Reaction Kinetics of the Synthesis of Methyl Chloroacetate from Chloroacetic Acid and Methanol

The use of sulfuric acid to catalyze the synthesis of methyl chloroacetate from chloroacetic acid and methanol leads to equipment corrosion and separation difficulties. To solve the above problems and treat chloroacetic acid efficiently, the esterification of chloroacetic acid was catalyzed with a cation exchange resin in this work. The effects of the alcohol/acid molar ratio, catalyst dosage, reaction temperature, and reaction time were investigated by single-factor and orthogonal experiments. The excellent catalytic performance was reached with 70.11% chloroacetic acid conversion under the optimal reaction conditions of 1.4:1 alcohol/acid molar ratio, 3 wt % catalyst dosage, 70 °C reaction temperature, and 2 h reaction time. In addition, a power-law kinetic model for methyl chloroacetate was developed over a cation exchange resin. The activation energy and the pre-exponential factor were calculated by the Arrhenius equation: Ea+ = 38.83 kJ/mol, Ea– = 53.64 kJ/mol, A+ = 1.71 × 105 L0.84 mol–0.84 h–1, and A– = 1.15 × 105 L0.54 mol–0.54 h–1. After verification, the kinetic model can accurately predict the esterification reaction results of chloroacetic acid and methanol under experimental conditions, which provides theoretical guidance for the simulation of the chloroacetic acid esterification process.