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Objectives. To study the possibility of hydroxyacetone–phenol binary mixture (a constituent of a mixture of phenol production by the cumene method) separation in flowsheets based on the use of distillation special methods. This is the addition of separating agents to increase the relative volatility of the components of the original mixture, and the variation of pressure in the columns.Methods. A computational simulation in Aspen Plus® was used as the research method. Mathematical modeling of the vapor–liquid equilibrium was carried out using a local compositions model Non-Random Two Liquid. The viability of the latter was confirmed by comparing experimental and calculated on phase equilibrium data, and azeotropic data. The average relative error does not exceed 3%.Results. The dependence of the composition and boiling point of the hydroxyacetone–phenol azeotrope on pressure was determined in a computational experiment (as the pressure increases, the azeotrope is enriched with phenol). The possibility of using a complex of columns operating under different pressures to separate the mixture was shown (the shift of the azeotrope is about 9%). The change in the relative volatility of components of the original mixture in the presence of a high(diethylene glycol) and a low-boiling (acetone) separating agent was investigated. Both solvents are selective agents used in extractive and re-extractive distillation processes. Three technological separation flowsheets containing two distillation columns were proposed.Conclusions. The study established the operation parameters of the columns (number of theoretical stages, feed stages of the original mixture and separating agent, and reflux ratio) and energy consumption (total heat supplied to the columns boiler) of three separation flowsheets ensuring the production of products of a given quality (not less than 0.99 mol fractions). The flowsheet with diethylene glycol is characterized by the lowest energy consumption. It is recommended that complexes of extractive and re-extractive distillation be further optimized. This enables the second product of cumulus production—acetone—to be involved in the technological cycle.

The extractive distillation process using propylene glycol (IUPAC name: 1,2 propanediol) as an extractive agent for the separation of the isopropanol–water system was investigated in this work. A systematic procedure was set out to obtain the optimal design and process conditions for extractive distillation and solvent recovery columns using the PRO/II process simulator. Four thermally integrated flowsheets were proposed, implying the recovery of the sensible heat and latent heat from the hot streams in the process. To establish the economic feasibility of the proposed process, we calculated the total annual cost for all the simulated versions, and the proposed fully thermally integrated flowsheets could save up to 43.13% in terms of the utility costs and up to 15.57% in terms of the TAC compared to the conventional design. Thus, propylene glycol (PG) is found to be suitable as a new solvent for isopropanol dehydration, being comparable with other classical solvents used for the dehydration of alcohols.

The near-azeotrope mixture of TFE and CO2 is an important concern urging the scientific community to develop new ways for TFE/CO2 separations. In this work, for the first time, Diisopropylamine (DIPA) and Diethanolamine (DEA) are used as solvents for separating a near-azeotropic mixture of CO2 and tetrafluoroethylene (TFE). The complete separation mechanism has been analyzed using ASPEN Plus process simulator. The binary parameters for CO2, TFE, DIPA and DEA have been taken from Cosmotherm software and the pure data parameters have been taken from the literature (NIST). The validation of the processes has been completed by comparing binary parameters with literature and pure parameters with the UNIFAC data. The separation of the near-azeotropic mixture of TFE and CO2 has been investigated where, both solvents can be proposed as good candidates, however DEA is proven better performer than DIPA. In addition, CO2 emissions analysis and Total Annual Cost (TAC) analysis has been performed for the payback period of 3, 5 and 7 years, where DEA proves to be most efficient for TAC while DIPA has less CO2 emissions. [ABSTRACT FROM AUTHOR]

Green solvent design is usually a multi-objective optimization problem that requires identification of a set of solvent molecules to balance multiple, often trade-off, properties. At the same time, process constraints need to be addressed since solvent properties impact the process feasibility like in the extractive distillation separation process. Hence, a green solvent multi-objective optimization framework is proposed with EH&S properties, process constraints, and energy consumption analysis, where the molecular design optimization model relies upon the ability of the proposed infinite dilution activity coefficient (IDAC) direct prediction model to accurately predict process properties in addition to molecular properties. The process properties are short-cut properties of the extractive distillation process, namely selectivity and solution capacity. To this end, the proposed IDAC direct prediction model is employed to prepare molecule pairs with selectivity and solution capacity improvement constraints to train the molecular multi-objective optimization model, which can learn the optimization path from the pre-set molecule pairs and then optimize a given solvent via the prediction of a disconnection site and molecular fragment addition or removal at that site. An extractive distillation process to separate a cyclohexane/benzene mixture is taken as an example to demonstrate the proposed framework. As a result, three candidate green solvents are optimized and designed to recover benzene from mixtures of benzene and cyclohexane. The proposed green solvent multi-objective optimization framework is flexible enough to be employed in other chemical separation processes, where solvent property assessment is needed to evaluate the feasibility and performance of the processes. [ABSTRACT FROM AUTHOR]

In the traditional production of acetic esters, water generated in the esterification reaction can form azeotropes with the ester or the unreacted alcohol, which requires subsequent multi-step distillation or extraction to purify the esters. A large number of intermediate streams in the separation process need to consume a lot of steam to obtain high-purity acetic esters, resulting in a high total energy consumption. In this review, a new extraction separation and purification technology, namely the salting-out effect for the purification of acetic esters, was summarized. Different salting-out agents were used to reduce the concentration of water/alcohols in the ester phase and increase the selectivity coefficient of esters to minimize energy consumption. The scaled particle theory provides a clear guideline for the baseline on the separation goal of the alkyl acetate/alcohol/water systems. Extractive distillation, reactive distillation, azeotropic distillation, pervaporation, adsorption, salting-out assisted distillation, and hybrid salting-out-distillation were compared to assess their advantages and disadvantages. Energy-saving production and separation of acetic esters can be achieved with the hybrid salting-out-distillation process because the salting-out agents are cheap, non-toxic, and non-volatile, and the salting-out process can be conducted at room temperature. [ABSTRACT FROM AUTHOR]

The separation of ternary azeotropes with a high content of one component using extractive distillation is energy intensive, and the introduction of preconcentration can significantly improve process economy. In this paper, the conventional three-column extractive distillation (TCED), four-column extractive distillation (FCED) with preconcentration, and three-column extractive distillation with integrated distillation column (TCED-IDC) are established and economically optimized to minimize the total annual cost (TAC) for recovering ethyl-acetate (EAc) and ethanol (EtOH) from wastewater containing a large amount of water. The preconcentration and solvent recovery functions can be integrated in IDC. Following that, the vapor recompression heat pump (VRHP) is introduced to further reduce energy consumption for the TCED-IDC process. The two VRHP-TCED-IDC processes are correspondingly designed. Simultaneously, the processes proposed are evaluated in terms of economy, energy consumption, environment and exergy destruction (4E analysis). The environmental analysis is performed via calculating Global Warming Potential (GWP) index using Life Cycle Assessment method. The two VRHP-TCED-IDC processes demonstrate superior performances with regard to 4E analysis. The most efficient VRHP-TCED-IDC process reduce over 32.0 %/16.0 %/6.8 % of TAC, 53.4 %/42.4 %/33.7 % of energy consumption, 62.0 %/53.0 %/45.9 % of GWP, and 49.7 %/35.7 %/29.3 % of exergy destruction compared to the TCED/FCED/TCED-IDC processes, respectively. • The separation of ternary azeotropes with one high-content component is studied. • The integration of preconcentration and solvent recovery functions is investigated. • Vapor recompressions heat pumps are introduced to reduce energy consumption. • Processes are evaluated using economic, energy, environmental, and exergy analyses. • The environmental analysis is preformed via Life Cycle Assessment method. [ABSTRACT FROM AUTHOR]

Cyclohexane and isopropyl alcohol are widely used in the chemical and pharmaceutical industries. There is a strong industrial need for the refinement of cyclohexane and isopropyl alcohol. In this study, the recovery of cyclohexane and isopropyl alcohol from wastewater was carried out sustainably and efficiently by extractive distillation. The suitability of ethylene glycol as entrainer was determined by relative volatility analysis. The process was optimized via multi-objective optimization, and the extractive distillation process obtained optimal parameters and process scheme. Finally, a comprehensive analysis was conducted to evaluate the economic, environmental and exergy efficiency of different process schemes. The results show that the extractive distillation coupled pervaporation technology has a 14.07% lower total annual cost than extractive distillation, and the pervaporation technology reduces gas emissions by 15.65% compared to the extractive distillation. This work explores the recovery of cyclohexane and isopropyl alcohol from wastewater by different process schemes, which has certain guiding significance for the sustainable and efficient separation of ternary azeotrope. [Display omitted] • Multi-objective optimization was used to obtain optimize parameters of process. • A pervaporation model of EG dehydration was established to realize solvent recovery. • The different energy saving intensification schemes were studied. • Detailed performance evaluation and analysis of process was done. [ABSTRACT FROM AUTHOR]

Distillation is significantly influenced by energy costs, prompting a need to explore effective strategies for reducing energy consumption. Among these, heat integration is a key approach, but evaluating its efficiency is paramount. Therefore, this study presents exergy as an energy quality indicator, analyzing irreversibility and efficiencies in tetrahydrofuran/water and acetone/chloroform distillations. Both systems have equimolar feed streams, yielding products with 99.99 mol% purity. The simulations are performed using Aspen Plus™, enabling evaluation at the column level, as a standalone process, or from a lean perspective that considers integration opportunities with other plants. The results show that, despite anticipated energy savings from heat integration, economic viability depends on pressure sensitivity. The results demonstrate that heat-integrated extractive distillation for acetone/chloroform raises utility energy consumption. Exergy calculations comparing standalone and total site integration reveal the variation in distillation efficiency with operation mode. Global exergy efficiency in both extractive and pressure-swing distillation depends on the fate of condenser duty. In heat-integrated extractive distillation, global exergy efficiency drops from 8.7% to 5.7% for tetrahydrofuran/water and 11.5% to 8.3% for acetone/chloroform. Similarly, heat-integrated pressure-swing distillation sees global exergy efficiency decrease from 34.2% to 23.7% for tetrahydrofuran/water and 9.5% to 3.6% for acetone/chloroform, underscoring the nuanced impact of heat integration, urging careful process design consideration. [ABSTRACT FROM AUTHOR]

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Distillation is widely recognized as the preferred method for separation due to its operational and control benefits. Traditional distillation processes, however, cannot successfully separate azeotropic mixtures with near boiling points. Numerous special distillation processes have been developed to address this limitation. Extractive distillation, in particular, has gained significant popularity in the chemical, petrochemical, pharmaceutical, and refining industries. This review examined the state-of-the-art advances in extractive distillation. The importance of the proper selection of a solvent was discussed. Several configurations of extractive distillation processes were presented. Additionally, alternative extractive distillation systems have been elaborated. However, significant research gaps remain, such as the need for an exhaustive investigation of various control variables, the impact of certain entrainers on distillation processes, and cost comparisons across specialized distillation systems. Furthermore, process intensification strategies require additional research to solve complexity and operability issues. The integration of energy-efficient technologies, developments in renewable energy consumption, and the development of cost-effective reactive or split distillation columns will shape the future of distillation operations. These advances will help the chemical process sector achieve improved energy efficiency, lower environmental impact, and increased sustainability. [ABSTRACT FROM AUTHOR]

In the process of producing isopropanol (IPA) by direct hydration of propylene, a mixture of IPA, n-propanol (NPA) and H 2 O is formed. In order to obtain high purity IPA and NPA, extractive distillation technology can be used to separate these three components. In this paper, Based on the COSMO-RS model, 1-ethyl-3-methylimidazolium dicyandiamide ([EMIM][DCA]) was selected as the extractant for extractive distillation in ionic liquids. The extractive distillation process for the separation of IPA-NPA-H 2 O system with ethylene glycol (EG) or [EMIM][DCA] as extractant was designed and optimized by multi-objective genetic algorithm. Process simulation results show that the process using [EMIM][DCA] can reduce total annual cost by 44.635% and total gas emission by 29.873% compared with the traditional organic solvent EG as extractant. These results show that [EMIM][DCA] is a good extractant, which can reduce the gas emission and energy consumption of the distillation process. In addition, we further explored the separation mechanism of the system at the molecular level by analyzing the σ-curve and the intermolecular interaction energy. • Based on COSMO-RS model, [EMIM][DCA] was selected as extractant. • The reason why EG and [EMIM][DCA] can break the IPA-H 2 O azeotrope was revealed. • Optimized the extractive distillation process with EG or [EMIM][DCA] as entrainers. • [EMIM][DCA] can realize the energy saving and emission reduction. [ABSTRACT FROM AUTHOR]

Incorporating sustainability metrics into the design of economically viable and environmentally responsible processes is crucial for achieving overall sustainability. Reactive distillation has been widely studied in this context, but studies on extractive distillation have been limited, particularly in ternary azeotropic separation. This study aims to address this gap by integrating green sustainability metrics into extractive distillation through multi-objective optimization, considering economic, environmental, and safety indicators simultaneously. The results showed that our approach resulted in greater sustainability improvements compared to a sequential approach, where optimization was initially based on economic objectives with the environmental and safety aspects evaluated subsequently. The optimized configurations for ethanol, tetrahydrofuran, and methanol separation using three column extractive distillation and four column extractive distillation in this work showed significant sustainability improvements compared to their base cases. Specifically, three column extractive distillation outperformed four column extractive distillation in energy, economic, environmental, and safety performance by 18%, 4%, 8%, and 18%, respectively. • Incorporation of sustainability metrics for design of extractive distillation (ED). • Multi-objective optimization (MOO) involving economic, environmental, and safety. • Result comparison with MOO using capital and operational cost as objective function. • Result comparison against sequential approach for sustainability evaluation. • Present approach provides better sustainability relative to a sequential approach. [ABSTRACT FROM AUTHOR]

In the chemical and petrochemical industries, an azeotropic mixture of acetone/methanol/butanone/tert-butanol needs to be separated for high-purity products. Following a previous work in which an energy-saving process composed of two extractive dividing-wall columns (EDWCs) was developed for the quaternary system, this paper focuses on the issue of dynamic control for this process. Several control strategies in combined with temperature control, temperature-difference control and composition control are established to maintain the purity of all products in the face of disturbances in feed flow and feed composition. Dynamic simulations demonstrate that a conventional temperature control structure provides very poor control while a control strategy that used three-temperature-difference control for both EDWCs is the most effective. • An effective control strategy is proposed for two extractive dividing-wall columns process of quaternary azeotropic mixtures. • Multiple temperature differences controls are designed to control the process. • A variety of feed disturbances are used to test control strategies. [ABSTRACT FROM AUTHOR]

The effect of boric acid amino ester, which was obtained from triethanolamine, boric acid, and triethylene glycol, on the conditions of vapor–liquid equilibrium in the ethyl acetate–ethanol and ethyl acetate–isopropanol azeotropic binary mixtures and the ethyl acetate–ethanol–water ternary mixture was studied both by experimental methods of open evaporation with a Świętosławski ebulliometer, and by modeling using the UNIFAC method. Parameters of the interaction of the CCOO group (in ethyl acetate) with the boron group B were determined, which are absent in the literature. A process for separating the ethyl acetate–ethanol–water azeotropic mixture by extractive distillation was proposed. [ABSTRACT FROM AUTHOR]

The pressure effect on the relative volatility of binary mixtures of different natures and ternary mixtures containing potential separating agents such as dimethylsulfoxide (DMSO) and butyl propionate is studied. A wide range of information is obtained based on the data on the vapor–liquid equilibrium, and effects of the pressure on the relative volatility of various nature and cause for a fixed composition of the initial mixture are determined. In the presence of intersection points of the phase-equilibrium curves in the initial binary mixture and pseudobinary mixture (in the section with a constant concentration of the third high-boiling component), the concentration simplex is divided into regions in which the values of the relative volatility decrease (increase) upon varying pressure. This fact makes it possible to improve the procedure of separation process optimization at the stage of operating pressure selection in the columns. [ABSTRACT FROM AUTHOR]

The efficient separation of azeotropes is of great significance for the effective recovery and utilization of chemical raw materials and environmental protection. This study investigated the separation efficiency and mechanism of deep eutectic solvents (DESs) with different combinations and ratios of hydrogen bond acceptors (HBA) and hydrogen bond donors (HBD) for cyclohexane/ethanol azeotropic systems. Through vapor-liquid phase equilibrium experiments, the effects of different DESs and different HBD: HBA molar ratios as solvents on the phase behavior of cyclohexane/ethanol azeotropic system were studied, and different combinations and molar ratios of DESs with the best separation performance were obtained. The effective separation of azeotropes by DESs is primarily due to the stronger molecular surface electrostatic potential of ethanol compared to that of cyclohexane, which results in a stronger interaction between the DESs and ethanol. Finally, through process simulations, a cyclohexane/ethanol extractive distillation separation process using a DES as the main solvent was established. The results showed that the separation effect of DESs increased with the increase of the interaction force between DESs and ethanol, achieving efficient recovery of chemical raw materials. This study established a safe and efficient separation process using DESs, which is of great significance for environmental protection and the development of safety processes. [ABSTRACT FROM AUTHOR]

This work investigates an efficient and sustainable process for recovering n-propyl acetate and n-propanol from wastewater via extractive distillation coupled with pervaporation (PV). The selection of potential extractants is based on the equilibrium data between the system and the extractants in vapor-liquid phase. For the ternary extractive distillation process, we optimize it using the Non-Dominated Sorting Genetic Algorithm II with the objectives of minimizing the total annual cost and gas emissions. The PV model is integrated with the distillation process to enhance solvent recovery, while an energy-efficient scheme combined with heat integration technology and heat pump improves separation efficiency. Economic, environmental and exergy analyses are conducted to evaluate feasibility, revealing that coupling extractive distillation with PV enhances economic and environmental benefits compared to basic processes. The combination of heat pump assisted heat integration technology further improves the economy performance, environmental protection and thermodynamic efficiency, and the process selection needs to be balanced according to the actual industry. [ABSTRACT FROM AUTHOR]

As property and process models with many variables need to be considered, integrated computer‐aided molecular and process design (CAMPD) problems are computationally expensive. An efficient CAMPD approach is proposed for the simultaneous design of solvents and extractive distillation (ED) processes based on a data‐driven modeling strategy. First, artificial neural network (ANN)‐based process models are trained to replace the physical models conventionally used in CAMPD. Subsequently, optimization is performed to maximize process performance, through which optimal solvent properties and corresponding optimal process parameters are obtained. Then, real solvents approximating the optimal property values are identified from a large solvent database. Rigorous simulations of the ED process are performed to evaluate the performance of the optimal solvents and corresponding process parameters. Further economic evaluation (6.11% lower annual cost compared to the benchmark process) and chemical hazard assessment confirm that acetylacetone is a promising solvent for the ED separation of 1‐butene from 1,3‐butadiene. [ABSTRACT FROM AUTHOR]

The density function theory (DFT) and solvation model are combined with the chemical engineering process analysis and synthesis course in this article, and separation process simulation experiments are designed to study the extractive distillation of acetonitrile and water. The targeted ionic liquid (IL) is determined according to the enhancement of relative volatility by the conductor-like screening model-segment activity coefficient (COSMO-SAC) solvation model. The microscopic mechanisms of IL-improved separation performance are studied using DFT calculation and molecular surface charge density curves, and the interactions among acetonitrile, water, and IL are analyzed using sigma profiles. The extractive distillation process is simulated and optimized by the integrated platform of Aspen Plus and MATLAB using the screened IL. These comprehensive simulation experiments involve the frontier contents of physical chemistry, chemical engineering thermodynamics, chemical engineering principles, and chemical engineering tech-economics and management, and combine frontier theories of the discipline and chemical engineering application. Thus, the fundamental knowledge of students is strengthened. The research interests of the discipline frontier of the students are inspired, and the ideas for the improvement and innovation of major course is provided to cultivate interdisciplinary talents in chemical engineering. [ABSTRACT FROM AUTHOR]

Bioethanol is commonly recovered from fermentation broth via distillation because it is the most economical and reliable process for large-scale industrial operations. Because extraction is a highly energy-efficient process applicable to low-composition bio-product separation, high-performance solvents are necessary for efficient bioethanol recovery. 2-Methyl pentanol, a branched long-chain alcohol, which was used as the extraction solvent, and a deep eutectic solvent, choline chloride and ethylene glycol (1:2), was employed as an entrainer for product refinement. Thermodynamic models of vapor–liquid equilibrium (VLE) and liquid–liquid equilibrium (LLE) systems were derived using molecular simulations and experimental results to develop the bioethanol extraction and refinement processes. The heat duty of the designed process was reduced by a quarter compared to that of previous recovery processes. [ABSTRACT FROM AUTHOR]

Ethanol purification has become of great interest recently because ethanol can be used as renewable energy, solvent in many industries, and for medicinal purposes. The separation of ethanol from water is challenging because the azeotropic point has appeared in this binary mixture. Extractive distillation technology is one of the most interesting methods to separate ethanol from water due to the competitiveness of its energy consumption and capital investment costs. Ionic liquids such as 1-butyl-3-methylimidazolium bromide [BMIM] [Br], categorized as a green solvent, produce a significant salting-out effect in the ethanol-water system. This makes ionic liquid a promising solvent in ethanol-water separation. This study simulated the extractive distillation of an ethanol-water system with 1-butyl-3-methylimidazolium bromide as a solvent. The simulation and sensitivity analysis were performed on the Aspen Plus Process Simulator to obtain the optimum configuration. The NRTL thermodynamic model was used in this study. The effects of the number of stages (NS), binary feed stage (BFS), entrainer feed stage (EFS), and reflux ratio (RR) on the ethanol concentration with minimum energy requirements were studied. The most optimal configurations to produce a high ethanol concentration with less energy are NS 28, BFS 22, EFS 4, and RR 1.5. [ABSTRACT FROM AUTHOR]

A new process for the synthesis of ethyl methyl carbonate through reactive extractive distillation was proposed to address the difficulties in separating azeotropic mixtures and the excessive formation of byproduct (diethyl carbonate) in the production of ethyl methyl carbonate via reactive distillation. Using Aspen Plus software, the effect of the extractant (diethyl carbonate) on the vapor-liquid equilibrium of the system was first investigated. Then the reactive extractive distillation column was simulated to study the effects of the number of theoretical plates in the reaction section, the number of theoretical plates in the extraction section, the feeding position, entrainer ratio, and reflux ratio on the reactive extractive distillation process. Under the optimized process parameters, the molar fraction of dimethyl carbonate at the top of the reactive extractive distillation column was reduced to 0.49%, and the single conversion of dimethyl carbonate, selectivity of ethyl methyl carbonate, and ethyl methyl carbonate yield reached 83.5%, 99.9% and 83.4% respectively. Finally, a process for the reactive extractive distillation was designed with the objective function of total annual cost, achieving process parameters that meet the production requirements. It was found by comparison that the reactive extractive distillation process exhibits better economic performance than conventional reactive distillation processes when the added value of 1 t of ethyl methyl carbonate is 145.50 CNY higher than that of diethyl carbonate. [ABSTRACT FROM AUTHOR]

Pemisahan n-propil asetat dari campuran terner n-propil asetat/n-propanol/air merupakan salah satu proses yang tidak dapat dilakukan dengan distilasi sederhana. Adanya azeotrop terner minimum dari campuran tersebut menyebabkan n-propil asetat hanya dapat dipisahkan dari campuran n-propanol dan air salah satunya dengan metode distilasi ekstraktif. Distilasi ekstraktif merupakan proses vaporisasi parsial dengan menambahkan suatu agen pemisah non-volatil yang disebut sebagai sovent atau agen ekstraktif. Solvent yang digunakan dalam simulasi proses ini adalah campuran DMSO (Dimetil Sulfoksida) dan Gliserol dengan komposisi 50 % massa dengan perbandingan 1:2 untuk massa umpan kolom : solvent. Feed yang digunakan adalah n-propanol (10 kmol/jam) dan asam asetat (13 kmol/jam) masing-masing pada suhu 25°C dan tekanan 101,3 kPa. Hasil n-propil asetat terbaik diperoleh saat solvent diumpankan pada stage 5 dengan fraksi mol n-propil asetat pada distilat 0,9975 disertai dengan minimumnya energi reboiler yang digunakan pada konfigurasi kolom ini. n-Propyl acetate separation of the n-propyl acetate /n-propanol/water mixture composition can't be done by simple distillation. The existence of minimum ternary azeotrope on the mixture causes n-propyl acetate can be separated only by extractive distillation method. Extractive distillation is a partial vaporization process in the presence of a non-volatile separating agent called as solvent or extractive agent. Solvent used in the simulation process is DMSO (Dimethyl Sulfoxide)-Glycerol mixture (50% mass) with a ratio of 1: 2 for column feed : solvent. n-Propanol (10 kmol/hour) and acetic acid (13 kmol/hour) are fed into reactor (before extractive distillation process) at 25°C and 101.3 kPa, respectively. The best results of n-propyl acetate were obtained when the solvent was fed to stage 5 in which mole fraction of n-propyl acetate in distillate 0.9975 accompanied by the minimum reboiler energy used in this column configuration.

Objectives. The study aims to investigate the effectiveness of the use of various options for organizing the process of diabatic distillation in the separation of a mixture of acetone-toluene-n-butanol by extractive distillation using dimethylformamide as an entrainer in a scheme with preliminary separation of azeotropic components.Methods. As the main research method, mathematical modeling in the Aspen Plus V. 12 software package was used. As a model for describing vapor-liquid equilibrium, the local composition Non-Random Two Liquid equation model was used. Parametric optimization of diabatic schemes was carried out according to the criterion of reduced energy costs.Results. Based on the scheme for extractive distillation of an acetone-toluene-n-butanol mixture with preliminary separation of azeotropic components, five options for organizing diabatic distillation schemes were considered, both with and without use of a compressor to reach a required flows temperature.Conclusion. It is shown that the use of diabatic schemes in the extractive distillation of a acetone-toluene-n-butanol mixture with dimethylformamide makes it possible to diminish the reduced energy costs by 8.9-43.5%. Meanwhile the maximum reduction in energy consumption is achieved in a scheme where upper vapor flows of two other columns are used to heat the azeotropic components separating column.

Conventional distillation methods cannot effectively separate the components of an azeotropic mixture since both phases have the same composition, thereby preventing further separation. Additional techniques such as pressure swing distillation or distillation with entrainers are often employed to overcome this limitation and achieve separation. The aim of this investigation was to select the most effective method for separating n-hexane and ethanol. The feasibility of three methods was analyzed: reduced pressure distillation, extractive distillation, and liquid–liquid extraction. The mutual solubility of n-hexane and prepared deep eutectic solvents (DESs) (nine hydrophilic: choline chloride with glycerol, ethylene glycol, or carboxylic acid (malic, citric, glycolic); tetramethylammonium chloride with glycolic acid; lactic acid with glycerol; K2CO3 with glycerol or ethylene glycol; two hydrophobic: menthol with decanoic or dodecanoic acid) was experimentally determined. Extraction experiments were conducted to test the solubility of DESs in the feed mixture. The effect of changing DES-to-feed mass ratio was further investigated with choline chloride–glycerol (1:2). The same DES and both hydrophobic DESs were able to increase the relative volatility and enhance the separation of ethanol and n-hexane. Based on the obtained results, extraction was selected as the most effective method for the separation of n-hexane and ethanol.

The current article deals with the separation of the azeotropic mixture of isopropyl alcohol (IPA) and water using an ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) and Deep Eutectic Solvents (DESs), Choline Chloride/glycerol (Glyceline) and Choline Chloride/Ethylene Glycol (Ethaline). Conventional dimethyl sulfoxide (DMSO) solvents are used to compare the results for IPA dehydration. Process modelling and simulation were carried out in the Aspen Plus simulator (v.8.6). The NRTL model was used to calculate the thermodynamic properties as well as the vapour-liquid equilibria of the ternary systems. The process parameters such as entrainer flow rate, binary feed stage, entrainer feed stage, column stages, reflux ratio, reboiler and condenser duties were evaluated using sensitivity analysis and design spec tools of the simulator. The industrial process for both systems, containing a separation column and a recovery column, was simulated at a steady state. Both processes were optimised using the optimisation tool of the simulator and compared based on the energy requirement. Further, based on the simulation results, we proposed an alternate process design for solvent recovery using a flash drum. The results show that more than 99.9 mol% IPA purity can be achieved using both ILs as well as DESs. The overall energy requirement for the separation of IPA-water mixture using [EMIM][BF4] entrainer in a conventional process was found to be lower than DMSO. The proposed alternate process further reduces the energy requirement compared to the conventional process for both IL and DESs systems.

Acetonitrile is known as a polar solvent that can dissolve in non-polar hydrocarbon liquids. As an example of a nonpolar solvent, toluene is one of the solvents that dissolves well in acetonitrile. If acetonitrile and toluene are mixed, a minimum boiling azeotrope will form. The maximum purity of acetonitrile when distilled is 89.5% mole at 81.19 °C under conventional distillation. To achieve high purity of acetonitrile, a new solvent should be added to this mixture. In this work, high purity of acetonitrile (99.9% mass) with extractive distillation method was simulated using Aspen Plus software. Based on the pseudo-binary analysis by Aspen Plus, butyl propionate can break the azeotrope mixture at concentration of 0.3 (mole fraction). The simulation results showed that, to get 99.9% mass of acetonitrile, a solvent to feed ratio of 1.5, reflux ratio of 1.5 a number of stages of 32 were required. After obtained the optimum parameters, economic evaluation was calculated using total annual cost (TAC) objective function method. From the economic evaluation, a feasible TAC of 1.225×106 $/year was obtained.

Sec-butyl alcohol (SBA), a common chemical intermediate, is used as an anti-emulsion, dye dispersant, industrial detergent, and raw material to produce methyl ethyl ketone. To further reduce the energy consumption and production cost of the hydrolysis of sec-butyl acetate (SBAC) to SBA, a reactive distillation coupled with extractive distillation using a mixed entrainers process was proposed in this study. Based on the relative volatility curve and quantum chemical calculations, EG and DMSO were selected as potential entrainers. Based on the total annual production cost, the appropriate ratio of mixed solvent is obtained (EG: DMSO = 9:1). The thermal coupling distillation technology is introduced into the proposed process to achieve energy-saving further. The results showed that the thermodynamic efficiency of the thermal coupling process using mixed entrainers increased by 18.02%, the total annual cost is saved by 15.18%, and CO 2 emissions were reduced by 391.82 kg/h compared to the process using single DMSO entrainers process. [Display omitted] • Quantum chemical calculation and VLE data were used to screen mixed extractants. • Combination of mixed extractant and thermal coupling process can effectively save energy. • The thermodynamic efficiency of the novel process can be improved by 18.02%. [ABSTRACT FROM AUTHOR]

In order to effectively separate complex azeotropic mixtures, it is crucial to consider economic, environmental, and safety factors during the process design and optimization. This study presents a systematic approach to separate a ternary azeotropic mixture of tetrahydrofuran, methanol, and water by employing multi-objective optimization and multi-criteria decision making. Two energy-efficient configurations, i.e., double-column reactive extractive distillation and reactive-extractive dividing wall column, are proposed by integrating reaction and extractive distillation in a single unit. The developed processes are then optimized using a multi-objective particle swarm optimization algorithm, considering the aforementioned factors. Finally, a multi-criteria decision making technique is applied to rank the Pareto frontier solutions obtained from the optimization process, using a combination of gray relational analysis and entropy weight method. Compared to the base case, the double-column reactive extractive distillation process exhibits a significant reduction in total annual cost (59.39 %) and CO 2 emissions (61.75 %). Through comprehensive evaluation, the double-column reactive extractive distillation process is found to be the most effective separation solution among the proposed and existing processes. This systematic approach can be extended to other complex aqueous azeotropic systems for their design, optimization, and decision making. [Display omitted] • A systematic approach for separating complex azeotropic mixtures is proposed. • Two intensified reactive-extractive distillation schemes are developed. • The developed processes are optimized via MOPSO algorithm. • The GRA combined with entropy weight is used for multi-criteria decision making. [ABSTRACT FROM AUTHOR]

Reclamation of mixed refrigerants can effectively reduce high global warming potential (GWP) fluorinated gases (F-gases) emissions. Two organic liquids (OLs), Dimethylformamide (DMF) and N, N-Dimethylacetamide (DMAC), were proposed to explore the possibility of separating high GWP and near-azeotropic mixture R410A (50 wt% R32 (difluoromethane) + 50 wt% R125 (pentafluoroethane)) by absorption. Solubilities of R125 in DMF and DMAC were measured from 283.15 to 333.15 K and well correlated with the five-parameter non-random two-liquid (NRTL) activity coefficient model. Ideal selectivity for R32 + R125 of DMAC were higher than that of DMF. Five ionic liquids (ILs) and DMAC on the Pareto front showed good overall performance (integration of capacity and selectivity) for separating R410A, and in the area below the Pareto front, the overall performances of the other solvents were not as good as those from the Pareto front. Subsequently, based on DMAC, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF 6 ]), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([EMIM][Tf 2 N]) and 1-ethyl-3-methylimidazolium thiocyanate ([EMIM][SCN]), the extractive distillation processes for R410A separation were simulated and evaluated in Aspen Plus. Results showed DMAC was a suitable choice of extractant nowadays due to the lower viscosity and consumption than ILs and the mature corresponding R410A separation process. ILs may be the mainstream extractant for R410A separation in the future, once the price of some ILs such as [BMIM][PF 6 ] can be reduced to $30/kg, the separation process using ILs as extractants will cost less than that of DMAC. Heat pump technology can be further applied for energy integration in the corresponding process of ILs with high ideal selectivity such as [EMIM][SCN]. Thermodynamic and economic analysis of OLs and ILs could provide the key information for the separation of commercial refrigerant R410A, which can also be used as a benchmark to screen more efficient extractants. [Display omitted] • DMF and DMAC were developed for extractive distillation separation of R410A. • The preferential absorption of R125 in DMAC and DMF was found. • DMAC was a suitable extractant due to the lower viscosity and consumption than ILs. • ILs may be the mainstream extractant once the price of ILs can be reduced to $30/kg. [ABSTRACT FROM AUTHOR]

A correlation model was explored and established for the first time, linking the properties of entrainers to the process economics of extractive distillation separation for ternary azeotropes. Firstly, the extraction process of ternary azeotrope (methyl tert-butyl ether/ethanol (EtOH)/water) with common entrainers was optimized using a multi-objective optimization method based on a genetic algorithm. The optimal process parameters were obtained, and dimethyl sulfolone emerged as the best entrainer for the system. An economic correlation model was developed using machine learning to link the properties of entrainers and total annual cost (TAC). The model exhibited a determination coefficient of 0.993 and a single percentage error of less than 2% for each data set, indicating a significant fitting degree and prediction accuracy. The feasibility of selecting the optimal entrainer and calculating the economic benefit of the model was verified through another ternary azeotrope system (i.e., tetrahydrofuran/EtOH/water). The model provides valuable insights into energy savings and entrainer screening in extractive distillation. Additionally, the influence of the heat integration process with different entrainers on the economic benefit was analyzed, and the optimum entrainer changed to glycerol after the heat integration process. This finding suggests that determining the optimum entrainer should consider the possible heat integration process design. Finally, the relationship between the intermolecular interaction mechanism and separation effect was revealed through quantum chemical calculations. [ABSTRACT FROM AUTHOR]

Benzene (BEN) and cyclohexane (CYH), which have very close boiling points and a binary azeotrope, are the most difficult binary components in the separation of aromatic and non-aromatic hydrocarbons. This study further explored the separation mechanism and industrial application prospects of BEN + CYH mixtures separated by a dicationic ionic liquid (DIL) [C5(MIM)2][NTf2]2 based on experimental research. The calculation results of the Conductor-like Screening model Segment Activity Coefficient (COSMO-SAC) model show that selectivity and solvent capacity of the DIL are significantly improved. The effects of different anions and cations on the microstructure distribution and diffusion behavior of BEN + CYH system were investigated by quantum chemistry (QC) calculations and molecular dynamics (MD) simulations. The results indicate that the anion [NTf2]- has low polarity, uniform charge distribution, and a dual role of hydrogen bonding and π-π bonding, and the cation [C5(MIM)2]2+ has stronger interaction with BEN and higher selectivity than conventional cations. The liquid-liquid extraction and extractive distillation (LLE-ED) process using an optimized 65 mol/mol DIL + 35 mol/mol H2O mixed solution as the extractant was proposed, which solved the problem of low product purity in the LLE process and high energy consumption in the ED process. Under the best operating conditions, the purity of CYH product was 99.9%, the purity of BEN product was 99.6%, the recovery rate of BEN reached 99.9%, and the recovery rate of DIL reached 99.9%. The heat-integrated LLE-ED process reduced total annual cost by 21.6%, and reduced CO2 emissions by 48.0%, which has broad industrial application prospects. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The dehydration of isopropanol (IPA) is a crucial process in numerous industries, and the optimization of its efficiency and economic viability is essential. This review provides a comprehensive analysis and comparison of various distillation processes, heat integration (HI) strategies, and process intensification (PI) techniques employed for IPA dehydration. The advantages, limitations, and applicability of distillation processes, such as extractive distillation, heterogeneous azeotropic distillation, and pressure swing distillation, are discussed. In addition, this review explores the potential of HI techniques to optimize energy consumption and reduce operating costs of IPA dehydration processes. PI techniques, including thermally coupled arrangements and dividing wall columns, are examined for their ability to improve the process efficiency and sustainability. It is crucial to conduct thorough evaluations, as well as energy and economic analyses, when choosing the appropriate distillation process, HI approach, and PI technique for specific IPA dehydration applications. This review emphasizes the potential for improving the energy efficiency, product purity, and cost-effectiveness of IPA dehydration through the integration of advanced distillation processes and PI techniques. [ABSTRACT FROM AUTHOR]

Controllability features of the extractive distillation process and the pressure‐swing distillation process were studied with dynamic tools and compared in the case study of separation of a mixture of 50 mol % tetrahydrofuran and 50 mol % water. Process simulations with Aspen Plus and Aspen Plus Dynamics were carried out to obtain 99.9 mol % product purity. Control structures for the two distillation techniques were determined. Load rejection studies were completed for ±10 % feed throughput and ±10 % feed composition disturbances, for both processes. The comparison of the dynamic responses, integral absolute errors, and integral square errors shows that the pressure‐swing distillation process has better controllability features than extractive distillation. [ABSTRACT FROM AUTHOR]

The process of distillation separation of the isobutyl acetate (IBA)–acetic acid (AA)–isoamyl acetate (IAA) industrial mixture, which is a product of the large-capacity waste processing of the alcohol industry, is considered. Various versions of the process flow diagramm (PFD) are proposed and the operating parameters of the distillation columns for providing isolation of IAA and IBA with purity higher than 99.5 mol % from the IBA–AA–IAA industrial mixture are determined. For the IBA–AA, IBA–IAA, IBA–SF, and AA–SF systems the binary interaction parameters of the NRTL-HOC model were estimated. New experimental data on the liquid–vapor phase equilibrium in the IBA–SF and AA–SF systems at 200 mm Hg are obtained for the estimation of the parameters. [ABSTRACT FROM AUTHOR]

BACKGROUND: The 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. RESULTS: We 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. CONCLUSION: Altogether, designing the intensified process via process optimization does not always guarantee significant improvement in all sustainability indicators. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Objectives. To investigate the effectiveness of various options for organizing the process of diabatic distillation in the separation of a mixture of acetone–toluene–n-butanol by extractive distillation (ED) with dimethylformamide as an entrainer in a scheme where an entrainer is used in the first column.Methods. Mathematical modeling in the Aspen Plus v. 12.1 software package was used as the primary research method. The local Non-Random Two Liquid composition equation was used as a model for describing vapor–liquid equilibrium. Parametric optimization of diabatic schemes was carried out according to the criterion of reduced energy costs.Results. Based on ED scheme for an acetone–toluene–n-butanol mixture with an entrainer in the first column, four options for organizing diabatic distillation schemes were considered, both with and without increasing the temperature of the flows due to compression.Conclusion. It is shown that the use of diabatic schemes in the ED of an acetone–toluene–n-butanol mixture with dimethylformamide can decrease energy consumption by 11–17%. While the maximum reduction in energy consumption is achieved in a scheme using a compressor, the efficiency of schemes without a compressor is slightly lower. Nevertheless, the technological design of the latter is much simpler.

Acetic acid is one of the top commodity chemicals used in various industrial processes. The separation of acetic acid from aqueous solutions is a crucial requirement in the production units. Effective sequestration and recovery of acetic acid is economically beneficial and significant from value addition and environmental protection perspectives. Simple distillation procedures are not usually viable owing to the necessity of a high number of stages and large reflux ratios in the separation column. Several methods such as solvent extraction, extractive distillation, and membrane separation have been studied to retrieve acetic acid from aqueous systems. Of these methods, solvent extraction is preferred due to less consumption of energy and fast mass transfer rates. The efficiency of solvent extraction primarily depends on the solvent chosen for the extraction. The current work is focused on the review of studies that have been extensively carried out for extracting acetic acid from aqueous solutions using various pure solvents and a combination of solvents. The role of modeling and computer-aided simulation studies in the design and evaluation of separation performance is elucidated. Strategies to enhance acetic acid extraction such as salting-out and buffering-out are highlighted. Future prospects are identified to develop sustainable separation systems. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The extractive distillation was used to separate ethylbenzene and m-xylene. After the solvent screening, 1,2,4-trichlorobenzene was chosen as the extractive solvent. The vapor–liquid equilibrium (VLE) of binary mixtures of m-xylene, ethylbenzene, and 1,2,4-trichlorobenzene was measured at 101.33 kPa. The measurements were taken with a modified Rose equilibrium still. The Wisniak's test was used to assess the thermodynamic consistency of the VLE experimental results. To obtain the binary interaction parameters, the binary VLE experimental data were correlated with the NRTL, Wilson, and UNIQUAC activity coefficient models. The results showed that three models all fit the experimental values of three binary systems well, and the ternary VLE data of m-xylene + ethylbenzene + 1,2,4-trichlorobenzene were estimated using Aspen Plus V11 based on these model parameters. The experimental data agree well with the estimation values generated from three models. Finally, the effect of 1,2,4-trichlorobenzene as an extractant was analyzed, and it is proved to have a good influence on the separation of ethylbenzene from mixed xylenes by extractive distillation. [ABSTRACT FROM AUTHOR]

The liquid–vapor equilibrium in the toluene–methanol–N-octylquinolinium bromide system has been studied at 101.3 kPa and various concentrations of the organic salt. It was shown that the quinolinium salt can be used as a separating agent for a toluene–methanol azeotrope mixture. For breaking the azeotrope and separating the mixed solvent into components, the N-octylquinolinium bromide concentration (in mole fractions) should be 0.55 or higher. [ABSTRACT FROM AUTHOR]

Copyright of Teknika: Jurnal Sains dan Teknologi is the property of Teknika: Jurnal Sains dan Teknologi, Universitas Sultan Ageng Titayasa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Low-Carbon Chemistry & Chemical Engineering is the property of Low-Carbon Chemistry & Chemical Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Here, 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. RESULTS: Two 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. CONCLUSION: Our 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). [ABSTRACT FROM AUTHOR]

The separation of mixtures with close boiling points is a critical task in the petrochemical industry, and one such mixture that requires separation is o-xylene/styrene. The STED process is used to separate o-xylene/styrene, which contains a certain amount of organic sulfur in the product due to the limitations of the process. In this study, the process underwent enhancements to attain the effective separation of styrene and accomplish deep desulfurization. A mixture of sulfolane (SUL) and N-methylpyrrolidone (NMP) was selected as the extraction solvent after calculating the UNIFAC group contributions. An orthogonal experiment was conducted to investigate the effects of the solvent/oil ratio, reflux ratio, water addition rate, and solvent ratio on the product. The correspondence between each factor and the indexes examined was determined, enabling the optimization and prediction of the styrene product quality. The final optimized conditions for the extractive distillation column are as follows: solvent/oil ratio of 7, reflux ratio of 4.5, water addition rate of 6000 kg/h, and a solvent ratio of 9:1. Under optimal conditions, the purity of the product was observed to be greater than that of the original process and the sulfur content of the product can be reduced to lower than 10 ppm at the cost of an increase of 12.31% in energy consumption. [ABSTRACT FROM AUTHOR]

Considerable effort is currently being put towards process intensification to design more sustainable and energy-efficient processes. Hybrid distillation-membrane processes are prime examples of such intensified processes. In this work, different strategies are presented for how to handle the complexity of the membrane network of the hybrid process in terms of initialisation and convergence for simulation and optimisation. A superstructure approach for optimisation of membrane networks within hybrid processes is presented and verified. The energy consumption and economic performance of a hybrid distillation-pervaporation process, as well as that of the corresponding extractive distillation process, to separate a minimum-boiling azeotropic mixture are compared for different feed compositions. The impact of membrane properties and cost is also briefly considered. The results show that the total heat duty for the hybrid process is always lower than that of the extractive process for the system considered, confirming that the hybrid process is more energy efficient. In terms of total annualised cost, however, the hybrid process is found to be more economically attractive at lower feed compositions, while the extractive process is preferred for higher compositions. [Display omitted] • Superstructure design and optimisation of hybrid distillation-membrane processes. • Simultaneous optimisation of membrane network and distillation column. • Comparison between hybrid process and extractive distillation process. • Evaluation based on feed compositions and key membrane parameters. [ABSTRACT FROM AUTHOR]

Isobaric vapor–liquid phase equilibrium (VLE) data for binary systems of n-hexane + methylcyclopentane, n-hexane + N,N-dimethylamide (DMF), methylcyclopentane + DMF and ternary system of n-hexane + methylcyclopentane + DMF were generated using a modified Rose still at 101.3 kPa. The thermodynamic consistency for the VLE data were confirmed by the Wisniak's test. Binary interaction parameters (BIPs) were obtained on the calculation of VLE for these binary systems by Wilson, NRTL and UNIQUAC activity coefficient models. The estimation values of the three models showed a good fit with the experimental data. The BIPs were also employed to predict the T–x–y data of ternary system n-hexane + methylcyclopentane + DMF. The results presented a favorable match between experimental data and the predicted values. The y–x diagram of methylcyclopentane + n-hexane system was plotted with or without DMF, which confirmed that DMF as a extractant has a remarkable effect on the extractive distillation of these two components. [ABSTRACT FROM AUTHOR]

Colloidal lignin particles (CLPs) are potentially one of the sustainable alternatives for petroleum‐based feedstock. CLPs address the heterogeneity of lignin by enhancing its homogeneous dispersion in aqueous phases. The main production steps are dissolving lignin in tetrahydrofuran, diluting the solution with ethanol, forming CLPs through self‐assembly after encountering water, recovering solvents, and finally drying CLPs. In this process, solvent recovery plays an important role in mitigating environmental problems. However, the formation of azeotropes makes the separation process energy‐intensive and costly. In this work, two separation methods, evaporation and distillation, are modelled in Aspen Plus® and compared based on their total annual costs (TACs). Sizing and cost estimations are conducted based on vendor quotations and using design and economic analyzer tools. Results show that distillation reduces costs by up to 37% compared to evaporation. Accordingly, as the main separation unit, distillation parameters are optimized based on the minimum TAC. For further assessment of the increase in the rate of costs by reaching nearly pure products, extractive distillation is simulated and examined. Results show that using an entrainer to enhance the tetrahydrofuran concentration from 88 to 99.5 wt.% substantially increases the TAC by over 50%. Finally, based on the results, the desired solvent recovery model is finalized by employing the rate‐based approach. Currently, studies with a focus on the techno‐economic assessment of pilot‐scale separation units are limited, and the developed model offers a good basis for designing optimal solvent recovery units, related to processes where lignin is dissolved, prior to commercialization. [ABSTRACT FROM AUTHOR]