二甲基硫醚-二硫化碳-甲醇体系等压汽液平衡

用泵式沸点仪测定了100 kPa下二甲基硫醚-二硫化碳、二甲基硫醚-甲醇2个二元系以及二甲基硫醚-二硫化碳-甲醇三元系在不同液相组成时的汽液平衡数据,用Wilson、NRTL、Margules和van Laar模型分别对2个二元系活度系数进行关联,用最小二乘法求出其液相活度系数模型参数,用这些模型参数来计算其汽相组成y,根据过量Gibbs自由能函数Q(GE/RT),采用间接法由Tpx推算了2个二元系的汽相平衡组成。用所得的液相活度系数计算2个二元系的过量吉布斯自由能函数GE/RT,并由2个二元系与三元系回归出二硫化碳-甲醇二元系的NRTL模型参数。用3个二元系NRTL模型参数对所测的三元系数据进行关联,建立三元系汽液平衡的热力学模型并计算平衡时的汽相组成y和泡点温度。分别由Herington法和McDermott-Ellis法对2个二元系和三元系进行热力学一致性检验,结果表明这些相平衡数据满足热力学一致性。

Isobaric vapor-liquid equilibrium for dimethyl sulfide-carbon disulfide-methanol system

Isobaric vapor-liquid equilibrium(VLE) data for the two constituent binary systems containing dimethyl sulfide-carbon disulfide,dimethyl sulfide-methanol and the ternary system of dimethyl sulfide-carbon disulfide-methanol were determined with different liquid phase compositions by using a pump-ebullionmeter at 100 kPa.The activity coefficients of two binary systems were correlated with the Wilson,nonrandom two-liquid(NRTL),Margules and van Laar models.The experimental T-x data were used to estimate Wilson,NRTL,Margules and van Laar model parameters through the least-squares method,and these parameters in turn were used to calculate the vapor-phase composition y.Based on the excess Gibbs function Q(GE/RT),the vapor-phase composition was predicted from Tpx by the indirect method,and the activity coefficients obtained were used to calculate excess Gibbs function Q(GE/RT) for the two binary systems.The optimum NRTL model parameters of the carbon disulfide-methanol binary system were determined by the linear regression based on the two binary systems and the ternary systems.The VLE data of the ternary system were correlated based on NRTL model parameters of these binary systems to build the thermodynamic model and obtain the vapor-phase compositions and the calculated bubble points.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.The results show that VLE data for these systems strictly satisfied thermodynamic consistency.