Esterification Of Acetic Acid Research Articles

How Two‐Dimensional Heterocovariance Spectroscopy and Data Fusion Level out the Inadequacies of Compact Spectrometers

ABSTRACTOver the past decade, sensors and compact spectrometers have emerged as a powerful means for real‐time monitoring of chemical and biochemical processes in the field of process analytical technologies (PATs). This is largely attributed to cost‐efficiency and their robustness in near‐line applications. In comparison to more sophisticated laboratory instruments, these devices exhibit limited sensitivity and resolution. In this study, a combination of near‐infrared, low‐field 1H nuclear magnetic resonance and compact Raman spectrometers were employed for the process monitoring of the acid‐catalyzed esterification of isoamyl alcohol and acetic acid to isoamyl acetate. The resulting real‐time data were transformed and visualized for interpretation using two‐dimensional heterocovariance spectroscopy. The data were also subjected to pretreatment, concatenation, and multivariate analysis in accordance with low‐ and mid‐level data fusion. The spectral interpretation derived from heterocovariance spectroscopy provided support for the data pretreatment during data fusion. By applying these computational techniques, the inherent limitations of sensitivity and resolution associated with compact spectroscopic instruments could be overcome, thereby facilitating the interpretation of data and yielding further insights into the process under study. A comparison of the process parameters resulting from the applied methods indicated that consistent data could be obtained. This study demonstrates that heterocovariance spectroscopy and data fusion allow to enhance compact, less expensive analytical instruments for process monitoring and to acquire process knowledge. This, in turn, enables material, financial, and energy resources to be conserved.

Catalytic behavior, electronic structure and spectroscopic (FT-IR, Raman, UV–vis) properties for the new ionic liquid imidazolium hydrogen sulfate

Catalytic performance, chemical reactivity, vibrational modes and electronic transitions of the ion pair [H–Im]+[HSO4]– were investigated in the current paper. Hence, a combined experimental (Hammett acidity function, infrared, Raman and ultraviolet-visible spectroscopies) and theoretical (molecular electrostatic potential surface, reduced density gradient, frontier molecular orbital analysis, quantum theory of atoms in molecules, net atomic charges, global and local reactivity descriptors) study was conducted. In terms of the catalytic performance, the acetic acid esterification with butanol was evaluated. Important kinetic (rate constant, activation energy, pre-exponential factor) and thermodynamic (enthalpy, entropy, Gibbs free energy barrier) factors for ester production as a function of the temperature and catalyst loading have been determined. Results revealed intensive electron density distribution in [H–Im]+[HSO4]– due to chemical interactions between the cationic and anionic moieties. These bonds were established as electrostatic in nature. The pronounced charge transfers within [H–Im]+[HSO4]– managed the title compound acidity (H0) and its catalytic behavior towards butyl acetate synthesis. Using the thermodynamic and kinetic measurements, a mechanism for acetic acid esterification with butanol in the presence of imidazolium hydrogen sulfate ionic liquid was offered.

HYDROCHLORINATION OF GLYCERIN

A study of the hydrochlorination of glycerol. In the current conditions, the development of alternative technologies for the synthesis of epochlorohydrin has become very relevant. Such technologies include a process based on the hydrochlorination of glycerol, especially since in recent years the chemical products market has been saturated with glycerol, a waste product of biodiesel production. However, the development of such technology requires the solution of a number of physico-chemical problems related to the hydrochlorination of glycerin and its chlorohydrides, dehydrochlorination of highly concentrated solutions of glycerin dichlorohydrins, as well as the establishment of the kinetics of the reactions of glycerol and esterification of acetic acid. In particular, we can talk about the effect of water as a solvent on the rate of reactions. This is all the more important because the data presented in the literature on the kinetics of hydrochlorination reactions of glycerin and its chlorohydrins are contradictory and inadequately describe the process over the operating temperature and concentration ranges. It can be assumed that understanding the physical chemistry of such processes and determining the characteristics of the kinetics of the reactions occurring during the production of epichlorohydrin from glycerin will provide an opportunity to choose the optimal conditions for the implementation of the process, including the type of reactors, operating temperatures, initial concentrations, proportions of reagents, etc. Keywords: Glycerin, hydrochlorination, chlorohydrides, epichlorohydrin.

Facile Synthesis of Copper Nanocubes in Aqueous Phase for Catalytic Esterification Using Green-Conditions

This work demonstrated a simple and environmentally friendly method for synthesizing silica-supported copper nanocubes (CuNCs/SiO2). The copper nanocubes, with a size of 15 ± 5 nm, were synthesized using green reagents and conditions. Ascorbic acid, water, and di-n-butyl sulfide were employed as reducing agent, solvent, and stabilizing ligand, respectively. The designed nanoscale catalyst was utilized for the esterification of acetic acid to methyl acetate at room temperature. The catalyst exhibited high efficiency, converting 80% of the reactant to the desired product (methyl acetate) after 24 hours of reaction at room temperature. The size and shape of copper nanocubes were characterized by transmission electron microscopy (TEM) and X-ray diffraction to characterize the formation of copper nanocubes, while the esterification product was characterized using gas chromatography-mass spectrometry.

Insight into the factors affecting the reactivity of sulfonic acid species anchored on hyper-cross-linked polymers in esterification

The global market for organic esters was estimated at around $89.4 billion in 2022, and is expected to continue to grow, reaching $127.4 billion in 2029. The wide application of mineral acids as homogeneous catalysts for the synthesis of organic esters causes several economic and environmental problems. For this reason, a lot of effort is undertaken to make esterification a more sustainable process. Nowadays, particular attention is paid to the development of new solid acid catalysts containing sulfonic acid groups (–SO3H) supported on organic polymers. This study fits into this scientific trend and aims at providing insight into the factors affecting the reactivity of –SO3H species anchored on hyper-cross-linked polymers (HCPs). For this purpose, polymers characterized by different cross-linking densities but with a comparable surface area of ca. 540–620 m2/g and a similar pore size of ca. 3.7 nm were applied as supports for anchoring of –SO3H through post-synthetic sulfonation. The loading of sulfonic acid species in all prepared catalysts varied from 1.19 to 2.22 mmol/g. Catalytic activity of the sulfonated HCPs (sHCPs) was evaluated in esterification of acetic acid with different alcohols. It was found that the key factors affecting the reactivity of –SO3H supported on HCPs are hydrophilicity of the polymer surface and the localization of the sulfonic acid species on the external surface of the polymer matrix. The latter was the most favoured during the post-synthetic sulfonation of the polymer characterized by the highest cross-linking density. In the case of this material, the –SO3H species were approximately 7 times more reactive than those of Amberlyst-15 (TOF = 11.36 vs. 1.57 h−1, respectively). The most efficient sHCP used in this study reached approximately two times higher conversion of n-butanol than Amberylst-15 (53.6 vs. 27.5 %) despite of the significantly lower loading of sulfonic acid species in the former polymer (2.22 vs. 4.66 mmol/g, respectively). It was also established that the catalytic esterification on the surface of sHCPs proceeded according to the Langmuir-Hinshelwood mechanism, in which chemisorption of the alcohol is the rate-determining step. Moreover, sHCP catalysts could be reused four times without significant deactivation.

TO ISSUE INCREASING THE EFFICIENCY OF THE MASS TRANSFER PROCESS IN AGITATORS

This study investigates the impact of impeller design on the rate of esterification reaction in a batch reactor. Different impeller designs were tested and compared, including Backswept impeller, C-shaped, Double Blade impeller, and Pitched impeller. The results showed that the choice of impeller design has a significant effect on the rate of esterification reaction, with the Backswept impeller proving to be the most effective. In this work, it is aimed to investigate the esterification of acetic acid and methanol in a batch stirred reactor for the synthesis of methyl acetate. The temperature range of 303.15 K is examined, with sulphuric acid used as the homogeneous catalyst in varying concentrations of 0.0633 mol·L1 to 0.3268 mol·L-1. The feed molar ratio of acetic acid to methanol also varied from 1:1 to 1:4 to observe its influence on the reaction rate. The research delves into the effects of temperature, catalyst concentration, and reactant concentration on the reaction rate. The experimental data is correlated using a second-order kinetic rate equation, and the forward and backward reaction rate constants and activation energies are determined from the Arrhenius plot. The developed kinetic model is compared with previous models in literature. In order to find the most effective impeller for esterification reaction, diameter of impellers was accepted same in the constant volume and dimension of batch reactor. The obtained kinetic equation proves useful for the simulation of a reactive distillation column for the synthesis of methyl acetate. Keywords: the batch reactor, impeller, esterification, effectivity, mass transfer, mixing, mechanical mixers, Logarithmic Shear Rate, Eddy Diffusivity.

Facile Synthesis of Ethyl Acetate over ZrO2.TiO2 Mixed Oxide Supported Vanadium Boasted Phosphomolybdic Acid Catalyst at Room Temperature

Initially, mixed oxide of ZrO2.TiO2 support was synthesized by the sol-gel method, and then after vanadium was incorporated, phosphomolybdic acid (VPMA) was synthesized by the hydrothermal method. VPMA supported on ZrO2.TiO2 support of various VPMA loadings that were synthesized by the impregnation method. The structure, surface area, acidity, and morphology of the materials were analysed by X-ray diffraction, BET surface area, ammonia TPD studies, and SEM analysis, respectively. The XRD result shows crystallites of zirconia, titania, and Keggin ion of VPMA catalysts, and also, below 20 wt% of VPMA loading, crystallites of Keggin ion are not observed. BET surface area analysis reveals that increase of VPMA loading, surface area was sharply declined at higher loadings. Ammonia TPD analysis finds that acidity is inclined with VPMA loadings. SEM studies reveal that bulk formation of the active phase is observed at higher loadings. Esterification of acetic acid was tested over VPMA/ZrO2.TiO2 catalyst that exhibited higher activity during reaction than pure VPMA catalyst. These findings were well correlated with surface area and acidity loadings.

Exploring Esterification and Pyrolysis Pathways for Sustainable Biofuel and Biomass Production

Abstract: The recent Years Increase the demand of the biofuels along with need of reduce the production cost of Improving the environmental sustainability of the biomass production or the biofuels. Biomass is on area of importance to reduce the overall uses of fossil fuels. In which the focusing the kinetic properties or the optical property of the production of the Biofuel or Biomass production. Process optimization and reaction kinetic model development were carried out for two stage esterification transesterifications... reactions of waste biomass. This study focused on these traditional processes due to their techno- economic feasibility- Which is an important factor before deciding on a type of Feedstock for Industrilisation.Since esterification reactions are acid catalyzed the synthesis of an efficient acidic catalyst will be very helpful for pretreatment. esterification of acetic acid which was used model reaction in Stabilization of biomass. The esterification is a potential route to remove the organic acid in biomass reacting them with alcohol Present in biomass with added alcohol. Water is a product of the esterification reaction. The concentration of acetic acid used to acidification; acetic acid is a common chemical species in biomass & was used as the model compound. The research compared the quality of slow pyrolysis produced. biomass collected. by condensing pyrolysis vapor using atomized ethanol (EtOH).Were also carried out for the analysis of biomass produced.

Photocatalytic esterification of acetic acid with methanol over metal-exchanged phosphotungstate

In this work, a series of metal-exchanged phosphotungstate salts, Fe-TPA, Ni-TPA, Cu-TPA, and Cr-TPA, were tested for esterification of acetic acid to methyl acetate under UV irradiation. The results of UV-DRS analysis confirmed the preservation of the Keggin structure, and the presence of metals in the structure, as well as the redshifts compared with P25 in the UV absorbance spectrum. All M−TPA photocatalysts exhibit significantly enhanced activity with respect to P25 for the esterification of acetic acid under UV irradiation, except for Cr-TPA. Among them, Fe-TPA salt was the best catalyst with the highest conversion. The excellent photocatalytic activity can be explained by the nano-size, good oxygen-to-transition metal charge transfer, and high acid concentration in the esterification reaction. Besides, the lower photoluminescence intensity of Fe-TPA suggests a lower recombination rate of electron-hole pairs, indicating efficient charge separation and a higher potential for catalytic reactions. Fe-TPA also absorbs light at slightly longer wavelengths, indicating modifications in the electronic structure that can enhance its ability to capture and utilize light energy for photocatalytic reactions. The optimum reaction conditions for the esterification reaction were found to be 25 °C, a methanol/acetic acid molar ratio of 15/1, and the presence of 5 wt% catalyst loading for 240 min. Experimental data agree with pseudo-first-order reaction kinetics with 44.9 kJ/mol of activation energy. The iron phosphotungstate salts are a promising photocatalyst with sustainable acidity during the reaction, high conversion at low temperature, easy synthesizability, inexpensiveness, and an environmentally friendly nature.

Characterization and Catalytic Performance of Al-SBA-15 Catalyst Fabricated Using Ionic Liquids with High Aluminum Content

This study involved the fabrication of a set of aluminum ion-grafted SBA-15 utilizing ethylenediamine and trimethylamine ionic liquids. The primary objective was to examine the impact of the fabrication environment on the physicochemical characteristics of the catalysts. Comprehensive characterization of the Al-SBA-15 catalysts was conducted using various techniques, including XRD, FTIR, surface area, pyridine FTIR, 27Al-NMR, TGA, HRTEM, and FESEM, to analyze their physicochemical characteristics. Furthermore, the acidic characteristics were examined by conducting potentiometric titration in a nonaqueous solvent and employing FTIR spectroscopy to analyze the chemisorbed pyridine. The effectiveness of the fabricated acid materials was evaluated by testing their performance in acetic acid esterification with butanol. The findings obtained reveal that mesostructured SBA-15 remains intact following the successful inclusion of Al3+ ions into the silica frameworks. Additionally, a remarkable enhancement in the existence of both Bronsted and Lewis acid centers was noted due to the grafting process of Al3+ ions. At temperatures of 80 °C and 100 °C, the reaction in Al-SBA-15(T-120) proceeds swiftly, reaching approximately 32% and 38% conversion, respectively, within a span of 110 min. The excellent catalytic performance observed in the esterification reaction can be attributed to two factors: the homogeneous distribution of Al3+ ions within the SBA-15 frameworks and the acidic character of Al-SBA-15. The findings further indicate that the grafting process for incorporating Al3+ ions into the silica matrix is more efficient.

Kinetics of esterification of acetic acid with n‐butanol over different homogeneous acid catalysts

AbstractThe esterification reaction of n‐butanol and acetic acid has been performed in batch reactor in the presence of different homogeneous acid catalyst, namely sulfuric acid, nitric acid, and para toluene sulfonic acid (p‐TSA). The objective of present research work is to investigate kinetic behavior of esterification reaction over the temperature range of 60°C–80°C. The effect of reaction parameter such as catalyst loading varied from 1% to 5% v/v and acid to alcohol molar ratio of 1:1, 1:3, and 1:5 has been observed. A pseudo homogeneous kinetic model has been applied. Kinetic parameters such as equilibrium constant, reaction rate constant, enthalpy, activation energy, and entropy were calculated by the experimental data for different acid catalyst system. It was observed that sulfuric acid gives higher conversion 73% than p‐TSA 68.5% and nitric acid 66.25% at temperature of 80°C, 1:1 molar ratio and 3% catalyst concentration. The activation energy was estimated 36448.49, 23324.31 and 19060.156 J/mol K for three different catalyst sulfuric acid, nitric acid and p‐TSA respectively. The enthalpy and entropy of the esterification reaction of acetic acid with n‐butanol over three different catalysts has been calculated (Enthalpy: 25.788 KJ/mol, 12.256 KJ/mol, 28.320 KJ/mol, Entropy: 88.1 J/mol K, 45.298 J/mol K, 91.44 J/mol K) and found enthalpy is having positive value that shows reaction is endothermic.

Towards Photothermal Acid Catalysts Using Eco-Sustainable Sulfonated Carbon Nanoparticles—Part I: Synthesis, Characterization and Catalytic Activity towards Fischer Esterification

The development of photothermal catalysts for biodiesel synthesis reaction (transesterification) requires the production of light-absorbing nanoparticles functionalized with catalytic (acid) groups. Using Stöber method, it is possible to produce resorcinol/formaldehyde resin (RF) nanoparticles, which can be carbonized (pyrolysis in an inert atmosphere) and sulfonated. In this work, vegetable tannins are used as a replacement for synthetic resorcinol in the Stöber synthesis of resin (TF) nanoparticles. The nanoparticles are characterized using DLS, FESEM, TEM and N2 adsorption-desorption isotherms. Both resin and carbon nanoparticles are sulfonated by reaction with concentrated sulfuric acid. The attachment of sulfonic groups is verified by FTIR and EDX. The number of sulfonic groups is measured by acid/base titration and TGA. All sulfonated nanoparticles show catalytic activities towards Fischer esterification of ethanoic acid with ethanol, and high (up to 70%) conversion is obtained. The conversion is lower with TF-based nanoparticles, but the turnover numbers are similar in the RF- and TF-based materials. Sulfonated carbon and resin nanoparticles show higher catalytic activity compared to commercial acidic catalysts (e.g., Nafion®). Photothermal heating of carbon nanoparticles is observed. In Part II, sunflower oil transesterification, catalyzed by sulfonated nanoparticles, is observed. Photothermal catalysis of acetic acid esterification and sunflower oil transesterification is demonstrated.

Green modification of corn starch through repeated freeze-thaw cycles (RFTC), microwave assisted solid state acetic acid esterification (MSAE), and by dual RFTC/MSAE treatment

Freeze-thaw treatment as a green technology has been extensively applied to improve the functional properties in types of starches. The present work aimed to compare the effects of repeated freeze-thaw cycles (RFTC), microwave assisted solid state acetic acid esterification (MSAE), and their combination (RFTC/MSAE) on structural and functional properties of corn starch (NS). RFTC/MSAE treatment provided higher esterification efficiency (68.7%) for the esterified starches compared to MSAE alone (32.6%) due to raised surface area of starch granules after applying RFTC. Esterification of starch chains by using acetic acid was confirmed through FTIR (1700 cm−1) and 1H NMR (2 ppm). SEM images showed that the pores and channels were formed on granules after applying RFTC treatment, while no change in their size was observed. Also, XRD and DSC were employed to scrutinize the changes in crystalline structure of granules after applying each modification. The dual treatment decreased crystallinity, viscosity, swelling power, digestibility rate, and gelatinization temperatures, while increased amylose extent, whiteness, solubility, and paste clarity compared to those of NS. The conformity of the dual treatment with principles of green chemistry was investigated by Eco-scale methodology. Starch acetate synthesized through the dual modification can be utilized in formulation of low-calorie foods due to its highlighted features such as low digestibility rate (RS: 54.7%) and viscosity (455 cp).

A mini review on manipulation of carbohydrate for better use in surimi and surimi products: modification and compounding.

Carbohydrate is widely used in the production of surimi and surimi products to improve their qualities, such as anti-freezing capability, gelling ability, nutrition, flavor and 3D printability. More and more native carbohydrates have been modified through physical methods (e.g., ball milling, irradiation and differential sedimentation), chemical method (e.g., deacetylation, hydroxypropylation and acetic acid esterification) or enzymatic method (e.g., chitosanase) before being used in the processing of surimi and surimi products in recent years. At the same time, different carbohydrates are compounded and applied to surimi and surimi products. The modified and compounded carbohydrates in surimi have been proved to improve quality of surimi and surimi products more pronouncedly than native carbohydrates. Therefore, this review summarizes the manipulation of carbohydrate by modification and compounding to improve the qualities of surimi and surimi products. Moreover, the prospects for carbohydrate modification and compounding for use in surimi and surimi products are discussed. © 2023 Society of Chemical Industry.

Vapor–Liquid and Chemical Equilibrium for Esterification of Acetic Acid + Isopropanol with [HSO3-bmim][HSO4] at 101.33 kPa

Vapor–Liquid and Chemical Equilibrium for Esterification of Acetic Acid + Isopropanol with [HSO3-bmim][HSO4] at 101.33 kPa

Hydrophobic Modification of Sulfonated Carbon Aerogels from Coir Fibers To Enhance Their Catalytic Performance for Esterification.

The hydrophilicity of sulfonic acid-functionalized solid catalysts tends to accelerate the deactivation of the catalyst for chemical reactions where water is produced during the process. In this work, we proposed a hydrophobic carbon aerogel acid catalyst derived from coir fibers by a sulfonation-hydrophobization route via the diazo reduction method. Sulfonation using the diazo reduction method offers some advantages such as the process takes only a few minutes and the modified surface can be easily modified further to be hydrophobic. The carbon aerogel was produced by direct pyrolysis of cellulose aerogels derived from coir fibers using an NH4OH-urea method and then sulfonated and hydrophobized using sulfanilic acid and 4-tert-butylaniline (TBA), respectively. The carbon aerogel exhibited a very high surface area (2624.93-3911.05 m2 g-1), which provides a lot of number of sites for sulfonate groups (2.30-2.70 mmol g-1). The water contact angle of the sulfonated catalyst after hydrophobization ranged from 70 to 115°, depending on the mass ratio of the TBA-to-solid catalyst. The hydrophobic catalyst exhibited better catalytic performance toward esterification of acetic acid with ethanol. A conversion of 65-74% could be achieved in a brief time using the hydrophobic catalyst. The conversions were much higher than that obtained by the unmodified hydrophilic catalyst. Our study offers a strategy to tune the surface hydrophobicity of the sulfonated solid acid catalyst to match for specific chemical reactions.

Kinetics of acetic acid and isoamyl alcohol liquid esterification over Amberlyst-70

This work is a kinetic study on liquid phase esterification between acetic acid and isoamyl alcohol using Amberlyst-70 as catalyst. There are not scientific papers with fitted kinetic models for this esterification system using this catalyst. Experiments were carried out in a laboratory batch reactor at controlled temperature conditions. Molar feed ratio (between 2 and 0.5), temperature (between 353.15 K and 383.15 K) and catalyst load (between 0.5 wt% and 2.0 wt%) were the manipulated experimental conditions. Measured composition profiles were used to fit the parameters for three versions of the pseudohomogeneous model (PHM) that differ in their activity model. At the end, a PHM model based on molar fractions is recommended to explain composition changes due to the esterification reaction. Calculated values for activation energy and chemical equilibrium constant are E = 43 kJ/mol and KE = 5.22, respectively. In accordance with the Weisz-Prater criterion, intraparticle mass transport effects were appreciable in experimental kinetic tests due mainly to the particle size used (0.363 mm). In order to take into account diffusional effects, the effectiveness factor was calculated using the Maxwell-Stephan equations. Therefore, adjusted models are the intrinsic kinetics and they can be used to simulate and design reactors and reactive distillation operations.

Carbon-based solid acids catalyze the synthesis of ethylene glycol monoacetate from ethylene glycol and acetic acid

Activation is essential for improving the structure and surface functional groups of carbon-based solid acids (CSA) during the preparation of carbon materials. This paper compared the catalytic activity of CSA treated non-, KOH-, H3PO4-, and ZnCl2-activation in esterification of ethylene glycol (EG) and acetic acid (HAc) to synthesize ethylene glycol monoacetate (EGMA). The catalysts were characterized using N2 isothermal adsorption–desorption, acid-base titration, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), Raman spectrometer, X-ray photoelectron spectroscopy (XPS), and X-ray diffractometer analysis (XRD). The results showed that activation treatment clearly enhanced the CSA’s specific surface area and significantly influenced the distribution of surface functional groups. Notably, the CSA activated with H3PO4 had a markedly higher density of –SO3H groups than the non- activated, KOH- activated, and ZnCl2-activated CSA. The high density of –SO3H on the catalyst surface is advantageous for the synthesis of EGMA from EG and HAc, making the H3PO4-activated CSA the best performer. The reaction conditions were optimized on H3PO4-activated CSA, resulting in a 74.1% conversion of EG and an 81.8% selectivity of EGMA at 100 °C for 30 min, and the EG/HAc molar ratio of 1:2. H3PO4-activated CSA was not obviously deactivated even after five cycles, and the decrease of its catalytic performance was related to the leaching of –SO3H on the catalyst surface. Overall, these findings suggest that H3PO4-activated CSA offers the benefits of less cost, a simpler preparation method, and greater catalytic activity compared to other catalysts, making it a desirable option for the synthesis of EGMA.

Esterification of acetic acid with isobutanol catalyzed by ionic liquid n-sulfopropyl-3-methylpyridinium trifluoromethanesulfonate: Experimental and kinetic study

As an important organic, isobutyl acetate (IbAc) has been widely used in industries because of its good biodegradability, low surface tension, and other properties. The industrial production of IbAc is usually catalyzed by sulfuric acid. However, the use of sulfuric acid has the drawbacks of causing considerable corrosion to equipment and being difficult to be separated. In this work, n-sulfopropyl-3-methylpyridinium trifluoromethanesulfonate ([HSO3-PMPY][CF3SO3]) Brönsted acidic ionic liquid (BAIL) was used as the catalyst and the catalytic activity, solubility, and corrosiveness were evaluated for the esterification of acetic acid with isobutanol. The reaction kinetics and chemical equilibrium were systemically studied. Compared to conventional acid catalysts, [HSO3-PMPY][CF3SO3] showed higher catalytic activity, more excellent reusability, more favorable phase separation, and non-corrosiveness. Three kinetic equations based on ideal homogeneous (IH), non-ideal homogeneous (NIH), and modified non-ideal homogeneous (NIH-M) models were established and correlated with the experimental data to determine the parameters and errors. The NIH-M model exhibited the best agreement with the experimental data, owing to its prediction considering the non-ideality and the self-catalysis effect of acetic acid in this system. Besides, the error of NIH-M model fitting was mainly caused by the difference in solubility between [HSO3-PMPY][CF3SO3] with reactants and products in the reaction system. Furthermore, the applicability of the NIH-M model was investigated by simulating the esterification of acetic acid with three short-chain alcohols (ethanol, n-butanol, and isobutanol) catalyzed by BAILs. The NIH-M model displayed an acceptable simulation for this type of acetic acid esterification reaction catalyzed by BAILs at different ranges of the BAILs concentration and temperature. This study confirmed the industrial prospects of [HSO3-PMPY][CF3SO3] in isobutyl acetate production and the applicability of the NIH-M kinetic model in the esterification of acetic acid.

Effects of the Inclusion of Ce and Ni Species on Ti for Modification of K10-Clay by Sol-Gel and their Use as Catalysts in the Liquid-Phase Esterification Systems

AbstractThe modification of montmorillonite with metallic species affects directly its crystalline structure, texture, porosity, and surface. The interaction of the metallic molecules with the clay matrix, derived from the modification pathway and the characteristics of the adsorbate, modifies the physicochemical properties of montmorillonite, enabling the creation of materials with varied characteristics to be used both as catalysts and adsorbents. Small amounts of metallic species can confer various structural and physicochemical characteristics on the same montmorillonite matrix, depending on the metal incorporated. The objective of the present study was to create an acid-base catalyst based on montmorillonite K10 (K10 Mnt), modified with Ti, Ce, and Ni, for the catalytic esterification of acetic acid and penta-1-ol. K10-Mnt was modified using particles of Ti and of Ti modified with Ce and Ni. The effect of the inclusion of Ti and modified Ti species on the transformation of the physicochemical properties of the K10 Mnt and their contributions to the catalytic esterification syntheses were investigated. Samples were characterized by scanning electron microscopy coupled to an energy-dispersive X-ray spectroscopy system (SEM-EDS), powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), physisorption of N2 at 77 K (BET and BJH), and thermogravimetric analysis (TGA-DTGA). Finally, the original and modified K10 Mnt samples were tested for their catalytic esterification of acetic acid and penta-1-ol in the liquid phase.