Sustainable Process Design and Multiobjective Optimization for Separation of n-Heptane/tert-Butyl Acetate by Extractive Distillation: from Separation Mechanism to Experimental

• DOI: 10.1021/acs.iecr.4c04569
• Publication Date: 2025-03-14T09:37:18Z
• Authors: Ruimin Zhang; Zhixia Xu; Jinlong Li; Jing Pan; Hui Wang; Tan Dai; Qing Ye
• Keywords: Extractive distillation; Heptane; Separation process; Separation (statistics)

Since tert-butyl acetate and n-heptane can form binary azeotropes, in this study, two special distillation methods of extractive (ED) improved side-stream were used to separate n-heptane. First, considering the properties molecular bond energy, relative volatility, azeotrope formation, n-methylpyrrolidone (NMP) was selected as most suitable solvent. Subsequently, missing interaction parameters for N-HEP-01/T-BUT-TE NMP/T-BUT-TE obtained by a vapor–liquid equilibrium experiment. Furthermore, multiobjective optimization performed minimize total annual cost (TAC), entropy generation, CO2 emissions. The results indicate that energy consumption process reduced 1.3% compared with ED process, but TAC increased 8.53%. To further enhance savings, heat integration technology introduced save more energy. Compared conventional ED, integration-assisted (EDH2) reduces 28.84%, generation 33.17%, emissions 42.28%.