Article pubs.acs.org/jced
Cite This: J. Chem. Eng. Data XXXX, XXX, XXX−XXX
Refractive Index and Vapor−Liquid Equilibrium Data for the Binary Systems of Anisole with Xylene Isomers at 93.13 kPa Satyajeet S. Yadav,‡ Nilesh A. Mali,*,† and Sunil S. Joshi† †
Chemical Engineering and Process Development Division, CSIR-National Chemical Laboratory, Pune, Maharashtra 411008, India Chemical Engineering Department, College of Engineering, Bharati Vidyapeeth Deemed University, Pune, Maharashtra 411030, India
‡
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S Supporting Information *
ABSTRACT: Phase equilibrium behavior of binary systems of anisole with xylene isomers was analyzed experimentally. An apparatus which establishes equilibrium conditions through continuous circulation of equilibrium vapor condensate and equilibrium liquid was used. Experimental data comprising refractive indices of binary mixtures, equilibrium compositions of vapor and liquid, and equilibrium temperature are reported for all binary systems. Thermodynamic consistency of vapor−liquid equilibrium data was established for using the Herington, Van Ness and absolute mean deviation tests. Interaction parameters of activity coefficient models, Wilson, nonrandom two liquid, and universal quasichemical, which are important for accounting nonideal behavior in process modeling, are also estimated through regression of the respective binary VLE data. Although VLE data shows that binary systems are nonazeotropic in nature, a pinch in the T−x,y plot indicates that separation of all binary system using distillation may need a significant number of stages.
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INTRODUCTION Anisole finds applications as an intermediate chemical in the pharmaceutical and agrochemical industries. With increasing demand for anisole from the perfume and drug industry, it is manufactured on a large scale. It also finds an application as an entrainer in extractive distillation for the separation of azeotropic mixtures. Hence, vapor−liquid equilibrium (VLE) data for anisole with various other solvents will be useful for designing separation unit operations such as distillation column, extraction column, evaporators, etc. Xylene isomers have numerous applications in the petrochemical industry and are produced from petroleum fractions. Xylene isomers are used as a starting material for production of various organic compounds. Their application as gasoline additives have also been reported.1 Many processes involve handling multiple solvents either on the process side or in downstream processing. Knowledge of the VLE of such solvent mixtures is necessary for designing the separation train and also for modeling unit operations. In the present work, isobaric phase equilibrium data in the form of T−x,y plots has been generated for anisole with four xylene isomers (p-xylene, m-xylene, o-xylene and ethylbenzene) at 93.13 kPa pressure which was the atmospheric pressure at the location of the experiment. The data will find application in the processes involving these combinations of components. The experimental data have been checked for thermodynamic consistency and correlated with three activity coefficient models, Wilson, nonrandom two liquid (NRTL) and unversal quasichemical (UNIQUAC), and the binary interaction parameters were estimated which can be used in process modeling. The data generated for p-xylene−anisole and © XXXX American Chemical Society
ethylbenzene−anisole were also compared with the data available in the literature.2 No data were reported in the literature for the other two pairs.
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EXPERIMENTAL SECTION Materials. Purities and source of various chemicals used for experimentation are listed in Table 1. Comparison of the Table 1. Details of Chemicals Used for Experiments chemical name
CASRN
source
purity (mass %)
anisole p-xylene m-xylene o-xylene ethylbenzene
100-66-3 106-42-3 108-38-3 95-47-6 100-41-4
Loba chemicals Loba chemicals Loba chemicals Merck chemicals Spectrochem
99 99 99 99 99
measured refractive index (nD) at 298.15 K with the reported values in the literature is given in Table 2. No data for boiling point at 93.13 kPa were available in the literature. Hence, the measured boiling points (Tb) at local atmospheric pressure of 93.13 kPa and reported boiling points at standard atmospheric pressure of 101.325 kPa are given in Table 2. Experimental Setup and Procedure. The schematic of the apparatus used for experimental work is as shown in Figure 1 which operates on the principle of bringing vapor and liquid in to the equilibrium condition by keeping the both phases in Received: May 1, 2018 Accepted: August 10, 2018
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DOI: 10.1021/acs.jced.8b00348 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
Journal of Chemical & Engineering Data
Article
Table 2. Measured and Literature Values of Refractive Indices (nD) and Boiling Points (Tb) Data refractive index (nD) at 298.15 K
boiling point (K)
chemical
literature
measureda
literature (at 101.325 kPa)
measureda (at 93.13 kPa)
anisole p-xylene m-xylene o-xylene ethylbenzene
1.51503 1.492865 1.494435 1.501775 1.492985
1.51548 1.49292 1.49433 1.50221 1.49297
426.564 411.385 412.225 417.555 409.315
423.38 408.37 409.13 414.40 406.22
a
Standard uncertainties u are u(nD) = 0.0001, u(T) = 0.1 K, u(P) = 0.1 kPa.
collecting equilibrium liquid and equilibrium vapor condensate is provided at the appropriate locations. Samples (
