Comparison of heterogeneous azeotropic distillation and extractive distillation methods for ternary azeotrope ethanol/toluene/water separation

2017 ◽  
Vol 100 ◽  
pp. 27-37 ◽  
Author(s):  
Lei Zhao ◽  
Xinyu Lyu ◽  
Wencheng Wang ◽  
Jun Shan ◽  
Tao Qiu
Keyword(s):  
Azeotropic Distillation ◽  
Extractive Distillation ◽  
Water Separation ◽  
Ternary Azeotrope

scholarly journals Simulasi CHEMCAD: Studi Kasus Distilasi Ekstraktif pada Campuran Terner n-Propil Asetat/n-Propanol/Air

2018 ◽  
Vol 2 (2) ◽  
pp. 75 ◽  
Author(s):  
Agung Ari Wibowo ◽  
Cucuk Evi Lusiani ◽  
Rizqy Romadhona Ginting ◽  
Dhoni Hartanto
Keyword(s):  
Extractive Distillation ◽  
Water Mixture ◽  
Distillation Process ◽  
Propyl Acetate ◽  
Extractive Agent ◽  
Simple Distillation ◽  
Simulation Process ◽  
Ternary Azeotrope ◽  
Vaporization Process ◽  
Separating Agent

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.

Production of Anhydrous Ethanol Using Azeotropic Distillation with Petroleum Cuts or Gasoline Pool

2008 ◽  
Vol 59 (2) ◽  
pp. 231-242
Author(s):  
Florin Oprea ◽  
Ionut Stoica
Keyword(s):  
Energy Consumption ◽  
Thermodynamic Model ◽  
Azeotropic Distillation ◽  
Extractive Distillation ◽  
Anhydrous Ethanol ◽  
Continuous Increase ◽  
Commercial Gasoline ◽  
Per Se ◽  
Pressure Swing ◽  
Pressure Swing Distillation

It is now a fact that biofuels have a certain future, whether it is about �biodiesel� or �bioethanol�. EU intends to impose continuous increase of biofuels proportion in commercial products. Ethanol can be used �per se� in commercial gasoline (in different proportions) or can be used instead of methanol in etherification reaction. In both cases it is necessary to use anhydrous ethanol. There are several drying processes: azeotropic distillation, extractive distillation, pressure swing distillation, and adsorption. Present work proposes azeotropic distillation using like entrainer petroleum cuts or commercial gasoline pool. Finally, anhydrous ethanol contains hydrocarbons in several proportions and can be used like commercial gasoline component. The main advantage of this process is that the separation alcohol-hydrocarbons is not so tight, resulting important reducing of the energy consumption in process. There is used a rigorous thermodynamic model as the results are very trusted.

Study on the Separation of Azeotrope of Tetrahydrofuran-Water Using a Combined Method of Extractive and General Distillation

2013 ◽  
Vol 803 ◽  
pp. 149-152 ◽  
Author(s):  
Zhi Dong Fan ◽  
Xu Bin Zhang ◽  
Lu Yang Zhao ◽  
Wang Feng Cai ◽  
Fu Min Wang
Keyword(s):  
Ethylene Glycol ◽  
Boiling Point ◽  
Mass Fraction ◽  
Azeotropic Distillation ◽  
Extractive Distillation ◽  
Combined Method ◽  
Production Water ◽  
Pressure Swing ◽  
Pressure Swing Distillation

As an important solvent, tetrahydrofuran has broad applications. Due to its process of production, water will be mixed into the product and should be removed. However, tetrahydrofuran will form a minimum boiling azeotrope with water, which has a boiling point of 63.4°C, so general distillation can not separate them. Common methods to solve this include extractive distillation, pressure swing distillation, azeotropic distillation, pervaporation and so on. In this experiment, we coupled extractive distillation and general distillation, selecting ethylene glycol as the extractant, and successfully dehydrated the azeotrope. The mass fraction of water is reduced from 18% to less than 500ppm,which matches the requirement.

Recovery of acetic acid from waste streams by extractive distillation

2003 ◽  
Vol 47 (10) ◽  
pp. 183-188 ◽  
Author(s):  
H. Demiral ◽  
M. Ercengiz Yildirim
Keyword(s):  
Acetic Acid ◽  
Feed Rate ◽  
Environmental Problem ◽  
Azeotropic Distillation ◽  
Extractive Distillation ◽  
Industrial Wastes ◽  
Reflux Ratio ◽  
Waste Streams ◽  
Relative Volatility ◽  
Solvent Type

Wastes have been considered to be a serious worldwide environmental problem in recent years. Because of increasing pollution, these wastes should be treated. However, industrial wastes can contain a number of valuable organic components. Recovery of these components is important economically. Using conventional distillation techniques, the separation of acetic acid and water is both impractical and uneconomical, because it often requires large number of trays and a high reflux ratio. In practice special techniques are used depending on the concentration of acetic acid. Between 30 and 70% (w/w) acetic acid contents, extractive distillation was suggested. Extractive distillation is a multicomponent-rectification method similar in purpose to azeotropic distillation. In extractive distillation, to a binary mixture which is difficult or impossible to separate by ordinary means, a third component termed an entrainer is added which alters the relative volatility of the original constituents, thus permitting the separation. In our department acetic acid is used as a solvent during the obtaining of cobalt(III) acetate from cobalt(II) acetate by an electrochemical method. After the operation, the remaining waste contains acetic acid. In this work, acetic acid which has been found in this waste was recovered by extractive distillation. Adiponitrile and sulfolane were used as high boiling solvents and the effects of solvent feed rate/ solution feed rate ratio and solvent type were investigated. According to the experimental results, it was seem that the recovery of acetic acid from waste streams is possible by extractive distillation.

scholarly journals Comparison of extractive distillation flowsheets for methanol–tetrahydrofuran–water mixtures

2020 ◽  
Vol 15 (3) ◽  
pp. 21-30
Author(s):  
V. M. Raeva ◽  
A. M. Dubrovsky
Keyword(s):  
Energy Consumption ◽  
Software Package ◽  
Extractive Distillation ◽  
Ternary Mixtures ◽  
Extractive Agent ◽  
Water Separation ◽  
Distillation Columns ◽  
Distillation Flowsheets ◽  
Pharmaceutical Industries ◽  
Vapor Liquid

Objectives. Synthesis and comparative analysis of the extractive distillation flowsheets for aqueous mixtures of solvents utilized in pharmaceutical industries using the example of a methanol−tetrahydrofuran−water system with various compositions. The ternary system contains two minimally boiling azeotropes that exist in a vapor–liquid phase equilibrium. To evaluate the selective effect of glycerol, the phase equilibria of the methanol–tetrahydrofuran–water and methanol–tetrahydrofuran–water–glycerol systems at 101.32 kPa were studied.Methods. The calculations were carried out in the Aspen Plus V.9.0 software package. The vapor–liquid equilibria were simulated using the non-random two-liquid (NRTL) equation with the binary interaction parameters of the software package database. To account for the non-ideal behavior of the vapor phase, the Redlich–Kwong equation of state was used. The calculations of the extractive distillation schemes were carried out at 101.32 kPa.Results. The conceptual flowsheets of extractive distillation are proposed. The flowsheets consist of three (schemes I–III) or four (scheme IV) distillation columns operating at atmospheric pressure. In schemes I and II, the extractive distillation of the mixtures is carried out with tetrahydrofuran isolation occurring in the distillate stream. Further separation in the schemes differs in the order of glycerol isolation: in the third column for scheme I (traditional extractive distillation complex) or in the second column for scheme II (two-column extractive distillation complex + methanol/water separation column). Sсheme III caters to the complete dehydration of the basic ternary mixtures, followed by the extractive distillation of the azeotropic methanol–tetrahydrofuran system, also with glycerol. Sсheme IV includes a preconcentration column (for the partial removal of water) and a traditional extractive distillation complex.Conclusions. According to the criterion of least energy consumption for separation (the total load of the reboilers of distillation columns), sсheme I (a traditional complex of extractive distillation) is recommended. Additionally, the energy expended for the separation of the basic equimolar mixture using glycerol as the extractive agent was compared with that expended using another selective agent: 1,2-ethanediol. Glycerol is an effective extractive agent because it reduces energy consumption, in comparison with 1,2-ethanediol, by more than 5%.

scholarly journals ANALYSIS OF ENERGY CONSUMPTION OF EXTRACTIVE DISTILLATION FLOWSHEETS OF FOUR-COMPONENT SOLVENT MIXTURE

2021 ◽  
Vol 64 (6) ◽  
pp. 47-55
Author(s):  
Dmitry A. Ryzhkin ◽  
Valentina M. Raeva
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Dimethyl Sulfoxide ◽  
Extractive Distillation ◽  
Pressure Change ◽  
Total Energy Consumption ◽  
Water Separation ◽  
Selective Agents ◽  
Distillation Flowsheets ◽  
Pharmaceutical Industries

A comparative analysis of energy consumption for extractive distillation flowsheets was carried out. This was done by the example of methanol - ethanol - acetonitrile - mixture. These solvents are used in pharmaceutical industries. The basic system methanol - ethanol - acetonitrile - water contains four binary and one ternary minimum-boiling azeotropes. Pressure change has almost no effect on the location of separatric surfaces. Therefore, extractive distillation should be used to separate solvents mixtures of any composition. Industrial entrainers dimethyl sulfoxide and glycerol are considered as selective agents. The effect of entrainer on vapor-liquid equilibrium at 30 and 101.32 kPa was evaluated by the relative volatility of the components forming azeotropes and the selectivity of the agents. The simulation was carried out on the Aspen Plus V.10.0 program environment. Two extractive distillation flosheets for the methanol - ethanol - acetonitrile - water separation are investigated. Both schemes include a two-column complex for the extractive distillation of the base mixture: in the first column, organic solvents are separated from water, and in the second column, the agent is regenerated. For subsequent separation of acetonitrile, extractive distillation with dimethyl sulfoxide or glycerol is also used. But separation of methanol-ethanol - entrainert zeotropic mixtures differs in the order of separation of components in schemes I and II. In scheme I, regeneration of the agent and further separation of the alcohol mixture is provided, in scheme II, methanol is first isolated, and then ethanol is separated from the agent. The optimized results for both schemes at columns pressures 30 and 101.32 kPa are performed. Different sets of selective agents introduced into extractive distillation columns are considered. The concept of an effective set of entrainers is introduced. The evaluation of the design alternatives need the assessment of energy demands. Total energy consumption for separation (reboiler duty) for the scheme II at 35-38% higher than values for scheme I. On the criterion of the minimum total energy consumption for the separation the scheme I was recommended: pressure columns 30 kPa, effective set of entrainers: glycerol for dehydration of the base mixture and dimethyl sulfoxide for acetonitrile isolation.

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