Abstract: A practical method for calculating VLE of NH3-H2O-CO2-N2-H2 system under high pressure is proposed in this paper. On the basis of the NH3-H2O-CO2 system, the molecular thermodynamic principle is used for calculating liquid-phase equilibria. The hyperbolic tangent function for the activity coefficient of the NH3-H2O system developed by Prausnitz is used in establishingthe VLE calculation method ior the NH3-H2O-CO2 system over a wide concentration range(NH3 10-90%(wt.)). PHS equation of state is used to calculate the vapor phase fugacity coefficient in the NH3-H2O-CO2-N2-H2 system under high pressure. Scope oi application: Temperature 30-70℃ Pressure 5.00-11.87MPa Liquid NH3 concentration 10-90%(wt. ) Liquid CO2 concentration 0-15%(wt. ) NH3/CO2 mole ratio in liquid phase≥ 5 The calculated results of the proposed model are in good agreement with both our experimental data and those from literature sources.

摘要： 本文从实用目的出发,提供一个高压下NH_3-H_2O-CO_2-N_2-H_2五元体系汽液平衡计算模型.本模型结构为:(1)以NH_3-H-2O-CO_2三元系为基础,液相内的平衡运用分子热力学原理——离解平衡、电荷平衡、质量平衡三原则;并以Prausnitz提供的NH_3-H_2O二元系双曲正切函数活度系数模型为骨架,建立了宽广的氨水浓度范围内[NH_310一90%(mass)]的NH_3-H_2O-CO_2三元系的汽液平衡计算方法.(2)对于高压下NH_3-H_2O-CO_2-N_2-H_2五元系,汽相非理想性,本文用PHS状态方程计算汽相逸度系数.本模型的适用性已被实验测定值及文献数据所证实,实验值与计算值一致.