Azeotropic Separation Research Articles

Design and Optimization of Hybrid Reactive-Extractive Distillation for Ternary Azeotropic Separation: A Case Considering the Effect of Side Reactions

Design and Optimization of Hybrid Reactive-Extractive Distillation for Ternary Azeotropic Separation: A Case Considering the Effect of Side Reactions

A FTIR and DFT Combination Study to Reveal the Mechanism of Eliminating the Azeotropy in Ethyl Propionate-n-Propanol System with Ionic Liquid Entrainer.

Ionic liquids (ILs) have presented excellent behaviors in the separation of azeotropes in extractive distillation. However, the intrinsic molecular nature of ILs in the separation of azeotropic systems is not clear. In this paper, Fourier-transform infrared spectroscopy (FTIR) and theoretical calculations were applied to screen the microstructures of ethyl propionate-n-propanol-1-ethyl-3-methylimidzolium acetate ([EMIM][OAC]) systems before and after azeotropy breaking. A detailed vibrational analysis was carried out on the v(C=O) region of ethyl propionate and v(O-D) region of n-propanol-d1. Different species, including multiple sizes of propanol and ethyl propionate self-aggregators, ethyl propionate-n-propanol interaction complexes, and different IL-n-propanol interaction complexes, were identified using excess spectroscopy and confirmed with theoretical calculations. Their changes in relative amounts were also observed. The hydrogen bond between n-propanol and ethyl propionate/[EMIM][OAC] was detected, and the interaction properties were also revealed. Overall, the intrinsic molecular nature of the azeotropy breaking was clear. First, the interactions between [EMIM][OAC] and n-propanol were stronger than those between [EMIM][OAC] and ethyl propionate, which influenced the relative volatilities of the two components in the system. Second, the interactions between n-propanol and [EMIM][OAC] were stronger than those between n-propanol and ethyl propionate. Hence, adding [EMIM][OAC] could break apart the ethyl propionate-n-propanol complex (causing the azeotropy in the studied system). When x([EMIM][OAC]) was lower than 0.04, the azeotropy still existed mainly because the low IL could not destroy the whole ethyl propionate-n-propanol interaction complex. At x(IL) > 0.04, the whole ethyl propionate-n-propanol complex was destroyed, and the azeotropy disappeared.

Analyzing the sustainability of intensified side‐stream extractive distillation for binary azeotropic separation: a comparative study

AbstractBACKGROUNDThe sustainability performance of extractive distillation (ED) that collectively considers energy efficiency, process safety, economic profitability, process control, and environmental emission has not been widely reported. Motivated by this lack of research, we analyzed and compared the sustainability performance of the intensified side‐stream ED (SSED) with that of the conventional extractive distillation (CED) for the separation of binary azeotropic mixtures. Two different design approaches were analyzed; the first approach involves designing the intensified SSED by preserving the original CED column configuration, while the second approach involves optimizing the original column configuration to become a new intensified SSED configuration.RESULTSWe found that preserving the original configuration usually provides energy‐savings, but this advantage is not guaranteed unless the process is optimized. Generally, the reduction in energy consumption improves economic and environmental performance. However, the optimized design has a higher risk index because it is usually larger in size, for the sake of lowering the energy consumption. In addition, the optimized design usually has a higher condition number, which signifies that a more complex control structure is required.CONCLUSIONAltogether, designing the intensified process via process optimization does not always guarantee significant improvement in all sustainability indicators. © 2023 Society of Chemical Industry (SCI).

Experimental study on separation of isopropanol-water azeotrope by packed capillary distillation and the prediction model of artificial neural network

ABSTRACT Capillary distillation is an azeotropic distillation technology, which combines the mechanism of surface adsorption, capillary action, as well as the distillation process. Different variations of activity coefficient and saturated vapor pressure of azeotropic components occur in the capillary pore structure, which leads to the separation. In this paper, 5A, 4A, and 3A molecular sieve capillary porous media were selected as capillary packing to study the separation effect on azeotropic mixture of isopropanol-water solution experimentally. It was found that 4A molecular sieve worked better, the best reflux ratio is 6, and the best packing height is 0.4 m. Based on the abovementioned experimental results, a back propagation (BP) neural network is developed and utilized in the separation process. The effects of parameters such as the composition of feedstock solution, reflux ratio, and packing height on the concentration of isopropyl alcohol at the top of packed capillary distillation column were predicted, and the accuracy reached 96.7%. The proposed prediction method is helpful for developing the technology of separating azeotropic solution by capillary distillation with packing suitable for industrial application.

Energy-saving strategy for separation of methylcyclohexane/tert-butanol azeotrope

With the increase in industrialization, researchers are striving to pursue energy-saving and environment-friendly separation technologies. In this regard, effective separation of azeotropes is one of the focus areas in recent years. According to the characteristics of methylcyclohexane (MCH) and tert-butanol (TBA) azeotropes, a pressure-swing distillation (PSD) process is established in the current work. Combined with steam recompression and heat integration, two improved separation processes for reduced energy consumption are designed. The operating parameters had a significant effect on the efficiency and cost of the process. Therefore, the selection of parameters was discussed in detail. The proposed PSD processes were evaluated according to the assessment indices including total energy consumption (TEC), CO2 emissions and total annual cost (TAC). The results showed that the improved processes obviously decreased the energy consumption and improved the economy whether it is heat pump pressure swing distillation (HP-PSD) or heat integrated pressure swing distillation (HI-PSD). The HI-PSD process can achieve a TAC savings of 30.86%, TEC reduction of 37.59% and CO2 reduction of 36.34%. The HP-PSD process is found to be the most economical and environment-friendly process among the studied processes, and could achieve 34.92% TAC savings, 42.89% TEC reduction and 50.98% CO2 reduction.

Control of new energy‐intensified triple column extractive distillation using feed split technique

AbstractBACKGROUNDHere, we investigated the control performance of extractive distillation intensified with ‘feed split’ (FS) technique – a process intensification technique that has not been widely applied to extractive distillation. Today, only a handful of studies have been reported on this topic, with only one focusing on the control performance and reporting the significant trade‐off between the steady‐state and dynamic performances. Nonetheless, the previous control study was based on the complex double column FS configuration. Recently, a new triple column FS configuration was reported (Sep. Purif. Technol. 2022 (297) 121467), but its control performance was not investigated. Hypothetically, the triple column FS configuration is less complex and does not involve any column integration and thus, may demonstrate a better dynamic performance. This study analyzed the control performances of the triple column FS configuration and the conventional configuration for the binary azeotropic separation of tetrahydrofuran and ethanol.RESULTSTwo types of control structures were examined for both configurations, i.e., the basic temperature control structure and the different feed forward temperature control schemes. The best control structure from each configuration is compared and findings showed that the conventional configuration provides better controllability performance.CONCLUSIONOur results suggested that the conventional configuration can bring the product qualities closer to their setpoint, while providing a lower transient deviation. © 2023 Society of Chemical Industry (SCI).

Insight on the sustainable design and multi-objective optimization for separating the ternary azeotropic mixture of toluene/n-butanol/water by natural decanting coupled with pressure swing distillation

The effective recovery of n-butanol (BuOH) and toluene from wastewater via sustainable separation process is critical to promote environmental protection and resource utilization. In this work, we propose a comprehensive methodology to develop a natural decanting coupled with pressure-swing distillation (NDPSD) for the azeotropic separation of BuOH/toluene/water system. Firstly, the thermodynamic topologic insights are employed to analyze the feasibility of the NDPSD. Secondly, conceptual design involving the understanding of mass balance lines, the liquid–liquid envelope, and distillation boundaries were applied to develop initial design of the NDPSD with two different separation sequences (i.e., configurations). Then, both initial designs are optimized to obtain the optimum column configurations via an improved non-sorting genetic algorithm, with the total capital and operating cost as dual objective function. Finally, both optimized schemes are heat-integrated for the purpose of energy conservation. The performance of all the developed configurations were examined using three indicators, i.e., economic, environmental, and energy efficiency, and our results revealed that the heat-integrated configuration B with separation sequence of water → BuOH → toluene provides the best economic, environmental, and thermodynamic efficiency.

Unveiling the thermodynamic and molecular mechanisms for the separation of diethoxymethane and ethanol azeotrope by deep eutectic solvents

The selection of efficient and environmental extractants is essential for the sustainable development of extraction processes. Based on the conductor-like screening model for the segment activity coefficient (COSMO-SAC), three deep eutectic solvents (DESs) were screened from 1000 DESs for the separation of diethoxymethane (DEM) and ethanol (EA). Subsequently, the liquid–liquid equilibrium behavior of the DEM + EA + DES system at different temperatures was measured. The results show that benzyltrimethylammonium chloride/glycerol (BTACl/GLY) has the highest selectivity and benzyltrimethylammonium chloride/ethylene glycol (BTACl/EG) and tetraethylammonium chloride/ethylene glycol (TEACl/EG) have similar extraction performance. More importantly, the extraction performance of DESs reported in this work is stronger than that of the solvents already reported. Additionally, analysis of the separation mechanism by various quantum chemical methods revealed that the purification of DEM and EA mixtures is mainly ascribed to the difference in electrostatic forces between the solvent and DEM/EA. The result confirmed that solvents with small molecular structures and strong nucleophilic sites are more competitive in separating the mixtures.

Azeotrope separation of ethyl propionate and ethanol by extractive distillation and pressure swing distillation method

Ethyl Propionate is produced by esterficating propanoic acid and ethanol in the presence of a catalyst (sulphuric acid). However, in ethyl propionate production, ethanol and ethyl propionate forms azeotrope, resulting in its poor purity. In this regard, Aspen Plus simulation software has been used to analyze the separation by performing property analysis and phase behavior of each component and then simulated azeotrope separation by using two methods: extractive distillation method-(EDM) and pressure swing distillation method-(PSDM). For extractive distillation method-(EDM) two novel heavy entrainers (glycerol and ethylene glycol) have been used. Property analysis for both materials was favorable, however, glycerol showed more promising results than ethylene glycol. In EDM-simulation process, the separation capability of glycerol was higher than ethylene glycol for ethyl propionate with the purities of 99.90 and 99.71 mol% respectively, which were extracted from 1st radfrac extractive distillation column-(RF-EDC-1). Whereas, the resultant purities for ethanol/glycerol and ethanol/ethylene glycol in 2nd radfrac extractive distillation column-(RF-EDC-2) were 99.83/99.99 and 99.47/99.99 mol%, respectively. However, reboilers total heat duty in (RF-EDC-1 + RF-EDC-2) for glycerol and ethylene glycol were 6818.38 kW and 5351.66 kW respectively. In PSDM, the property analysis was performed by the variation of pressure and were favorable for this process. The resultant purities of ethyl propionate and ethanol in their respective 1st radfrac distillation column-(RF-DC-1) and 2nd radfrac distillation column-(RF-DC-2) were 99.99 % and 99.00 % respectively. The reboilers total heat duty (RF-DC-1 + RF-DC-2) was 3839.638 kW. The economic analysis in terms of total annual cost (TAC) for EDM (glycerol and ethylene glycol) and PSDM was done, where, EDM(glycerol) was 27.01 and 33.47 percent more efficient among other two methods.

Inherent flexibility design strategy of extractive distillation for binary azeotropic separation

The steady-state design and control studies of extractive distillation (ED) for azeotropic separation has received significant interest in the recent years. These studies however are usually conducted sequentially where the steady-state design is first developed followed by conducting the control analysis. In contrast to existing studies, this work incorporated the operational flexibility into the steady-state design of the ED so that any external fluctuations can be accounted in the early stage of the design. Two case studies are used to exemplify the inherent flexibility design strategy, i.e., the IPA dehydration using dimethyl sulfoxide (DMSO) and ethylene glycol (EG) as entrainer. Each case study is optimized using two different objective function individually, i.e., the total annual cost (TAC) and the flexibility index (FI). Optimizing both cases using TAC as objective function provides a lower TAC relative to the base case, which aligned with existing studies. In contrast, optimizing both cases using FI enables a greater operational flexibility, but such benefit is always accompanied by the increase in the TAC. During the FI optimization, four different uncertainties are considered, i.e., A, B, C, and D, with a combination of ± 20% feed flowrate and IPA feed concentration. For both cases, the operational flexibility limitation was found to lie in the direction of vertex D when the system is experiencing an increase in feed flowrate and a decrease in IPA feed composition. Overall, it was found that using EG provides 2.3 times better operational flexibility in comparison to that using DMSO, as indicated by the higher FI, while using DMSO provides a lower TAC by about 9%. Here, it was also found that using EG provides a lower trade-off in an increase in TAC over using DMSO, when the FI is incorporated into the steady-state design of the ED.

Structure-activity relationship and experimental study of organic solvents and deep eutectic solvents in separation of cyclohexane-ethyl acetate

Selecting the appropriate extractant is of great significance for solving the problems of high energy consumption and difficult separation in the extractive distillation process. In this study, four deep eutectic solvents (DESs) were designed by combining menthol hydrogen bond acceptors with lauric acid and capric acid hydrogen bond donors and tetrabutylammonium bromide hydrogen bond acceptors with levulinic acid and ethylene glycol hydrogen bond donors. The interaction mechanism and structure–activity relationship between azeotropic system, hydrogen bond donor, hydrogen bond acceptor and deep eutectic solvent were studied. σ-profile, interaction energy, reduced density gradient, electrostatic potential, and natural bond orbital were used to study the microscopic mechanism and structure–activity relationship of azeotropes separated by DESs. On this basis, the vapor–liquid equilibrium experiments of separating ethyl acetate-cyclohexane azeotrope by DESs were carried out. The results showed that separating ethyl acetate-cyclohexane by using DESs is feasible and that the DES synthesized by using levulinic acid and tetrabutylammonium bromide is preferable for separation. Studying the relationship between DES structures and the azeotrope provides a theoretical basis for the screening and design of DES extractants for the separation of alkane-ester azeotropes using extractive distillation.

Control of heat-integrated indirect triple-column extractive distillation for separating ternary azeotropic mixture tetrahydrofuran-ethyl acetate-water

Most of the design and control studies for extractive distillation of the ternary azeotropic separation today focus only on the direct sequence extractive distillation (DED) while the design study for indirect sequence extractive distillation (IED) is rarely reported. Furthermore, there is no control study that worked on the IED. To bridge this gap, we analyze the control performance of the heat-integrated (HI) IED, exemplified using the separation of tetrahydrofuran (THF)/ethyl acetate (EtAc)/water as a case study. A single point temperature control (TC) (CS 1), dual TC (CS 2), and feed forward dual TC (CS 3) are developed in this work and their performances in rejecting feed flow and composition disturbances are tested. Overall, CS 3 exhibits the best control performance in returning all the three products purities to a value close to the products specification and provides the lowest transient deviation under feed flow and composition disturbances. The CS 3 also provides the lowest sum of integral absolute error with respect to CS 1 and CS 2, further reflecting its dynamic superiority.

Phase Equilibria and Mechanism Insights into the Separation of Isopropyl Acetate and Methanol by Deep Eutectic Solvents

Separation of methanol–isopropyl acetate (IPAC) obtained via isopropanol synthesis is essential. Deep eutectic solvents (DESs) have garnered extensive attention in the field of azeotropic separation owing to their advantages such as biodegradability, ecofriendliness, and cost-effectiveness. In this work, three choline-based DESs were prepared. Then, the experimental data of the synthesized DESs with methanol and IPAC were measured, which were linearly correlated with Hand and Othmer–Tobias equations. The GM/RT surface obtained using GUI-MATLAB software was used to determine the reliability of the fitting data based on the NRTL model. Choline chloride and ethylene glycol DES with a molar ratio of 1:2 exhibited the best methanol affinity. The effect of the solvent structure was studied using a combination of experimental and quantum chemistry and molecular dynamics (MD) calculations. Through electrostatic potential distribution, atoms-in-molecules, and independent gradient model analytical methods, the three DEEs were primarily extracted via a hydrogen bond interaction and van der Waals interaction, wherein the former played a dominant role in separation. MD simulation was used to reveal the effect of the structures of hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs) on the extraction process at the molecular level. The analysis results indicated that HBA was the main influencing factor in the separation, and the electrostatic interaction of Cl– and methanol was dominant in the separation. Additionally, HBDs were the secondary factor during the separation process. In this work, the reasons for the differences in the separation performances of different DESs were analyzed from a microscopic perspective, offering theoretical support for selecting suitable DESs for separating alcohol-containing azeotropic systems.

Economic, environmental, energy and exergy analysis and multi-objective optimization for efficient purification of a friendly gasoline additive by extractive distillation coupled with pervaporation

Ethyl tert-butyl ether, an environmentally friendly gasoline additive, has high industrial application value, which is very necessary to study the refined process. The development of an efficient ternary azeotropic separation and purification process promotes the establishment of an environment-friendly society. In this study, two common methods of extractive distillation and extractive pressure swing distillation and three enhanced methods of heat integration process and coupled pervaporation technology were used to efficiently separate ethyl tert-butyl ether/ethanol/water. The most effective and environmentally friendly extractants were screened by analyzing the effects of relative volatility, intermolecular interactions and biotoxicity. The multi-objective optimization method was adopted to optimize the process with the annual total cost and gas emissions as the goals and the optimal parameters and process plans for extractive distillation and extractive pressure swing distillation were obtained. Finally, five technological processes are analyzed from the aspects of economy, environment, energy and exergy. It was found that the use of pressure swing distillation would greatly increase the economic and energy loss. And compared with the conventional process, the total annual cost of the extractive distillation coupled pervaporation process was reduced by 15.12 % and the environment was reduced by 20.17%. The coupling process that is of great significance to the purification of ethyl tert-butyl ether, an environmentally friendly gasoline additive was superior to the single distillation process in terms of economy, environment and energy.

Application of dividing wall column in azeotropic distillation with intermediate boiling-point heteroazeotrope: Simulation and optimization

Dividing wall column (DWC), as a proven process intensification technology, has been used widely in separation of ideal multi-components, and some azeotrope systems. For heterogeneous azeotrope with the potential possibility of crossing distillation boundary by liquid-liquid splitting, it is advantageous to integrate liquid-liquid decanter with distillation column, especially with DWC to further simplify flowsheets and reduce energy consumption. In this work, existing heterogeneous azeotrope separation processes are described, and an innovative DWC-based process (MHADWC) is proposed for intermediate boiling-point heteroazeotropic systems. Then an industrial case of MIPK system, is used to evaluate mentioned configurations by rigorous simulation and optimization. These configurations are compared and analyzed in detail on energy consumption, exergy analysis and equipment invest. The results show that, from the perspective of process energy consumption, MHADWC process has the most advantages, because it saves 37% of energy consumption; if both equipment costs and exergy recovery are taken into account, HADWC2 has a higher thermodynamic efficiency (43.5%) at its TAC and can be used as a preferred target. And in this work, purification of an intermediate boiling-point heteroazeotrope is the main difference of these processes compared with the well-known heterogeneous azeotropic distillation process where the top vapor product is the lowest boiling point of the ternary system.

Optimization and control of extractive distillation for formic acid-water separation with maximum-boiling azeotrope

It is urgent to develop sustainable chemical process through process intensification, especially for the energy-intensive distillation process. Formic acid-water forms maximum azeotrope which is purified by pressure-swing distillation in Kemira–Leonard (K-L) process and extraction plus distillation in BASF route. However, either process for this maximum azeotrope separation is energy-intensive. In the present work, by selecting the effective heavy entrainer, extractive distillation and extractive dividing wall column was firstly synthesized and optimized with genetic algorithm for formic acid-water separation. Based on optimal design, the energy consumption and CO2 emission among these proposed and existent processes were compared, and extractive distillation shows its strength for achieving high efficiency and sustainability. Then multi-loop PI control scheme and linear model predictive control based on temperature and temperature difference were developed, respectively. Dynamic response validates the control performance superiority of advanced controllers, especially for controlled variables with large overshoot, oscillations and settling time.

Optimal design of the ternary azeotrope separation process assisted by reactive-extractive distillation for ethyl acetate/isopropanol/water

There are numerous issues with the separation process for ternary systems containing multi-azeotropes. Specially, for the aqueous azeotrope as ethyl acetate-isopropanol-water, the presence of water results in a ternary azeotrope, three binary azeotropes and a heterogeneous region. Reactive distillation is introduced to break the azeotropes and simplify complexity by consuming water through ethylene oxide hydration reaction. The triple-column extractive distillation process (TED) and two enhanced processes combined with reactive distillation (i.e., double-column reactive-extractive distillation process (DRED) and reactive-extractive dividing-wall column process (REDWC)) are designed for the separation in this work. A simultaneous optimization strategy is proposed to optimize the parameters through the Particle Swarm Optimization algorithm taking the total annual cost (TAC) as the optimization objective. Then, the CO2 emissions and thermodynamic efficiency are calculated to assess these three processes. Exergy analysis and entropy production are applied to quantify each component to the total irreversibility. Results show that reactive-extractive distillation effectively realize lower TACs with better environmental performance. The TACs of DRED and REDWC processes are reduced by 39.04% and 46.01% compared with TED process, respectively. The thermodynamic efficiency of DRED and REDWC processes increased from 5.40% to 42.88% and 43.64%, respectively.

Flowsheet generation through hierarchical reinforcement learning and graph neural networks

AbstractProcess synthesis experiences a disruptive transformation accelerated by artificial intelligence. We propose a reinforcement learning algorithm for chemical process design based on a state‐of‐the‐art actor‐critic logic. Our proposed algorithm represents chemical processes as graphs and uses graph convolutional neural networks to learn from process graphs. In particular, the graph neural networks are implemented within the agent architecture to process the states and make decisions. We implement a hierarchical and hybrid decision‐making process to generate flowsheets, where unit operations are placed iteratively as discrete decisions and corresponding design variables are selected as continuous decisions. We demonstrate the potential of our method to design economically viable flowsheets in an illustrative case study comprising equilibrium reactions, azeotropic separation, and recycles. The results show quick learning in discrete, continuous, and hybrid action spaces. The method is predestined to include large action‐state spaces and an interface to process simulators in future research.

Mechanistic insight into separation of benzene and cyclohexane by extractive distillation using deep eutectic solvent as entrainer

In this work, a technical scheme for separation of benzene and cyclohexane by extractive distillation using deep eutectic solvent (DESs) as entrainer was proposed. Acetic acid (AA) was selected as hydrogen bond donor (HBD), tetraethylammonium bromide (TEAB) and tetraethylammonium chloride (TEAC) were selected as hydrogen bond acceptors (HBA), and two kinds of DESs were successfully prepared (i.e., DES1 is TEAC : AA = 1:3, DES2 is TEAB : AA = 1:3). Vapor liquid equilibrium experiments show that the relative volatility of benzene cyclohexane system can be significantly improved by using DESs as an entrainer, so that the separation of the target system can be achieved by extractive distillation. Further, quantitative calculations and molecular dynamics simulations were performed to explore the separation mechanism at the molecular level. The interaction sites between molecules were revealed by ESP analysis, and the interaction types between molecules were further elaborated by IGMH analysis. The results show that the Br atom of TEAB and the Cl atom of TEAC have hydrogen bonding with benzene, while there is π - π interaction between AA and benzene. The intermolecular interaction energy and spatial distribution function (SDF) further proved that the interaction between DES and benzene was stronger than that with cyclohexane. In conclusion, DES as entrainer for azeotrope separation has broad industrial application prospects.

Phase behavior and extraction mechanism of ethanol in alcohol ester mixture separated by deep eutectic solvents

The production of diclofenac salt involves an azeotropic system consisting of ethanol and isopropyl acetate (IPAc). Owing to their simple preparation, low cost, and non-volatility, deep eutectic solvents (DESs) have attracted considerable attention in the field of azeotrope separation. The σ profiles were constructed using a conductor-like shielding model, and the hydrogen-bonding ability between several common hydrogen-bond acceptors (HBAs) and hetero-azeotropic systems was analyzed. To prepare the three types of DESs, choline chloride (ChCl) was selected as the HBA, while ethylene glycol, urea, and glycerol were selected as the hydrogen-bond donors (HBDs). The liquid–liquid equilibrium (LLE) experimental data of the IPAc, ethanol, and synthetic DES systems were then measured at 101.3 kPa and 298.15 K. The accuracy of the experimental data was verified by correlating the data with the Othmer–Tobias and Hand equations, and the NRTL model was used to fit the experimental results. According to the distribution (D) and selectivity (S) coefficients, ethanol had the highest affinity for the ChCl–ethylene glycol DES, and the experimental data and the molecular dynamics (MD) simulations data were well correlated. The interaction energy, spatial distribution functions (SDFs), radial distribution functions (RDFs), and self-diffusion coefficients were calculated using MD simulations to elucidate the extraction mechanism. The MD simulation results showed that the interaction between the HBA in the DESs and ethanol was dominant in the separation, whereas the interaction of the HBD in the DESs with ethanol played an auxiliary role. Based on the experimental and simulation results, the feasibility and effectiveness of the azeotropic system for the DES separation of ethanol and IPAc were verified, which is important for the sustainable utilization of resources.