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

The equilibrium constant (Keq) 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 Keq to errors in equilibrium composition of esterification reactions at different reaction conditions is presented. Rigorous error and Taguchi analyses showed that Keq is indeed a function of temperature only and not of molar ratio (MR) of the reactants and catalyst loading; reported dependency of Keq on reactants concentrations and catalyst loadings is due to errors in analysis of equilibrium composition. Sensitivity of Keq to these errors depends strongly on molar ratio (MR), and calculations show that Keq 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. Keq of esterification reactions should be obtained through kinetic data fitting to the rate model. For ...