乙烯淤浆聚合体系组分的物性计算方法

Physical Properties Computation of Pure Components for Ethylene Slurry Polymerization System

聚合反应体系的物性计算是聚合过程模拟和优化的难点问题之一。针对乙烯淤浆聚合反应体系,采用链扰动统计缔合流体理论(PC-SAFT)状态方程,通过再参数化方法确定了聚合物体系中乙烯、己烷、氮气、氢气、聚乙烯的PC-SAFT模型参数。物性计算结果分别与文献的PC-SAFT模型、统计缔合流体理论(SAFT)状态方程、Sanchez-Lancombe状态方程等方法进行了比较,表明研究所采用的PC-SAFT模型参数计算乙烯淤浆聚合体系物性的计算精度优于文献提供的方法。

Modeling and optimization of ethylene slurry polymerization process require accurate physical property computations of the components involved in the polymerization process. The main components in the reaction are ethylene, hexane, nitrogen, hydrogen and polyethylene. The equation of state of perturbed-chain statistical associating fluid theory （PC-SAFT EOS） with re-parameterized parameters was applied to predict the thermodynamic properties of the above components, in which the three pure-component parameters of the PC-SAFT model, segment diameter a, segment energy parameter ε/k and segment number m, were regressed based on the literature data. According to a brief comparison between PC-SAFT model with re-parameterized parameters, PC-SAFT model with parameters from open literatures, SAFT model and Sanchez-Lacombe model, it was found that, the predictions of the physical properties of the components involved in the ethylene slurry polymerization process using the re-parameterized PC-SAFT equations can have the higher accuracy than that of using other mentioned above models.