二元交互参数化PC-SAFT在超临界乙烯配位聚合体系相平衡计算中的应用  

Application of PC-SAFT with updated binary interaction parameters in phase equilibrium calculation for supercritical ethylene coordination polymerization system

作　　者：陈可冉 田洲[2] 罗娜[2] 杜文莉[2] 钱锋[2] 刘柏平[1] 

机构地区：[1]华东理工大学化学工程联合国家重点实验室,上海200237 [2]华东理工大学化工过程先进控制与优化技术教育部重点实验室,上海200237

出　　处：《化工学报》2014年第6期1978-1986,共9页CIESC Journal

基　　金：国家重点基础研究发展计划项目(2012CB720502);上海市自然科学基金项目(13ZR1411500);中国博士后科学基金项目(2013M540337)~~

摘　　要：超临界烯烃配位聚合技术是近年来国际聚烯烃工业领域中的重要进展之一,超临界体系相平衡计算则是该聚合工艺设计与优化操作的基础。本文以链扰动统计缔合流体理论(PC-SAFT)状态方程描述工业级超临界乙烯配位聚合体系的相平衡,得到了适用于该复杂体系的PC-SAFT二元交互参数。与公开报道的实验数据比较表明,获得的二元交互参数可准确描述该超临界体系在较宽温度、压力范围的相平衡。基于上述二元交互参数,针对2个不同双峰聚乙烯产品牌号,计算了工业装置内多组分的相平衡状态,结果表明,反应器内的[H2]/[C2H4]摩尔比、淤浆密度的计算值与工业数据吻合较好,验证了二元交互参数的适用性。研究结果为进一步的工艺流程模拟与优化奠定了基础。Supercritical olefin coordination polymerization technology is one of the most important progresses in polyolefin industry, and accurate calculation of the binary phase equilibrium of this supercritical system with polymer is the key for the design and operation of this process. In this study, the equation of state of perturbed-chain statistical associating fluid theory （PC-SAFT EOS） with updated parameters is applied to binary phase equilibrium in supercritical ethylene polymerization system. Based on the pure component parameters and phase equilibrium data in literatures, the binary interaction parameters between supercritical fluid-solvent, supercritical fluid-monomer, comonomer （1-butene）, chain transfer agent （hydrogen）, circulation cooling gas＆amp;nbsp;（nitrogen） and polymer （PE） are regressed, and calculation results are compared with experimental data in literatures. The results show that re-parameterized PC-SAFT can accurately predict the thermodynamic properties and phase equilibrium of supercritical ethylene coordination polymerization system in a wide range of temperature （340-380 K） and pressure （2.0-7.0 MPa）. The PC-SAFT EOS is validated by industrial data. The calculated supercritical fluid mixed density, vapor mixed density, and molar ratio of hydrogen to ethylene agree very well with industrial data for two product grades in the industrial process, with an average error less than 3%. The results provide a solid basis for further simulation and optimization of this supercritical process.

关 键 词：超临界流体 乙烯配位聚合 相平衡 PC-SAFT状态方程 二元交互参数 热力学性质 

分 类 号：TQ325.1[化学工程—合成树脂塑料工业]