Modelling, Simulation and Optimization of Fatty Acid Methyl Ester Reactive Distillation Process Using Aspen HYSYS

In this work, the modelling, simulation and optimization of a reactive distillation process used for the production of fatty acid methyl ester (FAME) has been carried out. The FAME considered was methyl palmitate, which was produced from an esterification reaction between palmitic acid and methanol. The reactive distillation column used for the process was set up in Aspen HYSYS environment using Distillation Column Sub-Flowsheet and the fluid package employed was Wilson model. The column had 17 stages, excluding the condenser and the reboiler, and it was divided into seven sections, viz, condenser section, rectifying section, upper feed section, reaction section, lower feed section, stripping section and reboiler section. Palmitic acid (fatty acid) entered the column through the upper feed section while methanol (alcohol) was fed at the lower feed section of the column. The developed model was simulated to convergence using Sparse Continuation Solver. Furthermore, the optimizer tool of Aspen HYSYS was used to obtain the optimum operating conditions of the process using three different algorithms (Box, Mixed and Sequential Quadratic Programming). The good convergence obtained from the simulation carried out on the developed Aspen HYSYS model of the reactive distillation process showed that Aspen HYSYS has been able to handle this process successfully. Furthermore, the achievement of the value of the objective function given by the optimization of the process when the estimated optimum values of reflux ratio, feed ratio and reboiler duty were used to run the model revealed that the optimum values obtained from Aspen HYSYS were theoretically valid. Therefore, it has been shown that the developed Aspen HYSYS model of this research work can be used to represent, simulate and optimize a FAME reactive distillation process successfully.