化工学报 ›› 2010, Vol. 61 ›› Issue (7): 1734-1739.

• 热力学 • 上一篇    下一篇

基于黏滞球模型的CPA状态方程应用于醇胺系统相平衡的计算

马俊;李进龙;彭昌军;刘洪来;胡英   

  1. 华东理工大学化学工程国家重点实验室,化学系
  • 出版日期:2010-07-05 发布日期:2010-07-05

Calculation of phase equilibrium of alkanolamines systems with CPA equation of state based on Shield-Sticky model

MA Jun;LI Jinlong;PENG Changjun;LIU Honglai;HU Ying   

  • Online:2010-07-05 Published:2010-07-05

摘要:

考虑到醇胺及其混合物中分子间存在缔合作用的事实,结合立方型PR状态方程,通过引入基于黏滞球模型(SSM)发展起来的缔合流体的分子热力学模型,建立了一个新的CPA(cubic-plus-association)状态方程,即CPA-SSM,并将方程应用到醇胺系统相平衡的计算中。通过关联对比温度0.55~0.90范围下醇胺流体的实验饱和蒸气压和液相体积得到了8种醇胺流体的分子参数。结果表明, CPA-SSM方程可满意地计算出醇胺饱和蒸气压和液体密度,总平均误差分别只有0.57%和1.80%。对醇胺混合物,无论是恒压还是恒温系统,只需引入一个与温度无关的可调参数,CPA-SSM方程即可满意关联二元系统的汽液平衡数据,并可进一步预测多元混合物的汽液平衡。

关键词:

CPA-SSM, 状态方程, 汽液平衡, 醇胺

Abstract:

Considering an association contribution, combining cubic P-R model with an association contribution, a new CPA (cubic-plus-association) equation of state (EoS) was presented in this paper. The association term was directly computed with association equation which was proposed based on the Shield-Sticky model(SSM).The new CPA-SSM EoS was then used for descriptions of phase behavior of pure alkanolamine fluids and their mixtures. New molecular parameters for 8 alkanolamines were obtained by fitting experimental saturated vapor pressures and liquid densities at reduced temperature range from 0.55 to 0.90. The overall average deviations of saturated vapor pressure and liquid density were only 0.57% and 1.80% respectively. Using an adjustable parameter independent temperature, satisfactory calculations for binary isothermal and isobaric vapor-liquid equilibria (VLE) were obtained. In addition, this model can successfully reproduce VLE of multi-component mixtures in virtue of binary information.

Key words:

CPA-SSM, 状态方程, 汽液平衡, 醇胺