Production of esters with numerous applications: Kinetics of Dowex 50W catalyzed transesterification of methyl acetate with three- and four-carbon structured alcohols

In this investigation, a strongly acidic exchange resin was used for the transesterification of methyl acetate with n-propanol, n-butanol, and iso-butanol. Kinetic and equilibrium experiments for the three systems were conducted using a temperature-controlled batch reactor setup. The effects of the following operating parameters on the transesterification were explored: reaction temperature, catalyst loading, and methyl acetate-to-alcohol molar ratio. The conversion of the limiting reactant in the reaction mixture increased with increasing reaction temperature, catalyst loading, and varying reactant proportions from 1:1 to other ratios. It was found that excess methyl acetate would result in higher limiting reactant conversion than using excess alcohol with the same initial molar proportionality between the excess and the limiting reactants. It was found that an increase in the chain length of the alcohol and/or branching suppressed the conversion of the reactants owing to steric hindrance. To mathematically correlate the data, several kinetic models were tested, and the Eley–Rideal model was selected. Accordingly, a reaction mechanism was proposed. (author)