Presence Of Ion Exchange Resin Research Articles

A Novel Process Using Ion Exchange Resins for the Coproduction of Ethyl and Butyl Acetates

Before proposing an innovative process for the coproduction of ethyl and butyl acetates, the individual syntheses of ethyl acetate and butyl acetate by two different routes were first studied. These syntheses involved the reaction of ethanol or n-butanol with acetic acid or acetic anhydride in the presence of ion exchange resins: Amberlyst 15, Amberlyst 16, Amberlyst 36 and Dowex 50WX8. Kinetic and thermodynamic studies were performed with all resins. The lowest activation energy (Ea) value was obtained with Dowex 50WX8, which was identified as the best-performing resin, able to be reused at least in four runs without regeneration. The presence of water-azeotropes during the synthesis of ethyl acetate makes its purification difficult. A new strategy was adopted here, involving the use of ethanol and acetic anhydride as the starting material. In order to minimize acetic acid as co-product of this reaction, a novel two-step process for the coproduction of ethyl and butyl acetates was developed. The first step involves the production of ethyl acetate and its purification. Butyl acetate was produced in the second step: n-butanol was added to the mixture of acetic acid and the resin remaining after the first-step distillation. This process yields ethyl acetate and butyl acetate at high purity and shows an environmental benefit over the independent syntheses by green metrics calculation and life cycle assessment.

An efficient and selective conversion of sorbitol in ionic liquids: Use of ion exchange resin as a solid acid catalyst

Sorbitol was readily converted by heating in hydrophobic ionic liquids by the presence of ion exchange resins. Chemoseletivity of the dehydration depended on the choice of ion exchange resin; Nafion selectively produced isosorbide while Amberlite gave 1,5-anhydrosorbitol along with unreacted sorbitol. Ionic liquids used in the reaction were readily recovered by simple extraction procedure. With these procedures, we succeeded to prepare isosorbide in pure form, not contaminated with either ionic liquids or acid catalyst, by simple experimental procedure.

Kinetics of soybean oil epoxidation with peracetic acid formed in situ in the presence of an ion exchange resin: Pseudo-homogeneous model

A kinetic model was proposed for the epoxidation of vegetable oils with peracetic acid formed in situ from acetic acid and hydrogen peroxide in the presence of an acidic ion exchange resin as a catalyst. The model is pseudo-homogeneous with respect to the catalyst. Besides the main reactions of peracetic acid and epoxy ring formation, the model takes into account the side reaction of epoxy ring opening with acetic acid. The partitioning of acetic acid and peracetic acid between the aqueous and organic phases and the change in the phases? volumes during the process were considered. The temperature dependency of the apparent reaction rate coefficients is described by a reparameterized Arrhenius equation. The constants in the proposed model were estimated by fitting the experimental data obtained for the epoxidations of soybean oil conducted under defined reaction conditions. The highest epoxy yield of 87.73% was obtained at 338 K when the mole ratio of oil unsaturation:acetic acid:hydrogen peroxide was 1:0.5:1.35 and when the amount of the catalyst Amberlite IR-120H was 4.04 wt.% of oil. Compared to the other reported pseudo-homogeneous models, the model proposed in this study better correlates the change of double bond and epoxy group contents during the epoxidation process.

Technological aspects of vegetable oils epoxidation in the presence of ion exchange resins: a review

Abstract A review paper of the technology basics of vegetable oils epoxidation by means of peracetic or performic acid in the presence of acidic ion exchange resins has been presented. The influence of the following parameters: temperature, molar ratio of acetic acid and hydrogen peroxide to ethylenic unsaturation, catalyst loading, stirring intensity and the reaction time on a conversion of ethylenic unsaturation, the relative percentage conversion to oxirane and the iodine number was discussed. Optimal technological parameters, mechanism of epoxidation by carboxylic peracids and the possibilities of catalyst recycling have been also discussed. This review paper shows the application of epoxidized oils.

Colloidal crystallization of poly(n-butyl acrylate) spheres in deionized aqueous suspension and the melting during dryness

Colloidal crystallization of poly(n-butyl acrylate) spheres (ammonium persulfate-poly(n-butyl acrylate) (APS-PBA), 320 ± 50 nm in diameter) was studied in deionized aqueous suspension. Coexistence of the crystal and distorted crystal structures was observed by the reflection spectroscopy. The critical concentrations of melting were ca. 0.01 and 0.03 in volume fraction in the presence of ion-exchange resins and in their absence, respectively. Crystal structures melted away during dryness by fusion of each spheres on the substrates, i.e., cover glass, watch glass, and Petri glass dish. Thickness profiles of the dried film changed sharply from the broad ring to the round hill as sphere concentration increased. The sharpness parameter S was evaluated from the ratio of the film size (diameter) against the full width at half maximum in the thickness profiles of the ring and/or the round hill. The S values decreased sharply from 30 to 1.2 as initial volume fraction of the spheres increased from 0.0005 to 0.1. The S values were significantly low compared with those of typical colloidal spheres, which supports the aggregate and/or fusion of the spheres resulting in their low convectional flow during dryness. The round hill profile at the high sphere concentration also supports that the fusion takes place easier during dryness. Microscopic observation of the dried film supports the formation of the homogeneous fused structures. It was clarified that colloidal crystallization of APS-PBA spheres takes place by the extended electrical double layers around the spheres like typical colloidal crystals of hard spheres. However, APS-PBA spheres are not so stable by the fusion especially at the high sphere concentrations and on the substrates.

Liquid Phase Esterification of Acrylic Acid with Isobutyl Alcohol Catalyzed by Different Cation Exchange Resins

The esterification reaction of acrylic acid with isobutyl alcohol in the presence of ion exchange resins, Amberlyst 15, Amberlyst 131, and Dowex 50wX-400, has been studied. According to experimental results, Amberlyst 131 was a more effective catalyst compared with the other ion exchange resins. The effects of catalyst loading, stirrer speed, initial alcohol to acid molar ratio, and temperature on the conversion of acrylic acid were investigated. The experimental data were tested by using Pseudohomogeneous, Eley–Rideal and Langmuir–Hinshelwood–Haugen–Watson models. The nonideality of the reaction medium was taken into account by using activities instead of concentrations. The activity coefficients were calculated using the UNIQUAC group contribution method. The activation energy and kinetic and adsorption constants were determined according to the model representing the dual site adsorption, which comprises the data with minimum error.

Kinetic Study of Catalytic Esterification of Butyric Acid and Ethanol over Amberlyst 15

The esterification reaction of butyric acid with ethanol has been studied in the presence of ion exchange resin (Amberlyst 15). Ethyl butyrate was obtained as the only product which is used in flavours and fragrances. Industrially speaking, it is also one of the cheapest chemicals, which only adds to its popularity. The influences of certain parameters such as temperature, catalyst loading, initial concentration of acid and alcohols, initial concentration of water, and molar ratio were studied. Conversions were found to increase with an increase in both molar ratio and temperature. The experiments were carried out in a batch reactor in the temperature range of 328.15–348.15 K. Variation of parameters on rate of reaction demonstrated that the reaction was intrinsically controlled. Experiment kinetic data were correlated by using pseudo-homogeneous model. The activation energy for the esterification of butyric acid with ethanol is found to be 30 k J/mol.

Ion-Exchange-Assisted Electrochemical Removal of Heavy Metals from Dilute Solutions in a Stirred-Tank Electrochemical Reactor: A Mass-Transfer Study

The rate of diffusion-controlled removal of Cu2+ from a dilute solution containing a fluidized bed of ion-exchange resin in a batch stirred parallel-plate electrochemical reactor was investigated. The variables studied were the concentration of ion-exchange resin, impeller rotation speed, and impeller geometry. The rate of mass transfer of Cu2+ removal was measured in three cases, namely, (i) ion exchange without electrolysis, (ii) electrolysis without ion exchange, and (iii) combined electrolysis and ion exchange. The presence of ion-exchange resin during electrolysis was found to increase the rate of Cu2+ removal by a factor ranging from 1.18 to 1.78 compared to that obtained by electrolysis alone. A simple mathematical model was developed to account for the enhancing effect of ion-exchange particles. The electrical energy consumption decreased in the presence of ion-exchange resin by an amount ranging from 3.6% to 53%. The radial-flow impeller was found to give higher rates of removal than the axial-fl...

Entrainer-Based Reactive Distillation for the Synthesis of 2-Ethylhexyl Acetate

The production of 2-ethylhexyl acetate by esterification of 2-ethylhexanol with acetic acid in the presence of ion-exchange resin (Amberlyst-15) as catalyst is investigated in a reactive distillation (RD) column using toluene as an entrainer. Toluene helps in removing water efficiently from the reactive zone and maintains the reactive zone temperature below the thermal stability limit of the catalyst. Experiments as well as simulations show that quantitative conversion is achievable using the proposed entrainer-based reactive distillation process. The effect of different parameters on the conversion is studied through simulations. The proposed RD process is compared with the conventional process that uses homogeneous p-toluenesulfonic acid (pTSA) as a catalyst and it is shown that the proposed process is more energy efficient and less capital intensive.

熱量・電導度・pH同時測定によるリン酸カルシウム化合物のイオン交換樹脂による溶解過程の解析

熱量・電導度・pH同時測定によるリン酸カルシウム化合物のイオン交換樹脂による溶解過程の解析

Recovery of Acetic Acid from Aqueous Solutions by Reactive Distillation

The recovery of acetic acid by reactive distillation through esterification with methanol in the presence of ion-exchange resin as a catalyst has been investigated in detail. A kinetic expression that is valid under the conditions that prevail in a continuous reactive distillation column has been developed. The insensitivity of reaction rate to catalyst loading under certain conditions has been addressed. The recovery as high as 80% was realized experimentally for the feed concentration of 30% (w/w) in a laboratory column. Various alternative scenarios such as effect of reboiler duty, feed flow rate, and feed composition were covered in the experiments. The equilibrium stage model for reactive distillation predicts the performance well in agreement with the experimental results. The effect of changing various design and operating parameters, over a wide range, was also studied through simulation. The model predicts close to quantitative recovery (∼100%) with a properly designed column. Some feasible alternative configurations for a complete recovery system have been suggested.

Kinetic Studies on the Dimerization of Isobutene with Ion-Exchange Resin in the Presence of Water as a Selectivity Enhancer

The dimerization of isobutene (IB) followed by hydrogenation is looked upon as an important route to produce the octane booster isooctane (IO), because of doubts being raised about methyl tert-butyl ether (MTBE) being a clean fuel additive because of its substantial solubility in water. In the present work, the dimerization of IB has been carried out in a batch reactor over a temperature range of 65−95 °C in the presence of ion-exchange resin as a catalyst and isooctane as a solvent. The influence of various parameters such as temperature, catalyst loading, concentration of water, and initial concentration of IB was examined. Because several side reactions are involved in this reacting system, the selectivity of IB toward the dimers is an important issue. The presence of a polar compound in the reaction mixture plays a vital role as an inhibitor to the side reactions and improves the selectivity toward the dimers. In the present system, water was used as an inhibitor, which leads to the formation of tert-...

Kinetic models of reaction systems for the in situ epoxidation of unsaturated fatty acid esters and triglycerides

Mathematical models that describe the kinetics of reaction systems for the in situ epoxidation of unsaturated fatty acid esters or triglyc?rides with organic peracids are reviewed in this paper. The advantages and inadequacies of each model are discussed. A mono-phase pseudo-first order kinetic model was compared with a two phase model based on the Langmuir-Hinshelwood-Hougen-Watson (LHHW) postulates proposed by the authors of this paper. The comparison was performed on the experimentally determined values for the in situ epoxidation of soybean oil by peracetic acid in the presence of different quantities of ion exchange resin used as the catalyst. It was concluded that a complete model for in situ epoxidation in the presence of ion exchange resin as the catalyst was still not given for perorganic acid formation. In particular, we report here the possibilities of the creation of an "ideal" model for in situ epoxidation.

Reaction of glycerol with fatty acids in the presence of ion-exchange resins: Preparation of monoglycerides

The preparation of monoglycerides from glycerol and fatty acids in the presence of ion-exchange resins is studied. A preliminary swelling in the glycerol inhibits the reaction, whereas a swelling of the resin in the oleic acid, before the reaction, increases the activity and the selectivity. This result shows that the competitive adsorption of glycerol and fatty acid influences greatly the esterification rate. Generally, water is an inhibitor of the esterification reaction (catalyst poisoning and thermodynamic equilibrium) and different procedures have already been suggested for its elimination. By using a molecular sieve as a water trap, the oleic acid conversion increases up to 90% without any change of the monoglyceride selectivity (85%). Moreover, owing to the pore structure of the catalyst, it has to be expected that the hydrocarbon chain length of the fatty acid will influence the activity and the selectivity, evidence of which we give in the present study. Finally, if an excess of glycerol increases the selectivity of the monoglycerides, it decreases the activity and can be considered as a selective inhibitor.

Importance of anion exchange resin as supported catalyst

Wofatit SBW anion exchange resin supported with Fe (III) hydroxide has been used as a new catalyst for H2 O2 decomposition in an aqueous medium. The rate constant, k (pgc), was evaluated with a resin crosslinked 4% divinylbenzene over the temperature range 25-40°C. The reaction was first order with respect to [H2 O2 ] in all cases. The rate constant increase in presence of ion exchange resin in the following forms : RSO4 2- 2- 3- 2- . This is attributed to the strength of the electrostatic attraction with respect to the system concerned here. The activation parameters were calculated which show a high negative value of ΔS# and low value of the activation energy. These values suggested that the reactions can involve both radicals (HO2 • ) and ions (HO2 - ).

Further investigation in the interaction of hydrogen peroxide with iron (III) hydroxide supported ion exchange resin

The kinetics of the reaction of hydrogen peroxide with iron (III) hydroxide supported ion exchange resin has been investigated in aqueous solution. These catalysts are very stable even after completion of the reaction. The study showed that the decomposition reaction is first order with respect to hydrogen peroxide concentration. The activity of the catalyst is very high with the mixed resin, MR-12 loaded with 2 Na + / [math] or 2 Na + /OH - . Generally, the rate constant, k (per g catalyst) increases in presence of ion exchange resin in the form of alkali metal. With Dowex-50W resin, the rate constant increases with the degree of resin crosslinkage. Also, it increases with the effective surface area. The data have been treated quantitatively in the light of the activation parameters. The mechanism of the reaction can be summerised by the equation:-[d H 2 O2]/ dt = k 1 (K 1 ) 1/2 K 2 [R / Fe (III) hydroxide] [ H 2 O 2 ] / [ H + ] in which the subsequent reactions of the probable active complex are discussed.

Melting temperature of colloidal crystals of monodisperse silica spheres in ethanol-water and ethylene glycol-water mixtures

The melting temperature (Tm) of colloidal crystals of monodisperse silica spheres in ethanol-water and ethylene glycol-water suspensions has been measured by reflection spectroscopy. A sphere of 110 nm in diameter and 0.041 in monodispersity index is used after purification and deionization processes. Transformation from the body-centered cubic lattice to the face-centered cubic lattice subphases is observed as the suspension temperature rises, which is similar to the purely aqueous suspension of the same sphere. A phase diagram including liquid-like and crystal-like structures is obtained in the presence of ion-exchange resins coexisted. The data ofTm are analyzed successfully with the theory of Williams, Crandall, and Wojtowicz. The heat of melting decreases by the addition of ethanol or ethylene glycol in the mixtures.

Melting temperature of colloidal crystals of monodisperse silica spheres

Melting temperature (Tm) of colloidal crystals of monodisperse silica spheres has been measured by the reflection spectroscopy as a function of sphere concentration. Spheres of their diameters of 110 and 178 nm from electron microscopy, and their monodispersity indices (standard deviation of sphere diameter divided by the mean diameter) of 0.041 and 0.05, respectively, are used after purification and deionization processes. Transformation from the body-centered cubic lattice to the face-centered cubic lattice subphases are observed as the suspension temperature rises. A phase diagram including liquid-like and crystal-like structures is obtained in the presence of ion-exchange resins or sodium chloride. The Tm values observed are analyzed with the theory of Crandall et al. successfully. The Tm values are also consistent with the theory of Robbins et al., which treats the repulsive Yukawa potential between colloidal spheres.

Exchange‐induced dissolution of gypsum and the reclamation of sodic soils

SUMMARYA study was undertaken to define the dissolution kinetics of gypsum in the presence of ion exchange resins and to study sodic soil reclamation in laboratory soil columns.Gypsum pellets were prepared at 1.5 MPa pressure and the time course of their dissolution followed by measuring the electrical conductivity of the solution. Dissolution experiments were carried out in distilled water with and without Na‐ and Cl‐saturated exchange resins or a combination of the two. The results indicate that in the presence of resin the reaction is first order as calcium and/or sulphate are removed from solution by the resin driving the reaction to completion. In water alone the reaction follows second‐order kinetics and depends on the rate of mixing as the reaction is transport controlled.The effect of gypsum placement (uniformly mixed with the entire soil, mixed with the top third of the soil, applied to the soil surface or applied as a saturated gypsum solution) on the efficiency of exchangeable sodium removal, leaching of soluble salts and soil hydraulic conductivity was studied. In addition, the effect of various flow rates on reclamation efficiency was investigated.The amount of leachate required for reclamation was found to be dependent on gypsum placement, tending to decrease in the order mixed < top third mixed < saturated gypsum solution < gypsum surface application < water. Soil hydraulic conductivity was much higher in the mixed gypsum column than in the gypsum applied on the surface; a result of the higher effective gypsum solubility. Sodic soil electrical conductivity in the presence of solid‐phase gypsum is linearly related to the total amount of exchangeable sodium expressed in mol dm−3.

Reaction of Styrene Oxide in the Presence of Ion-exchange Resins

The reactions of styrene oxide (1) with acetone, the isomerization of oxides, and reactions of (1) with alcohols in the presence of H-form ion-exchange resins (Dowex 50W-X8, Dowex 50 W-X4, Diaion PK 216, Amberlyst 15 and Nafion NR 50) were studied. The following results were obtained : 2, 2-Dimethyl-4-phenyl-1, 3-dioxolane was synthesized in a high yield (isolated yield 93%) by a simple reaction of (1) with acetone catalyzed by Amberlyst 15 or Nafion NR 50. Phenylacetaldehyde was obtained (isolated yield 91%) by the isomerization of (1) catalyzed by Amberlyst 15 or Nafion NR 50. 2-Phenyl-2-methoxyethanol was obtained in a high yield by the reaction of (1) with methanol catalyzed by ion-exchange resins.