Acid Cation Exchange Research Articles

Efficient one-pot production of 5-hydroxymethylfurfural from inulin in ionic liquids

An efficient one pot, two-step process was developed for the preparation of 5-hydroxymethylfurfural (5-HMF) from inulin in ionic liquids under mild conditions. In the first step, the ionic liquid 1-butyl-3-methyl imidazolium hydrogen sulfate ([BMIM][HSO4]) was used as both solvent and catalyst for the rapid hydrolysis of inulin into fructose with 84% fructose yield in 5 min reaction time. In the second step, 1-butyl-3-methyl imidazolium chloride ([BMIM][Cl]) and a strong acidic cation exchange resin were added to the mixture to selectively convert fructose into 5-HMF, giving a 5-HMF yield of 82% in 65 min at 80 °C, which is the highest 5-HMF yield reported by thus far for an inulin feedstock.

Study on Industrial Scale Chromatographic Separation Methods of Galactose from Biomass Hydrolysates

AbstractGalactose is an aldohexose, which has commercial uses in the pharmaceutical and food industries. Since monomeric galactose is not a freely occurring compound, it must be produced from galactose‐containing hydrolysates. This paper reports the results of experimental studies of the chromatographic separation of galactose in aqueous solutions by ion exchange resins on an industrial scale. Until now, galactose has only been determined from various solutions by liquid chromatography (HPLC) on an analytical scale. Chromatographic separation of galactose from carbohydrate mixtures was studied with strong acid cation exchange resins in Na+, Ca2+ forms and strong base anion exchange resin in SO42– form. The feed solutions were hydrolysates from three possible galactose sources: lactose, gum arabic and hemicellulose in spent sulfite liquor. The main monosaccharide impurities in these raw materials were glucose, arabinose, and xylose. It was demonstrated that large scale liquid chromatography can be used effectively for galactose separation from complex carbohydrate mixtures such as plant hydrolysates as well as lactose hydrolysate.

Highly accurate radiochemical neutron activation analysis of arsenic in biological materials involving selective isolation of arsenic by hybrid and conventional ion exchange

A highly accurate (definitive) radiochemical neutron activation analysis (RNAA) method was developed for the determination of traces of arsenic (As) in biological materials. It consists of the following steps: (a) irradiation in the nuclear reactor; (b) microwave-assisted sample digestion; (c) quantitative and selective radiochemical separation of arsenates on hydrated ferric oxide nanoparticles dispersed in a macroporous cation exchanger, preceded by a conventional strongly acidic cation exchanger column, and (d) gamma-ray spectrometric measurement of 76As. The suitability and accuracy of the method was demonstrated by analysing several certified reference materials. The detection limit is 8 ng g−1. The standard uncertainty in the determination of As in oriental tobacco leaves is around 3.4%. This, together with its compliance with several other formal requirements, makes the method comparable to primary methods based on isotope dilution mass spectrometry.

Study of nitric acid leachout characteristics from weak base anion exchanger to maintain a specified pH regime during Gd(NO3)3 removal from moderator system of 540 MWe PHWRs

AbstractNitric acid leachout characteristics from weak base anion exchanger (WBA) have been experimentally evaluated as a function of total nitric acid loading at a given flow velocity. An empirical first order model is used to explain the column outlet behaviour. Based on the experimental evaluation, a column configuration of a strong acid cation exchanger (SAC) topped mixed bed of SAC and WBA followed by a 5% nitric acid loaded WBA as the bottom layer of the column has been used to remove Gd(NO3)3 from water while maintaining the column outlet pH in the range of 5.0–5.5.

Hierarchical Superparamagnetic Magnetite Nanowafers from a Resin-Bound [Fe(bpy)3]2+ Matrix

The brilliant red [Fe(bpy)(3)](2+) complex upon immobilization on a strongly acidic cation exchanger or in situ formation of the same cationic complex onto a resin matrix and subsequent modified hydrothermolysis (MHT) at approximately 110 degrees C produces unusually stable hierarchical magnetite (Fe(3)O(4)) nanowafers. The slow hydrothermolysis, oxidation, and subsequent dehydration of the complex on the solid-liquid interface produce stable hierarchical nanostructures. The isolation of neat Fe(3)O(4) (uncapped) particles from the resin matrix as hierarchical nanowafers was achieved by magnetically stirring a CH(3)CN suspension of nanocomposites. The solid resin support not only aids nanowafer formation on its surface but also provides unique stability to the magnetite particles, where nanowafer oxidation is largely retarded. The utility of the as-prepared porous nanocomposite and characterization of the nanoparticles are promising for nanotechnological and soft ferromagnetic applications.

Synthesis and characterization of a thermally stable strongly acidic Cd(II) ion selective composite cation-exchanger: Polyaniline Ce(IV) molybdate

A polymer supported organic–inorganic composite and strongly acidic cation-exchanger polyaniline Ce(IV) molybdate was chemically synthesized and demonstrated to be an excellent ion-exchange material due to its high selectivity for Cd(II), thermal stability and fast elution of an exchangeable H + ion. The material was characterized for its ion exchange properties to study its cation - exchange behavior. Cd(II) selectivity depends upon the distribution coefficient in several solvent systems. The selectivity of this material varied depending upon its composition and the composition of the eluting solvent. Its selectivity was examined and some important binary separations such as Cd(II)–Pb(II), Cd(II)–Hg(II), Cd(II)–Zn(II) and Cd(II)–Ni(II) were also achieved. The physico-chemical properties of the material were also studied using C, H, N elemental analysis, ICP-MS, FTIR, TGA–DTA, X-ray and SEM studies.

Catalytic Hydrolysis of Ethyl Acetate using Cation Exchange Resin (Amberlyst - 15) : A Kinetic Study

The kinetic behavior of the heterogeneous hydrolysis of aqueous ethyl acetate over an acidic cation exchange resin, Amberlyst 15, was investigated. The experiments were carried out in a fixed bed reactor at temperatures from 313.15 to 343.15 K and feed molar ratios ,θBo (water to ethyl acetate) from 62.4 to 265.88. The conversion of ethyl acetate was found to increase with increasing reaction temperature. Gas bubble formation was observed at reaction temperature ≥ 343.15K. Absence of mass transfer resistance was verified by conducting the experiments at different catalyst loadings (20 g, 40 g, 64 g) under varied feed flow rates (1 to 25 cm3/min ). The kinetic data was correlated with pseudo first order model and model parameters were determined using Nelder-Mead algorithm for minimizing the objective function. © 2009 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)

Improvement of Isomerization Process of Crude Isoamylene with Tertiary-amyl-alcohol Addition

The present work contributed to a new developed production method for enhancing the quality of isoamylene (IA) by adding a small amount of tertiary amyl alcohol (TAA) to the catalyst of strong acid cation exchange resin. TAA improved the selectivity of 2-methyl-2-butene (2M2B) at a high conversion level for the isomerization of IA. Compared with the other results from the current IA units, the conversion of 2-methyl-1-butene (2M1B), the mass ratio of 2M2B to 2M1B and the selectivity of 2M2B were increased from 0.5474, 7.32 and 0.6864 to 0.72, 12 and 0.95, respectively, while the dimers content in the products decreased from 4.38% to below 1.0%. Optimized conditions for IA isomerization consisted of temperature between 28 and 33°C and system pressure of 0.5 MPa, weight hourly space velocity of 8.0 h −1 with TAA mass fraction of 0.7%–0.9% in raw material. The results in lab supported bases for the developed process in industrial application which was later proved to be successful. In addition, a possible mechanism of the isomerization process was speculated to propose a key step of water formation in the TAA-added isomerization process and a verified experiment was conducted to support this speculation.

Superheated Water Ion-Exchange Chromatography: An Experimental Approach for Interpretation of Separation Selectivity in Ion-Exchange Processes

Cation-exchange selectivity for alkali and alkaline-earth metal ions and tetraalkylammonium ions on a strongly acidic sulfonic acid cation-exchange resin has been investigated in the temperature range of 40-175 degrees C using superheated water chromatography. Dependence of the distribution coefficient (ln KD) on the reciprocal of temperature (1/T) is not linear for most of the ions studied, and the selectivity coefficient for a pair of alkali metal ions or that of alkaline-earth metal ions approaches unity as temperature increases. On the other hand, the retention order of tetraalkylammonium ions is reversed at 160 degrees C or above when eluted with Na2SO4 aqueous solution and the larger ions are eluted faster than the smaller ones contrary to the retention order obtained at ambient temperature. The change in ion-exchange selectivity with temperature observed with superheated water chromatography has been discussed on the basis of the effect of temperature on hydration of the ions and specific adsorption or distribution of ionic species between the external solution and ion-exchange resin. In superheated water, the electrostatic interaction or association of the ions with the fixed ion becomes a predominant mechanism resulting in different separation selectivity from that obtained at ambient temperature.

Enantioselective analysis of R- and S-propafenone in plasma by HPLC applying column switching and liquid–liquid extraction

Two HPLC methods are described for the enantioselective analysis of R- and S-propafenone in plasma. In a column switching approach, centrifuged plasma was injected onto a silica-based strong acid cation-exchanger and the fraction containing propafenone was switched on-line onto an enantioselective Chiralcel column for separation of the enantiomers. In another approach, propafenone was extracted from plasma by liquid–liquid extraction at pH 11.4. The extracted components were transferred into aqueous medium and separated on a Chiralcel ODR. Both methods were validated and showed comparable performance. Within-day and between-day precision was better than 5% for both methods. Linear calibration functions were obtained ( r 2 > 0.999), and the limit of detection for each enantiomer was 0.2 μg/mL for column switching and 0.55 μg/mL for liquid–liquid extraction. The analysis methods were applied for the determination of the effect of physical exercise on the enantiomeric ratio of R- and S-propafenone in plasma of healthy volunteers. During exercise, the concentration of both enantiomers reached a maximum, followed by a significant decrease during recovery.

Removal of chromium(III) by cation exchange resin, Indion 790 for tannery waste treatment

Extraction of chromium(III) from a model solution and from a tannery waste solution was studied by ion exchange using Indion 790 resin which is a macro-porous strongly acidic cation exchange resin of sulfonated polystyrene group. The resin was found to be selective for the sorption of chromium(III) in the pH range 0.5–3.5 from a model solution containing 500 ppm Cr(III). Beyond pH 3.5 extraction of chromium(III) drastically decreased from 92% to 76%. Sorption of chromium(III) on Indion 790 followed the Freundlich isotherm with a high Freundlich constant value ( K f = 8.57) confirming strong chemical interaction of the metal ion with the resin. Desorption of chromium(III) from the loaded resin increased with the increase in concentration of eluant (5–20% H 2SO 4). With 20% sulfuric acid solution 89% Cr(III) was eluted in two stages. The bench scale results were also validated in continuous mode in a fixed bed column and for the recovery of chromium(III) from a tannery solution.

Removal of metal from acid mine drainage (AMD) by using natural zeolite of Nizarneshwar Hills of Western India

The mining industry faces stringent effluent discharge regulations and has acknowledged that it is necessary to look into innovative technologies to recycle considerable amount of effluent rather than discharging into surface water. Effluents from mines give rise to aesthetic unpleasantness. The focus of the investigations was to cope with more stringent effluent discharge regulations and to protect the ecosystem from harmful pollutants in the mine effluents. Copper is one of the heavy metal in the mine systems, which are known to be a harmful element. The present study has been undertaken to investigate a process that might remove Cu(II) from mine waste water by using natural zeolite, such as stilbite, and compared with synthetic resins like CSA-9 and CSA-609D. In this study, natural zeolite was used as a low-cost adsorbent to evaluate its ability to remove heavy metals from acid mine drainage. The zeolite used in this study is the natural clay mineral from the Nizarneshwar Hills of Western India. Three resins tested are CSA-9, natural zeolite–stilbite, and CSA-609D. Batch testing has been conducted to select effective ion-exchange resins for copper removal and to determine effective regenerants for regeneration of exhausted resins. All tests were conducted at bench scale and in batch mode. Three strong acid cation exchangers were evaluated to compare their metal removal capacities. The metal concentration in the effluent was reduced with all resins tested. It was found that, among all the three types of natural zeolite, stilbite shows the highest removal efficiency of copper in every parameter that is considered for evaluating the performance of resins.

A Novel Chromatographic Production Scale Separation Process for L-Fucose

There is an increasing interest towards a special and very rare sugar, L-fucose, because of its functionalities, i.e., in the human body. There are only a few industrial production processes for L-fucose, and chromatographic separation of this valuable component from hemicellulose hydrolysates could be a feasible alternative. However, chromatographic separation of L-fucose with sufficient purity from other monosaccharides, especially deoxy sugars, has presented a problem in the state of the art. The aim of this work was to find a new process scale chromatographic purification method for L-fucose containing liquor. Of special interest was a process suitable for recovery of L-fucose from plant based biomass hydrolysate. This paper presents an industrial scale chromatographic separation method for the production of L-fucose. The use of a combination of strong and weak acid cation exchange resins increases L-fucose purity gradually, while the use of strong base anion exchange resin gives an excellent separation of L-fucose from other remaining sugar compounds.

Preparation and Characterization of Nonwoven Polypropylene Fabric Irradiation-grafted with Acrylic Acid as Weakly Acidic Cation Exchange Fiber

Graft polymerization of acrylic acid onto nonwoven polypropylene (PP) fabric was carried out by a preirradiation method using a 60Co gamma radiation source. Results showed that 2.2'-Azobisisobutyronitrile (AIBN), its concentration was 0.2%, was very important during the grafting polymerization without removal of polymerization inhibitor of AA. The most favorable grafting polymerization conditions were that the total preirradiation dose was under 60 kGy, the monomer concentration was lower than 30%, and the bath ratio was 1:200. FT-IR spectroscopy, surface morphology (SEM), wide angle X-ray diffraction (WAXD) spectra of the original PP and the grafted PP were also studied.

Ammonium removal from anaerobic digester effluent by ion exchange

The effluent of a 500 kW biogas plant is treated with a solid separation, a micro filtration and a reverse osmosis to achieve nutrient recovery and an effluent quality which should meet disposal quality into public water bodies. After the reverse osmosis, the ammonium concentration is still high (NH(4)-N = 467 mg/l), amongst other cations (K+ = 85 mg/l; Na+ = 67 mg/l; Mg2+ = 0.74 mg/l; Ca2+= 1.79 mg/l). The aim of this study was to remove this ammonium by ion exchange. Acidic gel cation exchange resins and clinoptilolite were tested in column experiments to evaluate their capacity, flow rates and pH. Amberjet 1,500 H was the most efficient resin, 57 BV of the substrate could be treated, 1.97 mol NH4-N/l resin were removed. The ammonium removal was more than 99% and the quality of the effluent was very satisfactory (NH4-N < 2 mg/l). The breakthrough of the observed parameters happened suddenly, the order was sodium-pH-ammonium-potassium. The sharp increase of the pH facilitates the online control, while the change in conductivity is less significant. A regeneration with 3 bed volumes of 2 M HCl recovered 91.7% of the original cation exchange capacity.

Catalytic Hydrolysis of Ethyl Acetate using Cation Exchange Resin (Amberlyst - 15) : A Kinetic Study

The kinetic behavior of the heterogeneous hydrolysis of aqueous ethyl acetate over an acidic cation exchange resin, Amberlyst 15, was investigated. The experiments were carried out in a fixed bed reactor at temperatures from 313.15 to 343.15 K and feed molar ratios ,θBo (water to ethyl acetate) from 62.4 to 265.88. The conversion of ethyl acetate was found to increase with increasing reaction temperature. Gas bubble formation was observed at reaction temperature ≥ 343.15K. Absence of mass transfer resistance was verified by conducting the experiments at different catalyst loadings (20 g, 40 g, 64 g) under varied feed flow rates (1 to 25 cm3/min ). The kinetic data was correlated with pseudo first order model and model parameters were determined using Nelder-Mead algorithm for minimizing the objective function. Copyright (c) 2009 by BCREC . All Rights reserved. [Received: 19 July 2009, Revised: 20 August 2009, Accepted: 22 August 2009] [How to Cite : K.R. Ayyappan, A.P. Toor , R. Gupta, A. Bansal, R.K. Wanchoo (2009). Catalytic Hydrolysis of Ethyl Acetate using Cation Exchange Resin (Amberlyst - 15) : A Kinetic Study. Bulletin of Chemical Reaction Engineering and Catalysis , 4(1): 16-22. doi:10.9767/bcrec.4.1.7114.16-22 ] [ How to Link/ DOI : http://dx.doi.org/10.9767/bcrec.4.1.7114.16-22 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/7114 ]

Preparation and application of acrylic acid grafted polytetrafluoroethylene fiber as a weak acid cation exchanger for adsorption of Er(III)

In this work, a weakly acidic ion exchange fiber (PTFE- g-AA) has been prepared by 60Co irradiation grafting with acrylic acid (AA) onto the polytetrafluoroethylene (PTFE) fiber. The grafted fiber was characterized by FTIR, SEM and TGA technique. The exchange capacity of the PTFE- g-AA fiber is 3.87 mmol/g. The adsorbent material was employed for Er(III) uptaking by batch and column experiments. Kinetics studies showed that the adsorption process obeyed pseudo-second-order kinetics. The adsorption isotherms followed both the Freundlich model and Langmuir model. The maximum adsorption capacity of the PTFE- g-AA fiber for Er(III) was evaluated to be 142.0 mg/g for the Langmuir model. It was found that 0.75 M HCl–0.25 M NaCl solution provided effectiveness of the desorption of Er(III) from the PTFE- g-AA fiber. Various thermodynamic parameters such as standard enthalpy (Δ H 0), standard entropy (Δ S 0) and standard free energy (Δ G 0) were evaluated. The adsorption of Er(III) on the PTFE- g-AA fiber was found to be endothermic in nature. The Thomas model was successfully applied to experimental data to predict the breakthrough curves and to determine the characteristics parameters of the column useful for process design.

Liquid-phase synthesis of ethyl tert-butyl ether over acid cation-exchange inorganic–organic resins

In this study the possibility to increase the productivity of acid cation-exchange resin catalysts active sites in ETBE synthesis was elucidated. For this purpose the inorganic–organic sulfonated cation-exchange resins with different polymer loadings (1.5–9.2 wt.%) have been synthesized. Such polymer/carrier composites as well as commercial acidic microporous gel-type ion-exchange resin KU-2-8 and macroporous Amberlyst 15 have been studied in the ETBE synthesis. Acid properties of all solids were determined by quasi-equilibrium thermogravimetry of ammonia desorption. We have found out that polymer loading and acid capacity affect oppositely on the ETBE productivity. As a result, there is no direct correspondence between the ETBE productivity of the inorganic–organic sulfonated cation-exchange resins per gram of catalyst on their acidity. However, there is a linear relation between the productivity per gram of polymeric phase and acidity. It was established that due to a better accessibility of acid sites for reactants loaded sulfonated cation-exchange resins exceeds the commercial catalysts by the site time yield values.

Application of two low-cost adsorption media for removal of toxic metals from contaminated water

Since the operational costs of commonly used materials for adsorption of toxic metals can be substantial, natural material may be of great interest for treatment applications. Two types of natural material that have shown particular promise are seaweed and seafood waste. In this study, adsorption capacity of Brown seaweed and shrimp shells were compared with a strong acid cation exchange resin (CER). A case study site was used as a reference point and column experiments were designed in a similar manner although at different scale. Each media reduced concentrations of the target metals to levels below defined reference values. If the alternative adsorption media perform as well in the field as the laboratory, the results suggest that the media tested would completely remove the toxic metals in groundwater and runoff water. Seaweed and shrimp shells had stronger affinities for Pb and Cu than CER. However, CER was superior in affinity for Zn, the most weakly bound metal. Moreover, the results showed that Ca in the solution reduced the adsorption capacity of the other metals. This illustrates the limitations of applying the behaviour of the batch studies with single metal solutions to a multi-component system with competitive adsorption.

Phosphoric acid cation exchanger based on immobilized cis-calix[4]resorcinolarene

New phosphoric acid cation exchanger was synthesized on the basis of immobilized calix[4] resorcinolarene and its service characteristics were determined.