Analysis of Sensitivity of Equilibrium Constant to Reaction Conditions for Esterification of Fatty Acids with Alcohols

作者：Hassan Saeikh Z; Vinjamur Madhu^*

来源：Industrial & Engineering Chemistry Research, 2013, 52(3): 1205-1215.

DOI：10.1021/ie301881g

The equilibrium constant (K-eq) depends on temperature only, but reported measurements for esterification reactions show that it also depends on reactant concentration and amount of catalyst. In this work, analysis of sensitivity of K-eq to errors in equilibrium composition of esterification reactions at different reaction conditions is presented. Rigorous error and Taguchi analyses showed that K-eq is indeed a function of temperature only and not of molar ratio (MR) of the reactants and catalyst loading; reported dependency of K-eq on reactants concentrations and catalyst loadings is due to errors in analysis of equilibrium composition. Sensitivity of K-eq to these errors depends strongly on molar ratio (MR), and calculations show that K-eq is least sensitive to error at 1.5 MR. However, phase separation of the reaction mixture is possible at 1.5 MR which can cause errors in measured equilibrium composition. K-eq of esterification reactions should be obtained through kinetic data fitting to the rate model. For sulfuric acid-catalyzed esterification of oleic acid with methanol, a single K-eq value for each reaction temperature is obtained through kinetics data fitting as 1.53 (+/-0.05), 1.67 (+/-0.04), and 1.91 (+/-0.06) at 313, 323, and 338 K, respectively. Equilibrium compositions are calculated reasonably well with these K-eq values.

• 出版日期2013-1-23