Kinetic Model of Gas‐Liquid‐Liquid Reactive Extraction for Production of Hydrogen Peroxide

The kinetic aspects of the gas‐liquid‐liquid reactive extraction process for the production of hydrogen peroxide were investigated in a batch reactor. It was observed that the gas‐liquid reaction rate is strongly affected by mass transfer of oxygen across the liquid film and the reaction can be simplified to pseudo‐first order. The extraction rate is governed by both reaction and liquid‐liquid mass transfer, and is slightly lower than the reaction rate. In addition, a kinetic model of the reactive extraction process for the production of hydrogen peroxide was developed. Kinetic parameters under different conditions were determined by experiments. The data calculated from the kinetic model match experimental data well under different conditions for hydrogen peroxide production in gas‐liquid‐liquid reactive extraction.     

Mass Transfer Investigation of Liquid Membrane Transport of Gold (III) by Methyl Isobutyl Ketone Mobile Carrier

Extraction of Au^III ions by an emulsion liquid membrane (ELM) system with methyl isobutyl ketone (MIBK) as the mobile carrier and also liquid‐liquid extraction of Au^III from aqueous solutions have been studied. Experiments on the transport of the gold ions in a liquid‐liquid extraction system and stripping of the extracted ions from the organic phase as well as the extraction by a three‐phase W/O/W emulsion liquid membrane system have been performed. The results showed that even when the distribution coefficient of the diffusing species in the phases is small, the extraction by emulsion liquid membranes would be an effective process. A first‐order extraction rate was proposed and examined for the extraction system.     

Study on the extraction of dyes into a room‐temperature ionic liquid and their mechanisms

The investigation of liquid–liquid extraction of dyes is carried out by using ionic liquid—1‐butyl‐3‐methylimidazolium hexafluorophosphate ([BMIM][PF₆])—as extraction phase. The effects of its process parameters are studied in detail, such as extraction phase ratio, pH of the aqueous phase, and concentration of dicyclohexyl‐18‐crown‐6 (DCH‐18C6) in the organic phase. Important results are obtained as follows: acid dyes can be extracted with [BMIM][PF₆] quantitatively; the removal of reactive dyes is low; however, it can be greatly increased by the addition of DCH‐18C6. The pH value has a great impact on the removal of the acid dye and the reactive dye. However, it does not influence the extraction of the weak acid dye. It is found that the extraction process of acid dyes adopts the form of anion exchange and the soluble part of the ionic liquid plays an important role as counter‐ions. Copyright © 2007 Society of Chemical Industry     

An ionic liquid proposed as solvent in aromatic hydrocarbon separation by liquid extraction

Liquid–liquid extraction is the most common method for extraction of aromatics from their mixtures with aliphatic hydrocarbons. An ionic liquid (IL) 1‐butyl‐1‐methylpyrrolidinium bis (trifluoromethylsulfonyl) imide [BMpyr][NTf₂] was tested as solvent for this separation. The liquid–liquid equilibria (LLE) of the ternary mixtures heptane + benzene, or toluene, or ethylbenzene + [BMpyr][NTf₂] were carried out at 298.15 K. The solvent ability of the IL was evaluated in terms of solute distribution ratio and selectivity. The results were compared with those previously reported for the extraction of aromatics from its mixtures with heptane by using ILs. The conventional process using sulfolane as solvent was discussed. The experimental LLE data were correlated by non‐random two liquid equation. A proposal of extraction process with this IL as solvent is simulated by conventional software and the results are shown. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

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

The 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.     

Reactive Processes for Recovery of Heavy Metals in Miniplants

Miniplants offer enormous time and cost savings when developing an industrial process. Initial product samples and the performance of the whole process with all recycle streams is the result saving pilot scale experiments. The potential use of reactive processes in a miniplant environment is discussed on different extraction techniques (liquid‐liquid extraction, membrane extraction and solvent impregnated resins).     

Salt Effects on the Recovery of Phenol by Liquid‐Liquid Extraction with Cyanex 923

Abstract

In this work, the effect of salt addition on the recovery of phenol from a 46 g/L aqueous solution simulating a phenolic resin plant effluent by liquid‐liquid extraction at 298 K has been studied by using an organic phase containing 0.6 M Cyanex 923 extractant in ShellSol T. Addition of sodium sulfate, potassium nitrate, and sodium chloride to the aqueous phase was tested and sodium chloride was selected. Based on the obtained results, a study of phenol recovery process was undergone by taking advantage of the salting‐out effect. Equilibrium curves are presented for liquid‐liquid extraction with and without salt addition to the aqueous phase. An integrated process involving salting‐out and liquid‐liquid extraction was proposed. The stripping concentrates can be reused for phenolic resin production.     

New Approach in the Prediction of RDC Liquid‐Liquid Extraction Column Parameters

The liquid‐liquid extraction process is well‐known for its complexity and often entails intensive modeling and computational efforts to simulate its dynamic behavior. This paper presents a new application of the Genetic Algorithm (GA) to predict the modeling parameters of a chemical pilot plant involving a rotating disc liquid‐liquid extraction contactor (RDC). In this process, the droplet behavior of the dispersed phase has a strong influence on the mass transfer performance of the column. The mass transfer mechanism inside the drops of the dispersed phase was modeled by the Handlos‐Baron circulating drop model with consideration of the effect of forward mixing. Using the Genetic Algorithm method and the Numerical Analysis Group (NAG) software, the mass transfer and axial dispersion coefficients in the continuous phase in these columns were optimized. In order to obtain the RDC column parameters, a least‐square function of differences between the simulated and experimental concentration profiles (SSD) and 95 % confidence limit in the plug flow number of the transfer unit prediction were considered. The minus 95 % confidence limit and sum of square deviations for the GA method justified it as a successful method for optimization of the mass transfer and axial dispersion coefficients of liquid‐liquid extraction columns.     

Dearomatization of pyrolysis gasoline with an ionic liquid mixture: Experimental study and process simulation

The pyrolysis gasoline is the main source of benzene, toluene, and xylenes. The dearomatization of this stream is currently performed by liquid – liquid extraction using sulfolane. However, the sulfolane process has high operating costs that could be minimized by employing ionic liquids as solvents because of their non‐volatile character. In this work, we proposed a novel process to perform the dearomatization of pyrolysis gasoline using a binary mixture of 1‐ethyl‐3‐methylimidazolium tricyanomethanide ([emim][TCM]) and 1‐ethyl‐4‐methylpyridinium bis(trifluoromethylsulfonyl)imide ([4empy][Tf₂N]) ILs. The composition in the IL mixture was optimized considering their extractive and thermophysical properties. The Kremser method was applied using the experimental data to determine the number of equilibrium stages in the liquid – liquid extractor which provides the same extraction yields of aromatics using the IL mixture that those of the sulfolane process. The recovery section was designed and simulated from the experimental vapor – liquid equilibrium between the hydrocarbons and the IL mixture. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4054–4065, 2017     

Enantioseparation of chiral aromatic acids in process intensified liquid–liquid extraction columns

Enantioselective liquid–liquid extraction (ELLE) is a powerful alternative to common technologies for separation of racemic mixtures. The first application of ELLE for aromatic acids in liquid–liquid extraction columns is described. The ELLE is investigated experimentally and theoretically for phenylsuccinic acid (PSA) as a representative for aromatic acids. A racemic mixture of (R/S)‐PSA is separated with hydroxypropyl‐β‐cyclodextrin as selector molecule. The ELLE obtained the highest operative selectivity (α_op = 1.8–2) for low pH‐values and temperatures. Because of the low operative selectivity, a countercurrent process is necessary to separate both enantiomers completely. The countercurrent process is investigated in process intensified extraction columns (Ø_in = 15 mm) with a high number of equilibrium stages. The experiments demonstrate a good symmetric separation with an enantiomeric excess of 60% and yields of 80% for both enantiomers. Finally, the back extraction is investigated to recycle the selector molecule and increase the efficiency. © 2014 American Institute of Chemical Engineers AIChE J, 61: 266–276, 2015     

Solvent extraction of uranium from acidic sulfate media by Alamine® 336: computer simulation and optimization of the flow‐sheets

BACKGROUND: A series of nine conventional and non‐conventional flow‐sheets have been considered for the recovery of uranium from acidic sulfate solution by liquid–liquid extraction with 0.146 mol L^?1 Alamine^® 336 in kerosene modified with 5% w/w 1‐tridecanol and stripping with a 199 g L^?1 Na₂CO₃ solution. The reference flow‐sheet was a classical counter‐current configuration with four mixers–settlers in the extraction stage and three mixers–settlers in the stripping stage. The others flow‐sheets possessing a total of eight mixers–settlers are unusual combined solvent extraction flow‐sheets with one or two independent extraction stripping loops and with one or two feed inlets. RESULTS: The configuration of the flow‐sheets strongly influences the extraction performance of the process depending on the working conditions (feed, stripping and solvent flow rates). The presence of two independent extraction–stripping loops may allow the delay of the saturation phenomenon encountered in the conventional flow‐sheet and thus, to operate at higher feed flow rates without loss of performance, as far as the residual fraction in the raffinate and the concentration factor in the stripping solution are concerned. Furthermore, the presence of a modification in the non‐conventional flow‐sheets with two independent extraction–stripping loops and two feed inlets leads to interesting configurations for uranium recovery from less concentrated solutions, such as heap leach solutions. CONCLUSION: The use of non‐conventional flow‐sheets is interesting as it allows the process of uranium (VI) recovery by liquid–liquid extraction to be improved. Copyright © 2009 Society of Chemical Industry     

Selective Separation of Toluene/n‐Heptane by Supported Ionic Liquid Membranes with [Bmim][BF4]

Room‐temperature ionic liquids serve as alternative solvents for volatile organic compounds in liquid‐liquid extraction and liquid membrane separation. 1‐Butyl‐3‐methylimidazolium tetrafluoroborate ([Bmim][BF₄]) was applied for extraction and supported ionic liquid membranes (SILMs) to separate toluene and n‐heptane. A high separation factor of toluene was achieved due to the strong interaction between ionic liquid cations and toluene. The mass transfer performance of the SILM process was enhanced by higher operating temperature. With the increase of initial toluene concentration in the feed phase, the mass transfer flux and removal efficiency of the SILM process were improved, while the separation factor decreased. The mass transfer flux was growing with the increase of flow rate at both sides. The SILM process was stable over a long time period due to the high viscosity and low volatility of [Bmim][BF₄].     

Extraction of Anthocyanins Using a Laboratory Robot and Innovative Extraction Technologies

Solid‐liquid extraction using a laboratory robot, where anthocyanins are leached from dried red vine leaves, is evaluated with respect to precision and accuracy. The solid handling of the robot results in standard deviations between ± 0.6 and ± 1.8 depending on the particle size. For liquid handling the standard deviations are slightly higher depending on the volatility of the solvents. The validated, fully automated natural plant extraction robot achieves varying yields based on dry matter for methanol, water, and ethanol which are improved with increasing particle size. Manually performed extraction kinetics experiments are compared with the robot. With respect to process intensification, a comparison of yields obtained by microwave‐ and ultrasonic‐supported extraction compared to laboratory robot shaking and stirred single‐stage batch experiments was performed.     

Determination of ternary solutions concentration in liquid–liquid extraction by the use of attenuated total reflectance‐Fourier transform infrared spectroscopy and multivariate data analysis

A simple and rapid Fourier transform infrared‐attenuated total reflectance (FTIR‐ATR) spectroscopic chemometric method was developed to determine the concentration of solute and solvent in the raffinate layer in a liquid–liquid extraction (LLE) process using partial least squares (PLS) regression. Five type I extraction systems were used with different solute–solvent affinity. The developed model (correlation coefficient from 0.91 to 0.99) was validated with known concentration samples, and in all cases the difference was not larger than 0.5%w. The LLE for the five extraction systems was carried out in a three‐stage crosscurrent extraction process, quantifying the solute and solvent with the chemometric model developed. The results were used to calculate the stage and overall stage efficiencies for the five systems. This method showed to be fast and precise for the quantification of ternary systems in LLE.     

Effective separation of aromatic hydrocarbons by pyridine‐based deep eutectic solvents

Many promising qualities of deep‐eutectic solvents made them suitable solvents in separation process. In this work, the pyridine‐based deep eutectic solvents were designed and synthesized with N‐ethylpyridinium bromide and two HBDs (N‐formyl morpholine and levulinic acid). Two ternary systems, benzene + cyclohexane + DES and toluene + n‐heptane + DES, were studied by the liquid‐liquid extraction. The effect of different HBDs, extraction time, volume ratio of DES to system solution, and the initial concentration of aromatic were studied. The DES with N‐formyl morpholine showed better separation performance than that with levulinic acid. The liquid‐liquid extraction equilibrium could be obtained in 10 minutes. The volume ratio of DES to system solution was set as 1:1. Both DESs showed their best separation performance at low temperatures (20°C) and low aromatic concentration system. For the benzene + cyclohexane system, the distribution coefficient of benzene was 1.733 and the selectivity was 23.8 at 20°C. For the toluene + n‐heptane system, the distribution coefficient of toluene was 0.853 and the selectivity was 40.7. Tie‐lines for two ternary systems were obtained, and the Othmer‐Tobias correlation was used to check the reliability of the obtained liquid‐liquid extraction experimental data. The experimental LLE data were correlated using the NRTL model and the calculated data correlated significantly with the experimental data.     

Membrane stability and enrichment of nickel in the liquid emulsion membrane process

The parameters affecting the stability of a liquid emulsion membrane (LEM) for enrichment of nickel were studied. The liquid membrane is made up of a carrier (di‐2‐ethylhexylphosphoric acid), organic diluent and an emulsifying agent (sorbitan monooleate). Swelling of the internal phase during extraction results in breakage of the emulsion. The role of pH is very important in the LEM process for extraction of nickel. A significant decrease in swelling was observed by maintaining the pH of the feed phase constant during extraction. A lower osmotic pressure difference between the external and internal phase brings about lower changes in the swelling and membrane breakdown. © 2000 Society of Chemical Industry     

Liquid Emulsion Membrane (LEM) Process for Vanadium (IV) Enrichment: Process Intensification

Abstract

A liquid emulsion membrane (LEM) system for vanadium (IV) transport has been designed using di‐2‐ethylhexyl phosphoric acid (D2EHPA), dissolved in n‐dodecane as carrier. The selection of extractant, D2EHPA, was made on the basis of conventional liquid‐liquid extraction studies. The work has been undertaken by first carrying out liquid‐liquid extraction studies for vanadium (IV) to get stoichiometric constant (n), and equilibrium constant (K_ex), which are important for process design.

Transport experiments were carried out at low vanadium (IV) concentration (ppm level). The studies on liquid emulsion membrane included i) the influence of process parameters i.e. feed phase pH, speed of agitation, treat ratio, residence time and ii) emulsion preparation study i.e., organic solvent, extractant concentration, surfactant concentration, internal strip phase concentration. When the strip phase concentration was 2 mol/dm³ (H₂SO₄) and feed phase pH 3 better extraction of vanadium was obtained. Higher V_m/V₁ gave higher extraction of vanadium (IV). A simplified, design engineer friendly model was developed.     

Acidification Optimization and Granulation of a Steel‐Slag‐Derived Sorbent for CO2 Capture

Steel slag was used as a low‐cost feedstock to prepare CaO‐based sorbents for CO₂ capture by acidification treatment, and the acidification process was optimized. Four main acidification parameters (i.e., extraction time, extraction temperature, acetic acid concentration, and solid/liquid ratio) were investigated. The solid/liquid ratio and extraction time are the most important factors that affect the CO₂ capture capacity and stability of the sorbents. The CO₂ sorption performance of optimal steel‐slag‐derived sorbent is more stable than that of naturally occurring limestone, due to the low Si/Ca ratio and the presence of MgO with high anti‐sintering ability. CaO‐based pellets with high resistance to attrition and compression were produced by extrusion of the steel‐slag‐derived sorbent powders.     

Development of a pre‐purification process for homoharringtonine

A novel pre‐purification method was developed for producing homoharringtonine from Cephalotaxus koreana, giving high purity and yield. The simple, efficient procedure involved biomass extraction, liquid–liquid extraction, and synthetic adsorbent treatment, followed by low‐pressure chromatography. The use of active clay treatment and silica gel low‐pressure chromatography in the pre‐purification process allowed for the rapid, efficient separation of homoharringtonine from interfering compounds and, compared with alternative processes, increased the yield and purity of crude homoharringtonine for subsequent high‐performance liquid chromatography (HPLC) purification. Homoharringtonine of over 52% purity could be obtained simply with high yield from biomass using this pre‐purification method, while minimizing solvent use and the scale and complexity of HPLC operations for homoharringtonine purification. Copyright © 2005 Society of Chemical Industry