DMF的力场构建及乙腈-甲醇-DMF三元体系的汽液相平衡模拟  

Force field construction for DMF and vapor-liquid phase equilibrium simulation of acetonitrile-methanol-DMF

作　　者：张旗[1] 陈文奇[1] 曾爱武[1] 

机构地区：[1]化学工程联合国家重点实验室,天津大学化工学院,天津300072

出　　处：《化工学报》2017年第2期567-574,共8页CIESC Journal

基　　金：国家科技支撑计划项目(2007BAB24B05)~~

摘　　要：采用量子化学和Gibbs系综Monte Carlo模拟相结合的方法,对Tra PPE-UA力场中缺失的N,N-二甲基甲酰胺(DMF)力场参数进行了补充,为含DMF多元体系的汽液相平衡模拟奠定了基础。采用新构建的力场参数,在NVT-Gibbs系综中计算了DMF的汽液相平衡性质,结果表明该力场能准确计算出DMF的饱和液相密度、蒸气压、沸点、临界值和蒸发焓。在NPT-Gibbs系综中,采用Tra PPE-UA力场分别计算了乙腈-甲醇、DMF-甲醇、DMF-乙腈二元混合物的汽液相平衡性质,并与实验值进行了比较。模拟结果与实验值较为吻合,验证了力场模型的可靠性。最后在NPT-Gibbs系综中采用Tra PPE-UA力场对乙腈-甲醇-DMF三元体系的汽液相平衡数据进行了预测,为设计和优化乙腈和甲醇的萃取分离过程提供了基础数据。An extensional Tra PPE-UA force field for N,N-dimethyl-formamide（DMF） was developed by combination of the quantum chemistry calculation and Gibbs ensemble Monte Carlo simulation, which lays the foundation for the simulation of vapor-liquid phase equilibrium with DMF. First of all, the vapor-liquid phase equilibrium for DMF was calculated in the NVT-Gibbs ensemble by using this new force filed. The results show that the new force field can be used to accurately calculate the saturated liquid densities, vapor pressures, normal boiling point, critical point and heats of vaporization of DMF. Secondly, the vapor-liquid equilibrium for binary mixtures of acetonitrile-methanol, DMF-methanol, DMF-acetonitrile were computed in the NPT-Gibbs ensemble by adopting the Tra PPE-UA force field. These simulation results were in good agreement with the experimental data, which validated the reliability of this model. Finally, the vapor-liquid equilibrium data of ternary mixture of acetonitrile-methanol-DMF were predicted in the NPT-Gibbs ensemble, which can provide basic data for design and optimization of the separation process of acetonitrile and methanol.

关 键 词：N N-二甲基甲酰胺 Monte CARLO模拟 Tra PPE-UA力场 乙腈 甲醇 汽液平衡 统计热力学 

分 类 号：O642.42[理学—物理化学]