Study On Liquid-liquid Equilibrium Of Ternary Systems Containing Diethyl Carbonate At Different Temperatures

With the improvement of human consciousness of environmental protection, diethyl carbonate(DEC), as a new kind of important organic chemical products has been attached great importance to everyone. Diethyl carbonate due to its high oxygen content, high octane number, low toxicity, decomposition product to carbon dioxide and ethanol, the environmental pollution-free, in the petrochemical industry is a kind of very good green gasoline additive. The liquid-liquid equilibrium data related to DEC are very vital to the design and optimization of reactors and separation processes, but the relevant literature is still relatively less. So present a large number of accurate and effective experimental data and as possible to get more valid interaction parameters are needed. Due to the great number of the systems and design condition of potential practical interest, the quantity of experimental data obtained will never amount to more than a small fraction of that required. Therefore it is necessary to make predictions from a minimum amount of experimental data. Determination of fluid phase equilibrium and thermodynamic data model is very important content.In this study by the self-designed constant temperature oscillator, the phase equilibrium data of the two binary systems( water + DEC),( water + 2-butanone) and ternary systems( water + acetone + DEC),( water + 2-butanone + DEC) were measured at( 293.15, 298.15, 303.15, 313.15) with a liquid-liquid equilibrium in the atmospheric pressure.This paper adopts the gas chromatographic peak area normalization method, each system equilibrium data obtained at different temperatures, and plotted the phase diagram. The reliability of the experimental tie-line data were using the famous Othmer-Tobias and Bachman equation. The experimental data are correlated with the modified and extended UNIQUAC models, as well as associated with two models according to the experiment results of ternary LLE systems to calculate the average root mean square difference. For the two surveyed ternary systems at the several temperatures, the average rmsd with the binary and ternary parameters were 0.58% for the modified UNIQUAC model, 2.12% for the extended UNIQUAC model. The two models represented excellently the two systems and the modified UNIQUAC model could reproduce accurately the experimental LLE results in comparison with the extended UNIQUAC models.