Simulation of the Tetrahydrofuran Dehydration Process by Extractive Distillation in Aspen Plus

The aim of this work is to simulate and analyze an extractive distillation process (extractive distillation and recovery columns) for the separation of Tetrahydrofuran(THF)-Water azeotropic mixture using Aspen Plus® and Aspen Split simulators. Calculation of vapor liquid equilibrium of Tetrahydrofuran–Water– Entrainer system was done using the NRTL model, which binary interaction parameters were regressed using experimental data. A methodology for the study and selection of different candidate entrainers was followed, determining that the most suitable is glycerol. A sensitivity analysis was performed to estimate the variables to be used in the simulation, establishing that the entrainer to feed ratio and the entrainer feed stage are determinant to obtain high purity THF. The entrainer feed temperature does not assure a high concentrated distillate, but is a significant parameter on the extractive column energy consumption. Certain values for the reflux ratio produce maximum THF composition in the product, as high reflux ratios would decrease the efficiency of the entrainer. The results obtained with the simulation demonstrate that glycerol decreases heat duty and entrainer consumption, compared to 1,4-butanediol and 1,2-propanediol.