Energy-efficient heat pump-assisted pre-concentration integrated with sequential [EMIM][BF4] and ethylene glycol-based extractive distillation for enhanced recovery of ethanol and isopropyl alcohol from wastewater

被引：0

作者：

Guo, Chao ^{[1
]}

Zheng, Yong ^{[1
]}

Wang, Shuai ^{[1
]}

He, Ge ^{[2
]}

Gui, Chengmin ^{[3
]}

机构：

[1] College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu,610059, China

[2] College of Chemical Engineering, Sichuan University, Chengdu,610065, China

[3] School of Chemistry & Chemical Engineering, Anhui University, Hefei,230601, China

来源：

Separation and Purification Technology | 2025年 / 357卷

关键词：

Ionic liquids;

D O I：

10.1016/j.seppur.2024.130073

中图分类号：

学科分类号：

摘要：

Recovering ethanol and isopropyl alcohol (IPA) from wastewater offers significant economic and environmental advantages. In this work, 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) and ethylene glycol (EG) are proposed as double entrainers for separating IPA/ethanol/water mixtures. The novel process sequentially uses [EMIM][BF4] to separate ethanol/water and IPA/water azeotropes, followed by EG for near-boiling mixture of ethanol/IPA. Energy-economic comparisons of extractive distillation process using single and double entrainers are performed. To address the issue of high water content in mixtures, the heat pump-assisted pre-concentration (HPP) integrated with extractive distillation processes are proposed. Subsequently, the effect of water content in the mixtures on process performances are analyzed. The results indicate that compared to using a single entrainer [EMIM][BF4] or EG process, the double entrainers process reduces energy cost and total annual cost (TAC) by 19.9% to 45.3% and 18.6% to 52.7%, respectively. The HPP scheme effectively reduces the mole fraction of water from 60% to 26.05%, further decreasing energy costs by 4.2% to 22.2%. The energy cost and TAC of the double entrainers process decreases by 4.8% to 50%, and 2.8% to 52.1% compared with the single entrainer process under HPP schemes. The double entrainers [EMIM][BF4]-EG process shows promising prospects from energy and economic perspectives. © 2024 Elsevier B.V.

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