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Vincent Gerbaud - One of the best experts on this subject based on the ideXlab platform.

  • Low pressure design for reducing energy cost of extractive distillation for separating Diisopropyl ether and Isopropyl alcohol
    Chemical Engineering Research and Design, 2016
    Co-Authors: Xinqiang You, Ivonne Rodriguez Donis, Vincent Gerbaud
    Abstract:

    We show how reducing pressure can improve the design of a 1.0-1a mixture homogeneous extractive distillation process and we use extractive efficiency indicators to compare the optimality of different designs. The case study concerns the separation of the diisopropyl ether (DIPE)–isopropyl alcohol (IPA) minimum boiling azeotrope with heavy entrainer 2-methoxyethanol. We first explain that the unexpected energy cost OF decrease following an increase of the distillate outputs is due to the interrelation of the two distillate flow rates and purities and the entrainer recycling through mass balance when considering both the extractive distillation column and the entrainer regeneration column. Then, we find that for the studied case a lower pressure reduces the usage of entrainer and increases the relative volatility of DIPE–IPA for the same entrainer content in the extractive column. A 0.4 atm operating pressure is selected to enable the use of cheap cooling water in the condenser. We run an optimization of the entrainer flow rate, both columns reflux ratios, distillates and feed locations by minimizing the total energy consumption per product unit. Double digit savings in energy consumption are achieved while TAC is reduced significantly. An extractive efficiency indicator that describes the ability of the extractive section to discriminate the desired product between the top and the bottom of the extractive section of the extractive section is calculated for comparing and explaining the benefit of lowering pressure on the basis of thermodynamic insight.

  • Systematic design of an extractive distillation for maximum-boiling azeotropes with heavy Entrainers
    AIChE Journal, 2015
    Co-Authors: Weifeng Shen, Lichun Dong, Shun An Wei, Xinqiang You, Hassiba Benyounes, Vincent Gerbaud
    Abstract:

    Extractive distillation is one of the most attractive approaches for separating azeotropic mixtures. Few contributions have been reported to design an extractive distillation for separating maximum-boiling azeotropes and no systematic approaches for entrainer screening have been presented. A systematic approach to design of two-column extractive distillation for separating azeotropes with heavy Entrainers has been proposed. A thermodynamic feasibility analysis for azeotropes with potential heavy Entrainers was first conducted. Then, five important properties are selected for entrainer evaluation. Fuzzy logic and develop membership functions to calculate attribute values of selected properties have been used. An overall indicator for entrainer evaluation is proposed and a ranking list is generated. Finally, the top five Entrainers from the ranking list have been selected and use process optimization techniques to further evaluate selected Entrainers and generate an optimal design. The capability of the proposed method is illustrated using the separation of acetone–chloroform azeotropes with five potential Entrainers.

  • investigation of separation efficiency indicator for the optimization of the acetone methanol extractive distillation with water
    Industrial & Engineering Chemistry Research, 2015
    Co-Authors: Xinqiang You, Ivonne Rodriguezdonis, Vincent Gerbaud
    Abstract:

    A multiobjective genetic algorithm optimization of the extractive distillation process of acetone–methanol minimum azeotropic mixture with heavy entrainer water is investigated. The process includes the extractive and entrainer regeneration columns, and the optimization minimizes the energy cost objective function (OF) and total annual cost (TAC) and maximizes efficiency indicators Eext and eext that describe the ability of the extractive section to discriminate the product between the top and the bottom of that section. Earlier work (You et al. Ind. Eng. Chem. Res. 2015, 54, 491) found that improvement of some designs in the literature led to an increase in those indicators. A two-step optimization strategy for extractive distillation is conducted to find suitable values of the entrainer feed flow rate, entrainer and azeotropic mixture feed locations, total number of trays, two reflux ratios, and two distillates in both the extractive column and the entrainer regeneration column. The first step relies up...

  • 1 Separation of n-hexane- ethyl acetate mixtures by azeotropic batch distillation with heterogeneous Entrainers.
    2015
    Co-Authors: Ivonne Rodriguez Donis, Vincent Gerbaud, J. Acosta-esquijarosa, E. Pardillo-fondevila
    Abstract:

    In this article, a systematic study of the separation of the n-hexane- ethyl acetate mixture with an entrainer by heterogeneous azeotropic batch distillation is performed. Based upon the thermodynamic behaviour of the ternary mixtures, potential Entrainers partially miscible with one or two original azeotropic components are chosen. In all cases, the entrainer adds a heterogeneous binary or ternary azeotrope that is the lowest boiling point in the ternary diagram. Therefore, it leaves the column by the overhead stream which is subcooled to get two liquid phases in the decanter. The phase with the highest amount of the original component is removed as distillate product whereas the entrainer – rich phase is continuously refluxed to the column. Considering methanol, acetonitrile, water and nitromethane as heterogeneous Entrainers, screening was performed based on the 2 composition of the unstable heteroazeotropic mixture, the ratio of both liquid phases in the condensed top vapour and the purity of the distillate product determined by the liquid – liquid envelope at the decanter temperature. The process feasibility analysis is validated by using rigorous simulation with the batch process simulator ProSimBatch. Simulation results are then corroborated in a bench experimental column for the selected entrainer, showing several advantages of heterogeneous batch distillation compared to homogeneous systems

  • Thermodynamic Insights on the Feasibility of Homogeneous Batch Extractive Distillation. 2. Low-Relative-Volatility Binary Mixtures with Heavy Entrainer
    Industrial and engineering chemistry research, 2009
    Co-Authors: Ivonne Rodriguez Donis, Vincent Gerbaud, Xavier Joulia
    Abstract:

    All former studies reported that the separation of the low relative volatility binary mixture by using a heavy entrainer in a batch rectifier imposed the obligatory withdrawal of the most volatile original component. In this paper, we demonstrate that this does not always happen and that the product sequence can be unambiguously determined from the sole analysis of thermodynamic properties of residue curve maps and the occurrence of unidistribution lines and univolatility lines, following the general feasibility criterion enounced in part I for the separation of azeotropic mixtures using heavy or light Entrainers. For low relative volatility mixtures, the original component having an intermediate boiling temperature can be also drawn as the first distillate product. Cases concerning 94% of statistically occuring zeotropic ternary mixtures are investigated, allowing to define the product sequence without any previous calculation of the liquid composition profile inside the column. Preliminary feasibility results are confirmed by computing maps of extractive and rectifying liquid composition profiles using a simplified mass balance. Final validation is done via rigourous simulation using ProSim Batch software.

Xavier Joulia - One of the best experts on this subject based on the ideXlab platform.

  • Thermodynamic Insights on the Feasibility of Homogeneous Batch Extractive Distillation. 2. Low-Relative-Volatility Binary Mixtures with Heavy Entrainer
    Industrial and engineering chemistry research, 2009
    Co-Authors: Ivonne Rodriguez Donis, Vincent Gerbaud, Xavier Joulia
    Abstract:

    All former studies reported that the separation of the low relative volatility binary mixture by using a heavy entrainer in a batch rectifier imposed the obligatory withdrawal of the most volatile original component. In this paper, we demonstrate that this does not always happen and that the product sequence can be unambiguously determined from the sole analysis of thermodynamic properties of residue curve maps and the occurrence of unidistribution lines and univolatility lines, following the general feasibility criterion enounced in part I for the separation of azeotropic mixtures using heavy or light Entrainers. For low relative volatility mixtures, the original component having an intermediate boiling temperature can be also drawn as the first distillate product. Cases concerning 94% of statistically occuring zeotropic ternary mixtures are investigated, allowing to define the product sequence without any previous calculation of the liquid composition profile inside the column. Preliminary feasibility results are confirmed by computing maps of extractive and rectifying liquid composition profiles using a simplified mass balance. Final validation is done via rigourous simulation using ProSim Batch software.

  • separation of azeotropes in batch extractive stripper with intermediate entrainer
    Computer-aided chemical engineering, 2006
    Co-Authors: Viktoria Varga, Xavier Joulia, Vincent Gerbaud, Erika R Frits, Z Fonyo, Zoltan Lelkes, Endre Rev
    Abstract:

    Batch extractive distillation is an attractive technique for separating azeotropic mixtures (Steger et al 2005). These processes can be carried out in a batch rectifier, and in a stripping column, as well; but, unfortunately, the necessary feasibility studies of the latter one are still missing from the scientific communications. Here we present the first preliminary results on the feasibility of separating azeotropes with intermediate boiling entrainer in batch extractive stripper. The following mixtures are studied here: 1: methanol (MeOH)/toluene (TOL) (minimum boiling azeotrope) with triethylamine (Et3N) as intermediate boiling entrainer; 2: chloroform (CHCl3)/ethyl acetate (EtOAc) (maximum boiling azeotrope) with 2-chlorobutane (2ClBu) as intermediate boiling entrainer. Separation of the same mixtures with the same Entrainers in rectifier have already been studied (Lelkes et al., 2002, Varga, 2003); thus, the results of the present feasibility study allow comparing the separation processes in a stripper or in a rectifier for the selected specified mixtures. Similar mixtures occure, in Rev et al., 2003. The mixture to be separated is charged to the reflux drum (the so-called vessel, or still vessel), of great hold-up capacity. Liquid entrainer is added to the stripping unit for enhancing the relative volatility of the mixture. The boiler at the bottom of the column serves as to evaporate the liquid. The product is removed from the bottom. The entrainer is either premixed to the charge (Solvent-enhanced Batch Stripping, SBS), or it can be continuously fed to the system (Batch Extractive Stripping, BES). The place of the continuous feeding can be the top vessel (BES-T), or some intermediate point in the column (BES-I).

  • heterogeneous batch extractive distillation of minimum boiling azeotropic mixtures
    Aiche Journal, 2003
    Co-Authors: Ivonne Rodriguez Donis, Vincent Gerbaud, Jhoany Acosta Esquijarosa, Xavier Joulia
    Abstract:

    Following previous studies on heterogeneous batch azeotropic distillation, the use of heterogeneous Entrainers for the separation of binary azeotropic mixtures by extractive distillation is evaluated. This process is well suited for systems where the entrainer forms a saddle heteregeneous azeotrope with any one of the original components, such systems being unsuitable for nonextractive heterogeneous batch-distillation processes. Process feasibility is assessed from the isovolatility curves and the volatility order diagram. It tells us whether the homogeneous original component or the heteroazeotrope is drawn at the column top and establishes the distillation tasks sequence using a batch-rectifying column. The theoretical insights are validated via rigourous simulation for the separation of the acetonitrile–water mixture with hexylamine or butyl acetate. Finally, the same method is applied for the theoretical analysis of a reported industrial example where water is used for the separation of a binary organic mixture, leading to a complex ternary system with several binary azeotropic points and a homogenous ternary azeotrope.

  • entrainer selection rules for the separation of azeotropic and close boiling temperature mixtures by homogeneous batch distillation process
    Industrial & Engineering Chemistry Research, 2001
    Co-Authors: Ivonne Rodriguezdonis, Vincent Gerbaud, Xavier Joulia
    Abstract:

    Batch distillation of nonideal mixtures usually produces the azeotropes often associated with those mixtures. Among various techniques available to break azeotropes, azeotropic and extractive distillation processes have a place of choice. They rely upon the selection of a suitable entrainer. Entrainer screening is therefore a key step for the synthesis and design of these processes. From an analysis of all ternary residue curve maps under assumptions of a large number of stages and total reflux/reboil ratio, we devise in this paper a complete set of rules for the selection of a suitable entrainer enabling the separation of minimum- and maximum-boiling azeotropic binary mixtures and close-boiling-temperature binary mixtures. These rules complete previously published rules and expand by many times the set of entrainer alternatives previously considered. Feasible batch distillation processes can always be obtained considering two batch task sequences using rectifier and stripper configurations. The effect of distillation boundary curvature on the selection of Entrainers is analyzed, and in this case, a sequence of up to a three batch distillation configurations must be used to separate the original mixture components. Several practical examples are shown to illustrate the application of the defined rules in each studied case.

  • entrainer selection rules for the separation of azeotropic and close boiling temperature mixtures by homogeneous batch distillation process
    Industrial & Engineering Chemistry Research, 2001
    Co-Authors: Ivonne Rodriguezdonis, Vincent Gerbaud, Xavier Joulia
    Abstract:

    Batch distillation of nonideal mixtures usually produces the azeotropes often associated with those mixtures. Among various techniques available to break azeotropes, azeotropic and extractive distillation processes have a place of choice. They rely upon the selection of a suitable entrainer. Entrainer screening is therefore a key step for the synthesis and design of these processes. From an analysis of all ternary residue curve maps under assumptions of a large number of stages and total reflux/reboil ratio, we devise in this paper a complete set of rules for the selection of a suitable entrainer enabling the separation of minimum- and maximum-boiling azeotropic binary mixtures and close-boiling-temperature binary mixtures. These rules complete previously published rules and expand by many times the set of entrainer alternatives previously considered. Feasible batch distillation processes can always be obtained considering two batch task sequences using rectifier and stripper configurations. The effect of distillation boundary curvature on the selection of Entrainers is analyzed, and in this case, a sequence of up to a three batch distillation configurations must be used to separate the original mixture components. Several practical examples are shown to illustrate the application of the defined rules in each studied case.

Ivonne Rodriguezdonis - One of the best experts on this subject based on the ideXlab platform.

  • investigation of separation efficiency indicator for the optimization of the acetone methanol extractive distillation with water
    Industrial & Engineering Chemistry Research, 2015
    Co-Authors: Xinqiang You, Ivonne Rodriguezdonis, Vincent Gerbaud
    Abstract:

    A multiobjective genetic algorithm optimization of the extractive distillation process of acetone–methanol minimum azeotropic mixture with heavy entrainer water is investigated. The process includes the extractive and entrainer regeneration columns, and the optimization minimizes the energy cost objective function (OF) and total annual cost (TAC) and maximizes efficiency indicators Eext and eext that describe the ability of the extractive section to discriminate the product between the top and the bottom of that section. Earlier work (You et al. Ind. Eng. Chem. Res. 2015, 54, 491) found that improvement of some designs in the literature led to an increase in those indicators. A two-step optimization strategy for extractive distillation is conducted to find suitable values of the entrainer feed flow rate, entrainer and azeotropic mixture feed locations, total number of trays, two reflux ratios, and two distillates in both the extractive column and the entrainer regeneration column. The first step relies up...

  • separation of ethyl acetate isooctane mixture by heteroazeotropic batch distillation
    Chemical Engineering Research & Design, 2014
    Co-Authors: Tom Ooms, Steven Vreysen, Guy Van Baelen, Vincent Gerbaud, Ivonne Rodriguezdonis
    Abstract:

    This paper studies the separation of an ethyl acetate–isooctane mixture by heterogeneous azeotropic distillation in a batch rectifying column. An initial list of 60 candidates was studied but only methanol and acetonitrile were obtained as potential heterogeneous Entrainers. These Entrainers form a low boiling heterogeneous azeotrope with isooctane. Experimental verification of the miscibility gap with isooctane was performed at 25 °C for each entrainer giving a smaller region for methanol than for acetonitrile. Feasibility of the heterogeneous azeotropic batch distillation was carried out experimentally in a laboratory batch distillation column having 44 theoretical equilibrium stages and using a high reflux ratio. Several distillate fractions were taken as a function of the temperature at the top of the column. For both methanol and acetonitrile, the main fraction was defined by the condensed vapor providing a liquid–liquid split of the isooctane/entrainer heteroazeotrope into the decanter. Ethyl acetate impurity was detected in both decanted phases, but in much lower amount when using acetonitrile as entrainer. The process with acetonitrile also resulted in a shorter operating time and higher purity and recovery yield of isooctane as the main distillate product. Pure ethyl acetate remained into the boiler at the end of each process.

  • entrainer selection rules for the separation of azeotropic and close boiling temperature mixtures by homogeneous batch distillation process
    Industrial & Engineering Chemistry Research, 2001
    Co-Authors: Ivonne Rodriguezdonis, Vincent Gerbaud, Xavier Joulia
    Abstract:

    Batch distillation of nonideal mixtures usually produces the azeotropes often associated with those mixtures. Among various techniques available to break azeotropes, azeotropic and extractive distillation processes have a place of choice. They rely upon the selection of a suitable entrainer. Entrainer screening is therefore a key step for the synthesis and design of these processes. From an analysis of all ternary residue curve maps under assumptions of a large number of stages and total reflux/reboil ratio, we devise in this paper a complete set of rules for the selection of a suitable entrainer enabling the separation of minimum- and maximum-boiling azeotropic binary mixtures and close-boiling-temperature binary mixtures. These rules complete previously published rules and expand by many times the set of entrainer alternatives previously considered. Feasible batch distillation processes can always be obtained considering two batch task sequences using rectifier and stripper configurations. The effect of distillation boundary curvature on the selection of Entrainers is analyzed, and in this case, a sequence of up to a three batch distillation configurations must be used to separate the original mixture components. Several practical examples are shown to illustrate the application of the defined rules in each studied case.

  • entrainer selection rules for the separation of azeotropic and close boiling temperature mixtures by homogeneous batch distillation process
    Industrial & Engineering Chemistry Research, 2001
    Co-Authors: Ivonne Rodriguezdonis, Vincent Gerbaud, Xavier Joulia
    Abstract:

    Batch distillation of nonideal mixtures usually produces the azeotropes often associated with those mixtures. Among various techniques available to break azeotropes, azeotropic and extractive distillation processes have a place of choice. They rely upon the selection of a suitable entrainer. Entrainer screening is therefore a key step for the synthesis and design of these processes. From an analysis of all ternary residue curve maps under assumptions of a large number of stages and total reflux/reboil ratio, we devise in this paper a complete set of rules for the selection of a suitable entrainer enabling the separation of minimum- and maximum-boiling azeotropic binary mixtures and close-boiling-temperature binary mixtures. These rules complete previously published rules and expand by many times the set of entrainer alternatives previously considered. Feasible batch distillation processes can always be obtained considering two batch task sequences using rectifier and stripper configurations. The effect of distillation boundary curvature on the selection of Entrainers is analyzed, and in this case, a sequence of up to a three batch distillation configurations must be used to separate the original mixture components. Several practical examples are shown to illustrate the application of the defined rules in each studied case.

  • middle vessel heterogeneous batch distillation of an azeotropic mixture
    Computer-aided chemical engineering, 2001
    Co-Authors: Ivonne Rodriguezdonis, Vincent Gerbaud, Xavier Joulia
    Abstract:

    Publisher Summary This chapter discusses the operation of heterogeneous batch distillation (HBD) in a middle vessel column (MVC). A feasibility analysis is attempted and simulations are carried out, which demonstrates the advantage of MVC compared to regular and inverted columns. HBD synthesis differs significantly from homogeneous batch distillation synthesis. Some advantages of HBD processes compared to homogeneous systems are more design alternatives for the separation of nonideal mixtures, simplified distillation sequences because of less distillation, addition of less entrainer, crossing of batch distillation boundaries because of a flexible reflux policy that enables to reflux to the column a mixture different from the distillate through any combination of the entrainer-rich phase and the distillate-rich phase. A complete set of rules for the selection of both homogeneous and heterogeneous Entrainers for the separation of minimum or maximum temperature azeotropic binary mixtures is determined. The feasibility of the separation of the water-acetonitrile-acrylonitrile-acetic acid mixture by simulating HBD process is discussed.

Lei Zhong - One of the best experts on this subject based on the ideXlab platform.

  • entrainer assisted pressure swing distillation for separating the minimum boiling azeotrope toluene pyridine design and control
    Industrial & Engineering Chemistry Research, 2017
    Co-Authors: Lei Zhong
    Abstract:

    The separation of toluene/pyridine by distillation still remains an obstacle in industry because of not only the formation of a minimum-boiling azeotrope but also their relative volatilities, whose ratio is close to unity throughout the whole composition range. Extractive distillation is still not feasible because it is hard to find suitable Entrainers. Heterogeneous azeotropic distillation might require high energy consumption to obtain both purified products. Conventional pressure-swing distillation is also not feasible. In this work, we apply entrainer-assisted pressure-swing distillation to separate toluene/pyridine (95 mol %/5 mol %) by introducing n-propanol as an entrainer. Based on the different compositions of the recycling stream sent back to the azeotropic column, a two-column sequence and a three-column sequence are established. Both sequences are partially heat-integrated. The steady-state designs of both sequences are optimized based on the total annual cost (TAC). The results reveal that th...

  • Entrainer-Assisted Pressure-Swing Distillation for Separating the Minimum-Boiling Azeotrope Toluene/Pyridine: Design and Control
    2017
    Co-Authors: Lei Zhong
    Abstract:

    The separation of toluene/pyridine by distillation still remains an obstacle in industry because of not only the formation of a minimum-boiling azeotrope but also their relative volatilities, whose ratio is close to unity throughout the whole composition range. Extractive distillation is still not feasible because it is hard to find suitable Entrainers. Heterogeneous azeotropic distillation might require high energy consumption to obtain both purified products. Conventional pressure-swing distillation is also not feasible. In this work, we apply entrainer-assisted pressure-swing distillation to separate toluene/pyridine (95 mol %/5 mol %) by introducing n-propanol as an entrainer. Based on the different compositions of the recycling stream sent back to the azeotropic column, a two-column sequence and a three-column sequence are established. Both sequences are partially heat-integrated. The steady-state designs of both sequences are optimized based on the total annual cost (TAC). The results reveal that the optimal two-column sequence has a 16.07% reduction of TAC and a 14.39% energy savings compared with the three-column sequence. Furthermore, the dynamic controllability of the two-column sequence is investigated by introducing ±10% disturbances in the feed flow rate and ±20% disturbances in the pyridine concentration. A conventional temperature control structure is implemented. As the fresh feed is quite dilute in pyridine, the purity of the pyridine product will be significantly influenced by even a small change in the recycling-stream flow rate. Therefore, the recycling-stream flow rate must be selected as a manipulated variable that is manipulated to control the pyridine product purity. The results reveal that robust control can be achieved

Gerbaud Vincent - One of the best experts on this subject based on the ideXlab platform.

  • Review of Extractive Distillation. Process design, operation optimization and control
    'Elsevier BV', 2019
    Co-Authors: Gerbaud Vincent, Rodríguez-donis Ivonne, Hegely Laszlo, Láng Péter, Dénes Ferenc, You Xinqiang
    Abstract:

    International audienceExtractive distillation processes enable the separation of non-ideal mixtures, including minimum or maximum boiling azeotropes and low relative volatility mixtures. Unlike azeotropic distillation, the entrainer fed at another location than the main mixture induces an extractive section within the column. A general feasibility criterion shows that intermediate and light Entrainers and heterogeneous Entrainers are suitable along common heavy Entrainers. Entrainer selection rules rely upon selectivity ratios and residue curve map (rcm) topology including univolatility curves. For each type of entrainer, we define extractive separation classes that summarize feasibility regions, achievable products and entrainer – feed flow rate ratio limits. Case studies are listed as supplementary materials. Depending on the separation class, a direct or an indirect split column configuration will allow to obtain a distillate product or a bottom product, which is usually a saddle point of rcm. Batch and continuous process operations differ mainly by the feasible ranges for the entrainer – feed flow rate ratio and reflux ratio. The batch process is feasible under total reflux and can orient the still path by changing the reflux policy. Optimisation of the extractive process must systematically consider the extractive column along with the entrainer regeneration column that requires energy and may limit the product purity in the extractive column through recycle. For the sake of reducing the energy cost and the total cost, pressure change can be beneficial as it affects volatility, or new process structures can be devised, namely heat integrated extractive distillation, extractive divided wall column or processes with preconcentrator

  • Review of Extractive Distillation. Process design, operation optimization and control
    'Elsevier BV', 2019
    Co-Authors: Gerbaud Vincent, Rodríguez-donis Ivonne, Hegely Laszlo, Láng Péter, Dénes Ferenc, You Xinqiang
    Abstract:

    Extractive distillation processes enable the separation of non-ideal mixtures, including minimum or maximum boiling azeotropes and low relative volatility mixtures. Unlike azeotropic distillation, the entrainer fed at another location than the main mixture induces an extractive section within the column. A general feasibility criterion shows that intermediate and light Entrainers and heterogeneous Entrainers are suitable along common heavy Entrainers. Entrainer selection rules rely upon selectivity ratios and residue curve map (rcm) topology including univolatility curves. For each type of entrainer, we define extractive separation classes that summarize feasibility regions, achievable products and entrainer – feed flow rate ratio limits. Case studies are listed as supplementary materials. Depending on the separation class, a direct or an indirect split column configuration will allow to obtain a distillate product or a bottom product, which is usually a saddle point of rcm. Batch and continuous process operations differ mainly by the feasible ranges for the entrainer – feed flow rate ratio and reflux ratio. The batch process is feasible under total reflux and can orient the still path by changing the reflux policy. Optimisation of the extractive process must systematically consider the extractive column along with the entrainer regeneration column that requires energy and may limit the product purity in the extractive column through recycle. For the sake of reducing the energy cost and the total cost, pressure change can be beneficial as it affects volatility, or new process structures can be devised, namely heat integrated extractive distillation, extractive divided wall column or processes with preconcentrator

  • CAMD for entrainer screening of extractive distillation process based on new thermodynamic criteria
    'Elsevier BV', 2019
    Co-Authors: Cignitti Stefano, Rodríguez-donis Ivonne, You Xinqiang, Abildskov Jens, Shcherbakova Nataliya, Gerbaud Vincent
    Abstract:

    International audienceThis paper presents a preliminary design framework for finding suitable homogeneous Entrainers E to separate minimum boiling azeotropic mixtures AB by extractive distillation. The framework incorporates techniques such as Computer Aided Molecular Design (CAMD), addressing process needs and targeted thermodynamic properties. New thermodynamic criteria are considered for the entrainer design based on both, the thermodynamic properties of the binary mixtures AE and BE and the isovolatility curves in the ternary mixture ABE. In the CAMD problem, energy related property constraints on the boiling point and the vaporization enthalpy are also considered, leading to a mixed integer non-linear programming problem. Entrainer candidates are ranked by the maximization of the driving force of separation of A and B from their respective mixtures AE and BE under constraints limiting the entrainer composition for fixed values of the relative volatility. Further process optimization is done for validating the entrainer ranking by using Aspen plus V7.3, which minimizes the energy consumption and computes the total annual cost to compare different designs. The new thermodynamic criteria perform better than selectivity alone or a combined selectivity — capacity criterion, as proposed in the literature. The framework is illustrated through an entrainer problem design for the separation of acetone–methanol. Ethylene glycol is obtained as the best design solution. Comparison with conventional Entrainers water and DMSO is carried out to validate the performance of the new criteria based on optimal process design study

  • CAMD for entrainer screening of extractive distillation process based on new thermodynamic criteria
    'Elsevier BV', 2019
    Co-Authors: Cignitti Stefano, Rodríguez-donis Ivonne, You Xinqiang, Abildskov Jens, Shcherbakova Nataliya, Gerbaud Vincent
    Abstract:

    This paper presents a preliminary design framework for finding suitable homogeneous Entrainers E to separate minimum boiling azeotropic mixtures AB by extractive distillation. The framework incorporates techniques such as Computer Aided Molecular Design (CAMD), addressing process needs and targeted thermodynamic properties. New thermodynamic criteria are considered for the entrainer design based on both, the thermodynamic properties of the binary mixtures AE and BE and the isovolatility curves in the ternary mixture ABE. In the CAMD problem, energy related property constraints on the boiling point and the vaporization enthalpy are also considered, leading to a mixed integer non-linear programming problem. Entrainer candidates are ranked by the maximization of the driving force of separation of A and B from their respective mixtures AE and BE under constraints limiting the entrainer composition for fixed values of the relative volatility. Further process optimization is done for validating the entrainer ranking by using Aspen plus V7.3, which minimizes the energy consumption and computes the total annual cost to compare different designs. The new thermodynamic criteria perform better than selectivity alone or a combined selectivity — capacity criterion, as proposed in the literature. The framework is illustrated through an entrainer problem design for the separation of acetone–methanol. Ethylene glycol is obtained as the best design solution. Comparison with conventional Entrainers water and DMSO is carried out to validate the performance of the new criteria based on optimal process design study

  • Systematic Design of an Extractive Distillation for Maximum-Boiling Azeotropes with Heavy Entrainers
    'Wiley', 2015
    Co-Authors: Shen Weifeng, You Xinqiang, Dong Lichun, Wei Shun'an, Li Jie, Benyounes Hassiba, Gerbaud Vincent
    Abstract:

    Extractive distillation is one of the most attractive approaches for separating azeotropic mixtures. Few contributions have been reported to design an extractive distillation for separating maximum-boiling azeotropes and no systematic approaches for entrainer screening have been presented. A systematic approach to design of two-column extractive distillation for separating azeotropes with heavy Entrainers has been proposed. A thermodynamic feasibility analysis for azeotropes with potential heavy Entrainers was first conducted. Then, five important properties are selected for entrainer evaluation. Fuzzy logic and develop membership functions to calculate attribute values of selected properties have been used. An overall indicator for entrainer evaluation is proposed and a ranking list is generated. Finally, the top five Entrainers from the ranking list have been selected and use process optimization techniques to further evaluate selected Entrainers and generate an optimal design. The capability of the proposed method is illustrated using the separation of acetone-chloroform azeotropes with five potential Entrainers. (c) 2015 American Institute of Chemical Engineer