To Study the Vapour Liquid Equilibrium Data for Cellosolve Acetate and Toluene

Isobaric vapour−liquid equilibrium data for pure components as well as binary mixtures of Cellosolve Acetate−Toluene was generated using a modified ebulliometer. Measurements are reported for four different pressures in the range of (61 to 101) kPa. Pure component vapor pressures were correlated using the Antoine correlation and compared with the literature data. Antoine constants are good match with literature and predicted data.


PHASE EQUILIBRIA (VAPOUR LIQUID EQUILIBRIUM):
Distillation occupies a very important position in chemical engineering. Distillation and chemical reactors represent the backbone of what distinguishes chemical engineering from other engineering disciplines. Operations involving heat transfer and fluid mechanics are common to several disciplines. But distillation is uniquely under the purview of chemical engineers.
The basis of distillation is phase equilibrium, specifically, vapor-liquid (phase) equilibrium (VLE) and in some cases vapor-liquid-liquid (phase) equilibrium (VLLE). Distillation can effect a separation among chemical components only if the compositions of the vapor and liquid phases that are in phase equilibrium with each other are different. A reasonable understanding of VLE is essential for the analysis, design, and control of distillation columns.
Vapour liquid equilibrium (VLE) is a condition in which a liquid and vapour phase are in equilibrium with each other, a condition or state where the rate of evaporation equals the rate of condensation on molecular level such that there is no net vapour-liquid interconversion. A substance at vapour liquid equilibrium is generally referred to as a saturated fluid. For a pure chemical substance this implies that it is at its boiling point. Such VLE information is useful in designing columns for distillation, especially fractional distillation.

EXPERIMENTALLY INVESTIGATED EQUILIBRIUM IN BINARY SYSTEM (CELLOSOLVE ACETATE-TOLUENE):
VLE data on binary mixture of organic compounds are of significant importance for the design of numerous Industrial chemical processes or for the purpose of environmental protection. In the plants of various branches of Industry, where organic solvents are used, spend mixtures from a flow of toxic liquid wastes whose discharge in to the environmental is unacceptable. This makes necessary the development of technologies for recovering the starting solvents from the wastes and recycling them. For which phase equilibrium information is necessary. VLE studies of those systems are the goal of the present study. Following Systems have been studied, 2-Ethoxyethanol (Cellosolve) Acetate-Pure component Toluene-Pure component 2-Ethoxyethanol (Cellosolve) Acetate-Toluene-Binary System This binary system finds application in Esterification Reaction and Reactive distillation. The Vapour-Liquid Equilibrium (VLE) of this system is difficult to model especially due to High Boiling point and no data is available in the literature on this aspect to the best of my knowledge. Experiment P-T-x data of 2-Ethoxyethanol (Cellosolve) Acetate -Toluene system are generated for eight different set of composition at five different pressure for each set of Mixture and This Experimental data are used to regress Activity coefficient model parameters which are further used to generate P-T-x-y data. Results are compared with G E based Models (Margules 2-sufffix, Margules 3-suffix, NRTL, Vanlaar, Wilson Model).

G E BASED MODELING
Isobaric VLE data for the binary mixture of 2-Ethanolethanol (Cellosolve) Acetate -Toluene have been generated. The experimental data were correlated by using G E based Models (Margules 2-sufffix, Margules 3-suffix, NRTL, Vanlaar, Wilson Model). Two vapour pressure models are used for the given system. For Cellosolve Acetate and for Toluene Antoine equation is used, whose constants are fitted to experimental Vapour pressure. By using regressed parameter BUBBLE T is found out. Activity coefficient Model parameters are regressed using experimental P-T-x data. Then experimental binary P-T-x data modelled to find Vapour phase composition using regressed parameters and compared the vapour phase composition and temperature with BUBBLE T calculated data. Parameters were regressed using the above mentioned models for all the binary mixture data and using them, BUBBL T or the bubble temperature was estimated. Experimental P-T-x data are modelled to find Vapour phase composition using G E based models with regressed parameters. Activity coefficient model parameters are regressed using experimental P-T-x data. Then experimental P-T-x are modelled to find vapour phase composition and the comparison of the vapor phase composition and temperature with the calculated BUBBLE T data was made.

RESULT AND DISCUSSION
Pure component and binary VLE data for Toluene -Cellosolve Acetate system have been generated using a differential Ebulliometer with a provision of drop counter. The parameters of the Antoine equation for pure components have been regressed from the experimental data. Similarly, the parameters of various G E based models have been determined by regression using BUBL T calculations. Experimental P-T-x data generated in this work are reported in chapter 3, the above system is modelled using various combinations of activity coefficient models and Table 5.1 shows pure component P-T data.