CO2/DME/CH3OH和CO2/DME/C2H5OH体系的汽液相平衡研究

文中基于对CO₂/DME,DME/CH₃OH,CO₂/CH₃OH和DME/C₂H₅OH体系汽液相平衡研究的文献调查,采用Gibbs-Duhems方程对实验数据做热力学一致性检验和热力学模型评价。研究表明,PR-NRTL模型组合对四个体系都有良好的表现。进而基于通过检验的二元体系数据拟合了5个组合的NRTL模型的交互作用参数,并以此模型研究了CO₂ /DME/CH₃OH和CO₂/DME/C₂H₅OH两个三元体系。计算给出的CH₃OH/DME/CO₂体系的VLE数据与文献值偏差很小,表明此PR NRTL模型组合能较好地描述其高压下的VLE行为,在此基础上对C₂ H₅OH/DME/CO₂体系的VLE行为进行了预测,给出了VLE相图。

Vapor-liquid equilibrium of CO2/DME/CH3OH and CO2/DME/C2H5OH systems

Gibbs-Duhem equation was applied to make the thermodynamic consistency test and the thermodynamic model estimation for CO 2/DME, DME/CH 3OH, CO 2/CH 3OH and DME/C 2H 5OH on the basis of the vapor-liquid equilibrium experimental data referred. The study shows that the PR-NRTL model combination is reasonable for the above four systems. Then, the NRTL binary interaction-parameters of the above systems were regressed from the vapor-liquid equilibrium data evaluated by the thermodynamic consistency test and the PR-NRTL model combination was emploied with the new parameters to calculate the vapor-liquid equilibrium for CH 3OH/DME/CO 2 at the temperature of 313.15K and 333.15K. Compared with the experimental data, the calculated deviation is small. On the basis of the above study, the vapor-liquid equilibrium in the system C 2H 5OH/DME/CO 2 was estimated and the phase diagrams of the system was presented.