Kinetics and mechanism of myristic acid and isopropyl alcohol esterification reaction with homogeneous and heterogeneous catalysts

Abstract

The reaction of myristic acid (MA) and isopropyl alcohol (IPA) was carried out by using both homogeneous and heterogeneous catalysts. For a homogeneously catalyzed system, the experimental data have been interpreted with a second order, using the power-law kinetic model, and a good agreement between the experimental data and the model has been obtained. In this approach, it was assumed that a protonated carboxylic acid is a possible reaction intermediate. After a mathematical model was proposed, reaction rate constants were computed by the Polymath (R) program. For a heterogeneously catalyzed system, interestingly, no pore diffusion limitation was detected. The influences of initial molar ratios, catalyst loading and type, temperature, and water amount in the feed have been examined, as well as the effects of catalyst size for heterogeneous catalyst systems. Among used catalysts, p-toluene sulfonic acid (p-TSA) gave highest reaction rates. Kinetic parameters such as activation energy and frequency factor were determined from model fitting. Experimental K values were found to be 0.54 and 1.49 at 60 degrees C and 80 degrees C, respectively. Furthermore, activation energy and frequency factor at forward were calculated as 54.2 kJ mol(-1) and 1828 L mol(-1) s(-1), respectively. (c) 2008 Wiley Periodicals, Inc.