Triethyl Citrate Synthesis by Reactive Distillation

A continuous reactive distillation process is proposed for the synthesis of triethyl citrate from citric acid and ethanol in the presence of macroporous Amberlyst 15 ion-exchange resin catalyst. The process design, developed using ASPEN Plus simulation software, is based on laboratory kinetic and thermodynamic studies and pilot-scale reactive distillation experiments. Pilot-scale experiments were carried out in a 5-m glass reactive distillation column; catalyst effectiveness was then determined from ASPEN Plus simulation of pilot-scale experiments using a user-written reaction kinetic module based on activity coefficients. Because citric acid esterification kinetics are slow, complete conversion could not be obtained in the pilot-scale column. Using parameters determined from simulation of a pilot-scale column experiment, design of a reactive distillation column to completely convert citric acid to triethyl citrate was carried out. Optimum column performance occurs at low reflux ratios (L/D < 0.1) to avoi...