Separation of tetrahydrofuran and water using pressure swing distillation: Modeling and optimization

Abstract

Computer simulations were performed to obtain highly pure tetrahydrofuran (THF) with over 99.9 mole% from the mixture of THF and water. Pressure swing distillation (PSD) was used since the azeotropic point between tetrahydrofuran and water can be varied with pressure. A commercial process simulator, PRO/II with PROVISION release 8.3, was used for the simulation studies. The Wilson liquid activity coefficient model was used to simulate the low pressure column, and the Peng-Robinson equation of state model was added to correct the vapor phase non-idealities for the modeling of the high pressure column. The most optimal reflux ratios and the most optimal feed stage locations that could minimize the total reboiler heat duties were determined.

Energy-Saving Reduced-Pressure Extractive Distillation with Heat Integration for Separating the Biazeotropic Ternary Mixture Tetrahydrofuran–Methanol–Water

“…Finding the Optimal Pressure. Since the two binary azeotropes (THF−water, THF−methanol) of the THF− methanol−water mixture are pressure-sensitive, 49,29,50 the effect of operating pressure (P 1 , P 2 , and P 3 ) on the total ED process should be studied. In this section, N 1 = 57, N 2 = 41, and N 3 = 16 are kept the same as that in case 2 for comparison.…”

Application of the cubic-plus-association (CPA) equation of state to model the fluid phase behaviour of binary mixtures of water and tetrahydrofuran

“…Lee et al [37] combined the Wilson equation with the assumption of ideal gas behaviour at pressures at or below 1 atm and the PR equation at pressures above 1 atm, in order to model VLE behaviour of the THF/water system. Two binary parameters were correlated in the Wilson model to get accurate VLE description at a pressure of 1 atm.…”

Design and control of pressure‐swing distillation for separating ternary systems with three binary minimum azeotropes

“…There are three most common and important nonconventional distillations including pressure‐swing, azeotropic, and extractive distillations that have been well developed for the separation of ternary nonideal mixtures in continuous modes. These distillations involve either changing operating pressures (i.e., pressure‐swing distillation) or at another location instead (i.e., extractive distillation) or adding an entrainer together with the feed (i.e., azeotropic distillation) . Although extractive distillations and azeotropic distillations can change the relative volatility of azeotropic mixtures by introducing an entrainer, some important characteristics of the entrainer such as solubility, toxicity, and stability require to be carefully investigated.…”