Synthesis of n-propyl propionate in a pilot-plant reactive distillation column: Experimental study and simulation

The catalytic esterification of n-propyl propionate using propionic acid and n-propyl alcohol as reactants via a conventional pilot plant reactive distillation column was carried-out. The strongly acidic ion-exchange resin Amberlyst46™ was used as the solid acid catalyst. The influence of the reflux ratio (from 2.0 to 2.5), the molar feed ratio (from 2.0 to 2.5), and total feed (from 3.0 to 4.0 kg/h) on the purity and conversion of the species and on the composition and temperature profiles along the column was analyzed. A 23 experimental design with six actual and two simulated experiments was carried-out. With the experimental conditions obtained from the simulation results, the experiments showed that a reflux ratio of 2.0, a molar feed ratio of 2.0 and a total feed of 4 kg/h, yielded the largest propyl propionate production (1.60 kg/h). The simulated experiments were carried out using a non-equilibrium model implemented into the simulation environment Aspen Custom Modeler™.

► A set of eight experiments, for the synthesis of propyl propionate in a pilot plant reactive distillation column was performed.
► The operating conditions of the RDC for two experiments were obtained through simulation using a non-equilibrium model (NEQ).
► The results shown that the NEQ model was capable of predicting the experimental data with minor deviations.
► Experimental and simulated results showed that a RR = 2, TF = 4 kg/h and FR = 2, the ProPro production rate was highest.
► The results shown that FR and D/F ratio have high impact in the conversion of POH, but not of ProAc.