固体-超临界流体相平衡的温度效应及其分子基础  

TEMPERATURE EFFECT ON SOLID-SUPERCRITICAL FLUID PHASE EQUILIBRIUM AND ITS MOLECULAR BASIS

作　　者：赵锁奇[1] 王仁安[1] 杨光华[1] 

机构地区：[1]石油大学重质油加工国家重点实验室,北京102200

出　　处：《化工学报》1996年第3期324-331,共8页CIESC Journal

摘　　要：本文从分子间相互作用研究了反常冷凝区温度对固体-超临界流体相平衡的影响，从作者测定的萘／CO2体系的相平衡等压线数据出发，根据Gibbs-Konowalow法则及PR方程考察了主要影响因素──体系的溶质偏摩尔焓的变化规律，结果显示在反常冷凝区固体-超临界流体相平衡的温度效应非常显著，随温度的变化，溶质的偏摩尔焓有负的发散现象，即有强的放热效应．应用Kirkwood-Buff溶液理论，从分子相互作用角度解释了这种强放热效应的产生原因，从理论上证明了溶质偏摩尔焓的值和溶质周围溶剂分子簇大小（ClusterSize）的相关性，对溶质-溶剂分子间吸引作用强于溶剂分子间吸引作用的体系，较大的偏摩尔焓（负值）对应于较大的溶剂分子簇．Temperature effect on solid-supereritical phase equilibrium and its molecular basis is studied in this Paper,based on the experimental isobaric solubility data of naphthalene/CO2 binary system.The Gibbs-Konowalow rule as well as PR-EOS are used to calculate the primary factor-solute excess partial molar enthalpy along the isobars.It is found that solute excess Partial molar enthalpy diverge negatively in retrograde region of the system and the temperature effect is significant.The strong exothermicity is explained by using Kirkwood-Buff solution theory.Solute excess partial molar enthalpy is proved to be proportional to cluster size of solvent molecules around a solute molecule.Theory and calculating results show that for an attractive system the stronger negative divergence of solute excess partial molar enthalpy corresponds to the larger cluster size.

关 键 词：超临界流体 固体 相平衡 温度效应 溶解度 

分 类 号：TQ013.1[化学工程]