Thermodynamic Investigation of Toluene–Butanol Separation Enhanced by a Ternary Solvent System Under Elevated Pressure: A Sustainable Simulation-Based Approach

Toluene and butanol are widely used solvents in chemical, petrochemical, and pharmaceutical industries. Their separation from azeotropic mixtures is challenging due to close boiling points and complex phase behavior. This study investigates the phase equilibrium of the toluene–butanol binary system under elevated pressures (۱, ۲, ۳, ۵, and ۷ atm) using Aspen Plus simulation software with NRTL and UNIQUAC thermodynamic models. To enhance separation efficiency, a third solvent—diethyl ether—was introduced to form a ternary mixture. Simulation results revealed that increasing pressure leads to convergence of boiling points and TXY curves, reducing the effectiveness of conventional distillation. However, the addition of diethyl ether significantly altered the azeotropic behavior, increasing relative volatility and enabling improved separation. These findings support the design of environmentally responsible and technically optimized separation processes.

کلیدواژه ها:

phase equilibrium ، thermodynamic models ، Simulation ، Toluene ، Butanol