Acidic Exchange Resin Research Articles

Synthesis and oxygen reduction properties of three-dimensional sulfur-doped graphene networks.

Novel three-dimensional sulfur-doped graphene networks were synthesized using an ion-exchange/activation combination method using a 732-type sulfonic acid ion exchange resin as the carbon precursor, which showed high electrocatalytic activity, good stability and excellent methanol tolerance for four-electron oxygen reduction in alkaline solution.

Epoxidized Vegetable Oil as a Sustainable Ingredient in Welding Electrode Coatings

Welding with coated (covered) electrodes is a manual process in which an electric arc is generated between the electrode and work piece to melt the metals at the welding point whereby they are joined. Among the several ingredients that constitute the electrode coating, there is the binder, which is usually sodium or potassium silicate. Recently, studies were conducted where the usual binders were successfully replaced by hydrophobic polymers in solution, making the electrode waterproof, therefore of very low diffusible hydrogen content, and eliminating the need for a drying step during the preparation of the electrode. In the present work, the use of epoxidized vegetable oils as binders was evaluated in order to minimize negative environmental impacts since the binders are produced from a renewable source. The epoxidized vegetable oils were prepared from a variety of vegetable oils using acetic acid and hydrogen peroxide as reagents and an acidic ion exchange resin as catalyst. The prepared resins were dully characterized and used as a binder in the formulation for coating of basic-type electrodes. The produced electrodes were evaluated for the quality of the weld.

Synthesis of new eburnamine-type alkaloid via direct hydroalkoxylation

AbstractThis study concerns the preparation of a new eburnamine-type alkaloid, methyl (3α,14β,15β,16α)-17,18-didehydro-14,15-dihydroeburnamine-15-methoxy-14-carboxylate (VIII). This alkaloid was prepared from (+)-17,18-dehydroapovincamine (V) using Lewis acid and/or ion exchange resin as catalyst. The hydroalkoxylation reaction of V with methanol was investigated in terms of catalyst, solvent, temperature, and time of reaction. A one-pot method for synthetising this alkaloid was established. The optimal conditions for the reaction are discussed.

Equilibrium of the simultaneous etherification of isobutene and isoamylenes with ethanol in liquid-phase

The simultaneous etherification of isobutene and isoamylenes with ethanol has been studied using macroreticular acid ion-exchange resins as catalyst. Most of the experiments were carried out over Amberlyst-35. In addition, Amberlyst-15 and Purolite CT-275 were also tested. Chemical equilibrium of four chemical reactions was studied: ethyl tert-butyl ether formation, tert-amyl ethyl ether formation from isoamylenes (2-methyl-1-butene and 2-methyl-2-butene) and isomerization reaction between both isoamylenes. Equilibrium data were obtained in a batchwise stirred tank reactor operated at 2.0MPa and within the temperature range from 323 to 353K. Experimental molar standard enthalpy and entropy changes of reaction were determined for each reaction. From these data, the molar enthalpy change of formation of ethyl tert-butyl ether and tert-amyl ethyl ether were estimated. Besides, the chemical equilibrium between both diisobutene dimers, 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene, was evaluated. A good agreement between thermodynamic results for the simultaneous etherification carried out in this work and those obtained for the isolated ethyl tert-butyl ether and tert-amyl ethyl ether systems was obtained.

Byproducts formation in the ethyl tert-butyl ether (ETBE) synthesis reaction on macroreticular acid ion-exchange resins

Ethyl tert-butyl ether (ETBE) production is one of the industrial processes of major importance today in Europe. However, the study of side reactions in this synthesis reaction appears scarcely in the open literature. Side reactions take place along with the etherification of C4 olefinic cuts with ethanol, catalyzed by acidic ion-exchange resins. In this work, byproducts formation is studied in a batch reactor. The presence of diethyl ether (DEE), ethyl sec-butyl ether (ESBE), dimers of isobutene (2,4,4-trimethyl-1-pentene (TMP-1) and 2,4,4-trimethyl-2-pentene (TMP-2)) and tert-butyl alcohol (TBA) has been studied in terms of production and selectivity. The effect of temperature, ranging from 323 to 383K, and the influence of initial molar ratio ethanol/isobutene (R°A/O), ranging from 0.5 to 2.0, on byproducts formation have been analyzed. All byproducts formation was favored by high temperatures. A low initial molar ratio ethanol/isobutene favored the formation of DEE, ESBE, TMP-1 and TMP-2, whereas high molar ratios favored TBA formation.

Development of a new poly silicate ferric coagulant and its application to coagulation-membrane filtration hybrid system in wastewater treatment

Coagulation is one of the effective pretreatment stages in membrane filtration of wastewaters to produce clean water. Using a suitable coagulant, one can mitigate membrane fouling. Membrane fouling is a process where particles deposit onto a membrane surface or into membrane pores in a way that degrades the membrane’s performance. Research in this area is currently being focused on development of improved coagulation reagents such as poly silicate ferric (PSiFe), which has a high molecular weight and large number of positive surface charges with high efficiency at low doses. In this paper, PSiFe was prepared by following two approaches: (a) acidification of water glass solution using HCl followed by FeCl3 addition (old-PSiFe); (b) acidification of water glass solution by passing it through an acidic ion exchange resin followed by fresh FeCl3 addition under different Fe/Si molar ratios (new-PSiFe). These coagulants were characterised by X-ray diffraction and scanning electron microscopy. According to coagulation jar test results when Fe/Si = 1, the best performance was achieved in terms of turbidity, total organic carbon (TOC) and UV254 removals. Another aspect is the comparison of the old-PSiFe, FeCl3 and new-PSiFe which showed that in a membrane filtration system, using the new-PSiFe not only reduces the required transmembrane pressure (TMP) due to lower fouling, but also improves the TOC removal efficiency.

Esterification of fatty acids with C8-C9 alcohols over selected sulfonic heterogeneous catalysts

Abstract A study on the synthesis of esters of fatty acids of natural origin (oleic acid from rapeseed oil) and branched synthetic isostearic acid with commercially available alcohols C8-C9 i.e. 2-ethylhexanol (2-EH) and 3,5,5-trimethylhexanol (TMH) in the presence of selected heterogeneous catalysts containing active sulfonic groups has been made. The catalysts were obtained using ready available amorphous silicas with different textural characteristics. The influence of catalyst porosity on the catalytic properties in the esterification of fatty acids has been investigated. The effect of the synthesis temperature has also been studied. The results were compared with the results of esterification with the use of acidic ion exchange resins. It was shown that catalysts obtained on the basis of amorphous silicas are good and reusable catalysts for the esterification of fatty acids with higher alcohols

Kinetic study of methyl-butenes dimerization and trimerization in liquid-phase over a macroreticular acid resin

A kinetic study of the dimerization and the trimerization of isoamylenes (2-methyl-1-butene and 2-methyl-2-butene) in liquid-phase catalyzed by the acidic macroreticular ion exchange resin Amberlyst™ 15 was performed in a continuous-stirred tank reactor in the temperature range 323–393K using n-hexane as a solvent. Reaction rate data were obtained free of internal and external mass transfer resistance effects. The best kinetic models that fit the experimental results were based on the LHHW–ER formalisms. They included the participation of isoamylene, dimer and n-hexane in the adsorption term. The number of active sites or clusters implied in the surface reaction was one for dimerization and three for trimerization. It was also inferred that trimers were formed via dimers. Finally, the obtained apparent activation energies for dimerization and trimerization were 37±2 and 89±3kJ/mol, respectively, being the dimerization activation energy value in agreement with literature data.

Pd-Au and Pd-Pt catalysts for the direct synthesis of hydrogen peroxide in absence of selectivity enhancers

Organic polymers are suitable candidates as catalytic materials for the direct synthesis of hydrogen peroxide (DSR) from dihydrogen and dioxygen, in view of the low temperature applied. In particular, strongly acidic ion-exchange resins have been already proposed for this reaction, either as carriers of PdII ions or Pd0 nanoparticles, but not for bimetallic Pd/Pt and Pd/Au catalysts, which are also active in this reaction. The introduction of PdII, PtII and AuIII precursors into the commercial ion-exchangers Lewatit K2621 and their subsequent reduction with an aqueous formaldehyde solution produced a library of bimetallic catalysts with 1% Pd (w/w) and a variable content of either Pt (0.1–1%, w/w) or Au (0.25–1%, w/w). The catalysts were tested with no selectivity enhancer in the DSR under batchwise condition at 2°C in MeOH at 2MPa, with a CO2/O2/H2 (72/25.5/2.5) mixture. In the Pd-Pt catalysts the addition of the smallest amount of Pt (0.1%, w/w) gave the best results in terms of the initial selectivity (43%) and the top concentration of H2O2 achieved in solution increased to 14.3mM from 10.8mM with the monometallic catalyst. With higher platinum amount the initial selectivity was lower, but in all these catalysts the addition of platinum limited the decrease of selectivity with time in comparison with the monometallic one. The addition of platinum in increasing amount seems also to favour poisoning of the catalysts by the products (most likely by H2O2). The presence of small amount of gold is also effective in achieving a comparatively high initial selectivity. With the addition of only 0.25% Au (w/w), the initial selectivity towards H2O2 and the top concentration of the product were boosted up to 61% and 17mM, respectively. Gold in relatively little amount is also useful to limit the decrease of selectivity with time. In particular, it seems to limit the combustion of hydrogen and to be much more effective than platinum in this respect. Preliminary TEM analysis of the size and size distribution of the metal nanoparticles in the Au-Pd bimetallic catalysts shows that relatively large nanoparticles are preferable to achieve higher and stable selectivity, but also that size is likely not the most important parameter in controlling the catalyst performance.

Hydrolyzed polyoxymethylenedimethylethers as liquid fuels for direct oxidation fuel cells

Polyoxymethylenedimethylether (POMM) fuels were investigated as alternatives to methanol for direct oxidation fuel cells (DOFCs) due to their advantageous properties, including negligible toxicity, low vapor pressure (comparable to that of pure water) and their feasibility for mass production in the future. As typical examples of the general class CH3O(CH2O)nCH3 (n=1–8) molecules (abbreviated as POMMn), POMM2 and POMM3 were studied in detail, specifically regarding the hydrolysis kinetics and anodic oxidation on Pt–Ru alloys over a wide range of operating temperatures. It was revealed that they were stable in pure water but formed methanol and formaldehyde easily through a first order hydrolysis reaction in the presence of acidic catalysts. A facile hydrolysis reaction was demonstrated in a convertor packed with particles of the acidic ion-exchange resin Amberlite, in comparison with that in HClO4 solution. The reaction rate increased with increasing n-value but it is expected that adequate reactivity will be retained in a similar range within the family. It was revealed that the fully hydrolyzed POMMn showed anodic oxidation performance on PtRu catalysts several times higher than that of methanol, considering an equivalent electron-discharge capacity, over the temperature range from 30°C to 90°C.

Immobilizing Cr3+ with SO3H-functionalized solid polymeric ionic liquids as efficient and reusable catalysts for selective transformation of carbohydrates into 5-hydroxymethylfurfural

A series of functional polymeric ionic liquids (FPILs) were prepared by coupling of SO3H-functionalized polymeric ionic liquids with different counterpart anions containing or excluding CrCl3·6H2O, and characterized by SEM, FT-IR, XRD, NH3-TPD, TG, melting point, ICP-AES, and TEM. The catalytic activity of the prepared solid FPILs was investigated for the conversion of biomass including fructose, glucose and cellulose into 5-hydroxymethylfurfural (HMF) with the presence of DMSO-mediated solvents, successively producing moderate to excellent yields of HMF under atmospheric pressure. The FPILs catalysts developed in this study present improved performance on fructose-to-HMF conversion over other solid catalysts, such as functional ionic liquids supported by silica, metal oxides and strong acid ion exchange resin catalysts, and can be very easily recycled at least five times without significant loss of activity. In addition, a kinetic analysis was carried out to illustrate the formation of HMF.

Glycerol acetals as diesel additives: Kinetic study of the reaction between glycerol and acetaldehyde

Certain acetals can be produced from renewable resources (bioalcohols) and seem to be good candidates for different applications, such as oxygenated diesel additives. This paper addresses the production of acetals (5-hydroxy-2-methyl-1,3 dioxane and 4-hydroxymethyl-2-methyl-1,3 dioxolane) from glycerol and acetaldehyde using Amberlyst 47 acidic ion exchange resin. This ion exchange resin performed well, recording 100% selectivity toward acetal formation at a suitably high initial glycerol concentration. When the initial acetaldehyde concentration was significantly higher than the glycerol concentration, 2,4,6 trimethyl-1,3,5 trioxane was the main reaction product. Unlike other acetalization reactions, the one studied here does not have thermodynamic limitations, and 100% conversion is achieved under different reaction conditions. A kinetic study was performed in a batch stirred tank reactor to study the influence of different process parameters, such as temperature, feed composition and stirring speed. A pseudo-homogeneous kinetic model was developed to describe this reaction kinetics, proving that its rate is just first order on the acetaldehyde concentration under the conditions studied.

Acetalization reaction between glycerol and n-butyraldehyde using an acidic ion exchange resin. Kinetic modelling

The acetalization reaction between glycerol and n-butyraldehyde using Amberlyst 47, an acidic ion exchange resin catalyst, was studied. These acetals can be obtained from renewable sources and seem to be good candidates for different applications such as oxygenated diesel additives. Amberlyst 47 acidic ion exchange showed good activity and stability after five consecutive cycles of reuse. Therefore, 100% of selectivity towards the formation of acetals and butyraldehyde conversions between 92% and 98% were obtained for different molar feed ratios of glycerol:aldehyde. For glycerol:aldehyde molar ratios lower than the stoichiometric one, 2,4,6-tripropyl-1,2,3-trioxane is also detected as product when glycerol is almost totally consumed. Moreover, a pseudo-homogeneous kinetic model able to explain the reaction mechanism was adjusted and the corresponding overall reaction order was determined. The addition of around 15wt% of water in the feed produces only a slight decrease in the butyraldehyde conversion, and it improves the mixing and transport properties of the reaction mixture.

Influence of acid ion-exchange resins morphology in a swollen state on the synthesis of ethyl octyl ether from ethanol and 1-octanol

Ethyl octyl ether (EOE) liquid-phase synthesis from ethanol and 1-octanol over ion-exchange resins is feasible at 423K, though diethyl ether and di-n-octyl ether are also formed. The influence of the catalyst morphology on the reaction was checked by testing 22 acidic resins. Gel-type resins of low cross-linking degree yielded larger amounts of EOE, whereas macroreticular ones of high cross-linking degree gave mainly diethyl ether. Ethanol conversion depends strongly on the resin acid capacity, [H+], whereas 1-octanol conversion and selectivity to EOE depend on the specific volume of swollen polymer, Vsp, and the porosity. The variation of ethanol and 1-octanol conversion and selectivity to EOE with respect to both alcohols, as well as ether TOF, as a function of [H+]/Vsp suggest that a fraction of the active sites does not take part in the EOE synthesis reaction on highly cross-linked resins. Amberlyst 70 could be interesting in industry due to its selectivity to EOE and higher thermal stability.

Investigation of Production of Motor Fuel Components on Heterogeneous Catalyst with Oligomerization

The production of high isoparaffin containing motor fuels which comply with the changing needs and standards is a significant research area. Because of this type of hydrocarbons have numerous application, environmental and economical benefits. One of the possible productions for this type of hydrocarbons is oligomerization of light olefins followed by their hydrogenation. Based on our experimental results we established that the examined various catalytic systems containing acidic ion exchange resin catalyst are suitable for the flexible production of different motor fuel blending components (gasoline, middle distillate) with high conversion (92.4 %) and good selectivity in particular at the process parameters (T: 130 °C, P: 30 bar, LHSV: 1.0 h−1) we found favourable.

Glycerol etherification over acid ion exchange resins: effect of catalyst concentration and reusability

AbstractBackgroundA study of the effect of different ion exchange resins, Amberlyst 15, Amberlite 200 and Amberlite IRC‐50, on glycerol etherification with tert‐butyl alcohol was performed. The best catalyst was selected based on the activity and selectivity values. The capability of reusing this catalyst after different pre‐treatments was analysed. A kinetic model was developed including the effect of catalyst concentration and temperature.ResultsAmberlyst 15 led to the highest glycerol conversion, the highest product yield, and it could be reused following proper pre‐treatment with methanol. The effect of catalyst concentration was evaluated and included in a previous kinetic model. Simulated results were found to be suitably fitted to the experimental ones.ConclusionsThe high activity value of Amberlyst 15 is related to its high acidity and better textural properties. Reuse of this catalyst was possible with an appropriate previous treatment. A kinetic model was validated including the effect of catalyst concentration and temperature on reactants conversion and products distribution. © 2013 Society of Chemical Industry

설폰화 활성탄 촉매를 이용한 솔비톨의 아이소소바이드로의 탈수반응

불균일계 고체산 촉매인 설폰기(Sulfonyl Group) 함유 활성탄 촉매를 이용하여 솔비톨(Sorbitol)의 아이소소바이드로(Isosorbide)의 탈수반응을 수행하였다. 설폰화 반응(Sulfonation)에 의해 제조된 설폰화 활성탄 물질에 대해 대표적인 상업용 산촉매인 설폰화 지르코니아(Sulfated <TEX>$ZrO_2$</TEX>)와 산성 이온교환수지 Amberlyst-36과 솔비톨 탈수반응의 촉매활성을 비교하였다. 설폰화 활성탄 촉매를 이용하여 423.15 K에서 솔비톨의 탈수 반응 결과, 100% 솔비톨 전환율과 52% 아이소소바이드 선택도를 얻었다. 설폰화 활성탄은 낮은 설폰기 농도(0.5 mmol/g)에도 불구하고 높은 표면적으로 인해 423.15 K에서 Amberlyst-36과 유사한 솔비톨 탈수 반응 특성을 보이며, Amberlyst-36 대비 473.15 K 이상 고온에서도 안정한 특성을 보이는 고체산 촉매로 판단되었다. 또한, 솔비톨 탈수반응 결과를 바탕으로 반응과 생성물의 분리를 동시에 할 수 있는 반응증류 공정에 설폰화 활성탄 촉매를 적용한 결과, 기존 황산 공정 대비 2배 이상 빠른 반응시간에 단위 설폰산 농도 기준으로 4배 이상 높은 아이소소바이드 수율을 얻을 수 있었다. A sulfonated activated carbon (AC-<TEX>$SO_3H$</TEX>) was used as a solid acid catalyst for dehydration of sorbitol to isosorbide and its catalytic performance was compared with the commercial solid acid such as acidic ion exchange resin, Amberlyst-36, and sulfated copper oxide. The catalytic performance with 100% sorbitol conversion and 52% isosorbide selectivity was obtained over AC-<TEX>$SO_3H$</TEX> at 423.15 K. Although AC-<TEX>$SO_3H$</TEX> possessed only 0.5 mmol/g of sulfur content, it showed the similar dehydration activity of sorbitol to isosorbide with Amberlyst-36 (5.4 mmol/g) at 423.15 K. Based on the high thermal and chemical stability of AC-<TEX>$SO_3H$</TEX>, one-step reactive distillation, where isosorbide separation can be carried out simultaneously with sorbitol dehydration, was tried to increase the recovery yield of isosobide from sorbitol. The reactive distillation process using AC-<TEX>$SO_3H$</TEX>, the turnover number of AC-<TEX>$SO_3H$</TEX> was 4 times higher than the conventional two-step process using sulfuric acid.

Metal-free oxidative synthesis of succinic acid from biomass-derived furan compounds using a solid acid catalyst with hydrogen peroxide

Green oxidation of 2-furaldehyde (furfural) and its homologues were investigated using solid acid catalyst and hydrogen peroxide (H2O2) in aqueous media to form succinic acid (SA), a key chemical that affords wide applications in macromolecular, pharmaceutical and agrochemical industries. Amberlyst-15, a strongly acidic ion-exchange resin, functioned as an efficient solid acid catalyst for a highly selective SA production in the furfural oxidation reaction. The synthesized SA was simply isolated in high purity (supported by NMR spectral data). Furthermore, the utilization of Amberlyst-15 with H2O2 was also useful in oxidizing carbonyl derivatives of furan (furfural, 5-hydroxymethyl-2-furaldehyde, furoic acid) to a one carbon less linear di-carboxylic acid such as SA and 2-oxoglutaric acid (OGA) under moderate conditions. This catalytic oxidation process with an acid catalyst and H2O2 promises to be a viable route for SA syntheses since they have the advantages of easy handling and simple purification decreasing the cost for the production, as compared to the current state of art.

The dehydration of fructose to 5-hydroxymethylfurfural efficiently catalyzed by acidic ion-exchange resin in ionic liquid

The efficient dehydration of fructose to 5-hydroxymethylfurfural (HMF) was developed in ionic liquids (ILs) with acidic ion-exchange resins as catalyst. By screening different resins and ILs respectively, it was found that the structure of resins and ILs had a prominent effect on the dehydration of fructose. In 1-butyl-3-methylimidazolium chloride ([Bmim]Cl), D001-cc resin showed a high activity. And then the effects of reaction temperatures, dosages of D001-cc, and different initial fructose loadings on the dehydration of fructose were studied in detail. The system of D001-cc resin and [Bmim]Cl exhibited a constant activity at 75°C for 20min and a 86.2% yield of HMF was obtained after seven recycles. At 75°C for 20min, a 93.0% yield of HMF from the dehydration of fructose was obtained.

New Green Synthesis and Antineoplastic Activity of Bis (3-Arylimidazolidinyl-1) Methanes

A new green synthesis and anti-tumor activity of the series of bis (3-arylimidazolidinyl-1) methanes 1 - 6 are described. The compounds were synthesized from the corresponding N-arylethylenediamine and trioxane as sources of formaldehyde and the reactions were performed in heterogeneous phase catalyzed by an acidic ion-exchange resin (Amberlyst 15). The compounds were tested with the Sulforhodamine B assay according to the protocol of the National Cancer Institute for several cell lines. The results were expressed as percentage inhibition of growth cell in comparison with the full growth of the cells without treatment. Cytotoxicity on normal cells using the Annexing-PI staining and flow cytometry has been evaluated. The parent compound, bis(3-phenylimidazolidinyl-1)methane 1 and the monohalogenated derivatives 4-chlorophenyl 3 and 3-bromophenyl 5 showed antineoplastic activity, 60%, 82% and 89% inhibition growth cell respectively on the human colon cell line (HCT116). The 4-tolyl derivative 6 presented inhibitory activity (73% inhibition of growth cell) on human lung adenocarcinoma cell line (A549) and 62% on human mammary cell line MCF-7.