Elsevier

Fluid Phase Equilibria

Volume 365, 15 March 2014, Pages 97-105
Fluid Phase Equilibria

Phase behavior of binary mixture for the isoalkyl acetate in supercritical carbon dioxide

https://doi.org/10.1016/j.fluid.2013.12.026Get rights and content

Highlights

  • Phase behaviors for the CO2 + isoalkyl acetate systems were measured by static method.

  • (P, x) isotherms of these systems are obtained at 313.2–393.2 K and pressure to 18.24 MPa.

  • Experimental results of three systems are correlated using Peng–Robinson equation of state.

Abstract

Pressure–composition isotherms of phase equilibria for the CO2 + isoalkyl acetate systems are investigated in the static method at five temperatures of (313.2, 333.2, 353.2, 373.2 and 393.2) K and pressures up to 18.24 MPa. The CO2 + isobutyl acetate, CO2 + isopentyl acetate and CO2 + isooctyl acetate systems have continuous critical mixture (locus) curves that exhibit maximums in pressure–temperature space between the critical temperatures of CO2 and isoalkyl acetate (isobutyl acetate, isopentyl acetate and isooctyl acetate). The solubility of isobutyl acetate, isopentyl acetate and isooctyl acetate for the CO2 + isobutyl acetate, CO2 + isopentyl acetate and CO2 + isooctyl acetate systems increases as the temperature increases at constant pressure. The CO2 + isobutyl acetate, CO2 + isopentyl acetate and CO2 + isooctyl acetate systems exhibit type-I phase behavior. The experimental results for the CO2 + isobutyl acetate, CO2 + isopentyl acetate and CO2 + isooctyl acetate systems are correlated with Peng–Robinson equation of state using a mixing rule including two adjustable parameters.

Introduction

Recently, we have reported the bubble point, dew point and critical point behavior of binary alkyl acetate + supercritical carbon dioxide mixture [1]. The isoalkyl acetate monomers is mainly used for a variety of applications such as polymer paints, extraction solvent, cosmetic solvent, adhesives, inks, leather polishes, pharmaceutical intermediates and coatings [2], [3], [4].

The phase behavior of the binary mixture consisting of isoalkyl acetate monomer with supercritical carbon dioxide plays an important role in chemical separation, supercritical fluid extraction, fine chemical processes, polymerization condition, and industrial application [5], [6], [7]. As one of the representative supercritical fluid solvents, supercritical carbon dioxide (scCO2) has several advantages as a solvent owing to its lower toxicity, inflammability, chemically inert nature, and natural abundance. ScCO2 possesses high diffusivity and low solubility for high molecular weight or polar monomeric materials owing to its low dielectric constant and lack of dipole moment [8].

Thermodynamics information on phase behavior for the supercritical CO2 + isoalkyl acetate monomer system is an important condition required for polymer synthesis and polymerization processes. Therefore, the phase behavior data for the CO2 + isoalkyl acetate systems have been reported by Monton et al. [9], Resa et al. [10], [11], and Byun et al. [12]. Monton et al. [9] used a dynamic-recirculating method to present the isobaric vapor–liquid equilibria for the isobutyl alcohol + isobutyl acetate system at temperatures ranging from (307.43 to 391.39) K and pressure up to 105.57 kPa. Resa et al. [10], [11] have reported the vapor–liquid equilibria for the methanol + isobutyl acetate and methanol + isopentyl acetate systems at temperatures of (415.30 to 337.65) K and pressures of 101.3 kPa by Othmer dynamic recirculating method. Byun et al. [12] reported the experimental data about a binary system for the CO2 + isooctyl acrylate system at temperatures from (313.2 to 393.2) K and pressures up to 20.0 MPa. To date, however, experimental data of the phase behavior for the supercritical solvents + isoalkyl acetate systems have not been found in the literature.

The purpose of this study is to obtain experimental data of the high pressure, phase behavior information on the systems of CO2 + isobutyl acetate, CO2 + isopentyl acetate and CO2 + isooctyl acetate mixture. The experimental pressure–composition (Px) isotherms are presented for the CO2 + isobutyl acetate, CO2 + isopentyl acetate and CO2 + isooctyl acetate mixture. The static method with a variable-volume high pressure view cell was employed to obtain experimental data at temperature ranges from 313.2 K to 393.2 K. The experimental data for the CO2 + isobutyl acetate, CO2 + isopentyl acetate and CO2 + isooctyl acetate systems obtained in this work are correlated with the Peng–Robinson equation of state (PR-EOS) [13] using a van der Waals one-fluid mixing rule including two adjustable parameters. The critical pressure, critical temperature and acentric factor of two components were estimated by the Joback–Lyderson method [14] with group-contributions while the vapor pressure is estimated by the Lee–Kesler method [14].

Section snippets

Materials

Isobutyl acetate [mass fraction purity > 0.980], isopentyl acetate [mass fraction purity > 0.980] and isooctyl acetate [mass fraction purity > 0.980] used in this study were purchased from Wako Pure Chemical Industries, Ltd. All components were used without further purification in the experiments. Carbon dioxide (mass fraction purity > 0.999) was obtained from Deok Yang Co., Ltd. and used as received. The specifications of all chemicals used are summarized in Table 1.

Apparatus and procedure

Fig. 1 shows the schematic diagram

Experimental results and discussion

Experimental data for the CO2 + isobutyl acetate, CO2 + isopentyl acetate and CO2 + isooctyl acetate systems are measured, and the experimental data was reproduced at least twice to within ±0.02 MPa and ±0.2 K for a given loading of the cell. The combined standard uncertainties of pressure and temperature were estimated to be ±0.02 MPa and ±0.12 K. The combined standard uncertainties of isobutyl acetate, isopentyl acetate and isooctyl acetate mole fractions are estimated to be ±0.0008 [16]. These systems

Conclusions

The pressure–composition (Px) isotherms for CO2 + isobutyl acetate, CO2 + isopentyl acetate and CO2 + isooctyl acetate binary mixture systems were measured using a static method comprised of a variable-volume view cell apparatus at temperature ranges from 313.2 K to 393.2 K and pressure up to 18.24 MPa. These two systems exhibit the type-I phase behavior and do not exhibit three phases at any five temperatures. The Peng–Robinson equation of state is able to predict the phase behavior for the two

Acknowledgement

This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (Grant No. 2012R1A2A2A01045769)

References (22)

  • H.S. Byun et al.

    J. Supercrit. Fluids

    (2006)
  • H. Tai et al.

    Polymer

    (2005)
  • J.B. Monton et al.

    Fluid Phase Equilibria

    (2005)
  • J.M. Resa et al.

    J. Chem. Thermodyn.

    (1998)
  • J.M. Resa et al.

    Fluid Phase Equilibria

    (2001)
  • S.H. Kim et al.

    Fluid Phase Equilibria

    (2011)
  • S.K. Quadri et al.

    J. Chem. Thermodyn.

    (1991)
  • ...
  • ...
  • http://www.hichem.com/info-spec/info/ISOOCTYL ACETATE...
  • J.M. DeSimone et al.

    Science

    (1994)
  • Cited by (11)

    • Bubble-point measurement for the binary mixture of propargyl acrylate and propargyl methacrylate in supercritical carbon dioxide

      2016, Journal of Chemical Thermodynamics
      Citation Excerpt :

      Supercritical carbon dioxide has a quadrupole moment, no dipole moment, and low dielectric constant [7], so it has been recommended as the solvent chosen for many industrial applications because it is an environmentally benign, non-hazardous, inexpensive, and non-toxic solvent with a nonpolar molecule. The experimental values for the binary mixture of solute monomer in supercritical carbon dioxide have been reported on the bubble-point, dew-point and critical-point phase behaviour [8,9]. Therefore, knowledge of thermodynamic properties of (carbon dioxide + solute) mixtures is required for practical uses in chemical processes.

    • Effect of cosolvent on the phase behavior of binary and ternary mixture for the poly(2-dimethylaminoethyl methacrylate) in supercritical solvents

      2014, Fluid Phase Equilibria
      Citation Excerpt :

      Phase behavior for the binary and ternary mixtures of polymers + supercritical solvents and polymer + supercritical solvent + cosolvent systems at relevant conditions of pressure, temperature and composition are extremely valuable for engineers in the design and operation of various polymer industrial processes [1–3]. Also, high-pressure phase equilibria of binary mixtures for the carbon dioxide + hydrocarbon systems are of interest in a wide range of numerous chemical processes such as separation processes [4,5], supercritical fluid (SCF) extraction [6,7], polymerization processes condition [8] and fine chemical industry. Recently modern plastic engineering technology is applying methacrylate-based polymers for a variety of uses.

    • Experimental measurement of cloud-point and bubble-point for the {poly(isobornyl methacrylate) + supercritical solvents + co-solvent} system at high pressure

      2014, Journal of Chemical Thermodynamics
      Citation Excerpt :

      And the cloud-point curve with this DME concentration exhibits LCST behaviour of a positive slope in a temperature ranging from (332.7 to 452.9) K. High pressure phase behaviour data for binary mixture of the (IBnMA + CO2) system was obtained, and the combined standard uncertainty of pressure and temperature were estimated to be ±0.02 MPa and ±0.12 K for a given loading of the cell [27,28]. The combined standard uncertainties of IBnMA mole fractions are estimated to be ±0.0008 [22,27].

    View all citing articles on Scopus
    View full text