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This perspective paper discusses the alignment between steady‐state design and control (dynamic) simulation in the context of flexibility analysis for distillation systems. Operational variations, such as fluctuations in feed composition or flowrate, can stem from external factors like raw material quality or temperature variations. These disturbances need to be mitigated to ensure optimal industrial performance. Traditionally, these process uncertainties are usually considered in a sequential manner, where the steady‐state flowsheet is established first, and control performance is analyzed afterwards. However, recent studies have started integrating flexibility index into the design phase to account for process uncertainties. While this integration has improved design strategies, aligning steady‐state and dynamic control simulations for comprehensive flexibility analysis remains underexplored. In this paper, we wish to share new perspectives and insights we have observed by analyzing the existing literature. We highlight some points not immediately apparent in our previous studies, hoping these insights will serve as guidelines for future research in this direction. We believe that validating results between steady‐state and control simulations is a long‐term endeavor that cannot be conclusively addressed soon. However, we hope this paper will be valuable to future researchers, contributing to advancing this field and reaching those who will appreciate and build upon these insights. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

We have designed a separation process of isobutyl alcohol (52.0 mol%) and isobutyl acetate (48.0 mol%) mixture using conventional extractive distillation (ED) and extractive dividing‐wall column (E‐DWC) with the solvent dimethyl sulfoxide (DMSO). The binary mixture exhibits a minimum boiling azeotrope that is sensitive to pressure. Thermodynamic analyses have shown that the vacuum pressures work better compared to the atmospheric pressure when DMSO is the solvent. Based on the separation with a purity of 99.9 mol%, the E‐DWC process has resulted in 9.6 % and 4.8 % reductions in the total annual cost and CO2 emission rates, respectively, in comparison to the conventional method. After further intensification using the heat pump technique, the E‐DWC process with the solvent DMSO has provided more than 40.0 % reduction in energy consumption compared to the ED systems studied in the literature using the solvents butyl propionate and dimethylformamide. [ABSTRACT FROM AUTHOR]

The increment in GreenHouse Gases (GHGs) promotes high Global Warming Potential (GWP) due to the production and consumption of hydrofluorocarbons (HFCs) that diverts the aim toward the recycling and reclaiming of refrigerant gases. However, the presence of azeotrope in refrigerant mixtures restricts the recycling process. Therefore, in this work, the refrigerant R410A and R508B have been separated through the hybrid extractive distillation method by using [HMIM][TF2N] and [BMIM][BF4] as a solvent in ASPEN Plus. UNIFAC model has been used for the correlation of ionic liquid in ASPEN Plus. For thermodynamic properties, Cosmotherm has been used with the collaboration of TurbromoleX. The Vapor-liquid Equilibrium (VLE) data has been predicted by using the UNIFAC group contribution method. The Total Annual Cost (TAC) analysis with optimization has been performed. Besides that, the energy analysis has also been performed. In the overall separation process and (TAC) analysis, [BMIM][BF4] proves to be more efficient with high separation efficiency and minimal TAC requirements. Whereas, [HMIM][TF2N]/R508B provides less CO2 emission. [ABSTRACT FROM AUTHOR]

Bioethanol, a sustainable energy solution derived from renewable biomass, has gained prominence, with corn stover emerging as a substantial biomass resource in Indonesia. Corn stover, a corn residue, is one of the top three agricultural wastes worldwide and is abundantly available. However, a significant portion of corn stover is burned in fields rather than utilized for bioethanol production, whereas it has potential as a bioethanol feedstock. As the world strives to realize sustainable and environmentally friendly energy security, bioethanol production from corn stover can be one of the solutions to be developed. Nonetheless, the current immaturity of bioethanol production technology is one of the causes of large‐scale production failure. The present paper comprehensively reviews the technological aspects and process optimization of bioethanol production using corn stover as a feedstock comprising pretreatment, hydrolysis, fermentation, and bioethanol purification processes. According to our critical review, ammonia fiber expansion (AFEX) pretreatment is the most effective conventional pretreatment, with glucose yield up to 90%. Moreover, ultrasound appears to be the most viable option for nonconventional pretreatment of corn stover for producing bioethanol. However, combining ultrasound pretreatment and dilute aqueous ammonia produced 80.6% sugar output. Furthermore, enzymatic hydrolysis emerges as the most effective saccharification, yielding up to 81.39%. Moreover, the fermentation process of corn stover with the saccharification and co‐fermentation (SScF) method and the process optimization with response surface methodology (RSM) could produce bioethanol with a concentration of up to 59.8 g/L and 92.07% ethanol yield, respectively. This review also reveals that pervaporation for the purification process is the best choice for producing bioethanol with high purity up to > 99%. In addition, this method could reduce the energy used by 6.6% lower, 24.2% lower carbon footprint, and have the lowest total capital and production costs compared to conventional molecular sieves and extractive distillation. We believe this review article can provide a reference for selecting the best bioethanol production process from corn stover for further research. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal 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.)

In the production of cyclohexene by benzene hydrogenation, the by-product cyclohexane forms an azeotrope with cyclohexene. For the extraction and distillation of the binary azeotrope (cyclohexene + cyclohexane), the selectivity and relative volatility of 24 different entrainers were compared and the intermolecular interaction forces and interaction energies were analyzed by the DMol3 module of Materials Studio (MS). N, N-dimethylformamide (DMF) was identified as the entrainer, and vapour–liquid equilibrium (VLE) data were measured at atmospheric pressure for the binary system {cyclohexane + cyclohexene} with a temperature range of 354 K to 356 K, the binary system {cyclohexane + DMF} with a temperature range of 354 K to 390 K, and the binary system {cyclohexene + DMF} with a temperature range of 357 K to 421 K. In addition, the thermodynamic consistency of the experimental data was checked using the Wisniak and Van Ness method. The Wilson, NRTL, and UNIQUAC models were used to regress and fit the experimental data to optimize the binary interaction parameters, and the root mean square (RMSD) and average absolute deviation (AAD) values of all models were below 0.01%, indicating that the experimental data provide a basis for the simulation and optimization of the extractive distillation process. [ABSTRACT FROM AUTHOR]

This study employs and validates a methodology for the efficient selection of optimal energy-integrated distillation configurations for azeotropic separations of binary mixtures. The study focuses on minimum-boiling tetrahydrofuran/water and maximum-boiling acetone/chloroform azeotropes, utilizing exergy, economic, and controllability analyses to identify the most suitable rectification structures. The evaluated distillation structures include those based on extractive and pressure swing distillations for non-heat-integrated and fully heatintegrated configurations. The selection of the most appropriate configuration is contingent upon the process energy requirements, exergy efficiency, and controllability. The findings reveal that, while there are expected energy savings from heat integration, the economic viability is determined by the pressure sensitivity of the azeotrope. The non-heat-integrated sequences consistently outperform other configurations in controllability while heat-integrated systems perform better in terms of exergy efficiency and total annual costs. This underscores the pivotal role of heat integration in azeotropic distillation systems, showcasing significant benefits from energetic, exergetic, and economic standpoints and highlighting its potential for substantial savings. Conversely, the use of heat integration in the extractive distillation of acetone/chloroform exhibits less favorable properties and alternative separation technologies may be considered. [ABSTRACT FROM AUTHOR]

Recycling hydrofluoric acid (HF) is a significant issue within the field of organofluoride chemistry. A key obstacle in this endeavor lies in the separation of azeotropic mixtures containing HF, such as the azeotropic mixture of HF and 1,1,1,3,3-pentafluoropropane (HFC-245fa), which exhibit similar boiling points. This study investigates the application of extractant distillation (ED) with ionic liquids (ILs) to achieve the separation of HF/HFC-245fa at the molecular scale, cell dimension, and systematic level (including the optimization and analysis of ED). COSMO-RS was employed to identify the suitable IL, with [Tf2N]-based ILs emerging as the most optimal extractants. Four representative [Tf2N]-based ILs were chosen based on their physical properties and thermodynamic behavior, and were applied in a continuous ED process simulation for the separation of HF/HFC-245fa using Aspen Plus, resulting in the production of 99.5 mol% HFC-245fa and 99.5 mol% HF. The determination of the optimal operational parameters was carried out through sequential quadratic programming, considering the purity requirements. An assessment of energy consumption analysis indicated that [C1Py][Tf2N] stands out as the most suitable IL for separation of HF/HFC-245fa, with heat and cooling duties of 467.82 kW and 304.80 kW, respectively. Economic analysis for the process with [C1Py][Tf2N] indicated that the annual operating costs and equipment costs are $ 5.58 × 104 and $ 3.75 × 106, respectively, of which the costs of IL are 93%, the total annual cost was comparable to that of the pressure-swing distillation process, suggesting that this ED process utilizing ILs for separating azeotropes is economically viable in terms of industrial application. [ABSTRACT FROM AUTHOR]

Furfural is potentially produced from lignocellulose waste of biorefinery processes and is widely used as a value-added in various chemical industries. However, the purification of furfural should be conducted to obtain high purity. This work aims to synthesize, design, and optimize the furfural production using some alternative distillation processes by simulation using Super Pro and ASPEN software. The pretreatment process of producing crude furfural from empty fruit bunch waste is also evaluated. The production cost of $0.23/kg of crude furfural (5 %) was obtained in the preliminary process. In the purification process, the sequenced distillation process was less prospective than the extractive distillation based on the simulation basis and economic evaluation. The extractive distillation using n‑butyl chloride performed better than toluene and benzene as the furfural recovery, and the purity was 98.60 % and 99.94 %, respectively. The payback period (PBP), internal rate return (IRR), and net present value (NPV) also indicated the great performance of the extractive distillation process with values of 1.24 years, 36.04 %, and $14,591,500, respectively. Therefore, the simulation, design, and economic evaluation presented promising results that are feasible for plant establishment.

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. [ABSTRACT FROM AUTHOR]

[Objective] Taking the separation of isobutene/isobutane by conventional and side-stream extractive distillation as the research object, the optimization design of conventional and side-stream extractive distillation was conducted based on decision variables. [Methods] A multi-objective evaluation was conducted from the perspectives of energy, economy, thermodynamics, and environment. The optimal operating parameters for the conventional and side-stream extractive distillation and solvent recovery columns were obtained through the optimization of decision variables. Two extractive distillation processes were optimized with TAC as the target, and the optimal feed stage, extractant feed stage, and number of theoretical and sideline extraction stages were obtained. [Results] The TAC of the optimized conventional and side-stream extractive distillation was 3.26 x 106 and 3.1 x 106 $/year, their TEC was 14 041.9 and 13 717.87 kW, and their CO2 emissions were 4 831 and 4 714 kg/h, respectively. Compared with those of the conventional extractive distillation process, the CO2 emissions, TAC, and TEC of the side-stream extractive distillation were reduced by 2.4%, 5.2%, and 2.4%, respectively. The thermodynamic efficiency increased from 22.4% of the conventional extractive distillation to 23.2% of the side-stream extractive distillation. These results show that, in terms of economic and environmental benefits, the side-stream extractive distillation had greater advantages than the conventional extractive distillation. With two extractive distillation design schemes, students' innovative thinking is stimulated, and new distillation technologies and methods are explored. [Conclusions] Through multi-objective evaluation methods, students' practical ability in distillation operations and awareness of energy saving and consumption reduction are cultivated, enhancing their awareness of energy efficiency and sustainable development concepts, which is conducive to improving their enthusiasm for learning and strengthening their innovative ability in engineering practice. [ABSTRACT FROM AUTHOR]

Extractive distillation is used for separating oxygenates from other components in the C6 cut oil from Fischer‐Tropsch Synthesis followed by separating 1‐hexene from N‐hexane using the same solvent as the extractant. Furfural (FUR) is identified as an excellent solvent for extractive distillation of the C6 cut from FTS oil for separating oxygenates from other components as well as for separating 1‐hexene from N‐hexane via searching from more than 100 solvents by simulation using Aspen Plus. The behavior of the newly found solvent FUR is compared with that of the reported best solvent N‐methyl‐2‐pyrrolidone (NMP) and the results show that FUR scheme has the advantages of lower market price, lower dosage needed, less reboiler duty required and higher overall tray efficiency for fulfilling the same separation task. [ABSTRACT FROM AUTHOR]

A thermally coupled distillation technology can bring energy‐saving benefits, but it poses challenges to process control. This article explores dynamic control of different side‐stream quaternary extractive distillation configurations. One the one hand, the open‐loop controllability of these processes is analyzed in terms of various criteria by the control design interface technology of Aspen Plus Dynamics. On the other hand, their control structures are established and examined by introducing large feed flow and composition perturbations. The results show that the triple‐side‐stream distillation still performs the best state and input–output controllability in spite of the strongest nonlinearity, and is also well resistant to large feed perturbations using a simple control structure. [ABSTRACT FROM AUTHOR]

Biobutanol is a green solvent commonly used as gasoline additive. In this study, it is proposed the separation of azeotropic mixtures of butanol and n‐butyl ether (DBE) using ionic liquids (ILs). Suitable anions [AC]− and [H2PO4]− were screened by COSMO‐RS, and the effect of carbon chain length on the separation effect was investigated using quantum chemical calculations. It was found that the anion was primarily responsible for the separation effect, which grew as the carbon chain grew. Molecular dynamics simulations were used to verify the separation performance of the selected ILs. The separation effect of ILs was further verified using vapor–liquid phase equilibrium (VLE) experiments. The extractive distillation process with [PrMIM][AC] as the extractant was investigated to demonstrate the feasibility of ILs for the separation of butanol and DBE. This study analyzes the whole process from microscopic mechanism of action, which provides new ideas for the separation of alcohol‐ether systems. [ABSTRACT FROM AUTHOR]

Acetonitrile (ACN) obtained as a by-product in the ammonification process of propene (SOHIO process) is necessary to be dehydrated. The presence of the azeotropic point limits the use of distillation for the separation of the mixture acetonitrile-water. Two alternative approaches are studied: extractive distillation and a hybrid process distillation-pervaporation. The both obtained pure ACN and for the point of view of energy consumption, the hybrid process proved to be more favorable. [ABSTRACT FROM AUTHOR]

The CO2‐derived dimethyl carbonate (DMC) synthesis process becomes greatly attentive but suffers high energy consumption in DMC distillation process. In this work, the DMC‐MeOH azeotropes separation process by pressure swing distillation and extractive distillation was compared, and key operating parameters, including the total number of trays and the feeding position of the mixture liquid, were optimized with the minimum total annual cost (TAC) as the objective function. On the basis of this optimization, economic evaluation of different distillation processes was conducted, and it was found that extractive distillation was more economical than pressure swing distillation. The application of the dividing‐wall distillation process upgraded by extractive distillation can significantly reduce the minimum annual total cost by 37.4% and 10.7% compared to the original pressure swing distillation and extractive distillation process, respectively. The optimization of relevant heat exchange network based on pinch technology resulted in energy consumption reduction by 27.2% and 25.9% for its hot and cold utilities, respectively. Carbon life cycle assessment (LCA) on the DMC distillation process revealed over 50% of energy as well as carbon emissions from steam consumption, whose reduction can significantly minimize CO2 emissions, energy consumption, and ultimate cost. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Ethanol is one of the most utilized additives in gasoline, and its obtaining and separation from regenerable resources is of great interest. Despite the enormous energy consumption, extractive and azeotropic distillation is still preferred for ethanol anhydrization. This work studies the utilization of dipropylene glycol (DPG) as an extractive agent. The vapor–liquid equilibrium (VLE) data for the ethanol + DPG binary system was experimentally determined and the VLE data obtained were regressed using Non-Random Two Liquid (NRTL) and Universal Quasi Chemical (UNIQUAC) thermodynamic models in PRO/II 2020 simulation software. The binary interaction parameters obtained from regression were used to simulate the water + ethanol separation by extractive distillation with DPG. There were realized a series of several simulations, using different solvent/feed ratios in the extractive distillation column, starting from two basic variants: variant A, where no heat recovery is considered, and variant B, where the heat of the hot streams in the process flow diagram (PFD) is recovered in three heat exchangers. The specific energy consumption (SEC) expressed as MJ/kg of anhydrous ethanol were calculated for each variant. It was found that the most economical is variant B which for the SEC is 7.53 MJ/kg of anhydrous ethanol. The SEC calculated for the best variant in this study is lower than the SEC calculated by other researchers for similar processes. [ABSTRACT FROM AUTHOR]

Background: Presently, there are no studies that examine the impact of side‐reactions of ethylene oxide hydration on triple‐column reactive‐extractive distillation (TC‐RED). This study addressed this gap by investigating how these side‐reactions influence the energy consumption, total annual cost (TAC), and CO2 emission of the TC‐RED process. Two case studies, which involve the ternary separation of tetrahydrofuran (THF)/ethanol (ETOH)/water and ethyl acetate (EA)/ETOH/water were conducted here. Results: Case studies 1 and 2 showed significant increase in energy consumption (39.68% and 16.56%), TAC (65.57% and 47.88%) and CO2 emission (21.15% and 12.89%) resulting from side‐reactions. The increase in energy consumption, TAC, and CO2 emission is primarily a consequence of the high boiling point of higher glycol product derivatives, altered chemical equilibrium behavior and increased reactant flowrates, which necessitate larger equipment sizes and incur higher capital costs. Notwithstanding this, TC‐RED with side‐reactions still outperforms pressure swing distillation (PSD) for separation of THF/ETOH/water and extractive distillation (ED) for separation of EA/ETOH/water. However, it falls short of double‐column reactive‐extractive distillation (DC‐RED) owing to the need for an additional column. Conclusion: Our study highlights the importance of considering side‐reactions in TC‐RED during process design. Although the decline in performance is a result of the additional complexities brought by side‐reactions, it is important to emphasize that the primary takeaway of this study is that the system model is more realistic. By incorporating side‐reactions into the simulation, we can model the system more comprehensively, providing future researchers with an opportunity to explore and address potential issues resulting from side‐reactions. © 2024 Society of Chemical Industry (SCI). [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 key to extractive distillation separation lies in screening a suitable entrainer. Based on chemical process system engineering (PSE) concepts, a novel heuristic process prediction model is proposed with a minimized process economic cost index (PECI) for the efficient screening of an optimal green entrainer with the advantages of cost-effectiveness, environmental friendliness, and sustainability, followed by outlining the principles of characterizations and mathematical modeling in chemical ED processes. The relationships of αHC/SOL and NTR with QR, TAC, PECI, and LTEDI indicated that the heuristic process prediction model was scientifically valid as well as efficient. Moreover, the proposed model progresses from binomial intersecting influencing factors to trinomial juxtaposing influencing factors; summarizes and discloses the system’s theoretical rules and influencing elements of the changes in parameters and their relative volatility, avoiding the new azeotropes in the solvent recovery column; reduces the workloads of process simulation and optimization of distillation processes from (M × N) times to (1 + N) times; can be extended efficiently and accurately to provide the targeted prediction and systematic theoretical principles for separating different feed azeotropes, predicting and screening organic solvents, ionic liquids, deep eutectic solvents, and mixed solvents with the optimal TAC and environmental friendliness (AP and GWP) and sustainability (FETP, HTP, and TETP) as LCA impacts; has broad predictability and applicability combined with different process optimization algorithms; and provides infinite composite patterns and opportunities for integrating and developing innovative optimization module algorithms for future green chemical separation processes. [ABSTRACT FROM AUTHOR]

In this work, production of ethyl acetate (EtAc) using Fischer esterification between acetic acid (AcOH) and ethyl alcohol (EtOH) is presented. Batch kinetics was developed with EtOH as the limiting reactant to avoid the problems associated with unreacted ethanol in the final product. Regression was performed to estimate the parameters of the Langmuir Hinshelwood type kinetic equation. Reaction mass obtained during kinetics was subjected to separation and purification. Molecular sieves (MS) were used to remove water. Distillation (simple and extractive distillation – with entrainer, dimethyl sulfoxide, DMSO) was used to obtain almost pure AcOH, EtOH, EtAc and DMSO. Future work in reactive separation environment is indicated. Use of EtOH as the limiting reactant, use of MS for water removal and complete separation sequence are important features of this work. [ABSTRACT FROM AUTHOR]

Allyl alcohol is an important chemical intermediate widely used in the synthesis of pharmaceuticals, pesticides, and perfumes. Therefore, studying the efficient separation of the azeotropic system of allyl alcohol-water has important practical significance. Based on the COSMO-RS predictive model and by using the selectivity and capacity as the evaluator, the performance of the ionic liquids as extractants for separating the azeotropic system of allyl alcohol-water were studied. First, two high-performance extractants named tetramethylammonium chloride (C12A11) and tetramethylammonium bromide (C12A12) were screened from 384 ion liquids designed by combining 16 anions and 24 cations. Second, the reliability of the model in predicting the vapor-liquid phase equilibrium behavior of the allyl alcohol-water system was verified. Then, tetramethylammonium chloride was used to investigate its effect on the vapor-liquid phase equilibrium of the allyl alcohol-water system. The results show that at a molar content of tetramethylammonium chloride of 0.1, the azeotrope of the system can be broken, which can be used for enhanced separation of the allyl alcohol-water system. On this basis, the mechanism of extractant selectivity for allyl alcohol was analyzed from the perspective of microscopic molecular interactions, providing theoretical support and data support for further designing high-performance ion liquid extractants. [ABSTRACT FROM AUTHOR]

A new azeotropic distillation process is presented to produce gasohol in an adequate concentration of bioethanol and isooctane, which emulates the properties of gasoline ready to use in conventional combustion engines. Since the mixing step is eliminated, there are significant economic savings which imply a competitive price of bioethanol. A comparison is provided with the traditional bioethanol dehydration process, extractive distillation. Both processes were simultaneously designed and optimized with differential evolution with a Tabu list algorithm (DETL) in order to reduce the total annual cost (TAC). Results showed that when obtaining E10 biofuel, a blend of up to 10% ethanol and 90% unleaded isooctane, via azeotropic distillation, over 40% of the TAC is saved compared to obtaining pure alcohol dehydrating through extractive distillation. Moreover, the reduction in carbon dioxide emissions results in an average of 27%. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

BACKGROUND: The direct epoxidation of allyl chloride is a clean and efficient synthesis method for producing epichlorohydrin (ECH), which is a crucial organic intermediate widely used in the fields of renewable energy and aerospace. However, the presence of multiple azeotropes in the synthesized product using this method complicates the separation process and results in high energy consumption. To efficiently separate high‐purity ECH, this paper investigates and analyzes three separation schemes based on phase‐equilibrium analysis: hybrid extractive distillation (HED), pressure swing distillation (PSD) and three‐column batch distillation (TCBD). RESULTS: The operating parameters of the three separation processes are optimized by the sequential iterative optimization method such that the minimum total annual cost can reach $493 491 yr−1. The thermal integration method is used for process energy‐saving optimization, and the total annual cost can be further reduced by 6.9%. In addition, a comprehensive evaluation based on economic, energy, environmental and exergy analysis is conducted, and reveals that the TCBD process with thermal integration is optimal. A control structure is designed for the TCBD process to enhance its robustness such that the purity of ECH remains above 99.9 mol% under ±10% disturbances in feed flowrate and composition. CONCLUSIONS: Compared with the HED and PSD processes, the TCBD process has better economic and environmental benefits, and its control structure can effectively resist disturbances. It is reasonable to believe that the TCBD process can be an excellent solution for the industrial production of ECH. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

We developed an artificial neural network (ANN) to predict mole fractions in the extractive distillation of an n-hexane and ethyl acetate mixture, which are common organic solvents in chemical and pharmaceutical manufacturing. The ANN was trained on 250 data pairs from simulations in DWSIM software. The training dataset consisted of four inputs: Feed flow inlet (T1-F), Feed Stream Mass Flow temperature pressure (FM1-F), Make-up stream mass flow (FM2-MU), and ERC tower reflux ratio (RR-ERC). The ANN demonstrated the ability to forecast four output variables (neurons): Mole fraction of n-hexane in the distillate of EDC (XHE-EDC), Mole fraction of N-methyl-2 pyrrolidone in the bottom of EDC (XNMP-EDC), Mole fraction of ethyl acetate in the distillate of ERC (XEA-ERC), and Mole fraction of N-methyl-2 pyrrolidone in the bottom of ERC (XNMP-ERC).The ANN architecture contained 80 hidden neurons. Bayesian regularization training yielded high prediction accuracy (MSE = 2.56 × 10–7, R = 0.9999). ANOVA statistical validation indicated that ANN could reliably forecast mole fractions. By integrating this ANN into process control systems, manufacturers could enhance product quality, decrease operating expenses, and mitigate composition variability risks. This data-driven modeling approach may also optimize energy consumption when combined with genetic algorithms. Further research will validate predictions onsite and explore hybrid energy optimization technologies.

The selection of entrainers primarily focuses on their ability to alter the relative volatility. However, the impact of feed composition on entrainer selection has often been overlooked. In this study, we conducted two case analyses of the minimum azeotropic mixtures in the ethyl acetate–ethanol and acetone–methanol systems to explore how the feed composition influences the entrainer selection when aiming for maximum economic efficiency. Additionally, the impact of the entrainer type (positive or reverse) on the economic benefits was also investigated. The cases revealed that economic benefits will be notably enhanced when the selected entrainer preferentially targets and removes the low-content component as the light key component. For the two cases studied, when the feed composition was 0.2–0.8, compared to preferentially separating the high-content component, preferentially separating the lower-content component resulted in a reduction in energy consumption by more than 24.14% and 22.72%, respectively. The results show that the ideal entrainer should be capable of converting the higher-content component in the feed into the heavy key component. [ABSTRACT FROM AUTHOR]

Novel distillation configurations continue to appear in the literature despite the predictions made many decades ago that distillation had attained the status of a mature and stagnant technology needing no further research and development. The driving force for improvement has traditionally been energy conservation, but political decisions related to environmental and sustainability issues have provided additional motivation for improving the efficiencies of chemical and petroleum processes. Since distillation columns require a large fraction of the total energy used in these processes, there is a significant incentive to improve process efficiency. An excellent example of this activity is a paper in which a conventional three-column extractive distillation configuration is compared with a novel two-column process that includes a single decanter. The chemical separation system is a ternary mixture of methanol, water and toluene, which is important in the pharmaceutical industry. The new configuration reduces total annual cost by 50%. The purpose of this paper is to propose a simple modification of the two-column configuration that reduces energy costs by an additional 14% by using two decanters in series operating at different temperatures. • A modified two-column configuration for separating a mixture of methanol, water and toluene is explored. • Using two decanters in series operating at different temperatures saves energy and capital costs. [ABSTRACT FROM AUTHOR]

We developed an artificial neural network (ANN) to predict mole fractions in the extractive distillation of an n-hexane and ethyl acetate mixture, which are common organic solvents in chemical and pharmaceutical manufacturing. The ANN was trained on 250 data pairs from simulations in DWSIM software. The training dataset consisted of four inputs: Feed flow inlet (T1-F), Feed Stream Mass Flow temperature pressure (FM1-F), Make-up stream mass flow (FM2-MU), and ERC tower reflux ratio (RR-ERC). The ANN demonstrated the ability to forecast four output variables (neurons): Mole fraction of n-hexane in the distillate of EDC (XHE-EDC), Mole fraction of N-methyl-2 pyrrolidone in the bottom of EDC (XNMP-EDC), Mole fraction of ethyl acetate in the distillate of ERC (XEA-ERC), and Mole fraction of N-methyl-2 pyrrolidone in the bottom of ERC (XNMP-ERC).The ANN architecture contained 80 hidden neurons. Bayesian regularization training yielded high prediction accuracy (MSE = 2.56 × 10–7, R = 0.9999). ANOVA statistical validation indicated that ANN could reliably forecast mole fractions. By integrating this ANN into process control systems, manufacturers could enhance product quality, decrease operating expenses, and mitigate composition variability risks. This data-driven modeling approach may also optimize energy consumption when combined with genetic algorithms. Further research will validate predictions onsite and explore hybrid energy optimization technologies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Isopropanol and acetone production by syngas fermentation is a promising alternative to conventional fossil carbon‐dependent production. However, this alternative technology has not yet been scaled up to an industrial level owing to the relatively low product concentrations (about 5 wt% in total). This original research aims to develop cost‐effective and energy‐efficient processes for the recovery of isopropanol and acetone from highly dilute fermentation broth (>94 wt% water) for large‐scale production (about 100 ktIPA+AC y−1). RESULTS: Vacuum distillation and pass‐through distillation enhanced with heat pumps or multi‐effect distillation were efficiently coupled with regular atmospheric distillation and extractive distillation in several innovative intensified downstream processes. Over 99.2% of isopropanol and 100% of acetone were recovered as high‐purity end‐products (>99.8 wt%). Advanced heat pumping (mechanical vapor recompression) and heat integration techniques were implemented to decrease total annual costs (0.109–0.137 USD kgIPA+AC−1), reduce energy requirements (1.348–2.043 kWth h kgIPA+AC−1) and lower CO2 emissions (0.067–0.191 kgCO2 kgIPA+AC−1), resulting in highly competitive recovery processes. CONCLUSION: The proposed three novel isopropanol and acetone recovery processes from dilute broth significantly contribute to the expansion of sustainable industrial fermentation. Furthermore, this original research is the first one to develop novel pass‐through distillation technology for the complex isopropanol–acetone–water system. All the designed processes are highly economically competitive and environmentally viable. In addition to recovering efficiently both isopropanol and acetone, the designed downstream processes offer the possibility to enhance the fermentation process by recycling all the present microorganisms and reducing fresh‐water requirements. © 2023 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

BACKGROUND: The tetrahydrofuran–ethanol azeotrope cannot be separated by common distillation, but can be effectively separated by extractive distillation. Extractive distillation can be simulated by Aspen Plus software. The minimum annual cost of the process can be calculated to assess ionic liquid separation ability. The interaction energy can be used to explain the separation mechanism. RESULTS: The non‐random two‐liquid model parameters of ternary mixtures for tetrahydrofuran and ethanol containing tributylmethylammonium acetate or 1‐octyl‐3‐methylimidazolium acetate were obtained. Thermodynamic property databases of tributylmethylammonium acetate, 1‐hexyl‐2,3‐dimethylimidazolium acetate and 1‐octyl‐3‐methylimidazolium acetate were established. Based on the thermodynamic model parameters and properties, the sequential iterative method was used to determine the best operating conditions and minimum total annual cost the of extractive distillation process. The interaction energy was calculated to explain the separation mechanism. CONCLUSIONS: The separation performance of tributylmethylammonium acetate is better than that of 1‐hexyl‐2,3‐dimethylimidazolium acetate or 1‐octyl‐3‐methylimidazolium acetate. The selection and design of the ionic liquids can be conducted in terms of the interaction energy. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The article is devoted to improving the separation technology of the methanol + water + methyl methacrylate mixture. Several alternative variants are proposed: separations based on the application of auto-extractive distillation and a combination of distillation and splitting process. The separation schemes are aimed at separating all components in pure form and increasing the yield of methyl methacrylate. A computational experiment is carried out to determine the operating parameters of the columns to ensure the production of substances of a given quality. The most energy-efficient scheme is based on the use of auto-extractive distillation and a combination of distillation with splitting process. [ABSTRACT FROM AUTHOR]

The results of extractive distillation of a four-component mixture of solvents are predicted by means of simulation using the Aspen Plus 10.0 software. Schematic flow diagrams of separation are suggested using various selective agents in distillation columns operating under different pressures. [ABSTRACT FROM AUTHOR]

This work explores the integration of dynamic simulation with the concept of protection layers to assess the dynamic safety of an extractive distillation operation. This particular study concentrates on the separation process of acetonitrile from water using ethylene glycol as the entrainer. It appraises the efficacy of different independent protection layers — ranging from basic process control systems, critical alarms, and operator interventions, to safety instrumented systems and pressure relief valves — against various potential risk scenarios. The study considers scenarios leading to overpressure situations, such as failures in the condenser system, surges in hot steam supply, or severe disturbances in feed. Using Aspen Dynamics for detailed dynamic simulation and safety evaluation, the study examines the response and effectiveness of each protection layer meticulously. It employs a scenario-based safety analysis to gauge the dynamic safety performance and the effectiveness of the protection layers. The research underscores the value of scenario analysis in grasping the dynamic responses of the distillation process and the spread of irregularities through the system. This understanding is crucial for estimating the process safety time and for crafting an efficient safety system. [Display omitted] • Dynamic rigorous simulation delves into the extractive distillation process. • Faults are categorized by protection layers for dynamic scenario simulation. • Analysis reveals condenser malfunctions as the main overpressure source. • Protection layers effectively mitigate these overpressure risks. [ABSTRACT FROM AUTHOR]

The extractive distillation is a commonly used method for the separation of azeotrope in the chemical industry. In this article, we investigate the safety issue of the extractive distillation process for targeted audience process engineers from the perspective of process safety. We conduct inherently safer design and multi-objective optimization of extractive distillation processes for the separation of methyl acetate/methanol via computer-aided molecular design, thermal hazard analysis, and multi-objective genetic algorithm. Firstly, the entrainers with good safety and separation performances are pre-screened by computer-aided molecular design (CAMD) based on flash point and entrainer selectivity. Then the entrainers with top-ranking separation performance are manually screened based on vapor-liquid equilibria. Next, the Pareto front solution is obtained by optimizing both safety and economic objective functions using a multi-objective genetic algorithm. Finally, the thermal hazard of the entrainer is also investigated via DSC (Differential scanning calorimetry) test. Finally, the optimization result and thermal hazard investigation demonstrate that 1,3-propanediol is inherently safer than dimethyl sulfoxide (DMSO) as a common entrainer in terms of not only a fire hazard but also a thermal hazard for the separation of methyl acetate/methanol mixture. The optimal TAC using 1,3-propanediol as an entrainer is 3.72% lower than that of dimethyl sulfoxide, and the corresponding GISI is 57.73% lower than that of dimethyl sulfoxide. As for DMSO, thermal decomposition can occur near its normal boiling point (189 ℃) and 1,3-propanediol, can be thermally stable over 330 ℃. [ABSTRACT FROM AUTHOR]

Producing dimethyl carbonate (DMC) as a green chemical with the desired purity is important in the industry. Although studies on the steady‐state design of energy‐efficient extractive distillation processes are important for the purification of DMC‐methanol (DMC‐MeOH) azeotropic mixtures, the dynamic controllability of these processes is also critical in the case of feed condition changes, and it should be investigated carefully. Results of the limited studies in the literature show that changing the operating pressures in extractive distillation processes might have different effects on the dynamic controllability of different systems. Thus, in this study, alternative control strategies are developed for a recently proposed increased‐pressure extractive distillation process to separate DMC‐MeOH mixture. All control structures are designed using inferential temperature controllers, which have a general acceptance in industrial applications. Effects of different ratio controllers are investigated by evaluating the dynamic responses of control structures for disturbances in feed flowrate and composition. Two metrics including integral absolute error and steady‐state deviation of purities are used in the evaluation of alternatives. Results of dynamic simulations show that a control structure including reflux ratio controller is not a suitable strategy for this process. It is demonstrated that a control structure including reflux to feed ratio controller for both distillation columns is necessary for the robust and efficient control of a pressure‐increased extractive distillation process. These efficient dynamic results support the economic advantage of increased‐pressure extractive distillation process separating DMC‐MeOH azeotropic mixtures. [ABSTRACT FROM AUTHOR]

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]