Indexed by:期刊论文

Date of Publication:2021-03-05

Journal:COMPUTERS & CHEMICAL ENGINEERING

Volume:143

ISSN No.:0098-1354

Key Words:Side-stream extractive distillation; Separation sequences; Intermediate boiling entrainer; Eco-efficiency analysis; Methanol-toluene

Abstract:The side-stream extractive distillation (SSED) system is attracting widespread attention due to its high eco-efficiency. In the article, three double-column SSED (DC-SSED) sequences and two single-column SSED (SC-SSED) sequences with different side-stream extraction locations are proposed for separating the methanol-toluene azeotrope with intermediate boiling entrainer triethylamine, which are compared with two conventional extractive distillation (CED) processes including direct and indirect CED sequences. The genetic algorithm is employed to optimize seven extractive distillation sequences to minimize the total annual costs (TAC). CO2 emissions and thermodynamic efficiency of the optimized processes are quantified as well as TAC to calculate the Eco-efficiency Comparison (ECI) Index for eco-efficiency analysis. The results illustrate that two DC-SSED sequences demonstrate the eco-efficiency superiority compared to the optimal CED process (direct CED), and their side-streams are located in the rectifying section and extractive section of the side extractive distillation column, while their ECI indexes reach 97.38% and 97.60%. (C) 2020 Elsevier Ltd. All rights reserved.