Kinetics of ion exchange resin catalyzed esterification

3 Kinetics of ion exchange resin catalyzed esterification reaction 

The overall rate of reaction (with catalyst) was studied using ion exchange resin as a catalyst following the procedure described in section 4.2.3. The effect of different parameters such as catalyst loading, initial concentration of reactants, temperature and particle size was studied. In each experiment, the concentrations of reactants and products were recorded as functions of time. A typical concentration- 

It is interesting to note that the concentration-time profiles under identical reaction conditions for the homogeneous and the heterogeneous reactions were almost similar (Figs. 4.2 and 4.11). The major difference was that for the ion exchanged resin catalyzed reaction, the amount of dimethyl maleate formed was significant compared to that in the homogeneous reaction. 

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Sanz, M., R. Murga, S. Beltran, J. Cabezas J. Coca (2002) Autocatalyzed and ion-exchange-resin-catalyzed esterification kinetics of lactic acid with methanol. Industrial Engineering Chemistry Research, 41,512-517,1SSN 0888-5885. 

Toor, A. P., M. Sharma, S. Thakur R. K Wanchoo (2011) Ion-exchange Resin Catalyzed Esterification of Lactic Acid with Isopropanol a Kinetic Study. Bulletin of Chemical Reaction Engineering Catalysis, 6,39-45, ISSN 1978-2993. 

Esterification of organic compounds often involves multiphase catalytic reactions in which contact of liquid (organic substrate) and solid (catalyst) phases are involved. The most common esterification processes fall into the category of two phase (liquid-solid) reactions. Both slurry and fixed bed reactors can be used for ion exchange resin catalyzed esterification reactions. The overall performance of these reactors depends on the inter phase mass transfer, intrinsic kinetics of reaction, physicochemical properties and mixing of the fluid phases. For a continuous process, fixed bed reactors should be preferred, however, in fixed bed reactors small catalyst particles cause higher pressure drop. Special type of support trays may also be required to support small catalyst particles in fixed bed reactors. 

As a model esterification reaction, the formation of ethyl lactate has been studied and its complete kinetic and thermodynamic analysis has been performed. The formation rate of ethyl lactate has been examined as a function of temperature and catalyst loading. In early experiments, it was determined that lactic acid itself catalyzes esterification, so that there is significant conversion even without ion exchange resin present. The Arrhenius plot for both resin-catalyzed and uncatalyzed reactions indicates that the uncatalyzed... 

The kinetics of octanoic acid esterification by t-butanol catalyzed by the macroretic-ular, sulfonylated ion-exchange resin, Amberlite-15, in a batch reactor was measured [37]. The effect of the catalyst amount, temperature and concentration of alcohol, water and butyl octanoate was investigated. Experimental data suggested that the solvated sulfo groups are bonded with the alcohol-water matrix. It was assumed that the examined reaction system included the heterogeneous reaction catalyzed by nonionized sulfo groups as well as the pseudohomogeneous reaction catalyzed by solvated protons. 

Herein, we review the mechanisms of esterification catalyzed by inorganic acid, Lewis acid, metallic compounds, solid acids, ion-exchange resin, respectively. Meanwhile, the kinetics for each esterification is also conducted in detail. The study on the mechanism of various catalysts is not only useful in the present applications but it is required to enhance the scope of their applications. Therefore, it is desired to research and develop more efficient catalysts for high yield ester production, under mild reaction conditions. The esterification kinetics is important for simulation and design of a reactor. 

Pereira, C. S. M., S. P. Pinho, V. M. T. M. Silva A. E. Rodrigues (2008) Thermodynamic equilibrium and reaction kinetics for the esterification of lactic acid with ethanol catalyzed by acid ion-exchange resin. Industrial Engineering Chemistry Research, 47,1453-1463,1SSN 0888-5885. 

The kinetics and equilibrium of autocatalyzed and ion exchange resin (Amberlyst-15) catalyzed esterification of acetic acid with methanol and hydrolysis of methyl acetate were studied by Popken et. al. (2000) in a temperature range of 303 - 343 K. The homogeneous reaction has been described with a simple power-law model. To compare pseudo-homogeneous and adsorption-based kinetic models for the heterogeneously catalyzed reaction, independent binary liquid phase adsorption experiments were used to estimate the adsorption equilibrium constants to keep the number of adjustable parameters the same for each model. 

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