Isobaric vapor–liquid equilibria for water + acetic acid + (N-methyl pyrrolidone or N-methyl acetamide)

doi:10.1016/j.fluid.2006.02.002

Fluid Phase Equilibria

Volume 242, Issue 2, 25 April 2006, Pages 204-209

https://doi.org/10.1016/j.fluid.2006.02.002 Get rights and content

Abstract

Isobaric vapor–liquid equilibria (VLE) data for acetic acid + N-methyl pyrrolidone, acetic acid + N-methyl acetamide, water + acetic acid + N-methyl pyrrolidone, and water + acetic acid + N-methyl acetamide systems have been measured at 101.33 kPa using a recirculating still. The nonideality of the vapor phase caused by the association of the acetic acid has been corrected by the chemical theory and Hayden–O’Connell method. The experimental binary data have been correlated by the NRTL, UNIQUAC, and Wilson models. The three models with their best fitted binary parameters have been used to predict ternary VLE data. A comparison of three model performances was made by using the criterion of average absolute deviations in equilibrium temperature and vapor-phase composition.

Introduction

The separation of organic acids from aqueous solutions is industrially important, and extractive distillation is an attractive process for such separation. Several solvents [1], [2], such as N-methyl pyrrolidone, N-methyl acetamide, dimethyl sulfoxide, sulfolane, and so on, have been used as solvents for the separation of acetic acid. It is known that vapor–liquid equilibria data is vital to the simulation and design of the extractive distillation process. However, for the water + acetic acid + (N-methyl pyrrolidone or N-methyl acetamide or dimethyl sulfoxide or sulfolane systems), only the vapor–liquid equilibria data for the water + (acetic acid or N-methyl pyrrolidone or N-methyl acetamide or dimethyl sulfoxide) systems are reported [3]. No experimental study of the vapor–liquid equilibria of acetic acid + (N-methyl acetamide or N-methyl pyrrolidone) system at 101.33 kPa has been found. The aim of this artical is mainly to investigate the vapor–liquid phase equilibria of acetic acid + N-methyl pyrrolidone, acetic acid + N-methyl acetamide, water + acetic acid + N-methyl pyrrolidone, and water + acetic acid + N-methyl acetamide systems at 101.33 kPa and supply basic data for the simulation and design of the extractive distillation process.

The acetic acid molecules strongly associate with each other due to the hydrogen bond between two molecules [4]. And the association effect on vapor–liquid equilibrium should not be neglected. In the present study, the deviation from ideal gas behavior is described with the chemical theory [5] and the Hayden–O’Connell (HOC) equation [6]. The theories have been commonly used to calculate the vapor–liquid equilibria of systems with associating components. The nonidealities are considered by the nonrandom two-liquids model (NRTL) [7], Wilson [8], and the universal quasi-chemical theory (UNIQUAC) [9]. In this work, the NRTL, Wilson and UNIQUAC models were all used in combination with the HOC method for correlating the vapor–liquid equilibria of binary systems and predicting the vapor–liquid equilibria of the ternary systems containing the associating component acetic acid.

Section snippets

Materials

The chemicals used were acetic acid (glacial) (PA grade) with a stated minimum purity of 99.9 mass% supplied by Shanghai Lingfeng Chemical Reagents Limited, deionized water (PA grade) supplied by the membrane science technology research laboratory of Nanjing University of Technology, N-methyl pyrrolidone (≥99.9 mass%) supplied by Nanjing Jinlong Chemical Plant, and N-methyl acetamide (≥99.9 mass%) supplied by Changzhou Baokang Chemical Reagents Limited The measured boiling points of the used

Experimental data

Vapor–liquid equilibria for the binary systems acetic acid + N-methyl pyrrolidone and acetic acid + N-methyl acetamide have been obtained at 101.33 kPa. The results were reported in Table 2, Table 3. Also, the vapor–liquid equilibria for the water + acetic acid + N-methyl pyrrolidone and water + acetic acid + N-methyl acetamide ternary systems were obtained at 101.33 kPa, and the results were reported in Table 4, Table 5. The Herington method [12] was used to check the thermodynamic consistency and the

Conclusions

The VLE data of the acetic acid + N-methyl pyrrolidone, acetic acid + N-methyl acetamide, water + acetic acid + N-methyl pyrrolidone, water + acetic acid + N-methyl acetamide systems were obtained at 101.33 kPa. The VLE data of the measured binary sytems were thermodynamic consistent. The NRTL, UNIQUAC, and Wilson models can all satisfactorily correlate the vapor–liquid equilibria data of the binary systems. The obtained interaction parameters were used to predict the vapor–liquid equilibria of the water +

References (14)

X.-L. Hu et al.
Influence of nitrogen containing complexing agents on the vapor–liquid equilibrium of water–acetic acid systems
Ind. Fine Chem.
(2002)
B. Lloyd et al.
The dehydration of the fatty acids by extractive distillation
Chem. Eng. Commun.
(1990)
J. Gmehling et al.
(1977)
J.-Q. FU
Phase Equilibrium and Simulation Calculation of Distillation for Special System
(2002)
J.M. Prausnitz et al.
Computer Calculation for Multicomponent Vapor–Liquid and Liquid–Liquid Equilibrium
(1980)
J.G. Hayden et al.
A generalized method for predicted second virial coefficients
Ind. Eng. Chem. Process Des. Dev.
(1975)
H. Renon et al.
Local composition in thermodynamic excess functions for liquid mixtures
AIChE J.
(1968)

There are more references available in the full text version of this article.

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Isobaric vapor–liquid equilibria for water + acetic acid + (N-methyl pyrrolidone or N-methyl acetamide)

Abstract

Introduction

Section snippets

Materials

Experimental data

Conclusions

Influence of nitrogen containing complexing agents on the vapor–liquid equilibrium of water–acetic acid systems

Ind. Fine Chem.

The dehydration of the fatty acids by extractive distillation

Chem. Eng. Commun.

Phase Equilibrium and Simulation Calculation of Distillation for Special System

Computer Calculation for Multicomponent Vapor–Liquid and Liquid–Liquid Equilibrium

A generalized method for predicted second virial coefficients

Ind. Eng. Chem. Process Des. Dev.

Local composition in thermodynamic excess functions for liquid mixtures

AIChE J.