CALPHAD应用于有机体系热力学相平衡/相图的计算

相图是一种化学图形,必须通过数学模型的方式才能实现其广泛的应用.而此前固-液平衡相图的计算多采用理想模型或经验模型,前者完全忽视了真实溶液的非理想性,后者的计算结果则可能是对相图完全不合理的预测.因此,为了充分考虑体系的非理想性以获得更为准确真实的相图,采用热力学模型,借助专业的金属及无机物材料的相图计算软件Thermo-Calc,设计实现了获得非理想有机体系中组分作用参数及平衡相图的软件计算方法.利用该计算方法,选择合理的热力学模型,成功地模拟出了二甲苯异构体系二元、三元及二氯苯异构体二元系的固-液平衡相图,模拟结果与文献的实验数据吻合程度较高,且相比于理想状态下的二甲苯三元系相图,正规溶液状态下的相图更能体现真实体系中组分间的作用对体系相平衡温度的影响.该软件计算方法具有较高的自动化程度,在实验数据非常有限的情况下,能够非常精确的模拟出各种无机或有机体系的相图及其它热力学性质,为化学热力学研究提供了一种新的、适用范围广、功能强大的研究手段.

The application of CALPHAD in the phase equilibrium/diagram calculation of organic system

The phase diagram is a type of chemical graph,which could be applied widely only via the mathematical model.And the previous solid-liquid equilibrium phase diagram,mostly calculated based on the ideal model or the experiential model.The former would neglect the interactions among the components of the system,and the latter might result a completely illogical forecast.There- fore,considering the non-ideal character of the system in order to get the more accurate phase diagram,the professional phase diagram software Thermo-Calc,which was used to the calculation of material of metal and mineral before,is used to design a method to calcu- late the interaction parameters among the components and the phase diagram in the non-ideal organic system.By this method,under the condition of a rational thermodynamics model,the solid-liquid equilibrium phase diagram of binary,ternary xylene and dichloro- benzene isomer system was simulated successfully.The results is matched excellent with the experimental data,and compared to the phase diagram of ternary xylene based on the ideal model,the phase diagram which applying the regular solution model,could much better expresses the effect of interactions among the components in a real system to the phase equilibrium temperature.This type of soft- ware has a high level of automatization,can be used in different kinds of organic or inorganic system not only for the phase diagram but also for the thermodynamic characters.Its function is powerful,which provide a now tool to the research of chemical thermodynamics.