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.

Simulation and Optimization on the Process of Acetic Acid Dehydration via Extraction Combined with Azeotropic Distillation

2012 ◽  
Vol 548 ◽  
pp. 349-354
Author(s):  
Yi Feng Chen ◽  
Ji He Yang
Keyword(s):  
Acetic Acid ◽  
Acetic Acid Solution ◽  
Azeotropic Distillation ◽  
Weight Percent ◽  
Dilute Solution ◽  
Relative Volatility ◽  
Simple Distillation ◽  
Simulation And Optimization ◽  
Isopropyl Acetate ◽  
Theoretical Plates

Some azeotropic entrainers in the process of acetic acid dehydration could extract acetic acid from its dilute solution; this text would observe the ability of extraction about these entrainers mentioned in the literatures. By using the EXTRACT module in Aspen Plus, it is found that isopropyl acetate was the most effective extracting agent. The process of acetic acid dehydration via extraction combined with azeotropic distillation by using isopropyl acetate was established. Acetic acid was first extracted from its dilute solution and then was distilled in the azeotropic column, finally acetic acid having 99.8%(weight percent) purity was obtained. This process avoided evaporating a lot of water from the solution, and the entrainer’s existence effectively enhanced the relative volatility between acetic acid and water. The simulation result indicated that when dealing with the acetic acid solution used in this research, the total heat exhaustion was reduced from 11.73MW to 2.98MW and the number of theoretical plates needed in the distillation was also reduced from 65 to 34 compared with simple distillation.

scholarly journals Extractive distillation: recent advances in operation strategies

2015 ◽  
Vol 31 (1) ◽  
Author(s):  
Weifeng Shen ◽  
Hassiba Benyounes ◽  
Vincent Gerbaud
Keyword(s):  
Extractive Distillation ◽  
Flow Rate Ratio ◽  
Reflux Ratio ◽  
Analysis Method ◽  
Relative Volatility ◽  
Pinch Point ◽  
Point Analysis ◽  
Process Operation ◽  
Map Analysis ◽  
Thermodynamic Feasibility

AbstractExtractive distillation is one of the efficient techniques for separating azeotropic and low-relative-volatility mixtures in various chemical industries. This paper first provides an overview of thermodynamic insight covering residue curve map analysis, the application of univolatility and unidistribution curves, and thermodynamic feasibility study. The pinch-point analysis method combining bifurcation shortcut presents another branch of study, and several achievements have been realized by the identification of possible product cut under the following key parameters: reflux ratio, reboil ratio, and entrainer-feed flow rate ratio. Process operation policies and strategy concerning batch extractive distillation processes are summarized in four operation steps. Several configurations and technological alternatives can be used when extractive distillation processes take place in a continuous or batch column, depending on the strategy selected for the recycle streams and for the main azeotropic feeds.

scholarly journals Valorization of secondary feedstocks from the agroindustry by selective catalytic oxidation to formic and acetic acid using the OxFA process

2021 ◽  
Author(s):  
Sebastian Ponce ◽  
Stefanie Wesinger ◽  
Daniela Ona ◽  
Daniela Almeida Streitwieser ◽  
Jakob Albert
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Reaction System ◽  
Value Added ◽  
Industrial Wastes ◽  
Raw Material ◽  
Gaseous Oxygen ◽  
Water As Solvent ◽  
Selective Catalytic Oxidation ◽  
Major Interest

AbstractThe selective oxidative conversion of seven representative fully characterized biomasses recovered as secondary feedstocks from the agroindustry is reported. The reaction system, known as the “OxFA process,” involves a homogeneous polyoxometalate catalyst (H8PV5Mo7O40), gaseous oxygen, p-toluene sulfonic acid, and water as solvent. It took place at 20 bar and 90 °C and transformed agro-industrial wastes, such as coffee husks, cocoa husks, palm rachis, fiber and nuts, sugarcane bagasse, and rice husks into biogenic formic acid, acetic acid, and CO2 as sole products. Even though all samples were transformed; remarkably, the reaction obtains up to 64, and 55% combined yield of formic and acetic acid for coffee and cocoa husks as raw material within 24 h, respectively. In addition to the role of the catalysts and additive for promoting the reaction, the influence of biomass components (hemicellulose, cellulose and lignin) into biogenic formic acid formation has been also demonstrated. Thus, these results are of major interest for the application of novel oxidation techniques under real recovered biomass for producing value-added products. Graphical abstract

Vapor-Liquid Equilibria for the Ternary System Ethyl Acetate-Acetonitrile-1-Octyl-3-Methylimidazolium Tetrafluoroborate

2013 ◽  
Vol 791-793 ◽  
pp. 141-144
Author(s):  
Xiu Min Shi ◽  
Min Wang
Keyword(s):  
Ionic Liquid ◽  
Ternary System ◽  
Ethyl Acetate ◽  
Mole Fraction ◽  
Salt Effect ◽  
Extractive Distillation ◽  
Relative Volatility ◽  
Azeotropic Point ◽  
Vapor Liquid Equilibria ◽  
Vapor Liquid

In order to research the possibility of separating the azeotrope of ethyl acetate + acetonitrile with ionic liquid as the extractant. Isobaric vapor-liquid equilibria for the ternary system ethyl acetate + acetonitrile + 1-octyl-3-methylimidazolium tetrafluoroborate ([OMIBF4) were measured at 101.32 kPa using a recirculation still. The results showed that the VLE of the ternary system was different from that of the binary system. The ionic liquid (IL) studied showed a slight crossover salt effect, which changed the relative volatility of ethyl acetate to acetonitrile and eliminated the azeotropic point when the mole fraction of IL in the liquid phase was greater than 0.05. Therefore, [OMIBF4 can be used as the extractant of extractive distillation for ethyl acetate + acetonitrile system, the suitable mole fraction of [OMIBF4 is about 10%.

scholarly journals Separation processes for high purity ethanol production

2010 ◽  
Author(s):  
◽  
Peterson Thokozani Ngema
Keyword(s):  
Salt Concentration ◽  
High Purity ◽  
Alternative Fuels ◽  
Water System ◽  
Extractive Distillation ◽  
Operating Pressure ◽  
Extractive Agent ◽  
Relative Volatility ◽  
Vle Data ◽  
Feed Temperature

Globally there is renewed interest in the production of alternate fuels in the form of bioethanol and biodiesel. This is mainly due to the realization that crude oil stocks are limited hence the swing towards more renewable sources of energy. Bioethanol and biodiesel have received increasing attention as excellent alternative fuels and have virtually limitless potential for growth. One of the key processing challenges in the manufacturing of biofuels is the production of high purity products. As bioethanol is the part of biofuels, the main challenge facing bioethanol production is the separation of high purity ethanol. The separation of ethanol from water is difficult because of the existence of an azeotrope in the mixture. However, the separation of the ethanol/water azeotropic system could be achieved by the addition of a suitable solvent, which influences the activity coefficient, relative volatility, flux and the separation factor or by physical separation based on molecular size. In this study, two methods of high purity ethanol separation are investigated: extractive distillation and pervaporation. The objective of this project was to optimize and compare the performance of pervaporation and extraction distillation in order to produce high purity ethanol. The scopes of the investigation include:  Study of effect of various parameters (i) operating pressure, (ii) operating temperature, and (iii) feed composition on the separation of ethanol-water system using pervaporation.  Study the effect of using salt as a separating agent and the operating pressure in the extractive distillation process. The pervaporation unit using a composite flat sheet membrane (hydrophilic membrane) produced a high purity ethanol, and also achieved an increase in water flux with increasing pressure and feed temperature. The pervaporation unit facilitated separation beyond the ethanol – water system azeotropic point. It is concluded that varying the feed temperature and the operating pressure, the performance of the pervaporation membrane can be optimised. v The extractive distillation study using salt as an extractive agent was performed using the low pressure vapour-liquid equilibrium (LPVLE) still, which was developed by (Raal and Mühlbauer, 1998) and later modified by (Joseph et al. 2001). The VLE study indicated an increase in relative volatility with increase in salt concentration and increase in pressure operating pressure. Salt concentration at 0.2 g/ml and 0.3 g/ml showed complete elimination of the azeotrope in ethanol-water system. The experimental VLE data were regressed using the combined method and Gibbs excess energy models, particular Wilson and NRTL. Both models have shown the best fit for the ethanol/water system with average absolute deviation (AAD) below 0.005. The VLE data were subjected to consistency test and according to the Point test, were of high consistency with average absolute deviations between experimental and calculated vapour composition below 0.005. Both extractive distillation using salt as an extractive agent and pervaporation are potential technologies that could be utilized for the production of high purity ethanol in boiethanol-production.

Steady-State Modelling and Simulation of a Reactive Distillation Process for n-Butyl Acetate Production Using CHEMCAD

2017 ◽  
Vol 29 ◽  
pp. 70-80 ◽  
Author(s):  
Abdulwahab Giwa ◽  
Saidat Olanipekun Giwa
Keyword(s):  
Acetic Acid ◽  
Steady State ◽  
Mole Fraction ◽  
Butyl Acetate ◽  
Reactive Distillation ◽  
Esterification Reaction ◽  
Reflux Ratio ◽  
Distillation Process ◽  
Condenser Section ◽  
Steady State Simulation

This work has been carried out to demonstrate the application of a process simulator known as CHEMCAD to the modelling and the simulation of a reactive distillation process used for the production of n-butyl acetate, with water as the by-product, from the esterification reaction between acetic acid and n-butanol. The esterification reaction, which is generally an equilibrium type, was modelled as two kinetic reaction types in the reaction section of the column used, which had 17 stages with the middle section (stages 6 – 12) being the reaction section. A reflux ratio of 3 and reboiler duty of 78 kJ/min as well as 30 mL/min of each of the reactants with 99% molar purity were used for the simulation of the column. The results obtained revealed that the developed model was a valid one because there was a very good agreement between the results and the theoretical knowledge of a distillation column based on the fact that the desired (which was the heavy) product (n-butyl acetate) was found to have the highest mole fraction in the bottom section of the column while the by-product of the process (water) was discovered to have a mole fraction higher than that of n-butyl acetate in the top (condenser) section of the column. Therefore, CHEMCAD has been applied to the steady-state simulation of the reactive distillation process used for the production of n-butyl acetate from the esterification reaction of acetic acid and n-butanol successfully.

Synthesis of High-Purity Methylal by Reactive and Extractive Distillation

2015 ◽  
Vol 723 ◽  
pp. 629-632
Author(s):  
Ji Quan Liu ◽  
Peng Wang
Keyword(s):  
Cation Exchange ◽  
High Purity ◽  
Distillation Column ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Extractive Distillation ◽  
Molar Ratio ◽  
Reflux Ratio ◽  
Optimum Conditions ◽  
Resin Catalyst

The process for production high-purity methylal, which used methanol and formalin in the presence of cation-exchange resin catalyst, was investigated in the reactive and extractive distillation column. Effect of feed mole ratio of formaldehyde in the extracting and reacting section, molar ratio of methanol and formaldehyde, reflux ratio on the content of methylal in the distillate were investigated. The results show that the purity of methylal can reach 99.1% under the optimum conditions.

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