(Liquid + liquid) equilibria of (water + propionic acid + dipropyl ether or diisopropyl ether) at T = 298.2 K

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Abstract

(Liquid + liquid) equilibrium (LLE) data for (water + propionic acid + dipropyl ether) and (water + propionic acid + diisopropyl ether) were measured at T = 298.2 K and atmospheric pressure. The tie-line data were correlated by means of the UNIQUAC equation, and compared with results predicted by the UNIFAC method. A comparison of the extracting capabilities of the solvents was made with respect to distribution coefficients, separation factors, and solvent free selectivity bases.

Introduction

This study is part of an ongoing investigation to find an efficient solvent for extracting propionic acid from dilute aqueous solutions. Liquid extraction is widely used in industry as a cheaper alternative or precursor to distillation.

Propionic acid has many applications in chemical and bio-chemical industries. It is used as a celluloic solvent in the pharmaceutical industry, and can also be used to provide propionates. Recovery of the organic acid from aqueous solutions that are resulted from fermentation processes is also of considerable economic importance. Many solvents have been used to enhance the extraction of propionic acid from aqueous solutions [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11].

In this work, dipropyl ether (DPE), and diisopropyl ether (IPE) were used as a solvent in the separation of propionic acid from water. (Liquid + liquid) equilibrium (LLE) data have been determined for each solvent at 298.2 K. Separation factors (S) for solvents separation efficiency were determined from the tie-line data. The experimental data have been correlated by means of UNIQUAC [12] equations. A comparison between the values predicted by the UNIFAC [13] method is also presented.

Section snippets

Chemicals

All chemicals used in this work (mass fraction purity >0.99) were supplied by Merck and were used without further purification. The purity of these materials was checked by gas chromatography. Deionised water was further distilled before use. The densities and refractive indexes of pure components were measured and compared with the literature [14] at 293.15 K and atmospheric pressure.

The densities were measured using a temperature controlled Anton Paar DMA 4500 density meter in an accuracy of ±1

Results and discussion

The experimental tie-line data of (water + propionic acid + DPE) and (water + propionic acid + IPE) at T = 298.2 K were reported in table 2, in which xiIandxiII refer to mole fraction of the ith component in the aqueous and solvent phase, respectively. From the LLE phase diagrams (water + solvent) mixture is the only pair that is partially miscible and two liquid pairs (propionic acid + water) and (propionic acid + solvent) are completely miscible (FIGURE 1, FIGURE 2).

The correlation of the experimental data

Conclusion

(Liquid + liquid) equilibrium for the systems (water + propionic acid + dipropyl ether) and (water + propionic acid + diisopropyl ether) were experimentally determined at T = 298.2 K and atmospheric pressure.

The LLE data were correlated by means of the UNIQUAC activity model.

The experimental tie-line data were compared to those predicted by the UNIFAC group contribution method. It was found that the UNIQUAC model gives a relatively good correlation of the (liquid + liquid) equilibrium of the investigated

Acknowledgements

This work was supported by the Research Found of Istanbul University. Project Number T-912/06112000. The author thank to Assist. Prof. Atilla Özmen.

References (16)

  • T.M. Letcher et al.

    Fluid Phase Equilibr.

    (2002)
  • S. Çehreli et al.

    J. Chem. Thermodyn.

    (2005)
  • D. Özmen et al.

    J. Chem. Thermodyn.

    (2005)
  • S. Çehreli et al.

    J. Chem. Thermodyn.

    (2005)
  • A. Badakhshan et al.

    J. Chem. Eng. Data

    (1985)
  • A. Arce et al.

    J. Chem. Eng. Data

    (1993)
  • A. Arce et al.

    J. Chem. Eng. Data

    (1995)
  • S. Çehreli et al.

    Chim. Acta Turcica

    (1999)
There are more references available in the full text version of this article.

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