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 ® 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 • C and 80 • C, respectively. Furthermore, activation energy and frequency factor at forward were calculated as 54.2 kJ mol −

Kinetics of Free Fatty Acid Esterification in Used Cooking Oil Using Hypercrosslinked Exchange Resin as Catalyst

“…A second order reversible PH model was demonstrated to fit the experimental data and this model gave a satisfactory interpretation of the experimental data. A similar finding was reported by Reference [12] when they investigated the esterification of myristic acid using homogeneous (p-toulene sulfonic acid) and heterogeneous (Amberlyst 15 and Degussa) catalysts. Their experimental data have been interpreted with a second order kinetic model and a good agreement was achieved between the experimental data and the model.…”

Esterification of oleic acid for biodiesel production catalyzed by 4-dodecylbenzenesulfonic acid

“…This (the separation of water in a second phase) has already been reported in the case of the esterification of myristic acid [28].…”

“…Although to our knowledge DBSA has not been used so far in this type of reaction, the esterification of many carboxylic acids has already been addressed by different authors and hence the variables that influence the kinetics and equilibrium of the reaction are well known: temperature (T), the catalyst/fatty acid molar ratio (Cat), the methanol/fatty acid molar ratio (Met), the initial water/fatty acid weight ratio (H 2 O) and the stirring rate [26][27][28][29]. Accordingly, in this work we studied the influence of all these variables and, additionally, the influence of the presence of triglycerides in the reaction mixture.…”

“…However, these acids are frequently used in the esterification of fatty acids [26,[28][29][30][31][32], and their application in the synthesis of biodiesel from raw materials with high FFA contents is also possible when the overall process consists of two steps [12][13][14].…”

Homogeneous and Heterogeneous Catalyzed Esterification of Acrylic Acid with Ethanol: Reaction Kinetics and Modeling

“…Aafaqi et al [8] reported that the homogeneous catalyst gives better conversion than the heterogeneous catalyst for esterification of palmitic acid with isopropanol. Yalcinyuva et al [9] reported similar comparative results for esterification of myristic acid with isopropyl alcohol. They concluded that heterogeneous catalysts gave poor conversions due to the diffusion problem of fatty acid into the pores of the catalyst.…”