关键词: 二甲基硫醚, 吡啶, N,N-二甲基乙酰胺, 关联, 预测, 汽液平衡

Abstract: Isobaric vapor-liquid equilibrium (VLE) data at 101.325 kPa for the three binary systems containing dimethyl sulfide-pyridine, dimethyl sulfide-N,N-dimetylacetamide and pyridine-N,N-dimetylacetamide and the ternary system containing dimethyl sulfide-pyridine-N,N-dimetylacetamide were measured by different liquid phase compositions using an ebullionmeter. The activity coefficients were correlated with the Wilson, NRTL, Margules, van Laar and UNIQUAC models. The experimental T-x data are used to these model parameters through the least square method, and these parameters in turn are used to calculate vapor-phase compositions. Moreover, the vapor-phase compositions had been predicted from Tpx according to the function of molar excess Gibbs energy by the indirect method. The activity coefficients are useful to calculate excess Gibbs function for the three binary systems. The VLE data of the ternary system were correlated based on Wilson, NRTL, Margules, van Laar and UNIQUAC model parameters of these binary systems in order to build the thermodynamic model of VLE for the ternary system and obtain the vapor-phase compositions and the calculated bubble points, respectively. The thermodynamic consistency of the experimental VLE data were checked out by means of the Herington test for the binary systems and the McDermott-Ellis test for the ternary system, respectively, and the results showed that VLE data for these systems strictly satisfied thermodynamic consistency.

Key words: dimethyl sulfide, pyridine, N,N-dimethylacetamide, correlation, prediction, vapor-liquid equilibrium