Isothermal vapour-liquid equilibrium data for the binary systems 2-propanone + (2-butanol or propanoic acid)
Introduction
Ketones, alcohols, and carboxylic acids are examples of oxygenated compounds found in the aqueous waste streams of petrochemical industries such as SASOL (Pty) Limited. Accurately measured VLE data are essential in order to understand the phase behaviour of mixtures containing these oxygenated compounds. Such experimentally measured VLE data, if well correlated, can be useful for the design and optimization of the chemical processes in which those compounds are found.
Isothermal VLE measurements for binary systems involving 2-propanone with aliphatic and aromatic hydrocarbons have previously been reported in the literature; measurements undertaken using a static total pressure apparatus at temperatures between (318.6 and 332.1) K [2], [3]. Extensive studies on the thermodynamic properties of amine and ketone mixtures at 298.15 K have also been reported [4]. The present work reports experimental vapour-liquid equilibrium data for oxygenated binary mixtures, namely, 2-propanone + 2-butanol at (333.15 and 353.15) K and for the 2-propanone + propanoic acid binary mixtures at (333.15, 353.15, and 373.15) K. The present authors previously reported VLE data for 2-propanone + 2-butanol at 373.15 K obtained using a novel dynamic recirculating stainless steel apparatus at moderate pressures [5].
These components are part of the industrial waste from the exit streams of SASOL's Fischer Tropsch process. For industrial design of separation processes involving these streams, accurate liquid phase activity coefficients are required as functions of temperature. For the moderate pressure ketone-alcohol system, relatively straightforward data reduction procedures are usually adequate, with, e.g. the Hayden-O'Connell [6] corresponding states correlation for second virial coefficients in the vapour phase. Data reduction for the 2-propanone + propanoic acid system however, involved application of the much more complex Prausnitz et al. [1] iterative procedure with values required for dipole moments, radii of gyration, association parameters, and solvation parameters.
For the measurement of VLE data, the dynamic recirculating glass still of Joseph et al. [7], which is reliable for sub-atmospheric pressures (with a maximum pressure limit of 101 kPa), was utilized alongside the novel dynamic recirculating stainless steel VLE still used by Reddy et al. [5] with a maximum pressure capability of 750 kPa. The latter apparatus mimics the architecture of the glass still, with a similar packed equilibrium chamber and an insulated centrally located Cottrell pump.
Section snippets
Materials
2-Propanone used was purchased from Sigma-Aldrich, while 2-butanol and propanoic acid were from Fluka. Gas chromatographic (GC) analysis revealed no significant impurities; hence, the chemicals were used without further purification. The refractive indices of the chemicals were checked using an ATAGO® Refractometer RX-7000α at a temperature of 293.15 K, and compared to literature. The uncertainty in the refractive index measurements is 0.0004. The literature refractive index is reported for
Data reduction of newly measured VLE systems
For the 2-propanone + 2-butanol system, the measured VLE data were regressed with the combined gamma-phi (γ-Φ) method using the pure component properties listed in Table 2. The liquid phase activity coefficient was correlated using the NRTL and the Wilson model equations. For the vapour phase, the Hayden and O'Connell [6] correlation was used. The vapour phase association parameter values in Table 2 are reported by Fredenslund et al. [12] as well as Prausnitz et al. [1]. This modelling approach
Results and discussion
VLE data were measured at isothermal conditions for 2-propanone + 2-butanol and 2-propanone + propanoic acid systems. The correlation of the VLE data was performed with two liquid-phase activity coefficient models, namely the Wilson and NRTL equations. The Wilson and NRTL parameters were determined by the Marquardt method [22] with an objective function that minimizes the square root of the sum of the squares of the deviations in pressure and vapour phase composition during the optimization of
Conclusions
Five isothermal VLE sets have been measured which have not been reported previously in literature. These VLE binary systems consist of a polar, non-associating component + polar, associating component, and a polar, non-associating + polar, dimerizing component. The 2-propanone + 2-butanol VLE data were successfully correlated using a combination of the NRTL and Wilson liquid phase GE models with the Hayden and O'Connell [6] method for calculating the second virial coefficients. Experimental
Acknowledgements
This study is based upon research supported by the South African Research Chairs Initiative of the Department of Science and Technology and National Research Foundation.
References (26)
- et al.
Fluid Phase Equilib.
(2004) - et al.
Fluid Phase Equilib.
(2013) - et al.
Fluid Phase Equilib.
(2013) - et al.
Fluid Phase Equilib.
(2013) - et al.
Fluid Phase Equilib.
(2001) - et al.
Fluid Phase Equilib.
(2004) - et al.
Computer Calculations for Multicomponent Vapour–liquid and Liquid–liquid Equilibria
(1980) - et al.
Ind. Eng. Chem. Proc. Des. Dev.
(1975) CRC Handbook of Chemistry and Physics
(2005)- et al.
J. Chem. Eng. Data
(2002)
Phase Equilibria: Measurement and Computation
The Properties of Gases and Liquids
Vapor-liquid Equilibria Using Unifac: a Group-contribution Method
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