Adsorption of acetic acid on ion-exchange resins in non-aqueous conditions (original) (raw)
Related papers
2005
Adsorption isotherms for the removal of oleic acid from ethanol + water solutions using a strong anionexchange resin (Amberlyst A26 OH) were experimentally determined. The equilibrium data were correlated using the Langmuir model by adjusting the parameters q m /(g of acid‚g of dry resin-1), maximum content that can be adsorbed on solid phase, and K d /(g of acid‚g of solvent-1), the equilibrium constant. The Freundlich and Redlich-Petersen models were also used, but the Langmuir model shows the lower average deviations between experimental and calculated results. The behavior and the capacity of the resin to remove the fatty acid from the liquid phase were evaluated at different experimental conditions: the water content in ethanol was varied within the range (0 to 15) mass %, and two equilibrium temperatures were investigated: (298.15 and 313.15) K. It was observed that both variables, water content in ethanol and equilibrium temperature, do not significantly influence the equilibrium behavior. It was also observed that the strong anion-exchange resin (Amberlyst A26 OH) has a good performance in the removal of the fatty acid from the liquid phase. To determine exactly the mechanism for the uptake of oleic acid by the resin, equilibrium experiments were done with different oleic acid concentrations (7, 9, and 11) mass % in solution with water content in ethanol (0.57 (0.01) mass % at 298.15 K. In this way the concentration of oleic acid in resin phase was determined, and it was observed than the most important mechanism of uptake is the ion exchange.
Adsorptive Removal of Unsaturated Fatty Acids Using Ion Exchange Resins
Journal of Chemical & Engineering Data, 2020
The main aim of present investigation was to elucidate efficacy of silver ion chromatography for selective separation of unsaturated (oleic, linoleic, and linoleneic) fatty acids on a preparative scale. Accordingly, the present work was predominantly divided into two parts. In the first part, adsorption of oleic acid was carried using commercially available ion exchange resins and silver ion loaded resin (R-Ag +) prepared in the laboratory from non-polar and polar solvents in a batch mode. The maximum adsorption of oleic acid was found on RAg + (454.55 g.kg-1) when compared with other commercially available ion exchange resins from heptane at ambient temperature (303 K). The effect of temperature on adsorption of oleic acid on RAg + from heptane was investigated at 303, 313, and 323 K. Adsorption of oleic acid was favored at 303 K and further decreased with an increase in temperature. Experimental batch equilibrium data were modeled using Langmuir isotherm and Freundlich isotherm. Further, thermodynamic parameters viz.
Journal of Chromatography A, 1997
Ion-exclusion chromatography of aliphatic carboxylic acids of different acidity (pKa) and hydrophobicity was investigated on a polystyrene-divinylbenzene (PS-DVB) based strongly acidic cation-exchange resin in the H + form and conductivity detection by elution with polyvinyl alcohol (PVA). When water was used as an eluent, the resolution of the carboxylic acids was very low and the peak accompanied a fronting depending on their hydrophobicities. Therefore, to improve the peak shape and the peak resolution, aqueous eluents containing PVAs (degrees of polymerization, n=500, 1500 and 2000) with many OH groups were tested for the ion-exclusion chromatographic separation of the carboxylic acids. When aqueous eluents containing PVA were used, the fronting was decreased dramatically by the effect of increased hydrophilicity of the PS-DVB cation-exchange resin surface due to adsorption of OH group in PVA. The high resolution ion-exclusion chromatographic separation without the fronting and highly sensitive conductimetric detection of the carboxylic acids was accomplished successfully by elution with a 0.2% PVA (n=1500)-10% methanol-water.
Sorption studies on ion exchange resins. 1. Sorption of strong acids on weak base resins
Industrial & Engineering Chemistry Research, 1992
Sorption equilibria and batch dynamics of weak acids (formic acid and monochloroacetic acid) on weak base ion exchange resins, in free base form, are studied. The reversible sorption model based on double layer theory, developed in part 1 of these studies, is extended to take into account undissociated acid species. The model fits the experimental dynamics satisfactorily over the entire range of resin conversion. Values of effective ionic pore diffusion coefficient, regressed from the observed experimental dynamics, have been satisfactorily correlated on the basis of the model. These studies reveal that the contributions of both the ionic and the undissociated molecular species are important in determining the total diffusive flux of the acid in the pores of the resin. .. Cliffs, Nj, 1978. Process Technol. 1981.2, 1. I Wadekar, V. V.; Sharma, M. M. Dissociation extraction. J. Sep.
Sorption studies on ion exchange resins. 2. Sorption of weak acids on weak base resins
Industrial & Engineering Chemistry Research, 1992
Sorption equilibria and batch dynamics of weak acids (formic acid and monochloroacetic acid) on weak base ion exchange resins, in free base form, are studied. The reversible sorption model based on double layer theory, developed in part 1 of these studies, is extended to take into account undissociated acid species. The model fits the experimental dynamics satisfactorily over the entire range of resin conversion. Values of effective ionic pore diffusion coefficient, regressed from the observed experimental dynamics, have been satisfactorily correlated on the basis of the model. These studies reveal that the contributions of both the ionic and the undissociated molecular species are important in determining the total diffusive flux of the acid in the pores of the resin. .. Cliffs, Nj, 1978. Process Technol. 1981.2, 1. I Wadekar, V. V.; Sharma, M. M. Dissociation extraction. J. Sep.
Uptake of Alkanes and Alcohols by Ion-Exchange Resins in Aqueous Solution
Analytical Sciences, 2003
Uptake of alkane (C5-C9) and alcohol (C4-C7) solutes by both strong acid cation exchange resins and strong base anion exchange resins in aqueous medium has been studied. The amount of solute taken up by resins is directly proportional to the solute concentration equilibrium with resins. Hydrophobic interaction between the solute and the resin matrix appears
Oleic acid removal from ethanolic solutions by ion exchange
Chemical Engineering Journal, 2012
Oleic acid uptake from ethanolic solutions was studied at (298.15 ± 0.1) K using a strong anion exchange resin (Amberlyst A26OH). Kinetic data measured at a high stirring rate and different oleic acid concentrations were correlated assuming that the mass transfer resistance is concentrated in the solid phase. In this way it was possible to determine the effective diffusivities of the solute inside the porous structure of the resin. The oleic acid concentration (8-16% by mass) did not influence the calculated values. They were employed as initial estimates for modeling breakthrough data reported on the literature, using the package Chromatography from Aspen Plus software. The selected model takes into account the mass transfer around the resin beads, the axial dispersion in the liquid phase and the diffusion inside the resin phase. The parameter selected for the fitting procedure was the effective diffusivity, so that the values obtained from the modeling of the breakthrough curves and those from the kinetic study could be compared. Both set of values were coherent, varying within the range from (4.5 to 10.2) × 10 −12 m 2 s −1. This study indicates that the removal of oleic acid from ethanolic solutions using ion exchange is a viable process.
Sorption of carboxylate ions by strongly basic anion exchangers
Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases
Equilibrium data are reported for the exchange between chloride and a series of carboxylate ions on certain strong-base anion exchange resins. The carboxylates ranged from butyrate to decanoate and, within this range, sorption of the anions was entirely accounted for by ionexchange, i.e. no significant electrolyte sorption or uptake of free acid occurred. Polystyrene resins showed a regular increase in afhity for carboxylate as the chain length of the latter increased and a value for the standard free energy change for the transfer of a methylene group from aqueous solution to the resin phase has been estimated as -2200 J mol-l. This vdue is comparable to that for certain adsorption processes and it is concluded that hydrophobic interaction between the resin matrix and the hydrocarbon chains of the carboxylates is responsible for the increasing afiinity. With an acrylic resin, however, no such interaction occurs and there is strong evidence of association of carboxylate ions within the resin, rather like the formation of micelles in bulk solution.
Interactions between Organic Model Compounds and Ion Exchange Resins
Environmental Science & Technology, 2019
Ion exchange (IEX) can successfully remove natural organic matter (NOM) from surface water. However, the removal mechanism is not well understood due to the complexity and variability of NOM in real source waters as well as the influence of multiple parameters on the removal behaviour. For example, this includes the physicochemical properties of the NOM and IEX resin, and the presence of competing anions. Model compounds with a range of physical and chemical characteristics were therefore used to determine the mechanisms of NOM removal by IEX resins. Fifteen model compounds were selected to evaluate the influence of hydrophobicity, size and charge of organic molecules on the removal by ion exchange, both individually and in mixtures. Three different resins, comprising polystyrene and polyacrylic resin of macroporous and gellular structure, showed that charge density (CD) was the most important characteristic that controlled the removal, with CD of >5 meq mg DOC-1 resulting in high removal (89%). Size exclusion of compounds with high MW (8 kDa) was evident. The hydrophobicity of the resin and model compound was particularly important for removal of neutral molecules such as resorcinol, which was best removed by the more hydrophobic polystyrene resin. Relationships were identified that provided explanations of the interactions observed between NOM and IEX resin in real waters.
IOSR Journal of Applied Chemistr, 2013
New chelating ion exchange resin containing hydroximate of 5 amino salicylic acid was synthesized by incorporating it in divinylbenzene styrene (DVBS) copolymer. Hydrophilic polysaccharidematrix ofguaran was also used to incorporate hydroximate of 5 amino salicylic acid in it. The resin characteristics were studied by determining its bulk density, specific bulk volume, moisture content, degree of substitution and ion exchange capacity. The resin was characterized by means of IR spectra, Nitrogen content and pH titration. The distribution coefficient values of different metal ions namely Fe(II), Cu(II) , Zn(II) , Cd(II) , Co(II) , Ni(II), Ca(II), U(VI), Cr(VI) & W(VI) was carried out on these resins as a function of pH. Metal analysis was done by Atomic Absorption Spectrophotometer. The hydroximate derivative of guaran is found to be more selective than that of diving benzene co-polymer.