Acid Ion Exchange Research Articles

Transport of Indium, Gallium and Thallium Metal Ions Through Chromatographic Fiber Supported Solid Membrane in Acetylacetone Containing Mixed Solvents

The transport of metal ions of indium, gallium and thallium from source solution to receiving phase through the chromatographic fiber supported solid membrane in the acetylacetone (HAA) containing mixed solvent system has been explored. The fibers supported solid membranes were prepared with chemical synthesis from cellulose fibers and citric acid with the carboxylic acid ion exchange groups introduced. The experimental variables, such as concentration of metal ions (10 −2 to 10 −4 mol·L −1) in the source solution, mixed solvent composition [for example, acetylacetone, (2,4-pentanedione), (HAA) 20% (by volume), 1,4-dioxane 10% to 60% and HCl 0.25 to 2 mol·L −1] in the receiving phase and stirring speed (50–130 r·min −1) of the bulk source and receiving phase, were explored. The efficiency of mixed solvents for the transport of metal ions from the source to receiving phase through the fiber supported solid membrane was evaluated. The combined ion exchange solvent extraction (CIESE) was observed effective for the selective transport of thallium, indium and gallium metal ions through fiber supported solid membrane in mixed solvents. The oxonium salt formation in the receiving phase enhances thallium, indium and gallium metal ion transport through solid membrane phase. The selective transport of thallium metal ions from source phase was observed from indium and gallium metal ions in the presence of hydrochloric acid in organic solvents in receiving phase. The separation of thallium metal ions from the binary mixtures of Be(II), Ti(IV), Al(III), Ca(II), Mg(II), K (I), La(III) and Y(III) was carried out in the mixed solvent system using cellulose fiber supported solid membrane.

Synthesis of ethyl octyl ether from diethyl carbonate and 1-octanol over solid catalysts. A screening study

The synthesis of ethyl octyl ether (EOE) from a mixture of diethyl carbonate (DEC) and 1-octanol (1:2 molar ratio) over several solid catalysts was studied in batch mode at 150 °C and 25 bar. Catalyst screening revealed that EOE could be successfully obtained over some acid catalysts. In particular the highest yield was achieved over acid ion-exchange resins (33% after 8 h). A reaction scheme of the process is proposed. Selectivity to EOE was mainly affected by the production of diethyl ether (DEE) and di-n-octyl ether (DNOE). However, EOE was the main ether obtained (60 mol%), followed by DEE (20 mol%) and DNOE (20 mol%). By comparing the behavior of several acid resins, it was seen that the synthesis of EOE was highly related to the structural resin properties. It was found that the accessibility of DEC and 1-octanol to acid centers was improved over highly swollen and low polymer density resins. Thus, gel-type resins with low divinylbenzene content are the most suitable to produce EOE (e.g., Amberlyst 121, Dowex ® 50Wx2-100 and CT224).

Selective epoxidation of natural triglycerides using acidic ion exchange resin as catalyst

ABSTRACTEpoxidation is a very useful reaction in organic synthesis. Due to the high reactivity of the epoxide group it can be used as an active intermediate for the synthesis of many high‐value products. Epoxides are commercial products and they have many industrial uses. Understanding the kinetics of epoxidation reactions can lead to production of value‐added products from locally available renewable natural resources. This research investigated the kinetics of epoxidation of cottonseed oil by peroxyacetic acid (PAA) generated in situ from hydrogen peroxide and glacial acetic acid (AA) in the presence of acidic ion exchange resin (AIER) catalysts, namely Amberlite IR‐120. The effect of several variables including temperature, stirring speed, catalyst loading, and particle size, concentration of hydrogen peroxide and AA on oxirane conversion was studied. A satisfactory level of oxirane conversion (greater than 65%) with high selectivity (greater than 90%) could be obtained if the epoxidation was carried out at optimum conditions, using in situ generated PAA. The Langmuir–Hinshelwood–Hougen–Watson (L–H–H–W) kinetic model approach has been adopted for the development of overall reaction rate equations, and the proposed kinetic model includes the major side reactions for the estimation of kinetic parameters. Kinetic parameters were estimated by fitting experimental data using a nonlinear regression method. From the estimated kinetic constants, the activation energy for the AIER catalysed epoxidation of cottonseed oil was found to be 10.1 kcal mol−1. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.

Experimental study and model of reaction kinetics of heterogeneously catalyzed methylal synthesis

Reaction kinetics of the heterogeneously catalyzed formation of methylal from aqueous methanolic formaldehyde solutions are studied in a plug flow reactor at 323, 333 and 343K using the acidic ion exchange resin Amberlyst 15 (Rohm and Haas) as catalyst. Parameters of an activity-based pseudo-homogeneous reaction kinetic model are fitted to the experimental results. The model is based on the true speciation in the reacting solution and explicitly includes the oligomerization reactions of formaldehyde in aqueous methanolic solutions. The reaction kinetic model describes the experimental data well and is suited for process simulations in which both chemical reactions and phase equilibria have to be described simultaneously.

Sulfonic acid modified hollow silica spheres and its application in proton exchange membranes

In order to improve the proton conductivity of hollow silica spheres (HSS)/perfluorosulfonic acid ion-exchange (PFSA) composite membranes as proton exchange membrane, sulfonic acid groups were grafted onto the surfaces of HSS via post grafting methods. TEM images and FT-IR spectra of the obtained sulfonic acid groups modified hollow silica spheres (SAMHSS) illustrated that the sulfonic acid groups were successfully grafted onto the surfaces of HSS. Water uptake and swelling degree of SAMHSS/PFSA composite membranes were found much higher than those of HSS/PFSA membranes due to the introduction of hydrophilic sulfonic acid groups. In a range from 50 °C to 130 °C, the highest conductivity of composite membranes was obtained when 5 wt% SAMHSS was loaded. The maximum conductivity reached 7.5×10−2 S·cm−1 at 100 °C and 100% relative humidity, even the temperature increased to 130 °C, the conductivity of composite membranes with 5 wt% SAMHSS could reach 3.7×10−2 S·cm−1 at 100 % relative humidity, while the conductivity of the recast PFSA was only 2.2×10−3 S·cm−1.

Investigation of the Dissolution of Colemanite Ore in Water and Boric Acid Solutions Including Highly Acidic Ion Exchangers under Microwave Heating

The dissolution of colemanite obtained from Bandırma Boraks Corporation was investigated in boric acid solutions containing highly acidic ion exchangers in a classical and microwave energy heating environment and the results showed that superior conversions can be obtained via microwave heating. Particle size, acid concentration, reaction temperature, stirring speed, amount of ion exchanger, solid to liquid ratio, and microwave power were selected as parameters. Dissolution kinetics of colemanite was also examined and it was observed that the dissolution rate increased with decreasing particle size and solid to liquid ratio and increased with stirring speed, acid concentration, and amount of acidic ion exchanger. The relationship between conversion and system parameters was determined with nonlinear estimation by using the statistical program Statistica 7.0. The activation energies (E) for classical and microwave heating methods were found as 24.40 and 22.98 kJmol–1, respectively.

Quantifying temperature and flow rate effects on the performance of a fixed-bed chromatographic reactor

Chromatographic reactors are based on coupling chemical reactions with chromatographic separation in fixed-beds. Temperature and flow rate are important parameters for the performance of such reactors. Temperature affects mainly adsorption, chemical equilibria, mass transfer and reaction kinetics, whereas flow rate influences residence time and dispersion. In order to evaluate the mentioned effects, the hydrolysis reactions of methyl formate (MF) and methyl acetate (MA) were chosen as case studies. These reactions were performed experimentally in a lab-scale fixed-bed chromatographic reactor packed with a strong acidic ion exchange resin. The chosen reactions can be considered to represent a relative fast (MF) and a relative slow (MA) reaction. The processes which take place inside the reactor were described and simulated using an isothermal equilibrium dispersive model. The essential model parameters were determined experimentally at different temperatures and flow rates. The performance of the chromatographic reactor was evaluated at several discrete constant temperature levels by quantifying product purity, productivity and yield. The work provides insight regarding the influence of temperature and flow rate on values of the model parameters and the performance criteria.

Effect of low-molecular-weight organic acids on the leaching of thallium and accompanying cations from soil – A model rhizosphere solution approach

The kinetic batch leaching of Tl-bearing mineral soil in 500 μM solutions of citric, oxalic and acetic acid was performed to simulate the release of Tl and main cations (Al, Fe, Si, K, Ca, Mn) in the rhizosphere-like environment. The obtained data demonstrate that low-molecular-weight organic acids (LMWOAs) significantly contribute to soil alteration accompanied by the release of lithogenic Tl (if present). The highest mobilization rates for Tl were observed after 0.5 h of leaching (with maximal values obtained for oxalate) followed by a substantial decrease. Thallium extractability in the organic acid solutions was up to 2.8-fold higher compared to water. Based on the experimental and speciation modeling data, Tl release is mainly pH-driven and can be attributed to acid ion exchange and/or acid leaching, as the formation of Tl-LMWOA complexes is negligible. The main Tl solubility-controlling phases predicted include illite and the identified Mn(III,IV) oxide due to their ability to efficiently sorb Tl + on the mineral surfaces from which Tl can be potentially mobilized. The role of primary silicates (i.e., orthoclase and muscovite) in the total process of Tl mobilization seems to be of lesser importance because the supposed alteration/dissolution of these phases during LWMOA leaching was limited.

Glycerol acetals, kinetic study of the reaction between glycerol and formaldehyde

The acetalization reaction between glycerol and formaldehyde using Amberlyst 47 acidic ion exchange resin was studied. These acetals can be obtained from renewable sources (bioalcohols and bioalcohol derived aldehydes) and seem to be good candidates for different applications such as oxygenated diesel additives. A preliminary kinetic study was performed in a batch stirred tank reactor studying the influence of different process parameters like temperature, feed composition and the stirring speed. A pseudo homogenous kinetic model able to explain the reaction mechanism was adjusted. Thus, the corresponding order of reaction was determined. Amberlyst 47 acidic ion exchange resin showed a fairly good behavior allowing 100% of selectivity towards acetals formation. However, the studied acetalization reaction showed high thermodynamic limitations achieving glycerol conversions around 50% using a stoichiometric feed ratio at 353 K. The product is a mixture of two isomers (1,3-Dioxan-5-ol and 1,3-dioxolane-4-methanol) and the conversion of 1,3-dioxolane-4-methanol into 1,3-Dioxan-5-ol was also observed. ► The reaction between glycerol and acetaldehyde shows thermodynamic limitations. ► Amberlyst 47 ion exchange resins show 100% of selectivity. ► A pseudo-homogeneous kinetic model is able to predict the reaction progress. ► Isomerization reactions were observed from dioxalanes to dioxanes.

Utilization of green seed canola oil for in situ epoxidation

Green seed canola oil is underutilized for edible purposes due to its high chlorophyll content, which makes it more susceptible to photo-oxidation and ultimately reduces the oxidation stability. The present work is an attempt to compare the kinetics of epoxidation of crude green seed canola oil (CGSCO) and treated green seed canola oil (TGSCO) with peroxyacids generated in situ in presence of an Amberlite IR-120 acidic ion exchange resin (AIER) as catalyst. Among the two oxygen carrier studied, acetic acid was found to be a better carrier than the formic acid, as it gives 8% more conversion of double bond than the formic acid. A detailed process developmental study was then performed with the acetic acid/AIER combination. For the oils under investigation parameters optimized were temperature (55°C), hydrogen peroxide to double bond molar ratio (2.0), acetic acid to double bond molar ratio (0.5), and AIER loading (15%). An iodine conversion of 90.33, 90.20%, and a relative epoxide yield of 90, 88.8% were obtained at the optimum reaction conditions for CGSCO and TGSCO, respectively. The formation of the epoxide product of CGSCO and TGSCO was confirmed by Fourier Transform IR Spectroscopy (FTIR) and NMR (1H NMR) spectral analysis.

Synthesis of dimethyl ether (DME) by catalytic distillation

The intrinsic kinetics of liquid phase catalytic dehydration of methanol to dimethyl ether over a macroporous sulphonic acid ion exchange resin was determined in a fixed-bed micro-reactor in the temperature range of 391–423 K and pressures up to 2.0 MPa. The kinetic model based on Eley–Rideal mechanism, as well as the power-rate law model, was adopted for fitting the experimental data. However, the Langmuir–Hinshelwood mechanism is not feasible for describing the dehydration reaction of methanol, as deduced from the macroscopic kinetic data and/or no dependence of methanol conversion on initial methanol concentration in the absence of water at the inlet using acetone as inert solvent. Moreover, an improved process consisting of the combination of a fixed-bed reactor and a catalytic distillation column for the synthesis of DME (Process A) was proposed, and a mathematical model was established, into which the intrinsic kinetics obtained in this work was incorporated. The comparison of operating performance among the improved process, Process B consisting of a fixed-bed reactor and two ordinary distillation columns, and Process C consisting of a catalytic distillation column and an ordinary distillation column was also made. It was found that the improved process is more promising than others in energy consumption, production capacity and column number under the same product purity, and is easy to be implemented based on Process B that is currently used in the actual industrial plants with a long catalyst lifetime.

Supported ionic liquid silica nanoparticles (SILnPs) as an efficient and recyclable heterogeneous catalyst for the dehydration of fructose to 5-hydroxymethylfurfural

Supported ionic liquid nanoparticles (SILnPs) having particle size ranging from 293 ± 2 to 610 ± 11 nm have been prepared by immobilization of ionic liquid, 1-(tri-ethoxy silyl-propyl)-3-methyl-imidazolium hydrogen sulfate (IL-HSO4) on the surface of silica nanoparticles. The catalytic activity of the prepared SILnPs was investigated for the dehydration of fructose to 5-hydroxymethylfurfural (HMF) in the presence of dimethylsulfoxide (DMSO) as a solvent. The reaction temperature and amount of catalyst have been optimized for dehydration of fructose over SILnPs using experimental design leading to 99.9% fructose conversion and 63.0% HMF yield using silica SILnPs (d = 610 ± 11) nm at 130.0 °C in 30 min reaction time. The SILnPs catalysts developed in this study present improved performances over other zeolites and strong acid ion exchange resin catalysts, and they have been efficiently and very easily recycled over seven times without any significant loss in fructose conversion and HMF yield.

IDENTIFYING THE PLANT ORIGIN OF ARTISTS' YELLOW LAKE PIGMENTS BY ELECTROSPRAY MASS SPECTROMETRY

Dyes containing flavonoids are found in yellow lake pigments used as artists' materials. Pre-treating a sample of a flavonoid-based lake pigment with an acidic ion exchange resin followed by reversed-phase HPLC electrospray mass spectrometry enables the identification of key diagnostic yellow compounds, even when the pigment is bound in paint media. Reference raw plant materials of weld and buckthorn berries were also treated similarly for comparison with the lake pigments derived from these plants. This method is suitable for microsamples and thus suitable for analysis of samples that can be ethically removed from works of art in the course of their conservation. The flavonoid content is analysed and plant origins are suggested for yellow lake samples taken from Reclining Tiger by Jean-Baptiste Oudry and the 1893 version of The Scream by Edvard Munch.

Heterogeneous reactive extraction for secondary butyl alcohol liquid phase synthesis: Microkinetics and equilibria

The reaction kinetics for the liquid phase synthesis of a racemic mixture of the secondary butyl alcohols (SBA) from linear butene isomers (1-butene (1B); cis-2-butene ( c2B); trans-2-butene ( t2B)) and water (W) using a macroporous sulfonic acid ion exchange resin as catalyst were determined experimentally in a multiphase CSTR in the temperature range 39–433 K at 6–8 MPa. This range of pressures is necessary to dissolve butenes in the aqueous phase and to ensure a liquid state of all components. For temperatures higher than 423 K the reaction kinetics for the used catalyst size are influenced by mass transfer resistances within the catalyst matrix. The reaction takes place in the water swollen gel phase of the catalysts microspheres. Due to the large excess of water in the gel phase the compositions in the gel phase, in the macropore fluid, and in the catalyst surrounding aqueous phase are assumed to be identical. According to the literature the reaction is rather catalyzed by hydrated acid protons ( specific catalysis) than by polymer-bonded-SO 3H groups ( general catalysis). The experimental results can therefore be described sufficiently by a pseudo-homogeneous 3-parameter rate expression in aqueous phase activities. The forward reaction is first-order in butene. The reverse reaction is first-order in secondary butyl alcohol. The activation energy was determined to be 108 kJ/mol. Practically no pressure dependence could be observed for pressures exceeding 6 MPa. The ever-present isomerization of the linear butenes on acid catalysts was found to be remarkably faster than the hydration of butenes to SBA. Therefore, the isomerization is considered to be always in equilibrium during the olefin hydration. The formation of the possible by-product di- sec-butyl ether (DSBE) was never observed to a measurable extent. Simultaneous chemical and phase equilibria were investigated theoretically using the volume translated Peng–Robinson equation of state (VTPR-EoS) in combination with a g E -mixing rule. Parameters of the used g E -model were adjusted to experimental ternary liquid–liquid equilibrium (LLE) data.

Preparation of submicron ion-exchange fibers and application in copper ions removal from aqueous solutions

AbstractThe submicron ion-exchange fibers (IEF) of polystyrene (PS) and styrene-isoprene-styrene block copolymer (SIS) blends (80/20, w/w) obtained by electrospinning technology were further sulfonated with sulfuric acid to produce strong acidic cation ion exchange fibers. Scanning electron microscopy (SEM) images showed that there were obvious increase in the diameters, scratches, cracks, and micro-pores on the rough IEF surface. Fourier transform infrared (FTIR) spectroscopy analysis showed there were many sulfonated acid groups introduced onto the benzene wreath of styrene. The maximum adsorption capacity and the adsorption rate of copper ions were carried out and their removal rate determined by spectrophotometry. The results of the adsorption for copper ions showed that submicron IEF from PS/SIS blends with a high porosity (85%) and a high specific surface (760 m2/g) possess a rapid adsorption rate and a high ion adsorption amount (305.9 mmg/g). This high adsorption capacity suggests that the IEF can be efficiently applied to filter out toxic metal ions, and has excellent efficiency to remove copper ions from aqueous solution.

Biobased Epoxidized Vegetable Oils and Its Greener Epoxy Blends: A Review

Epoxidized vegetable oils (EVO) have drawn much attention in recent years, especially in the polymer industry as they are economical, available, environmentally friendly, non-noxious and renewable. Vegetable oils can be transformed into useful polymerizable oxygenated monomers commonly by Prileshajev-epoxidation, catalytic epoxidation using acidic ion exchange resin, chemo-enzymatic epoxidation, or metal-catalyzed epoxidation. Among those epoxidation methods, chemo-enzymatic epoxidation has achieved considerable interest nowadays since this method is safe, environmentally friendly and conversion rate of epoxidation usually exceeds 90%. Bio-based epoxidized vegetable oils from renewable natural resources are potential green materials to partially substitute and toughen petrochemical-based polymers.

Investigation of the Oligomerization of Light Olefins on Ion Exchange Resin Catalyst

The requirements against the quality of motor fuels were rendered more rigorous in the past decade; the most important ones were the major reductions of the sulphur and aromatic content. Besides the changing of the regulation of the motor fuels, the harmful material emission of the Otto- and Diesel-engine built vehicles was also limited significantly. These effects make necessary the greater use of the environmentally friendly, relatively “clean burning”, technically heteroatom- and aromatic free, great n- and i-paraffinic containing blending components in the case of gasoline and diesel gas oils. During our experimental work we studied the possibilities of producing motor fuel blending components like these blending components with the oligomerization of the olefin content of light FCC-naphtha – assuming later industrial application – on Amberlyst-15 acidic ion exchange resin type catalyst. This topic is very important in a modern oil refinery, because different isoparaffin-rich motor fuel blending components can be produced (depending on the catalyst and the process parameters), and this technology can grow considerably the gasoline- and diesel gas oil flexibility of the oil refinery, too. The aim of our experiments was to produce motor fuel blending components with the oligomerization of C4-C6 olefins in light FCC-naphtha matrix. Working on the acidic ion exchange resin catalyst under different process parameters (T: 80–130 °C, P: 15–30 bar, LHSV: 0.5–3.0 h-1) we determined that in the studied process parameter range in preferable case (T: 100–110 °C, P: 25–30 bar, LHSV 0.5–1.0 h-1) the liquid product yield was: greater than 95%, the conversion of olefins: 90–92%, the selectivity of C8-C11: 70–76%, while the selectivity of C12+: 24–30%.

ChemInform Abstract: Dithioacetalization Catalyzed by an Acidic Ion-Exchange Resin.

ChemInform Abstract: Dithioacetalization Catalyzed by an Acidic Ion-Exchange Resin.

Basic Ion Exchange Resins as Heterogeneous Catalysts for Biodiesel Synthesis

Basic and acidic ion exchange resins were used as catalysts for the synthesis of biodiesel from soybean oil and methanol. The impact of reaction parameters like molar methanol/oil relationship, catalyst mass and reaction temperature were studied. The catalysts did not show deactivation and the reaction medium remained neutral. The performance of the resins was compared against reference catalysts (NaOH; MgO). A strongly basic macroporous resin was the most active catalyst and it was possible to reach 100 % selectivity to methyl esters. A series reaction mechanism was consistent with the evolutions of the intermediate reaction products.

Development of a Strong Acid Ion Exchange Resin with a Monolithic Microhoneycomb Structure Using the Ice Templating Method

In this work, the synthesis of a strong acid ion-exchange resin with a monolithic microhoneycomb structure was attempted using the ice templating method, a new micromolding technique developed by the authors. The obtained monoliths were found to have micrometer-sized straight channels, and the thickness of the walls which form the channels were also in the micrometer range. Through titration experiments, it was confirmed that the monoliths have a sufficient ion exchange capacity and strong acidity. The monoliths also showed catalysis in esterification reactions which indicates that they can be used as an effective solid acid catalyst with an extremely low hydraulic resistance in various commercial reactions.