separation factors between the actinides and rare earths were calculated. The effects of the major process parameters, such as reducing agent content in the metal phase, number of stages, and salt/metal flow ratio, etc., on the extraction behavior were also examined.

Deterpenation of mandarin ( Citrus reticulata) peel oils by means of countercurrent multistage extraction and adsorption/desorption with supercritical CO 2

The mandarin ( Citrus reticulata) peel oil consists of more than 98 wt.% terpenes and a small fraction of oxygenated components responsible for its distinct smell. The terpene fraction is composed mostly of limonene and the oxygenated aroma fractions are composed mainly of linalool and decanal. The removal of terpenes must be performed in order to increase the storage time of citrus oils. In this work, the deterpenation of two different cold-pressed mandarin peel oils employing countercurrent extraction and ad-/desorption with supercritical CO 2 and a combination of these processes were investigated. Countercurrent experiments were carried out at pressures ranging from 8.5 to 10.0 MPa and at 50 and 60 °C. At 10.0 MPa and 60 °C, a maximum selectivity of 12.8 between terpenes and aromas could be obtained at a folding ratio of 5.0, showing that the fractionation by means of countercurrent gas extraction could be employed. To investigate the complete removal of terpenes, ad-/desorption experiments were also performed and both the raffinate samples obtained through the countercurrent fractionation and the crude cold-pressed peel oils were used as feed material. The components evaluated were desorbed from silica-gel and the best fractionation results were obtained at 40 °C, 25 wt.% oil loading in two sequential pressure steps. Initially, terpenes were completely desorbed at 8.0 MPa. The second desorption step was carried out at 20.0 MPa and a selective fractionation of important aroma components was observed. Additionally, scale-up experiments were performed.

Experimental and Simulation Study on the Extraction of p-Cresol Using Centrifugal Extractors

In this study, extraction of p-cresol from the simulated wastewater has been studied using centrifugal extractors and QH-1 extractant. The distribution ratio of p-cresol was approximately 308.5 in the QH-1- p-cresol (pH=2.0) system. The extraction stage efficiency of the single-stage centrifugal extractor was higher than 92%, and the extraction rate of the three-stage cascade was higher than 99%. When 15% NaOH was used for the stripping of p-cresol in QH-1 solution, the stripping rate of the three-stage cascade reached 100%. A mathematical model of multistage countercurrent extraction process that considers the phase volume change, extraction stage efficiency, and phase entrainment was used to simulate the extraction of p-cresol using centrifugal extractors. The calculated results using this model were in good agreement with the experimental results.

ICONE15-10756 Counter-current Multistage Extraction of Heavy Metal by Centrifuge Extractor with Taylor-Couette Flow

The multistage extraction of metal ion was studied by a centrifuge extractor, in which oil and water were flown counter-currently through the narrow gap between a rotated inner cylinder and a static outer cylinder. Oil (dodecane) was dispersed finely by increasing the rotating speed of inner cylinder and flown up against the downflow of water. The small drops of dispersed oil were sucked down by Taylor vortices accumulated on the inner-cylinder surface. Stable belt-shaped structures of oil phase were observed at even intervals on the surface of inner cylinder. The extraction of Zn(II) with di-2-ethylhexylphosphoric acid dissolved in dodecane was examined. The extraction of Zn was promoted by the increase of oil hold-up and the improvement of oil dispersion, which were observed by increasing the rotating speed of inner cylinder and the flow rates of oil and water. The number of theoretical stages was evaluated as about 3 stages under the conditions that the rotating speed and the flow rates of oil and water were given as 1200 rpm and 17 ml/min, respectively. The multistage extraction was achievable successfully by the proposed centrifuge extractor with Taylor-Couette flow.

An Assessment of the Multi-stage Counter Current Extraction of TRUs from Spent Molten Salt, into Liquid Metal

An Assessment of the Multi-stage Counter Current Extraction of TRUs from Spent Molten Salt, into Liquid Metal

An Assessment of the Multi-stage Counter Current Extraction of TRUs from Spent Molten Salt, into Liquid Metal

An Assessment of the Multi-stage Counter Current Extraction of TRUs from Spent Molten Salt, into Liquid Metal

Development of multi-stage countercurrent extraction technology for the extraction of glycyrrhizic acid (GA) from licorice ( Glycyrrhiza uralensis Fisch)

Multi-stage countercurrent extraction (MCE) technique has been developed for the extraction of glycyrrhizic acid (GA) from Glycyrrhiza uralensis Fisch, a particular plant species of licorice. The effects of extraction stage numbers, temperature, extraction time and solvent to licorice ratio on the extraction yield of GA were investigated in detail. The process conditions of MCE were optimized using orthogonal array experimental design (OAD) technique. Under optimum process conditions (five stages, 60 min extracting time for every stage, 60 °C temperature and 6 ml/g solvent to licorice ratio), the extraction efficiency of MCE has been compared with those of conventional techniques including batch single pot extraction (SPE), microwave-assisted extraction (MAE), ultrasonic extraction (USE), Soxhlet extraction (SHE) and room temperature extraction (RTE). Results show that the MCE process offers the highest GA extraction yield and considerable savings in time, energy and solvent consumption.

Treatment of strong acid dye wastewater by solvent extraction

The acid dye intermediates 1-diazo-2-naphthol-4-sulfonic acid wastewater treatment by using solvent (trialkylamine N 235) extraction, and the raffinate treatment by hydrogen peroxide catalytic oxidation were studied. The extraction and stripping conditions were tested and the optimum process parameters were obtained. In addition, the multistage countercurrent extraction and stripping experiments were carried out. The results showed that the single stage extraction rate was higher than 82%, decoloration rate was 95%; the single stage stripping rate was higher than 91%; the two stages countercurrent extraction rate reached 93%, the five stages countercurrent stripping rate reached almost 100%. After hydrogen peroxide catalytic oxidation, the solution was achromatic, and the COD of the effluent was below 100 mg/l (the first-order national discharge standard).

Experimental Investigation and Simulation of a Gas‐agitated Sieve Plate Column

AbstractThe extraction of hydrogen peroxide by means of deionized water from anthraquinone working solution via anthraquinone process was carried out in a gas‐agitated sieve plate extraction column. The effects of the superficial velocity of air, dispersed phase and continuous phase on the overall plate extraction efficiency have been investigated. The corrections for the prediction of the overall plate extraction efficiency were presented. The correction proposed to predict the overall plate extraction efficiency in the air, water, anthraquinone working solution three‐phase system agreed satisfactory with experimental data with a maximum absolute deviation of 5.6 %. A new design method for gas‐liquid‐liquid three‐phase extractors is developed based on the multistage countercurrent extraction model. The calculated data by the model agreed well with experimental data and the average relative deviation was less than 10 %. Moreover, the model was used to predict a gas‐agitated sieve plate extraction column for industrial production of hydrogen peroxide. The results show that the plate numbers of gas‐agitated sieve plate extraction column are 30–40 % less than that of liquid‐liquid sieve plate column.

Improved apparatus for solid–liquid multi-stage counter-current extraction

An improved apparatus for solid–liquid multi-stage counter-current extraction (SLME) was developed. The apparatus has a set of 24 extraction vessels. Each extraction vessel unit is composed of a piston-cylinder in which the solid phase is placed, and a cup-cylinder in which the liquid phase is set. Of the 24 extraction vessels, 20 were used for the separation stage, and the other 4 were used for the back-extraction stage. (±)-Troger’s base was selected as a racemic model compound for the continuous enantioseparation by the apparatus, and a cellulose derivative was used as the chiral separator. After 50 cycles of the operation (in 9 h), 0.1 g of (−)-enantiomer (85% in purity) was recovered from the solid phase by back-extraction with ethanol, whereas 1.1 g of (+)-isomer (75% in purity) was collected from the liquid phase (ethanol).

Studies of U(IV) Oxidation Kinetics in Nitric Acid and TBP Phases

U(IV) is an important reagent in current reprocessing plants since it is used to reduce Pu(IV) to Pu(III), therefore, allowing the efficient separation of U and Pu in multi-stage counter-current solvent extraction contactors. The benefits of U(IV) are that it is a kinetically fast reductant and it is a salt free reagent, since U(IV) is oxidised to U(VI) and so does not add to the aqueous waste volumes. Many kinetic reactions of U(IV) have been studied in the past and these are used by BNFL to model the behaviour of U(IV) in process flowsheets. However, some reactions have either not been studied or have been previously studied but without conclusive resolution. Therefore, to expand our understanding of U(IV) in the process and to generate data that underpins process models, we are studying a series of U(IV) reactions, and this paper will summarise the results of our kinetic and mechanistic studies.

Separation of La and Ce with PC-88A by counter-current mixer-settler extraction column

Abstract The separation of La and Ce with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (commercially known as PC-88A) from nitrate media was studied with a multistage counter-current mixer-settler extraction column of seven stages developed by the authors. The effect of flow rate ratio of the aqueous phase ( Q w ) to the organic phase ( Q o ) on the separation was studied. The maximum separation was obtained at Q w / Q o =3.2 and the separation degree was 63. Scrubbing of the organic phase was also studied in order to enhance the separation. La was scrubbed from the organic phase with nitric acid at pH 2.7 and the separation degree during scrubbing was 45. Simulations of the extraction and scrubbing processes were carried out and compared with the obtained experimental results. Stripping of Ce was achieved by using 100 mol/m 3 nitric acid. The organic phase was successfully recycled during the experiments without any effect on the extraction efficiency.

Solvent extraction separation of indium and gallium from sulphate solutions using D2EHPA

Abstract Solvent extraction and stripping experiments have been performed to separate indium from gallium in sulfuric acid solutions. In the extraction process, the separation factor between indium and gallium decreased with pH and a maximum value of the separation factor was obtained by extracting metals from the mixed solutions with stoichiometric concentration of di-2-ethyl-hexylphosphoric acid (D2EHPA) to extract both metals. It was found that aliphatic kerosene was superior to benzene as a diluent in respect of loading capacity. In the stripping process, the stripping percentage of indium decreased from 95% to 5% with pH in the pH range of 0.2–1.4, while separation factors increased with the pH of the stripping solutions. From simulation experiments for multistage countercurrent extraction, nearly complete separation of indium and gallium would be accomplished by a two-stage extraction.