Macroporous Ion Exchange Resin Research Articles

Reaction Thermodynamic and Kinetics for Esterification of 1-Methoxy-2-Propanol and Acetic Acid over Ion-Exchange Resin.

The esterification of 1-methoxy-2-propanol (PM) and acetic acid (AA) is an important reaction for the production of 1-methoxy-2-propyl acetate (PMA). Herein, we used the macroporous ion-exchange resin Amberlyst-35 as a catalyst to explore the effects of reaction conditions on the reaction rate and equilibrium yield of PMA. Under the optimized conditions of a reaction temperature of 353 K, using the initial reactant PM/AA with a molar ratio of 1:3, and a catalyst loading of 10 wt%, the PMA equilibrium yield reached 78%, which is the highest equilibrium yield so far. The reaction equilibrium constants and activity coefficients were estimated to obtain reaction thermodynamic properties, indicating the exothermicity of the reaction. Furthermore, pseudo-homogeneous (PH), Eley-Rideal (ER), and Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetic models were fitted based on experimental reaction kinetic data. The results demonstrate that the LHHW model is the most consistent with experimental data, indicating a surface reaction-controlled process and exhibiting an apparent activation energy of 62.0 ± 0.2 kJ/mol. This work represents a valuable example of calculating reaction thermodynamics and kinetics, which are particularly essential for promising industrial reactor designs.

Adsorption Mechanisms of CO2 on Macroporous Ion-Exchange Resin Organic Amine Composite Materials by the Density Functional Theory.

The adsorption mechanisms of CO2 on macroporous cation exchange resin (MCER), D001 ion-exchange resin, and macroporous ion-exchange resin organic amine composite materials (MCER-DEA and D001-PEI) were studied by density functional theory (DFT). The adsorption energies and Mulliken atomic charges in the adsorption process were analyzed, indicating that CO2 on MCER and D001 were physisorbed. The adsorption heat of the adsorption process of MCER-DEA and D001-PEI was calculated by the Monte Carlo method, and it was found that the adsorption process of CO2 by MCER-DEA and D001-PEI was both physical adsorption and chemical adsorption. Besides, the chemical adsorption mechanism of CO2 by MCER-DEA and D001-PEI was investigated by analyzing the free energy barrier and the Gibbs free energy change of the involved chemical reactions and the results showed that the free energy barrier required for MCER-DEA to generate zwitterion was 26.23 kcal/mol, which is 1.74 times that of D001-PEI (15.04 kcal/mol); meanwhile, the free energy barriers of the deprotonation process of zwitterions in MCER-DEA and D001-PEI were 16.23 and 9.89 kcal/mol, respectively, indicating that D001-PEI chemically adsorbs CO2 and requires more energy than MCER-DEA chemical adsorption of CO2. D001-PEI is more conducive to the chemical adsorption of CO2. In addition, H2O molecules were incorporated on the polymer models to study the influence of humidity on the CO2 adsorption mechanism. The analysis revealed that the adsorption of CO2 slowed under humid conditions.

A low-cost and sustainable solution for nitrate removal from secondary effluent: Macroporous ion exchange resin treatment

Macroporous ion exchange resin has excellent selectivity to nitrogen (N), phosphorus (P) and partially soluble refractory organic compounds contained in the secondary effluent of wastewater treatment plants (WWTP). In this study, macroporous ion exchange resins were chosen as an alternative to single biochemical nitrogen removal processes. Various conditions were examined to optimize adsorption performance, and the adsorption mechanism was explored through isotherm fitting, thermodynamic parameter calculation, and kinetic analysis. The experiment demonstrated that the resin exhibited strong selectivity for nitrate (NO3−) and achieved an equilibrium adsorption amount of 9.8924 mg/g and an equilibrium adsorption time of 60 min at 25 °C. The resin denitrification pilot plant demonstrated stable operation for two months and achieved COD<20 mg/L, TN < 1.5 mg/L, and NH4+-N<0.5 mg/L. The removal rates of COD, TP, NH4+-N, NO3−-N, and TN were 41.65%, 42.96%, 55.37%, 91.8%, and 90.81%, respectively. After the resin was regenerated, the removal rates of NO3−-N, TN and the regeneration recovery rate were above 90%. Through cost analysis, the treatment cost of the pilot plant is only 0.104 $/m3. This study presents a practical, low-cost, and efficient treatment method for the deep treatment of secondary effluent from WWTP in practical engineering, providing new ideas and theoretical guidance.

Deactivation of macroporous ion-exchange resins by acetonitrile and inhibition by water in the simultaneous synthesis of ethyltert-butyl ether (ETBE) andtert-amyl ethyl ether (TAEE)

The deactivating effect of acetonitrile (ACN) and ACN/water mixtures on the feed stream has been investigated for the simultaneous syntheses of ethyltert-butyl ether andtert-amyl ethyl ether over Amberlyst™35 and Purolite®CT-275 ion-exchange resins.

Preparation of macroporous ion-exchange resin organic amine composite material by using waste plastics and its application in CO2 capture

ABSTRACT Two new types of solid adsorption material (macroporous cation exchange resin (MCER) and macroporous ion-exchange resin organic amine composite material (MCER-DEA)) were prepared from waste television plastics outer shell (WTPS) and used to capture CO2 in flue gas from coal-fired power plants. The results showed that the CO2 adsorption capacity of MCER-DEA was 2.87 mmol/g, while MCER was 1.87 mmol/g. The preparation mechanism and action mechanism of MCER and MCER-DEA was studied by Fourier transform infrared and quantum chemical calculations. The results showed that the electrophilic substitution occurs in between an H atom of meta position on the benzene ring and H2SO4. The electron energy of MCER-DEA was calculated to be 1.14 ev, indicating these MCERs formed acid–base coordination with diethanolamine (DEA). Besides, the electron energy of between MCER and CO2 was 0.27 ev, and the interaction force was dominated by hydrogen bonds. The electron energy of the MCER-DEA and CO2 was 3.02 ev, and the interaction force was mainly controlled by coordination bonds. It indicated that MCER and CO2 were primarily based on physical adsorption, while MCER-DEA and CO2 were mainly based on chemisorption adsorption. Adsorption kinetics studies showed that internal diffusion was a rate-controlling step.

The Gut Microbiota Regulates the Metabolic Benefits Mediated by Red Raspberry Polyphenols

ObjectivesRed raspberry (RR) polyphenols, including ellagic acid and their gut-derived metabolites, the urolithins, reduce inflammation and improve insulin sensitivity. However, it is unknown whether the gut microbiota is responsible for these health benefits and why certain individuals do not transform ellagic acid into urolithins. Here, we determined the causative role for the microbiome in mediating the health benefits from RR polyphenols using germ-free and conventionalized mouse models of diet-induced obesity. We also tested whether Gordonibacter urolithinfaciens (G. uro), a gut microbe previously shown to metabolize ellagic acid into urolithins, could enhance metabolic benefits when administered as a synbiotic with RR polyphenols. MethodsRR polyphenols were extracted using a macroporous ion-exchange resin column to remove sugars and fibers. C3H/HeN mice with (CVZ) or without a microbiota (GF) were fed either a low fat (LF), high fat (HF), or HF diet with RR polyphenols (HF + RR) for 12 weeks. For synbiotic studies, GF C57BL/6 mice were given a G. uro deficient-microbiome and then fed either a HF or HF + RR diet plus 20% fructose water with or without G. uro for 7 weeks. ResultsFeeding a HF diet increased body weight and fat mass for both GF and CVZ mice compared to feeding a LF diet (P < 0.05). Feeding a HF diet with RR polyphenols significantly decreased visceral adipose tissue and liver triglycerides (P < 0.05) compared to a HF control diet in CVZ but not GF mice. G. uro administration to mice receiving a HF diet and fructose water significantly reduced body weight, body fat percentage, fasting blood glucose, and subcutaneous adipose tissue mass as well as increased ileal tight junction protein gene expression (P < 0.05) compared to controls. Notably, mice supplemented with both G. uro and RR polyphenols experienced no metabolic improvements compared to controls (P < 0.05). ConclusionsOur results demonstrate that the microbiome is required for mediating RR polyphenol metabolic benefits. Supplementation of G. uro improved metabolic health; however, those beneficial effects were abrogated in the presence of RR polyphenols. Together, these results highlight the importance of considering specific diet-microbiota interactions when developing foods for preventing and treating obesity-related diseases. Funding SourcesUSDA NIFA.

Facile synthesis of a Ni3S2@C composite using cation exchange resin as an efficient catalyst to improve the kinetic properties of MgH2

Carbon materials have excellent catalytic effects on the hydrogen storage performance of MgH2. Here, carbon-supported Ni3S2 (denoted as Ni3S2@C) was synthesized by a facile chemical route using ion exchange resin and nickel acetate tetrahydrate as raw materials and then introduced to improve the hydrogen storage properties of MgH2. The results indicated the addition of 10 wt.% Ni3S2@C prepared by macroporous ion exchange resin can effectively improve the hydrogenation/dehydrogenation kinetic properties of MgH2. At 100 °C, the dehydrogenated MgH2-Ni3S2@C-4 composite could absorb 5.68 wt.% H2. Additionally, the rehydrogenated MgH2-Ni3S2@C-4 sample could release 6.35 wt.% H2 at 275 °C. The dehydrogenation/hydrogenation enthalpy changes of MgH2-Ni3S2@C-4 were calculated to be 78.5 kJ mol−1/−74.7 kJ mol−1, i.e., 11.0 kJ mol−1/7.3 kJ mol−1 lower than those of MgH2. The improvement in the kinetic properties of MgH2 was ascribed to the multi-phase catalytic action of C, Mg2Ni, and MgS, which were formed by the reaction between Ni3S2 contained in the Ni3S2@C catalyst and Mg during the first hydrogen absorption–desorption process.

Nano zero-valent iron supported by macroporous styrene ion exchange resin for enhanced Cr(VI) removal from aqueous solution

In view of problem that nanoscale zero-valent (nZVI) is easy to agglomerate and deactivate in the process of wastewater treatment, a styrene-based ion exchange resin D201 is selected as the carrier to load it. D201-loaded nZVI (D201@nZVI) was applied to treat simulated Cr(VI) wastewater. Receiving the effect and influence of electrostatic attraction, Cr(VI) will attach to D201@nZVI, partly reduced to Cr(III) by nZVI to form Cr x Fe1− x (OH)3 co-precipitation. D201@nZVI shows good treatment capacity of a wide pH range, and excellent regeneration performance. The removal rate and maximum adsorption amounts of 50 mg L−1 Cr(VI) reached 100% and 123.14 mg g−1, respectively. D201@nZVI has promising potential to be applied in situ groundwater remediation.

Resin loaded palladium nanoparticle catalyst, characterization and application in –C–C– coupling reaction

Macroporous ion-exchange resins were used to immobilize palladium (Pd) metal in order to produce nanoparticle catalysts. The complexation of palladium acetate and the following reduction with NaBH4 resulting Pd nanoparticles are loaded on to DIANION™ PK228 macroporous cation exchange resins. Palladium loading was characterized by inductively coupled plasma-atomic emission spectroscopy, field emission scanning electron microscope/energy-dispersive X-ray spectrometry, BET (Brunauer–Emmett–Teller) and HR-TEM. Palladium nanoparticles are loaded on to DIANION™ PK228 macroporous cation exchange resin which shows and excellent catalytic activity for Suzuki–Miyaura cross coupling reaction. Furthermore, the catalyst can be recycled without significant loss of its catalytic activity up to ten times.

Adsorption potential of macroporous Amberlyst-15 for Cd(II) removal from aqueous solutions

The macroporous ion exchange resins are unique and most suitable for the adsorption of heavy metal ions due to their porous three-dimensional structures and large specific surface areas. In the current investigation, a macroporous sulphonic acid cation exchange resin Amberlyst-15 was implemented for the adsorption of Cd (II) using batch adsorption technique to evaluate its removal efficiency. The characterization of resin surface was performed by several techniques: Scanning Electron Microscopy/Energy dispersive x-ray Spectroscopy (SEM/EDS), Thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller (BET) surface area and Point of zero charge (PZC). The effects of various experimental parameters such as time, temperature, concentration, pH and dosage amount were examined in detail. The optimum pH for maximum uptake of Cd(II) onto the Amberlyst.15 was observed at pH 3 showing the efficient working of resin under highly acidic conditions. The results also proved that Amberlyst-15 showed tremendous adsorption potential toward Cd(II) removal; 99.95% removal within 30 min reaction time and 2.01 mmol g−1 maximum adsorption capacity at 323 K. The adsorption data was well described by Langmuir adsorption isotherm and pseudo second order models. The thermodynamic parameters revealed that the adsorption was endothermic, spontaneous and feasible process with increased randomness at resin surface. The free energy of adsorption (E) (13–15 kJ mol−1) determined from Dubinin-Radushkevitch (D-R) model proved the ion exchange reaction mechanism for Cd(II) adsorption. The experimental results reported herein validate that Amberlyst.15 resin is a promising adsorbent for the enhanced removal of Cd(II) and other toxic metals from contaminated water and waste effluents.

Preparation and characterization of nano ZnS by ion exchange resin method

D113 macroporous ion exchange resins were used as the supplier of Zn2+ ions and the regulator of ZnS morphology to prepare nano ZnS materials. The morphology and structure of the products were researched using the traditional batch method including Na2S concentration, temperature and resin addition time. Some means of characterization, such as SEM, XRD and FT-IR, were adopted well. The results showed that when Na2S concentration was lower for 0.05 mol/L, the product is well dispersed, showing a fine nano-particle size of about 100 nm; and when Na2S concentration was higher for 0.3 mol/L, the products liked a multi-petal flower in bloom with a thickness of less than 100 nm. When the reactive temperature was 30 °C, the characteristic diffraction peak has higher intensity and wider half-peak width. Under the resin addition time of 5 min, the product is mainly needle-like, like a cluster of pine leaves. When the resin addition time reached 20 min, the products showed a flaky structure. FT-IR was positively used to confirm the feasibility of this method.

Selective isolation of heavy metals from spent electronic waste solution by macroporous ion-exchange resins.

Electronic waste (e-waste) has become an urgent issue in digitally dependent world, owing to the unprecedented use of electronic devices and this has compelled the world to develop new techniques to recycle such wastes. In this work, one of problematic and high volume global waste stream, i.e., end-of-life printed circuit boards (PCBs), was examined for recycling. Using ion-exchange (adsorption/desorption) technique, heavy metals (Cu, Zn, Ni, and Pb), and Al were selectively recovered and separated. Three macroporous ion-exchange resins (Amberlite IRA 743, Lewatit TP 208, and Lewatit TP 260) were applied to extract, isolate and concentrate the heavy metals. The process factors (resin load, solution temperature and contact time) were investigated and kinetic behavior of adsorption was studied using three different models. Based on the process factors, the functionality and selectivity of the ion-exchange resins were discussed. A negligible amount of Ni and Zn adsorption on the surface of resin 743 indicates its high selectivity. This study also proves that selective isolation of hazardous elements such as Pb can be performed under specified sorption parameters. Also, the distribution of adsorbed cations throughout the resin beads was studied via elemental analysis. The distribution of Cu as the main element was not homogenous that signifies the higher practical capacity of the ion-exchanger. Finally, a stripping step was applied to modify the working media and to examine the reversibility and selectivity of the desorption process.

Perfection of Drinking and Technical Water Supply Systems in the Implementation of the Concept a Heat and Power Complex for Highly Efficient Use Of Secondary and Renewable Energy Sources

A number of the aspects influencing economic indicators of work of baromembranny installations by preparation of water of the surface water sources for drinking and technical water supply of private housing constructions is considered. Technical water supply in this case is intended for the system of feed of the heat power complex working on secondary and renewables. In article advantages of the flow diagrams of surface preparation the reduced quality water approved under production conditions, in particular, highperformance of chromacity sizes are proved. Comparative evaluation test of a filtrate when using various options of prerefining of water - with use of macroporous ion-exchange resins, installations of nanofiltration, cation-exchange flocculants is given.

Selectivity of Ion Exchange on Iminocarboxyl Resin and the Hydration Energy of Its Ionic Forms

Characteristics of the hydration of macroporous iminodicarboxyl ion-exchange resin in the protonated, sodium, copper, and nickel forms are determined, and the Gibbs energy of hydration and its change upon transitioning from the initial ionic form to the ion-sorbed form are calculated. The way of calculating the Gibbs energy of the interfacial transfer of a solvent during the ion-exchange process is substantiated. It is established that the selectivity of an ion-exchange resin in the functional form toward the extracted transition-metal cations depends not only on the mean amount of solvent per functional group of the polyampholite, but also on the change in sorbent hydration during the ion exchange. The contribution determining the selectivity of copper(II) and nickel(II) cations toward iminodicarboxyl ion-exchange resin is an ion-exchange component with the formation of ionite complexes. In addition, the change in hydration (being an energetically advantageous process) facilitates sorption as a whole.

Catalytic Dehydration of Fructose to 5-Hydroxymethylfurfural (HMF) in Low-Boiling Solvent Hexafluoroisopropanol (HFIP).

A mixture of hexafluoroisopropanol (HFIP) and water was used as a new and unknown monophasic reaction solvent for fructose dehydration in order to produce HMF. HFIP is a low-boiling fluorous alcohol (b.p. 58 °C). Hence, HFIP can be recovered cost efficiently by distillation. Different ion-exchange resins were screened for the HFIP/water system in batch experiments. The best results were obtained for acidic macroporous ion-exchange resins, and high HMF yields up to 70% were achieved. The effects of various reaction conditions like initial fructose concentration, catalyst concentration, water content in HFIP, temperature and influence of the catalyst particle size were evaluated. Up to 76% HMF yield was attained at optimized reaction conditions for high initial fructose concentration of 0.5 M (90 g/L). The ion-exchange resin can simply be recovered by filtration and reused several times. This reaction system with HFIP/water as solvent and the ion-exchange resin Lewatit K2420 as catalyst shows excellent performance for HMF synthesis.

Synthesis of coumarin derivative using polymer supported reagents

Recently, there has been a surge in use of polymer-supported reagents and catalysts become common tools for organic synthesis in what is known as polymer-assisted synthesis since they can simplify product isolation and purification. In this context, coumarin derivative 3 was prepared in good yield and high purity, starting from 3-methoxy salicylaldehyde, using reagents supported on a macroporous ion exchange resin. For this purpose, iminocoumarin and unsaturated nitrile were used as starting materials. The synthesized compounds were characterized by IR, NMR and mass spectrometry.

Synthesis, properties and mechanism of the ion exchange resins based on 2-methyl-5-vinylpyridine and divinylbenzene in the catalytic disproportionation of trichlorosilane

The variety of catalysts based on macroporous ion exchange resins using 2-methyl-5-vinylpyridine cross-linked with divinylbenzene (2M5VP/DVB) was investigated in the disproportionation of trichlorosilane (TCS) in a continuous-flow reactor. The effects of the reaction temperature and surface area on TCS disproportionation kinetics was invesitigated using three types of catalysts based on 2M5VP/DVB with a different pore ratios (toluene(tol)/heptane(hep)) and in the temperature range of 333.2K and 453.2K. The results indicate that within this range, the higher reaction temperatures result in an increase in the conversion rate to TCS at equilibrium. The effects on the specific catalyst surfaces were determined and the catalyst (2M5VP/DVB-hep/tol) with the highest specific surface area exhibited better catalytic activity. Variable temperature studies on the catalytic activity of 2M5VP/DVB-hep/tol revealed an activation energy of 24,06±0.72kJmol−1 for 2M5VP-hep/tol and 34.30±1.03kJmol−1 for Amberlyst A-21 resins. TCS disproportionation was investigated using a non-stationary process and showed the desorption of STC from the active sites of the catalyst to be the rate determining step. Using FTIR analysis, we have already established that the resin after exposure to HCl or TCS undergoes protonation of the nitrogen atom in the pyridine ring with intermediate formation of N+H⋯Cl−/N+H⋯SiCl3−. Based on the reaction data obtained in this study, a probable mechanism of the reaction has been proposed.

Dehydration of Glucose to 5-Hydroxymethylfurfural Using Combined Catalysts in Ionic Liquid by Microwave Heating

The dehydration of glucose into 5-hydroxymethylfurfural (HMF) was catalyzed by NKC-9 (a macroporous sulfonated polystyrene ion-exchange resin) combined with metal oxides (TiO2, ZrO2, Al2O3 calcined at different temperatures). In the combined catalytic system, Al2O3 calcined at 550°C exhibited excellent catalytic activity, when the dosage of NKC-9 was kept constant. Four parameters (catalyst dosage, reaction temperature, reaction time, and initial glucose amount) were optimized by employing response surface methodology (RSM), with HMF yield as the response parameter. The maximum HMF yield of 62.09% was obtained at catalyst 0.07 g, temperature 140°C, time 20 min, and glucose 0.01 g. The catalytic activity of the binary catalyst (NKC-9 and Al2O3) for the conversion of glucose into HMF did not show significant decrease after five-times uses at 140°C for 20 min.

Kinetics studies on the adsorption behaviour of Basic Blue 9 dye on macroporous ion exchanger resins

Among various types of adsorbents used in the treatment of wastewaters impurified with dyes, the ion exchange resins still have an important place. The aims of this paper are: to evaluate the influence of contact time on the dye adsorption from aqueous solutions on Purolite macroporous ion exchange resins for strong acid (C-145) and for weak acid (C-107E), to understand the mechanisms that govern dye removal and to find an appropriate kinetic model to describe the process. In order to investigate the mechanism of adsorption and the potential rate controlling steps, pseuso-first- and second-order equations, the intraparticle diffusion equation and the Elovich equation have been used to test experimental data. The kinetics of the adsorption process of Basic Blue 9 dye onto Purolite ion exchanges follows a pseudo-second- order rather than pseudo-first- order model, and both the film and the intraparticle diffusion mechanisms are involved in the adsorption processes, and may be the rate determining step. The value of activation energy (Ea) confirms the endothermic nature of the adsorption process.

Resin-immobilized palladium nanoparticle catalysts for Suzuki–Miyaura cross-coupling reaction in aqueous media

Macroporous ion-exchange resins were used to immobilize palladium (Pd) metal in order to produce nanoparticle catalysts. The complexation of palladium acetate and the following reduction with sodium borohydride to Pd nanoparticles was carried out on two macroporous ion-exchange resins: (1) a Dowex Marathon anion free weak base including a styrene–divinylbenzene polymer matrix and polyamine active groups, and (2) a Dowex M4195 anion exchange resin, a chelating type of resin having styrene–divinylbenzene polymer matrix with bispicolylamine active groups. Pd loading was quantified by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM/EDX) and transmission electron microscopy (TEM) of the catalyst were obtained for further characterization. Pd nanoparticles immobilized on a macroporous Dowex Marathon ion exchange resin exhibited excellent catalytic activity for the Suzuki–Miyaura reaction of bromobenzene with phenylboronic acid and thus it was further tested on various aryl bromides and aryl boronic acid derivatives using water as a solvent and either KOH or K2CO3 as a base at 100 °C. This protocol offers an environmentally benign alternative to several existing methods for the Suzuki–Miyaura reaction. Furthermore, the catalyst can be recycled without significant loss of its catalytic activity. Pd nanoparticles immobilized on a macroporous Dowex Marathon ion exchange resin exhibited excellent catalytic activity for the Suzuki–Miyaura reaction of bromobenzene with phenylboronic acid and thus it was further tested on various aryl bromides and aryl boronic acid derivatives using water as a solvent and either KOH or K2CO3 as a base at 100oC. This protocol offers an environmentally benign alternative to several existing methods for the Suzuki–Miyaura reaction. Furthermore, the catalyst can be recycled without significant loss of its catalytic activity