Measurement of Residue Curve Maps and Heterogeneous Kinetics in Methyl Acetate Synthesis

Kinetic studies on esterification of acetic acid with isopropyl alcohol in presence of novel solid catalyst

The reaction of isopropyl alcohol with acetic acid was carried out in an isothermal batch reactor in presence of solid resin catalyst to produce isopropyl acetate and water. A novel solid resin catalyst Indion 140 was used in the present study. The temperature of reaction mixture was maintained in the range of 333.15 – 363.15 K. The effects of reaction temperature, catalyst loading, mole ratio, size of catalyst, agitation speed were investigated on acetic acid conversion. Further, pseudo-homogeneous kinetic model was developed for the catalyzed reaction. The forward reaction rate constants and activation energies were determined from the Arrhenius plot. The forward and backward activation energies are found to 53,459 J/mol and 54,748 J/mol, respectively. The heat of reaction is −1.289 kJ/mol with Indion 140 catalyst. The mathematical equation was developed for frequency factor as function of the catalyst loading and found that it follows a linear relationship between frequency factor and catalyst loading. The simulations were performed for pseudo homogeneous kinetic model and found that the model is able to predict the experimental data very well. The developed kinetic equation is useful for the simulation of a reactive distillation column for the synthesis of isopropyl acetate.

Brick-CFCMC: Open Source Software for Monte Carlo Simulations of Phase and Reaction Equilibria Using the Continuous Fractional Component Method

We present a new molecular simulation code, Brick-CFCMC, for performing Monte Carlo simulations using state-of-the-art simulation techniques. The Continuous Fractional Component (CFC) method is implemented for simulations in the NVT/NPT ensembles, the Gibbs Ensemble, the Grand-Canonical Ensemble, and the Reaction Ensemble. Molecule transfers are facilitated by the use of fractional molecules which significantly improve the efficiency of the simulations. With the CFC method, one can obtain phase equilibria and properties such as chemical potentials and partial molar enthalpies/volumes directly from a single simulation. It is possible to combine trial moves from different ensembles. This enables simulations of phase equilibria in a system where also a chemical reaction takes place. We demonstrate the applicability of our software by investigating the esterification of methanol with acetic acid in a two-phase system.

Development of an Activity Based Kinetic Model for an Esterification Process with Indion 180 Catalyst

The kinetics of esterification reaction between acetic acid and methanol was studied with the Indion 180 catalyst in the temperature range between 323.15 and 353.15K, and the catalyst loading between 0.01 g/cc to0.05 g/cc. The effects of temperature, catalyst loading, size of the catalyst and agitation speed on the reaction rate were investigated. The experimental results have shown the negligible effect of mass transfer resistances on the reaction rate. A second order kinetic rate expression was used to correlate the experimental data. An activity based kinetic model was also developed for the esterification process, which was validated against experimental results. The activity based model is found advantageous as it involves only two reaction rate parameters which were determined based on the kinetic rate parameters of the concentration based model. The comparison of the model predictions with the experimental results for different temperature and catalyst loading conditions has shown the better suitability of the activity based kinetic model for the esterification process with Indion 180 catalyst.

Data on acetic acid-methanol-methyl acetate-water mixture analysised by dual packed column Gas Chromatography

The composition of multicomponent determination by colorimetric titration is difficult. This complexity is easily overcome by using Gas Chromatography technique instead of wet method for multi-component mixture analysis. In Gas Chromatography, first the standard chart is prepared by using the known amount sample concentration as the reference. Once calibration chart is prepared the unknown sample concentration easily measured by using the standard chart. In the present study a standard calibration chart developed for the four component system of acetic acid–methanol–methyl acetate–water. The samples were taken at various concentrations of all components and different chromatograms obtained under various concentrations respectively. The method of optimization was first carried out to get the sharp peaks of individual components and binary pairs also. By using those conditions, the multi components concentrations were estimated. From the present results, the area under gas chromatogram is linearly varying with mole% of the components compared to mass%.

Kinetics of esterification of acetic acid and methanol using Amberlyst 36 cation-exchange resin solid catalyst

Catalytic esterification of acetic acid with methanol to produce methyl acetate in a stirred batch reactor was investigated in the presence of Amberlyst 16, Indion 180 and Amberlyst 36 catalysts. Amberlyst 36 was found to be an effective solid catalyst for this reaction compared to the other solid catalysts. The reaction was performed in the temperature range of 323.15–353.15 K and the catalyst loading in the range of 0.01–0.05 g cm−3. The initial reactant feed molar ratios of acetic acid to methanol were varied from 1:1 to 1:4. The influence of different parameters like temperature, catalyst loading, magnetic stirrer speed and average catalyst particle sizes on the conversion kinetics of acetic acid has been investigated. The maximum conversion of acetic acid was increased on increasing the feed molar ratio. From the experimental results, it was observed that the reaction is kinetically controlled rather than controlled by internal and external mass transfer. The experimental data were correlated with the pseudo homogeneous (PH), Eley–Rideal (ER) and Langmuir–Hinshelwood (LH) models. The activity coefficients were calculated using UNIQUAC model to account for the non-ideal behaviour of the components. Of the different kinetic models; the LH, surface rate-determining model, fitted best with the experimental data.

Ultrasound assisted synthesis of methyl butyrate using heterogeneous catalyst

Ultrasound assisted esterification of butyric acid with methanol was investigated in an ultrasound irradiated isothermal batch reactor using acid ion-exchange resin (amberlyst-15) as a catalyst. Effect of parameters such as temperature (323-353 K), catalyst loading (0-8.5%w/w), alcohol to acid ratio, M (2-6), ultrasound power (0-145 W), duty cycle (0-85%) and amount of molecular sieves added (0-11%w/w) on the rate of reaction was studied. At optimized parameters, a maximum conversion of 91.64% was obtained in 120 min in presence of ultrasound. Experimental kinetic data were correlated by using Eley-Rideal (ER) and Langmuir-Hinshelwood-Hougen-Watson (LHH W) models taking into account reverse reaction. Studies showed that single site LHHW with reactants and products both adsorbing on catalyst surface was most suited for the obtained experimental data. Activation energy determined based on heterogeneous kinetics was in the range 49.31-57.54 kJ/mol while it was 18.29 kJ/mol using homogeneous model.

Nano and micro-TiO2 for the photodegradation of ethanol: experimental data and kinetic modelling

In this work we show the possibility of using pigmentary TiO₂-powders as photocatalysts and we develop a kinetic model which is able to follow the behavior of nano-TiO₂versus micro-TiO₂ in ethanol degradation.

Esterification of Acetic Acid with Methanol over a Cation Exchange Resin

The esterification kinetics of acetic acid with methanol in the presence of ResinTech SACMP-H ion exchange resin as a heterogeneous catalyst were studied at temperatures of 303, 313 and 323 K. The effects of various parameters such as temperature, catalyst loading, stirrer speed and also the effect of the mole ratio of reactants, and the reaction mechanism, have been investigated in detail. The uncatalysed reaction was shown to be second-order reversible process. For heterogeneously catalysed reaction, three different kinetic models were applied to the experimental data, the best fit being the Eley-Rideal mechanism. It was found that ResinTech SACMP-H catalyst acts by reducing the activation energy from 58 to 48.2 kJ mol−1.

A kinetic model of the Amberlyst-15 catalyzed transesterification of methyl stearate with n-butanol

An attractive approach to improving cold flow properties of biodiesel is to transesterify fatty acid methyl esters with higher alcohols such as n-butanol or with branched alcohols such as isopropanol. In this study, the reaction kinetics of Amberlyst-15 catalyzed transesterification of methyl stearate, a model biodiesel compound, with n-butanol have been examined. After identifying conditions to minimize both internal and external mass transfer resistances, the effects of catalyst loading, temperature, and the mole ratio of n-butanol to methyl stearate in the transesterification reaction were investigated. Experimental data were fit to a pseudo-homogeneous, activity-based kinetic model with inclusion of etherification reactions to appropriately characterize the transesterification system.

Determination of Adsorption and Kinetic Parameters for Butanol-Acetic Acid Esterification System Catalysed by Amberlyst 15

The esterification of acetic acid with butanol catalysed by Amberlyst 15 was studied over a range of catalyst loadings, temperature, molar ratio of reactants, stirrer speed and particle size of catalyst. The equilibrium constant was experimentally determined and the reaction was found to be exothermic. Swelling and adsorption studies were performed to estimate the adsorption constants. The values found for the adsorption constants follow the order: water > butanol > acetic acid > butyl acetate. Experimental kinetic data for the esterification were correlated with the Pseudohomogeneous (PH), Eley-Rideal (ER) and Langmuir-Hinshelwood-Haugen-Watson (LHHW) models. The activity coefficients were calculated according to the UNIQUAC method. A possible mechanism of this reaction involved following the Eley-Rideal mechanism in which an adsorbed and protonated butanol molecule reacts with an acetic acid molecule in the bulk. The activation energy of the forward reaction was found to be 45.4kJ mol−1.