Dynamic Controllability Study of Extractive and Pressure-Swing Distillations for Tetrahydrofuran/Water Separation

Abstract

Controllability features of the extractive distillation process and the pressure-swing distillation process were studied with dynamic tools and compared in the case study of separation of a mixture of 50 mol % tetrahydrofuran and 50 mol % water. Process simulations with Aspen Plus and Aspen Plus Dynamics were carried out to obtain 99.9 mol % product purity. Control structures for the two distillation techniques were determined. Load rejection studies were completed for ±10 % feed throughput and ±10 % feed composition disturbances, for both processes. The comparison of the dynamic responses, integral absolute errors, and integral square errors shows that the pressure-swing distillation process has better controllability features than extractive distillation.