状态方程模拟醇胺系统的密度和汽液相平衡

Modeling of density and vapor-liquid equilibrium for alcohol-amine systems with equation of state

通过考虑醇胺分子间的缔合作用,结合先前开发的非缔合变阱宽链流体状态方程(SWCF-VREOS)建立了一个缔合方阱链流体状态方程,并利用方程模拟了醇胺系统的密度和汽液相平衡。通过关联不同温度下醇胺的饱和蒸气压和液体体积得到了18种醇胺流体的分子参数,新方程计算的饱和蒸气压和液体密度总的平均误差分别为0.94%和0.88%。结合简单的混合规则,将此方程扩展到混合系统。研究发现,建立的方程可预测二元和三元醇胺混合物的密度。当引入一个与温度无关的可调参数时,方程能满意关联二元系统的汽液相平衡数据,并可进一步预测多元混合系统的汽液相平衡,预示着新方程可模拟醇胺系统的相行为。

Considering the association contribution,the equation of state for square-well chain fluid with variable range（SWCF-VR EOS）in a previous work was extended for calculations of density and vapor-liquid equilibrium（VLE）of alcohol-amines.New molecular parameters of 18 alcohol-amines were obtained by fitting saturated vapor pressures and liquid densities at different temperatures.The overall average deviations of saturated vapor pressure and liquid density were only 0.94% and 0.88% respectively.Coupling with a simple mixing rule,the model was further applied to mixtures.The results show that the densities of binary and ternary alcohol-amine mixtures are satisfactorily predicted.Using an adjustable parameter independent of temperature,VLE data of binary alcohol-amine mixtures are well correlated.The model can reproduce phase behavior of multi-component mixtures,indicating that the new equation of state is appropriate for modeling phase behavior of alcohol-amine systems.