Abstract: The calculation of solubilities of substances in a supercritical fluid (SCF) is one of the most important thermodynamic calcalations. This paper discusses the characteristics of extraction with SCF. The P-V-T properties of SCF can be described by an equation of state of gases and the separation mechanism of SCF extraction is fairly similar to that of liquid-liquid extraction. Besides, this paper puts forward a physical model of SCF extraction ma-chanism. Based on this model, a general formula for calculating solubilities of substances in a SCF could be derived as fellows: This formula could be simplified and modified as a semi-empirical correlation: whers, α is an enhancement factor of solubilities. For pure substances a good agreement between experimental results and calculation data with this semi-empirical correlation, was obtained with an average error less than tan percent.

摘要： 本文分析了超临界流体萃取过程的特点.认为超临界流体的P-V-T行为可采用某种气体状态方程来描述.在分离作用机理上更近于液液萃取过程.提出了其萃取历程的物理化学模式,据此推导了超临界流体中物质溶解度计算公式.通过对此式的剖析和简化,得到了固体及液体纯物质在超临界流体中溶解度的半理论、半经验计算公式.并用文献发表的实验数据对半经验式的适用性进行验算,获得了较满意的结果,平均偏差≤10%.