ISSN 00231584, Kinetics and Catalysis, 2015, Vol. 56, No. 4, pp. 419–427. © Pleiades Publishing, Ltd., 2015. 419 INTRODUCTION 1 Organic esters are very important chemicals. There is a wide range of applications of organic esters such as production of cosmetics, plasticizers, pharmaceutical substances, polymers, textiles, flavours and in food industry. Several synthetic processes are available to obtain organic esters. A comprehensive review of esters synthesis is available [1]. Methyl acetate manu factured commercially is in great demand. It is espe cially useful for the manufacturing nail polish remov ers, printing inks, perfumery, paints, dyes, industrial coatings and as a solvent in adhesives. Methyl acetate is produced by the esterification reaction between the acetic acid and methanol. At room temperature, the reaction is very slow and revers ible and several days are usually required to attain equi librium in the absence of the catalyst. The addition of the catalyst increases the reaction rate and therefore decreases the time needed to reach an equilibrium state. One can discriminate between heterogeneous and homogeneous catalytic reactions. Homogenous catalysis occurs when the catalyst and the reactants are both in the same phase while in the case of heteroge neous catalysis the catalyst and the reactants are in dif ferent phases. Homogeneous catalysts, such as HCl, HI, H 2 SO 4 , and HBr, provide an acid medium. Ion exchange resins are frequently used as heterogeneous catalysts. Heterogeneous catalysts are preferable to the 1 The article is published in the original. homogeneous catalysts due to several advantages like easy separation of catalyst from the post reaction mix ture, better selectivity towards desired product, high purity of the product due to suppression of side reac tions and elimination of the corrosive environment [2]. One of the earliest works relating to kinetics of cat alytic esterification of acetic acid with methanol was published by Rolfe and Hinshelwood [3]. Ronnback et al. [4] investigated the kinetics of esterification of acetic acid with methanol using a homogeneous hydrogen iodide as a catalyst. It was observed that hydrogen iodide also reacted with methanol and pro duced methyl iodide as a byproduct. Agreda et al. [5] proposed a rate expression for the esterification reac tion in which sulphuric acid was used as a homoge neous catalyst. Many solid catalysts were used, such as solid acids and bases, ionexchange resins, zeolites and acid clay catalysts. Ionexchange resins are the most common heterogeneous catalysts used for esterification reac tion [6–8]. These ionexchange resins not only catal yse the reaction but also improve conversion because of selective adsorption of reactants and swelling nature [9, 10]. In the heterogeneous catalysis, the active solid surface can distort or even dissociate an absorbed reac tant molecule and increase the rate of reaction [11]. Most of the esterification reactions were studied by using the solid catalyst Amberlyst 15 [12–18]. Liu et al. [19] investigated the similarities and differences between heterogeneous and homogeneous catalysed Kinetic Study of Esterification of Acetic Acid with Methanol over Indion 190 Acidic Solid Catalyst 1 Mekala Mallaiah* and Goli Venkat Reddy Department of Chemical Engineering, National Institute of Technology, Warangal 506004, India *email: mmyadav2001@gmail.com Received August 27, 2014 Abstract—Esterification of acetic acid with methanol to synthesize methyl acetate in an isothermal well mixed batch reactor was studied in the temperature range of 323.15–353.15 K. Indion 190 ionexchange resin was used as a solid catalyst. Feed molar ratios were varied from 1 : 1 to 1 : 4. The influence of tempera ture, catalyst loading, stirring rate, catalyst particle size and initial molar ratio on the reaction rate was inves tigated. Experimental results showed that the reaction is kinetically controlled. The sorption experiments were carried out independently to find the adsorption constants. For the constituent components the values of adsorption constants decrease in the order of water > methanol > acetic acid > methyl acetate. The kinetic data were correlated with the pseudohomogeneous (ideal and nonideal), Eley–Rideal and Langmuir–Hin shelwood–Hougen–Watson (LHHW) models to determine the kinetic parameters. All the models were suit able to predict the experimental data, but with the LHHW model a more accurate match of the experimental data was achieved. Keywords: kinetics, esterification, Indion 190 catalyst, adsorption, nonideal model, LHHW model DOI: 10.1134/S0023158415040126